RU2830186C2 - Disclosed are 3,6-diaminopyridazin-3-yl derivatives containing pharmaceutical compositions and use thereof as pro-apoptotic agents - Google Patents

Abstract

FIELD: pharmaceutics.

SUBSTANCE: invention relates to a compound of formula (I) or its enantiomers and diastereomers and addition salts thereof with a pharmaceutically acceptable acid or base, which have inhibitory activity on protein Bcl-xL and can be used to treat malignant neoplasms, autoimmune diseases or diseases of the immune system. In formula (I) R₁ and R₂ independently represent a group selected from hydrogen; linear or branched C₁-C₆ alkyl, optionally substituted with a hydroxyl or C₁-C₆ alkoxy group; C₃-C₆ cycloalkyl; trifluoromethyl, etc., R₃ is a group selected from hydrogen; C₃-C₆ cycloalkyl; linear or branched C₁-C₆ alkyl, etc., Het₁ is a group selected from the following, Het₂ is a group selected from the following, A₁ denotes S, A₂ denotes CH, G is selected from a group consisting of -C(O)OR_G3, -C(O)NR_G1R_G2, -C(O)R_G2, -NR_G1C(O)R_G2, etc., R_G1 and R_G2 in each case are independently selected from a group consisting of hydrogen, C₁-C₆ alkyl, optionally substituted with 1–3 halogen atoms, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, phenyl and -(CH₂)_1–4-phenyl; R_G3 is selected from a group consisting of C₁-C₆ alkyl optionally substituted with 1–3 halogen atoms, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, phenyl and -(CH₂)_1–4-phenyl, R₄ is a fluorine, chlorine or bromine atom, a methyl, hydroxyl or methoxy group, R₆ is a group selected from hydrogen, -C₂-C₆ alkenyl, etc., m=0, 1 or 2. Invention also relates to a pharmaceutical composition containing said compound and an intermediate synthesis compound.

EFFECT: disclosed are 3,6-diaminopyridazin-3-yl derivatives, pharmaceutical compositions containing them and use thereof as pro-apoptotic agents.

45 cl, 6 tbl, 290 ex

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

The present invention relates to 3,6-diaminopyridazin-3-yl derivatives, pharmaceutical compositions containing them and their use as proapoptotic agents. The compounds of the present invention inhibit the activity of the Bcl-xL protein and may be of interest for the treatment of malignant neoplasms, immunopathological and autoimmune diseases.

PREREQUISITES FOR THE CREATION OF THE INVENTION

Apoptosis (programmed cell death) is an evolutionarily conserved pathway that is critical for tissue homeostasis, development, and clearance of damaged cells. Deregulation of apoptosis contributes to human diseases, including malignancies, neurodegenerative disorders, immune system disorders, and autoimmune diseases (Hanahan and Weinberg, Cell. 2011 Mag 4; 144(5):646–74; Marsden and Strasser, Annu Rev Immunol. 2003; 21:71–105; Vaux and Flavell, Curr Opin Immunol. 2000 Dec; 12(6):719–24). Evasion of apoptosis is considered a characteristic feature of malignant neoplasms, participating in the development, as well as in the sustained growth of tumors, and in the emergence of resistance to antitumor therapy methods (Hanahan and Weinberg, Cell. 2000 Jan 7; 100(1):57-70).

The Bcl-2 family of proteins includes key regulators of cell viability that can suppress (e.g., Bcl-2, Bcl-xL, Mcl-1) or stimulate (e.g., Bad, Bax) apoptosis (Gross et al., Genes Dev. 1999 Aug 1; 13(15):1899-911, Youle and Strasser, Nat. Rev. Mol. Cell Biol. 2008 Jan; 9(1):47-59).

In the presence of stress stimuli, whether a cell survives or undergoes apoptosis depends on the degree of pairing between Bcl-2 family members that promote cell death and family members that promote cell survival. In most cases, these interactions involve docking of the Bcl-2 homology 3 (BH3) domain of pro-apoptotic family members to the surface groove of pro-survival members. The presence of a Bcl-2 homology (BH) domain determines membership in the Bcl-2 family, which is divided into three major groups based on which specific BH domains are present in the protein. Pro-survival members such as Bcl-2, Bcl-xL, and Mcl-1 contain BH domains 1–4, whereas Bax and Bak, pro-apoptotic effectors of outer mitochondrial membrane permeabilization during apoptosis, contain BH domains 13 (Youle and Strasser, Nat. Rev. Mol. Cell Biol. 2008 Jan; 9(1):47–59).

Overexpression of pro-survival Bcl-2 family members is a hallmark of malignancy, and these proteins have been shown to play important roles in tumor development, maintenance, and resistance to anticancer therapy (Czabotar et al., Nat. Rev. Mol. Cell Biol. 2014 Jan; 15(1):49-63). Bcl-xL (also called BCL2L1, for BCL2-like 1) is frequently amplified in malignancy (Beroukhim et al., Nature 2010 Feb 18; 463(7283):899-905), and its expression has been shown to inversely correlate with sensitivity to more than 120 anticancer therapeutic molecules in a representative panel of cancer cell lines (NCI-60) (Amundson et al., Cancer Res. 2000 Nov 1; 60(21):6101-10).

In addition, several studies using transgenic knockout mouse models and transgenic overexpression of Bcl-2 family members have highlighted the importance of these proteins in immune system and autoimmune diseases (for review, see Merino et al., Apoptosis 2009 Apr; 14(4):570-83. doi: 10.1007/s10495-008-0308-4.PMID: 19172396). Transgenic overexpression of Bcl-xL in the T cell compartment resulted in resistance to apoptosis induced by glucocorticoids, gamma radiation, and CD3 cross-linking, suggesting that transgenic Bcl-xL overexpression can reduce apoptosis in resting and activated T cells (Droin et al., Biochim Biophys Acta 2004 Mar 1; 1644(2-3): 179-88. doi: 10.1016/j.bbamcr.2003.10.011.PMID: 14996502). Patient-derived samples have demonstrated persistent or high expression of anti-apoptotic proteins of the Bcl-2 family (Pope et al., Nat Rev Immunol. 2002 Jul; 2(7):527-35. doi: 10.1038/nri846.PMID: 12094227). In particular, T cells isolated from joints of patients with rheumatoid arthritis demonstrated increased expression of Bcl-xL and were resistant to spontaneous apoptosis (Salmon et al., J Clin Invest. 1997 Feb 1; 99(3):439-46. doi: 10.1172/JCI119178.PMID: 9022077). BH3 mimetics have shown benefit in preclinical models of immune system and autoimmune diseases. Treatment with ABT-737 (an inhibitor of Bcl-2, Bcl-xL, and Bcl-w) resulted in potent inhibition of lymphocyte proliferation in vitro. Importantly, mice treated with ABT-737 in animal models of arthritis and lupus showed significant reductions in disease severity (Bardwell et al., J Clin Invest. 1997 Feb 1; 99(3):439-46. doi: 10.1172/JCI119178.PMID: 9022077). In addition, ABT-737 was shown to prevent allogeneic T cell activation, proliferation, and cytotoxicity in vitro and suppress allogeneic T and B cell responses following skin transplantation with high selectivity for lymphoid cells (Cippa et al., Transpl Int. 2011 Jul; 24(7):722-32. doi: 10.1111/j.1432-2277.2011.01272.x. Epub 2011 May 25. PMID: 21615547).

The above findings prompted the discovery and development of a new class of drugs called BH3 mimetics. These molecules are capable of disrupting the interaction between proapoptotic and antiapoptotic members of the Bcl-2 family and are potent inducers of apoptosis. This new class of drugs includes inhibitors of Bcl-2, Bcl-xL, Bcl-w, and Mcl-1. The first described BH3 mimetics were ABT-737 and ABT-263, which target Bcl-2, Bcl-xL, and Bcl-w (Park et al., J. Med. Chem. 2008 Nov 13; 51(21):6902-15; Roberts et al., J. Clin. Oncol. 2012 Feb 10; 30(5):488-96). Since then, selective inhibitors of Bcl-2 (ABT-199 and S55746 - Souers et al., Nat Med. 2013 Feb; 19(2):202-8; Casara et al., Oncotarget 2018 Apr 13; 9(28):20075-20088), Bcl-xL (A-1155463 and A-1331852 - Tao et al., ACS Med Chem Lett. 2014 Aug 26; 5(10): 1088-93; Leverson et al., Sci Transl Med. 2015 Mar 18; 7(279):279ra40) and Mcl-1 (A-1210477, S63845, S64315, AMG-176 and AZD-5991 - Leverson et al., Cell Death Dis. 2015 Jan 15; 6:e1590.; Kotschy et al., Nature 2016, 538, 477-482; Maragno et al., AACR 2019, Poster #4482; Kotschy et al., WO 2015/097123; Caenepeel et al., Cancer Discov. 2018 Dec; 8(12): 1582-1597; Tron et al., Nat. Commun. 2018 Dec 17; 9(1):5341). The selective Bcl-2 inhibitor ABT-199 is currently approved for the treatment of patients with CLL and AML as part of combination therapy, while other inhibitors are still in preclinical or clinical trials. In preclinical models, ABT-263 has demonstrated activity in several hematologic malignancies and solid tumors (Shoemaker et al., Clin. Cancer Res. 2008 Jun 1; 14(11):3268-77; Ackler et al., Cancer Chemother. Pharmacol. 2010 Oct; 66(5):869-80; Chen et al., Mol. Cancer Ther. 2011 Dec; 10(12):2340-9). In clinical studies, ABT-263 has demonstrated objective antitumor activity in lymphoid malignancies (Wilson et al., Lancet Oncol. 2010 Dec; 11(12): 1149-59; Roberts et al., J. Clin. Oncol. 2012 Feb 10; 30(5):488-96), and its activity is being investigated in combination with several solid tumor treatments. Selective Bcl-xL inhibitors, A-1155463 or A-1331852, have demonstrated in vivo activity in preclinical models of T-ALL (T-cell acute lymphoblastic leukemia) and various types of solid tumors (Tao et al., ACS Med. Chem. Lett. 2014 Aug 26; 5(10): 1088–93; Leverson et al., Sci. Transl. Med. 2015 Mar 18; 7(279):279ra40). Selective Mcl-1 inhibitors have shown promising in vivo activity in several types of hematological malignancies in preclinical models, and three of them, inhibitors S64315, AMG176 and AZD5991, are currently being investigated in clinical trials (Yang et al., Eur. J. Med. Chem. 2019 May 8; 177:63-75). Thus, BH3 mimetics represent an extremely attractive approach for the development of new therapies in oncology, as well as in the field of immunopathology and autoimmune diseases. In particular, there is a need for small molecules that selectively inhibit the Bcl-xL protein. The present invention addresses this need.

SUMMARY OF THE INVENTION

The present invention provides potent selective Bcl-xL inhibitors of formula (I) as defined below. The present application shows that these compounds are capable of inducing apoptosis of cancer cells in vivo, triggering tumor regression in mice. Due to their pro-apoptotic properties, the compounds of the present invention may be of interest for the treatment of pathologies involving deregulation of apoptosis, such as, for example, malignant neoplasms, autoimmune diseases and diseases of the immune system. In addition, these compounds were well tolerated in mice without clinically significant weight loss when treated with effective doses, indicating an acceptable therapeutic window for the use of these small molecules targeting Bcl-xL in the treatment of cancer. Consistent with the previously described role of Bcl-xL in regulating platelet survival (Zhang et al., Cell Death Differ. 2007 May; 14(5):943-51; Mason et al., Cell. 2007 Mar 23; 128(6): 1173-86), we observed a decrease in circulating platelet counts following treatment of mice with these inhibitors and a recovery following cessation of treatment. Given this effect on platelet survival, the Bcl-xL inhibitors of the present invention may also be useful for the treatment of diseases or conditions characterized by excessive or deregulated platelet activity, such as, for example, prothrombotic conditions.

DETAILED DESCRIPTION OF THE INVENTION

In a first embodiment (E1), the present invention provides compounds of formula (I):

Where:

R ₁ and R ₂ independently of one another represent a group selected from hydrogen; linear or branched C ₁ -C ₆ alkyl optionally substituted with a hydroxyl or C ₁ -C ₆ alkoxy group; C ₃ -C ₆ cycloalkyl; trifluoromethyl; linear or branched C ₁ -C ₆ alkylene heterocycloalkyl, wherein the heterocycloalkyl group is optionally substituted with a linear or branched C ₁ -C ₆ alkyl group;

or R ₁ and R ₂ together with the carbon atoms that carry them form a C ₃ -C ₆ cycloalkylene group,

R ₃ is a group selected from hydrogen; C ₃ -C ₆ cycloalkyl; linear or branched C ₁ -C ₆ alkyl; -X ₁ -NR _a R _b ; -X ₁ -N ⁺ R _a R _b R _c ; -X ₁ -OR _c ; -X ₁ -COOR _c ; -X ₁ -PO(OH) ₂ ; -X ₁ -SO ₂ (OH); -X ₁ -N ₃ and

R _a and R _b independently of one another represent a group selected from hydrogen; heterocycloalkyl; -SO ₂ -phenyl, wherein phenyl may be substituted with linear or branched C ₁ -C ₆ alkyl; linear or branched C ₁ -C ₆ alkyl optionally substituted with one or two hydroxyl groups; C ₁ -C ₆ alkylene-SO ₂ OH; C ₁ -C ₆ alkylene-SO ₂ O-; C ₁ -C ₆ alkylene-COOH; C ₁ -C ₆ alkylene-PO(OH) ₂ ; C ₁ -C ₆ alkylene-NR _d R _c ; C ₁ -C ₆ alkylene-N ⁺ R _d R _c R _f ; C ₁ -C ₆ alkylenephenyl, wherein phenyl may be substituted with a C ₁ -C ₆ alkoxy group;

groups:

or R _a and R _b together with the nitrogen atom carrying them form the B ₁ cycle;

or R _a , R _b and R _c together with the nitrogen atom carrying them form a bridging C ₃ -C ₈ heterocycloalkyl,

R _c , R _d , R _e , R _f independently of each other represent hydrogen or a linear or branched C ₁ -C ₆ alkyl group,

or R _d and R _e together with the nitrogen atom carrying them form the B ₂ cycle,

or R _d , R _e and R _f together with the nitrogen atom carrying them form a bridging C ₃ -C ₈ heterocycloalkyl,

Het ₁ is a group selected from:

Het ₂ is a group selected from:

A ₁ means -NH-, -NXC ₁ -C ₃ alkyl), O, S or Se,

A ₂ means N, CH or C(R ₅ ),

G is selected from the group consisting of:

-C(O)OR _G3 , -C(O)NR _G1 R _G2 , -C(O)R _G2 , -NR _G1 C(O)R _G2 , -NR _G1 C(O)NR _G1 R _G2 , -OC (O)NR _G1 R _G2 , -NR _G1 C(O)OR _G3 , -C(=NOR _G1 )NR _G1 R _G2 , -NR _G1 C(=NCN)NR _G1 R _G2 , -NR _G1 S(O) ₂ NR _G1 R _G2 , -S(O) ₂ R _G3 , -S(O) ₂ NR _G1 R _G2 , -NR _G1 S(O) ₂ R _G2 , -NR _G1 C(=NR _G2 )NR _G1 R _G2 , -C(=S)NR _G1 R _G2 , -C(=NR _G1 )NR _G1 R _G2 , halogen, -NO ₂ and -CN, where:

- R _G1 and R _G2 in each case are each independently selected from the group consisting of hydrogen, C ₁ -C ₆ alkyl optionally substituted with 1-3 halogen atoms, C ₂ -C ₆ alkenyl, C ₂ -C ₆ alkynyl, C ₃ -C ₆ cycloalkyl, phenyl and -(CH ₂ ) _1-4 -phenyl;

- R _G3 is selected from the group consisting of C ₁ -C ₆ alkyl optionally substituted with 1-3 halogen atoms, C ₂ -C ₆ alkenyl, C ₂ -C ₆ alkynyl, C ₃ -C ₆ cycloalkyl, phenyl and -(CH ₂ ) _1-4 -phenyl; or

R _G1 and R _G2 , together with the atom to which each is attached, are combined to form a C ₃ -C ₈ heterocycloalkyl; or, alternatively, G is selected from the group consisting of:

where R _G4 is selected from C ₁ -C ₆ alkyl optionally substituted with 1-3 halogen atoms, C ₂ -C ₆ alkenyl, C ₂ -C ₆ alkynyl and C ₃ -C ₆ cycloalkyl,

R ₄ represents hydrogen, a fluorine, chlorine or bromine atom, a methyl, hydroxyl or methoxy group,

R ₅ is a group selected from C ₁ -C ₆ alkyl optionally substituted with 1 to 3 halogen atoms; C ₂ -C ₆ alkenyl; C ₂ -C ₆ alkynyl; halogen or -CN,

R ₆ is a group selected from: hydrogen;

-C ₂ -C ₆ alkenyl;

-X ₂ -OR ₇ ;

-X ₂ -NSO ₂ -R ₇ ;

-C=C(R ₉ )-Y ₁ -OR ₇ ;

_C3 - _C6 cycloalkyl;

_C3 - _C6 heterocycloalkyl, optionally substituted with hydroxyl group;

C ₃ -C ₆ cycloalkylene-Y ₂ -R ₇ ;

groups C ₃ -C ₆ heterocycloalkylene-Y ₂ -R ₇ ,

heteroarylene-R ₇ groups, optionally substituted by a linear or branched C ₁ -C ₆ alkyl group,

R ₇ is a group selected from: a linear or branched C ₁ -C ₆ alkyl group; (C ₃ -C ₆ )cycloalkylene-R ₈ ; or:

where Cy is _C3 - _C8 cycloalkyl,

R ₈ is a group selected from hydrogen; linear or branched C ₁ -C ₆ alkyl, -NR' _a R'_b;-NR' _a -CO-OR'_c;-NR' _a -CO-R'_c;-NR' _a R' _b R'_c;-O-R'_c;-NH-X' ₂ -N ⁺ R' _a R' _b R'_c;-O-X' ₂ -NR' _a R' _b , -X' ₂ -NR' _a R' _b , -NR' _c -X' ₂ -N ₃ and:

R ₉ is a group selected from linear or branched C ₁ -C 6 alkyl, trifluoromethyl, hydroxyl, halogen, C ₁ -C ₆ alkoxy,

R ₁₀ is a group selected from hydrogen, fluorine, chlorine, bromine, -CF ₃ and methyl,

R ₁₁ is a group selected from hydrogen, C ₁ -C ₃ alkylene-R ₈ , -O-C ₁ -C ₃ alkylene-R ₈ , -CO-NR _h R _i and -CH=CH-C ₁ -C ₄ alkylene-NR _h R _i , -CH=CH-CHO, C ₃ -C ₈ cycloalkylene-CH ₂ -R ₈ , C ₃ -C ₈ heterocycloalkylene-CH ₂ -R ₈ ,

R ₁₂ and R ₁₃ independently of each other represent a hydrogen atom or a methyl group,

R ₁₄ and R ₁₅ independently of each other represent hydrogen or a methyl group, or R ₁₄ and R ₁₅ together with the carbon atom carrying them form cyclohexyl,

R _h and R _i independently of each other represent hydrogen or a linear or branched C ₁ -C ₆ alkyl group,

X ₁ and X ₂ independently of each other represent a linear or branched C ₁ -C ₆ alkylene group optionally substituted with one or two groups selected from trifluoromethyl, hydroxyl, halogen, C ₁ -C ₆ alkoxy,

X' ₂ is a linear or branched C ₁ -C ₆ alkylene,

R' _a and R' _b independently of each other represent a group selected from hydrogen; heterocycloalkyl; -SO ₂ -phenyl, wherein phenyl may be substituted with linear or branched C ₁ -C ₆ alkyl; linear or branched C ₁ -C ₆ alkyl optionally substituted with one or two hydroxyl or C ₁ -C ₆ alkoxy groups; C ₁ -C ₆ alkylene-SO ₂ OH; C ₁ -C ₆ alkylene-SO ₂ O ^- ; C ₁ -C ₆ alkylene-COOH; C ₁ -C ₆ alkylene-PO(OH) ₂ ; C ₁ -C ₆ alkylene-NR' _d R'_e; C ₁ -C ₆ alkylene-N ⁺ R' _d R' _e R'_f; C ₁ -C ₆ alkylene-O-C ₁ -C ₆ alkylene-OH; C ₁ -C ₆ alkylenephenyl, wherein phenyl may be substituted by hydroxyl or C ₁ -C ₆ alkoxy group;

groups:

or R' _a and R' _b together with the nitrogen atom carrying them form the B ₃ cycle,

or R' _a , R' _b and R' _c together with the nitrogen atom carrying them form a bridging C ₃ -C ₈ heterocycloalkyl,

R' _c , R' _d , R' _e , R' _f independently of each other represent hydrogen or a linear or branched C ₁ -C ₆ alkyl group,

or R' _d and R' _e together with the nitrogen atom carrying them form the B ₄ cycle,

or R' _d , R' _e and R' _f together with the nitrogen atom carrying them form a bridging C ₃ -C ₈ heterocycloalkyl,

Y ₁ is a linear or branched C ₁ -C ₄ alkylene,

Y ₂ is a bond, -O-, -O-CH ₂ -, -O-CO-, -O-SO ₂ -, -CH ₂ -, -CH ₂ -O, -CH ₂ -CO-, -CH ₂ -SO ₂ -, -C ₂ H ₅ -, -CO-, -CO-O-, -CO-CH ₂ -, -CO-NH-CH ₂ -, -SO ₂ -, -SO ₂ -CH ₂ -, -NH-CO-, -NH-SO ₂ -,

m=0, 1 or 2,

p=1, 2, 3 or 4,

_B1 , _B2 , _B3 and _B4 independently of one another represent a _C3 - _C8 heterocycloalkyl group which: (i) may be a mono- or bicyclic group, wherein the bicyclic group comprises a fused, bridged or spiro ring system, (ii) may contain, in addition to the nitrogen atom, one or two heteroatoms independently selected from oxygen, sulfur and nitrogen, (iii) may be substituted with one or two groups selected from: fluorine, bromine, chlorine, linear or branched _C1 - _C6 alkyl, hydroxyl, _-NH2 , oxo or piperidinyl,

It should also be understood that:

- "aryl" means a phenyl, naphthyl, biphenyl or indenyl group,

- "heteroaryl" means any mono- or bicyclic group consisting of 5 to 10 ring members, having at least one aromatic moiety and containing from 1 to 4 heteroatoms selected from oxygen, sulfur and nitrogen (including quaternary nitrogen atoms),

- "cycloalkyl" means any mono- or bicyclic non-aromatic carbocyclic group containing from 3 to 10 ring members which may include fused, bridged or spiro ring systems,

- "heterocycloalkyl" means any mono- or bicyclic non-aromatic carbocyclic group consisting of 3 to 10 ring members and containing from 1 to 3 heteroatoms selected from oxygen, sulfur SO, _SO2 and nitrogen, it being understood that the bicyclic group may be of the fused or spiro ring type,

- heteroarylene, cycloalkylene, heterocycloalkylene mean divalent heteroaryl, cycloalkyl and heterocycloalkyl,

their enantiomers and diastereoisomers, and their addition salts with a pharmaceutically acceptable acid or base.

Among the pharmaceutically acceptable acids, there may be mentioned, without implying any limitation, hydrochloric acid, hydrobromic acid, sulfuric acid, phosphonic acid, acetic acid, trifluoroacetic acid, lactic acid, pyruvic acid, malonic acid, succinic acid, glutaric acid, fumaric acid, tartaric acid, maleic acid, citric acid, ascorbic acid, oxalic acid, methanesulfonic acid and camphoric acid.

Among the pharmaceutically acceptable bases, there may be mentioned, without implying any limitation, sodium hydroxide, potassium hydroxide, triethylamine and tert-butylamine.

Further numbered embodiments (E) of the present invention are described below. It should be understood that the features specifically indicated in each embodiment can be combined with other specifically indicated features to provide further embodiments of the present invention.

E2. A compound according to variant E1, where Het ₁ is:

E3. A compound according to embodiment E1 or E2, wherein R ₁ represents a methyl group and R ₂ represents a hydrogen atom.

E4. A compound according to embodiment E1 or E2, wherein each of R ₁ and R ₂ represents a methyl group or a hydrogen atom.

E5. A compound according to embodiment E1 or E2, wherein R ₁ or R ₂ is a linear or branched C ₁ -C ₆ alkyl, optionally substituted with a hydroxyl or C ₁ -C ₆ alkoxy group, preferably a group selected from methyl, methoxymethyl, hydroxymethyl, ethyl and prop-2-yl.

E6. A compound according to embodiment E1 or E2, wherein R ₁ or R ₂ represents a C ₃ -C ₆ cycloalkyl, preferably cyclopropyl group.

E7. A compound according to embodiment E1 or E2, wherein R ₁ represents a trifluoromethyl group.

E8. A compound according to embodiment E1 or E2, wherein R ₂ is a linear or branched C ₁ -C ₆ alkylene heterocycloalkyl, preferably (4-methylpiperazin-1-yl)propyl group.

E9. A compound according to variant E1 or E2, where R ₁ and R ₂ together with the carbon atoms carrying them form a cyclohexene or cyclopentene group.

E10. A compound according to any of the embodiments E1 to E9, wherein R ₃ represents a hydrogen atom or a methyl group.

E11. A compound according to any of embodiments E1 to E9, wherein R ₃ is -X ₁ -PO(OH) ₂ , -X ₁ -SO ₂ (OH), -X ₁ -NR _a R _b ; -X ₁ -N ⁺ R _a R _b R _c , wherein R _a or R _b , or both of them, are a group selected from C ₁ -C ₆ alkylene-SO ₂ OH, C ₁ -C ₆ alkylene-SO ₂ O- and C ₁ -C ₆ alkylene-PO(OH) ₂ .

E12. A compound according to any of the embodiments E1 to E9, wherein R ₈ is -NR' _a R'_b; -N ⁺ R' _a R' _b R'_c;-NH-X' ₂ -N ⁺ R' _a R' _b R' _c , wherein R' _a and R'b, or both of them, are a group selected from C ₁ -C ₆ alkylene-SO ₂ OH and C ₁ -C ₆ alkylene-PO(OH) ₂ .

E13. A compound according to any of the embodiments E1 - E9, where R ₃ is a group selected from ethyl, propyl; 2-methoxyethyl, 2-(morpholin-4-yl)ethyl, 3-(morpholin-4-yl)propyl, 3-diethylaminopropyl, 3-methoxypropyl, 3-hydroxypropyl, 3,4-dihydroxybutyl, 4-methoxy-3-hydroxybutyl, 4-hydroxy-3-methoxybutyl, 2,3-dihydroxypropyl, 4,5-dihydroxypentyl, 4-hydroxybutyl, 3-hydroxy-2-morpholinopropyl, 5-hydroxy-4-methoxypentyl, 5-morpholino-4-hydroxypentyl, 3-hydroxy-2-methoxypropyl, 5-[2-(dimethylamino)ethylmethylamino]-4-hydroxypentyl, 5-hydroxypentyl, 5-methoxy-4-hydroxypentyl, 5-(dimethylamino)-4-hydroxypentyl, 4-hydroxy-5-(trimethylammonio)pentyl, 5-[3-sulfonatepropyldimethylammonio]-4-hydroxypentyl, 4-hydroxy-5-(methylamino)pentyl, 3-carboxypropyl, 5-[methyl(4-piperidyl)amino]pentyl, 5-(2-morpholinoethylamino)pentyl, 5-[2-(4-methylpiperazin-1-yl)ethylamino)pentyl, 4-[2-(4-methylpiperazin-1-yl)ethylamino)butyl, 4-hydroxy-5-[methyl-[2-(methylamino)ethyl]amino]pentyl, 5-[2-(diethylamino)ethylamino]-4-hydroxypentyl, 5-(4-amino-1-piperidyl)-4-hydroxypentyl, 4-hydroxy-5-piperazin-1-ylpentyl, 5-[2-(1-piperidyl)ethylamino]pentyl, 4-(4-amino-1-piperidyl)butyl, 4-[2-(diethylamino)ethylamino]butyl, 5-(4-amino-1-piperidyl)pentyl, 4-[methyl-[2-(methylamino)ethyl]amino]butyl, 4-(2-morpholinoethylamino)butyl, 4-[2-(4-methylpiperazin-1 -yl)ethylamino)butyl, 4-[(1-methyl-4-piperidyl)amino]butyl, 5-[2-(diethylamino)ethylamino]pentyl, 4-piperazin-1-ylbutyl, 4-(methylamino)butyl, 5-piperazin-1-ylpentyl, 5-[methyl-[2-(methylamino)ethyl, 5-aminopentyl, 4-aminobutyl, 5-(methylamino)pentyl, 5-[3-(4-methylpiperazin-1-yl)propylamino]pentyl, 4-hydroxy-5-[methyl(2-phosphonoethyl)amino]pentyl, 6-(dimethylamino)hexyl, 3-(dimethylamino)propyl, 2-(trimethylammonio)ethyl, 3-(trimethylammonio)propyl, 2-(dimethylamino)ethyl, 4-(dimethylamino)butyl, 5-[3-sulfonatepropyldimethylammonio]pentyl, 4-(trimethylammonio)butyl, 4-hydroxy-5-quinuclidin-1-ium-1-ylpentyl, 4-hydroxy-5-(1-aza-4-azoniabicyclo[2.2.2]octan-4-yl)pentyl, 4-hydroxy-5-(4-methylmorpholin-4-ium-4-yl)pentyl, 5-(trimethylammonio)pentyl, 4-hydroxy-5-(1-methylpiperidin-1-ium-1-yl)pentyl, 5-(1,4-dimethylpiperazin-1-ium-1-yl)-4-hydroxypentyl, 6-(trimethylammonio)hexyl, 5-[3-hydroxypropyl(dimethyl)ammonio]pentyl, 5-[2-hydroxyethyl(dimethyl)ammonio]pentyl, 5-[carboxymethyl(dimethyl)ammonio]pentyl, 5-[carboxymethyl(dimethyl)ammonio]pentyl, 3-phosphonopropyl, 3-[3-sulfonatepropyldimethylammonio]propyl, 3-sulfopropyl, 4-sulfobutyl, 4-phosphonobutyl, 4-carboxybutyl, 3-aminopropyl, 3-azidopropyl, pent-4-yn-1-yl, 4-aminobutyl, 4-azidobutyl, hex-5-yn-1-yl, 5-azidopentyl.

E14. A compound according to any of the options E1 to E13, where Het ₂ is:

E15. A connection according to any of the options E1 to E13, where Het ₂ is:

E16. A compound according to embodiment E14 or E15, wherein R ₆ represents a hydrogen atom.

E17. A compound according to embodiment E14, wherein R ₆ represents a group -X ₂ -OR ₇ , where X ₂ represents a propylene group.

E18. A compound according to variant E17, where R ₇ represents the following group:

E19. A compound according to variant E17, where R ₇ represents the following group:

E20. Compound according to variant E17, where R ₇ represents the following group:

E21. A compound according to any of the embodiments E18 to E20, where R ₈ is NR' _a R' _b .

E22. A compound according to any of the embodiments E18 to E20, wherein R ₈ is a group selected from dimethylamino, methylamino, methylethylamino, diethylamino, methyl[2-(methylamino)ethyl]amino, (2-hydroxyethyl)(methyl)amino, 4-morpholinyl, pyrrolidin-1-yl, 1-piperidyl, [(tert-butoxy)carbonyl](methyl)amino, hydroxyl, bis(3-sulfopropyl)amino, 3-sulfopropylamino, methyl(3-sulfopropyl)amino, methyl(i-tolylsulfonyl)amino, (4-methoxyphenyl)methylmethylamino, 2-(dimethylamino)ethylamino and:

E23. A compound according to any of the embodiments E18 to E20, wherein R ₈ is a group selected from: 3-piperazin-1-yl, 4-methylpiperazin-1-yl, 3-hydroxypropyl(methyl)amino, [(3S)-3,4-dihydroxybutyl]-methylamino, 3-hydroxypropylamino, [(3S)-3,4-dihydroxybutyl]amino, 4-hydroxybutyl(methyl)amino, [(3R)-3,4-dihydroxybutyl]-methylamino, 4-hydroxybutylamino, [(3R)-3,4-dihydroxybutyl]amino.

E24. Compound according to variant E17, where R ₇ represents:

where R ₁₁ is selected from dimethylcarbamoyl, 3-(dimethylamino)propyl, 3-(methylamino)propyl, 3-(methylamino)propyl.

E25. A compound according to embodiment E14, wherein R ₆ is a C ₃ -C ₆ heterocycloalkylene-Y ₂ -R ₇ group, wherein the heterocycloalkylene group is selected from:

E26. A compound according to embodiment E25, wherein R ₇ is selected from methyl, methylethyl, tert-butyl, 2-methylpropyl and phenyl, preferably phenyl.

E27. A compound according to embodiment E14 or E15, wherein R ₆ is -C=C(R ₉ )-Y ₁ -OR ₇ , where Y ₁ is a methylene group.

E28. A compound according to variant E14 or E15, where R ₆ is:

E29. A compound according to embodiment E28, wherein R ₇ is a group selected from:

where R ₈ is -O-X' ₂ -NR' _a R' _b or -X' ₂ NR' _a R' _b , preferably -O-X' ₂ -NR' _a R' _b .

E30. A compound according to embodiment E28, wherein R ₇ is a group selected from:

where R ₈ is a group selected from hydrogen, 2-(methylamino)ethoxy and:

E31. A compound according to embodiment E28, wherein R ₇ is a group selected from:

where R ₈ is a group selected from 2-(dimethylamino)ethoxy, 2-[(2-sulfoethyl)amino]ethoxy, 2-[methyl(2-sulfoethyl)amino]ethoxy, 2-(3-hydroxypropylamino)ethoxy, 2-(3-methoxypropylamino)ethoxy, 2-morpholinoethoxy, 2-(2-carboxyethylamino)ethoxy, 2-[(3-hydroxyphenyl)methylamino]ethoxy, 2-(methylamino)ethoxy, 2-pyrrolidin-1-ylethoxy, 2-(4-methylpiperazin-1-yl)ethoxy, 2-(4-hydroxybutylamino)ethoxy, 2-piperazin-1-ylethoxy, 2-[3-hydroxypropyl(methyl)amino]ethoxy, 2-[4-hydroxybutyl(methyl)amino]ethoxy; 2-[[3-hydroxy-2-(hydroxymethyl)propyl]amino]ethoxy; 2-[bis(3-hydroxypropyl)amino]ethoxy.

E32. A connection according to option E1, selected from the following group of connections:

- 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-hydroxybutyl)amino)-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid,

- 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-4-methoxybutyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(2,3-dihydroxypropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4,5-dihydroxypentyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxypropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(trimethylammonio)pentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate,

- 3-[[5-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-carboxy-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazol-2-yl]amino]-2-hydroxypentyl]-dimethylammonio]propane-1-sulfonate,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-[methyl(3-sulfopropyl)amino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid,

- 5-{1-[(Adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid,

- 5-{1-[(Adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-cyclopropylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(diethylamino)ethylamino]-4-hydroxypentyl]amino]-5-[ 3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(4-methylpiperazin-1-yl)ethylamino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-5-piperazin-1-ylpentyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid,

- 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(2S)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl]-1,3-thiazole-4-carboxylic acid,

- 2-[4-Aminobutyl-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[5-Aminopentyl-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[3-(dimethylamino)propyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-5-[3-[4-[3-(dimethylamino)but-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(trimethylammonio)pentyl]amino]-5-[3-[4 -[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate,

- 3-[2-[3-[4-[3-[2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-4-carboxythiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynylamino]ethyl dimethylammonio] propane-1-sulfonate,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(4-methylmorpholin-4-ium-4-yl)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate,

- 2-[3-[4-[3-[2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-4-carboxythiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynylamino]ethyltrimethylammonium,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[6-(trimethylammonio)hexyl]amino]-5-[3-[2-fluoro-4 -[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-hydroxyethyl(dimethyl)ammonio]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[carboxymethyl(dimethyl)ammonio]pentyl]amino]-5-[3-[4 -[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate,

- 3-[[5-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-carboxy-5-[3-[2-fluoro-4-[(E)-3-oxoprop-1-enyl]phenoxy]propyl]thiazol-2-yl]amino]-2-hydroxypentyl]-dimethylammonio]propane-1-sulfonate,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-5-[3-[4-[1-[(dimethylamino)methyl]-3 -bicyclo[1.1.1]pentanyl]phenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-phosphonopropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid,

- 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-carboxypropyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid,

- 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-phosphonopropyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid,

- 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-sulfopropyl)amino)-5-(3-{4-[3-( dimethylamino)prop-1-in-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazol-4-carboxylic acid,

- 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-sulfobutyl)amino)-5-(3-{4-[3-( dimethylamino)prop-1-in-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazol-4-carboxylic acid,

- 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-phosphonobutyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid,

- 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-carboxybutyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid,

- 2-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(pent-4-yn-1-yl)amino]-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid,

- 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-[2-fluoro-4-(3-{methyl[2-(methylamino)ethyl]amino}prop-1-yn-1-yl)phenoxy]propyl}-1,3-thiazole-4-carboxylic acid,

- 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(2-fluoro-4-{3-[(2-hydroxyethyl)(methyl)amino]prop-1-yn-1-yl}phenoxy)propyl]-1,3-thiazole-4-carboxylic acid,

- 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-[2-fluoro-4-(3-hydroxyprop-1-yn-1-yl)phenoxy]propyl}-1,3-thiazole-4-carboxylic acid,

- 2-[5-Azidopentyl-[6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]-1,3-thiazole-4-carboxylic acid,

its enantiomers and diastereoisomers, and their addition salts with a pharmaceutically acceptable acid or base.

E33. A connection according to option E1, selected from the following group of connections:

- 6-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino]-3-[1-({3-[2-(dimethylamino)ethoxy]-5,7-dimethyladamantan-1-yl}methyl)-5-methyl-1H-pyrazol-4-yl]pyridine-2-carboxylic acid,

- 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-3-[1-[[3-[2-(3-hydroxypropylamino)ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid,

- 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-3-[1-[[3-[2-(3-methoxypropylamino)ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid,

- 6-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino]-3-(1-{[3-(2-{[(3S)-3,4-dihydroxybutyl]amino}ethoxy)-5,7-dimethyladamantan-1-yl]methyl}-5-methyl-1H-pyrazol-4-yl)pyridine-2-carboxylic acid,

- 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-3-[1-[[3,5-dimethyl-7-(2-morpholinoethoxy)-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid,

- 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-3-[1-[[3-[2-(2-carboxyethylamino)ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid,

- 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-3-[1-[[3-[2-[(3-hydroxyphenyl)methylamino]ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxypropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid,

- 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-5-[3-[2-fluoro-4-(3-pyrrolidin-1-ylprop-1-ynyl)phenoxy]propyl]thiazole-4-carboxylic acid,

its enantiomers and diastereoisomers, and their addition salts with a pharmaceutically acceptable acid or base.

E34. A method for producing a compound of formula (I) in accordance with any of the variants E1 to E33, which is characterized in that a compound of formula (II) is used as the starting material:

wherein R ₁ and R ₂ are as defined for formula (I), said compound of formula (II) being subjected to a Buchwald reaction in an aqueous or organic medium in the presence of a palladium catalyst (preferably Pd ₂ (dba) ₃ ), a base (preferably Cs ₂ CO ₃ and DIPEA), a phosphine (preferably xantphos) and a compound of formula (III):

where R ₄ and m are as defined for formula (I),

to obtain a compound of formula (IV):

the amine function of the compound of formula (IV) is then protected to obtain a compound of formula (V):

Where represents a protecting group (preferably 2-trimethylsilylethoxymethyl group),

the compound of formula (V) is then subjected to a Buchwald reaction in an aqueous or organic medium in the presence of a palladium catalyst (preferably Pd ₂ (dba) ₃ ), a base (preferably Cs ₂ CO ₃ and DIPEA), a phosphine (preferably xantphos) and a compound of formula (VI):

where A ₁ , R ₃ and R ₆ are as defined for formula (I) and Alk represents a C ₁ -C ₆ alkyl group,

to obtain a compound of formula (VII-a) or (VII-b):

and then the benzothiazole group of said compound of formula (VII-a) or (VII-b) is deprotected (preferably using HF×Pyr) and the ester function is hydrolyzed (preferably using LiOH×H ₂ O) to obtain a compound of formula (I),

wherein the compound of formula (I) can be purified according to a conventional separation technique, can be converted into its addition salts with a pharmaceutically acceptable acid or base, and optionally separated into its isomers according to a conventional separation technique,

It should be understood that, at any time deemed appropriate during the process described above, the hydroxy, amino, carboxyl and phosphono groups of the reactants or synthesis intermediates may be protected and then deprotected as required by the synthesis.

E35. The method according to embodiment E34, wherein compound (VI-b) is:

and where R ₇ is selected from the group consisting of:

where R ₈ , R ₁₂ and R ₁₃ are as defined for formula (I).

E36. A process for producing a compound of formula (I) according to variant E28, wherein R ₆ is:

and R ₇ is as defined for formula (I),

which is distinguished by the fact that a compound of formula (II) is used as the starting material:

where R ₁ and R ₂ are as defined for formula (I), wherein the compound of formula (II) is subjected to a Buchwald reaction in an aqueous or organic medium in the presence of a palladium catalyst (preferably Pd ₂ (dba) ₃ ), a base (preferably Cs ₂ CO ₃ and DIPEA), a phosphine (preferably xantphos) and a compound of formula (III):

where R ₄ and m are as defined for formula (I),

to obtain a compound of formula (IV):

the amine function of the compound of formula (IV) is then protected to obtain a compound of formula (V):

Where represents a protecting group (preferably 2-trimethylsilylethoxymethyl group),

the compound of formula (V) is then subjected to a Buchwald reaction in an aqueous or organic medium in the presence of a palladium catalyst (preferably Pd ₂ (dba) ₃ ), a base (preferably Cs ₂ CO ₃ and DIPEA), a phosphine (preferably xantphos) and a compound of formula (VF):

where A ₁ and R ₃ are as defined for formula (I) and Alk is a C ₁ -C ₆ alkyl group, to obtain a compound of formula (VIII):

the compound of formula (VIII) is subjected to halogenation (preferably using N-bromosuccinimide or N-iodosuccinimide) to obtain the compound of formula (IX):

where Hal represents a halogen atom,

the compound of formula (IX) is then subjected to a Suzuki coupling reaction, in an aqueous or organic medium in the presence of a palladium catalyst (preferably Pd(dppf) _Cl2 ), a base (preferably potassium carbonate), with a compound of formula (X):

to obtain a compound of formula (XI):

and then the benzothiazole group of said compound of formula (XI) is deprotected (preferably using HF×Pyr) and the ester function is hydrolyzed (preferably using LiOH×H ₂ O) to obtain the compound of formula (I),

wherein the compound of formula (I) can be purified according to a conventional separation technique, can be converted into its addition salts with a pharmaceutically acceptable acid or base and optionally separated into its isomers according to a conventional separation technique,

It should be understood that, at any time deemed appropriate during the process described above, the hydroxy, amino, carboxyl and phosphono groups of the reactants or synthesis intermediates may be protected and then deprotected as required by the synthesis.

E37. An intermediate compound of the synthesis according to variant E34 or E36, which is:

where R ₄ and m are as defined for general formula (I), preferably R ₄ represents a hydrogen atom.

E38. A compound according to embodiment E1, wherein R ₄ represents hydrogen, a fluorine, chlorine or bromine atom, a methyl or methoxy group.

E39. The compound according to embodiment E1, wherein R ₈ is a group selected from hydrogen; linear or branched C ₁ -C ₆ alkyl, -NR' _a R'_b;-NR' _a -CO-OR'_c; -N ⁺ R' _a R' _b R'_c;-O-R'_c;-NH-X' ₂ -N ⁺ R' _a R' _b R'_c;-O-X' ₂ -NR' _a R' _b , -NR' _c -X' ₂ -N ₃ and:

E40. The compound according to E1, wherein R' _a and R' _b independently of one another represent a group selected from hydrogen; heterocycloalkyl; -SO ₂ -phenyl, wherein phenyl may be substituted by linear or branched C ₁ -C ₆ alkyl; linear or branched C ₁ -C ₆ alkyl optionally substituted by one or two hydroxyl groups; C ₁ -C ₆ alkylene-SO ₂ OH; C ₁ -C ₆ alkylene-SO ₂ O-; C ₁ -C ₆ alkylene-COOH; C ₁ -C ₆ alkylene-PO(OH) ₂ ; C ₁ -C ₆ alkylene-NR' _d R'_e; C ₁ -C ₆ alkylene-N ⁺ R' _d R' _e R'_f; C ₁ -C ₆ alkylene-O-C ₁ -C ₆ alkylene-OH; C ₁ -C ₆ alkylenephenyl, wherein phenyl may be substituted by a C ₁ -C ₆ alkoxy group;

groups:

or R' _a and R' _b together with the nitrogen atom carrying them form the B ₃ cycle,

or R' _a , R' _b and R' _c together with the nitrogen atom carrying them form a bridged C ₃ -C ₈ heterocycloalkyl.

E41. Connection in accordance with any of the options E1 - E31, where m=1.

Pharmacological study of the compounds of the present invention showed that they have proapoptotic properties. The ability to reactivate the apoptotic process in cells is of great therapeutic interest for the treatment of malignant neoplasms and immunopathological and autoimmune diseases. In particular, the compounds according to the invention will be useful for the treatment of chemo- or radioresistant malignant neoplasms.

In another embodiment, the compounds of the present invention may be used to treat diseases or conditions characterized by excessive or deregulated platelet activity, particularly prothrombotic conditions.

As used herein, the term "treat" or "treating" any disease or disorder refers in one embodiment to ameliorating the disease or disorder (i.e., slowing or stopping or reducing the progression of the disease or at least one of its clinical symptoms). In another embodiment, the term "treat" or "treating" refers to alleviating or reducing the intensity of at least one physical parameter, including those that may not be perceived by the patient. In yet another embodiment, the term "treat" or "treating" refers to modulating the disease or disorder, either physically (e.g., stabilizing a perceptible symptom) or physiologically (e.g., stabilizing a physical parameter), or both.

Among the treatment options for malignancies outlined in this application, mention may be made, without implying any limitation, of the treatment of hematological malignancies and solid tumors. Hematological malignancies include myeloma, in particular multiple myeloma, lymphoma, in particular non-Hodgkin's lymphoma (NHL) and more particularly diffuse large B-cell lymphoma (DLBCL), and leukemia, in particular chronic lymphocytic leukemia (CLL), T-cell acute lymphoblastic leukemia (T-ALL), B-cell acute lymphoblastic leukemia (B-ALL), and acute myelocytic leukemia (AML). Solid tumors include bladder, brain, breast, uterine, esophageal, and liver cancers, colorectal cancer, kidney cancer, melanoma, ovarian cancer, prostate cancer, pancreatic cancer, and lung cancer, especially non-small cell lung cancer and small cell lung cancer.

In particular, T-ALL arises from leukemic transformation of thymic progenitor cells and their arrest at certain stages of differentiation. Despite valuable information recently obtained from extensive studies of the molecular and cellular mechanisms responsible for the occurrence and progression of T-ALL, this knowledge has not been translated into effective targeted therapies. Current clinical treatments include chemotherapy associated or not with hematopoietic stem cell transplantation with survival rates remaining around 50 and 70% in adults and children, respectively. In both children and adults, relapses show a very poor prognosis, reinforcing the need to identify new therapeutic options (Passaro et al., Immunol. Rev. 2016 May; 271(1): 156-72). Dual Bcl-2/Bcl-xL inhibitors like ABT-263 and ABT-737 have been shown to have promising activity in patient-derived xenograft models of T-ALL (Van Delft et al. Cancer Cell 2006; 10:389–99; Suryani et al. Clin. Cancer Res. 2014; 20:4520–31). Other studies have reported a differential requirement for Bcl-xL or Bcl-2 for survival of mature versus very immature (EPP subset) T-ALL (Chonghaile et al. Cancer Discov. 2014; 4:1074–87). The previously described selective Bcl-xL inhibitor A-1331852 has also been shown to have in vitro and in vivo activity in a xenograft model of the mature T-ALL cell line MOLT-4 (Leverson et al., Sci. Transl. Med. 2015 Mar 18; (279):279ra40). In a separate embodiment, inhibition of tumor growth was also observed in the MOLT-4 xenograft model following treatment with the Bcl-xL inhibitors of the present invention. These data support the use of the compounds of the present invention for the treatment of T-ALL.

Among the treatment options for autoimmune diseases outlined in this application, mention may be made, without implying any limitation, of the treatment of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

The present invention also relates to pharmaceutical compositions containing at least one compound of formula (I) as an active ingredient, in combination with one or more pharmaceutically acceptable excipients. In particular, such pharmaceutical compositions are of interest for use as proapoptotic and/or antiproliferative agents, in particular for the treatment of malignant neoplasms, as well as autoimmune diseases and diseases of the immune system.

Suitable excipients according to the invention include diluents, lubricants, binders, disintegrating agents, stabilizers, preservatives, absorbents, colorants, sweeteners and flavoring agents.

As a non-limiting example, the following may be mentioned:

• as diluents: lactose, dextrose, sucrose, mannitol, sorbitol, cellulose, glycerin,

• as lubricants: silicon dioxide, talc, stearic acid and its magnesium and calcium salts, polyethylene glycol,

• as binders: magnesium aluminum silicate, starch, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose and polyvinylpyrrolidone,

• as leavening agents: agar, alginic acid and its sodium salt, effervescent mixtures.

Among the pharmaceutical compositions according to the invention, mention may be made more particularly of those which are suitable for oral, parenteral, nasal, trans- or transdermal, rectal, perlingual, ophthalmic or respiratory administration, in particular tablets, dragees, sublingual tablets, capsules, glossettes, capsules, lozenges, injectable or drinkable preparations, aerosols, eye drops or nasal drops, suppositories, creams, ointments, skin gels.

The actual dosage levels of the active ingredients in the pharmaceutical compositions of the present invention may vary to provide an amount of the active ingredient that is effective to achieve the desired therapeutic response for a particular patient, composition and route of administration, but is not toxic to the patient. The dosage level selected will depend on a number of factors, including the activity of the particular compound used in the present invention, the route of administration, the time of administration, the rate of elimination or metabolism of the particular compound used, the rate and extent of absorption, the duration of treatment, other drugs, compounds and/or substances used in combination with the particular compound used, the age, sex, weight, condition, general health and previous medical history of the patient being treated, and similar factors well known in the medical art.

A suitable daily dose of the compound of the present invention will depend on the factors described above and may vary from 0.01 mg to 2.5 g per day in one or more administrations.

In another aspect, the present invention also relates to a combination of a compound of formula (I) with an antitumor agent selected from genotoxic agents, mitotic poisons, antimetabolites, proteasome inhibitors, kinase inhibitors and antibodies, as well as to pharmaceutical compositions containing this type of combination, and their use for the manufacture of medicaments for use in the treatment of malignant neoplasm.

In another aspect, the compounds of the present invention can be used in combination with radiotherapy for the treatment of malignancy.

Alternatively, the compounds of the present invention can be linked to monoclonal antibodies. Antibody drug conjugates (ADCs) are a new class of therapeutic agents that are formed by chemically linking a cytotoxic agent to a monoclonal antibody via a linker. The monoclonal antibody of the ADC selectively binds to a target antigen of a cell (e.g., a cancer cell) and releases the drug into the cell. ADCs have therapeutic potential because they combine the specificity of an antibody and the cytotoxic potential of a drug. However, the development of ADCs as therapeutic agents has so far had only limited success due to a variety of factors, such as an unfavorable toxicity profile, low efficacy, and poor pharmacological parameters. Accordingly, there is still a need for new ADCs that overcome these problems and can selectively deliver Bcl-xL to target cancer cells.

In another aspect, the compounds of the present invention may be linked to fragments of monoclonal antibodies or linked to scaffold proteins, which may or may not be monoclonal antibodies. Antibody fragments are to be understood as fragments of the Fv, scFv, Fab, F(ab') ₂ , F(ab'), scFv-Fc type or diabody, which generally have the same binding specificity as the antibody from which they are derived. According to the present invention, fragments of antibodies of the present invention can be obtained starting from antibodies by methods such as digestion with enzymes such as pepsin or papain and/or by cleavage of disulfide bridges by chemical reduction. Alternatively, fragments of antibodies included in the present invention can be obtained by using genetic recombination techniques also well known to those skilled in the art, or even by peptide synthesis using, for example, automated peptide synthesizers such as those supplied by Applied Biosystems, etc.

By scaffold proteins, which may or may not be monoclonal antibodies, is meant a protein which may or may not contain an immunoglobulin chain fold and which provides the same binding ability as a monoclonal antibody. The person skilled in the art knows how to select a protein scaffold. More specifically, it is known that a scaffold should be selected which exhibits several of the following distinctive features (Skerra, J. Mol. Recogn. 2000, 13, 167-187): good phylogenetic conservation, robust architecture with a well-known three-dimensional molecular organization (such as based on crystallography or NMR), small size, no or only a low degree of post-translational modifications, ease of production, expression and purification. Such a scaffold protein may be, but is not limited to, a structure selected from the group consisting of fibronectin and preferably the tenth domain of fibronectin type III (FNfn10), lipocalin, anticalin (Skerra, J. Biotechnol. 2001, 74, 257-75), protein Z, which is derived from domain B of staphylococcal protein A, thioredoxin A, or any protein with a repeat domain such as an "ankyrin repeat" (Kohl et al. PNAS 2003, 100, 1700-1705), an "armadillo repeat", a "leucine-rich repeat", or a "tetratricopeptide repeat". Also worth mentioning is a scaffold derived from toxins (such as scorpion, insect, plant or shellfish toxins) or protein inhibitors of neuronal nitric oxide synthase (PIN).

The following Examples illustrate the invention but do not limit it in any way. All intermediates for preparing the compounds of the Examples are either commercially available or can be prepared by a person skilled in the art using conventional chemical reactions described in the literature.

GENERAL METHODS

All reagents obtained from commercial sources were used without further purification. Anhydrous solvents were obtained from commercial sources and used without further drying.

Column chromatography

Automated flash column chromatography was performed on an ISCO CombiFlash ^® Rf 200 or CombiFlash ^® Rf+Lumen™ instrument using RediSep ^® Rf normal-phase silica flash chromatography columns (35–70 μm, 60 Å), RediSep Rf Gold ^® normal-phase silica high-performance chromatography columns (20–40 μm, 60 Å), C18 RediSep ^® Rf reversed-phase columns (40–63 μm, 60 Å), or C18 RediSep Rf Gold ^® reversed-phase high-performance chromatography columns (20–40 μm, 100 Å).

TLC

Thin layer chromatography was performed on 5×10 cm plates coated with Merck Type 60 F ₂₅₄ silica gel.

Reactions in a microwave reactor

Microwave heating was performed in a CEM Discover ^® SP instrument or an Anton Raag single-mode microwave reactor.NMR

¹ H NMR measurements were performed on a Bruker Avance III 500 MHz, Bruker Avance III 400 MHz or Bruker DPX-400 spectrometer using DMSO-d ₆ or CDCl ₃ as solvent. ¹ H NMR data are presented as delta values reported in parts per million (ppm) using the residual solvent peak (2.50 ppm for DMSO-d ₆ and 7.26 ppm for CDCl ₃ ) as an internal standard. Splitting patterns are designated as: s (singlet), d (doublet), t (triplet), q (quartet), quint (quintet), sept (septet), m (multiplet), br s (broad singlet), dd (doublet of doublets), td (triplet of doublets), dt (doublet of triplets), ddd (doublet of doublet of doublets).

Analytical LC-MS

Certain compounds of the present invention were characterized by high performance liquid chromatography mass spectroscopy (HPLC-MS) on an Agilent HP 1200 with an Agilent 6140 quadrupole LC/MS operating with electrospray ionization in positive or negative ion mode. The molecular weight scan range was from 100 to 1350. Parallel UV detection was performed at 210 nm and 254 nm. Samples were injected as 1 mM in ACN or THF/ _H2O (1:1) in 5 µL using a loop injector. LCMS analyses were performed on two instruments, one operating with basic and one with acidic eluents.

Primary LCMS: Gemini-NX, 3 µm, C18, 50 mm x 3.00 mm i.d. column at 23°C, with a flow rate of 1 ml min-1, using 5 mM ammonium bicarbonate (solvent A) and acetonitrile (solvent B) with a gradient starting with 100% solvent A and ending with 100% solvent B for various/specified times.

Acidic LCMS: KINATEX XB-C18-100A, 2.6 µm, 50 mm*2.1 mm column at 40°C, with a flow rate of 1 ml min ^-1 , using 0.02% v/v aqueous formic acid (solvent A) and 0.02% v/v formic acid in acetonitrile (solvent B) with a gradient starting with 100% solvent A and ending with 100% solvent B for different/defined periods of time.

Certain other compounds of the present invention were characterized by HPLC-MS using the specifically named methods as outlined below. For all of these methods, UV detection was performed using a diode array detector at wavelengths of 230, 254, and 270 nm. The sample injection volume was 1 μl. Gradient elution steps were performed by setting the flow rates and component percentages of the following mobile phase mixtures using HPLC grade solvents:

Solvent A: 10 mM aqueous ammonium formate solution + 0.04% (v/v) formic acid.

Solvent B: acetonitrile + 5.3% (v/v) solvent A + 0.04% (v/v) formic acid.

Retention times (RT) for these named methods are given in minutes. Ionization was recorded in positive ion, negative ion, or positive/negative ion switchable mode. Specific details for individual methods are given below.

LCMS-V-V methods

An Agilent 1200 SL Series instrument coupled to an Agilent MSD 6140 single quadrupole detector with a multimode SI-ADCI source was used (LCMS-V-B1 and LCMS-V-B2 methods) or an Agilent 1290 Infinity II Series instrument coupled to an Agilent TOF 6230 with a Jet Stream SI source (LCMS-V-B1 method); column: Thermo Accucore 2.6 μm, C18, 50 mm × 2.1 mm at 55 °C. Gradient details for LCMS-V-B1 and LCMS-V-B2 methods:

LCMS-V-C method

An Agilent 1200 SL series instrument was used, coupled with an Agilent MSD 6140 single quadrupole detector with a multimode ERI-HIAD source; column: Agilent Zorbax Eclipse plus 3.5 μm, C18(2), 30 mm × 2.1 mm at 35°C. Detailed data regarding the gradient for the LCMS-V-C method:

Preparative HPLC

Certain compounds of the present invention were purified by high performance liquid chromatography (HPLC) on an Armen Spot Liquid Chromatography or Teledyne EZ system with a Gemini-NX® 10 µm C18, 250 mm x 50 mm i.d. column, operating at a flow rate of 118 mL min ^-1 with a diode array UV detector (210,400 nm), and using 25 mM aqueous NH ₄ HCO ₃ and MeCN or 0.1% TFA in water and MeCN as eluents.

Certain other compounds of the present invention were purified by HPLC using the specifically named methods as follows:

HPLC-U-A methods

The experiments were performed on a Waters FractionLynx MS autocleaning system, with a Gemini 5 μm C18(2), 100 mm × 20 mm i.d. column from Phenomenex, running at a flow rate of 20 cm ³ min ^-1 with a diode array UV detector (210-400 nm) and mass-directed collection. The mass spectrometer was a Waters Micromass ZQ2000 spectrometer operating with electrospray ionization in positive or negative ion mode with a molecular weight scanning range of 150 to 1000.

HPLC-V-A1 method (pH 4):

Solvent A: 10 mM ammonium acetate aqueous solution + 0.08% (v/v) formic acid; Solvent B: acetonitrile + 5% (v/v) solvent A + 0.08% (v/v) formic acid.

HPLC-V-A2 method (pH 9):

Solvent A: 10 mM ammonium acetate aqueous solution + 0.08% (v/v) concentrated ammonia solution; Solvent B: acetonitrile + 5% (v/v) solvent A + 0.08% (v/v) concentrated ammonia solution.

HPLC-V-V methods

The experiments were performed on an AccQPrep HP 125 system (Teledyne ISCO) with a Gemini® NX 5 µm C18(2), 150 mm × 21.2 mm i.d. column from Phenomenex, running at a flow rate of 20 cm ³ min ^-1 with UV (214 and 254 nm) and IR spectrophotometer detection.

HPLC-V-B1 method (pH 4):

Solvent A: water+0.08% (v/v) formic acid; Solvent B: acetonitrile+0.08% (v/v) formic acid. HPLC-V-B2 method (pH 9):

Solvent A: water + 0.08% (v/v) concentrated ammonia solution; Solvent B: acetonitrile + 0.08% (v/v) concentrated ammonia solution. HPLC-V-B3 (neutral) method: Solvent A: water; Solvent B: acetonitrile.

Analytical GC-MS

Combined gas chromatography-low-resolution mass spectrometry (GC-MS) was performed on an Agilent 6850 gas chromatograph and an Agilent 5975C mass spectrometer using a 15 m × 0.25 mm column with 0.25 μm HP-5MS coating and helium as the carrier gas. Ion source: EI ⁺ , 70 eV, 230°C, quadrupole: 150°C, interface: 300°C.

High Resolution MS

High-resolution mass spectra were acquired on an Agilent 6230 time-of-flight mass spectrometer equipped with a Jet Stream electrospray ion source, operating in positive ion detection mode. An injection volume of 0.5 µL was directed into the mass spectrometer at a flow rate of 1.5 mL/min (gradient program: 5 mM ammonium formate in water and acetonitrile) using an Agilent 1290 Infinity HPLC system. Jet Stream parameters: drying gas (N ₂ ) flow rate and temperature: 8.0 L/min and 325 °C, respectively; nebulizer gas (N ₂ ) pressure: 30 psi; capillary voltage: 3000 V; shield gas flow rate and temperature: 325 °C and 10.0 L/min; TOFMS parameters: fragmentor voltage: 100 V; skimmer potential: 60 V; OST 1 RF Vpp: 750 V. Full scan mass spectra were obtained in the m/z 105–1700 range at a data acquisition rate of 995.6 ms/spectrum and processed using Agilent MassHunter B.04.00 software.

Name of chemical compounds

Preferred IUPAC names were generated using ChemAxon's 'Structure to Name' (s2n) function within MarvinSketch or JChem for Excel (JChem versions 16.6.13 18.22.3), or using the chemical compound name generation function provided by Biovia® Draw 4.2.

Abbreviations

Ahx - 6-hexanoic acid monomer

Boc - mpem-butyloxycarbonyl

Boc ₂ O - di-tert-butyl dicarbonate

^t BuOH - mpem-butanol

conc. - concentrated

CuOH - cyclohexanol

dba - (1E,4E)-1,5-diphenylpenta-1,4-dien-3-one, dibenzylideneacetone

DCM - dichloromethane

DEA - diethanolamine

DIAD - diisopropyl azodicarboxylate

DIBAL-H - diisobutylaluminum hydride

DIPA - N-isopropylpropan-2-amine, diisopropylamine

DIPEA - N-ethyl-N-isopropylpropan-2-amine, diisopropylethylamine

EtO ₂ - diethyl ether

EtOAc - ethyl acetate

eqv. - equivalent

HF×Pyr - hydrogen fluoride pyridine

hs - homo sapiens

LDA - lithium diisopropylamide

MeCN - acetonitrile

MeOH - methanol

MTBE - methyl tert-butyl ether

VN - during the night

Pd\C - palladium on carbon

PPh ₃ - triphenylphosphine

r.t. - room temperature

RT - retention time (in minutes)

TBAF - tetrabutylammonium fluoride

TBAOH - tetrabutylammonium hydroxide

TBSCl - tert-butylchlorodimethylsilane

TEA - N,N-diethylethanamine

TFA - 2,2,2-trifluoroacetic acid

pTSA - 4-methylbenzenesulfonic acid

THF - tetrahydrofuran

TIPSCl - chloro(triisopropyl)silane

Xantphos - 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene

Xantphos Pd G3 - methanesulfonate [(4,5-bis(diphenylphosphino)-9,9-dimethylxanthene)-2-(2'-amino-1,1'-biphenyl)]palladium(II)

BINAP - 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl

rac-BINAP Pd G3 - [(2,2'-bis(diphenylphosphino)-1,1'-binaphthyl)-2-(2'-amino-1,1'-biphenyl)]palladium(II) methanesulfonate

Pd(dppf)Cl ₂ - CH ₂ Cl ₂ [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II)

Pd ₂ (dba) _{3 -} tris(dibenzylideneacetone)dipalladium(0)

Pd( _PPh3 ) _2Cl2 - bis( _{triphenylphosphine} )palladium chloride

Pd(AtaPhos) ₂ Cl ₂ - bis(di-tert-butyl(4-dimethylaminophenyl)phosphine)dichloropalladium(II)

Methods with a well-known name

Below are given representative experimental procedures that are mentioned by name in the following Syntheses.

General procedure for carrying out the Sonogashira reaction

A mixture of 1 equiv. aryl halide, 2 equiv. acetylene, 0.05 equiv. Pd(PPh ₃ ) ₂ Cl ₂ , 0.05 equiv. CuI and DIPA (1 ml/mmol) in THF (5 ml/mmol) was heated at 60 °C. After a suitable conversion was achieved, the volatiles were removed under reduced pressure and the crude intermediate was purified by flash column chromatography.

General Methodology for Removing Protection via HFIP

The substrate in 1,1,1,3,3,3-hexafluoropropan-2-ol (10 ml/mmol) was maintained at 100-120 °C in a pressure reaction vessel. After a suitable degree of conversion was achieved, the volatiles were removed under reduced pressure and the crude intermediate was purified by flash column chromatography.

General Alkylation Procedure

A mixture of 1 equiv. phenol/carbamate, 1-2 equiv. alkyl _iodide or bromide and 2-3 equiv. _Cs2CO3 in acetone (5 ml/mmol) was stirred at rt for phenols and at 55°C for carbamates. After reaching a suitable conversion, the volatiles were removed under reduced pressure and the crude intermediate was purified by flash column chromatography or reversed phase flash column chromatography.

General procedure for carrying out the Mitsunobu reaction

To a mixture of 1.0-1.5 equiv. of the aliphatic alcohol, 1 equiv. of the carbamate/phenol and 1-2 equiv. of triphenylphosphine in THF or toluene (5 ml/mmol) were added 1-3 equiv. of di-tert-butyl azodicarboxylate/diisopropyl azodicarboxylate in one portion. The mixture was stirred at rt or, if necessary, 50 °C in the case of the carbamate and at rt in the case of the phenol. After a suitable degree of conversion was achieved, the volatiles were removed under reduced pressure and the crude intermediate was purified by flash column chromatography.

General Method I for Carrying Out the Buchwald Reaction

A mixture of 1 equiv. of the chlorinated substrate, 2 equiv. of 1,3-benzothiazol-2-amine, 0.1 equiv. of Pd ₂ (dba) ₃ , 0.2 equiv. of XantPhos, and 3 equiv. of DIPEA in CyOH (5 ml/mmol) was heated at 140 °C. After reaching a suitable conversion, the reaction mixture was diluted with DCM (10 ml/mmol), injected onto a preconditioned silica gel column, and purified by flash column chromatography.

General Method II for Carrying Out the Buchwald Reaction

A mixture of 1 equiv. thiazolamine, 1.2-1.5 equiv. (Z)-N-(6-chloro-4-methylpyridazin-3-yl)-3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-imine, 3 equiv. _Cs2CO3 , 0.1 equiv. _Pd2 (dba) ₃ , 0.2 equiv. XantPhos and 3 equiv. _DIPEA in 1,4-dioxane (5 ml/mmol) was heated at reflux. After a suitable conversion was achieved, the volatiles were removed under reduced pressure and the crude intermediate was purified by flash column chromatography.

General procedure for the Finkelstein reaction A mixture of 1 equiv. alkyl chloride and 2 equiv. NaI in acetone (5 mL/mmol) was heated under reflux. After a suitable degree of conversion was achieved, the volatiles were removed under reduced pressure and the crude intermediate was purified by flash column chromatography.

General procedure for carrying out the nucleophilic substitution reaction A mixture of 1 equiv. thiazolamine, 1 equiv. 3,6-dichloro-4-methylpyridazine and 1.5 equiv. _Cs2CO3 in toluene (4 ml/mmol) was heated at 150°C. After reaching a suitable degree of conversion _, the volatiles were removed under reduced pressure, the crude intermediate was purified by flash column chromatography.

General procedure for alkylation with tosylate

The oven-dried flask was fitted with a PTFE-lined magnetic stir bar and charged with 1 equiv. of the tosylate and 5 equiv. of the appropriate amine suspended in MeCN (5 mL/mmol). The reaction mixture was then heated to 50 °C and stirred at this temperature until no further conversion was observed. The reaction mixture was diluted with DCM and then applied to a DCM-preconditioned silica gel column. The crude product was then purified by flash column chromatography using DCM and MeOH (1.2% NH ₃ ) as eluents.

General procedure for alkylation with in situ generated tosylate

An oven-dried vessel was fitted with a PTFE-lined magnetic stir bar and charged with 1 equiv of the hydroxy derivative, 3 equiv of N,N-diethylethanamine, a catalytic amount of N,N-dimethylpyridin-4-amine and DCM (5 mL/mmol), then 2 equiv of 4-methylbenzenesulfonyl chloride were added in one portion and the mixture was stirred at rt until no further conversion was observed (typically >90%, 1-5 h). After evaporation of the volatiles at 40 °C using N ₂ , 30 equiv of methyl sulfonyl chloride were added. of the appropriate primary, secondary or tertiary amine in acetonitrile (3 ml/mmol) and the mixture was stirred at 50°C until complete conversion was observed for the tosyl derivative (typically 1-3 h). The reaction mixture was concentrated on celite and purified by flash column chromatography using EtOAc and MeOH (1.2% NH ₃ ) as eluents or by reversed-phase flash column chromatography (0.1% TFA in water:MeCN).

General procedure for alkylation with an in situ generated iodine containing compound

An oven dried vessel was fitted with a PTFE coated magnetic stir bar, 2 equiv. of _PPh3 and 2 equiv. of imidazole were added followed by the addition of DCM (5 mL/mmol). To the resulting mixture was added 2 equiv. of iodine portionwise and then stirred for 15 min at rt. To the resulting mixture was added 1 equiv. of the appropriate alcohol dissolved in DCM and stirred at rt until no further conversion was observed. To the formed iodine compound was added 5 equiv. of the appropriate amine and the mixture was then stirred for 30 min at rt during which time the reaction reached complete conversion. Celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was then purified by flash chromatography using DCM and MeOH (1.2% NH ₃ ) as eluents. General Procedure for the Alkylation of Silyl-Protected Phenols A mixture of 1 equiv of silyl-protected phenol, 1 equiv of alkyl iodide, and 1.15 equiv of TBAF (1 M in THF) in THF (2 mL/mmol) was stirred at rt. After a suitable conversion was achieved, the volatiles were removed under reduced pressure and the crude intermediate was purified by flash column chromatography.

General Method of Deprotection and Hydrolysis

A mixture of 1 equiv. of the substrate and 100 equiv. of HF×Pyr in MeCN (15 mL/mmol) was stirred at 60 °C. After reaching a suitable conversion, the volatiles were removed under reduced pressure and the residue was suspended in a 1:1 mixture of 1,4-dioxane:water (30 mL/mmol), treated with 150 equiv. LiOH×H ₂ O, and stirred at 60 °C. After reaching a suitable conversion, the volatiles were removed under reduced pressure and the crude product was purified by flash column chromatography using DCM and MeOH (containing 1.2% NH ₃ ) as eluents.

General Method of Formation of Quaternary Salt

The oven-dried vessel was fitted with a PTFE-lined magnetic stir bar and charged with 1 equiv. of the tosylate and 20 equiv. of the appropriate amine suspended in CyOH (5 mL/mmol). The reaction mixture was then heated to 140 °C and stirred at this temperature until no further conversion was observed. The reaction mixture was diluted with DCM and then applied to a DCM-preconditioned silica gel column. The crude product was then purified by flash column chromatography using DCM and MeOH (1.2% NH ₃ ) as eluents.

General Method for Removing Protection from Quaternary Salt

To a solution of the appropriate quaternary salt in THF (5 mL/mmol) were added 3 equiv. TBAF, and the mixture was stirred at rt until no further conversion was observed. The reaction mixture was evaporated to dryness under reduced pressure. To a suspension of 1 equiv. of the desilylated quaternary salt in dry MeCN (15 mL/mmol) were added 100 equiv. HF×Pyr, and the mixture was stirred at 60 °C. After the appropriate conversion was achieved, the volatiles were removed under reduced pressure, the residue was suspended in 1:1 THF:water (30 mL/mmol), 150 equiv. LiOH× _H2O were added, and the mixture was stirred at rt. After the appropriate conversion was achieved, the volatiles were removed under reduced pressure. The crude product was purified by flash column chromatography using DCM and MeOH (containing 1.2% NH ₃ ) as eluents.

General procedure for alkylation, deprotection and hydrolysis

A mixture of tertiary amine (1 equiv.) and alkalizing agent (10 equiv.) in acetonitrile (3 ml/mmol) was stirred at rt. After reaching a suitable conversion, the volatiles were removed under reduced pressure and the crude product was purified by reverse phase flash column chromatography if necessary, or the residue was directly dissolved in acetonitrile (3 ml/mmol), HF×Pyr (100 equiv.) was added and the mixture was stirred at 60 °C. After reaching a suitable conversion, the volatiles were removed under reduced pressure, the residue was suspended in a 1:1 mixture of 1,4-dioxane:water (10 ml/mmol), LiOH×H ₂ O (150 equiv.) was added and the mixture was stirred at 60 °C. After achieving a suitable degree of conversion to the desired product, the volatiles were removed under reduced pressure and the crude product was purified by reverse phase flash column chromatography.

General procedure for removing the tert-butyldimethylsilyl protecting group

The appropriate TBS-protected compound and [(1S,4R)-7,7-dimethyl-2-oxonorbornane-1-yl]methanesulfonic acid (typically 0.25 equiv, 1.25 equiv if the N,N-dimethylamino moiety is present in the molecule) were mixed in a mixture of methanol (2.5 ml/mmol) and dichloromethane (2.5 ml/mmol) in a sealed tube and stirred at 50 °C until complete conversion was observed (typically 1-5 h). After the reaction time, the mixture was poured into a separatory funnel, diluted with DCM and washed with conc. NaHCO ₃ solution and water. It was dried over MgSO ₄ , filtered through celite and then purified by flash column chromatography.

General procedure for deprotection and hydrolysis of phosphonic acid derivatives

A solution of the diethylphosphonate derivative in DCM (5 mL/mmol) and MeCN (5 mL/mmol) was purged with nitrogen, 40 equiv. TEA was added and the mixture was then cooled to 0 °C. 20 equiv. bromo(trimethyl)silane were added in one portion and the mixture was then stirred for an additional 30 min at 0 °C. The mixture was allowed to warm to rt and stirred until complete conversion of the ethyl ester was achieved (typically 1-5 h). The Boc protecting group(s) were usually cleaved, but only partially, yielding a mixture of products. After complete conversion, the mixture was quenched with a few mL of MeOH at 0 °C, concentrated onto Celite, and then purified by flash column chromatography using EtOAc and MeOH (containing 1.2% NH ₃ ) as eluents. The two products (with Boc, without Boc) were combined and proceeded to the General Procedure for Deprotection and Hydrolysis.

General procedure for carrying out the amine substitution and hydrolysis reaction

To the product of Preparation 14 in a 1:1 mixture of acetonitrile and N-methyl-2-pyrrolidone (10 mL/mmol), the appropriate amine (3-10 equiv) was added and the mixture was stirred at 50 °C for 2-24 h. After adding 70% HF in pyridine (50-100 equiv) at rt, the mixture was stirred for 4-18 h. After purification of the substitution product by column chromatography (silica gel, using DCM and MeOH as eluents), the product was dissolved in THF (8 mL/mmol), and water (2 mL/mmol) and LiOH×H ₂ O (5 equiv) were added, and the mixture was stirred at 20-40 °C for 1-4 h. The hydrolyzed product was purified by preparative HPLC (using acetonitrile and 5 μM aqueous solution of NH ₄ HCO ₃ as eluents) to obtain the target product.

Syntheses

The following experimental details describe the preparation of synthetic intermediates.

Synthesis of 1a: Methyl 2-{[(tert-butoxy)carbonyl]amino}-5-[3-(2-fluoro-4-iodophenoxy)propyl]-1,3-thiazole-4-carboxylate

Step A: Methyl 2-(tert-butoxycarbonylamino)-5-iodothiazole-4-carboxylate

50.00 g of methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate (193.55 mmol, 1 equiv) was suspended in 600 mL of dry MeCN. 52.25 g of N-iodosuccinimide (232.30 mmol, 1.2 equiv) was added and the resulting mixture was stirred overnight at room temperature. The reaction mixture was diluted with brine and then extracted with _EtOAc . _The combined organic layers were extracted with 1 M _Na2S2O3 solution and then with brine again. It was dried over _Na2SO4 , filtered and _the filtrate was concentrated under reduced pressure. The crude product was purified by flash column chromatography using heptane as eluent to afford 60 g (156 mmol, 80%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 12.03/11.06 (br s), 3.78 (s, 3H), 1.47 (s, 9H); ¹³ C NMR (400 MHz, DMSO-d ₆ ) δ ppm 153.8, 82.5, 77.7, 52.3, 28.3; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₁₀ H ₁₄ IN ₂ O ₄ S: 384.9713, found: 384.9708.

Step B: Methyl 2-(tert-butoxycarbonylamino)-5-(3-hydroxyprop-1-ynyl)thiazole-4-carboxylate

A 500 mL oven-dried, single-neck, round-bottomed flask was fitted with a PTFE-lined magnetic stir bar and a reflux condenser. The flask was charged with 9.6 g of the product from Step A (25 mmol, 1 equiv), 2.80 g of prop-2-yn-1-ol (2.91 mL, 50 mmol, 2 equiv), and 36.10 g of DIPA (50 mL, 356.8 mmol, 14.27 equiv), then 125 mL of dry THF was added and the system was purged with argon. After 5 min of stirring under inert atmosphere, 549 mg Pd( _PPh3 ) _2Cl2 (1.25 mmol, 0.05 equiv) and 238 mg CuI (1.25 mmol _, 0.05 equiv) were added. The resulting mixture was then heated to 60 °C and stirred at this temperature until no further conversion was observed. Celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was then purified by flash column chromatography using heptane and EtOAc as eluents to afford 7.30 g (23 mmol, 93%) of the desired product as a yellow solid.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 12.10 (br s, 1H), 5.45 (t, 1H), 4.36 (d, 2H), 3.79 (s, 3H), 1.48 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 161.3, 142.4, 118.1, 101.4, 73.9, 52.4, 50.2, 28.3; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₁₃ H ₁₇ N ₂ O ₅ S: 313.0853, found: 313.0866.

Step C: Methyl 2-(tert-butoxycarbonylamino)-5-(3-hydroxypropyl)thiazole-4-carboxylate

A 1 L oven-dried pressure reaction vessel equipped with a PTFE-lined magnetic stir bar was charged with 44.75 g of the product from Step B (143.3 mmol, 1 equiv.) and 7.62 g of Pd/C (7.17 mmol, 0.05 equiv.) in 340 mL of ethanol and then blanketed with nitrogen using a hydrogenation system. The vessel was then flushed with H2 gas at 4 bar and the reaction mixture was stirred at rt overnight. Complete conversion was observed, however, only the olefin product was formed. After filtering the catalyst through a pad of celite, the entire procedure was repeated with 5 mol % new catalyst. The resulting mixture was stirred overnight, which ensured complete conversion. Celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was then purified by flash column chromatography using heptane and EtOAc as eluents to afford 31.9 g (101 mmol, 70%) of the desired product as light yellow crystals.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 11.61 (br s, 1H), 4.54 (t, 1H), 3.76 (s, 3H), 3.43 (m, 2H), 3.09 (t, 2H), 1.74 (m, 2H), 1.46 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 162.8, 143.1, 135.4, 60.3, 51.9, 34.5, 28.3, 23.4; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₃ H ₂ 1N ₂ O ₅ S: 317.1166, found: 317.1164.

Step D: Methyl 2-{[(tert-butoxy)carbonyl]amino}-5-[3-(2-fluoro-4-iodophenoxy)propyl]-1,3-thiazole-4-carboxylate

A 250 mL oven-dried, single-necked round-bottom flask fitted with a PTFE-lined magnetic stir bar was charged with 3.40 g of 2-fluoro-4-iodophenol (14 mmol, 1 equiv), 5.00 g of the product from Step C (16 mmol, 1.1 equiv), 4.10 g of _PPh3 (16 mmol, 1.1 equiv), and 71 mL of dry toluene. After stirring for 5 min under nitrogen, 3.10 mL of DIAD (3.20 g, 16 mmol, 1.1 equiv) was added in one portion while heating the reaction mixture. The reaction mixture was then heated to 50 °C and stirred at this temperature for 30 min, during which time the reaction reached complete conversion. The reaction mixture was directly injected onto a preconditioned silica gel column, and the crude product was then purified by flash column chromatography using heptane and EtOAc as eluents. The crude product was crystallized from MeOH to afford 4.64 g (9.24 mmol, 66%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 11.64 (br s, 1H), 7.59 (dd, 1H), 7.45 (dd, 1H), 6.98 (t, 1H), 4.06 (t, 2H), 3.73 (s, 3H), 3.22 (t, 2H), 2.06 (m, 2H), 1.46 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 134.0, 124.9, 117.6, 68.2, 51.9, 30.5, 28.3, 23.2; MSHR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₉ H ₂₃ N ₂ O ₅ FSI: 537.0351, found: 537.0348.

Synthesis 1b: Methyl 2-(tert-butoxycarbonylamino)-5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

A 500 mL oven-dried single-neck round-bottomed flask was fitted with a PTFE-coated magnetic stir bar and a reflux condenser. The flask was charged with 13.41 g of Preparation 1a (25 mmol, 1 equiv), 8.46 g of tert-butyl N-methyl-N-prop-2-ynylcarbamate (50 mmol, 2 equiv), and 50 mL of DIPA (36.10 g, 50 mL, 356.8 mmol, 14.27 equiv), then 125 mL of dry THF was added and the system was purged with argon. After 5 min of stirring under inert atmosphere, 549 mg Pd( _PPh3 ) _2Cl2 (1.25 mmol, 0.05 equiv) and 238 mg CuI (1.25 mmol _, 0.05 equiv) were added. The resulting mixture was then heated to 60 °C and stirred at this temperature until no further conversion was observed. Celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was then purified by flash column chromatography using heptane and EtOAc as eluents to afford 10.5 g (18.2 mmol, 73%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 11.65 (br s, 1H), 7.31 (br d, 1H), 7.21 (br d, 1H), 7.14 (t, 1H), 4.23 (s, 2H), 4.10 (t, 2H), 3.73 (s, 3H), 3.23 (t, 2H), 2.86 (s, 3H), 2.07 (m, 2H), 1.46/1.41 (s, 18H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 129.1, 119.2, 115.4, 68.1, 51.9, 38.6, 33.8, 30.5, 23.2; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₈ H ₃₇ FN ₃ O ₇ S: 578.2331, found: 578.2331.

Synthesis 1 c: Methyl 2-(tert-butoxycarbonylamino)-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

A 250 mL oven-dried single-neck round-bottomed flask was fitted with a PTFE-coated magnetic stir bar and a reflux condenser. The flask was charged with 5.36 g of Preparation 1a (10 mmol, 1 equiv), 1.66 g of N,N-dimethylprop-2-yn-1-amine (20 mmol, 2 equiv), and 20 mL of DIPA (142.7 mmol, 14.27 equiv), then 50 mL of dry THF was added and the system was purged with argon. After 5 min of stirring under inert atmosphere, 220 mg Pd( _PPh3 ) _2Cl2 (0.5 mmol, 0.05 equiv) and 95 mg CuI (0.5 mmol, _0.05 equiv) were added. The resulting mixture was then heated to 60 °C and stirred at this temperature until no further conversion was observed. Celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was then purified by flash column chromatography using DCM and MeOH (1.2% NH3 ₎ as eluents to afford 4.5 g (7.8 mmol, 78%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 11.66 (s, 1H), 7.29 (dd, 1H), 7.19 (m, 1H), 7.12 (t, 1H), 4.09 (t, 2H), 3.73 (s, 3H), 3.44 (s, 2H), 3.23 (t, 2H), 2.24 (s, 6H), 2.07 (m, 2H), 1.45 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 162.8, 147.3, 129.0, 119.2, 115.4, 84.3, 68.0, 51.9, 48.1, 44.2, 30.6, 28.3, 23.2; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₄ H ₃₁ FN ₃ O ₅ S: 492.1963, found: 492.1956.

Synthesis 2a: 5-[tert-Butyl(dimethyl)silyl]oxy-4-[tert-butyl(diphenyl)silyl]oxypentan-1-ol Step A: pent-4-enyl benzoate

30.00 g of pent-4-en-1-ol (0.35 mol, 1 equiv.) and 58.5 mL of N,N-diethylethanamine (0.42 mol, 1.2 equiv.) were mixed in 200 mL of DCM and then cooled to 0 °C. 48.5 mL of benzoyl chloride (0.42 mol, 1.2 equiv.) was added to the mixture at 0 °C using a dropping funnel under an inert atmosphere. After the addition, the mixture was further stirred at 0 °C for 30 min and then at rt. The mixture was diluted with 100 mL of DCM and the organic phase was washed with water, 1 M NaOH, 1 M HCl, and brine, respectively. The organic phase was dried over _MgSO4 , filtered, concentrated and purified by flash column chromatography using heptane and EtOAc as eluents to give 63.19 g (95%) of the desired product as a colorless liquid.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.97 (dd, 2H), 7.66 (t, 1H), 7.53 (t, 2H), 5.91-5.81 (m, 1H), 5.09-4.97 (m, 2H), 4.27 (t, 2H), 2.17 (q, 2H), 1.81 (qv, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 166.2, 138.2, 133.8, 130.3, 129.6, 129.2, 115.8, 64.5, 30.1, 27.8; GC-MS-EI (m/z): [M] ⁺ , calculated for C ₁₂ H ₁₄ O ₂ : 190.1, found: 190.

Step B: 4,5-dihydroxypentyl benzoate

42.22 g of the product from Step A (0.26 mol, 1.0 equiv) and 50.40 g of 4-methyl-4-oxidomorpholin-4-ium hydrate (0.37 mol, 1.7 equiv) were mixed in 360 mL of 2-methylpropan-2-ol and 40 mL of water, then 6.57 g of osmium tetroxide (2.5 wt % in 2-methylpropan-2-ol, 0.64 mmol, 0.002 equiv) was added and the mixture was stirred at 60 °C for 24 h. Complete conversion was observed. The mixture was cooled to rt _and 1 _{M Na2S2O3 was} added, then stirred for another 10 min at rt. DCM was added and the organic phase was separated, washed with water and brine, respectively. The solution was dried over _MgSO4 , filtered, concentrated and purified by flash column chromatography using heptane and EtOAc as eluents to give 36.9 g (63%) of the desired product as a white solid.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.99-7.50 (m, 5H), 4.50 (m, 2H), 4.28 (m, 2H), 3.45 (m, 1H), 3.30-3.24 (m+m, 2H), 1.85-1.72 (m+m, 2H), 1.59-1.33 (m+m, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 166.2, 133.8-129.1, 71.2, 66.3, 65.5, 30.3, 25.2; HR-MSR (m/z): [M+Na] ⁺ , calculated for C ₁₂ H ₁₆ NaO ₄ : 247.0941, found: 247.0941.

Step C: 5-[tert-butyl(dimethyl)silyl]oxy-4-hydroxypentyl] benzoate

24.86 g of the product from Step B (0.11 mol, 1 equiv) and 15.09 g of imidazole (0.22 mol, 2 equiv) were mixed in 120 mL of N,N-dimethylformamide and then cooled to -20 °C under an inert atmosphere. 16.71 g of tert-butylchlorodimethylsilane (0.11 mol, 1 equiv) in 40 mL of N,N-dimethylformamide was added slowly over a period of 30 min, supplemented with 10 mL of DCM, then allowed to warm to rt and stirred additionally. Complete conversion was observed. Quenching was done with conc. NH ₄ Cl solution, then most of the volatiles were evaporated. EtOAc and water were added to the residue, the organic phase was separated, then washed with water and brine, dried over _MgSO4 , filtered, concentrated and purified by flash column chromatography using heptane and EtOAc as eluents to give 33.71 g (90%) of the desired product as a colorless oil.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.95 (m, 2H), 7.66 (m, 1H), 7.52 (m, 2H), 4.58 (d, 1H), 4.29 (m, 2H), 3.51-3.35 (dd+dd, 2H), 3.48 (m, 1H), 1.86-1.74 (m+m, 2H), 1.67-1.34 (m+m, 2H), 0.83 (s, 9H), 0.01 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 166.2, 133.7, 130.4, 129.5, 129.2, 70.6, 67.7, 65.3, 30.2, 26.3, 24.9, -4.9.

Step D: [5-[tert-butyl(dimethyl)silyl]oxy-4-[tert-butyl(diphenyl)silyl]oxypentyl] benzoate

33.51 g of the product from Step C (0.10 mol, 1 equiv), 16.85 g of imidazole (0.25 mol, 2.5 equiv) and 1.21 g of N,N-dimethylpyridin-4-amine (0.01, 0.1 equiv) were mixed in 230 mL of N,N-dimethylformamide, then 38 mL of tert-butylchlorodiphenylsilane (0.15 mol, 1.5 equiv) were slowly added, supplemented with 20 mL of N,N-dimethylformamide and then stirred at 50 °C overnight. Complete conversion was observed. The mixture was cooled to rt, quenched with conc. NH ₄ Cl solution and then most of the volatiles were evaporated. EtOAc and water were added to the residue, the organic phase was separated, then washed with water and brine, dried over _MgSO4 , filtered, concentrated and purified by flash column chromatography using heptane and EtOAc as eluents to give 56.43 g (99%) of the desired product as a colorless viscous oil.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.91-7.37 (m, 15H), 4.17 (m, 2 H), 3.76 (m, 1H), 3.45 (m, 2H), 1.72 (m, 2H), 1.66-1.57 (m+m, 2H), 0.99 (s, 9H), 0.74 (s, 9H), -0.12/-0.16 (s+s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 166.1, 136.0-128.0, 73.3, 66.0, 65.1, 30.3, 27.3, 26.1, 24.0, -5.1; HR-ESI (m/z): [M+Na] ⁺ , calculated for C ₃₄ H ₄₈ NaO ₄ Si ₂ : 599.2983, found: 599.2981.

Step E: 5-[tert-butyl(dimethyl)silyl]oxy-4-[tert-butyl(diphenyl)silyl]oxypentan-1-ol

46.10 g of the product from Step D (0.08 mol, 1 equiv) was dissolved in 227 mL of MeOH and 117 mL of THF, and then 12.79 g of NaOH (0.32 mol, 4.0 equiv) in 85 mL of water was slowly added while cooling the mixture with ice. After the addition, the mixture was stirred at rt until complete conversion was observed (approximately 4 h). EtOAc and water were added, then the mixture was separated and the organic phase was washed with brine, dried over _MgSO4 , filtered, concentrated and purified by flash column chromatography using heptane and EtOAc as eluents to give 29.32 g (78%) of the desired product as a colorless oil.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.65-7.37 (m, 10H), 4.34 (t, 1H), 3.71 (m, 1H), 3.42 (m, 2H), 3.26 (m, 2H), 1.52 (m, 2H), 1.42 (m, 2H), 0.99 (s, 9H), 0.77 (s, 9H), -0.13 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 135.8, 135.8, 134.3, 134.0, 130.3, 130.2, 128.2, 128.0, 74.0, 66.4, 61.4, 30.4, 28.3, 27.3, 26.2, -5.1; HR-ESI (m/z): [M+Na] ⁺ , calculated for C ₂₇ H ₄₄ NaO ₃ Si ₂ : 495.2721, found: 495.2706.

Synthesis 2b: 5-[tert-Butyl(dimethyl)silyl]oxy-4-methoxypentan-1-ol

Step A: [5-[tert-butyl(dimethyl)silyl]oxy-4-methoxypentyl] benzoate

3.66 g of the product of Synthesis 2a, Step C (10.8 mmol, 1 equiv.), 6.95 g of N1,N1,N8,N8-tetramethylnaphthalene-1,8-diamine (32.4 mmol, 3 equiv.) and a small portion of molecular sieves were mixed in 210 mL of DCM, then 4.00 g of trimethyloxonium tetrafluoroborate (27.0 mmol, 2.5 equiv) was added in one portion and the mixture was stirred at rt for 5 h. Complete conversion was observed. The mixture was filtered through a pad of celite, washed with DCM, then concentrated. The residue was redissolved in DCM and washed with water, 1 M _CuSO4 , and brine, respectively. The solution was dried over _MgSO4 , filtered, concentrated on celite, and purified by flash column chromatography using heptane and EtOAc as eluents to give 2.58 g (68%) of the desired product as a colorless oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.95 (d, 2H), 7.65 (t, 1H), 7.51 (t, 2H), 4.27 (t, 2H), 3.56 (ddd, 2H), 3.30 (s, 3H), 3.23-3.18 (m, 1H), 1.84-1.44 (m, 4H), 0.83 (s, 9H), 0.02 (s, 6H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm. 165.7, 133.2, 129.9, 129.0, 128.7, 80.5, 64.7, 63.9, 57.0, 27.2, 25.7, 24.2, 17.9, -5.5, -5.5.

Step B: 5-[tert-Butyl(dimethyl)silyl]oxy-4-methoxypentan-1-ol 2.54 g of the product from Step A (7.20 mol, 1 equiv) was dissolved in 54 mL of MeOH, then 1.44 g of NaOH (36 mmol, 5.0 equiv) in 18 mL of water was slowly added to the mixture. After the addition, the mixture was stirred at rt until complete conversion was observed (approximately 1.5 h). EtOAc and water were added, then the mixture was separated and the organic phase was washed with brine, dried over MgSO ₄ , filtered and concentrated to give 1.76 g (98%) of the desired product as a light yellow oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 4.37 (t, 1H), 3.58-3.50 (m, 2H), 3.39-3.32 (m, 2H), 3.29 (s, 3H), 3.17-3.10 (m, 1H), 1.51-1.32 (m, 4H), 0.86 (s, 9H), 0.03 (s, 6H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 81.0, 64.4, 60.9, 57.0, 28.4, 27.2, 25.8, 18.0, -5.4, -5.4; LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₁₂ H ₂₉ O ₃ Si: 249.2, found: 249.2.

Synthesis 2c: 5-Methoxy-4-triisopropylsilyloxypentan-1-ol

Step A: [5-[tert-butyl(dimethyl)silyl]oxy-4-triisopropylsilyloxypentyl] benzoate

2.0 g of the product of Preparation 2a, Step C (5.91 mmol, 1 equiv) and 1.21 g of imidazole (17.73 mmol, 3 equiv) were mixed in 6 mL of N,N-dimethylformamide, then 1.71 g of chloro(triisopropyl)silane (8.86 mol, 1.5 equiv) was added in one portion and the mixture was stirred at 60 °C for 3.5 h. Additional amounts of chloro(triisopropyl)silane (0.5 equiv) and imidazole (1 equiv) were added and stirred for another 3 h. Complete conversion was observed. The mixture was cooled to rt, then EtOAc and water were added, the organic phase was separated, washed with brine, dried over _MgSO4 , filtered, concentrated on celite and purified by flash column chromatography using heptane and EtOAc as eluents to give 2.27 g (99%) of the desired product as a colorless viscous oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.94 (d, 2H), 7.66 (t, 1H), 7.52 (t, 2H), 4.29 (t, 2H), 3.86 (qv, 1H), 3.53 (ddd, 2H), 1.83-1.56 (m, 4H), 1.02 (m, 21H), 0.84 (s, 9H), 0.02 (s, 6H).

Step B: (5-hydroxy-4-triisopropylsilyloxypentyl) benzoate Using the General Procedure for Removal of the tert-butyldimethylsilyl Protective Group starting from 2.25 g of the product from Step A (4.54 mmol, 1 equiv) followed by purification by flash column chromatography using heptane and EtOAc as eluents gave 1.13 g (65%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.95 (d, 2H), 7.65 (t, 1H), 7.52 (t, 2H), 4.63 (t, 1H), 4.29 (qv, 2H), 3.85-3.78 (m, 1H), 3.45-3.26 (m, 2H), 1.83-1.54 (m, 4H), 1.01 (s, 21H); LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₃₇ O ₄ Si: 381.2, found: 381.3.

Step C: (5-methoxy-4-triisopropylsilyloxypentyl) benzoate 1.11 g of the product from Step B (2.91 mmol, 1 equiv) and 1.87 g of N1,N1,N8,N8-tetramethylnaphthalene-1,8-diamine (8.7 mmol, 3 equiv) were mixed in 45 mL of DCM, then 1.87 g of trimethyloxonium tetrafluoroborate (8.7 mmol, 3 equiv) were added in one portion and the mixture was stirred at rt for 4 h. Complete conversion was observed. The mixture was filtered through a pad of celite, washed with DCM, then the organic phase was washed with water, 1 M _CuSO4 , and brine, respectively. The solution was dried over _MgSO4 , filtered, concentrated on Celite and purified by flash column chromatography using heptane and EtOAc as eluents to give 963 mg (84%) of the desired product as a colorless oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.95 (d, 2H), 7.66 (t, 1H), 7.52 (t, 2H), 4.28 (t, 2H), 3.96 (qv, 1H), 3.31 (d, 2H), 3.25 (s, 3H), 1.82-1.54 (m, 4H), 1.01 (m, 21H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm. 165.7, 133.3, 129.8, 129.0, 128.7, 75.9, 70.4, 64.7, 58.4, 30.7, 23.5, 18.0, 17.9, 12.0.

Step D: 5-methoxy-4-triisopropylsilyloxypentan-1-ol 953 mg of the product from Step C (2.41 mmol, 1 equiv) was dissolved in 12 mL of MeOH and 6 mL of THF, then 487 mg of NaOH (12.1 mmol, 5.0 equiv) in 6 mL of water was slowly added. After the addition, the mixture was stirred at rt until complete conversion was observed (approximately 2 h). EtOAc and water were added, then the mixture was separated and the organic phase was washed with brine, dried over _MgSO4 , filtered, concentrated on celite and purified by flash column chromatography using heptane and EtOAc as eluents to give 687 mg (78%) of the desired product as a colorless oil.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 4.39 (t, 1H), 3.89 (m, 1H), 3.37 (m, 2H), 3.27 (d, 2H), 3.24 (s, 3H), 1.47 (m, 2H), 1.47 (m, 2H), 1.03 (m, 21H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 76.8, 71.4, 61.4, 58.8, 31.4, 28.3, 18.5, 12.5; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁₅ H ₃₅ O-3Si: 291.2350, found: 291.2349.

Synthesis 2d: 4-[tert-Butyl(dimethyl)silyl]oxy-5-(dimethylamino)pentan-1-ol

Step A: 3-(oxiran-2-yl)propyl benzoate

19.01 g of 3-chlorobenzenecarboperoxylic acid (77 wt %, 85.83 mmol, 1.3 equiv) was dissolved in DCM (3 mL/mmol) in a separatory funnel, then the organic phase (3-4 mL of water were discarded) was directly added to a solution of 12.41 g of the product of Preparation 2a, Step A (65.25 mmol, 1 equiv) in DCM (3 mL/mmol), and stirred at rt for 4 h. Complete conversion was observed. 100 mL of DCM was added, then washed with 2×100 mL conc. NaHCO ₃ solution and 1×100 mL of brine, dried over MgSO ₄ , filtered, concentrated and purified by flash column chromatography using heptane and EtOAc as eluents to give 13.92 g (quant.) of the desired product as a colorless oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.97 (dm, 2H), 7.66 (tm, 1H), 7.53 (tm, 2H), 4.31 (m, 2H), 2.97 (m, 1H), 2.68-2.48 (dd+dd, 2H), 1.84 (m, 2H), 1.67-1.56 (m+m, 2H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 166.2, 133.8, 129.6, 129.3, 64.8, 51.7, 46.6, 29.1, 25.4; MSHR-EI (m/z): [M] ⁺ , calculated for C ₁₂ H ₁₄ O ₃ : 206.0943, found: 206.0941.

Step B: [4-[tert-butyl(dimethyl)silyl]oxy-5-(dimethylamino)pentyl]benzoate

7.01 g of the product from Step A (34 mmol, 1 equiv) and 51 mL of dimethylamine solution (2 M in MeOH, 102 mmol, 3 equiv) were mixed in a sealed tube and stirred at 60 °C for 1 h. Complete conversion was observed. The reaction mixture was concentrated and [5-(dimethylamino)-4-hydroxypentyl]benzoate was obtained as a viscous light yellow oil. HR-MS ESI (m/z): [M+H] ⁺ , calculated for C ₁₄ H ₂₂ NO ₃ : 252.1594, found: 252.1597.

The crude product was redissolved in N,N-dimethylformamide (2 mL/mmol), then 6.95 g imidazole (102 mmol, 3 equiv), 208 mg N,N-dimethylpyridin-4-amine (1.70 mmol, 0.05 equiv) were added and, after the mixture became clear, a solution of 12.8 g tert-butylchlorodimethylsilane (85.0 mmol, 2.5 equiv) was added in one portion. The mixture was stirred at 60 °C for 3 h (>95% conversion was observed). The mixture was cooled to rt, then 3-4 mL conc. NH ₄ Cl solution was added, stirred for 5 min, and then the volatiles were evaporated. 300 mL EtOAc, 50 mL water and 50 mL conc. NaHCO ₃ solution, and then the organic layer was separated. The organic phase was washed with 1×50 mL H ₂ O, 1×50 mL brine, then dried over MgSO ₄ , filtered and then concentrated. The crude product was purified by flash column chromatography using DCM and MeOH as eluents to give 8.37 g (67%) of the desired product as a colorless oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.99-7.49 (m, 5H), 4.29-4.27 (m+m, 2H), 3.78 (m, 1H), 2.20-2.17 (dd+dd, 2H), 2.13 (s, 6H), 1.80-1.73 (m+m, 2H), 1.67-1.46 (m+m, 2H), 0.84 (s, 9H), 0.05 (s, 3H), 0.04 (s, 3H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm. 166.2, 130.3, 70.0, 66.0, 65.3, 46.6, 32.0, 26.3, 24.5, -3.8, -4.4; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₀ H ₃₆ NO ₃ Si: 366.2459, found: 366.2463.

Step C: 4-[tert-butyl(dimethyl)silyl]oxy-5-(dimethylamino)pentan-1-ol

3.12 g of the product from Step B (8.53 mmol, 1 equiv) was dissolved in 34 mL of MeOH and 17 mL of THF, then 1.36 g of NaOH (34 mmol, 4.0 equiv) in 17 mL of water was slowly added. After the addition, the mixture was stirred at rt until complete conversion was observed (approximately 1.5 h). EtOAc and water were added, then the mixture was separated and the organic phase was washed with brine, dried over MgSO ₄ , filtered, concentrated on celite and purified by flash column chromatography using DCM and MeOH as eluents to give 1.60 g (72%) of the desired product as a colorless oil.

^1H NMR (400 MHz, CDCl ₃ ) 3.83-3.76 (m, 1H), 3.65-3.55 (m, 3H), 2.31 (ddd, 2H), 2.22 (s, 6H), 1.72-1.54 (m, 4H) , 0.87 (s, 9Н), 0.05 (s, 3H), 0.05 (s, 3H); ¹³ C NMR (100 MHz, CDCl ₃ ) δ ppm; 70.1, 65.2, 62.9, 46.4, 31.9, 27.9, 26.0, 18.2, -4.36, -4.62; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁₃ H ₃₂ NO ₂ Si: 262.2197, found: 262.2197.

Synthesis 2e: 4-[tert-Butyl(dimethyl)silyl]oxy-5-morpholino-pentan-1-ol

Step A: [4-[tert-butyl(dimethyl)silyl]oxy-5-morpholinopentyl] benzoate

1.50 g of the product of Preparation 2d, Step A (7.27 mmol, 1 equiv) and 1.91 g of morpholine (21.87 mmol, 3 equiv) were stirred in 15 mL of MeCN at 82 °C for 24 h. The reaction mixture was concentrated and (4-hydroxy-5-morpholinopentyl) benzoate was obtained as a viscous light yellow oil. LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₁₆ H ₂₄ NO ₄ : 294.2, found: 294.2.

The crude product was redissolved in 7 mL of N,N-dimethylformamide, then 1.19 g of imidazole (17.52 mmol, 3 equiv) was added and after the mixture became clear, a solution of 1.76 g of tert-butylchlorodimethylsilane (11.68 mmol, 2 equiv) was added in one portion. The mixture was stirred at 60 °C for 2 h. The mixture was cooled to rt, then EtOAc was added and the organic layer was washed with H ₂ O, brine, then dried over MgSO ₄ , filtered and then concentrated onto celite. The crude product was purified by flash column chromatography using heptane and EtOAc as eluents to give 2.18 g (92%) of the desired product as a colorless oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.96 (dd, 2H), 7.66 (t, 1H), 7.53 (t, 2H), 4.29 (t, 2H), 3.85 (m, 1H), 3.52 (t, 4H), 2.42-2.30 (m, 4H), 2.26 (t, 2H), 1.85-1.44 (m, 4H), 0.85 (s, 9H), 0.07 (s, 3H), 0.04 (s, 3H); ¹³ C NMR (100 MHz, CDCl ₃ ) δ ppm. 165.7, 133.3, 129.9, 129.0, 128.7, 68.7, 66.2, 64.8, 64.7, 54.2, 31.6, 25.8, 24.1, 17.8, -4.2, -4.8; LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₂₂ H ₃₈ NO ₄ Si: 408.3, found: 408.3.

Step B: 4-[tert-butyl(dimethyl)silyl]oxy-5-morpholinopentan-1-ol

2.18 g of the product from Step A (8.53 mmol, 1 equiv) was dissolved in 20 mL of MeOH and 20 mL of THF, then 2.22 g _{of K2CO3} (16.06 mmol, 3.0 equiv) was added in one portion. After the addition, the mixture was stirred at rt until complete conversion was observed. Most of the volatiles were evaporated, then EtOAc and water were added, the mixture was separated and the organic phase was washed with brine, dried over _MgSO4 , filtered and concentrated. This gave 1.49 g (72%) of the desired product as a colorless oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.97 (d, 2H), 7.66 (t, 1H), 7.53 (t, 2H), 4.37 (t, 1H), 3.80-3.72 (m, 1H), 3.55 (t, 4H), 3.37 (q, 2H), 2.44-2.29 (m, 4 H), 2.22 (ddd, 2H), 1.56-1.29 (m, 4H), 0.85 (s, 9H), 0.06 (s, 3H), 0.04 (s, 3H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 69.3, 66.2, 65.3, 61.0, 54.3, 32.1, 28.5, 25.8, 17.9, -4.2, -4.7; LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₁₅ H ₃₄ NO ₃ Si: 304.2, found: 304.3.

Synthesis 2f: 4-[tert-Butyl(dimethyl)silyl]oxy-5-[2-(dimethylamino)ethylmethylamino]pentan-1-ol

Step A: [4-[tert-butyl(dimethyl)silyl]oxy-5-[2-(dimethylamino)ethylmethylamino]pentyl] benzoate

908 mg of the product of Preparation 2d, Step A (4.40 mmol, 1 equiv) and 1.35 g of N,N',N'-trimethylethane-1,2-diamine (13.2 mmol, 3 equiv) were stirred in 12 mL of MeCN at 82 °C BH. The reaction mixture was concentrated and [5-[2-(dimethylamino)ethylmethylamino]-4-hydroxypentyl]benzoate was obtained as a viscous light yellow oil. LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₁₇ H ₂₉ N ₂ O ₃ : 309.2, found: 309.3.

The crude product was redissolved in 4 mL of N,N-dimethylformamide, then 609 mg of imidazole (8.95 mmol, 3 equiv) was added and after the mixture became clear, a solution of 898 mg of tert-butylchlorodimethylsilane (5.96 mmol, 2 equiv) was added in one portion. The mixture was stirred at 60 °C for 2 h. The mixture was cooled to rt, then EtOAc was added and the organic layer was washed with H ₂ O, brine, then dried over MgSO ₄ , filtered and then concentrated onto celite. The crude product was purified by flash column chromatography using DCM and MeOH as eluents to give 1.11 g (88%) of the desired product as a colorless oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.95 (d, 2H), 7.66 (t, 1H), 7.52 (t, 2H), 4.28 (t, 2H), 3.81-3.74 (m, 1H), 2.42-2.36 (m, 2H), 2.32-2.26 (m, 4H), 2.16 (s, 3H), 2.10 (s, 6H), 1.83-1.40 (m, 4H), 0.84 (s, 9H), 0.05 (s, 3H), 0.04 (s, 3H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 165.7, 133.3, 129.9, 129.0, 128.7, 69.8, 64.8, 63.9, 57.0, 56.1, 45.4, 43.4, 31.5, 25.8, 24.0, 17.8, -4.3, -4.8; LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₂₃ H ₄₃ N ₂ O ₃ Si: 423.3, found: 423.3.

Step B: 4-[tert-butyl(dimethyl)silyl]oxy-5-[2-(dimethylamino)ethylmethylamino]pentan-1-ol

3.42 g of the product from Step A (8.09 mmol, 1 equiv) was dissolved in 40 mL of MeOH and 20 mL of THF, then 1.62 g of NaOH (40.5 mmol, 5.0 equiv) in 20 mL of water was added in one portion. After the addition, the mixture was stirred at rt until complete conversion was observed. EtOAc and water were added, the mixture was separated and the organic phase was washed with brine, dried over MgSO ₄ , filtered and concentrated. This gave 2.60 g (quant.) of the desired product as a light yellow oil.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 3.69 (m, 1H), 3.36 (t, 2H), 2.39 (m, 2H), 2.30 (m, 2H), 2.25 (m, 2H), 2.16 (s, 3H), 2.13 (s, 6H), 1.56-1.30 (m+m, 2H), 1.50-1.40 (m+m, 2H), 0.85 (s, 9H), 0.04 (s, 3H), 0.03 (s, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 70.7, 64.8, 61.5, 57.5, 56.7, 46.0, 43.8, 32.3, 29.0, 26.3, -3.8, -4.3; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₁₆ H ₃₉ N ₂ O ₂ Si: 319.2775, found: 319.2788.

Synthesis 2g: 3-[tert-Butyl(dimethyl)silyl]oxy-4-morpholinobutan-1-ol

Step A: 2-(oxiran-2-yl)ethyl benzoate

4.063 g of but-3-enyl benzoate (23.06 mmol, 1 equiv) was dissolved in 50 mL of CHCl ₃ , then 4.97 g of 3-chlorobenzenecarboperoxylic acid (77 wt %, 28.80 mmol, 1.25 equiv) was added and stirred at rt. 60 mL of DCM was added, then washed with conc. NaHCO ₃ solution and brine, dried over MgSO ₄ , filtered, concentrated and purified by flash column chromatography using heptane and EtOAc as eluents to give 3.81 g (86%) of the desired product as a colorless oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.98 (d, 2H), 7.66 (t, 1H), 7.53 (t, 2H), 4.39 (t, 2H), 3.11-3.05 (m, 1H), 2.73 (t, 1H), 2.53 (dd, 1H), 2.03-1.82 (m, 2H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 165.7, 133.4, 129.7, 129.2, 128.8, 62.0, 49.2, 45.9, 31.4; LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₁₁ H ₁₃ O ₃ : 193.1, found: 193.1.

Step B: [3-[tert-butyl(dimethyl)silyl]oxy-4-morpholinobutyl] benzoate

723 mg of the product from Step A (3.76 mmol, 1 equiv) and 983 mg of morpholine (11.28 mmol, 3 equiv) were stirred in 10 mL of MeCN at 82 °C for 24 h. The reaction mixture was concentrated and (3-hydroxy-4-morpholinobutyl) benzoate was obtained as a viscous light yellow oil. LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₁₅ H ₂₂ NO ₄ : 280.2, found: 280.2.

The crude product was redissolved in 5 mL of N,N-dimethylformamide, then 487 mg of imidazole (7.15 mmol, 3 equiv) was added and after the mixture became clear, a solution of 719 mg of tert-butylchlorodimethylsilane (4.77 mmol, 2 equiv) was added in one portion. The mixture was stirred at 60 °C for 2 h. It was cooled to rt, then EtOAc was added and the organic layer was washed with H ₂ O, brine, then dried over MgSO ₄ , filtered and then concentrated onto celite. The crude product was purified by flash column chromatography using heptane and EtOAc as eluents to give 669 mg (71%) of the desired product as a colorless oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.96 (d, 2H), 7.66 (t, 1H), 7.53 (t, 2H), 4.42-4.26 (m, 2H), 4.04-3.97 (m, 1H), 3.54 (t, 4H), 2.45-2.27 (m, 6H), 2.08-1.98 (m, 1H), 1.82-1.73 (m, 1H), 0.85 (s, 9H), 0.07 (s, 3H), 0.02 (s, 3H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 165.7, 133.3, 129.8, 129.0, 128.8, 66.3, 66.2, 65.1, 61.7, 54.2, 34.3, 25.8, 17.8, -4.2, -5.1; LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₃₆ NO ₄ Si: 394.2, found: 394.3.

Step C: 3-[tert-butyl(dimethyl)silyl]oxy-4-morpholinobutan-1-ol

366 mg of the product from Step B (0.93 mmol, 1 equiv) was dissolved in 2 mL of MeOH and 6.75 mL of THF, then 186 mg of NaOH (4.65 mmol, 5.0 equiv) in 2.25 mL of water were added in one portion. After the addition, the mixture was stirred at rt until complete conversion was observed. EtOAc and water were added, the mixture was separated and the organic phase was washed with brine, dried over MgSO ₄ , filtered and concentrated. This gave 262 mg (97%) of the desired product as a colorless oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 4.42 (br., 1H), 3.93-3.87 (m, 1H), 3.55 (t, 4H), 3.52-3.41 (m, 2H), 2.37 (dm, 4H), 2.29-2.20 (m, 2H), 1.73 -1.66 (m, 1H), 1.52-1.44 (m, 1H), 0.85 (s, 9H), 0.06 (s, 3H), 0.04 (s, 3H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 66.2, 65.4, 57.4, 54.2, 39.0, 25.8, 17.8, -4.3, -4.8; LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₁₄ H ₃₂ NO ₃ Si: 290.2, found: 290.3.

Synthesis 2h: 3-[tert-Butyl(dimethyl)silyl]oxy-4-methoxybutan-1-ol Step A: methyl 3-hydroxy-4-methoxybutanoate

To 1.00 g of methyl 4-methoxy-3-oxobutanoate (6.84 mmol, 1 equiv.) in 30 mL of MeOH at 0 °C were added 264 mg of NaBH ₄ (6.98 mmol, 1 equiv.) portionwise, and the mixture was stirred at 0 °C for 10 h. After concentration, the residue was diluted with water and extracted with EtOAc. The combined organic phases were dried and concentrated to give 0.72 g (71%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 4.97 (d, 1H), 3.97 (m, 1H), 3.58 (s, 3H), 3.27 (dd, 1H), 3.24 (s, 3H), 3.20 (dd, 1H), 2.46 (dd, 1H), 2.27 (dd, 1H).

Step B: Methyl 3-[tert-butyl(dimethyl)silyl]oxy-4-methoxybutanoate

To 8.89 g of the product from Step A (60 mmol, 1 equiv) and 4.3 g of imidazole (63.2 mmol, 1.05 equiv) in 100 mL of DMF was added 10 g of tert-butylchlorodimethylsilane (66.3 mmol, 1.1 equiv) in one portion and the mixture was stirred for 18 h. After diluting the mixture with 300 mL of brine and extracting with EtOAc, the combined organic phases were dried, concentrated and purified by flash column chromatography using heptane and EtOAc as eluents to afford 11.77 g (75%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 4.17 (sx, 1H), 3.58 (s, 3H), 3.27 (m. 2H), 3.26 (s, 3H), 2.54 (dd, 1H), 2.32 (dd, 1H), 0.82 (s, 9H), 0.03 (d, 6H).

Step C: 3-[tert-butyl(dimethyl)silyl]oxy-4-methoxybutan-1-ol

To 10.77 g of the product from Step B (41 mmol, 1 equiv) in 288 mL of DCM at 0 °C was slowly added 124 mL of DIBAL-H (1 M in THF, 124 mmol, 3 equiv). The mixture was then stirred for 2.5 h at 0 °C, 5 mL of water, 5 mL of 15 wt % NaOH solution, 0.5 mL of water and anhydrous MgSO ₄ were added successively. After stirring for 15 min, the mixture was filtered and concentrated to give 6.73 g (70%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 4.34 (t, 1H), 3.89 (m, 1H), 3.48/3.44 (m+m, 2H), 3.24 (s, 3H), 3.24/3.21 (dd+dd, 2H), 1.59/1.46 (m+m , 2Н), 0.85 (s, 9Н), 0.04/0.03 (s+s, 6H); MSHR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₁ H ₂₇ O ₃ Si: 235.1729, found: 235.1725.

Synthesis 2i: 4-[tert-Butyl(dimethyl)silyl]oxy-3-methoxybutan-1-ol

Step A: 3,4-dihydroxybutyl benzoate

A mixture of 20.1 g but-3-enyl benzoate (113.5 mmol, 1 equiv), 21.8 g 4-methyl-4-oxidomorpholin-4-ium hydrate (161.3 mmol, 1.42 equiv) and 2.83 g osmium tetroxide (2.5 wt % in 2-methylpropan-2-ol, 0.28 mmol, 0.0025 equiv) in 227 mL 2-methylpropan-2-ol and 27 mL water was stirred at 60 °C for 18 h. The reaction mixture was then quenched by adding 270 mL 1 M Na ₂ S ₂ O ₃ solution at rt, the mixture was diluted with DCM and the organic phase was washed with water and brine, dried and concentrated to yield 22.22 g (93%). 3,4-dihydroxybutyl benzoate.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.97 (m, 2H), 7.65 (m, 1H), 7.53 (m, 2H), 4.68 (d, 1H), 4.59 (t, 1H), 4.39/4.34 (m+m, 2H), 3.63 (m, 1H), 3.37/3.30 (m+m, 2H), 1.93/1.64 (m+m, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 166.2, 133.7, 129.5, 129.2, 68.5, 66.4, 62.5, 33.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁₁ H ₁₅ O ₄ : 211.0970, found: 211.0971.

Step B: [4-[tert-butyl(dimethyl)silyl]oxy-3-hydroxybutyl] benzoate

To 10 g of the product from Step A (47.6 mmol, 1 equiv) and 6.52 g of imidazole (0.096 mol, 2 equiv) in 100 mL of DMF was added 7.17 g of tert-butylchlorodimethylsilane (47.6 mmol, 1 equiv) in one portion, and the mixture was stirred for 1 h. The mixture was then diluted with EtOAc, the organic phase was washed with conc. NaHCO ₃ , water, and brine, dried over MgSO ₄ , filtered, and concentrated to afford 14.1 g (91%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.95 (m, 2H), 7.64 (m, 1H), 7.51 (t, 2H), 4.76 (s, 1H), 4.38 (m, 2H), 3.65 (m, 1H), 3.56 (dd, 1H), 3.43 (dd, 1H), 1.96 (m, 1H), 1.65 (m, 1H), 0.84 (s, 9H), 0.02 (s, 6H).

Step C: [4-[tert-butyl(dimethyl)silyl]oxy-3-methoxybutyl] benzoate

7.03 g of the product from Step B (21.7 mmol, 1 equiv) and 13.9 g of N1,N1,N8,N8-tetramethylnaphthalene-1,8-diamine (64.9 mmol, 3 equiv) were mixed in 420 mL of DCM, then 8.0 g of trimethyloxonium tetrafluoroborate (54.1 mmol, 2.5 equiv) were added in one portion and the mixture was stirred at rt for 18 h. Complete conversion was observed. The mixture was filtered through a pad of celite, washed with DCM, and the organic phase was washed with water and brine, respectively. The solution was dried over _MgSO4 , filtered, concentrated on Celite and purified by flash column chromatography using heptane and EtOAc as eluents to give 4.03 g (55%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.97 (m, 2H), 7.67 (tt, 1H), 7.52 (t, 2H), 4.35 (m, 2H), 3.63 (m, 2H), 3.35 (m, 1H), 3.33 (s, 3H), 1.94 (m, 1H), 1.80 (m, 1H), 0.85 (s, 9H), 0.03 (s, 6H).

Step D: 4-[tert-butyl(dimethyl)silyl]oxy-3-methoxybutan-1-ol

To 4.0 g of the product from Step C (11.83 mmol, 1 equiv.) in 100 mL of a 1:1 mixture of THF and MeOH at 0 °C was added 5.1 g of K ₂ CO ₃ (36.96 mmol, 3 equiv.), and the mixture was stirred for 3 h at 0 °C and for 2 h at rt. After adding conc. NH ₄ Cl and DCM at 0 °C, the organic phase was washed with conc. NaHCO ₃ , water and brine, dried over MgSO ₄ , filtered and concentrated to give 4.14 g (94%) of a 1:1 mixture of the desired product and methyl benzoate.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 4.38 (t, 1H), 3.57 (dd, 2H), 3.45 (q, 2H), 3.29 (s, 3H), 3.28 (m, 1H), 1.53 (m, 2H), 0.87 (s, 9H), 0.04 (s, 6H).

Synthesis 2j: 3-[tert-Butyl(dimethyl)silyl]oxy-2-methoxypropan-1-ol

Step A: (2,2-dimethyl-1,3-dioxolan-4-yl)methyl benzoate

To 20 g of (2,2-dimethyl-1,3-dioxolan-4-yl)methanol (151 mmol, 1 equiv) and 25 mL of N,N-diethylethanamine (182 mmol, 1.2 equiv) in 92 mL of DCM at 0 °C were added 21 mL of benzoyl chloride (182 mmol, 1.2 equiv) and the mixture was stirred at rt for 18 h. The reaction mixture was quenched with conc. NaHCO ₃ solution and the organic phase was washed with brine, dried and concentrated to give 37.0 g (98%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.98 (dd, 2H), 7.67 (m, 1H), 7.54 (t, 2H), 4.42 (m, 1H), 4.37 (dd, 1H), 4.27 (dd, 1H), 4.09 (dd, 1H), 3.82 (dd, 1H), 1.33 (s, 3H), 1.29 (s, 3H).

Step B: 2,3-dihydroxypropyl benzoate

A mixture of 20 g of the product from Step A (80 mmol, 1 equiv.), 220 mL of 1 N HCl and 220 mL _of EtOH was stirred at rt for 18 h. The reaction mixture was then quenched with conc. _Na2CO3 and concentrated, the residue was extracted with EtOAc. The combined organic phases were washed with brine and dried to give 15.48 g (98.7%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 8.00 (dd, 2H), 7.67 (tt, 1H), 7.54 (t, 2H), 5.03 (d, 1H), 4.71 (t, 1H), 4.30 (dd, 1H), 4.17 (dd, 1H), 3.79 (sx, 1H), 3.45 (m, 2H).

Step C: [3-[tert-butyl(dimethyl)silyl]oxy-2-hydroxypropyl] benzoate

To 5.62 g of the product from Step B (28.7 mmol, 1 equiv) and 3.47 g of imidazole (51.0 mol, 2 equiv) in 50 mL of DMF was added 4.04 g of tert-butylchlorodimethylsilane (26.8 mmol, 1 equiv) in one portion and the mixture was stirred for 1 h. The mixture was then diluted with EtOAc, the organic phase was washed with conc. NaHCO ₃ solution, water and brine, dried over MgSO ₄ , filtered, concentrated and purified by flash column chromatography using heptane and EtOAc as eluents to afford 3.23 g (36%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.99 (dd, 2H), 7.66 (tt, 1H), 7.53 (t, 2H), 5.13 (d, 1H), 4.31 (dd, 1H), 4.19 (dd, 1H), 3.83 (sx, 1H), 3.63 (m, 2H), 0.85 (s, 9H), 0.03 (s, 6H).

Step D: [3-[tert-butyl(dimethyl)silyl]oxy-2-methoxypropyl]benzoate

3.0 g of the product from Step C (9.6 mmol, 1 equiv) and 6.2 g of N1,N1,N8,N8-tetramethylnaphthalene-1,8-diamine (28.9 mmol, 3 equiv) were mixed in 160 mL of DCM, then 3.54 g of trimethyloxonium tetrafluoroborate (23.9 mmol, 2.5 equiv) were added in one portion and the mixture was stirred at rt for 18 h. The mixture was filtered through a pad of celite, washed with DCM, and then the organic phase was washed with water and brine, respectively. The solution was dried over _MgSO4 , filtered, concentrated on Celite and purified by flash column chromatography using heptane and EtOAc as eluents to give 1.7 g (55%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.97 (dd, 2H), 7.67 (tt, 1H), 7.54 (t, 2H), 4.44 (dd, 1H), 4.26 (dd, 1H), 3.72 (d, 2H), 3.57 (m, 1H), 3.38 (s, 3H), 0.86 (s, 9H), 0.05 (s, 3H), 0.04 (s, 3H).

Step E: 3-[tert-butyl(dimethyl)silyl]oxy-2-methoxypropan-1-ol

To 1.68 g of the product from Step D (5.17 mmol, 1 equiv.) in 40 mL of a 1:1 mixture of THF and MeOH at 0 °C was added 2.19 g of K ₂ CO ₃ (15.85 mmol, 3 equiv.), and the mixture was stirred for 3 h at 0 °C and for 2 h at rt. After adding conc. NH ₄ Cl and DCM at 0 °C, the organic phase was washed with conc. NaHCO ₃ , water and brine, dried over MgSO ₄ , filtered and concentrated to give 1.26 g (quant.) of a 1:0.25 mixture of the desired product and methyl benzoate.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 4.54 (t, 1H), 3.63 (dd, 1H), 3.55 (dd, 1H), 3.39 (m, 2H), 3.32 (s, 3H), 3.15 (m, 1H), 0.86 (s, 9H), 0.03 (s, 6H).

Synthesis 2k: 3-[tert-Butyl(dimethyl)silyl]oxy-2-morpholinopropan-1-ol

Step A: Diethyl 2-morpholinopropanedioate

To 16 g morpholine (184 mmol, 1.6 equiv) and 30 g _K2CO3 (217 mmol, 1.9 equiv) in 50 mL MeCN was added 27 g diethyl bromomalonate (113 mmol, ₁ equiv) and the exothermic reaction mixture was stirred for 0.5 h. After cooling the mixture to rt, it was filtered and concentrated, and the crude product was purified by flash column chromatography using heptane and EtOAc as eluents to afford 26.2 g (94%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 4.27 (s, 1H), 4.16 (q, 4H), 3.57 (dd, 4H), 2.68 (dd, 4H), 1.20 (s, 6H).

Stage B: 2-morpholinopropane-1,3-diol

To 3.0 g LiAlH ₄ (79 mmol, 4.8 equiv.) in 60 mL THF at 0 °C was added 4.0 g of the product from Step A (16.3 mmol, 1 equiv.) in 25 mL THF, and the mixture was stirred at 60 °C for 4 h. After cooling to rt, the mixture was treated with 10 N NaOH solution and the resulting precipitate was filtered and washed with DCM. The phases were then separated, the aqueous phase was extracted with DCM, and the combined organic phases were washed with brine, dried over MgSO ₄ , filtered and concentrated to afford 1.4 g (53%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 4.28 (dd, 2H), 3.52 (m, 4H), 3.49/3.44 (m+m, 4H), 2.59 (m, 4H), 2.40 (qui, 1H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 67.5, 67.3, 59.1, 50.5; IR: 3373, 2856; HR-EI (m/z): [M] ⁺ , calculated for C ₇ H ₁₅ NO ₃ : 161.1052, found: 161.1053.

Step C: 3-[tert-Butyl(dimethyl)silyl]oxy-2-morpholino-propan-1-ol

To 1.32 g of the product from Step B (8.22 mmol, 1 equiv) and 0.56 g of imidazole (8.24 mmol, 1 equiv) in 60 mL of DCM was added dropwise 1.24 g of tert-butylchlorodimethylsilane (8.23 mmol, 1 equiv) in 10 mL of DCM, and the mixture was stirred at rt for 0.5 h. After addition of DCM, the solution was washed with water and brine, dried, concentrated and purified by flash column chromatography using heptane and EtOAc as eluents to afford 0.79 g (35%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 4.30 (brt, 1H), 3.69/3.65 (dd+dd, 2H), 3.51 (m, 4H), 3.48/3.43 (m+m, 2H), 2.64/2.59 (m+m, 4H), 2.44 (m, 1H), 0.87 (s, 9H), 0.04/0.03 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 67.4, 67.4, 61.2, 59.2, 50.8, 26.3, 18.3, -5.0; IR: 2855; HR-EI MS (m/z): [MS ₄ H ₉ ] ₊ , calculated for C ₉ H ₂₀ NO ₃ Si: 218.1217, found: 218.1202.

Synthesis 3a: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[5-[tert-butyl(dimethyl )silyl]oxy-4-[tert-butyl(diphenyl)silyl]oxypentyl]amino]thiazole-4-carboxylate

Stage A: methyl 2-[tert-butoxycarbonyl-[5-[tert-butyl(dimethyl)silyl]oxy-4-[tert-butyl(diphenyl)silyl]oxypentyl]amino]-5-[3-[4-[3-[tert -butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from the product of Preparation 1b as the appropriate carbamate and the product of Preparation 2a as the appropriate alcohol, 2.5 g (61%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.60-7.33 (m, 10H), 7.28 (dd, 1H), 7.17 (m, 1H), 7.1 (t, 1H), 4.22 (s, 2H), 4.09 (t, 2H), 3.94 (m, 2H) , 3.71 (s, 3Н), 3.67 (m, 1Н), 3.38 (m, 2H), 3.22 (t, 2H), 2.85 (s, 3H), 2.07 (m, 2H), 1.65 (m, 2H), 1.48 (m, 2H), 1.45/1.40 (s+s, 18Н), 0.93 (s, 9Н), 0.71 (s, 9Н), -0.17/-0.22 (s+s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 147.4, 129, 119.3, 115.4, 85.1, 82.3, 73.3, 68.1, 65.6, 51.9, 46.5, 38.4, 33.8 , 30.5, 30.5, 28.5/28, 27.2, 26.0, 23.1, 23.0, -5.3; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₅ H ₇₉ FN ₃ O ₉ SSi ₂ : 1032.5054 , found: 1032.5060.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[5-[tert-butyl(dimethyl )silyl]oxy-4-[tert-butyl(diphenyl)silyl]oxypentyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 1.2 g (53%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.68-7.35 (m, 10H), 7.56 (t, 1H), 7.30 (d, 1H), 7.20 (d, 1H), 7.11 (t, 1H), 4.22 (br., 2H), 4.07 (t, 2H ), 3.70 (m, 1H), 3.68 (s, 3H), 3.42/3.38 (dd+dd, 2H), 3.11 (t, 2H), 3.04 (brq., 2H), 2.86 (br., 3H), 1.99 (quint., 2H), 1.54 (m, 2H), 1.53 /1.45 (m+m, 2H), 1.41 (s, 9H), 0.97 (s, 9Н), 0.74 (s, 9H), -0.14/-0.18 (s+s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 164.6, 163.0, 154.9, 151.4, 147.5, 136.9, 136.0, 129.1, 119.3, 115.4, 114.8, 85.2, 82.3, 79.8, 73.6, 68.0, 66.2, 51.7, 44.7, 38.5, 33.8, 31.1, 30.6, 28.5, 27.2, 26.2, 24.3, 23.3, 19.4, 18.3, -5.2; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₅₀ H ₇₁ FN ₃ O ₇ SSi ₂ : 932.4530, found: 932.4526.

Synthesis 3b: Methyl 2-[[5-[tert-butyl(dimethyl)silyl]oxy-4-[tert-butyl(diphenyl)silyl]oxypentyl]amino]-5-[3-[4-[3-(dimethylamino )prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Step A: methyl 2-[tert-butoxycarbonyl-[5-[tert-butyl(dimethyl)silyl]oxy-4-[tert-butyl(diphenyl)silyl]oxypentyl]amino]-5-[3-[4-[ 3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from the product of Preparation 1c as the appropriate carbamate and the product of Preparation 2a as the appropriate alcohol, 3.2 g (65%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.60-7.35 (m, 10H), 7.28 (dd, 1H), 7.18 (m, 1H), 7.10 (t, 1H), 4.10 (t, 2H), 3.95 (m, 2H), 3.72 (s, 3H) , 3.68 (m, 1H), 3.41 (s, 2H), 3.38 (m, 2H), 3.22 (t, 2H), 2.21 (s, 6H), 2.07 (m, 2H), 1.66 (m, 2H), 1.45 (s, 9H), 1.45 (m, 2H), 0.94 (s, 9Н), 0.72 (s, 9Н), -0.16/-0.21 (s+s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 162.8, 147.2, 128.9, 119.2, 115.4, 84.2, 73.3, 68.1, 65.6, 52.0, 48.2, 46.7, 44.3, 30.7, 30.5, 28.0, 27.2 , 26.1, 23.1, 23.0, -5.3; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₁ H ₇₃ FN ₃ O ₇ SSi ₂ : 946.4686, found: 946.4684.

Step B: methyl 2-[[5-[tert-butyl(dimethyl)silyl]oxy-4-[tert-butyl(diphenyl)silyl]oxypentyl]amino]-5-[3-[4-[3-(dimethylamino )prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 2.2 g (55%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) 5 ppm. 7.64-7.37 (m, 10H), 7.56 (t, 1H), 7.28 (dd, 1H), 7.18 (m, 1H), 7.10 (t, 1H), 4.07 (t, 2H), 3.69 (q, 1H) , 3.69 (s, 3Н), 3.41 (s, 2Н), 3.41 (m, 2H), 3.11 (t, 2H), 3.04 (q, 2H), 2.21 (s, 6H), 2.00 (m, 2H), 1.55 (m, 2H), 1.54/1.45 (m+m, 2Н), 0.97 (s, 9Н), 0.74 (s, 9Н), -0.14/-0.17 (s+s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 164.6, 147.2, 129.0, 119.2, 115.4, 73.6, 68.0, 66.2, 51.7, 48.2, 44.8, 44.3, 31.1 , 30.7, 27.2, 26.2, 24.4, 23.3, -5.2; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₄₆ H ₆₆ FN ₃ O ₅ SSi ₂ : 846.4162, found: 846.4160.

Synthesis of 3 c: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[4-[tert-butyl(dimethyl )silyl]hydroxybutylamino]thiazole-4-carboxylate

Step A: Methyl 2-[tert-butoxycarbonyl-[4-[tert-butyl(dimethyl)silyl]oxybutyl]amino]-5-[3-(2-fluoro-4-iodophenoxy)propyl]thiazole-4-carboxylate

Using the General Alkylation Procedure starting from 5.36 g of Preparation 1a (10 mmol, 1 equiv) and 3.77 g of tert-butyl (4-iodobutoxy) dimethylsilane (3.10 mL, 12 mmol, 1.2 equiv) as the appropriate halide, 6.1 g (84%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.58 (dd, 1H), 7.45 (m, 1H), 6.97 (t, 1H), 4.06 (t, 2H), 4.01 (t, 2H), 3.75 (s, 3H), 3.58 (t, 2H), 3.21 (t, 2H), 2.06 (m, 2H), 1.68 (m, 2H), 1.50 (s, 9H), 1.43 (m, 2H), 0.82 (s, 9H), -0.01 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 147.0, 134.0, 124.9, 117.6, 68.2, 62.6, 52.1, 46.4, 30.5, 30.0, 28.1, 26.2, 24.5, 23.2, -4.9; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₉ H ₄₅ N ₂ O ₆ FSiSI: 723.1791, found: 723.1775.

Step B: Methyl 2-[4-[tert-butyl(dimethyl)silyl]oxybutylamino]-5-[3-(2-fluoro-4-iodophenoxy)propyl]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with 6.0 g of the product from Step A (8.30 mmol) as the appropriate carbamate, 3.0 g (58%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.59 (dd, 1H), 7.58 (t, 1H), 7.45 (dm, 1H), 6.97 (t, 1H), 4.03 (t, 2H), 3.69 (s, 3H), 3.58 (t, 2H), 3.16 (q, 2H), 3.11 (t, 2H), 1.98 (m, 2H), 1.59-1.44 (m, 4H), 0.84 (s, 9H), 0.01 (s, 6 H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 164.7, 163.0, 152.1, 147.0, 136.9, 136.1, 134.0, 124.9, 117.6, 82.4, 68.0, 62.7, 51.7, 44.3, 30.6, 30.6, 26.3, 25.6, 23.3, -4.8; HR-MS (m/z): [M+H]++, calculated for C ₂₄ H ₃₇ FIN ₂ O ₄ SSi: 623.1266, found: 623.1272.

Step C: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[4-[tert-butyl(dimethyl) silyl]hydroxybutylamino]thiazole-4-carboxylate

Using the General Sonogashira reaction procedure starting with 3.00 g of the product from Step B (4.82 mmol, 1 equiv) and 1.63 g of tert-butyl N-methyl-N-prop-2-ynylcarbamate (9.63 mmol, 2 equiv) as the appropriate acetylene, 2.50 g (65%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.58 (t, 1H), 7.31 (brd., 1H), 7.21 (d, 1H), 7.13 (t, 1H), 4.23 (br., 2H), 4.07 (t, 2H), 3.69 (s, 3H), 3.58 (t, 2H), 3.16 (q, 2H), 3.11 (t, 2H), 2.86 (br., 3H), 2 (quint., 2H), 1.54 (m, 2H), 1.49 (m, 2H), 1.41 (s, 9H), 0.84 (s, 9H), 0.01 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 119.3, 115.4, 68.0, 62.7, 51.7, 44.3, 38.6, 33.8, 30.6, 30.1, 28.5, 26.3, 25.6, 23.3, -4.8; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₅₁ FN ₃ O ₆ SSi: 664.3246, found: 664.3245.

Synthesis 3d: Methyl 2-[4-[tert-butyl(dimethyl)silyl]oxybutylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol- 4-carboxylate

Using the General Sonogashira reaction procedure, starting with 3.00 g of the product from Preparation 3c, Step B (4.82 mmol, 1 equiv) and 801 mg of N,N-dimethyl-N-prop-2-yn-1-amine (9.63 mmol, 2 equiv) as the appropriate acetylene, 2.20 g (79%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.58 (t, 1H), 7.30 (dd, 1H), 7.20 (dm, 1H), 7.12 (t, 1H), 4.07 (t, 2H), 3.69 (s, 3H), 3.58 (t, 2H), 3.44 (s, 2H), 3.16 (q, 2H), 3.12 (t, 2H), 2.24 (s, 6H), 2.00 (m, 2H), 1.60-1.44 (m, 4H), 0.84 (s, 9H), 0.01 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.0, 119.2, 115.4, 84.9, 84.3, 68.0, 62.7, 51.7, 48.1, 44.3, 44.2, 30.6, 30.2, 26.3, 25.6, 23.3, -4.8; HR-MS (m/z): [M+H] ⁺ , calculated for C ₂₉ H ₄₅ FN ₃ O ₄ SSi: 578.2878, found: 578.2865.

Synthesis 3e: Ethyl 5-(3-chloropropyl)-2-(methylamino)thiazole-4-carboxylate

A suspension of 2.25 g methylthiourea (25.0 mmol, 1 equiv) in 100 mL ethanol was cooled to 0 °C and 7.46 g ethyl 3-bromo-6-chloro-2-oxohexanoate (27.5 mmol, 1.1 equiv) was added dropwise at this temperature. After stirring for 15 min at 0 °C, 7 mL TEA (5.06 g, 50 mmol, 2 equiv) was added. The resulting mixture was stirred overnight at rt. Complete conversion was observed. The volatiles were removed in vacuo and the resulting residue was partitioned between EtOAc and water. The layers were separated and the organic layer was washed with water followed by brine. _The combined organic layers were dried over _Na2SO4 , filtered, and the filtrate was concentrated under reduced pressure. The crude product was then purified by flash column chromatography using heptane and EtOAc as eluents to afford 5 g (76%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.55 (q, 1H), 4.21 (q, 2H), 3.65 (t, 2H), 3.09 (m, 2H), 2.78 (d, 3H), 1.98 (m, 2H), 1.26 (t, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 165.6, 162.5, 137.4, 135.5, 60.5, 45.0, 34.1, 31.2, 24.4, 14.7; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁₀ H ₁₆ ClN ₂ O ₂ S: 263.0616, found: 263.0615.

Synthesis 3f: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[5-[tert-butyl(dimethyl )silyl]oxy-4-methoxypentyl]amino]thiazole-4-carboxylate

Stage A: methyl 2-[tert-butoxycarbonyl-[5-[tert-butyl(dimethyl)silyl]oxy-4-[tert-butyl(diphenyl)silyl]oxypentyl]amino]-5-[3-[4-[3-[tert -butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from 577 mg of Preparation 1b (1 mmol) as the appropriate carbamate and 496 mg of Preparation 2b (2 mmol) as the appropriate alcohol, 790 mg (96%) of the desired product were obtained.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[5-[tert-butyl(dimethyl )silyl]oxy-4-methoxypentyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with 790 mg of the product from Step A (0.95 mmol) as the appropriate carbamate, 270 mg (38%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.58 (t, 1H), 7.31 (brd, 1H), 7.21 (dm, 1H), 7.13 (t, 1H), 4.23 (brs, 2H), 4.07 (t, 2H), 3.69 (s, 3H), 3.56 /3.53 (dd+dd, 2Н), 3.29 (s, 3H), 3.16 (m, 1H), 3.15 (m, 2H), 3.11 (t, 2H), 2.86 (brs, 3H), 2.00 (m, 2H), 1.63-1.43 (m, 4H), 1.42 (s , 9Н), 0.84 (s, 9Н), 0.02 (s, 6Н); HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₅ H ₅₅ FN ₃ O ₇ SSi: 708.3508, found: 708.3502.

Synthesis of 3g: Methyl 5-[3-[4-[3-(tert-butoxycarbonylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[4-[tert-butyl(dimethyl)silyl]oxybutylamino] thiazole-4-carboxylate

Using the General Sonogashira reaction procedure starting from 880 mg of the product from Preparation 3c, Step B (1.41 mmol, 1 equiv) and 438 mg of tert-butyl N-prop-2-ynylcarbamate (2.82 mmol, 2 equiv) as the appropriate acetylene, 918 mg (85%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.58 (t, 1H), 7.34 (t, 1H), 7.26 (ff, 1H), 7.17 (m, 1H), 7.12 (t, 1H), 4.06 (t, 2H), 3.95 (d, 2H), 3.69 (s, 3H), 3.58 (t, 2H), 3.17 (q, 2H), 3.11 (t, 2H), 2.00 (m, 2H), 1.54 (m, 2H), 1.50 (m, 2H), 1.39 (s, 9H), 0.85 (s, 9H), 0.01 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 164.7, 163.0, 147.4, 136.9, 136.1, 129.0, 119.1, 115.4, 68.0, 62.7, 51.7, 44.3, 30.6, 30.5, 30.2, 28.7, 26.3, 25.6, 23.3, 18.4, -4.8 HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₂ H ₄₉ FN ₃ O ₆ SSi: 650.3090, found: 650.3093.

Synthesis 3h: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethylamino]thiazole-4-carboxylate

Step A: Methyl 2-[tert-butoxycarbonyl-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethyl]amino]-5-[3-(2-fluoro-4-iodophenoxy)propyl]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from 2.68 g of the product of Preparation 1a (5 mmol, 1 equiv) and 1.46 g of 2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethanol (1.42 mL, 10 mmol, 2 equiv) as the appropriate alcohol, 2.8 g (84%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.57 (dd, 1H), 7.44 (dm, 1H), 6.96 (t, 1H), 4.12/4.02 (m+m, 2H), 4.07 (m, 1H), 4.05 (t, 2H), 4.02/3.54 (dd+dd, 2H), 3.75 (s, 3H), 3.21 (t, 2H), 2.06 (m, 2H), 1.86/1.82 (m+m, 2H), 1.51 (s, 9H), 1.29 (s, 3H), 1.22 (s, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 134.0, 124.9, 117.6, 73.8, 68.9, 68.1, 52.0, 44.0, 32.2, 30.5, 28.1, 27.3, 25.9, 23.1; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₆ H ₃₅ FIN ₂ O ₇ S: 665.1188, found: 665.1175.

Step B: Methyl 2-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethylamino]-5-[3-(2-fluoro-4-iodophenoxy)propyl]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with 2.5 g of the product from Step A (3.80 mmol) as the appropriate carbamate, 1.6 g (75%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.6 (t, 1H), 7.59 (dd, 1H), 7.45 (dm, 1H), 6.97 (dd, 1H), 4.10 (m, 1H), 4.03 (t, 2H), 4.01/3.48 (dd+dd, 2H), 3.69 (s, 3H), 3.27/3.19 (m+m, 2H), 3.11 (t, 2H), 1.99 (m, 2H), 1.76/1.72 (m+m, 2H), 1.31 (s, 3H), 1.25 (s, 3 H); HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₂₇ FIN ₂ O ₅ S: 565.0663, found: 565.0642.

Step C: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[2-(2,2-dimethyl- 1,3-dioxolan-4-yl)ethylamino]thiazole-4-carboxylate

Using the General Sonogashira reaction procedure, starting with 400 mg of the product from Step B (0.71 mmol, 1 equiv) and 240 mg of tert-butyl N-methyl-N-prop-2-ynylcarbamate (1.42 mmol, 2 equiv) as the appropriate acetylene, 300 mg (70%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.60 (t, 1H), 7.31 (brd, 1H), 7.21 (dd, 1H), 7.13 (t, 1H), 4.23 (brs, 2H), 4.09 (m, 1H), 4.07 (t, 2H), 4.00 /3.48 (dd+dd, 2H), 3.69 (s, 3H), 3.27/3.19 (m+m, 2H), 3.12 (t, 2H), 2.86 (brs, 3H), 2.00 (m, 2H), 1.74 (m, 2H), 1.41 (s, 9H), 1.31 (s, 3H), 1.25 (s, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 164.5, 136.9, 136.4, 129.1, 119.3, 115.4, 85.2, 82.3, 73.8, 69.0, 68.0, 51.7, 41.4, 38.4, 33.8, 33.2, 30.6 , 28.5, 27.3, 26.1, 23.3; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₀ H ₄₁ FN ₃ O ₇ S: 606.2644, found: 606.2650.

Synthesis 3i: Methyl 5-[3-[4-[3-(dimethyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethylamino]thiazole-4-carboxylate

Using the General Sonogashira reaction procedure, starting with 400 mg of the product from Preparation 3h, Step B (0.71 mmol, 1 equiv) and 117 mg of N,N-dimethylprop-2-yn-1-amine (1.42 mmol, 2 equiv) as the appropriate acetylene, 250 mg (58%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.61 (t, 1H), 7.29 (dd, 1H), 7.2 (dd, 1H), 7.12 (t, 1H), 4.1 (m, 1H), 4.07 (t, 2H), 4/3.48 (dd+dd, 2H), 3.69 (s, 3H), 3.41 (s, 2H), 3.28/3.19 (m+m, 2H), 3.12 (t, 2H), 2.22 (s, 6H), 2 (qn, 2H), 1.75/1.72 (m+m, 2H), 1.31 (s, 3H), 1.25 (s, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 164.5, 163, 151.5, 147.3, 136.9, 136.4, 128.9, 119.2, 115.4, 115.3, 108.4, 85.2, 84.2, 73.8, 69.0, 68.0, 51.8, 48.1, 44.3, 41.4, 33.3, 30.6, 27.4, 26.1, 23.4; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₆ H ₃₅ FN ₃ O ₅ S: 520.2281, found: 520.2272.

Synthesis of 3j: Methyl 2-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethylamino]-5-[3-[2-fluoro-4-[3-[(4-methoxyphenyl)methylmethylamino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Using the General Sonogashira reaction procedure starting from 400 mg of the product from Preparation 3h, Step B (0.71 mmol, 1 equiv) and 268 mg of N-[(4-methoxyphenyl)methyl]-N-methyl-prop-2-yn-1-amine (1.42 mmol, 2 equiv) as the appropriate acetylene, 280 mg (63%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.61 (t, 1H), 7.33 (dd, 1H), 7.24 (dd, 1H), 7.23 (d, 2H), 7.13 (t, 1H), 6.89 (d, 2H), 4.10 (qn, 1H), 4.07 (t, 2H), 4/3.48 (dd+dd, 2H), 3.73 (s, 3H), 3.7 (s, 3H), 3.49 (s, 2H), 3.44 (s, 2H), 3.28/3.19 (m+m, 2H), 3.13 (t, 2H), 2.24 (s, 3H), 2.01 (qn, 2H), 1.75/1.73 (m+m, 2H), 1.31(s, 3H), 1.25 (s, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 164.5, 163.0, 158.8, 151.5, 147.3, 136.6, 136.5, 130.8, 130.5, 129.0, 119.3, 115.4, 115.3, 114.1, 108.4, 84.9, 84.5, 73.8, 69.0, 68.0, 59.4, 55.5, 51.8, 45.8, 41.7, 41.4, 33.3, 30.6, 27.3, 26.1, 23.4; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₄₁ FN ₃ O ₆ S: 626.2694, found: 626.2697.

Synthesis 3k: Methyl 2-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethylamino]-5-[3-[2-fluoro-4-[3-[methyl(p-tolylsulfonyl)amino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Using the General Sonogashira reaction procedure starting from 400 mg of the product from Preparation 3h, Step B (0.71 mmol, 1 equiv) and 316 mg of N,4-dimethyl-N-prop-2-ynylbenzenesulfonamide (1.42 mmol, 2 equiv) as the appropriate acetylene, 260 mg (55%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.72 (d, 2H), 7.61 (t, 1H), 7.4 (d, 2H), 7.07 (t, 1H), 6.88 (dd, 1H), 6.86 (dd, 1H), 4.25 (s, 2H), 4.1 (qn, 1H), 4.05 (t, 2H), 4/3.48 (dd+dd, 2H), 3.69 (s, 3H), 3.27/3.19 (m+m, 2H), 3.11 (t, 2H), 2.79 (s, 3H), 2.33 (s, 3H), 1.99 (qn, 2H), 1.75/1.73 (m+m, 2H), 1.31 (s, 3H), 1.25 (s, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 164.5, 163.0, 151.2, 147.5, 144.0, 136.9, 136.4, 134.4, 130.2, 128.9, 128.2, 119.1, 115.2, 114.2, 108.4, 84.6, 81.9, 73.9, 69.0, 68.1, 51.8, 41.5, 40.4, 34.9, 33.3, 30.6, 27.4, 26.1, 23.4, 21.4; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₂ H ₃₉ FH ₃ O ₇ S ₂ : 660.22079, found: 660.2231.

Synthesis 31: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[3-[tert-butyl(dimethyl )silyl]oxy-4-methoxybutyl]amino]thiazole-4-carboxylate

Step A: methyl 2-[tert-butoxycarbonyl-[3-[tert-butyl(dimethyl)silyl]oxy-4-methoxybutyl]amino]-5-[3-[4-[3-[tert-butoxycarbonyl(methyl) amino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiaeol-4-carboxylate

Using the General Procedure for the Mitsunobu reaction, starting from 577 mg of Preparation 1b (1 mmol, 1 equiv) as the appropriate carbamate and 469 mg of Preparation 2h (2 mmol, 2 equiv) as the appropriate alcohol, 794 mg (99%) of the desired product were obtained.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[3-[tert-butyl(dimethyl )silyl]oxy-4-methoxybutyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with 794 mg of the product from Step A (1 mmol) as the appropriate carbamate, 320 mg (46%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.54 (t, 1H), 7.28 (d, 1H), 7.18 (d, 1H), 7.09 (t, 1H), 4.04 (t, 2H), 4.20 (bs, 2H), 3.89-3.81 (m, 1H), 3.67 (s, 3H), 3.23-3.14 (m, 4H), 3.22 (s, 3H), 3.10 (t, 2H), 2.83 (brs, 3H), 2.03-1.93 (m, 2H), 1.74-1.50 (m, 2H), 1.39 (s, 9H), 0.81 (s, 9H), 0.00 (s, 3H), -0.01 (s, 3H).

Synthesis 3m: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-[tert-butyl(dimethyl) silyl]oxypentylamino]thiazole-4-carboxylate

Step A: Methyl 2-[tert-butoxycarbonyl-[5-[tert-butyl(dimethyl)silyl]oxypentyl]amino]-5-[3-(2-fluoro-4-iodophenoxy)propyl]thiazole-4-carboxylate

Using the General Alkylation Procedure starting from 5.00 g of Preparation 1a (7.55 mmol, 1 equiv) and 2.97 g of tert-butyl (5-iodopentoxy) dimethylsilane (9.06 mmol, 1.2 equiv) as the appropriate halide, 4.72 g (85%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.59 (dm, 1H), 7.46 (dm, 1H), 6.99 (t, 1H), 4.07 (t, 2H), 4.01 (t, 2H), 3.76 (s, 3H), 3.56 (t, 2H), 3.21 (t, 2H), 2.07 (m, 2H), 1.64 (m, 2H), 1.52 (s, 9H), 1.48 (m, 2H), 1.30 (m, 2H), 0.82 (s, 9H), -0.02 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 163.1, 156.3/153.2, 151.8, 147.0, 143.2, 135.6, 133.9, 124.9, 117.6, 83.5, 82.3, 67.3, 62.5, 52.0, 46.5, 32.3, 30.5, 28.1, 27.6, 26.3, 22.9, 22.6, 18.1, -4.9; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₀ H ₄₇ FIN ₂ O ₆ SSi: 737.1947, found: 737.1948.

Step B: Methyl 2-[[5-[tert-butyl(dimethyl)silyl]oxypentyl]amino]-5-[3-(2-fluoro-4-iodophenoxy)propyl]thiazole-4-carboxylate

The General HFIP deprotection procedure was used starting with 2.36 g of the product from Step A (3.20 mmol) as the appropriate carbamate. After completion of the reaction, the reaction mixture was evaporated to dryness under reduced pressure to afford the crude desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) s ppm 7.60-7.54 (m, 2H), 7.44 (d, 1H), 6.96 (t, 1H), 4.03 (t, 2H), 3.69 (s, 3H), 3.56 (t, 2H), 3.18-3.08 (m, 4H), 1.98 (qv., 2H), 1.55-1.42 (m, 4H), 1.37-1.29 (m, 2H), 0.84 (s, 9H), 0.00 (s, 6H).

Step C: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-[tert-butyl(dimethyl) silyl]oxypentylamino]thiazole-4-carboxylate

Using the General Sonogashira reaction procedure, starting from the crude product from Step B and tert-butyl N-methyl-N-prop-2-ynylcarbamate as the appropriate acetylene, 1.92 g (89% over 2 steps) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.57 (br., 1H), 7.31 (d, 1H), 7.21 (d, 1H), 7.12 (t, 1H), 4.23 (br., 2H), 4.07 (t, 2H), 3.69 (s, 3H), 3.56 (t, 2H), 3.14 (m, 2H), 3.11 (t, 2 H), 2.86 (br., 3 H), 2.00 (quint., 2H), 1.51 (m, 2H), 1.45 (m, 2H), 1.41 (s, 9H), 1.33 (m, 2H), 0.84 (s, 9H), 0.00 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 119.3, 115.4, 68.0, 62.8, 51.7, 44.5, 38.6, 33.8, 32.4, 30.6, 28.9, 28.5, 26.3, 23.3, 23.2, -4.9; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₅₃ FN ₃ O ₆ SSi: 678.3403, found: 678.3393.

Synthesis of 3n: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[3-[tert-butyl(dimethyl) silyl]hydroxypropylamino]thiazole-4-carboxylate

Step A: methyl 2-[tert-butoxycarbonyl-[3-[tert-butyl(dimethyl)silyl]oxypropyl]amino]-5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop- 1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from 577 mg of the product of Preparation 1b (1 mmol, 1 equiv) as the appropriate carbamate and 380 mg of 3-[tert-butyl(dimethyl)silyl]oxypropan-1-ol (2 mmol, 2 equiv) as the appropriate alcohol, 600 mg (80%) of the desired product were obtained.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[3-[tert-butyl(dimethyl) silyl]hydroxypropylamino]thiaeol-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 310 mg (47%) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.50 (t, 1H), 7.30 (d, 1H), 7.20 (d, 1H), 7.11 (t, 1H), 4.21 (bs, 2H), 4.05 (t, 2H), 3.62 (t, 2H), 3.67 (s, 3H), 3.19 (q, 2H), 3.10 (t, 2H), 2.84 (brs, 3H), 2.04-1.94 (m, 2H), 1.74-1.63 (m, 2H), 1.40 (s, 9H), 0.84 (s, 9H), 0.00 (s, 6H).

Synthesis of 3о: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[(2,2-dimethyl-1, 3-dioxolan-4-yl)methylamino]thiazol-4-carboxylate

Step A: methyl 2-[tert-butoxycarbonyl-[(2,2-dimethyl-1,3-dioxolan-4-yl)methyl]amino]-5-[3-[4-[3-[tert-butoxycarbonyl( methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure for the Mitsunobu reaction, starting from 577 mg of the product of Preparation 1b (1 mmol, 1 equiv) as the appropriate carbamate and 264 mg of (2,2-dimethyl-1,3-dioxolan-4-yl)methanol (2 mmol, 2 equiv) as the appropriate alcohol, 640 mg (92%) of the desired product were obtained.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[(2,2-dimethyl-1, 3-dioxolan-4-yl)methylamino]thiazol-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 282 mg (51%) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.73 (t, 1H), 7.31 (d, 1H), 7.21 (d, 1H), 7.13 (t, 1H), 4.23 (bs, 2H), 4.19 (q, 1H), 4.07 (t, 2H), 4.05-3.96 (m, 2H), 3.64 (dd, 1H), 3.69 (s, 3H), 3.31-3.24 (m, 1H), 3.11 (t, 2H), 2.86 (brs, 3H), 2.05-1.95 (m, 2H), 1.41 (s, 9H), 1.33 (s, 3H), 1.26 (s, 3H).

Synthesis of 3p: Methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[(2,2-dimethyl-1,3-dioxolane-4- yl)methylamino]thiazole-4-carboxylate

Step A: methyl 2-[tert-butoxycarbonyl-[(2,2-dimethyl-1,3-dioxolan-4-yl)methyl]amino]-5-[3-[4-[3-(dimethylamino)prop- 1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from 491 mg of the product of Preparation 1 with (1 mmol, 1 equiv) as the appropriate carbamate and 292 mg of (2,2-dimethyl-1,3-dioxolan-4-yl)methanol (2 mmol, 2 equiv) as the appropriate alcohol, 573 mg (92%) of the desired product were obtained.

Step B: Methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[(2,2-dimethyl-1,3-dioxolane-4- yl)methylamino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with the product from Step A as the appropriate carbamate, 378 mg (74%) of the product of Preparation 3p was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.74 (t, 1H), 7.30 (dd, 1H), 7.21 (d, 1H), 7.13 (t, 1H), 4.21 (qui, 1H), 4.07 (t, 2H), 4.02-3.96 (m, 2H) , 3.70 (s, 3H), 3.65 (dd, 1H), 3.42 (s, 2H), 3.33-3.26 (m, 1H), 3.12 (t, 2H), 2.23 (s, 6H), 2.05-1.96 (m, 2H), 1.34(s, 3H), 1.26 (s, 3H).

Synthesis of 3q: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[3-[tert-butyl(dimethyl )silyl]oxy-2-methoxypropyl]amino]thiazole-4-carboxylate

Step A: methyl 2-[tert-butoxycarbonyl-[3-[tert-butyl(dimethyl)silyl]oxy-2-methoxypropyl]amino]-5-[3-[4-[3-[tert-butoxycarbonyl(methyl) amino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of the Mipunobu reaction, starting from 577 mg of Preparation 1b (1 mmol, 1 equiv) as the appropriate carbamate and 440 mg of Preparation 2j (2 mmol, 2 equiv) as the appropriate alcohol, 780 mg (quant.) of the desired product were obtained.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[3-[tert-butyl(dimethyl )silyl]oxy-2-methoxypropyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 400 mg (58%) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.60 (t, 1H), 7.31 (d, 1H), 7.21 (d, 1H), 7.13 (t, 1H), 4.23 (bs, 2H), 4.07 (t, 2H), 3.69 (s, 3H), 3.67-3.57 (m, 2H), 3.40-3.31 (m, 2H), 3.33 (s, 3H), 3.26-3.18 (m, 1H), 3.12 (t, 2H), 2.87 (brs, 3H), 2.01 (qui, 2H), 1.42 (s, 9H), 0.86 (s, 9H), 0.03 (s, 3H), 0.02 (s, 3H).

Synthesis of 3r: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[3-[tert-butyl(dimethyl )silyl]oxy-2-morpholinopropyl]amino]thiazole-4-carboxylate

Step A: methyl 2-[tert-butoxycarbonyl-[3-[tert-butyl(dimethyl)silyl]oxy-2-morpholinopropyl]amino]-5-[3-[4-[3-[tert-butoxycarbonyl(methyl) amino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from 577 mg of Preparation 1b (1 mmol, 1 equiv) as the appropriate carbamate and 413 mg of Preparation 2k (1.5 mmol, 1.5 equiv) as the appropriate alcohol, 473 mg (56%) of the desired product were obtained.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[3-[tert-butyl(dimethyl )silyl]oxy-2-morpholinopropyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 390 mg (93%) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.38 (t, 1H), 7.32 (d, 1H), 7.21 (d, 1H), 7.12 (t, 1H), 4.23 (bs, 2H), 4.07 (t, 2H), 3.73 (dd, 1H), 3.69 (s, 3H), 3.64 (dd, 1H), 3.58-3.46 (m, 4H), 3.25 (t, 2H), 3.13 (t, 2H), 2.87 (brs, 3H), 2.72-2.63 (m, 3H), 2.59-2.53 (m, 2H), 2.01 (qui, 2H), 1.42 (s, 9H), 0.86 (s, 9H), 0.03 (s, 6H).

Synthesis 3s: Methyl 5-[3-(2-fluoro-4-iodophenoxy)propyl]-2-(methylamino)thiazole-4-carboxylate

Step A: Methyl 2-[tert-butoxycarbonyl(methyl)amino]-5-[3-(2-fluoro-4-iodophenoxy)propyl]thiazole-4-carboxylate

Using the General Alkylation Procedure, starting from 2.68 g of the product of Preparation 1a (10 mmol, 1 equiv.) and 1.70 g of iodomethane (12 mmol, 1.2 equiv.) as the appropriate alkyl halide, 2.8 g (77%) of the desired product were obtained.

Step B: Methyl 5-[3-(2-fluoro-4-iodophenoxy)propyl]-2-(methylamino)thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with 2.0 g of the product from Step A (4.44 mmol) as the appropriate carbamate, 1.2 g (73%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.59 (dd, 1H), 7.50 (q, 1H), 7.45 (m, 1H), 6.97 (t, 1H), 4.03 (t, 2H), 3.70 (s, 3H), 3.12 (t, 2H), 2.77 (d, 3H), 1.99 (m, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 165.4, 163.0, 147.0, 134.0, 124.9, 117.6, 68.0, 51.8, 31.1, 30.6, 23.3; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁₅ H ₁₇ FIN ₂ O ₃ S: 450.9983, found: 450.9971.

Synthesis 3t: Methyl2-[5-[tert-butyl(dimethyl)silyl]oxypentylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4 -carboxylate

Using the General Sonogashira reaction procedure, starting from the crude product of Preparation 3m, Step B, and N,N-dimethylprop-2-yn-1-amine as the appropriate acetylene, 3.73 g (quant. over 2 steps) of the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₀ H ₄₇ FN ₃ O ₄ SSi: 592.3035, found: 592.3033.

Synthesis 3u: Ethyl 2-amino-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylate

Stage A: ethyl 3-bromo-6-chloro-2-oxohexanoate

To a stirred solution of ethyl 6-chloro-2-oxohexanoate (5 g, 26.0 mmol, 1 equiv.) in chloroform (70 mL) was added bromine (1.6 mL, 31.2 mmol, 1.2 equiv.). The reaction mixture was stirred at ambient temperature for 6.5 h, then diluted with dichloromethane and washed with 10% aqueous sodium thiosulfate, followed by water and then brine. The organic extract was dried (magnesium sulfate) and the solvent removed in vacuo to give the title compound (7 g, 25.8 mmol, 99%) as a colorless oil.

¹ H NMR (400 MHz, DMSO-d6) δ 5.25 (dd, J = 9.0, 4.7 Hz, 1H), 4.30 (q, J = 7.1 Hz, 2H), 3.72 (t, J = 6.3 Hz, 2H), 2.24 - 2.10 (m, 1H), 2.07 - 1.89 (m, 2H), 1.92 -1.76 (m, 1H), 1.30 (t, J = 7.1 Hz, 3H).

Step B: Ethyl 5-(3-chloropropyl)-2-acetamido-1,3-thiazole-4-carboxylate

To a stirred solution of the product from Step A (7 g, 25.8 mmol, 1 equiv) in ethanol (150 mL) was added N-acetylthiourea (3.05 g, 25.78 mmol, 1 equiv). The reaction mixture was heated at reflux for 6 h, then allowed to cool to ambient temperature and the solvent was removed in vacuo. The residue was dissolved in dichloromethane (150 mL), then acetic anhydride (4.74 mL, 50.21 mmol, 2 equiv) and 4-dimethylaminopyridine (6.13 g, 50.21 mmol, 2 equiv) were added. After stirring at ambient temperature for 2 h, the mixture was diluted with dichloromethane, then washed with water (x2), followed by brine. The organic extract was dried (magnesium sulfate) and the solvent was removed in vacuo. The crude material was triturated with diethyl ether and the solid was collected by filtration and washed with diethyl ether to give the title product (1.1 g, 3.78 mmol, 13.9%). Two cycles of evaporation of the filtrate, repeated trituration and filtration afforded additional crops of product (3.42 g, 11.76 g, 43%). Finally, evaporation of the final filtrate and purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 to 100% ethyl acetate in isoheptane afforded additional title product (1.46 g, 5.02 mmol, 18.5%) [overall yield: 76%].

LC/MS (C ₁₁ H ₁₅ ClN ₂ O ₃ S) 291 [M+H] ⁺ ; RT 1.08 (LCMS-V-B1);

¹ H NMR (400 MHz, DMSO-d6) δ 12.43 (s, 1H), 4.26 (q, J = 7.1 Hz, 2H), 3.68 (t, J = 6.4 Hz, 2H), 3.27 - 3.18 (m, 2H), 2.13 (s, 3H), 2.19 - 2.00 (m, 2H), 1.29 (t, J = 7.1 Hz, 3H).

Step C: Ethyl 2-acetamido-5-(3-iodopropyl)-1,3-thiazole-4-carboxylate

A solution of the product from Step B (5.84 g, 20.1 mmol, 1 equiv) and sodium iodide (18.1 g, 0.12 mol, 6 equiv) in acetonitrile (130 mL) was heated at reflux for 6 h. The mixture was cooled to ambient temperature and the solvent was removed in vacuo. The mixture was diluted with ethyl acetate and washed with water and brine. The organic extract was dried (magnesium sulfate) and concentrated in vacuo. The resulting solid was triturated with diethyl ether and then collected by filtration to give the title product as a cream-colored solid (6.28 g, 16.4 mmol, 82%).

LC/MS (C ₁₁ H ₁₅ IN ₂ O ₃ S) 383 [M+H] ⁺ ; RT 0.96 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.43 (s, 1H), 4.26 (q, J = 7.1 Hz, 2H), 3.29 (t, J = 6.7 Hz, 2H), 3.18 (t, J = 7.4 Hz, 2H), 2.12 (s, 3H), 2.16 - 2.04 (m, 2H), 1.30 (t, J = 7.1 Hz, 3H).

Step D: Ethyl 5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-2-acetamido-1,3-thiazol-4-carboxylate

To a stirred solution of the product from Step C (1.64 g, 8.46 mmol, 1.2 equiv) in dimethylformamide (20 mL) was added sodium hydride (60% in mineral oil) (0.56 g, 14.1 mmol, 2 equiv). The reaction mixture was stirred at ambient temperature for 30 min, then cooled in an ice bath and a solution of the product of Preparation 6b (2.7 g, 7.05 mmol, 1 equiv) in dimethylformamide (20 mL) was slowly added. After 40 min, the reaction mixture was allowed to warm to ambient temperature and stirred for 5 h. The solvent was removed in vacuo and the crude material was partitioned between ethyl acetate and water, washed with brine and dried (magnesium sulfate). The solvent was removed in vacuo and the crude product was purified by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge), eluting with a gradient of 0 - 10% methanol in dichloromethane to give the title product as a cream solid (1.48 g, 3.32 mmol, 47%).

LC/MS (C ₂₂ H ₂₆ FH ₃ O ₄ S) 448 [M+H] ⁺ ; RT 0.76 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.41 (s, 1H), 7.30 (dd, J = 11.9, 2.3 Hz, 1H), 7.25 - 7.18 (m, 1H), 7.17 - 7.10 (m, 1H), 4.22 (q, J = 7.1 Hz, 2H), 4.11 (t, J = 6.1 Hz, 2H), 3.42 (s, 2H), 3.24 (dt, J = 14.7, 7.5 Hz, 2H), 2.23 (s, 6H), 2.10 (s, 3H), 2.12 - 2.01 (m, 2H), 1.27 (t, J = 7.1 Hz, 3H).

Step E: Ethyl 2-amino-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylate

A solution of the product from Step D (1.49 g, 3.32 mmol, 1 equiv) and hydrochloric acid (4 M in 1,4-dioxane) (8.3 mL, 0.03 mol, 10 equiv) in ethanol (40 mL) was heated at 60 °C for 18 h. The reaction mixture was allowed to cool to ambient temperature, then the solvent was removed in vacuo. The resulting oil was dissolved in a small amount of methanol, then loaded onto an SCX-2 cartridge (50 g, rinsed with methanol). The cartridge was rinsed with methanol, then eluted with 3.5 N methanolic ammonia. The solvent was removed in vacuo and the resulting oil was purified by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% methanol in dichloromethane to give the desired product as a creamy solid (0.78 g, 1.93 mmol, 58%).

LC/MS (C ₂₀ H ₂₄ FN ₃ O ₃ S) 406 [M+H] ⁺ ; RT 0.706 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.30 (dd, J = 12.0, 2.0 Hz, 1H), 7.25 - 7.17 (m, 1H), 7.13 (t, J = 8.7 Hz, 1H), 7.02 (s, 2H), 4.16 (q, 2H), 4.07 (t, 2H), 3.42 (s, 2H), 3.12 (t, J = 7.5 Hz, 2H), 2.23 (s, 6H), 2.09 - 1.94 (m, 2H), 1.23 (t, J = 7.1 Hz, 3H).

Synthesis 3v: Ethyl 2-amino-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylate

Step A: Ethyl 5-bromo-2-acetamido-1,3-thiazole-4-carboxylate

A solution of ethyl 2-amino-5-bromo-1,3-thiazole-4-carboxylate (2 g, 7.96 mmol, 1 equiv), acetic anhydride (0.83 ml, 8.76 mmol, 1.1 equiv), and 4-dimethylaminopyridine (1.12 g; 9.16 mmol, 1.15 equiv) in dichloromethane (30 ml) was stirred at ambient temperature for 3 days. The reaction mixture was diluted with dichloromethane, washed successively with water and brine, then dried (magnesium sulfate), and the solvent was removed in vacuo. The resulting solid was triturated with diethyl ether, filtered and dried under vacuum to give the desired product as an off-white solid (1.8 g, 6.14 mmol, 77%).

LC/MS (C ₈ H ₉ BrN ₂ O ₃ S) 293 [M+H] ⁺ ; RT 1.01 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.80 (s, 1H), 4.28 (q, J = 7.1 Hz, 2H), 2.16 (s, 3H), 1.30(t, J = 7.1 Hz, 3H).

Step B: Ethyl 2-acetamido-5-(3-phenoxyprop-1-yn-1-yl)-1,3-thiazol-4-carboxylate

The product from Step A (200 mg, 0.68 mmol, 1 equiv), phenyl propargyl ether (0.18 mL, 1.36 mmol, 2 equiv), triethylamine (0.28 mL, 2.05 mmol, 3 equiv), copper(I) iodide (13 mg, 0.07 mmol, 0.1 equiv), and tetrakis(triphenylphosphine)palladium(0) (39.4 mg, 0.03 mmol, 0.05 equiv) were combined. The mixture was sparged with nitrogen (10 min) and then heated at 100 °C for 1 h under microwave irradiation. The reaction mixture was partitioned between ethyl acetate and water, and the organics were washed with water, followed by brine, and dried (magnesium sulfate). The solvent was removed in vacuo and the crude product was purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 100% ethyl acetate in isoheptane to give the title product as an off-white solid (122 mg, 0.35 mmol, 52%).

LC/MS (C ₁₇ H ₁₆ N ₂ O ₄ S) 345 [M+H] ⁺ ; RT 1.21 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.85 (s, 1H), 7.34 (t, J = 7.8 Hz, 2H), 7.09 - 7.03 (m, 2H), 7.02 - 6.96 (m, 1H), 5.13 (s, 2H), 4.24 (q, J = 7.0 Hz, 2H), 2.16 (s, 3H), 1.27(t, J = 7.1 Hz, 3H).

Step C: Ethyl 2-acetamido-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylate

Ethyl acetate (10 mL) was charged to a flask containing the product from Step B (122 mg, 0.35 mmol, 1 equiv) and platinum(IV) oxide (8.04 mg, 0.04 mmol, 0.1 equiv) under nitrogen. The mixture was shaken at ambient temperature under hydrogen for 6.5 h. Additional platinum(IV) oxide (on the tip of a spatula) was added and the reaction mixture was shaken under hydrogen for an additional 18 h. The mixture was filtered through a methanol-wetted Celite pad, eluted with methanol, and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 100% ethyl acetate in isoheptane afforded the title product as a cream-colored solid (77.2 mg, 0.22 mmol, 63%).

LC/MS (C ₁₇ H ₂₀ N ₂ O ₄ S) 349 [M+H] ⁺ ; RT 1.22 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.41 (s, 1H), 7.36 - 7.24 (m, 2H), 7.03 - 6.88 (m, 3H), 4.23 (q, J = 7.1 Hz, 2H), 4.00 (t, J = 6.2 Hz, 2H), 3.26 (dd, J = 8.3, 6.8 Hz, 2H), 2.12 (s, 3H), 2.11 - 2.01 (m, 2H), 1.28 (t, J = 7.1 Hz, 3H).

Step D: Ethyl 2-amino-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 0.55 mL, 2.22 mmol, 10 equiv) was added to a stirred solution of the product from Step C (77.2 mg, 0.22 mmol, 1 equiv) in ethanol (5 mL). The reaction mixture was heated at 60 °C for 5 h. The solvent was removed in vacuo, then the residue was dissolved in methanol and loaded onto a methanol-wetted SCX-2 cartridge (5 g). The cartridge was washed with methanol, then eluted with 3.5 N methanolic ammonia, and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% methanol in dichloromethane afforded the desired product as a yellow gum (48.2 mg, 0.16 mmol, 71%).

LC/MS (C ₁₅ H ₁₈ N ₂ O ₃ S) 307 [M+H] ⁺ ; RT 1.16 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.33 - 7.24 (m, 2H), 7.02 (s, 2H), 6.95 - 6.90 (m, 3H), 4.16 (q, J = 7.1 Hz, 2H), 3.97 (t, J = 6.2 Hz, 2H), 3.13 (t, 2H), 2.03 - 1.94 (m, 2H), 1.24 (t, J = 7.1 Hz, 3H).

Synthesis 3w: Ethyl 2-amino-5-(3-methoxypropyl)-1,3-thiazole-4-carboxylate

Step A: Ethyl 2-acetamido-5-(3-methoxyprop-1-yn-1-yl)-1,3-thiazol-4-carboxylate

Dimethylformamide (10 mL) was added to the product of Preparation 3v, Step A (400 mg, 1.36 mmol, 1 equiv), methyl propargyl ether (0.23 mL, 2.73 mmol, 2 equiv), triethylamine (0.57 mL, 4.09 mmol, 3 equiv), and copper(I) iodide (26 mg, 0.14 mmol, 0.1 equiv), followed by the addition of tetrakis(triphenylphosphine)palladium(0) (78.8 mg, 0.07 mmol, 0.05 equiv). The flask was sparged with nitrogen (10 min) and then heated at 100 °C for 1 h under microwave irradiation. The solvent was removed in vacuo and the crude product was purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 5% methanol in dichloromethane to give a solid that was triturated with diethyl ether to give the title product as a cream solid (213.7 mg, 0.76 mmol, 55%). The filtrate was evaporated to give a second crop of the title product as an orange gum (94.6 mg, 0.34 mmol, 24%) [overall yield 79%].

LC/MS (C ₁₂ H ₁₄ N ₂ O ₄ S) 283 [M+H] ⁺ ; RT 1.00 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.84 (s, 1H), 4.41 (s, 2H), 4.28 (q, J = 7.1 Hz, 2H), 3.36 (s, 3H), 2.16 (s, 3H ), 1.30 (t, J = 7.1 Hz, 3H).

Step B: Ethyl 2-acetamido-5-(3-methoxypropyl)-1,3-thiazole-4-carboxylate

A solution of the product from Step A (308 mg, 1.09 mmol, 1 equiv) in 2:1 ethyl acetate/methanol (15 mL) was charged to a flask containing a catalytic amount of platinum(IV) oxide under nitrogen. The flask was evacuated and backfilled with nitrogen (x3), then evacuated and placed under hydrogen. After shaking at ambient temperature for 18 h, the reaction mixture was filtered through celite, eluted with methanol, and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 to 100% ethyl acetate in isoheptane afforded the title product as a cream-colored solid (207 mg, 0.72 mmol, 66%).

LC/MS (C ₁₂ H ₁₈ N ₂ O ₄ S) 287 [M+H] ⁺ ; RT 0.99 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.40 (s, 1H), 4.25 (q, J = 7.1 Hz, 2H), 3.39 - 3.31 (m, 2H), 3.24 (s, 3H), 3.17 - 3.08 (m, 2H), 2.12 (s, 3H), 1.89 - 1.77 (m, 2H), 1.29 (t, J = 7.1 Hz, 3H).

Step C: Ethyl 2-amino-5-(3-methoxypropyl)-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 2.1 mL, 8.38 mmol, 10 equiv) was added to a stirred solution of the product from Step B (240 mg, 0.84 mmol, 1 equiv) in ethanol (10 mL). The mixture was heated to 60 °C for 7 h, then allowed to cool to ambient temperature and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% methanol in dichloromethane afforded the title product as a brown gum (219 mg, 0.81 mmol, 97%).

LC/MS (C ₁₀ H ₁₆ N ₂ O ₃ S) 245 [M+H] ⁺ ; RT 0.88 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 8.00 (br s, 2H), 4.25 (q, J = 7.1 Hz, 2H), 3.34 (t, J = 6.3 Hz, 2H), 3.23 (s, 3H) , 3.05 - 2.96 (m, 2H), 1.84 - 1.72 (m, 2H), 1.28 (t, J = 7.1 Hz, 3H).

Synthesis 3x: Ethyl 2-amino-5-[3-(2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylate

Step A: Ethyl 2-acetamido-5-(3-hydroxyprop-1-yn-1-yl)-1,3-thiazol-4-carboxylate

To a mixture of the product of Preparation 3v, Step A (1 g, 3.41 mmol, 1 equiv), propargyl alcohol (0.4 mL, 6.82 mmol, 2 equiv), triethylamine (1.42 mL, 10.2 mmol, 3 equiv), and copper(I) iodide (65 mg, 0.34 mmol, 0.1 equiv) in dimethylformamide (20 mL) was added tetrakis(triphenylphosphine)palladium(0) (197 mg, 0.17 mmol, 0.05 equiv). The mixture was bubbled with nitrogen (10 min) and then heated at 100 °C for 1 h under microwave irradiation. The solvent was removed in vacuo; subsequent purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% methanol in dichloromethane afforded the desired product as a brown solid (1.01 g, 3.75 mmol, >100%).

LC/MS (C ₁₁ H ₁₂ N ₂ O ₄ S) 269 [M+H] ⁺ ; RT 0.82 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.80 (s, 1H), 5.45 (t, J = 6.0 Hz, 1H), 4.37 (d, J = 6.1 Hz, 2H), 4.27 (q, J = 7.1 Hz, 2H), 2.16 (s, 3H), 1.30 (t, J = 7.1 Hz, 3H).

Step B: Ethyl 2-acetamido-5-(3-hydroxypropyl)-1,3-thiazole-4-carboxylate

A solution of the product from Step A (1.01 g, 3.75 mmol, 1 equiv) in 4:1 ethyl acetate/methanol (25 mL) was charged to a flask containing platinum(IV) oxide hydrate (on a spatula tip) under nitrogen. The reaction mixture was evacuated and backfilled with nitrogen (x3), then evacuated and placed under hydrogen. The reaction mixture was shaken at ambient temperature for 30 h, then filtered through Celite, eluted with methanol, and the solvent removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% methanol in dichloromethane afforded the desired product as a brown gum (582 mg, 2.14 mmol, 57%).

LC/MS (C ₁₁ H ₁₆ N ₂ O ₄ S) 273 [M+H] ⁺ ; RT 0.81 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.39 (s, 1H), 4.54 (t, J = 5.1 Hz, 1H), 4.25 (q, J = 7.1 Hz, 2H), 3.44 (td, J = 6.4 , 5.1 Hz, 2H), 3.15 - 3.09 (m, 2H), 2.12 (s, 3H), 1.81 1.69 (m, 2H), 1.29 (t, J = 7.1 Hz, 3H).

Step C: Ethyl 2-acetamido-5-[3-(2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylate

A solution of 2-fluorophenol (0.1 mL, 1.1 mmol, 1.5 equiv), the product from Step B (200 mg, 0.73 mmol, 1 equiv), and triphenylphosphine (289 mg, 1.1 mmol, 1.5 equiv) in tetrahydrofuran (10 mL) was cooled in an ice bath and diisopropyl azobicarboxylate (0.22 mL, 1.1 mmol, 1.5 equiv) was added dropwise. The reaction mixture was allowed to gradually warm to ambient temperature and then stirred for 18 h. The mixture was diluted with ethyl acetate, washed with brine, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 100% ethyl acetate in heptane afforded the title product as a white solid (162 mg, 0.44 mmol, 60%).

LC/MS (C ₁₇ H ₁₉ FN ₂ O ₄ S) 367 [M+H] ⁺ ; RT 1.22 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.41 (s, 1H), 7.29 - 7.07 (m, 3H), 7.00 - 6.89 (m, 1H), 4.23 (q, J = 7.1 Hz, 2H), 4.08 (t, J = 6.2 Hz, 2H), 3.27 (dd, J = 8.2, 6.9 Hz, 2H), 2.12 (s, 3H), 2.18 - 2.03 (m, 2H), 1.27 (t, J = 7.1 Hz, 3H).

Step D: Ethyl 2-amino-5-[3-(2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylate

A solution of the product from Step C (217 mg, 0.59 mmol, 1 equiv) and hydrochloric acid (4 M in dioxane; 1.48 mL, 5.92 mmol, 10 equiv) in ethanol (8 mL) was heated at 60 °C overnight. The mixture was allowed to cool to ambient temperature, then the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% methanol in dichloromethane afforded the title product as a yellow foam (181 mg, 0.56 mmol, 94%).

LC/MS (C ₁₅ H ₁₇ FN ₂ O ₃ S) 325 [M+H] ⁺ ; RT 1.16 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.62 (br s, 2H), 7.26 - 7.07 (m, 3H), 6.99 - 6.89 (m, 1H), 4.20 (q, J = 7.1 Hz, 2H), 4.07 (t, J = 6.1 Hz, 2H), 3.15 (t, J = 7.5 Hz, 2H), 2.08 - 1.99 (m, 2H), 1.25 (t, J = 7.1 Hz, 3H).

Synthesis 3u: Ethyl 2-amino-5-[3-(4-bromo-2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylate

Step A: Ethyl 5-[3-(4-bromo-2-fluorophenoxy)propyl]-2-acetamido-1,3-thiazole-4-carboxylate

A solution of the product of Preparation 3x, Step B (248 mg, 0.91 mmol, 1 equiv), 4-bromo-2-fluorophenol (0.15 mL, 1.37 mmol, 1.5 equiv), and triphenylphosphine (358 mg, 1.37 mmol, 1.5 equiv) in tetrahydrofuran (10 mL) was cooled in an ice bath, then diisopropyl azodicarboxylate (0.27 mL, 1.37 mmol, 1.5 equiv) was added dropwise. The reaction mixture was stirred in an ice bath for 30 min, then stirred at ambient temperature for 3 h. The reaction mixture was diluted with ethyl acetate and washed with water then brine. The organics were dried (magnesium sulfate) and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 100% ethyl acetate in heptane afforded the title product as a white solid (229 mg, 0.51 mmol, 56%).

LC/MS (C ₁₇ H ₁₈ BrFN ₂ O ₄ S) 445 [M+H] ⁺ ; RT 1.36 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.42 (s, 1H), 7.53 (dd, J = 10.9, 2.4 Hz, 1H), 7.32 (ddd, J = 8.8, 2.4, 1.5 Hz, 1H), 7.13 (t, J = 9.0 Hz, 1H), 4.22 (q, J = 7.1 Hz, 2H), 4.08 (t, J = 6.1 Hz, 2H), 3.25 (dd, J = 8.4, 6.7 Hz, 2H), 2.12 (s, 3H), 2.18 - 2.02 (m, 2H), 1.27 (t, J = 7.1 Hz, 3H).

Step B: Ethyl 2-amino-5-[3-(4-bromo-2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylate

A solution of the product from Step A (229 mg, 0.51 mmol, 1 equiv) and hydrochloric acid (4 M in dioxane; 1.29 mL, 5.14 mmol, 10 equiv) in ethanol (8 mL) was heated at 60 °C for 18 h. The reaction mixture was allowed to cool to ambient temperature, then the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% methanol in dichloromethane afforded the desired product as a yellow gum (199 mg, 0.49 mmol, 96%).

LC/MS (C ₁₅ H ₁₆ BrFN ₂ O ₃ S) 405 [M+H] ⁺ ; RT 1.30 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.54 (dd, J = 11.0, 2.4 Hz, 1H), 7.33 (ddd, J = 8.8, 2.4, 1.5 Hz, 1H), 7.13 (t, J = 9.0 Hz, 1H), 4.19 (q, J = 7.1 Hz, 2H), 4.07 (t, J = 6.1 Hz, 2H), 3.16-3.10 (m, 2H), 2.11-1.96 (m, 2H), 1.24 (t, J = 7.1 Hz, 3H).

Synthesis 3z: Ethyl 2-[(2-methoxyethyl)amino]-1,3-thiazole-4-carboxylate

Ethyl bromopyruvate (2.5 mL, 17.9 mmol, 1.07 equiv) was added under nitrogen to a suspension of 2-methoxyethylthiourea (2.25 g, 16.8 mmol, 1 equiv) in ethanol (40 mL) at 0 °C and the mixture was stirred for 1 h at ambient temperature. Triethylamine (4.7 mL, 33.5 mmol, 2 equiv) was added and the mixture was heated at 75 °C for 18 h. The solution was allowed to cool to ambient temperature and partitioned between ethyl acetate (300 mL) and water (200 mL). The organic phase was washed with water (200 mL) and brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with 1:1 ethyl acetate/heptane afforded a solid which was triturated with heptane (20 mL), filtered, washed with heptane (2 × 15 mL), and dried in vacuo to afford the title product as a pale brown solid (3.15 g, 13.7 mmol, 82%).

LC/MS (C ₉ H ₁₄ N ₂ O ₃ S) 231 [M+H] ⁺ ; RT 0.88 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.40 (s, 1H), 5.78 (t, 1H), 4.34 (q, J = 7.1 Hz, 2H), 3.60 - 3.54 (m, 2H), 3.48 (td, J = 5.5, 4.4 Hz, 2H), 3.36 (s, 3H), 1.36 (t, J = 7.1 Hz, 3H).

Synthesis of 3za: Ethyl 5-[4-(benzyloxy)piperidin-1-yl]-2-(methylamino)-1,3-thiazole-4-carboxylate

Step A: Ethyl 5-[4-(benzyloxy)piperidin-1-yl]-1,3-thiazole-4-carboxylate

A solution of ethyl 5-bromothiazole-4-carboxylate (500 mg, 2.12 mmol, 1 equiv), 4-benzyloxypiperidine hydrochloride (579 mg, 2.54 mmol, 1.2 equiv), and 1,8-diazabicyclo[5.4.0]undec-7-ene (0.64 mL, 4.24 mmol, 2 equiv) in acetonitrile (10 mL) was heated at 100 °C for 2 h under microwave irradiation. The reaction mixture was allowed to cool to ambient temperature, then concentrated in vacuo, partitioned between dichloromethane and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 100% ethyl acetate in isoheptane afforded the desired product as a yellow oil (499 mg, 1.44 mmol, 68%).

LC/MS (C ₁₈ H ₂₂ N ₂ O ₃ S) 347 [M+H] ⁺ ; RT 1.08 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 8.46 (s, 1H), 7.41 - 7.33 (m, 4H), 7.32 - 7.26 (m, 1H), 4.55 (s, 2H), 4.25 (q, J = 7.1 Hz, 2H), 3.62 (tt, J = 7.7, 3.6 Hz, 1H), 3.42 - 3.30 (m, 2H), 3.08 - 2.97 (m, 2H), 2.05 - 1.95 (m, 2H), 1.81 - 1.66 (m, 2H), 1.28 (t, J = 7.1 Hz, 3H).

Step B: Ethyl 5-[4-(benzyloxy)piperidin-1-yl]-2-bromo-1,3-thiazole-4-carboxylate

N-Bromosuccinimide (308 mg, 1.73 mmol, 1.2 equiv) was added to a stirred solution of the product from Step A (499 mg, 1.44 mmol, 1 equiv) in acetonitrile (20 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with ethyl acetate, washed with water followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 to 60% ethyl acetate in isoheptane afforded the desired product as a yellow solid (454 mg, 1.07 mmol, 74%).

LC/MS (C ₁₈ H ₂₁ BrN ₂ O ₃ S) 427 [M+H] ⁺ ; RT 1.26 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.41 - 7.33 (m, 4H), 7.32 - 7.26 (m, 1H), 4.54 (s, 2H), 4.24 (q, J = 7.1 Hz, 2H), 3.62 (tt, J = 7.5, 3.5 Hz, 1H), 3.43 - 3.28 (m, 2H), 3.07 (ddd, J = 11.8, 8.5, 3.4 Hz, 2H), 2.06 - 1.88 (m, 2H), 1.79 - 1.65 (m, 2H), 1.28 (t, J = 7.1 Hz, 3H).

Step C: Ethyl 5-[4-(benzyloxy)piperidin-1-yl]-2-{[(tert-butoxy)carbonyl](methyl)amino}-1,3-thiazolum-4-carboxylate

The product from Step B (454 mg, 1.07 mmol, 1 equiv) and tert-butyl methyl carbamate (0.19 mL, 1.28 mmol, 1.2 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone) dipalladium(0) (48.9 mg, 0.05 mmol, 0.05 equiv) and xantphos (61.8 mg, 0.11 mmol, 0.1 equiv) in 1,4-dioxane (10 mL). Cesium carbonate (522 mg, 1.6 mmol, 1.5 equiv) was added and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. The residue was dissolved in ethyl acetate, washed with water followed by brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 50 g RediSep™ silica gel cartridge) eluting with a gradient of 0:50% ethyl acetate in isoheptane afforded the title product as a cream solid (339 mg, 0.71 mmol, 67%).

LC/MS (C ₂₄ H ₃₃ H ₃ O ₅ S) 476 [M+H] ⁺ ; RT 1.37 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.41 - 7.33 (m, 4H), 7.32 - 7.26 (m, 1H), 4.55 (s, 2H), 4.23 (q, J = 7.1 Hz, 2H), 3.59 (tt, J = 8.0, 3.7 Hz, 1H), 3.38 (s, 3H), 3.37 - 3.29 (m, 2H), 2.97 (ddd, J = 11.6, 8.8, 3.1 Hz, 2H), 2.06 - 1.91 (m, 2H), 1.76 - 1.62 (m, 2H), 1.52 (s, 9H), 1.28 (t, J = 7.1 Hz, 3H).

Step D: Ethyl 5-[4-(benzyloxy)piperidin-1-yl]-2-(methylamino)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (0.53 mL, 7.11 mmol, 10 equiv) was added to a stirred solution of the product from Step C (339 mg, 0.71 mmol, 1 equiv) in dichloromethane (10 mL) at 0 °C and the mixture was allowed to warm to ambient temperature and stirred overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate and the organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. The material was triturated with diethyl ether, filtered and dried in vacuo to give the title product as a white solid (213 mg, 0.57 mmol, 80%).

LC/MS (C ₁₉ H ₂₅ N ₃ O ₃ S) 376 [M+H] ⁺ ; RT 1.07 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.38 - 7.33 (m, 3H), 7.32 - 7.23 (m, 2H), 4.53 (s, 2H), 4.18 (q, J = 7.1 Hz, 2H), 3.54 (dt, J = 8.2, 4.3 Hz, 1H), 3.19 - 3.08 (m, 2H), 2.83 - 2.72 (m, 5H), 2.02 - 1.89 (m, 2H), 1.76 - 1.60 (m, 2H), 1.26 (t, J = 7.1 Hz, 3H) .

Synthesis of 3zb: Ethyl 5-{1-[(tert-butoxy)carbonyl]azetidin-3-yl}-2-(methylamino)-1,3-thiazole-4-carboxylate

Step A: ({1-[(tert-butoxy)carbonyl]azetidin-3-yl}methyl)(iodo)zinc

An oven-dried Schlenk flask was charged with zinc (3.3 g, 50.5 mmol, 1.5 equiv) and the flask was heated at 160 °C for 20 min under vacuum, then allowed to cool to ambient temperature and blanketed with nitrogen. Dimethylacetamide (25 mL) was added followed by the slow addition of a mixture of trimethylchlorosilane (0.69 mL, 5.42 mmol, 0.16 equiv) and 1,2-dibromoethane (0.49 mL, 5.69 mmol, 0.17 equiv). The resulting mixture was allowed to cool to ambient temperature, then a solution of 1-boc-3-(iodomethyl)azetidine (10 g, 33.65 mmol, 1 equiv.) in dimethylacetamide (7 mL) was added slowly and the mixture was stirred overnight. Cannulation through a cotton wool/celite/cotton wool filter into a dry 25 mL Schlepka flask afforded the desired product as a 0.62 M solution (as determined by titration with 0.5 M iodine), which was used without further characterization.

Step B: tert-butyl 3-(3-ethoxy-2,3-dioxopropyl)azetidine-1-carboxylate

A solution of copper(I) iodide (3.54 g, 18.6 mmol, 2 equiv) in tetrahydrofuran (20 mL) was cooled to -20 °C, then the product from Step A (0.62 M in dimethylacetamide; 30 mL, 18.6 mmol, 2 equiv) was slowly added and the mixture was stirred at -20 °C for 10 min and then at 0 °C for 20 min. The mixture was cooled to -20 °C, then ethyl chloroglyoxylate (1.04 mL, 9.3 mmol, 1 equiv) was added slowly and the mixture was allowed to warm to ambient temperature and stirred for 1 h. The reaction mixture was quenched by addition of saturated aqueous ammonium chloride solution, extracted with ethyl acetate (x2) and the combined organic extracts were washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 30% ethyl acetate in isoheptane afforded the title product as a colourless oil (0.57 g, 2.1 mmol, 23%).

¹ H NMR (400 MHz, Chloroform-d) δ 4.33 (q, J = 7.2 Hz, 2H), 4.13 (t, J = 8.5 Hz, 2H), 3.57 (dd, J = 8.9, 5.4 Hz, 2H), 3.20 (d, J = 7.5 Hz, 2H), 2.99 - 2.84 (m, 1H), 1.43 (s, 9H), 1.37 (t, J = 7.1 Hz, 3H).

Step C: tert-butyl 3-[(1Z)-3-ethoxy-3-oxo-2-[(trimethylsilyl)oxy]prop-1-en-1-yl]azetidine-1-carboxylate

To a solution of the product from Step B (570 mg, 2.1 mmol, 1 equiv) and chlorotrimethylsilane (0.3 mL, 2.35 mmol, 1.12 equiv) in tetrahydrofuran (10 mL) was slowly added triethylamine (0.38 mL, 2.73 mmol, 1.3 equiv), and the mixture was stirred at ambient temperature for 3.5 h. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo to give the title product as a colorless oil (643 mg, 1.87 mmol, 89%).

¹ H NMR (400 MHz, Chloroform-d) δ 6.23 (d, J = 8.9 Hz, 1H), 4.22 (q, J = 7.1 Hz, 2H), 4.14 (t, J = 8.5 Hz, 2H), 3.74 (dd, J = 8.4, 6.0 Hz, 2H), 3.61 - 3.46 (m, 1H), 1.44 (s, 9H), 1.32 (t, J = 7.1 Hz, 3H), 0.20 (s, 9H).

Step D: tert-butyl 3-(1-bromo-3-ethoxy-2,3-dioxopropyl)azetidine-1-carboxylate

A solution of the product from Step C (643 mg, 1.87 mmol, 1 equiv) and N-bromosuccinimide (367 mg, 2.06 mmol, 1.1 equiv) in tetrahydrofuran (15 mL) was heated at reflux for 2.5 h and then allowed to cool to ambient temperature. The reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 40% ethyl acetate in isoheptane afforded the title product as a yellow gum (507 mg, 1.45 mmol, 77%).

¹ H NMR (400 MHz, Chloroform-d) δ 5.25 (d, J = 9.3 Hz, 1H), 4.40 (q, 2H), 4.14 (t, 1H), 4.08 (t, J = 8.8 Hz, 1H), 3.85 (dd, J = 9.1, 5.5 Hz, 1H), 3.58 (dd, J = 9.3, 5.2 Hz, 1H), 3.25 - 3.10 (m, 1H), 1.44 (s, 9H), 1.40 (t, J = 7.2 Hz, 3H).

Step E: Ethyl 5-(azetidin-3-yl)-2-(methylamino)-1,3-thiazole-4-carboxylate

A solution of the product from Step D (452 mg, 1.29 mmol, 1 equiv) and N-methylthiourea (140 mg, 1.55 mmol, 1.2 equiv) in ethanol (8 mL) was heated at reflux for 4.5 h and then allowed to cool to ambient temperature. The resulting precipitate was collected by filtration, washed with ethanol (2 mL), and dried in vacuo to give the title product as a white solid (161 mg, 0.5 mmol, 39%). The filtrate was transferred to a microwave treatment vessel and hydrochloric acid (4 M in 1,4-dioxane, 0.2 mL, 0.8 mmol) was added, and the mixture was heated at 60 °C for 40 min under microwave irradiation. The reaction mixture was loaded onto a methanol-conditioned SCX-2 cartridge (10 g), washed with methanol, and eluted with 3.5 N methanolic ammonia. The solvent was removed in vacuo and the crude product was purified by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 15% 2.33 N methanolic ammonia in dichloromethane to afford the desired product as a colorless gum (115 mg, 0.48 mmol, 37%). The two crops were combined and used in the next steps.

LC/MS (C ₁₀ H ₁₅ N ₃ O ₂ S) 242 [M+H] ⁺ ; RT 0.34 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 8.84 (s, 1H), 8.57 (s, 1H), 7.83 (q, J = 4.8 Hz, 1H), 4.76 (p, J = 8.8 Hz, 1H), 4.32 - 4.17 (m, 4H), 3.95 (q, J = 8.0 Hz, 2H), 2.82 (d, J = 4.7 Hz, 3H), 1.28 (t, J = 7.1 Hz, 3H).

Step F: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-{1-[(tert-butoxy)carbonyl]azetidin-3-yl}-1,3-thiazole-4-carboxylate

To a solution of the product from Step E (298 mg, 1.23 mmol, 1 equiv) in dichloromethane (10 mL) were added di-tert-butyl dicarbonate (809 mg, 3.7 mmol, 3 equiv), 4-(dimethylamino)pyridine (45.3 mg, 0.37 mmol, 0.3 equiv), and triethylamine (0.51 mL, 3.7 mmol, 3 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0:40% ethyl acetate in isoheptane afforded the title product as a white foam (390 mg, 0.88 mmol, 72%).

LC/MS (C ₂₀ H ₃₁ H ₃ O ₆ S) 442 [M+H] ⁺ ; RT 1.47 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 4.53 (tt, J = 8.6, 5.8 Hz, 1H), 4.38 - 4.30 (m, 2H), 4.27 (q, 4H), 3.85 - 3.76 (m, 2H), 3.45 (s, 3H), 1.54 (s, 9H), 1.40 (s, 9H), 1.30 (t, J = 7.1 Hz, 3H).

Step G: Ethyl 5-{1-[(tert-butoxy)carbonyl]ethidin-3-yl}-2-(methylamino)-1,3-thiaol-4-carboxylate

A solution of the product from Step F (390 mg, 0.88 mmol, 1 equiv) in 1,1,1,3,3,3-hexafluoro-2-propanol (3 mL) was heated at 100 °C for 55 min under microwave irradiation. The mixture was concentrated in vacuo and purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 100% ethyl acetate in isoheptane to give the desired product as a white solid (199 mg, 0.58 mmol, 66%).

LC/MS (C ₁₅ H ₂₃ N ₃ O ₄ S) 342 [M+H] ⁺ ; RT 0.98 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.70 (q, J = 4.7 Hz, 1H), 4.49 (tt, J = 8.6, 5.9 Hz, 1H), 4.28 (t, J = 8.6 Hz, 2H), 4.21 (q, J = 7.1 Hz, 2H), 3.73 - 3.65 (m, 2H), 2.81 (d, J = 4.7 Hz, 3H), 1.39 (s, 9H), 1.26 (t, J = 7.1 Hz, 3H).

Synthesis of 3zc: Methyl 5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2,2-dimethylpropyl)-2-(methylamino)-1,3-thiazole-4-carboxylate

Step A: 4-methoxy-2,2-dimethyl-4-oxobutanoic acid

To a solution of 2,2-dimethylsuccinic acid (20 g, 137 mmol, 1 equiv.) in methanol (200 mL) cooled to 0 °C was added sulfuric acid (2 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was concentrated in vacuo, then quenched by portionwise addition of saturated aqueous sodium bicarbonate solution (200 mL), and washed with isoheptane (x2). The aqueous phase was cooled to 0 °C, acidified with 6 N aqueous hydrochloric acid, and extracted with diethyl ether (x2). The combined organic extracts were dried (magnesium sulfate) and concentrated in vacuo to give the title product as a clear oil (13.7 g, 85.4 mmol, 62%).

¹ H NMR (400 MHz, Chloroform-d) δ 3.67 (s, 3H), 2.62 (s, 2H), 1.30 (s, 6H).

Step B: Methyl 4-hydroxy-3,3-dimethylbutanoate

A solution of the product from Step A (13.7 g, 85.4 mmol, 1 equiv) in tetrahydrofuran (140 mL) was cooled to -30 °C, and borane dimethyl sulfide complex (13 g, 16.2 mL, 171 mmol, 2 equiv) was added dropwise. The mixture was stirred at -30 °C for 1.5 h, then warmed to 0 °C and stirred at this temperature for 45 min. The reaction mixture was quenched by the slow addition of methanol (50 mL), and then concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 220 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 50% ethyl acetate in isoheptane afforded the desired product as a clear oil (8.14 g, 55.7 mmol, 65%).

¹ H NMR (400 MHz, DMSO-d6) δ 4.65 (t, J = 5.4 Hz, 1H), 3.57 (s, 3H), 3.15 (d, J = 5.4 Hz, 2H), 2.19 (s, 2H), 0.89 (s, 6H).

Step C: Methyl 4-[(tert-butyldiphenylsilyl)oxy]-3,3-dimethylbutanoate

To a solution of the product from Step B (8.14 g, 55.7 mmol, 1 equiv) in dimethylformamide (200 mL) were added tert-butyl(chloro)diphenylsilane (17.4 mL, 66.8 mmol, 1.2 equiv) and imidazole (7.36 mL, 111 mmol, 2 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between heptane (500 mL) and a 2:1 mixture of water/saturated aqueous ammonium chloride solution (500 mL), and the aqueous phase was extracted with heptane (500 mL). The combined organic extracts were dried (magnesium sulfate) and purified by automated flash column chromatography (CombiFlash Rf, 330 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% ethyl acetate in isoheptane to give the title product as a clear oil (14.4 g, 37.4 mmol, 67%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.65 - 7.58 (m, 4H), 7.53 - 7.40 (m, 6H), 3.56 (s, 3H), 3.41 (s, 2H), 2.33 (s, 2H), 1.01 (s, 9H), 0.97 (s, 6H).

Step D: 4-[(tert-butyldiphenylsilyl)oxy]-3,3-dimethylbutan-1-ol

A solution of the product from Step C (14.4 g, 37.4 mmol, 1 equiv) in tetrahydrofuran (70 mL) was cooled to -78 °C and diisobutylaluminum hydride (1 M in tetrahydrofuran; 112 mL, 112 mmol, 3 equiv) was added and the mixture was stirred at -78 °C for 2 h. Saturated aqueous ammonium chloride was added and the mixture was stirred at -78 °C for 10 min and then allowed to warm to ambient temperature. The mixture was filtered through a pad of celite eluting with ethyl acetate, and the organics were dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 220 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 15% ethyl acetate in isoheptane afforded the desired product as a clear oil (12.5 g, 35 mmol, 94%).

LC/MS (C ₂₂ H ₃₂ O ₂ Si) 357 [M+H] ⁺ ; RT 2.68 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.65 - 7.56 (m, 4H), 7.53 - 7.40 (m, 6H), 4.28 (t, J = 5.0 Hz, 1H), 3.50 - 3.41 (m, 2H), 3.30 (s, 2H), 1.48 (dd, J = 8.1, 7.1 Hz, 2H), 1.02 (s, 9H), 0.88 (s, 6H).

Step E: 4-[(tert-butyldiphenylsilyl)oxy]-3,3-dimethylbutyl methanesulfonate

To a stirred solution of the product from Step D (12.5 g, 35 mmol, 1 equiv) in dichloromethane (200 mL) cooled to 0 °C were added triethylamine (7.31 mL, 52.5 mmol, 1.5 equiv) and methanesulfonyl chloride (3.25 mL, 42 mmol, 1.2 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane, washed with saturated aqueous sodium bicarbonate, dried (PTFE phase separator), and concentrated in vacuo to give the title product as a yellow oil (15.1 g, 34.8 mmol, 99%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.66 - 7.58 (m, 4H), 7.53 - 7.40 (m, 6H), 4.27 (t, J = 7.4 Hz, 2H), 3.33 (s, 2H), 3.15 (s, 3H), 1.74 (t, J = 7.4 Hz, 2H), 1.02 (s, 9H), 0.92 (s, 6H).

Stage F: (4-bromo-2,2-dimethylbutoxy)(tert-butyl)diphenylsilane

To a solution of the product from Step E (15.1 g, 34.8 mmol, 1 equiv.) in tetrahydrofuran (400 mL) was added lithium bromide (9.07 g, 105 mmol, 3 equiv.) portionwise and the mixture was stirred at 70 °C for 4 h and then allowed to cool to ambient temperature. The reaction mixture was concentrated in vacuo, then partitioned between dichloromethane and brine, and the organic phase was washed with 10% aqueous sodium thiosulfate, dried (PTFE phase separator), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 220 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 2% ethyl acetate in isoheptane afforded the desired product as a clear oil (12.8 g, 30.5 mmol, 88%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.65 - 7.55 (m, 4H), 7.53 - 7.40 (m, 6H), 3.52 - 3.42 (m, 2H), 3.34 (s, 2H), 1.96 - 1.86 (m, 2H), 1.03 (s, 9H), 0.88 (s, 6H).

Step G: Ethyl 6-[(tert-butyldiphenylsilyl)oxy]-5,5-dimethyl-2-oxohexanoate

Magnesium (496 mg, 20.4 mmol, 1.2 equiv) was charged to an oven-dried flask, and the solid was stirred vigorously under nitrogen for 20 min. A solution of the product from Step F (7.13 g, 17 mmol, 1 equiv) in tetrahydrofuran (12 mL) was sparged with nitrogen (10 min), and an aliquot of this solution was added to the magnesium (without stirring). The mixture was heated briefly to reflux (heat gun), and an iodine crystal was added. Stirring was started, and the remaining solution was added to the magnesium suspension at a rate sufficient to maintain gentle reflux. After complete addition, the mixture was heated to reflux for 2 h, then allowed to cool to ambient temperature. A stirred solution of diethyl oxalate (2.31 mL, 17 mmol, 1 equiv.) in tetrahydrofuran (6 mL) was sparged with nitrogen (10 min) and then cooled to -78 °C. The above Grignard reagent solution was added portionwise to the solution and the mixture was then allowed to gradually warm to ambient temperature over 2 h. The reaction mixture was partitioned between ethyl acetate and saturated aqueous ammonium chloride solution and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 220 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 8% ethyl acetate in isoheptane afforded the title product as a clear oil (3.06 g, 6.95 mmol, 41%).

¹ H NMR (400 MHz, Chloroform-d) δ 7.67 - 7.61 (m, 4H), 7.45 - 7.34 (m, 6H), 4.31 (q, J = 7.0 Hz, 2H), 3.31 (s, 2H), 2.80 - 2.71 (m, 2H), 1.67 - 1.58 (m, 2H), 1.36 (s, 3H), 1.05 (s, 9H), 0.88 (s, 6H).

Stage GH: Ethyl 3-bromo-6-[(tert-butyldiphenylsilyl)oxy]-5,5-dimethyl-2-oxohexanoate

To a stirred mixture of copper(II) bromide (3.1 g, 13.9 mmol, 2 equiv) in ethyl acetate (80 mL) was added a solution of the product from Step G (3.06 g, 6.94 mmol, 1 equiv) in chloroform (40 mL) portionwise, and the reaction mixture was heated at reflux for 16 h. The reaction mixture was allowed to cool to ambient temperature, then filtered through a pad of celite, eluted with dichloromethane, and evaporated. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% ethyl acetate in isoheptane afforded the desired product as a clear oil (2.62 g, 5.04 mmol, 72%).

LC/MS (C ₂₆ H ₃₅ BrO ₄ Si) 441 [M-Ph] ⁺ ; RT 1.36 (LCMS-V-B2)

¹ H NMR (400 MHz, Chloroform-d) δ 7.69 - 7.61 (m, 4H), 7.50 - 7.34 (m, 6H), 5.28 (dd, J = 8.4, 4.5 Hz, 1H), 4.36 (qd, J = 7.1, 1.4 Hz, 2H), 3.33 (d, J = 1.5 Hz, 2H), 2.56 (dd, J = 14.9, 8.5 Hz, 1H), 2.11 (dd, J = 14.9, 4.5 Hz, 1H), 1.38 (t, J = 7.1 Hz, 3H), 1.07 (s, 9H), 0.88 (d, J = 3.7 Hz, 6H).

Step H: Ethyl 5-{3-[(tert-butyldiphenylsilyl)oxy]-2,2-dimethylpropyl}-2-(methylamino)-1,3-thiazole-4-carboxylate

To a solution of the product from Step GH (2.62 g, 5.04 mmol, 1 equiv) in ethanol (35 mL) were added N-methylthiourea (455 mg, 5.04 mmol, 1 equiv) and triethylamine (1.4 mL, 10.1 mmol, 2 equiv), and the mixture was heated at 85 °C for 4 h and then allowed to cool to ambient temperature. The reaction mixture was partitioned between dichloromethane and brine, and the organic phase was dried (PTFE phase separator) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 50% ethyl acetate in isoheptane afforded the title product as a yellow solid (1.45 g, 2.84 mmol, 56%).

LC/MS (C ₂₈ H ₃₈ N ₂ O ₃ SiS) 511 [M+H] ⁺ ; RT 1.28 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-d6) δ 7.66 - 7.58 (m, 4H), 7.52 - 7.40 (m, 6H), 4.15 (q, J = 7.1 Hz, 2H), 3.37 (s, 2H), 3.08 (s, 2H), 2.77 (d, J = 4.8 Hz, 3H), 1.20 (t, 3H), 1.04 (s, 9H), 0.86 (s, 6H).

Step I: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-{3-[(tert-butyldiphenylsilyl)oxy]-2,2-dimethylpropyl}-1,3-thiazole-4-carboxylate

To a solution of the product from Step H (1 g, 1.96 mmol, 1 equiv) in tetrahydrofuran (20 mL) were added 4-(dimethylamino)pyridine (23.9 mg, 0.2 mmol, 0.1 equiv), triethylamine (0.82 mL, 5.87 mmol, 3 equiv), and di-tert-butyl dicarbonate (0.84 mL, 3.92 mmol, 2 equiv), and the mixture was stirred at ambient temperature for 3 h. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0:15% ethyl acetate in isoheptane afforded the title product as a yellow oil (1.19 g, 1.95 mmol, 100%).

LC/MS (C ₃₃ H ₄₆ N ₂ O ₅ Sis) 611 [M+H] ⁺ ; RT 1.48 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-d6) δ 7.68 - 7.60 (m, 4H), 7.52 - 7.39 (m, 6H), 4.22 (q, J = 7.1 Hz, 2H), 3.44 (s, 3H), 3.37 (s, 2H), 3.20 (s, 2H), 1.54 (s, 9H), 1.23 (t, 3H), 1.04 (s, 9H), 0.87 (s, 6H).

Step J: 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-(3-hydroxy-2,2-dimethylpropyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step I (600 mg, 0.98 mmol, 1 equiv) in tetrahydrofuran (12 mL) was added TBAF (1 M in tetrahydrofuran; 2.95 mL, 2.95 mmol, 3 equiv) and the mixture was stirred at ambient temperature for 2 h. The reaction mixture was partitioned between ethyl acetate and water and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 100% ethyl acetate in isoheptane afforded the title product as a white solid (178 mg, 0.52 mmol, 53%).

LC/MS (C ₁₅ H ₂₄ N ₂ O ₅ S) 345 [M+H] ⁺ ; RT 1.87 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 12.69 (br s, 1H), 4.72 (br s, 1H), 3.34 (s, 3H), 3.16 (s, 2H), 3.10 (s, 2H), 1.53 (s, 9H), 0.83 (s, 6H).

Step K: Methyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-(3-hydroxy-2,2-dimethylpropyl)-1,3-thiazol-4-carboxylate

To a solution of the product from Step J (178 mg, 0.52 mmol, 1 equiv) in 1:1 dichloromethane/methanol (4 mL) cooled to 0 °C was added (trimethylsilyl)diazomethane (2 M in hexanes; 0.31 mL, 0.62 mmol, 1.2 equiv) and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and water, and the organic phase was dried (PTFE phase separator) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 50% ethyl acetate in isoheptane afforded the title product as a white solid (119 mg, 0.33 mmol, 64%).

LC/MS (C ₁₆ H ₂₆ N ₂ O ₅ S) 359 [M+H] ⁺ ; RT 2.10 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 4.74 (t, J = 5.1 Hz, 1H), 3.78 (s, 3H), 3.43 (s, 3H), 3.16 (d, J = 5.2 Hz, 2H), 3.10 (s, 2H), 1.53 (s, 9H), 0.82 (s, 6H).

Step L: Methyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-[3-(2-fluoro-4-iodophenoxy)-2,2-dimethylpropyl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step K (119 mg, 0.33 mmol, 1 equiv) in toluene (2 mL) were added 2-fluoro-4-iodophenol (158 mg, 0.66 mmol, 2 equiv), triphenylphosphine (174 mg, 0.66 mmol, 2 equiv), and diisopropyl azodicarboxylate (131 μL, 0.66 mmol, 2 equiv), and the mixture was heated at 120 °C for 24 h. The reaction mixture was partitioned between dichloromethane and water, and the organic phase was dried (PTFE phase separator) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 20% ethyl acetate in isoheptane afforded the desired product as a clear gum (136 mg, 0.24 mmol, 71%).

LC/MS (C ₂₂ H ₂₈ FIN ₂ O ₅ S) 579 [M+H] ⁺ ; RT 2.76 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.60 (dd, J = 10.7, 2.1 Hz, 1H), 7.49 - 7.42 (m, 1H), 3.75 (s, 5H), 3.42 (s, 3H), 3.26 (s, 2H), 1.49 (s, 9H), 1.01 (s, 6H).

Step M: methyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2,2-dimethylpropyl)-1,3-thiazole-4-carboxylate

To a solution of the product from Step L (136 mg, 0.24 mmol, 1 equiv) in tetrahydrofuran (6 mL) were added 3-dimethylamino-1-propyne (38.1 μL, 0.35 mmol, 1.5 equiv), copper(I) iodide (4.48 mg, 0.02 mmol, 0.1 equiv), and N,N-diisopropylethylamine (81.9 μL, 0.47 mmol, 2 equiv). The mixture was sparged with nitrogen (10 min), then bis(triphenylphosphine)palladium(II) dichloride (16.5 mg, 0.02 mmol, 0.1 equiv) was added, and the mixture was heated at 70 °C overnight. The reaction mixture was partitioned between ethyl acetate and brine, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 4% methanol in dichloromethane afforded the title product as a brown gum (27 mg, 0.05 mmol, 22%).

LC/MS (C ₂₇ H ₃₆ FN ₃ O ₅ S) 534 [M+H] ⁺ ; RT 2.053 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.31 (dd, J = 11.9, 2.0 Hz, 1H), 7.25 - 7.18 (m, 1H), 7.13 (t, J = 8.7 Hz, 1H), 3.78 (s, 2H), 3.75 (s, 3H), 3.43 (s, 2H), 3.42 (s, 3H), 3.27 (s, 2H), 2.24 (s, 6H), (s, 9H), 1.02 (s, 6H).

Step N: Methyl 5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2,2-dimethylpropyl)-2-(methylamino)-1,3-thiazole-4-carboxylate

To a solution of the product from Step M (27 mg, 0.05 mmol, 1 equiv.) in dichloromethane (5 mL) was added trifluoroacetic acid (1 mL), and the mixture was stirred at ambient temperature for 2 h. The reaction mixture was diluted with dichloromethane, then cooled to 0 °C and neutralized by adding 2 N aqueous sodium hydroxide solution. The layers were separated and dried (PTFE phase separator), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 7% methanol in dichloromethane afforded the desired product as a brown solid (8 mg, 0.02 mmol, 37%).

LC/MS (C ₂₂ H ₂₈ FN ₃ OS) 434 [M+H] ⁺ ; RT 1.62 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.52 - 7.46 (m, 1H), 7.32 (dd, J = 11.8, 2.0 Hz, 1H), 7.24 - 7.19 (m, 1H), 7.13 (t, J = 8.7 Hz, 1H), 3.76 (s, 2H), 3.71 (s, 3H), 3.42 (s, 2H), 3.16 (s, 2H), 2.76 (d, J = 4.8 Hz, 3H), 2.23 (s, 6H), 1.00 (s, 6H).

Synthesis of 3zd: Methyl 5-{[1-({4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}methyl)cyclopropyl]methyl}-2-(methylamino)-1, 3-thiazole-4-carboxylate

Step A: 2-(1-{[(tert-butyldiphenylsilyl)oxy]methyl}cyclopropyl)acetonitrile

To a solution of 2-[1-(hydroxymethyl)cyclopropyl]acetonitrile (8 g, 72 mmol, 1 equiv) in dimethylformamide (200 mL) were added tert-butyl(chloro)diphenylsilane (22.5 mL, 86.4 mmol, 1.2 equiv) and imidazole (9.51 mL, 144 mmol, 2 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between isoheptane (600 mL) and a 2:1 mixture of water/saturated aqueous ammonium chloride solution (600 mL), and the aqueous phase was extracted with isoheptane (600 mL). The combined organic extracts were dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 330 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 6% ethyl acetate in isoheptane afforded the desired product as a clear oil (23 g, 65.7 mmol, 91%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.67 - 7.57 (m, 4H), 7.53 - 7.36 (m, 6H), 3.54 (s, 2H), 2.71 (s, 2H), 1.02 (s, 9H), 0.57 - 0.50 (m, 2H), 0.50 - 0.43 (m, 2H).

Step B: 2-(1-{[(tert-butyldiphenylsilyl)oxy]methyl}cyclopropyl)acetaldehyde

To a solution of the product from Step A (23 g, 65.7 mmol, 1 equiv) in dichloromethane (300 mL) cooled to 0 °C was added diisobutylaluminum hydride (1 M in hexanes; 72.3 mL, 72.3 mmol, 1.1 equiv) portionwise and the mixture was stirred at 0 °C for 1.5 h. The reaction mixture was quenched by the addition of water, then 2 N aqueous hydrochloric acid (100 mL) was added followed by saturated aqueous potassium sodium tartrate solution (500 mL). The mixture was extracted with dichloromethane (2 x 400 mL) and the combined organic extracts were dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 330 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% ethyl acetate in isoheptane afforded the desired product as a clear oil (19.6 g, 55.5 mmol, 85%).

LC/MS (C ₂₂ H ₂₈ O ₂ Si) 353 [M+H] ⁺ ; RT 1.19 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-d6) δ 9.77 (t, J = 2.5 Hz, 1H), 7.61 - 7.56 (m, 4H), 7.50 - 7.38 (m, 6H), 3.33 (s, 2H), 2.41 (d, J = 2.5 Hz, 2H), 0.97 (s, 9H), 0.57 - 0.50 (m, 2H), 0.47 - 0.40 (m, 2H).

Step C: 2-(1-{[(tert-butyldiphenylsilyl)oxy]methyl}cyclopropyl)ethan-1-ol

To a solution of the product from Step B (19.6 g, 55.5 mmol, 1 equiv.) in methanol (200 mL) cooled to 0 °C was added sodium borohydride (2.31 g, 61.1 mmol, 1.1 equiv.) portionwise, and the mixture was stirred at ambient temperature for 3 h. The reaction mixture was concentrated in vacuo, then partitioned between ethyl acetate and water, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo to give the desired product as a clear oil (18.8 g, 53 mmol, 96%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.66 - 7.57 (m, 4H), 7.52 - 7.37 (m, 6H), 4.32 (t, J = 5.1 Hz, 1H), 3.57 - 3.47 (m, 2H), 3.46 (s, 2H), 1.59 (t, J = 7.3 Hz, 2H), 1.00 (s, 9H), 0.35 - 0.26 (m, 4H).

Step D: 2-(1-{[(tert-butyldiphenylsilyl)oxy]methyl}cyclopropyl)ethyl methanesulfonate

To a solution of the product from Step C (18.8 g, 53 mmol, 1 equiv) in dichloromethane (300 mL) cooled to 0 °C were added triethylamine (22.1 mL, 159 mmol, 3 equiv) and methanesulfonyl chloride (4.92 mL, 63.6 mmol, 1.2 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was separated and dried (PTFE phase separator), and concentrated in vacuo to give the title product as a brown oil (23.3 g, 53 mmol, 100%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.67 - 7.56 (m, 4H), 7.53 - 7.37 (m, 6H), 4.31 (t, J = 7.1 Hz, 2H), 3.48 (s, 2H), 3.13 (s, 3H), 1.84 (t, J = 7.1 Hz, 2H), 1.01 (s, 9H), 0.49 - 0.38 (m, 2H), 0.36 - 0.29 (m, 2H).

Step E: {[1-(2-bromoethyl)cyclopropyl]methoxy}(tert-butyl)diphenylsilane

To a solution of the product from Step D (23.3 g, 53.9 mmol, 1 equiv) in tetrahydrofuran (600 mL) was added lithium bromide (14 g, 162 mmol, 3 equiv) and the mixture was heated at 70 °C for 5 h, then allowed to cool to ambient temperature and the solvent removed in vacuo. The residue was partitioned between dichloromethane and brine, and the organic phase was washed with 10% aqueous sodium thiosulfate, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 330 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 2% diethyl ether in isoheptane afforded the desired product as a clear oil (17.4 g, 41.6 mmol, 77%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.65 - 7.58 (m, 4H), 7.53 - 7.39 (m, 6H), 3.54 (dd, J = 8.6, 7.4 Hz, 2H), 3.47 (s, 2H), 1.98 (dd, J = 8.6, 7.3 Hz, 2H), 1.02 (s, 9H), 0.46 - 0.38 (m, 2H), 0.35 - 0.28 (m, 2H).

Step F: Ethyl 4-(1-{[(tert-butyldiphenylsilyl)oxy]methyl}cyclopropyl)-2-oxobutanoate

Magnesium (1.21 g, 49.9 mmol, 1.2 equiv) was charged to an oven-dried flask and the solid was stirred vigorously under nitrogen for 20 min. A solution of the product from Step E (17.4 g, 41.6 mmol, 1 equiv) in tetrahydrofuran (30 mL) was sparged with nitrogen (10 min), an aliquot of this solution was added to the magnesium (without stirring), the mixture was heated briefly to reflux, and an iodine crystal was added. Stirring was started and the remaining solution was added to the magnesium at a rate sufficient to maintain gentle reflux. After complete addition, the mixture was heated at reflux for 2 h and then allowed to cool to ambient temperature. A solution of diethyl oxalate (5.64 mL, 41.6 mmol, 1 equiv.) in tetrahydrofuran (15 mL) was sparged with nitrogen (10 min) and then cooled to -78 °C. The above Grignard reagent solution was added slowly and the mixture was then allowed to warm to ambient temperature over 2 h. The reaction mixture was partitioned between ethyl acetate and saturated aqueous ammonium chloride solution and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 330 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 8% ethyl acetate in isoheptane afforded the title product as a clear oil (10 g, 22.8 mmol, 55%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.65 - 7.57 (m, 4H), 7.53 - 7.36 (m, 6H), 4.19 (q, J = 24.7, 7.1 Hz, 2H), 3.45 (s, 2H), 2.89 - 2.80 (m, 2H), 1.67 - 1.59 (m, 2H), 1.33 -1.17 (m, 5H), 1.05 - 0.96 (s, 11H).

Step G: Ethyl 3-bromo-4-(1-{[(tert-butyldiphenylsilyl)oxy]methyl}cyclopropyl)-2-oxobutanoate

A solution of the product from Step F (10 g, 22.8 mmol, 1 equiv) in chloroform (125 mL) was added to copper(II) bromide (10.2 g, 45.6 mmol, 2 equiv) in ethyl acetate (250 mL), and the mixture was heated at 85 °C overnight. The reaction mixture was filtered through celite, eluted with dichloromethane, and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 220 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 8% ethyl acetate in isoheptane afforded the title product as a yellow oil (2.09 g, 4.04 mmol, 18%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.68 - 7.59 (m, 4H), 7.53 - 7.40 (m, 6H), 5.52 (dd, J = 8.9, 5.2 Hz, 1H), 4.28 (q, 2H) , 3.68 (d, 1H), 3.37 (s, 1H), 2.44 (dd, J = 15.2, 5.2 Hz, 1H), 2.02 - 1.88 (m, 1H), 1.26 (t, 3H), 1.03 (s, 9H), 0.62 - 0.53 (m, 1H ), 0.48 - 0.39 (m, 1H), 0.39 - 0.32 (m, 1H), 0.32 - 0.23 (m, 1H).

Step H: Ethyl 5-[(1-{[(tert-butyldiphenylsilyl)oxy]methyl}cyclopropyl)methyl]-2-(methylamino)-1,3-thiazole-4-carboxylate

To a solution of the product from Step G (2.09 g, 4.04 mmol, 1 equiv) in ethanol (30 mL) were added N-methylthiourea (364 mg, 4.04 mmol, 1 equiv) and triethylamine (1.12 mL, 8.08 mmol, 2 equiv), and the mixture was heated at 85 °C overnight. The reaction mixture was partitioned between dichloromethane and brine, and the organic phase was dried (PTFE phase separator) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 50% ethyl acetate in isoheptane afforded the title product as an orange solid (1.8 g, 3.53 mmol, 88%).

LC/MS (C ₂₈ H ₃₆ N ₂ O ₃ SiS) 509 [M+H] ⁺ ; RT 2.69 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.59 - 7.51 (m, 4H), 7.46 - 7.36 (m, 6H), 4.16 (q, J = 7.1 Hz, 2H), 3.44 (s, 2H), 3.22 (s, 2H), 2.79 (d, J = 4.8 Hz, 3H), 1.20 (t, 3H), 0.96 (s, 9H), 0.55 - 0.48 (m, 2H), 0.48 - 0.41 (m, 2H).

Step I: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-[(1-{[(tert-butyldiphenylsilyl)oxy]methyl}cyclopropyl)methyl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step H (1.8 g, 3.54 mmol, 1 equiv) in tetrahydrofuran (40 mL) were added 4-(dimethylamino)pyridine (43.2 mg, 0.35 mmol, 0.1 equiv), triethylamine (1.48 mL, 10.6 mmol, 3 equiv), and di-tert-butyl dicarbonate (1.51 mL, 7.08 mmol, 2 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0:15% ethyl acetate in isoheptane afforded the title product as a yellow oil (2.03 g, 3.33 mmol, 94%).

LC/MS (C ₃₃ H ₄₄ N ₂ O ₅ SiS) 609 [M+H] ⁺ ; RT 1.98 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.56 - 7.48 (m, 4H), 7.46 - 7.34 (m, 6H), 4.23 (q, J = 7.1 Hz, 2H), 3.48 - 3.42 (m, 5H) , 3.32 (s, 2H), 1.53 (s, 9H), 1.24 (t, 3H), 0.94 (s, 9H), 0.62 - 0.55 (m, 1H), 0.55 - 0.46 (m, 1H).

Step J: 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-{[1-(hydroxymethyl)cyclopropyl]methyl}-1,3-thiaeol-4-carboxylic acid

To a solution of the product from Step I (2.03 g, 3.33 mmol, 1 equiv) in tetrahydrofuran (35 mL) was added tetrabutylammonium fluoride (1 M in tetrahydrofuran; 10 mL, 10 mmol, 3 equiv) and the mixture was stirred at 70 °C for 2.5 h. The reaction mixture was partitioned between ethyl acetate and water and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the title product as a yellow solid (460 mg, 1.34 mmol, 40%).

LC/MS (C ₁₅ H ₂₂ N ₂ O ₅ S) 343 [M+H] ⁺ ; RT 1.77 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 4.54 (br s, 1H), 3.44 (s, 3H), 3.22 (s, 2H), 3.19 (s, 2H), 1.53 (s, 9H), 0.50 - 0.42 (m, 4H).

Step K: methyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-{[1-(hydroxymethyl)cyclopropyl]methyl}-1,3-thiazol-4-carboxylate

To a solution of the product from Step J (460 mg, 1.34 mmol, 1 equiv) in 1:1 dichloromethane/methanol (12 mL) cooled to 0 °C was added (trimethylsilyl)diazomethane (2 M in hexanes; 0.87 mL, 1.75 mmol, 1.3 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and water, and the organic phase was dried (PTFE phase separator) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 50% ethyl acetate in isoheptane afforded the title product as a white solid (418 mg, 1.17 mmol, 87%).

LC/MS (C ₁₆ H ₂₄ N ₂ O ₅ S) 357 [M+H] ⁺ ; RT 1.98 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 4.54 (t, J = 5.5 Hz, 1H), 3.78 (s, 3H), 3.44 (s, 3H), 3.22 (d, 2H), 3.20 (s, 2H), 1.53 (s, 9H), 0.51 - 0.44 (m, 4H).

Step L: methyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-({1-[(2-fluoro-4-iodophenoxy)methyl]cyclopropyl}methyl)-1,3-thiazol- 4-carboxylate

To a solution of the product from Step K (418 mg, 1.17 mmol, 1 equiv) in toluene (10 mL) were added 2-fluoro-4-iodophenol (558 mg, 2.35 mmol, 2 equiv), triphenylphosphine (615 mg, 2.35 mmol, 2 equiv), and diisopropyl azodicarboxylate (0.46 mL, 2.35 mmol, 2 equiv), and the mixture was heated at 120 °C overnight, then allowed to cool to ambient temperature. The reaction mixture was partitioned between dichloromethane and water, and the organic phase was separated, dried (PTFE phase separator), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 20% ethyl acetate in isoheptane afforded the desired product as a yellow oil (649 mg, 1.13 mmol, 96%).

LC/MS (C ₂₂ H ₂₆ FIN ₂ O ₅ S) 577 [M+H] ⁺ ; RT 2.65 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.56 (dd, J = 10.8, 2.1 Hz, 1H), 7.39 (dt, J = 8.6, 1.7 Hz, 1H), 6.84 (t, J = 8.8 Hz, 1H), 3.75 (s, 3H), 3.42 (s, 3H), 3.34 (s, 2H), 3.31 (s, 2H), 1.52 (s, 9H), 0.77 - 0.64 (m, 4H).

Step M: methyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-{[1-({4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}methyl)cyclopropyl]methyl}-1,3-thiazole-4-carboxylate

To a solution of the product from Step L (649 mg, 1.13 mmol, 1 equiv) in tetrahydrofuran (12 mL) were added 3-dimethylamino-1-propyne (182 µL, 1.69 mmol, 1.5 equiv), copper(I) iodide (21.4 mg, 0.11 mmol, 0.1 equiv), and N,N-diisopropylethylamine (392 µL, 2.25 mmol, 2 equiv). The mixture was sparged with nitrogen (10 min), then bis(triphenylphosphine)palladium(II) dichloride (79 mg, 0.11 mmol, 0.1 equiv) was added and the mixture was heated at 80 °C for 24 h. The reaction mixture was partitioned between ethyl acetate and brine, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 7% methanol in dichloromethane afforded the desired product as a brown solid (173 mg, 0.33 mmol, 29%).

LC/MS (C ₂₇ H ₃₄ FN ₃ O ₅ S) 532 [M+H] ⁺ ; RT 2.004 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.27 (dd, J = 11.9, 2.0 Hz, 1H), 7.18 - 7.10 (m, 1H), 6.99 (t, J = 8.7 Hz, 1H), 3.79 (s, 2H), 3.65 (s, 3H), 3.42 (s, 5H), 3.32 (s, 2H), 2.23 (s, 6H), 1.52 (s, 9H), 0.77 - 0.65 (m, 4H).

Step N: methyl 5-{[1-({4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}methyl)cyclopropyl]methyl}-2-(methylomino)-1, 3-thiazole-4-carboxylate

To a solution of the product from Step M (173 mg, 0.33 mmol, 1 equiv.) in dichloromethane (10 mL) was added trifluoroacetic acid (2 mL), and the mixture was stirred at ambient temperature for 2 h. The reaction mixture was diluted with dichloromethane, then cooled to 0 °C and neutralized by adding 2 N aqueous sodium hydroxide solution. The organic phase was separated and dried (PTFE phase separator), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 7% methanol in dichloromethane afforded the desired product as a yellow solid (84 mg, 0.19 mmol, 60%).

LC/MS (C ₂₂ H ₂₆ FN ₃ O ₃ S) 432 [M+H] ⁺ ; RT 1.55 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.51 (q, J = 4.7 Hz, 1H), 7.28 (dd, J = 11.9, 2.0 Hz, 1H), 7.19 - 7.12 (m, 1H), 7.01 (t, J = 8.7 Hz, 1H), 3.78 (s, 2H), 3.60 (s, 3H), 3.42 (s, 2H), 3.20 (s, 2H), 2.78 (d, J = 4.7 Hz, 3H), 2.23 (s, 6H), 0.69 - 0.60 (m, 4H).

Synthesis of 3ze: Ethyl 2-{[4-(tert-butoxy)-4-oxobutyl]amino}-1,3-thiazole-4-carboxylate

Step A: Ethyl 2-{[4-(tert-butoxy)-4-oxobutyl][(tert-butoxy)carbonyl]amino}-1,3-thiazole-4-carboxylate

To a solution of ethyl 2-[(tert-butoxycarbonyl)amino]-1,3-thiazole-4-carboxylate (5.2 g, 19.1 mmol, 1 equiv.) and tert-butyl 4-hydroxybutanoate (4.59 g, 28.6 mmol, 1.5 equiv.) in tetrahydrofuran (150 mL) was added triphenylphosphine (7.51 g, 28.6 mmol, 1.5 equiv.) followed by the dropwise addition of diisopropyl azodicarboxylate (5.64 mL, 28.6 mmol, 1.5 equiv.), and the mixture was stirred at ambient temperature for 1 h. The reaction mixture was partitioned between ethyl acetate and water, the aqueous phase was extracted with ethyl acetate (3 × 60 mL), and the combined organic extracts were washed with brine solution (100 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 120 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 20% ethyl acetate in isoheptane afforded the title product as a colorless oil (7.7 g, 18.6 mmol, 97%).

LC/MS (C ₁₉ H ₃₀ N ₂ O ₆ S) 415 [M+H] ⁺ ; RT 1.49 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 8.07 (s, 1H), 4.27 (q, J = 7.1 Hz, 2H), 4.12 - 4.02 (m, 2H), 2.26 (t, J = 7.2 Hz, 2H), 1.90 (p, J = 7.1 Hz, 2H), 1.54 (s, 9H), 1.37 (s, 9H), 1.30 (t, J = 7.1 Hz, 3H).

Step B: Ethyl 2-{[4-(tert-butoxy)-4-oxobutyl]amino}-1,3-thiazole-4-carboxylate

A solution of the product from Step A (7.7 g, 18.6 mmol, 1 equiv.) in 1,1,1,3,3,3-hexafluoro-2-propanol (40 mL) was heated in a sealed flask at 80 °C for 7 h. The reaction mixture was concentrated in vacuo and purified by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 35% ethyl acetate in isoheptane to give the desired product as a white solid (3.61 g, 11.5 mmol, 62%).

LC/MS (C ₁₄ H ₂₂ N ₂ O ₄ S) 315 [M+H] ⁺ ; RT 1.20 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.82 (t, J=5.4 Hz, 1H), 7.50 (s, 1H), 4.21 (q, J=7.1 Hz, 2H), 3.22 (td, J=7.0, 5.4 Hz, 2H), 2.29 (t, J=7.4 Hz, 2H), 1.76 (p, J=7.2 Hz, 2H), 1.40 (s, 9H), 1.26 (t, J=7.1 Hz, 3H).

Synthesis of 3zf: Ethyl 5-[(2S)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl]-2-(methylamino)-1,3-thiazole-4-carboxylate

Step A: [(2R)-3-bromo-2-methylpropoxy](tert-butyl)diphenylsilane

To a solution of (R)-(-)-3-bromo-2-methyl-1-propanol (5 g, 32.68 mmol, 1 equiv) in dimethylformamide (120 mL) were added imidazole (4.32 mL, 65.4 mmol, 2 equiv) and tert-butyl(chloro)diphenylsilane (11.1 mL, 42.5 mmol, 1.3 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between isoheptane (300 mL) and a 2:1 mixture of water/saturated aqueous ammonium chloride solution (200 mL), the aqueous phase was extracted with isoheptane (200 mL), and the combined organic extracts were dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 220 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 2% diethyl ether in isoheptane afforded the desired product as a clear oil (12.1 g, 30.9 mmol, 95%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.67-7.59 (m, 4H), 7.53-7.40 (m, 6H), 3.63 (d, 2H), 3.61-3.54 (m, 2H), 2.10-1.98 (m, 1H), 1.01 (s, 9H), 0.96 (d, 3H).

Step B: (3S)-4-[(tert-butyldiphenylsilyl)oxy]-3-methylbutanenitrile

To a solution of the product from Step A (12.1 g, 30.9 mmol, 1 equiv.) in dimethyl sulfoxide (120 mL) was added sodium cyanide (4.54 g, 92.7 mmol, 3 equiv.), and the mixture was heated at 120 °C for 5 h. The reaction mixture was partitioned between diethyl ether and water, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 220 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 3% ethyl acetate in isoheptane afforded the title product as a clear oil (7.17 g, 21.2 mmol, 69%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.67-7.57 (m, 4H), 7.55-7.40 (m, 6H), 3.62-3.46 (m, 2H), 2.68-2.53 (m, 2H), 2.12-1.96 (m, 1H), 1.02 (m, 9H), 0.98 (d, 3H).

Step C: (3S)-4-[(tert-butyldiphenylsilyl)oxy]-3-methylbutanal

To a solution of the product from Step B (7.17 g, 21.2 mmol, 1 equiv.) in dichloromethane (100 mL) cooled to 0 °C was added diisobutylaluminum hydride (23.4 mL, 23.4 mmol, 1.1 equiv.) and the mixture was stirred overnight. Water was added followed by 2 N aqueous hydrochloric acid (36 mL) and saturated aqueous potassium sodium tartrate (180 mL). The mixture was diluted with additional water and dichloromethane, and the organic phase was washed successively with water and brine, dried (PTFE phase separator), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 220 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 6% ethyl acetate in isoheptane afforded the desired product as a clear oil (6.21 g, 18.2 mmol, 86%).

^1H NMR (400 MHz, DMSO-d6) δ 9.70 (t, J=1.9 Hz, 1H), 7.66-7.57 (m, 4H), 7.53-7.40 (m, 6H), 3.56-3.42 (m, 2H) , 2.57-2.44 (m, 1H), 2.37-2.20 (m, 2H), 0.99 (s, 9H), 0.90 (d, J=6.0 Hz, 3H).

Step D: (3S)-4-[(tert-butyldiphenylsilyl)oxy]-3-methylbutan-1-ol

To a solution of the product from Step C (6.21 g, 18.24 mmol, 1 equiv) in methanol (80 mL) cooled in an ice/water bath was added sodium borohydride (759 mg, 20.1 mmol, 1.1 equiv), and the mixture was allowed to warm to ambient temperature and stirred for 3 h. The reaction mixture was concentrated in vacuo, then partitioned between ethyl acetate and water, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo to give the title product as a clear oil (6.36 g, 18.6 mmol, >100%).

^1H NMR (400 MHz, DMSO-d6) δ 7.66-7.56 (m, 4H), 7.52-7.39 (m, 6H), 4.35 (t, J=5.1 Hz, 1H), 3.56-3.34 (m, 4H) , 1.85-1.70 (m, 1H), 1.65 1.51 (m, 1H), 1.31-1.21 (m, 1H), 1.01 (s, 9H), 0.91 (d, J=6.7 Hz, 3H).

Step E: (3S)-4-[(tert-butyldiphenylsilyl)oxy]-3-methylbutyl methanesulfonate

To a cooled solution of the product from Step D (6.36 g, 18.6 mmol, 1 equiv) in dichloromethane (100 mL) were added triethylamine (7.75 mL, 55.7 mmol, 3 equiv) and methanesulfonyl chloride (1.72 mL, 22.3 mmol, 1.2 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was separated and dried (PTFE phase separator), and concentrated in vacuo to give the title product as a brown oil (8.28 g, 19.7 mmol, >100%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.66-7.58 (m, 4H), 7.53-7.40 (m, 6H), 4.25 (t, J=6.6 Hz, 2H), 3.56-3.46 (m, 2H), 3.15 (s, 3H), 1.95-1.76 (m, 2H), 1.59-1.46 (m, 1H), 1.01 (s, 9H), 0.93 (d, J=6.7 Hz, 3H).

Step F: [(2S)-4-bromo-2-methylbutoxy](tert-butyl)diphenylsilane

To a solution of the product from Step E (8.28 g, 19.7 mmol, 1 equiv) in tetrahydrofuran (180 mL) was added lithium bromide (5.13 g, 59.1 mmol, 3 equiv) and the mixture was heated at 70 °C for 5 h. The reaction mixture was concentrated in vacuo, the residue was partitioned between dichloromethane and brine, and the organic phase was separated and dried (PTFE phase separator) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 120 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 2% diethyl ether in isoheptane afforded the desired product as a clear oil (6.3 g, 15.5 mmol, 79%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.66-7.58 (m, 4H), 7.53-7.40 (m, 6H), 3.64-3.47 (m, 4H), 2.08-1.93 (m, 1H), 1.92- 1.79 (m, 1H), 1.74-1.60 (m, 1H), 1.01 (s, 9H), 0.90 (d, J=6.8 Hz, 3H).

Step G: Ethyl (5S)-6-[(tert-butyldiphenylsilyl)oxy]-5-methyl-2-oxohexanoate

An oven-dried flask was charged with magnesium (453 mg, 18.7 mmol, 1.2 equiv) under nitrogen and the solid was stirred vigorously for 20 min, and then the stirring was stopped. A solution of the product from Step F (6.3 g, 15.5 mmol, 1 equiv) in tetrahydrofuran (12 mL) was prepared and an aliquot was added to the magnesium followed by iodine (39.4 mg, 0.16 mmol, 0.01 equiv) and the mixture was heated briefly at reflux. The remaining solution was added at a rate that maintained gentle reflux, and upon complete addition the mixture was heated at reflux for 2 h and then allowed to cool to ambient temperature. To a stirred solution of diethyl oxalate (2.11 mL, 15.5 mmol, 1 equiv.) in tetrahydrofuran (6 mL) cooled to -78 °C was added the Grignard reagent solution via cannula and the mixture was allowed to warm to ambient temperature and stirred for 5 h. The reaction mixture was partitioned between ethyl acetate and saturated aqueous ammonium chloride solution and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0:8% ethyl acetate in isoheptane afforded the title product as a clear oil (4.13 g, 9.68 mmol, 62%).

¹ H NMR (400 MHz, DMSO-d6) δ 7.65-7.57 (m, 4H), 7.53-7.38 (m, 6H), 4.32-4.18 (m, 2H), 3.53-3.45 (m, 2H), 2.86-2.74 (m, 1H), 1.74-1.61 (m, 1H), 1.32-1.14 (m, 6H), 1.01 (s, 9H), 0.88 (d, 3H).

Step H: Ethyl (5S)-3-bromo-6-[(tert-butyldiphenylsilyl)oxy]-5-methyl-2-oxohexanoate

To a mixture of copper(II) bromide (4.14 g, 18.5 mmol, 2 equiv) in ethyl acetate (120 mL) was added a solution of the product from Step G (3.95 g, 9.26 mmol, 1 equiv) in chloroform (60 mL), and the mixture was heated at 85 °C overnight. The reaction mixture was filtered through celite, eluting with dichloromethane, then concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0-8% ethyl acetate in isoheptane afforded the title product as a yellow oil (1.92 g, 3.8 mmol, 41%), which was used directly in the next step without characterization.

Step I: Ethyl 5-[(2S)-3-[(tert-butyldiphenylsilyl)oxy]-2-methylpropyl]-2-(methylamino)-1,3-thiazole-4-carboxylate

To a solution of the product from Step H (1.67 g, 3.3 mmol, 1 equiv) in ethanol (30 mL) was added N-methylthiourea (298 mg, 3.3 mmol, 1 equiv) followed by triethylamine (0.92 mL, 6.61 mmol, 2 equiv) and the mixture was heated at 80 °C for 4 h. The reaction mixture was allowed to cool to ambient temperature and the solvent was removed by rotary evaporation. The crude material was partitioned between dichloromethane and water, the aqueous phase was extracted with dichloromethane and the combined organics were washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 50% ethyl acetate in isoheptane afforded the desired product as a brown gum (914 mg, 1.84 mmol, 56%).

LC/MS (C ₂₇ H ₃₆ N ₂ O ₃ SiS) 497 [M+H] ⁺ ; RT 1.46 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.64-7.56 (m, 4H), 7.55-7.36 (m, 6H), 4.16 (q, J=7.1 Hz, 2H), 3.60-3.47 (m, 2H), 3.08 (dd, J=14.4, 6.6 Hz, 1H), 2.92 (dd, J=14.4, 7.7 Hz, 1H), 2.78 (d, J=4.8 Hz, 3H), 1.96-1.84 (m, 1H), 1.21 (t, J=7.1 Hz, 3H), 1.01 (s, 9H), 0.92 (d, J=6.7 Hz, 3H).

Step J: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-[(2S)-3-[(tert-butyldiphenylsilyl)oxy]-2-methylpropyl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step I (914 mg, 1.84 mmol, 1 equiv) in tetrahydrofuran (20 mL) was added di-tert-butyl dicarbonate (803 mg, 3.68 mmol, 2 equiv), followed by triethylamine (0.77 mL, 5.52 mmol, 3 equiv) and 4-(dimethylamino)pyridine (22.5 mg, 0.18 mmol, 0.1 equiv), and the mixture was stirred at ambient temperature for 2 h. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0:20% ethyl acetate in isoheptane afforded the title product as a brown gum (961 mg, 1.61 mmol, 88%).

LC/MS (C ₃₂ H ₄₄ N ₂ O ₅ SiS) 597 [M+H] ⁺ ; RT 1.67 (LCMS-V-Bl)

¹ H NMR (400 MHz, DMSO-d6) δ 7.64-7.56 (m, 4H), 7.51-7.37 (m, 6H), 4.23 (q, J=7.1 Hz, 2H), 3.60-3.47 (m, 2H), 3.44 (s, 3H), 3.19 (dd, J=14.4, 6.8 Hz, 1H), 3.00 (dd, J=14.3, 7.5 Hz, 1H), 2.06-1.94 (m, 1H), 1.54 (s, 9H), 1.24 (t, J=7.1 Hz, 3H), 1.00 (s, 9H), 0.94 (d, J=6.7 Hz, 3H).

Step K: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-[(2S)-3-hydroxy-2-methylpropyl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step J (961 mg, 1.61 mmol, 1 equiv) in tetrahydrofuran (20 mL) was added tetrabutylammonium fluoride (1 M in tetrahydrofuran, 4.83 mL, 4.83 mmol, 3 equiv) and the mixture was heated at reflux for 1.5 h. The reaction mixture was allowed to cool to ambient temperature, then partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 80% ethyl acetate in isoheptane afforded the title product as a colourless gum (204 mg, 0.57 mmol, 35%).

LC/MS (C ₁₆ H ₂₆ N ₂ O ₅ S) 359 [M+H] ⁺ ; RT 1.07 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 4.59 (t, J=5.2 Hz, 1H), 4.26 (q, J=7.1 Hz, 2H), 3.43 (s, 3H), 3.37-3.22 (m, 2H), 3.12 (dd, J=14.3, 6.0 Hz, 1H), 2.91 (dd, J=14.3, 8.2 Hz, 1H), 1.89-1.75 (m, 1H), 1.53 (s, 9H), 1.29 (t, J=7.1 Hz, 3H), 0.85 (d, J=6.7 Hz, 3H).

Step L: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-[(2S)-3-(2-fluoro-4-iodophenoxy)-2-methylpropyl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step K (159 mg, 0.44 mmol, 1 equiv) in toluene (6 mL) was added 2-fluoro-4-iodophenol (211 mg, 0.89 mmol, 2 equiv), followed by triphenylphosphine (233 mg, 0.89 mmol, 2 equiv) and diisopropyl azodicarboxylate (0.17 mL, 0.89 mmol, 2 equiv), and the mixture was heated at 120 °C overnight. The reaction mixture was allowed to cool to ambient temperature and the solvent was removed by rotary evaporation. The resulting oil was partitioned between dichloromethane and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 20% ethyl acetate in isoheptane afforded the title product as a colourless gum (203 mg, 0.35 mmol, 79%).

LC/MS (C ₂₂ H ₂₈ FIN ₂ O ₅ S) 579 [M+H] ⁺ ; RT 1.46 (LCMS-V-Bl)

¹ H NMR (400 MHz, DMSO-d6) δ 7.59 (dd, J=10.8, 2.1 Hz, 1H), 7.48-7.42 (m, 1H), 6.97 (t, J=8.8 Hz, 1H), 4.24 (q, 2H), 3.99-3.87 (m, 2H), 3.43 (s, 3H), 3.24 (dd, J=14.2, 6.5 Hz, 1H), 3.08 (dd, J=14.3, 7.9 Hz, 1H), 2.33-2.20 (m, 1H), 1.51 (s, 9H), 1.27 (t, J=7.1 Hz, 3H), 1.01 (d, J=6.7 Hz, 3H).

Step M: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-[(2S)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step L (226 mg, 0.39 mmol, 1 equiv) in tetrahydrofuran (5 mL) were added 3-dimethylamino-1-propyne (0.08 mL, 0.78 mmol, 2 equiv), N,N-diisopropylethylamine (0.19 mL, 1.17 mmol, 3 equiv), and copper(I) iodide (7.44 mg, 0.04 mmol, 0.1 equiv), followed by tetrakis(triphenylphosphine)palladium(0) (45.2 mg, 0.04 mmol, 0.1 equiv), and the mixture was heated at reflux for 24 h. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuum. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 5% methanol in dichloromethane afforded the desired product as a brown gum (68 mg, 0.13 mmol, 33%).

LC/MS (C ₂₇ H ₃₆ FN ₃ O ₅ S) 534 [M+H] ⁺ ; RT 1.07 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.30 (dd, J=11.9, 2.0 Hz, 1H), 7.25-7.17 (m, 1H), 7.12 (t, J=8.7 Hz, 1H), 4.24 (q, 2H), 4.02-3.90 (m, 2H), 3.43 (s, 3H), 3.42 (s, 2H), 3.25 (dd, J=14.2, 6.5 Hz, 1H), 3.09 (dd, J=14.3, 8.0 Hz, 1H), 2.31-2.24 (m, 1H), 2.23 (s, 6H), 1.51 (s, 9H), 1.28 (t, J=7.1 Hz, 3H), 1.02 (d, J=6.7 Hz, 3H).

Step N: Ethyl 5-[(2S)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl]-2-(methylamino)-1,3-thiazole-4-carboxylate

To a solution of the product from Step M (68 mg, 0.13 mmol, 1 equiv) in dichloromethane (3 mL) was added trifluoroacetic acid (0.3 mL, 4.03 mmol, 31.6 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane, cooled in an ice bath, and quenched by addition of saturated aqueous sodium bicarbonate. The organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 7% methanol in dichloromethane afforded the desired product as a brown gum (40 mg, 0.09 mmol, 72%).

LC/MS (C ₂₂ H ₂₈ FN ₃ O ₃ S) 434 [M+H] ⁺ ; RT 0.82 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.52 (q, J=4.8 Hz, 1H), 7.30 (dd, J=11.9, 2.0 Hz, 1H), 7.25-7.17 (m, 1H), 7.12 (t, J=8.7 Hz, 1H), 4.19 (q, J=7.1 Hz, 2H), 4.00-3.88 (m, 2H), 3.42 (s, 2H), 3.13 (dd, J=14.5, 6.6 Hz, 1H), 3.02 (dd, J=14.4, 7.8 Hz, 1H), 2.78 (d, J=4.7 Hz, 3H), 2.23 (s, 6H), 2.21-2.12 (m, 1H), 1.25 (t, J=7.1 Hz, 3H), 1.01 (d, J=6.8 Hz, 3H).

Synthesis of 3zg: Ethyl 5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-(oxan-2-yloxy)propyl)-2-(methylamino)-1,3-thiazole-4-carboxylate

Step A: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-(prop-2-en-1-yl)-1,3-thiazole-4-carboxylate

Isopropylmagnesium chloride (2 M in tetrahydrofuran; 6 mL, 12 mmol, 1.2 equiv) was added dropwise to a solution of ethyl 5-bromo-2-[(tert-butoxycarbonyl)(methyl)amino]-1,3-thiazole-4-carboxylate (3.65 g, 9.99 mmol, 1 equiv) in dichloromethane (30 mL) at -78 °C and the mixture was stirred for 30 min. A solution of zinc chloride (1.9 M in 2-methyltetrahydrofuran; 8 mL, 15.2 mmol, 1.52 equiv) was added dropwise and the mixture was stirred for 60 min at -78 °C and then for 3 h at ambient temperature. The solution was cooled in ice water and copper(I) cyanide-lithium dichloride complex (1 M in tetrahydrofuran; 2 mL, 2 mmol, 0.2 equiv) and allyl bromide (2 mL, 23.11 mmol, 2.31 equiv) were added slowly. The mixture was stirred for 60 min at 0 °C and then at ambient temperature for 18 h. Dichloromethane (125 mL) was added and the mixture was washed successively with saturated aqueous ammonium chloride solution (75 mL), water (2 x 75 mL), and brine (75 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with a gradient of 0-10% ethyl acetate in isoheptane afforded the title product as a colorless gum (1.64 g, 5.02 mmol, 50%).

LC/MS (C ₁₅ H ₂₂ N ₂ O ₄ S) 327 [M+H] ⁺ ; RT 1.43 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 6.04-5.90 (m, 1H), 5.20-5.06 (m, 2H), 4.37 (q, J=7.1 Hz, 2H), 3.86 (dt, J=6.6, 1.4 Hz, 2H), 3.55 (s, 3H), 1.56 (s, 9H), 1.39 (t, J=7.1 Hz, 3H).

Step B: Ethyl 5-(3-bromo-2-hydroxypropyl)-2-{[(tert-butoxy)carbonyl](methyl)amino}-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (1.29 g, 3.95 mmol, 1 equiv) in acetone (16 mL) cooled in ice-water were added N-bromosuccinimide (774 mg, 4.35 mmol, 1.1 equiv), ammonium acetate (30.5 mg, 0.4 mmol, 0.1 equiv), and water (4 mL), and the resulting solution was stirred for 45 min at ambient temperature. Ethyl acetate (150 mL) was added, and the mixture was washed successively with water (2 x 75 mL) and brine (75 mL), dried (magnesium sulfate), and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with a gradient of 0-25% ethyl acetate in isoheptane afforded the title product as a colorless gum (960 mg, 2.27 mmol, 57%).

LC/MS (C ₁₅ H ₂₃ BrN ₂ O ₅ S) 425 [M+H] ⁺ ; RT 1.29 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 5.59 (d, J=5.4 Hz, 1H), 4.27 (q, 2H), 3.95-3.80 (m, 1H), 3.54-3.45 (m, 3H), 3.44 (s, 3H), 3.08 (dd, J=14.7, 8.3 Hz, 1H), 1.53 (s, 9H), 1.30 (t, J=7.1 Hz, 3H).

Step C: Ethyl 5-[3-bromo-2-(oxan-2-yloxy)propyl]-2-{[(tert-butoxy)carbonyl](methyl)amino}-1,3-thiazole-4-carboxylate

To a solution of the product from Step B (1.15 g, 2.72 mmol, 1 equiv) in dichloromethane (30 mL) cooled to 0 °C was added 3,4-dihydro-2H-pyran (1 mL, 11 mmol, 4 equiv) followed by pyridinium p-toluenesulfonate (75 mg, 0.3 mmol, 0.11 equiv) and the mixture was stirred for 30 min at 0 °C and then for 5 h at ambient temperature. Dichloromethane (30 mL) was added and the mixture was washed successively with water (2 x 25 mL) and brine (25 mL), dried (magnesium sulfate) and concentrated in vacuo to give the title product as a yellow gum (1.52 g, 2.7 mmol, 99%), which was used directly in the next step without further characterization.

Step D: Ethyl 5-[3-(4-bromo-2-fluorophenoxy)-2-(oxan-2-yloxy)propyl]-2-{[(tert-butoxy)carbonyl](methyl)amino}-1,3-thiazole-4-carboxylate

4-Bromo-2-fluorophenol (0.4 mL, 3.65 mmol, 1.35 equiv) was added to a suspension of potassium tert-butoxide (400 mg, 3.56 mmol, 1.32 equiv) in dimethyl sulfoxide (5 mL) and the mixture was stirred. A solution of the product from Step C (1.52 g, 2.7 mmol, 1 equiv) in dimethyl sulfoxide (10 mL) was added and the mixture was stirred for 60 min at ambient temperature and then at 60 °C for 3 h. The reaction mixture was allowed to cool to ambient temperature and partitioned between ethyl acetate (150 mL) and water (75 mL) and the organic phase was washed successively with water (2 x 75 mL) and brine (75 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with a gradient of 0-25% ethyl acetate in isoheptane gave the title product as a pale yellow gum (1.05 g, 1.7 mmol, 63%).

LC/MS (C ₂₆ H ₃₄ BrFN ₂ O ₇ S) 617 [M+H] ⁺ ; RT 1.61 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.54 (dd, J=10.8, 2.4, 0.8 Hz, 1H), 7.35-7.28 (m, 1H), 7.12 (td, J=9.0, 1.1 Hz, 1H) , 4.25 (q, 3H), 4.19-4.08 (m, 2H), 3.56-3.37 (m, 7H), 1.77-1.55 (m, 4H), 1.52 (d, J=2.2 Hz, 9H), 1.49-1.38 (m, 4H), 1.27 ( t, J=7.1 Hz, 3H).

Step E: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-(oxan-2-yloxy)propyl)-1,3-thiazole-4-carboxylate

To a solution of the product from Step D (1.05 g, 1.7 mmol, 1 equiv.) in dimethylformamide (10 mL) were added dimethyl(prop-2-yn-1-yl)amine (0.25 mL, 2.32 mmol, 1.37 equiv.), copper(I) iodide (32.4 mg, 0.17 mmol, 0.1 equiv.), and bis(triphenylphosphine)palladium(II) dichloride (119 mg, 0.17 mmol, 0.1 equiv.). N,N-Diisopropylethylamine (0.9 mL, 5.1 mmol, 3 equiv) was added and the mixture was heated at 75 °C for 24 h. The reaction mixture was allowed to cool to ambient temperature and partitioned between ethyl acetate (150 mL) and water (75 mL), and the organic phase was washed successively with water (75 mL) and brine (75 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with a gradient of 0-100% ethyl acetate in isoheptane gave the title product as a brown gum (395 mg, 0.64 mmol, 38%).

LC/MS (C ₃₁ H ₄₂ FN ₃ O ₇ S) 620 [M+H] ⁺ ; RT 1.31 (LCMS-V-B1)

Step F: Ethyl 5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-(oxan-2-yloxy)propyl)-2-(methylamino )-1,3-thiazole-4-carboxylate

A solution of the product from Step E (390 mg, 0.63 mmol, 1 equiv) in 1,1,1,3,3,3-hexafluoropropan-2-ol (7 mL) was heated in a sealed tube at 100 °C for 60 min, then allowed to cool to ambient temperature and concentrated in vacuo. Purification by flash column chromatography (20 g silica gel) eluting with a gradient of 0-2.5% methanol in dichloromethane afforded the title product as a brown gum (170 mg, 0.33 mmol, 52%).

LC/MS (C ₂₆ H ₃₄ FN ₃ O ₅ S) 520 [M+H] ⁺ ; RT 1.05 (LCMS-V-B1)

Synthesis 3zh: Ethyl 5-(2-methoxy-3-{[tris(propan-2-yl)silyl]oxy}propyl)-2-(methylamino)-1,3-thiazole-4-carboxylate

Step A: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-(2,3-dihydroxypropyl)-1,3-thiazole-4-carboxylate

To a solution of the product of Preparation 3zg, Step A (8.39 g, 25.7 mmol, 1 equiv) in 9:1 acetone/water (250 mL) was added 4-methylmorpholine-N-oxide (4.75 g, 40.6 mmol, 1.58 equiv) followed by osmium tetroxide (3.5 mL, 0.28 mmol, 0.01 equiv) and the resulting mixture was stirred for 18 h at ambient temperature. Water (300 mL) was added and the mixture was extracted with ethyl acetate (4×200 mL) and the combined organics were washed with brine (150 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a brown gum (8.66 g, 24 mmol, 94%).

LC/MS (C ₁₅ H ₂₄ N ₂ O ₆ S) 361 [M+H] ⁺ ; RT 1.07 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 4.95 (d, J=5.4 Hz, 1H), 4.66 (t, J=5.6 Hz, 1H), 4.26 (q, J=7.1 Hz, 2H), 3.69-3.58 (m, 1H), 3.49-3.40 (m, 1H), 3.38-3.26 (m, 2H), 2.89 (dd, J=14.9, 8.7 Hz, 1H), 1.53 (s, 9H), 1.29 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-(2-hydroxy-3-{[tris(propan-2-yl)silyl]oxy}propyl)-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (8.65 g, 24 mmol, 1 equiv) in dichloromethane (100 mL) cooled in ice-water was added imidazole (3.5 g, 51.4 mmol, 2.14 equiv) followed by the dropwise addition of triisopropylsilyl chloride (6 mL, 28 mmol, 1.17 equiv) and the mixture was stirred for 60 min at 0 °C and then for 18 h at ambient temperature. The reaction mixture was concentrated in vacuo and purified by flash column chromatography (100 g silica gel) eluting with a gradient of 0-25% ethyl acetate in isoheptane to give the title product as a colorless oil (12.2 g, 23.5 mmol, 98%).

LC/MS (C ₂₄ H ₄₄ N ₂ O ₆ SiS) 517 [M+H] ⁺ ; RT 1.69 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 5.07 (d, J=5.2 Hz, 1H), 4.24 (q, J=7.1 Hz, 2H), 3.75-3.61 (m, 2H), 3.55-3.48 (m, 2H), 3.42 (s, 3H), 2.98 (dd, J=15.0, 8.3 Hz, 1H), 1.53 (s, 9H), 1.28 (t, J=7.1 Hz, 3H), 1.09-0.97 (m, 21H).

Step C: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-(2-methoxy-3-{[tris(propan-2-yl)silyl]oxy}propyl)-1,3-thiazole-4-carboxylate

Trimethyloxonium tetrafluoroborate (1.5 g, 10.1 mmol, 2.02 equiv) was added to a cooled solution of the product from Step B (2.6 g, 5.03 mmol, 1 equiv) and N,N,N',N'-tetramethylnaphthalene-1,8-diamine (2.2 g, 10.3 mmol, 2.04 equiv) in dichloromethane (75 mL), and the mixture was stirred at 0 °C for 60 min and then for 24 h at ambient temperature. The mixture was diluted with dichloromethane (75 mL) and washed successively with 1 M aqueous copper(II) sulfate (2 x 75 mL), water (75 mL), and brine (75 mL), dried (magnesium sulfate), and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with a gradient of 0-5% ethyl acetate in isoheptane afforded the title product as a colorless gum (2.54 g, 4.79 mmol, 95%).

LC/MS (C ₂₅ H ₄₆ N ₂ O ₆ SiS) 531 [M+H] ⁺ ; RT 1.80 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 4.37 (q, J=7.1 Hz, 2H), 3.75 (dd, J=5.0, 2.6 Hz, 2H), 3.55 (s, 3H), 3.52-3.44 (m, 2H), 3.41 (s, 3H), 3.26-3.14 (m, 1H), 1.39 (t, J=7.1 Hz, 3H), 1.09-1.01 (m, 21H).

Step D: Ethyl 5-(2-methoxy-3-{[tris(propan-2-yl)silyl]oxy}propyl)-2-(methylamino)-1,3-thiazole-4-carboxylate

A solution of the product from Step C (2.54 g, 4.79 mmol, 1 equiv.) in 1,1,1,3,3,3-hexafluoropropan-2-ol (20 mL) was heated in a sealed tube at 100 °C for 5 h. The solution was allowed to cool to ambient temperature, concentrated in vacuo, and dried in vacuo to give the desired product as a white solid (1.75 g, 4.06 mmol, 85%).

¹ H NMR (400 MHz, DMSO-d6) δ 5.44 (q, J=5.1 Hz, 1H), 4.35 (q, J=7.1 Hz, 2H), 3.79-3.69 (m, 2H), 3.52 (dd, J=15.0, 4.1 Hz, 1H), 3.48-3.39 (m, 4H), 3.13 (dd, J=15.0, 7.8 Hz, 1H), 2.95 (d, J=5.0 Hz, 3H), 1.37 (t, J=7.1 Hz, 3H), 1.09-1.01 (m, 21H).

Synthesis 4a: N-(6-Chloro-4-methylpyridazin-3-yl)-3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-imine

Step A: N-(6-chloro-4-methylpyridazin-3-yl)-1,3-benzothiazol-2-amine

A 2 L oven-dried, single-neck, round-bottomed flask was fitted with a PTFE-coated magnetic stir bar and a reflux condenser. The flask was charged with 34.0 g 6-chloro-4-methylpyridazin-3-amine (237 mmol, 1 equiv), 34 mL 2-chloro-1,3-benzothiazole (44.2 g, 260 mmol, 1.1 equiv), 124 mL DIPEA (91.8 g, 710 mmol, 3 equiv), and 137 g _Cs2CO3 (710 mmol, 3 equiv), then 1 L DMF was added and the system was purged _with argon. After 5 min of stirring under inert atmosphere, 2.01 g of _Pd2 (dba) ₃ (5.9 mmol, 0.025 equiv) and 6.85 g of XantPhos (11.8 mmol, 0.05 equiv) were added. The resulting mixture was then heated to 75 °C and stirred at this temperature for 4 h until complete conversion was achieved. The reaction mixture was allowed to cool to rt and then poured into 3 L of water with vigorous stirring. After 30 min, the precipitated product was removed by filtration and then washed twice with water (2 x 2 L). The product was dried overnight under high vacuum. The dry crude product was stirred in 1 L of heptane: _Et2O (3:2) for 30 min and then filtered to give 64.5 g (98%) of the desired product as a green powder.

¹ H NMR (500 MHz, DMSO-d6) δ ppm 11.96 (brs, 1H), 7.86 (d, 1H), 7.65 (s, 1H), 7.51 (d, 1H), 7.38 (t, 1H), 7.21 (t, 1H), 2.37 (s, 3H); ¹³ C NMR (125 MHz, DMSO-d6) δ ppm 130.3, 129.5, 126.6, 122.8, 122.3, 17.2; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₁₂ H ₁₀ ClN ₄ S: 277.0309, found: 277.0305.

Step B: N-(6-chloro-4-methylpyridazin-3-yl)-3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-imine

A 2 L oven-dried, single-necked, round-bottomed flask fitted with a PTFE-lined magnetic stir bar was charged with 64.5 g of the product from Step A (236 mmol, 1 equiv), 123 mL of DIPEA (9.16 g, 708 mmol, 3 equiv), and 14.43 g of N,N-dimethylpyridin-4-amine (11.81 mmol, 0.05 equiv) in 1 L of dry DCM and cooled to 0 °C under N ₂ . With vigorous mechanical stirring, 46.00 mL of 2-(chloromethoxy)ethyltrimethylsilane (43.32 g, 259 mmol, 1.1 equiv) was added dropwise to the mixture over a period of 5 min. The mixture was stirred at 0°C for 30 min, during which time the reaction reached complete conversion. 24.5 mL of water was added to the reaction mixture, then celite was added and the volatiles were removed under reduced pressure. The crude product was purified by flash column chromatography using heptane and EtOAc as eluents to afford 46.62 g (48%) of the desired product.

¹ H NMR (500 MHz, DMSO-d6) δ ppm 7.85 (dm, 1H), 7.72 (q, 1H), 7.53 (dm, 1H), 7.47 (m, 1H), 7.29 (m, 1H), 5.89 (s, 2H), 3.70 (m, 2H), 2.39 (d, 3H), 0.90 (m, 2H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d6) δ ppm. 159.5, 158.5, 150.0, 138.1, 137.4, 129.5, 127.4, 125.5, 123.8, 123.2, 112.4, 73.0, 66.8, 17.7, 17.1, -1.0; HR-MS (m/z): [M+H] ⁺ , calculated for C ₁₈ H ₂₄ ClN ₄ OSSi: 407.1123, found: 407.1120.

Synthesis of 4b: (2Z)-N-(6-Chloropyridazin-3-yl)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-imine

N,N-Diisopropylethylamine (3 mL, 16.6 mmol, 3 equiv) was added to a suspension of the product of Preparation 9b (1.45 g, 5.52 mmol, 1 equiv) in dichloromethane (75 mL) at 0 °C under nitrogen atmosphere. [2-(chloromethoxy)ethyl]trimethylsilane (1.2 mL, 6.78 mmol, 1.23 equiv) and 4-dimethylaminopyridine (33.7 mg, 0.28 mmol, 0.05 equiv) were added and the mixture was stirred at room temperature for 3 h. Dichloromethane (75 mL) was added and the mixture was washed with water (2×75 mL) and brine (75 mL). The solution was dried (magnesium sulfate) and concentrated in vacuo. Trituration with methanol (20 mL) gave a solid which was filtered, washed with methanol (2×10 mL) and dried in vacuo to give the title product as a pale brown solid (1.85 g, 4.71 mmol, 85%).

LC/MS (C ₁₇ H ₂₁ ClN ₄ OSiS) 393 [M+H] ⁺ ; RT 1.56 (LCMS-V-B1).

Synthesis 5a: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[4-[tert-butyl(diphenyl)silyl]oxy -5-(n-tolylsulfone yloxy)pentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4- carboxylate

Stage A: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[5-[tert-butyl(dimethyl)silyl]oxy -4-[tert-butyl(biphenyl silyl]oxypentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4- carboxylate

Using General Procedure II for the Buchwald reaction, starting from 12 g of Preparation 3a (13 mmol) and 6.30 g of Preparation 4a (15.6 mmol) as the appropriate halide, 14 g (83%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d6) δ ppm 7.85-7.23 (m, 14H), 7.58 (s, 1H), 7.31 (t, 1H), 7.19 (m, 1H), 7.14 (t, 1H), 5.86 (s, 2H), 4.37 (t, 2H) , 4.20 (s, 2H), 4.15 (t, 2H), 3.73 (s, 3H), 3.71 (t, 2H), 3.67 (m, 1H), 3.39 (m, 2H), 3.27 (t, 2H), 2.83 (s, 3H), 2.41 (s, 3H), 2.12 (m, 2H), 1.72 (m, 2H), 1.52 (m, 2H), 1.40 (s, 9H), 0.90 (t, 2H), 0.89 (s, 9H), 0.69 (s, 9H), -0.14 (s, 9H), -0.19/-0.23 (s+s, 6H); ¹³ C NMR (125 MHz, DMSO-d6) δ ppm 147.5, 129.1, 119.3, 117.5, 115.4, 73.4, 72.3, 68.4, 66.8, 65.8, 51.8, 46.6, 38.5, 33.8, 31.0, 30.5, 28.5, 27.1, 26.1, 23.0, 22.6, 17.9, 17.8, -1.0, - 5.3; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₆₈ H ₉₃ FN ₇ O ₈ S ₂ Si ₃ : 1302.5813, found: 1302.5819.

Stage B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[4-[tert-butyl(diphenyl)silyl]oxy -5-hydroxy pentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

A 100 mL oven-dried single-neck round-bottom flask was fitted with a PTFE-lined magnetic stir bar and a reflux condenser. The flask was charged with 1.40 g of the product from Step A (1.1 mmol, 1 equiv.) and 12 mg of camphorsulfonic acid (0.054 mmol, 0.05 equiv.), 5 mL of DCM, and 1 mL of MeOH. The resulting mixture was stirred overnight at rt until complete conversion was achieved. The reaction mixture was directly concentrated onto Celite and then purified by flash column chromatography using heptane and EtOAc as eluents to afford 700 mg (55%) of the desired product as a yellow solid.

¹ H NMR (500 MHz, DMSO-d6) δ ppm 7.85-7.14 (m, 14H), 7.56 (s, 1H), 7.32 (dd, 1H), 7.20 (m, 1H), 7.15 (t, 1H), 5.86 (s, 2H), 4.56 (t, 1H) , 4.33 (m, 2H), 4.20 (s, 2H), 4.15 (t, 2H), 3.74 (s, 3H), 3.72 (t, 2H), 3.65 (m, 1H), 3.27 (t, 2H), 3.27 (t, 2H), 2.83 (s, 3H), 2.41 (s, 3H), 2.13 (m, 2H), 1.73/1.64 (m+m, 2H), 1.52 (m, 2H), 1.40 (s, 9H), 0.90 (t, 2H), 0.86 (s, 9H), -0.13 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d6) δ m. d. 154.9, 147.6, 129.1, 119.4, 117.5, 115.4, 82.4, 73.7, 72.9, 68.4, 66.8, 64.5, 51.9, 46.8, 38.5, 33.8, 31.0, 30.6, 28.5, 27.2, 23.1, 22.5, 17.9, 17.8, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₆₂ H ₇₉ FN ₇ O ₈ S ₂ Si ₂ : 1188.4949, found: 1188.4938.

Stage C: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[4-[tert-butyl(diphenyl)silyl]oxy -5-(n-tolyl sulfone yloxy)pentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4- carboxylate

A 100 mL oven-dried single-neck round-bottom flask was fitted with a PTFE-coated magnetic stir bar, 700 mg of the product from Step B (0.58 mmol, 1 equiv) and 907 mg of N,N-dimethyl-1-(p-tolylsulfonyl)pyridin-1-ium-4-amine chloride (2.9 mmol, 5 equiv, Tetrahedron Lett. 2016, 57, 4620) were dissolved in 35 mL of DCM and the solution was stirred overnight at rt. The reaction reached complete conversion. The reaction mixture was concentrated directly onto Celite and then purified by flash column chromatography using heptane and EtOAc as eluents to give 450 mg (56%) of the desired product.

¹ H NMR (500 MHz, DMSO-d6) δ ppm 7.88-7.23 (m, 14H), 7.58 (m, 2H), 7.53 (s, 1H), 7.31 (m, 2H), 7.31 (dd, 1H), 7.19 (m, 1H), 7.15 (t, 1H) , 5.86 (s, 2Н), 4.20 (s, 2Н), 4.16 (t, 2H), 4.15 (t, 2H), 3.92 (m, 2H), 3.84 (m, 1H), 3.72 (t, 2H), 3.70 (s, 3H), 3.27 (t, 2H), 2.83 (s, 3H), 2.41 (s, 3H), 2.33 (s, 3H), 2.13 (m, 2H), 1.47 (m, 2H), 1.47 (m, 2H), 1.40 (s, 9H), 0.91 (t, 2H), 0.86 (s, 9H), -0.13 (s, 9H); ¹³ C NMR ( 125 MHz, DMSO-d6) δ ppm 147.5, 145.3, 130.4, 129.1, 128.0, 119.3, 117.4, 115.5, 72.9, 72.6, 70.4, 68.4, 66.8, 51.8, 46.2, 38.6, 33.8, 31.0, 30.1, 28.5, 27.0, 23.1, 22.4, 21.5, 17.8, 17.8, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₆₉ H ₈₅ FN ₇ O ₁₀ S ₃ S ₁₂ : 1342.5037, found: 1342.5039.

Synthesis 5b: Methyl 2-[[4-[tert-butyl(diphenyl)silyl]oxy-5-(n-tolylsulfonyloxy)pentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1, 3-ben Zothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4-carboxylate

Stage A: methyl 2-[[5-[tert-butyl(dimethyl)silyl]oxy-4-[tert-butyl(diphenyl)silyl]oxypentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl )-1.3 -benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 6.0 g of Preparation 3b (7.1 mmol, 1 equiv) and 3.46 g of Preparation 4a (8.51 mmol, 1.2 equiv) as the appropriate halide, 7.0 g (81%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d6) δ ppm 7.84-7.25 (m, 4H), 7.60-7.11 (m, 10H), 7.58 (s, 1H), 7.29 (t, 1H), 7.19 (dd, 1H), 7.14 (m, 1H), 5.86 (s, 2H), 4.37 (t, 2H), 4.15 (t, 2H), 3.74 (s, 3H), 3.71 (t, 2H), 3.67 (m, 1H), 3.39 (d, 2H), 3.38 (s, 2H), 3.27 (t, 2H), 2.41 (s, 3H ), 2.19 (s, 6Н), 2.13 (m, 2Н), 1.73 (m, 2H), 1.51 (m, 2H), 0.91 (t, 2H), 0.89 (s, 9H), 0.69 (s, 9H), -0.13 (s, 9H), -0.19/-0.23 (s+s, 6H); ¹³ C NMR (125 MHz, DMSO-d6) δ ppm 135.9-111.3, 127.2-112.0, 128.9, 119.2, 117.6, 115.5, 73.4, 72.9, 68.4, 66.8, 65.9, 51.9, 48.1, 46.6, 44.2, 31.0, 30.9, 27.3, 26.0, 23.1, 22.6, 17.9, 17.8, -1.0, -5.3; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₆₄ H ₈₇ FN ₇ O ₆ S ₂ Si ₃ : 1216.5446, found: 1216.5425.

Stage B: methyl 2-[[4-[tert-butyl(diphenyl)silyl]oxy-5-hydroxypentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazo l-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4-carboxylate

A 100 mL oven-dried single-neck round-bottom flask was fitted with a PTFE-lined magnetic stir bar and a reflux condenser. The flask was charged with 7.0 g of the product from Step A (5.75 mmol, 1 equiv) and 1.60 g of camphorsulfonic acid (6.90 mmol, 1.2 equiv) dissolved in 25 mL of DCM and 5 mL of MeOH. The resulting mixture was stirred overnight at rt until complete conversion was achieved. The reaction mixture was concentrated directly onto Celite and purified by flash column chromatography using DCM and MeOH (1.2% NH ₃ ) as eluents to afford 3.0 g (47%) of the desired product as a yellow solid.

Stage C: methyl 2-[[4-[tert-butyl(diphenyl)silyl]oxy-5-(n-tolylsulfonyloxy)pentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1, 3-ben Zothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4-carboxylate

A 100 mL oven-dried single-neck round-bottom flask was fitted with a PTFE-lined magnetic stir bar and charged with 3.80 g of the product from Step B (3.40 mmol, 1 equiv), 5.40 g of N,N-dimethyl-1-(p-tolylsulfonyl)pyridin-1-ium-4-amine chloride (17.0 mmol, 5 equiv, Tetrahedron Lett. 2016, 57, 4620) and 20 mL of DCM, and then stirred overnight at rt. The reaction reached complete conversion. The reaction mixture was directly concentrated onto Celite and then purified by flash column chromatography using DCM and MeOH (1.2% NH ₃ ) as eluents to afford 3.58 g (83%) of the desired product.

¹ H NMR (500 MHz, DMSO-d6) δ ppm (m, 10H), 7.85 (d, 1H), 7.59 (d, 2H), 7.53 (m, 1H), 7.47 (d, 1H), 7.44 (t, 1H), 7.32 (d, 2H), 7.3 ( dd, 1H), 7.26 (t, 1H), 7.20 (d, 1H), 7.15 (t, 1H), 5.87 (s, 2H), 4.16 (t, 2H), 4.16 (br., 2H), 3.92 (m, 2H), 3.84 (m, 1H), 3.72 (t, 2H), 3.70 (s, 3H), 3.38 (s, 2H), 3.27 (t, 2H), 2.42 (s, 3H), 2.33 (s, 3H), 2.19 (s, 6H), 2.13 (m, 2H), 1.47 (br., 2H), 1.47 (br., 2H), 0.91 (t, 2H), 0.87 (s, 9H), -0.13 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d6) δ ppm. 130.5, 128.9, 128.0, 127.2, 123.5, 123.2, 119.2, 117.4, 115.5, 112.0, 72.9, 72.6, 70.4, 68.4, 66.8, 51.8, 48.1, 46.1, 44.2, 31.0, 30.1, 27.0, 23.1, 22.4, 21.5, 17.8, 17.8, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₆₅ H ₇₉ FN ₇ O ₈ S ₃ Si ₂ : 1256.4669, found: 1256.4677.

Synthesis 5 s: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[4-hydroxybutyl-[5-methyl-6 -[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Stage A: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[4-[tert-butyl(dimethyl)silyl]oxybutyl -[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 250 mg of Preparation 3c (0.38 mmol, 1 equiv.) and 250 mg of Preparation 4a (0.38 mmol, 1 equiv.) as the appropriate halide, 295 mg (75%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d6) δ ppm 7.83-7.25 (m, 4H), 7.64 (s, 1H), 7.31 (dd, 1H), 7.21 (m, 1H), 7.15 (t, 1H), 5.85 (s, 2H), 4.41 (t, 2H) , 4.20 (s, 2H), 4.14 (t, 2H), 3.77 (s, 3H), 3.71 (t, 2H), 3.61 (t, 2H), 3.26 (t, 2H), 2.84 (s, 3H), 2.44 (s, 3H), 2.12 (m, 2H), 1.74 (m, 2H), 1.51 (m, 2H), 1.40 (s, 9H), 0.91 (t, 2H), 0.79 (s, 9H), -0.03 (s, 6H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d6) δ ppm 147.5, 137.6, 129.1, 127.2- 112, 119.3, 117.7, 115.5, 72.8, 68.4, 66.8, 62.5, 51.9, 46.7, 38.3, 33.8, 31.0, 29.8, 28.5, 26.2, 23.8, 23.1, 17.9, 17.8, -1.0, -4.9; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₁ H ₇₃ FN ₇ O ₇ S ₂ Si ₂ : 1034.4530, found: 1034.4517.

Stage B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[4-hydroxybutyl-[5-methyl-6 -[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Procedure for Removal of the tert-Butyldimethylsilyl Protecting Group starting from 650 mg of the product from Step A (0.63 mmol, 1 equiv) and 36 mg of [(1S,4R)-7,7-dimethyl-2-oxonorbornan-1-yl]methanesulfonic acid (0.16 mmol, 0.25 equiv), 178 mg (31%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d6) δ ppm 7.84 (d, 1H), 7.68 (s, 1H), 7.46 (d, 1H), 7.43 (td, 1H), 7.32 (brd., 1H), 7.25 (td, 1H), 7.22 (d, 1H), 7.17 (t, 1H), 5.86 (s, 2H), 4.39 (t, 2H), 4.20 (br., 2H), 4.15 (t, 2H), 3.76 (s, 3H), 3.72 (t, 2H), 3.45 (q, 2H), 3.26 (t, 2H), 2.84 (br., 3H), 2.45 (s, 3H), 2.12 (m, 2H), 1.72 (m, 2H), 1.50 (m, 2H), 1.40 (s, 9H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d6) δ ppm 129.1, 127.2, 123.4, 123.2, 119.3, 117.6, 115.5, 111.9, 72.9, 68.4, 66.7, 60.9, 52.0, 46.8, 38.5, 33.8, 31.0, 29.9, 28.5, 24.1, 23.2, 17.9, 17.8, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₅ H ₅₉ FN ₇ O ₇ S ₂ Si: 920.3665, found: 920.3650.

Synthesis 5d: Methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy] propyl]-2-[4-hydroxybutyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino ]thiazole-4-carboxylate

Stage A: methyl 2-[4-[tert-butyl(dimethyl)silyl]oxybutyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-or den]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 1800 mg of Preparation 3d (3.11 mmol, 1 equiv) and 1267 mg of Preparation 4a (3.11 mmol, 1 equiv) as the appropriate halide, 2035 mg (69%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d6) δ ppm 7.82 (dm, 1H), 7.61 (s, 1H), 7.44 (dm, 1H), 7.42 (m, 1H), 7.29 (dd, 1H), 7.23 (m, 1H), 7.19 (dm, 1H), 7.13 (t, 1H), 5.83 (s, 2H), 4.40 (t, 2H), 4.13 (t, 2H), 3.77 (s, 3H), 3.70 (m, 2H), 3.60 (t, 2H), 3.38 (s, 2H), 3.25 (m, 2H), 2.42 ( s, 3Н), 2.19 (s, 6Н), 2.11 (m, 2Н), 1.73 (m, 2H), 1.51 (m, 2H), 0.90 (m, 2H), 0.78 (s, 9H), -0.03 (s, 6H), -0.13 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d6) δ m .d. 128.9, 127.1, 123.4, 123.2, 119.2, 117.5, 115.4, 111.9, 72.8, 68.4, 66.7, 62.5, 51.9, 48.1, 46.5, 44.2, 30.9, 29.7, 26.2, 23.7, 23.1, 17.9, 17.8, - 1.0, -4.9; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₇ H ₆₇ FN ₇ O ₅ S ₂ Si ₂ : 948.4162, found: 948.4161.

Stage B: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[4-hydroxybutyl-[5-methyl-6-[(Z)-[3- (2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Procedure for Removal of the mpem-Butyldimethylsilyl Protective Group, starting from 7.23 g of the product from Step A (7.63 mmol, 1 equiv) and 2.22 g of [(1S,4R)-7,7-dimethyl-2-oxonorbornan-1-yl]methanesulfonic acid (9.54 mmol, 1.25 equiv), 5.23 g (82%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.69 (s, 1H), 7.47 (d, 1H), 7.44 (td, 1H), 7.35 (dd, 1H), 7.25 (td, 1H), 7.25 (dm, 1H), 7.18 (t, 1H), 5.86 (s, 2H), 4.46 (t, 1H), 4.39 (t, 2H), 4.15 (t, 2H), 3.78 (s, 3H), 3.72 (m, 2H), 3.65 (s, 2H), 3.45 (q, 2H), 3.27 ( t, 2H), 2.46 (s, 3H), 2.39 (s, 6H), 2.13 (m, 2H), 1.72 (m, 2H), 1.50 (m, 2H), 0.92 (m, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d6) δ ppm 163.2, 129.2, 127.2, 123.4, 123.2, 119.3, 117.6, 115.5, 112.0, 72.9, 68.4, 66.8, 60.9, 52.0, 47.8, 46.8, 43.6, 31.0, 29.9, 24.1, 23.1, 17.9, 17.8, -0.9; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₅₃ FN ₇ O ₅ S ₂ Si: 834.3297, found: 834.3296.

Synthesis 5e: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-hydroxypentyl-[5-methyl-6 -[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Stage A: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-[tert-butyl(dimethyl)silyl]oxypentyl -[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 350 mg of Preparation 3m (0.52 mmol, 1 equiv) and 210 mg of Preparation 4a (0.52 mmol, 1 equiv) as the appropriate halide, 481 mg (88%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.81 (dd, 1H), 7.62 (s, 1H), 7.45 (dd, 1H), 7.42 (m, 1H), 7.28 (dd, 1H), 7.24 (m, 1H), 7.19 (m, 1H), 7.15 (t, 1H), 5.84 (s, 2H), 4.38 (t, 2H), 4.20 (s, 2H), 4.16 (t, 2H), 3.78 (s, 3H), 3.73 (t, 2H), 3.55 (t, 2H), 3.26 (t, 2H), 2.85 (s, 3H ), 2.44 (s, 3Н), 2.13 (m, 2Н), 1.71 (m, 2H), 1.51 (m, 2H), 1.41 (s, 9H), 1.40 (m, 2H), 0.92 (t, 2H), 0.80 (s, 9H), -0.04 (s, 6H), -0.10 (s, 9H) ; ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 163.2, 147.5, 137.6, 129.0, 127.1, 123.5, 123.1, 119.3, 117.7, 115.7, 111.9, 73.0, 68.6, 66.8, 62.7, 51.8, 47.0, 38.6, 33.8, 32.4, 31.0, 28.5, 27.1, 26.2, 23.1, 23.0, 17.9, 17.8, -1.0, -5.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₂ H ₇₅ FN ₇ O ₇ S ₂ Si ₂ : 1048.4686, found: 1048.4692.

Stage B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-hydroxypentyl-[5-methyl-6 -[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Procedure for Removal of the tert-Butyldimethylsilyl Protecting Group starting from 2.52 g of the product from Step A (2.40 mmol, 1 equiv) and 0.70 g of [(1S,4R)-7,7-dimethyl-2-oxonorbornan-1-yl]methanesulfonic acid (3.00 mmol, 1.25 equiv), 1.19 g (53%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.66 (s, 1H), 7.46 (d, 1H), 7.43 (t, 1H), 7.32 (d, 1H), 7.25 (t, 1H), 7.22 (d, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.36 (t, 2H), 4.20 (s, 2H), 4.15 (t, 2H), 3.78 (s, 3H), 3.72 (t, 2H), 3.4 ( t, 2H), 3.26 (t, 2H), 2.84 (s, 3H), 2.46 (s, 3H), 2.12 (qn, 2H), 1.69 (qn, 2H), 1.49 (m, 2H), 1.40 (s, 9H), 1.40 (qn, 2H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ m .d. 129.1, 127.2, 123.4, 123.2, 119.3, 117.6, 115.5, 112.0, 72.9, 68.4, 66.7, 61.0, 52.0, 47.0, 38.5, 33.9, 32.5, 31.0, 28.5, 27.1, 23.2, 23.1, 17.9, 17.8, -1.0 ; HR-MSR (m/z): [M+Na] ⁺ , calculated for C ₄₆ H ₆₀ FN ₇ NaO ₇ S ₂ Si: 956.3641, found: 956.3646.

Synthesis 5f: Methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy] propyl]-2-[5-hydroxypentyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino ]thiazole-4-carboxylate

Stage A: methyl 2-[5-[tert-butyl(dimethyl)silyl]oxypentyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-or den]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 3.68 g of Preparation 3t (6.22 mmol, 1 equiv) and 3.29 g of Preparation 4a (8.08 mmol, 1.3 equiv) as the appropriate halide, 3.92 g (65%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.83 (dm, 1H), 7.66 (s, 1H), 7.46 (dm, 1H), 7.43 (m, 1H), 7.30 (dd, 1H), 7.25 (m, 1H), 7.15 (dm, 1H), 5.85 (s, 2H), 4.40 (t, 2H), 4.14 (t, 2H), 4.14 (t, 1H), 3.77 (s, 3H), 3.71 (m, 2H), 3.54 (t, 2H), 3.38 (s, 2H), 3.26 (t, 2H), 2.44 ( s, 3Н), 2.19 (s, 6Н), 2.12 (m, 2Н), 1.70 (m, 2H), 1.49 (m, 2H), 1.37 (m, 2H), 0.91 (m, 2H), 0.79 (s, 9H), -0.06 (s, 6H), -0.12 (s, 9H); MSVR-ERI (m/ z): [M+H] ⁺ , calculated for C ₄₈ H ₆₉ FN ₇ O ₅ S ₂ Si ₂ : 962.4319, found: 962.4301.

Stage B: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-hydroxypentyl-[5-methyl-6-[(Z)-[3- (2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Procedure for Removal of the tert-butyldimethylsilyl Protective Group starting from 3.91 g of the product from Step A (4.06 mmol, 1 equiv) and 1.18 g of [(1S,4R)-7,7-dimethyl-2-oxonorbornan-1-yl]methanesulfonic acid (5.08 mmol, 1.25 equiv), 2.61 g (76%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.67 (s, 1H), 7.47 (dm, 1H), 7.42 (td, 1H), 7.31 (dd, 1H), 7.25 (td, 1H), 7.21 (dd, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.37 (m, 1H), 4.37 (m, 2H), 4.14 (t, 2H), 3.78 (s, 3H), 3.72 (t, 2H), 3.40 (m, 2H), 3.38 (s, 2H), 3.27 (t, 2H), 2.46 (s, 3H), 2.20 (s, 6H), 2.12(m, 2H), 1.69 (m, 2H), 1.49 (m, 2H), 1.39 (m, 2H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.0, 127.2, 123.5, 123.2, 119.2, 117.6, 115.5, 111.9, 72.9, 68.4, 66.7, 61.0, 52.0, 48.1, 47.0, 44.2, 32.5, 31.0, 27.1, 23.1, 23.1, 17.8, 17.8, -0.9; HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₄₂ H ₅₆ FN ₇ O ₅ S ₂ Si: 424.6764, found: 424.6755.

Synthesis 5g: Ethyl 5-(3-iodopropyl)-2-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazole-4-carboxylate

Step A: Ethyl 5-(3-chloropropyl)-2-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazole-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 3.15 g of Preparation 3e (12 mmol, 1.2 equiv) and 4.07 g of Preparation 4a (10 mmol, 1 equiv) as the appropriate halide, 2.6 g (41%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.65 (s, 1H), 7.45 (d, 1H), 7.43 (tin, 1H), 7.25 (tin, 1H), 5.85 (s, 2H), 4.30 (q, 2H), 3.77 (s, 3H), 3.71 (t, 2H), 3.71 (t, 2H), 3.22 (t, 2H), 2.48 (s, 3H), 2.10 (quin, 2H), 1.31 (t, 3H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 162.6, 157.4, 156.8, 155.1, 151.7, 140.5, 137.6, 137.1, 135.3, 125.6, 123.5, 123.2, 123.1, 117.6, 111.9, 72.9, 66.7, 60.7, 45.3, 35.4, 34.4, 24.3, 18.0, 17.8, 14.7, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₂₈ H ₃₈ ClN ₆ O ₃ S ₂ Si: 633.1899, found: 633.1891.

Step B: ethyl 5-(3-iodopropyl)-2-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino] pyridazin-3-yl]amino]thiazol-4-carboxylate

A 100 mL single-neck round-bottom flask was fitted with a PTFE-lined magnetic stir bar and a reflux condenser. The flask was charged with 2.6 g of the product from Step A (4.10 mmol, 1 equiv), 1.23 g of NaI (8.2 mmol, 2 equiv) and 20 mL of dry acetone. The reaction mixture was heated to 60 °C and stirred at this temperature for 3 days, during which time the reaction reached complete conversion. The reaction mixture was diluted by adding water and then the precipitated product was collected by filtration, washed with water and then dried under high vacuum to give 2.5 g (84%) of the desired product.

^1H NMR (500 MHz, DMSO- _d6 ) δ 7.82 (d, 1H), 7.61 (s, 1H), 7.47-7.39 (m, 1H), 7.47-7.39 (m, 1H), 7.23 (t, 1H ), 5.83 (s, 2H), 4.29 (q, 2H), 3.75 (s, 3H), 3.71 (t, 2H), 3.33 (t, 2H), 3.16 (t, 2H), 2.42 (s, 3H), 2.13 (quint, 2H), 1.33 (t, 3H ), 0.91 (t, 2H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 162.6, 157.3, 156.7, 155.1, 151.6, 140.2, 137.6, 137.1, 135.2, 127.1, 125.4, 123.4, 123.2, 117.5, 111.9, 72.8, 66.7 , 60.7, 35.2, 35.2, 27.6, 17.8, 17.8, 14.8, 7.8, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₂₈ H ₃₈ IN ₆ O ₃ S ₂ Si: 725.1255, found: 725.1248.

Synthesis 5h: Ethyl 5-[3-[4-[3-[tert-butoxycarbonyl-[2-(dimethylamino)ethyl]amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazole-4-carboxylate

Step A: tert-butyl N-[2-(dimethylamino)ethyl]-N-prop-2-ynylcarbamate

365 mg N',N'-dimethyl-N-prop-2-ynylethane-1,2-diamine (1.83 mmol, 1 equiv) and 22 mg N,N-dimethylpyridin-4-amine (0.18 mmol, 0.1 equiv) were mixed in dichloromethane (2.2 ml/mmol), then 600 mg tert-butoxycarbonyl tert-butyl carbonate (2.75 mmol, 1.5 equiv) were added in one portion at rt and the mixture was stirred at ambient temperature for 3 h. After the reaction time, ca. 10 ml DCM and ca. 10 ml conc. NaHCO ₃ were added, the layers were separated and the organic layer was dried over MgSO ₄ , filtered and concentrated. A yellowish oil was obtained as a crude product: 332 mg (77%) of the target product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 4.02 (s, 2H), 3.29 (t, 2H), 3.18 (t, 1H), 2.37 (t, 2H), 2.15 (s, 6H), 1.40 (s, 9H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 149.3, 106.7, 79.2, 57.0, 45.3, 43.7, 38.6, 28.0.

Stage B: (2-fluoro-4-iodophenoxy)-triisopropylsilane

A 100 mL oven-dried, single-necked, round-bottomed flask was fitted with a PTFE-coated magnetic stir bar. The flask was charged with 2.38 g 2-fluoro-4-iodophenol (10.00 mmol), 1.98 g K ₂ CO ₃ (20.00 mmol, 2 equiv), and acetonitrile (4 mL/mmol). To the resulting mixture, 2.31 g chloro(triisopropyl)silane (12.00 mmol, 1.2 equiv) was added dropwise with near-vigorous stirring. The resulting mixture was stirred at rt for 30 min, during which time the reaction reached complete conversion. The reaction mixture was filtered through a pad of celite, then concentrated on celite and purified by flash column chromatography using heptane and EtOAc as eluents to give 3.70 g (94%) of the desired product (94%) as a colorless oil.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.60 (dd, 1H), 7.40 (dm, 1H), 6.82 (dd, 1H), 1.24 (sp, 3H), 1.04 (d, 18H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 153.9, 143.8, 134.2, 125.5, 124.1, 83.6, 18.0, 12.5; MSVR-EI (m/z): [M] ⁺ , calculated for C ₁₅ H ₂₄ FIOSi: 394.0625, found: 394.0616.

Step C: tert-butyl N-[2-(dimethylamino)ethyl]-N-[3-(3-fluoro-4-triisopropylsilyloxyphenyl)prop-2-ynyl]carbamate

Using the General Sonogashira reaction procedure, starting from 99 mg of the product from Step B (0.25 mmol, 1 equiv.) and 73 mg of the product from Step A, 90 mg (75%) of the desired product was obtained as a yellow oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.09 (dd, 1H), 7.03 (d, 1H), 6.83 (t, 1H), 4.40-4.15 (br., 2H), 3.46 (brt, 2H), 2.50 (t, 2H), 2.26 (s, 6H), 1.47 (s, 9H), 1.25 (m, 3H), 1.07 (d, 18H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm. 128.1, 121.6, 119.7, 57.5, 45.7, 44.2, 37.8, 36.8, 28.4, 17.7, 12.7; HR-MS (m/z): [M+H] ⁺ , calculated for C ₂₇ H ₄₆ FN ₂ O ₃ Si: 493.3256, found: 493.3264.

Step D: Ethyl 5-[3-[4-[3-[tert-butoxycarbonyl-[2-(dimethylamino)ethyl]amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazole-4-carboxylate

Using the General Procedure for the Alkylation of Silyl-Protected Phenols, starting from 147 mg of the product from Preparation 5g, Step B (0.20 mmol, 1 equiv) and 100 mg of the product from Step C (0.20 mmol, 1 equiv) gave 164 mg (87%) of the desired product as a brown solid.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.66 (s, 1H), 7.45 (m, 1H), 7.44 (td, 1H), 7.30 (br, 1H), 7.25 (td, 1H), 7.20 (m, 1H), 7.17 (t, 1H), 5.86 (s, 2H), 4.26 (q, 2H), 4.22 (br, 2H), 4.15 (t, 2H), 3.77 (s, 3H), 3.72 (t, 2H), 3.37 (m, 2H), 3.27 (t, 2H), 2.48 ( m, 2H), 2.45 (s, 3H), 2.22 (br, 6H), 2.12 (quin, 2H), 1.41 (s, 9H), 1.28 (t, 3H), 0.92 (t, 2H), -0.10 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 171.0, 157.6, 156.7, 155.3, 154.7, 151.7, 151.5, 147.6, 141.2, 137.6, 137.1, 135.3, 129.0, 127.2, 125.4, 123.5, 123.1, 119.2, 117.8, 115.5, 114.7, 111.9, 85.6, 82.1, 79.9, 72.8, 68.7, 66.7, 60.3, 57.0, 45.8, 44.0, 36.9, 35.2, 31.2, 28.5, 23.3, 17.8, 17.5, 14.7, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₆ H ₆₂ FN ₈ O ₆ S ₂ Si: 933.3982, found: 933.3977.

Synthesis 5i: Methyl 5-[3-[4-[3-(tert-butoxycarbonylamino)prop-1-ynyl]-2-fluorophenoxy] propyl]-2-[4-[tert-butyl(dimethyl)silyl]oxybutyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene] amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 780 mg of Preparation 3g (1.20 mmol, 1 equiv) and 489 mg of Preparation 4a (1.20 mmol, 1 equiv) as the appropriate halide, 570 mg (47%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.83 (dd, 1H), 7.64 (s, 1H), 7.45 (dd, 1H), 7.43 (m, 1H), 7.33 (t, 1H), 7.27 (dd, 1H), 7.26 (m, 1H), 7.18 (m, 1H), 7.15 (t, 1H), 5.85 (s, 2H), 4.41 (t, 2H), 4.14 (t, 2H), 3.93 (d, 2H), 3.76 (s, 3H), 3.71 (t, 2H), 3.61 (t, 2H), 3.25 (t, 2H ), 2.44 (s, 3Н), 2.12 (m, 2Н), 1.74 (m, 2H), 1.51 (m, 2H), 1.39 (s, 9H), 0.91 (t, 2H), 0.79 (s, 9H), -0.03 (s, 6H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 162.2, 147.4, 137.6, 129.0, 127.2, 123.4, 123.2, 119.2, 117.6, 115.4, 111.9, 80.8, 72.8, 68.4, 66.7, 62.5, 51.9, 46.5, 31.1, 30.5, 29.7, 28.7, 26.1, 23.8, 23.1, 17.9, 17.8, -1.0, -4.9; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₀ H ₇₁ FN ₇ O ₇ S ₂ Si ₂ : 1020.4373, found: 1020.4373.

Synthesis of 5j: Ethyl 5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Step A: Ethyl 5-{3-[4-(3-{[(tert-butoxy)carbonyl](methyl)amino}prop-1-yn-1-yl)-2-fluorophenoxy]propyl}-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To the product of Preparation 5g (1.75 g, 2.41 mmol, 1 equiv) in dimethylformamide (50 mL) was added the product of Preparation 6a (877 mg, 3.14 mmol, 1.3 equiv) in dimethylformamide (10 mL) and cesium carbonate (2.36 g, 7.24 mmol, 3 equiv), and the mixture was heated at 80 °C for 16 h. The reaction mixture was concentrated in vacuo, then partitioned between ethyl acetate and brine, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSe™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the desired product as a yellow oil (1.75 g, 2 mmol, 83%).

LC/MS (C ₄₃ H ₅₄ FN ₇ O ₆ SiS ₂ ) 876 [M+H] ⁺ ; RT 1.46 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.83 (dd, 1H), 7.65 (d, J=1.1 Hz, 1H), 7.49-7.39 (m, 2H), 7.35-7.28 (m, 1H), 7.27-7.12 (m, 3H), 5.86 (s, 2H), 4.25 (q, J=7.1 Hz, 2H), 4.19 (s, 2H), 4.14 (t, J=6.1 Hz, 2H), 3.77 (s, 3H), 3.76-3.68 (m, 2H), 3.26 (t, J=7.7 Hz, 2H), 2.84 (s, 3H), 2.45 (s, 3H), 2.19-2.05 (m, 1H), 1.41 (s, 9H), 1.30 (t, 3H), 0.97-0.88 (m, 2H), -0.12 (s, 9H).

Step B: Ethyl 5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (20 mL) was added to a stirred solution of the product from Step A (1.5 g, 1.71 mmol, 1 equiv) in dichloromethane (60 mL), and the mixture was stirred at ambient temperature for 5 h. The reaction mixture was diluted with dichloromethane, cooled to 0 °C, and basified by addition of 2 N aqueous sodium hydroxide solution. The organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded the desired product as a yellow gum (329 mg, 0.42 mmol, 25%).

LC/MS (C ₃₈ H ₄₆ FN ₇ O ₄ SiS ₂ ) 776 [M+H] ⁺ ; RT 2.58 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.84 (dd, 1H), 7.67 (d, J=1.0 Hz, 1H), 7.49-7.40 (m, 2H), 7.31-7.22 (m, 2H), 7.21-7.11 (m, 2H), 5.86 (s, 2H), 4.26 (q, J=7.1 Hz, 2H), 4.15 (t, J=6.1 Hz, 2H), 3.76 (s, 3H), 3.76-3.67 (m, 2H), 3.45 (s, 2H), 3.33-3.22 (m, 2H), 2.46 (d, J=1.0 Hz, 3H), 2.30 (s, 3H), 2.18-2.06 (m, 2H), 1.29 (t, J=7.1 Hz, 3H), 0.97-0.88 (m, 2H), -0.11 (s, 9H).

Synthesis of 5k: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-(piperidin-4-yl)-1,3-thiazole-4-carboxylate

Step A: Bromo({1-[(tert-butoxy)carbonyl]piperidin-4-yl})zinc

A 50 mL Schlenk flask equipped with a magnetic stir bar was charged with zinc (1.96 g, 30 mmol, 1.5 equiv) and lithium chloride (1.27 g, 30 mmol, 1.5 equiv) and the mixture was heated with a heat gun under high vacuum (<1 mbar) for 10 min with gentle stirring. Still under high vacuum, the mixture was allowed to cool to ambient temperature and then transferred to a Schlenk line that was flushed with nitrogen. Tetrahydrofuran (15 mL) was added followed by 1,2-dibromoethane (0.06 mL, 0.75 mmol, 0.04 equiv) and the mixture was heated to 60 °C for 10 min. Heating of the reaction mixture was then stopped and trimethylchlorosilane (0.02 mL, 0.15 mmol, 0.01 equiv) was added followed by iodine (0.5 M in tetrahydrofuran; 0.15 mL, 0.175 mmol, 0.05 equiv). The mixture was then heated at 60 °C for 10 min and then cooled to <35 °C. A solution of tert-butyl 4-bromopiperidine-1-carboxylate (5.28 g, 20 mmol, 1 equiv) in tetrahydrofuran (10 mL) was added over 3 min and the mixture was stirred at 50 °C for 6 h and then at ambient temperature overnight. The reaction mixture was allowed to cool to ambient temperature and then cannulated through a filter (cotton wool/celite/cotton wool) under low vacuum into a dry 25 mL Schlenk flask to give the desired product as a 0.5 M solution (as determined by titration with 0.5 M iodine), which was used without further characterization.

Step B: tert-Butyl 4-[4-(ethoxycarbonyl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazol-5-yl]piperidine-1-carboxylate

An oven-dried flask was charged with the product from Synthesis lib (500 mg, 0.79 mmol, 1 equiv) and copper(I) iodide (300 mg, 1.57 mmol, 2 equiv) and the mixture was evacuated and flushed with nitrogen (×3). Dimethylacetamide (15 mL) was added, resulting in a brown suspension that was allowed to stir for 5 min. The product from Step A (0.5 M in tetrahydrofuran; 9.44 mL, 4.72 mmol, 6 equiv) was added and the mixture was stirred at ambient temperature overnight. The reaction mixture was quenched by the addition of saturated aqueous ammonium chloride (25 mL) and then further diluted with a 1:1 mixture of water/saturated aqueous ammonium chloride (150 mL). The organics were extracted with dichloromethane (×3) and the combined organic extracts were washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-40% ethyl acetate in isoheptane afforded the title product as a pale yellow foam (429 mg, 0.58 mmol, 74%).

LC/MS (C ₃₅ H ₄₉ N ₇ O ₅ SiS ₂ ) 740 [M+H] ⁺ ; RT 1.40 (LCMS-V-B2)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.63 (dt, J=7.7, 1.0 Hz, 1H), 7.46-7.34 (m, 2H), 7.31 (d, J=1.2 Hz, 1H), 7.22 (ddd, J=7.7, 5.8, 2.6 Hz, 1H), 5.85 (s, 2H), 4.40 (q, J=7.1 Hz, 2H), 4.26 (s, 2H), 3.90 (ddd, J=12.1, 8.5, 3.7 Hz, 1H), 3.85 (s, 3H), 3.80-3.69 (m, 2H), 2.85 (s, 2H), 2.47 (d, J=1.0 Hz, 3H), 2.04 (d, J=12.8 Hz, 2H), 1.71 (q, J=12.1 Hz, 2H), 1.50 (s, 9H), 1.47 (s, 10H), 1.44 (t, J=7.1 Hz, 3H), 1.02-0.93 (m, 2H), -0.07 (s, 9H).

Step C: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-(piperidin-4-yl)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (0.5 mL, 6.71 mmol, 49.7 equiv) was slowly added to a cooled solution of the product from Step B (100 mg, 0.14 mmol, 1 equiv) in dichloromethane (6 mL), and the mixture was stirred at 0 °C for 1.5 h. The reaction mixture was quenched by addition of saturated aqueous sodium bicarbonate solution, extracted with dichloromethane, and the organic extract was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded the title product as an off-white glass (59 mg, 0.09 mmol, 68%).

LC/MS (C ₃₀ H ₄₁ N ₇ O ₃ SiS ₂ ) 640 [M+H] ⁺ ; RT 1.23 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.85 (dd, J=7.6, 1.1 Hz, 1H), 7.67 (d, J=1.1 Hz, 1H), 7.51-7.40 (m, 2H), 7.25 (ddd, J=8.3, 6.9, 1.5 Hz, 1H), 5.87 (s, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.90-3.61 (m, 6H), 3.12 (d, J=12.2 Hz, 2H), 2.68 (td, J=12.5, 2.3 Hz, 3H), 2.46 (d, J=1.0 Hz, 3H), 2.00-1.89 (m, 2H), 1.71-1.54 (m, 2H), 1.32 (t, J=7.1 Hz, 3H), 0.92 (dd, J=8.6, 7.4 Hz, 2H), -0.11 (s, 9H).

Synthesis 51: Ethyl 5-(azetidin-3-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Step A: Ethyl 5-{1-[(tert-butoxy)carbonyl]azetidin-3-yl}-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of Preparation 4a (401 mg, 0.98 mmol, 2 equiv) in 1,4-dioxane (5 mL) was added Preparation 3zb (168 mg, 0.49 mmol, 1 equiv), N,N-diisopropylethylamine (0.24 mL, 1.48 mmol, 3 equiv), cesium carbonate (481 mg, 1.48 mmol, 3 equiv), and xantphos (56.9 mg, 0.1 mmol, 0.2 equiv), and the mixture was sparged with nitrogen (10 min). Tris(dibenzylideneacetone)dipalladium(0) (45.1 mg, 0.05 mmol, 0.1 equiv) was added, and the mixture was heated at 120 °C for 2 h under microwave irradiation. The reaction mixture was diluted with dichloromethane, washed with water followed by brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 100% ethyl acetate in isoheptane afforded the desired product as a brown solid (99 mg, 0.14 mmol, 28%).

LC/MS (C ₃₃ H ₄₅ N ₇ O ₅ SiS ₂ ) 712 [M+H] ⁺ ; RT 1.52 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.90-7.81 (m, 1H), 7.70 (d, J=1.1 Hz, 1H), 7.52-7.39 (m, 2H), 7.29-7.21 (m, 1H), 5.87 (s, 2H), 4.59 (tt, J=8.6, 6.0 Hz, 1H), 4.37 (t, J=8.6 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.89 (t, J=7.3 Hz, 2H), 3.79 (s, 3H), 3.76-3.68 (m, 2H), 2.46 (d, J=1.0 Hz, 3H), 1.43 (s, 9H), 1.32 (t, J=7.1 Hz, 3H), 0.99 0.83 (m, 2H), -0.11 (s, 9H).

Step B: ethyl 5-(azetidin-3-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro -1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazol-4-carboxylate

To a solution of the product from Step A (78 mg, 0.11 mmol, 1 equiv) in dichloromethane (6 mL) cooled in an ice bath was slowly added trifluoroacetic acid (0.5 mL, 6.71 mmol, 61.2 equiv), and the mixture was stirred at 0 °C for 5 h. The reaction mixture was quenched by addition of saturated aqueous sodium bicarbonate solution, then extracted with dichloromethane, washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% methanol in dichloromethane afforded the title product as a cream-colored solid (29.6 mg, 0.05 mmol, 44%).

LC/MS (C ₂₈ H ₃₇ N ₇ O ₃ SiS ₂ ) 612 [M+H] ⁺ ; RT 1.18 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.83 (d, J=7.7 Hz, 1H), 7.71 (s, 1H), 7.52-7.40 (m, 2H), 7.30-7.23 (m, 1H), 5.87 (s, 2H), 4.76 (p, J=8.2 Hz, 1H), 4.29 (q, J=7.1 Hz, 2H), 4.17 (t, J=9.0 Hz, 2H), 3.91 (t, J=8.5 Hz, 2H), 3.79 (s, 3H), 3.75- 3.66 (m, 2H), 2.47 (s, 3H), 1.32 (t, J=7.1 Hz, 3H), 0.98-0.87 (m, 2H), -0.11 (s, 9H).

Synthesis of 5m: Ethyl 5-[(1E)-3-hydroxy-2-methylprop-1-en-1-yl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Step A: tert-butyldimethyl(prop-2-yn-1-yloxy)silane

To a cooled solution of propargyl alcohol (5.21 mL, 89.2 mmol, 1 equiv) in dichloromethane (250 mL) were added imidazole (8.84 mL, 134 mmol, 1.5 equiv) and tert-butyldimethylsilyl chloride (20.2 g, 134 mmol, 1.5 equiv), and the mixture was stirred at 0 °C for 90 min. The reaction mixture was partitioned between dichloromethane and saturated aqueous ammonium chloride, the layers were separated (PTFE phase separator), and the organic phase was concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 220 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% ethyl acetate in isoheptane afforded the desired product as a clear oil (4.07 g, 23.9 mmol, 27%).

^1H NMR (400 MHz, DMSO-d6) δ 4.28 (d, J=2.4 Hz, 2H), 3.37 (t, J=2.4 Hz, 1H), 0.86 (s, 9H), 0.08 (s, 6H).

Step B: tert-butyldimethyl{[(2E)-2-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)prop-2-en-1-yl ]oxy}silane

Copper(I) chloride (237 mg, 2.39 mmol, 0.1 equiv), xantphos (1.38 g, 2.39 mmol, 0.1 equiv), bis(pinacolato)diboron (6.67 g, 26.3 mmol, 1.1 equiv), and tetrahydrofuran (17 mL) were charged into an oven-dried flask and the mixture was sparged with nitrogen (10 min). A solution of sodium 2-methylpropan-2-olate (2.53 g, 26.3 mmol, 1.1 equiv) in tetrahydrofuran (14 mL) was added and the mixture was stirred for 5 min. A solution of the product from Step A (4.07 g, 23.9 mmol, 1 equiv) in tetrahydrofuran (14 mL) was added followed by methyl iodide (5.95 mL, 95.6 mmol, 4 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 5% ethyl acetate in isoheptane afforded the title product as a clear oil (616 mg, 1.97 mmol, 8%).

¹ H NMR (400 MHz, DMSO-d6) δ 5.34-5.30 (m, 1H), 4.04-3.97 (m, 2H), 1.83 (s, 3H), 1.23-1.16 (m, 12H), 0.88 (s, 9H), 0.03 (s, 6H).

Stage C: ethyl 5-[(1E)-3-[(tert-butyldimethylsilyl)oxy]-2-methylprop-1-en-1-yl]-2-[methyl(5-methyl-6-{[(2Z)-3- {[2-(trimethylsi lyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazol-4-carboxylate

To a solution of Preparation 11e (224 mg, 0.33 mmol, 1 equiv) in tetrahydrofuran (7.5 mL) was added the product from Step B (123 mg, 0.39 mmol, 1.2 equiv), followed by water (2.5 mL) and potassium carbonate (136 mg, 0.98 mmol, 3 equiv). The mixture was sparged with nitrogen (10 min), after which [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (24 mg, 0.03 mmol, 0.1 equiv) was added and the mixture was heated at 100 °C for 1 h under microwave irradiation. The reaction mixture was partitioned between ethyl acetate and brine, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 40% ethyl acetate in isoheptane afforded the title product as a white solid (192 mg, 0.26 mmol, 79%).

LC/MS (C ₃₅ H ₅₂ N ₆ O ₄ Si ₂ S ₂ ) 741 [M+H] ⁺ ; RT 1.58 (LCMS-V-B2)

^1H NMR (400 MHz, DMSO-d6) δ 7.86-7.79 (m, 1H), 7.70 (d, J=1.1 Hz, 1H), 7.51-7.40 (m, 2H), 7.29-7.20 (m, 2H) , 5.86 (s, 2H), 4.28 (q, 2H), 4.22 (s, 2H), 3.79 (s, 3H), 3.76-3.67 (m, 2H), 2.46 (s, 3H), 1.93 (s, 3H), 1.30 (t, 3H), 0.93 (s , 9H), 0.91-0.83 (m, 2H), 0.11 (s, 6H), -0.12 (s, 9H).

Step D: Ethyl 5-[(1E)-3-hydroxy-2-methylprop-1-en-1-yl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product from Step C (192 mg, 0.26 mmol, 1 equiv) in tetrahydrofuran (6 mL) was added tetrabutylammonium fluoride (1 M in tetrahydrofuran; 0.39 mL, 0.39 mmol, 1.5 equiv) and the mixture was stirred at ambient temperature for 2 h. The reaction mixture was partitioned between ethyl acetate and water and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a yellow solid (160 mg, 0.26 mmol, 99%).

LC/MS (C ₂₉ H ₃₈ N ₆ O ₄ SiS ₂ ) 627 [M+H] ⁺ ; RT 2.71 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.86-7.80 (m, 1H), 7.70 (d, J=1.1 Hz, 1H), 7.49-7.39 (m, 2H), 7.28-7.21 (m, 2H), 5.86 (s, 2H), 5.12 (t, J=5.7 Hz, 1H), 4.29 (q, J=7.1 Hz, 2H), 4.09-3.98 (m, 2H), 3.81 (s, 3H), 3.77-3.67 (m, 2H), 2.46 (d, J=6.8 Hz, 3H), 1.94 (s, 3H), 1.31 (t, J=7.1 Hz, 3H), 0.97-0.89 (m, 2H), -0.12 (s, 9H).

Synthesis 6a: tert-Butyl N-[3-(3-fluoro-4-hydroxyphenyl)prop-2-ynyl]-N-methylcarbamate

Using the General Sonogashira reaction procedure, starting from 10.00 g of 2-fluoro-4-iodophenol (42.0 mmol, 1 equiv) as the appropriate phenol and 10.67 g of tert-butyl N-methyl-N-prop-2-ynylcarbamate (63.1 mmol, 1.5 equiv) as the alkyne reagent, 10.8 g (92%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 10.32 (s, 1H), 7.22 (brd, 1H), 7.08 (dm, 1H), 6.92 (dd, 1H), 4.21 (s, 2H), 2.85 (s, 3H), 1.41 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 150.8, 146.4, 129.0, 119.6, 118.4, 113.2, 84.4, 82.7, 38.5, 33.8, 28.5; HR-MSR (m/z): [M-C ₄ H ₈ +H] ⁺ , calculated for C ₁₁ H ₁₁ FNO ₃ : 224.0717, found: 224.0720.

Synthesis of 6b: 4-[3-(Dimethylamino)prop-1-ynyl]-2-fluorophenol

Using the General Sonogashira reaction procedure, starting from 10.00 g of 2-fluoro-4-iodophenol (42.0 mmol, 1 equiv) as the appropriate phenol and 5.24 g of N,N-dimethylprop-2-yn-1-amine (63 mmol, 1.5 equiv) as the alkyne reagent, 7.30 g (90%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.20 (dd, 1H), 7.07 (dm, 1H), 6.91 (m, 1H), 3.39 (m, 2H), 2.21 (m, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 150.9, 146.2, 128.9, 119.5, 118.4, 113.6, 84.5, 84.2, 48.2, 44.3; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₁₁ H ₁₃ FNO: 194.0976, found: 194.0981.

Synthesis of BS: 2-Fluoro-4-(3-pyrrolidin-1-ylprop-1-ynyl)phenol

Step A: 3-(3-fluoro-4-triisopropylsilyloxyphenyl)prop-2-yn-1-ol

A 500 mL oven-dried, single-necked, round-bottomed flask fitted with a PTFE-lined magnetic stir bar was charged with 4.76 g of 2-fluoro-4-iodophenol (20 mmol, 1 equiv.) and 3.96 g _{of K2CO3} (40 mmol, 2 equiv.), followed by the addition of 100 mL of dry MeCN. To the resulting mixture, 5.13 mL of TIPSCl (4.62 g, 24 mmol, 1.2 equiv.) was added dropwise under near-vigorous stirring at rt. The resulting mixture was stirred at room temperature for 30 min, during which time the reaction reached complete conversion. The reaction mixture was filtered through a pad of celite to remove solid particles, then 2.33 mL of prop-2-yn-1-ol (2.24 g, 40 mmol, 2 equiv) and 20 mL _of DIPA were added to the filtrate and a nitrogen atmosphere was introduced through the gas inlet. After adding 702 mg of Pd( _PPh3 ) _2Cl2 (1 mmol, 0.05 equiv) and 190 mg of CuI (1 mmol, 0.05 equiv), the resulting mixture was stirred at room temperature for 30 min, during which time the reaction reached complete conversion. Celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was then purified by flash column chromatography using heptane and EtOAc as eluents to afford 5.2 g (81%) of the desired product as a brown oil.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.26 (dd, 1H), 7.14 (dm, 1H), 6.96 (t, 1H), 4.27 (d, 2H), 1.23 (m, 3H), 1.03 (d, 18H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 153.3, 144.1, 128.8, 122.3, 119.6, 116.5, 89.8, 82.8, 49.8, 17.9, 12.5; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁₈ H ₂₈ FO ₂ Si: 323.1837, found: 323.1832.

Step B: [2-fluoro-4-(3-pyrrolidin-1-ylprop-1-ynyl)phenoxy]-triisopropylsilane

Using the General Procedure for Alkylation with an In Situ Generated Iodocontaining Compound starting with 322 mg of the product from Step A (1 mmol, 1 equiv) as the appropriate alcohol and 355 mg of pyrrolidine (5 mmol, 5 equiv), 130 mg (34%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.29 (dd, 1H), 7.14 (dm, 1H), 6.97 (t, 1H), 3.56 (s, 2H), 2.55 (m, 4H), 1.71 (m, 4H), 1.25 (m, 3H), 1.05 (d, 18H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 153.2, 144.0, 129.0, 122.3, 119.8, 116.6, 86.2, 83.2, 52.3, 43.3, 23.8, 18.0, 12.5; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₂₂ H ₃₅ FNOSi: 376.2466, found: 376.2456.

Step C: 2-fluoro-4-(3-pyrrolidin-1-ylprop-1-ynyl)phenol

A 4 mL oven-dried flask fitted with a PTFE-lined magnetic stir bar was charged with 83 mg of the product from Step B (0.221 mmol, 1 equiv) and 1.1 mL of dry THF, then 265 μL of TBAF (1 M in THF, 225.9 mg, 0.2652 mmol, 1.2 equiv) were added dropwise at rt. The resulting mixture was stirred at rt for 15 min, during which time the reaction reached complete conversion. The reaction mixture was quenched by adding 200 μL of conc. _NH4Cl solution, and then celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was then purified by flash column chromatography using DCM and MeOH (1.2% NH ₃ ) as eluents to afford 43 mg (88%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 10.30 (brs, 1H), 7.17 (dd, 1H), 7.04 (dm, 1H), 6.88 (t, 1H), 3.53 (s, 2H), 2.54 (m, 4H), 1.70 (m, 4H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 151.1, 146.8, 128.9, 119.4, 118.5, 113.1, 84.8, 83.8, 52.3, 43.4, 23.8; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₃ H ₁₅ FNO: 220.1132, found: 220.1129.

Synthesis of 6d: 2-Fluoro-4-[3-(1-piperidyl)prop-1-ynyl]phenol

Step A: [2-fluoro-4-[3-(1-piperidyl)prop-1-ynyl]phenoxy]-triisopropylsilane

Using the General Procedure for Alkylation with an In Situ Generated Iodo-Containing Compound, starting with 322 mg of the product from Preparation 6c, Step A (1 mmol, 1 equiv) as the appropriate alcohol and 425 mg of piperidine (5 mmol, 5 equiv), 250 mg (64%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.3 (dd, 1H), 7.15 (dm, 1H), 6.98 (t, 1H), 3.42 (s, 2H), 2.46 (br., 4H), 1.51 (m, 4H), 1.37 (br., 2H) , 1.26 (m, 3H), 1.05 (d, 18H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 153.2, 144.0, 129.0, 122.3, 119.8, 116.6, 85.9, 83.8, 53.1, 48.0, 25.9, 24.0, 18.0, 12.5; HR-MS (m/z): [M+H] ⁺ , calculated for C ₂₃ H ₃₇ FNOSi: 390.2622, found: 390.2608.

Step B: 2-fluoro-4-[3-(1-piperidyl)prop-1-ynyl]phenol

A 4 mL oven-dried flask fitted with a PTFE-lined magnetic stir bar was charged with 272 mg of the product from Step A (0.69 mmol, 1 equiv) dissolved in 3.5 mL of dry THF and then 698 μL of TBAF (1 M in THF, 0.69 mmol, 1 equiv) was added dropwise at rt. The resulting mixture was stirred at rt for 15 min, during which time the reaction reached complete conversion. The reaction mixture was quenched by adding 200 μL of conc. _NH4Cl solution and then celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was then purified by flash column chromatography using DCM and MeOH (1.2% NH ₃ ) as eluents to afford 143 mg (87%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 10.27 (s, 1H), 7.20 (dd, 1H), 7.07 (dm, 1H), 6.90 (t, 1H), 3.40 (s, 2H), 2.44 (br, 4H), 1.51 (m, 4H), 1.37 (br, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 150.9, 146.1, 128.9, 119.5, 118.4, 113.7, 84.7, 84.2, 53.1, 48.0, 25.9, 24.1; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₄ H ₁₇ FNO: 234.1289, found: 234.1292.

Synthesis 6e: 2-Fluoro-4-(3-morpholinoprop-1-ynyl)phenol Step A: [2-fluoro-4-(3-morpholinoprop-1-ynyl)phenoxy]-triisopropylsilane

Using the General Procedure for Alkylation with an In Situ Generated Iodocontaining Compound, starting with 322 mg of the product of Preparation 6c, Step A (1 mmol, 1 equiv) as the appropriate alcohol and 435 mg of morpholine (5 mmol, 5 equiv), 160 mg (41%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.32 (dd, 1H), 7.16 (dd, 1H), 6.98 (t, 1H), 3.6 (t, 4H), 3.47 (s, 2H), 2.49 (t, 4H), 1.25 (m, 3H), 1.05 (d, 18H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 153.3, 144.1, 129.0, 122.3, 119.8, 116.4, 85.3, 84.1, 66.6, 52.3, 47.5, 18.0, 12.5; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₂₂ H ₃₅ FNO ₂ Si: 392.2415, found: 392.2408.

Stage B: 2-fluoro-4-(3-morpholinoprop-1-ynyl)phenol

A 4 mL oven-dried flask fitted with a PTFE-lined magnetic stir bar was charged with 220 mg of the product from Step A (0.56 mmol, 1 equiv) dissolved in 3.0 mL of dry THF and then 525 μL of TBAF (1 M in THF, 0.52 mmol, 1 equiv) was added dropwise at rt. The resulting mixture was stirred at rt for 15 min, during which time the reaction reached complete conversion. The reaction mixture was quenched by adding 200 μL of conc. _NH4Cl solution and then celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was purified by flash column chromatography using DCM and MeOH (1.2% NH ₃ ) as eluents to afford 120 mg (91%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 10.28 (s, 1H), 7.22 (dd, 1H), 7.08 (dm, 1H), 6.91 (dd, 1H), 3.60 (m, 4H), 3.45 (s, 2H), 2.48 (m, 4H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 150.8, 146.2, 128.9, 119.5, 118.4, 113.6, 84.6, 84.1, 66.5, 52.2, 47.5; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₃ H ₁₅ FNO ₂ : 236.1081, found: 236.1082.

Synthesis of 6f: 4-[3-(Dimethylamino)but-1-ynyl]-2-fluorophenol

Step A: 4-(3-fluoro-4-triisopropylsilyloxyphenyl)but-3-yn-2-ol

A 500 mL oven-dried, single-necked, round-bottomed flask was fitted with a PTFE-lined magnetic stir bar. 4.76 g of 2-fluoro-4-iodophenol (20 mmol, 1 equiv) and 3.96 g _{of K2CO3} (40 mmol, 2 equiv) were charged, followed by the addition of 100 mL of dry MeCN. To the resulting mixture, 5.13 mL of TIPSC1 (4.62 g, 24 mmol, 1.2 equiv) was added dropwise under near-vigorous stirring at rt. The resulting mixture was stirred at room temperature for 30 min, during which time the reaction reached complete conversion. The reaction mixture was filtered through a pad of celite to remove solid particles, then 3.10 mL of but-3-yn-2-ol (2.81 g, 40 mmol, 2 equiv) and 20 mL _of DIPA were added to the filtrate and a nitrogen atmosphere was introduced through the gas inlet. After adding 702 mg of Pd( _PPh3 ) _2Cl2 (1 mmol, 0.05 equiv) and 190 mg of CuI (1 mmol, 0.05 equiv), the resulting mixture was stirred at room temperature for 30 min, during which time the reaction reached complete conversion. Celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was then purified by flash column chromatography using heptane and EtOAc as eluents to afford 6.2 g (92%) of the desired product as a yellow oil.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.26 (dd, 1H), 7.12 (dm, 1H), 6.98 (t, 1H), 5.44 (d, 1H), 4.55 (m, 1H), 1.36 (d, 3H), 1.24 (sp, 1H), 1.05 (d, 18H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 153.2, 144.1, 128.8, 122.3, 119.6, 116.5, 93.4, 81.4, 57.1, 25.0, 18.0, 12.5; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁₉ H ₃₀ FO ₂ Si: 337.1994, found: 337.1994.

Step B: 4-(3-fluoro-4-triisopropylsilyloxyphenyl)-N,N-dimethyl-but-3-yn-2-amine

Using the General Procedure for Alkylation with an In Situ Generated Iodocontaining Compound, starting with 644 mg of the product from Step A (2 mmol, 1 equiv) as the appropriate alcohol and 5 mL of N-methylmethanamine (10 mmol, 5 equiv, 2 M solution in MeOH) gave 360 mg (50%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.28 (dd, 1H), 7.14 (dm, 1H), 6.97 (t, 1H), 3.67 (q, 1H), 2.19 (s, 6H), 1.27 (d, 3H), 1.25 (m, 3H), 1.05 (d, 18H); ¹³ C NMR (500 MHz, DMSO-d ₆ ) δ ppm 153.1, 144.0, 129.0, 122.3, 119.8, 116.6, 88.2, 84.1, 52.3, 41.3, 20.1, 18.0, 12.5; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₃₅ FNOSi: 364.2466, found: 364.2470.

Step C: 4-[3-(dimethylamino)but-1-ynyl]-2-fluorophenol

A 4 mL oven-dried flask fitted with a PTFE-lined magnetic stir bar was charged with 200 mg of the product from Step B (0.55 mmol, 1 equiv) dissolved in 3.0 mL of dry THF, and then 660 μL of TBAF (1 M in THF, 0.66 mmol, 1.1 equiv) was added dropwise at rt. The resulting mixture was stirred at rt for 15 min, during which time the reaction reached complete conversion. The reaction mixture was quenched by adding 200 μL of conc. _NH4Cl solution, and then celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was then purified by flash column chromatography using DCM and MeOH (1.2% NH ₃ ) as eluents to afford 80 mg (70%) of the desired product.

Synthesis of 6g and 6h: 2-Fluoro-4-(3-morpholinobut-1-ynyl)phenol (enantiomers 1 and 2)

Step A: [2-fluoro-4-(3-morpholinobut-1-ynyl)phenoxy]-triisopropylsilane

Using the General Procedure for Alkylation with an In Situ Generated Iodocontaining Compound, starting from 644 mg of the product from Preparation 6f, Step A (2 mmol, 1 equiv) as the appropriate alcohol and 5 mL of morpholine (10 mmol, 5 equiv, 2 M solution in MeOH) gave 370 mg (45%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.29 (dd, 1H), 7.15 (dm, 1H), 6.98 (t, 1H), 3.69 (q, 1H), 3.60 (m, 4H), 2.6/2.45 (m+m, 4H), 1.30 (d, 3H), 1.25 (m, 3H), 1.05 (d, 18H); ¹³ C NMR (500 MHz, DMSO-d ₆ ) δ ppm. 153.2, 144.0, 129.0, 122.3, 119.8, 116.5, 88.5, 84.1, 66.7, 52.1, 49.5, 19.3, 18.0, 12.5; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₃ H ₃₇ FNO ₂ Si: 406.2572, found: 406.2579.

Step B: 2-fluoro-4-(3-morpholinobut-1-ynyl)phenol

A 4 mL oven-dried flask fitted with a PTFE-lined magnetic stir bar was charged with 370 mg of the product from Step A (0.90 mmol, 1 equiv) dissolved in 3.0 mL of dry THF, and then 990 μL of TBAF (1 M in THF, 0.99 mmol, 1.1 equiv) was added dropwise at rt. The resulting mixture was stirred at rt for 15 min, during which time the reaction reached complete conversion. The reaction mixture was quenched by adding 200 μL of conc. _NH4Cl solution, and then celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was then purified by flash column chromatography using DCM and MeOH (1.2% NH ₃ ) as eluents to afford 150 mg (60%) of the desired product.

Enantiomers were separated by chiral chromatography. Column: AD-H, eluents: heptane/EtOH + 0.1% DEA; the earlier eluting enantiomer was collected as the product of Synthesis 6g with 99.8% ee, and the later eluting enantiomer was collected as the product of Synthesis 6h with 99.4% ee.

Synthesis 6i: 4-[1-[(Dimethylamino)methyl]-3-bicyclo[1.1.1]pentanyl]phenol

Step A: 1-(4-methoxyphenyl)-N,N-dimethylbicyclo[1.1.1]pentane-3-carboxamide

300 mg of 1-(4-methoxyphenyl)bicyclo[1.1.1]pentane-3-carboxylic acid (1.38 mmol, 1 equiv) and 278 mg of N,N-diethylethanamine (2.75 mmol, 2 equiv) were mixed in EtOAc (3 mL/mmol), then 1312 mg of 2,4,6-tripropyl- l,3,5,2λ ^Λ {5},4λ ^Λ {5},6λ ^Λ {5}-trioxatriphosphinane 2,4,6-trioxide (50 wt % in EtOAc, 2.06 mmol, 1.5 equiv) were added in one portion, and the mixture was stirred at rt for 40 min. After the reaction time, 1.03 mL of N-methylmethanamine (2 M in MeOH, 2.06 mmol, 1.5 equiv) was added and the mixture was stirred at rt until complete conversion was observed (30 min). The reaction mixture was diluted with DCM, washed with conc. _NaHCO3 , then the organic phase was washed with conc. NaCl, dried over _MgSO4 , filtered, concentrated, and dried in vacuo to give 346 mg (quant.) of the desired product as a peach-colored solid.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.14 (m, 2H), 6.86 (m, 2H), 3.72 (s, 3H), 3.08 (s, 3H), 2.81 (s, 3H), 2.26 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 168.9, 158.6, 132.5, 127.6, 114.1, 55.5, 54.2, 42.0, 39.0, 37.4, 35.9; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁ 5H ₂₀ NO ₂ : 246.1488, found: 246.1495.

Step B: 1-[3-(4-methoxyphenyl)-1-bicyclo[1.1.1]pentanyl]-N,N-dimethylmethanamine

289 mg of the product from Step A (1.18 mmol, 1 equiv) was dissolved in THF (5 mL/mmol), then 2.36 mL of _LiAlH4 (1 M in THF, 2.36 mmol, 2 equiv) was added at ambient temperature under nitrogen, and the mixture was stirred until complete conversion was achieved (approximately 1 h). The mixture was cooled to 0 °C, then quenched with conc. _NH4Cl . After quenching, ~5 mL of water and ~10 mL of EtOAc were added, and the mixture was shaken well. 2 M HCl was added and the (acidic) aqueous phase was separated, and the organic phase was then extracted with additional 2 M HCl. The combined aqueous phases were basified with 2 M NaOH and extracted with DCM.

The combined organic phases were washed with brine, dried over _MgSO4 , concentrated and dried in vacuo to give 219 mg (80%) of the desired product as a viscous oil.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.10 (m, 2H), 6.84 (m, 2H), 3.71 (s, 3H), 2.35 (s, 2H), 2.16 (s, 6H), 1.89 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 158.4, 133.4, 127.4, 114, 60.8, 55.5, 52.9, 46.6, 41.9, 38.0; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₅ H ₂₂ NO: 232.1696, found: 232.1700.

Step C: 4-[1-[(dimethylamino)methyl]-3-bicyclo[1.1.1]pentanyl]phenol

50 mg of the product from Step B (0.22 mmol, 1 equiv) was dissolved in DCM (5 mL/mmol), then 0.65 mL of _BBr3 (1 M in DCM, 0.65 mmol, 3 equiv) was added under nitrogen at 0 °C and the mixture was stirred for 30 min at 0 °C and at rt until complete conversion was achieved (approximately 45 min). DCM was added, the mixture was poured into _NaHCO3 solution, stirred for several minutes and then brought to neutrality with conc. _NH4Cl solution. The organic phase was separated and washed with brine, dried over _MgSO4 , concentrated and dried in vacuo. This gave 47 mg (quant.) of crude title product as a viscous oil.

¹ H NMR (400 MHz, CDCl ₃ ) δ ppm 7.07 (d, 2H), 6.81 (d, 2H), 5.18 (br. s, 1H), 3.83 (s, 2H), 3.17/3.16 (s+s, 6H), 2.23 (s, 6H); ¹³ C NMR (100 MHz, CDCl ₃ ) δ ppm 155.0, 131.3, 127.3, 115.4, 59.6, 54.7, 53.4, 46.0, 44.1; LC-ESI MS (m/z): [M+H] ⁺ , calculated for C ₁₄ H ₂₀ NO: 218.2, found: 218.2.

Synthesis of 6j: N,N-Dimethyl-3-(4-triisopropylsilyloxyphenyl)prop-2-yn-1-amine

500 mg 4-iodophenol (2.27 mmol, 1 equiv.) and 628 mg K ₂ CO ₃ (4.55 mmol, 2 equiv.) were mixed in acetonitrile (5 mL/mmol), then 526 mg chloro(triisopropyl)silane (2.73 mmol, 1.2 equiv.) were added at rt, and the mixture was stirred for 1 h. The reaction mixture was filtered through a pad of celite, then 236 mg N,N-dimethylprop-2-yn-1-amine (2.84 mmol, 1.25 equiv.), 50 mg Pd(PPh ₃ ) ₂ Cl ₂ (0.11 mmol, 0.05 equiv.), 22 mg CuI (0.11 mmol, 0.05 equiv.) and 2.27 mL of N-isopropylpropan-2-amine (1 mL/mmol) was added, and then the mixture was stirred at 50 °C for 3 h. The reaction mixture was concentrated on celite and purified by flash column chromatography using heptane and EtOAc as eluents to give 449 mg (60%) of the desired product as a yellow oil.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.32 (dm, 2H), 6.84 (dm, 2H), 3.41 (s, 2H), 2.22 (s, 6H), 1.24 (m, 3H), 1.06 (d, 18H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) 156, 133.5, 120.3, 116, 85.1/84.5, 44.3, 18.3, 12.4; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₀ H ₃₄ NOSi: 332.2404, found: 332.2405.

Synthesis of 6k: 2-Fluoro-4-{3-[(4-methoxyphenyl)methoxy]prop-1-yn-1-yl}phenol

Step A: 4-bromo-2-fluorophenyl acetate

To a solution of 4-bromo-2-fluorophenol (2.29 mL, 20.9 mmol, 1 equiv) in dichloromethane (60 mL) were added 4-(dimethylamino)pyridine (5.12 g, 41.9 mmol, 2 equiv) and acetic anhydride (4.94 mL, 52.4 mmol, 2.5 equiv), and the mixture was stirred at ambient temperature for 18 h. The reaction mixture was concentrated, then partitioned between dichloromethane and water, washed with brine, separated (phase separator), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0:10% ethyl acetate in isoheptane afforded the title product as a clear oil (5.1 g, 21.9 mmol, >100%).

^1H NMR (400 MHz, DMSO-d ₆ ) δ 7.75 (dd, J=10.0, 2.3 Hz, 1H), 7.48 (ddd, J=8.6, 2.3, 1.3 Hz, 1H), 7.30 (t, J=8.5 Hz, 1H), 2.41 (s, 3H).

Step B: 1-methoxy-4-[(prop-2-yn-1-yloxy)methyl]benzene

To a stirred suspension of sodium hydride (60% dispersion; 856 mg, 21.4 mmol, 1.2 equiv) in tetrahydrofuran (25 mL) cooled to 0°C was added a solution of propargyl alcohol (1.04 mL, 17.8 mmol, 1 equiv) in tetrahydrofuran (10 mL), followed by the addition of 1-(bromomethyl)-4-methoxybenzene (3.09 mL, 21.4 mmol, 1.2 equiv), and the mixture was stirred at ambient temperature for 18 h. The reaction mixture was partitioned between ethyl acetate and saturated aqueous ammonium chloride, and the organic phase was dried (magnesium sulfate), filtered, and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0:10% ethyl acetate in isoheptane afforded the title product as a clear oil (2.44 g, 13.9 mmol, 78%).

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.31 - 7.18 (m, 2H), 6.97 - 6.86 (m, 2H), 4.44 (s, 2H), 4.13 (d, J=2.4 Hz, 2H), 3.75 (s, 3H), 3.48 (t, J=2.4 Hz, 1H).

Step C: 2-fluoro-4-{3-[(4-methoxyphenyl)methoxy]prop-1-yn-1-yl}phenyl acetate

An oven-dried pressure tube was charged with the product from Step A (1.68 g, 7.23 mmol, 1 equiv), triethylamine (18 mL), the product from Step B (1.91 g, 10.8 mmol, 1.5 equiv), copper(I) iodide (275 mg, 1.45 mmol, 0.2 equiv), and tetrakis(triphenylphosphine)palladium(0) (835 mg, 0.72 mmol, 0.1 equiv), and the mixture was sparged with nitrogen (10 min), then the tube was stoppered and heated at 90 °C for 4 h. The reaction mixture was allowed to cool to ambient temperature, then partitioned between dichloromethane and brine, and the organic phase was separated, dried (PTFE phase separator). and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-30% ethyl acetate in isoheptane afforded the desired product as an orange solid (2.11 g, 6.43 mmol, 89%).

^1H NMR (400 MHz, DMSO-d ₆ ) δ 7.55 (dd, J=11.1, 1.7 Hz, 1H), 7.44-7.28 (m, 4H), 6.96-6.91 (m, 2H), 4.53 (s, 2H ), 4.39 (s, 2H), 3.76 (s, 3H), 2.34 (s, 3H).

Step D: 2-fluoro-4-{3-[(4-methoxyphenyl)methoxy]prop-1-yn-1-yl}phenol

To a solution of the product from Step C (200 mg, 0.61 mmol, 1 equiv) in methanol (15 mL) was added potassium carbonate (253 mg, 1.83 mmol, 3 equiv) and the mixture was stirred at ambient temperature for 3 h. The reaction mixture was concentrated in vacuo, partitioned between dichloromethane and dilute aqueous hydrochloric acid, and the organic phase was separated (PTFE phase separator) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-40% ethyl acetate in isoheptane afforded the desired product as a yellow gum (128 mg, 0.45 mmol, 73%).

LC/MS (C ₁₇ H ₁₅ FO ₃ ) 285 [M-H] ^- ; RT 2.09 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 10.37 (s, 1H), 7.32-7.24 (m, 3H), 7.16-7.10 (m, 1H), 6.98-6.90 (m, 3H), 4.50 (s, 2H), 4.34 (s, 2H), 3.75 (s, 3H).

Synthesis of 7c: 3,6-Dichloro-4-(propan-2-yl)pyridazine

3,6-Dichloropyridazine (5 g, 33.6 mmol, 1 equiv), silver nitrate (5.7 g, 33.6 mmol, 1 equiv), and isobutyric acid (2.96 g, 33.6 mmol, 1 equiv) were suspended in water (100 mL). The mixture was heated to 50 °C and sulfuric acid (9.88 g, 101 mmol, 3 equiv) was added. The mixture was heated to 60 °C and 1.6 M aqueous ammonium persulfate solution (62.9 mL, 101 mmol, 3 equiv) was added dropwise, and the reaction mixture was heated at 70 °C for 30 min. The mixture was allowed to cool to ambient temperature, then cooled to 0°C and slowly neutralized with concentrated ammonium hydroxide solution to pH 7, and then adjusted to pH 8-9. A yellow precipitate formed, which was filtered and washed with water and ethyl acetate to give a white solid. The filtrates were combined, the layers were separated, and the aqueous phase was extracted with ethyl acetate (100 ml). The combined organics were washed with brine (100 ml), dried (magnesium sulfate), and concentrated in vacuo to give a yellow oil. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% ethyl acetate in heptane afforded the title product as a colourless oil (4.61 g, 24.1 mmol, 72%).

LC/MS (C ₇ H ₈ C ₁₂ N ₂ ) 191 [M+H] ⁺ ; RT 1.11 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 8.00 (d, J=0.6 Hz, 1H), 3.16 (h, 1H), 1.26 (d, J=6.8 Hz, 6H).

Synthesis 7e: 3,6-Dichloro-4-methyl-5-(propan-2-yl)pyridazine

A suspension of 3,6-dichloro-4-methylpyridazine (0.5 g, 3.07 mmol, 1 equiv), isobutyric acid (0.28 mL, 3.07 mmol, 1 equiv), and silver nitrate (0.52 g, 3.07 mmol, 1 equiv) in water (10 mL) was heated to 50 °C. Sulfuric acid (0.49 mL, 9.2 mmol, 3 equiv) was added and the mixture was heated to 60 °C. Aqueous 1.6 M ammonium persulfate solution (5.75 mL, 9.2 mmol, 3 equiv) was added dropwise and the mixture was stirred for 30 min and then allowed to cool to ambient temperature. Neutralization with ammonium hydroxide, filtration through Celite, and elution with ethyl acetate afforded a biphasic mixture. The layers were separated, the aqueous phase was extracted with ethyl acetate, and the combined organics were dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0:15% ethyl acetate in isoheptane afforded the title product as a white solid (476 mg, 2.32 mmol, 76%).

LC/MS (C ₈ H ₁₀ Cl ₂ N ₂ ) 205 [M+H] ⁺ ; RT 1.15 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 3.57 (hept, J=7.2 Hz, 1H), 2.49 (s, 3H), 1.35 (d, J=7.2 Hz, 6H).

Synthesis of 7f: 3,6-Dichloro-4-ethyl-5-methylpyridazine

To a stirred suspension of 3,6-dichloro-4-methylpyridazine (5 g, 30.7 mmol, 1 equiv) and propionic acid (2.75 mL, 36.8 mmol, 1.2 equiv) in water (100 mL) was added silver nitrate (5.21 g, 30.7 mmol, 1 equiv) and the mixture was heated to 50 °C. Sulfuric acid (4.91 mL, 92 mmol, 3 equiv) was added dropwise and the reaction mixture was heated to 60 °C. Then 1.6 M aqueous ammonium persulfate solution (57.5 mL, 92 mmol, 3 equiv) was added dropwise over 20 min. The reaction mixture was heated to 70 °C for 30 min and then allowed to cool to ambient temperature. The mixture was basified to pH 8 using concentrated ammonium hydroxide solution and the product was extracted into ethyl acetate (100 mL x 2). The combined organic extracts were dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 120 g RediSep™ silica gel cartridge) eluting with a gradient of 0:25% ethyl acetate in isoheptane afforded the title product as a white solid (4.11 g, 21.5 mmol, 70%).

LC/MS (C ₇ H ₈ Cl ₂ N ₂ ) 191 [M+H] ⁺ ; RT 2.17 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 2.82 (q, J=7.6 Hz, 2H), 2.44 (s, 3H), 1.13 (t, J=7.6 Hz, 3H).

Synthesis of 7g: 4-[(Benzyloxy)methyl]-3,6-dichloro-5-methylpyridazine

To a suspension of 3,6-dichloro-4-methylpyridazine (5.1 g, 30.7 mmol, 1 equiv) and benzyloxyacetic acid (5.61 g, 33.7 mmol, 1.1 equiv) in water (100 mL) was added silver nitrate (5.21 g, 30.7 mmol, 1 equiv) and the mixture was heated to 50 °C. Sulfuric acid (4.91 mL, 92 mmol, 3 equiv) was added and the mixture was heated to 60 °C. Aqueous 1.6 M ammonium persulfate solution (57.5 mL, 92 mmol, 3 equiv) was added dropwise and the reaction mixture was heated at 70 °C for 30 min. The mixture was allowed to cool to ambient temperature and basified to pH 8 with concentrated aqueous ammonium hydroxide. The mixture was extracted with ethyl acetate (2 x 150 mL) and the combined organics were washed with brine (200 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 120 g RediSep™ silica gel cartridge) eluting with a gradient of 0:25% ethyl acetate in isoheptane afforded the title product as a yellow oil (4.67 g, 16.5 mmol, 54%).

LC/MS (C ₁₃ H ₁₂ Cl ₂ N ₂ O) 283 [M+H] ⁺ ; RT 1.26 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.42 - 7.27 (m, 5H), 4.71 (s, 2H), 4.60 (s, 2H), 2.46 (s, 3H).

Synthesis 7h: 3,6-Dichloro-4-cyclopropyl-5-methylpyridazine

To a suspension of 3,6-dichloro-4-methylpyridazine (4.88 g, 29.9 mmol, 1 equiv.) and cyclopropanecarboxylic acid (2.63 mL, 32.9 mmol, 1.1 equiv.) in water (100 mL) was added silver nitrate (5.09 g, 29.9 mmol, 1 equiv.), and the mixture was heated to 50 °C. Sulfuric acid (4.79 mL, 89.8 mmol, 3 equiv.) was added to the mixture, and the mixture was heated to 60 °C. 1.6 M aqueous ammonium persulfate solution (56.1 mL, 89.8 mmol, 3 equiv.) was added dropwise over 20 min, and the mixture was then heated to 70 °C and stirred for 30 min. The mixture was allowed to cool to ambient temperature and basified to pH 8 with concentrated ammonium hydroxide solution. The product was extracted into the organic phase using ethyl acetate (2 x 200 mL) and the combined organic extracts were washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 120 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 30% ethyl acetate in isoheptane afforded the title product as a white solid (3.99 g, 19.7 mmol, 66%).

LC/MS (C ₈ H ₈ Cl ₂ N ₂ ) 203 [M+H] ⁺ ; RT 1.09 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 2.49 (d, J=0.9 Hz, 3H), 1.98 - 1.88 (m, 1H), 1.26-1.11 (m, 2H), 0.78-0.67 (m, 2H ).

Synthesis 71: 3,6-Dichloro-4-cyclopropylpyridazine

To a suspension of 3,6-dichloropyridazine (2 g, 13.4 mmol, 1 equiv) and cyclopropanecarboxylic acid (1.07 mL, 13.4 mmol, 1 equiv) in water (85 mL) was added silver nitrate (2.28 g, 13.4 mmol, 1 equiv) and the mixture was heated to 50 °C. Sulfuric acid (2.15 mL, 40.3 mmol, 3 equiv) was added and the mixture was heated to 60 °C. Aqueous 1.6 M ammonium persulfate solution (25.2 mL, 40.3 mmol, 3 equiv) was added dropwise over 15 min and the reaction mixture was then heated at 70 °C for 30 min. The mixture was allowed to cool to ambient temperature and basified to pH 10 with concentrated ammonium hydroxide solution. The product was extracted into ethyl acetate (2 x 150 mL) and the extracts were washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 20% ethyl acetate in isoheptane afforded the title product as a white solid (985 mg, 5.21 mmol, 39%).

LC/MS (C ₇ H ₆ Cl ₂ N ₂ ) 189 [M+H] ⁺ ; RT 1.00 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.61 (d, J=0.6 Hz, 1H), 2.19-2.09 (m, 1H), 1.25-1.19 (m, 2H), 1.08-1.03 (m, 2H ).

Synthesis 7m: 4-[3-(Benzyloxy)propyl]-3,6-dichloro-5-methylpyridazine Step A: [(pent-4-yn-1-yloxy)methyl]benzene

An oven-dried flask was charged with 4-pentyn-1-ol (5.53 mL, 59.4 mmol, 1 equiv) and tetrahydrofuran (50 mL) and the solution was cooled to 0 °C. Sodium hydride (60%; 2.85 g, 119 mmol, 2 equiv) was added portionwise and the reaction mixture was allowed to stir for 30 min at 0 °C. Benzyl bromide (7.42 mL, 62.4 mmol, 1.05 equiv) was added dropwise and the reaction mixture was allowed to warm to ambient temperature and stirred for 16 h. The reaction mixture was cooled to 0 °C and quenched by adding saturated aqueous ammonium chloride (20 mL). Water (20 mL) was added and the layers were separated. The aqueous layer was extracted with ethyl acetate (2 x 50 mL) and the combined organics were washed with brine (50 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 120 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% ethyl acetate in isoheptane afforded the title product as a yellow oil (8.93 g, 51.3 mmol, 86%).

LC/MS (C ₁₂ H ₁₄ O) 175 [M+H] ⁺ ; RT 1.25 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.42 - 7.21 (m, 5H), 4.52 (s, 2H), 3.57 (t, J=6.2 Hz, 2H), 2.32 (td, J=7.1, 2.7 Hz, 2H), 1.94 (t, J=2.7 Hz, 1H), 1.84 (tt, J=7.1, 6.2 Hz, 2H).

Step B: [(hex-4-yn-1-yloxy)methyl]benzene

A solution of the product from Step A (3.9 g, 22.4 mmol, 1 equiv.) in tetrahydrofuran (30 mL) was charged into an oven-dried flask under nitrogen atmosphere. The reaction mixture was cooled to -78 °C and n-butyl lithium (2.2 M in hexane; 12.2 mL, 26.9 mmol, 1.2 equiv) was added over 30 min and the mixture was stirred at -78 °C for 1 h. Iodomethane (2.09 mL, 33.6 mmol, 1.5 equiv) was added dropwise and the resulting mixture was allowed to warm to 0 °C over 2 h. The reaction mixture was quenched by the addition of saturated aqueous ammonium chloride solution (20 mL), then diluted with water (20 mL) and extracted with ethyl acetate (3 x 20 mL). The combined organic extracts were washed successively with 2 M aqueous sodium thiosulfate solution (50 mL) and brine (50 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0:10% ethyl acetate in isoheptane afforded the title product as a straw-yellow liquid (3.61 g, 19.2 mmol, 86%).

LC/MS (C ₁₃ H ₁₆ O) without ionization; RT 1.15 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.43-7.19 (m, 5H), 4.46 (s, 2H), 3.48 (t, J=6.3 Hz, 2H), 2.23-2.14 (m, 2H), 1.72 (t, 3H), 1.71-1.62 (m, 2H).

Step C: 4-[3-(Benzyloxy)propyl]-3,6-dichloro-5-methylpyridazine A solution of dichloro-1,2,4,5-tetrazine (2.5 g, 16.6 mmol, 1 equiv) and the product from Step B (3.74 g, 19.9 mmol, 1.2 equiv) in toluene (15 mL) was heated in a sealed tube at 160°C for 20 h. The mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0-35% ethyl acetate in isoheptane afforded the title product as an orange oil (3.06 g, 9.83 mmol, 62%).

LC/MS (C ₁₅ H ₁₆ Cl ₂ N ₂ O) 311 [M+H] ⁺ ; RT 1.35 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.47-7.14 (m, 5H), 4.48 (s, 2H), 3.53 (t, J=5.9 Hz, 2H), 2.96-2.81 (m, 2H), 2.42 (s, 3H), 1.87-1.72 (m, 2H).

Synthesis of 8ca and 8cb: 6-Chloro-5-(propan-2-yl)pyridazin-3-amine and 6-Chloro-4-(propan-2-yl)pyridazin-3-amine

The product of Preparation 7c (3.61 g, 18.9 mmol, 1 equiv) was suspended in ammonia water (20 mL) and heated at 150 °C for 4 h under microwave irradiation. The solids were collected by filtration, washed with water and dried to give 6-chloro-5-(propan-2-yl)pyridazin-3-amine (2.06 g, 12 mmol, 64%) as an off-white solid [~9:1 mixture with other regioisomer] (Product of Preparation 8ca).

LC/MS (C7H ₁₀ ClN ₃ ) 172 [M+H] ⁺ ; RT 0.81 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 6.76 (d, J=0.7 Hz, 1H), 6.51 (s, 2H), 3.06-2.82 (m, 1H), 1.18 (d, 6H).

The filtrate was concentrated in vacuo and the crude solid residue was extracted with dichloromethane, filtered and evaporated to give 6-chloro-4-isopropylpyridazin-3-amine (447 mg, 2.6 mmol, 14%) as a yellow oil [~7:3 mixture with other regioisomer] (Synthesis product 8cb).

LC/MS (C ₇ H ₁₀ ClN ₃ ) 172 [M+H] ⁺ ; RT 0.79 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.23 (s, 1H), 6.53 (s, 2H), 2.95 - 2.80 (m, 1H), 1.15 (d, 6H).

Synthesis of 8d: 6-Chloro-5-methylpyridazin-3-amine and 6-Chloro-4-methylpyridazin-3-amine

A suspension of 3,6-dichloro-4-methylpyridazine (2 g, 12.3 mmol, 1 equiv.) in ammonia water (40 mL) was heated in a high-pressure reactor at 150 °C for 6 h and then allowed to cool to ambient temperature. The resulting precipitate was filtered, washed with water (10 mL), and dried to give the title product as fine brown needles (1.31 g, 0.01 mol, 74%) [regioisomer ratio ~6:4]. The mixture of isomers was used in the next step without further purification.

LC/MS (C ₅ H ₆ ClN ₃ ) without ionization; RT 0.28 (LCMS-V-B1)

Synthesis 8e: 6-Chloro-4-methyl-5-(propan-2-yl)pyridazin-3-amine and 6-Chloro-5-methyl-4-(propan-2-yl)pyridazin-3-amine

The product of synthesis 7e (480 mg, 2.34 mmol, 1 equiv) was introduced into a high-pressure reaction vessel. Ammonia water (15 mL) was added, the vessel was stoppered, and the mixture was stirred at 160 °C for 6 h. Then the reaction mixture was allowed to cool to ambient temperature, the vessel was opened, and the reaction mixture was concentrated in vacuo, and the mixture of isomers was used in the next step without purification.

LC/MS (C ₈ H ₁₂ ClN ₃ ) 186 [M+H] ⁺ ; RT 0.88 (LCMS-V-B1)

Synthesis of 8f: 6-Chloro-5-ethyl-4-methylpyridazin-3-amine and 6-Chloro-4-ethyl-5-methylpyridazin-3-amine

A suspension of Preparation 7f (4 g, 21 mmol, 1 equiv) in ammonia water (15 mL) was stirred at 160 °C in a sealed flask for 24 h. The mixture was allowed to cool to ambient temperature and precipitation of a brown solid was observed. The solid was collected by filtration, washed with water and dried in vacuo to give the desired products as a brown solid (1.4 g, 8.16 mmol, 39%) [2:1 mixture of regioisomers]. The mixture of isomers was used in the next step without purification.

LC/MS (C ₇ H ₁₀ ClN ₃ ) 172 [M+H] ⁺ ; RT 1.53 (LCMS-VC)

Synthesis 8g: 5-[(Benzyloxy)methyl]-6-chloro-4-methylpyridazin-3-amine and 4-[(Benzyloxy)methyl]-6-chloro-5-methylpyridazin-3-amine

The product of Synthesis 7g (600 mg, 2.12 mmol, 1 equiv) was suspended as an oil in ammonia water (7 mL) and heated at 160 °C for 5 h in a sealed tube. The mixture was allowed to cool to ambient temperature and precipitation of a brown solid was observed. The solid was collected by filtration, washed with water and dried in vacuo to give the desired product (455 mg, 1.73 mmol, 81%) as a mixture of two regioisomers, which was used directly in the next step.

LC/MS (C ₁₃ H ₁₄ ClN ₃ O) 264 [M+H] ⁺ ; RT 1.02 (LCMS-V-B1)

Synthesis of 8ha and 8hb: 6-Chloro-5-cyclopropyl-4-methylpyridazin-3-amine and 6-Chloro-4-cyclopropyl-5-methylpyridazin-3-amine

The product of Synthesis 7h (3.99 g, 19.7 mmol, 1 equiv) was suspended in ammonia water (10 mL) and heated in a sealed tube for 20 h. The mixture was allowed to cool to ambient temperature and the precipitated solid was collected by filtration and dried to give 6-chloro-5-cyclopropyl-4-methylpyridazin-3-amine (2.44 g, 13.3 mmol, 68%) [Synthesis product 8ha], which was used directly in the next step without further purification.

LC/MS (C ₈ H ₁₀ ClN ₃ ) 184 [M+H] ⁺ ; RT 0.80 (LCMS-V-B1)

The filtrate was concentrated under reduced pressure and then evaporated with toluene (x3) to remove residual water to give a crude product (2.00 g, 10.89 mmol, 55%) containing 6-chloro-4-cyclopropyl-5-methylpyridazin-3-amine, which was directly used in the next steps without further purification [Synthesis product 8hb].

LC/MS (C ₈ H ₁₀ ClN ₃ ) 184 [M+H] ⁺ ; RT 0.79 (LCMS-V-B1)

Synthesis of 8ia and 8ib: (6-Amino-3-chloro-5-methylpyridazin-4-yl)methanol and (3-Amino-6-chloro-5-methylpyridazin-4-yl)methanol

To a cooled solution of Preparation 8g (3.1 g, 11.8 mmol, 1 equiv.) in dichloromethane (100 mL) was added boron trichloride solution (58.8 mL, 1 M, 0.06 mol, 5 equiv.) dropwise, and the mixture was stirred at ambient temperature for 2 h. The reaction mixture was cooled to 0-5 °C and carefully quenched by adding methanol (30 mL). Additional methanol (30 mL) was added, and the mixture was heated under reflux for 30 min. The solvent was removed in vacuo and the crude product was purified by automated flash column chromatography (CombiFlash Rf, 120 g RediSep™ silica gel cartridge) eluting with a gradient of 0-17.5% methanol in dichloromethane to afford the desired regioisomeric products:

(3-Amino-6-chloro-5-methylpyridazin-4-yl)methanol as a beige solid (0.87 g, 5.0 mmol, 42%) [Synthesis product 8ib].

LC/MS (C ₆ H ₈ ClN ₃ O) 174 [M+H] ⁺ ; RT 0.26 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 8.13 (s, 2H), 4.57 (s, 2H), 2.40 (s, 3H). (6-Amino-3-chloro-5-methylpyridazin-4-yl)methanol as a beige solid (1.38 g, 7.9 mmol, 67%) [Synthesis product 8ia].

LC/MS (C ₆ H ₈ ClN ₃ O) 174 [M+H] ⁺ ; RT 0.18 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 8.18 (s, 2H), 4.56 (s, 2H), 2.31 (s, 3H).

Synthesis of 8ja: 6-Chloro-5-(methoxymethyl)-4-methylpyridazin-3-amine

Step A: 5-(bromomethyl)-6-chloro-4-methylpyridazin-3-amine

To a suspension of the product of Synthesis 8ia (960 mg, 5.53 mmol, 1 equiv) in dichloromethane (50 mL) was added phosphorus tribromide (0.62 mL, 6.34 mmol, 1.2 equiv) and the mixture was stirred for 1 h at ambient temperature. The reaction mixture was quenched by addition of methanol (20 mL) and concentrated in vacuo to give a solid (3.2 g). The material was used directly in the next step without further purification.

LC/MS (C ₆ H ₇ BrClN ₃ ) 238 [M+H] ⁺ ; RT 0.81 (LCMS-V-B1)

Step B: 6-chloro-5-(methoxymethyl)-4-methylpyridazin-3-amine

A solution of the crude product from Step A (780 mg) in methanol (10 mL) was heated at 120 °C for 1 h under microwave irradiation. The mixture was concentrated in vacuo and purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane to give the desired product as a brown oil (323 mg, 0.90 mmol, 66% for both steps).

LC/MS (C ₇ H ₁₀ ClN ₃ O) 188 [M+H] ⁺ ; RT 0.61 (LCMS-V-B1)

Synthesis of 8jb: 6-Chloro-4-(methoxymethyl)-5-methylpyridazin-3-amine

Step A: 4-(bromomethyl)-6-chloro-5-methylpyridazin-3-amine

To a suspension of the product of Synthesis 8ib (500 mg, 2.88 mmol, 1 equiv) in dichloromethane (50 mL) was added phosphorus tribromide (0.32 mL, 3.46 mmol, 1.2 equiv) and the mixture was stirred for 1 h at ambient temperature. The reaction mixture was quenched by the addition of methanol (20 mL) and then the volatile organics were removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the desired product as an orange solid (695 mg, 2.94 mmol, 100%).

LC/MS (C ₆ H ₇ BrClN ₃ ) 238 [M+H] ⁺ ; RT 0.82 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.84 (br s, including water peak), 4.76 (s, 2H), 2.38 (s, 3H).

Step B: 6-chloro-4-(methoxymethyl)-5-methylpyridazin-3-amine

A solution of the product from Step A (430 mg, 1.82 mmol, 1 equiv.) in methanol (10 mL) was heated at 120 °C for 30 min under microwave irradiation. The mixture was concentrated in vacuo and purified by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane to give the desired product as a purple crystalline solid (91 mg, 0.49 mmol, 27%).

LC/MS (C ₇ H10ClN ₃ O) 188 [M+H] ⁺ ; RT 0.70 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.66 (s, 2H), 4.50 (s, 2H), 3.32 (s, 3H), 2.38 (s, 3H).

Synthesis of 8ka: 6-Chloro-5-(ethoxymethyl)-4-methylpyridazin-3-amine

A solution of the product of Preparation 8ja, Step A (500 mg, 2.11 mmol, 1 equiv) in ethanol (15 mL) was heated at 120 °C for 1 h under microwave irradiation. The mixture was concentrated in vacuo and purified by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane to afford the desired product as a viscous oil that crystallized upon scratching (136 mg, 0.67 mmol, 32%).

LC/MS (C ₈ H ₁₂ ClN ₃ O) 202 [M+H] ⁺ ; RT 0.63 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 4.56 (s, 2H), 3.55 (q, J=7.0 Hz, 2H), 2.28 (s, 3H), 1.14 (t, J=7.0 Hz, 3H).

Synthesis of 8ma and 8mb: 5-[3-(Benzyloxy)propyl]-6-chloro-4-methylpyridazin-3-amine and 4-[3-(Benzyloxy)propyl]-6-chloro-5-methylpyridazin-3-amine

The product of Synthesis 7m (3.06 g, 9.83 mmol, 1 equiv.) and ammonia water (15 mL) were heated in a sealed flask for 48 h at 160 °C. The mixture was allowed to cool to ambient temperature and extracted with dichloromethane (2 x 100 mL). The organics were washed with brine (50 mL) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0 100% ethyl acetate in isoheptane afforded the desired regioisomeric products:

5-[3-(Benzyloxy)propyl]-6-chloro-4-methylpyridazin-3-amine as a beige solid (1.3 g, 4.46 mmol, 45%) [Synthesis product 8 ta].

LC/MS (C ₁₅ H ₁₈ ClN ₃ O) 292 [M+H] ⁺ ; RT 1.12 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.47-7.20 (m, 5H), 6.33 (s, 2H), 4.48 (s, 2H), 3.49 (t, J=6.0 Hz, 2H), 2.79-2.66 (m, 2H), 2.08 (s, 3H), 1.84-1.65 (m, 2H).

4-[3-(Benzyloxy)propyl]-6-chloro-5-methylpyridazin-3-amine as a beige solid (500 mg, 1.71 mmol, 17%) [Synthesis product 8mb].

LC/MS (C ₁₅ H ₁₈ ClN ₃ O) 292 [M+H] ⁺ ; RT 1.15 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.49-7.15 (m, 5H), 6.34 (s, 2H), 4.48 (s, 2H), 3.47 (t, J=6.2 Hz, 2H), 2.72-2.54 (m, 2H), 2.22 (s, 3H), 1.83-1.61 (m, 2H).

Synthesis 9a: N-(6-Chloro-4,5-dimethylpyridazin-3-yl)-1,3-benzothiazol-2-amine

To a solution of 3-amino-6-chloro-4,5-dimethylpyridazine (450 mg, 2.86 mmol, 1 equiv) and 2-bromo-1,3-benzothiazole (672 mg, 3.14 mmol, 1.1 equiv) in 1,4-dioxane (20 mL) was added sodium hydride (60% dispersion; 457 mg, 11.42 mmol, 4 equiv) portionwise and the mixture was heated under reflux for 16 h. The reaction mixture was allowed to cool to ambient temperature and then quenched with acetic acid. The mixture was diluted with ethyl acetate (200 mL) and washed with aqueous saturated sodium bicarbonate (100 mL) and brine (100 mL). The organic extract was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-3% methanol in dichloromethane afforded the title product as a yellow solid (673 mg, 2.32 mmol, 81%).

LC/MS (C ₁₃ H ₁₁ ClN ₄ S) 291 [M+H] ⁺ ; RT 1.22 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d ₆ ) δ 11.80 (br s, 1H), 7.86 (d, J=7.75 Hz, 1H), 7.50 (s, 1H), 7.40 (td, J=1.28, 7.69 Hz , 1H), 7.22 (t, J=7.67 Hz, 1H), 2.37 (s, 3H), 2.33 (s, 3H).

Synthesis 9b: N-(6-Chloropyridazin-3-yl)-1,3-benzothiazol-2-amine

To a solution of 3-amino-6-chloropyridazine (2 g, 15.4 mmol, 1 equiv) and 2-bromo-1,3-benzothiazole (3.64 g, 17.0 mmol, 1.1 equiv) in 1,4-dioxane (120 mL) was added sodium hydride (60% dispersion; 2.47 g, 61.8 mmol, 4 equiv) portionwise and the mixture was heated at reflux for 30 min. The reaction mixture was allowed to cool to ambient temperature and then cooled in an ice/water bath and quenched with methanol. Removal of methanol by rotary evaporation caused precipitation of a solid. The mixture was cooled in ice-water and the solid was collected by filtration, washed with ice-cold 1,4-dioxane (100 mL) and then with diethyl ether (100 mL). Finally, the solid was suspended in water, the pH was adjusted to 7 and the solid was collected by filtration and dried in vacuo to give the title product (1.94 g, 7.38 mmol, 48%).

LC/MS (C ₁₁ H ₇ ClN ₄ S) 263 [M+H] ⁺ ; RT 1.1 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d ₆ ) δ 12.03 (s, 1H), 8.00-7.93 (m, 1H), 7.82 (d, J=9.3 Hz, 1H), 7.69 (d, J=8.0 Hz, 1H), 7.59 (d, J=9.3 Hz, 1H), 7.46-7.37 (m, 1H), 7.30-7.23 (m, 1H).

Synthesis of 9ca: N-[6-Chloro-5-(propan-2-yl)pyridazin-3-yl]-1,3-benzothiazol-2-amine

To a suspension of the product of Synthesis 8ca (2.06 g, 12 mmol, 1 equiv.) in 1,4-dioxane (70 mL) was added 2-bromo-1,3-benzothiazole (2.83 g, 13.2 mmol, 1.1 equiv.) followed by portionwise addition of sodium hydride (60% dispersion; 0.96 g, 24.01 mmol, 2 equiv.) and the mixture was heated at 90 °C for 30 min. The reaction mixture was then allowed to cool to ambient temperature, after which the mixture was cooled in ice-water, quenched by addition of acetic acid and concentrated in vacuo. The resulting solid was triturated with water, filtered and dried in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 120 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded a solid that was triturated with ethyl acetate, filtered, and dried under vacuum to afford the title product as an off-white solid (1.54 g, 5.05 mmol, 42%).

LC/MS (C ₁₄ H ₁₃ ClN ₄ S) 305 [M+H] ⁺ ; RT 1.31 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.87 (s, 1H), 7.99-7.91 (m, 1H), 7.69 (d, J=8.1 Hz, 1H), 7.51 (s, 1H), 7.42 ( ddd, J=8.3, 7.2, 1.3 Hz, 1H), 7.26 (ddd, J=8.2, 7.3, 1.2 Hz, 1H), 3.25 3.06 (m, 1H), 1.26 (d, J=6.8 Hz, 6H).

Synthesis of 9cb: N-[6-Chloro-4-(propan-2-yl)pyridazin-3-yl]-1,3-benzothiazol-2-amine

To a solution of Preparation 8cb (47 mg, 2.6 mmol, 1 equiv) and 2-bromo-1,3-benzothiazole (669 mg, 3.13 mmol, 1.2 equiv) in 1,4-dioxane (10 mL) was added sodium hydride (60% dispersion; 208 mg, 5.21 mmol, 2 equiv) portionwise and the mixture was heated under reflux for 1 h. The mixture was allowed to cool to ambient temperature, then cooled to 0 °C and quenched by addition of acetic acid. After evaporation, the residue was partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0:20% ethyl acetate in isoheptane afforded the title product as a bright yellow solid (367 mg, 1.2 mmol, 46%).

LC/MS (C ₁₄ H ₁₃ ClN ₄ S) 305 [M+H] ⁺ ; RT 1.35 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 12.64 (s, 1H), 7.82 (br s, 1H), 7.61 (s, 1H), 7.40 (br s+1, J=7.3 Hz, 2H), 7.22 (t, J=6.8 Hz, 1H), 3.49 (p, J=6.8 Hz, 1H), 1.25 (d, J=6.9 Hz, 6H).

Synthesis of 9da and 9db: N-(6-Chloro-5-methylpyridazin-3-yl)-1,3-benzothiazol-2-amine and N-(6-Chloro-4-methylpyridazin-3-yl)-1,3-benzothiazol-2-amine

To a suspension of Preparation 8d (1.31 g, 9.1 mmol, 1 equiv) and 2-bromo-1,3-benzothiazole (2.14 g, 10.01 mmol, 1.1 equiv) in 1,4-dioxane (50 mL) was added sodium hydride (60% dispersion; 0.73 g, 18.2 mmol, 2 equiv) portionwise and the mixture was heated at reflux for 1 h. The reaction mixture was allowed to cool to ambient temperature, quenched with acetic acid, then neutralized with aqueous sodium bicarbonate. The mixture was extracted with ethyl acetate (100 mL x 3) and the combined organic extracts were washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 120 g RediSep™ silica gel cartridge) eluting with a gradient of 0 80% ethyl acetate in isoheptane afforded the desired products:

N-(6-Chloro-4-methylpyridazin-3-yl)-1,3-benzothiazol-2-amine as a yellow solid (140 mg, 0.51 mmol, 5.6%) [Synthesis product 9db].

LC/MS (C ₁₂ H ₉ ClN ₄ S) 277 [M+H] ⁺ ; RT 1.18 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d ₆ ) δ 7.90 (s, 1H), 7.71 (s, 1H), 7.57 (br s, 1H), 7.41 (t, J=7.5 Hz, 1H), 7.24 (t , J=7.5 Hz, 1H), 2.39 (s, 3H).

N-(6-Chloro-5-methylpyridazin-3-yl)-1,3-benzothiazol-2-amine as a yellow solid (69 mg, 0.25 mmol, 2.7%) [Synthesis product 9da].

LC/MS (C ₁₂ H ₉ ClN ₄ S) 277 [M+H] ⁺ ; RT 1.15 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.92 (s, 1H), 7.96 (d, J=7.7 Hz, 1H), 7.69 (d, J=8.5 Hz, 1H), 7.48 (d, J=1.2 Hz, 1H), 7.42 (ddd, J=8.2, 7.2, 1.3 Hz, 1H), 7.26 (ddd, J=8.2, 7.3, 1.2 Hz, 1H), 2.38 (d, J=1.0 Hz, 3H).

Synthesis of 9ea and 9eb: N-[6-Chloro-4-methyl-5-(propan-2-yl)pyridazin-3-yl]-1,3-benzothiazol-2-amine and N-[6-Chloro-5-methyl-4-(propan-2-yl)pyridazin-3-yl]-1,3-benzothiazol-2-amine

To a suspension of Preparation 8e (434 mg, 2.34 mmol, 1 equiv) and 2-bromo-1,3-benzothiazole (551 mg, 2.57 mmol, 1.1 equiv) in 1,4-dioxane (10 mL) was added sodium hydride (60% dispersion; 187 mg, 4.68 mmol, 2 equiv) portionwise and the mixture was heated at reflux for 1 h. The mixture was then diluted with aqueous sodium bicarbonate and the product was extracted with dichloromethane. The organics were washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 30% ethyl acetate in isoheptane afforded the desired regioisomeric products:

N-[6-Chloro-5-methyl-4-(propan-2-yl)pyridazin-3-yl]-1,3-benzothiazol-2-amine as a yellow solid (114 mg, 0.36 mmol, 15%) [Synthesis product 9eb].

LC/MS (C ₁₅ H ₁₅ ClN ₄ S) 319 [M+H] ⁺ ; RT 1.39 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 12.48 (s, 1H), 7.73 (d, J=7.8 Hz, 1H), 7.41-7.32 (m, 1H), 7.3 7.26 (m, 1H), 7.18 (t, J=7.5 Hz, 1H), 3.76-3.58 (m, 1H), 2.41 (s, 3H), 1.41 (d, J=7.0 Hz, 6H).

N-[6-Chloro-4-methyl-5-(propan-2-yl)pyridazin-3-yl]-1,3-benzothiazol-2-amine as an orange solid (300 mg, 0.94 mmol, 40%) [Synthesis product 9ea].

LC/MS (C ₁₅ H ₁₅ ClN ₄ S) 319 [M+H] ⁺ ; RT 1.36 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO- _d6 ) δ 12.64 (br s, 1H), 7.91-7.78 (m, 1H), 7.46 (br s, 1H), 7.40 (t, 1H), 7.22 (t, 1H ), 3.56 (h, 1H), 2.47 (s, 3H), 1.37 (d, J=7.2 Hz, 6H).

Synthesis of 9fa and 9fb: N-(6-Chloro-5-ethyl-4-methylpyridazin-3-yl)-1,3-benzothiazol-2-amine and N-(6-chloro-4-ethyl-5-methylpyridazin-3-yl)-1,3-benzothiazol-2-amine

To a suspension of Preparation 8f (1.4 g, 8.16 mmol, 1 equiv) and 2-bromo-1,3-benzothiazole (2.1 g, 9.79 mmol, 1.2 equiv) in 1,4-dioxane (50 mL) was added sodium hydride (60% dispersion; 1.31 g, 32.6 mmol, 4 equiv) portionwise. The mixture was heated at reflux for 1.5 h and then allowed to cool to ambient temperature. The reaction mixture was quenched with acetic acid and neutralized with sodium bicarbonate. The mixture was extracted with ethyl acetate (×2) and the combined organic extracts were washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 120 g RediSep™ silica gel cartridge) eluting with a gradient of 0-35% ethyl acetate in isoheptane afforded the desired regioisomeric products:

N-(6-Chloro-4-ethyl-5-methylpyridazin-3-yl)-1,3-benzothiazol-2-amine as a yellow solid (330 mg, 1.08 mmol, 13%) [Synthesis product 9fb].

LC/MS (C ₁₄ H ₁₃ ClN ₄ S) 305 [M+H] ⁺ ; RT 1.31 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.82 (br s, 1H), 7.38 (br s+1, 2H), 7.21 (t, 1H), 2.91 (q, J=7.4 Hz, 2H), 2.38 (s, 3H), 1.12 (t, J=7.5 Hz, 3H).

N-(6-Chloro-5-ethyl-4-methylpyridazin-3-yl)-1,3-benzothiazol-2-amine as a yellow solid (750 mg, 2.46 mmol, 30%) [Synthesis product 9fa].

LC/MS (C ₁₄ H ₁₃ ClN ₄ S) 305 [M+H] ⁺ ; RT 1.30 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.86 (s, 1H), 7.49 (br s, 1H), 7.40 (t, 1H), 7.22 (t, 1H), 2.79 (q, J=7.5 Hz, 2H), 2.41 (s, 3H), 1.14 (t, J=7.5 Hz, 3H).

Synthesis of 9ga and 9gb: N-{5-[(Benzyloxy)methyl]-6-chloro-4-methylpyridazin-3-yl}-1,3-benzothiazol-2-amine and N-{4-[(benzyloxy)methyl ]-6-chloro-5-methylpyridazin-3-yl}-1,3-benzothiazol-2-amine

To a solution of Preparation 8g (1.16 g, 4.4 mmol, 1 equiv) and 2-bromo-1,3-benzothiazole (1.22 g, 5.72 mmol, 1.3 equiv) in 1,4-dioxane (30 mL) was added sodium hydride (60% dispersion; 352 mg, 8.8 mmol, 2 equiv) portionwise and the reaction mixture was heated at reflux for 2 h. The mixture was allowed to cool to ambient temperature, quenched with acetic acid and neutralized with sodium bicarbonate. The product was extracted using ethyl acetate (200 mL x 2) and washed with brine (100 mL). The organic extract was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 120 g RediSep™ silica gel cartridge) eluting with a gradient of 0-30% ethyl acetate in isoheptane afforded the desired regioisomeric products:

N-{4-[(Benzyloxy)methyl]-6-chloro-5-methylpyridazin-3-yl}-1,3-benzothiazol-2-amine as a yellow solid (250 mg, 0.63 mmol, 14%) [Synthesis product 9gb].

LC/MS (C ₂₀ H ₁₇ ClN ₄ OS) 398 [M+H] ⁺ ; RT 1.43 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 12.53 (br s, 1H), 7.84 (d, J=7.6 Hz, 1H), 7.55-7.27 (m, 7H), 7.23 (t, 1H), 4.89 (s, 2H), 4.61 (s, 2H), 2.38 (s, 3H).

N-{5-[(Benzyloxy)methyl]-6-chloro-4-methylpyridazin-3-yl}-1,3-benzothiazol-2-amine as a yellow solid (253 mg, 0.64 mmol, 14%) [Synthesis product 9ga].

LC/MS (C ₂₀ H ₁₇ ClN ₄ OS) 398 [M+H] ⁺ ; RT 1.39 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 12.71 (br s, 1H), 7.85 (s, 1H), 7.45-7.27 (m, 7H), 7.26-7.15 (m, 1H), 4.67 (s, 2H), 4.60 (s, 2H), 2.44 (s, 3H).

Synthesis of 9ha: N-(6-Chloro-5-cyclopropyl-4-methylpyridazin-3-yl)-1,3-benzothiazol-2-amine

To a solution of the product of Synthesis 8ha (2.44 g, 13.3 mmol, 1 equiv.) and 2-bromo-1,3-benzothiazole (3.7 g, 17.3 mmol, 1.3 equiv.) in 1,4-dioxane (50 mL) was added sodium hydride (60% dispersion; 1.06 g, 26.6 mmol, 2 equiv.) portionwise, and the mixture was heated under reflux for 1 h. The reaction mixture was allowed to cool to ambient temperature, then quenched with acetic acid and neutralized by addition of sodium bicarbonate. The resulting precipitate was collected by filtration and dried in vacuo to give the desired product (0.98 g, 3.09 mmol, 23%).

LC/MS (C ₁₅ H ₁₃ ClN ₄ S) 317 [M+H] ⁺ ; RT 1.30 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d ₆ ) δ 11.88 (br s, 1H), 7.82 (d, 1H), 7.47 (d, J=8.0 Hz, 1H), 7.39-7.32 (m, 1H), 7.21 -7.13 (m, 1H), 2.47 (d, J=1.0 Hz, 3H), 1.93-1.79 (m, 1H), 1.23-1.08 (m, 2H), 0.69 (td, J=6.2, 4.4 Hz, 2H).

Synthesis of 9hb: N-(6-Chloro-4-cyclopropyl-5-methylpyridazin-3-yl)-1,3-benzothiazol-2-amine

To a solution of 2-bromo-1,3-benzothiazole (2.8 g, 13.1 mmol, 1.2 equiv) and the product of Preparation 8hb (2 g, 10.9 mmol, 1 equiv) in 1,4-dioxane (50 mL) was added sodium hydride (60% dispersion; 0.52 g, 21.8 mmol, 2 equiv) portionwise, and the reaction mixture was heated at reflux for 1 h. The residue was taken up in ethyl acetate, filtered, and the solid residue was extracted with ethyl acetate. The combined organic extracts were washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0:40% ethyl acetate in isoheptane afforded the title product as a yellow solid (219 mg, 0.69 mmol, 6%).

LC/MS (C ₁₅ H ₁₃ ClN ₄ S) 317 [M+H] ⁺ ; RT 1.28 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO- _d6 ) δ 10.74 (br s, 1H), 8.05-7.85 (m, 1H), 7.78-7.55 (m, 1H), 7.42 (t, 1H), 7.25 (t, 1H), 2.47 (d, J=0.9 Hz, 4H), 2.01-1.89 (m, 1H), 1.14-1.02 (m, 2H), 0.72-0.60 (m, 2H).

Synthesis of 9ja: N-[6-Chloro-5-(methoxymethyl)-4-methylpyridazin-3-yl]-1,3-benzothiazol-2-amine

To a solution of Preparation 8ja (323 mg, 1 equiv.) and 2-bromo-1,3-benzothiazole (442 mg, 2.07 mmol, 1.2 equiv.) in 1,4-dioxane (10 mL) was added sodium hydride (60% dispersion; 138 mg, 3.44 mmol, 2 equiv.) portionwise, and the mixture was heated under reflux for 1.5 h. The mixture was cooled to ambient temperature, neutralized with acetic acid, and concentrated in vacuo. The crude material was partitioned between dichloromethane and water, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0:50% ethyl acetate in isoheptane afforded the title product as a bright yellow solid (85 mg, 0.26 mmol, 15%).

LC/MS (C ₁₄ H13ClN ₄ OS) 321 [M+H] ⁺ ; RT 1.19 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 8.18-6.98 (m, 5H), 4.58 (s, 2H), 3.35 (s, 3H), 2.46 (s, 3H).

Synthesis of 9jb: N-[6-Chloro-4-(methoxymethyl)-5-methylpyridazin-3-yl]-1,3-benzothiazol-2-amine

To a solution of Preparation 8jb (140 mg, 0.81 mmol, 1 equiv) and 2-bromo-1,3-benzothiazole (224 mg, 1.05 mmol, 1.3 equiv) in 1,4-dioxane (7 mL) was added sodium hydride (60% dispersion; 58.1 mg, 2.42 mmol, 3 equiv) portionwise and the mixture was heated at reflux for 30 min. The reaction mixture was cooled to 0 °C and slowly quenched with water, diluted with ethyl acetate and washed with sodium bicarbonate and brine. The organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0:100% ethyl acetate in isoheptane afforded the title product as a yellow solid (169 mg, 0.53 mmol, 58%).

LC/MS (C ₁₄ H ₁₃ ClN ₄ OS) 321 [M+H] ⁺ ; RT 1.23 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 12.63 (s, 1H), 7.79 (s, 1H), 7.54-7.26 (m, 2H), 7.22 (s, 1H), 4.77 (s, 2H), 3.36 (s, 3H), 2.41 (s, 3H).

Synthesis of 9ka: N-[6-Chloro-5-(ethoxymethyl)-4-methylpyridazin-3-yl]-1,3-benzothiazol-2-amine

To a solution of the product of Synthesis 8ka (136 mg, 0.67 mmol, 1 equiv) and 2-bromo-1,3-benzothiazole (173 mg, 0.81 mmol, 1.2 equiv) in 1,4-dioxane (10 mL) was added sodium hydride (60% dispersion; 53.9 mg, 1.35 mmol, 2 equiv) portionwise and the mixture was heated at reflux for 1 h. The reaction mixture was allowed to cool to ambient temperature and quenched with water. The mixture was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, then dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0:40% ethyl acetate in isoheptane afforded the title product as a yellow solid (113 mg, 0.34 mmol, 50%).

LC/MS (C ₁₅ H ₁₅ ClN ₄ OS) 335 [M+H] ⁺ ; RT 1.28 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.86 (s, 1H), 7.46 (br s, 1H), 7.41 (t, 1H), 7.23 (t, J=7.7 Hz, 1H), 4.61 (s, 2H), 3.56 (q, J=7.0 Hz, 2H), 2.47 (s, 3H), 1.16 (t, J=7.0 Hz, 3H).

Synthesis of 9ma: N-{5-[3-(Benzyloxy)propyl]-6-chloro-4-methylpyridazin-3-yl}-1,3-benzothiazol-2-amine

To a solution of Preparation 8 (1.3 g, 4.46 mmol, 1 equiv) and 2-bromo-1,3-benzothiazole (1.14 g, 5.35 mmol, 1.2 equiv) in 1,4-dioxane (50 mL) was added sodium hydride (60% dispersion; 356 mg, 8.91 mmol, 2 equiv) portionwise and the mixture was heated at reflux for 1 h. The reaction mixture was allowed to cool to ambient temperature, then quenched by addition of water and partitioned between ethyl acetate (100 mL) and sodium bicarbonate (50 mL). The organic phase was washed with brine (50 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0-55% ethyl acetate in isoheptane afforded the title product as a cream-colored solid (1.59 g, 3.74 mmol, 84%).

LC/MS (C ₂₂ H ₂₁ ClN ₄ OS) 425 [M+H] ⁺ ; RT 1.25 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.86 (s, 1H), 7.67-7.11 (m, 8H), 4.50 (s, 2H), 3.53 (t, J=6.0 Hz, 2H), 2.94-2.81 (m, 2H), 2.41 (s, 3H), 1.89-1.72 (m, 2H).

Synthesis 10a: 1-(1-Adamantylmethyl)-5-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazole

Step A: 1-(1-adamantylmethyl)-4-iodopyrazole

A mixture of 35.9 g 1-adamantylmethanol (216 mmol), 73.48 g triphenylphosphine (280 mmol, 1.3 equiv), 54.25 g 4-iodo-1H-pyrazole (280 mmol, 1.3 equiv), and 64.4 g tert-butyl N-(tert-butoxycarbonyliminomethylene)carbamate (266 mmol, 1.3 equiv) in 1078 mL THF was stirred at rt for 48 h. After addition of an additional 10.94 g 4-iodo-1H-pyrazole (56 mmol, 0.26 equiv), 12.81 g tert-butyl N-(tert-butoxycarbonyliminomethylene)carbamate (53 mmol, 0.26 equiv) and 14.69 g triphenylphosphine (56 mmol, 0.26 equiv), the reaction mixture was stirred at rt for 24 h, then concentrated, purified by flash column chromatography using DCM as eluent, and the resulting material was triturated with cold MeOH and filtered to give 53.6 g (73%) of the desired product.

Step B: 1-(1-adamantylmethyl)-4-iodo-5-methylpyrazole

To 9.8 mL of diisopropylamine (69.5 mmol, 1.1 equiv.) in 180 mL of THF at -78 °C were added dropwise 33.4 mL of 2.5 M butyl lithium solution (84 mmol, 1.3 equiv.), and the mixture was stirred at -78 °C for 0.5 h, treated with 22.0 g of the product from Step A (64.28 mmol, 1 equiv.) in 90 mL of THF, stirred at -78 °C for 1 h, treated with 4.67 mL of methyl iodide (73.3 mmol, 1.14 equiv.), and stirred at -78 °C for 18 h. After quenching the reaction mixture with conc. _NH4Cl solution, the reaction mixture was extracted with EtOAc and the combined organic phases were washed with brine, dried, concentrated, triturated with MeOH and filtered to give 21 g (92%) of the desired product.

¹ H NMR (400 MHz, CDC13) δ ppm 7.44 (s, 1H), 3.77 (s, 2H), 2.30 (s, 3H), 1.99 (bs, 3H), 1.74/1.52 (m, 12H).

Step C: 1-(1-adamantylmethyl)-5-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazole

To 21 g of the product from Step B (58.95 mmol, 1 equiv.) in 300 mL of THF at -78 °C was added 28.3 mL of 2.5 M butyl lithium solution (70.8 mmol, 1.2 equiv.), and the mixture was stirred at -78 °C for 0.5 h, treated with 16.4 g of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (88.1 mmol, 1.5 equiv.) (added portionwise over 40 min), and kept at - 78 °C for 24 h. After quenching the reaction mixture with conc. _NH4Cl solution at rt, the reaction mixture was extracted with EtOAc and the combined organic phases were washed with brine, dried, concentrated, triturated with MeOH, and filtered to give 19.7 g (94%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.45 (s, 1H), 3.69 (s, 2H), 2.36 (s, 3H), 1.91 (m, 1H), 1.64/1.54 (m, 6H), 1.50 (m, 6H), 1.24 (s, 12H) ; ¹³ C NMR (500 MHz, DMSO-d ₆ ) δ ppm 146.9, 144.1, 104.6, 59.7, 40.6, 36.8, 35.4, 28.1, 25.1, 12.1; HR-MSR (m/z): [M+H] ⁺ , calculated for C21H34BN2O2: 357.2713, found: 357.2704.

Synthesis 10b: 1-{[1-(3-Methoxypropyl)cyclooctyl]methyl}-5-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H -pyrazole

Step A: Methyl 1-(3-methoxypropyl)cyclooctanecarboxylate

To 4.74 g (1.14 equiv) of diisopropylamine in 90 mL of tetrahydrofuran at -78 °C were added 18.8 mL (1.14 equiv) of 2.5 M butyl lithium solution and, after 0.5 h at -78 °C, 7.0 g (41.1 mmol) of methyl cyclooctanecarboxylate in 40 mL of tetrahydrofuran were added over 1 h. After 1 h at -78 °C, 7.2 g (1.14 equiv) of 1-bromo-3-methoxypropane were added and the mixture was stirred for 18 h. After quenching the reaction mixture by adding a saturated solution of NH ₄ Cl, the mixture was extracted with EtOAc and the organic phases were dried over MgSO ₄ and concentrated to give 8.0 g (80%) of the target product.

¹ H NMR (400 MHz, CDCl ₃ ) δ ppm 3.66 (s, 3H), 3.33 (t, 2H), 3.31 (s, 3H), 2.03-1.94 (m, 2H), 1.64-1.38 (m, 16H).

Step B: [1-(3-methoxypropyl)cyclooctyl]methanol

To 9.0 g (37.13 mmol) of the product from Step A in 93 mL of diethyl ether at 0 °C was added lithium aluminum hydride (1.76 g, 1.25 equiv.) portionwise. After stirring at rt for 2 h, the reaction mixture was quenched by adding ice water and EtOAc, and 10% NaOH solution was added. The mixture was extracted with EtOAc, dried, and concentrated to afford 7.4 g (93%) of the desired product.

¹ H NMR (400 MHz, CDC13) δ ppm 3.37 (t, 2H), 3.34 (s, 3H), 3.30 (s, 2H), 1.61-1.23 (m, 18H).

Step C: 4-iodo-1-[[1-(3-methoxypropyl)cyclooctyl]methyl]pyrazole

To 1.39 g (6.5 mmol) of the product from Step B and 1.64 g (1.3 equiv) of 4-iodo-1H-pyrazole in 33 mL of tetrahydrofuran were added 2.22 g (1.3 equiv) of triphenylphosphine and 1.95 g (1.3 equiv) of di-tert-butyl azodicarboxylate, and the mixture was stirred at rt for 67 h. To the mixture were added 278 mg of 4-iodo-1H-pyrazole, 444 mg of triphenylphosphine, and 390 mg of di-tert-butyl azodicarboxylate and stirred at rt for 24 h. After the additions of the reactants and stirring at rt for 24 h were repeated (115 h of stirring in total), the mixture was concentrated and purified by column flash chromatography (silica gel) using heptane and EtOAc as eluents to give 1.24 g (49%) of the desired product.

¹ H NMR (400 MHz, CDCl ₃ ) δ ppm 7.47 (s, 1H), 7.42 (s, 1H), 3.93 (s, 2H), 3.37 (t, 2H), 3.36 (s, 3H), 1.68-1.18 (m, 18H).

Step D: 4-iodo-1-[[1-(3-methoxypropyl)cyclooctyl]methyl]-5-methylpyrazole

To 1.2 g (3.07 mmol) of the product from Step C in 5 mL of tetrahydrofuran at -78 °C was added 3.7 mL (1.2 equiv) of 1 M LDA solution. After 0.6 h at -78 °C, 0.5 mL (1.14 equiv) of methyl iodide was added dropwise and the mixture was allowed to warm to rt over 20 h. The reaction mixture was quenched with saturated NH4Cl solution and extracted with EtOAc. The combined organic phases were dried, concentrated and purified by flash column chromatography (silica gel) using heptane and EtOAc as eluents to afford 0.79 g (64%) of the desired product.

¹ H NMR (400 MHz, CDCl ₃ ) δ ppm 7.43 (s, 1H), 3.85 (s, 2H), 3.38 (t, 2H), 3.35 (s, 3H), 2.29 (s, 3H), 1.69-1.24 (m, 18H).

Step E: 1-[[1-(3-methoxypropyl)cyclooctyl]methyl]-5-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazole

To a solution of 0.81 g (2 mmol) of the product from Step D in 15 ml of tetrahydrofuran at -78°C was added dropwise 0.96 ml (1.2 equiv.) of 2.5 M butyl lithium solution. After 0.5 h, 0.5 ml (1.2 equiv) of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane was added over 20 min and the mixture was heated at -78 °C for 6 h and at rt for 6 h. After quenching the reaction mixture with saturated NH ₄ Cl solution and extracting with EtOAc, the combined organic phases were washed with brine, dried and purified by flash column chromatography (silica gel) using heptane and EtOAc as eluents to give 0.33 g (34%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.46 (s, 1H), 3.75 (s, 2H), 3.27 (t, 2H), 3.21 (s, 3H), 2.36 (s, 3H), 1.66-1.1 (m, 14H), 1.57 (m, 2H), 1.24 (s, 12H), 1.24 (m, 2H). ¹³ C NMR (500 MHz, DMSO-d ₆ ) δ ppm 147.3, 144.5, 104.5, 73.2, 58.2, 54.4, 40.5, 33.2, 25.1, 23.6, 11.8. IR: 2922, 1556, 1246, 1144, 1055. HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₃ H ₄₂ N ₂ O ₃ B: 405.3289, found: 404.3334.

Synthesis 10c: 1-{[1-(3-Methoxypropyl)cyclohexyl]methyl}-5-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Step A: Methyl 1-(3-methoxypropyl)cyclohexanecarboxylate

To 6.84 g (1.09 equiv) of diisopropylamine in 130 mL of tetrahydrofuran at -78 °C were added 27 mL (1.09 equiv) of 2.5 M butyl lithium solution, and after 0.5 h at -78 °C, 8.8 g of methyl cyclohexanecarboxylate in 50 mL of tetrahydrofuran were added over 1 h. After 1 h at -78 °C, 10.7 g (1.13 equiv) of 1-bromo-3-methoxypropane were added and the mixture was stirred for 18 h. After quenching the reaction mixture by adding saturated NH ₄ Cl solution, the mixture was extracted with EtOAc and the organic phases were dried over MgSO ₄ and concentrated to give 12 g (92%) of the desired product.

¹ H NMR (400 MHz, CDCl ₃ ) δ ppm 3.67 (s, 3H), 3.35 (d, 1H), 3.32 (d, 1H), 3.31 (s, 3H), 2.11-2.03 (m, 2H), 1.60-1.16 (m, 12H).

Step B: [1-(3-methoxypropyl)cyclohexyl]methanol

To 12 g (56.41 mmol) of the product from Step A in 140 mL of diethyl ether at 0 °C were added lithium aluminum hydride (2.68 g, 1.25 equiv.) portionwise. After stirring at rt for 2 h, the reaction mixture was quenched by adding ice water and EtOAc and 10% NaOH solution were added. The mixture was extracted with EtOAc, dried and concentrated to give 9.37 g (89%) of the desired product.

¹ H NMR (400 MHz, CDC13) δ ppm 3.41 (s, 2H), 3.38 (t, 2H), 3.35 (s, 3H), 1.56-1.27 (m, 14H).

Step C: 4-iodo-1-[[1-(3-methoxypropyl)cyclohexyl]methyl]pyrazole

To 1.21 g (6.5 mmol) of the product from Step B and 2.58 g (2.05 equiv) of 4-iodo-1H-pyrazole in 33 mL of tetrahydrofuran were added 3.5 g (2.05 equiv) of triphenylphosphine and 3.07 g (2.05 equiv) of di-tert-butyl azodicarboxylate, and the mixture was stirred at rt for 2 h. To the mixture were added 140 mg of 4-iodo-1H-pyrazole, 230 mg of triphenylphosphine and 200 mg of di-tert-butyl azodicarboxylate, and stirred at rt for 24 h. After the additions of the reactants and stirring at rt for 24 h were repeated twice (96 h of stirring in total), the mixture was concentrated and purified using flash column chromatography (silica gel) using heptane and EtOAc as eluents to give 1.4 g (59.5%) of the desired product.

¹ H NMR (400 MHz, CDCl ₃ ) δ ppm 7.47 (s, 1H), 7.41 (s, 1H), 4.00 (s, 2H), 3.36 (t, 2H), 3.35 (s, 3H), 1.62-1.21 (m, 14H).

Step D: 4-iodo-1-[[1-(3-methoxypropyl)cyclohexyl]methyl]-5-methylpyrazole

To 3.7 g (10.21 mmol) of the product from Step C in 15 mL of tetrahydrofuran at -78 °C was added 1 M LDA solution in tetrahydrofuran (12.3 mL, 1.2 equiv). After 0.6 h at -78 °C, 0.73 mL (1.14 equiv) of methyl iodide was added dropwise and the mixture was allowed to warm to rt over 20 h. The reaction mixture was quenched with saturated NH ₄ Cl solution and extracted with EtOAc. The combined organic phases were dried, concentrated and purified by flash column chromatography (silica gel) using heptane and EtOAc as eluents to afford 2.85 g (74%) of the desired product.

¹ H NMR (400 MHz, CDCl ₃ ) δ ppm 7.44 (s, 1H), 3.92 (s, 2H), 3.38 (t, 2H), 3.35 (s, 3H), 2.29 (s, 3H), 1.58-1.13 (m, 14H).

Step E: 1-[[1-(3-methoxypropyl)cyclohexyl]methyl]-5-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazole

To a solution of 5.0 g (13.3 mmol) of the product from Step D in 71 mL of tetrahydrofuran at -78°C was added dropwise 6.38 mL (1.2 equiv.) of 2.5 M butyl lithium solution. After 0.5 h, 4.1 mL (1.5 equiv) of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane was added over 40 min and the mixture was heated at -78 °C for 6 h and at rt for 6 h. After quenching the reaction mixture with saturated NH ₄ Cl solution and extracting with EtOAc, the combined organic phases were washed with brine, dried and purified by flash column chromatography (silica gel) using heptane and EtOAc as eluents to give 2.3 g (46%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.47 (s, 1H), 3.84 (s, 2H), 3.27 (t, 2H), 3.2 (s, 3H), 2.37 (s, 3H), 1.54-1.07 (m, 10H), 1.46 (m, 2H), 1.32 (m, 2H), 1.24 (s, 12H). ¹³ C NMR (500 MHz, DMSO-d ₆ ) δ ppm 147.3, 144.4, 104.6, 73.1, 58.2, 55.7, 37.9, 30.6, 25.1, 23.1, 12.0. IR: 2927, 1556, 1257, 1144, 1053. HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₃₈ N ₂ O ₃ B: 376.2897, found: 376.3019.

Synthesis of 11a: Ethyl 5-bromo-2-[(4,5-dimethyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Step A: (2Z)-N-(6-chloro-4,5-dimethylpyridazin-3-yl)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-imine

N,N-Diisopropylethylamine (3.6 mL, 20.6 mmol, 2 equiv) was added under nitrogen to a suspension of the product of Preparation 9a (3 g, 10.3 mmol, 1 equiv) in dichloromethane (75 mL) at 0 °C. [2-(chloromethoxy)ethyl]trimethylsilane (2 mL, 11.3 mmol, 1.1 equiv) and 4-dimethylaminopyridine (63.0 mg, 0.52 mmol, 0.05 equiv) were added and the mixture was stirred at room temperature for 3 h. Dichloromethane (75 mL) was added and the mixture was washed with water (2 x 75 mL) and brine (75 mL). The solution was dried (magnesium sulfate) and concentrated in vacuo. Purification by column chromatography on flash silica gel Isolute (20 g) eluting with dichloromethane afforded the title product as a pale brown solid (3.95 g, 8.44 mmol, 82%), which was used directly in the next step without further characterization.

Step B: Ethyl 2-[(4,5-dimethyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

The product from Step A (500 mg, 1.19 mmol, 1 equiv) and ethyl 2-amino-1,3-thiazole-4-carboxylate (245.4 mg, 1.43 mmol, 1.2 equiv) were added under nitrogen to a solution of cesium carbonate (1.16 g, 3.56 mmol, 3 equiv), tris(dibenzylideneacetone)dipalladium(0) (54.4 mg, 0.06 mmol, 0.05 equiv), and xantphos (68.7 mg, 0.12 mmol, 0.1 equiv) in alpha,alpha,alpha-trifluorotoluene (10 mL). The mixture was sparged with nitrogen (10 min) and then heated at 170 °C for 1 h under microwave irradiation. The solution was allowed to cool to ambient temperature and concentrated in vacuo. The mixture was partitioned between ethyl acetate and water and the organic phase was washed with brine, dried (magnesium sulfate) and the solvent removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0:50% ethyl acetate in isoheptane afforded the title product as an orange foam (301 mg, 0.54 mmol, 46%).

LC/MS (C ₂₅ H ₃₂ N ₆ O ₃ SiS ₂ ) 557 [M+H] ⁺ ; RT 1.49 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 10.98 (s, 1H), 7.93 (s, 1H), 7.81 (dd, J=7.6, 1.1 Hz, 1H), 7.48-7.37 (m, 2H), 7.27-7.20 (m, 1H), 5.84 (s, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.71 (dd, J=8.4, 7.5 Hz, 2H), 2.41 (s, 3H), 2.35 (s, 3H), 1.31 (t, J=7.1 Hz, 3H), 0.97 - 0.86 (m, 2H), -0.12 (s, 9H).

Step C: Ethyl 5-bromo-2-[(4,5-dimethyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

N-Bromosuccinimide (125 mg, 0.7 mmol, 1.3 equiv) was added to a stirred solution of the product from Step B (301 mg, 0.54 mmol, 1 equiv) in dichloromethane (15 mL). The reaction mixture was stirred at ambient temperature for 1.5 h, then the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 60% ethyl acetate in isoheptane afforded the desired product as a brown gum (198 mg, 0.31 mmol, 58%).

LC/MS (C ₂₅ H ₃₁ BrN ₆ O ₃ SiS ₂ ) 637 [M+H] ⁺ ; RT 1.57 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.31 (s, 1H 7.82 (d, 1H), 7.48-7.38 (m, 2H), 7.28-7.20 (m, 1H), 5.84 (s, 2H), 4.30 (q, J=7.1 Hz, 2H), 3.70 (dd, J=8.5, 7.4 Hz, 2H), 2.41 (s, 3H), 2.34 (s, 3H), 1.32 (t, J=7.1 Hz, 3H), 0.97-0.86 (m, 2H), -0.12 (s, 9H).

Synthesis of 11b: Ethyl 5-bromo-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Step A: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)(methyl)amino]-1,3-thiazole-4-carboxylate

A solution of 3,6-dichloro-4-methylpyridazine (662 mg, 4.06 mmol, 1.02 equiv) and ethyl 2-(methylamino)-1,3-thiazole-4-carboxylate (742 mg, 3.98 mmol, 1 equiv) in tetrahydrofuran (20 mL) was cooled in an ice bath, then sodium hydride (60% in mineral oil; 188 mg, 4.7 mmol, 1.18 equiv) was added slowly. The mixture was kept in the ice bath for 1 h, then stirred at ambient temperature for 3 h. Saturated aqueous ammonium chloride solution was added, and the resulting solution was extracted with dichloromethane (x2). The combined organic extracts were washed with water (x2) followed by brine, then dried (magnesium sulfate) and the solvent removed in vacuo. The residue was triturated with a mixture of dichloromethane and methanol and the solids were collected by filtration and dried in vacuo to give the title product as a cream solid (324 mg, 1.04 mmol, 26%).

LC/MS (C ₁₂ H ₁₃ ClN ₄ O ₂ S) 313 [M+H] ⁺ ; RT 1.15 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 8.04 (s, 1H), 7.87 (d, J=1.2 Hz, 1H), 4.30 (q, J=7.1 Hz, 2H), 3.83 (s, 3H), 2.44 (d, J=1.0 Hz, 3H), 1.32 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

The product from Step A (467 mg, 1.49 mmol, 1 equiv) and 2-aminobenzothiazole (269 mg, 1.79 mmol, 1.2 equiv) were added under nitrogen to a mixture of cesium carbonate (1.46 g, 4.47 mmol, 3 equiv), tris(dibenzylideneacetone)dipalladium(0) (68.3 mg, 0.07 mmol, 0.05 equiv), and xantphos (86.3 mg, 0.15 mmol, 0.1 equiv) in alpha,alpha,alpha-trifluorotoluene (10 mL). The mixture was sparged with nitrogen (10 min) and then heated at 170 °C for 1 h under microwave irradiation. The solution was allowed to cool to ambient temperature, filtered, eluting with dichloromethane, and the filtrate was concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a yellow solid (133 mg, 0.31 mmol, 21%).

LC/MS (C ₁₉ H ₁₈ N6O ₂ S ₂ ) 427 [M+H] ⁺ ; RT 1.30 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.10 (s, 1H), 7.99 (d, J=6.9 Hz, 1H), 7.76-7.67 (m, 1H), 7.54-7.34 (m, 2H), 7.28-7.17 (m, 1H), 4.30 (q, J=7.2 Hz, 2H), 3.83 (s, 3H), 2.48 (s, 3H), 1.31 (t, 3H).

Step C: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

A solution of the product from Step B (133 mg, 0.31 mmol, 1 equiv) in dichloromethane (5 mL) was cooled in an ice bath, then N,N-diisopropylethylamine (0.1 mL, 0.62 mmol, 2 equiv) was added. After 5 min, 4-dimethylaminopyridine (1.9 mg, 0.02 mmol, 0.05 equiv) was added followed by 2-(trimethylsilyl)ethoxymethyl chloride (0.06 mL, 0.34 mmol, 1.1 equiv). The mixture was allowed to warm slowly to ambient temperature and stirred overnight. The reaction mixture was diluted with dichloromethane, washed successively with water (×2) and brine, dried (magnesium sulfate), and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a yellow glass (56.3 mg, 0.1 mmol, 32%).

LC/MS (C ₂₅ H ₃₂ N ₆ O ₃ SiS ₂ ) 557 [M+H] ⁺ ; RT 1.64 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.97 (s, 1H), 7.85 (dd, J=7.6, 1.0 Hz, 1H, 7.71 (d, J=1.1 Hz, 1H), 7.50-7.40 (m, 2H), 7.29-7.22 (m, 1H), 5.87 (s, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.83 (s, 3H), 3.78-3.67 (m, 2H), 2.46 (d, J=1.0 Hz, 3H), 1.31 (t, J=7.1 Hz, 3H), 0.98-0.87 (m, 2H), -0.12 (s, 9H).

Step D: Ethyl 5-bromo-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

N-Bromosuccinimide (23.4 mg, 0.13 mmol, 1.3 equiv) was added to a stirred solution of the product from Step C (56.3 mg, 0.1 mmol, 1 equiv) in dichloromethane (5 mL). The reaction mixture was stirred at ambient temperature for 1.5 h, then the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 60% ethyl acetate in isoheptane afforded the title product as a white solid (54.7 mg, 0.09 mmol, 85%).

LC/MS (C ₂₅ H ₃₁ BrN ₆ O ₃ SiS ₂ ) 635 [M+H] ⁺ ; RT 1.73 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.86 (dd, J=7.7, 1.0 Hz, 1H), 7.73 (d, J=1.1 Hz, 1H), 7.52-7.38 (m, 2H), 7.25 (ddd, J=8.3, 7.0, 1.5 Hz, 1H), 5.87 (s, 2H), 4.31 (q, J=7.1 Hz, 2H), 3.78 (s, 3H), 3.76 - 3.66 (m, 2H), 2.46 (d, J=1.0 Hz, 3H), 1.32 (t, J=7.1 Hz, 3H), 0.98 - 0.85 (m, 2H), -0.11 (s, 9H).

Synthesis of 11c: Ethyl 5-bromo-2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Step A: Ethyl 2-[(3-methoxypropyl)amino]-1,3-thiazole-4-carboxylate

Ammonia (2 M in isopropanol; 60 mL, 0.12 mol, 3.45 equiv) at 0 °C was added to a solution of 3-methoxypropyl isothiocyanate (4.5 g, 34.3 mmol, 1 equiv) in isopropanol (15 mL), and the mixture was stirred for 1 h at 0 °C and then for 18 h at ambient temperature. The suspension was concentrated in vacuo to give a pale yellow gum. Ethanol (60 mL) and ethyl bromopyruvate (5 mL, 35.9 mmol, 1.05 equiv) were added, and the mixture was stirred for 1 h under nitrogen. Triethylamine (10 mL, 68.6 mmol, 2 equiv) was added and the mixture was stirred at ambient temperature for 18 h. The reaction mixture was partitioned between ethyl acetate (300 mL) and water, and the organic phase was washed successively with water (150 mL) and brine (100 mL), dried (magnesium sulfate), and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with 99:1 dichloromethane/methanol gave a dark yellow oil, which was triturated with heptane (30 mL), filtered, washed with heptane (20 mL), and dried in vacuo to give the title product as a pale brown powder (5.75 g, 23.5 mmol, 69%).

LC/MS (C ₁₀ H ₁₆ N ₂ O ₃ S) 245 [M+H] ⁺ ; RT 0.99 (LCMS-V-B1)

¹ H NMR (400 MHz, CDC13) δ 7.38 (d, J=0.7 Hz, 1H), 6.03 (t, J=5.6 Hz, 1H), 4.34 (q, J=7.1 Hz, 2H), 3.54-3.42 (m, 2H), 3.40-3.33 (m, 2H), 3.32 (s, 3H), 1.97-1.83 (m, 2H), 1.36 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)(3-methoxypropyl)amino]-1,3-thiazole-4-carboxylate

Sodium hydride (60% dispersion; 350 mg, 8.75 mmol, 1.22 equiv) under nitrogen atmosphere was added to a solution of the product from Step A (1.75 g, 7.16 mmol, 1 equiv) and 3,6-dichloro-4-methylpyridazine (1.3 g, 7.98 mmol, 1.11 equiv) in 1,4-dioxane (30 mL) at 0 °C, the mixture was stirred for 1 h at 0 °C and then heated at 60 °C for 6 h. The reaction mixture was allowed to cool to ambient temperature then partitioned between ethyl acetate (300 mL) and saturated aqueous ammonium chloride solution (150 mL). The organic phase was washed successively with water (2 x 150 ml) and brine (100 ml), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with 39:1 dichloromethane/methanol afforded a brown oil which was triturated with diethyl ether (10 ml), filtered, washed with diethyl ether (10 ml) and dried in vacuo to afford the title product as a pale brown powder (1.3 g, 3.51 mmol, 49%).

LC/MS (C ₁₅ H ₁₉ ClN ₄ O ₃ S) 371 [M+H] ⁺ ; RT 1.28 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.81 (s, 1H), 7.55 (d, J=1.1 Hz, 1H), 4.57-4.44 (m, 2H), 4.37 (q, J=7.1 Hz, 2H), 3.45 (t, J=5.5 Hz, 2H), 3.34 (s, 3H), 2.45 (d, J=0.9 Hz, 3H), 2.20-2.06 (m, 2H), 1.39 (t, J=7.1 Hz, 3H).

Step C: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-1,3-thiazole-4-carboxylate

The product from Step B (1.3 g, 3.51 mmol, 1 equiv) and 2-aminobenzothiazole (600 mg, 3.99 mmol, 1.14 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone)dipalladium(0) (161 mg, 0.18 mmol, 0.05 equiv) and xantphos (203 mg, 0.35 mmol, 0.1 equiv) in 1,4-dioxane (20 mL), and the mixture was stirred. N,N-Diisopropylethylamine (1.9 mL, 10.5 mmol, 3 equiv) was added and the mixture was heated in a sealed tube at 150 °C for 24 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with 99:1 dichloromethane/methanol afforded a red gum, which was triturated with methanol (15 mL), filtered, washed with methanol (10 mL), and dried in vacuo to afford the title product as a yellow solid (1.35 g, 2.79 mmol, 80%).

LC/MS (C ₂₂ H ₂₄ N ₆ O ₃ S ₂ ) 485 [M+H] ⁺ ; RT 1.41 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.15 (br s, 1H), 7.97 (s, 1H), 7.92 (br s, 1H), 7.69 (s, 1H), 7.56 (br s, 1H), 7.40 (t, J=7.4 Hz, 1H), 7.22 (t, J=7.5 Hz, 1H), 4.44 (t, J=7.2 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.43 (t, J=6.0 Hz, 2H), 3.25 (s, 3H), 2.48 (s, 3H), 2.05-1.93 (m, 2H), 1.32 (t, J=7.1 Hz, 3H).

Step D: Ethyl 2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

A solution of the product from Step C (860 mg, 1.77 mmol, 1 equiv) in dichloromethane (30 mL) was cooled in an ice bath, then N,N-diisopropylethylamine (0.59 mL, 3.55 mmol, 2 equiv) was added. After stirring for 10 min, 2-(trimethylsilyl)ethoxymethyl chloride (0.37 mL, 2.13 mmol, 1.2 equiv) was added followed by 4-(dimethylamino)pyridine (10.8 mg, 0.09 mmol, 0.05 equiv). The reaction mixture was allowed to warm to ambient temperature and stirred for 5 h. The mixture was diluted with dichloromethane, then washed with water followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a creamy foam (0.83 g, 1.35 mmol, 76%).

LC/MS (C ₂₈ H ₃₈ N ₆ O ₄ SiS ₂ ) 615 [M+H] ⁺ ; RT 1.51 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO- _d6 ) δ 7.96 (s, 1H), 7.85 (d, 1H), 7.69 (s, 1H, 7.50-7.40 (m, 2H), 7.30-7.22 (m, 1H) , 5.86 (s, 2H), 4.43 (t, J=7.2 Hz, 2H), 4.28 (q, J=7.1 Hz, 2H), 3.78-3.67 (m, 2H), 3.42 (t, J=6.0 Hz, 2H), 3.24 (s, 3H), 2.46 ( d, J=0.9 Hz, 3H), 2.06-1.92 (m, 2H), 1.31 (t, J=7.1 Hz, 3H), 0.98-0.86 (m, 2H), -0.12 (s, 9H).

Step E: Ethyl 5-bromo-2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

N-Bromosuccinimide (63.7 mg, 0.36 mmol, 1.1 equiv) was added to a stirred solution of the product from Step A (200 mg, 0.33 mmol, 1 equiv) in dichloromethane (10 mL) and the mixture was stirred for 4 h. The solvent was removed in vacuo and the crude product was purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane to give the title product as a creamy foam (193 mg, 0.28 mmol, 85%).

LC/MS (C ₂₈ H ₃₇ BrN ₆ O ₄ SiS ₂ ) 695 [M+H] ⁺ ; RT 1.60 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.87 (dd, J=7.6, 1.1 Hz, 1H), 7.72 (d, J=1.2 Hz, 1H), 7.53-7.39 (m, 2H), 7.26 ( ddd, J=8.3, 7.0, 1.4 Hz, 1H), 5.87 (s, 2H), 4.43 (t, J=7.1 Hz, 2H), 4.31 (q, J=7.1 Hz, 2H), 3.77-3.67 (m, 2H), 3.41 (t, J=6.0 Hz, 2H), 3.23 (s, 3H), 2.47 (s, 3H), 2.04-1.90 (m, 2H), 1.32 (t, J=7.1 Hz, 3H), 0.97-0.86 (m, 2H), -0.11 (s, 9H).

Synthesis of 11d: Ethyl 5-bromo-2-[(5-cyclopropyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)(methyl)amino]-1,3-thiazole-4-carboxylate

Step A: Ethyl 2-[(6-chloro-5-cyclopropylpyridazin-3-yl)(methyl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product of Preparation 71 (495 mg, 2.62 mmol, 1 equiv) and ethyl 2-(methylamino)-1,3-thiazole-4-carboxylate (488 mg, 2.62 mmol, 1 equiv) in tetrahydrofuran (25 mL) under nitrogen was slowly added sodium hydride (60% in mineral oil; 124 mg, 3.09 mmol, 1.18 equiv) at 0 °C. The mixture was stirred for 1 h at 0 °C, then allowed to warm to ambient temperature and stirred for 18 h. Saturated aqueous ammonium chloride (75 mL) was added and the mixture was extracted with dichloromethane (250 mL). The organics were washed successively with water (2 x 75 mL) and brine (75 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0:60% ethyl acetate in isoheptane afforded the title product as a white crystalline solid (398 mg, 1.17 mmol, 45%).

LC/MS (C ₁₄ H ₁₅ ClN ₄ O ₂ S) 339 [M+H] ⁺ ; RT 1.25 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 8.03 (s, 1H), 7.24 (s, 1H), 4.30 (q, J=7.1 Hz, 2H), 3.83 (s, ZH), 2.23-2.12 ( m, 1H), 1.32 (t, J=7.1 Hz, 3H), 1.24-1.16 (m, 2H), 1.13 1.06 (m, 2H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-cyclopropylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

2-Aminobenzothiazole (0.21 g, 1.41 mmol, 1.2 equiv) and the product from Step A (398 mg, 1.17 mmol, 1 equiv) were added under nitrogen to a solution of xantphos (68 mg, 0.12 mmol, 0.1 equiv) and tris(dibenzylideneacetone)dipalladium(0) (53.8 mg, 0.06 mmol, 0.05 equiv) in 1,4-dioxane (20 mL). N,N-Diisopropylethylamine (0.61 mL, 3.52 mmol, 3 equiv) was added and the mixture was heated in a sealed tube at 150 °C for 24 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-90% ethyl acetate in isoheptane afforded the title product as a yellow solid (249 mg, 0.55 mmol, 47%).

LC/MS (C ₂₁ H ₂₀ N ₆ O ₂ S ₂ ) 453 [M+H] ⁺ ; RT 1.38 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.96 (s, 1H), 7.90 (s, 1H), 7.50 (br s, 1H), 7.39 (t, J=7.6 Hz, 1H), 7.29-7.08 (m, 2H), 4.30 (q, 3H), 3.82 (s, 3H), 1.32 (t, 3H), 1.21-1.07 (m, 2H), 1.06-0.95 (m, 2H).

Step C: Ethyl 2-[(5-cyclopropyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)(methyl)amino]-1,3-thiazole-4-carboxylate

A solution of the product from Step B (221 mg, 0.49 mmol, 1 equiv) in dichloromethane (10 mL) was cooled in an ice bath, then N,N-diisopropylethylamine (0.16 mL, 0.98 mmol, 2 equiv) was added and the mixture was stirred for 10 min. 2-(Trimethylsilyl)ethoxymethyl chloride (0.1 mL, 0.59 mmol, 1.2 equiv) was added followed by 4-(dimethylamino)pyridine (2.98 mg, 0.02 mmol, 0.05 equiv) and the mixture was stirred at ambient temperature for 7 h. The reaction mixture was partitioned between dichloromethane and water, and the organic phase was washed with water, followed by brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a creamy foam (185 mg, 0.32 mmol, 65%).

LC/MS (C ₂₇ H ₃₄ N ₆ O ₃ SiS ₂ ) δ83 [M+H] ⁺ ; RT 1.45 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.95 (s, 1H), 7.84 (dd, J=7.9, 1.1 Hz, 1H), 7.51-7.40 (m, 2H), 7.29-7.21 (m, 1H), 7.11 (s, 1H), 5.88 (s, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.82 (s, 3H), 3.77-3.65 (m, 2H), 2.73-2.61 (m, 1H), 1.31 (t, J=7.1 Hz, 3H), 1.24 1.12 (m, 2H), 1.11-1.03 (m, 2H), 0.96 0.86 (m, 2H), -0.13 (s, 9H).

Step D: Ethyl 5-bromo-2-[(5-cyclopropyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)(methyl)amino]-1,3-thiazole-4-carboxylate

N-Bromosuccinimide (62.2 mg, 0.35 mmol, 1.1 equiv) was added to a stirred solution of the product from Step C (185 mg, 0.32 mmol, 1 equiv) in dichloromethane (10 mL). After 2.5 h, the solvent was removed in vacuo and the crude product was purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane to give the desired product as a creamy solid (149 mg, 0.23 mmol, 71%).

LC/MS (C ₂₇ H ₃₃ BrN ₆ O ₃ SiS ₂ ) 663 [M+H] ⁺ ; RT 1.52 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.86 (dd, J=7.8, 1.1 Hz, 1H), 7.52-7.39 (m, 2H), 7.30-7.22 (m, 1H), 7.09 (s, 1H), 5.88 (s, 2H), 4.31 (q, J=7.1 Hz, 2H), 3.79 (s, 3H), 3.75-3.66 (m, 2H), 2.74-2.61 (m, 1H), 1.33 (t, J=7.1 Hz, 3H), 1.22-1.13 (m, 2H), 1.13-1.05 (m, 2H), 0.95-0.84 (m, 2H), -0.13 (s, 9H).

Synthesis 11e: Ethyl 5-iodo-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Step A: Ethyl 2-(methylamino)-1,3-thiazole-4-carboxylate

To a suspension of N-methylthiourea (5 g, 55.5 mmol, 1 equiv) in ethanol (80 mL) cooled in ice-water was slowly added ethyl bromopyruvate (7.45 mL, 59.4 mmol, 1.07 equiv). After 10 min, the mixture was allowed to warm to ambient temperature and stirred for 1.5 h. Triethylamine (15.4 mL, 111 mmol, 2 equiv) was added and the mixture was stirred at ambient temperature for 18 h. The reaction mixture was concentrated in vacuo, the residue was partitioned between ethyl acetate and water, the aqueous phase was extracted with ethyl acetate (×2), and the combined organic extracts were dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the title product as a beige solid (5.26 g, 28.2 mmol, 51%).

LC/MS (C ₇ H ₁₀ N ₂ O ₂ S) 187 [M+H] ⁺ ; RT 0.85 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.73 (q, J=4.7 Hz, 1H), 7.51 (d, J=0.5 Hz, 1H), 4.22 (q, J=7.1 Hz, 2H), 2.83 (d, J=4.8 Hz, 3H), 1.27 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)(methyl)amino]-1,3-thiazole-4-carboxylate

A solution of 3,6-dichloro-4-methylpyridazine (4.6 g, 28.2 mmol, 1 equiv) and the product from Step A (5.26 g, 28.2 mmol, 1 equiv) in tetrahydrofuran (100 mL) was cooled in an ice bath and sodium hydride (60% in mineral oil; 1.24 g, 31.1 mmol, 1.1 equiv) was added portionwise. The mixture was allowed to warm gradually to ambient temperature and stirred for 18 h. Dichloromethane and saturated aqueous ammonium chloride solution were added and a precipitate was observed to form. The solid was collected by filtration, washed with water and then dried under vacuum at 40°C for 12 h to give the title product as a cream-colored solid (4.24 g, 13.6 mmol, 48%).

LC/MS (C ₁₂ H ₁₃ ClN ₄ O ₂ S) 313 [M+H] ⁺ ; RT 1.19 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 8.04 (s, 1H), 7.87 (d, J=1.1 Hz, 1H), 4.30 (q, J=7.1 Hz, 2H), 3.83 (s, 3H), 2.44 (d, J=1.0 Hz, 3H), 1.32 (t, J=7.1 Hz, 3H).

Step C: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

To a stoppered flask containing the product from Step B (4.24 g, 13.6 mmol, 1 equiv), 2-aminobenzothiazole (2.44 g, 16.3 mmol, 1.2 equiv), and Xantphos (0.78 g, 1.36 mmol, 0.1 equiv) in 1,4-dioxane (250 mL) under nitrogen was added tris(dibenzylideneacetone)dipalladium(0) (0.62 g, 0.68 mmol, 0.05 equiv), followed by N,N-diisopropylethylamine (6.74 mL, 40.7 mmol, 3 equiv), and the flask was stoppered and heated at 150 °C for 24 h. The reaction mixture was allowed to cool to ambient temperature. and purified by automated flash column chromatography (CombiFlash Rf, 120 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane to give the desired product as a beige solid (3.05 g, 7.14 mmol, 53%).

LC/MS (C ₁₉ H ₁₈ N ₆ O ₂ S ₂ ) 427 [M+H] ⁺ ; RT 1.16 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.97 (s, 1H), 7.95-7.82 (m, 1H), 7.71 (s, 1H), 7.55 (br s, 1H), 7.39 (t, J=7.5 Hz, 1H), 7.22 (t, J=7.5 Hz, 1H), 4.31 (q, 3H), 3.83 (s, 3H), 2.48 (s, 3H), 1.33 (t, 3H).

Step D: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a suspension of the product from Step C (3.05 g, 7.15 mmol, 1 equiv) in dichloromethane (100 mL) cooled to 0 °C was added N,N-diisopropylethylamine (2.37 mL, 14.3 mmol, 2 equiv). After 10 min, 2-(trimethylsilyl)ethoxymethyl chloride (1.51 mL, 8.58 mmol, 1.2 equiv) was added followed by 4-(dimethylamino)pyridine (43.7 mg, 0.36 mmol, 0.05 equiv), and the mixture was allowed to warm to ambient temperature and stirred for 6 h. The reaction mixture was washed with water, followed by brine, then dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0:50% ethyl acetate in isoheptane afforded the title product as a white solid (1.38 g, 2.47 mmol, 35%).

LC/MS (C ₂₅ H ₃₂ N ₆ O ₃ SiS ₂ ) δ57 [M+H] ⁺ ; RT 1.65 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.96 (s, 1H), 7.84 (dd, 1H), 7.70 (d, J=0.9 Hz, 1H), 7.51-7.39 (m, 2H), 7.25 (ddd, J=8.3, 6.9, 1.6 Hz, 1H), 5.86 (s, 2H), 4.28 (q, J=7.1 Hz, 2H), 3.83 (s, 3H), 3.77-3.66 (m, 2H), 2.46 (d, J=1.0 Hz, 3H), 1.32 (t, J=7.1 Hz, 3H), 0.99-0.879 (m, 2H), -0.10 (s, 9H).

Step E: ethyl 5-iodo-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazole -2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazol-4-carboxylate

N-Iodosuccinimide (0.05 mL, 2.25 g/mL, 0.54 mmol, 1.5 equiv) was added to a stirred solution of the product from Step D (200 mg, 0.36 mmol, 1 equiv) in dichloromethane (6 mL), and the mixture was stirred at ambient temperature for 18 h. The reaction mixture was washed successively with water and brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a cream-colored solid (180 mg, 0.26 mmol, 73%).

LC/MS (C ₂₅ H ₃₁ IN ₆ O ₃ SiS ₂ ) 683 [M+H] ⁺ ; RT 1.73 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.88 (dd, J=7.5, 1.0 Hz, 1H), 7.71 (s, 1H), 7.53-7.40 (m, 2H), 7.31-7.22 (m, 1H), 5.86 (s, 2H), 4.32 (q, J=7.1 Hz, 2H), 3.82 (s, 3H), 3.78-3.69 (m, 2H), 2.48 (d, J=1.0 Hz, 3H), 1.34 (t, J=7.1 Hz, 3H), 0.99-0.89 (m, 2H), - 0.13 (s, 9H).

Synthesis of 11f: Ethyl 5-bromo-2-[(6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Step A: Ethyl 2-[(6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

The product of Synthesis 4b (1 g, 2.54 mmol, 1 equiv) and ethyl 2-amino-1,3-thiazole-4-carboxylate (500 mg, 2.9 mmol, 1.14 equiv) were added under nitrogen atmosphere to a solution of tris(dibenzylideneacetone)dipalladium(0) (116.5 mg, 0.13 mmol, 0.05 equiv) and xantphos (147.2 mg, 0.25 mmol, 0.1 equiv) in 1,4-dioxane (20 mL). N,N-Diisopropylethylamine (1.5 mL, 7.63 mmol, 3 equiv) was added and the mixture was heated at 100 °C for 18 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Purification by column chromatography (50 g silica gel) eluting with 50% ethyl acetate in heptane gave a dark yellow solid. Trituration with heptane (20 mL) gave a solid that was collected by filtration, washed with heptane (2 x 10 mL), and dried in vacuo to give the title product as a yellow solid (995 mg, 1.88 mmol, 74%) [mixture of isomers].

LC/MS (C ₂₃ H ₂₈ N ₆ O ₃ SiS ₂ ) δ29 [M+H] ⁺ ; RT 1.54 (LCMS-V-B1)

^1H NMR (400 MHz, Chloroform-d) δ 10.83 (s, 1H), 7.90-7.29 (m, 6H), 7.26 -7.13 (m, 1H), 5.95-5.68 (m, 2H), 4.53 -4.19 ( m, 2H), 3.85-3.68 (m, 2H), 1.39 -1.19 (m, 3H), 1.06-0.77 (m, 2H), 0.21--0.31 (m, 9H).

Step B: Ethyl 5-bromo-2-[(6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

N-Bromosuccinimide (45.2 mg, 0.25 mmol, 1.3 equiv) was added to a stirred solution of the product from Step A (100 mg, 0.19 mmol, 1 equiv) in dichloromethane (10 mL) and the mixture was stirred at ambient temperature for 1 h. The solvent was removed in vacuo and the crude product was purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-80% ethyl acetate in isoheptane to give the desired product as a cream solid (64.1 mg, 0.11 mmol, 56%) [mixture of isomers].

LC/MS (C ₂₃ H ₂₇ BrN ₆ O ₃ SiS ₂ ) 609 [M+H] ⁺ ; RT 1.47(LCMS-U-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.45 (s, 1H), 12.31 (s, 1H), 8.13-8.04 (m, 1H), 8.04-7.90 (m, 2H), 7.84-7.71 (m, 1H), 7.69-7.48 (m, 5H), 7.46-7.32 (m, 3H), 5.98 (s, 2H), 5.92 (s, 2H), 4.41 (qd, J=7.1, 2.4 Hz, 4H), 3.87- 3.74 (m, 4H), 1.43 (td, J=7.1, 1.1 Hz, 6H), 1.03 (s, 2H), 1.08-0.98 (m, 2H), 0.26 - -0.36 (m, 18H).

Synthesis 12: tert-Butyldiphenyl-[2-[[3,5-dimethyl-7-[[5-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazol-1-yl]methyl]-1-adamantyl]oxy]ethoxy]silane

Step A: 3-bromo-5,7-dimethyladamantane-1-carboxylic acid

After stirring iron (6.7 g, 120 mmol) in bromine (30.7 mL, 600 mmol, 5 equiv) at 0 °C for 1 h, 3,5-dimethyladamantane-1-carboxylic acid (25 g, 1 equiv) was added and the reaction mixture was stirred at rt for 2 days. After adding EtOAc, the reaction mixture was carefully treated with saturated sodium thiosulfate solution at 0 °C and stirred for 15 min. After filtering through a pad of celite and washing with EtOAc, the organic phase was separated, washed with saturated sodium thiosulfate solution and brine, dried, and concentrated to give the title product (34.28 g, 74.6%), which was used without further purification.

¹ H NMR (400 MHz, DMSO-d6): δ ppm 12.33 (br., 1H), 2.21 (s, 2H), 1.96/1.91 (d+d, 4H), 1.50/1.43 (d+d, 4H), 1.21/1.14 (dm+dm, 2H), 0.86 (s, 6H); ¹³ C NMR (100 MHz, DMSO-d6) δ ppm 176.8, 66.8, 54.0, 48.7, 48.5, 45.7, 43.3, 35.5, 29.4; HR-MSR (m/z): [M-H] ^- , calculated for C ₁₃ H ₁₈ BrO ₂ : 285.0496; found: 285.0498.

Step B: 3-bromo-5,7-dimethyl-1-adamantylmethanol

To the product from Step A (34.3 g, 119 mmol) in THF (77.6 mL) was slowly added 1 M solution of BH ₃ -THF in THF (358 mL, 3 equiv), and the reaction mixture was stirred for 18 h. After addition of methanol and stirring for 30 min, purification by column chromatography (silica gel, heptane and MTBE as eluents) afforded the desired product (16.19 g, 49.6%).

¹ H NMR (400 MHz, DMSO-d ₆ ): 5 ppm 4.51 (t, 1H), 3.05 (d, 2H), 1.91 (s, 2H), 1.91 (s, 4H), 1.19/1.09 (d+d, 2H), 1.19/1.05 (d+d, 4H), 0.85 (s, 6H) ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 70.4, 68.9, 54.9, 49.8, 49.3, 43.8, 41.4, 35.7, 29.7; MSHR-ERI (m/z): [M-Br] ^- , calculated for C ₁₃ H ₂₁ O: 193.1598 found: 193.1589.

Step C: 1-[3-bromo-5, 7-dimethyl-1-adamantyl]methyl]pyrazole

To the product from Step B (16.19 g, 59.26 mmol) and 1H-pyrazole (4.841 g, 1.2 equiv) in toluene (178 mL), (cyanomethylene)tributylphosphorane (18.64 mL, 1.2 equiv) was added in one portion, and the reaction mixture was stirred at 90 °C for 2 h. Purification by column chromatography (silica gel, heptane and MTBE as eluents) afforded the desired product (17.88 g, 93%).

¹ H NMR (400 MHz, DMSO-d ₆ ): δ ppm 7.63 (d, 1H), 7.43 (d, 1H), 6.23 (t, 1H), 3.90 (s, 2H), 1.92-1.02 (m, 12H), 0.83 (s, 6H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 139.0, 131.8, 105.2, 67.7, 61.4, 54.4/48.8/44.6, 50.4, 35.7, 29.6; MSHR-ERI (m/z): [M] ⁺ , calculated for C ₁₆ H ₂₃ BrN ₂ : 322.1045 found: 322.1014.

Step D: 5-methyl-1-[[-3-bromo-5,7-dimethyl-1-adamantyl]methyl]pyrazole

To a solution of the product from Step C (17.88 g, 55.3 mmol) in THF (277 mL) at -78 °C was added butyllithium (2.5 M in THF, 66 mL, 3 equiv), followed after 1 h by the addition of iodomethane (17.2 mL, 5 equiv). After 10 min, the reaction mixture was quenched with saturated NH ₄ Cl solution, extracted with EtOAc, and the combined organic layers were dried and concentrated to give the desired product (18.7 g, 100%), which was used in the next step without further purification.

¹ H NMR (400 MHz, DMSO-d ₆ ): δ ppm 7.31 (d, 1H), 6.00 (d, 1H), 3.79 (s, 2H), 2.23 (s, 3H), 2.01 (s, 2H), 1.89/1.85 (d+d, 4H), 1.23/1.15 ( d+d, 4H), 1.16/1.05 (d+d, 2H), 0.83 (s, 6H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 139.2, 138.0, 105.2, 67.8, 57.8, 54.4, 50.6, 48.8, 44.8, 41.5, 35.7, 29.6, 11.8; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁₇ H ₂₆ BrN ₂ : 337.1279 found: 337.1289.

Step E: 2-[[3,5-dimethyl-7-[(5-methylpyrazol-1-yl)methyl]-1-adamantyl]oxy]ethanol

A mixture of the product from Step D (18.7 g, 55.3 mmol), ethylene glycol (123 mL, 40 equiv), and DIPEA (48.2 mL, 5 equiv) was stirred at 120 °C for 6 h. The reaction mixture was then diluted with water and extracted with EtOAc, and the combined organic layers were dried and concentrated to give the title product (18.5 g, 105%), which was used in the next step without further purification.

¹ H NMR (400 MHz, DMSO-d ₆ ): δ ppm 7.29 (d, 1H), 5.99 (d, 1H), 4.45 (t, 1H), 3.78 (s, 2H), 3.39 (q, 2H), 3.32 (t, 2H), 2.23 (s, 3H), 1.34 (s, 2H), 1.27/1.21 (d+d, 4H), 1.13/1.07 (d+d, 4H), 1.04/0.97 (d+d, 2H), 0.84 (s, 6H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 139.0, 137.8, 105.1, 74.0, 62.1, 61.5, 58.5, 50.1, 47.0, 46.1, 43.3, 39.7, 33.5, 30.2, 11.9; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₁₉ H ₃₁ N ₂ O ₂ : 319.2386 found: 319.2387.

Step F: tert-butyldiphenyl-[2-[[3,5-dimethyl-7-[(5-methylpyrazol-1-yl)methyl]-1-adamantyl]oxy]ethoxy]silane

To a mixture of the product from Step E (17.6 g, 55.3 mmol) and imidazole (5.65 g, 1.5 equiv) in DCM (150 mL) was added tert-butylchlorodiphenylsilane (18.6 g, 1.2 equiv), and the reaction mixture was stirred for 1 h. Purification by column chromatography (silica gel, heptane and MTBE as eluents) afforded the desired product (27.0 g, 87.8%).

¹ H NMR (400 MHz, DMSO-d ₆ ): δ ppm 7.72-7.34 (m, 10H), 7.29 (d, 1H), 5.99 (br., 1H), 3.78 (s, 2H), 3.67 (t, 2H), 3.44 (t, 2H), 2.21 (s, 3H), 1.33 (s, 2H), 1.26/1.18 (d+d, 4H), 1.12/1.06 (d+d, 4H), 1.03/0.96 (d+d, 2H), 0.98 (s, 9H), 0.82 (s, 6H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 139.0, 137.8, 105.1, 74.2, 64.4, 61.7, 58.5, 50.0, 46.9, 46.0, 43.4, 39.6, 33.5, 30.1, 27.1, 19.3, 11.9; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₅ H ₄₉ N ₂ O ₂ Si: 557.3563 found: 557.3564.

Step G: tert-butyldiphenyl-[2-[[3-[(4-iodo-5-methylpyrazol-1-yl)methyl]-5,7-dimethyl-1-adamantyl]oxy]ethoxy]silane

To a solution of the product from Step F (27.0 g, 48.56 mmol) in DMF (243 mL) was added N-iodosuccinimide (13.6 g, 1.25 equiv), and the reaction mixture was stirred for 2 h. After dilution with water, the mixture was extracted with DCM. The combined organic layers were washed with saturated sodium thiosulfate solution and brine, dried, and concentrated to give the title product (30.1 g, 90%).

¹ H NMR (400 MHz, DMSO-d ₆ ): δ ppm 7.68-7.37 (m, 10H), 7.45 (s, 1H), 3.89 (s, 2H), 3.67 (t, 2H), 3.44 (t, 2H), 2.23 (s, 3H), 1.30 (s, 2H), 1.26/1.17 (d+d, 4H), 1.12/1.05 (d+d, 4H), 1.00/0.96 (d+d, 2H), 0.98 (s, 9H), 0.82 (s, 6H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 142.5, 140.8, 133.7, 64.4, 61.7, 60.3, 59.9, 49.9, 46.8, 45.9, 43.2, 39.7, 33.5, 30.1, 27.1, 19.3, 12.2; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₅ H ₄₈ IN ₂ O ₂ Si: 683.2530 found: 683.2533.

Step H: tert-butyldiphenyl-[2-[[3,5-dimethyl-7-[[5-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazol-1-yl]methyl]-1-adamantyl]oxy]ethoxy]silane

To the product from Step G (17.5 g, 25.6 mmol) in THF (128 mL) at 0 °C was added chloro(isopropyl)magnesium-LiCl (1.3 M in THF, 24 mL, 1.2 equiv), stirred for 40 min, treated with 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (15.7 mL, 3 equiv), and the reaction mixture was stirred for 10 min. After dilution with saturated NH ₄ Cl solution and extraction with EtOAc, the combined organic phases were concentrated and purified by column chromatography (silica gel, heptane and MTBE as eluents) to give the desired product (15.2 g, 86.9%).

¹ H NMR (400 MHz, DMSO-d ₆ ): ^δ 5 ppm 7.65 (dm, 4H), 7.47 (s, 1H), 7.45 (tm, 2H), 7.40 (tm, 4H), 3.80 (s, 2H), 3.66 (t, 2H), 3.44 (t, 2H), 2.35 (s, 3H), 1.35-0.94 (m, 12H), 1.24 (s, 12H), 0.97 (s, 9H), 0.83 (s, 6H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 146.9, 144.3, 135.6, 130.2, 128.2, 104.7, 83.0, 74.2, 64.4, 61.7, 58.4, 30.1, 27.1, 25.2, 19.3, 12.0; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₆₀ BN ₂ O ₄ Si: 683.4415 found: 683.4423.

Synthesis 13: Methyl 3-bromo-6-(methylamino)pyridine-2-carboxylate

Step A: Methyl 6-[bis(tert-butoxycarbonyl)amino]-3-bromopyridine-2-carboxylate

To methyl 6-amino-3-bromopyridine-2-carboxylate (25.0 g, 108.2 mmol) and DMAP (1.3 g, 0.1 equiv) in DCM (541 mL) at 0 °C was added Boc ₂ O (59.0 g, 2.5 equiv), and the reaction mixture was stirred for 2.5 h. After addition of saturated NaHCO ₃ solution and extraction with DCM, the combined organic phases were dried and concentrated to give the desired product (45.0 g, 72.3%).

LC/MS (C ₁₇ H ₂₃ BrN ₂ O ₆ Na) 453 [M+H] ⁺ .

Step B: Methyl 3-bromo-6-(tert-butoxycarbonylamino)pyridine-2-carboxylate

To the product from Step A (42.7 g, 74.34 mmol) in DCM (370 mL) at 0 °C was added TFA (17.1 mL, 3 equiv.), and the reaction mixture was stirred for 18 h. After washing with saturated NaHCO ₃ solution and brine, the combined organic phases were dried, concentrated and purified by column chromatography (silica gel, heptane and EtOAc as eluents) to give the desired product (28.3 g, 115.2%).

¹ H NMR (400 MHz, DMSO-d ₆ ): δ ppm 10.29 (s, 1H), 8.11 (d, 1H), 7.88 (d, 1H), 3.87 (s, 3H), 1.46 (s, 9H) ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm . 165.6, 153.1, 151.8/148.3, 143.5, 116.3, 109.2, 53.2, 28.4. LC/MS (C ₁₂ H ₁₅ Br ₂ O ₄ Na) 353 [M+H] ⁺ .

Step C: Methyl 3-bromo-6-[tert-butoxycarbonyl(methyl)amino]pyridine-2-carboxylate

To the product from Step B (2.96 g, 8.93 mmol) in acetone (45 _mL ) were added _Cs2CO3 (8.7 g, 3 equiv) and iodomethane (0.67 mL, 1.2 equiv), and the reaction mixture was stirred for 3 h. After dilution with water and extraction with EtOAc, the combined organic phases were washed with brine, dried and concentrated to give the desired product (3.5 g, 112%).

¹ H NMR (400 MHz, DMSO-d ₆ ): δ ppm 8.13 (d, 1H), 7.78 (d, 1H), 3.90 (s, 3H), 3.27 (s, 3H), 1.47 (s, 9H); ¹³ C NMR (100 MHz, DMSO-de) δ ppm 165.5, 153.6, 153.6, 147.5, 142.8, 122.5, 111.3, 82.0, 53.3, 34.3, 28.2; MSHR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₃ H ₁₈ BrN ₂ O ₄ : 345.0450 found: 345.0429.

Step D: Methyl 3-bromo-6-(methylamino)pyridine-2-carboxylate

The product from Step C (3.0 g, 8.9 mmol) in 1,1,1,3,3,3-hexafluoroisopropanol (90 mL) was stirred at 100 °C for 18 h. Purification by column chromatography (silica gel, heptane and EtOAc as eluents) afforded the desired product (2.1 g, 96%).

¹ H NMR (400 MHz, DMSO-d ₆ ): δ ppm 7.63 (d, 1H), 7.04 (q, 1H), 6.53 (d, 1H), 3.83 (s, 3H), 2.73 (d, 3H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 166.6, 158.2, 148.2, 141.3, 112.1, 101.3, 52.9, 28.3; HR-ESI (m/z): [M] ⁺ , calculated for C ₈ H ₉ BrN ₂ O ₂ : 243.9847 found: 243.9843.

Synthesis 14: Methyl 3-[1-[[3,5-dimethyl-7-[2-[p-tolylsulfonyloxy)ethoxy]-1-adamantyl]methyl]-5-methylpyrazol-4-yl]-6-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]pyridine-2-carboxylate

Step A: methyl 3-[1-[[3-[2-[tert-butyl(diphenyl)silyl]oxyethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]- 6-(methylamino)pyridine-2-carboxylate

A mixture of the product of Preparation 13 (2.07 g, 8.45 mmol), the product of Preparation 12 (6.9 g, 1.2 equiv) _{, Cs2CO3 (} 8.26 g, 3 equiv) and Pd(AtaPhos) _2Cl2 (374 mg, 0.1 equiv) in 1,4-dioxane (51 mL) and water (8.5 _mL ) was stirred at 80°C for 1 h. Purification by column chromatography (silica gel, heptane and EtOAc as eluents) afforded the desired product (4.5 g, 74%).

¹ H NMR (400 MHz, DMSO-d ₆ ): δ ppm 7.66 (dm, 4H), 7.47-7.38 (m, 6H), 7.31 (d, 1H), 7.23 (s, 1H), 6.78 (q, 1H), 6.59 (d, 1H), 3.82 (s, 2H) , 3.67 (t, 2H), 3.58 (s, 3H), 3.46 (t, 2H), 2.77 (d, 3H), 2.06 (s, 3H), 1.35 (s, 2H), 1.27/1.20 (d+d, 4H), 1.14/1.09 (d+d, 4H), 1.05/0.97 (d+d, 2H), 0.98 (s, 9H), 0.84 (s, 6H); ¹³ C NMR (100 MHz, DMSO-de) δ ppm 140.1, 137.4, 135.6, 130.2/128.3, 109.8, 74.2, 64.4, 61.7, 58.9, 52.2, 50.0, 46.9, 46.0, 43.4, 39.8, 33.5, 30.1, 28.4, 27.1, 10.8; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₃ H ₅₇ N ₄ O ₄ Si: 721.4149 found: 721.4148.

Stage B: methyl 3-[1-[[3-[2-[tert-butyl(diphenyl)silyl]oxyethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]-6-[methyl -[5th til-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]pyridine-2-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product from Step A and reacting under reflux for 18 h, 4.7 g (86%) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ): δ ppm 7.78 (dm, 1H), 7.69-7.36 (m, JH), 7.63 (q, 1H), 7.63 (d, 1H), 7.47 (dm, 1H), 7.44 (m, 1H), 7.35 (s, 1H) , 7.31 (d, 1H), 7.24 (m, 1H), 5.86 (s, 2H), 3.86 (s, 2H), 3.72 (m, 2H), 3.67 (t, 2H), 3.64 (s, 3H), 3.61 (s, 3H), 3.46 (t, 2H), 2.36 (d, 3H), 2.13 (s, 3H), 1.40-0.94 (m, 12H), 0.97 (s, 9H), 0.92 (m, 2H), 0.85 (s, 6H), -0.11 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₆₁ H ₇₉ N ₈ O ₅ SSi ₂ : 1091.5433 found: 1091.5426.

Stage C: methyl 3-[1-[[3-(2-hydroxyethoxy)-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]-6-[methyl-[5-methyl-6-[ (Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]pyridine-2-carboxylate

To the product from Step B (1.0 g, 0.916 mmol) in THF (9 mL) at 0 °C was added 1 M TBAF in THF (1.0 mL, 1.1 equiv), and the reaction mixture was stirred for 1 h. After quenching the reaction mixture with saturated NH ₄ Cl solution and extracting with EtOAc, the combined organic phases were dried, concentrated and purified by column chromatography (silica gel, DCM and MeOH as eluents) to give the desired product (752 mg, 96%).

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.79 (dm, 1H), 7.66 (d, 1H), 7.64 (s, 1H), 7.47 (dm, 1H), 7.43 (m, 1H), 7.36 (s, 1H), 7.33 (d, 1H), 7.25 (m, 1H), 5.87 (s, 2H), 4.46 (t, 1H), 3.86 (s, 2H), 3.73 (m, 2H), 3.68 (s, 3H), 3.62 (s, 3H), 3.40 (m, 2H), 3.35 (t, 2H), 2.37 ( s, 3Н), 2.14 (s, 3Н), 1.42-0.96 (m, 12H), 0.92 (m, 2H), 0.86 (s, 6H), -0.10 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₅ H ₆₁ N ₈ O ₅ SSi: 853.4255 found: 853.4256.

Stage D: methyl 3-[1-[[3,5-dimethyl-7-[2-(n-tolylsulfonyloxy)ethoxy]-1-adamantyl]methyl]-5-methylpyrazol-4-yl]-6-[methyl-[5- methyl- 6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]pyridine-2-carboxylate

To the product from Step C (752 mg, 0.88 mmol) and triethylamine (0.5 mL, 4 equiv) in DCM (4.4 mL) was added p-tolylsulfonyl 4-methylbenzenesulfonate (575.4 mg, 1.76 mmol, 2 equiv), and the reaction mixture was stirred for 1 h. Purification by column chromatography (silica gel, heptane and EtOAc as eluents) afforded the desired product (722 mg, 81%).

¹ H NMR (400 MHz, DMSO-d ₆ ): δ ppm 7.79 (dm, 1H), 7.76 (dm, 2H), 7.68 (d, 1H), 7.64 (s, 1H), 7.47 (m, 1H), 7.46 (dm, 2H), 7.43 (td, 1H), 7.36 (s, 1H), 7.33 (d, 1H), 7.25 (td, 1H), 5.87 (s, 2H), 4.06 (m, 2H), 3.84 (s, 2H), 3.73 (t, 2H), 3.66 (s, 3H), 3.62 (s, 3H), 3.48 ( m, 2H), 2.40 (s, 3H), 2.37 (s, 3H), 2.13(s, 3H), 1.31-0.94 (m, 12H), 0.92 (t, 2H), 0.83 (s, 6H), -0.10 (s, 9H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm . 141.2, 137.5, 130.6, 128.1, 127.2, 123.4, 123.4, 123.1, 114.7, 112.0, 72.9, 71.5, 66.7, 58.8, 58.4, 52.6, 36.6, 30.1, 21.6, 17.8, 17.4, 10.8, -0.9; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₂ H ₆₇ N ₈ O ₇ S ₂ Si: 1007.4343 found: 1007.4344.

Example 1: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with ethyl 2-aminothiazole-4-carboxylate (71 mg, 0.41 mmol, 1.2 equiv), Preparation 9a (100 mg, 0.34 mmol, 1 equiv), xantphos (19.9 mg, 0.03 mmol, 0.1 equiv), tris(dibenzylideneacetone)dipalladium(0) (15.8 mg, 0.02 mmol, 0.05 equiv), and cesium carbonate (134.5 mg, 0.41 mmol, 1.2 equiv). The vessel was evacuated and flushed with nitrogen (×3), and toluene (6 mL) was added. The mixture was sparged with nitrogen (10 min) and then heated at 180 °C for 1.5 h under microwave irradiation. The mixture was partitioned between ethyl acetate (100 mL) and brine (50 mL), and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0:100% ethyl acetate in isoheptane afforded the title product (63 mg, 0.15 mmol, 43%).

LC/MS (C ₁₉ H ₁₈ N ₆ O ₂ S ₂ ) 427 [M+H] ⁺ ; RT 1.32 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 10.99 (s, 1H), 10.87 (br s, 1H), 7.95 (s, 1H), 7.89 (br s, 1H), 7.57 (br s, 1H), 7.37 (t, J=7.59 Hz, 1H), 7.20 (t, 1H), 4.30 (q, J=7.10 Hz, 2H), 2.38 (s, 3H), 2.36 (s, 3H), 1.32 (t, J=7.11 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (38 mg, 0.09 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide solution (90 µL, 0.18 mmol, 2 equiv), and the mixture was stirred at ambient temperature for 30 min, then heated at 40 °C for 1 h, and finally at 80 °C for 1 h. The reaction mixture was then allowed to cool to ambient temperature, the reaction mixture was partitioned between ethyl acetate (10 mL) and water (10 mL), and the pH was adjusted to 6. The aqueous phase was concentrated in vacuo, and the residue was triturated with water and collected by filtration. Washing with water, diethyl ether, then dichloromethane, and subsequent drying under vacuum afforded the desired product as an orange solid (14 mg, 0.04 mmol, 39%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₇ H ₁₅ N ₆ O ₂ S ₂ : 399.0692, found: 399.0729.

Example 2: 6-({6-[(1,3-Benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)pyridine-2-carboxylic acid

Step A: Ethyl 6-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)pyridine-2-carboxylate

An oven-dried microwave processing vessel was charged with ethyl 6-aminopyridine-2-carboxylate (171 mg, 1.03 mmol, 1.5 equiv), the product of Preparation 9a (200 mg, 0.69 mmol, 1 equiv), xantphos (39.8 mg, 0.07 mmol, 0.1 equiv), tris(dibenzylideneacetone)dipalladium(0) (31.5 mg, 0.03 mmol, 0.05 equiv), and cesium carbonate (336 mg, 1.03 mmol, 1.5 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then toluene (5 mL) was added. The mixture was sparged with nitrogen (10 min) and then heated at 180 °C for 3 h under microwave irradiation. The mixture was diluted with ethyl acetate and water and filtered through a small pad of celite. The organic layer was washed with brine, dried (magnesium sulfate), filtered and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in hexane afforded the title compound as a yellow, glassy solid (55 mg, 0.13 mmol, 19%).

LC/MS (C ₂₁ H ₂₀ N ₆ O ₂ S) 421 [M+H] ⁺ ; RT 1.17 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 10.91 (br s, 1H), 9.17 (s, 1H), 7.85 (br s, 1H), 7.84 (dd, J=7.32, 8.47 Hz, 1H), 7.66 (d, J=8.47 Hz, 1H), 7.55 (d, J=7.20 Hz, 1H), 7.37 (t, J=7.73 Hz, 1H), 7.19 (s, 1H), 4.32 (q, J=7.13 Hz, 2H), 2.38 (s, 3H), 2.27 (s, 3H), 1.32 (t, J=7.10 Hz, 3H).

Step B: 6-({6-[1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)pyridine-2-carboxylic acid

To a solution of the product from Step A (50 mg, 0.12 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide solution (0.12 mL, 0.24 mmol, 2 equiv) and the mixture was heated at 90 °C for 1 h. The mixture was cooled to ambient temperature, the solvent was evaporated in vacuo and the residue was triturated with water and collected by filtration to give the desired product as an orange solid (9 mg, 0.02 mmol, 19%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₉ H ₁₇ N ₆ O ₂ S: 393.1128, found: 393.1163.

Example 3: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with Preparation 9a (376 mg, 1.29 mmol, 1.5 equiv), Preparation 3u (350 mg, 0.86 mmol, 1 equiv), cesium carbonate (394 mg, 1.21 mmol, 1.4 equiv), xantphos (49.9 mg, 0.09 mmol, 0.1 equiv), and tris(dibenzylideneacetone)dipalladium(0) (39.5 mg, 0.04 mmol, 0.05 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then trifluorotoluene (10 mL) was added. The mixture was sparged with nitrogen (10 min) and then heated at 180 °C for 1 h under microwave irradiation. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 43 g RediSep column) eluting with 5-95% acetonitrile in water afforded the desired product as a bright yellow glass (266 mg, 0.4 mmol, 47%).

LC/MS (C ₃₃ H ₃₄ FN ₇ O ₃ S ₂ ) 660 [M+H] ⁺ ; RT 1.18 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.31 (br s, 1H), 10.81 (br s, 1H), 7.88 (d, J=7.8 Hz, 1H), 7.50 (d, J=7.8 Hz, 1H), 7.37 (ddd, J=8.2, 7.3, 1.3 Hz, 1H), 7.31 (dd, J=11.9, 2.0 Hz, 1H), 7.25-7.11 (m, 3H), 4.26 (q, J=7.1 Hz, 2H), 4.16 (t, J=6.2 Hz, 2H), 3.39 (s, 2H), 3.30 (t, J=7.6 Hz, 2H), 2.37 (s, 3H), 2.35 (s, 3H), 2.21 (s, 6H), 2.14 (q, J=7.2, 6.5 Hz, 2H), 1.29 (t, J=7.1 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (266 mg, 0.4 mmol, 1 equiv) in 1,4-dioxane (10 mL) was added 2 M aqueous lithium hydroxide (0.4 mL, 0.81 mmol, 2 equiv) and the mixture was stirred at reflux for 3 h. The reaction mixture was then allowed to cool to ambient temperature, concentrated in vacuo and triturated with water (10 mL). The solids were collected by filtration, washed with water and dried in vacuo to give the title product as a bright yellow solid (209 mg, 0.33 mmol, 82%) [as the lithium salt].

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₁ H ₃₁ FN ₇ O ₃ S ₂ : 632.1908, found: 632.1914.

Example 4: 2-({6-[(1,3-Benzothiazol-2-yl)amino]pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried flask was charged with the product of Preparation 9b (500 mg, 1.9 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (393 mg, 2.28 mmol, 1.2 equiv), cesium carbonate (930 mg, 2.85 mmol, 1.5 equiv), xantphos (110 mg, 0.19 mmol, 0.1 equiv), and tris(dibenzylideneacetone)dipalladium(0) (87.1 mg, 0.1 mmol, 0.05 equiv). The flask was evacuated and purged with nitrogen (×3), and then toluene (20 mL) was added. The mixture was then bubbled with nitrogen (15 min) and heated at 180°C for 1.5 h under microwave irradiation. The mixture was partitioned between dichloromethane (200 mL) and water (200 mL) and the organic phase was concentrated in vacuo. The crude material was triturated with dichloromethane and filtered, washed with dichloromethane and dried to give the title product as a yellow solid (417 mg, 1.05 mmol, 55%).

LC/MS (C ₁₇ H ₁₄ N ₆ O ₂ S ₂ ) 397 [M+H] ⁺ ; RT 1.20 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.86 (s, 2H), 7.97 (s, 1H), 7.95 (s, 1H), 7.65 (d, J=8.1 Hz, 1H), 7.52 (d, J=9.3 Hz, 1H), 7.46-7.32 (m, 2H), 7.23 (t, 1H), 4.29 (q, J=7.1 Hz, 2H), 1.32 (t, J=7.1 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (417 mg, 1.05 mmol, 1 equiv) in 1,4-dioxane (20 mL) was added 2 M aqueous lithium hydroxide (1.05 mL, 2.09 mmol, 2 equiv) and the reaction mixture was heated at reflux for 1 h. The mixture was allowed to cool to ambient temperature, then the solvent was removed in vacuo and the residue was triturated with acetone followed by trituration with 1:1 isopropanol/water. The solid was collected by filtration and dried in vacuo to give the desired product as a brown solid (161 mg, 0.43 mmol, 42%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₅ H ₁₁ N ₆ O ₂ S ₂ : 371.0379, found: 371.0404.

Example 5: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-(propan-2-yl)pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-(propan-2-yl)pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Preparation 9cb (367 mg, 1.2 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (249 mg, 1.44 mmol, 1.2 equiv), cesium carbonate (589 mg, 1.81 mmol, 1.5 equiv), xantphos (69.7 mg, 0.12 mmol, 0.1 equiv), and tris(dibenzylideneacetone)dipalladium(0) (55.1 mg, 0.06 mmol, 0.05 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then toluene (10 mL) was added. The mixture was bubbled with nitrogen (15 min) and then heated at 180 °C for 1 h under microwave irradiation. The mixture was partitioned between ethyl acetate and water, and the aqueous phase was extracted with ethyl acetate. The combined organics were washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a bright yellow solid (303 mg, 0.69 mmol, 57%).

LC/MS (C ₂₀ H ₂₀ N ₆ O ₂ S ₂ ) 441 [M+H] ⁺ ; RT 1.39 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.03 (d, J=233.3 Hz, 1H), 11.72 (s, 1H), 7.94 (s, 1H), 7.85-7.09 (m, 5H), 4.29 (q, J=7.1 Hz, 2H), 3.33 (s, 1H), 1.32 (t, J=7.1 Hz, 3H), 1.25 (d, J=6.8 Hz, 6H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-(propan-2-yl)pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (300 mg, 0.68 mmol, 1 equiv) in 1,4-dioxane (10 mL) was added 2 M aqueous lithium hydroxide (0.68 mL, 1.36 mmol, 2 equiv) and the reaction mixture was heated at 60 °C for 18 h. The residue was diluted with water and acidified with 2 M aqueous hydrochloric acid. The resulting solid was collected by filtration, washed with water, and dried in vacuo to give a brown solid (130 mg, 0.32 mmol, 46%) [as the hydrochloric acid salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₈ H ₁₇ N ₆ O ₂ S ₂ : 413.0849, found: 413.0885.

Example 6: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4-(propan-2-yl)pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-(propan-2-yl)pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

The product of Synthesis 9ca (500 mg, 1.64 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (339 mg, 1.97 mmol, 1.2 equiv), xantphos (94.9 mg, 0.16 mmol, 0.1 equiv), cesium carbonate (802 mg, 2.46 mmol, 1.5 equiv), and tris(dibenzylideneacetone)dipalladium(0) (75.1 mg, 0.08 mmol, 0.05 equiv) were charged into an oven-dried flask. The flask was evacuated and flushed with nitrogen (×3), and then toluene (20 mL) was added. The mixture was bubbled with nitrogen (10 min) and then heated at 200 °C for 1.5 h under microwave irradiation. Additional xantphos (94.9 mg, 0.16 mmol, 0.1 equiv) and tris(dibenzylideneacetone)dipalladium(0) (75.1 mg, 0.08 mmol, 0.05 equiv) were added, the mixture was bubbled with nitrogen (10 min) and then heated at 180 °C for 3 h under microwave irradiation. The reaction mixture was partitioned between ethyl acetate and water, the aqueous phase was extracted with ethyl acetate, and the combined organics were washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0:55% ethyl acetate in isoheptane afforded the title product as an orange solid (147 mg, 0.33 mmol, 20%).

LC/MS (C ₂₀ H ₂₀ N ₆ O ₂ S ₂ ) 441 [M+H] ⁺ ; RT 1.35 (LCMS-V-B1)

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-(propan-2-yl)pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (147 mg, 0.33 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide (0.33 mL, 0.67 mmol, 2 equiv), and the mixture was heated at reflux for 1 h. The mixture was cooled to ambient temperature and concentrated in vacuo. The residue was taken up in water and acidified to pH 6. The aqueous phase was extracted with ethyl acetate, and the organics were dried (magnesium sulfate) and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 4.3 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow solid (7 mg, 0.02 mmol, 5%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₈ H ₁₇ N ₆ O ₂ S ₂ : 413.0849, found: 413.0886.

Example 7: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Preparation 9db (400 mg, 1.45 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (373 mg, 2.17 mmol, 1.5 equiv), cesium carbonate (706 mg, 2.17 mmol, 1.5 equiv), tris(dibenzylideneacetone)dipalladium(0) (66.2 mg, 0.07 mmol, 0.05 equiv), and xantphos (83.6 mg, 0.14 mmol, 0.1 equiv). The vessel was evacuated and flushed with nitrogen (x3), and then toluene (15 mL) was added. The mixture was bubbled with nitrogen (5 min) and then heated at 150 °C for 2 h under microwave irradiation. Additional amounts of ethyl 2-amino-1,3-thiazole-4-carboxylate (375 mg, 2.17 mmol, 1.5 equiv), xantphos (83.6 mg, 0.14 mmol, 0.1 equiv), and tris(dibenzylideneacetone)dipalladium(0) (66.2 mg, 0.07 mmol, 0.05 equiv) were added, the mixture was bubbled with nitrogen (5 min), and then heated at 180 °C for 1 h under microwave irradiation. The mixture was concentrated in vacuo and purified by reversed-phase automated flash chromatography (CombiFlash Rf, C18 4.3 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water to give the desired product (169 mg, 0.41 mmol, 28%).

LC/MS (C ₁₈ H ₁₆ N ₆ O ₂ S ₂ ) 413 [M+H] ⁺ ; RT 1.27 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.81 (s, 1H), 11.04 (br s, 1H), 7.94 (s, 1H), 7.90 (br s, 1H), 7.55 (br s, 1H), 7.39 (t, J=7.6 Hz, 1H), 7.21 (t, J=7.5 Hz, 1H), 7.14 (s, 1H), 4.29 (q, J=7.1 Hz, 2H), 2.40 (s, 3H), 1.32 (t, J=7.1 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a stirred suspension of the product from Step A (169 mg, 0.41 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide (0.49 mL, 0.49 mmol, 1.2 equiv) and the mixture was stirred at 100 °C for 4.5 h. The crude product was suspended in 2:1 isopropanol/water and stirred for 30 min. The solids were collected by filtration and dried in vacuo to give the title product as a bright yellow solid (17 mg, 0.04 mmol, 11%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₆ H ₁₃ N ₆ O ₂ S ₂ : 385.0536, found: 385.0567.

Example 8: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methyl-4-(propan-2-yl)pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methyl-4-(propan-2-yl)pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Preparation 9ea (300 mg, 0.94 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (243 mg, 1.41 mmol, 1.5 equiv), cesium carbonate (460 mg, 1.41 mmol, 1.5 equiv), xantphos (218 mg, 0.38 mmol, 0.4 equiv), and tris(dibenzylideneacetone)dipalladium(0) (172.4 mg, 0.18 mmol, 0.2 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then toluene (4 mL) was added. The mixture was sparged with nitrogen (15 min) and then heated at 180°C for 2 h under microwave irradiation. The mixture was concentrated in vacuo and the residue was adsorbed onto Isolute. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 4.3 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product (22 mg, 0.05 mmol, 5%).

LC/MS (C ₂₁ H ₂₂ N ₆₀₂ S ₂ ) 455 [M+H] ⁺ ; RT 1.42 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 10.96 (s, 1H), 7.92 (s, 1H), 7.87 (br s, 1H), 7.53 (br s, 1H), 7.38 (t, J=7.5 Hz, 1H), 7.20 (t, J=7.6 Hz, 1H), 4.30 (q, J=7.1 Hz, 2H), 3.66 (p, J=7.0 Hz, 1H), 2.48 (s, 3H), 1.35 (d, 6H), 1.32 (t, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methyl-4-(propan-2-yl)pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (22 mg, 0.05 mmol, 1 equiv) in tetrahydrofuran (2 mL) and methanol (0.5 mL) was added 2 M aqueous lithium hydroxide (50 µL, 0.1 mmol, 2 equiv), and the mixture was heated at 75 °C for 1 h. The resulting solid was taken up again in water (2 mL) and the pH was adjusted to 6. The organics were extracted with ethyl acetate (20 mL), dried (magnesium sulfate), concentrated in vacuo, and dried in vacuo to give the title product as a light orange solid (19 mg, 0.04 mmol, 92%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₉ H ₁₉ N ₆ O ₂ S ₂ : 427.1005, found: 427.1043.

Example 9: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with Preparation 9a (45.7 mg, 0.16 mmol, 1 equiv), Preparation 3v (48.2 mg, 0.16 mmol, 1 equiv), Xantphos (9.1 mg, 0.02 mmol, 0.1 equiv), tris(dibenzylideneacetone)dipalladium(0) (7.2 mg, 0.01 mmol, 0.05 equiv), and cesium carbonate (61.5 mg, 0.19 mmol, 1.2 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then toluene (2 mL) was added. The mixture was sparged with nitrogen (10 min) and then heated at 180 °C for 2 h under microwave irradiation. The reaction mixture was partitioned between ethyl acetate and water, then washed successively with water and brine. The organic phase was dried (magnesium sulfate) and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded the title product as a brown glass (19.2 mg, 0.03 mmol, 22%).

LC/MS (C ₂₈ H ₂₈ N ₆ O ₃ S ₂ ) δ61 [M+H] ⁺ ; RT 1.51 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 10.81 (br s, 2H), 7.65 (s, 1H), 7.38 (s, 1H), 7.31 (t, 2H), 7.21 (s, 2H), 7.00- 6.89 (m, 3H), 4.27 (q, J=7.2 Hz, 2H), 4.06 (t, J=6.2 Hz, 2H), 3.30 (d, J=8.3 Hz, 2H), 2.37 (s, 3H), 2.35 (s, 3H), 2.13 (q, 2H), 1.30 (t, J=7.1 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (19 mg, 0.03 mmol, 1 equiv) in 1,4-dioxane (2 mL) was added 2 M aqueous lithium hydroxide (14.2 mg, 0.34 mmol, 10 equiv) and the mixture was heated under reflux for 10 h. The reaction mixture was then allowed to cool to ambient temperature, the solvent was removed in vacuo, the residue was triturated with water and the crude product was collected by filtration. Purification by reversed-phase preparative HPLC (HPLC-V-A2 method) afforded the desired product as a beige solid (3.5 mg, 6.6 μmol, 19%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₆ H ₂₅ N ₆ O ₃ S ₂ : 533.1424, found: 533.1460.

Example 10: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4-methyl-5-(propan-2-yl)pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-methyl-5-(propan-2-yl)pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Preparation 9eb (114 mg, 0.36 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (92.4 mg, 0.54 mmol, 1.5 equiv), cesium carbonate (175 mg, 0.54 mmol, 1.5 equiv), xantphos (41.4 mg, 0.07 mmol, 0.2 equiv), and tris(dibenzylideneacetone)dipalladium(0) (32.7 mg, 0.04 mmol, 0.1 equiv). The vessel was evacuated and flushed with nitrogen (×3), and toluene (4 mL) was added. The mixture was bubbled with nitrogen (15 min) and then heated at 180 °C for 1 h under microwave irradiation. The mixture was concentrated in vacuo and purified by reversed-phase automated flash chromatography (CombiFlash Rf, C18 4.3 g RediSep column) eluting with a gradient of 5-70% acetonitrile in water to give the desired product as a yellow solid (20 mg, 0.04 mmol, 12%).

LC/MS (C ₂₁ H ₂₂ N ₆ O ₂ S ₂ ) 455 [M+H] ⁺ ; RT 1.45 (LCMS-V-B1).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-methyl-5-(propan-2-yl)pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (20 mg, 0.04 mmol, 1 equiv) in tetrahydrofuran (2 mL) and methanol (0.5 mL) was added lithium hydroxide monohydrate (3.69 mg, 0.09 mmol, 2 equiv), and the reaction mixture was heated at reflux for 1 h. The mixture was allowed to cool to ambient temperature and concentrated in vacuo. The product was taken up in water (3 mL), acidified to pH 6 with 1 M aqueous hydrochloric acid, and extracted with 19:1 dichloromethane/isopropanol. The organic extract was dried (magnesium sulfate) and concentrated in vacuo to give the title product as a loose yellow solid (13.5 mg, 0.03 mmol, 72%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₉ H ₁₉ N ₆ O ₂ S ₂ : 427.1005, found: 427.1043.

Example 11: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Preparation 9da (240 mg, 0.87 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (224 mg, 1.3 mmol, 1.5 equiv), cesium carbonate (424 mg, 1.3 mmol, 1.5 equiv), tris(dibenzylideneacetone)dipalladium(0) (39.7 mg, 0.04 mmol, 0.05 equiv), and xantphos (50.2 mg, 0.09 mmol, 0.1 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then toluene (15 mL) was added. The mixture was bubbled with nitrogen (5 min) and then heated at 180 °C for 3 h under microwave irradiation. The mixture was concentrated in vacuo and purified by reverse phase automated flash chromatography (CombiFlash Rf, C18 26 g RediSep column) eluting with a gradient of 5 95% acetonitrile in water to give the desired product as a brown solid (44 mg, 0.11 mmol, 12%).

LC/MS (C ₁₈ H ₁₆ N ₆ O ₂ S ₂ ) 413 [M+H] ⁺ ; RT 1.24 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.61 (br s, 1H), 11.17 (s, 1H), 7.97 (s, 1H), 7.95 (br s, 1H), 7.64 (d, J=8.0 Hz, 1H), 7.39 (ddd, J=8.2, 7.2, 1.3 Hz, 1H), 7.31 (d, J=1.2 Hz, 1H), 7.22 (ddd, J=8.2, 7.3, 1.2 Hz, 1H), 4.30 (q, J=7.1 Hz, 2H), 2.42 (s, 3H), 1.32 (t, J=7.1 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (44 mg, 0.11 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide (0.21 mL, 0.21 mmol, 2 equiv), and the reaction mixture was heated at reflux for 1 h. The solid was triturated with 4:1 isopropanol/water (4 mL) and stirred for 30 min. The solid was collected by filtration, washed with additional cold isopropanol (3 mL), and dried in vacuo to give the desired product as a brown solid (33 mg, 0.09 mmol, 80%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₆ H ₁₃ N ₆ O ₂ S ₂ : 385.0536, found: 385.0572.

Example 12: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(3-methoxypropyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(3-methoxypropyl)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with Preparation 9a (260 mg, 0.89 mmol, 1 equiv), Preparation 3w (219 mg, 0.89 mmol, 1 equiv), xantphos (51.8 mg, 0.09 mmol, 0.1 equiv), tris(dibenzylideneacetone)dipalladium(0) (41 mg, 0.04 mmol, 0.05 equiv), and cesium carbonate (350 mg, 1.07 mmol, 1.2 equiv). The vessel was evacuated and flushed with nitrogen (x3), and then toluene (5 mL) was added. The mixture was sparged with nitrogen (10 min) and then heated at 180 °C for 1 h under microwave irradiation. The reaction mixture was diluted with ethyl acetate, washed successively with water and brine, then dried (magnesium sulfate) and the solvent removed in vacuo. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with 5-95% acetonitrile in water afforded the desired product as a yellow glass (72.5 mg, 0.15 mmol, 16%).

LC/MS (C ₂₃ H ₂₆ N ₆ O ₃ S ₂ ) 499 [M+H] ⁺ ; RT 1.38 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 10.76 (br s, 1H), 7.88 (d, J=7.7 Hz, 1H), 7.50 (br s, 1H), 7.37 (td, J=8.1, 7.7, 1.3 Hz, 1H), 7.20 (t, J=7.7 Hz, 1H), 4.29 (q, J=7.1 Hz, 2H), 3.41 (t, J=6.3 Hz, 1H), 3.27 (s, 3H), 3.21-3.12 (m, 2H), 2.37 (s, 3H), 2.35 (s, 3H), 1.96-1.84 (m, 2H), 1.32 (t, J=7.1 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(3-methoxypropyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (72.5 mg, 0.15 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (12.2 mg, 0.29 mmol, 2 equiv) and the mixture was heated at reflux for 10 h. The reaction mixture was allowed to cool to ambient temperature and the solvent was removed in vacuo. The resulting residue was triturated with water, then collected by filtration, washed with water, and dried in vacuo to give the title product as a brown solid (40.9 mg, 0.09 mmol, 60%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₁ H ₂₃ N ₆ O ₃ S ₂ : 471.1268, found: 471.1306.

Example 13: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-[3-(2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-[3-(2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with Preparation 9a (162 mg, 0.56 mmol, 1 equiv), Preparation 3x (181 mg, 0.56 mmol, 1 equiv), xantphos (36.0 mg, 0.06 mmol, 0.11 equiv), tris(dibenzylideneacetone)dipalladium(0) (25.6 mg, 0.03 mmol, 0.05 equiv), and cesium carbonate (243 mg, 0.75 mmol, 1.34 equiv). The vessel was evacuated and flushed with nitrogen (×3), and toluene (4 mL) and dimethylformamide (1 mL) were added. The mixture was sparged with nitrogen (10 min) and then heated at 180 °C for 1 h under microwave irradiation. The reaction mixture was diluted with ethyl acetate, washed successively with water and brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, CI8 13 g RediSep column) eluting with a gradient of 5 95% acetonitrile in water afforded the desired product as a brown glass (76.1 mg, 0.13 mmol, 24%).

LC/MS (C ₂₈ H ₂₇ FN ₆ O ₃ S ₂ ) δ79 [M+H] ⁺ ; RT 1.49 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 10.78 (br s, 1H), 7.89 (brs, 1H), 7.42-7.28 (m, 2H), 7.28-7.08 (m, 4H), 7.00-6.86 (m, 1H), 4.26 (q, J=7.1 Hz, 2H), 4.14 (t, J=6.2 Hz, 2H), 3.30 (d, J=6.8 Hz, 2H), 2.37 (s, 3H), 2.35 (s, 3H), 2.21-2.11 (m, 2H), 1.30 (t, J=7.1 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-[3-(2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (76 mg, 0.13 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (11.02 mg, 0.26 mmol, 2 equiv), and the mixture was heated under reflux for 8 h. The mixture was allowed to cool to ambient temperature and the solvent was removed in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the material, which was further purified by reversed-phase preparative HPLC (HPLC-U-A2 method) to afford the desired product as a beige solid (7.2 mg, 0.01 mmol, 10%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₆ H ₂₄ FN ₆ O ₃ S ₂ : 551.1330, found: 551.1368.

Example 14: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-{3-[4-(dimethylcarbamoyl)-2-fluorophenoxy]propyl}-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-{3-[4-(dimethylcarbamoyl)-2-fluorophenoxy]propyl}-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with Preparation 9a (143 mg, 0.49 mmol, 1 equiv), Preparation 3u (199 mg, 0.49 mmol, 1 equiv), xantphos (28.5 mg, 0.05 mmol, 0.1 equiv), tris(dibenzylideneacetone)dipalladium(0) (22.5 mg, 0.02 mmol, 0.05 equiv), and cesium carbonate (192 mg, 0.59 mmol, 1.2 equiv). The vessel was evacuated and flushed with nitrogen (×3), and toluene (4 mL) and dimethylformamide (1 mL) were then added. The mixture was sparged with nitrogen (10 min) and then heated at 180 °C for 1 h under microwave irradiation. The reaction mixture was diluted with ethyl acetate, then washed with water followed by brine. The organic extract was dried (magnesium sulfate) and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded the title product as a brown glass (60 mg, 0.09 mmol, 19%).

LC/MS (C ₃₁ H ₃₂ FN ₇ O ₄ S ₂ ) 650 [M+H] ⁺ ; RT 1.36 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 10.77 (br s, 1H), 7.87 (s, 1H), 7.42-7.28 (m, 2H), 7.26-7.17 (m, 4H), 4.26 (q, J=7.1 Hz, 2H), 4.19 (t, J=6.2 Hz, 2H), 2.97-2.94 (m, 2H), 2.93 (s, 6H), 2.37 (s, 3H), 2.35 (s, 3H), 2.18 (q, J=7.3, 6.9 Hz, 2H), 1.29 (t, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-{3-[4-(dimethylcarbamoyl)-2-fluorophenoxy]propyl}-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (60 mg, 0.09 mmol, 1 equiv) in 1,4-dioxane was added lithium hydroxide monohydrate (19.4 mg, 0.46 mmol, 5 equiv) and the mixture was heated at reflux for 14 h. The reaction mixture was allowed to cool to ambient temperature and the solvent was removed in vacuo. The residue was triturated with water, followed by trituration with ethanol, and then purified by reverse-phase preparative HPLC (HPLC-V-A2 method) to give the desired product as a brown solid (11.6 mg, 0.02 mmol, 20%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₉ H ₂₉ FN ₇ O ₄ S ₂ : 622.1701, found: 622.1740.

Example 15: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4-ethyl-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-ethyl-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of the Synthesis of 9fa (400 mg, 1.31 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (316 mg, 1.84 mmol, 1.4 equiv), cesium carbonate (599 mg, 1.84 mmol, 1.4 equiv), xantphos (75.9 mg, 0.13 mmol, 0.1 equiv), and tris(dibenzylideneacetone)dipalladium(0) (60.1 mg, 0.07 mmol, 0.05 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then toluene (15 mL) was added. The mixture was bubbled with nitrogen (10 min) and then heated at 200 °C for 2 h under microwave irradiation. The reaction mixture was concentrated in vacuo and purified by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water to give the desired product (70 mg, 0.16 mmol, 12%).

LC/MS (C ₂₀ H ₂₀ N ₆ O ₂ S ₂ ) 441 [M+H] ⁺ ; RT 1.37 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.08 (s, 1H), 10.88 (br s, 1H), 7.94 (s, 1H), 7.89 (br s, 1H), 7.53 (br s, 1H), 7.38 (t, 1H), 7.20 (t, 1H), 4.30 (q, J=7.1 Hz, 2H), 2.93 (q, J=7.4 Hz, 2H), 2.40 (s, 3H), 1.32 (t, J=7.1 Hz, 3H), 1.09 (t, J=7.4 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-ethyl-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (70 mg, 0.16 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (0.32 mL, 0.32 mmol, 2 equiv) and the mixture was heated at reflux for 1 h. The residue was then suspended in water, the pH was adjusted to 6, and the mixture was then concentrated again. The solid was triturated with isopropanol with a few drops of water, then collected by filtration, washed with isopropanol, and dried in vacuo to give the title product as a brown solid (38.8 mg, 0.09 mmol, 59%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₁₈ H ₁₅ N ₆ O ₂ S ₂ : 411.0703, found: 411.0707.

Example 16: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-ethyl-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-ethyl-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Preparation 9fb (300 mg, 0.98 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (220 mg, 1.28 mmol, 1.3 equiv), cesium carbonate (449 mg, 1.38 mmol, 1.4 equiv), xantphos (57 mg, 0.1 mmol, 0.1 equiv), and tris(dibenzylideneacetone)dipalladium(0) (45.1 mg, 0.05 mmol, 0.05 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then toluene (15 mL) was added. The mixture was bubbled with nitrogen (10 min) and then heated at 200 °C for 2 h under microwave irradiation. The reaction mixture was concentrated in vacuo and purified by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with 5-95% acetonitrile in water to give the desired product as a yellow solid (54 mg, 0.12 mmol, 12%).

LC/MS (C ₂₀ H ₂₀ N ₆ O ₂ S ₂ ) 441 [M+H] ⁺ ; RT 1.38 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 10.98 (s, 1H), 7.95 (s, 1H), 7.84 (s, 1H), 7.43 (br s, 1H), 7.36 (t, J=7.5 Hz, 1H), 7.18 (t, J=7.5 Hz, 1H), 4.30 (q, J=7.1 Hz, 2H), 2.92 (q, J=7.5, 7.1 Hz, 2H), 2.38 (s, 3H), 1.32 (t, J=7.1 Hz, 3H), 1.11 (t, J=7.4 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-ethyl-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (54 mg, 0.12 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added 2 M aqueous lithium hydroxide (0.12 mL, 0.25 mmol, 2 equiv), and the reaction mixture was heated under reflux for 2 h. The mixture was concentrated in vacuo, then suspended in water and the pH adjusted to 5-6, after which the mixture was concentrated in vacuo again. The crude solid was triturated with water, stirred for 30 min, then collected by filtration, washed with cold water, and dried in vacuo to give the desired product as a yellow solid (28.9 mg, 0.07 mmol, 57%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₈ H ₁₇ N ₆ O ₂ S ₂ : 413.0849, found: 413.0848.

Example 17: 2-[[4-(1,3-Benzothiazol-2-ylamino)-5,6,7,8-tetrahydrophthalazin-1-yl]amino]thiazole-4-carboxylic acid

Stage A: 4-bromo-5,6,7,8-tetrahydrophthalazine-1-amine

A mixture of 4.0 g of 1,4-dibromo-5,6,7,8-tetrahydrophthalazine (13.7 mmol) in 50 ml of 25% NH ₃ solution in water was heated at 100°C for 18 h. After concentration, the residue was taken up in methanol, treated with charcoal, stirred, filtered, concentrated, taken up in EtOAc, washed with 10% NaOH solution, dried over MgSO ₄ , filtered and concentrated to give 1.28 g (41%) of the desired product.

LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₈ H ₁₁ BrN ₃ : 228, 230, found: 228, 230.

Step B: N-(4-bromo-5,6,7,8-tetrahydrophthalazin-1-yl)-1,3-benzothiazol-2-amine

A mixture of 1.05 g of the product from Step A (4.6 mmol, 1 equiv), 1.8 g of 2-bromo-1,3-benzothiazole (8.4 mmol, 1.8 equiv), and 736 mg of sodium hydride (60% suspension, 18.4 mmol, 3.6 equiv) in 80 mL of 1,4-dioxane was heated at reflux for 0.5 h. After cooling and quenching the reaction mixture with methanol, the mixture was concentrated, treated with water, and the product was filtered and dried. The solid was triturated with EtOAc, filtered, and dried to give 1.56 g (94%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 11.51 (br., 1H), 7.83 (d, 1H), 7.53 (brd., 1H), 7.38 (td, 1H), 7.22 (td, 1H), 2.75/2.62 (m+m, 4H), 1.79 ( m, 4H); ¹³ C NMR (125 MHz, DMSO-d6) δ ppm 126.6, 122.9, 122.2, 28.8/24, 21.4/21.1; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₅ H ₁₄ BrN4S: 361.0117, found: 361.0107.

Step C: Ethyl 2-[[4-(1,3-benzothiazol-2-ylamino)-5,6,7,8-tetrahydrophthalazin-1-yl]amino]thiazole-4-carboxylate

A mixture of 120 mg of the product from Step B (0.33 mmol, 1 equiv), 57 mg of ethyl 2-aminothiazole-4-carboxylate (0.33 mmol, 1 equiv), 12 mg of Pd2(dba)3 (0.013 mmol, 0.04 equiv), 19 mg of Xantphos (0.033 mmol, 0.1 equiv) and 217 mg _{of Cs2CO3} (0.66 mmol, 2 equiv) in 10 mL of trifluoromethylbenzene was heated at 200 °C for 0.5 h. The reaction mixture was concentrated and purified by preparative HPLC to give 31 mg (21%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.90 (s, 1H), 7.86 (br., 1H), 7.55 (br., 1H), 7.36 (t, 1H), 7.19 (t, 1H), 4.31 (q, 2H), 2.75 (br., 4H), 1.81 (br., 4H), 1.33 (t, 3H); ¹³ C NMR (125 MHz DMSO-d ₆ ) δ ppm 126.3, 122.5, 121.5; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₂₁ N ₆ O ₂ S ₂ : 453.1162, found: 453.1151.

Step D: 2-[[4-(1,3-benzothiazol-2-ylamino)-5,6,7,8-tetrahydrophthalazin-1-yl]amino]thiazole-4-carboxylic acid

A mixture of 31 mg of the product from Step C (0.069 mmol, 1 equiv.), 5.8 mg LiOH× _H2O (2 equiv.) and 8 drops of water in 10 mL of 1,4-dioxane was heated under reflux for 2 h. The reaction mixture was concentrated and purified by preparative HPLC to give 24 mg (83%) of the desired product.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁₉ H ₁₇ N ₆ O ₂ S ₂ : 425.0849, found: 425.0854.

Example 18: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4-(hydroxymethyl)-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-[(benzyloxy)methyl]-5-methylpyridin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Synthesis 9ga (176 mg, 0.44 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (115 mg, 0.67 mmol, 1.5 equiv), cesium carbonate (202 mg, 0.62 mmol, 1.4 equiv), tris(dibenzylideneacetone)dipalladium(0) (40.6 mg, 0.04 mmol, 0.1 equiv), and xantphos (12.8 mg, 0.02 mmol, 0.05 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then toluene (15 mL) was added. The mixture was bubbled with nitrogen (5 min) and then heated at 180 °C for 1 h under microwave irradiation. The mixture was concentrated in vacuo and purified by reversed-phase automated flash chromatography (CombiFlash Rf, C18 24 g RediSep column) eluting with a gradient of 5 95% acetonitrile in water to give the desired product (82 mg, 0.15 mmol, 35%).

LC/MS (C ₂₆ H ₂₄ N ₆ O ₃ S ₂ ) δ33 [M+H] ⁺ ; RT 1.44 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 10.91 (br s, 1H), 7.96 (s, 1H), 7.88 (br s, 1H), 7.56 (br s, 1H), 7.43-7.26 (m, 6H ), 7.23-7.18 (m, 1H), 4.87 (s, 2H), 4.65 (s, 2H), 4.31 (q, J=7.1 Hz, 2H), 2.40 (s, 3H), 1.33 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-(hydroxymethyl)-5-methylpyridin-3-yl}amino)-1,3-thiazole-4-carboxylate

A solution of the product from Step A (72 mg, 0.14 mmol, 1 equiv) in dichloromethane (5 mL) was cooled to 0 °C and 1 M boron trichloride solution (0.68 mL, 0.68 mmol, 5 equiv) was added dropwise. The mixture was then allowed to warm to ambient temperature over 2 h. The reaction mixture was quenched by addition of methanol and concentrated in vacuo. The resulting solid was triturated with dichloromethane, filtered, washed with dichloromethane, and dried in vacuo to afford the desired product as a cream-colored solid (54 mg, 0.12 mmol, 90%).

LC/MS (C ₁₉ H ₁₈ N ₆ O ₃ S ₂ ) 443 [M+H] ⁺ ; RT 1.23 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.97 (s, 1H), 7.89 (d, J=7.7 Hz, 1H), 7.51 (d, J=8.0 Hz, 1H), 7.39 (ddd, J=8.2, 7.3, 1.3 Hz, 1H), 7.22 (td, J=7.5, 1.2 Hz, 1H), 4.83 (s, 2H), 4.30 (q, J=7.1 Hz, 2H), 2.43 (s, 3H), 1.32 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-(hydroxymethyl)-5-methylpyridin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (50 mg, 0.11 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide (0.56 mL, 0.56 mmol, 5 equiv) and the mixture was heated at reflux for 30 min. The mixture was cooled to ambient temperature and concentrated in vacuo. The solid was taken up in water (5 mL) and neutralized to pH 6 with 1 M HCl and then concentrated in vacuo. The solid was then triturated with 4:1 isopropanol/water and stirred for 30 min. The solids were collected by filtration and dried in vacuo to give the title product as an orange solid (30 mg, 0.07 mmol, 64%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₇ H ₁₅ N ₆ O ₃ S ₂ : 415.0642, found: 415.0638.

Example 19: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4-cyclopropyl-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-cyclopropyl-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Preparation 9ha (300 mg, 0.95 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (245 mg, 1.42 mmol, 1.5 equiv), cesium carbonate (463 mg, 1.42 mmol, 1.5 equiv), xantphos (54.8 mg, 0.09 mmol, 0.1 equiv), and tris(dibenzlideneacetone)dipalladium(0) (43.4 mg, 0.05 mmol, 0.05 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then alpha,alpha,alpha-trifluorotoluene (10 mL) was added. The mixture was sparged with nitrogen (5 min) and then heated at 180 °C for 1 h under microwave irradiation. The reaction mixture was concentrated in vacuo and purified by reversed-phase automated flash chromatography (CombiFlash Rf, C18 26 g RediSep column) eluting with a gradient of 5-95% acetonitrile (with 0.08% formic acid as modifier) in water (with 0.08% formic acid as modifier) to give the desired product as a bright yellow solid (67 mg, 0.15 mmol, 16%).

LC/MS (C ₂₁ H ₂₀ N ₆ O ₂ S ₂ ) 453 [M+H] ⁺ ; RT 1.34 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 11.37 (br s, 1H), 10.56 (s, 1H), 7.96 (s, 1H), 7.89 (d, J=7.7 Hz, 1H), 7.51 (s, 1H), 7.38 (td, J=7.7, 1.3 Hz, 1H), 7.20 (t, 1H), 4.30 (q, J=7.1 Hz, 2H), 2.49 (s, 3H), 1.90 (q, 1H), 1.31 (t, 3H), 1.27-1.21 (m , 2H), 0.59 (dt, J=5.9, 3.1 Hz, 2H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-cyclopropyl-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (67 mg, 0.15 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide (0.15 mL, 0.3 mmol, 2 equiv) and the mixture was heated at reflux for 1 h. The reaction mixture was concentrated in vacuo, then added to water and the pH adjusted to 6 with 1 N aqueous hydrochloric acid, then re-concentrated in vacuo. Trituration with 5:1 isopropanol/water (5 mL) afforded a solid which was collected by filtration, washed with isopropanol and dried in vacuo to give the title product as a yellow solid (28 mg, 0.07 mmol, 45%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₉ H ₁₇ N ₆ O ₂ S ₂ : 425.0849, found: 425.0857.

Example 20: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-cyclopropyl-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-cyclopropyl-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Preparation 9hb (219 mg, 0.69 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (179 mg, 1.04 mmol, 1.5 equiv), cesium carbonate (338 mg, 1.04 mmol, 1.5 equiv), xantphos (40 mg, 0.07 mmol, 0.1 equiv), and tris(dibenzylideneacetone)dipalladium(0) (31.7 mg, 0.03 mmol, 0.05 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then alpha,alpha,alpha-trifluorotoluene (15 mL) was added. The mixture was bubbled with nitrogen (5 min) and then heated at 170 °C for 1 h under microwave irradiation. The reaction mixture was concentrated in vacuo and purified by reversed-phase automated flash chromatography (CombiFlash Rf, C18 24 g RediSep column) eluting with a gradient of 5-95% acetonitrile (containing 0.08% formic acid) in water (containing 0.08% formic acid) to give the desired product (54 mg, 0.12 mmol, 17%).

LC/MS (C ₂₁ H ₂₀ N ₆ O ₂ S ₂ ) 453 [M+H] ⁺ ; RT 1.16 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 10.86 (br s, 1H), 10.56 (s, 1H), 7.96 (s, 1H), 7.87 (s, 1H), 7.55 (br s, 1H), 7.38 (t, J=7.5 Hz, 1H), 7.20 (t, J=7.5 Hz, 1H), 4.30 (q, J=7.1 Hz, 2H), 2.49 (s, 3H), 1.91 (p, J=7.7 Hz, 1H), 1.33 (t, 3H), 1.27 -1.21 (m, 2H), 0.59 (dt, J=5.9, 3.1 Hz, 2H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-cyclopropyl-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (54 mg, 0.12 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide (0.24 mL, 0.24 mmol, 2 equiv) and the mixture was heated at reflux for 1 h. The residue was taken up in water and neutralized to pH 6 with 1 M aqueous hydrochloric acid and then concentrated in vacuo. The solid was triturated with 4:1 isopropanol/water and stirred for 30 min. The solids were collected by filtration, washed with cold isopropanol and dried in vacuo to give the title product as an orange solid (30 mg, 0.07 mmol, 59%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₉ H ₁₇ N ₆ O ₂ S ₂ : 425.0849, found: 425.0853.

Example 21: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)(methyl)amino]-1,3-thiazole-4-carboxylate

Sodium hydride (60% dispersion, 240 mg, 6 mmol, 1.18 equiv) under nitrogen atmosphere was slowly added to a solution of 3,6-dichloro-4-methylpyridazine (850 mg, 5.21 mmol, 1.02 equiv) and ethyl 2-(methylamino)-1,3-thiazole-4-carboxylate (950 mg, 5.1 mmol, 1 equiv) in tetrahydrofuran (25 mL) at 0 °C. The mixture was stirred for 1 h at 0 °C and for 18 h at ambient temperature to give a dark brown suspension. Saturated aqueous ammonium chloride solution (75 mL) was added and the mixture was extracted with dichloromethane (250 mL). The extracts were washed with water (2 x 75 mL) and brine (75 mL). The solution was dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with 1% methanol in dichloromethane afforded a solid which was triturated with diethyl ether (15 mL), filtered, washed with diethyl ether (2 x 10 mL), and dried in vacuo to afford the title product as a pale brown solid (960 mg, 3.07 mmol, 60%).

LC/MS (C ₁₂ H ₁₃ ClN ₄ O ₂ S) 313 [M+H] ⁺ ; RT 1.17 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 8.04 (s, 1H), 7.86 (s, 1H), 4.30 (q, J=7.1 Hz, 2H), 3.83 (s, 3H), 2.43 (s, 3H), 1.32 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

2-Aminobenzothiazole (245 mg, 1.63 mmol, 1.16 equiv) and the product from Step A (440 mg, 1.41 mmol, 1 equiv) were added under nitrogen to a solution of tris(dibenzlideneacetone)dipalladium(0) (64.4 mg, 0.07 mmol, 0.05 equiv) and xantphos (81.4 mg, 0.14 mmol, 0.1 equiv) in 1,4-dioxane (20 mL), and the mixture was stirred. N,N-Diisopropylethylamine (0.75 mL, 4.22 mmol, 3 equiv) was added and the mixture was heated in a sealed tube at 150 °C for 24 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel), eluting with ethyl acetate, gave a yellow solid, which was triturated with methanol (10 mL), filtered, washed with methanol (15 mL), and dried in vacuo to give the title product as a yellow solid (315 mg, 0.74 mmol, 53%).

LC/MS (C ₁₉ H ₁₈ N ₆ O ₂ S ₂ ) 427 [M+H] ⁺ ; RT 1.32 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.23 (br s, 1H), 7.97 (s, 1H), 7.91 (br s, 1H), 7.70 (s, 1H), 7.54 (br s, 1H), 7.39 (td, J=7.7, 1.2 Hz, 1H), 7.22 (t, 1H), 4.30 (q, J=7.1 Hz, 2H), 3.82 (s, 3H), 2.46 (s, 3H), 1.32 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (200 mg, 0.47 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (98.4 mg, 2.34 mmol, 5 equiv) and the mixture was stirred at ambient temperature for 3 h. Water (10 mL) was added and the solution was filtered through celite, the solids were washed with water (5 mL) and the combined filtrate was acidified with acetic acid to give a pale yellow suspension. The solids were collected by filtration, washed with water (20 mL) and dried in vacuo to give the title product as a pale yellow solid (150 mg, 0.34 mmol, 72%).

LC/MS (C ₁₇ H ₁₄ N ₆ O ₂ S ₂ ) 399 [M+H] ⁺ ; RT 1.1 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.21 (br s, 2H), 7.95-7.84 (m, 2H), 7.71 (s, 1H), 7.54 (d, J=8.0 Hz, 1H), 7.39 (ddd, J=8.2, 7.3, 1.3 Hz, 1H), 7.22 (td, J=7.6, 1.2 Hz, 1H), 3.82 (s, 3H), 2.47 (s, 3H).

Example 22: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(3-{4-[3-(dimethylamino)propyl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Step A: ethyl 5-(3-{4-[(1E)-3-(dimethylamino)prop-1-en-1-yl]-2-fluorophenoxy}propyl)-2-acetamido-1,3-thiazol- 4-carboxylate

Sodium hydride (60% in mineral oil) (1.61 g, 40.3 mmol, 2.34 equiv) was added to a stirred solution of Preparation 6b (4.65 g, 24.1 mmol, 1.4 equiv) in dimethylformamide (70 mL). The reaction mixture was stirred at ambient temperature for 30 min, then cooled in an ice bath and a solution of Preparation 3u, Step C (6.57 g, 17.2 mmol, 1 equiv) in dimethylformamide (30 mL) was slowly added. After 40 min, the reaction mixture was allowed to warm to ambient temperature and stirred for 5 h. The mixture was cooled, acidified with 2 N aqueous HCl and the organics were extracted with ethyl acetate and then with a 3:1 mixture of dichloromethane and isopropanol. The combined organics were dried (magnesium sulfate) and the solvent removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded the desired product as a brown foam (2.26 g, 5.69 mmol, 33%), which was used in the subsequent steps without further purification. The sample was further purified by preparative HPLC (HPLC-V-A1 method) to obtain analytical data.

LC/MS (C ₂₂ H ₂₈ FN ₃ O ₄ S) 450 [M+H] ⁺ ; RT 0.75 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.25-7.08 (m, 2H), 7.05 (dd, J=8.5, 2.0 Hz, 1H), 6.45 (dt, J=12.0, 1.9 Hz, 1H), 5.69 (dt, J=12.4, 6.4 Hz, 1H), 4.23 (qd, J=7.1, 2.2 Hz, 2H), 4.09 (t, 2H), 3.27 (t, J=7.5 Hz, 2H), 3.11 (dd, J=6.4, 1.9 Hz, 2H), 2.16 (s, 6H), 2.12 (s, 3H), 2.11-2.06 (m, 2H), 1.27 (t, J=7.1 Hz, 3N).

Step B: Ethyl 2-amino-5-(3-{4-[(1E)-3-(dimethylamino)prop-1-en-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (2.25 g, 4.99 mmol, 1 equiv) in ethanol (40 mL) was added hydrochloric acid (4 M in 1,4-dioxane; 12.5 mL, 49.9 mmol, 10 equiv) and the mixture was heated at 60 °C for 18 h. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-20% methanol in dichloromethane afforded the crude product. This was dissolved in methanol and loaded onto a methanol-wetted SCX-2 cartridge (10 g). Elution with methanol followed by 3.5 N methanolic ammonia and then evaporation afforded the desired product as a brown gum (2.07 g, 5.07 mmol, 100%).

LC/MS (C ₂₀ H ₂₆ FN ₃ O ₃ S) 408 [M+H] ⁺ ; RT 0.71 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.34 (br s, 2H), 7.26-7.15 (m, 3H), 6.74 (d, J=11.9 Hz, 1H), 5.80 (dt, J=12.5, 6.5 Hz, 1H), 4.16 (q, 2H), 4.09 (t, 2H), 4.03 (dd, 2H), 3.14 (t, J=7.5 Hz, 2H), 2.73 (s, 6H), 2.02 (p, J=6.3 Hz, 2H), 1.24 (t, 3H).

Step C: Ethyl 2-amino-5-(3-{4-[3-(dimethylamino)propyl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylate

A solution of the product from Step B (0.84 g, 2.06 mmol, 1 equiv) in a 1:1 mixture of ethyl acetate/methanol (40 mL) was charged to a flask containing platinum(IV) oxide hydrate (on a spatula tip) under nitrogen. The flask was evacuated and backfilled with nitrogen (x3), then evacuated, flushed with hydrogen, and shaken at ambient temperature for 72 h. The mixture was filtered through Celite (10 g pre-packed cartridge), eluted with methanol, and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-20% methanol (containing 20% ammonia) in dichloromethane afforded the title product as a yellow gum (519 mg, 1.27 mmol, 53%).

LC/MS (C ₂₀ H ₂₈ FN ₃ O ₃ S) 410 [M+H] ⁺ ; RT 0.70 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.15-7.03 (m, 2H), 7.02 (s, 2H), 6.95 (dt, J=8.3, 1.3 Hz, 1H), 4.16 (q, J=7.1 Hz, 2H), 4.02 (t, J=6.2 Hz, 2H), 3.12 (dd, J=8.2, 6.8 Hz, 2H), 2.63-2.57 (m, 2H), 2.54 (t, 2H), 2.44 (s, 6H), 2.05-1.93 (m, 2H), 1.79 (p, J=7.9 Hz, 2H), 1.24 (t, J=7.1 Hz, 3H).

Step D: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(3-{4-[3-(dimethylamino)propyl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Preparation 9a (118 mg, 0.41 mmol, 1 equiv), the product from Step C (200 mg, 0.49 mmol, 1.2 equiv), cesium carbonate (265 mg, 0.81 mmol, 2 equiv), xantphos (23.6 mg, 0.04 mmol, 0.1 equiv), and tris(dibenzylideneacetone)dipalladium(0) (18.6 mg, 0.02 mmol, 0.05 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then alpha,alpha,alpha-trifluorotoluene (4 mL) was added. The mixture was sparged with nitrogen (5 min) and then heated at 170 °C for 1 h under microwave irradiation. The mixture was partitioned between ethyl acetate and water, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with 5-95% acetonitrile in water afforded the title product as a yellow foam (36 mg, 0.05 mmol, 13%).

LC/MS (C ₃₃ H ₃₈ FN ₇ O ₃ S ₂ ) 664 [M+H] ⁺ ; RT 1.01 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 10.71 (br s, 1H), 7.81 (d, J=7.8 Hz, 1H), 7.44 (d, J=8.0 Hz, 1H), 7.30 (td, 1H), 7.13 (td, J=7.5, 1.1 Hz, 1H), 7.05-6.95 (m, 2H), 6.91-6.82 (m, 1H), 4.20 (q, J=7.1 Hz, 2H), 4.03 (t, J=6.2 Hz, 2H), 3.28-3.19 (m, 4H), 2.30 (s, 3H), 2.28 (s, 3H), 2.15-2.02 (m, 4H), 2.04 (s, 6H), 1.57 (p, J=7.4 Hz, 2H), 1.23 (t, J=7.1 Hz, 3H).

Step E: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(3-{4-[3-(dimethylamino)propyl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step D (57.1 mg, 0.09 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (14.4 mg, 0.34 mmol, 4 equiv) and the mixture was heated at reflux for 5.5 h. The residue was triturated with water and the solids were collected by filtration. The solids were further triturated with diethyl ether, then collected by filtration and dried in vacuo to give the title product as a brown solid (19.1 mg, 0.03 mmol, 35%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₁ H ₃₅ FN ₇ O ₃ S ₂ : 636.2221, found: 636.2224.

Example 23: 2-[[1-(1,3-Benzothiazol-2-ylamino)-6,7-Dihydro-5H-cyclopenta[d]pyridazin-4-yl]amino]thiazole-4-carboxylic acid

Step A: 1,4-dibromo-6,7-dihydro-5H-cyclopenta[d]pyridazine

A mixture of 1.86 g 2,3,6,7-tetrahydro-1H-cyclopenta[d]pyridazine-1,4(5H)-dione (12.3 mmol, 1 equiv) and 10.55 g (36.8 mmol, 3 equiv) POBr ₃ in 50 mL 1,2-dichloroethane was heated under reflux for 3 h. After cooling to rt and concentration, the residue was treated with 100 g ice, the pH was adjusted to 7 by adding conc. NaHCO ₃ , and the solid precipitate was filtered off to give 1.88 g (55%) of the desired product.

Step B: 4-bromo-6,7-dihydro-5H-cyclopenta[d]pyridazine-1-amine

A mixture of 1.88 g of the product from Step A (6.8 mmol) in 25 mL of 30% NH ₃ solution in water was heated at 130°C for 18 h. After concentration, the residue was taken up in EtOAc, washed with 10% NaOH solution, dried over MgSO ₄ , filtered and concentrated to give 1.28 g (88%) of the desired product.

LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₇ H ₉ BrN ₃ : 214, 216, found: 214, 216.

Step C: N-(4-bromo-6,7-dihydro-5H-cyclopenta[y]pyridazin-1-yl)-1,3-benzothiazol-2-amine

A mixture of 214 mg of the product from Step B (1 mmol, 1 equiv), 321 mg of 2-bromo-1,3-benzothiazole (1.50 mmol, 1.5 equiv), and 160 mg of sodium hydride (60% suspension) (4 mmol, 4 equiv) in 25 mL of 1,4-dioxane was heated at reflux for 1 h. After cooling and quenching the reaction mixture with methanol, the mixture was concentrated, treated with water, and the product was filtered and dried. The solid was triturated with EtOAc and dried to give 275 mg (79%) of the desired product.

LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₁₄ H ₁₂ BrN ₄ S: 347, 349, found: 347, 349.

Step D: Ethyl 2-[[1-(1,3-benzothiazol-2-ylamino)-6,7-dihydro-5H-cyclopenta[d]pyridazin-4-yl]amino]thiazole-4-carboxylate

A mixture of 270 mg of the product from Step C (0.778 mmol, 1 equiv), 134 mg of ethyl 2-aminothiazole-4-carboxylate (0.78 mmol, 1 equiv), 29 mg of Pd ₂ (dba) ₃ (0.032 mmol, 0.04 equiv), 45 mg of Xantphos (0.078 mmol, 0.1 equiv) and 507 mg of Cs ₂ CO ₃ (1.56 mmol, 2 equiv) in 10 mL of trifluoromethylbenzene was heated at 200 °C for 0.5 h. The reaction mixture was concentrated and purified by preparative HPLC to give 97 mg (28%) of the desired product.

LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₂₀ H ₁₉ N ₆ O ₂ S ₂ : 439.5, found: 439.

Step E: 2-[[1-(1,3-benzothiazol-2-ylamino)-6,7-dihydro-5H-cyclopenta[(1]pyridazin-4-yl]amino]thiazole-4-carboxylic acid

A mixture of 90 mg of the product from Step D (0.22 mmol, 1 equiv), 18 mg LiOH× _H2O (0.43 mmol, 2 equiv) and 13 drops of water in 5 mL of 1,4-dioxane was heated under reflux for 2 h. The reaction mixture was concentrated and purified by preparative HPLC to give 54 mg (64%) of the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₈ H ₁₅ N ₆ O ₂ S ₂ : 411.0697, found: 411.0685.

Example 24: 6-[[4-(1,3-Benzothiazol-2-ylamino)-5,6,7,8-tetrahydrophthalazin-1-yl]amino]pyridine-2-carboxylic acid

Step A: Ethyl 6-[[4-(1,3-benzothiazol-2-ylamino)-5,6,7,8-tetrahydrophthalazin-1-yl]amino]pyridine-2-carboxylate

A mixture of 245 mg of Example 17, Step B (0.68 mmol, 1 equiv), 113 mg of ethyl 6-aminopyridine-2-carboxylate (0.68 mmol, 1 equiv), 25 mg of _Pd2 (dba) ₃ (0.027 mmol, 0.04 equiv), 40 mg of Xantphos (0.069 mmol, 0.1 equiv) and 443 mg of _Cs2CO3 (1.36 _mmol , 2 equiv) in 10 mL of trifluoromethylbenzene was heated at 200 °C for 1.5 h. The reaction mixture was concentrated and purified by preparative HPLC to give 45 mg (15%) of the desired product.

LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₂₃ H ₂₃ N ₆ O ₂ S: 447, found: 447.

Step B: 6-[[4-(1,3-benzothiazol-2-ylamino)-5,6,7,8-tetrahydrophthalazin-1-yl]amino]pyridine-2-carboxylic acid

A mixture of 45 mg of the product from Step A (0.11 mmol, 1 equiv), 8.5 mg LiOH× _H2O (0.20 mmol, 2 equiv) and 10 drops of water in 10 mL of 1,4-dioxane was heated under reflux for 2 h. The reaction mixture was concentrated and purified by preparative HPLC to give 21 mg (50%) of the desired product.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₁₉ N ₆ O ₂ S: 419.1290, found: 419.1294.

Example 25: 6-[[4-(1,3-Benzothiazol-2-ylamino)-6,7-dihydro-5H-cyclopenta[d]pyridazin-1-yl]amino]pyridine-2-carboxylic acid

Step A: 6-[[4-(1,3-benzothiazol-2-ylamino)-6,7-dihydro-5H-cyclopenta[d]pyridazin-1-yl]amino]pyridine-2-carboxylate

A mixture of 290 mg of Example 23, Step C (0.84 mmol, 1 equiv), 139 mg of ethyl 6-aminopyridine-2-carboxylate (0.84 mmol, 1 equiv), 31 mg of _Pd2 (dba) ₃ (0.034 mmol, 0.04 equiv), 48 mg (0.083 mmol, 0.1 equiv) of xantphos and 545 mg of _Cs2CO3 (1.67 _mmol , 2 equiv) in 10 mL of trifluoromethylbenzene was heated at 200°C for 1.5 h. The reaction mixture was concentrated and purified by preparative HPLC to give 70 mg (19.4%) of the desired product.

LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₂₂ H ₂₁ N ₆ O ₂ S: 433.5, found: 433 and 431 [M-H] ⁺ .

Step B: 6-[[4-(1,3-benzothiazol-2-ylamino)-6,7-dihydro-5H-cyclopenta[d]pyridazin-1-yl]amino]pyridine-2-carboxylic acid

A mixture of 70 mg of the product from Step A (0.16 mmol, 1 equiv), 14 mg LiOH× _H2O (0.33 mmol, 2 equiv) and 10 drops of water in 10 mL of 1,4-dioxane was heated under reflux for 2 h. The reaction mixture was concentrated and purified by preparative HPLC to give 24 mg (31%) of the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₀ H ₁₇ N ₆ O ₂ S: 405.1134, found: 405.1123.

Example 26: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[(6-chloro-4,5-dimethylpyridazin-3-yl)(methyl)amino]-1,3-thiazole-4-carboxylate

Sodium hydride (60% dispersion, 250 mg, 6.25 mmol, 1.16 equiv) under nitrogen atmosphere was slowly added to a solution of 3,6-dichloro-4,5-dimethylpyridazine (950 mg, 5.37 mmol, 1 equiv) and ethyl 2-(methylamino)-1,3-thiazole-4-carboxylate (1.2 g, 6.44 mmol, 1.2 equiv) in 1,4-dioxane (20 mL) at 0 °C. The mixture was stirred for 1 h at ambient temperature, then at 60 °C for 2 h. Saturated aqueous ammonium chloride solution (75 mL) was added, and the mixture was extracted with ethyl acetate (150 mL). The organic extract was washed with water (2 x 75 mL), brine (75 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by column chromatography (100 g silica gel) eluting with ethyl acetate afforded the title product as a brown gum (715 mg, 2.19 mmol, 41%).

LC/MS (C ₁₃ H ₁₅ ClN ₄ O ₂ S) 327 [M+H] ⁺ ; RT 1.09 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.56 (s, 1H), 4.34 (q, J=7.2 Hz, 2H), 3.66 (s, 3H), 2.43 (s, 3H), 2.23 (s, 3H), 1.36 (t, J=7.2 Hz, 3H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

2-Aminobenzothiazole (250 mg, 1.66 mmol, 1.21 equiv) and the product from Step A (500 mg, 1.38 mmol, 1 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone)dipalladium(0) (63.1 mg, 0.07 mmol, 0.05 equiv) and xantphos (79.7 mg, 0.14 mmol, 0.1 equiv) in 1,4-dioxane (20 mL), and the mixture was stirred. N,N-Diisopropylethylamine (0.75 mL, 4.13 mmol, 3 equiv) was added and the mixture was heated in a sealed tube at 150 °C for 24 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with 1% methanol in dichloromethane gave a dark yellow gum, which was triturated with diethyl ether (15 mL), filtered, washed with diethyl ether (15 mL), and dried in vacuo to give the title product as a pale yellow solid (365 mg, 0.83 mmol, 60%).

LC/MS (C ₂₀ H ₂₀ N ₆ O ₂ S ₂ ) 441 [M+H] ⁺ ; RT 1.26 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 11.22 (br s, 1H), 7.87 (br s, 1H), 7.76 (s, 1H), 7.56 (br s, 1H), 7.40 (t, J=7.5 Hz, 1H), 7.23 (t, J=7.7 Hz, 1H), 4.25 (q, J=7.1 Hz, 2H), 3.49 (s, 3H), 2.41 (s, 3H), 2.19 (s, 3H), 1.28 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (200 mg, 0.45 mmol, 1 equiv) in 1:3 water/1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (95.3 mg, 2.27 mmol, 5 equiv) and the mixture was stirred at ambient temperature for 18 h. Water (10 mL) was added and the solution was filtered through celite, the solids were washed with water (5 mL) and the combined filtrate was acidified with acetic acid to give a pale yellow suspension. The solids were collected by filtration, washed with water (20 mL) and dried in vacuo to give the title product as a pale yellow solid (150 mg, 0.36 mmol, 80%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₁₈ H ₁₅ N ₆ O ₂ S ₂ : 411.0703, found: 411.0689.

Example 27: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-(hydroxymethyl)-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-(methoxymethyl)-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Preparation 9jb (169 mg, 0.53 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (109 mg, 0.63 mmol, 1.2 equiv), cesium carbonate (240 mg, 0.74 mmol, 1.4 equiv), xantphos (30.5 mg, 0.05 mmol, 0.1 equiv), and tris(dibenzylideneacetone)dipalladium(0) (24.1 mg, 0.03 mmol, 0.05 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then alpha,alpha,alpha-trifluorotoluene (10 mL) was added. The mixture was bubbled with nitrogen (10 min) and then heated at 180 °C for 1 h under microwave irradiation. The mixture was concentrated in vacuo and purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane to give the desired product (138 mg, 0.30 mmol, 57%).

LC/MS (C ₂₀ H ₂₀ N ₆ O ₃ S ₂ ) 457 [M+H] ⁺ ; RT 1.17 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 12.25 (br s, 1H), 11.07 (br s, 1H), 10.63 (br s, 1H), 7.96 (s, 1H), 7.87 (s, 1H), 7.49 (br s, 1H), 7.38 (t, J=7.5 Hz, 1H), 7.20 (t, 1H), 4.78 (s, 2H), 4.30 (q, J=7.1 Hz, 2H), 3.38 (s, 3H), 2.43 (s, 3H), 1.33 ( t, J=7.1 Hz, 3H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-(hydroxymethyl)-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (55 mg, 0.12 mmol, 1 equiv) in dichloromethane (2 mL) at 0 °C was added boron tribromide (0.6 mL, 1 M, 0.6 mmol, 5 equiv) and the mixture was stirred at ambient temperature for 1 h. The solid was added to methanol and heated at reflux for 30 min, then allowed to cool to ambient temperature. Purification by reversed-phase automated flash column chromatography (CombiFlash Rf, C18 4.3 g RediSep column) eluting with a gradient of 5-95% acetonitrile afforded the crude product (53 mg), which was carried on to the next step without further purification.

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-(hydroxymethyl)-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (53.3 mg, 0.12 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide (0.24 mL, 0.24 mmol, 2 equiv) and the mixture was heated at reflux for 1 h. The residue was taken up in a minimum amount of water, acidified to pH 6 with 1 M aqueous hydrochloric acid and allowed to stir for 10 min. The solvent was removed in vacuo and the residue was triturated with 5:1 isopropanol/water. The suspension was stirred for 30 min, then the solid was collected by filtration, washed with isopropanol and dried under vacuum to give the desired product as a brown solid (16 mg, 0.04 mmol, 32%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₁₇ H ₁₃ N ₆ O ₃ S ₂ : 413.0496, found: 413.0499.

Example 28: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-(methoxymethyl)-4-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Example 27, Step A (59 mg, 0.13 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide (0.26 mL, 0.26 mmol, 2 equiv) and the mixture was heated at reflux for 1 h. The residue was taken up in a minimum amount of water, acidified to pH 6 with 1 M aqueous hydrochloric acid and allowed to stir for 10 min. The solvent was removed in vacuo and the residue was triturated with 5:1 isopropanol/water. The suspension was stirred for 30 min, then the solids were collected by filtration, washed with isopropanol and dried under vacuum to give the desired product as an orange solid (18.5 mg, 0.04 mmol, 33%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₁₈ H ₁₅ N ₆ O ₃ S ₂ : 427.0653, found: 427.0650.

Example 29: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4-(methoxymethyl)-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: methyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-(methoxymethyl)-5-methylpyridazin-3-yl}amino)-1,3-thiazol-4- carboxylate

An oven-dried microwave processing vessel was charged with the product of Preparation 9ja (85 mg, 0.26 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (59.3 mg, 0.34 mmol, 1.3 equiv), cesium carbonate (121 mg, 0.37 mmol, 1.4 equiv), xantphos (7.67 mg, 0.01 mmol, 0.05 equiv), and tris(dibenzylideneacetone)dipalladium(0) (24.3 mg, 0.03 mmol, 0.1 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then alpha,alpha,alpha-trifluorotoluene (10 mL) was added. The mixture was sparged with nitrogen (10 min) and then heated at 180 °C for 1 h under microwave irradiation. The mixture was concentrated in vacuo and purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane to give the desired product as an orange glassy solid (82.5 mg, 0.18 mmol, 68%).

LC/MS (C ₁₉ H ₁₈ N ₆ O ₃ S ₂ ) 443 [M+H] ⁺ ; RT 1.26 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 10.78 (br s, 1H), 7.98 (s, 1H), 7.42-7.34 (m, 2H), 7.25-7.14 (m, 2H), 4.77 (s, 2H), 3.83 (s, 3H), 3.39 (s, 3H), 2.44 (s, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-(methoxymethyl)-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (82.5 mg, 0.18 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide (0.18 mL, 0.36 mmol, 2 equiv) and the mixture was heated at reflux for 1 h. The residue was taken up in a minimal amount of water, acidified to pH 6 with 1 M aqueous hydrochloric acid and allowed to stir for 10 min. The solvent was removed in vacuo and the residue was triturated with 5:1 isopropanol/water. The solids were collected by filtration, washed with isopropanol (2×4 mL) and dried in vacuo. Purification by reversed-phase HPLC (method HPLC-V-A2) afforded the desired product as a yellow solid (22 mg, 0.05 mmol, 28%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₈ H ₁₇ N ₆ O ₃ S ₂ : 429.0798, found: 429.0800.

Example 30: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4-(ethoxymethyl)-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-(ethoxymethyl)-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Synthesis 9ka (113 mg, 0.34 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (69.7 mg, 0.4 mmol, 1.2 equiv), cesium carbonate (154 mg, 0.47 mmol, 1.4 equiv), xantphos (19.5 mg, 0.03 mmol, 0.1 equiv), and tris(dibenzlideneacetone)dipalladium(0) (15.5 mg, 0.02 mmol, 0.05 equiv). The vessel was evacuated and flushed with nitrogen (×3), and then alpha,alpha,alpha-trifluorotoluene (7 mL) was added. The mixture was bubbled with nitrogen (10 min) and then heated at 180 °C for 1 h under microwave irradiation. The mixture was concentrated in vacuo and purified by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane to give the desired product (47 mg, 0.1 mmol, 30%).

LC/MS (C ₂₁ H ₂₂ N ₆ O ₃ S ₂ ) 471 [M+H] ⁺ ; RT 1.36 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.82 (s, 1H), 7.73 (d, J=35.3 Hz, 3H), 7.43 (m, 1H), 7.28-7.23 (m, 1H), 4.72 (s, 2H), 4.45 (q, J=7.1 Hz, 2H), 3.68 (q, J=7.0 Hz, 2H), 2.47 (s, 3H), 1.45 (t, J=7.1 Hz, 3H), 1.35 (t, J=7.0 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-(ethoxymethyl)-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (49 mg, 0.1 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide (0.1 mL, 0.21 mmol, 2 equiv) and the mixture was heated at reflux for 2 h. The residue was taken up in a minimal amount of water, acidified to pH 6 with 1 M aqueous hydrochloric acid and allowed to stir for 10 min. The sample was triturated with 5:1 isopropanol/water and the solids were collected by filtration, washed with isopropanol and dried in vacuo to give the title product as a brown solid (23.9 mg, 0.05 mmol, 52%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₁₉ H ₁₇ N ₆ O ₃ S ₂ : 441.0809, found: 441.0803.

Example 31: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-cyclopropylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product of Preparation 11d, Step B (249 mg, 0.55 mmol, 1 equiv) in 1,4-dioxane (10 mL) was added 2 M aqueous lithium hydroxide (0.55 mL, 1.1 mmol, 2 equiv) and the mixture was heated at reflux for 3 h. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 43 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow powder (33 mg, 0.08 mmol, 14%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₉ H ₁₇ N ₆ O ₂ S ₂ : 425.0849, found: 425.0851.

Example 32: 5-{1-[(Adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-[(6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of Preparation 11f (64 mg, 0.11 mmol, 1 equiv), Preparation 10a (45.0 mg, 0.13 mmol, 1.2 equiv), and potassium carbonate (43.7 mg, 0.32 mmol, 3 equiv) in 3:1 tetrahydrofuran/water (4 mL) was added [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (7.71 mg, 0.01 mmol, 0.1 equiv). The mixture was sparged with nitrogen (10 min) and then heated at 120 °C for 1 h under microwave irradiation. The mixture was diluted with ethyl acetate and then washed successively with water and brine. The organic extract was dried (magnesium sulfate) and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a cream-colored solid (39.2 mg, 0.05 mmol, 49%).

LC/MS (C ₃₈ H ₄₈ N ₈ O ₃ SiS ₂ ) 757 [M+H] ⁺ ; RT 1.64 (LCMS-V-B1)

Step B: Ethyl 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

A solution of the product from Step A (39 mg, 0.05 mmol, 1 equiv) in dichloromethane (2 mL) was cooled to 0 °C and trifluoroacetic acid (0.3 mL, 4.03 mmol, 78.1 equiv) was added. The mixture was allowed to warm to ambient temperature and stirred for 18 h. The mixture was diluted with dichloromethane and washed successively with saturated aqueous sodium bicarbonate, water, and brine. The organic phase was dried (magnesium sulfate) and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-7% methanol in dichloromethane afforded the title product as a cream-colored solid (10.5 mg, 0.02 mmol, 33%).

LC/MS (C ₃₂ H ₃₄ N ₈ O ₂ S ₂ ) 627 [M+H] ⁺ ; RT 1.38 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.87 (br s, 1H), 11.67 (br s, 1H), 7.93 (d, J=7.8 Hz, 1H), 7.64 (d, 1H), 7.57 (s, 1H), 7.51 (d, J=27.8 Hz, 1H), 7.44-7.33 (m, 2H), 7.21 (t, J=7.6 Hz, 1H), 4.17 (q, J=7.1 Hz, 2H), 3.80 (s, 2H), 2.23 (s, 3H), 1.98 (s, 3H), 1.72-1.56 (m, 12H), 1.20 (t, J=7.1 Hz, 3H).

Step C: 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (10.5 mg, 0.02 mmol, 1 equiv) in 1,4-dioxane (2 mL) was added lithium hydroxide monohydrate (3.51 mg, 0.08 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and the solvent was removed in vacuo. The residue was triturated with water and the solids were collected by filtration and dried in vacuo to give the title product as a beige solid (7.2 mg, 0.01 mmol, 71%).

MSHR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₀ H ₃₁ N ₈ O ₂ S ₂ : 599.2006, found: 599.2037.

Example 33: 5-{1-[(Adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-[(4,5-dimethyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a mixture of Preparation 11a (99 mg, 0.16 mmol, 1 equiv), Preparation 10a (66.6 mg, 0.19 mmol, 1.2 equiv), and potassium carbonate (64.6 mg, 0 mol, 3 equiv) in 3:1 tetrahydrofuran/water (4 mL) was added [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (11.4 mg, 0.02 mmol, 0.1 equiv). The mixture was sparged with nitrogen (10 min) and then heated at 120 °C for 1 h under microwave irradiation. The reaction mixture was diluted with ethyl acetate and then washed successively with water and brine. The organic extract was dried (magnesium sulfate), and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a yellow glass (65.5 mg, 0.08 mmol, 54%).

LC/MS (C ₄₀ H ₅₂ N ₈ O ₃ SiS ₂ ) 785 [M+H] ⁺ ; RT 1.82 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d ₆ ) δ 10.93 (br s, 1H), 7.78 (d, J=7.6 Hz, 1H), 7.54 (s, 1H), 7.46-7.38 (m, 2H), 7.21 (dt, 1H), 5.84 (s, 2H), 4.17 (q, J=7.1 Hz, 2H), 3.78 (s, 2H), 3.71 (t, 2H), 2.40 (s, 3H), 2.36 (s, 3H), 2.20 (s, 3H), 1.96 (s , 3H), 1.71-1.55 (m, 12H), 1.17 (t, 3H), 0.91 (t, 2H), 0.00 (s, 9H).

Step B: Ethyl 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

A solution of the product from Step A (65.5 mg, 0.08 mmol, 1 equiv) in dichloromethane (4 mL) was cooled in an ice bath and trifluoroacetic acid (0.4 mL, 5.37 mmol, 64 equiv) was added. The mixture was allowed to warm to ambient temperature and stirred for 18 h. The reaction mixture was diluted with dichloromethane and washed successively with saturated aqueous sodium bicarbonate, water, and brine. The organics were dried (magnesium sulfate) and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a yellow glass (34.2 mg, 0.05 mmol, 63%).

LC/MS (C ₃₄ H ₃₈ N ₈ O ₂ S ₂ ) 655 [M+H] ⁺ ; RT 1.47 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 10.94 (br s, 1H), 7.88 (br s, 1H), 7.64 (br s, 1H), 7.55 (s, 1H), 7.36 (t, 1H), 7.22-7.13 (m, 1H), 4.18 (q, J=7.1 Hz, 2H), 3.80 (s, 2H), 2.38 (s+s, 6H), 2.21 (s, 3H), 1.99 (d, J=8.2 Hz, 3H), 1.73-1.54 (m, 12H ), 1.18 (t, J=7.1 Hz, 3H).

Step C: 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (34.2 mg, 0.05 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (22 mg, 0.52 mmol, 10 equiv) and the mixture was heated at reflux for 18 h. The reaction mixture was allowed to cool to ambient temperature and then the solvent was removed in vacuo. The residue was triturated with water and the solids were collected by filtration and dried in vacuo to give the title product as a yellow solid (28 mg, 0.04 mmol, 86%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₂ H ₃₅ N ₈ O ₂ S ₃ : 627.2319, found: 627.2357.

Example 34: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-(propan-2-yl)pyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-{[6-chloro-5-(propan-2-yl)pyridazin-3-yl](methyl)amino}-1,3-thiazole-4-carboxylate

To a solution of Preparation 7c (300 mg, 1.57 mmol, 1 equiv) and ethyl 2-(methylamino)-1,3-thiazole-4-carboxylate (292 mg, 1.57 mmol, 1 equiv) in tetrahydrofuran (25 mL) under nitrogen atmosphere was slowly added sodium hydride (60% in mineral oil; 75.4 mg, 1.88 mmol, 1.2 equiv) at 0 °C, and the mixture was stirred at 0 °C for 1 h, then at ambient temperature for 18 h. Saturated aqueous ammonium chloride solution (20 mL) was added, and the mixture was extracted with dichloromethane (75 mL). The organic extracts were washed successively with water (2 x 50 mL) and brine (50 mL), then dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0:50% ethyl acetate in isoheptane afforded the title product as a white crystalline solid (340 mg, 1 mmol, 64%).

LC/MS (C ₁₄ H ₁₇ ClN ₄ O ₂ S) 341 [M+H] ⁺ ; RT 1.31 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 8.05 (s, 1H), 7.67 (s, 1H), 4.30 (q, J=7.1 Hz, 2H), 3.88 (s, 3H), 3.20 (hept, J=6.9 Hz, 1H), 1.32 (dt, J=7.1, 3.7 Hz, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-(propan-2-yl)pyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (340 mg, 1 mmol, 1 equiv) and 2-aminobenzothiazole (180 mg, 1.2 mmol, 1.2 equiv) in 1,4-dioxane (15 mL) under nitrogen were added Xantphos (115 mg, 0.2 mmol, 0.2 equiv) and tris(dibenzylideneacetone)dipalladium(0) (91.4 mg, 0.1 mmol, 0.1 equiv). N,N-Diisopropylethylamine (0.52 mL, 2.99 mmol, 3 equiv) was added and the mixture was heated in a sealed tube at 150 °C for 18 h. The mixture was allowed to cool to ambient temperature and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-3% methanol in dichloromethane afforded the title product as a yellow solid (110 mg, 0.24 mmol, 24%).

LC/MS (C ₂₁ H ₂₂ N ₆ O ₂ S ₂ ) 455 [M+H] ⁺ ; RT 1.44 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 12.40 (br s, 1H), 7.97 (s, 1H), 7.79 (br s, 1H), 7.55 (s, 1H), 7.37 (br s+t, 2H ), 7.19 (br s, 1H), 4.30 (q, J=7.1 Hz, 2H), 3.87 (s, 3H), 3.57 (p, J=6.8 Hz, 1H), 1.40-1.27 (m, 9H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-(propan-2-yl)pyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

To a stirred solution of the product from Step B (111 mg, 0.24 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide (0.24 mL, 0.49 mmol, 2 equiv) and the mixture was heated at reflux for 2 h. The crude material was triturated with diethyl ether (10 mL) and the solids were collected by filtration, washed with diethyl ether and dried in vacuo. The resulting material was dissolved in water and acidified to pH 5-6 with 1 M aqueous hydrochloric acid and then concentrated in vacuo. The solids were triturated with 4:1 isopropanol/water (5 mL), collected by filtration, and dried in vacuo to give the title product as a yellow solid (66.7 mg, 0.16 mmol, 64%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₉ H ₁₉ N ₆ O ₂ S ₂ : 427.1005, found: 427.1042.

Example 35: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(1-{[1-(3-methoxypropyl)cyclooctyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[(4,5-dimethyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-(1-{[1-(3-methoxypropyl)cyclooctyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylate

To a mixture of Preparation 11a (99 mg, 0.16 mmol, 1 equiv), Preparation 10b (75.6 mg, 0.19 mmol, 1.2 equiv), and potassium carbonate (64.6 mg, 0 mol, 3 equiv) in 3:1 tetrahydrofuran/water (4 mL) was added [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (11.4 mg, 0.02 mmol, 0.1 equiv). The mixture was sparged with nitrogen (10 min) and then heated at 120 °C for 2 h under microwave irradiation. The reaction mixture was diluted with ethyl acetate, then washed with water, followed by brine. The organic extract was dried (magnesium sulfate) and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as an orange glass (43.4 mg, 0.05 mmol, 33%).

LC/MS (C ₄₂ H ₆₀ N ₈ O ₄ SiS ₂ ) 834 [M+H] ⁺ ; RT 1.88 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 10.92 (br s, 1H), 7.77 (d, J=7.8 Hz, 1H), 7.56 (s, 1H), 7.45-7.37 (m, 2H), 7.21 ( t, J=7.0 Hz, 1H), 5.84 (s, 2H), 4.17 (q, J=7.1 Hz, 2H), 3.85 (s, 2H), 3.71 (t, J=8.0 Hz, 2H), 2.67 (q, 3H), 2.41 (s, 3H), 2.36 ( s, 3H), 2.33 (q, 2H), 2.19 (s, 3H), 1.65-1.52 (m, 6H), 1.49-1.36 (m, 6H), 1.34-1.22 (m, 8H), 1.18 (t, J=7.1 Hz, 3H), 1.07 (s, 2H), 0.91 (t, 3H), -0.11 (s, 9H ).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(1-{[1-(3-methoxypropyl)cyclooctyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylate

A solution of the product from Step A (43.4 mg, 0.05 mmol, 1 equiv) in dichloromethane (4 mL) was cooled in an ice bath, then trifluoroacetic acid (0.4 mL, 5.37 mmol, 103 equiv) was added. The mixture was allowed to warm to ambient temperature, at which it was stirred for 18 h. The reaction mixture was diluted with dichloromethane, then washed successively with saturated aqueous sodium bicarbonate, water, and brine. The organics were dried (magnesium sulfate) and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 5% methanol in dichloromethane afforded the desired product as a yellow glass (21.3 mg, 0.03 mmol, 58%).

LC/MS (C ₃₆ H ₄₆ N ₈ O ₃ S ₂ ) 703 [M+H] ⁺ ; RT 1.33 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 10.94 (br s, 1H), 7.88 (br s, 1H), 7.63 (br s, 1H), 7.57 (s, 1H), 7.40-7.32 (m, 1H ), 7.22-7.14 (m, 1H), 4.18 (q, J=7.1 Hz, 2H), 3.86 (s, 2H), 3.25 (s, 3H), 2.38 (s+s, 6H), 2.21 (s, 3H), 1.70-1.51 (m, 9H) , 1.50-1.35 (m, 6H), 1.34-1.23 (m, 95), 1.18 (t, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(1-{[1-(3-methoxypropyl)cyclooctyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (21.3 mg, 0.03 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (12.7 mg, 0.3 mmol, 10 equiv) and the mixture was heated at reflux for 18 h. The reaction mixture was allowed to cool to ambient temperature and the solvent was removed in vacuo. The residue was triturated with water and the solids were collected by filtration and dried in vacuo to give the title product as a beige solid (13.9 mg, 0.02 mmol, 68%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₄ H ₄₃ N ₈ O ₃ S ₂ : 675.2894, found: 675.2933.

Example 36: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(1-{[1-(3-methoxypropyl)cyclooctyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylic acid

Stage A: ethyl 2-[(4,5-dimethyl-6-{[(2Z)-3-{[3-(trimethylsilyl)propoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino} pyrid azin-3-yl)amino]-5-(1-{[1-(3-methoxypropyl)cyclohexyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazol-4-carboxylate

To a mixture of Preparation 11a (110 mg, 0.17 mmol, 1 equiv), Preparation 10c (81 mg, 0.22 mmol, 1.25 equiv), and potassium carbonate (71.4 mg, 0.52 mmol, 3 equiv) in 3:1 tetrahydrofuran/water (4 mL) was added [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (12.6 mg, 0.02 mmol, 0.1 equiv). The mixture was sparged with nitrogen (10 min) and then heated at 120 °C for 1 h under microwave irradiation. The reaction mixture was diluted with ethyl acetate and washed successively with water and brine. The organics were dried (magnesium sulfate) and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as an orange gum (81.2 mg, 0.1 mmol, 59%).

LC/MS (C ₄₀ H ₅₆ N ₈ O ₄ SiS ₂ ) 805 [M+H] ⁺ ; RT 1.85 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 10.94 (s, 1H), 7.77 (d, J=7.7 Hz, 1H), 7.56 (s, 1H), 7.47-7.37 (m, 2H), 7.24-7.19 (m, 1H), 5.84 (s, 2H), 4.17 (q, J=7.1 Hz, 2H), 3.93 (s, 2H), 3.71 (t, 2H), 3.24 (s, 3H), 2.41 (s, 3H), 2.37 (s, 3H), 2.21 (s , 3H), 1.56-1.47 (m, 5H), 1.42-1.31 (m, 8H), 1.24-1.14 (m, 6H), 0.91 (t, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(1-{[1-(3-methoxypropyl)cyclohexyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylate

A solution of the product from Step A (81.2 mg, 0.1 mmol, 1 equiv) in dichloromethane (5 mL) was cooled in an ice bath and trifluoroacetic acid (0.5 mL, 6.71 mmol, 67 equiv) was added. The mixture was allowed to warm to ambient temperature and stirred for 18 h. The reaction mixture was diluted with dichloromethane, then washed successively with saturated aqueous sodium bicarbonate, water, and brine. The organics were dried (magnesium sulfate) and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a yellow glass (49.6 mg, 0.07 mmol, 73%).

LC/MS (C ₃₄ H ₄₂ N ₈ O ₃ S ₂ ) 675 [M+H] ⁺ ; RT 1.54 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 10.94 (br s, 1H), 7.88 (br s, 1H), 7.57 (s, 1H), 7.40-7.32 (m, 1H), 7.22-7.13 (m, 1H), 4.18 (q, 2H), 3.95 (s, 2H), 3.25 (s, 3H), 2.37 (s+s, 6H), 2.22 (s, 3H), 1.60-1.45 (m, 6H), 1.44-1.34 (m, 8H), 1.28-1.22 (m, 2H), 1.19 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl}amino)-5-(1-{[1-(3-methoxypropyl)cyclohexyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (49.6 mg, 0.07 mmol, 1 equiv) in 1,4-dioxane was added lithium hydroxide monohydrate (14.7 mg, 0.37 mmol, 5 equiv) and the mixture was heated at reflux for 2 h. The reaction mixture was allowed to cool to ambient temperature and the solvent was removed in vacuo. The residue was triturated with water and the solids were collected by filtration, washed successively with 2 M aqueous hydrochloric acid and then dichloromethane, and dried in vacuo to give the title product as a pale yellow solid (10.8 mg, 0.02 mmol, 23%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₂ H ₃₉ N ₈ O ₃ S ₂ : 647.2581, found: 647.2620.

Example 37: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(ethyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)(ethyl)amino]-1,3-thiazole-4-carboxylate

Sodium hydride (60% dispersion; 150 mg, 3.75 mmol, 1.25 equiv) under nitrogen atmosphere was added to a solution of 3,6-dichloro-4-methylpyridazine (530 mg, 3.25 mmol, 1.09 equiv) and ethyl 2-(ethylamino)-1,3-thiazole-4-carboxylate (600 mg, 3 mmol, 1 equiv) in 1,4-dioxane (20 mL) at 0°C. The mixture was stirred for 1 h at 0°C and for 18 h at ambient temperature. Ethyl acetate (150 ml) was added and the mixture was washed successively with saturated aqueous ammonium chloride solution (75 ml), water (2 x 75 ml) and brine (75 ml), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with dichloromethane gave a pale yellow solid. Trituration with diethyl ether (10 ml) gave a solid which was collected by filtration, washed with diethyl ether (2 x 5 ml) and dried in vacuo to give the title product as an off-white solid (475 mg, 1.45 mmol, 49%).

LC/MS (C ₁₃ H ₁₅ ClN ₄ O ₂ S) 327 [M+H] ⁺ ; RT 1.25 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 8.03 (s, 1H), 7.89 (s, 1H), 4.46 (q, 2H), 4.30 (q, 2H), 2.44 (s, 3H), 1.35-1.26 (m, 6H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(ethyl)amino)-1,3-thiazole-4-carboxylate

2-Aminobenzothiazole (250 mg, 1.66 mmol, 1.2 equiv) and the product from Step A (450 mg, 1.38 mmol, 1 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone)dipalladium(0) (63.1 mg, 0.07 mmol, 0.05 equiv) and xantphos (79.7 mg, 0.14 mmol, 0.1 equiv) in 1,4-dioxane (10 mL). N,N-Diisopropylethylamine (0.75 mL, 4.13 mmol, 3 equiv) was added and the mixture was heated in a sealed tube at 150 °C for 7 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with ethyl acetate afforded a yellow solid. Trituration with methanol (10 mL) afforded a solid which was collected by filtration, washed with methanol (2 x 5 mL) and dried in vacuo to afford the title product as a yellow solid (265 mg, 0.6 mmol, 44%).

LC/MS (C ₂₀ H ₂₀ N ₆ O ₂ S ₂ ) 441 [M+H] ⁺ ; RT 1.37 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.12 (br s, 1H), 7.97 (s, 1H), 7.92 (s, 1H), 7.74 (s, 1H), 7.57 (br s, 1H), 7.39 (t, J=7.5 Hz, 1H), 7.22 (t, J=7.5 Hz, 1H), 4.46 (q, J=6.9 Hz, 2H), 4.30 (q, J=7.1 Hz, 2H), 2.49 (s, 3H), 1.31 (t+t, 6H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(ethyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (210 mg, 0.48 mmol, 1 equiv) in 1:3 water/1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (80.0 mg, 1.91 mmol, 4 equiv), and the mixture was stirred at ambient temperature overnight. Water (5 mL) was added, the mixture was filtered through celite, and the solids were washed with water (10 mL). The combined filtrate was acidified with acetic acid to give a yellow suspension, and the solids were collected by filtration, washed with water (30 mL), and dried in vacuo to give the title product as a yellow solid (170 mg, 0.41 mmol, 86%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₈ H ₁₇ N ₆ O ₂ S ₂ : 413.0849, found: 413.0882.

Example 38: 6-({6-[(1,3-Benzothiazol-2-yl)amino]pyridazin-3-yl}(methyl)amino)pyridine-2-carboxylic acid

Step A: tert-butyl N-[(tert-butoxy)carbonyl]-N-(6-chloropyridazin-3-yl)carbamate

4-Dimethylaminopyridine (122 mg, 1 mmol, 0.02 equiv) was added under nitrogen to a suspension of 3-amino-6-chloropyridazine (6.5 g, 50.2 mmol, 1 equiv) and di-tert-butyl dicarbonate (25.2 g, 115 mmol, 2.3 equiv) in dimethylformamide (45 mL). The suspension was heated at 50 °C for 3 h, then allowed to cool to ambient temperature and water (350 mL) was added. The solids were collected by filtration, washed with water (250 mL) then dissolved in dichloromethane (250 mL) and the solution filtered through silica gel (25 g) eluting with dichloromethane. The filtrate was concentrated in vacuo and triturated with heptane (50 mL) to give a solid which was collected by filtration, washed with heptane (50 mL) and dried in vacuo to give the title product as a white solid (9.85 g, 29.9 mmol, 60%).

LC/MS (C ₁₄ H ₂₀ ClN ₃ O ₄ ) 174 [M-Boc-tBu+3H] ⁺ ; RT 1.28 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.53 (d, 2H), 1.46 (s, 18H).

Step B: Methyl 6-[(6-{bis[(tert-butoxy)carbonyl]amino}pyridazin-3-yl)amino]pyridine-2-carboxylate

Methyl 6-aminopyridine-2-carboxylate (1.65 g, 10.8 mmol, 1.1 equiv) and the product from Step A (3.25 g, 9.86 mmol, 1 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone)dipalladium(0) (451 mg, 0.49 mmol, 0.05 equiv) and xantphos (570 mg, 0.99 mmol, 0.1 equiv) in 1,4-dioxane (60 mL). N,N-Diisopropylethylamine (5.2 mL, 29.6 mmol, 3 equiv) was added and the mixture was heated at 100 °C for 3 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. The residue was partitioned between dichloromethane (300 ml) and water (200 ml) and the organic phase was washed successively with water (200 ml) and brine (150 ml), then dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with 2:3 ethyl acetate/heptane gave a yellow solid. Trituration with diethyl ether (20 ml) gave a solid which was collected by filtration, washed with diethyl ether (20 ml) and dried in vacuo to give the title product as a pale yellow solid (3.35 g, 7.52 mmol, 76%).

LC/MS (C ₂₁ H ₂₇ N ₅ O ₆ ) 446 [M+H] ⁺ ; RT 1.27 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 10.41(s, 1H), 9.02 (d, 1H), 7.97 (dd, 1H), 7.83-7.73 (m, 2H), 7.45 (d, 1H), 4.01 (s, 3H), 1.46 (s, 9H).

Step C: methyl 6-[(6-{bis[(tert-butoxy)carbonyl]amino}pyridazin-3-yl)(methyl)amino]pyridine-2-carboxylate

Potassium tert-butoxide (750 mg, 6.68 mmol, 1.32 equiv) was added under nitrogen to a suspension of the product from Step B (2.25 g, 5.05 mmol, 1 equiv) in dimethyl sulfoxide (25 mL), and the mixture was stirred for 30 min. Methyl iodide (0.5 mL, 8.03 mmol, 1.59 equiv) was added and the suspension was stirred for 3 h. The mixture was partitioned between ethyl acetate (250 mL) and saturated aqueous ammonium chloride (150 mL), washed with water (2×150 mL) and brine (100 mL), dried (magnesium sulfate), and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with 2:3 ethyl acetate/heptane afforded the title product as a yellow solid (1.4 g, 2.59 mmol, 51%), which was used directly in the next step without further purification.

LC/MS (C ₂₂ H ₂₉ N ₅ O ₆ ) 460 [M+H] ⁺ ; RT 1.29 (LCMS-V-B1).

Step D: Methyl 6-[(6-aminopyridazin-3-yl)(methyl)amino]pyridine-2-carboxylate

Trifluoroacetic acid (5 mL, 64.7 mmol, 25 equiv) was added to the product from Step C (1.4 g, 2.59 mmol, 1 equiv) in dichloromethane (35 mL) at 0 °C and the solution was stirred for 1 h at 0 °C and then for 18 h at ambient temperature. The solution was concentrated in vacuo and water (25 mL) was added to give a pale yellow suspension which was neutralized with sodium bicarbonate and the solids were collected by filtration, washed with water (75 mL) and dried in vacuo to give the title product as a yellow solid (650 mg, 2.51 mmol, 97%) which was used directly in the next step without further purification or characterization.

Step E: methyl 6-({6-[(1,3-benzothiazol-2-yl)amino]pyridazin-3-yl}(methyl)amino)pyridine-2-carboxylate

The product from Step D (650 mg, 2.51 mmol, 1 equiv) and 2-bromo-1,3-benzothiazole (600 mg, 2.8 mmol, 1.12 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone)dipalladium(0) (115 mg, 0.13 mmol, 0.05 equiv) and xantphos (145 mg, 0.25 mmol, 0.1 equiv) in 1,4-dioxane (10 mL). N,N-Diisopropylethylamine (1.4 mL, 7.52 mmol, 3 equiv) was added and the mixture was heated at 100 °C for 24 h. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Water (20 mL) was added to give a brown suspension and the solids were collected by filtration, washed with water (40 mL) and dried in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with 39:1 dichloromethane/methanol gave a solid which was triturated with methanol (10 mL), filtered, washed with methanol (10 mL) and dried in vacuo to give the title product as a pale brown solid (225 mg, 0.57 mmol, 23%).

LC/MS (C ₁₉ H ₁₆ N ₆ O ₂ S) 393 [M+H] ⁺ ; RT 1.14 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 11.73 (br s, 1H), 7.94 (d, 1H), 7.91-7.85 (m, 1H), 7.80 (d, J=9.5 Hz, 1H), 7.70- 7.59 (m, 2H), 7.46 (d, 1H), 7.43-7.35 (m, 2H), 7.28-7.19 (m, 1H), 3.86 (s, 3H), 3.64 (s, 3H).

Step F: 6-({6-[(1,3-benzothiazol-2-yl)amino]pyridazin-3-yl}(methyl)amino)pyridine-2-carboxylic acid

To a solution of the product from Step E (200 mg, 0.51 mmol, 1 equiv) in 1:3 water/1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (85.5 mg, 2.04 mmol, 4 equiv), and the mixture was stirred at ambient temperature for 2 h. Water (5 mL) was added, the solution was filtered through celite, and the solids were washed with water (10 mL). The combined filtrate was acidified with acetic acid to give a solid, which was collected by filtration, washed with water (20 mL), and dried in vacuo to give the title product as a yellow solid (160 mg, 0.42 mmol, 83%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₈ H ₁₅ N ₆ O ₂ S: 379.0972, found: 379.0993.

Example 39: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(2-methoxyethyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)(2-methoxyethyl)amino]-1,3-thiazole-4-carboxylate

Sodium hydride (60% dispersion; 650 mg, 16.3 mmol, 1.2 equiv) under nitrogen atmosphere was added to a solution of the product of Synthesis 3z (3.15 g, 13.7 mmol, 1 equiv) and 3,6-dichloro-4-methylpyridazine (2.5 g, 15.3 mmol, 1.12 equiv) in 1,4-dioxane (50 mL) at 0°C. The mixture was stirred for 1 h at 0 °C, then heated at 60 °C for 24 h. The mixture was allowed to cool to ambient temperature, then partitioned between ethyl acetate (300 mL) and saturated aqueous ammonium chloride (150 mL), and the organic phase was washed successively with water (2 x 150 mL) and brine (100 mL), dried (magnesium sulfate), and concentrated in vacuo. Trituration with diethyl ether (25 mL) gave a solid which was collected by filtration, washed with diethyl ether (15 mL), and dried in vacuo to give the title product as a pale pink solid (2.55 g, 7.15 mmol, 52%).

LC/MS (C ₁₄ H ₁₇ ClN ₄ O ₃ S) 357 [M+H] ⁺ ; RT 1.22 (LCMS-V-B1)

^1H NMR (400 MHz, CDCl ₃ ) δ 7.83 (s, 1H), 7.65 (s, 1H), 4.60 (t, 2H), 4.39 (q, 2H), 3.91 (t, 2H), 3.32 (s, 3Н), 2.46 (s, 3Н), 1.41 (t, 3H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(2-methoxyethyl)amino)-1,3-thiazole-4-carboxylate

2-Aminobenzothiazole (1.15 g, 7.66 mmol, 1.09 equiv) and the product from Step A (2.5 g, 7.01 mmol, 1 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone)dipalladium(0) (321 mg, 0.35 mmol, 0.05 equiv) and xantphos (405 mg, 0.7 mmol, 0.1 equiv) in 1,4-dioxane (45 mL). N,N-Diisopropylethylamine (3.8 mL, 21.0 mmol, 3 equiv) was added and the mixture was heated in a stoppered flask at 150 °C for 18 h. The solution was allowed to cool to ambient temperature, filtered through celite, and the solids were washed with dichloromethane. The combined filtrate was concentrated in vacuo and triturated with methanol (25 mL) to give a solid that was collected by filtration, washed with methanol (3 x 15 mL), and dried in vacuo to give the title product as an orange solid (2.55 g, 5.42 mmol, 77%).

LC/MS (C ₂₁ H ₂₂ N ₆ O ₃ S ₂ ) 471 [M+H] ⁺ ; RT 1.35 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.85-7.80 (m, 1H), 7.79 (s, 1H), 7.77-7.69 (m, 1H), 7.66 (d, J=1.3 Hz, 1H), 7.48- 7.36 (m, 1H), 7.31-7.21 (m, 1H), 4.64-4.48 (m, 2H), 4.41 (q, J=7.1 Hz, 2H), 3.94-3.85 (m, 2H), 3.40-3.31 (m, 3H), 2.44 (s, 3H ), 1.43 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(2-methoxyethyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (250 mg, 0.53 mmol, 1 equiv) in 1:3 water/1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (89.2 mg, 2.13 mmol, 4 equiv), and the mixture was stirred at ambient temperature for 18 h. Water (10 mL) was added and the suspension was acidified with acetic acid. The solids were collected by filtration, washed with water (3 x 25 mL), and dried in vacuo to give the title product as a yellow solid (175 mg, 0.4 mmol, 74%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₉ H ₁₉ N ₆ O ₃ S ₂ : 443.0955, found: 443.0983.

Example 40: 5-{1-[(Adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl) amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazol-4-carboxylic acid

Step A: Ethyl 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a mixture of Preparation 11b (54.7 mg, 0.09 mmol, 1 equiv), Preparation 10a (36.8 mg, 0.1 mmol, 1.2 equiv), and potassium carbonate (35.7 mg, 0.26 mmol, 3 equiv) in 3:1 tetrahydrofuran/water (4 mL) was added [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (6.3 mg, 0.01 mmol, 0.1 equiv). The mixture was sparged with nitrogen (10 min) and then heated at 120 °C for 1 h under microwave irradiation. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0:50% ethyl acetate in isoheptane afforded the title product as a brown glass (46.7 mg, 0.06 mmol, 69%).

LC/MS (C ₄₀ H ₅₂ N ₈ O ₃ SiS ₂ ) 785 [M+H] ⁺ ; RT 1.91 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d) δ 7.82 (dd, J=7.7, 1.1 Hz, 1H), 7.71 (d, J=1.1 Hz, 1H), 7.53 (s, 1H), 7.48-7.39 (m, 2H), 7.23 (ddd, J=8.3, 7.0, 1.5 Hz, 1H), 5.86 (s, 2H), 4.16 (q, J=7.1 Hz, 2H), 3.82 (s, 3H), 3.78 (s, 2H), 3.71 (t, 2H), 2.46 (s, 3H), 2.18 (s, 3H), 1.95 (s, 3H), 1.72-1.54 (m, 12H), 1.16 (t, J=7.1 Hz, 3H), 0.92 (t, 3H), -0.11 (s, 9H).

Step B: Ethyl 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

A solution of the product from Step A (46.7 mg, 0.06 mmol, 1 equiv) in dichloromethane (3 mL) was cooled in an ice bath, trifluoroacetic acid (0.3 mL, 4.03 mmol, 67.7 equiv) was added, the mixture was allowed to warm to ambient temperature and stirred for 18 h. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed successively with water and brine, then dried (magnesium sulfate) and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a yellow glass (24.2 mg, 0.04 mmol, 62%).

LC/MS (C ₃₄ H ₃₈ N ₈ O ₂ S ₂ ) 655 [M+H] ⁺ ; RT 1.53 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-d6) δ 7.90 (br s, 1H), 7.73 (s, 1H), 7.54 (s, 1H), 7.37 (t, J=7.7 Hz, 1H), 7.24-7.15 ( m, 1H), 4.17 (q, J=7.1 Hz, 2H), 3.81 (s, 3H), 3.79 (s, 2H), 2.47 (s, 3H), 2.20 (s, 3H), 1.97 (s, 3H), 1.72-1.55 (m, 12H), 1.17 (t , J=7.1 Hz, 3H).

Step C: 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (24.2 mg, 0.04 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (7.8 mg, 0.18 mmol, 5 equiv) and the mixture was heated at reflux for 18 h. The reaction mixture was allowed to cool to ambient temperature and then the solvent was removed in vacuo. The residue was triturated with water, filtered, and dried in vacuo to give the title product as a yellow solid (16.3 mg, 0.03 mmol, 70%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₂ H ₃₅ N ₈ O ₂ S ₂ : 627.2319, found: 627.2358.

Example 41: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}[2-(morpholin-4-yl)ethyl]amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[(2,2-dimethoxyethyl)amino]-1,3-thiazole-4-carboxylate

Ammonia (2 M in isopropanol; 25 mL, 50 mmol, 2.1 equiv) under nitrogen was added to a solution of 1,1-dimethoxy-2-isothiocyanatoethane (3.5 g, 20 mmol, 1 equiv) in isopropanol (15 mL) at 0 °C, and the mixture was stirred for 1 h at 0 °C and then for 18 h at ambient temperature. The solvent was removed in vacuo and the residue was dissolved in ethanol (60 mL) and cooled to 0 °C. Ethyl bromopyruvate (3.6 mL, 25.8 mmol, 1.09 equiv) was added to the solution under nitrogen and the mixture was allowed to warm to ambient temperature and stirred for 1.5 h. Triethylamine (5.6 mL, 39.9 mmol, 2 equiv) was added and the mixture was stirred for 2 h and then concentrated in vacuo. The residue was partitioned between ethyl acetate (250 mL) and water (150 mL) and the organic phase was washed successively with water (150 mL) and brine (150 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with 2:3 ethyl acetate/heptane afforded a pale yellow solid which was triturated with heptane (40 mL), filtered, washed with heptane (40 mL), and dried in vacuo to afford the title product as an off-white solid (2.95 g, 11.33 mmol, 48%).

LC/MS (C ₁₀ H ₁₆ N ₂ O ₄ S) 261 [M+H] ⁺ ; RT 0.92 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.41 (s, 1H), 5.59 (t, J=5.5 Hz, 1H), 4.52 (t, J=5.4 Hz, 1H), 4.35 (q, J=7.1 Hz, 2H), 3.41 (dd+s, 8H), 1.36 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)(2,2-dimethoxyethyl)amino]-1,3-thiazole-4-carboxylate

Sodium hydride (60% dispersion; 500 mg, 12.5 mmol, 1.25 equiv) under nitrogen atmosphere was added to a solution of the product from Step A (2.6 g, 9.99 mmol, 1 equiv) and 3,6-dichloro-4-methylpyridazine (1.85 g, 11.4 mmol, 1.14 equiv) in 1,4-dioxane (40 mL) at 0 °C, and the mixture was stirred for 1 h at 0 °C and then for 5 h at 60 °C. The solution was allowed to cool to ambient temperature, then partitioned between ethyl acetate (300 mL) and saturated aqueous ammonium chloride solution (150 mL). The organic phase was washed successively with water (2 x 150 ml) and brine (150 ml), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with 99:1 dichloromethane/methanol afforded an orange gum which was triturated with diethyl ether (15 ml) to give a solid which was collected by filtration, washed with diethyl ether (20 ml) and dried in vacuo to give the title product as a pale pink powder (1.95 g, 5.04 mmol, 50%).

LC/MS (C ₁₅ H ₁₉ ClN ₄ O ₄ S) 387 [M+H] ⁺ ; RT 1.26 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 8.06 (s, 1H), 7.95 (d, J=1.1 Hz, 1H), 4.78 (t, J=5.2 Hz, 1H), 4.51 (d, J=5.2 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.34 (s, 6H), 2.42 (d, J=0.9 Hz, 3H), 1.31 (t, J=7.1 Hz, 3H).

Step C: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(2,2-dimethoxyethyl)amino)-1,3-thiazole-4-carboxylate

The product from Step B (1.6 g, 4.14 mmol, 1 equiv) and 2-aminobenzothiazole (700 mg, 4.66 mmol, 1.13 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone)dipalladium(0) (189 mg, 0.21 mmol, 0.05 equiv) and xantphos (239 mg, 0.41 mmol, 0.1 equiv) in 1,4-dioxane (20 mL), and the mixture was stirred. N,N-Diisopropylethylamine (2.2 mL, 12.4 mmol, 3 equiv) was added, and the mixture was heated in a sealed tube at 150 °C for 18 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Trituration with diethyl ether (20 mL) gave a solid which was collected by filtration, washed with diethyl ether (2 x 10 mL) and dried in vacuo to give the title product as a yellow/green solid (1.9 g, 3.42 mmol, 83%) which was used in the next step without further purification.

LC/MS (C ₂₂ H ₂₄ N ₆ O ₄ S ₂ ) 501 [M+H] ⁺ ; RT 1.37 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.11 (br s, 1H), 7.99 (s, 1H), 7.92 (br s, 1H), 7.78 (s, 1H), 7.57 (br s, 2H), 7.40 (t, J=7.6 Hz, 1H), 7.22 (t, J=7.6 Hz, 1H), 4.78 (t, J=5.2 Hz, 1H), 4.48 (d, J=5.2 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.35 (s, 6H), 2.46 (s, 3H), 1.31 (t, J=7.1 Hz, 3H).

Step D: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}[2-(morpholin-4-yl)ethyl]amino)-1,3-thiazole-4-carboxylate

Formic acid (10 mL, 0.27 mol, 177 equiv) was added to a suspension of the product from Step C (750 mg, 1.5 mmol, 1 equiv) in water (5 mL), and the mixture was heated at 85 °C for 3 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Dichloromethane (20 mL) was added followed by morpholine (0.5 mL, 5.78 mmol, 3.86 equiv) and sodium triacetoxyborohydride (1.59 g, 7.49 mmol, 5 equiv), and the mixture was stirred for 18 h. The reaction mixture was partitioned between dichloromethane (125 mL) and 10% aqueous potassium carbonate solution (75 mL), and the organic phase was washed successively with water (2 x 75 mL) and brine (75 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (20 g silica gel) eluting with 19:1 dichloromethane/methanol afforded a yellow solid which was triturated with diethyl ether (15 mL), filtered, washed with diethyl ether (15 mL), and dried in vacuo to afford the title product as a pale orange solid (375 mg, 0.71 mmol, 48%).

LC/MS (C ₂₄ H ₂₇ N ₇ O ₃ S ₂ ) 526 [M+H] ⁺ ; RT 1.08 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.18 (br s, 1H), 7.97 (s, 1H), 7.91 (br s, 1H), 7.75 (s, 1H), 7.55 (br s, 1H), 7.39 (t, 1H), 7.22 (t, J=7.6 Hz, 1H), 4.53 (t, J=6.5 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.48 (t, J=4.5 Hz, 4H), 2.65 (t, J=6.5 Hz, 2H), 2.47 (s, 3H), 1.31 (t, J=7.1 Hz, 3H).

Step E: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}[2-(morpholin-4-yl)ethyl]amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step D (275 mg, 0.52 mmol, 1 equiv) in a 2:3 mixture of water/1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (87.8 mg, 2.09 mmol, 4 equiv), and the mixture was stirred at ambient temperature for 18 h. The solids were collected by filtration, washed with water, and dried in vacuo to give the desired product as a pale orange solid (215 mg, 0.43 mmol, 83%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₂₂ H ₂₂ N ₇ O ₃ S ₂ : 496.1231, found: 496.1232.

Example 42: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-{[1-(3-methoxypropyl)cyclohexyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(1-{[1-(3-methoxypropyl)cyclohexyl]methyl}-5-methyl-1H-pyrazol-4-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a mixture of Preparation 11b (110 mg, 0.17 mmol, 1 equiv), Preparation 10c (78.2 mg, 0.21 mmol, 1.2 equiv), and potassium carbonate (71.8 mg, 0.52 mmol, 3 equiv) in 10:1 tetrahydrofuran (4 mL)/water (0.4 mL) was added [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (12.7 mg, 0.02 mmol, 0.1 equiv). The mixture was sparged with nitrogen (10 min) and then heated at 120 °C for 1 h under microwave irradiation. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0:50% ethyl acetate in isoheptane afforded the title product as a yellow foam (56.1 mg, 0.07 mmol, 40%).

LC/MS (C ₄₀ H ₅₆ N ₈ O ₄ SiS ₂ ) 805 [M+H] ⁺ ; RT 1.74 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-dd) δ 7.92 (dd, J=7.6, 1.0 Hz, 1H), 7.82 (d, J=1.1 Hz, 1H), 7.66 (s, 1H), 7.61-7.47 (m, 2H), 7.35 (ddd, J=8.3, 7.0, 1.5 Hz, 1H), 5.96 (d, J=9.8 Hz, 2H), 4.28 (q, J=7.1 Hz, 2H), 4.05 (s, 2H), 3.93 (s, 3H), 3.83 (t, 2H), 3.35 (s, 3H), 2.58 (d, J=1.0 Hz, 3H), 2.31 (s, 3H), 1.69-1.58 (m, 5H), 1.52-1.44 (m, 7H), 1.38-1.32 (s, 4H), 1.28 (t, J=7.1 Hz, 3H), 1.03 (t, 2H), 0.00 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-{[1-(3-methoxypropyl)cyclohexyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylate

A solution of the product from Step A (56.1 mg, 0.07 mmol, 1 equiv) in dichloromethane (3 mL) was cooled in an ice bath and trifluoroacetic acid (0.5 mL, 6.71 mmol, 96 equiv) was added. The mixture was allowed to warm to ambient temperature and stirred overnight. The solvent was removed in vacuo and the crude product was purified by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) to give the title product as a yellow glass (34.2 mg, 0.05 mmol, 73%).

LC/MS (C ₃₄ H ₄₂ N ₈ O ₃ S ₂ ) 675 [M+H] ⁺ ; RT 1.47 (LCMS-V-B2)

^1H NMR (400 MHz, DMSO-d6) δ 7.88 (br s, 1H), 7.73 (s, 1H), 7.55 (s, 1H), 7.52 (br s, 1H), 7.37 (t, 1H), 7.19 (t, 1H), 4.17 (q, J=7.1 Hz, 2H), 3.94 (s, 2H), 3.82 (s, 3H), 3.24 (s, 3H), 2.48 (s, 3H), 2.20 (s, 3H), 1.60 - 1.45 (m, 6H), 1.45 - 1.31 (m, 8H), 1.29 - 1.21 (m, 2H), 1.17 (t, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-{[1-(3-methoxypropyl)cyclohexyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (34 mg, 0.05 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (10.6 mg, 0.25 mmol, 5 equiv), and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature, then the solvent was removed in vacuo. The residue was diluted with water, acidified with 2 N aqueous hydrochloric acid, and extracted with 3:1 dichloromethane/isopropanol. The organic extracts were dried (magnesium sulfate), concentrated in vacuo, and dried in vacuo to give the title product as a cream-colored solid (16.7 mg, 0.03 mmol, 51%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₂ H ₃₉ N ₈ O ₃ S ₂ : 647.2581, found: 647.2591.

Example 43: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-{[1-(3-methoxypropyl)cyclooctyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(1-{[1-(3-methoxypropyl)cyclooctyl]methyl}-5-methyl-1H-pyrazol-4-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a mixture of Preparation 11b (106 mg, 0.17 mmol, 1 equiv), Preparation 10b (80.9 mg, 0.2 mmol, 1.2 equiv), and potassium carbonate (69.1 mg, 0.5 mmol, 3 equiv) in 3:1 tetrahydrofuran/water (4 mL) was added [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (12.2 mg, 0.02 mmol, 0.1 equiv). The mixture was sparged with nitrogen (10 min) and then heated at 120 °C for 1 h under microwave irradiation. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 50% ethyl acetate in isoheptane afforded the title product as a colorless gum (81.3 mg, 0.1 mmol, 59%).

LC/MS (C ₄₂ H ₆₀ N ₈ O ₄ SiS ₂ ) 833 [M+H] ⁺ ; RT 1.81 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-d6) δ 7.92 (d, J=7.6 Hz, 1H), 7.82 (s, 1H), 7.66 (s, 1H), 7.61 - 7.50 (m, 2H), 7.37 - 7.28 (m, 1H), 5.98 (s, 2H), 4.28 (q, J=7.1 Hz, 2H), 3.96 (s, 2H), 3.93 (s, 3H), 3.83 (t, J=8.0 Hz, 2H), 3.35 (s, 3H), 2.58 (s, 3H), 2.29 (s, 3H), 1.76 - 1.64 (m, 9H), 1.60 - 1.45 (m, 5H), 1.46 - 1.33 (m, 6H), 1.28 (t, J=7.1 Hz, 3H), 1.03 (t, 3H), 0.00 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-{[1-(3-methoxypropyl)cyclooctyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylate

A solution of the product from Step A (81.3 mg, 0.1 mmol, 1 equiv) in dichloromethane (3 mL) was cooled in an ice bath, then trifluoroacetic acid (0.3 mL, 4.03 mmol, 41 equiv) was added and the mixture was stirred at ambient temperature for 18 h. The solvent was removed in vacuo and the crude product was purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 5% methanol in dichloromethane to give the desired product as a white solid (81.5 mg, 0.12 mmol, >100%).

LC/MS (C ₃₆ H ₄₆ N ₈ O ₃ S ₂ ) 703 [M+H] ⁺ ; RT 1.56 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-d6) 7.88 (br s, 1H), 7.73 (s, 1H), 7.56 (s, 1H), 7.50 (br s, 1H), 7.38 (t, J=7.5 Hz, 1H), 7.20 (t, J=7.6 Hz, 1H), 4.17 (q, J=7.1 Hz, 2H), 3.85 (s, 2H), 3.81 (s, 3H), 3.33 (t, J=6.5 Hz, 2H), 3.25 (s, 3H), 2.48 (s, 3H), 2.19 (s, 3H), 1.66 - 1.54 (m, 9H), 1.49 - 1.36 (m, 4H), 1.33 - 1.22 (m, 5H), 1.18 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-{[1-(3-methoxypropyl)cyclooctyl]methyl}-5-methyl-1H-pyrazol-4-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (81.5 mg, 0.12 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (24.3 mg, 0.58 mmol, 5 equiv), and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and the solvent was removed in vacuo. The residue was diluted with water, acidified with 2 N aqueous hydrochloric acid, and extracted with 3:1 dichloromethane/isopropanol. The organic extracts were dried (magnesium sulfate) and concentrated under reduced pressure to give the title product as a cream-colored solid (53.6 mg, 0.08 mmol, 69%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₄ H ₄₃ N ₈ O ₃ S ₂ : 675.2894, found: 675.2890.

Example 44: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}[3-(morpholin-4-yl)propyl]amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-{[3-(morpholin-4-yl)propyl]amino}-1,3-thiazole-4-carboxylate

Ethyl bromopyruvate (2.5 mL, 17.9 mmol, 1.18 equiv) was added under nitrogen to a suspension of 3-(morpholin-4-yl)propylthiourea (3.1 g, 15.3 mmol, 1 equiv) in ethanol (50 mL) at 0 °C and the mixture was stirred for 1 h at ambient temperature. Triethylamine (4.5 mL, 30.5 mmol, 2 equiv) was added and the mixture was heated at 85 °C for 4 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Aqueous 10% potassium carbonate solution (150 mL) was added and the mixture was extracted with ethyl acetate (5 × 100 mL). The combined organic extracts were washed with water (2 x 150 ml) and brine (100 ml), then dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with 19:1 dichloromethane/methanol (19:1) gave a solid that was triturated with heptane (50 ml), filtered, washed with heptane (50 ml) and dried in vacuo to give the title product as a pale brown solid (4 g, 13.4 mmol, 88%).

LC/MS (C ₁₃ H ₂₁ N ₃ O ₃ S) 300 [M+H] ⁺ ; RT 0.58 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.41 (s, 1H), 6.48 (t, 1H), 4.37 (q, J=7.1 Hz, 2H), 3.75 (t, J=4.7 Hz, 4H), 3.42 (q, J=6.0 Hz, 2H), 2.54 - 2.43 (m, 6H), 1.83 (p, J=6.4 Hz, 2H), 1.39 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)[3-(morpholin-4-yl)propyl]amino]-1,3-thiazole-4-carboxylate

Sodium hydride (60% dispersion; 350 mg, 8.75 mmol, 1.31 equiv) under nitrogen atmosphere was added to a solution of the product from Step A (2 g, 6.68 mmol, 1 equiv) and 3,6-dichloro-4-methylpyridazine (1.25 g, 7.67 mmol, 1.15 equiv) in 1,4-dioxane (30 mL) at 0 °C, and the mixture was stirred for 1 h at 0 °C and then for 3 h at 60 °C. The solution was allowed to cool to ambient temperature, then partitioned between ethyl acetate (300 mL) and saturated aqueous ammonium chloride (100 mL). The organic phase was washed successively with water (150 ml) and brine (100 ml), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with ethyl acetate gave a brown oil. Trituration with heptane (15 ml) gave a solid which was collected by filtration, washed with heptane (20 ml) and dried in vacuo to give the title product as a pale brown solid (1.5 g, 3.52 mmol, 53%).

LC/MS (C ₁₈ H ₂₄ ClN ₅ O ₃ S) 426 [M+H] ⁺ ; RT 0.96 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.83 (s, 1H), 7.56 (d, J=1.1 Hz, 1H), 4.51 (t, 2H), 4.40 (q, J=7.1 Hz, 2H), 3.75 (t, J=4.6 Hz, 4H), 2.52 - 2.42 (m, 9H), 2.06 (p, 2H), 1.41 (t, J=7.1 Hz, 3H).

Step C: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}[3-(morpholin-4-yl)propyl]amino)-1,3-thiazole-4-carboxylate

The product from Step B (900 mg, 2.11 mmol, 1 equiv) and 2-aminobenzothiazole (350 mg, 2.33 mmol, 1.1 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone)dialladium(0) (96.8 mg, 0.11 mmol, 0.05 equiv) and xantphos (122 mg, 0.21 mmol, 0.1 equiv) in 1,4-dioxane (20 mL), and the mixture was stirred. N,N-Diisopropylethylamine (1.1 mL, 6.34 mmol, 3 equiv) was added and the mixture was heated in a sealed tube at 150 °C for 24 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with 10:1 dichloromethane/methanol gave a red/brown gum. Trituration with diethyl ether (20 mL) gave a solid which was collected by filtration, washed with diethyl ether (2 x 10 mL) and dried in vacuo to give the title product as a pale brown solid (875 mg, 1.62 mmol, 77%).

LC/MS (C ₂₅ H ₂₉ N ₇ O ₃ S ₂ ) 540 [M+H] ⁺ ; RT 1.12 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.16 (br s, 1H), 7.96 (s, 1H), 7.92 (s, 1H), 7.76 (s, 1H), 7.63 - 7.47 (m, 1H), 7.39 (t, 1H), 7.22 (t, J=7.5 Hz, 1H), 4.43 (t, J=7.4 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.59 (t, J=5.0 Hz, 4H), 2.48 (s, 3H), 2.43 - 2.33 (m, 6H), 1.99 - 1.85 (m, 2H), 1.32 (t, J=7.1 Hz, 3H).

Step D: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}[3-(morpholin-4-yl)propyl]amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step C (300 mg, 0.56 mmol, 1 equiv) in a 3:1 mixture of 1,4-dioxane/water (4 mL) was added lithium hydroxide monohydrate (93.3 mg, 2.22 mmol, 4 equiv), and the mixture was stirred at ambient temperature overnight. Water (5 mL) was added and the mixture was filtered through celite and washed with water (10 mL). The filtrate was acidified with acetic acid and stirred for 15 min, then the solids were collected by filtration, washed with water (10 mL), and dried in vacuo to give the title product as a yellow solid (180 mg, 0.35 mmol, 63%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₂₃ H ₂₄ N ₇ O ₃ S ₂ : 510.1388, found: 510.1406.

Example 45: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(propyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-(propylamino)-1,3-thiazole-4-carboxylate

Ethyl bromopyruvate (4 mL, 28.7 mmol, 1.13 equiv) was added to a solution of propylthiourea (3 g, 25.4 mmol, 1 equiv) in ethanol (50 mL) under nitrogen at 0 °C and the mixture was stirred for 1 h at ambient temperature. Triethylamine (7 mL, 50.8 mmol, 2 equiv) was added and the mixture was stirred for 18 h. The reaction mixture was partitioned between ethyl acetate (300 mL) and water (150 mL) and the organic phase was washed successively with water (150 mL) and brine (100 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with dichloromethane afforded the title product as a pale brown oil that solidified on standing (3.4 g, 15.9 mmol, 63%).

LC/MS (C ₉ H ₁₄ N ₂ O ₂ S) 215 [M+H] ⁺ ; RT 1.04 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.42 (s, 1H), 5.63 (s, 1H), 4.37 (q, 2H), 4.40 (q, J=7.1 Hz, 2H), 3.24 (q, 2H), 1.75 - 1.64 (m, 2H), 1.39 (t, 3H), 1.00 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)(propyl)amino]-1,3-thiazole-4-carboxylate

Sodium hydride (60% dispersion; 500 mg, 12.5 mmol, 1.25 equiv) under nitrogen atmosphere was added to a solution of the product from Step A (2.15 g, 10.0 mmol, 1 equiv) and 3,6-dichloro-4-methylpyridazine (1.75 g, 10.7 mmol, 1.07 equiv) in 1,4-dioxane (30 mL) at 0 °C, and the mixture was stirred for 1 h at 0 °C and then for 18 h at ambient temperature. The reaction mixture was partitioned between ethyl acetate (300 ml) and saturated aqueous ammonium chloride solution (150 ml), and the organic phase was washed successively with water (2 x 150 ml) and brine (100 ml), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with dichloromethane gave a solid which was triturated with heptane (30 ml), filtered, washed with heptane (15 ml) and dried in vacuo to give the title product as a white solid (1.3 g, 3.81 mmol, 38%).

LC/MS (C ₁₄ H ₁₇ ClN ₄ O ₂ S) 341 [M+H] ⁺ ; RT 1.32 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.82 (s, 1H), 7.39 (d, 1H), 4.47 - 4.35 (m, 4H), 2.48 (d, J=1.0 Hz, 3H), 1.93 - 1.78 ( m, 2H), 1.42 (t, J=7.1 Hz, 3H), 1.05 (t, J=7.4 Hz, 3H).

Step C: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(propyl)amino)-1,3-thiazole-4-carboxylate

The product from Step B (850 mg, 2.49 mmol, 1 equiv) and 2-aminobenzothiazole (425 mg, 2.83 mmol, 1.13 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone)dipalladium(0) (114 mg, 0.12 mmol, 0.05 equiv) and xantphos (144 mg, 0.25 mmol, 0.1 equiv) in 1,4-dioxane (10 mL), and the mixture was stirred. N,N-Diisopropylethylamine (1.3 mL, 7.48 mmol, 3 equiv) was added, and the mixture was heated in a sealed tube at 150 °C for 24 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with 39:1 dichloromethane/methanol afforded a dark yellow solid, which was triturated with methanol (15 mL), filtered, washed with methanol (15 mL), and dried in vacuo to afford the title product as a yellow solid (915 mg, 2.01 mmol, 81%).

LC/MS (C ₂₁ H ₂₂ N ₆ O ₂ S ₂ ) 455 [M+H] ⁺ ; RT 1.44 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.12 (br s, 1H), 7.96 (s, 1H), 7.92 (br s, 1H), 7.73 (s, 1H), 7.59 (br s, 1H), 7.39 (t, J=7.5 Hz, 1H), 7.22 (t, J=7.3 Hz, 1H), 4.37 (dd, J=9.0, 6.3 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 2.48 (s, 3H), 1.74 (q, J=7.5 Hz, 2H), 1.32 (t, J=7.1 Hz, 3H), 0.96 (t, J=7.4 Hz, 3H).

Step D: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(propyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step C (250 mg, 0.55 mmol, 1 equiv) in a 3:1 mixture of 1,4-dioxane/water (4 mL) was added lithium hydroxide monohydrate (92.3 mg, 2.2 mmol, 4 equiv) and the mixture was stirred at ambient temperature for 18 h. Water (5 mL) was added and the solution was filtered through celite and washed with water (10 mL). The filtrate was acidified with acetic acid to give a suspension which was collected by filtration, the crude product was washed with water (10 mL) and dried in vacuo to give the title product as a pale yellow solid (185 mg, 0.43 mmol, 79%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₁₉ H ₁₇ N ₆ O ₂ S ₂ : 425.0860, found: 425.0867.

Example 46: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}[3-(diethylamino)propyl]amino)-1,3-thiazol-4 -carboxylic acid

Step A: ethyl 2-{[3-(diethylamino)propyl]amino}-1,3-thiazol-4-carboxylate

Ammonia (2 M in isopropanol; 60 mL, 0.12 mol, 3.45 equiv) at 0 °C was added to a solution of 3-(diethylamino)propyl isothiocyanate (6 g, 34.8 mmol, 1 equiv) in isopropanol (15 mL), and the mixture was stirred for 1 h at 0 °C and then for 18 h at ambient temperature. The suspension was concentrated in vacuo, then triturated with heptane (50 mL), the solids were filtered and washed with heptane (2 x 25 mL). Ethanol (150 mL) and ethyl bromopyruvate (5 mL, 39.8 mmol, 1.14 equiv) were added and the mixture was stirred under nitrogen for 1 h. Triethylamine (10 mL, 69.7 mmol, 2 equiv) was added and the mixture was heated at 85 °C for 4 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with 19:1 dichloromethane/methanol afforded the title product as a dark brown gum (3.95 g, 13.8 mmol, 40%).

LC/MS (C ₁₃ H ₂₃ N ₃ O ₂ S) 286 [M+H] ⁺ ; RT 0.78 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.39 (s, 1H), 7.05 (s, 1H), 4.37 (q, J=7.1 Hz, 2H), 3.42 (td, J=6.2, 3.1 Hz, 2H), 2.64-2.51 (m, 6H), 1.84 - 1.76 (m, 2H), 1.39 (t, J=7.1 Hz, 3H), 1.06 (t, J=7.1 Hz, 6H).

Step B: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)[3-(diethylamino)propyl]amino]-1,3-thiazol-4-carboxylate

Sodium hydride (60% dispersion; 700 mg, 17.5 mmol, 1.26 equiv) under nitrogen atmosphere was added to a solution of the product from Step A (3.95 g, 13.8 mmol, 1 equiv) and 3,6-dichloro-4-methylpyridazine (2.5 g, 15.3 mmol, 1.11 equiv) in 1,4-dioxane (50 mL) at 0 °C, and the mixture was stirred for 1 h at 0 °C and then for 18 h at ambient temperature. The reaction mixture was partitioned between ethyl acetate (300 mL) and water (150 mL), and the organic phase was washed successively with water (150 mL) and brine (100 mL), dried (magnesium sulfate), and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with 19:1 dichloromethane/methanol afforded the title product as a brown gum (2.3 g, 5.58 mmol, 40%).

LC/MS (C ₁₈ H ₂₆ ClN ₅ O ₂ S) 412 [M+H] ⁺ ; RT 1.00 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.80 (s, 1H), 7.63 (d, J=1.1 Hz, 1H), 4.47 (q, 2H), 4.37 (q, J=7.1 Hz, 2H), 2.64 - 2.54 (m, 6H), 2.45 (d, J=0.9 Hz, 3H), 1.98 (q, 2H), 1.39 (t, J=7.1 Hz, 3H), 1.06 (t, J=7.1 Hz, 6H).

Step C: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}[3-(diethylamino)propyl]amino)-1,3-thiazole-4-carboxylate

The product from Step B (2.1 g, 5.1 mmol, 1 equiv) and 2-aminobenzothiazole (850 mg, 5.66 mmol, 1.11 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone)dipalladium(0) (233 mg, 0.25 mmol, 0.05 equiv) and xantphos (295 mg, 0.51 mmol, 0.1 equiv) in 1,4-dioxane (20 mL), and the mixture was stirred. N,N-Diisopropylethylamine (2.7 mL, 15.3 mmol, 3 equiv) was added, and the mixture was heated in a sealed tube at 150 °C for 24 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with a gradient of 5:10% methanol in dichloromethane gave a dark yellow gum, which was triturated with diethyl ether (10 mL), filtered, washed with diethyl ether (10 mL), and dried in vacuo to give the title product as a yellow solid (240 mg, 0.46 mmol, 9%).

LC/MS (C ₂₅ H ₃₁ N ₇ O ₂ S ₂ ) 526 [M+H] ⁺ ; RT 1.18 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.78 (br s, 1H), 7.88 - 7.67 (m, 4H), 7.44 -7.34 (m, 1H), 7.26 - 7.18 (m, 1H), 4.49 (s, 2H), 4.36 (q, J=7.1 Hz, 2H), 3.31 - 3.22 (m, 2H), 3.22 - 3.12 (m, 4H), 2.52 - 2.39 (m, 5H), 1.39 (t, J=7.1 Hz, 9H).

Step D: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}[3-(diethylamino)propyl]amino)-1,3-thiazol-4 -carboxylic acid

To a solution of the product from Step C (200 mg, 0.38 mmol, 1 equiv) in a 3:1 mixture of 1,4-dioxane/water (4 mL) was added lithium hydroxide monohydrate (63.9 mg, 1.52 mmol, 4 equiv) and the mixture was stirred at ambient temperature for 18 h. Water (5 mL) was added and the mixture was filtered through celite, washing with water (10 mL). The filtrate was acidified with acetic acid to give a solid, which was collected by filtration, washed with water (10 mL), and dried in vacuo to give the title product as a pale yellow solid (105 mg, 0.21 mmol, 55%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₂₃ H ₂₆ N ₇ O ₂ S ₂ : 496.1595, found: 496.1614.

Example 47: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product of Preparation 11c, Step C (300 mg, 0.62 mmol, 1 equiv) in a 3:1 mixture of 1,4-dioxane/water (4 mL) was added lithium hydroxide monohydrate (104 mg, 2.48 mmol, 4 equiv), and the mixture was stirred at ambient temperature overnight. Water (15 mL) was added and the mixture was acidified with acetic acid to give a solid, which was collected by filtration, washed with water (25 mL), and dried in vacuo to give the desired product as an orange solid (245 mg, 0.54 mmol, 87%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₀ H ₂₁ N ₆ O ₃ S ₂ : 457.1111, found: 457.1119.

Example 48: 2-[[4,5-Dimethyl-6-[(4-methyl-1,3-benzothiazol-2-yl)amino]pyridazin-3-yl]amino]thiazole-4-carboxylic acid

Step A: N-(6-chloro-4,5-dimethylpyridazin-3-yl)-4-methyl-1,3-benzothiazol-2-amine

To 611 mg of 6-chloro-4,5-dimethylpyridazin-3-amine (3.9 mmol, 1 equiv.) and 884 mg of 2-bromo-4-methyl-1,3-benzothiazole (3.9 mmol, 1 equiv.) in 13 mL of 1,4-dioxane was added 1.5 g of sodium hydride (60 wt %, 37.5 mmol, 9.6 equiv.), and the mixture was stirred under reflux for 1 h. After cooling, the reaction mixture was poured onto ice-water and acidified with 2 N HCl solution. The precipitate was filtered off, washed with NaHCO ₃ solution, and dried to give 810 mg (67%) of the desired product.

LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₁₄ H ₁₄ ClN ₄ S: 305, found: 305.

Step B: Ethyl 2-[[4,5-dimethyl-6-[(4-methyl-1,3-benzothiazol-2-yl)amino]pyridazin-3-yl]amino]thiazole-4-carboxylate

A mixture of 600 mg of the product from Step A (1.96 mmol, 1 equiv), 730 mg of ethyl 2-aminothiazole-4-carboxylate (4.24 mmol, 2.1 equiv), 78 mg of Pd ₂ (dba) ₃ (0.085 mmol, 0.04 equiv), 124 mg of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (0.21 mmol, 0.1 equiv) and 2.8 mL of DIPEA (8 equiv) in 16 mL of 1,4-dioxane was stirred at 185 °C in a microwave reactor for 1.5 h. After cooling, the volatiles were removed and the crude intermediate was purified by flash column chromatography using heptane and EtOAc as eluents with obtaining 328 mg (38%) of the target product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 11.00/10.81 (s+brs, 2H), 7.94 (s, 1H), 7.72 (brs, 1H), 7.19 (d, 1H), 7.10 (t, 1H), 4.29 (q, 2H), 2.57 (brs, 3H), 2.39/2.36 (s+s, 6H), 1.31 (t, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 126.9, 122.4, 121.7, 119.4, 60.8, 18.4, 14.7; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₀ H ₂₀ N ₆ O ₂ S ₂ : 441.1167, found: 441.1165.

Step C: 2-[[4,5-dimethyl-6-[(4-methyl-1,3-benzothiazol-2-yl)amino]pyridazin-3-yl]amino]thiazole-4-carboxylic acid

A mixture of the product from Step B, LiOH× _H2O , water and 1,4-dioxane was stirred at reflux for 1 h. After cooling and concentration, 1 N HCl was added, the precipitate was filtered and further purified by reverse phase preparative chromatography to give the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₈ H ₁₇ N ₆ O ₂ S ₂ : 413.0854, found: 413.0855.

Example 49: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-hydroxypropyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)(3-hydroxypropyl)amino]-1,3-thiazole-4-carboxylate

Boron tribromide (1 M in dichloromethane; 16 mL, 16.2 mmol, 2 equiv) was added under nitrogen to a solution of the product of Preparation 11c, Step B (3 g, 8.09 mmol, 1 equiv) in dichloromethane (50 mL) at -78 °C. The mixture was stirred for 1 h at -78 °C, then heated at 50 °C for 1 h. The suspension was allowed to cool to ambient temperature, then partitioned between dichloromethane (250 mL) and saturated aqueous sodium hydrogen carbonate solution (150 mL). The organic phase was washed successively with water (2 × 150 mL) and brine (100 mL), dried (magnesium sulfate), and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with 39:1 dichloromethane/methanol afforded a solid which was triturated with diethyl ether (15 mL), filtered, washed with diethyl ether (20 mL), and dried in vacuo to afford the title product as an orange solid (900 mg, 2.52 mmol, 31%).

LC/MS (C ₁₄ H ₁₇ ClN ₄ O ₃ S) 357 [M+H] ⁺ ; RT 1.15 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 8.04 (s, 1H), 7.87 (dd, J=18.1, 1.1 Hz, 1H), 4.71 (td, J=5.4, 1.1 Hz, 1H), 4.46 (t, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.50 (q, J=5.9 Hz, 2H), 2.43 (dd, J=2.6, 0.9 Hz, 3H), 1.89 (p, J=6.5 Hz, 2H), 1.31 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-hydroxypropyl)amino)-1,3-thiazole-4-carboxylate

The product from Step A (500 mg, 1.4 mmol, 1 equiv) and 2-aminobenzothiazole (240 mg, 1.6 mmol, 1.14 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone)dipalladium(0) (64.2 mg, 0.07 mmol, 0.05 equiv) and xantphos (81.1 mg, 0.14 mmol, 0.1 equiv) in 1,4-dioxane (10 mL), and the mixture was stirred. N,N-Diisopropylethylamine (0.75 mL, 4.2 mmol, 3 equiv) was added, and the mixture was heated in a sealed tube at 150 °C for 24 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with 19:1 dichloromethane/methanol afforded a red/orange gum which was triturated with diethyl ether (15 mL), filtered, washed with diethyl ether (2 x 10 mL), and dried in vacuo to give the title product as an orange solid (490 mg, 0.94 mmol, 67%).

LC/MS (C ₂₁ H ₂₂ N ₆ O ₃ S ₂ ) 471 [M+H] ⁺ ; RT 1.31 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.12 (br s, 1H), 7.98 (s, 1H), 7.92 (br s, 1H), 7.72 (s, 1H), 7.63 (br s, 1H), 7.40 (t, J=7.6 Hz, 1H), 7.23 (t, 1H), 4.74 (t, J=5.4 Hz, 1H), 4.46 (t, J=7.1 Hz, 2H), 4.30 (q, J=7.1 Hz, 2H), 3.54 - 3.46 (m, 2H), 2.48 (s, 3H), 1.90 (p, J=6.5 Hz, 2H), 1.32 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-hydroxypropyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (275 mg, 0.53 mmol, 1 equiv) in a 3:1 mixture of 1,4-dioxane/water (4 mL) was added lithium hydroxide monohydrate (88.3 mg, 2.1 mmol, 4 equiv), and the mixture was stirred at ambient temperature for 18 h. Water (15 mL) was added and the mixture was filtered through celite. The filtrate was acidified with acetic acid to give a solid, which was collected by filtration, washed with water (30 mL), and dried in vacuo to give the title product as a yellow solid (190 mg, 0.43 mmol, 82%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₁₉ H ₁₉ N ₆ O ₃ S ₂ : 443.0955, found: 443.0996.

Example 50: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Step A: ethyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[methyl-[5-methyl-6-[(Z)-[ 3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Alkylation Procedure, starting from Preparation 5g and Preparation 6b as the appropriate phenol, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.67 (s, 1H), 7.47 (d, 1H), 7.44 (t, 1H), 7.33 (dd, 1H), 7.25 (t, 1H), 7.22 (dd, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.26 (q, 2H), 4.15 (t, 2H), 3.77 (s, 3H), 3.72 (t, 2H), 3.49 (brs, 2H), 3.27 ( t, 2H), 2.46 (s, 3H), 2.27 (s, 6H), 2.13 (qn, 2H), 1.29 (t, 3H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.0, 127.2, 123.5, 123.2, 119.2, 117.7, 115.5, 111.9, 72.8, 68.5, 66.7, 60.7, 48.2 , 44.0, 35.3, 31.1, 23.2, 17.9, 17.8, 14.6, -0.9; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₉ H ₄₉ FN ₇ O ₄ S ₂ Si: 790.3035, found: 790.3023.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate ethyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₁ H ₃₁ FN ₇ O ₃ S ₂ : 632.1908, found: 632.1913.

Example 51: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methyl-4-[3-(4-methylpiperazin-1-yl)propyl]pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-[3-(benzyloxy)propyl]-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Synthesis 9ma (500 mg, 1.18 mmol, 1 equiv), ethyl 2-amino-1,3-thiazole-4-carboxylate (284 mg, 1.65 mmol, 1.4 equiv), cesium carbonate (575 mg, 1.76 mmol, 1.5 equiv), xantphos (68.1 mg, 0.12 mmol, 0.1 equiv), and tris(dibenzylideneacetone)dipalladium(0) (53.9 mg, 0.06 mmol, 0.05 equiv). The vessel was evacuated and flushed with nitrogen (x3), and then alpha,alpha,alpha-trifluorotoluene (20 mL) was added. The mixture was sparged with nitrogen (10 min) and then heated at 180 °C for 1 h under microwave irradiation. The reaction mixture was concentrated in vacuo and purified by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-70% ethyl acetate in isoheptane to give the desired product as a yellow solid (336 mg, 0.6 mmol, 51%).

LC/MS (C ₂₈ H ₂₈ N ₆ O ₃ S ₂ ) 561 [M+H] ⁺ ; RT 1.53 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.08 (br s, 1H), 7.95 (d, 1H), 7.88 (br s, 1H), 7.40 - 7.33 (m, 6H), 7.32 - 7.26 (m, 1H), 7.20 (t, 1H), 4.51 (s, 2H), 4.30 (q, J=7.1 Hz, 2H), 3.54 (t, J=6.2 Hz, 2H), 2.96 (t, J=7.8 Hz, 2H), 2.39 (s, 3H), 1.76 (p, 2H), 1.32 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-4-(3-hydroxypropyl)-5-methylpyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

To a cooled solution of the product from Step A (330 mg, 0.59 mmol, 1 equiv) in anhydrous dichloromethane (15 mL) was added boron trichloride (1 M in dichloromethane; 1.18 mL, 1.18 mmol, 2 equiv) dropwise and the mixture was stirred for 3 h. The reaction mixture was cooled to 0 °C and quenched by addition of saturated aqueous sodium bicarbonate solution. The mixture was diluted with dichloromethane and the layers were separated. The organic phase was washed successively with water and brine, dried (magnesium sulfate) and concentrated in vacuo to give the title product (301 mg, 0.64 mmol, >100%) as a mixture with the appropriate methyl ester, which was used directly in the next step without further purification.

LC/MS (C ₂₁ H ₂₂ N ₆ O ₃ S ₂ ) 471 [M+H] ⁺ ; RT 1.295 (LCMS-V-B1).

Step C: Ethyl 2-{[4-(3-hydroxypropyl)-5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl]amino}-1,3-thiazole-4-carboxylate

To a cooled solution of the product from Step B (300 mg, 0.64 mmol, 1 equiv) in dichloromethane (15 mL) were added 2-(trimethylsilyl)ethoxymethyl chloride (0.12 mL, 0.7 mmol, 1.1 equiv), N,N-diisopropylethylamine (0.22 mL, 1.28 mmol, 2 equiv), and DMAP (3.89 mg, 0.03 mmol, 0.05 equiv). The mixture was stirred for 2 h at ambient temperature, then cooled to 0 °C and quenched by addition of aqueous sodium bicarbonate. The layers were separated and the organic phase was washed with water followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 70% ethyl acetate in isoheptane afforded the desired product as an orange solid (105 mg, 0.17 mmol, 27%), which was found to be a mixture with the corresponding methyl ester. The mixture was used directly in the next step without further purification.

LC/MS (C ₂₇ H ₃₆ N ₆ O ₄ SiS ₂ ) 601 [M+H] ⁺ ; RT 1.59 (LCMS-V-B1)

Step_D: Ethyl 2-{[5-methyl-4-(3-oxopropyl)-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl]amino}-1,3-thiazole-4-carboxylate

Dimethyl sulfoxide (29.6 µL, 0.42 mmol, 2.5 equiv) in dichloromethane (5 mL) was charged into an oven-dried flask and the stirred solution was cooled to -78°C. A solution of oxalyl chloride (2 M; 91.5 µl, 0.18 mmol, 1.1 equiv) was added dropwise and the mixture was stirred for 1 h. A solution of the product from Step C (100 mg, 0.17 mmol, 1 equiv) in dichloromethane (5 ml) was added dropwise and the resulting mixture was stirred at -78 °C for 1 h. Triethylamine (0.14 ml, 1 mmol, 6 equiv) was added and the mixture was allowed to warm to 0 °C over 1 h. The reaction mixture was quenched with water (10 ml), diluted with sodium bicarbonate (10 ml) and extracted with dichloromethane (2 x 50 ml). The combined organic extracts were washed with brine (50 ml), dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 50% ethyl acetate in isoheptane afforded the title product as an orange glass (68 mg, 0.11 mmol, 68%), which was found to be a mixture with the corresponding methyl ester, which was used directly in the next step without further purification.

LC/MS (C ₂₇ H ₃₄ N ₆ O ₄ SiS ₂ ) 599 [M+H] ⁺ ; RT 1.62 (LCMS-V-B1).

Step E: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methyl-4-[3-(4-methylpiperazin-1-yl)propyl]pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylate

To a solution of the product from Step D (68 mg, 0.11 mmol, 1 equiv) in 3:1 methanol/acetic acid (8 mL) was added 1-methylpiperazine (25.2 μL, 0.23 mmol, 2 equiv) followed by sodium cyanoborohydride (14.3 mg, 0.23 mmol, 2 equiv) and the mixture was stirred at ambient temperature for 40 min. The reaction mixture was quenched by the addition of 1 M aqueous sodium hydroxide solution and the mixture was extracted with dichloromethane (3 × 50 mL). The combined organic extracts were washed with water followed by brine (50 mL), dried (magnesium sulfate) and concentrated in vacuo. The residue was dissolved in dichloromethane (5 mL), trifluoroacetic acid (1 mL) was added and the mixture was stirred for 1 h. The mixture was diluted with dichloromethane (20 mL) and washed with 1 M aqueous sodium hydroxide solution (20 mL). The organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-20% 7 N methanolic ammonia in dichloromethane gave the title product as an orange glass (40 mg, 0.07 mmol, 64%), which was found to be a mixture with the corresponding methyl ester, which was used directly in the next step without further purification.

LC/MS (C ₂₆ H ₃₂ N ₈ O ₂ S ₂ ) 553 [M+H] ⁺ ; RT 1.17 (LCMS-V-B1).

Step F: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methyl-4-[3-(4-methylpiperazin-1-yl)propyl]pyridazin-3-yl}amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step E (40 mg, 0.07 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 2 M aqueous lithium hydroxide (0.14 mL, 0.14 mmol, 2 equiv) and the mixture was heated at reflux for 1 h. The reaction mixture was concentrated in vacuo, then hydrochloric acid (4 M in 1,4-dioxane) was added and the mixture was stirred for 1 h. The mixture was concentrated in vacuo and triturated with diethyl ether, filtered, washed with diethyl ether and dried in vacuo to give the title product as a dark yellow solid (14.4 mg, 0.03 mmol, 38%) [as the bis-hydrochloric acid salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₄ H ₂₉ N ₈ O ₂ S ₂ : 525.1849, found: 525.1888.

Example 52: 5-{1-[(Adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl) amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-1,3-thiazol-4-carboxylic acid

Step A: Ethyl 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a mixture of Preparation 11c (100 mg, 0.14 mmol, 1 equiv), Preparation 10a (61.6 mg, 0.17 mmol, 1.2 equiv), and potassium carbonate (59.8 mg, 0.43 mmol, 3 equiv) in 4:1 tetrahydrofuran/water (5 mL) was added [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (10.6 mg, 0.01 mmol, 0.1 equiv). The mixture was sparged with nitrogen (10 min) and then heated at 120 °C for 1 h under microwave irradiation. The reaction mixture was diluted with ethyl acetate, washed with water and brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0:50% ethyl acetate in isoheptane afforded the title product as a creamy foam (89.2 mg, 0.11 mmol, 73%).

LC/MS (C ₄₃ H ₅₈ N ₈ O ₄ SiS ₂ ) 843 [M+H] ⁺ ; RT 1.88 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-d6) δ 7.82 (dd, J=7.7, 1.0 Hz, 1H), 7.70 (d, J=1.1 Hz, 1H), 7.52 (s, 1H), 7.48 - 7.40 (m, 2H), 7.23 (ddd, J=8.3, 7.0, 1.5 Hz, 1H), 5.87 (s, 2H), 4.44 (t, J=7.2 Hz, 2H), 4.14 (q, J=7.1 Hz, 2H), 3.78 (s, 2H), 3.72 (t, 2H), 3.44 (t, J=6.0 Hz, 2H), 3.25 (s, 3H), 2.45 (s, 3H), 2.19 (s, 3H), 2.06 - 1.91 (m, 5H), 1.72 - 1.54 (m, 12H), 1.14 (t, J=7.1 Hz, 3H), 0.91 (t, 2H), -0.13 (s, 9H).

Step B: Ethyl 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-1,3-thiazole-4-carboxylate

A solution of the product from Step A (89 mg, 0.11 mmol, 1 equiv) in dichloromethane (5 mL) was cooled in an ice bath and trifluoroacetic acid (0.5 mL, 6.71 mmol, 64 equiv) was added. The mixture was allowed to warm to ambient temperature and stirred overnight. The reaction mixture was diluted with dichloromethane, washed with saturated aqueous sodium bicarbonate, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 5% methanol in dichloromethane afforded the desired product as a yellow glass (63.2 mg, 0.09 mmol, 84%).

LC/MS (C ₃₇ H ₄₄ N ₈ O ₃ S ₂ ) 713 [M+H] ⁺ ; RT 1.48 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 11.10 (br s, 1H), 7.93 (br s, 1H), 7.71 (br s + s, 2H), 7.54 (s, 1H), 7.38 (t, 1H ), 7.25 - 7.16 (m, 1H), 4.44 (t, J=7.2 Hz, 2H), 4.16 (q, J=7.1 Hz, 2H), 3.79 (s, 2H), 3.46 (t, J=6.0 Hz, 2H), 3.26 (s, 3H), 2.48 (s, 3H), 2.20 (s, 3H), 2.07- 1.97 (m, 5H), 1.72 - 1.56 (m, 12H), 1.16 (t, J=7.1 Hz, 3H).

Step C: 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (63 mg, 0.09 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (18.5 mg, 0.44 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature then concentrated in vacuo. The residue was triturated with water and the solids were collected by filtration, washed with water and dried in vacuo to give the title product as a yellow solid (11.5 mg, 0.02 mmol, 19%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₅ H ₄₁ N ₈ O ₃ S ₂ : 685.2738, found: 685.2753.

Example 53: 5-{1-[(Adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-cyclopropylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-[(5-cyclopropyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)(methyl)amino]-1,3-thiazole-4-carboxylate

To a mixture of Preparation 11d (149 mg, 0.23 mmol, 1 equiv), Preparation 10a (96.3 mg, 0.27 mmol, 1.2 equiv), and potassium carbonate (93.4 mg, 0.68 mmol, 3 equiv) in 5:2 tetrahydrofuran/water (7 mL) was added [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (16.5 mg, 0.02 mmol, 0.1 equiv). The mixture was sparged with nitrogen (10 min) and then heated at 120 °C for 1 h under microwave irradiation. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 50% ethyl acetate in isoheptane afforded the title product as a white foam (130 mg, 0.16 mmol, 71%).

LC/MS (C ₄₂ H ₅₄ N ₈ O ₃ SiS ₂ ) 811 [M+H] ⁺ ; RT 1.64 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.81 (dd, J=7.6, 1.0 Hz, 1H), 7.52 (s, 1H), 7.49 - 7.40 (m, 2H), 7.23 (ddd, J=8.3, 7.0, 1.4 Hz, 1H), 7.10 (s, 1H), 5.88 (s, 2H), 4.15 (q, J=7.1 Hz, 2H), 3.80 (s, 3H), 3.79 (s, 2H), 3.70 (t, 2H), 2.72 - 2.62 (m, 1H), 2.18 (s, 3H), 2.01 - 1.92 (m, 3H), 1.71 - 1.54 (m, 12H), 1.21 - 1.13 (m, 5H), 1.12 - 1.07 (m, 2H), 0.90 (t, 3H), -0.13 (s, 9H).

Step B: Ethyl 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-cyclopropylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1 mL, 13.4 mmol, 78.9 equiv) was added to a stirred solution of the product from Step A (138 mg, 0.17 mmol, 1 equiv) in dichloromethane (3 mL) and the mixture was stirred for 18 h. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, washed successively with water and brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 5% methanol in dichloromethane afforded the title product as a yellow glass (104 mg, 0.15 mmol, 90%).

LC/MS (C ₃₆ H ₄₀ N ₈ O ₂ S ₂ ) 681 [M+H] ⁺ ; RT 1.45 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.16 (br s, 1H), 7.76 (br s, 2H), 7.51 (s, 1H), 7.41 - 7.33 (m, 1H), 7.24 - 7.14 (m, 2H), 4.16 (q, J=7.1 Hz, 2H), 3.81 (s, 3H), 3.78 (s, 2H), 2.18 (s, 3H), 2.00 - 1.92 (m, 3H), 1.72 - 1.53 (m, 12H), 1.20 - 1.12 (m, 5H), 1.07 - 1.00 (m, 2H).

Step C: 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-cyclopropylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (104 mg, 0.15 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (32 mg, 0.76 mmol, 5 equiv), and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. The resulting solid was triturated with water, filtered, and dried in vacuo to give the title product as a yellow solid (83.5 mg, 0.13 mmol, 84%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₄ H ₃₇ N ₈ O ₂ S ₂ : 653.2475, found: 653.2475.

Example 54: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(3-hydroxyprop-1-yn-1-yl)-2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Tetrakis(triphenylphosphine)palladium(0) (140.6 mg, 0.12 mmol, 0.1 equiv) under nitrogen atmosphere was added to a stirred solution of the product of Preparation 11c (844 mg, 1.22 mmol, 1 equiv), propargyl alcohol (0.28 mL, 4.86 mmol, 4 equiv), triethylamine (1.02 mL, 7.3 mmol, 6 equiv), and copper(I) iodide (46.4 mg, 0.24 mmol, 0.2 equiv) in dimethylformamide (20 mL), and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature then concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the desired product as a brown gum (671 mg, 1 mmol, 83%).

LC/MS (C ₃₁ H ₄₀ N ₆ O ₅ SiS ₂ ) 669 [M+H] ⁺ ; RT 1.43 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.88 (d, 1H), 7.73 (s, 1H), 7.50 - 7.41 (m, 2H), 7.26 (ddd, J=8.3, 7.0, 1.5 Hz, 1H), 5.88 (s, 2H), 4.45 (t, 2H), 4.29 (q, J=7.1 Hz, 2H), 4.17 (d, 3=6.1 Hz, 2H), 3.72 (t, 2H), 3.42 (t, J=5.9 Hz, 2H), 3.22 (s, 3H), 2.47 (s, 3H), 1.98 (p, J=6.7 Hz, 2H), 1.33 (t, J=7.1 Hz, 3H), 0.92 (t, 2H), -0.11 (s, 9H).

Step B: Ethyl 5-(3-hydroxypropyl)-2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

A suspension of the product from Step A (671 mg, 1 mmol, 1 equiv) in 1:1 ethyl acetate/methanol (30 mL) was charged into a flask containing platinum(IV) oxide (0.02 g, 0.1 mmol, 0.1 equiv) under nitrogen. The mixture was evacuated and backfilled with nitrogen (x3), then evacuated and placed under hydrogen. The mixture was shaken for 3.5 h, then filtered through celite (10 g) and washed with methanol. The solvent was removed in vacuo and the crude product was purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0:60% ethyl acetate in isoheptane to give the title product as a yellow foam (431 mg, 0.64 mmol, 64%).

LC/MS (C ₃₁ H ₄₄ N ₆ O ₅ SiS ₂ ) 673 [M+H] ⁺ ; RT 1.43 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.86 (d, 1H), 7.66 (s, 1H), 7.49 - 7.40 (m, 2H), 7.28 - 7.22 (m, 1H), 5.87 (s, 2H), 4.39 (t, J=7.2 Hz, 2H), 4.27 (q, J=7.1 Hz, 2H), 3.72 (t, 2H), 3.48 (q, 2H), 3.42 (t, 2H), 3.24 (s, 3H), 3.12 (t, 2H), 2.46 (s, 3H), 1.96 (p, J=6.2 Hz, 2H), 1.80 (p, 2H), 1.30 (t, J=7.1 Hz, 3H), 0.92 (t, 2H), -0.11 (s, 9H).

Step C: ethyl 5-(3-iodopropyl)-2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3 -dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazol-4-carboxylate

To a stirred solution of the product from Step B (431 mg, 0.64 mmol, 1 equiv) in 4:1 diethyl ether/acetonitrile (25 mL) were added imidazole (65.4 mg, 0.96 mmol, 1.5 equiv), triphenylphosphine (252 mg, 0.96 mmol, 1.5 equiv), and iodine (244 mg, 0.96 mmol, 1.5 equiv), and the mixture was stirred for 18 h. The reaction mixture was diluted with ethyl acetate and washed successively with 10% aqueous sodium thiosulfate, water, and brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a yellow gum (378 mg, 0.48 mmol, 75%).

LC/MS (C ₃₁ H ₄₃ IN ₆ O ₄ SiS ₂ ) 783 [M+H] ⁺ ; RT 1.78 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.85 (d, 1H), 7.67 (s, 1H), 7.49 - 7.40 (m, 2H), 7.25 (ddd, J=8.2, 6.9, 1.6 Hz, 1H), 5.87 (s, 2H), 4.38 (t, J=7.2 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.72 (t, 2H), 3.42 (t, J=6.0 Hz, 2H), 3.33 (t, 2H), 3.23 (s, 3H), 3.21 - 3.14 (m, 2H), 2.46 (s, 3H), 2.14 (p, J=6.9 Hz, 2H), 1.97 (p, J=6.2 Hz, 2H), 1.32 (t, J=7.1 Hz, 3H), 0.92 (t, 2H), -0.11 (s, 9H).

Step D: Ethyl 5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Sodium hydride (60% in mineral oil; 38.6 mg, 0.96 mmol, 2 equiv) was added to a solution of the product of Preparation 6b (103 mg, 0.53 mmol, 1.1 equiv) in dimethylformamide (8 mL). After 10 min, the reaction mixture was cooled to 0 °C and a solution of the product from Step C (378 mg, 0.48 mmol, 1 equiv) in dimethylformamide (8 mL) was added. The mixture was allowed to warm to ambient temperature and stirred for 5 h. The reaction mixture was quenched with water, acidified with 2 N aqueous hydrochloric acid, and extracted with ethyl acetate (×2). The combined organic extracts were washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded the desired product as a brown foam (115 mg, 0.14 mmol, 28%).

LC/MS (C ₄₂ H ₅₄ FN ₇ O ₅ SiS ₂ ) 848 [M+H] ⁺ ; RT 1.43 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.84 (dd, J=7.5, 1.1 Hz, 1H), 7.67 (s, 1H), 7.49 - 7.41 (m, 2H), 7.39 - 7.34 (m, 1H), 7.28 - 7.23 (m, 2H), 7.19 (t, J=8.6 Hz, 1H), 5.86 (s, 2H), 4.38 (t, J=7.3 Hz, 2H), 4.24 (q, J=7.1 Hz, 2H), 4.16 (t, J=6.1 Hz, 2H), 3.72 (t, J=8.0 Hz, 2H), 3.41 (t, J=5.9 Hz, 2H), 3.33 (s, 2H), 3.31 - 3.25 (m, 2H), 3.24 (s, 3H), 2.35 (s, 2H), 2.48 - 2.41 (m, 9H), 2.13 (p, 2H), 1.97 (p, 2H), 1.29 (t, J=7.1 Hz, 3H), 0.92 (t, 2H), -0.12 (s, 9H).

Step E: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1 mL, 13.4 mmol, 99 equiv) was added to a stirred solution of the product from Step D (115 mg, 0.14 mmol, 1 equiv) in dichloromethane (3 mL), and the mixture was stirred for 18 h. The reaction mixture was diluted with dichloromethane, washed with saturated aqueous sodium bicarbonate, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded the title product as a yellow glass (32.2 mg, 0.04 mmol, 33%).

LC/MS (C ₃₆ H ₄₀ FN ₇ O ₄ S ₂ ) 718 [M+H] ⁺ ; RT 1.32 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.91 (d, J=7.6 Hz, 1H), 7.67 (s, 1H), 7.54 (d, J=8.2 Hz, 1H), 7.44 - 7.37 (m, 1H), 7.31 (dd, 1H), 7.26 - 7.12 (m, 3H), 4.39 (t, J=7.2 Hz, 2H), 4.26 (q, J=7.0 Hz, 2H), 4.16 (t, J=6.1 Hz, 2H), 3.43 (t, J=6.0 Hz, 2H), 3.40 (s, 2H), 3.31 - 3.26 (m, 2H), 3.25 (s, 3H), 2.47 (s, 3H), 2.21 (s, 6H), 2.17 - 2.10 (m, 2H), 1.97 (p, 2H), 1.30 (t, J=7.1 Hz, 3H).

Step F: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step E (32.2 mg, 0.04 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (9.41 mg, 0.22 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. The residue was triturated with water, then centrifuged and the solvent decanted. Toluene was added to the residual solid and the mixture was sonicated, centrifuged and the solvent decanted. Drying in vacuo afforded the title product as a yellow solid (29.6 mg, 0.04 mmol, 96%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₄ H ₃₇ FN ₇ O ₄ S ₂ : 690.2327, found: 690.2318.

Example 55: 2-[[6-[(4-Fluoro-1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl]amino]thiazole-4-carboxylic acid

Step A: N-(6-chloro-4,5-dimethylpyridazin-3-yl)-4-fluoro-1,3-benzothiazol-2-amine

To 158 mg of 6-chloro-4,5-dimethylpyridazin-3-amine (1 mmol, 1 equiv.) and 232 mg of 2-bromo-4-fluoro-1,3-benzothiazole (1 mmol, 1 equiv.) in 8 mL of 1,4-dioxane were added 160 mg of sodium hydride (60 wt %, 4 mmol, 4 equiv.), and the mixture was stirred at reflux for 1 h. After cooling, the reaction mixture was quenched with water and the mixture was extracted with EtOAc. The combined and dried organic phases were concentrated to give 311 mg (101%) of the desired product.

LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₁₃ H ₁₁ ClFN ₄ S: 309, found: 309.

Step B: Ethyl 2-[[6-[(4-fluoro-1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl]amino]thiazole-4-carboxylate

A mixture of 300 mg of the product from Step A (0.97 mmol, 1 equiv), 167 mg of ethyl 2-aminothiazole-4-carboxylate (0.97 mmol, 1 equiv), 33 mg of Pd ₂ (dba) ₃ (0.036 mmol, 0.04 equiv), 53 mg of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (0.092 mmol, 0.1 equiv) and 0.23 mL of DIPEA (2 equiv) in 8 mL of 1,4-dioxane was stirred at 160 °C in a microwave reactor for 0.75 h. After cooling, the crude product was purified by reversed-phase preparative chromatography to give 110 mg (26%) of the desired product.

¹ H NMR (400 MHz, DMSO-d6) δ ppm 11.17 (s, 1H), 11.05 (s, 1H), 7.96 (s, 1H), 7.81 (m, 1H), 7.24 (m, 1H), 7.22 (m, 1H), 4.29 (q, 2H), 2.39/2.37 (s+s, 6H), 1.31 (t, 3H).

Step C: 2-[[6-[(4-fluoro-1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl]amino]thiazole-4-carboxylic acid

A mixture of the product from Step B, LiOH× _H2O , water and 1,4-dioxane was stirred under reflux for 9 h. After cooling and concentration, 1 N HCl was added and the precipitate was filtered off to give the desired product.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁₇ H ₁₄ FN ₆ O ₂ S ₂ : 417.0604, found: 417.0595.

Example 56: 5-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)thiophene-2-carboxylic acid

Step A: tert-butyl N-[(tert-butoxy)carbonyl]-N-(6-chloro-4-methylpyridazin-3-yl)carbamate

To a solution of di-tert-butyl dicarbonate (5.7 g, 26.1 mmol, 3 equiv) in dichloromethane (40 mL) was added 6-chloro-4-methylpyridazin-3-amine (1.25 g, 8.71 mmol, 1 equiv) followed by 4-dimethylaminopyridine (53.2 mg, 0.44 mmol, 0.05 equiv) and the mixture was stirred overnight. The reaction mixture was concentrated in vacuo and purified by flash column chromatography (50 g silica gel) eluting with 2:3 ethyl acetate/heptane to give a yellow solid. Trituration with heptane (15 mL) gave a solid which was collected by filtration, washed with heptane (2 x 15 mL) and dried in vacuo to give the title product as a pale yellow solid (1.85 g, 5.38 mmol, 62%).

LC/MS (C ₁₅ H ₂₂ ClN ₃ O ₄ ) 188 [M-Boc-tBu+3H] ⁺ ; RT 1.28 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.43 (d, 1H), 2.27 (d, 3H), 1.40 (s, 9H).

Step B: Methyl 5-[(6-{bis[(tert-butoxy)carbonyl]amino}-5-methylpyridazin-3-yl)amino]thiophene-2-carboxylate

Tris(dibenzylideneacetone)dipalladium(0) (107 mg, 0.12 mmol, 0.05 equiv) under nitrogen was added to a stirred solution of the product from Step A (800 mg, 2.33 mmol, 1 equiv), methyl 5-aminothiophene-2-carboxylate (439 mg, 2.79 mmol, 1.2 equiv), N,N-diisopropylethylamine (1.16 mL, 6.98 mmol, 3 equiv), and xantphos (135 mg, 0.23 mmol, 0.1 equiv) in 1,4-dioxane (20 mL), and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded a material that was triturated with diethyl ether and the solids were then collected by filtration to give the title product as a beige solid (442 mg, 0.95 mmol, 41%).

LC/MS (C ₂₁ H ₂₈ N ₄ O ₆ S) 465 [M+H] ⁺ ; RT 1.10 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.22 (s, 1H), 7.64 (d, J=4.2 Hz, 1H), 7.17 (s, 1H), 6.74 (d, J=4.3 Hz, 1H), 3.78 (s, 3H), 2.17 (s, 3H), 1.39 (s, 18H).

Step C: Methyl 5-[(6-{bis[(tert-butoxy)carbonyl]amino}-5-methylpyridazin-3-yl)(methyl)amino]thiophene-2-carboxylate

Sodium hydride (60% dispersion; 60.9 mg, 1.52 mmol, 1.6 equiv) was added to a stirred solution of the product from Step B (442 mg, 0.95 mmol, 1 equiv) in dimethylformamide (10 mL). After 15 min, iodomethane (0.12 mL, 1.9 mmol, 2 equiv) was added and the mixture was stirred at ambient temperature for 5 h. The reaction mixture was diluted with ethyl acetate, then washed with water (x2) followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0:100% ethyl acetate in isoheptane afforded the title product as a cream-colored solid (295 mg, 0.62 mmol, 65%).

LC/MS (C ₂₂ H ₃₀ N ₄ O ₆ S) 479 [M+H] ⁺ ; RT 1.23 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.73 (s, 1H), 7.69 (d, 1H), 6.92 (d, J=4.4 Hz, 1H), 3.79 (s, 3H), 3.66 (s, 3H), 2.22 (d, J=0.9 Hz, 3H), 1.40 (s, 18H).

Step D: Methyl 5-[(6-amino-5-methylpyridazin-3-yl)(methyl)amino]thiophene-2-carboxylate

A solution of the product from Step C (343 mg, 0.72 mmol, 1 equiv) in dichloromethane (8 mL) was cooled in an ice bath, then trifluoroacetic acid (2 mL, 26.8 mmol, 37 equiv) was added. The mixture was allowed to warm to ambient temperature and stirred for 18 h. The solvent was removed in vacuo, then the residue was dissolved in methanol and loaded onto a methanol-conditioned SCX-2 cartridge (5 g). The cartridge was washed with methanol, then eluted with 3.5 N methanolic ammonia. The solvent was removed in vacuo, and the resulting solid was triturated with diethyl ether and filtered to afford the desired product as a cream-colored solid (142 mg, 0.51 mmol, 71%).

LC/MS (C ₁₂ H ₁₄ N ₄ O ₂ S) 279 [M+H] ⁺ ; RT 0.67 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.59 (d, J=4.4 Hz, 1H), 7.35 (s, 1H), 6.58 (d, J=4.4 Hz, 1H), 6.00 (s, 2H), 3.75 (s, 3H), 3.50 (s, 3H), 2.16 (s, 3H).

Step E: methyl 5-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)thiophene-2-carboxylate

Tris(dibenzylideneacetone)dipalladium(0) (23.4 mg, 0.03 mmol, 0.05 equiv) under nitrogen atmosphere was added to a stirred solution of the product from Step D (142 mg, 0.51 mmol, 1 equiv), 2-bromo-1,3-benzothiazole (131 mg, 0.61 mmol, 1.2 equiv), N,N-diisopropylethylamine (0.25 mL, 1.53 mmol, 3 equiv), and xantphos (29.5 mg, 0.05 mmol, 0.1 equiv) in 1,4-dioxane (5 mL), and the mixture was heated at 100 °C for 18 h. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 6% methanol in dichloromethane afforded the desired product as a brown solid (158 mg, 0.38 mmol, 75%).

LC/MS (C ₁₉ H ₁₇ N ₅ O ₂ S ₂ ) 412 [M+H] ⁺ ; RT 1.18 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 11.04 (br s, 1H), 8.01 (br s, 1H), 7.70 - 7.63 (m, 3H), 7.43 - 7.35 (m, 1H), 7.27 - 7.17 ( m, 1H), 6.80 (d, J=4.4 Hz, 1H), 3.81 (s, 3H), 3.63 (s, 3H), 2.46 (s, 3H).

Step F: 5-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)thiophene-2-carboxylic acid

To a suspension of the product from Step E (158 mg, 0.38 mmol, 1 equiv) in 1,4-dioxane (10 mL) was added lithium hydroxide monohydrate (161 mg, 3.84 mmol, 10 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and the resulting suspension was centrifuged, decanted and dried in vacuo to give the desired product as a yellow solid (90.5 mg, 0.23 mmol, 59%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₁₈ H ₁₄ N ₅ O ₂ S ₂ : 396.0594, found: 396.0576.

Example 57: 2-[[6-[(5,6-Difluoro-1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl]amino]thiazole-4-carboxylic acid

Step A: N-(6-chloro-4,5-dimethylpyridazin-3-yl)-5,6-difluoro-1,3-benzothiazol-2-amine

To 158 mg of 6-chloro-4,5-dimethylpyridazin-3-amine (1 mmol, 1 equiv.) and 250 mg of 2-bromo-5,6-difluoro-1,3-benzothiazole (1 mmol, 1 equiv.) in 8 mL of 1,4-dioxane were added 160 mg of sodium hydride (60 wt %, 4 mmol, 4 equiv.), and the mixture was stirred under reflux for 1 h. After cooling, the reaction mixture was quenched with water and the mixture was extracted with EtOAc. The combined and dried organic phases were concentrated to give 300 mg (92%) of the desired product.

LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₁₃ H ₁₀ ClF ₂ N ₄ S: 327, found: 327.

Step B: Ethyl 2-[[6-[(5,6-difluoro-1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl]amino]thiazole-4-carboxylate

A mixture of 300 mg of the product from Step A (0.9 mmol, 1 equiv), 155 mg of ethyl 2-aminothiazole-4-carboxylate (0.9 mmol, 1 equiv), 33 mg of Pd ₂ (dba) ₃ (0.036 mmol, 0.04 equiv), 53 mg of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (0.092 mmol, 0.1 equiv) and 0.23 mL of DIPEA (2 equiv) in 8 mL of 1,4-dioxane was stirred at 200 °C in a microwave reactor for 1 h. After cooling, the crude product was purified by reversed-phase preparative chromatography to yield 110 mg (26%) of the desired product.

LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₁₉ H ₁₇ F ₂ N ₆ O ₂ S ₂ : 463, found: 463.

Step C: 2-[[6-[(5,6-difluoro-1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl]amino]thiazole-4-carboxylic acid

A mixture of the product from Step B, LiOH× _H2O , water and 1,4-dioxane was stirred at reflux for 9 h. After cooling, the crude product was purified by reverse phase preparative chromatography to give the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₇ H ₁₃ F ₂ N ₆ O ₂ S ₂ : 435.0509, found: 435.0506.

Example 58: 2-[[6-[(5-Fluoro-1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl]amino]thiazole-4-carboxylic acid

Step A: N-(6-chloro-4,5-dimethylpyridazin-3-yl)-5-fluoro-1,3-benzothiazol-2-amine

To 158 mg of 6-chloro-4,5-dimethylpyridazin-3-amine (1 mmol, 1 equiv.) and 348 mg of 2-bromo-5-fluoro-1,3-benzothiazole (1.5 mmol, 1.5 equiv.) in 20 mL of 1,4-dioxane was added 160 mg of sodium hydride (60 wt %, 4 mmol, 4 equiv.), and the mixture was stirred at reflux for 1 h. After cooling, the reaction mixture was quenched with 2 mL of EtOH, concentrated, and treated with 20 mL of water. The precipitated solid was filtered off to give 300 mg (97%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.81 (dd, 1 N), 7.29 (dd, 1 N), 7.00 (td, 1 N), 2.34 (s, 3 N), 2.29 (s, 3 N); ¹³ C NMR (125 MHz DMSO-d ₆ ) δ ppm 162.2, 161.9, 154.1, 152.0, 145.5, 137.4, 131.1, 125.8, 123.3, 110.6, 103.5, 15.7, 13.3; LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₁₃ H ₁₁ ClFN ₄ S: 309.8, found: 309 and 307 [M-H] ^- .

Step B: Ethyl 2-[[6-[(5-fluoro-1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl]amino]thiazole-4-carboxylate

A mixture of 300 mg of the product from Step A (0.97 mmol, 1 equiv), 167 mg of ethyl 2-aminothiazole-4-carboxylate (0.97 mmol, 1 equiv), 36 mg of Pd ₂ (dba) ₃ (0.039 mmol, 0.04 equiv), 56 mg of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (0.097 mmol, 0.1 equiv) and 0.34 mL of DIPEA (2 equiv) in 10 mL of 1,4-dioxane was stirred at 200 °C in a microwave reactor for 1 h. After cooling, the crude product was purified by reversed-phase preparative chromatography to yield 150 mg (35%) of the desired product.

LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₁₉ H ₁₈ FN ₆ O ₂ S ₂ : 445.5, found: 445 and 443 [M-H] ^- .

Step C: 2-[[6-[(5-fluoro-1,3-benzothiazol-2-yl)amino]-4,5-dimethylpyridazin-3-yl]amino]thiazole-4-carboxylic acid

A mixture of 150 mg of the product from Step B (0.338 mmol, 1 equiv), 28 mg of LiOH× _H2O (0.67 mmol, 2 equiv) and 10 drops of water in 10 mL of 1,4-dioxane was stirred under reflux for 3 h. After cooling and concentration, the crude product was purified by reverse-phase preparative chromatography to yield 112 mg (79%) of the desired product.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁₇ H ₁₄ FN ₆ O ₂ S ₂ : 417.0604, found: 417.0598.

Example 59: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[3-(2-fluorophenoxy)propyl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Sodium hydride (60% in mineral oil; 19.5 mg, 0.49 mmol, 2 equiv) was added to a solution of 2-fluorophenol (0.03 mL, 0.29 mmol, 1.2 equiv) in dimethylformamide (4 mL). After 15 min, the reaction mixture was cooled to 0 °C and a solution of the product of Preparation 5g (177 mg, 0.24 mmol, 1 equiv) in dimethylformamide (3 mL) was added. The mixture was allowed to warm to ambient temperature and stirred for 18 h. The reaction mixture was quenched by addition of water, acidified with 2 N aqueous hydrochloric acid and extracted with ethyl acetate (×2). The combined organic extracts were washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% methanol in dichloromethane afforded the desired product as a beige foam (144 mg, 0.2 mmol, 83%).

LC/MS (C ₃₄ H ₄₁ FN ₆ O ₄ SiS ₂ ) 709 [M+H] ⁺ ; RT 1.62 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.84 (dd, J=7.6, 1.0 Hz, 1H), 7.67 (d, J=1.1 Hz, 1H), 7.49 - 7.40 (m, 2H), 7.28 - 7.08 (m, 4H), 6.96 - 6.89 (m, 1H), 5.86 (s, 2H), 4.26 (q, J=7.1 Hz, 2H), 4.13 (t, J=6.2 Hz, 2H), 3.77 (s, 3H), 3.72 (t, 2H), 3.31 -3.25 (m, 2H), 2.45 (d, J=1.0 Hz, 3H), 2.17 - 2.08 (m, 2H), 1.29 (t, J=7.1 Hz, 3H), 0.92 (t, 2H), -0.12 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1 mL, 13.4 mmol, 66 equiv) was added to a stirred solution of the product from Step A (144 mg, 0.2 mmol, 1 equiv) in dichloromethane (3 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5 - 95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow solid (71 mg, 0.12 mmol, 61%).

LC/MS (C ₂₈ H ₂₇ FN ₆ O ₃ S ₂ ) 579 [M+H] ⁺ ; RT 1.37 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.07 (br s, 1H), 7.92 (s, 1H), 7.69 (s, 1H), 7.61 (br s, 1H), 7.40 (t, J=7.6 Hz, 1H), 7.32 - 7.08 (m, 4H), 6.98 - 6.90 (m, 1H), 4.27 (q, J=7.1 Hz, 2H), 4.13 (t, J=6.2 Hz, 2H), 3.77 (s, 3H), 3.34 - 3.24 (m, 2H), 2.47 (s, 3H), 2.14 (p, J=6.2 Hz, 2H), 1.30 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (71 mg, 0.12 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (25.7 mg, 0.61 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. The residue was triturated with water and the solids were collected by filtration. The solid was further triturated with diethyl ether, filtered and dried in vacuo to give the title product as a yellow solid (49 mg, 0.09 mmol, 73%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₆ H ₂₄ FN ₆ O ₃ S ₂ : 551.1330, found: 551.1335.

Example 60: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-methoxypropyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(3-methoxyprop-1-yn-1-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Tetrakis(triphenylphosphine)palladium(0) (36.4 mg, 0.04 mmol, 0.1 equiv) under nitrogen atmosphere was added to a stirred solution of the product of Preparation 11b (200 mg, 0.31 mmol, 1 equiv), methyl propargyl ether (0.06 mL, 0.76 mmol, 2.4 equiv), triethylamine (0.26 mL, 1.88 mmol, 6 equiv), and copper(I) iodide (12 mg, 0.06 mmol, 0.2 equiv) in dimethylformamide (5 mL), and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature then concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 100% ethyl acetate in isoheptane afforded the title product as a cream-colored solid (78 mg, 0.12 mmol, 40%).

LC/MS (C ₂₉ H ₃₆ N ₆ O ₄ SiS ₂ ) 625 [M+H] ⁺ ; RT 1.56 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.86 (d, J=7.7 Hz, 1H), 7.74 (s, 1H), 7.51 - 7.41 (m, 2H), 7.26 (td, J=7.6, 1.5 Hz, 1H), 5.87 (s, 2H), 4.43 (s, 2H), 4.31 (q, J=7.1 Hz, 2H), 3.82 (s, 3H), 3.72 (t, J=8.0 Hz, 2H), 3.38 (s, 3H), 2.47 (s, 3H), 1.32 (t, J=7.1 Hz, 3H), 0.91 (dd, J=10.7, 5.4 Hz, 2H), 0.00 (s, 9H).

Step B: Ethyl 5-(3-methoxypropyl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

A suspension of the product from Step A (78 mg, 0.12 mmol, 1 equiv) in 1:1 ethyl acetate/methanol (8 mL) was charged to a flask containing platinum(IV) oxide (2.83 mg, 0.01 mmol, 0.1 equiv) under nitrogen. The flask was evacuated and backfilled with nitrogen (x3), then evacuated, flushed with hydrogen, and shaken overnight. The mixture was filtered through celite (2.5 g), eluted with methanol, and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% methanol in dichloromethane afforded the desired product as a white foam (56.1 mg, 0.09 mmol, 71%).

LC/MS (C ₂₉ H ₄₀ N ₆ O ₄ SiS ₂ ) 629 [M+H] ⁺ ; RT 1.54 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.84 (dd, J=7.7, 1.0 Hz, 1H), 7.66 (d, J=1.1 Hz, 1H), 7.49 - 7.41 (m, 2H), 7.25 (ddd, J=8.4, 6.9, 1.6 Hz, 1H), 5.86 (s, 2H), 4.28 (q, J=7.1 Hz, 2H), 3.77 (s, 3H), 3.72 (t, 2H), 3.38 (t, J=6.3 Hz, 2H), 3.26 (s, 3H), 3.189 - 3.09 (m, 2H), 2.46 (d, J=1.1 Hz, 3H), 1.86 (p, 1H), 1.31 (t, J=7.1 Hz, 3H), 0.97 - 0.87 (m, 2H), 0.00 (s, 9H).

Step C: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-methoxypropyl)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1 mL, 13.4 mmol, 150 equiv) was added to a stirred solution of the product from Step B (56 mg, 0.09 mmol, 1 equiv) in dichloromethane (3 mL) and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate and the organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 6% methanol in dichloromethane afforded the title product as a yellow glass (40 mg, 0.08 mmol, 90%).

LC/MS (C ₂₃ H ₂₆ N ₆ O ₃ S ₂ ) 499 [M+H] ⁺ ; RT 1.25 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 11.11 (br s, 1H), 7.93 (br s, 1H), 7.69 (s, 1H), 7.58 (br s, 1H), 7.39 (t, J=7.5 Hz, 1H), 7.22 (t, 1H), 4.29 (q, J=7.1 Hz, 2H), 3.77 (s, 3H), 3.39 (t, J=6.3 Hz, 2H), 3.27 (s, 3H), 3.18 - 3.10 (m, 2H), 2.47 (s, 3H), 1.94 -1.82 (m, 2H), 1.33 (t, J=7.1 Hz, 3H).

Step D: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-methoxypropyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step C (40 mg, 0.08 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (16.8 mg, 0.4 mmol, 5 equiv) and the mixture was heated at reflux for 5 h. The reaction mixture was allowed to cool to ambient temperature, concentrated in vacuo, triturated with water and the solids collected by filtration. The solid was suspended in 1,4-dioxane (4 mL) and then hydrochloric acid (4 M in 1,4-dioxane; 0.5 mL) was added. The suspension was stirred at ambient temperature for 2 h, then centrifuged and the solvent removed by decantation. The solid was washed with 1,4-dioxane (2 x 2 mL), then centrifuged again and the solvent removed by decantation. The solid was finally triturated with water, filtered and dried in vacuo to give the title product as an off-white solid (28.4 mg, 0.06 mmol, 75%) [as the hydrochloric acid salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₁ H ₂₃ N ₆ O ₃ S ₂ : 471.1268, found: 471.1271.

Example 61: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(cyclohexyloxy)propyl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[3-(cyclohexyloxy)prop-1-yn-1-yl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Tetrakis(triphenylphosphine)palladium(0) (36.4 mg, 0.04 mmol, 0.1 equiv) under nitrogen atmosphere was added to a stirred solution of the product of Preparation 11b (200 mg, 0.31 mmol, 1 equiv), (prop-2-yn-1-yloxy)cyclohexane (120 mg, 0.86 mmol, 2.76 equiv), triethylamine (0.26 mL, 1.88 mmol, 6 equiv), and copper(I) iodide (12 mg, 0.06 mmol, 0.2 equiv) in dimethylformamide (6 mL), and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature, then diluted with ethyl acetate, washed with water (x2) followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 70% ethyl acetate in isoheptane afforded the title product as a cream solid (50 mg, 0.07 mmol, 23%).

LC/MS (C ₃₄ H ₄₄ N ₆ O ₄ SiS ₂ ) 693 [M+H] ⁺ ; RT 1.66 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.85 (d, J=7.7 Hz, 1H), 7.75 (d, J=1.1 Hz, 1H), 7.52 - 7.39 (m, 2H), 7.25 (td, J=7.5, 1.4 Hz, 1H), 5.88 (s, 2H), 4.48 (s, 2H), 4.30 (q, J=7.1 Hz, 2H), 3.82 (s, 3H), 3.72 (t, 2H), 3.57 - 3.49 (m, 1H), 2.48 (d, J=1.0 Hz, 3H), 1.95 - 1.86 (m, 2H), 1.73 - 1.65 (m, 2H), 1.55 - 1.46 (m, 2H), 1.32 (t, 3H), 1.32 - 1.22 (m, 4H), 0.92 (dd, J=8.5, 7.5 Hz, 2H), 0.00 (s, 9H).

Step B: Ethyl 5-{3-(cyclohexyloxy)propyl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

A suspension of the product from Step A (50 mg, 0.07 mmol, 1 equiv) in 1:1 ethyl acetate/methanol (6 mL) was charged to a flask containing platinum(IV) oxide (21.6 mg, 0.01 mmol, 0.1 equiv) under nitrogen. The flask was evacuated and backfilled with nitrogen (x3), then evacuated, flushed with hydrogen, and shaken for 18 h. The reaction mixture was filtered through celite (2.5 g), eluted with ethyl acetate and methanol, and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the desired product as a colorless glass (42.2 mg, 0.06 mmol, 84%).

LC/MS (C ₃₄ H ₄₈ N ₆ O ₄ SiS ₂ ) 697 [M+H] ⁺ ; RT 1.71 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.82 (d, J=7.5 Hz, 1H), 7.67 (d, J=1.1 Hz, 1H), 7.50-7.41 (m, 2H), 7.28-7.23 (m , 1H), 5.87 (s, 2H), 4.28 (q, J=7.1 Hz, 2H), 3.77 (s, 3H), 3.72 (t, 2H), 3.45 (t, J=6.1 Hz, 2H), 3.27-3.20 (m, 1H), 3.18-3.11 ( m, 2H), 2.46 (d, J=1.0 Hz, 3H), 1.90-1.79 (m, 4H), 1.72-1.62 (m, 2H), 1.51-1.42 (m, 2H), 1.31 (t, J=7.1 Hz, 3H), 1.28-1.17 (m, 5H), 0.96-0.89 (m, 2H), 0.00 ( s, 9H).

Step C: Ethyl 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(cyclohexyloxy)propyl]-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (0.6 mL, 8.06 mmol, 134 equiv) was added to a stirred solution of the product from Step B (42 mg, 0.06 mmol, 1 equiv) in dichloromethane (3 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow glass (19.6 mg, 0.03 mmol, 57%).

LC/MS (C ₂₈ H ₃₄ N ₆ O ₃ S ₂ ) 567 [M+H] ⁺ ; RT 1.43 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.085 (br s, 1H), 7.90 (s, 1H), 7.68 (s, 1H), 7.60 (br s, 1H), 7.38 (t, 1H), 7.22 (t, 1H), 4.29 (q, J=7.1 Hz, 2H), 3.77 (s, 3H), 3.46 (t, J=6.2 Hz, 2H), 3.28-3.20 (m, 1H), 3.15 (t, 2H), 2.47 (s, 3H), 1.92-1.81 (m, 4H), 1.73-1.62 (m, 2H), 1.52-1.43 (m, 2H), 1.32 (t, 3H), 1.29-1.15 (m, 4H).

Step D: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-(cyclohexyloxy)propyl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step C (19.6 mg, 0.03 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (7.26 mg, 0.17 mmol, 5 equiv) and the mixture was heated at 100 °C for 6.5 h, then allowed to cool to ambient temperature and concentrated in vacuo. The residue was triturated with water, filtered, and dried in vacuo to give the title product as a yellow solid (11 mg, 0.02 mmol, 59%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₆ H ₃₁ N ₆ O ₃ S ₂ : 539.1894, found: 539.1895.

Example 62: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-cyclopropylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[(5-cyclopropyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)(methyl)amino]-5-(3-hydroxyprop-1-yn-1-yl)-1,3-thiazole-4-carboxylate

Tetrakis(triphenylphosphine)palladium(0) (422 mg, 0.36 mmol, 0.1 equiv) under nitrogen atmosphere was added to a stirred solution of the product of Preparation 11d (2.42 g, 3.65 mmol, 1 equiv), propargyl alcohol (0.86 mL, 14.6 mmol, 4 equiv), triethylamine (3.04 mL, 21.9 mmol, 6 equiv), and copper(I) iodide (139 mg, 0.72 mmol, 0.2 equiv) in dimethylformamide (50 mL), and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature then concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the title product as a cream-colored solid (0.91 g, 1.43 mmol, 39%).

LC/MS (C ₃₀ H ₃₆ N ₆ O ₄ SiS ₂ ) 637 [M+H] ⁺ ; RT 1.44 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.18 (br s, 1H), 7.87 (d, 1H), 7.50-7.40 (m, 2H), 7.26 (td, 1H), 7.11 (s, 1H), 6.00 (d, J=10.2 Hz, 2H), 5.88 (s, 2H), 5.43 (t, 1H), 4.39 (d, J=5.9, 0.8 Hz, 2H), 4.30 (q, J=7.1 Hz, 2H), 3.82 (s, 3H), 3.75-3.67 (m, 2H), 2.72-2.62 (m, 1H), 1.32 (t, J=7.1 Hz, 3H), 1.22-1.12 (m, 2H), 1.12-1.06 (m, 2H), 0.94-0.85 (m, 2H), 0.00 (s, 9H).

Step B: Ethyl 2-[(5-cyclopropyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)(methyl)amino]-5-(3-hydroxypropyl)-1,3-thiazole-4-carboxylate

A suspension of the product from Step A (913 mg, 1.43 mmol, 1 equiv) in 1:1 ethyl acetate/methanol (40 mL) was charged to a flask containing platinum(IV) oxide (32.6 mg, 0.14 mmol, 0.1 equiv) under nitrogen. The flask was evacuated and backfilled with nitrogen (x3), then evacuated, flushed with hydrogen, and shaken for 3.5 h. The reaction mixture was filtered through celite (10 g), eluted with methanol, and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-70% ethyl acetate in isoheptane afforded the title product as a creamy foam (762 mg, 1.19 mmol, 83%).

LC/MS (C ₃₀ H ₄₀ N ₆ O ₄ SiS ₂ ) 641 [M+H] ⁺ ; RT 1.44 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.85 (dd, J=7.5, 1.0 Hz, 1H), 7.49-7.39 (m, 2H), 7.28-7.22 (m, 1H), 7.07 (s, 1H) , 5.87 (s, 2H), 4.56 (t, J=5.1, 3.1 Hz, 1H), 4.28 (q, J=7.1 Hz, 3H), 3.76 (s, 3H), 3.75-3.66 (m, 2H), 3.48 (q, 2H), 3.17-3.07 (m , 2H), 2.71-2.62 (m, 1H), 1.79 (p, 2H), 1.31 (t, J=7.1 Hz, 3H), 1.19-1.12 (m, 2H), 1.11-1.04 (m, 2H), 0.94-0.86 (m, 2H), 0.00 (s, 9H).

Step C: ethyl 2-[(5-cyclopropyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene] amino}pyridazin-3-yl)(methyl)amino]-5-(3-iodopropyl)-1,3-thiazol-4-carboxylate

To a stirred solution of the product from Step B (762 mg, 1.19 mmol, 1 equiv) in 10:3 diethyl ether/acetonitrile (26 mL) were added imidazole (122 mg, 1.78 mmol, 1.5 equiv), triphenylphosphine (468 mg, 1.78 mmol, 1.5 equiv), and iodine (453 mg, 1.78 mmol, 1.5 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with ethyl acetate, washed with 10% aqueous sodium thiosulfate solution followed by water and then brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a creamy foam (613 mg, 0.82 mmol, 69%).

LC/MS (C ₃₀ H ₃₉ IN ₆ O ₃ SiS ₂ ) 751 [M+H] ⁺ ; RT 1.62 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.84 (dd, J=7.7, 1.0 Hz, 1H), 7.49-7.38 (m, 2H), 7.25 (ddd, J=8.2, 7.0, 1.5 Hz, 1H) , 7.07 (s, 1H), 5.88 (s, 2H), 4.30 (q, J=7.1 Hz, 2H), 3.75 (s, 3H), 3.74-3.65 (m, 2H), 3.38-3.29 (m, 2H), 3.17 (t, J=6.8 Hz, 2H ), 2.70-2.60 (m, 1H), 2.14 (p, 2H), 1.32 (t, J=7.1 Hz, 3H), 1.20-1.11 (m, 2H), 1.10-1.04 (m, 2H), 0.95-0.85 (m, 2H), 0.00 (s, 9H).

Step D: Ethyl 2-[(5-cyclopropyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)(methyl)amino]-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylate

Sodium hydride (60% in mineral oil; 65.3 mg, 1.63 mmol, 2 equiv) was added to a solution of the product of Preparation 6b (189 mg, 0.98 mmol, 1.2 equiv) in dimethylformamide (10 mL). After 10 min, the reaction mixture was cooled to 0 °C and a solution of the product from Step C (613 mg, 0.82 mmol, 1 equiv) in dimethylformamide (10 mL) was added. The mixture was allowed to warm to ambient temperature and stirred for 3.5 h. The reaction mixture was quenched by addition of water, acidified with 2 N aqueous hydrochloric acid, and extracted with dichloromethane (×2). The combined organic extracts were washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded a solid, which was further purified by preparative HPLC (HPLC-V-A1 method) to afford the title product as an off-white solid (283 mg, 0.35 mmol, 43%).

LC/MS (C ₄₁ H ₅₀ FN ₇ O ₄ SiS ₂ ) 816 [M+H] ⁺ ; RT 1.41 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 8.35 (s, 1H), 7.82 (d, 1H), 7.48-7.39 (m, 2H), 7.33-7.11 (m, 3H), 7.06 (s, 1H) , 5.86 (s, 2H), 4.25 (q, J=7.1 Hz, 2H), 4.13 (t, J=6.2 Hz, 2H), 3.75 (s, 3H), 3.70 (t, 2H), 3.37 (s, 2H), 3.25 (t, J=7.6 Hz, 2H), 2.69-2.59 (m, 1H), 2.19 (s, 6H), 2.10 (p, J=6.3 Hz, 2H), 1.28 (t, J=7.1 Hz, 3H), 1.19-1.11 (m, 2H), 1.10-1.02 (m, 2H), 0.89 (dd, J=8.7, 7.4 Hz, 2H), 0.00 (s , 9H).

Step E: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-cyclopropylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (4 mL, 53.7 mmol, 155 equiv) was added to a stirred solution of the product from Step D (283 mg, 0.35 mmol, 1 equiv) in dichloromethane (10 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow glass (56.5 mg, 0.08 mmol, 24%).

LC/MS (C ₃₅ H ₃₆ FN ₇ O ₃ S ₂ ) 686 [M+H] ⁺ ; RT 1.12 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.71 (br s, 1H), 7.89 (d, 1H), 7.50 (d, J=8.0 Hz, 1H), 7.39 (ddd, J=8.2, 7.3, 1.3 Hz, 1H), 7.31 (dd, J=12.0, 2.0 Hz, 1H), 7.27-7.10 (m, 4H), 4.26 (q, J=7.1 Hz, 2H), 4.15 (t, J=6.2 Hz, 2H), 3.77 (s, 3H), 3.40 (s, 2H), 3.30-3.24 (m, 2H), 2.49-2.45 (m, 1H), 2.21 (s, 6H), 2.13 (p, J=6.3 Hz, 2H), 1.30 (t, J=7.1 Hz, 2H), 1.20-1.10 (m, 2H), 1.06-0.99 (m, 2H).

Step F: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-cyclopropylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step E (56.5 mg, 0.08 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (17.3 mg, 0.41 mmol, 5 equiv) and the mixture was heated at 100 °C for 6.5 h. The residue was triturated with water, filtered, and dried in vacuo to give the title product as a yellow solid (46.5 mg, 0.07 mmol, 86%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₃ H ₃₃ FN ₇ O ₃ S ₂ : 658.2065, found: 658.2070.

Example 63: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-{methyl(5-methyl-6-{[(2Z)-3-{{2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-(3-phenoxyprop-1-yn-1-yl)-1,3-thiazole-4-carboxylate

Tetrakis(triphenylphosphine)palladium(0) (85.2 mg, 0.08 mmol, 0.1 equiv) under nitrogen atmosphere was added to a stirred solution of the product of Preparation 11b (469 mg, 0.74 mmol, 1 equiv), phenyl propargyl ether (0.38 mL, 2.96 mmol, 4 equiv), triethylamine (0.62 mL, 4.42 mmol, 6 equiv), and copper(I) iodide (28.1 mg, 0.14 mmol, 0.2 equiv) in dimethylformamide (12 mL), and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the desired product as a brown foam (296 mg, 0.43 mmol, 58%).

LC/MS (C ₃₄ H ₃₈ N ₆ O ₄ SiS ₂ ) 687 [M+H] ⁺ ; RT 1.57 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.87 (dd, J=7.8, 1.0 Hz, 1H), 7.74 (d, J=1.1 Hz, 1H), 7.51-7.42 (m, 2H), 7.38-7.33 (m, 2H), 7.26 (ddd, J=9.2, 5.5, 1.5 Hz, 1H), 7.10-7.06 (m, 2H), 7.00 (tt, J=7.4, 1.1 Hz, 1H), 5.87 (s, 2H), 5.15 (s, 2H), 4.26 (q, J=7.1 Hz, 2H), 3.83 (s, 3H), 3.76-3.70 (m, 2H), 2.47 (d, J=1.0 Hz, 3H), 1.28 (t, J=7.1 Hz, 3H), 0.97-0.88 (m, 2H), 0.00 (s, 9H).

Step B: Ethyl 2-{methyl(5-methyl-6-{{(2Z)-3-{{2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylate

A suspension of the product from Step A (296 mg, 0.43 mmol, 1 equiv) in 1:1 ethyl acetate/methanol (10 mL) was charged to a flask containing platinum(IV) oxide (9.78 mg, 0.04 mmol, 0.1 equiv) under nitrogen. The flask was evacuated and backfilled with nitrogen (x3), then evacuated, flushed with hydrogen, and shaken overnight. The reaction mixture was filtered through celite (2.5 g), eluted with methanol, and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-40% ethyl acetate in isoheptane afforded the desired product as a brown gum (148 mg, 0.21 mmol, 50%).

LC/MS (C ₃₄ H ₄₂ N ₆ O ₄ SiS ₂ ) 691 [M+H] ⁺ ; RT 1.59 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.84 (d, J=7.7 Hz, 1H), 7.67 (d, J=1.2 Hz, 1H), 7.51-7.40 (m, 2H), 7.33-7.22 (m, 3H), 7.05-6.88 (m, 3H), 5.76 (s, 2H), 4.26 (q, 2H), 4.04 (t, J=6.2 Hz, 2H), 3.78 (s, H), 3.73 (t, 2H), 3.33-3.22 (m, 2H), 2.46 (s, 3H), 2.11 (p, 1H), 1.30 (t, J=7.1 Hz, 3H), 0.93 (t, J=8.0 Hz, 2H), 0.00 (s, 9H).

Step C: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 3 mL) was slowly added to a solution of the product from Step B (148 mg, 0.21 mmol, 1 equiv.) in tetrahydrofuran (5 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate, washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow glass (46.7 mg, 0.08 mmol, 39%).

LC/MS (C ₂₈ H ₂₈ N ₆ O ₃ S ₂ ) 561 [M+H] ⁺ ; RT 1.37 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.07 (br s, 1H), 8.01-7.81 (m, 2H), 7.69 (s, 1H), 7.39 (t, 1H), 7.35-7.26 (m, 2H ), 7.25-7.19 (m, 1H), 7.00-6.88 (m, 3H), 4.28 (q, J=7.1 Hz, 2H), 4.05 (t, J=6.2 Hz, 2H), 3.78 (s, 3H), 3.34-3.24 (m, 2H), 2.47 (s, 3H), 2.21-1.99 (m, 2H), 1.31 (t, J=7.1 Hz, 3H).

Step D: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step C (46.7 mg, 0.08 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (17.5 mg, 0.42 mmol, 5 equiv) and the mixture was heated at 100 °C for 6 h. The residue was triturated with water, filtered, and dried in vacuo to give the title product as a yellow solid (28.7 mg, 0.05 mmol, 65%) [as the lithium salt].

MSHR-ERI (m/z) [MH] ^- , calculated for C ₂₆ H ₂₃ N ₆ O ₃ S ₂ : 531.1279, found: 531.1285.

Example 64: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-(3-methoxypropyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(3-methoxyprop-1-yn-1-yl)-2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Tetrakis(triphenylphosphine)palladium(0) (83.3 mg, 0.08 mmol, 0.1 equiv) under nitrogen atmosphere was added to a stirred solution of the product of Preparation 11c (500 mg, 0.72 mmol, 1 equiv), methyl propargyl ether (0.24 mL, 2.88 mmol, 4 equiv), triethylamine (0.6 mL, 4.32 mmol, 6 equiv), and copper(I) iodide (27.5 mg, 0.14 mmol, 0.2 equiv) in dimethylformamide (10 mL), and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature then concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-80% ethyl acetate in isoheptane afforded the desired product as a brown gum (337 mg, 0.49 mmol, 68%).

LC/MS (C ₃₂ H ₄₂ N ₆ O ₅ SiS ₂ ) 683 [M+H] ⁺ ; RT 1.57 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.87 (dd, J=7.4, 1.1 Hz, 1H), 7.73 (d, J=1.1 Hz, 1H), 7.51-7.42 (m, 2H), 7.26 (dt , 1H), 5.87 (s, 2H), 4.51-4.44 (m, 2H), 4.43 (s, 2H), 4.30 (q, J=7.1 Hz, 2H), 3.72 (t, 2H), 3.42 (t, J=5.9 Hz, 2H), 3.37 (s , 3H), 3.23 (s, 3H), 2.48 (d, J=0.9 Hz, 3H), 1.99 (p, J=6.6 Hz, 2H), 1.32 (t, J=7.1 Hz, 3H), 0.92 (t, J=8.6, 7.4 Hz, 2H), 0.00 (s, 9H).

Step B: ethyl 5-(3-methoxypropyl)-2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3 -dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazol-4-carboxylate

A suspension of the product from Step A (337 mg, 0.49 mmol, 1 equiv) in 1:1 ethyl acetate/methanol (10 mL) was charged to a flask containing platinum(IV) oxide (11.2 mg, 0.05 mmol, 0.1 equiv) under nitrogen. The flask was evacuated and backfilled with nitrogen (x3), then evacuated, flushed with hydrogen, and shaken overnight. The reaction mixture was filtered through celite (2.5 g), eluted with ethyl acetate then methanol, and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-3% methanol in dichloromethane afforded the title product as a yellow gum (286 mg, 0.42 mmol, 84%).

LC/MS (C ₃₂ H ₄₆ N ₆ O ₅ SiS ₂ ) 687 [M+H] ⁺ ; RT 1.58 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.85 (d, 1H), 7.66 (s, 1H), 7.49-7.41 (m, 2H), 7.29-7.22 (m, 1H), 5.86 (s, 2H) , 4.39 (t, J=7.2 Hz, 2H), 4.28 (q, J=7.1 Hz, 2H), 3.77-3.68 (m, 2H), 3.48-3.36 (m, 4H), 3.27 (s, 3H), 3.24 (s, 3H), 3.16-3.09 (m, 2H), 2.46 (s, 3H), 2.02-1.93 (m, 2H), 1.92-1.82 (m, 2H), 1.31 (t, J=7.1 Hz, 3H), 0.97-0.88 (m, 2H), 0.00 (s, 9H).

Step C: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-(3-methoxypropyl)-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 5 mL, 20 mmol, 48 equiv) was added to a stirred solution of the product from Step B (286 mg, 0.42 mmol, 1 equiv) in 1,4-dioxane (2 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate, washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow foam (162 mg, 0.29 mmol, 70%).

LC/MS (C ₂₆ H ₃₂ N ₆ O ₄ S ₂ ) 557 [M+H] ⁺ ; RT 1.28 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.06 (br s, 1H), 7.94 (s, 1H), 7.67 (br s + s, 2H), 7.40 (t, J=7.5 Hz, 1H), 7.22 (s, 1H), 4.39 (t, J=7.2 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.49-3.37 (m, 4H), 3.28 (s, 3H), 3.25 (s, 3H), 3.14 (dd, J=8.7, 6.7 Hz, 2H ), 2.47 (s, 3H), 2.03-1.93 (m, 2H), 1.96-1.82 (m, 2H), 1.32 (t, J=7.1 Hz, 3H).

Step D: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-(3-methoxypropyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step C (162 mg, 0.29 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (60.9 mg, 1.45 mmol, 5 equiv) and the mixture was heated at reflux for 7 h. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo, then dissolved in water, acidified with 2 N aqueous hydrochloric acid and re-evaporated. The residue was triturated with water, filtered and dried in vacuo to give the title product as a beige solid (87.8 mg, 0.17 mmol, 57%) [as the hydrochloric acid salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for c ₂₄ h ₂₉ n ₆ o ₄ s ₂ : 529.1686, found: 529.1685.

Example 65: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-(3-phenoxyprop-1-yn-1-yl)-1,3-thiazole-4-carboxylate

Tetrakis(triphenylphosphine)palladium(0) (83.3 mg, 0.08 mmol, 0.1 equiv) under nitrogen atmosphere was added to a stirred solution of the product of Preparation 11c (500 mg, 0.72 mmol, 1 equiv), phenyl propargyl ether (0.36 mL, 2.88 mmol, 4 equiv), triethylamine (0.6 mL, 4.32 mmol, 6 equiv), and copper(I) iodide (27.5 mg, 0.14 mmol, 0.2 equiv) in dimethylformamide (10 mL), and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the desired product as a brown foam (356 mg, 0.48 mmol, 66%).

LC/MS (C ₃₇ H ₄₄ N ₆ O ₅ SiS ₂ ) 745 [M+H] ⁺ ; RT 1.67 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.87 (dd, J=7.9, 1.1 Hz, 1H), 7.73 (s, 1H), 7.52-7.42 (m, 2H), 7.38-7.32 (m, 2H) , 7.30-7.24 (m, 1H), 7.10-7.05 (m, 2H), 7.00 (tt, J=7.4, 1.1 Hz, 1H), 5.88 (s, 2H), 5.15 (s, 2H), 4.45 (t, J=7.1 Hz, 2H), 4.25 (q, J=7.1 Hz, 2H), 3.77-3.67 (m, 2H), 3.41 (t, J=5.9 Hz, 2H), 3.21 (s, 2H), 2.47 (s, 3H), 1.98 (p, 2H), 1.28 (t, J=7.1 Hz, 3H), 0.92 (dd, J=8.5, 7.5 Hz, 2H), 0.00 (s, 9H).

Step B: Ethyl 2-{(3-methoxypropyl)(5-methyl-6-{{(2Z)-3-{{2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazole -2-ylidene]amino}pyridazin-3-yl)amino]-5-(3-phenoxypropyl)-1,3-thiazol-4-carboxylate

A suspension of the product from Step A (356 mg, 0.48 mmol, 1 equiv) in ethyl acetate (5 mL) was charged into a flask containing platinum(IV) oxide (10.8 mg, 0.05 mmol, 0.1 equiv) under nitrogen. The flask was evacuated and backfilled with nitrogen (x3), then evacuated, flushed with hydrogen, and shaken overnight. The reaction mixture was filtered through Celite (2.5 g), eluted with ethyl acetate and methanol, the solvent was removed in vacuo and the crude product was purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-40% ethyl acetate in isoheptane to give the desired product as a yellow gum (286 mg, 0.38 mmol, 80%).

LC/MS (C ₃₇ H ₄₈ N ₆ O ₅ SiS ₂ ) 749 [M+H] ⁺ ; RT 1.66 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.84 (dd, J=7.7, 1.0 Hz, 1H), 7.66 (s, 1H), 7.50-7.40 (m, 2H), 7.32-7.23 (m, 3H) , 6.98-6.88 (m, 3H), 5.88 (s, 2H), 4.40 (t, J=7.3 Hz, 2H), 4.26 (q, 2H), 4.05 (t, J=6.1 Hz, 2H), 3.78-3.68 (m, 2H), 3.42 (t, J=6.0 Hz, 2H), 3.31-3.26 (m, 2H), 3.23 (s, 3H), 2.46 (s, 3H), 2.17-2.06 (m, 2H), 2.03-1.92 (m, 2H), 1.30 (t, J=7.1, 5.2 Hz, 3H), 0.97-0.88 (m, 2H), 0.00 (s, 9H) .

Step C: Ethyl 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 5 mL, 20 mmol, 52 equiv) was slowly added to a solution of the product from Step B (286 mg, 0.38 mmol, 1 equiv) in 1,4-dioxane (2 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow foam (145 mg, 0.23 mmol, 62%).

LC/MS (C ₃₁ H ₃₄ N ₆ O ₄ S ₂ ) 619 [M+H] ⁺ ; RT 1.40 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.07 (br s, 1H), 7.95 (br s, 1H), 7.68 (br s + s, 2H), 7.40 (t, 1H), 7.29 (dd, J =8.8, 7.3 Hz, 2H), 7.26-7.19 (m, 1H), 7.00-6.89 (m, 3H), 4.39 (t, J=7.2 Hz, 2H), 4.27 (q, J=7.1 Hz, 2H), 4.05 (t, J=6.2 Hz, 2H) , 3.44 (t, J=6.0 Hz, 2H), 3.33-3.27 (m, 2H), 3.25 (s, 3H), 2.47 (s, 3H), 2.18-2.06 (m, 2H), 2.03-1.93 (m, 2H), 1.31 (t, J=7.1 Hz, 3H).

Step D: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-(3-phenoxypropyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step C (145 mg, 0.23 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (49.3 mg, 1.17 mmol, 5 equiv) and the mixture was heated at 100 °C for 7 h. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo, triturated with water, filtered and dried in vacuo to give the desired product as a brown solid (90.6 mg, 0.15 mmol, 65%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₉ H ₃₁ N ₆ O ₄ S ₂ : 591.1843, found: 591.1843.

Example 66: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-[3-(cyclohexyloxy)propyl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[3-(cyclohexyloxy)prop-1-yn-1-yl]-2-[(3-methoxypropyl)(5-methyl-6-{{(2Z)-3-{{2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Tetrakis(triphenylphosphine)palladium(0) (83.3 mg, 0.08 mmol, 0.1 equiv) under nitrogen atmosphere was added to a stirred solution of the product of Preparation 11c (500 mg, 0.72 mmol, 1 equiv), (prop-2-yn-1-yloxy)cyclohexane (400 mg, 2.88 mmol, 4 equiv), triethylamine (0.60 mL, 4.32 mmol, 6 equiv), and copper(I) iodide (27.5 mg, 0.14 mmol, 0.2 equiv) in dimethylformamide (10 mL), and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-70% ethyl acetate in isoheptane afforded the desired product as a brown gum (330 mg, 0.44 mmol, 61%).

LC/MS (C ₃₇ H ₅₀ N ₆ O ₅ SiS ₂ ) 751 [M+H] ⁺ ; RT 1.81 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.86 (d, 1H), 7.73 (s, 1H), 7.51-7.39 (m, 2H), 7.27 (ddd, J=8.3, 7.1, 1.4 Hz, 1H) , 5.88 (s, 2H), 4.50 (s, 2H), 4.46 (t, 2H), 4.30 (q, J=7.1 Hz, 2H), 3.73 (t, 2H), 3.60-3.50 (m, 1H), 3.42 (t, J=6.0 Hz, 2H), 3.23 (s, 3H), 2.48 (s, 3H), 1.98 (p, J=6.3 Hz, 2H), 1.94-1.86 (m, 2H), 1.75-1.63 (m, 2H), 1.54-1.45 (m, 2H), 1.36-1.17 (m, 7H), 0.92 (dd, J=8.4, 7.6 Hz, 2H), 0.00 (s, 9H).

Stage B: ethyl 5-[3-(cyclohexyloxy)propyl]-2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3- dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazol-4-carboxylate

A suspension of the product from Step A (330 mg, 0.44 mmol, 1 equiv) in 1:1 ethyl acetate/methanol (10 mL) was charged to a flask containing platinum(IV) oxide (9.98 mg, 0.04 mmol, 0.1 equiv) under nitrogen. The flask was evacuated and backfilled with nitrogen (x3), then evacuated, flushed with hydrogen, and shaken overnight. The reaction mixture was filtered through celite (2.5 g), eluted with ethyl acetate and methanol, and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-40% ethyl acetate in isoheptane afforded the title product as a yellow gum (272 mg, 0.36 mmol, 82%).

LC/MS (C ₃₇ H ₅₄ N ₆ O ₅ SiS ₂ ) 755 [M+H] ⁺ ; RT 1.79 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.82 (d, J=7.7 Hz, 1H), 7.66 (s, 1H), 7.51-7.40 (m, 2H), 7.26 (ddd, J=8.2, 6.9, 1.6 Hz, 1H), 4.38 (t, 2H), 4.27 (q, J=7.0 Hz, 2H), 3.71 (t, 2H), 3.50-3.38 (m, 4H), 3.24 (s, 3H), 3.23-3.19 (m, 1H), 3.14 (t, J=7.6 Hz, 2H), 2.45 (s, 3H), 1.97 (p, 2H), 1.91-1.79 (m, 5H), 1.72-1.58 (m, 2H), 1.52-1.39 (m, 2H), 1.31 (t, J=7.1 Hz, 3H), 1.28-1.14 (m, 4H), 0.92 (t, 2H), 0.00 (s, 9H).

Step C: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-{3-(cyclohexyloxy)propyl]-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 4 mL, 16 mmol, 45 equiv) was added to a stirred solution of the product from Step B (272 mg, 0.36 mmol, 1 equiv) in 1,4-dioxane (4 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow foam (120 mg, 0.19 mmol, 53%).

LC/MS (C ₃₁ H ₄₀ N ₆ O ₄ S ₂ ) 625 [M+H] ⁺ ; RT 1.45 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.09 (br s, 1H), 7.93 (s, 1H), 7.67 (br s + s, 2H), 7.39 (t, 1H), 7.23 (t, 1H) , 4.39 (t, J=7.2 Hz, 2H), 4.28 (q, J=7.1 Hz, 2H), 3.45 (dt, J=9.9, 6.1 Hz, 4H), 3.25 (s, 3H), 3.24-3.20 (m, 1H), 3.15 (t, J=7.6 Hz, 2H), 2.47 (s, 3H), 1.97 (p, J=6.3 Hz, 2H), 1.94-1.78 (m, 4H), 1.74-1.62 (m, 2H), 1.54-1.41 (m, 2H), 1.32 (t, J=7.1 Hz, 3H), 1.29-1.16 (m, 4H).

Step D: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-[3-(cyclohexyloxy)propyl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step C (120 mg, 0.19 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (40.3 mg, 0.96 mmol, 5 equiv) and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo, triturated with water, filtered, and dried in vacuo to give the title product as a yellow solid (98 mg, 0.16 mmol, 86%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₉ H ₃₇ N ₆ O ₄ S ₂ : 597.2312, found: 597.2314.

Example 67: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-[3-(2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(3-hydroxyprop-1-yn-1-yl)-2-[(3-methoxypropyl)(5-methyl-6-{{(2Z)-3-{{2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Tetrakis(triphenylphosphine)palladium(0) (83.3 mg, 0.08 mmol, 0.1 equiv) under nitrogen atmosphere was added to a stirred solution of the product of Preparation 11c (500 mg, 0.72 mmol, 1 equiv), propargyl alcohol (0.16 mL, 2.88 mmol, 4 equiv), triethylamine (0.60 mL, 4.32 mmol, 6 equiv), and copper(I) iodide (27.5 mg, 0.14 mmol, 0.2 equiv) in dimethylformamide (10 mL), and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature then concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the title product as a brown solid (362 mg, 0.54 mmol, 75%).

LC/MS (C ₃₁ H ₄₀ N ₆ O ₅ SiS ₂ ) 669 [M+H] ⁺ ; RT 1.45 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.88 (dd, J=7.4, 1.1 Hz, 1H), 7.72 (s, 1H), 7.51-7.41 (m, 2H), 7.27 (ddd, J=8.3, 7.1, 1.4 Hz, 1H), 5.89 (s, 2H), 5.44 (t, J=6.0 Hz, 1H), 4.45 (t, J=7.2 Hz, 2H), 4.40 (d, J=5.9 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.77-3.68 (m, 2H), 3.42 (t, J=6.0 Hz, 2H), 3.24 (s, 3H), 2.48 (s, 3H), 1.99 (p, J=6.3 Hz, 2H), 1.33 (t, J=7.1 Hz, 3H), 0.99-0.88 (m, 2H), 0.00 (s, 9H).

Step B: Ethyl 5-(3-hydroxypropyl)-2-[(3-methoxypropyl)(5-methyl-6-{{(2Z)-3-{{2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

A suspension of the product from Step A (362 mg, 0.54 mmol, 1 equiv) in 1:1 ethyl acetate/methanol (10 mL) was charged to a flask containing platinum(IV) oxide (12.3 mg, 0.05 mmol, 0.1 equiv) under nitrogen. The flask was evacuated and backfilled with nitrogen (x3), then evacuated, flushed with hydrogen, and shaken overnight. The mixture was filtered through celite (2.5 g), eluted with methanol, and the solvent was removed in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-80% ethyl acetate in isoheptane afforded the title product as a creamy foam (230 mg, 0.34 mmol, 63%).

LC/MS (C ₃₁ H ₄₄ N ₆ O ₅ SiS ₂ ) 673 [M+H] ⁺ ; RT 1.47 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.86 (dd, J=7.5, 1.1 Hz, 1H), 7.66 (s, 1H), 7.51-7.40 (m, 2H), 7.25 (ddd, J=8.3, 6.9, 1.6 Hz, 1H), 5.87 (s, 2H), 4.57 (t, J=5.1 Hz, 1H), 4.39 (t, J=7.2 Hz, 2H), 4.28 (q, J=7.1 Hz, 2H), 3.72 (dd, J=8.5, 7.5 Hz, 2H), 3.52-3.44 (m, 2H), 3.43 (t, 2H), 3.23 (s, 3Н), 3.16 3.08 (m, 2H), 2.46 (s, 3H), 1.96 (p, J=6.4 Hz, 2H), 1.86-1.75 (m, 2H), 1.31 (t, J=7.1 Hz, 3H), 0.92 (dd , J=8.6, 7.4 Hz, 2H), 0.00 (s, 9H).

Step C: ethyl 5-(3-iodopropyl)-2-[(3-methoxypropyl)(5-methyl-6-{{(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3 -dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazol-4-carboxylate

To a stirred solution of the product from Step B (230 mg, 0.34 mmol, 1 equiv) in 3:1 diethyl ether/acetonitrile (16 mL) were added imidazole (34.9 mg, 0.51 mmol, 1.5 equiv), triphenylphosphine (135 mg, 0.51 mmol, 1.5 equiv), and iodine (130 mg, 0.51 mmol, 1.5 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with ethyl acetate, washed with 10% aqueous sodium thiosulfate solution followed by water and then brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a yellow gum (129 mg, 0.16 mmol, 48%).

LC/MS (C ₃₁ H ₄₃ IN ₆ O ₄ SiS ₂ ) 783 [M+H] ⁺ ; RT 1.63 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.85 (dd, J=7.5, 1.1 Hz, 1H), 7.67 (s, 1H), 7.49-7.41 (m, 2H), 7.26 (ddd, J=8.3, 6.9, 1.6 Hz, 1H), 5.87 (s, 2H), 4.40 (t, J=7.3 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.73 (dd, J=8.6, 7.4 Hz, 2H), 3.42 (t, J=6.0 Hz, 2H), 3.40-3.28 (m, 2H), 3.24 (s, 3H), 3.21-3.14 (m, 2H), 2.45 (s, 3H), 2.14 (p, J=7.0 Hz, 2H), 2.02-1.95 (m, 2H), 1.34 (t, J=7.1 Hz, 3H), 0.92 (dd, J=8.6, 7.4 Hz, 2H), 0.00 (s, 9H).

Stage D: ethyl 5-[3-(2-fluorophenoxy)propyl]-2-[(3-methoxypropyl)(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2, 3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazol-4-carboxylate

Sodium hydride (60% in mineral oil; 13.2 mg, 0.33 mmol, 2 equiv) was added to a solution of 2-fluorophenol (0.02 mL, 0.2 mmol, 1.2 equiv) in dimethylformamide (3 mL). After 15 min, the mixture was cooled to 0 °C and a solution of the product from Step C (129 mg, 0.16 mmol, 1 equiv) in dimethylformamide (3 mL) was added. The mixture was allowed to warm to ambient temperature and stirred overnight. The reaction mixture was quenched by the addition of water, acidified with 2 N aqueous hydrochloric acid, and extracted with ethyl acetate (×2). The combined organic extracts were washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-6% methanol in dichloromethane afforded the title product as a cream-colored gum (75.6 mg, 0.1 mmol, 60%).

LC/MS (C ₃₇ H ₄₇ FN ₆ O ₅ SiS ₂ ) 767 [M+H] ⁺ ; RT 1.61 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.84 (d, 1H), 7.67 (s, 1H), 7.51-7.40 (m, 2H), 7.30-7.07 (m, 4H), 6.97-6.89 (m, 1H), 5.87 (s, 2H), 4.40 (t, J=7.2 Hz, 2H), 4.26 (q, J=7.0 Hz, 2H), 4.13 (t, J=6.1 Hz, 2H), 3.78-3.69 (m, 2H), 3.42 (t, J= 6.0 Hz, 2H), 3.31-3.25 (m, 2H), 3.24 (s, 3H), 2.46 (s, 3H), 2.25-2.05 (m, 2H), 1.97 (p, J=6.2 Hz, 2H), 1.29 (t, J=7.1 Hz, 3H), 0.98-0.89 (m, 2H), 0.00 (s, 9H).

Step E: ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-{3-(2-fluorophenoxy) )propyl]-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 1 mL, 4 mmol, 40.6 equiv) was added to a stirred solution of the product from Step D (75.6 mg, 0.1 mmol, 1 equiv) in 1,4-dioxane (2 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow glass (36.2 mg, 0.06 mmol, 58%).

LC/MS (C ₃₁ H ₃₃ FN ₆ O ₄ S ₂ ) 637 [M+H] ⁺ ; RT 1.39 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) 7.92 (br s, 1H), 7.67 (br s + s, 2H), 7.39 (t, J=7.5 Hz, 1H), 7.27-7.08 (m, 4H), 6.99-6.89 (m, 1H), 4.39 (t, J=7.3 Hz, 2H), 4.26 (q, J=7.1 Hz, 2H), 4.14 (t, J=6.1 Hz, 2H), 3.44 (t, J=6.0 Hz, 2H), 3.34-3.24 (m, 2H), 3.25 (s, 3H), 2.47 (s, 2H), 2.22-2.06 (m, 2H), 1.97 (p, 2H), 1.30 (t, J=7.1 Hz, 3H).

Step F: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-methoxypropyl)amino)-5-[3-(2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step E (36.2 mg, 0.06 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (11.9 mg, 0.28 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a beige solid (19.5 mg, 0.03 mmol, 56%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₉ H ₃₀ FN ₆ O ₄ S ₂ : 609.1749, found: 609.1753.

Example 68: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(benzyloxy)azetidin-1-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[3-(benzyloxy)azetidin-1-yl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

An oven-dried microwave processing vessel was charged with the product of Preparation 11b (500 mg, 0.79 mmol, 1 equiv), 3-(benzyloxy)azetidine hydrochloride (314 mg, 1.57 mmol, 2 equiv), cesium carbonate (769 mg, 2.36 mmol, 3 equiv), and 1,4-dioxane (10 mL). The mixture was sparged with nitrogen (10 min), after which Xantphos Pd G3 (74.7 mg, 0.08 mmol, 0.1 equiv) was added, and the mixture was heated at 140 °C for 2 h under microwave irradiation.

The reaction mixture was diluted with ethyl acetate, then washed with water followed by brine, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the desired product as a yellow foam (380 mg, 0.53 mmol, 67%).

LC/MS (C ₃₅ H ₄₃ N ₇ O ₄ SiS ₂ ) 718 [M+H] ⁺ ; RT 1.53 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.82 (d, 1H), 7.57 (d, J=1.0 Hz, 1H), 7.50-7.42 (m, 2H), 7.40-7.35 (m, 4H), 7.34-7.28 (m, 1H), 7.27-7.21 (m, 1H), 5.84 (s, 2H), 4.52 (s, 2H), 4.52-4.44 (m, 1H), 4.32 (ddd, J=8.9, 6.3, 1.2 Hz, 2H), 4.19 (q, J=7.1 Hz, 2H), 4.03-3.94 (m, 2H), 3.76-3.70 (m, 2H), 3.66 (s, 3H), 2.44 (d, J=1.0 Hz, 3H), 1.26 (t, J=7.1 Hz, 3H), 0.97-0.88 (m, 2H), 0.00 (s, 9H).

Step B: ethyl 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(benzyloxy)azetidine-1 -yl]-1,3-thiazol-4-carboxylate

Trifluoroacetic acid (1 mL, 13.4 mmol, 96.3 equiv) was added to a stirred solution of the product from Step A (100 mg, 0.14 mmol, 1 equiv) in dichloromethane (3 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane and washed with saturated aqueous sodium bicarbonate, then brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow glass (48 mg, 0.08 mmol, 59%).

LC/MS (C ₂₉ H ₂₉ N ₇ O ₃ S ₂ ) 588 [M+H] ⁺ ; RT 1.31 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.02 (br s, 1H), 7.90 (br s, 1H), 7.59 (br s + s, 2H), 7.44-7.28 (m, 6H), 7.21 (t , J=7.5 Hz, 1H), 4.52 (s, 2H), 4.51-4.46 (m, 1H), 4.37-4.28 (m, 2H), 4.20 (q, J=7.1 Hz, 2H), 4.01-3.96 (m, 2H), 3.66 (s, 3H), 2.45 (s, 3H), 1.27 (t, J=7.1 Hz, 3H).

Step C: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(benzyloxy)azetidin-1-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (48 mg, 0.08 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (17.1 mg, 0.41 mmol, 5 equiv) and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. The residue was triturated with water, filtered, and dried in vacuo to give the title product as a beige solid (33.2 mg, 0.06 mmol, 73%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₇ H ₂₆ N ₇ O ₃ S ₂ : 560.1533, found: 560.1531.

Example 69: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-phenoxyazetidin-1-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{{2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-(3-phenoxyazetidin-1-yl)-1,3-thiazole-4-carboxylate

An oven-dried flask was charged with the product of Preparation 11b (100 mg, 0.16 mmol, 1 equiv), 3-phenoxyazetidine hydrochloride (58.4 mg, 0.31 mmol, 2 equiv), cesium carbonate (154 mg, 0.47 mmol, 3 equiv), and 1,4-dioxane (4 mL). The mixture was sparged with nitrogen (10 min), and rac-BINAP Pd G3 (15.6 mg, 0.02 mmol, 0.1 equiv) was added, and the mixture was heated at 100 °C for 24 h. The reaction mixture was diluted with ethyl acetate, washed with water followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a yellow glass (55.7 mg, 0.08 mmol, 50%).

LC/MS (C ₃₄ H ₄₁ N ₇ O ₄ SiS ₂ ) 704 [M+H] ⁺ ; RT 1.60 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.82 (d, 1H), 7.59 (d, J=1.1 Hz, 1H), 7.51-7.39 (m, 2H), 7.39-7.30 (m, 2H), 7.29 -7.20 (m, 1H), 7.00 (tt, J=7.4, 1.1 Hz, 1H), 6.91 (dt, J=7.7, 1.1 Hz, 2H), 5.85 (s, 2H), 5.16 (tt, J=6.6, 3.8 Hz, 1H), 4.62-4.53 (m , 2H), 4.22 (q, J=7.1 Hz, 2H), 4.18-4.09 (m, 2H), 3.73 (dd, J=8.5, 7.5 Hz, 2H), 3.69 (s, 3H), 2.45 (d, J=1.0 Hz, 3H), 1.28 (t, J=7.1 Hz, 3H), 0.97-0.88 (m , 2H), 0.00 (s, 9H).

Step B: Ethyl 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-phenoxyazetidin-1-yl)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1 mL, 13.4 mmol, 170 equiv) was added to a stirred solution of the product from Step A (55.7 mg, 0.08 mmol, 1 equiv) in dichloromethane (3 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane, washed with saturated aqueous sodium bicarbonate, then brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow glassy solid (20.4 mg, 0.04 mmol, 45%).

LC/MS (C ₂₈ H ₂₇ N ₇ O ₃ S ₂ ) 574 [M+H] ⁺ ; RT 1.31 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.92 (br s, 1H), 7.60 (br s + s, 2H), 7.41-7.30 (m, 3H), 7.21 (s, 1H), 7.01 (tt, J=7.4, 1.1 Hz, 1H), 6.91 (dt, J=7.8, 1.1 Hz, 2H), 5.16 (tt, J=6.5, 3.7 Hz, 1H), 4.62-4.53 (m, 2H), 4.22 (q, J=7.1 Hz, 2H), 4.17-4.10 (m, 2H), 3.68 (s, 3H), 2.45 (s, 2H), 1.28 (t, J=7.1 Hz, 3N).

Step C: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-phenoxyazetidin-1-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (20 mg, 0.03 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (7.31 mg, 0.17 mmol, 5 equiv) and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature, concentrated in vacuo, triturated with water, filtered, and dried in vacuo to give the title product as a beige solid (11.2 mg, 0.02 mmol, 59%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₆ H ₂₄ N ₇ O ₃ S ₂ : 546.1377, found: 546.1381.

Example 70: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3S)-3-(benzyloxy)pyrrolidin-1-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-{(3S)-3-(benzyloxy)pyrrolidin-1-yl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

An oven-dried flask was charged with the product of Preparation 11b (200 mg, 0.31 mmol, 1 equiv), (S)-3-benzyloxypyrrolidine hydrochloride (135 mg, 0.63 mmol, 2 equiv), cesium carbonate (308 mg, 0.94 mmol, 3 equiv), and 1,4-dioxane (8 mL). The mixture was sparged with nitrogen (10 min), after which rac-BINAP Pd G3 (15.6 mg, 0.02 mmol, 0.05 equiv) was added, and the mixture was heated at 100 °C for 24 h. The reaction mixture was diluted with ethyl acetate, then washed with water followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a yellow foam (113 mg, 0.15 mmol, 49%).

LC/MS (C ₃₆ H ₄₅ N ₇ O ₄ SiS ₂ ) 732 [M+H] ⁺ ; RT 1.54 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.82 (d, 1H), 7.57 (d, 1H), 7.49-7.40 (m, 2H), 7.36-7.31 (m, 4H), 7.31-7.22 (m, 2H), 5.84 (s, 2H), 4.60-4.48 (m, 2H), 4.30-4.26 (m, 1H), 4.25-4.17 (m, 2H), 3.71 (t, 2H), 3.68 (s, 3H), 3.64-3.52 (m, 2H), 3.48-3.36 (m, 2H), 2.44 (d, J=1.0 Hz, 3H), 2.14 (s, 2H), 1.29 (t, J=7.1 Hz, 3H), 0.97-0.88 (m, 2H), 0.00 (s, 9H).

Step B: Ethyl 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(3S)-3-(benzyloxy)pyrrolidin-1-yl]-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 4 mL, 16 mmol, 104 equiv) was added to a stirred solution of the product from Step A (113 mg, 0.15 mmol, 1 equiv) in 1,4-dioxane (5 mL), and the mixture was stirred at 40 °C overnight. The reaction mixture was diluted with ethyl acetate, washed with saturated aqueous sodium bicarbonate, then brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a yellow glass (83 mg, 0.14 mmol, 89%).

LC/MS (C ₃₀ H ₃₁ N ₇ O ₃ S ₂ ) 602 [M+H] ⁺ ; RT 1.32 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 10.96 (br s, 1H), 7.96 (br s, 1H), 7.60 (br s + s, 2H), 7.42-7.23 (m, 5H), 7.21 (s , 2H), 4.61-4.48 (m, 2H), 4.33-4.26 (m, 1H), 4.25-4.16 (m, 2H), 3.73 (dd, J=11.4, 4.6 Hz, 1H), 3.67 (s, 3H), 3.64-3.53 (m, 1H), 3.45- 3.36 (m, 2H), 2.45 (s, 3H), 2.26-2.05 (m, 2H), 1.29 (t, J=7.1 Hz, 3H).

Step C: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(3S)-3-(benzyloxy)pyrrolidin-1-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (83 mg, 0.14 mmol, 1 equiv) in 1,4-dioxane (8 mL) was added lithium hydroxide monohydrate (28.9 mg, 0.69 mmol, 5 equiv), and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo, triturated with water, filtered, and dried in vacuo to give the desired product as a yellow solid (65.6 mg, 0.11 mmol, 83%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₈ H ₂₈ N ₇ O ₃ S ₂ : 574.1690, found: 574.1687.

Example 71: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(3R)-3-(benzyloxy)pyrrolidin-1-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[(3R)-3-(benzyloxy)pyrrolidin-1-yl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

An oven-dried flask was charged with the product of Preparation 11b (200 mg, 0.31 mmol, 1 equiv), (R)-3-benzyloxypyrrolidine hydrochloride (135 mg, 0.63 mmol, 2 equiv), cesium carbonate (308 mg, 0.94 mmol, 3 equiv), and 1,4-dioxane (8 mL). The mixture was sparged with nitrogen (10 min), after which rac-BINAP Pd G3 (31.2 mg, 0.03 mmol, 0.1 equiv) was added, and the mixture was heated at 100 °C for 24 h. The reaction mixture was diluted with ethyl acetate, washed with water followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a yellow glass (101 mg, 0.14 mmol, 44%).

LC/MS (C ₃₆ H ₄₅ N ₇ O ₄ SiS ₂ ) 732 [M+H] ⁺ ; RT 1.55 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.82 (d, 1H), 7.57 (d, J=1.1 Hz, 1H), 7.49-7.38 (m, 2H), 7.36-7.31 (m, 4H), 7.30 -7.21 (m, 2H), 5.84 (s, 2H), 4.60-4.47 (m, 2H), 4.32-4.25 (m, 1H), 4.25-4.16 (m, 2H), 3.77-3.68 (m, 2H), 3.67 (s, 3H), 3.62-3.52 ( m, 2H), 3.45-3.36 (m, 2H), 2.43 (s, 3H), 2.22-2.09 (m, 2H), 1.29 (t, J=7.1 Hz, 3H), 0.91 (dd, J=8.4, 7.5 Hz, 2H), 0.00 (s, 9H).

Step B: Ethyl 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(3R)-3-(benzyloxy)pyrrolidin-1-yl]-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 4 mL, 16 mmol, 117 equiv) was added to a stirred solution of the product from Step A (101 mg, 0.14 mmol, 1 equiv) in 1,4-dioxane (5 mL), and the mixture was stirred at 40 °C overnight. The reaction mixture was diluted with dichloromethane, washed with saturated aqueous sodium bicarbonate, then brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the desired product as a yellow gum (80 mg, 0.13 mmol, 97%).

LC/MS (C ₃₀ H ₃₁ N ₇ O ₃ S ₂ ) 602 [M+H] ⁺ ; RT 1.32 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 10.98 (br s, 1H), 7.91 (s, 1H), 7.60 (br s + s, 2H), 7.42-7.11 (m, 7H), 4.60-4.48 ( m, 2H), 4.33-4.27 (m, 1H), 4.27-4.13 (m, 2H), 3.67 (s, 3H), 3.63-3.55 (m, 2H), 3.42 (td, J=9.3, 8.7, 3.4 Hz, 2H), 2.46 (s, 3H) , 2.25-2.06 (m, 2H), 1.30 (t, J=7.1 Hz, 3H).

Step C: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(3R)-3-(benzyloxy)pyrrolidin-1-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (80 mg, 0.13 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (28 mg, 0.67 mmol, 5 equiv) and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo, triturated with water, filtered, and dried in vacuo to give the title product as a yellow solid (50.1 mg, 0.09 mmol, 65%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₈ H ₂₈ N ₇ O ₃ S ₂ : 574.1690, found: 574.1723.

Example 72: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-hydroxyazetidin-1-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-hydroxyazetidin-1-yl)-1,3-thiazole-4-carboxylate

A solution of the product from Example 68, Step B (94.2 mg, 0.16 mmol, 1 equiv) in dichloromethane (5 mL) was cooled to -78 °C and boron trichloride (1 M in dichloromethane; 0.48 mL, 0.48 mmol, 3 equiv) was added slowly. The mixture was kept at -78 °C for 1 h and then allowed to warm to ambient temperature over 2 h. The reaction mixture was quenched by the addition of saturated aqueous sodium bicarbonate solution, then extracted with dichloromethane (x2) followed by extraction with 3:1 dichloromethane/isopropanol, and the combined organic extracts were dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-6% methanol in dichloromethane afforded the title product as a yellow solid (13.4 mg, 0.03 mmol, 17%).

LC/MS (C ₂₂ H ₂₃ N ₇ O ₃ S ₂ ) 498 [M+H] ⁺ ; RT 1.00 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.87 (d, J=7.7 Hz, 1H), 7.56 (s, 1H), 7.51 (br s, 1H), 7.41-7.32 (m, 1H), 7.18 ( t, J=7.6 Hz, 1H), 5.75 (d, 1H), 4.55 (h, J=6.0 Hz, 1H), 4.40-4.31 (m, 2H), 4.21 (q, J=7.1 Hz, 2H), 3.88-3.80 (m, 2H), 3.65 (s, 3H ), 2.43 (s, 3H), 1.28 (t, J=7.1 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-hydroxyazetidin-1-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step C (13.4 mg, 0.03 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (5.65 mg, 0.13 mmol, 5 equiv) and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a beige solid (8.1 mg, 0.02 mmol, 64%).

MSHR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₀ H ₂₀ N ₇ O ₃ S ₂ : 470.1064, found: 470.1072.

Example 73: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (20 mL) was added to a stirred solution of the product of Preparation 5j, Step A (1.5 g, 1.71 mmol, 1 equiv) in dichloromethane (60 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane, cooled to 0 °C, then basified by addition of 2 N aqueous sodium hydroxide solution, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded the desired product as a yellow solid (361 mg, 0.56 mmol, 33%).

LC/MS (C ₃₂ H ₃₂ FN ₇ O ₃ S ₂ ) 646 [M+H] ⁺ ; RT 1.98 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.91 (d, 1H), 7.68 (d, J=1.2 Hz, 1H), 7.53 (d, J=7.9 Hz, 1H), 7.39 (ddd, J=8.2, 7.2, 1.3 Hz, 1H), 7.32-7.11 (m, 4H), 4.25 (q, J=7.1 Hz, 2H), 4.15 (t, J=6.2 Hz, 2H), 3.77 (s, 3H), 3.46 (s, 2H), 3.27 (t, J=7.7 Hz, 2H), 2.47 (d, J=1.0 Hz, 3H), 2.31 (s, 3H), 2.19-2.07 (m, 2H), 2.23 (s, 1H), 1.30 (t, J=7.1 Hz, 3H).

Step B: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (361 mg, 0.56 mmol, 1 equiv) in 1,4-dioxane (15 mL) was added lithium hydroxide monohydrate (352 mg, 8.39 mmol, 15 equiv) and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. The residue was triturated with water, filtered, washed with water then diethyl ether, and dried in vacuo to give the title product as a yellow solid (286 mg, 0.46 mmol, 83%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₀ H ₂₉ FN ₇ O ₃ S ₂ : 618.1752, found: 618.1767.

Example 74: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-[2-fluoro-4-(3-{methyl[2-(methylamino)ethyl]amino}prop-1-yn-1-yl)phenoxy]propyl}-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[3-(4-{3-[(2-{[(tert-butoxy)carbonyl](methyl)amino}ethyl)(methyl)amino]prop-1-yn-1-yl}-2-fluorophenoxy)propyl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product of Synthesis 5j (523 mg, 0.67 mmol, 1 equiv.) in acetonitrile (30 mL) were added N-Boc-(methylamino)acetaldehyde (234 mg, 1.35 mmol, 2 equiv.), sodium triacetoxyborohydride (343 mg, 1.62 mmol, 2.4 equiv.) and glacial acetic acid (50 μL), and the mixture was stirred at ambient temperature for 6 h. The reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the desired product as a yellow gum (705 mg, 0.76 mmol, >100%).

LC/MS (C ₄₆ H ₆₁ N ₈ O ₆ FSiS ₂ ) 933 [M+H] ⁺ ; RT 1.39 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-d6) δ 7.84 (d, 1H), 7.67 (d, 1H), 7.51-7.40 (m, 2H), 7.33-7.12 (m, 4H), 5.87 (s, 2H) , 4.25 (q, J=7.1 Hz, 2H), 4.15 (t, J=6.1 Hz, 2H), 3.77 (s, 3H), 3.76-3.68 (m, 2H), 3.49 (s, 2H), 3.31-3.20 (m, 6H), 2.76 (s, 3H) , 2.47 (d, J=1.0 Hz, 3H), 2.26 (s, 3H), 2.18-2.07 (m, 2H), 1.37 (s, 9H), 1.28 (t, J=7.1 Hz, 3H), 0.98-0.87 (m, 2H), 0.00 (s, 9H).

Step B: Ethyl 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-[2-fluoro-4-(3-{methyl[2-(methylamino)ethyl]amino}prop-1-yn-1-yl)phenoxy]propyl}-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (5 mL) was added to a stirred solution of the product from Step A (705 mg, 0.76 mmol, 1 equiv) in dichloromethane (20 mL) and the mixture was stirred at ambient temperature for 12 h. The reaction mixture was diluted with dichloromethane, cooled to 0 °C and basified by addition of 2 N aqueous sodium hydroxide solution, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of dichloromethane to 20% methanol in dichloromethane afforded the title product as a yellow gum (123 mg, 0.17 mmol, 22%).

LC/MS (C ₃₅ H ₃₉ FN ₈ O ₃ S ₂ ) 703 [M+H] ⁺ ; RT 2.07 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.90 (d, 1H), 7.67 (d, J=1.2 Hz, 1H), 7.53 (d, 1H), 7.42-7.36 (m, 1H), 7.34-7.26 (dd, 1H), 7.25-7.12 (m, 3H), 4.27 (q, J=7.1 Hz, 2H), 4.15 (t, J=6.1 Hz, 2H), 3.76 (s, 3H), 3.48 (s, 2H), 3.30-3.20 (m, 2H), 2.60 (dd, J=6.7, 5.2 Hz, 2H), 2.51-2.46 (m, 2H), 2.46 (s, 3H), 2.30 (s, 3H), 2.23 (s, 3H), 2.19-2.08 (m, 2H), 1.30 (t, J=7.1 Hz, 3H).

Step C: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-{2-fluoro-4-(3-{methyl{2-(methylamino)ethyl]amino}prop-1-yn-1-yl)phenoxy]propyl}-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (123 mg, 0.17 mmol, 1 equiv) in 1,4-dioxane (15 mL) was added lithium hydroxide monohydrate (110 mg, 2.62 mmol, 15 equiv), and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 9; ammonium formate) in water (pH 9; ammonium formate) afforded the title product as a yellow solid (75.8 mg, 0.11 mmol, 64%) [as the lithium salt].

MSHR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₃ H ₃₆ FN ₈ O ₃ S ₂ : 675.2330, found: 675.2331.

Example 75: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[4-(benzyloxy)piperidin-1-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[4-(benzyloxy)piperidin-1-yl]-2-[(6-chloro-5-methylpyridazin-3-yl)(methyl)amino]-1,3-thiazole-4-carboxylate

Sodium hydride (60% in mineral oil; 27.2 mg, 0.68 mmol, 1.2 equiv) was added to a cooled solution of the product of Preparation 3za (213 mg, 0.57 mmol, 1 equiv) and 3,6-dichloro-4-methylpyridazine (92.5 mg, 0.57 mmol, 1 equiv) in tetrahydrofuran (6 mL), and the mixture was allowed to warm to ambient temperature and stirred overnight. The reaction mixture was diluted with dichloromethane, washed with saturated aqueous ammonium chloride solution then with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a yellow solid (101 mg, 0.2 mmol, 35%).

LC/MS (C ₂₄ H ₂₈ ClN ₅ O ₃ S) 502 [M+H] ⁺ ; RT 1.29 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.77 (d, J=1.2 Hz, 1H), 7.40-7.33 (m, 4H), 7.32-7.26 (m, 1H), 4.56 (s, 2H), 4.25 (q, J=7.1 Hz, 2H), 3.70 (s, 3H), 3.66-3.56 (m, 1H), 3.45-3.33 (m, 2H), 3.02 (td, J=10.1, 8.7, 3.0 Hz, 2H), 2.41 (d, J=1.0 Hz, 3H), 2.07-1.93 (m, 2H), 1.79-1.63 (m, 2H), 1.30 (t, J=7.1 Hz, 3N).

Step B: Ethyl 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[4-(benzyloxy)piperidin-1-yl]-1,3-thiazole-4-carboxylate

A solution of the product from Step A (101 mg, 0.2 mmol, 1 equiv), 2-aminobenzothiazole (36.2 mg, 0.24 mmol, 1.2 equiv), N,N-diisopropylethylamine (0.1 mL, 0.6 mmol, 3 equiv), and xantphos (11.6 mg, 0.02 mmol, 0.1 equiv) in 1,4-dioxane (4 mL) was sparged with nitrogen (10 min), then tris(dibenzylideneacetone)dipalladium(0) (9.19 mg, 0.01 mmol, 0.05 equiv) was added and the mixture was heated in a sealed flask at 150 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow glass (31.2 mg, 0.05 mmol, 25%).

LC/MS (C ₃₁ H ₃₃ N ₇ O ₃ S ₂ ) 616 [M+H] ⁺ ; RT 1.36 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.90 (s, 1H), 7.63 (br s + s, 2H), 7.43-7.32 (m, 5H), 7.32-7.25 (m, 1H), 7.24-7.16 (m, 1H), 4.56 (s, 2H), 4.26 (q, J=7.1 Hz, 2H), 3.70 (s, 3H), 3.68-3.57 (m, 1H), 3.46-3.35 (m, 2H), 3.08-2.97 (m, 2H), 2.46 (s, 3H), 2.08-1.97 (m, 2H), 1.80-1.69 (m, 2H), 1.32 (t, 3H).

Step C: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[4-(benzyloxy)piperidin-1-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (31.2 mg, 0.05 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (10.6 mg, 0.25 mmol, 5 equiv) and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the title product as a cream-colored solid (12.2 mg, 0.02 mmol, 41%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₉ H ₃₀ N ₇ O ₃ S ₂ : 588.1846, found: 588.1854.

Example 76: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(2-fluoro-4-{3-[(2-hydroxyethyl)(methyl)amino]prop-1-yn-1-yl}phenoxy)propyl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(3-{4-[3-({2-[(tert-butyldimethylsilyl)oxy]ethyl}(methyl)amino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-2-[methyl(5-methyl-6-{{(2Z)-3-{{2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product of Synthesis 5j (747 mg, 0.96 mmol, 1 equiv.) in acetonitrile (50 mL) was added (tert-butyldimethylsiloxy)acetaldehyde (367 µL, 1.93 mmol, 2 equiv.), followed by sodium triacetoxyborohydride (612 mg, 2.89 mmol, 3 equiv.) and glacial acetic acid (50 µL), and the mixture was stirred at ambient temperature overnight.

The reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a clear oil (907 mg, 0.96 mmol, 100%).

LC/MS (C ₄₆ H ₆₄ FN ₇ O ₅ Si ₂ S ₂ ) 934 [M+H] ⁺ ; RT 1.47 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-d6) δ 7.84 (d, 1H), 7.67 (d, 1H), 7.50-7.40 (m 2H), 7.31-7.22 (m, 2H), 7.21-7.12 (m, 2H ), 5.87 (s, 1H), 4.26 (q, J=7.1 Hz, 2H), 4.14 (t, J=6.1 Hz, 2H), 3.77 (s, 3H), 3.75-3.62 (m, 4H), 3.50 (s, 2H), 2.46 (s, 3H), 2.24 (s, 3H), 2.19-2.06 (m, 2H), 1.29 (t, 3H), 1.24 (s, 6H), 0.96-0.89 (m, 2H), 0.04 (s, 9H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(2-fluoro-4-{3-[(2-hydroxyethyl)(methyl)amino]prop-1-yn-1-yl}phenoxy)propyl]-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (13 mL) was added to a stirred solution of the product from Step A (907 mg, 0.97 mmol, 1 equiv) in dichloromethane (40 mL) and the mixture was stirred at ambient temperature for 9 h. The reaction mixture was diluted with dichloromethane, cooled to 0 °C and basified by addition of 2 N aqueous sodium hydroxide solution, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-20% methanol in dichloromethane afforded the desired product as a yellow solid (95 mg, 0.14 mmol, 14%).

LC/MS (C ₃₄ H ₃₆ FN ₇ O ₄ S ₂ ) 690 [M+H] ⁺ ; RT 1.98 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.91 (d, J=7.9 Hz, 1H), 7.67 (s, 1H), 7.56-7.48 (m, 1H), 7.39 (dt, 1H), 7.29 (dd , J=11.9, 1.9 Hz, 1H), 7.26-7.11 (m, 3H), 4.41 (t, J=5.5 Hz, 1H), 4.26 (q, J=7.1 Hz, 2H), 4.14 (t, J=6.1 Hz, 2H), 3.76 (s, 3H ), 3.48 (s, 3H), 3.47-3.43 (m, 2H), 3.31-3.25 (m, 2H), 2.46 (s, 3H), 2.24 (s, 3H), 2.21-2.09 (m, 2H), 1.29 (t, J=7.1 Hz, 3H).

Step C: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(2-fluoro-4-{3-[(2-hydroxyethyl)(methyl)amino]prop-1-yn-1-yl}phenoxy)propyl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (95 mg, 0.14 mmol, 1 equiv) in 1,4-dioxane (15 mL) was added lithium hydroxide monohydrate (57.8 mg, 1.38 mmol, 10 equiv) and the mixture was heated at 100 °C for 6 h. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 9; ammonium acetate) in water (pH 9; ammonium acetate) afforded the desired product as a yellow solid (61.8 mg, 0.09 mmol, 67%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₂ H ₃₃ FN ₇ O ₄ S ₂ : 662.2014, found: 662.2035.

Example 77: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(3S)-3-phenoxypyrrolidin-1-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{{2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-[(3S)-3-phenoxypyrrolidin-1-yl]-1,3-thiazole-4-carboxylate

An oven-dried flask was charged with the product of Preparation 11b (200 mg, 0.31 mmol, 1 equiv), (3S)-3-phenoxypyrrolidine hydrochloride (0.09 mL, 0.63 mmol, 2 equiv), cesium carbonate (308 mg, 0.94 mmol, 3 equiv), and 1,4-dioxane (8 mL). The mixture was sparged with nitrogen (10 min), then rac-BINAP Pd G3 (31.2 mg, 0.03 mmol, 0.1 equiv) was added, and the mixture was heated at 100 °C for 6 h.

The reaction mixture was diluted with ethyl acetate, washed with water followed by brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the desired product as a yellow foam (184 mg, 0.26 mmol, 81%).

LC/MS (C ₃₅ H ₄₃ N ₇ O ₄ SiS ₂ ) 718 [M+H] ⁺ ; RT 1.54 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.82 (d, 1H), 7.58 (d, 1H), 7.48-7.37 (m, 2H), 7.35-7.20 (m, 4H), 7.01-6.91 (m, 3H), 5.86 (s, 2H), 5.18-5.13 (m, 1H), 4.21 (qd, J=7.1, 2.3 Hz, 2H), 3.96 (dd, J=11.8, 4.5 Hz, 1H), 3.77-3.60 (m, 2H), 3.68 (s, 3H), 3.67-3.61 (m, 1H), 3.49 (td, J=8.7, 2.9 Hz, 1H), 3.37-3.32 (m, 1H), 2.45 (d, J=1.0 Hz, 3H), 2.37-2.26 (m, 1H), 2.25-2.15 (m 1H), 1.27 (t, J=7.1 Hz, 3H), 0.92 (dd, J=8.4, 7.6 Hz, 2H), 0.00 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(3S)-3-phenoxypyrrolidin-1-yl]-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 3 mL, 12 mmol, 47 equiv) was added to a stirred solution of the product from Step A (184 mg, 0.26 mmol, 1 equiv) in 1,4-dioxane (7 mL), and the mixture was stirred at 50 °C overnight. The reaction mixture was diluted with dichloromethane, washed with saturated aqueous sodium bicarbonate, then brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with 5 95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow gum (55.8 mg, 0.09 mmol, 37%).

LC/MS (C ₂₉ H ₂₉ N ₇ O ₃ S ₂ ) 588 [M+H] ⁺ ; RT 1.32 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.89 (br s, 1H), 7.59 (br s + s, 2H), 7.38 (t, J=7.5 Hz, 1H), 7.33-7.26 (m, 2H), 7.19 (t, J=7.6 Hz, 1H), 7.01-6.91 (m, 3H), 5.18-5.13 (m, 1H), 4.21 (qd, J=7.1, 2.3 Hz, 2H), 3.96 (dd, J=11.8, 4.5 Hz, 1H), 3.66 (s, 3H), 3.66-3.59 (m, 1H), 3.48 (td, J=9.2, 8.8, 2.8 Hz, 1H), 3.38-3.28 (m, 1H), 2.44 (s, 3H), 2.40-2.26 (m, 1H), 2.24-2.15 (m, 2H), 1.26 (t, J=7.1 Hz, 3H).

Step C: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(3S)-3-phenoxypyrrolidin-1-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (55.8 mg, 0.09 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (19.9 mg, 0.47 mmol, 5 equiv) and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature, concentrated in vacuo, and the residue was triturated with water, filtered, and dried in vacuo to give the title product as a yellow solid (38.5 mg, 0.07 mmol, 72%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₇ H ₂₆ N ₇ O ₃ S ₂ : 560.1533, found: 560.1541.

Example 78: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-cyclobutyl-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-cyclobutyl-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

An oven-dried flask was charged with Preparation 11b (500 mg, 0.79 mmol, 1 equiv) and copper(I) iodide (300 mg, 1.57 mmol, 2 equiv), the flask was evacuated and flushed with nitrogen (×3), and then dimethylacetamide (15 mL) was added. Cyclobutylzinc bromide (0.5 M in tetrahydrofuran; 9.44 mL, 4.72 mmol, 6 equiv) was added in one portion, and the reaction mixture was stirred overnight at ambient temperature. The mixture was diluted with dichloromethane and then quenched with saturated aqueous sodium bicarbonate, causing a precipitate to form. The mixture was stirred vigorously for 5 min, then filtered through a dichloromethane-wetted celite pad and eluted with dichloromethane and saturated aqueous sodium bicarbonate. The layers were separated and the aqueous phase was extracted with dichloromethane (x2). The combined organic extracts were washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-30% ethyl acetate in isoheptane afforded the title product as a pale yellow glass/foam (313 mg, 0.51 mmol, 65%).

LC/MS (C ₂₉ H ₃₈ N ₆ O ₃ SiS ₂ ) 611 [M+H] ⁺ ; RT 1.38 (LCMS-V-B2)

^1H NMR (400 MHz, CDCl ₃ ) δ 7.60 (dt, J=7.5, 0.9 Hz, 1H), 7.45-7.32 (m, 3H), 7.21 (ddd, J=7.6, 5.9, 2.5 Hz, 1H), 5.85 (s, 2H), 4.51-4.28 (m, 3H), 3.84 (s, 3H), 3.81-3.67 (m, 2H), 2.62-2.47 (m, 2H), 2.46 (s, 3H), 2.38-2.16 (m, 2H), 2.15-1.83 (m, 2H), 1.42 (t, J=7.1 Hz, 3H), 1.05-0.93 (m, 2H), -0.07 (s, 9H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-cyclobutyl-1,3-thiazole-4-carboxylic acid

Trifluoroacetic acid (5.04 mL, 65.8 mmol, 130 equiv) was added to a stirred solution of the product from Step A (309 mg, 0.51 mmol, 1 equiv) in dichloromethane (10 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was concentrated in vacuo. 1,4-Dioxane (10 mL) was added with stirring to give a viscous off-white suspension, to which 1 N aqueous sodium hydroxide solution (5 mL) was added, and the mixture was heated at reflux for 20 min. The mixture was allowed to cool to ambient temperature, then filtered through a pad of Celite, eluting with water and then dioxane, and concentrated in vacuo. The residue was partitioned between chloroform and saturated aqueous sodium bicarbonate, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. The solid was triturated with diethyl ether, filtered, and dried in vacuo to give the title product as a yellow powder (98.5 mg, 0.22 mmol, 43%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₁ H ₂₁ N ₆ O ₂ S ₂ : 453.1162, found: 453.1172.

Example 79: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(3R)-3-phenoxypyrrolidin-1-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-[(3R)-3-phenoxypyrrolidin-1-yl]-1,3-thiazole-4-carboxylate

An oven-dried flask was charged with the product of Preparation 11b (300 mg, 0.44 mmol, 1 equiv), (R)-3-phenoxypyrrolidine (0.13 mL, 0.88 mmol, 2 equiv), cesium carbonate (430 mg, 1.32 mmol, 3 equiv), and 1,4-dioxane (12 mL). The mixture was sparged with nitrogen (10 min), rac-BINAP Pd G3 (43.6 mg, 0.04 mmol, 0.1 equiv) was added, and the mixture was heated at 100 °C overnight. The reaction mixture was diluted with ethyl acetate, then washed with water followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a yellow foam (253 mg, 0.35 mmol, 80%).

LC/MS (C ₃₅ H ₄₃ N ₇ O ₄ SiS ₂ ) 718 [M+H] ⁺ ; RT 1.54 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.85-7.78 (m, 1H), 7.57 (d, J=1.1 Hz, 1H), 7.47-7.38 (m, 2H), 7.35-7.19 (m, 3H), 7.01-6.80 (m, 3H), 5.85 (s, 2H), 5.22-5.10 (m, 1H), 4.21 (qd, J=7.1, 2.4 Hz, 2H), 3.96 (dd, J=11.8, 4.5 Hz, 1H), 3.76-3.59 (m, 3H), 3.49 (td, J=8.6, 2.8 Hz, 1H), 3.33 (s, 4H), 3.36-3.28 (m, 1H), 2.44 (d, J=1.0 Hz, 3H), 2.39-2.28 (m, 1H), 2.26-2.16 (m, 1H), 1.27 (t, J=7.1 Hz, 3H), 0.96-0.83 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(3R)-3-phenoxypyrrolidin-1-yl]-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 4 mL, 16 mmol, 45 equiv) was added to a stirred solution of the product from Step A (253 mg, 0.35 mmol, 1 equiv) in 1,4-dioxane (8 mL), and the mixture was stirred at 50 °C overnight. The reaction mixture was diluted with dichloromethane, washed with saturated aqueous sodium bicarbonate, then brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the desired product as a yellow foam (189 mg, 0.32 mmol, 91%).

LC/MS (C ₂₉ H ₂₉ N ₇ O ₃ S ₂ ) 588 [M+H] ⁺ ; RT 1.32 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 10.98 (br s, 1H), 7.94-7.87 (m, 1H), 7.60 (br s+s, 2H), 7.39 (t, J=7.7 Hz, 1H) , 7.34-7.27 (m, 2H), 7.25-7.16 (s, 1H), 7.02-6.87 (m, 3H), 5.20-5.13 (m, 1H), 4.21 (qd, J=7.1, 2.2 Hz, 2H), 3.97 (dd, J=11.8, 4.5 Hz, 1H), 3.67 (s, 3H), 3.74-3.60 (m, 1H), 3.55-3.43 (m, 1H), 3.38-3.30 (m, 1H), 2.45 (s, 3H), 2.41-2.27 (m, 1H), 2.26-2.17 (m, 1H), 1.27 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(3R)-3-phenoxypyrrolidin-1-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (189 mg, 0.32 mmol, 1 equiv) in 1,4-dioxane (10 mL) was added lithium hydroxide monohydrate (67.4 mg, 1.61 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature, then concentrated in vacuo, triturated with water, filtered, and dried in vacuo to give the title product as a beige solid (118 mg, 0.21 mmol, 65%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₇ H ₂₆ N ₇ O ₃ S ₂ : 560.1533, found: 560.1535.

Example 80: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(piperidin-1-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(piperidin-1-yl)-1,3-thiazol-4-carboxylate

A solution of ethyl 5-bromothiazole-4-carboxylate (500 mg, 2.12 mmol, 1 equiv), piperidine (0.25 mL, 2.54 mmol, 1.2 equiv), and 1,8-diazabicyclo[5.4.0]undec-7-ene (0.64 mL, 4.24 mmol, 2 equiv) in acetonitrile (15 mL) was heated at 80°C overnight. The reaction mixture was allowed to cool to ambient temperature, then concentrated in vacuo and purified by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane to give the desired product as a brown oil (376 mg, 1.57 mmol, 74%).

LC/MS (C ₁₁ H ₁₆ N ₂ O ₂ S) 241 [M+H] ⁺ ; RT 1.12 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 8.45 (s, 1H), 4.24 (q, J=7.1 Hz, 2H), 3.15-3.07 (m, 4H), 1.67 (p, J=5.6 Hz, 4H ), 1.58-1.49 (m, 2H), 1.28 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-bromo-5-(piperidin-1-yl)-1,3-thiazol-4-carboxylate

N-Bromosuccinimide (453 mg, 2.55 mmol, 1.2 equiv) was added to a stirred solution of the product from Step A (510 mg, 2.12 mmol, 1 equiv) in acetonitrile (20 mL), and the mixture was stirred at ambient temperature for 7 h. The reaction mixture was partitioned between 10% aqueous sodium thiosulfate and ethyl acetate, and the organic phase was washed with water followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-40% ethyl acetate in isoheptane afforded the title product as a colourless oil (482 mg, 1.51 mmol, 71%).

LC/MS (C ₁₁ H ₁₅ BrN ₂ O ₂ S) 273 [M-OEt ^- ] ⁺ ; RT 1.14 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 4.23 (q, J=7.1 Hz, 2H), 3.18-3.10 (m, 4H), 1.70-1.60 (m, 4H), 1.59-1.49 (m, 2H) , 1.28 (t, J=7.1 Hz, 3H).

Step C: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-(piperidin-1-yl)-1,3-thiazole-4-carboxylate

The product from Step B (482 mg, 1.51 mmol, 1 equiv) and tert-butyl methylcarbamate (0.26 mL, 1.81 mmol, 1.2 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone)dipalladium(0) (69.1 mg, 0.08 mmol, 0.05 equiv) and xantphos (87.4 mg, 0.15 mmol, 0.1 equiv) in 1,4-dioxane (10 mL). Cesium carbonate (738 mg, 2.26 mmol, 1.5 equiv) was added and the mixture was heated at 100 °C for 7.5 h. The solution was allowed to cool to ambient temperature and concentrated in vacuo. The mixture was diluted with ethyl acetate and washed with water followed by brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 50 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a yellow gum (434 mg, 1.17 mmol, 78%).

LC/MS (C ₁₇ H ₂₇ N ₃ O ₄ S) 370 [M+H] ⁺ ; RT 1.304 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 4.21 (q, J=7.1 Hz, 2H), 3.37 (s, 3H), 3.11-3.03 (m, 4H), 1.64 (p, J=5.6 Hz, 4H), 1.55-1.51 (m, 2H), 1.51 (s, 9H), 1.26 (t, J=7.1 Hz, 3H).

Step D: Ethyl 2-(methylamino)-5-(piperidin-1-yl)-1,3-thiazol-4-carboxylate

Trifluoroacetic acid (1.32 mL, 17.6 mmol, 15 equiv) was added to a stirred solution of the product from Step C (434 mg, 1.17 mmol, 1 equiv) in dichloromethane (15 mL) at 0 °C and the mixture was allowed to warm to ambient temperature and stirred overnight. The reaction mixture was partitioned between saturated aqueous sodium bicarbonate and dichloromethane and the organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. The resulting solid was triturated with diethyl ether, collected by filtration and dried in vacuo to give the title product as a white solid (197 mg, 0.73 mmol, 62%).

LC/MS (C ₁₂ H ₁₉ N ₃ O ₂ S) 270 [M+H] ⁺ ; RT 0.91 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.26 (q, J=4.8 Hz, 1H), 4.17 (q, J=7.1 Hz, 2H), 2.91-2.84 (m, 4H), 2.75 (d, J=4.8 Hz, 3H), 1.61 (p, J=5.6 Hz, 4H), 1.52-1.42 (m, 2H), 1.25 (t, J=7.1 Hz, 3H).

Step E: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)(methyl)amino]-5-(piperidin-1-yl)-1,3-thiazole-4-carboxylate

Sodium hydride (60% in mineral oil; 35.2 mg, 0.88 mmol, 1.2 equiv) was added to a cooled solution of the product from Step D (197 mg, 0.73 mmol, 1 equiv) and 3,6-dichloro-4-methylpyridazine (119 mg, 0.73 mmol, 1 equiv) in tetrahydrofuran (8 mL), and the mixture was allowed to warm to ambient temperature and stirred for 3.5 h. The reaction mixture was diluted with dichloromethane, washed with saturated aqueous ammonium chloride followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a yellow solid (131 mg, 0.33 mmol, 45%).

LC/MS (C ₁₇ H ₂₂ ClN ₅ O ₂ S) 396 [M+H] ⁺ ; RT 1.20 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.76 (d, J=1.0 Hz, 1H), 4.25 (q, J=7.1 Hz, 2H), 3.70 (s, 3H), 3.16-3.08 (m, 4H), 2.41 (d, J=1.0 Hz, 3H), 1.66 (q, J=5.8 Hz, 4H), 1.60-1.46 (m, 2H), 1.30 (t, J=7.1 Hz, 3H).

Step F: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(piperidin-1-yl)-1,3-thiazole-4-carboxylate

A solution of the product from Step E (131 mg, 0.33 mmol, 1 equiv), 2-aminobenzothiazole (74.7 mg, 0.5 mmol, 1.5 equiv), N,N-diisopropylethylamine (0.16 mL, 0.99 mmol, 3 equiv), and xantphos (19.2 mg, 0.03 mmol, 0.1 equiv) in 1,4-dioxane (7 mL) was sparged with nitrogen (10 min), then tris(dibenzylideneacetone)dipalladium(0) (15.2 mg, 0.02 mmol, 0.05 equiv) was added, and the mixture was heated in a sealed flask at 150 °C overnight. The reaction mixture was allowed to cool to ambient temperature, then partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the title product as a yellow foam (64.8 mg, 0.13 mmol, 38%).

LC/MS (C ₂₄ H ₂₇ N ₇ O ₂ S ₂ ) 510 [M+H] ⁺ ; RT 1.32 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.91 (br s, 1H), 7.63 (br s+s, 2H), 7.39 (t, J=7.6 Hz, 1H), 7.22 (t, J=7.5 Hz , 1H), 4.26 (q, 2H), 3.70 (s, 3H), 3.18-3.08 (m, 4H), 2.46 (s, 3H), 1.72-1.61 (m, 4H), 1.59-1.47 (m, 2H), 1.31 (t, J=7.1, 2.7 Hz, 3H) .

Step G: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(piperidin-1-yl)-1, 3-thiazole-4-carboxylic acid

To a solution of the product from Step F (64.8 mg, 0.13 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (26.7 mg, 0.64 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow solid (23 mg, 0.05 mmol, 38%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₂ H ₂₄ N ₇ O ₂ S ₂ : 482.1427, found: 482.1435.

Example 81: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(4-phenoxypiperidin-1-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(4-phenoxypiperidin-1-yl)-1,3-thiazol-4-carboxylate

A solution of ethyl 5-bromothiazole-4-carboxylate (500 mg, 2.12 mmol, 1 equiv), 4-phenoxypiperidine (451 mg, 2.54 mmol, 1.2 equiv), and 1,8-diazabicyclo[5.4.0]undec-7-ene (0.64 mL, 4.24 mmol, 2 equiv) in acetonitrile (15 mL) was heated at 80°C overnight, then allowed to cool to ambient temperature and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the desired product as a brown oil (424 mg, 1.27 mmol, 60%).

LC/MS (C ₁₇ H ₂₀ N ₂ O ₃ S) 333 [M+H] ⁺ ; RT 1.28 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 8.49 (s, 1H), 7.35-7.25 (m, 2H), 7.05-6.96 (m, 2H), 6.94 (tt, J=7.3, 1.0 Hz, 1H), 4.61 (tt, J=7.6, 3.6 Hz, 1H), 4.25 (q, J=7.1 Hz, 2H), 3.45-3.35 (m, 2H), 3.20-3.08 (m, 2H), 2.15-2.02 (m, 2H), 1.88-1.75 (m, 2H), 1.29 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-bromo-5-(4-phenoxypiperidin-1-yl)-1,3-thiazole-4-carboxylate

N-Bromosuccinimide (272 mg, 1.53 mmol, 1.2 equiv) was added to a stirred solution of the product from Step A (424 mg, 1.27 mmol, 1 equiv) in acetonitrile (20 mL), and the mixture was stirred at ambient temperature for 5.5 h. The reaction mixture was quenched by addition of 10% aqueous sodium thiosulfate solution, then extracted with ethyl acetate, washed with water followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-40% ethyl acetate in isoheptane afforded the title product as a white solid (404 mg, 0.98 mmol, 77%).

LC/MS (C ₁₇ H ₁₉ BrN ₂ O ₃ S) 413 [M+H] ⁺ ; RT 1.26 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.35-7.25 (m, 2H), 7.04-6.89 (m, 3H), 4.62 (dt, J=7.6, 3.9 Hz, 1H), 4.25 (q, 2H) , 3.46-3.36 (m, 2H), 3.24-3.13 (m, 2H), 2.12-2.01 (m, 2H), 1.87-1.74 (m, 2H), 1.28 (t, 3H).

Step C: Ethyl 2-{[(tert-butoxy)carbonyl](methyl)amino}-5-(4-phenoxypiperidin-1-yl)-1,3-thiazole-4-carboxylate

The product from Step B (404 mg, 0.98 mmol, 1 equiv) and tert-butyl methyl carbamate (0.17 mL, 1.18 mmol, 1.2 equiv) were added under nitrogen to a solution of tris(dibenzylideneacetone) dipalladium(0) (45 mg, 0.05 mmol, 0.05 equiv) and xantphos (56.8 mg, 0.1 mmol, 0.1 equiv) in 1,4-dioxane (10 mL). Cesium carbonate (480 mg, 1.47 mmol, 1.5 equiv) was added and the mixture was heated at 100 °C overnight. The reaction mixture was allowed to cool to ambient temperature and then concentrated in vacuo. The residue was partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a yellow gum (285 mg, 0.62 mmol, 63%).

LC/MS (C ₂₃ H ₃₁ N ₃ O ₅ S) 462 [M+H] ⁺ ; RT 1.37 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.34-7.24 (m, 2H), 7.02-6.97 (m, 2H), 6.93 (tt, J=7.2, 1.1 Hz, 1H), 4.58 (dt, J= 7.9, 4.1 Hz, 1H), 4.23 (q, J=7.1 Hz, 2H), 3.38 (s, 3H), 3.37-3.33 (m, 2H), 3.09 (ddd, J=11.8, 8.5, 3.2 Hz, 2H), 2.15-1.99 (m, 2H ), 1.79 (dtd, J=12.3, 8.2, 3.6 Hz, 2H), 1.52 (s, 9H), 1.27 (t, J=7.1 Hz, 3H).

Step D: Ethyl 2-(methylamino)-5-(4-phenoxypiperidin-1-yl)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (0.46 mL, 6.17 mmol, 10 equiv) was added to a stirred solution of the product from Step C (285 mg, 0.62 mmol, 1 equiv) in dichloromethane (8 mL) at 0 °C and the mixture was allowed to warm to ambient temperature and stirred overnight. The reaction mixture was quenched by addition of saturated aqueous sodium bicarbonate solution, extracted with dichloromethane, and the organic extract was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. The resulting solid was triturated with diethyl ether/heptane, filtered, and dried in vacuo to give the title product as a cream-colored solid (161 mg, 0.45 mmol, 72%).

LC/MS (C ₁₈ H ₂₃ N ₃ O ₃ S) 362 [M+H] ⁺ ; RT 1.08 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.35-7.24 (m, 3H), 7.02-6.97 (m, 2H), 6.93 (tt, J=7.3, 1.1 Hz, 1H), 4.53 (dt, J=7.9, 4.1 Hz, 1H), 4.19 (q, J=7.1 Hz, 2H), 3.22-3.12 (m, 2H), 2.90 (ddd, J=11.6, 8.6, 3.2 Hz, 2H), 2.76 (d, J=4.7 Hz, 3H), 2.10-1.95 (m, 2H), 1.77 (dtd, J=12.3, 8.2, 3.6 Hz, 2H), 1.26 (t, J=7.1 Hz, 3H).

Step E: Ethyl 2-[(6-chloro-5-methylpyridazin-3-yl)(methyl)amino]-5-(4-phenoxypiperidin-1-yl)-1,3-thiazole-4-carboxylate

Sodium hydride (60% in mineral oil; 21.4 mg, 0.53 mmol, 1.2 equiv) was added to a cooled solution of the product from Step D (161 mg, 0.45 mmol, 1 equiv) and 3,6-dichloro-4-methylpyridazine (72.6 mg, 0.45 mmol, 1 equiv) in tetrahydrofuran (5 mL), and the mixture was allowed to warm to ambient temperature and stirred overnight. The reaction mixture was diluted with dichloromethane, then washed with saturated aqueous ammonium chloride followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the desired product as a yellow foam (63.3 mg, 0.13 mmol, 29%).

LC/MS (C ₂₃ H ₂₆ ClN ₅ O ₃ S) 488 [M+H] ⁺ ; RT 1.289 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.77 (d, J=1.0 Hz, 1H), 7.34-7.25 (m, 2H), 7.04-6.98 (m, 2H), 6.93 (tt, J=7.4, 1.1 Hz, 1H), 4.59 (dt, J=8.1, 4.1 Hz, 1H), 4.25 (q, J=7.1 Hz, 2H), 3.70 (s, 3H), 3.45-3.35 (m, 2H), 3.13 (ddd, J=11.5, 8.5, 3.2 Hz , 2H), 2.41 (d, J=1.0 Hz, 3H), 2.14-2.01 (m, 2H), 1.81 (dtd, J=12.2, 8.3, 3.5 Hz, 2H), 1.30 (t, J=7.1 Hz, 3H).

Step F: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(4-phenoxypiperidin-1-yl)-1,3-thiazole-4-carboxylate

A solution of the product from Step E (63.3 mg, 0.13 mmol, 1 equiv), 2-aminobenzothiazole (29.2 mg, 0.19 mmol, 1.5 equiv), N,N-diisopropylethylamine (0.06 mL, 0.39 mmol, 3 equiv), and xantphos (7.51 mg, 0.01 mmol, 0.1 equiv) in 1,4-dioxane (4 mL) was sparged with nitrogen (10 min), then tris(dibenzylideneacetone)dipalladium(0) (5.94 mg, 0.01 mmol, 0.05 equiv) was added, and the mixture was heated in a sealed flask at 150 °C overnight. The reaction mixture was allowed to cool to ambient temperature, then partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the title product as a yellow foam (23 mg, 0.04 mmol, 30%).

LC/MS (C ₃₀ H ₃₁ N ₇ O ₃ S ₂ ) 602 [M+H] ⁺ ; RT 1.37 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.92 (br s, 1H), 7.64 (br s+s, 2H), 7.36 (dd, J=31.4, 7.1 Hz, 1H), 7.29 (dd, J= 8.6, 7.3 Hz, 2H), 7.25-7.17 (m, 1H), 7.07-6.98 (m, 2H), 6.97-6.89 (m, 1H), 4.61 (dt, 1H), 4.27 (q, 2H), 3.71 (s, 3H), 3.49-3.36 (m , 2H), 3.22-3.09 (m, 3H), 2.46 (s, 3H), 2.18-2.02 (m, 2H), 1.91-1.73 (m, 2H), 1.32 (t, 3H).

Step G: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(4-phenoxypiperidin-1-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step F (23 mg, 0.04 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (8.02 mg, 0.19 mmol, 5 equiv) and the mixture was heated at reflux overnight, then allowed to cool to ambient temperature and concentrated in vacuo. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the title product as a yellow solid (3.7 mg, 0.01 mmol, 17%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₈ H ₂₈ N ₇ O ₃ S ₂ : 574.1690, found: 574.1697.

Example 82: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-[4-(3-{[(tert-butoxy)carbonyl](methyl)amino}prop-1-yn-1-yl)-2-fluorophenoxy]propyl}-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-iodopropyl)-1,3-thiazole-4-carboxylate

To a solution of the product of Synthesis 5g (176 mg, 0.24 mmol, 1 equiv.) in dichloromethane (5 mL) was added trifluoroacetic acid (5 mL), and the mixture was stirred at ambient temperature for 4 h. The reaction mixture was diluted with dichloromethane, washed with 2 N aqueous sodium hydroxide solution, dried (magnesium sulfate), and concentrated in vacuo. The residue was triturated with acetonitrile, filtered, and dried in vacuo to afford the title product as a white solid (93 mg, 0.16 mmol, 64%).

LC/MS (C ₂₂ H ₂₃ IN ₆ O ₂ S ₂ ) 595 [M+H] ⁺ ; RT 2.63 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.92 (s, 1H), 7.69 (s, 1H), 7.54 (br s, 1H), 7.40 (t, J=7.8 Hz, 1H), 7.22 (t, J=7.5 Hz, 1H), 4.31 (q, J=7.1 Hz, 2H), 3.77 (s, 3H), 3.35 (t, J=6.8 Hz, 2H), 3.24-3.16 (m, 2H), 2.47 (s, 3H), 2.20-2.11 (m, 2H), 1.34 (t, J=7.1 Hz, 3H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-[4-(3-{[(tert-butoxy)carbonyl](methyl)amino}prop-1-yn-1-yl)-2-fluorophenoxy]propyl}-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (93 mg, 0.16 mmol, 1 equiv) in dimethylformamide (5 mL) were added the product of Preparation 6a (56.8 mg, 0.2 mmol, 1.3 equiv) and cesium carbonate (153 mg, 0.47 mmol, 3 equiv), and the mixture was heated at 80 °C overnight, then allowed to cool to ambient temperature and concentrated in vacuo. The residue was partitioned between ethyl acetate and brine, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the desired product as a yellow gum (45 mg, 0.06 mmol, 39%).

LC/MS (C ₃₇ H ₄₀ FN ₇ O ₅ S ₂ ) 747 [M+H] ⁺ ; RT 2.77 (LCMS-VC)

^1H NMR (400 MHz, DMSO-d6) δ 7.91 (d, J=19.8 Hz, 1H), 7.68 (s, 1H), 7.54 (br s, 1H), 7.39 (t, 1H), 7.33 (d, 1H), 7.26-7.12 (m, 3H), 4.26 (q, 2H), 4.21 (s, 2H), 4.15 (t, 3=6.1 Hz, 2H), 3.77 (s, 2H), 3.31-3.22 (m, 2H), 2.85 (s, 3H), 2.47 ( s, 3H), 2.20-2.09 (m, 2H), 1.41 (s, 9H), 1.30 (t, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-[4-(3-{[(tert-butoxy)carbonyl](methyl)amino}prop-1-yn-1-yl)-2-fluorophenoxy]propyl}-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (45 mg, 0.06 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (25.3 mg, 0.6 mmol, 10 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded the desired product as a yellow solid (5.1 mg, 0.01 mmol, 12%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₅ H ₃₇ FN ₇ O ₅ S ₂ : 718.2276, found: 718.2284.

Example 83: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(piperidin-4-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(piperidin-4-yl)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1 mL, 13.4 mmol, 166 equiv) was added to a stirred solution of the product of Preparation 5k, Step B (60 mg, 0.08 mmol, 1 equiv) in dichloromethane (4 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was loaded onto an SCX-2 cartridge (5 g, preconditioned with dichloromethane then methanol) and then washed with dichloromethane followed by methanol. Elution with 3.5 N methanolic ammonia and concentration in vacuo afforded the desired product as a yellow solid (40.9 mg, 0.08 mmol, 99%).

LC/MS (C ₂₄ H ₂₇ N ₇ O ₂ S ₂ ) 510 [M+H] ⁺ ; RT 0.857 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.91 (d, J=7.9, 1.2 Hz, 1H), 7.68 (d, J=1.2 Hz, 1H), 7.53 (d, J=8.0 Hz, 1H), 7.39 (ddd, J=8.2, 7.3, 1.3 Hz, 1H), 7.21 (td, J=7.6, 1.2 Hz, 1H), 4.29 (q, J=7.1 Hz, 2H), 3.90-3.67 (m, 4H), 3.18-3.09 (m, 2H), 2.75-2.63 (m, 2H), 2.46 (d, J=1.0 Hz, 3H), 2.00-1.92 (m, 2H), 1.63 (qd, J=12.4, 3.9 Hz, 2H), 1.32 (t, J=7.1 Hz, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(piperidin-4-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (40.9 mg, 0.08 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (16.8 mg, 0.4 mmol, 5 equiv), and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature, then concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) gave a solid that was triturated with chloroform, filtered, and dried in vacuo to give the title product as a yellow solid (27.4 mg, 0.06 mmol, 71%).

LC/MS (C ₂₂ H ₂₃ N ₇ O ₂ S ₂ ) 482 [M+H] ⁺ ; RT 0.772 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.83 (d, J=7.7 Hz, 1H), 7.55 (s, 1H), 7.46 (d, J=7.9 Hz, 1H), 7.35-7.27 (m, 1H), 7.16-7.05 (m, 1H), 4.21 (tt, J=12.0, 3.8 Hz, 1H), 3.65 (s, 3H), 3.09-2.95 (m, 2H), 2.62-2.53 (m, 2H), 2.43 (d, J=1.1 Hz, 3H), 1.83 (dd, J=12.9, 9.4 Hz, 2H), 1.47 (qd, J=12.1, 3.9 Hz, 2H)

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₂ H ₂₃ N ₇ O ₂ S ₂ : 482.1427, found: 482.1430.

Example 84: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{1-[(tert-butoxy)carbonyl]piperidin-4-yl}-1,3-thiazole-4-carboxylic acid

Step A: tert-Butyl 4-[2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-4-(ethoxycarbonyl)-1,3-thiazol-5-yl]piperidine-1-carboxylate

Tetrabutylammonium fluoride (1 M in tetrahydrofuran, 0.48 mL, 0.48 mmol, 6 equiv) was added to a stirred solution of the product of Preparation 5k, Step B (60 mg, 0.08 mmol, 1 equiv) in tetrahydrofuran (3 mL), and the mixture was heated at 55 °C overnight. The mixture was allowed to cool to ambient temperature, partitioned between ethyl acetate and saturated aqueous sodium bicarbonate, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded the title product as a yellow glass (37.7 mg, 0.06 mmol, 76%).

LC/MS (C ₂₉ H ₃₅ N ₇ O ₄ S ₂ ) 610 [M+H] ⁺ ; RT 1.356 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 8.00 (br s, 1H), 7.68 (br s+s, 2H), 7.52-7.351 (m, 1H), 7.31-7.14 (m, 1H), 4.31 ( q, J=7.1 Hz, 2H), 4.22 (d, J=12.8 Hz, 2H), 3.86-3.70 (m, 4H), 2.97-2.71 (m, 2H), 2.46 (s, 3H), 2.05-1.94 (m, 2H), 1.59-1.46 (m, 2H) , 1.44 (s, 9H), 1.35 (t, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{1-[(tert-butoxy)carbonyl]piperidin-4-yl}-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (47 mg, 0.08 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (16.2 mg, 0.39 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile (pH 4; formic acid) in water (pH 4; formic acid) afforded the desired product as a yellow solid (23 mg, 0.04 mmol, 51%).

MSHR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₇ H ₃₁ N ₇ O ₄ S ₂ : 582.1952, found: 582.1956.

Example 85: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethyl]amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate and 2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethanol as starting materials, 3.07 g (99%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 8.08 (s, 1H), 4.17/4.07 (m+m, 2H), 4.08 (m, 1H), 4.03/3.54 (dd+dd, 2H), 3.80 (s, 3H), 1.88/1.84 (m+m, 2H), 1.53 (s, 9H), 1.28 (s, 3H), 1.22 (s, 3H); HR-ESI (m/z): [M+H] ⁺ , calculated for C ₁₇ H ₂₆ N ₂ O ₆ S: 387.1589, found: 387.1585.

Step B: Methyl 2-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethylamino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 1.21 g (60%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.82 (t, 1H), 7.53 (s, 1H), 4.11 (m, 1H), 4.02/3.49 (dd+dd, 2H), 3.74 (s, 3H), 3.33/3.24 (m+m, 2H), 1.78/1.75 (m+m, 2H), 1.32 (s, 3H), 1.26 (s, 3H); HR-ESI (m/z): [M+H] ⁺ , calculated for C ₁₂ H ₁₈ N ₂ O ₄ S: 287.1065, found: 287.1055.

Step C: methyl 2-[(6-chloro-5-methylpyridazin-3-yl)-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethyl]amino]thiazole-4-carboxylate

Using the General Procedure for Carrying Out a Nucleophilic Substitution Reaction, starting from the product from Step B as the starting material, 178 mg (35%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 8.07 (s, 1H), 7.85 (d, 1H), 4.57/4.37 (m+m, 2H), 4.17 (m, 1H), 4.03/3.62 (dd+dd, 2H), 3.82 (s, 3H), 2.43 (d, 3H), 1.96 (m, 2H), 1.35/1.23 (s+s, 6H); MSHR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₇ H ₂₂ ClN ₄ O ₄ S: 413.1045, found: 413.1048.

Step D: Methyl 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethyl]amino]thiazole-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product from Step C and reacting in toluene at 150°C for 4 h, 184 mg (81%) of the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₄ H ₂₇ N ₆ O ₄ S ₂ : 527.1530, found: 527.1512.

Step E: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]thiazole-4-carboxylic acid

To a solution of the product from Step D in 1,4-dioxane was added 2 M NaOH solution, and the mixture was stirred at 80 °C for 1 h. After acidifying the mixture with 1 N HCl solution, the reaction mixture was stirred at 80 °C for 0.5 h, then the precipitate was filtered off and purified by flash column chromatography to obtain the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₀ H ₂₁ N ₆ O ₄ S ₂ : 473.1066, found: 473.1055.

Example 86: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-benzylpiperidin-4-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(1-benzylpiperidin-4-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a stirred solution of Preparation 5k (65 mg, 0.1 mmol, 1 equiv) in acetonitrile (5 mL) were added benzaldehyde (0.02 mL, 0.2 mmol, 2 equiv), sodium triacetoxyborohydride (64.6 mg, 0.3 mmol, 3 equiv), and glacial acetic acid (5 μL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a colourless gum (44.7 mg, 0.06 mmol, 60%).

LC/MS (C ₃₇ H ₄₇ N ₇ O ₃ SiS ₂ ) 730 [M+H] ⁺ ; RT 1.32 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.89 (d, 1H), 7.66 (d, J=1.1 Hz, 1H), 7.51-7.41 (m, 2H), 7.40-7.31 (m, 4H), 7.30 -7.22 (m, 2H), 5.86 (s, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.76 (s, 3H), 3.76-3.69 (m, 2H), 3.63 (tt, J=12.3, 3.8 Hz, 1H), 3.51 (s, 2H ), 2.94 (d, J=11.1 Hz, 2H), 2.46 (d, J=1.0 Hz, 3H), 2.15-1.89 (m, 4H), 1.67 (qd, J=12.2, 3.6 Hz, 2H), 1.32 (t, J=7.1 Hz, 3H), 0.92 (dd, J=8.6, 7.4 Hz, 2H), - 0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-benzylpiperidin-4-yl)-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 3 mL, 12 mmol, 196 equiv) was added to a stirred solution of the product from Step A (44.7 mg, 0.06 mmol, 1 equiv) in 1,4-dioxane (3 mL), and the mixture was stirred at 60 °C overnight. The reaction mixture was allowed to cool to ambient temperature, partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the desired product as a yellow gum (22 mg, 0.04 mmol, 60%).

LC/MS (C ₃₁ H ₃₃ N ₇ O ₂ S ₂ ) 600 [M+H] ⁺ ; RT 0.99 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 11.05 (br s, 1H), 7.98 (br s, 1H), 7.68 (br s+s, 2H), 7.43-7.31 (m, 5H), 7.30-7.19 (m, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.76 (s, 3H), 3.63 (tt, J=12.0, 3.8 Hz, 1H), 3.52 (s, 2H), 2.98-2.91 (m, 2H), 2.46 (s, 3H), 2.05 (t, 2H), 2.01-1.94 (m, 2H), 1.67 (qd, J=12.2, 3.6 Hz, 2H), 1.32 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-benzylpiperidin-4-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (22 mg, 0.04 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (7.7 mg, 0.18 mmol, 5 equiv), and the mixture was heated at reflux overnight, then allowed to cool to ambient temperature and concentrated in vacuo. The resulting solid was triturated with water, then with diethyl ether, filtered, and dried in vacuo to afford the title product as a yellow solid (9.6 mg, 0.02 mmol, 46%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₉ H ₃₀ N ₇ O ₂ S ₂ : 572.1897, found: 572.1903.

Example 87: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(2-methylpropyl)piperidin-4-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-[1-(2-methylpropyl)piperidin-4-yl]-1,3-thiazole-4-carboxylate

To a stirred solution of Preparation 5k (134 mg, 0.21 mmol, 1 equiv) in 2:1 acetonitrile/dichloromethane (6 mL) were added isobutyraldehyde (0.04 mL, 0.42 mmol, 2 equiv), sodium triacetoxyborohydride (133 mg, 0.63 mmol, 3 equiv), and glacial acetic acid (10 μL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as an off-white solid (114 mg, 0.16 mmol, 79%).

LC/MS (C ₃₄ H ₄₉ N ₇ O ₃ SiS ₂ ) 696 [M+H] ⁺ ; RT 1.30 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.92-7.85 (m, 1H), 7.66 (d, J=1.1 Hz, 1H), 7.50-7.38 (m, 2H), 7.29-7.20 (m, 1H) , 5.86 (s, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.76 (s, 3H), 3.75-3.68 (m, 2H), 3.66-3.53 (m, 1H), 2.99-2.90 (m, 2H), 2.46 (d, J=1.0 Hz , 3H), 2.07 (d, J=7.4 Hz, 2H), 2.00-1.88 (m, 4H), 1.79 (hept, J=6.7 Hz, 1H), 1.73-1.59 (m, 2H), 1.32 (t, J=7.1 Hz, 3H), 0.97 -0.85 (m, 8H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(2-methylpropyl)piperidin-4-yl]-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1.2 mL, 16.1 mmol, 98 equiv) was added to a stirred solution of the product from Step A (114 mg, 0.16 mmol, 1 equiv) in dichloromethane (4 mL) and the mixture was stirred at ambient temperature overnight. The reaction mixture was allowed to cool to ambient temperature, then partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a yellow solid (76.8 mg, 0.14 mmol, 83%).

LC/MS (C ₂₈ H ₃₅ N ₇ O ₂ S ₂ ) 566 [M+H] ⁺ ; RT 0.96 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.96 (br s, 1H), 7.68 (s, 1H), 7.56 (br s, 1H), 7.39 (t, J=7.6 Hz, 1H), 7.21 (t , J=7.4 Hz, 1H), 4.30 (q, J=7.1 Hz, 2H), 3.76 (s, 3H), 3.67-3.55 (m, 1H), 2.96 (d, J=11.5 Hz, 2H), 2.47 (s, 3H), 2.08 (d, J=7.4 Hz, 2H ), 2.02-1.89 (m, 4H), 1.80 (hept, J=6.7 Hz, 1H), 1.66 (td, J=14.3, 13.7, 10.3 Hz, 2H), 1.33 (t, J=7.1 Hz, 3H), 0.90 (d, J=6.5 Hz, 6H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(2-methylpropyl)piperidin-4-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (76.8 mg, 0.14 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (28.5 mg, 0.68 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow solid (50 mg, 0.09 mmol, 69%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₆ H ₃₂ N ₇ O ₂ S ₂ : 538.2053, found: 538.2060.

Example 88: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[4-(phenoxymethyl)piperidin-1-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-[4-(phenoxymethyl)piperidin-1-yl]-1,3-thiazole-4-carboxylate

To a stirred solution of Preparation 11b (200 mg, 0.31 mmol, 1 equiv), 4-(phenoxymethyl)piperidine hydrochloride (143 mg, 0.63 mmol, 2 equiv), and cesium carbonate (308 mg, 0.94 mmol, 3 equiv) in 1,4-dioxane (8 mL) under nitrogen was added rac-BINAP-Pd-G3 (31.2 mg, 0.03 mmol, 0.1 equiv), and the mixture was heated at 100°C overnight. The reaction mixture was allowed to cool to ambient temperature, then diluted with ethyl acetate, washed with water and then brine, dried (magnesium sulfate), and concentrated in vacuo to give the desired product as a yellow foam (153 mg, 0.2 mmol, 65%).

LC/MS (C ₃₇ H ₄₇ N ₇ O ₄ SiS ₂ ) 746 [M+H] ⁺ ; RT 1.60 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.82 (d, 1H), 7.61 (d, J=1.1 Hz, 1H), 7.50-7.39 (m, 2H), 7.33-7.20 (m, 3H), 6.99 -6.90 (m, 3H), 5.85 (s, 2H), 4.25 (q, J=7.1 Hz, 2H), 3.91 (d, 3=6.1 Hz, 2H), 3.79-3.68 (m, 5H), 3.55 (d, J=11.2 Hz, 2H), 2.88 ( td, J=11.6, 2.3 Hz, 2H), 2.44 (d, J=0.9 Hz, 3H), 2.00-1.82 (m, 3H), 1.54 (qd, J=12.0, 3.9 Hz, 2H), 1.31 (t, J=7.1 Hz, 3H), 0.95-0.89 (m, 2H), -0.11 (s, 9H ).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[4-(phenoxymethyl)piperidin-1-yl]-1,3-thiazole-4-carboxylate

Hydrochloric acid (4 M in 1,4-dioxane; 3 mL, 12 mmol, 58.7 equiv) was added to a stirred solution of the product from Step A (153 mg, 0.2 mmol, 1 equiv) in dichloromethane (10 mL), and the mixture was stirred at 50 °C overnight. The reaction mixture was allowed to cool to ambient temperature, then partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a yellow glass (83.8 mg, 0.14 mmol, 67%).

LC/MS (C ₃₁ H ₃₃ N ₇ O ₃ S ₂ ) 616 [M+H] ⁺ ; RT 1.39 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 11.01 (br s, 1H), 7.94 (br s, 1H), 7.63 (br s+s, 2H), 7.42-7.35 (m, 1H), 7.34-7.26 (m, 2H), 7.23-7.15 (m, 1H), 7.00-6.88 (m, 3H), 4.25 (q, J=7.1 Hz, 2H), 3.91 (d, J=6.1 Hz, 2H), 3.70 (s, 3H), 3.55 (d, J=14.2 Hz, 2H), 2.88 (dd, J=12.2, 9.8 Hz, 2H), 2.45 (s, 3H), 2.02-1.81 (m, 3H), 1.62-1.47 (m, 2H), 1.30 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[4-(phenoxymethyl)piperidin-1-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (83.8 mg, 0.14 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (28.6 mg, 0.68 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow solid (59.7 mg, 0.1 mmol, 75%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₉ H ₃₀ N ₇ O ₃ S ₂ : 588.1846, found: 588.1853.

Example 89: 5-(1-Benzoylpiperidin-4-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(1-benzoylpiperidin-4-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a stirred solution of the product of Synthesis 5k (88 mg, 0.14 mmol, 1 equiv) and triethylamine (0.04 mL, 0.28 mmol, 2 equiv) in dichloromethane (3 mL) was added benzoyl chloride (0.02 mL, 0.17 mmol, 1.2 equiv) and the mixture was stirred at ambient temperature for 4.5 h and then concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the title product as an off-white foam (89.6 mg, 0.12 mmol, 88%).

LC/MS (C ₃₇ H ₄₅ N ₇ O ₄ SiS ₂ ) 744 [M+H] ⁺ ; RT 1.49 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.88 (d, J=7.7 Hz, 1H), 7.67 (d, J=1.2 Hz, 1H), 7.51-7.40 (m, 7H), 7.25 (ddd, J =8.1, 7.0, 1.5 Hz, 1H), 5.86 (s, 2H), 4.66 (br s, 1H), 4.30 (q, J=7.1 Hz, 2H), 3.97-3.85 (m, 1H), 3.77 (s, 3H), 3.75-3.67 (m, 2H) , 3.19 (br s, 1H), 2.88 (br s, 1H), 2.47 (d, J=0.9 Hz, 3H), 2.10-1.87 (m, 2H), 1.77-1.55 (m, 2H), 1.35 (t, J=7.1 Hz, 3H), 0.98-0.88 (m, 2H), -0.07 (s, 9H).

Step B: Ethyl 5-(1-benzoylpiperidin-4-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1.2 mL, 16.1 mmol, 134 equiv) was added to a stirred solution of the product from Step A (89.6 mg, 0.12 mmol, 1 equiv) in dichloromethane (4 mL) and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate and the organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a yellow glass (55 mg, 0.09 mmol, 74%).

LC/MS (C ₃₁ H ₃₁ N ₇ O ₃ S ₂ ) 614 [M+H] ⁺ ; RT 1.41 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 11.08 (br s, 1H), 7.96 (br s, 1H), 7.69 (br s+s, 2H), 7.64-7.43 (m, 5H), 7.40 (t , J=7.5 Hz, 1H), 7.23 (t, 1H), 4.69 (br s, 1H), 4.31 (q, J=7.1 Hz, 2H), 4.00-3.80 (m, 1H), 3.82-3.66 (m, 4H), 3.30-2.74 (m, 2H), 2.47 (s, 3H), 2.21-1.84 (m, 2H), 1.76-1.57 (m, 2H), 1.33 (t, J=7.1 Hz, 3H).

Step C: 5-(1-benzoylpiperidin-4-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (55 mg, 0.09 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (18.8 mg, 0.45 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow solid (35.8 mg, 0.06 mmol, 68%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₉ H ₂₈ N ₇ O ₃ S ₂ : 586.1690, found: 586.1702.

Example 90: 3-{1-[(Adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-6-({6-[(1,3-benzothiazol-2-yl) amino]-5-methylpyridazin-3-yl}(methyl)amino)pyridine-2-carboxylic acid

Step A: Ethyl 3-bromo-6-{[(tert-butoxy)carbonyl](methyl)amino}pyridine-2-carboxylate

Cesium carbonate (4.9 g, 15.1 mmol, 1.5 equiv) was added under nitrogen to a solution of ethyl 3,6-dibromopyridine-2-carboxylate (3.1 g, 10.03 mmol, 1 equiv), tert-butyl N-methylcarbamate (1.65 g, 12.6 mmol, 1.25 equiv), tris(dibenzlideneacetone)dipalladium(0) (91.9 mg, 0.1 mmol, 0.01 equiv), and xantphos (116 mg, 0.2 mmol, 0.02 equiv) in 1,4-dioxane (40 mL), and the mixture was heated at 100°C overnight. The reaction mixture was allowed to cool to ambient temperature and ethyl acetate (250 ml) was added. The mixture was washed with water (2 x 100 ml), brine (100 ml), dried (magnesium sulfate) and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with dichloromethane gave the title product as a pale green oil (1.78 g, 4.96 mmol, 49%).

LC/MS (C ₁₄ H ₁₉ BrN ₂ O ₄ ) 303 [M-tBu+H] ⁺ ; RT 1.43 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.85-7.74 (m, 2H), 4.45 (q, J=7.1 Hz, 2H), 3.40 (s, 3H), 1.52 (s, 9H), 1.42 (t, J=7.1 Hz, 3H).

Step B: Ethyl 3-bromo-6-(methylamino)pyridine-2-carboxylate

Trifluoroacetic acid (1.9 ml, 24.8 mmol, 5 equiv) was added to a solution of the product from Step A (1.78 g, 4.96 mmol, 1 equiv) in dichloromethane (15 ml) at 0 °C and the mixture was allowed to warm to ambient temperature and stirred overnight. The reaction mixture was partitioned between dichloromethane (50 ml) and saturated aqueous sodium bicarbonate solution and the organic phase was washed with water (2 x 50 ml) and brine (50 ml), dried (magnesium sulfate) and concentrated in vacuo to give the title product as a yellow oil (1.2 g, 4.63 mmol, 94%).

LC/MS (C ₉ H ₁₁ BrN ₂ O ₂ ) 260 [M+H] ⁺ ; RT 1.11 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.61 (d, J=8.9 Hz, 1H), 6.36 (d, J=8.9 Hz, 1H), 4.82 (s, 1H), 4.43 (q, J=7.1 Hz, 2H), 2.90 (d, J=4.3 Hz, 3H), 1.41 (t, J=7.1 Hz, 3H).

Step C: Ethyl 3-bromo-6-[(6-chloro-1,2,4,5-tetrazin-3-yl)(methyl)amino]pyridine-2-carboxylate

A solution of 3,6-dichloro-1,2,4,5-tetrazine (664 mg, 4.4 mmol, 0.95 equiv) and the product from Step B (1.2 g, 4.63 mmol, 1 equiv) in acetonitrile (20 mL) was heated in a sealed flask for 18 h. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-15% ethyl acetate in isoheptane afforded the desired product as a red solid (898 mg, 2.4 mmol, 55%).

LC/MS (C ₁₁ H ₁₀ BrClN ₆ O ₂ ) 373 [M+H] ⁺ ; RT 1.31 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.99 (d, J=8.7 Hz, 1H), 7.69 (d, J=8.7 Hz, 1H), 4.49 (q, J=7.1 Hz, 2H), 3.87 (s, 3H), 1.44 (t, J=7.1 Hz, 3H).

Step D: Ethyl 3-bromo-6-[(6-chloro-5-methylpyridazin-3-yl)(methyl)amino]pyridine-2-carboxylate

Ethyl 1-propenyl ether (2.64 mL, 23.8 mmol, 10 equiv) was added to a solution of the product from Step C (890 mg, 2.38 mmol, 1 equiv) in 1,4-dioxane (15 mL), and the mixture was heated in a sealed tube at 100 °C for 24 h. Purification by automated flash column chromatography (CombiFlash Rf, 80 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the desired product as an orange solid (776 mg, 2.01 mmol, 85%).

LC/MS (C ₁₄ H ₁₄ BrClN ₄ O ₂ ) 385 [M+H] ⁺ ; RT 1.29 (LCMS-V-B1)

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.86 (d, J=8.9 Hz, 1H), 7.65 (q, J=1.0 Hz, 1H), 7.15 (d, J=8.8 Hz, 1H), 4.44 (q, J=7.1 Hz, 2H), 3.70 (s, 3H), 2.35 (d, J=1.0 Hz, 3H), 1.42 (t, J=7.1 Hz, 3H).

Step E: Ethyl 3-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-6-[(6-chloro-5-methylpyridazin-3-yl)(methyl)amino]pyridine-2-carboxylate

To a suspension of the product from Step D (770 mg, 2 mmol, 1 equiv) and the product of Preparation 10a (783 mg, 2.2 mmol, 1.1 equiv) in tetrahydrofuran (12 mL) was added a solution of potassium carbonate (552 mg, 3.99 mmol, 2 equiv) in water (2 mL), and the mixture was sparged with nitrogen (10 _min ). Pd(dppf) _Cl2.CH2Cl2 (163 mg, 0.2 mmol, _0.1 equiv) was added, and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature, then partitioned between ethyl acetate and brine, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a cream-colored solid (680 mg, 1.27 mmol, 64%).

LC/MS (C ₂₉ H ₃₅ ClN ₆ O ₂ ) 535 [M+H] ⁺ ; RT 1.55 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.82-7.73 (m, 2H), 7.50 (d, J=8.6 Hz, 1H), 7.35 (s, 1H), 4.14 (q, J=7.1 Hz, 2H ), 3.77 (s, 2H), 3.63 (s, 3H), 2.32 (d, J=1.0 Hz, 3H), 2.18 (s, 3H), 2.01-1.88 (m, 3H), 1.72-1.62 (m, 3H), 1.61-1.52 (m, 9H), 1.13 (t, J=7.1 Hz, 3H).

Step F: Ethyl 3-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-6-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)pyridine-2-carboxylate

To a solution of the product from Step E (600 mg, 1.12 mmol, 1 equiv) and 2-aminobenzothiazole (253 mg, 1.68 mmol, 1.5 equiv) in 1,4-dioxane (20 mL) were added N,N-diisopropylethylamine (0.59 mL, 3.36 mmol, 3 equiv), xantphos (64.9 mg, 0.11 mmol, 0.1 equiv), and tris(dibenzylideneacetone)dipalladium(0) (51.3 mg, 0.06 mmol, 0.05 equiv), and the mixture was heated in a sealed tube for 64 h. The reaction mixture was allowed to cool to ambient temperature, then diluted with ethyl acetate, washed with brine, and concentrated in Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 130 g RediSep column) eluting with a gradient of 30-95% acetonitrile in water afforded the desired product as a yellow glass (513 mg, 0.79 mmol, 71%).

LC/MS (C ₃₆ H ₄₀ N ₈ O ₂ S) 649 [M+H] ⁺ ; RT 1.62 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 11.09 (br s, 1H), 7.89 (br s, 1H), 7.74-7.51 (m, 3H), 7.40 (t, 1H), 7.33 (s, 1H) , 7.30 (d, 1H), 7.22 (t, 1H), 4.13 (q, J=7.1 Hz, 2H), 3.76 (s, 2H), 3.61 (s, 3H), 2.39 (s, 3H), 2.17 (s, 3H), 1.95 (s, 3H), 1.74-1.62 (m, 3H), 1.62-1.46 (m, 9H), 1.12 (t, J=7.1 Hz, 3H).

Step G: 3-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-6-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)pyridine-2-carboxylic acid

To a solution of the product from Step F (510 mg, 0.79 mmol, 1 equiv) in 1,4-dioxane (10 mL) was added lithium hydroxide monohydrate (82.5 mg, 1.97 mmol, 2.5 equiv) and the mixture was heated at reflux for 1 h. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo, then water (5 mL) was added and the pH was adjusted to 3 by adding 2 M aqueous hydrochloric acid. The mixture was extracted into dichloromethane and the organic extract was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. The resulting solid was triturated with methanol, filtered, washed with methanol and dried under vacuum to give the desired product as an off-white solid (362 mg, 0.58 mmol, 74%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₄ H ₃₇ N ₈ O ₂ S: 621.2755, found: 621.2765.

Example 91: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-phenylpiperidin-4-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-(1-phenylpiperidin-4-yl)-1,3-thiazole-4-carboxylate

Tris(dibenzylideneacetone)dipalladium(0) (10.7 mg, 0.01 mmol, 0.05 equiv) under nitrogen atmosphere was added to a stirred solution of the product of Preparation 5k (150 mg, 0.23 mmol, 1 equiv), bromobenzene (0.04 mL, 0.35 mmol, 1.5 equiv), cesium carbonate (229 mg, 0.7 mmol, 3 equiv), and xantphos (13.6 mg, 0.02 mmol, 0.1 equiv) in 1,4-dioxane (5 mL), and the mixture was heated at 100°C overnight. The reaction mixture was allowed to cool to ambient temperature, then partitioned between dichloromethane and water, and the organic phase was washed with water, then brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a brown foam (156 mg, 0.22 mmol, 93%).

LC/MS (C ₃₆ H ₄₅ N ₇ O ₃ SiS ₂ ) 716 [M+H] ⁺ ; RT 1.68 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.84 (d, 1H), 7.67 (d, J=1.1 Hz, 1H), 7.50 -7.39 (m, 2H), 7.30-7.18 (m, 3H), 7.04 -6.96 (m, 2H), 6.79 (t, 1H), 5.86 (s, 2H), 4.31 (q, J=7.1 Hz, 2H), 3.94-3.64 (m, 8H), 2.83-2.68 (m, 2H), 2.46 (d, J=1.0 Hz, 3H ), 2.10 (d, J=12.1 Hz, 2H), 1.88-1.71 (m, 2H), 1.34 (t, J=7.1 Hz, 3H), 1.00 -0.86 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-phenylpiperidin-4-yl)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1.2 mL, 16.1 mmol, 74 equiv) was added to a stirred solution of the product from Step A (156 mg, 0.22 mmol, 1 equiv) in dichloromethane (6 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. The resulting solid was triturated with 1:1 dichloromethane/heptane, filtered, and dried in vacuo to afford the title product as a yellow solid (92 mg, 0.16 mmol, 72%).

LC/MS (C ₃₀ H ₃₁ N ₇ O ₂ S ₂ ) 586 [M+H] ⁺ ; RT 1.40 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 12.44 (br s, 1H), 11.02 (br s, 1H), 7.98 (br s, 1H), 7.81-7.54 (m, 2H), 7.38 (br s, 1H), 7.30-7.12 (m, 3H), 7.05-6.97 (m, 2H), 6.80 (t, 1H), 4.31 (q, J=7.1 Hz, 2H), 3.91-3.69 (m, 6H), 2.82-2.70 (m, 2H), 2.47 (s, 3H), 2.11 (d, J=12.4 Hz, 2H), 1.88-1.69 (m, 2H), 1.33 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-phenylpiperidin-4-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (92 mg, 0.16 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (33 mg, 0.79 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and the solids were collected by filtration, washed with 1,4-dioxane, then triturated with water, filtered and dried in vacuo to give the title product as a yellow solid (50.3 mg, 0.09 mmol, 57%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₈ H ₂₈ N ₇ O ₂ S ₂ : 558.1740, found: 558.1749.

Example 92: 5-[1-(Benzenesulfonyl)piperidin-4-yl]-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[1-(benzenesulfonyl)piperidin-4-yl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a stirred solution of Preparation 5k (200 mg, 0.31 mmol, 1 equiv) and triethylamine (0.09 mL, 0.63 mmol, 2 equiv) in dichloromethane (5 mL) were added benzenesulfonyl chloride (0.05 mL, 0.38 mmol, 1.2 equiv) and a catalytic amount of 4-(dimethylamino)pyridine, and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a cream-colored solid (204 mg, 0.26 mmol, 84%).

LC/MS (C ₃₆ H ₄₅ N ₇ O ₅ SiS ₃ ) 780 [M+H] ⁺ ; RT 1.53 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.94-7.87 (m, 1H), 7.85-7.64 (m, 6H), 7.51-7.40 (m, 2H), 7.31-7.22 (m, 1H), 5.87 ( s, 2H), 4.24 (q, J=7.1 Hz, 2H), 3.84 (d, J=11.8 Hz, 2H), 3.78-3.68 (m, 5H), 3.61-3.49 (m, 1H), 2.46 (d, J=0.9 Hz, 3H), 2.39-2.29 (m, 2H), 2.05 (d, J=11.2 Hz, 2H), 1.77-1.61 (m, 2H), 1.25 (t, J=7.1 Hz, 3H), 0.97-0.88 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 5-[1-(benzenesulfonyl)piperidin-4-yl]-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1 mL, 13.4 mmol, 51 equiv) was added to a stirred solution of the product from Step A (204 mg, 0.26 mmol, 1 equiv) in dichloromethane (6 mL) and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate and the organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a yellow glass (121 mg, 0.19 mmol, 71%).

LC/MS (C ₃₀ H ₃₁ N ₇ O ₄ S ₃ ) 650 [M+H] ⁺ ; RT 1.28 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 12.44 (br s, 1H), 11.06 (br s, 1H), 8.14-7.86 (m, 2H), 7.86-7.63 (m, 6H), 7.45-7.34 ( m, 1H), 7.28-7.16 (m, 1H), 4.23 (q, J=7.1 Hz, 2H), 3.88-3.80 (m, 2H), 3.75 (s, 3H), 3.62-3.47 (m, 1H), 2.46 (s, 3H), 2.40-2.29 (m, 2H), 2.04 (d, J=12.5 Hz, 2H), 1.75-1.58 (m, 2H), 1.25 (t, J=7.1 Hz, 3H).

Step C: 5-[1-(benzenesulfonyl)piperidin-4-yl]-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (121 mg, 0.19 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (39.1 mg, 0.93 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and the solids were collected by filtration and washed with 1,4-dioxane. The material was triturated with water, filtered and dried in vacuo to give the title product as a yellow solid (102 mg, 0.16 mmol, 88%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₈ H ₂₈ N ₇ O ₄ S ₃ : 622.1359, found: 622.1367.

Example 93: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-4-methoxybutyl)amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[3-[tert-butyl(dimethyl)silyl]oxy-4-methoxybutyl]amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate and the product of Preparation 2h as starting materials and performing the reaction in THF at rt for 1 h, 4.16 g (81%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 8.08 (s, 1H), 4.14/4.07 (m+m, 2H), 3.86 (m, 1H), 3.79 (s, 3H), 3.35/3.29 (dd+dd, 2H), 3.26 (s, 3H), 1.83/1.74 (m+m, 2H), 1.53 (s, 9H), 0.85 (s, 9H), 0.04/0.03 (s+s, 6H). ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 161.9, 160.7, 153.0, 141.0, 124.8, 83.8, 76.6, 69.8, 58.9, 52.3, 44.4, 32.7, 28.1, 26.2, 18.3, -4.1/-4.5.

Step B: Methyl 2-[[3-[tert-butyl(dimethyl)silyl]oxy-4-methoxybutyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 3.1 g (55%) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.79 (t, 1H), 7.52 (s, 1H), 3.91 (m, 1H), 3.74 (s, 3H), 3.29-3.21 (m, 7H), 1.75(m, 1H), 1.63 (m, 1H), 0.86 (s, 9H), 0.04 (s, 6H).

Step C: methyl 2-[[3-[tert-butyl(dimethyl)silyl]oxy-4-methoxybutyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3 -benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting with the product from Step B and the product of Preparation 4a as the appropriate halide, 118 mg (61%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.99 (s, 1H), 7.84 (d, 1H), 7.58 (s, 1H), 7.47 (d, 1H), 7.44 (td, 1H), 7.25 (td, 1H), 5.87 (s, 2H), 4.52 /4.44 (m+m, 2H), 4.02 (m, 1H), 3.81 (s, 3H), 3.72 (t, 2H), 3.37 (m, 2H), 3.29 (s, 3H), 2.46 (s, 3H), 1.93/1.81 (m+m, 2H), 0.92 (t, 2Н), 0.89 (s, 9Н), 0.09/0.07 (s+s, 6H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 162.3, 160.4, 157.7, 155.3, 150.9, 140.5, 137.5, 137.2, 127.2, 125.4, 123.5, 123.2, 123.2 , 117.5, 112.0, 76.7, 72.9, 69.6, 66.7, 58.9, 52.2, 44.8, 31.8, 26.3, 17.9, 17.8, -1.0, -4.1/-4.5; LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₅₃ N ₆ O ₅ S ₂ Si ₂ : 745, found: 745.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-4-methoxybutyl)amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₂₃ N ₆ O ₄ S ₂ : 487.1217, found: 487.1222.

Example 94: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-methanesulfonylpiperidin-4-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(1-methanesulfonylpiperidin-4-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a stirred solution of Preparation 5k (150 mg, 0.23 mmol, 1 equiv) and triethylamine (0.07 mL, 0.47 mmol, 2 equiv) in dichloromethane (5 mL) was added methanesulfonyl chloride (0.02 mL, 0.28 mmol, 1.2 equiv) followed by a catalytic amount of 4-(dimethylamino)pyridine, and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane, then washed with water followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a white foam (106 mg, 0.15 mmol, 63%).

LC/MS (C ₃₁ H ₄₃ N ₇ O ₅ SiS ₃ ) 718 [M+H] ⁺ ; RT 1.45 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.89 (dd, J=7.9, 1.1 Hz, 1H), 7.68 (d, J=1.1 Hz, 1H), 7.51-7.39 (m, 2H), 7.29-7.21 (m, 1H), 5.87 (s, 2H), 4.31 (q, J=7.1 Hz, 2H), 3.77 (s, 3H), 3.76-3.63 (m, 5H), 2.93 (s, 3H), 2.89-2.78 (m, 2H), 2.46 (d, J= 1.0 Hz, 3H), 2.12 (d, J=12.3 Hz, 2H), 1.78-1.63 (m, 2H), 1.33 (t, J=7.1 Hz, 3H), 0.97-0.88 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-methanesulfonylpiperidin-4-yl)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1 mL, 13.4 mmol, 91 equiv) was added to a stirred solution of the product from Step A (106 mg, 0.15 mmol, 1 equiv) in dichloromethane (5 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded a solid that was triturated with diethyl ether, filtered and dried under vacuum to afford the desired product as a yellow solid (75 mg, 0.13 mmol, 86%).

LC/MS (C ₂₅ H ₂₉ N ₇ O ₄ S ₃ ) 588 [M+H] ⁺ ; RT 1.36 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.95 (br s, 1H), 7.68 (s, 1H), 7.53 (br s, 1H), 7.38 (t, J=7.6 Hz, 1H), 7.20 (t, J=7.5 Hz, 1H), 4.30 (q, J=7.1 Hz, 2H), 3.80-3.67 (m, 6H), 2.93 (s, 3H), 2.84 (dd, J=13.0, 10.6 Hz, 2H), 2.46 (s, 3H), 2.12 (d, J=11.9 Hz, 2H), 1.79-1.59 (m, 2H), 1.33 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-methanesulfonylpiperidin-4-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (75 mg, 0.13 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (26.8 mg, 0.64 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and the solids were collected by filtration and washed with 1,4-dioxane. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow solid (37.1 mg, 0.07 mmol, 52%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₃ H ₂₆ N ₇ O ₄ S ₃ : 560.1203, found: 560.1209.

Example 95: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-phenylmethanesulfonylpiperidin-4-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-(1-phenylmethanesulfonylpiperidin-4-yl)-1,3-thiazole-4-carboxylate

To a stirred solution of the product of Preparation 5k and triethylamine (0.07 mL, 0.47 mmol, 2 equiv) in dichloromethane (5 mL) was added alpha-toluenesulfonyl chloride (53.6 mg, 0.28 mmol, 1.2 equiv) followed by a catalytic amount of 4-(dimethylamino)pyridine, and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane, washed with water followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a creamy foam (95 mg, 0.12 mmol, 51%).

LC/MS (C ₃₇ H ₄₇ N ₇ O ₅ SiS ₃ ) 794 [M+H] ⁺ ; RT 1.50 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.81 (dd, J=7.8, 1.1 Hz, 1H), 7.67 (d, J=1.1 Hz, 1H), 7.53-7.36 (m, 7H), 7.27-7.20 (m, 1H), 5.86 (s, 2H), 4.49 (s, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.77 (s, 3H), 3.77-3.64 (m, 5H), 2.82 (td, J=12.4, 2.3 Hz, 2H), 2.46 (d, J=1.0 Hz, 3H), 2.03-1.95 (m, 2H), 1.62-1.46 (m, 2H), 1.32 (t, J=7.1 Hz, 3H), 0.92 (dd, J=8.6, 7.4 Hz, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-phenylmethanesulfonylpiperidin-4-yl)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (0.5 mL, 6.71 mmol, 56 equiv) was added to a stirred solution of the product from Step A (95 mg, 0.12 mmol, 1 equiv) in dichloromethane (5 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. The resulting solid was triturated with diethyl ether, filtered, and dried in vacuo to afford the title product as a yellow solid (74 mg, 0.11 mmol, 93%).

LC/MS (C ₃₁ H ₃₃ N ₇ O ₄ S ₃ ) 664 [M+H] ⁺ ; RT 1.27 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 11.03 (br s, 1H), 7.91 (br s, 1H), 7.74-7.65 (m, 1H), 7.53-7.33 (m, 7H), 7.25-7.13 ( m, 1H), 4.49 (s, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.76 (s, 3H), 3.74-3.64 (m, 3H), 2.88-2.77 (m, 2H), 2.50-2.44 (m, 3H), 2.03-1.94 ( m, 2H), 1.60-1.46 (m, 2H), 1.32 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-phenylmethanesulfonylpiperidin-4-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (74 mg, 0.11 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (23.4 mg, 0.56 mmol, 5 equiv) and the mixture was heated at reflux for 6.5 h. The reaction mixture was allowed to cool to ambient temperature and purified by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water to give the desired product as a yellow solid (43.2 mg, 0.07 mmol, 61%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₉ H ₃₀ N ₇ O ₄ S ₃ : 636.1516, found: 636.1521.

Example 96: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(2-phenylacetyl)piperidin-4-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-[1-(2-phenylacetyl)piperidin-4-yl]-1,3-thiazole-4-carboxylate

To a stirred solution of Preparation 5k (150 mg, 0.23 mmol, 1 equiv) and triethylamine (0.07 mL, 0.47 mmol, 2 equiv) in dichloromethane (5 mL) was added phenylacetyl chloride (0.04 mL, 0.28 mmol, 1.2 equiv) and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane, then washed with saturated aqueous sodium bicarbonate followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as an off-white foam (122 mg, 0.16 mmol, 69%).

LC/MS (C ₃₈ H ₄₇ N ₇ O ₄ SiS ₂ ) 758 [M+H] ⁺ ; RT 1.49 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.88-7.81 (m, 1H), 7.66 (d, J=1.1 Hz, 1H), 7.51-7.41 (m, 2H), 7.39-7.32 (m, 2H), 7.30-7.20 (m, 4H), 5.87 (s, 2H), 4.59 (d, J=12.7 Hz, 1H), 4.29 (q, J=7.1 Hz, 2H), 4.10 (d, J=13.6 Hz, 1H), 3.94-3.66 (m, 8H), 3.09 (t, J=12.7 Hz, 1H), 2.72-2.57 (m, 1H), 2.46 (d, J=1.0 Hz, 3H), 2.11 -1.83 (m, 2H), 1.50-1.36 (m, 2H), 1.32 (t, J=7.1 Hz, 3H), 0.97-0.87 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(2-phenylacetyl)piperidin-4-yl]-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (0.5 mL, 6.71 mmol, 42 equiv) was added to a stirred solution of the product from Step A (122 mg, 0.16 mmol, 1 equiv) in dichloromethane (5 mL) and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate solution and the organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the desired product as a yellow solid (81.8 mg, 0.13 mmol, 81%).

LC/MS (C ₃₂ H ₃₃ N ₇ O ₃ S ₂ ) 628 [M+H] ⁺ ; RT 1.22 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.06 (br s, 1H), 7.98 (br s, 1H), 7.71-7.65 (m, 2H), 7.43-7.32 (m, 3H), 7.31-7.14 (m, 4H), 4.59 (d, J=13.3 Hz, 1H), 4.29 (q, J=7.1 Hz, 2H), 4.10 (d, J=13.9 Hz, 1H), 3.91-3.70 (m, 6H), 3.09 (t, J=12.4 Hz, 1H), 2.72-2.58 (m, 1H), 2.48-2.43 (m, 3H), 2.07 (d, J=12.6 Hz, 1H), 1.91 (d, J=13.0 Hz, 1H), 1.50-1.33 (m, 2H), 1.32 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(2-phenylacetyl)piperidin-4-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (81.8 mg, 0.13 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (27.3 mg, 0.65 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and purified by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water to give the desired product as a yellow solid (54.3 mg, 0.09 mmol, 70%).

MSHR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₀ H ₃₀ N ₇ O ₃ S ₂ : 600.1846, found: 600.1850.

Example 97: 5-(1-Acetylpiperidin-4-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(1-acetylpiperidin-4-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a stirred solution of Preparation 5k and triethylamine (0.07 mL, 0.47 mmol, 2 equiv) in dichloromethane (5 mL) was added acetyl chloride (0.02 mL, 0.28 mmol, 1.2 equiv) and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane, then washed with saturated aqueous sodium bicarbonate followed by brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the title product as a colourless foam (119 mg, 0.17 mmol, 74%).

LC/MS (C ₃₂ H ₄₃ N ₇ O ₄ SiS ₂ ) 682 [M+H] ⁺ ; RT 1.44 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.90-7.83 (m, 1H), 7.67 (d, J=1.2 Hz, 1H), 7.50-7.39 (m, 2H), 7.29-7.21 (m, 1H), 5.86 (s, 2H), 4.57 (d, J=13.3 Hz, 1H), 4.31 (q, J=7.1 Hz, 2H), 3.96 (d, J=13.6 Hz, 1H), 3.91-3.82 (m, 1H), 3.77 (s, 3H), 3.75-3.67 (m, 2H), 3.14 (t, J=12.2 Hz, 1H), 2.69-2.54 (m, 1H), 2.45 (d, 3H), 2.06 (s, 3H), 2.06-1.95 (m, 2H), 1.72-1.56 (m, 1H), 1.54-1.38 (m, 1H), 1.33 (t, J=7.1 Hz, 3H), 0.96-0.87 (m, 2H), -0.11 (s, 9Н).

Step B: Ethyl 5-(1-acetylpiperidin-4-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

To a stirred solution of the product from Step A (119 mg, 0.17 mmol, 1 equiv) in tetrahydrofuran (5 mL) were added tetrabutylammonium fluoride (1 M in tetrahydrofuran; 0.07 mL, 0.5 mmol, 3 equiv) and ethylenediamine (0.03 mL, 0.5 mmol, 3 equiv), and the mixture was heated at 60 °C overnight. The reaction mixture was allowed to cool to ambient temperature, then partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-4% methanol in dichloromethane afforded the title product as a yellow solid (40 mg, 0.07 mmol, 42%).

LC/MS (C ₂₆ H ₂₉ N ₇ O ₃ S ₂ ) 552 [M+H] ⁺ ; RT 1.09 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.08 (br s, 1H), 7.94 (br s, 1H), 7.69 (s, 1H), 7.57 (br s, 1H), 7.39 (t, J=7.5 Hz, 1H), 7.23 (t, 1H), 4.58 (d, J=13.3 Hz, 1H), 4.31 (q, J=7.1 Hz, 2H), 4.02-3.93 (m, 1H), 3.92-3.82 (m, 1H), 3.77 (s, 3H), 3.21-3.09 (m, 1H), 2.66-2.55 (m, 1H), 2.47 (s, 3H), 2.07 (s, 3H), 2.06-1.96 (m, 2H), 1.76-1.57 (m, 1H), 1.54-1.39 (m, 1H), 1.34 (t, J=7.1 Hz, 3H).

Step C: 5-(1-acetylpiperidin-4-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (40 mg, 0.07 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (15.2 mg, 0.36 mmol, 5 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and purified by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water to give the desired product as a yellow solid (32.4 mg, 0.06 mmol, 85%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₄ H ₂₆ N ₇ O ₃ S ₂ : 524.1533, found: 524.1541.

Example 98: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-3-methoxybutyl)amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[4-[tert-butyl(dimethyl)silyl]oxy-3-methoxybutyl]amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate and Preparation 2i as starting materials and reacting in THF at rt for 3 h, 4.54 g (86%) of the desired product was obtained.

LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₃₉ N ₂ O ₆ SSi: 475, found: 475.

Step B: Methyl 2-[[4-[tert-butyl(dimethyl)silyl]oxy-3-methoxybutyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 2.88 g (55%) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.80 (t, 1H), 7.52 (s, 1H), 3.74 (s, 3H), 3.59 (m, 2H), 3.32 (s, 3H), 3.28 (m, 3H), 1.76 (m, 1H), 1.61 (m, 1H), 0.86 (s, 9H), 0.04 (s, 6H).

Step C: methyl 2-[[4-[tert-butyl(dimethyl)silyl]oxy-3-methoxybutyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3 -benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product of Step B and the product of Preparation 4a as the appropriate halide, 319 mg (70%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.99 (s, 1H), 7.85 (dm, 1H), 7.66 (s, 1H), 7.48 (dm, 1H), 7.44 (m, 1H), 7.26 (m, 1H), 5.88 (s, 2H), 4.60 (m, 1H), 4.47 (m, 1H), 3.81 (s, 3H), 3.72 (m, 2H), 3.66 (dd, 1H), 3.53 (dd, 1H), 3.29 (s, 3H), 3.27 (m, 1H), 2.46 (s, 3H), 2.03 ( m, 1H), 1.76 (m, 1H), 0.92 (m, 2H), 0.77 (s, 9Н), 0.00 (s, 3H), -0.01 (s, 3H), -0.12 (s, 9H).

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-3-methoxybutyl)amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₂₃ N ₆ O ₄ S: 487.1217, found: 487.1222.

Example 99: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-methylpiperidin-4-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-(1-methylpiperidin-4-yl)-1,3-thiazole-4-carboxylate

To a stirred solution of Preparation 5k (150 mg, 0.23 mmol, 1 equiv) in 1:1 acetonitrile/dichloromethane (10 mL) were added formaldehyde (37% in water; 0.04 mL, 0.47 mmol, 2 equiv), sodium triacetoxyborohydride (149 mg, 0.7 mmol, 3 equiv), and glacial acetic acid (10 μL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the title product as an off-white foam (76.7 mg, 0.12 mmol, 50%).

LC/MS (C ₃₁ H ₄₃ N ₇ O ₃ SiS ₂ ) 654 [M+H] ⁺ ; RT 1.24 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.88 (dd, J=7.7, 1.0 Hz, 1H), 7.67 (d, J=1.2 Hz, 1H), 7.51-7.39 (m, 2H), 7.28- 7.22 (m, 1H), 5.87 (s, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.76 (s, 3H), 3.75-3.67 (m, 2H), 3.64-3.52 (m, 1H), 2.89 (d, J=11.1 Hz, 2H), 2.46 (d, J=1.0 Hz, 3H), 2.21 (s, 3H), 2.01-1.90 (m, 4H), 1.75-1.61 (m, 2H), 1.32 (t, J=7.1 Hz, 3H), 0.99-0.88 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-methylpiperidin-4-yl)-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1.0 mL, 13.4 mmol, 114 equiv) was added to a stirred solution of the product from Step A (76.7 mg, 0.12 mmol, 1 equiv) in dichloromethane (4 mL), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded the title product as a yellow glass (24.1 mg, 0.05 mmol, 39%).

LC/MS (C ₂₅ H ₂₉ N ₇ O ₂ S ₂ ) 524 [M+H] ⁺ ; RT 0.87 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 8.01-7.90 (m, 1H), 7.69 (s, 1H), 7.54 (br s, 1H), 7.44-7.35 (m, 1H), 7.22 (t, J=7.7 Hz, 1H), 4.30 (q, J=7.1 Hz, 2H), 3.76 (s, 3H), 3.64-3.53 (m, 1H), 2.97-2.86 (m, 2H), 2.47 (s, 3H), 2.22 (s, 3H), 2.04-1.89 (m, 4H), 1.77-1.60 (m, 2H), 1.33 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-methylpiperidin-4-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (24 mg, 0.05 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added lithium hydroxide monohydrate (9.62 mg, 0.23 mmol, 5 equiv), and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow solid (17.2 mg, 0.03 mmol, 76%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₃ H ₂₆ N ₇ O ₂ S ₂ : 496.1584, found: 496.1602.

Example 100: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-[2-fluoro-4-(3-hydroxyprop-1-yn-1-yl)phenoxy]propyl}-1,3-thiazole-4-carboxylic acid

Stage A: ethyl 5-[3-(2-fluoro-4-{3-[(4-methoxyphenyl)methoxy]prop-1-yn-1-yl}phenoxy)propyl]-2-[methyl(5-methyl-6-{ [(2Z)-3-{[2-(trime tilsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazol-4-carboxylate

To a solution of Preparation 5g (249 mg, 0.34 mmol, 1 equiv) in dimethylformamide (5 mL) were added Preparation 6k (128 mg, 0.45 mmol, 1.3 equiv) and cesium carbonate (336 mg, 1.03 mmol, 3 equiv), and the mixture was heated at 80 °C overnight. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a yellow gum (231 mg, 0.26 mmol, 76%).

LC/MS (C ₄₅ H ₅₁ FN ₆ O ₆ SiS ₂ ) 883 [M+H] ⁺ ; RT 1.41 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.84 (d, 1H), 7.67 (d, J=1.1 Hz, 1H), 7.49 -7.40 (m, 2H), 7.37 (dd, J=11.9, 2.0 Hz, 1H), 7.31-7.22 (m, 4H), 7.21-7.14 (m, 1H), 6.94-6.89 (m, 2H), 5.86 (s, 2H), 5.87 (s, 2H), 4.48 (s, 2H), 4.32 (s, 2H), 4.26 (t, 2H), 4.16 (t, J=6.1 Hz, 2H), 3.78 (s, 3H), 3.75 (s, 3H), 3.75-3.68 (m, 2H), 3.34-3.22 (m, 2H), 2.46 (d, J=1.0 Hz, 3H), 2.19-2.08 (m, 2H), 1.30 (t, 3H ), 0.97-0.88 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 5-{3-[2-fluoro-4-(3-hydroxyprop-1-yn-1-yl)phenoxy]propyl}-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

Trifluoroacetic acid (1.8 mL) was added to a solution of the product from Step A (391 mg, 0.44 mmol, 1 equiv) in dichloromethane (18 mL), and the mixture was stirred at ambient temperature for 1 h. The reaction mixture was diluted with dichloromethane, cooled to 0 °C, and neutralized by adding 0.5 M aqueous sodium hydroxide solution. The layers were separated and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0:50% ethyl acetate in isoheptane afforded the title product as an off-white solid (121 mg, 0.16 mmol, 36%).

LC/MS (C ₃₇ H ₄₃ FN6O ₅ SiS ₂ ) 763 [M+H] ⁺ ; RT 1.29 (LCMS-V-B2)

^1H NMR (400 MHz, DMSO- _d6 ) δ 7.87-7.81 (m, 1H), 7.67 (s, 1H), 7.50-7.40 (m, 2H), 7.33-7.13 (m, 4H), 5.86 (s , 2H), 5.30 (t, J=6.0 Hz, 1H), 4.34-4.21 (m, 4H), 4.15 (t, J=6.2 Hz, 2H), 3.77 (s, 3H), 3.76-3.67 (m, 2H), 3.32-3.22 (m, 2H), 2.46 (d, J=1.0 Hz, 3H), 2.20-2.06 (m, 2H), 1.28 (t, 3H), 0.97-0.88 (m, 2H), -0.12 (s, 9H).

Step C: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-[2-fluoro-4-(3-hydroxyprop-1-yn-1-yl)phenoxy]propyl}-1,3-thiazole-4-carboxylate

To a solution of the product from Step B (121 mg, 0.16 mmol, 1 equiv) in tetrahydrofuran (15 mL) were added ethylenediamine (31.8 µL, 0.48 mmol, 3 equiv) and TBAF (476 µL, 0.48 mmol, 3 equiv), and the mixture was heated at 65 °C overnight. The reaction mixture was allowed to cool to ambient temperature, then partitioned between ethyl acetate and water, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0:100% ethyl acetate in isoheptane afforded the title product as a yellow solid (43 mg, 0.07 mmol, 43%).

LC/MS (C ₃₁ H ₂₉ FN ₆ O ₄ S ₂ ) 633 [M+H] ⁺ ; RT 2.43 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.08 (br s, 1H), 7.92 (br s, 1H), 7.67 (br s+s, 2H), 7.39 (t, J=7.5 Hz, 1H), 7.29 (dd, J=11.9, 1.9 Hz, 1H), 7.25-7.12 (m, 2H), 5.29 (t, J=5.9 Hz, 1H), 4.33-4.20 (m, 4H), 4.14 (t, 2H), 3.77 (s, 3H), 3.31-3.21 (m, 1H), 2.46 (s, 3H), 2.20-2.07 (m, 2H), 1.29 (t, J=7.1 Hz, 3N).

Step D: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-[2-fluoro-4-(3-hydroxyprop-1-yn-1-yl)phenoxy]propyl}-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step C (50 mg, 0.08 mmol, 1 equiv) in 1,4-dioxane (15 mL) was added lithium hydroxide monohydrate (33.2 mg, 0.79 mmol, 10 equiv) and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 30-95% acetonitrile in water afforded the desired product as a yellow solid (31.9 mg, 0.05 mmol, 67%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₂₉ H ₂₄ FN ₆ O ₄ S ₂ : 603.1290, found: 603.1294.

Example 101: 3-[3-[4-[3-[2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-4-carboxythiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynyldimethylammonio]propane-1-sulfonate

Using the General Alkylation, Deprotection, and Hydrolysis Procedure starting from the compound of Example 50, Step A, and oxathiolane 2,2-dioxide, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₇ FN ₇ O ₆ S ₃ : 754.1946, found: 754.1947.

Example 102: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-cyclohexyl-1,3-thiazole-4-carboxylic acid

Stage A: Cyclohexyl(iodine)zinc

Zinc (3.03 g, 46.3 mmol, 3 equiv) and lithium chloride (0.98 g, 23.1 mmol, 1.5 equiv) were added to a 50 mL oven-dried Schlenk flask and the mixture was heated at 160 °C for 20 min under high vacuum, then allowed to cool to ambient temperature and placed under nitrogen on a Schlenk line. Dimethylacetamide (10 mL) was added followed by 1,2-dibromoethane (0.13 mL, 1.54 mmol, 0.1 equiv) and the mixture was stirred for 20 min. Iodocyclohexane (2 mL, 15.4 mmol, 1 equiv) was added slowly and the mixture was then heated at 40 °C overnight. The reaction mixture was allowed to cool to ambient temperature and cannulated through a filter (cotton wool/celite/cotton wool) under low vacuum into a dry 25 mL Schlenk flask to give the desired product as a 1 M solution (as determined by titration with 0.5 M iodine), which was used without further characterization.

Step B: Ethyl 5-cyclohexyl-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

An oven-dried flask was charged with a solution of Preparation 11b (200 mg, 0.31 mmol, 1 equiv) and copper(I) iodide (112 mg, 0.63 mmol, 2 equiv). Dimethylacetamide (5 mL) was added and the mixture was stirred for 5 min, after which the product from Step A (1 M in dimethylacetamide; 1.42 mL, 1.42 mmol, 4.5 equiv) was slowly added and the mixture was stirred at ambient temperature overnight. The reaction mixture was poured onto saturated aqueous ammonium chloride then extracted with dichloromethane (×2). The combined organic extracts were washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-30% ethyl acetate in isoheptane afforded the desired product as a yellow gum (135 mg, 0.21 mmol, 67%).

LC/MS (C ₃₁ H ₄₂ N ₆ O ₃ S ₂ Si) 639 [M+H] ⁺ ; RT 1.68 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.85 (dd, J=7.6, 1.0 Hz, 1H), 7.66 (d, J=1.2 Hz, 1H), 7.50-7.40 (m, 2H), 7.29-7.22 (m, 1H), 5.86 (s, 2H), 4.28 (q, J=7.1 Hz, 2H), 3.76 (s, 3H), 3.75-3.69 (m, 2H), 3.68-3.56 (m, 1H), 2.45 (s, 3H), 2.05-1.97 (m, 2H), 1.87-1.78 (m, 2H), 1.77-1.68 (m, 2H), 1.52-1.35 (m, 4H), 1.32 (t, 3H), 0.96 0.88 (m, 2H), -0.11 (s, 9H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-cyclohexyl-1,3-thiazole-4-carboxylic acid

Trifluoroacetic acid (1 mL, 13.4 mmol, 63.7 equiv) was added to a stirred solution of the product from Step B (135 mg, 0.21 mmol, 1 equiv) in dichloromethane (6 mL) and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate and the organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. The resulting solid was suspended in 1,4-dioxane (4 mL) then lithium hydroxide (44.2 mg, 1.05 mmol, 5 equiv) was added and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow solid (42 mg, 0.09 mmol, 41%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₃ H ₂₅ N ₆ O ₂ S ₂ : 481.1475, found: 481.1518.

Example 103: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(2,3-dihydroxypropyl)amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[(2,2-dimethyl-1,3-dioxolan-4-yl)methyl]amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate and (2,2-dimethyl-1,3-dioxolan-4-yl)methanol and reacting in THF at rt for 19 h, 5.09 g (91%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 8.10 (s, 1H), 4.40 (m, 1H), 4.26/4.07 (dd+dd, 2H), 4.01/3.79 (dd+dd, 2H), 3.80 (s, 3H), 1.53 (s, 9H), 1.34 (s, 3H), 1.23 (s, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 161.8, 161.1, 153.2, 140.9, 124.9, 73.1, 67.1, 52.4, 49.1, 28.1, 27.1, 25.8; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₁₆ H ₂₅ N ₂ O ₆ S: 373.1433 found: 373.1431.

Step B: Methyl 2-[(2,2-dimethyl-1,3-dioxolan-4-yl)methylamino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 1.77 g (48%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.94 (t, 1H), 7.53 (s,H), 4.23 (m, 1H), 4.00/3.66 (dd+dd, 2H), 3.74 (s, 3H), 3.39/3.35 (m+m, 2H), 1.34 (s, 3H), 1.26 (s, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 168.7, 162.0, 142.3, 117.6, 74.3, 67.0, 52.1, 47.4, 27.3, 25.8; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₁ H ₁₇ N ₂ O ₄ S: 273.0909 found: 273.0906.

Step C: methyl 2-[(2,2-dimethyl-1,3-dioxolan-4-yl)methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3 -benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product of Step B and the product of Preparation 4a as the appropriate halide, 450 mg (33%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 8.00 (s, 1H), 7.84 (d, 1H), 7.83 (s, 1H), 7.47 (d, 1H), 7.44 (td, 1H), 7.25 (td, 1H), 5.87 (s, 2H), 4.60 (m, 2H), 4.55 (m, 1H), 4.09/3.83 (dd+dd, 2H), 3.82 (s, 3H), 3.71 (t, 2H), 2.44 (s, 3H), 1.27/1.19 (s+s, 6H), 0.92 (t, 2H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 162.2, 161.1, 157.7, 155.4, 151.7, 140.4, 137.5, 136.4, 127.2, 125.4, 123.5, 123.4, 123.2, 119.1, 112.0, 73.9, 72.8, 66.9, 66.7, 52.3, 50.2, 26.6/25.6, 17.8, 17.7, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₂₉ H ₃₉ N ₆ O ₅ S ₂ Si: 643.2192 found: 643.2184.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(2,3-dihydroxypropyl)amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 25 mM _{NH4HCO3 water} :MeCN), the product from Step C was obtained to give the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₉ H ₁₉ N ₆ O ₄ S ₂ : 459.0909 found: 459.0891.

Example 104: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4,5-dihydroxypentyl)amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl(pent-4-enyl)amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction starting from methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate and 4-penten-1-ol and reacting in THF at rt for 2 h, 4.36 g (89%) of the desired product was obtained.

Step B: Methyl 2-[3-(2,2-dimethyl-1,3-dioxolan-4-yl)propylamino]thiazole-4-carboxylate

To 4.35 g of the product from Step A (13.3 mmol) were added 3.6 g of 4-methyl-4-oxidomorpholin-4-ium hydrate (26.6 mmol, 2 equiv), 135 mg of osmium tetroxide (2.5 wt% in 2-methylpropan-2-ol, 0.013 mmol, 0.001 equiv), 10 mL of water and 100 mL of 2-methylpropan-2-ol, and the mixture was stirred at rt for 18 h. After addition of 50 mL of 1 M _{Na2S2O3 and} removal of ^tBuOH under _reduced pressure, the mixture was extracted with DCM and the combined organic phases were dried and concentrated to give 6.25 g (130%) of methyl 2-[tert-Butoxycarbonyl(4,5-dihydroxypentyl)amino]thiazole-4-carboxylate. The crude product was taken up in 100 mL EtOH, treated with 20 mL 1 N HCl at 100°C for 24 h, and concentrated to give 5.42 g (157%) of methyl 2-(4,5-dihydroxypentylamino)thiazole-4-carboxylate (LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₁₀ H ₁₇ N ₂ O ₄ S: 261, found: 261). The product was then taken up in 50 mL of 2,2-dimethoxypropane and 124 mg of 4-methylbenzenesulfonic acid (0.72 mmol, 0.05 equiv) was added and the mixture was stirred at reflux for 3 h. After concentration, the residue was taken up in DCM and washed with conc. NaHCCb to give 3.66 g (92% over three steps) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.81 (t, 1H), 7.50 (s, 1H), 4.04 (m, 1H), 3.98/3.42 (dd+dd, 2H), 3.73 (s, 3H), 3.23 (q, 2H), 1.54 (m, 2H), 1.54 (m, 2H), 1.30 (s, 3H), 1.25 (s, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 117.0, 75.6, 69.0, 52.0, 44.7, 27.3, 27.3, 26.1, 25.5; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₃ H ₂₁ N ₂ O ₄ S: 301.1222 found: 301.1217.

Step C: methyl 2-[3-(2,2-dimethyl-1,3-dioxolan-4-yl)propyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1 ,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product of Step B and the product of Preparation 4a as the appropriate halide, 74 mg (50%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.99 (s, 1H), 7.84 (d, 1H), 7.72 (brs., 1H), 7.47 (d, 1H), 7.44 (td, 1H), 7.25 (td, 1H), 5.87 (s, 2H), 4.49/4.39 (m+m, 2H), 4.13 (m, 1H), 4.02/3.44 (dd+t, 2H), 3.82 (s, 3H), 3.72 (m, 2H), 2.47 (s, 3H), 1.79/1.73 (m+m, 2H), 1.67-1.52 ( m, 2H), 1.29/1.26 (s+s, 6H), 0.92 (m, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 162.3, 157.7, 155.3, 150.9, 137.5, 137.2, 127.2, 125.4, 123.5, 123.2, 123.2, 117.7, 112.0 , 75.5, 72.9, 69.1, 66.7, 52.3, 47.3, 30.3, 27.4/26.1, 23.7, 17.8, 17.8, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₁ H ₄₃ N ₆ O ₅ S ₂ Si: 671.2505 found: 671.2489.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4,5-dihydroxypentyl)amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 25 mM _{NH4HCO3 water} :MeCN), the product from Step C was obtained to give the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₂₃ N ₆ O ₄ S ₂ : 487.1222, found: 487.1212.

Example 105: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-cyclopentyl-1,3-thiazole-4-carboxylic acid

Stage A: Bromine (cyclopentyl) zinc

Zinc (1.83 g, 28 mmol, 3 equiv) and lithium chloride (593 mg, 14 mmol, 1.5 equiv) were charged into an oven-dried Schlenk flask (50 mL). The flask was evacuated and the mixture was heated at 160 °C for 20 min, then allowed to cool to ambient temperature and placed under nitrogen on a Schlenk line. Dimethylacetamide (10 mL) was added followed by 1,2-dibromoethane (0.08 mL, 0.93 mmol, 0.1 equiv) and the mixture was stirred for 20 min. Bromocyclopentane (1 mL, 9.33 mmol, 1 equiv) was added slowly and the reaction mixture was then heated at 40 °C overnight. The reaction mixture was allowed to cool to ambient temperature and cannulated through a filter (cotton wool/celite/cotton wool) under low vacuum into a dry 25 mL Schlenk flask to give the desired product as a 0.25 M solution (as determined by titration with 0.5 M iodine), which was used without further characterization.

Step B: Ethyl 5-cyclopentyl-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

An oven-dried flask was charged with the product of Preparation 11b (200 mg, 0.31 mmol, 1 equiv) and copper(I) iodide (120 mg, 0.63 mmol, 2 equiv) followed by the addition of dimethylacetamide (5 mL) and the mixture was stirred for 5 min after which the product from Step A (0.25 M in dimethylacetamide; 5.66 mL, 1.42 mmol, 4.5 equiv) was slowly added and the mixture was stirred overnight. The reaction mixture was poured onto saturated aqueous ammonium chloride and extracted with dichloromethane (×2). The organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded a solid that was triturated with isoheptane, filtered, washed with diethyl ether, and dried in vacuo to afford the title product as a white solid (112 mg, 0.18 mmol, 57%).

LC/MS (C ₃₀ H ₄₀ N ₆ O ₃ S ₂ Si) 625 [M+H] ⁺ ; RT 1.79 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.88-7.80 (m, 1H), 7.66 (d, J=1.1 Hz, 1H), 7.52-7.39 (m, 2H), 7.29- 7.21 (m, 1H), 5.86 (s, 2H), 4.29 (q, J=7.1 Hz, 2H), 4.06-3.88 (m, 1H), 3.75 (s, 3H), 3.74-3.68 (m, 2H), 2.45 (d, J=1.0 Hz, 3H), 2.24-2.12 (m, 2H), 1.90-1.76 (m, 2H), 1.73-1.49 (m, 2H), 1.31 (t, J=7.1 Hz, 3H), 0.96-0.81 (m, 2H), -0.11 (s, 9H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-cyclopentyl-1,3-thiazole-4-carboxylic acid

Trifluoroacetic acid (0.8 mL, 10.73 mmol, 60 equiv) was added to a stirred solution of the product from Step B (112 mg, 0.18 mmol, 1 equiv) in dichloromethane (4 mL) and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate and the organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. The resulting solid was suspended in 1,4-dioxane (3 mL) then lithium hydroxide (37.6 mg, 0.9 mmol, 5 equiv) was added and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a brown solid (34.8 mg, 0.07 mmol, 42%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₂₂ H ₂₁ N ₆ O ₂ S ₂ : 465.1173, found: 465.1175.

Example 106: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-ethenyl-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-ethenyl-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of Preparation 11b (100 mg, 0.16 mmol, ₁ equiv) in 5:1 tetrahydrofuran/water (6 mL) were added Pd(dppf) _Cl2.CH2Cl2 (12.9 mg, 0.02 mmol, 0.1 equiv), potassium vinyl trifluoroborate (31.6 mg, 0.24 mmol, 1.5 equiv), and potassium carbonate ( _65.2 mg, 0.47 mmol, 3 equiv), and the mixture was heated under reflux for 3 days. The reaction mixture was allowed to cool to ambient temperature, then partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a white solid (39.5 mg, 0.07 mmol, 43%).

LC/MS (C ₂₇ H ₃₄ N ₆ O ₃ S ₂ Si) 583 [M+H] ⁺ ; RT 1.52 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.88-7.80 (m, 1H), 7.71 (d, J=1.1 Hz, 1H), 7.59-7.40 (m, 3H), 7.28-7.23 (m, 1H ), 5.87 (s, 2H), 5.71-5.62 (m, 1H), 5.45-5.37 (m, 1H), 4.32 (q, J=7.1 Hz, 2H), 3.80 (s, 3H), 3.78-3.68 (m, 2H), 2.46 (d, J=1.0 Hz, 3H), 1.33 (t, J=7.1 Hz, 3H), 0.97-0.87 (m, 2H), -0.11 (s, 9H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-ethenyl-1,3-thiazole-4-carboxylic acid

Trifluoroacetic acid (0.5 mL, 6.71 mmol, 99 equiv) was added to a stirred solution of the product from Step A (39.5 mg, 0.07 mmol, 1 equiv) in dichloromethane (3 mL) and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate and the organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. The resulting solid was suspended in 1,4-dioxane (3 mL), lithium hydroxide monohydrate (14.2 mg, 0.34 mmol, 5 equiv) was added and the mixture was heated at reflux overnight. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow solid (13.4 mg, 0.03 mmol, 47%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₁₉ H ₁₅ N ₆ O ₂ S ₂ : 423.0703, found: 423.0711.

Example 107: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-2-morpholinopropyl)amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[3-[tert-butyl(dimethyl)silyl]oxy-2-morpholinopropyl]amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate and the product of Preparation 2k as starting materials and performing the reaction at rt for 1 h, 1.29 g (89%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 8.08 (s, 1H), 4.36/3.86 (dd+dd, 2H), 3.78 (s, 3H), 3.77/3.67 (dd+dd, 2H), 3.32/3.21 (m+m, 4H), 3.01 (m , 1Н), 2.82/2.36 (m+m, 4Н), 1.53 (s, 9H), 0.86 (s, 9H), 0.04/0.03 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 161.8, 161.6, 153.3, 140.7, 124.5, 67.4, 63.8, 61.0, 52.3, 50.1, 45.8, 28.2, 26.2, 18.3, -5.1; IR: 2954, 1703; HR-MSR (m/z): [M+H ] ⁺ , calculated for C ₂₃ H ₄₃ N ₃ O ₆ SSi: 516.2564, found: 516.2570.

Step B: Methyl 2-[[3-[tert-butyl(dimethyl)silyl]oxy-2-morpholinopropyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 0.71 g (68%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.58 (t, 1H), 7.51 (s, 1H), 3.74/3.66 (dd+dd, 2H), 3.73 (s, 3H), 3.59-3.45 (m, 4H), 3.32/3.29 (m+m, 2H), 2.71 (m, 1H), 2.70/2.56 (m+m, 4H), 0.87 (s, 9H), 0.04 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 168.8, 162.0, 142.5, 117.1, 67.3, 64.5, 61.2, 52.0, 50.1, 43.2, 26.3, 18.3, -5.0; IR: 2854, 1729; HR-ESI (m/z): [M-C ₄ H ₉ ] ⁺ , calculated for C ₁₄ H ₂₄ N ₃ O ₄ SSi: 358.1262, found: 358.1255.

Step C: methyl 2-[[3-[tert-butyl(dimethyl)silyl]oxy-2-morpholinopropyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3 -benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction starting from the product of Step B and the product _{of Preparation 4a as the appropriate halide followed by purification by reverse phase preparative chromatography (C18, 25 mM NH4HCO3water :} MeCN) gave 270 mg (70%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.97 (s, 1H), 7.84 (d, 1H), 7.74 (s, 1H), 7.48 (d, 1H), 7.44 (t, 1H), 7.26 (t, 1H), 5.89 (s, 2H), 4.71 /4.26 (dd+dd, 2H), 3.84/3.79 (dd+dd, 2H), 3.80 (s, 3H), 3.71 (t, 2H), 3.27/3.16 (t+t, 4H), 2.97 (m, 1H), 2.88/2.39 (t+t, 4H) , 2.45 (s, 3Н), 0.92 (t, 2Н), 0.88 (s, 9Н), 0.06 (s, 6H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 127.2, 123.5, 123.2, 122.9, 118.5, 112.0, 72.8, 67.3, 66.7, 64.2, 61.0, 52.3, 50.3, 46.4, 26.3, 17.8, 17.8, -1, -5.1; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₆ H ₅₆ N ₇ O ₅ S ₂ Si ₂ : 786.3322 , found: 786.3312.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-2-morpholinopropyl)amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 25 mM _{NH4HCO3 water} :MeCN), the product from Step C was obtained to give the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₃ H ₂₆ N ₇ O ₄ S ₂ : 528.1487, found: 528.1489.

Example 108: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethyl-[5-methyl-6-f(Z)-[3-(2-trimethylsilylethoxime ethyl3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazole-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 350 mg of Preparation 3h (0.57 mmol, 1 equiv) and 235 mg of Preparation 4a (0.57 mmol, 1 equiv) as the appropriate halide, 490 mg (87%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.68 (s, 1H), 7.47 (d, 1H), 7.44 (td, 1H), 7.32 (brd., 1H), 7.25 (td, 1H), 7.22 (d, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.49/4.33 (m+m, 2H), 4.20 (br., 2H), 4.17 (m, 1H), 4.15 (t, 2H), 4.04/3.63 (dd+dd, 2H), 3.77 (s, 3H) , 3.72 (t, 2H), 3.27 (t, 2H), 2.84 (br., 3H), 2.45 (s, 3H), 2.13 (m, 2H), 1.75 (m, 2H), 1.40 (s, 9H), 1.37/1.24 (s+s, 6H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 129.1, 127.2, 123.5, 123.2, 119.3, 117.5, 115.5, 112.0, 108.6, 73.7, 72.8, 68.9, 68.4, 66.7, 51.9, 44.4, 38.5, 33.8, 30.9, 28.5, 27.3/26.0, 23.3, 23.1, 17.9, 17.8, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₈ H ₆₃ FN ₇ O ₈ S ₂ Si: 976.3927, found: 976.3916.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₅ FN ₇ O ₅ S ₂ : 692.2120, found: 692.2114.

Example 109: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-4-methoxybutyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[3-[tert-butyl(dimethyl)silyl]oxy -4-methoxy butyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 320 mg of Preparation 31 (0.46 mmol, 1 equiv) and 188 mg of Preparation 4a (0.46 mmol, 1 equiv) as the appropriate halide, 415 mg (84%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.55 (s, 1H), 7.47 (d, 1H), 7.44 (td, 1H), 7.32 (brd., 1H), 7.25 (td, 1H), 7.21 (d, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.49/4.37 (m+m, 2H), 4.20 (br., 2H), 4.14 (t, 2H), 4.01 (m, 1H), 3.76 (s, 3H), 3.71 (t, 2H), 3.36 (m , 2Н), 3.28 (s, 3Н), 3.27 (t, 2Н), 2.84 (br., 3H), 2.45 (s, 3H), 2.12 (m, 2H), 1.90/1.79 (m+m, 2H), 1.40 (s, 9H), 0.92 (t, 2H), 0.88 (s, 9H), 0.08/0.06 ( s/s, 6H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 129.1, 127.2, 123.4, 123.2, 119.3, 117.3, 115.5, 112.0, 76.6, 72.8, 69.6, 68.4, 66.7, 58.8, 51.9, 44.2, 38.5, 33.8, 31.8, 30.9, 28.5, 26.3, 23.1, 17.8, 17.8, -1.0, -4.1/-4.5; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₂ H ₇₅ FN ₇ O ₈ S ₂ Si ₂ : 1064.4636, found: 1064.4629.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-4-methoxybutyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₇ FN ₇ O ₅ S ₂ : 706.2276, found: 706.2285.

Example 110: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[4-[tert-butyl(dimethyl)silyl]oxybutyl]amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction starting from methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate and 4-[tert-butyl(dimethyl)silyl]oxybutan-1-ol and reacting in THF at rt for 1 h, 3.38 g (98%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 8.09 (s, 1H), 4.07 (t, 2H), 3.79 (s, 3H), 3.59 (t, 2H), 1.69 (qn, 2H), 1.53 (s, 9H), 1.45 (qn, 2H), 0.83 (s, 9H), 0.00 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 161.9, 160.9, 153.1, 141.0, 124.8, 83.7, 62.5, 52.4, 47, 30.0, 28.1, 26.3, 24.5, 18.3, -4.9; HR-MS (m/z): [M+H] ⁺ , calculated for C ₂₀ H ₃₇ N ₂ O ₅ SSi: 445.2192 found: 445.2193.

Step B: Methyl 2-[tert-butoxycarbonyl-[4-[tert-butyl(dimethyl)silyl]oxybutyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 2.0 g (80%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.79 (t, 1H), 7.50 (s, 1H), 3.73 (s, 3H), 3.59 (t, 2H), 3.22 (q, 2H), 1.58 (m, 2H), 1.51 (m, 2H), 0.85 (s, 9H), 0.02 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 168.7, 162.0, 142.6, 116.9, 62.7, 52.0, 44.7, 30.2, 26.3, 25.6, -4.8; IR: 2929, 1732; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₁₅ H ₂₉ N ₂ O ₃ SSi: 345.1668 found: 345.1652.

Step C: methyl 2-[4-[tert-butyl(dimethyl)silyl]oxybutyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene ]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product from Step B and the product of Preparation 4a as the appropriate halide, 451 mg (73%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.98 (s, 1H), 7.84 (dm, 1H), 7.69 (s, 1H), 7.47 (dm, 1H), 7.44 (m, 1H), 7.25 (m, 1H), 5.87 (s, 2H), 4.47 (t, 2H), 3.82 (s, 3H), 3.72 (m, 2H), 3.62 (t, 2H), 2.46 (s, 3H), 1.76 (m, 2H), 1.53 (m, 2H), 0.92 (m, 2H), 0.80 (s, 9H), -0.01 (s, 6H), -0.10 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 127.2, 123.5, 123.2, 123.1, 117.7, 112.0, 72.9, 66.7, 62.5, 52.2, 47.2, 29.7, 26.2, 23.8, 17.8, 17.8, - 1.0, -4.9; IR: 2951, 1732; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₅₁ N ₆ O ₄ S ₂ Si ₂ : 715.2952 found: 715.2963.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 25 mM _{NH4HCO3 water} :MeCN), the product from Step C was obtained to give the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₀ H ₂₁ N ₆ O ₃ S ₂ : 457.1117, found: 457.1108.

Example 111: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-2-methoxypropyl)amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[3-[tert-butyl(dimethyl)silyl]oxy-2-methoxypropyl]amino]thiazole-4-carboxylate

Using the General Procedure for the Mitsunobu reaction, starting from methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate and the product

Synthesis of 2j as starting materials and reaction in THF at rt for 1 h afforded 683 mg (88%) of the target product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 8.09 (s, 1H), 4.22 (dd, 1H), 4.06 (dd, 1H), 3.79 (s, 3H), 3.71-3.55 (m, 3H), 3.29 (s, 3H), 1.52 (s, 9H), 0.84 (s, 9H), 0.01 (s, 3H), 0.00 (s, 3H).

Step B: Methyl 2-[[3-[tert-butyl(dimethyl)silyl]oxy-2-methoxypropyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 514 mg (quant.) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.80 (t, 1H), 7.52 (s, 1H), 3.73 (s, 3H), 3.34 (s, 3H), 3.66 (dd, 1H), 3.62 (dd, 1H), 3.41 (m. 1H), 3.39 (m, 1H), 3.26 (m, 1H), 0.86 (s, 9H), 0.04 (s, 3H), 0.03 (s, 3H); LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₁₅ H ₂₉ N ₂ O ₄ SSi: 361, found: 361.

Step C: methyl 2-[[3-[tert-butyl(dimethyl)silyl]oxy-2-methoxypropyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3 -benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product of Step B and the product of Preparation 4a as the appropriate halide, 313 mg (70%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.98 (s, 1H), 7.84 (d, 1H), 7.75 (s, 1H), 7.51-7.41 (m, 2H), 7.26 (tm, 1H), 5.88 (s, 1H), 5.87 (s, 1H) , 4.53 (dd, 1H), 4.41 (dd, 1H), 3.81 (s, 3H), 3.78 (m, 2H), 3.75-3.65 (m, 3H), 3.29 (s, 3H), 2.44 (s, 3H), 0.92 (t, 2H), 0.86 (s, 9H) , 0.05 (s, 3Н), 0.04 (s, 3Н), -0.12 (s, 9H).

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-2-methoxypropyl)amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₀ H ₂₁ N ₆ O ₄ S ₂ : 473.1066 found: 473.1063.

Example 112: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(5-hydroxy-4-methoxypentyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[5-[tert-butyl(dimethyl)silyl]oxy -4-methoxyp entyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 12 g of Preparation 3f (13 mmol) and 6.30 g of Preparation 4a (15.6 mmol) as the appropriate halide, 14 g (83%) of the desired product were obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(5-hydroxy-4-methoxypentyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.91 (d, 1H), 7.66 (s, 1H), 7.53 (d, 1H), 7.39 (td, 1H), 7.26 (dd, 1H), 7.21 (td, 1H), 7.18 (dd, 1H), 7.15 (t, 1H), 4.38 (m, 2H), 4.14 (t, 2H), 3.47 (s, 2H), 3.41/3.36 (dd+dd, 2H), 3.28 (s, 3H), 3.26 (t, 2H), 3.20 (m, 1H), 2.46 (s, 3H ), 2.31 (s, 3Н), 2.13 (m, 2Н), 1.72 (m, 2H), 1.57/1.49 (m+m, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 128.9, 126.6, 122.6, 122.3, 119.1, 118.3, 116.9, 115.5, 81.4, 68.5, 62.7, 57.1, 47.0, 40.2, 35.2, 31.0, 28.2, 23.3, 23.1, 17.8 HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₅ H ₃₉ FN ₇ O ₅ S ₂ : 720.2433, found: 720.2437.

Example 113: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-5-morpholinopentyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[4-[tert-butyl(diphenyl)silyl]oxy -5-morpholino pentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Tosylate Alkylation Procedure, starting from Preparation 5a and morpholine as the appropriate amine, the desired product was obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-5-morpholinopentyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₈ H ₄₄ FN ₈ O ₅ S ₂ : 775.2855, found: 775.2851.

Example 114: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-hydroxybutyl)amino)-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure starting from the appropriate methyl ester from Preparation 5c, Step A, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₅ FN ₇ O ₄ S ₂ : 676.2170, found: 676.2177.

Example 115: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-2-morpholinopropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[3-[tert-butyl(dimethyl)silyl]oxy -2-morpholino propyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 390 mg of Preparation 3r (0.59 mmol, 1 equiv) and 216 mg of Preparation 4a (0.59 mmol, 1 equiv) as the appropriate halide, 500 mg (83%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.71 (s, 1H), 7.47 (dm, 1H), 7.44 (m, 1H), 7.31 (brd, 1H), 7.25 (m, 1H), 7.21 (brd, 1H), 7.14 (t, 1H), 5.88/5.85 (d+d, 2H), 4.66/4.19 (dd+dd, 2H), 4.20 (brs, 2H), 4.14 (t, 2H), 3.82/3.77 (dd+dd, 2H), 3.75 (s, 3H), 3.71 (m, 2H), 3.29/3.26 (m+m, 2H), 3.28/3.18 (m+m, 4H), 2.95 (m, 1H), 2.89/2.39 (m+m, 4H), 2.84 (brs, 3H), 2.43 (s, 3H), 2.13 (m, 2H), 1.40 (s, 9H), 0.92 (m, 2H), 0.87 (s, 9H), 0.05 (s, 6H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 163.1, 157.4, 156.8/151.5, 141.2, 134.6, 129.0, 127.2, 123.4, 123.1, 119.2, 118.3, 115.4, 111.9, 85.1, 82.2, 72.7, 68.3, 67.3, 66.6, 64.1, 60.9, 51.8, 50.1, 45.9, 38.5, 33.7, 30.9, 28.4, 26.2, 23.0, 17.9, 17.7, -1.1, -5.2; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₄ H ₇₈ FN ₈ O ₈ S ₂ Si ₂ : 1105.4901, found: 1105.4896.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-2-morpholinopropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₆ H ₄₀ FN ₈ O ₅ S ₂ : 747.2542, found: 747.2531.

Example 116: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-(2-methyl-3-oxopropyl)-1,3-thiazole-4-carboxylate

To a solution of the product of Synthesis 11b (1.2 g, 1.89 mmol, 1 equiv.) in 1,4-dioxane (20 mL) were added 2-methyl-2-propen-1-ol (0.48 mL, 5.66 mmol, 3 equiv.), N,N-dicyclohexylmethylamine (0.81 mL, 3.78 mmol, 2 equiv.) and 2-(di-tert-butylphosphino)-1-phenyl-1H-pyrrole (54.3 mg, 0.19 mmol, 0.1 equiv.). The mixture was sparged with nitrogen (10 min) and tris(dibenzylideneacetone)dipalladium(0) (86.4 mg, 0.09 mmol, 0.05 equiv) was added and the mixture was heated at 100 °C in a sealed flask overnight. The reaction mixture was partitioned between ethyl acetate and water and the organic phase was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0-40% ethyl acetate in isoheptane afforded the title product as a yellow oil (779 mg, 1.24 mmol, 66%).

LC/MS (C ₂₉ H ₃₈ N ₆ O ₄ SiS ₂ ) 627 [M+H] ⁺ ; RT 2.86 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 9.67 (d, J=1.4 Hz, 1H), 7.88-7.81 (m, 1H), 7.68-7.63 (m, 1H), 7.51-7.40 (m, 2H), 7.29-7.21 (m, 1H), 5.85 (s, 2H), 4.28 (q, 2H), 3.77 (s, 3H), 3.75-3.66 (m, 2H), 3.49 (dd, J=14.4, 6.7 Hz, 1H), 3.16 (dd, J=14.4, 7.6 Hz, 1H), 2.86-2.74 (m, 1H), 2.44 (d, 3H), 1.31 (t, 3H), 1.08 (d, 3H), 0.95-0.88 (m, 2H), -0.12 (s, 9H).

Step B: Ethyl 5-(3-hydroxy-2-methylpropyl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (779 mg, 1.24 mmol, 1 equiv) in methanol (20 mL) cooled to 0 °C was added sodium borohydride (51.7 mg, 1.37 mmol, 1.1 equiv) and the mixture was stirred for 20 min. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a yellow foam (336 mg, 0.53 mmol, 43%).

LC/MS (C ₂₉ H ₄₀ N ₆ O ₄ SiS ₂ ) 629 [M+H] ⁺ ; RT 2.74 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.87-7.83 (m, 1H), 7.66 (d, J=1.1 Hz, 1H), 7.49-7.40 (m, 2H), 7.28-7.21 (m, 1H), 5.85 (s, 2H), 4.62 (t, J=5.2 Hz, 1H), 4.27 (q, J=7.1 Hz, 2H), 3.76 (s, 3H), 3.75-3.66 (m, 3H), 3.42-3.26 (m, 2H), 3.13 (dd, J=14.2, 6.0 Hz, 1H), 2.96 (dd, J=14.2, 8.5 Hz, 1H), 2.45 (d, J=1.0 Hz, 3H), 1.95-1.83 (m, 1H), 1.31 (t, 3H), 0.95-0.89 (m, 2H), 0.88 (d, 3H), -0.11 (s, 9H).

Step C: Ethyl 5-(3-iodo-2-methylpropyl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product from Step B (469 mg, 0.75 mmol, 1 equiv) in 6:1 diethyl ether/acetonitrile (21 mL) were added iodine (284 mg, 1.12 mmol, 1.5 equiv), triphenylphosphine (293 mg, 1.12 mmol, 1.5 equiv), and imidazole (0.07 mL, 1.12 mmol, 1.5 equiv), and the mixture was stirred at ambient temperature for 16 h. The reaction mixture was partitioned between ethyl acetate and 10% aqueous sodium thiosulfate, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-30% ethyl acetate in isoheptane afforded the desired product as a yellow oil (523 mg, 0.71 mmol, 95%).

LC/MS (C ₂₉ H ₃₉ IN ₆ O ₃ SiS ₂ ) 739 [M+H] ⁺ ; RT 3.23 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.87-7.81 (m, 1H), 7.67 (d, J=1.2 Hz, 1H), 7.52-7.40 (m, 2H), 7.28-7.22 (m, 1H), 5.85 (s, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.78 (s, 3H), 3.75-3.67 (m, 2H), 3.48-3.37 (m, 1H), 3.35-3.27 (m, 1H), 3.17-3.03 (m, 2H), 2.45 (d, J=1.0 Hz, 3H), 1.94-1.78 (m, 1H), 1.32 (t, J=7.1 Hz, 3H), 0.97 (d, J=6.5 Hz, 3H), 0.95-0.87 (m, 2H), -0.13 (s, 9H).

Step D: Ethyl 5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product from Step C (523 mg, 0.71 mmol, 1 equiv.) in dimethylformamide (20 mL) were added the product of Preparation 6b (178 mg, 0.92 mmol, 1.3 equiv.) and cesium carbonate (692 mg, 2.12 mmol, 3 equiv.), and the mixture was heated at 80 °C for 3 h. The reaction mixture was partitioned between ethyl acetate and brine, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the desired product as a yellow oil (257 mg, 0.32 mmol, 45%).

LC/MS (C ₄₀ H ₅₀ FN ₇ O ₄ SiS ₂ ) 804 [M+H] ⁺ ; RT 2.66 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.86-7.80 (m, 1H), 7.66 (d, J=1.1 Hz, 1H), 7.49-7.40 (m, 2H), 7.33-7.10 (m, 4H), 5.85 (s, 2H), 4.26 (q, 2H), 4.08-3.95 (m, 2H), 3.77 (s, 3H), 3.75-3.65 (m, 2H), 3.36 (s, 2H), 3.32-3.25 (m, 1H), 3.17-3.05 (m, 1H), 2.44 (d, J=1.0 Hz, 3H), 2.37-2.24 (m, 1H), 2.18 (s, 6H), 1.29 (t, J=7.1 Hz, 3H), 1.04 (d, J=6.7 Hz, 3H), 0.96-0.85 (m, 2H), -0.12 (s, 9H).

Step E: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl)-1,3-thiazole-4-carboxylate

To a solution of the product from Step D (257 mg, 0.32 mmol, 1 equiv) in tetrahydrofuran (15 mL) was added ethylenediamine (64 µL, 0.96 mmol, 3 equiv) followed by TBAF (1 M in tetrahydrofuran; 0.96 mL, 0.96 mmol, 3 equiv), and the mixture was heated at 60 °C for 18 h. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the desired product as a yellow glass (110 mg, 0.16 mmol, 51%).

LC/MS (C ₃₄ H ₃₆ FN ₇ O ₃ S ₂ ) 674 [M+H] ⁺ ; RT 2.11 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.55 (br s, 1H), 7.92 (d, J=8.0 Hz, 1H), 7.69 (s, 1H), 7.54 (d, J=8.0 Hz, 1H), 7.43-7.36 (m, 1H), 7.31 (dd, J=11.9, 1.9 Hz, 1H), 7.27-7.17 (m, 2H), 7.15 (t, J=8.6 Hz, 1H), 4.26 (q, 2H), 4.08-3.95 (m, 2H), 3.78 (s, 3H), 3.38 (s, 2H), 3.33-3.27 (m, 1H), 3.18-3.07 (m, 1H), 2.47 (d, J=1.0 Hz, 3H), 2.40-2.27 (m, 1H), 2.20 (s, 6H), 1.31 (t, J=7.1 Hz, 3H), 1.05 (d, J=6.7 Hz, 3H).

Step F: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step E (110 mg, 0.16 mmol, 1 equiv) in 1,4-dioxane (15 mL) was added lithium hydroxide monohydrate (68.5 mg, 1.63 mmol, 10 equiv) and the mixture was heated under reflux for 16 h. The reaction mixture was concentrated in vacuo and the residue was triturated with water (5 mL), filtered, washed with water and dried in vacuo to give the title product as a yellow solid (91.2 mg, 0.14 mmol, 87%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₂ H ₃₃ FN ₇ O ₃ S ₂ : 646.2065, found: 646.2091.

Example 117: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(2,3-dihydroxypropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[(2,2-dimethyl-1,3-dioxolane- 4-yl)methyl -[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 280 mg of Preparation 3o (0.47 mmol, 1 equiv.) and 193 mg of Preparation 4a (0.47 mmol, 1 equiv.) as the appropriate halide, 400 mg (88%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.80 (s, 1H), 7.47 (d, 1H), 7.44 (td, 1H), 7.32 (brd., 1H), 7.26 (td, 1H), 7.22 (d, 1H), 7.16 (t, 1H), 5.87 (s, 2H), 4.55 (m, 2H), 4.53 (m, 1H), 4.20 (br., 2H), 4.15 (t, 2H), 4.07/3.83 (dd+dd, 2H), 3.77 (s, 3H), 3.71 (t, 2H), 3.27 (t, 2H), 2.84 (br., 3H), 2.43 (s, 3H), 2.13 (m, 2H), 1.40 (s, 9H), 1.27/1.20 (s+s, 6H), 0.92 (t, 2H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 127.2, 123.2, 123.2, 119.3, 118.9, 115.5, 112.0, 109.2, 74.0, 72.8, 68.4, 66.9, 66.7, 52.0, 49.6, 38.5, 33.8, 30.9, 28.5, 26.6/25.7, 23.1, 17.8, 17.7, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₇ H ₆₁ FN ₇ O ₈ S ₂ Si: 962.3771, found: 962.3767.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(2,3-dihydroxypropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₂ H ₃₃ FN ₇ O ₅ S ₂ : 678.1963, found: 678.1965.

Example 118: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-2-methoxypropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[3-[tert-butyl(dimethyl)silyl]oxy -2-methoxyp ropyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 400 mg of Preparation 3q (0.59 mmol, 1 equiv) and 240 mg of Preparation 4a (0.59 mmol, 1 equiv) as the appropriate halide, 534 mg (86%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.72 (s, 1H), 7.47 (dm, 1H), 7.44 (m, 1H), 7.31 (brd, 1H), 7.25 (m, 1H), 7.21 (dd, 1H), 7.16 (t, 1H), 5.88/5.85 (d+d, 2H), 4.48/4.35 (dd+dd, 2H), 4.20 (brs, 2H), 4.15 (t, 2H), 3.77/3.66 (dd+dd, 2H), 3.76 (m, 1H), 3.76 (s, 3H), 3.71 (m, 2H), 3.27 (m, 2H), 3.23 (s, 3H), 2.84 (brs, 3H), 2.42 (s, 3H), 2.12 (m, 2H), 1.40 (s, 9H), 0.92 (m, 2H), 0.85 (s, 9H), 0.04 (s, 3H), 0.03 (s, 3H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 127.2, 123.4, 123.2, 119.3, 118.6, 115.5, 112.0, 79.4, 72.8, 68.4, 66.7, 63.1, 58.2, 51.8, 48.4, 38.3, 33.7, 30.9, 28.4, 26.2, 23.0, 18.0, 17.7, -1.6 , -5.1, -5.1; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₁ H ₇₃ FN ₇ O ₈ S ₂ Si ₂ : 1050.4479, found: 1050.4469.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-2-methoxypropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₅ FN ₇ O ₅ S ₂ : 692.2120, found: 692.2117.

Example 119: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4,5-dihydroxypentyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product of Preparation 5a, Step A, as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₇ FN ₇ O ₅ S ₂ : 706.2276, found: 706.2274.

Example 120: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-[methyl(i-tolylsulfonyl)amino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: Methyl 2-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[2-fluoro-4-[3-[methyl(p-tolylsulfonyl)amino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 470 mg of Preparation 3k (0.71 mmol, 1 equiv) and 290 mg of Preparation 4a (0.71 mmol, 1 equiv) as the appropriate halide, 660 mg (90%) of the desired product were obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-[methyl(p-tolylsulfonyl)amino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₀ H ₄₁ FN ₇ O ₇ S ₃ : 846.2208, found: 846.2201.

Example 121: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-[(4-methoxyphenyl)methylmethylamino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazole -2-ylidene]amino ]pyridazin-3-yl]amino]-5-[3-[2-fluoro-4-[3-[(4-methoxyphenyl)methylmethylamino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 625 mg of Preparation 3j (1 mmol, 1 equiv.) and 407 mg of Preparation 4a (1 mmol, 1 equiv.) as the appropriate halide, 550 mg (55%) of the desired product were obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-[(4-methoxyphenyl)methylmethylamino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₄₃ FN ₇ O ₆ S ₂ : 812.2695, found: 812.2674.

Example 122: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(2,3-dihydroxypropyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[(2,2-dimethyl-1,3-dioxolan-4-yl)methyl- [5-methyl- 6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-6ensothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 380 mg of Preparation 3p (0.75 mmol, 1 equiv) and 306 mg of Preparation 4a (0.75 mmol, 1 equiv) as the appropriate halide, 480 mg (72%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.78 (s, 1H), 7.47 (dm, 1H), 7.44 (m, 1H), 7.30 (dd, 1H), 7.26 (m, 1H), 7.21 (m, 1H), 7.15 (t, 1H), 5.86 (s, 2H), 4.57/4.53 (m+m, 2H), 4.52 (m, 1H), 4.15 (t, 2H), 4.07/3.83 (dd+dd, 2H), 3.77 (s, 3H), 3.71 (m, 2H), 3.38 (s, 2Н), 3.27 (m, 2Н), 2.43 (s, 3H), 2.20 (s, 6H), 2.13 (m, 2H), 1.27 (s, 3H), 1.20 (s, 3H), 0.92 (m, 2H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 163.1, 157.6, 156.8/151.7, 141.5, 137.6, 134.9, 128.9, 127.1, 123.4, 123.2, 119.2, 118.8, 115.4, 111.9, 85.1, 84.1, 73.9, 72.7, 68.3, 66.9, 66.6, 51.9, 49.6, 48.1, 44.2, 30.9, 26.6, 25.6, 23.0, 17.8, 17.7, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₃ H ₅₅ FN ₇ O ₆ S ₂ Si: 876.3403, found: 876.3408.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(2,3-dihydroxypropyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₅ FN ₇ O ₅ S ₂ : 692.2120, found: 692.2117.

Example 123: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[2-(2,2-dimethyl-1,3-dioxolan-4-yl) ethyl-[5-methyl- 6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 350 mg of Preparation 3i (0.67 mmol, 1 equiv) and 275 mg of Preparation 4a (0.67 mmol, 1 equiv) as the appropriate halide, 510 mg (85%) of the desired product were obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₇ FN ₇ O ₅ S ₂ : 706.2276, found: 706.2270.

Example 124: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(dimethylamino)ethylmethylamino]-4-hydroxypentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[[4-[tert-butyl(diphenyl)silyl]oxy-5-[2-(dimethylamino)ethylmethylamino]pentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl) -1, 3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4- carboxylate

Using the General Tosylate Alkylation Procedure starting from Preparation 5b and N,N',N'-trimethylethane-1,2-diamine as the appropriate amine, the desired product was obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(dimethylamino)ethylmethylamino]-4-hydroxypentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₀ H ₅₁ FN ₉ O ₄ S ₂ : 804.3484, found: 804.3487.

Example 125: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(5-hydroxypentyl)amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[5-[tert-butyl(dimethyl)silyl]oxypentyl]amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction starting from methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate and 5-[tert-butyl(dimethyl)silyl]oxypentan-1-ol and reacting in THF at rt for 2 h, 565 mg (82%) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 8.08 (s, 1H), 4.05 (t, 2H), 3.79 (s, 3H), 3.56 (t, 2H), 1.65 (m, 2H), 1.52 (s, 9H), 1.48 (m, 2H), 1.31 (m, 2H), 0.83 (s, 9H), -0.02 (s, 6H).

Step B: Methyl 2-[5-[tert-butyl(dimethyl)silyl]oxypentylamino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A as the appropriate carbamate, 484 mg (113%) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.78 (t, 1H), 7.50 (s, 1H), 3.57 (t, 2H), 3.73 (s, 3H), 3.20 (q, 2H), 1.59-1.42 (m, 4H), 1.40-1.29 (m, 2H), 0.85 (s, 9H), 0.02 (s, 6H).

Step C: methyl 2-[5-[tert-butyl(dimethyl)silyl]oxypentyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene ]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product from Step B and the product of Preparation 4a as the appropriate halide, 535 mg (61%) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.97 (s, 1H), 7.84 (d, 1H), 7.70 (s, 1H), 7.46 (t, 1H), 7.43 (t, 1H), 7.25 (dt, 1H), 5.86 (s, 2H), 4.45 (t, 2H), 3.81 (s, 3H), 3.72 (t, 2H), 3.55 (t, 2H), 2.46 (s, 3H), 1.72 (m, 2H), 1.50 (m, 2H), 1.38 (m, 2H), 0.92 (t, 2H), 0.79 (s, 9H ), -0.04 (s, 6H), -0.11 (s, 9H).

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(5-hydroxypentyl)amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 25 mM _{NH4HCO3 water} :MeCN), the product from Step C was obtained to give the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₂₃ N ₆ O ₃ S ₂ : 471.1273, found: 471.1271.

Example 126: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxypropyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: ethyl 3-bromo-6-chloro-2-oxohexanoate

To 2 g of ethyl 6-chloro-2-oxohexanoate (10.4 mmol, 1 equiv.) in 20 mL of CCl ₄ was added dropwise 0.6 mL of bromine (11.5 mmol, 1.1 equiv.) and the mixture was stirred at rt for 1 h. The mixture was then poured into 50 mL of 1 M aqueous Na ₂ S ₂ O ₃ solution and extracted with 2×50 mL of ethyl acetate, and the combined organic layers were washed with brine, dried, concentrated and purified by silica gel chromatography using petroleum ether and EtOAc as eluents to give 2.05 g (73%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 5.25 (dd, 1H), 4.30 (q, 2H), 3.71 (t, 2H), 2.21-1.80 (m, 4H), 1.29 (t, 3H); GC/EI-MS: [M] ⁺ = 270.

Step B: 3-[tert-butyl(dimethyl)silyl]oxypropan-1-amine

To 8.25 g 3-aminopropan-1-ol (110 mmol, 1 equiv), 23 mL N,N-diethylethanamine (170 mmol, 1.5 equiv) and 30 mg imidazole (0.44 mmol, 0.004 equiv) in 200 mL DCM were added 18.2 g tert-butyldimethylsilyl chloride (150 mmol, 1.4 equiv) and the mixture was stirred at rt for 15 h. Then the reaction mixture was poured into 250 mL water and extracted with 2×200 mL DCM, the combined organic layers were washed with 50 mL water and 50 mL brine, dried and concentrated to give 20.9 g (100%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 3.60 (t, 2H), 2.55 (t, 2H), 1.50 (quint, 2H), 0.80 (s, 9H), 0.10 (s, 6H); IR: 3000-2900, 1100, 830-770.

Step C: 3-[tert-butyl(dimethyl)silyl]oxypropylthiourea

To 5.3 g of 9-fluorenyl methoxycarbonyl isothiocyanate (18.9 mmol, 1 equiv) and 6.4 mL of DIPEA (37.6 mmol, 2 equiv) in 50 mL of DCM was added dropwise a solution of 3.5 g of the product from Step B (18.5 mmol, 1 equiv) in 10 mL of DCM, and the mixture was stirred at rt for 2 h. After concentration, the crude product was purified by silica gel chromatography using petroleum ether and EtOAc as eluents to afford 3.87 g (80%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.49 (brs, 1H), 6.83 (brs, 1H), 7.21 (s, 1H), 3.57 (t, 2H), 3.34/3.02 (m, 2H), 1.61 (m, 2H), 0.83 (s, 9 H), 0.02 (s, 6 H); IR: 3275, 1619.

Step D: Ethyl 2-[3-[tert-butyl(dimethyl)silyl]oxypropylamino]-5-(3-chloropropyl)thiazole-4-carboxylate

A solution of 7.4 g of the product from Step C (29.7 mmol, 1 equiv), 8.1 g of the product from Step A (30 mmol, 1 equiv), and 8.2 mL of N,N-diethylethanamine (59.4 mmol, 2 equiv) in 206 mL of ethanol was heated under reflux for 18 h. After concentration, the crude residue was taken up in DCM, washed with water, dried, concentrated, and purified by silica gel chromatography using petroleum ether and EtOAc as eluents to give 10.1 g (81%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.56 (t, 1H), 4.17 (q, 2H), 3.62 (2t, 4H), 3.18 (q, 2H), 3.06 (t, 2H), 1.95 (m, 2H), 1.69 (m, 2H), 1.23 (t, 3H), 0.83 (s, 9H), 0.01 (s, 6H); IR: 3197, 1716, 1586.

Step E: Ethyl 2-[3-[tert-butyl(dimethyl)silyl]oxypropyl-(6-chloropyridazin-3-yl)amino]-5-(3-chloropropyl)thiazole-4-carboxylate

To 10 g of the product from Step D (23.7 mmol, 1 equiv) and 5.8 g of 3,6-dichloro-4-methylpyridazine (35.6 mmol, 1.5 equiv) in 120 mL of THF was added 2.1 g of sodium hydride (52.1 mmol, 2.2 equiv) portionwise at 50 °C. The cooled mixture was poured onto ice and extracted with 2×200 mL of ethyl acetate. The combined organic layers were washed with brine, dried, concentrated, and purified by silica gel chromatography using petroleum ether and EtOAc as eluents to afford 4.3 g (32%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.76 (s, 1H), 4.39 (t, 2H), 4.26 (q, 2H), 3.68 (m, 4H), 3.19 (t, 2H), 2.39 (s, 3H), 2.06 (m, 2H), 1.89 (m, 2H), 1.29 (t, 3H), 0.83 (s, 9H), 0.01 (s, 6H); IR: 1704, 1592, 1195, 1095+1066, 649.

Step F: Ethyl 2-[3-[tert-butyl(dimethyl)silyl]oxypropyl-(6-chloro-5-methylpyridazin-3-yl)amino]-5-(3-iodopropyl)thiazole-4-carboxylate

A mixture of 4.6 g of the product from Step E (8.42 mmol, 1 equiv.) and 12.6 g of sodium iodide (84.2 mmol, 10 equiv.) in 58 mL of acetone was heated at 60°C for 18 h. After concentration, the residue was taken up in ethyl acetate, washed with water and brine, dried and concentrated to give the title product, which was used in the next step without further purification.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.78 (s, 1H), 4.41 (t, 2H), 4.29 (q, 2H), 3.71 (t, 2H), 3.31 (t, 2H), 3.17 (t, 2H), 2.41 (s, 3H), 2.12 (m, 2H), 1.91 (m, 2H), 1.32 (t, 3H), 0.84 (s, 9H), 0.02 (s, 6H).

Step G: Ethyl 2-[3-[tert-butyl(dimethyl)silyl]oxypropyl-(6-chloro-5-methylpyridazin-3-yl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

A mixture of 800 mg of the product from Step F (1.25 mmol, 1 equiv), 821 mg of cesium carbonate (2.5 mmol, 2 equiv) and 290 mg of the product of Preparation 6b (1.5 mmol, 1.2 equiv) in 6 mL of MeCN was heated under reflux for 2 h. After diluting the mixture with 100 mL of ethyl acetate, the organic layer was washed with 50 mL of water and 50 mL of brine, dried, concentrated and purified by silica gel chromatography using DCM and MeOH (containing 7 N NH ₃ ) as eluents to give 500 mg (57%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.77 (m, 1H), 7.27 (dd, 1H), 7.18 (d, 1H), 7.11 (t, 1H), 4.40 (t, 2H), 4.23 (q, 2H), 4.11 (t, 2H), 3.69 (t, 2H), 3.40 (s, 2H), 3.24 (t, 2H), 2.40 (s, 3H), 2.21 (s, 6H), 2.10 (m, 2H), 1.89 (m, 2H), 1.27 (t, 3H), 0.83 (s, 9H), 0.00 (s, 6H ); IR: 3600-3100, 2237, 1716, 835, 777.

Step H: Ethyl 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxypropyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

A mixture of 100 mg of the product from Step G (0.142 mmol, 1 equiv), 28 mg of 1,3-benzothiazol-2-amine (0.185 mmol, 1.3 equiv), 10 mg of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (0.017 mmol, 0.12 equiv), 8 mg of tris(dibenzylideneaceto)dipalladium(0) (8.52 μmol, 0.06 equiv), and 72 μL of DIPEA (0.426 mmol, 3 equiv) in 0.7 mL of N-methyl-2-pyrrolidone was heated at 120 °C for 18 h. The mixture was then poured into 50 mL of DCM, the organic layer was washed with 10 mL of water and 10 mL of saturated aqueous lithium chloride solution, dried, concentrated and purified by silica gel chromatography using DCM and MeOH (containing 7N _NH3 ) as eluents to give 40 mg (40%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 11.54 (brs, 1H), 7.91 (d, 1H), 7.69 (s, 1H), 7.53 (d, 1H), 7.39 (t, 1H), 7.30 (dd, 1H), 7.22 (dd, 1H), 7.21 (dd, 1H), 7.16 (t, 1H), 4.72 (t, 1H), 4.41 (t, 2H), 4.25 (q, 2H), 4.16 (t, 2H), 3.48 (q, 2H), 3.39 (s, 2H), 3.27 (t, 2H), 2.46 ( s, 3H), 2.2 (s, 6H), 2.13 (m, 2H), 1.87 (m, 2H), 1.29 (t, 3H); IR: 3414, 3400-2200, 1709, 1602, 1149/1087.

Step I: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxypropyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

A mixture of the product from Step H and LiOH× _H2O (4 equiv.) in 1,4-dioxane and water was stirred at rt for 3 h. After addition of an additional 1 equiv. LiOH× _H2O in water, the reaction mixture was stirred at rt for 18 h. After slow addition of 2 N HCl, the reaction mixture was concentrated and purified by reverse phase preparative _{chromatography} (0.2 M _NH4CO3 in water:MeCN) to afford the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₅ FN ₇ O ₄ S ₂ : 676.2170 found: 676.2169.

Example 127: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxypropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[3-[tert-butyl(dimethyl)silyl]oxypropyl -[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 300 mg of Preparation 3n (0.46 mmol, 1 equiv) and 187 mg of Preparation 4a (0.46 mmol, 1 equiv) as the appropriate halide, 395 mg (83%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.82 (dd, 1H), 7.60 (s, 1H), 7.44 (m, 1H), 7.44 (dd, 1H), 7.31 (dd, 1H), 7.24 (m, 1H), 7.20 (m, 1H), 7.15 (t, 1H), 5.84 (s, 2H), 4.39 (t, 2H), 4.20 (s, 2H), 4.14 (t, 2H), 3.76 (s, 3H), 3.70 (t, 2H), 3.70 (t, 2H), 3.25 (t, 2H), 2.84 (s, 3H ), 2.42 (s, 3Н), 2.11 (m, 2Н), 1.91 (m, 2H), 1.40 (s, 9H), 0.91 (t, 2H), 0.85 (s, 9H), 0.01 (s, 6H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 162.2, 147.5, 137.6, 129.1, 127.2, 123.4, 123.2, 119.3, 117.5, 115.4, 112.0, 79.7, 72.8, 68.4, 66.7, 60.5, 51.9, 44.6, 38.1, 33.8, 30.9, 30.4, 28.6, 26.3, 23.1, 17.9, 17.8, -0.9, -5.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₀ H ₇₁ FN ₇ O ₇ S ₂ Si ₂ : 1020.4373, found: 1020.4365.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxypropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₂ H ₃₃ FN ₇ O ₄ S ₂ : 662.2014, found: 662.2016.

Example 128: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(5-hydroxypentyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure starting from the appropriate methyl ester from Preparation 5e, Step A, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₇ FN ₇ O ₄ S ₂ : 690.2327, found: 690.2318.

Example 130: 3-[3-[4-[3-[2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-4-carboxythiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynyldimethylammonio]propane-1-sulfonate

Step A: 3-[3-[4-[3-[2-[4-[tert-butyl(dimethyl)silyl]oxybutyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-4-methyloxycarbonylthiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynyldimethylammonio]propane-1-sulfonate

To a suspension of 660 mg of the product of Preparation 5d, Step A (0.7 mmol, 1 equiv) in 5 mL of dry acetonitrile were added 257 mg of oxathiolane 2,2-dioxide (2.1 mmol, 3 equiv) in one portion. The resulting mixture was stirred overnight at rt. The crude product was purified by flash column chromatography to afford 550 mg (75%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.83-7.20 (m, 4H), 7.62 (s, 1H), 7.58 (dd, 1H), 7.41 (m, 1H), 7.22 (t, 1H), 5.83 (s, 2H), 4.55 (s, 2H) , 4.40 (t, 2H), 4.17 (t, 2H), 3.77 (s, 3H), 3.70 (t, 2H), 3.60 (t, 2H), 3.57 (t, 2H), 3.25 (t, 2H), 3.12 (s, 6H), 2.52 (t, 2H), 2.42 (s, 3Н), 2.12 (m, 2Н), 2.12 (m, 2H), 2.05 (m, 2H), 1.73 (m, 2H), 0.90 (t, 2H), 0.78 (s, 9H), -0.03 (s, 6H), -0.13 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 163.2, 148.5, 137.5, 129.8, 120.0, 117.5, 115.3, 89.6, 72.8, 68.5, 66.7, 63.1, 62.5, 54.6, 51.9, 50.3, 48.2, 46.5, 31.0, 29.7, 26.2, 23.7, 23.2, 19.6, 17.9, 17.7, -1.0, -4.9; HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₅₀ H ₇₄ FN ₇ O ₈ S ₃ Si ₂ : 535.7136, found: 535.7136.

Step B: 3-[3-[4-[3-[2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-4-carboxythiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynyldimethylammonio]propane-1-sulfonate

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₇ H ₄₃ FN ₇ O ₇ S ₃ : 812.2365, found: 812.2357.

Example 131: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-5-morpholinopentyl)amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[4-[tert-butyl(dimethyl)silyl]oxy-5-morpholinopentyl]amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction starting from 639 mg of methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate (2.47 mmol, 1.5 equiv) and 500 mg of the product of Preparation 2e (1.65 mmol, 1 equiv) as the appropriate alcohol, 730 mg (81%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 8.08 (s, 1H), 4.09-4.03 (m, 2H), 3.79 (s+m, 4H), 3.51 (t, 4H), 2.39-2.28 (m, 4H), 2.21 (ddd, 2H). 1.85-1.73 (m, 1H), 1.70-1.59 (m, 1H), 1.53 (s+m, 10H), 1.39-1.28 (m, 1H), 0.79 (s, 9H), 0.02 (s, 3H), -0.01 (s, 3H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) 160.3, 140.6, 124.2, 71.2, 68.9, 66.2, 64.7, 59.8, 54.2, 51.8, 46.8, 32.3, 27.6, 25.7, 23.2, 21.8, 21.5, 20.8, 17.7, 14.1, -4.3, -4.9; LC-ESI MS (m/z): [M+H] ⁺ , calculated for C ₂₅ H ₄₆ N ₃ O ₆ SSi: 544.3, found: 544.3.

Step B: Methyl 2-[[4-[tert-butyl(dimethyl)silyl]oxy-5-morpholinopentyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with 304 mg of the product from Step A (0.56 mmol) as the appropriate carbamate, 231 mg (93%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.81 (t, 1H), 7.49 (s, 1H), 3.79 (brs, 1H), 3.73 (s, 3H), 3.53 (t, 4H), 3.21 (q, 2H), 2.42-2.23 (m, 4H), 2.23 (ddd, 2H), 1.69-1.34 (m, 4H), 0.84 (s, 9H), 0.05 (s, 3H), 0.03 (s, 3H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) 168.3, 161.6, 142.2, 116.3, 66.2, 65.2, 59.8, 54.3, 51.5, 44.5, 32.7, 25.8, 24.5, 17.8, -4.2, -4.8; LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₂₀ H ₃₈ N ₃ O ₄ SSi: 444.2, found: 444.3.

Step C: methyl 2-[[4-[tert-butyl(dimethyl)silyl]oxy-5-morpholinopentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3 -benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting with 231 mg of the product from Step B (0.52 mmol, 1 equiv) and 315 mg of the product from Preparation 4a (0.77 mmol, 1.5 equiv) as the appropriate halide, 344 mg (81%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.97 (s, 1H), 7.85-7.23 (4H), 7.69 (s, 1H), 5.86 (d, 2H), 4.49 (t, 2H), 3.81 (m, 1H), 3.81 (s, 3H), 3.71 (t, 2H), 3.50-2.13 (8H), 2.45 (s, 3H), 2.20 (m, 2H), 1.83-1.73 (m+m, 2H), 1.56-1.41 (m+m, 2H), 0.91 (t, 2H), 0.75 (s, 9H), 0.01 -(-0.05) (s+s, 6H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 162.3, 160.8, 157.6, 155.3, 123.1, 117.9, 72.9, 69.0, 66.7, 65.4, 52.3, 47.1, 32.4, 26.2, 22.9, 17.9, 17.8 , -1.0, -3.8, -4.5; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₈ H ₆₀ N ₇ O ₅ S ₂ Si ₂ : 814.3630, found: 814.3629.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-5-morpholinopentyl)amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by purification by reversed-phase preparative chromatography (C18, 25 mM _NH4HCO3 in water:MeCN), the product from Step C was obtained to give the desired product _.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₅ H ₃₀ N ₇ O ₄ S ₂ : 556.1795, found: 556.1807.

Example 132: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-5-methoxypentyl)amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-(5-methoxy-4-triisopropylsilyloxypentyl)amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction starting from 284 mg of methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate (1.10 mmol, 1.1 equiv) and 291 mg of the product of Preparation 2 with (1.00 mmol, 1 equiv) as the appropriate alcohol, 456 mg (86%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 8.08 (s, 1H), 4.07 (dt, 2H), 3.89 (qv, 1H), 3.79 (s 3H), 3.27 (dd, 2H), 3.23 (s, 3H), 1.73 (qv, 2H), 1.52 (s, 9H), 1.50-1.38 (m, 2H), 0.96 (s, 21H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm. 161.4, 160.3, 140.6, 124.2, 75.7, 70.5, 58.4, 51.9, 46.8, 31.2, 22.5, 17.89, 17.87, 11.9; LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₂₅ H ₄₇ N ₂ O ₆ SSi: 531.3, found: 531.4.

Step B: Methyl 2-[(5-methoxy-4-triisopropylsilyloxypentyl)amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with 444 mg of the product from Step A (0.84 mmol) as the appropriate carbamate, 334 mg (93%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.82 (t, 1H), 7.50 (s, 1H), 3.91 (t, 1H), 3.73 (s, 3H), 3.28 (d, 2H), 3.24 (s, 3H), 3.21 (q, 2H), 1.61 (m, 2H), 1.52 (m, 2H), 1.01 (m, 21H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 162.0, 116.9, 76.7, 71.2, 58.9, 52.0, 45.0, 32.2, 24.4; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₀ H ₃₉ N ₂ O ₄ SSi: 431.2394, found: 431.2392.

Step C: methyl 2-[(5-methoxy-4-triisopropylsilyloxypentyl)-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino] pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting with 324 mg of the product from Step B (0.75 mmol, 1 equiv) and 337 mg of the product from Preparation 4a (0.83 mmol, 1.1 equiv) as the appropriate halide, 540 mg (90%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.97 (s, 1H), 7.85-7.22 (4H), 7.68 (s, 1H), 5.86 (s, 2H), 4.48 (m, 2H), 3.88 (m, 1H), 3.81 (s, 3H), 3.71 (t, 2H), 3.26 (d, 2H), 3.21 (s, 3H), 2.44 (s, 3H), 1.79 (m, 2H), 1.53 (m, 2H), 0.91 (t, 2H), 0.91 (m, 21H), -0.13 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 162.3, 160.7, 123.1, 117.7, 76.4, 73.0, 71.0, 66.7, 58.8, 52.2, 47.2, 31.4, 22.5, 18.3, 12.3, 17.8, 17.8 , -1.0 HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₈ H ₆₁ N ₆ O ₅ S ₂ Si ₂ : 801.3678, found: 801.3671.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-5-methoxypentyl)amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by purification by reversed-phase preparative chromatography (C18, 25 mM NH4HCO3 in water:MeCN), the product from Step C was obtained to give the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₂ H ₂₅ N ₆ O ₄ S ₂ : 501.1373, found: 501.136.

Example 133: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(5-hydroxy-4-methoxypentyl)amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[5-[tert-butyl(dimethyl)silyl]oxy-4-methoxypentyl]amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction starting from 571 mg of methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate (2.21 mmol, 1.1 equiv) and 500 mg of the product of Preparation 2b (2.01, 1 equiv) as the appropriate alcohol, 818 mg (83%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 8.08 (s, 1H), 4.06 (t, 2H), 3.79 (s, 3H), 3.53 (ddd, 2H), 3.28 (s, 3H), 3.20-3.14 (m, 1H), 1.77-1.63 (m, 2H), 1.53 (s, 3H), 1.49-1.33 (m, 2H), 0.82 (s, 9H), -0.01 (s, 6H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm. 161.4, 160.4, 140.6, 124.3, 80.4, 63.6, 56.9, 51.9, 46.8, 27.4, 27.6, 25.7, 23.4, 17.9 -5.5; LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₂₂ H ₄₁ N ₂ O ₆ SSi: 489.2, found: 489.3.

Step B: Methyl 2-[[5-[tert-butyl(dimethyl)silyl]oxy-4-methoxypentyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with 306 mg of the product from Step A (0.63 mmol) as the appropriate carbamate, 234 mg (96%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.80 (t, 1H), 7.50 (s, 1H), 3.73 (s, 3H), 3.60-3.51 (m, 2H), 3.30 (s, 3H), 3.24-3.15 (m, 3H), 1.64-1.34 (m, 4H), 0.85 (s, 9H), 0.03 (s, 6H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm. 168.3, 161.6, 142.1, 116.4, 80.7, 64.3, 57.0, 51.6, 44.5, 25.8, 24.6, 17.9, -5.4; LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₁₇ H ₃₃ N ₂ O ₄ SSi: 389.2, found: 389.3.

Step C: methyl 2-[[5-[tert-butyl(dimethyl)silyl]oxy-4-methoxypentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3 -benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting with 224 mg of the product from Step B (0.58 mmol, 1 equiv) and 349 mg of the product from Preparation 4a (0.86 mmol, 1.5 equiv) as the appropriate halide, 357 mg (82%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.98 (s, 1H), 7.83 (d, 1H), 7.69 (s, 1H), 7.46 (d, 1H), 7.43 (td, 1H), 7.25 (td, 1H), 5.86 (s, 2H), 4.46 (t, 2H), 3.81 (s, 3H), 3.72 (t, 2H), 3.56-3.51 (dd+dd, 2H), 3.29 (s, 3H), 3.22 (m, 1H), 2.45 (s, 3H), 1.76 (m, 2H), 1.54-1.47 (m +m, 2H), 0.91 (t, 2H), 0.79 (s, 9H), -0.04 (s, 6H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 162.3, 127.2, 123.4, 123.2, 123.1, 117.6, 112.0, 80.9, 72.9, 66.7, 64.2, 57.3, 52.2, 47.4, 28.1, 26.2, 23.3, 17.9, 17.8, -1.0, -5.1; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₅ H ₅₅ N ₆ O ₅ S ₂ Si ₂ : 759.3208, found: 759.3212.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(5-hydroxy-4-methoxypentyl)amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by purification by reversed-phase preparative chromatography (C18, 25 mM _NH4HCO3 in water:MeCN), the product from Step C was obtained to give the desired product _.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₂ H ₂₅ N ₆ O ₄ S ₂ : 501.1373, found: 501.1366.

Example 134: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure starting from the appropriate methyl ester from Preparation 5d, Step A, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₇ FN ₇ O ₄ S ₂ : 690.2327, found: 690.2347.

Example 135: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{1-[(tert-butoxy)carbonyl]azetidin-3-yl}-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{1-[(tert-butoxy)carbonyl]azetidin-3-yl}-1,3-thiazole-4-carboxylate

To a solution of the product of Preparation 51, Step A (122 mg, 0.17 mmol, 1 equiv) in tetrahydrofuran (6 mL) was added tetrabutylammonium fluoride (1 M in tetrahydrofuran; 0.24 mL, 1.38 mmol, 8 equiv), and the mixture was heated at 50 °C for 13 h. The reaction mixture was allowed to cool to ambient temperature, then partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-10% methanol in dichloromethane afforded the title product as a yellow glass (38 mg, 0.07 mmol, 38%).

LC/MS (C ₂₇ H ₃₁ N ₇ O ₄ S ₂ ) δ82 [M+H] ⁺ ; RT 1.26 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.05 (br s, 1H), 7.98 (br s, 1H), 7.81-7.61 (m, 2H), 7.50-7.33 (m, 1H), 7.31-7.16 (m, 1H), 4.65-4.53 (m, 1H), 4.37 (t, 2H), 4.29 (q, J=7.1 Hz, 2H), 3.98-3.84 (m, 2H), 3.78 (s, 3H), 2.47 (s, 3H), 1.43 (s, 9H), 1.31 (t, 3H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{1-[(tert-butoxy)carbonyl]azetidin-3-yl}-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (38 mg, 0.07 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added 2 M aqueous sodium hydroxide (0.5 mL, 1 mmol, 15 equiv) and the mixture was heated at 100 °C for 30 min. The reaction mixture was allowed to cool to ambient temperature and concentrated in vacuo. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5 95% acetonitrile in water afforded the desired product as a yellow solid (21.4 mg, 0.04 mmol, 59%).

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₂₅ H ₂₆ N ₇ O ₄ S ₂ : 552.1493, found: 552.1511.

Example 136: 5-(1-Benzoylazetidin-3-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(l-benzoyl azetidin-3-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product of Synthesis 51 (29.6 mg, 0.05 mmol, 1 equiv) and benzoyl chloride (6.74 µL, 0.06 mmol, 1.2 equiv) in dichloromethane (3 mL) was added triethylamine (0.01 mL, 0.1 mmol, 2 equiv), and the mixture was stirred at ambient temperature for 3.5 h. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-85% ethyl acetate in isoheptane afforded the desired product as a colorless glass (32 mg, 0.04 mmol, 92%).

LC/MS (C ₃₅ H ₄₁ N ₇ O ₄ SiS ₂ ) 716 [M+H] ⁺ ; RT 1.59 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.86 (dd, J=7.6, 1.1 Hz, 1H), 7.75-7.67 (m, 3H), 7.58-7.39 (m, 5H), 7.29-7.22 (m, 1H), 5.87 (s, 2H), 4.88-4.77 (m, 1H), 4.75-4.66 (m, 1H), 4.65-4.54 (m, 1H) 4.46-4.34 (m, 1H), 4.29 (q, J=7.1 Hz, 2H), 4.22-4.10 (m, 1H), 3.79 (s, 3H), 3.76-3.67 (m, 2H), 2.47 (d, J=1.0 Hz, 3H), 1.31 (t, J=7.1 Hz, 3H), 0.97-0.88 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 5-(1-benzoyl azetidin-3-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (32 mg, 0.04 mmol, 1 equiv) in dichloromethane (3 mL) was added trifluoroacetic acid (0.45 mL, 6.05 mmol, 135 equiv) and the mixture was stirred at ambient temperature for 5 h. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with saturated aqueous sodium bicarbonate, then brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the desired product as a yellow glass (17.5 mg, 0.03 mmol, 67%).

LC/MS (C ₂₉ H ₂₇ N ₇ O ₃ S ₂ ) δ86 [M+H] ⁺ ; RT 1.30 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.94 (br s, 1H), 7.76-7.68 (m, 3H), 7.60-7.44 (m, 4H), 7.43-7.32 (m, 1H), 7.29-7.15 (m, 1H), 4.86-4.77 (m, 1H), 4.76-4.67 (m, 1H), 4.66-4.57 (m, 1H), 4.43-4.34 (m, 1H), 4.29 (q, 2H), 4.21-4.11 (m, 1H), 3.79 (s, 3H), 2.47 (s, 3H), 1.32 (t, J=7.1 Hz, 3H).

Step C: 5-(1-benzoyl azetidin-3-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (17.5 mg, 0.03 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added 2 M aqueous sodium hydroxide solution (0.5 mL, 1 mmol, 33.5 equiv) and the mixture was heated at reflux for 2 h. The reaction mixture was allowed to cool to ambient temperature and purified by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water to give the desired product as a yellow solid (16 mg, 0.03 mmol, 96%) [as the sodium salt].

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₂₇ H ₂₂ N ₇ O ₃ S ₂ : 556.1231, found: 556.1260.

Example 137: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2,2-dimethylpropyl)-1,3-thiazole-4-carboxylic acid

Step A: Methyl 5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2,2-dimethylpropyl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of Preparation 3zc (8 mg, 0.02 mmol, 1 equiv) in 1,4-dioxane (2 mL) was added Preparation 4a (9.76 mg, 0.02 mmol, 1.3 equiv), xantphos (2.14 mg, 3.69 μmol, 0.2 equiv), cesium carbonate (18 mg, 0.06 mmol, 3 equiv), and N,N-diisopropylethylamine (9.64 μL, 0.06 mmol, 3 equiv). The mixture was sparged with nitrogen (10 min), then tris(dibenzylideneacetone)dipalladium(0) (1.69 mg, 0.1 equiv) was added, and the mixture was heated at 120 °C overnight. The reaction mixture was partitioned between ethyl acetate and brine, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0-6% methanol in dichloromethane afforded the title product as a yellow solid (15 mg, 0.02 mmol, 100%).

LC/MS (C ₄₀ H ₅₀ FN ₇ O ₄ SiS ₂ ) 804 [M+H] ⁺ ; RT 2.65 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.83 (d, J=7.9 Hz, 1H), 7.67 (d, J=1.2 Hz, 1H), 7.49-7.42 (m, 2H), 7.35-7.23 (m, 2H), 7.22-7.13 (m, 2H), 5.86 (s, 2H), 3.83 (s, 2H), 3.79-3.75 (m, 5H), 3.75-3.67 (m, 2H), 2.45 (s, 3H), 2.15 (s, 6H), 1.05 (s, 6H), 0.96 -0.88 (m, 2H), -0.11 (s, 9H).

Step B: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2,2-dimethylpropyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step A (60 mg, 0.07 mmol, 1 equiv) in tetrahydrofuran (6 mL) were added ethylenediamine (15 µL, 0.22 mmol, 3 equiv) and tetrabutylammonium fluoride (1 M in tetrahydrofuran, 224 µL, 0.22 mmol, 3 equiv), and the mixture was heated at 70°C overnight. The solvent was removed in vacuo and the crude product was purified by reverse phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5:95% acetonitrile in water to give a solid that was triturated with diethyl ether, filtered and dried in vacuo to give the desired product as a yellow solid (13.1 mg, 0.02 mmol, 27%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₃ H ₃₅ FN ₇ O ₃ S ₂ : 660.2221, found: 660.2264.

Example 138: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(2-phenylacetyl)azetidin-3-yl]-1,3-thiazole-4-carboxylic acid

Stage A: ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazine -3-yl)amino]-5-[1-(2-phenylacetyl)azetidin-3-yl]-1,3-thiazol-4-carboxylate

To a solution of the product of Synthesis 51 (105 mg, 0.17 mmol, 1 equiv.) in dichloromethane (6 mL) were added triethylamine (0.05 mL, 0.34 mmol, 2 equiv.) and phenylacetyl chloride (0.03 mL, 0.21 mmol, 1.2 equiv.), and the mixture was stirred at ambient temperature for 3 h. The reaction mixture was diluted with dichloromethane, then washed with water and brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the desired product as a yellow foam (66 mg, 0.09 mmol, 53%).

LC/MS (C ₃₆ H ₄₃ N ₇ O ₄ SiS ₂ ) 730 [M+H] ⁺ ; RT 1.45 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.85 (dd, J=7.8, 1.1 Hz, 1H), 7.70 (d, J=1.1 Hz, 1H), 7.52-7.39 (m, 2H), 7.34-7.25 (m, 5H), 7.24-7.18 (m, 1H), 5.87 (s, 2H), 4.74-4.58 (m, 2H), 4.39 (t, J=9.1 Hz, 1H), 4.29 (q, J=7.1 Hz, 2H), 4.23 (dd, J=8.1, 5.8 Hz, 1H), 3.96 (dd, J=9.7, 6.1 Hz, 1H), 3.79 (s, 3H), 3.77-3.68 (m, 2H), 3.51 (d, J=2.1 Hz, 2H), 2.47 (d, J=1.0 Hz, 3H), 1.32 (t, J=7.1 Hz, 3H), 0.98-0.87 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(2-phenylacetyl)azetidin-3-yl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (66 mg, 0.09 mmol, 1 equiv) in dichloromethane (3 mL) was added trifluoroacetic acid (1 mL, 13.4 mmol, 148 equiv) and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, washed with saturated aqueous sodium bicarbonate then brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a yellow glass (39 mg, 0.07 mmol, 72%).

LC/MS (C ₃₀ H ₂₉ N ₇ O ₃ S ₂ ) 600 [M+H] ⁺ ; RT 1.33 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 11.07 (br s, 1H), 8.00 (br s, 1H), 7.72 (br s+s, 2H), 7.40 (br s, 1H), 7.37-7.25 (m, 4H), 7.27-7.18 (m, 1H), 4.75-4.57 (m, 2H), 4.40 (t, J=9.1 Hz, 1H), 4.30 (q, J=7.1 Hz, 2H), 4.24 (dd, J=8.1, 5.9 Hz, 1H), 3.96 (dd, J=9.7, 6.1 Hz, 1H), 3.79 (s, 3H), 3.52 (s, 2H), 1.33 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(2-phenylacetyl)azetidin-3-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (39 mg, 0.07 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added 2 M aqueous sodium hydroxide solution (1 mL, 2 mmol, 30.8 equiv) and the mixture was heated at reflux for 1.5 h. The solvent was removed in vacuo and the crude product was purified by reverse phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water to give the desired product as a yellow solid (28.7 mg, 0.05 mmol, 77%) [as the sodium salt].

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₂₈ H ₂₄ N ₇ O ₃ S ₂ : 570.1388, found: 570.1423.

Example 139: 5-(Azetidin-3-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

In the preparation of Example 138, Step C, sodium 5-(azetidin-3-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate (7.5 mg, 0.02 mmol, 25%) was isolated as a by-product [as the sodium salt].

MSHR-ERI (m/z) [M-H] ^- , calculated for C ₂₀ H ₁₈ N ₇ O ₂ S ₂ : 452.0969, found: 452.0977.

Example 140: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{[1-({4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}methyl)cyclopropyl]methyl}-1,3-thiazole-4-carboxylic acid

Stage A: methyl 5-{[1-({4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}methyl)cyclopropyl]methyl}-2-[methyl(5-methyl-6-{ [(2Z)-3-{[2-(t rimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazol-4-carboxylate

To a solution of Preparation 3zd (84 mg, 0.19 mmol, 1 equiv) in 1,4-dioxane (6 mL) were added Preparation 4a (103 mg, 0.25 mmol, 1.3 equiv), xantphos (22.5 mg, 0.04 mmol, 0.2 equiv), cesium carbonate (190 mg, 0.58 mmol, 3 equiv), and N,N-diisopropylethylamine (102 μL, 0.58 mmol, 3 equiv). The mixture was sparged with nitrogen (10 min), then tris(dibenzylideneacetone)dialladium(0) (17.8 mg, 0.02 mmol, 0.1 equiv) was added, and the mixture was heated at 120 °C overnight. The reaction mixture was partitioned between ethyl acetate and brine, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a brown solid (98 mg, 0.12 mmol, 63%).

LC/MS (C ₄₀ H ₄₈ FN ₇ O ₄ SiS ₂ ) 802 [M+H] ⁺ ; RT 2.63 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.87-7.80 (m, 1H), 7.67 (d, 1H), 7.52-7.40 (m, 2H), 7.33-7.22 (m, 2H), 7.18-7.11 (m, 1H), 7.03 (t, J=8.7 Hz, 1H), 5.87 (s, 2H), 3.83 (s, 2H), 3.76 (s, 3H), 3.76-3.69 (m, 2H), 3.66 (s, 3H), 3.39 (s, 2H), 3.36 (s, 2H), 2.46 (d, J=1.0 Hz, 3H), 2.18 (s, 6H), 0.97-0.88 (m, 2H), 0.78-0.65 (m, 4H), -0.10 (s, 9H).

Step B: methyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{[1-({4-[ 3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}methyl)cyclopropyl]methyl}-1,3-thiazol-4-carboxylate

To a solution of the product from Step A (98 mg, 0.12 mmol, 1 equiv) in tetrahydrofuran (6 mL) were added ethylenediamine (24.5 μL, 0.37 mmol, 3 equiv) and tetrabutylammonium fluoride (1 M in tetrahydrofuran; 224 μL, 0.37 mL, 0.37 mmol, 3 equiv), and the mixture was heated at 70 °C overnight. The reaction mixture was partitioned between water and 9:1 dichloromethane/methanol, and the organic phase was separated, dried (PTFE phase separator), and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow solid (5.01 mg, 0.01 mmol, 6%).

LC/MS (C ₃₄ H ₃₄ FN ₇ O ₃ S ₂ ) 672 [M+H] ⁺ ; RT 2.04 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 11.52 (br s, 1H), 7.95-7.88 (m, 1H), 7.69 (d, J=1.2 Hz, 1H), 7.54 (d, J=7.9 Hz, 1H), 7.45-7.35 (m, 1H), 7.33-7.18 (m, 2H), 7.19-7.11 (m, 1H), 7.03 (t, J=8.8 Hz, 1H), 3.83 (s, 2H), 3.75 (s, 3H), 3.67 (s, 3H), 3.40 (s, 2H), 3.38 (s, 2H), 2.47 (d, J=1.1 Hz, 3H), 2.19 (s, 6H), 0.78-0.65 (m, 4H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{[1-({4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}methyl)cyclopropyl]methyl}-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (35 mg, 0.05 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added lithium hydroxide monohydrate (21.9 mg, 0.52 mmol, 10 equiv) and the mixture was heated at 110 °C overnight. The reaction mixture was concentrated in vacuo and the residue was triturated with water, filtered and dried in vacuo to give the title product as a yellow solid (23.8 mg, 0.04 mmol, 70%) [as the lithium salt].

MSHR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₃ H ₃₃ FN ₇ O ₃ S ₂ : 658.2065, found: 658.2109.

Example 141: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(5-hydroxypentyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Method of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 25 mM NH ₄ HCO ₃ in water:MeCN), the desired product was obtained starting from Preparation 5f.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₅ H ₃₉ FN ₇ O ₄ S ₂ : 704.2489 found: 704.2483.

Example 142: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(dimethylamino)ethylmethylamino]-4-hydroxypentyl]amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[4-[tert-butyl(dimethyl)silyl]oxy-5-[2-(dimethylamino)ethylmethylamino]pentyl]amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction starting from 426 mg of methyl 2-(t/?-butoxycarbonylamino)thiazole-4-carboxylate (1.65 mmol, 1.1 equiv) and 478 mg of the product of Preparation 2f (1.65 mmol, 1 equiv) as the appropriate alcohol, 359 mg (43%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 8.08 (s, 1H), 3.79 (s, 3H), 3.72 (m, 1H), 2.44-2.20 (m, 8H), 2.18 (s, 6H), 2.14 (s, 3H), 1.85-1.56 (m, 3H), 1.53 (s, 9H), 1.39-1.25 (m, 1H), 0.79 (s, 9H), 0.01 (s, 3H), -0.02 (s, 3H); LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₂₆ H ₅₁ N ₄ O ₅ SSi: 559.3, found: 559.4.

Step B: Methyl 2-[[4-[tert-butyl(dimethyl)silyl]oxy-5-[2-(dimethylamino)ethylmethylamino]pentyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with 811 mg of the product from Step A (1.45 mmol) as the appropriate carbamate, 262 mg (39%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.81 (t, 1H), 7.50 (s, 1H), 3.73 (s, 3H), 3.72 (m, 1H), 3.20 (m, 2H), 2.40 (m, 2H), 2.32 (m, 2H), 2.27 (d, 2H), 2.16 (s, 3H), 2.14 (s, 6H), 1.63-1.54 (m+m, 2H), 1.61-1.37 (m+m, 2H), 0.84 (s, 9H), 0.04 (s, 3H), 0.03 (s, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 168.7, 162.0, 142.6, 116.8, 70.4, 64.6, 57.4, 56.5, 52.0, 45.9, 45.1, 43.8, 33.0, 26.3, 24.9, -3.8, -4.3; LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₂₁ H ₄₃ N ₄ O ₃ SSi: 459.3, found: 459.4.

Step C: methyl 2-[[4-[tert-butyl(dimethyl)silyl]oxy-5-[2-(dimethylamino)ethylmethylamino]pentyl]-[5-methyl-6-[(Z)-[3-( 2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting with 255 mg of the product from Step B (0.56 mmol, 1 equiv) and 226 mg of the product from Preparation 4a (0.77 mmol, 1.0 equiv) as the appropriate halide, 311 mg (67%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.97 (s, 1H), 7.83 (dd, 1H), 7.70 (s, 1H), 7.46 (dd, 1H), 7.43 (m, 1H), 7.25 (m, 1H), 5.86 (s, 2H), 4.48 (t, 2H), 3.81 (s, 3H), 3.77 (m, 1H), 3.71 (t, 2H), 2.65 (m, 2H), 2.51 (m, 2H), 2.45 (s, 3H), 2.38 (brs, 6H), 2.29 (m, 2H), 2.15 (s, 3H ), 1.83-1.72 (m+m, 2H), 1.65-1.43 (m+m, 2H), 0.91 (t, 2H), 0.74 (s, 9H), -0.01 & -0.06 (s+s, 6H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 127.2, 123.4, 123.2, 123.1, 117.7, 112.0, 72.9, 69.9, 66.7, 64.0, 55.7, 54.9, 52.2, 47.3, 44.5, 43.2, 32.1, 26.1, 22.8, 17.9, 17.8, -0.9, -3.9, -4.5; HR-MSR (m/z): [M+H] ⁺ , calculated for C39H65N804S2Si2: 829.4103, found: 829.4096.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(dimethylamino)ethylmethylamino]-4-hydroxypentyl]amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by purification by reversed-phase preparative chromatography (C18, 25 mM _NH4HCO3 in water:MeCN), the product from Step C was obtained to give the desired product _.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₆ H ₃₄ N ₈ O ₃ S ₂ : 571.2268, found: 571.2270.

Example 143: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-(dimethylamino)-4-hydroxypentyl]amino]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[4-[tert-butyl(dimethyl)silyl]oxy-5-(dimethylamino)pentyl]amino]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction starting from 568 mg of methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate (2.2 mmol, 1.1 equiv) and 523 mg of the product of Preparation 2d (2.0 mmol, 1 equiv) as the appropriate alcohol, 530 mg (53%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 8.08 (s, 1H), 4.06 (m, 2H), 3.79 (s, 3H), 3.72 (m, 1H), 2.15 (d, 2H), 2.11 (s, 6H), 1.79-1.63 (m+m, 2H), 1.55-1.34 (m+m, 2H), 1.52 (s, 9H), 0.79 (s, 9H), 0.01 & -0.02 (s+s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 160.8, 153.3, 124.7, 70.1, 65.9, 52.3, 47.3, 46.6, 32.7, 28.1, 26.2, 23.7, -3.8, -4.5; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₃ H ₄₄ N ₃ O ₅ SSi: 502.2765, found: 502.2762.

Step B: Methyl 2-[[4-[tert-butyl(dimethyl)silyl]oxy-5-(dimethylamino)pentyl]amino]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with 132 mg of the product from Step A (0.26 mmol) as the appropriate carbamate, 78 mg (74%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.81 (t, 1H), 7.50 (s, 1H), 3.73 (s, 1H),

3.73 (s, 3H), 3.21 (q, 2H), 2.17 (d, 2H), 2.13 (s, 6H), 1.63-1.55 (m+m, 2H), 1.60-1.37 (m+m, 2H), 0.84 (s, 9H), 0.04 & 0.03 (s+s, 6H); ¹³ C NMR (125 MHz, DMSO-dg) δ ppm 168.7, 162.0, 116.9, 70.3, 66.3, 52.0, 46.6, 45.0, 33.1, 26.3, 25.0, -3.8, -4.3; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₁₈ H ₃₆ N ₃ O ₃ SSi: 402.2241, found: 402.2249.

Step C: methyl 2-[[4-[tert-butyl(dimethyl)silyl]oxy-5-(dimethylamino)pentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)- 1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting with 72 mg of the product from Step B (0.18 mmol, 1 equiv) and 73 mg of the product from Preparation 4a (0.18 mmol, 1.5 equiv) as the appropriate halide, 126 mg (91%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.86-7.23 (4H), 7.97 (s, 1H), 7.69 (s, 1H), 5.87 (dd, 2H), 4.48 (m, 2H), 3.81 (s, 3H), 3.74 (m, 1H), 3.72 (t, 2H), 3.72 (t, 2H), 2.45 (s, 3H), 2.10 (brs, 6H), 1.83-1.71 (m+m, 2H), 1.59-1.41 (m+m, 2H), 0.92 (t, 2H), 0.74 (s, 9H), - 0.01 & -0.06 (s+s, 6H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 123.1, 117.9, 72.9, 69.9, 66.8, 66.7, 52.2, 47.3, 46.6, 32.4, 26.2, 22.9, 17.8, 17.8, -1.0, -4.5 ; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₆ H ₅₇ N ₇ O ₄ S ₂ Si ₂ : 772.3525, found: 772.3521.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-(dimethylamino)-4-hydroxypentyl]amino]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by purification by reversed-phase preparative chromatography (C18, 25 mM _NH4HCO3 in water:MeCN), the product from Step C was obtained to give the desired product _.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₃ H _28/ N ₇ O ₃ S ₂ : 514.1690, found: 514.1694.

Example 144: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(trimethylammonio)pentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Stage A: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[4-[tert-butyl(diphenyl)silyl]oxy -5-(dimethyls but)pentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4- carboxylate

Using the General Tosylate Alkylation Procedure starting from Preparation 5a and N-methylmethanamine as the appropriate amine, the desired product was obtained.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₆₄ H ₈₄ FN ₈ O ₇ S ₂ Si ₂ : 1215.5421, found: 1215.5389.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(trimethylammonio)pentyl]amino]-5-[3- [2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

The product from Step A was dissolved in a mixture of acetonitrile (4 mL/mmol) and N,N-dimethylformamide (1 mL/mmol), then iodomethane (5 eq.) was added and the mixture was stirred at rt until complete conversion was observed (approx. 1 h). The reaction mixture was concentrated. The crude mixture, which contained [5-[[5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]-[5-methyl-6-[^)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-2-[tert-butyl(diphenyl)silyl]oxypentyl]trimethylammonium (LC-ESI-MS (m/z): [M] ⁺ , calculated for C ₆₅ H ₈₆ FN ₈ O ₇ S ₂ Si ₂ : 1229.6, found: 1229.4), was introduced into the next reaction step using the General Procedure for Deprotection of a Quaternary Salt, with obtaining the target product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₇ H ₄₄ FN ₈ O ₄ S ₂ : 747.2905, found: 747.2900.

Example 145: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl} (methyl)amino)-5-(1-benzylazetidin-3-yl)- 1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(1-benzylazetidin-3-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product of Synthesis 51 (36.3 mg, 0.06 mmol, 1 equiv) in acetonitrile (3 mL) were added benzaldehyde (12.1 μL, 0.12 mmol, 2 equiv), sodium triacetoxyborohydride (37.7 mg, 0.18 mmol, 3 equiv), and glacial acetic acid (two drops), and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with ethyl acetate and washed with saturated aqueous sodium bicarbonate, then with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-70% ethyl acetate in isoheptane afforded the title product as a colourless gum (28.6 mg, 0.04 mmol, 69%).

LC/MS (C ₃₅ H ₄₃ N ₇ O ₃ SiS ₂ ) 702 [M+H] ⁺ ; RT 1.49 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.78 (dd, J=7.7, 1.1 Hz, 1H), 7.69 (d, J=1.1 Hz, 1H), 7.52-7.41 (m, 2H), 7.40-7.30 (m, 4H), 7.29-7.20 (m, 2H), 5.88 (s, 2H), 4.46-4.35 (m, 1H), 4.27 (q, J=7.1 Hz, 2H), 3.78 (s, 3H), 3.77-3.65 (m, 6H), 3.18 (dd, J=7.0, 5.9 Hz, 2H), 2.47 (d, J=1.0 Hz, 3H), 1.30 (t, J=7.1 Hz, 3H), 0.93 (dd, J=8.6, 7.4 Hz, 2H), -0.10 (s, 9H).

Step B: ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl} (methyl) amino)-5-(1-benzylazetidin-3-yl) -1,3-thiazole-4-carboxylate

To a solution of the product from Step A (28.6 mg, 0.04 mmol, 1 equiv) in dichloromethane (3 mL) was added trifluoroacetic acid (0.3 mL, 4.03 mmol, 99 equiv) and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with saturated aqueous sodium bicarbonate, then brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a yellow glass (17 mg, 0.03 mmol, 73%).

LC/MS (C ₂₉ H ₂₉ N ₇ O ₂ S ₂ ) 572 [M+H] ⁺ ; RT 1.14 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.86 (br s, 1H), 7.71 (br s+s, 2H), 7.45-7.31 (m, 5H), 7.30-7.18 (m, 2H), 4.47-4.36 (m, 1H), 4.27 (q, J=7.1 Hz, 2H), 3.78 (s, 3H), 3.73-3.61 (m, 4H), 3.19 (t, J=6.3 Hz, 2H), 2.48 (s, 3H), 1.31 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-benzylazetidin-3-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (17 mg, 0.03 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added 2 M aqueous sodium hydroxide (0.5 mL, 1 mmol, 33.6 equiv) and the mixture was heated at reflux for 2 h. The reaction mixture was allowed to cool to ambient temperature and the solvent was removed in vacuo. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, CI 8 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow solid (13.9 mg, 0.03 mmol, 86%) [as the sodium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₇ H ₂₆ N ₇ O ₂ S ₂ : 544.1584, found: 544.1616.

Example 146: 3-[[5-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-carboxy-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazol-2-yl]amino]-2-hydroxypentyl]-dimethylammonio]propane-1-sulfonate

The compound of Example 144, Step A, was suspended in MeCN (5 mL/mmol), then oxathiolane 2,2-dioxide (10 equiv) was added and the mixture was stirred at 60 °C BH (complete conversion was observed). The reaction mixture was concentrated. The crude mixture, which contained 3-[[5-[[5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-2-[tert-butyl(diphenyl)silyl]oxypentyl]dimethylammonio]propane-1-sulfonate (LC-ESI-MS (m/z): [M+H] ⁺ , calculated for C ₆₇ H ₉₀ FN ₈ O ₁₀ S ₃ Si ₂ : 1337.5, found: 1337.6) was directly added to the next reaction step using the General Procedure for Deprotection of a Quaternary Salt to give the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₉ H ₄₈ FN ₈ O ₇ S ₃ : 855.2787, found: 855.2786.

Example 147: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-hydroxybutyl)amino)-5-[3-(4-{3 -[bis(3-sulfopropyl)amino]prop-1-yn-1-yl}-2-fluorophenoxy)propyl]-1,3-thiazol-4-carboxylic acid

Example 147 was isolated as a by-product during the reaction of Example 148, Step B.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₈ H ₄₄ FN ₇ O ₁₀ S ₄ : 906.2089, found: 906.2098.

Example 148: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-(3-sulfopropylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: 5-[3-[4-(3-aminoprop-1-ynyl)-2-fluorophenoxy]propyl]-2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from 370 mg of the product from Preparation 5i, Step A (0.36 mmol, 1 equiv) gave 150 mg (62%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.88 (d, 1H), 7.66 (s, 1H), 7.53 (d, 1H), 7.38 (t, 1H), 7.22 (dd, 1H), 7.22 (t, 1H), 7.16 (dd, 1H), 7.14 (t, 1H), 4.39 (t, 2H), 4.15 (t, 2H), 3.51 (s, 2H), 3.47 (t, 2H), 3.27 (t, 2H), 2.47 (s, 3H), 2.14 (m, 2H), 1.74 (m, 2H), 1.52 (m, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 126.7, 126.5, 122.6, 122.2, 119.1, 118.6, 116.8, 115.9, 91.0, 81.1, 68.8, 60.9, 47.2, 31.6, 31.0, 29.9, 24.2, 23.2, 17.7; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₂ H ₃₃ FN ₇ O ₄ S ₂ : 662.2014, found: 662.2011.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-(3-sulfopropylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

To a suspension of the product from Step A in dry acetonitrile, oxathiolane 2,2-dioxide was added in one portion. The resulting mixture was stirred overnight at rt, whereby the disubstituted product was also formed (Example 147). The crude product was dissolved in DMSO and then purified by reverse phase preparative chromatography (25 mM NH4HCO3 in water:MeCN) to afford the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₅ H ₃₉ FN ₇ O ₇ S ₃ : 784.2052, found: 784.2052.

Example 149: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-methanesulfonylazetidin-3-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(1-methanesulfonylazetidin-3-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product of Preparation 51 (24.6 mg, 0.04 mmol, 1 equiv) in dichloromethane (3 mL) was added methanesulfonyl chloride (3.73 µL, 0.05 mmol, 1.2 equiv), followed by a catalytic amount of 4-(dimethylamino)pyridine and triethylamine (0.01 mL, 0.08 mmol, 2 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the title product as an off-white solid (16.4 mg, 0.02 mmol, 59%).

LC/MS (C ₂₉ H ₃₉ N ₇ O ₅ SiS ₃ ) 690 [M+H] ⁺ ; RT 1.41 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.87 (dd, J=7.6, 1.1 Hz, 1H), 7.71 (d, J=1.1 Hz, 1H), 7.51-7.39 (m, 2H), 7.29-7.22 (m, 1H), 5.87 (s, 2H), 4.61 (tt, J=8.4, 6.5 Hz, 1H), 4.39 (t, J=8.5 Hz, 2H), 4.30 (q, J=7.1 Hz, 2H), 3.93 (dd, J=8.3, 6.4 Hz, 2H), 3.80 (s, 3H), 3.76-3.67 (m, 2H), 3.10 (s, 3H), 2.47 (d, J=1.0 Hz, 3H), 1.32 (t, J=7.1 Hz, 3H), 1.00-0.88 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-methanesulfonylazetidin-3-yl)-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (16.4 mg, 0.02 mmol, 1 equiv) in dichloromethane (3 mL) was added trifluoroacetic acid (0.2 mL, 2.68 mmol, 113 equiv) and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane, washed with saturated aqueous sodium bicarbonate (×2) then brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 to 10% methanol in dichloromethane afforded the desired product as a beige solid (10 mg, 0.02 mmol, 75%).

LC/MS (C ₂₃ H ₂₅ N ₇ O ₄ S ₃ ) δ60 [M+H] ⁺ ; RT 1.24 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.92 (br s, 1H), 7.72 (s, 1H), 7.51-7.42 (m, 1H), 7.40-7.34 (m, 1H), 7.27-7.15 (m, 1H), 4.68-4.54 (m, 1H), 4.49 (td, J=8.5, 2.9 Hz, 2H), 4.40 (t, 2H), 4.28 (q, 2H), 4.04 (dd, J=8.2, 6.5 Hz, 2H), 3.78 (s, 3H), 3.11 (s, 3H), 2.48 (s, 3H), 1.32 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-methanesulfonylazetidin-3-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (10 mg, 0.02 mmol, 1 equiv) in 1,4-dioxane (2 mL) was added 2 M aqueous sodium hydroxide solution (0.2 mL, 0.4 mmol, 22.4 equiv) and the mixture was heated at 60 °C for 1.5 h. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5 95% acetonitrile in water afforded the desired product as a yellow solid (7.6 mg, 0.01 mmol, 80%) [as the sodium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₁ H ₂₂ N ₇ O ₄ S ₃ : 532.0890, found: 532.0894.

Example 150: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(methylamino)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

The General Procedure for Alkylation with Tosylate was used starting from the product of Preparation 5b and methanamine as the appropriate amine, whereby the intermediate methyl 2-[[4-[tert-butyl(diphenyl)silyl]oxy-5-(methylamino)pentyl]-[5-methyl-6-[(7)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate was not isolated and after evaporation of the volatiles the General Procedure for Deprotection and Hydrolysis was used to give the desired product.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₃₆ H ₄₃ FN ₈ O ₄ S ₂ : 367.1411, found: 367.1413.

Example 151: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-[methyl(3-sulfopropyl)amino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: 3-[methyl(prop-2-ynyl)amino]propane-1-sulfonic acid

To 0.34 mL of N-methylpropargylamine (4 mmol, 1 equiv.) in 1 mL of MeCN was added 244 mg of oxathiolane 2,2-dioxide (2 mmol, 0.5 equiv.), and the mixture was stirred at 60 °C for 3 h. After concentration, the residue was purified by flash column chromatography using DCM and MeOH as eluents to afford 299 mg (78%) of the desired product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 10.10 (br, 1H), 4.01 (s, 2H), 3.75 (s, 1H), 3.12 (m, 2H), 2.72 (s, 3H), 2.59 (t, 2H), 1.94 (qui, 2H).

Step B: 3-[3-[4-[3-[2-[tert-butoxycarbonyl-[4-[tert-butyl(dimethyl)silyl]oxybutyl]amino]-4-methoxycarbonylthiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynylmethylamino]propane-1-sulfonic acid

Using the General Procedure for the Sonogashira reaction, starting from the product from Step A and the product of Preparation 3c, Step A, as starting materials, 303 mg (56%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 12.45 (vbrs, 1H), 7.45 (dd, 1H), 7.33 (dm, 1H), 7.18 (t, 1H), 4.24 (brs, 2H), 4.16-4.06 (m, 4H), 4.02 ( t, 2H), 3.75 (s, 3H), 3.58 (t, 2H), 3.22 (t, 2H), 2.80 (brs, 3H), 2.61 (brt, 2H), 2.08 (m, 2H), 1.97 (m, 2H), 1.68 (m, 2H), 1.57 (s, 9H ), 1.43 (m, 2H), 0.82 (s, 9H), -0.01 (s, 6H).

Step C: 3-[3-[4-[3-[2-[4-[tert-butyl(dimethyl)silyl]oxybutylamino]-4-methoxycarbonylthiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynylmethylamino]propane-1-sulfonic acid

Using the General HFIP deprotection procedure, starting from the product from Step B as the appropriate carbamate, 200 mg (81%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 10.38 (s, 1H), 7.59 (t, 1H), 7.47 (dd, 1H), 7.33 (m, 1H), 7.18 (t, 1H), 4.28 (brs, 2H), 4.09 (t, 2H), 3.67 (s, 3H), 3.59 (t, 2H), 3.27 (brs, 2H), 3.17 (q, 2H), 3.12 (t, 2H), 2.82 (s, 3H), 2.62 (t, 2H), 2.00 (q, 2H), 2.00 (m, 2H), 1.54 ( m, 2H), 1.49 (m, 2H), 0.84 (s, 9H), 0.02 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 148.2, 129.6, 119.7, 115.4, 68.1, 62.6, 55.2, 51.7, 49.3, 45.8, 44.4, 40.0, 30.6, 30.2, 26.3, 25.6, 23.3 , 21.0, -4.8.

Step D: 3-[3-[4-[3-[2-[4-[tert-butyl(dimethyl)silyl]oxybutyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-4-methoxycarbonylthiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynylmethylamino]propane-1-sulfonic acid

Using General Procedure II for the Buchwald reaction, starting from the product from Step C and the product of Preparation 4a as the appropriate halide, 270 mg (88%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.66 (s, 1H), 7.47 (dm, 1H), 7.47 (dd, 1H), 7.44 (t, 1H), 7.33 (d, 1H), 7.26 (td, 1H), 7.21 (t, 1H), 5.86 (s, 2H), 4.42 (t, 2H), 4.24 (br., 2H), 4.17 (t, 2H), 3.77 (s, 3H), 3.72 (t, 2H), 3.61 (t, 2H), 3.29 (br., 2H), 3.27 (t, 2H), 2.79 (br., 3H), 2.60 (br., 2H), 2.45 (s, 3H), 2.13 (m, 2H), 1.97 (br., 2H), 1.74 (m, 2H), 1.52 (m, 2H), 0.92 (t, 2H), 0.79 (s, 9H), -0.02 (s , 6H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 129.5, 127.2, 123.5, 123.2, 119.7, 117.6, 115.4, 112.0, 72.9, 68.5, 66.7, 62.5, 51.9, 49.3, 46.5, 45.7, 40.0, 31.0, 29.7, 26.2, 23.8, 23.1, 21.1, 17.9, 17.8, -1.0, -4.9.

Step E: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-[methyl(3-sulfopropyl)amino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

The product from Step D and LiOH× _H2O (10 equiv.) in a 1:1 mixture of THF and water were heated at 50°C for 18 h. After treating the reaction mixture with 2 mL of conc. HCl at 0°C, the reaction mixture was heated at 50°C for 1 h. The reaction mixture was then poured onto cold ammonia solution and the precipitated material was filtered and purified by reverse phase preparative chromatography (25 mM _NH4HCO3 in water:MeCN) to afford the desired product _.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₆ H ₄₁ FN ₇ O ₇ S ₃ : 798.2214 found: 798.2204.

Example 152: 5-(1-Acetylazetidin-3-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(1-acetylazetidin-3-yl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product of Synthesis 51 (100 mg, 0.16 mmol, 1 equiv.) in dichloromethane (5 mL) were added acetyl chloride (14 μL, 0.2 mmol, 1.2 equiv.) and triethylamine (0.05 mL, 0.33 mmol, 2 equiv.), and the mixture was stirred at ambient temperature for 4 h. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 100% ethyl acetate in isoheptane afforded the title product as a creamy foam (67.7 mg, 0.1 mmol, 63%).

LC/MS (C ₃₀ H ₃₉ N ₇ O ₄ SiS ₂ ) 654 [M+H] ⁺ ; RT 1.37 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.87 (dd, J=7.7, 1.1 Hz, 1H), 7.70 (d, J=1.2 Hz, 1H), 7.51 - 7.39 (m, 2H), 7.29 - 7.22 (m, 1H), 5.87 (s, 2H), 4.69 - 4.56 (m, 2H), 4.43 - 4.33 (m, 1H), 4.29 (q, 2H), 4.22 - 4.12 (m, 1H), 3.92 (dd, J=9.8, 5.3 Hz, 1H), 3.79 ( s, 3H), 3.76 - 3.67 (m, 2H), 2.47 (d, J=1.0 Hz, 3H), 1.82 (s, 3H), 1.33 (t, J=7.1 Hz, 3H), 0.97 - 0.88 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 5-(1-acetylazetidin-3-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (67.7 mg, 0.1 mmol, 1 equiv) in tetrahydrofuran (3 mL) were added tetrabutylammonium fluoride (1 M in tetrahydrofuran; 0.04 mL, 0.31 mmol, 3 equiv) and ethylenediamine (0.02 mL, 0.31 mmol, 3 equiv), and the mixture was stirred at 60 °C overnight. The reaction mixture was allowed to cool to ambient temperature, then partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 5% methanol in dichloromethane afforded the desired product as a yellow glass (10.5 mg, 0.02 mmol, 19%).

LC/MS (C ₂₄ H ₂₅ N ₇ O ₃ S ₂ ) δ24 [M+H] ⁺ ; RT 0.97 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.94 (br s, 1H), 7.72 (s, 1H), 7.55 (br s, 1H), 7.39 (t, J=7.5 Hz, 1H), 7.21 (t, J=7.6 Hz, 1H), 4.69 - 4.56 (m, 2H), 4.41 - 4.33 (m, 1H), 4.31 (q, 2H), 4.23 - 4.14 (m, 1H), 3.92 (dd, J=9.9, 5.3 Hz, 1H), 3.79 (s, 3H), 2.48 (s, 3H), 1.83 (s, 3H), 1.33 (t, J=7.1 Hz, 3H).

Step C: 5-(1-acetylazetidin-3-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (10.5 mg, 0.02 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added 1 M aqueous lithium hydroxide (0.1 mL, 0.1 mmol, 5 equiv), and the mixture was heated at 100 °C overnight. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a white solid (2 mg, 4.04 μmol, 20%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C22H22N ₇ 03S ₂ : 496.1220, found: 496.1252.

Example 153: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-phenylazetidin-3-yl)-1,3-thiazole-4-carboxylic acid

Step A: ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene ]amino}pyridazin-3-yl)amino]-5-(1-phenylazetidin-3-yl)-1,3-thiazol-4-carboxylate

To a solution of the product of Synthesis 51 (100 mg, 0.16 mmol, 1 equiv.) in 1,4-dioxane (3 mL) were added bromobenzene (20.6 µL, 0.2 mmol, 1.2 equiv.), cesium carbonate (160 mg, 0.49 mmol, 3 equiv.)-N,N-diisopropylethylamine (0.08 mL, 0.49 mmol, 3 equiv.), xantphos (18.9 mg, 0.03 mmol, 0.2 equiv.), and tris(dibenzylideneacetone)dipalladium(0) (15 mg, 0.02 mmol, 0.1 equiv.), and the mixture was heated under reflux overnight. The reaction mixture was partitioned between dichloromethane and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0:50% ethyl acetate in isoheptane afforded the title product as a yellow solid (44.2 mg, 0.06 mmol, 39%).

LC/MS (C ₃₄ H ₄₁ N ₇ O ₃ SiS ₂ ) 688 [M+H] ⁺ ; RT 1.58 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.82 (dd, J=7.7, 1.1 Hz, 1H), 7.69 (d, J=1.1 Hz, 1H), 7.49 - 7.35 (m, 2H), 7.28 - 7.17 (m, 3H), 6.74 (tt, J=7.4, 1.1 Hz, 1H), 6.64 - 6.49 (m, 2H), 5.85 (s, 2H), 4.81 - 4.69 (m, 1H), 4.38 - 4.23 (m, 4H), 3.86 (dd, J=7.3, 5.8 Hz, 2H), 3.79 (s, 3H), 3.76 - 3.67 (m, 2H), 2.45 (d, J=1.0 Hz, 3H), 1.34 (t, J=7.1 Hz, 3H), 0.96 - 0.87 (m, 2H), -0.12 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-phenylazetidin-3-yl)-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (44 mg, 0.06 mmol, 1 equiv) in dichloromethane (5 mL) was added trifluoroacetic acid (0.5 mL, 6.71 mmol, 105 equiv) and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane and washed with saturated aqueous sodium bicarbonate (x2) followed by brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 to 5% methanol in dichloromethane afforded the title product as a yellow glass (18 mg, 0.03 mmol, 51%).

LC/MS (C ₂₈ H ₂₇ N ₇ O ₂ S ₂ ) δ58 [M+H] ⁺ ; RT 1.49 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 7.83 (br s, 1H), 7.70 (s, 1H), 7.52 (br s, 1H), 7.39 - 7.31 (m, 1H), 7.27 - 7.16 (m, 3H), 6.78 - 6.70 (m, 1H), 6.60 - 6.51 (m, 2H), 4.82 - 4.68 (m, 1H), 4.39 - 4.25 (m, 4H), 3.93 - 3.81 (m, 2H), 3.79 (s, 3H), 2.47 (s, 3H), 1.34 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-phenylazetidin-3-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (18 mg, 0.03 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added 1 M aqueous lithium hydroxide (0.16 mL, 0.16 mmol, 5 equiv) and the mixture was heated under reflux for 6 h. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5 - 95% acetonitrile in water afforded the desired product as a yellow solid (9.5 mg, 0.02 mmol, 56%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₆ H ₂₄ N ₇ O2S ₂ : 530.1427, found: 530.1455.

Example 154: 5-[1-(Benzenesulfonyl)azetidin-3-yl]-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[1-(benzenesulfonyl)azetidin-3-yl]-2-[methyl(5-methyl-6-{[(21)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product of Preparation 51 (46.7 mg, 0.08 mmol, 1 equiv) in dichloromethane (3 mL) was added benzenesulfonyl chloride (11.7 µL, 0.09 mmol, 1.2 equiv), followed by 4-(dimethylamino)pyridine (2 mg, 0.02 mmol, 0.21 equiv) and triethylamine (0.02 mL, 0.15 mmol, 2 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane and washed with saturated aqueous sodium bicarbonate, then brine, then dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 67% ethyl acetate in isoheptane afforded the title product as a yellow glass (40.3 mg, 0.05 mmol, 70%).

LC/MS (C ₃₄ H ₄₁ N ₇ O ₅ SiS ₃ ) 752 [M+H] ⁺ ; RT 1.47 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.97 - 7.86 (m, 3H), 7.81 - 7.72 (m, 2H), 7.70 - 7.60 (m, 2H), 7.54 - 7.41 (m, 2H), 7.31 - 7.25 (m, 1H), 5.89 (s, 2H), 4.52 -4.39 (m, 1H), 4.29 - 4.18 (m, 4H), 3.79 - 3.67 (m, 7H), 2.47 (d, J=1.0 Hz, 3H), 1.27 (t, J=7.1 Hz, 3H), 0.98 - 0.89 (m, 2H), -0.10 (s, 9H).

Step B: Ethyl 5-[1-(benzenesulfonyl)azetidin-3-yl]-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (40.3 mg, 0.05 mmol, 1 equiv) in dichloromethane (5 mL) was added trifluoroacetic acid (0.5 mL, 6.71 mmol, 125 equiv) and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with dichloromethane and washed with saturated aqueous sodium bicarbonate (x2) followed by brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 to 6% methanol in dichloromethane afforded the desired product as a yellow solid (20 mg, 0.03 mmol, 60%).

LC/MS (C ₂₈ H ₂₇ N ₇ O ₄ S ₃ ) 622 [M+H] ⁺ ; RT 1.37 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 8.00 (br s, 1H), 7.94 - 7.88 (m, 2H), 7.77 (t, J=7.6 Hz, 2H), 7.72 - 7.64 (m, 2H), 7.56 (br s, 1H), 7.40 (t, 1H), 7.24 (t, J=7.6 Hz, 1H), 4.46 (p, J=7.6 Hz, 1H), 4.30 - 4.18 (m, 4H), 3.81 - 3.66 (m, 5H), 2.45 (s, 3H ), 1.26 (t, 3H).

Step C: 5-[1-(benzenesulfonyl)azetidin-3-yl]-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (20 mg, 0.03 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added 1 M aqueous lithium hydroxide (0.16 mL, 0.16 mmol, 5 equiv), and the mixture was heated at 100 °C overnight. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 15.5 g Gold RediSep column) eluting with a gradient of 5 - 95% acetonitrile in water afforded the desired product as a cream-colored solid (4.9 mg, 0.01 mmol, 26%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₆ H ₂₄ N ₇ O ₄ S ₃ : 594.1046, found: 594.1060.

Example 155: 5-(1-Benzenesulfonamido-3-hydroxypropan-2-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid

5-(1-Benzenesulfonamido-3-hydroxypropan-2-yl)-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid (2.9 mg, 4.74 μmol, 15%) was isolated as a by-product during the purification of Example 154, Step C.

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₆ H ₂₆ N ₇ O ₅ S ₃ : 612.1152, found: 612.1154

Example 156: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(2-methylpropyl)azetidin-3-yl]-1,3-thiazole-4-carboxylic acid

Stage A: ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazine -3-yl)amino]-5-[1-(2-methylpropyl)azetidin-3-yl]-1,3-thiazol-4-carboxylate

To a solution of the product of Synthesis 51 (134 mg, 0.22 mmol, 1 equiv) in 2:1 acetonitrile/dichloromethane (6 mL) was added isobutyraldehyde (0.04 mL, 0.44 mmol, 2 equiv) followed by sodium triacetoxyborohydride (139 mg, 0.66 mmol, 3 equiv) and glacial acetic acid (10 μL), and the mixture was stirred at ambient temperature for 4.5 h. The reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0-60% ethyl acetate in isoheptane afforded the title product as a creamy foam (81.5 mg, 0.12 mmol, 56%).

LC/MS (C ₃₂ H ₄₅ N ₇ O ₃ SiS ₂ ) 668 [M+H] ⁺ ; RT 1.25 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.85 - 7.76 (m, 1H), 7.68 (d, 1H), 7.51 - 7.39 (m, 2H), 7.29 - 7.23 (m, 1H), 5.87 (s, 2H), 4.44 - 4.32 (m, 1H), 4.27 (q, J=7.1 Hz, 2H), 3.77 (s, 3H), 3.75 - 3.70 (m, 2H), 3.64 (t, J=7.0 Hz, 2H), 3.09 (t, J=6.4 Hz, 2H), 2.46 (d, J=1.0 Hz, 3H), 2.26 (d, J=7.1 Hz, 2H), 1.58 (hept, J=6.8 Hz, 1H), 1.31 (t, J=7.1 Hz, 3H), 0.98 0.86 (m, 8H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(2-methylpropyl)azetidin-3-yl]-1,3-thiazole-4-carboxylate

To a cooled solution of the product from Step A (81.5 mg, 0.12 mmol, 1 equiv) in dichloromethane (5 mL) was added trifluoroacetic acid (0.5 mL, 6.71 mmol, 55 equiv) and the mixture was stirred at ambient temperature overnight. The reaction mixture was quenched by addition of saturated aqueous sodium bicarbonate solution, then extracted with dichloromethane and the organic extract was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 5% methanol in dichloromethane afforded the desired product as a yellow solid (50 mg, 0.09 mmol, 76%).

LC/MS (C ₂₆ H ₃₁ N ₇ O ₂ S ₂ ) δ38 [M+H] ⁺ ; RT 0.91 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.87 (s, 1H), 7.70 (s, 1H), 7.52 (br s, 1H), 7.40 (t, J=7.6 Hz, 1H), 7.22 (t, J=7.5 Hz, 1H), 4.44 - 4.33 (m, 1H), 4.28 (q, J=7.1 Hz, 2H), 3.77 (s, 3H), 3.64 (t, J=7.0 Hz, 2H), 3.10 (t, J=6.3 Hz, 2H), 2.47 (s, 3H), 2.27 (d, J=7.0 Hz, 2H), 1.66 - 1.51 (m, 1H), 1.32 (t, J=7.1 Hz, 3H), 0.93 (d, J=6.6 Hz, 6H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(2-methylpropyl)azetidin-3-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (50 mg, 0.09 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added 1 M aqueous lithium hydroxide (0.46 mL, 0.46 mmol, 5 equiv), and the mixture was heated at 100 °C overnight. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5 95% acetonitrile in water afforded the desired product as a yellow solid (34.2 mg, 0.07 mmol, 72%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₄ H ₂₈ N ₇ O ₂ S ₂ : 510.1740, found: 510.1776.

Example 157: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-methylazetidin-3-yl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-(1-methylazetidin-3-yl)-1,3-thiazole-4-carboxylate

To a solution of the product of Synthesis 51 (134 mg, 0.22 mmol, 1 equiv) in 2:1 acetonitrile/dichloromethane (6 mL) was added formaldehyde (37% in water; 0.03 mL, 0.44 mmol, 2 equiv) followed by sodium triacetoxyborohydride (139 mg, 0.66 mmol, 3 equiv) and glacial acetic acid (10 μL), and the mixture was stirred at ambient temperature for 4.5 h. The reaction mixture was diluted with dichloromethane, then washed with saturated aqueous sodium bicarbonate followed by brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 100% ethyl acetate in isoheptane afforded the title product as a cream-colored solid (65 mg, 0.1 mmol, 47%).

LC/MS (C ₂₉ H ₃₉ N ₇ O ₃ SiS ₂ ) 626 [M+H] ⁺ ; RT 1.18 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.89 - 7.82 (m, 1H), 7.68 (d, J=1.2 Hz, 1H), 7.53 - 7.39 (m, 2H), 7.28 - 7.22 (m, 1H), 5.86 (s, 2H), 4.42 - 4.30 (m, 1H), 4.27 (q, J=7.1 Hz, 2H), 3.77 (s, 3H), 3.76 - 3.69 (m, 2H), 3.65 (t, J=7.2 Hz, 2H), 3.18 - 3.10 (m, 2H), 2.46 (d, J=1.0 Hz, 3H), 2.29 (s, 3H), 1.31 (t, J=7.1 Hz, 3H), 0.97 - 0.86 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-methylazetidin-3-yl)-1,3-thiazole-4-carboxylate

To a cooled solution of the product from Step A (65 mg, 0.1 mmol, 1 equiv) in dichloromethane (3 mL) was added trifluoroacetic acid (0.3 mL, 4.03 mmol, 38.8 equiv) and the mixture was stirred at ambient temperature overnight. The reaction mixture was quenched by addition of saturated aqueous sodium bicarbonate solution, then extracted with dichloromethane and the organic extract was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% methanol in dichloromethane afforded the desired product as a yellow solid (40 mg, 0.08 mmol, 78%).

LC/MS (C ₂₃ H ₂₅ N ₇ O ₂ S ₂ ) 496 [M+H] ⁺ ; RT 0.80 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.92 (d, J=7.8 Hz, 1H), 7.69 (d, J=1.2 Hz, 1H), 7.53 (s, 1H), 7.44 - 7.32 (m, 1H), 7.25 - 7.16 (m, 1H), 4.42 - 4.30 (m, 1H), 4.27 (q, J=7.1 Hz, 2H), 3.76 (s, 3H), 3.65 (t, J=7.2 Hz, 2H), 3.15 (t, 2H), 2.47 (d, J=1.0 Hz, 3H), 2.29 (s, 3H), 1.31 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(1-methylazetidin-3-yl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (40 mg, 0.08 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added 1 M aqueous lithium hydroxide (0.4 mL, 0.4 mmol, 5 equiv), and the mixture was heated at 100 °C overnight. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5 95% acetonitrile in water afforded the desired product as a yellow solid (15.5 mg, 0.03 mmol, 41%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₁ H ₂₂ N ₇ O ₂ S ₂ : 468.1271, found: 468.1301.

Example 158: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-carboxypropyl)amino)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-{[4-(tert-butoxy)-4-oxobutyl](5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino}-1,3-thiazole-4-carboxylate

To a solution of Preparation 3ze (1.74 g, 5.53 mmol, 1.5 equiv.) in 1,4-dioxane (60 mL) were added Preparation 4a (1.5 g, 3.69 mmol, 1 equiv.), N,N-diisopropylethylamine (1.93 mL, 11.1 mmol, 3 equiv.), cesium carbonate (3.6 g, 11.1 mmol, 3 equiv.), and xantphos (427 mg, 0.74 mmol, 0.2 equiv.), and the mixture was sparged with nitrogen (10 min). Tris(dibenzylideneacetone)dipalladium(0) (338 mg, 0.37 mmol, 0.1 equiv) was added and the mixture was heated in a sealed flask at 140°C for 2 h. The reaction mixture was allowed to cool to ambient temperature, then partitioned between water and ethyl acetate, the aqueous phase was extracted with ethyl acetate (3 x 80 ml) and the combined organic extracts were washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 40 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 25% ethyl acetate in isoheptane afforded the title product as a pale yellow solid (0.93 g, 1.36 mmol, 37%).

LC/MS (C ₃₂ H ₄₄ N ₆ O ₅ SiS ₂ ) 685 [M+H] ⁺ ; RT 1.75 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.96 (s, 1H), 7.87 - 7.92 (m, 1H), 7.76 (d, J=1.2 Hz, 1H), 7.47 - 7.40 (m, 2H), 7.28 - 7.22 (m, 1H), 5.878 (s, 2H), 4.42 (t, J=7.4 Hz, 2H), 4.28 (q, J=7.1 Hz, 2H), 3.79 - 3.67 (m, 2H), 2.47 (d, J=1.0 Hz, 3H) , 2.36 (t, J=7.3 Hz, 2H), 1.95 (p, J=7.4 Hz, 2H), 1.37 (s, 9H), 1.31 (t, J=7.1 Hz, 3H), 0.96 0.88 (m, 2H), -0.11 (s, 9H).

Step B: 4-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}[4-(ethoxycarbonyl)-1,3-thiazol-2-yl]amino)butanoic acid

To a solution of the product from Step A (929 mg, 1.36 mmol, 1 equiv) in dichloromethane (45 mL) was added trifluoroacetic acid (8.31 mL, 109 mmol, 80 equiv) and the mixture was stirred at ambient temperature for 4 h. The reaction mixture was quenched by addition of saturated aqueous sodium bicarbonate solution, then extracted with dichloromethane (3×40 mL) and the combined organic extracts were washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-20% methanol in dichloromethane afforded the title product as a yellow solid (186.8 mg, 0.37 mmol, 28%).

LC/MS (C ₂₂ H ₂₂ N ₆ O ₄ S ₂ ) 499 [M+H] ⁺ ; RT 1.27 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 9.23 (br s, 2H), 7.97 (s, 1H), 7.95 - 7.87 (m, 1H), 7.82 (s, 1H), 7.54 (br s, 1H), 7.42 - 7.36 (m, 1H), 7.25 - 7.18 (m, 1H), 4.39 (t, J=7.7 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 2.47 (s, 3H), 2.39 (t, J=7.2 Hz, 2H), 2.01 -1.98 (m, 2H), 1.31 (t, J=7.1 Hz, 2H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-carboxypropyl)amino)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (80 mg, 0.16 mmol, 1 equiv) in 1,4-dioxane (10 mL) was added lithium hydroxide monohydrate (13.5 mg, 0.32 mmol, 2 equiv), and the mixture was heated at reflux for 2 h. The reaction mixture was concentrated in vacuo and purified by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with 5-95% acetonitrile in water to afford the crude product. It was dissolved in methanol with a few drops of triethylamine and then loaded onto a methanol-conditioned PE-AX cartridge, washed successively with methanol and dichloromethane, then eluted with 10% formic acid in dichloromethane and concentrated in vacuo to give the desired product as a yellow solid (28.9 mg, 0.06 mmol, 38%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₀ H ₁₉ N ₆ O ₄ S ₂ : 471.0904, found: 471.0915.

Example 159: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl} (methyl)amino)-5-[1-(benzylcarbamoyl)azetidin-3- yl]-1,3-thiazol-4-carboxylic acid

Stage A: ethyl 5-[1-(benzylcarbamoyl)azetidin-3-yl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3- dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazol-4-carboxylate

To a solution of the product of Preparation 51 (150 mg, 0.25 mmol, 1 equiv) in dichloromethane (5 mL) was added benzyl isocyanate (0.04 mL, 0.29 mmol, 1.2 equiv) followed by triethylamine (0.07 mL, 0.49 mmol, 2 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous ammonium chloride, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0:100% ethyl acetate in isoheptane afforded the title product as a yellow solid (125 mg, 0.17 mmol, 68%).

LC/MS (C ₃₆ H ₄₄ N ₈ O ₄ SiS ₂ ) 745 [M+H] ⁺ ; RT 1.43 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.84 (dd, J=7.5, 1.1 Hz, 1H), 7.70 (d, J=1.2 Hz, 1H), 7.51 - 7.39 (m, 2H), 7.35 - 7.20 (m, 5H), 7.19 (td, J=6.3, 2.8 Hz, 1H), 7.08 (t, J=6.0 Hz, 1H), 5.87 (s, 2H), 4.64 - 4.51 (m, 1H), 4.36 (t, J=8.4 Hz, 2H), 4.29 (q, J=7.1 Hz, 2H), 4.24 (d, J=6.0 Hz, 2H), 3.88 (dd, J=8.2, 6.0 Hz, 2H), 3.79 (s, 3H), 3.76 - 3.69 (m, 2H), 2.47 (d, J=1.0 Hz, 3H), 1.32 (t, J=7.1 Hz, 3H), 0.97 - 0.88 (m, 2H), -0.11 (s, 9H).

Step B: ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl} (methyl) amino)-5-[1-(benzylcarbamoyl)azetidin-3 -yl]-1,3-thiazol-4-carboxylate

To a solution of the product from Step A (125 mg, 0.17 mmol, 1 equiv) in dichloromethane (5 mL) was added trifluoroacetic acid (0.7 mL, 9.39 mmol, 56 equiv) and the mixture was stirred at ambient temperature overnight. The reaction mixture was quenched by addition of saturated aqueous sodium bicarbonate solution, then extracted with dichloromethane, and the organic extract was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 9% methanol in dichloromethane afforded the title product as a yellow glass (87.6 mg, 0.14 mmol, 85%).

LC/MS (C ₃₀ H ₃₀ N ₈ O ₃ S ₂ ) 615 [M+H] ⁺ ; RT 1.10 (LCMS-V-B1)

^1H NMR (400 MHz, DMSO-d6) δ 11.04 (br s, 1H), 7.95 (br s, 1H), 7.73 - 7.62 (m, 1H), 7.50 - 7.34 (m, 1H), 7.34 - 7.15 ( m, 7H), 7.07 (t, J=6.0 Hz, 1H), 4.62 - 4.52 (m, 1H), 4.36 (t, 2H), 4.29 (q, 2H), 4.24 (d, 2H), 3.94 - 3.83 (m, 2H), 3.77 (s, 3H), 2.47 (d, 3H), 1.32 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(benzylcarbamoyl)azetidin-3-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (87.6 mg, 0.14 mmol, 1 equiv) in 1,4-dioxane (5 mL) was added 1 M aqueous lithium hydroxide (0.71 mL, 0.71 mmol, 5 equiv), and the mixture was heated at 100 °C overnight. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5 95% acetonitrile in water afforded the desired product as a yellow solid (25.6 mg, 0.04 mmol, 31%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₈ H ₂₇ N8O ₃ S ₂ : 587.1642, found: 587.1669.

Example 160: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(ethylcarbamoyl)azetidin-3-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[1-(ethylcarbamoyl)azetidin-3-yl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product of Preparation 51 (100 mg, 0.16 mmol, 1 equiv) in dichloromethane (3 mL) was added ethyl isocyanate (0.02 mL, 0.2 mmol, 1.2 equiv) followed by triethylamine (0.03 mL, 0.25 mmol, 1.5 equiv), and the mixture was stirred at ambient temperature overnight. The reaction mixture was partitioned between dichloromethane and saturated aqueous ammonium chloride, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 100% ethyl acetate in isoheptane afforded the title product as a cream-colored solid (78 mg, 0.11 mmol, 70%).

LC/MS (C ₃₁ H ₄₂ N ₈ O ₄ SiS ₂ ) 683 [M+H] ⁺ ; RT 1.38 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.86 (dd, J=7.6, 1.1 Hz, 1H), 7.69 (d, J=1.1 Hz, 1H), 7.51 - 7.39 (m, 2H), 7.29 - 7.20 (m, 1H), 6.46 (t, J=5.6 Hz, 1H), 5.87 (s, 2H), 4.61 - 4.49 (m, 1H), 4.35 - 4.23 (m, 4H), 3.82 (dd, J=8.2, 6.0 Hz, 2H), 3.79 (s, 3H), 3.77 - 3.68 (m, 2H), 3.09 - 3.01 (m, 2H), 2.47 (d, J=1.0 Hz, 3H), 1.32 (t, J=7.1 Hz, 3H), 1.03 (t, J=7.1 Hz, 3H), 1.00 -0.88 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(ethylcarbamoyl)azetidin-3-yl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (78 mg, 0.11 mmol, 1 equiv) in dichloromethane (3 mL) was added trifluoroacetic acid (0.4 mL, 5.37 mmol, 47 equiv) and the mixture was stirred at ambient temperature overnight. The reaction mixture was quenched by addition of saturated aqueous sodium bicarbonate solution and extracted with dichloromethane, and the organic extract was washed with brine, dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% methanol in dichloromethane afforded the desired product as a yellow glass (44 mg, 0.08 mmol, 70%).

LC/MS (C ₂₅ H ₂₈ N ₈ O ₃ S ₂ ) 553 [M+H] ⁺ ; RT 1.00 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.18 (br s, 1H), 7.93 (br s, 1H), 7.70 (s, 1H), 7.46 (br s, 1H), 7.43 - 7.34 (m, 1H), 7.27 - 7.14 (m, 1H), 6.46 (t, J=5.6 Hz, 1H), 4.62 - 4.48 (m, 1H), 4.36 - 4.22 (m, 4H), 3.87 - 3.79 (m, 2H), 3.77 (s, 3H), 3.11 -2.98 ( m, 2H), 2.47 (s, 3H), 1.32 (t, J=7.1 Hz, 3H), 1.02 (t, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[1-(ethylcarbamoyl)azetidin-3-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (44 mg, 0.08 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added 1 M aqueous lithium hydroxide (0.4 mL, 0.4 mmol, 5 equiv) and the mixture was heated at 100 °C for 4.5 h. Purification by reverse-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5 95% acetonitrile in water afforded the desired product as a yellow solid (27.4 mg, 0.05 mmol, 66%) [as the lithium salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₃ H ₂₅ N ₈ O ₃ S ₂ : 525.1486, found: 525.1516.

Example 161: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(2S)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[(2S)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of Preparation 3zf (40 mg, 0.09 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added Preparation 4a (37.6 mg, 0.09 mmol, 1 equiv), N,N-diisopropylethylamine (0.05 mL, 0.28 mmol, 3 equiv), cesium carbonate (90.2 mg, 0.28 mmol, 3 equiv), and xantphos (10.7 mg, 0.02 mmol, 0.2 equiv), followed by the addition of tris(dibenzylideneacetone)dipalladium(0) (8.45 mg, 0.01 mmol, 0.1 equiv), and the mixture was heated at 100 °C for 24 h and then allowed to cool to ambient temperature. The reaction mixture was partitioned between dichloromethane and water, and the organic phase was washed with brine, dried (magnesium sulfate), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 7% methanol in dichloromethane afforded the title product as a brown glass (30.7 mg, 0.04 mmol, 41%).

LC/MS (C ₄₀ H ₅₀ FN ₇ O ₄ SiS ₂ ) 804 [M+H] ⁺ ; RT 1.59 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.88 - 7.81 (m, 1H), 7.67 (d, J=1.1 Hz, 1H), 7.51 - 7.39 (m, 2H), 7.34 - 7.23 (m, 2H), 7.22 -7.11 (m, 2H), 5.86 (s, 2H), 4.26 (q, J=7.1 Hz, 2H), 4.07 - 3.94 (m, 2H), 3.78 (s, 2H), 3.76 - 3.68 (m, 2H), 3.37 (s, 3H), 3.32 - 3.26 (m, 1H), 3.18 - 3.06 (m, 1H), 2.60 - 2.52 (m, 1H), 2.46 (d, J=1.0 Hz, 3H), 2.19 (s, 6H), 1.30 (t, J=7.1 Hz, 3H), 1.04 (d, J=6.7 Hz, 3H), 0.97 - 0.88 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(2S)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (30.7 mg, 0.04 mmol, 1 equiv) in tetrahydrofuran (5 mL) were added tetrabutylammonium fluoride (1 M in tetrahydrofuran, 0.22 mL, 0.22 mmol, 6 equiv) and ethylenediamine (0.02 mL, 0.22 mmol, 6 equiv) in tetrahydrofuran (5 mL), and the mixture was heated at reflux overnight. The reaction mixture was partitioned between ethyl acetate and water, the aqueous phase was extracted with ethyl acetate (×2) and then dichloromethane (×2), and the combined organic extracts were dried (magnesium sulfate) and concentrated in vacuo to give the title product, which was used directly in the next step without further purification.

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(2S)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (38 mg, 0.06 mmol, 1 equiv) in 1,4-dioxane (3 mL) was added 1 M aqueous lithium hydroxide (0.56 mL, 0.56 mmol, 10 equiv) and the mixture was heated at 100 °C for 2.5 h. The reaction mixture was allowed to cool to ambient temperature and purified by reversed-phase automated flash chromatography (CombiFlash Rf, C18 13 g RediSep column) eluting with a gradient of 5 95% acetonitrile in water to give a brown glass. The material was dissolved in a mixture of dichloromethane and methanol and loaded onto a 2 g PE-AX cartridge (pre-conditioned with dichloromethane then methanol). The cartridge was washed with dichloromethane followed by methanol, then eluted with 10% formic acid in dichloromethane, and the solvent was removed and dried in vacuo to give the desired product as a brown glass (6.4 mg, 0.01 mmol, 18%) [as the formate salt].

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₂ H ₃₃ FN ₇ O ₃ S ₂ : 646.2065, found: 646.2110.

Example 162: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(1E)-2-methyl-3-phenoxyprop-1-en-1-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-5-[(1E)-2-methyl-3-phenoxyprop-1-en-1-yl]-1,3-thiazole-4-carboxylate

To a solution of the product of Synthesis 5t (160 mg, 0.26 mmol, 1 equiv.) in toluene (3 mL) were added phenol (34 μL, 0.38 mmol, 1.5 equiv.), triphenylphosphine (100 mg, 0.38 mmol, 1.5 equiv.), and diisopropyl azodicarboxylate (75 μL, 0.38 mmol, 1.5 equiv.), and the mixture was heated at 120 °C for 1 h under microwave irradiation. The reaction mixture was partitioned between dichloromethane and water, and the organic phase was separated, dried (PTFE phase separator), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0:60% ethyl acetate in isoheptane afforded the title product as a yellow gum (100 mg, 0.14 mmol, 56%).

LC/MS (C ₃₅ H ₄₂ N ₆ O ₄ SiS ₂ ) 703 [M+H] ⁺ ; RT 3.12 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.86 - 7.81 (m, 1H), 7.72 (d, 1H), 7.51 - 7.40 (m, 2H), 7.36 - 7.21 (m, 4H), 7.06 - 7.00 (m, 2H), 6.99 - 6.93 (m, 1H), 5.87 (s, 2H), 4.68 (s, 2H), 4.26 (q, J=7.1 Hz, 1H), 3.81 (s, 3H), 3.76 - 3.68 (m, 2H), 2.46 (s, 3H), 2.06 (s, 3H), 1.28 (t, 3H), 0.97 - 0.88 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(1E)-2-methyl-3-phenoxyprop-1-en-1-yl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (496 mg, 0.71 mmol, 1 equiv) in tetrahydrofuran (15 mL) were added ethylenediamine (141 µL, 2.12 mmol, 3 equiv) and tetrabutylammonium fluoride (1 M in tetrahydrofuran; 2.12 mL, 2.12 mmol, 3 equiv), and the mixture was heated at 70 °C overnight. The reaction mixture was partitioned between ethyl acetate and water, and the organic phase was dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the title product as a yellow solid (37 mg, 0.06 mmol, 9%).

LC/MS (C ₂₉ H ₂₈ N ₆ O ₃ S ₂ ) δ73 [M+H] ⁺ ; RT 2.65 (LCMS-VC).

^1H NMR (400 MHz, DMSO-d6) δ 7.91 (br s, 1H), 7.73 (s, 1H), 7.43 - 7.35 (m, 2H), 7.34 - 7.28 (m, 3H), 7.25 - 7.16 (m , 1H), 7.06 - 7.00 (m, 2H), 6.99 - 6.93 (m, 1H), 4.67 (s, 2H), 4.26 (q, J=7.1 Hz, 2H), 3.80 (s, 3H), 2.47 (s, 3H), 2.05 ( s, 3H), 1.28 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(1E)-2-methyl-3-phenoxyprop-1-en-1-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (37 mg, 0.06 mmol, 1 equiv) in 1,4-dioxane (4 mL) was added lithium hydroxide monohydrate (27.1 mg, 0.65 mmol, 10 equiv) and the mixture was heated at 110 °C overnight. The reaction mixture was allowed to cool to ambient temperature and purified by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 10% 7 N methanolic ammonia in dichloromethane to give a dark yellow solid. The solid was triturated with acetonitrile, filtered and dried under vacuum to give the desired product as a yellow solid (12.1 mg, 0.02 mmol, 34%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₂₇ H ₂₅ N ₆ O ₃ S ₂ : 545.1424, found: 545.1426.

Example 163: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(1E)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylprop-1-en-1-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[(1E)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylprop-1-en-1-yl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of Preparation 5b (618 mg, 0.99 mmol, 1 equiv) in toluene (18 mL) were added Preparation 6b (286 mg, 1.48 mmol, 1.5 equiv), triphenylphosphine (388 mg, 1.48 mmol, 1.5 equiv), and diisopropyl azodicarboxylate (291 μL, 1.48 mmol, 1.5 equiv), and the mixture was heated at 120 °C for 1 h under microwave irradiation. The reaction mixture was partitioned between dichloromethane and water, and the organic phase was separated, dried (PTFE phase separator), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0:100% ethyl acetate in isoheptane afforded the desired product as a brown oil (406 mg, 0.51 mmol, 51%).

LC/MS (C ₄₀ H ₄₈ FN ₇ O ₄ SiS ₂ ) 802 [M+H] ⁺ ; RT 2.68 (LCMS-VC)

^1H NMR (400 MHz, DMSO-d6) δ 7.86 - 7.80 (m, 1H), 7.70 (s, 1H), 7.50 - 7.39 (m, 2H), 7.38 - 7.21 (m, 5H), 5.86 (s, 2H), 4.78 (s, 2H), 4.25 (q, J=7.2 Hz, 2H), 3.81 (s, 3H), 3.76 - 3.67 (m, 2H), 3.41 (s, 2H), 2.46 (d, J=1.0 Hz, 3H), 2.22 (s , 6H), 2.05 (s, 3H), 1.28 (t, J=7.1 Hz, 3H), 0.97 -0.85 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(1E)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylprop-1-en-1-yl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (406 mg, 0.51 mmol, 1 equiv) in acetonitrile (5 mL) was added pyridinium polyfluoride (0.88 mL, 10.1 mmol, 20 equiv) and the mixture was heated at 60 °C overnight. The reaction mixture was allowed to cool to ambient temperature, then partitioned between dichloromethane and 2 N aqueous sodium hydroxide solution (25 mL), and the organic phase was separated and dried (PTFE phase separator) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 5% methanol in dichloromethane afforded the title product as a yellow solid (139 mg, 0.21 mmol, 41%).

LC/MS (C ₃₄ H ₃₄ FN ₇ O ₃ S ₂ ) 672 [M+H] ⁺ ; RT 2.07 (LCMS-VC)

^1H NMR (400 MHz, DMSO-d6) δ 11.56 (br s, 1H), 7.90 (d, J=7.6 Hz, 1H), 7.72 (s, 1H), 7.57 - 7.50 (m, 1H), 7.44 - 7.28 (m, 3H), 7.27 - 7.17 (m, 3H), 4.79 (s, 2H), 4.27 (q, J=7.2 Hz, 2H), 3.81 (s, 3H), 3.43 (s, 2H), 2.47 (s, 3H), 2.23 (s , 6H), 2.06 (s, 3H), 1.29 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(1E)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylprop-1-en-1-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (139 mg, 0.21 mmol, 1 equiv) in 1,4-dioxane (10 mL) was added lithium hydroxide monohydrate (86.8 mg, 2.07 mmol, 10 equiv) and the mixture was heated at 110 °C for 4 h. The reaction mixture was allowed to cool to ambient temperature and the solvent was removed by rotary evaporation. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 to 25% 7 N methanolic ammonia in dichloromethane afforded a solid. The material was triturated with acetonitrile, filtered and dried in vacuo to give the desired product as a yellow solid (77.9 mg, 0.12 mmol, 59%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₂ H ₃₁ FN ₇ O ₃ S ₂ : 644.1908, found: 644.1908.

Example 164: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-hydroxypropyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-(oxan-2-yloxy)propyl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

The product of Synthesis 4a (150 mg, 0.37 mmol, 1.16 equiv) and the product of Synthesis 3zg (165 mg, 0.32 mmol, 1 equiv) were added to a solution of tris(dibenzylideneacetone)dnpalladium(0) (29.1 mg, 0.03 mmol, 0.1 equiv) and xantphos (36.8 mg, 0.06 mmol, 0.2 equiv) in 1,4-dioxane (8 mL). Cesium carbonate (310 mg, 0.95 mmol, 3 equiv) and N,N-diisopropylethylamine (0.2 mL, 0.95 mmol, 3 equiv) were added and the mixture was heated in a sealed tube at 125 °C for 18 h. The suspension was allowed to cool and the mixture was filtered through celite, the solids were washed with ethyl acetate (30 mL) and the filtrate was concentrated in vacuo. Purification by flash column chromatography (20 g silica gel) eluting with a gradient of 0 - 2.5% methanol in dichloromethane gave the title product as a dark brown gum (230 mg, 0.26 mmol, 81%).

LC/MS (C ₄₄ H ₅₆ FN ₇ O ₆ SiS ₂ ) 890 [M+H] ⁺ ; RT 1.59 (LCMS-V-B1)

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-hydroxypropyl)-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (225 mg, 0.25 mmol, 1 equiv) in chloroform (4.5 mL) cooled in ice-water was added trifluoroacetic acid (0.5 mL, 6.32 mmol, 25 equiv) and the mixture was stirred for 1 h at 0 °C and for 18 h at ambient temperature. Dichloromethane (50 mL) was added and the mixture was washed successively with saturated aqueous sodium bicarbonate (30 mL), water (2 x 30 mL), and brine (30 mL), dried (magnesium sulfate), and concentrated in vacuo. Purification by flash column chromatography (20 g silica gel) eluting with a gradient of 0-5% methanol in dichloromethane afforded the title product as a dark yellow solid (98 mg, 0.15 mmol, 57%).

LC/MS (C ₃₃ H ₃₄ FN ₇ O ₄ S ₂ ) 676 [M+H] ⁺ ; RT 1.15 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d6) δ 7.86 - 7.63 (m, 2H), 7.48 - 7.31 (m, 2H), 7.30 - 7.21 (m, 1H), 7.20 - 7.11 (m, 2H), 6.96 - 6.85 (m, 1H), 4.46 - 4.31 (m, 3H), 4.16 - 4.01 (m, 2H), 3.92 - 3.76 (m, 3H), 3.64 - 3.53 (m, 1H), 3.51 - 3.44 (m, 1H), 3.42 (s, 3H), 2.44 (s, 3H), 2.34 (s, 6H), 1.43 (t, J=7.1 Hz, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-hydroxypropyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (90 mg, 0.13 mmol, 1 equiv) in 1:3 1,4-dioxane/water (2 mL) was added lithium hydroxide monohydrate (11.2 mg, 0.27 mmol, 2 equiv) and the suspension was heated at 40 °C for 7 h. The reaction mixture was allowed to cool and the resulting solution was acidified with acetic acid to pH 5 to give a yellow precipitate. The solids were collected by filtration, washed with water and dried in vacuo to give the desired product as a yellow solid (54 mg, 0.08 mmol, 63%).

HR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₁ H ₃₁ FN ₇ O ₄ S ₂ : 648.1857, found: 648.1888.

Example 165: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[methyl(4-piperidyl)amino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[5-[(1-tert-butoxycarbonyl-4-piperidyl)-methylamino]pentyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothi azol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5f and tert-butyl 4-(methylamino)piperidine-1-carboxylate as the appropriate amine, the desired product was obtained.

HR-MSR (m/z): [M+2H]2+, calculated for C ₅₃ H ₇₄ FN ₉ O ₆ S ₂ Si: 522.7551, found: 522.7542.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[methyl(4-piperidyl)amino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₄₁ H ₅₂ FN ₉ O ₃ S ₂ : 400.6804, found: 400.6803.

Example 166: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-(2-morpholinoethylamino)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl l)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]-[5-(2-morpholinoethylamino)pentyl]amino]thiazol-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5f and 2-morpholinoethanamine as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.66 (s, 1H), 7.47 (dm, 1H), 7.44 (m, 1H), 7.30 (dd, 1H), 7.25 (m, 1H), 7.21 (dd, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.37 (t, 2H), 4.14 (t, 2H), 3.78 (s, 3H), 3.72 (m, 2H), 3.52 (m, 4H), 3.38 (s, 2H), 3.26 (m, 2H), 2.56 ( t, 2H), 2.49 (t, 2H), 2.46 (s, 3H), 2.32 (t, 2H), 2.31 (m, 4H), 2.19 (s, 6H), 2.12 (m, 2H), 1.69 (m, 2H), 1.47 (m, 2H), 1.37 (m, 2H), 0.92 (m, 2H), - 0.11 (s, 9H); HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₄₈ H ₆₈ FN ₉ O ₅ S ₂ Si: 480.7269, found: 480.7264.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-(2-morpholinoethylamino)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₄₁ H ₅₂ FN ₉ O ₄ S ₂ : 408.6779, found: 408.6769.

Example 167: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(4-methylpiperazin-1-yl)ethylamino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Step A: Methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-[2-(4-methylpiperazin-1-yl)ethylamino]pentyl-[5-methyl-6-f(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazole-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5f and 2-(4-methylpiperazin-1-yl)ethanamine as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.67 (s, 1H), 7.47 (dm, 1H), 7.44 (m, 1H), 7.30 (dd, 1H), 7.26 (m, 1H), 7.21 (dd, 1H), 7.15 (t, 1H), 5.86 (s, 2H), 4.36 (t, 2H), 4.14 (t, 2H), 3.78 (s, 3H), 3.72 (m, 2H), 3.38 (s, 2H), 3.26 (m, 2H), 2.53 (t, 2H), 2.50- 2.10 (brs, 4H), 2.50-2.10 (brs, 4H), 2.48 (t, 2H), 2.46 (s, 3H), 2.30 (t, 2H), 2.20 (s, 6H), 2.13 (m, 2H), 2.10 (s, 3H), 1.69 (m, 2H), 1.45 (m, 2H), 1.37 (m, 2H), 0.92 (m, 2H), -0.11 (s, 9H); HR-MSR (m/z): [M+2H]2+, calculated for C ₄₉ H ₇₁ FN ₁₀ O ₄ S ₂ Si: 487.2422, found: 487.2422.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(4-methylpiperazin-1-yl)ethylamino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+2H] ²⁺ , calculated for C ₄₂ H ₅₅ FN ₁₀ O ₃ S ₂ : 415.19366, found: 415.1939.

Example 168: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-[2-(4-methylpiperazin-1-yl)ethylamino]butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[4-[2-(4-methylpiperazin-1-yl)ethylamino]butyl-[ 5-met yl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5d and 2-(4-methylpiperazin-1-yl)ethanamine as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-dg) δ ppm 2.50-2.00 (brs, 8H), 7.84 (dm, 1H), 7.72 (s, 1H), 7.47 (dm, 1H), 7.43 (m, 1H), 7.30 (dd, 1H), 7.25 (m, 1H) , 7.21 (dd, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.38 (t, 2H), 4.15 (t, 2H), 3.78 (s, 3H), 3.72 (m, 2H), 3.39 (s, 2H), 3.27 (t, 2H), 2.56 (t, 2H), 2.54 (t, 2H), 2.46 (s, 3H), 2.31 (t, 2H), 2.20 (brs, 6H), 2.13 (m, 2H), 2.06 (s, 3H), 1.71 (m, 2H), 1.47 (m, 2H), 0.92 (m, 2H), -0.11 (s, 9H); HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₄₈ H ₆₉ FN ₁₀ O ₄ S ₂ Si: 480.2344, found: 480.2340.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-[2-(4-methylpiperazin-1-yl)ethylamino]butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+2H] ²⁺ , calculated for C ₄₁ H ₅₃ FN ₁₀ O ₃ S ₂ : 408.1858, found: 408.1857.

Example 169: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-[methyl- [2-(methylamino)ethyl]amino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[[5-[2-[tert-butoxycarbonyl(methyl)amino]ethylmethylamino]-4-[tert-butyl(diphenyl)silyl]oxypentyl]-[5-methyl-6-[(Z)-[3- (2-trimethylsilylethox imethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl ]thiazole-4-carboxylate

Using the General Tosylate Alkylation Procedure, starting from the product of Preparation 5b and tert-butyl N-methyl-N-[2-(methylamino)ethyl]carbamate as the appropriate amine, the desired product was obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-[methyl-[2-(methylamino)ethyl]amino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₉ H ₄₉ FN ₉ O ₄ S ₂ : 790.3327, found: 790.3317.

Example 170: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(diethylamino)ethylamino]-4-hydroxypentyl]amino]-5 -[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy] propyl]thiazole-4-carboxylic acid

Step A: Methyl 2-[[4-[tert-butyl(diphenyl)silyl]oxy-5-[2-(diethylamino)ethylamino]pentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Tosylate Alkylation Procedure starting from Preparation 5b and N,'N'-diethylethane-1,2-diamine as the appropriate amine, the desired product was obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(diethylamino)ethylamino]-4-hydroxypentyl]amino]-5 -[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₅₃ FN ₉ O ₄ S ₂ : 818.3640, found: 818.3613.

Example 171: 2-[[5-(4-Amino-1-piperidyl)-4-hydroxypentyl]-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[[5-[4-(tert-butoxycarbonylamino)-1-piperidyl]-4-[tert-butyl(diphenyl)silyl]oxypentyl]-[5-methyl-6-[(Z)-[3-( 2-trimethylsilylethoxymeth l)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl ]thiazole-4-carboxylate

Using the General Tosylate Alkylation Procedure starting from Preparation 5b and tert-butyl N-(4-piperidyl)carbamate as the appropriate amine, the desired product was obtained.

Step B: 2-[[5-(4-amino-1-piperidyl)-4-hydroxypentyl]-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₀ H ₄₉ FN ₉ O ₄ S ₂ : 802.3327, found: 802.3324.

Example 172: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-5-piperazin-1-ylpentyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[[5-(4-tert-butoxycarbonylpiperazin-1-yl)-4-[tert-butyl(diphenyl)silyl]oxypentyl]-[5-methyl-6-[(Z)-[3-(2- trimethylsilylethoxymethyl) -1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole -4-carboxylate

Using the General Tosylate Alkylation Procedure, starting from the product of Preparation 5b and tert-butyl piperazine-1-carboxylate as the appropriate amine, the desired product was obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-5-piperazin-1-ylpentyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₃₉ H ₄₈ FN ₉ O ₄ S ₂ : 394.6622, found: 394.6614.

Example 173: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-[2-(1-piperidyl)ethylamino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[[4-[tert-butyl(diphenyl)silyl]oxy-5-[2-(1-piperidyl)ethylamino]pentyl]-[5-methyl-6-[(Z)-[3-(2- trimethylsilylethoxymethyl)-1,3-b enzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4-carboxylate

Using the General Tosylate Alkylation Procedure starting from Preparation 5b and 2-(1-piperidyl)ethanamine as the appropriate amine, the desired product was obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-[2-(1-piperidyl)ethylamino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate methyl ester, the desired product was obtained.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₄₂ H ₅₄ FN ₉ O ₄ S ₂ : 415.6857, found: 415.6853.

Example 174: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(1E)-3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}-2-methylprop-1-en-1-yl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[(1E)-3-[4-(3-{[(tert-butoxy)carbonyl](methyl)amino}prop-1-yn-1-yl)-2-fluorophenoxy]-2-methylprop-1-en-1-yl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of Preparation 5a (641 mg, 1.02 mmol, 1 equiv.) in toluene (18 mL) were added Preparation 6a (428 mg, 1.53 mmol, 1.5 equiv.), triphenylphosphine (402 mg, 1.53 mmol, 1.5 equiv.), and diisopropyl azodicarboxylate (0.3 mL, 1.53 mmol, 1.5 equiv.), and the mixture was heated at 120 °C for 1 h. The reaction mixture was partitioned between dichloromethane and water, and the organic phase was separated and dried (PTFE phase separator), and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 24 g RediSep™ silica gel cartridge) eluting with a gradient of 0:40% ethyl acetate in isoheptane afforded the title product as a yellow solid (380 mg, 0.43 mmol, 42%).

LC/MS (C ₄₄ H ₅₄ FN ₇ O ₆ SiS ₂ ) 888 [M+H] ⁺ ; RT 1.43 (LCMS-V-B2)

^1H NMR (400 MHz, DMSO- _d6 ) δ 7.86 - 7.81 (m, 1H), 7.71 (d, 1H), 7.51 - 7.40 (m, 2H), 7.39 - 7.32 (m, 1H), 7.32 - 7.21 (m, 4H), 5.86 (s, 2H), 4.79 (s, 2H), 4.32 -4.17 (m, 4H), 3.81 (s, 3H), 3.78 - 3.66 (m, 2H), 2.86 (s, 3H), 2.46 (s, 3H ), 2.06 (m, 3H), 1.41 (s, 9H), 1.28 (t, 3H), 0.97 - 0.88 (m, 2H), -0.11 (s, 9H).

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(1E)-3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}-2-methylprop-1-en-1-yl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (380 mg, 0.43 mmol, 1 equiv) in acetonitrile (5 mL) was added pyridinium polyfluoride (744 μL, 8.56 mmol, 20 equiv) and the mixture was heated at 60 °C for 3 h. The reaction mixture was allowed to cool to ambient temperature, then partitioned between dichloromethane and 2 N aqueous sodium hydroxide, the aqueous phase was extracted 1:3 with isopropanol/dichloromethane, and the combined organics were dried (PTFE phase separator) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 6% methanol in dichloromethane afforded the title product as a yellow solid (133 mg, 0.2 mmol, 47%).

LC/MS (C ₃₃ H ₃₂ FN ₇ O ₃ S ₂ ) 658 [M+H] ⁺ ; RT 2.02 (LCMS-VC)

¹ H NMR (400 MHz, DMSO-d6) δ 7.90 (d, J=7.8 Hz, 1H), 7.73 (s, 1H), 7.54 (d, J=8.0 Hz, 1H), 7.44 - 7.36 (m, 1H), 7.35 - 7.28 (m, 2H), 7.27 - 7.18 (m, 3H), 4.79 (s, 2H), 4.27 (q, J=7.1 Hz, 2H), 3.81 (s, 3H), 3.49 (s, 2H), 2.48 (d, J=1.0 Hz, 3H), 2.34 (s, 3H), 2.07 (s, 3H), 1.29 (t, 3H).

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(1E)-3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}-2-methylprop-1-en-1-yl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (133 mg, 0.2 mmol, 1 equiv) in 1,4-dioxane (6 mL) was added lithium hydroxide monohydrate (84.9 mg, 2.02 mmol, 10 equiv) and the mixture was heated at 110 °C for 4 h. The reaction mixture was allowed to cool to ambient temperature and purified by automated flash column chromatography (CombiFlash Rf, 12 g RediSep™ silica gel cartridge) eluting with a gradient of 0 - 25% 7 N methanolic ammonia in dichloromethane to give a solid. The solid was triturated with acetonitrile, filtered and dried under vacuum to give the desired product as a yellow solid (4.32 mg, 0.01 mmol, 3%).

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₁ H ₂₉ FN ₇ O ₃ S ₂ : 630.1752, found: 630.1781.

Example 175: 2-[4-(4-Amino-1-piperidyl)butyl-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[4-[4-(tert-butoxycarbonylamino)-1-piperidyl]butyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazole -2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure for Alkylation with an In Situ Generated Tosylate, starting from the product of Preparation 5d and tert-butyl N-(4-piperidyl)carbamate as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.65 (q, 1H), 7.33 (dd, 1H), 7.26 (dd, 1H), 7.18 (t, 1H), 6.80 (brs, 1H), 5.86 (s, 2H), 4.40 (t, 2H), 4.20 (t, 2H), 3.82 (s, 3H), 3.79 (s, 2H), 3.77 (m, 2H), 3.54 (brs, 1H), 3.36/3.00 (brs, 4H), 3.29 (t, 2H), 3.14 (t, 2H), 2.52 (brs, 6H), 2.48 (d , 3H), 2.15 (m, 2H), 1.94/1.66 (t+t, 4H), 1.79 (m, 2H), 1.76 (m, 2H), 1.40 (s, 9H), 0.94 (m, 2H), -0.07 (s, 9H); HR-ERI (m/z): [M +Н] ⁺ , calculated for C ₅₁ H ₇₁ FN ₉ O ₆ S ₂ Si: 1016.4716, found: 1016.4704.

Step B: 2-[4-(4-amino-1-piperidyl)butyl-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₉ H ₄₆ FN ₉ O ₃ S ₂ : 772.3222, found: 772.3228.

Example 176: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-[2-(diethylamino)ethylamino]butyl]amino]-5-[3 -[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Step A: Methyl 2-[4-[2-(diethylamino)ethylamino]butyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5d and N',N'-diethylethane-1,2-diamine as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.71 (s, 1H), 7.47 (dm, 1H), 7.44 (m, 1H), 7.30 (dd, 1H), 7.25 (m, 1H), 7.21 (dd, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.39 (t, 2H), 4.15 (t, 2H), 3.78 (s, 3H), 3.72 (m, 2H), 3.38 (s, 2H), 3.27 (t, 2H), 2.57 (t, 2H), 2.51 ( t, 2H), 2.46 (s, 3H), 2.41 (t, 2H), 2.40 (q, 4H), 2.19 (s, 6H), 2.12 (m, 2H), 1.71 (m, 2H), 1.48 (m, 2H), 0.92 (m, 2H), 0.89 (t, 6H), -0.11 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₇ H ₆₇ FN ₉ O ₄ S ₂ Si: 932.4505, found: 932.4489.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-[2-(diethylamino)ethylamino]butyl]amino]-5-[3 -[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+2H] ²⁺ , calculated for C ₄₀ H ₅₂ FN ₉ O ₃ S ₂ : 394.6804, found: 394.6802.

Example 177: 2-[5-(4-Amino-1-piperidyl)pentyl-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[5-[4-(tert-butoxycarbonylamino)-1-piperidyl]pentyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazo l-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4-carboxylate

Using the General Procedure for Alkylation with an In Situ Generated Tosylate, starting from the product of Preparation 5f and tert-butyl N-(4-piperidyl)carbamate as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.91-7.18 (m, 4H), 7.70 (s, 1H), 7.33 (dd, 1H), 7.24 (dd, 1H), 7.17 (t, 1H), 7.04 (d, 1H), 5.87 (s, 2H) , 4.16 (t, 2H), 3.79 (s, 3H), 3.72 (t, 2H), 3.53 (s, 2H), 3.49/3.31 (m+m, 4H), 3.27 (t, 2H), 2.94 (t, 2H), 2.91 (m, 1H), 2.47 (s, 3Н), 2.30 (s, 6Н), 2.13 (m, 2Н), 1.89/1.60 (m+m, 4H), 1.73 (m, 2H), 1.70 (m, 2H), 1.38 (m, 2H), 1.38 (m, 2H), 1.38 (s, 9H), 0.92 (t, 2H), -0.11 (s, 9H); HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₅₂ H ₇₄ FN ₉ O ₆ S ₂ Si: 515.7473, found: 515.74725.

Step B: 2-[5-(4-amino-1-piperidyl)pentyl-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+2H] ²⁺ , calculated for C ₄₀ H ₅₀ FN ₉ O ₃ S ₂ : 393.6726, found: 393.6723.

Example 178: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-[methyl-[2-(methylamino)ethyl]amino]butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[4-[2-[tert-butoxycarbonyl(methyl)amino]ethylmethylamino]butyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzoate iazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4-carboxylate

Using the General Procedure for Alkylation with an In Situ Generated Tosylate, starting from the product of Preparation 5d and tert-butyl N-methyl-N-[2-(methylamino)ethyl]carbamate as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.68 (s, 1H), 7.46 (dm, 1H), 7.44 (m, 1H), 7.30 (dd, 1H), 7.25 (m, 1H), 7.20 (dd, 1H), 7.15 (t, 1H), 5.86 (s, 2H), 4.38 (t, 2H), 4.14 (t, 2H), 3.77 (s, 3H), 3.72 (m, 2H), 3.38 (s, 2H), 3.26 (t, 2H), 3.19 (brm, 2H), 2.71 ( brs, 3H), 2.46 (s, 3H), 2.37 (t, 2H), 2.36 (t, 2H), 2.19 (s, 6H), 2.15 (s, 3H), 2.12 (m, 2H), 1.69 (m, 2H), 1.48 (m, 2H), 1.31 (brs, 9H), 0.92 (m, 2H ), -0.11 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₀ H ₇₁ FN ₉ O ₆ S ₂ Si: 1004.4716, found: 502.73931.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-[methyl-[2-(methylamino)ethyl]amino]butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₃₈ H ₄₈ FN ₉ O ₃ S ₂ : 380.6647, found: 380.6640.

Example 179: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-[2-(1-piperidyl)ethylamino]butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Step A: Methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]-[4-[2-(1-piperidyl)ethylamino]butyl]amino]thiazole-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5d and 2-(1-piperidyl)ethanamine as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.79 (dm, 1H), 7.68 (s, 1H), 7.48 (dm, 1H), 7.44 (m, 1H), 7.30 (dd, 1H), 7.26 (m, 1H), 7.24 (dd, 1H), 7.17 (t, 1H), 5.86 (s, 2H), 4.42 (t, 2H), 4.19 (t, 2H), 3.82 (s, 3H), 3.77 (m, 2H), 3.63 (brs, 2H), 3.28 (t, 2H), 3.07 (t, 2H), 3.04 ( t, 2H), 2.76 (t, 2H), 2.60 (brm, 4H), 2.48(s, 3H), 2.41 (brs, 6H), 2.14 (m, 2H), 1.83 (m, 2H), 1.73 (m, 2H), 1.58 (m, 4H), 1.43 (m, 2H), 0.94 (m, 2H ), -0.07 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₈ H ₆₇ FN ₉ O ₄ S ₂ Si: 944.4505, found: 944.44978.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-[2-(1-piperidyl)ethylamino]butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₅₁ FN ₉ O ₃ S ₂ : 800.3535, found: 800.3540.

Example 180: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-(2-morpholinoethylamino)butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymeth yl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]-[4-(2-morpholinoethylamino)butyl]amino]thiazol-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5d and 2-morpholinoethanamine as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.81 (dm, 1H), 7.76 (s, 1H), 7.48 (dm, 1H), 7.44 (m, 1H), 7.40 (dd, 1H), 7.28 (dm, 1H), 7.27 (m, 1H), 7.20 (t, 1H), 5.87 (s, 2H), 4.42 (t, 2H), 4.17 (t, 2H), 3.85 (brs, 2H), 3.79 (s, 3H), 3.72 (m, 2H), 3.56 (m, 4H), 3.27 (t, 2H), 3.01 (t, 2H), 2.99 (t, 2H), 2.58 (brm, 2H), 2.51 (brs, 6H), 2.47 (s, 3H), 2.39 (brm, 4H), 2.13 (m, 2H), 1.84-1.68 (m, 4H), 0.92 (m, 2H), -0.11 (s, 9H); HR-ESI (m/z): [M+2H] ²⁺ , calculated for C ₄₇ H ₆₆ FN ₉ O ₅ S ₂ Si: 473.7186, found: 473.7183.

Step B: -[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-(2-morpholinoethylamino)butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₄₀ H ₅₀ FN ₉ O ₄ S ₂ : 401.6700, found: 401.6697.

Example 181: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-[(1-methyl-4-piperidyl)amino]butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[4-[(1-methyl-4-piperidyl)amino]butyl-[5- methyl-6 -[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5d and 1-methylpiperidin-4-amine as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.70 (s, 1H), 7.47 (dm, 1H), 7.43 (m, 1H), 7.30 (dd, 1H), 7.25 (m, 1H), 7.21 (dm, 1H), 7.15 (t, 1H), 5.86 (s, 2H), 4.39 (t, 2H), 4.14 (t, 2H), 3.77 (s, 3H), 3.72 (m, 2H), 3.38 (s, 2H), 3.26 (t, 2H), 2.65/1.84 (m+m, 4H ), 2.56 (t, 2H), 2.46 (s, 3H), 2.27 (m, 1H), 2.19 (s, 6H), 2.12 (m, 2H), 2.09 (s, 3H), 1.72 (m, 2H), 1.7/1.19 (m+m, 4H), 1.46 (m, 2H), 0.92 (m, 2H ), -0.11 (s, 9H); HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₄₇ H ₆₄ FN ₉ O ₄ S ₂ Si: 465.7211, found: 465.7210.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-[(1-methyl-4-piperidyl)amino]butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+2H] ²⁺ , calculated for C ₄₀ H ₄₈ FN ₉ O ₃ S ₂ : 393.6726, found: 393.6735.

Example 182: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(diethylamino)ethylamino]pentyl]amino]-5-[3 -[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Step A: Methyl 2-[5-[2-(diethylamino)ethylamino]pentyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5f and N',N'-diethylethane-1,2-diamine as the appropriate amine, the desired product was obtained.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₄₈ H ₇₀ FN ₉ O ₄ S ₂ Si: 473.7367, found: 473.7360.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(diethylamino)ethylamino]pentyl]amino]-5-[3 -[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₅₃ FN ₉ O ₃ S ₂ : 802.3691, found: 802.3702.

Example 183: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methoxypropyl)-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-(2-methoxy-3-{[tris(propan-2-yl)silyl]oxy}propyl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

The product of Synthesis 4a (1.6 g, 3.93 mmol, 1 equiv.) and the product of Synthesis 3zh (1.75 g, 4.06 mmol, 1.03 equiv.) were added to a solution of tris(dibenzylideneacetone)dipalladium(0) (180 mg, 0.2 mmol, 0.05 equiv.) and xantphos (228 mg, 0.39 mmol, 0.1 equiv.) in 1,4-dioxane (40 mL). Cesium carbonate (3.84 g, 11.8 mmol, 3 equiv) and N,N-diisopropylethylamine (2.1 mL, 11.8 mmol, 3 equiv) were added and the mixture was heated in a sealed tube at 125 °C for 24 h. The suspension was allowed to cool and the mixture was filtered through celite, the solids were washed with 1,4-dioxane (30 mL) and the filtrate was concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with a gradient of 0-25% ethyl acetate in isoheptane gave the title product as a pale yellow solid (2.49 g, 3.11 mmol, 79%).

LC/MS (C ₃₈ H ₆₀ N ₆ O ₅ Si ₂ S ₂ ) 801 [M+H] ⁺ ; RT 1.74 (LCMS-V-B2)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.58 (dt, J=7.6, 0.9 Hz, 1H), 7.42 (d, J=1.2 Hz, 1H), 7.40-7.36 (m, 2H), 7.24-7.17 (m, 1H), 5.85 (s, 2H), 4.39 (q, J=7.1 Hz, 2H), 3.85 (s, 3H), 3.80 (dd, J=4.8, 2.4 Hz, 2H), 3.78-3.72 (m, 2H), 3.60-3.49 (m, 2H), 3.45 (s, 3H), 3.32-3.15 (m, 1H), 2.46 (d, J=1.0 Hz, 3H), 1.42 (t, J=7.1 Hz, 3H), 1.16 1.02 (m, 21H), 1.01 0.92 (m, 2H), -0.07 (s, 9H).

Step B: Ethyl 5-(3-hydroxy-2-methoxypropyl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (2.45 g, 3.06 mmol, 1 equiv.) in tetrahydrofuran (15 mL) cooled in ice-water was added tetrabutylammonium fluoride (1 M in tetrahydrofuran; 10 mL, 9.17 mmol, 3 equiv.), and the mixture was stirred for 60 min at 0 °C. The reaction mixture was partitioned between water (75 mL) and ethyl acetate (150 mL), and the organic phase was washed successively with water (2 x 75 mL) and brine (75 mL), dried (magnesium sulfate), and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a pale yellow/green foam (1.83 g, 2.84 mmol, 93%).

LC/MS (C ₂₉ H ₄₀ N ₆ O ₅ SiS ₂ ) 645 [M+H] ⁺ ; RT 1.56 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.59 (dt, J=7.6, 0.9 Hz, 1H), 7.40-7.36 (m, 2H), 7.33 (d, J=1.1 Hz, 1H), 7.24-7.18 (m, 1H), 5.84 (s, 2H), 4.41 (q, J=7.1 Hz, 2H), 3.85 (s, 3H), 3.79-3.70 (m, 2H), 3.47-3.36 (m, 2H), 2.66 (t, J=6.6 Hz, 1H), 2.46 (d, J=1.0 Hz, 3H), 1.43 (t, 3H), 1.03-0.90 (m, 2H), -0.07 (s, 9H).

Step C: Ethyl 5-[3-(2-fluoro-4-iodophenoxy)-2-methoxypropyl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product from Step B (750 mg, 1.16 mmol, 1 equiv) in toluene (15 mL) were added diisopropyl azodicarboxylate (0.5 mL, 2.33 mmol, 2 equiv), 2-fluoro-4-iodophenol (500 mg, 2.1 mmol, 1.81 equiv), and triphenylphosphine (610 mg, 2.33 mmol, 2 equiv), and the mixture was heated at 100 °C for 18 h, then allowed to cool to ambient temperature and concentrated in vacuo. Purification by flash column chromatography (100 g silica gel) eluting with a gradient of 0-35% ethyl acetate in isoheptane afforded the title product as an orange gum (1.2 g, 1.04 mmol, 90%).

LC/MS (C ₃₅ H ₄₂ FIN ₆ O ₅ SiS ₂ ) 865 [M+H] ⁺ ; RT 1.78 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.60 (d, 1H), 7.42-7.30 (m, 5H), 7.25-7.19 (m, 1H), 6.72 (t, J=8.6 Hz, 1H), 5.85 (s, 2H), 4.40 (q, J=7.1 Hz, 2H), 4.16-4.10 (m, 1H), 4.08-4.01 (m, 1H), 3.98-3.89 (m, 1H), 3.86 (s, 3H), 3.80-3.68 (m, 2H), 3.59-3.49 (m, 4H), 3.48-3.39 (m, 1H), 2.47 (s, 3H), 1.42 (t, J=7.1 Hz, 3H), 1.01-0.92 (m, 2H), -0.07 (s, 9H).

Step D: Ethyl 5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methoxypropyl)-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of the product from Step C (1.2 g, 1.04 mmol, 1 equiv) in dimethylformamide (15 mL) were added copper(I) iodide (19.8 mg, 0.1 mmol, 0.1 equiv), bis(triphenylphosphine)palladium(II) dichloride (73 mg, 0.1 mmol, 0.1 equiv), and dimethyl(prop-2-yn-1-yl)amine (0.25 mL, 2.32 mmol, 2.23 equiv). N,N-Diisopropylethylamine (0.55 mL, 3.12 mmol, 3 equiv) was added, and the mixture was heated at 80 °C for 90 min. The solution was allowed to cool to ambient temperature and partitioned between ethyl acetate (100 mL) and water (75 mL), and the organic phase was washed successively with water (2 x 75 mL) and brine (75 mL), dried (magnesium sulfate), and concentrated in vacuo. Purification by flash column chromatography (50 g silica gel) eluting with a gradient of 0-100% ethyl acetate in isoheptane afforded the title product as a brown gum (460 mg, 0.56 mmol, 54%).

LC/MS (C ₄₀ H ₅₀ FN ₇ O ₅ SiS ₂ ) 820 [M+H] ⁺ ; RT 1.52 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.70-7.64 (m, 1H), 7.63-7.58 (m, 1H), 7.42-7.34 (m, 2H), 7.24-7.19 (m, 1H), 7.17-7.09 (m, 2H), 6.88 (t, J=8.7 Hz, 1H), 5.85 (s, 2H), 4.40 (q, J=7.1 Hz, 2H), 4.19-4.06 (m, 2H), 4.01-3.89 (m, 1H), 3.86 (s, 3H), 3.80-3.68 (m, 2H), 3.61-3.49 (m, 4H), 3.49-3.37 (m, 3H), 2.47 (t, J=0.9 Hz, 3H), 2.34 (s, 6H), 1.43 (t, 3H), 1.01-0.92 (m, 2H), -0.07 (d, J=0.7 Hz, 9H).

Step E: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methoxypropyl)-1,3-thiazole-4-carboxylate

To a solution of the product from Step D (460 mg, 0.56 mmol, 1 equiv) in dichloromethane (4 mL) was added trifluoroacetic acid (1.1 mL, 14 mmol, 25 equiv) and the mixture was stirred for 72 h at ambient temperature. Dichloromethane (150 mL) was added and the mixture was washed successively with 10% aqueous potassium carbonate solution (75 mL), water (2 x 75 mL), and brine (75 mL), dried (magnesium sulfate), and concentrated in vacuo. Trituration with diethyl ether (10 mL) afforded a solid that was collected by filtration, washed with diethyl ether (2 x 10 mL), and dried in vacuo to give the title product as a green powder (250 mg, 0.33 mmol, 58%).

LC/MS (C ₃₄ H ₃₆ FN ₇ O ₄ S ₂ ) 690 [M+H] ⁺ ; RT 1.23 (LCMS-V-B1)

¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.83-7.69 (m, 2H), 7.62-7.53 (m, 1H), 7.51-7.39 (m, 1H), 7.32-7.25 (m, 1H), 7.25-7.16 (m, 2H), 6.94 (t, J=8.7 Hz, 1H), 4.47 (q, J=7.1 Hz, 2H), 4.28-4.06 (m, 2H), 4.05-3.95 (m, 1H), 3.95-3.82 (m, 3H), 3.72-3.64 (m, 1H), 3.60 (s, 3H), 3.57-3.52 (m, 1H), 3.50 (s, 2H), 2.51 (s, 3H), 2.41 (s, 6H), 1.49 (t, J=7.1 Hz, 3H).

Step F: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methoxypropyl)-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step E (240 mg, 0.31 mmol, 1 equiv) in a 1:2 mixture of 1,4-dioxane (6 mL) was added lithium hydroxide monohydrate (131 mg, 3.13 mmol, 10 equiv) and the suspension was heated at 60 °C for 1 h. The reaction mixture was allowed to cool and filtered through celite and the solids were washed with water (4 mL). The filtrate was acidified with acetic acid to pH 6 to give a suspension and the solids were collected by filtration, washed with water (20 mL) and dried in vacuo to give the title product as a green solid (110 mg, 0.17 mmol, 53%).

MSHR-ERI (m/z) [M+H] ⁺ , calculated for C ₃₂ H ₃₃ FN ₇ O ₄ S ₂ : 662.2014, found: 662.2052.

Example 184: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-piperazin-1-ylbutyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[4-(4-tert-butoxycarbonylpiperazin-1-yl)butyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2 -ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5d and tert-butyl piperazine-1-carboxylate as the appropriate amine, the desired product was obtained.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₀ H ₆₉ FN ₉ O ₆ S ₂ Si: 1002.4560, found: 1002.4544.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-piperazin-1-ylbutyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₃₈ H ₄₆ FN ₉ O ₃ S ₂ : 379.6569, found: 379.6565.

Example 185: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-5-[3-[2-fluoro-4-[(E)-3-(methylamino)prop-1-enyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: tert-butyl N-methyl-N-[(E)-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)allyl]carbamate

A mixture of 1.50 g tert-butyl N-methyl-N-prop-2-ynylcarbamate (8.86 mmol, 1 equiv), 1.70 g 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (13.30 mmol, 1.5 equiv), 90 mg N,N-diethylethanamine (0.89 mmol, 0.1 equiv) and 229 mg chloridobis(η ⁵ -cyclopentadienyl)hydridozirconium (Schwartz reagent) (0.89 mmol, 0.1 equiv) was stirred at 65 °C overnight. After completion of the reaction, EtOAc and conc. NH ₄ Cl solution were added, the organic layer was separated and washed with conc. NaHCO ₃ , conc. NaCl, dried over _MgSO4 , filtered and then concentrated onto Celite. The crude product was purified by flash column chromatography using heptane and EtOAc as eluents to afford 1347 mg (51%) of the desired product as a colorless viscous oil.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 6.38 (dt, 1H), 5.35 (dt, 1H), 3.84 (dd, 2H), 2.75 (s, 3H), 1.39 (s, 9H), 1.21 (s, 12H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 155.3, 148.9, 119.1, 83.4, 79.1, 52.2, 34.5, 28.5, 25.1; HR-EI (m/z): [M- ^t Bu+H] ⁺ , calculated for C ₁₁ H ₂₀ BNO ₄ : 241.1480, found: 241.1597.

Step B: Methyl 5-[3-[4-[(E)-3-[tert-butoxycarbonyl(methyl)amino]prop-1-enyl]-2-fluorophenoxy]propyl]-2-[4-[tert-butyl(dimethyl)silyl]oxybutylamino]thiazole-4-carboxylate

1.00 g of the product from Preparation 3c, Step B (1.61 mmol, 1 equiv), 716 mg of the product from Step A (2.41 mmol, 1.5 equiv), 93 mg of Pd(PPh ₃ ) ₄ (0.08 mmol, 0.05 equiv), and 666 mg of K ₂ CO ₃ (4.82 mmol, 3 equiv) were mixed in 15 mL of 1,2-dimethoxyethane and 1.9 mL of water in a MB flask and irradiated at 110 °C for 1 h. Complete conversion was observed. EtOAc and water were added, the organic layer was separated and washed with conc. NaCl, dried over MgSO ₄ , filtered, and then concentrated onto celite. The crude product was purified by flash column chromatography using heptane and EtOAc as eluents to give 708 mg (66%) of the desired product as a colorless viscous oil.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.46 (t, 1H), 7.33 (dd, 1H), 7.14 (dd, 1H), 7.07 (t, 1H), 6.39 (brd, 1H), 6.13 (dt, 1H), 4.06 (t, 2H), 3.90 (brd, 2H), 3.71 (s, 3H), 3.60 (t, 2H), 3.18 (m, 2H), 3.12 (t, 2H), 2.79 (s, 3H), 2.00 (m, 2H), 1.57 ( m, 2H), 1.51 (m, 2H), 1.41 (s, 9H), 0.86 (s, 9H), 0.02 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 164.8, 163.0, 155.3, 152.5, 146.3, 137.0, 136.1, 130.7, 130.5, 125.3, 123.4, 115.7, 113.8, 79.1, 68.4, 62.7, 51.6 , 50.5, 44.5, 34.1, 30.9, 30.2, 28.6, 26.3, 25.7, 23.4, 18.4, -4.8; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₅₃ FN ₃ O ₆ SSi: 666.3403, found: 666.3409.

Stage C: methyl 5-[3-[4-[(E)-3-[tert-butoxycarbonyl(methyl)amino]prop-1-enyl]-2-fluorophenoxy]propyl]-2-[4-[tert-butyl(dimethyl) silyl]hydroxybut yl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting with 138 mg of the product from Step B (0.21 mmol, 1 equiv) and 101 mg of the product from Preparation 4a (0.25 mmol, 1.2 equiv) as the appropriate halide, 102 mg (48%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.81 (dm, 1H), 7.62 (brs, 1H), 7.46 (dm, 1H), 7.43 (m, 1H), 7.33 (ddd, 1H), 7.25 (m, 1H), 7.15 (dm, 1H), 7.10 (t, 1H), 6.38 (d, 1H), 6.10 (dt, 1H), 5.86 (s, 2H), 4.42 (t, 2H), 4.14 (t, 2H), 3.88 (d, 2H), 3.79 (s, 3H), 3.75 (m, 2H), 3.63 (t, 2H), 3.27 (t, 2H), 2.77 (s, 3H), 2.45 (d, 3H), 2.12 (m, 2H), 1.77 (m, 2H), 1.54 (m, 2H), 1.40 (s, 9H), 0.92 (m, 2H), 0.81 (s, 3H), -0.01 (s, 6H), -0.09 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₁ H ₇₅ FN ₇ O ₇ S ₂ Si ₂ : 1036.4686, found: 1036.4706.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-5-[3-[2-fluoro-4-[(E)-3-(methylamino)prop-1-enyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the product from Step C was converted to the TFA salt of the desired product with an isomeric ratio of approximately 82% E and 18% Z (based on NMR).

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₇ FN ₇ O ₄ S ₂ : 678.2327, found: 678.2326.

Example 186: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)propyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]propyl]-2-fluorophenoxy]propyl]-2-[4-[tert-butyl(dimethyl)silyl]oxybutylamino] thiazole-4-carboxylate

A 20 mL oven-dried pressure reaction vessel equipped with a PTFE-lined magnetic stir bar was charged with 400 mg of Example 185, Step B (0.60 mmol, 1 equiv), 64 mg of 10 wt % Pd/C (0.06 mmol, 0.1 equiv) in 6 mL of methanol and then blanketed with nitrogen using a hydrogenation system. The vessel was then filled with _H2 gas at 4 bar and the reaction mixture was stirred at rt for 3 h. Complete conversion was observed, celite was added to the reaction mixture and the volatiles were removed under reduced pressure. The crude product was then purified by flash column chromatography using heptane and EtOAc as eluents to give 381 mg (95%) of the desired product as a colorless oil.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.57 (t, 1H), 7.07 (dd, 1H), 7.02 (t, 1H), 6.93 (d, 1H), 4.01 (t, 2H), 3.69 (s, 3H), 3.59 (t, 2H), 3.17 (q, 2H), 3.13 (m, 2H), 3.11 (t, 2H), 2.75 (brs, 3H), 2.47 (t, 2H), 1.98 (quin, 2H), 1.72 (br, 2H), 1.54 (m, 2H), 1.50 (m, 2H), 1.38/1.33 (brs +brs, 9Н), 0.85 (s, 9Н), 0.01 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 164.6, 163.1, 155.2, 152.0, 144.7, 136.5, 135.3, 124.6, 116.2, 115.3, 79.0, 68.1, 62.7, 51.7, 47.9, 44.4, 34.1 , 31.7, 30.9, 30.1, 29.3, 28.6, 26.3, 25.7, 23.4, 18.5, -4.9; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₅₅ FN ₃ O ₆ SSi: 668.3559, found: 668.3544.

Stage B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]propyl]-2-fluorophenoxy]propyl]-2-[4-[tert-butyl(dimethyl)silyl]oxybutyl-[5 -methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting with 375 mg of the product from Step A (0.56 mmol, 1 equiv) and 274 mg of the product from Preparation 4a (0.67 mmol, 1.2 equiv) as the appropriate halide, 479 mg (82%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.80 (dm, 1H), 7.65/7.61 (s/s, 1H), 7.46 (dd, 1H), 7.43 (td, 1H), 7.24 (td, 1H), 7.05 (t, 1H), 7.04 (m, 1H), 6.93 (dm, 1H), 5.85 (s, 2H), 4.41 (t, 2H), 4.10 (t, 2H), 3.80/3.79 (s/s, 3H), 3.74 (m, 2H), 3.63/3.47 (t, 2H), 3.26 (m, 2H) , 3.13 (t, 2H), 2.74 (s, 3H), 2.47 (t, 2H), 2.46/2.45 (s/s, 3H), 2.11 (m, 2H), 1.77 (m, 2H), 1.72 (m, 2H), 1.54 (m, 2H), 1.35 (br., 9H), 0.92 (m , 2H), 0.85/0.81 (s/s, 9H), -0.01/-0.03 (s, 6H), -0.09/-0.1 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ m.d. 155.4/155.3, 127.1, 124.6, 123.4, 123.1, 117.8, 116.2, 116.1, 111.9, 78.7, 73.1, 68.9, 66.8, 62.6/61, 51.8, 48.0, 46.9, 34.2, 31.8, 31.2, 29.8, 29.2, 28.5, 26.3/26.2, 23.9, 23.2, 17.9, 17.7, -1.0, -2.7/-4.9; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₁ H ₇₇ FN ₇ O ₇ S ₂ Si ₂ : 1038.4843, found: 1038.4837.

Step C: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)propyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step B.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₉ FN ₇ O ₄ S ₂ : 680.2483, found: 680.2469.

Example 187: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(1-piperidyl)ethylamino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Step A: Methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]-[5-[2-(1-piperidyl)ethylamino]pentyl]amino]thiazole-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from Preparation 5f and 2-(1-piperidyl)ethanamine as the appropriate amine, the desired product was obtained.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₄₉ H ₇₀ FN ₉ O ₄ S ₂ Si: 479.7367, found: 479.7353.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(1-piperidyl)ethylamino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₂ H ₅₃ FN ₉ O ₃ S ₂ : 814.3691, found: 814.3670.

Example 188: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-(methylamino)butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[4-(methylamino)butyl-[5-methyl-6-[(Z)- [3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5d and methanamine as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.72 (s, 1H), 7.47 (dm, 1H), 7.44 (m, 1H), 7.31 (dd, 1 I), 7.25 (m, 1H), 7.21 (dm, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.37 (t, 2H), 4.15 (t, 2H), 3.78 (s, 3H), 3.72 (m, 2H), 3.38 (s, 2H), 3.27 (t, 2H), 2.52 (t, 2H), 2.46 ( s, 3Н), 2.26 (s, 3Н), 2.19 (s, 6Н), 2.13 (m, 2H), 1.71 (m, 2H), 1.49 (m, 2H), 0.92 (m, 2H), -0.11 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₂ H ₅₆ FN ₈ O ₄ S ₂ Si: 847.3614, found: 847.3594.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-(methylamino)butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₃₅ H ₄₁ FN ₈ O ₃ S ₂ : 352.1358, found: 352.1361.

Example 189: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(5-piperazin-1-ylpentyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[5-(4-tert-butoxycarbonylpiperazin-1-yl)pentyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2 -ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5f and tert-butyl piperazine-1-carboxylate as the appropriate amine, the desired product was obtained.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₁ H ₇₁ FN ₉ O ₆ S ₂ Si: 1016.4716, found: 1016.4710.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(5-piperazin-1-ylpentyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₃₉ H ₄₈ FN ₉ O ₃ S ₂ : 386.6647, found: 386.6642.

Example 190: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[methyl-[2-(methylamino)ethyl]amino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 2-[5-[2-[tert-butoxycarbonyl(methyl)amino]ethylmethylamino]pentyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzoate iazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4-carboxylate

Using the General Procedure for Alkylation with an In Situ Generated Tosylate, starting from the product of Preparation 5f and tert-butyl N-methyl-N-[2-(methylamino)ethyl]carbamate as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.66 (s, 1H), 7.47 (d, 1H), 7.43 (td, 1H), 7.3 (dd, 1H), 7.25 (td, 1H), 7.20 (dd, 1H), 7.15 (t, 1H), 5.86 (s, 2H), 4.37 (t, 2H), 4.14 (t, 2H), 3.77 (s, 3H), 3.72 (m, 2H), 3.38 (s, 2H), 3.26 ( t, 2H), 3.16 (br., 2H), 2.73 (s, 3H), 2.45 (s, 3H), 2.35 (br., 2H), 2.28 (brt., 2H), 2.19 (s, 6H), 2.13 (s, 3H), 2.12 (m, 2H), 1.68 (m, 2H), 1.45 (m, 2H), 1.35 (m, 2H), 1.33 (s, 9H ), 0.92 (m, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 129.0, 127.2, 123.4, 123.2, 119.2, 117.6, 115.5, 112.0, 72.9, 68.4, 66.7, 57.4, 55.2, 51.9, 48.1, 46.8, 46.4, 44.2, 42.6, 34.5, 31.0, 28.5, 27.0, 26.8, 24.1, 23.1, 17.8, 17.8, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₁ H ₇₃ FN ₉ O ₆ S ₂ Si: 1018.4873, found: 1018.4869.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[methyl-[2-(methylamino)ethyl]amino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₃₉ H ₅₀ FN ₉ O ₃ S ₂ : 387.6726, found: 387.6731.

Example 191: 2-[5-Aminopentyl-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Step A: methyl 2-[tert-butoxycarbonyl-[5-(tert-butoxycarbonylamino)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl ]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction starting from 250 mg of the product of Preparation 1c (0.51 mmol, 1 equiv) and 207 mg of tert-butyl N-(5-hydroxypentyl)carbamate (1.02 mmol, 2 equiv) as the appropriate alcohol, 189 mg (55%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.29 (dd, 1H), 7.21 (d, 1H), 7.13 (t, 1H), 6.75 (t, 1H), 4.10 (t, 2H), 3.97 (t, 2H), 3.75 (s, 3H), 3.49 (br.s, 2H), 3.22 (t, 2H), 2.90 (q, 2H), 2.08 (qv, 2H), 1.99 (s, 6H), 1.66-1.56 (m, 2H), 1.50 (s, 9H ), 1.44-1.36 (m, 2H), 1.35 (s, 9H), 1.28-1.20 (m, 2H); LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₅₀ FN ₄ O ₇ S: 677.3, found: 677.4.

Step B: Methyl 2-[5-(tert-butoxycarbonylamino)pentylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with 182 mg of the product from Step A (0.27 mmol, 1 equiv) as the appropriate Boc-protected amine, 106 mg (68%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.56 (t, 1H), 7.30 (dd, 1H), 7.21 (d, 1H), 7.12 (t, 1H), 6.77 (t, 1H), 4.07 (t, 2H), 3.69 (s, 3H), 3.44 (s, 2H), 3.16-3.09 (m, 4H), 2.92-2.86 (m, 2H), 2.25 (s, 6H), 2.04-1.97 (m, 2H), 1.53-1.45 (m, 2H), 1.40-1.33 (m, 2H), 1.36 (s, 9H), 1.31-1.24 (m, 2H); LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₂₉ H ₄₂ FN ₄ O ₅ S: 577.3, found: 577.4.

Stage C: methyl 2-[5-(tert-butoxycarbonylamino)pentyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylide en]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from 102 mg of the product from Step B (0.18 mmol, 1 equiv) and 90 mg of the product from Preparation 4a (0.22 mmol, 1.25 equiv) as the appropriate halide, 102 mg (61%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.67 (s, 1H), 7.47 (d, 1H), 7.44 (td, 1H), 7.31 (dd, 1H), 7.25 (td, 1H), 7.21 (dm, 1H), 7.16 (t, 1H), 6.77 (t, 1H), 5.86 (s, 2H), 4.34 (t, 2H), 4.15 (t, 2H), 3.78 (s, 3H), 3.72 (t, 2H), 3.39 ( s, 2H), 3.27 (t, 2H), 2.92 (q, 2H), 2.47 (s, 3H), 2.21 (s, 6H), 2.13 (m, 2H), 1.69 (m, 2H), 1.44 (m, 2H), 1.35 (s, 18H), 1.34 (m, 2H), 0.92 (t, 2H), -0.11 (s, 9H); HR-ERI (m/z ): [M+H] ⁺ , calculated for C ₄₇ H ₆₄ FN ₈ O ₆ S ₂ Si: 947.4138, found: 947.4133.

Step D: 2-[5-aminopentyl-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino) prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Method, the target product was obtained from the product in Step C.

HR-ERI (m/z): [M+2H] ²⁺ , calculated for C ₃₅ H ₄₁ FN ₈ O ₃ S ₂ : 352.1364, found: 352.1370.

Example 192: 2-[4-Aminobutyl-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Step A: methyl 2-[tert-butoxycarbonyl-[4-(tert-butoxycarbonylamino)butyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl ]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from 250 mg of the product of Preparation 1c (0.51 mmol, 1 equiv) and 193 mg of tert-butyl N-(4-hydroxybutyl)carbamate (1.02 mmol, 2 equiv) as the appropriate alcohol, 220 mg (65%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.30 (dd, 1H), 7.21 (d, 1H), 7.13 (t, 1H), 6.80 (t, 1H), 4.10 (t, 2H), 4.01-3.95 (m, 2H), 3.75 (s, 3H), 3.45 (s, 2H), 3.22 (t, 2H), 2.91 (q, 2H), 2.25 (s, 6H), 2.08 (qv, 2H), 1.63-1.54 (m, 2H), 1.50 (s, 9H), 1.40-1.35 (m, 2H), 1.35 (s, 9H); LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₄₈ FN ₄ O ₇ S: 663.3, found: 663.4.

Step B: Methyl 2-[4-(tert-butoxycarbonylamino)butylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting with 215 mg of the product from Step A (0.33 mmol, 1 equiv) as the appropriate Boc-protected amine, 137 mg (75%) of the desired product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.57 (t, 1H), 7.30 (d, 1H), 7.21 (d, 1H), 7.12 (t, 1H), 6.81 (t, 1H), 4.07 (t, 2H), 3.69 (s, 3H), 3.42 (s, 2H), 3.17-3.09 (m, 4H), 2.94-2.88 (m, 2H), 2.23 (s, 6H), 2.04-2.00 (m, 2H), 1.53-1.37 (m, 4H), 1.36 (s, 9H); LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₂₈ H ₄₀ FN ₄ O ₅ S: 563.3, found: 563.2.

Stage C: methyl 2-[4-(tert-butoxycarbonylamino)butyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylide n]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting with 133 mg of the product from Step B (0.24 mmol, 1 equiv) and 120 mg of the product from Preparation 4a (0.29 mmol, 1.25 equiv) as the appropriate halide, 220 mg (98%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.69 (s, 1H), 7.47 (d, 1H), 7.44 (td, 1H), 7.31 (dd, 1H), 7.25 (td, 1H), 7.21 (dm, 1H), 7.16 (t, 1H), 6.82 (t, 1H), 5.86 (s, 2H), 4.36 (t, 2H), 4.15 (t, 2H), 3.78 (s, 3H), 3.72 (t, 2H), 3.38 ( s, 2H), 3.27 (t, 2H), 2.98 (q, 2H), 2.46 (s, 3H), 2.19 (s, 6H), 2.13 (m, 2H), 1.67 (m, 2H), 1.46 (m, 2H), 1.34 (s, 9H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ m .d. 156.1, 128.9, 127.2, 123.5, 123.2, 119.2, 117.6, 115.5, 112.0, 72.9, 68.4, 66.7, 52.0, 48.1, 46.7, 44.2, 39.8, 31.0, 28.7, 27.2, 24.7, 23.1, 17.9, 17.8, -1.0 ; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₆ H ₆₂ FN ₈ O ₆ S ₂ Si: 933.3982, found: 933.3995.

Step D: 2-[4-aminobutyl-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₃₄ H ₃₉ FN ₈ O ₃ S ₂ : 345.1280, found: 345.1281.

Example 193: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-(dimethylamino)-4-hydroxypentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure for Deprotection of a Quaternary Salt starting from Example 144, Step A, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₆ H ₄₂ FN ₈ O ₄ S ₂ : 733.2749, found: 733.2745.

Example 194: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-(methylamino)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-(methylomino)pentyl-[5-methyl-6-[(Z)- [3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Alkylation Procedure with In Situ Generated Tosylate starting from Preparation 5f and methanamine as the appropriate amine, the desired product was obtained after concentration and carried directly to the next step without any further purification.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-(methylamino)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the crude product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₆ H ₄₂ FN ₈ O ₃ S ₂ : 717.2800, found: 717.2785.

Example 195: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[3-(4-methylpiperazin-1-yl)propylamino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Stage A: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-[3-(4-methylpiperazin-1-yl)propylamino]pentyl-[ 5th til-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Alkylation Procedure with an In Situ Generated Tosylate, starting from the product of Preparation 5f and 3-(4-methylpiperazin-1-yl)propan-1-amine as the appropriate amine, the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.83 (dm, 1H), 7.65 (s, 1H), 7.42-7.46 (m, 2H), 7.36-7.08 (m, 4H), 5.85 (s, 2H), 4.36 (t, 2H), 4.14 (t, 2H), 3.78 (s, 3H), 3.72 (t, 2H), 3.26 (t, 2H), 2.70-2.00 (m, 26H), 2.45 (s, 3H), 1.80-1.30 (m, 8H), 0.91 (t, 2H), -0.12 (s, 9H); LC-MS-ESI (m/z): [M+H] ⁺ , calculated for C ₅₀ H ₇₂ FN ₁₀ O ₄ S ₂ Si: 987.5, found: 987.4.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[3-(4-methylpiperazin-1-yl)propylamino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₃ H ₅₆ FN ₁₀ O ₃ S ₂ : 843.3962 found: 843.3943.

Example 196: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-[methyl(2-phosphonoethyl)amino]pentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: 2-diethoxyphosphoryl-N-methylethanamine

3.28 g of 1-[ethoxy(vinyl)phosphoryl]oxyethane (20 mmol, 1.0 equiv.) and 25 mL of methanamine (33 wt% in EtOH, 200 mmol, 100 equiv.) were mixed in a sealed tube and stirred at rt for 20 h. Complete conversion was observed. The reaction mixture was concentrated to give 3.87 g (99%) of crude title product.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 4.04-3.90 (m, 4H), 2.67-2.58 (m, 2H), 2.25 (s, 3H), 2.18-1.95 (brs, 1H), 1.93-1.82 (m, 2H), 1.22 (t, 6H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 60.9, 60.8, 45.03, 45.01, 35.6, 26.1, 24.7, 16.32, 16.26; GC-TOF (EI) (m/z): [M] ⁺ , calculated for C ₇ H ₁₈ NO ₃ P: 195.1024, found: 195.1009.

Stage B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[4-[tert-butyl(diphenyl)silyl]oxy -5-[2-diethoxyphosphorylethy l(methyl)amino]pentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino] thiazole-4-carboxylate

Using the General Tosylate Alkylation Procedure, starting with the product of Preparation 5a and the product from Step A as the appropriate amine, the desired product was obtained.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₆₉ H ₉₅ FN ₈ O ₁₀ PS ₂ Si ₂ : 1365.5867, found: 1365.5916.

Step C: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-[methyl(2-phosphonoethyl)amino]pentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure for Deprotection and Hydrolysis of Phosphonic Acid Derivatives, the target product was obtained starting from the product in Step B.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₇ H ₄₅ FN ₈ O ₇ PS ₂ : 827.2569, found: 827.2561.

Example 197: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-({4-fluoro-6-[3-(methylamino)prop-1-yn-1-yl]pyridin-3-yl}oxy)propyl]-1,3-thiazole-4-carboxylic acid

Step A: 2-chloro-4-fluoro-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine

To a solution of 2-chloro-4-fluoropyridine (2.5 g; 19.01 mmol) in tetrahydrofuran (30 mL) were added successively bis(pinacolato)diboron (2.41 g; 9.50 mmol; 0.5 equiv), 4,4'-di-tert-butyl-2,2'-dipyridyl (51.0 mg; 0.190 mmol; 0.01 equiv), and (1,5-cyclooctadiene)(methoxy)iridium(1) dimer (63.0 mg; 0.095 mmol; 0.005 equiv). The reaction mixture was flushed with argon and stirred at 80 °C for 16 h, and then concentrated to dryness. The resulting residue was purified by silica gel column chromatography using cyclohexane/ethyl acetate as eluent to give the title compound (3.64 g; 74%).

¹ H NMR (DMSO-d ₆ ) δ ppm 1.33 (s, 12H), 7.58 (d, 1H, J=8.8 Hz), 8.55 (d, 1H, J=9.2 Hz).

Stage B: 6-chloro-4-fluoropyridin-3-ol

To a solution of the product from Step A (2.00 g, 7.77 mmol) in tetrahydrofuran (16 mL) at 0 °C were added sodium hydroxide (311 mg, 7.77 mmol, 1.0 equiv) and 33% aqueous hydrogen peroxide solution (2.38 mL, 23.3 mmol, 3.0 equiv). The reaction mixture was stirred at 0 °C for 3 h and at rt for 16 h. The reaction mixture was diluted with water (50 mL) and acidified with 1 N aqueous hydrochloric acid to pH = 1. The aqueous layer was extracted with dichloromethane (3×100 mL) and the combined organic layers were dried over sodium sulfate, filtered and concentrated to dryness. The resulting residue was purified by silica gel column chromatography using cyclohexane/ethyl acetate as eluent to give the title compound (640 mg; 56%).

¹ H NMR (DMSO-d ₆ ) δ ppm 7.53 (d, 1H, J=10.4 Hz), 8.06 (d, 1H, J=10.8 Hz), 10.76 (s, 1H).

Step C: tert-butyl N-[3-(4-fluoro-5-hydroxy-2-pyridyl)prop-2-ynyl]-N-methylcarbamate

To a solution of the product from Step B (300 mg, 2.03 mmol) in acetonitrile (12 mL) were added sequentially tert-butyl N-methyl-N-prop-2-ynylcarbamate (688 mg, 4.07 mmol, 2.0 equiv), cesium carbonate (1.66 g, 5.08 mmol, 2.5 equiv), Xphos (145.4 mg, 0.305 mmol, 0.15 equiv), and bis(acetonitrile)palladium(II) chloride (29.43 mg, 0.102 mmol, 0.05 equiv). The reaction mixture was flushed with argon and stirred for 16 h at 70 °C. The reaction mixture was diluted with water (50 mL) and acidified with 1 N HCl. aqueous hydrochloric acid solution to pH=1. The aqueous layer was extracted with dichloromethane (3×100 ml) and the combined organic layers were dried over sodium sulfate, filtered and concentrated to dryness. The resulting residue was purified by column chromatography on silica gel using cyclohexane/ethyl acetate as eluent to give the title compound (257 mg; 45%).

^1H NMR (DMSO): 1.41 (s, 9H), 2.86 (s, 3H), 4.25 (s, 2H), 7.45 (d, 1H, J=11.6 Hz), 8.20 (d, 1H, J=11.2 Hz ), 10.87 (s, 1H); ¹³ C NMR (DMSO): 28.01, 33.45, 37.80, 79.41, 82.10, 82.13, 83.56, 115.42, 115.53, 115.58, 133.79, 133.87, 140.96, 141.00, 142.56, 142.65, 154.13, 154.47, 156.69; LC/MS [M -tBu] ⁺ : 225.02.

Step D: Ethyl 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[[6-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-4-fluoro-3-pyridyl]oxy]propyl]thiazole-4-carboxylate

Using the General Alkylation Procedure, starting from the product of Preparation 5g and the product from Step C as the appropriate phenol, the title compound was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 8.46 (d, 1H), 7.91 (br., 1H), 7.67 (s, 1H), 7.55 (d, 1H), 7.53 (br., 1H), 7.38 (t, 1H), 7.21 (t, 1H), 4.28 (t, 2H), 4.25 (q, 2H), 4.24 (br., 2H), 3.76 (s, 3H), 3.27 (t, 2H), 2.85 (br., 3H), 2.46 (s, 3H), 2.14 (m, 2H), 1.41 (s, 9H), 1.29 (t, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 138.8, 126.6, 122.6, 122.3, 118.4, 115.7, 69.3, 60.7, 38.4, 35.3, 33.9, 31.0, 28.4, 23.1, 17.8, 14.6; MSHR-ERI (m/z): [M+H] ⁺ , calculated for C36H40FN8O5S2: 747.2541, found: 747.2526.

Step E: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-({4-fluoro-6-[3-(methylamino)prop-1-yn-1-yl]pyridin-3-yl}oxy)propyl]-1,3-thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step D as the appropriate ethyl ester, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 8.44 (d, 1H), 7.91 (d, 1H), 7.67 (s, 1H), 7.53 (d, 1H), 7.48 (d, 1H), 7.39 (tm, 1H), 7.21 (tm, 1H), 4.27 (t, 2H), 3.76 (s, 3H), 3.48 (s, 2H), 3.27 (t, 2H), 2.46 (s, 3H), 2.31 (s, 3H), 2.14 (quin, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 164.1, 156.8, 156.7, 151.9, 151.9, 145.5, 143.8, 140.2, 138.8, 137.0, 136.0, 133.1, 130.3, 126.6, 122.6, 122.4, 118.4, 116.8, 115.4, 88.2, 82.4, 69.4, 40.0, 35.3, 35.3, 30.9, 23.1, 17.7; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₉ H ₂₈ FN ₈ O ₃ S ₂ : 619.1704, found: 619.1698.

Example 198: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-(3-morpholinoprop-1-ynyl)phenoxy]propyl]thiazole-4-carboxylic acid

Step A: ethyl 5-[3-[2-fluoro-4-(3-morpholinoprop-1-ynyl)phenoxy]propyl]-2-[methyl-[5-methyl-6-[(Z)-[3- (2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Alkylation Procedure, starting from Preparation 5g and Preparation 6e as the appropriate phenol, the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.84 (brd, 1H), 7.64 (d, 1H), 7.45 (dm, 1H), 7.42 (tm, 1H), 7.32 (dd, 1H), 7.25 (tm, 1H), 7.21 (dm, 1H), 7.15 (t, 1H), 5.85 (s, 2H), 4.25 (q, 2H), 4.15 (t, 2H), 3.77 (s, 3H), 3.71 (t, 2H), 3.58 (t, 4H), 3.44 (s, 2H), 3.26 (t, 2H), 2.48 (br, 4H), 2.44 (s, 3H), 2.12 (quin, 2H), 1.29 (t, 3H), 0.82 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm. 162.6, 157.4, 156.7, 155.1, 151.7, 151.6, 147.3, 141.0, 137.6, 137.0, 135.2, 129.0, 127.2, 125.6, 123.5, 123.2, 119.2, 117.6, 115.4, 115.2, 111.9, 85.0, 84.3, 72.8, 68.4, 66.7, 66.5, 60.6, 52.2, 47.4, 35.3, 31.1, 23.3, 17.8, 17.8, 14.6, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₅₁ FN ₇ O ₅ S ₂ Si: 832.3141, found: 832.3146.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-(3-morpholinoprop-1-ynyl)phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate ethyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₃ FN ₇ O ₄ S ₂ : 674.2014, found: 674.2006.

Example 199: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[6-(dimethylamino)hexyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: methyl 2-[tert-butoxycarbonyl-[6-(dimethylamino)hexyl]amino]-5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2 -fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from the product of Preparation 1b and 6-(dimethylamino)hexan-1-ol, 1.51 g (containing approx. 40 mol/mol % DIAD-2H) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.30 (dd, 1H), 7.21 (dm, 1H), 7.13 (t, 1H), 4.23 (s, 2H), 4.10 (t, 2H), 3.98 (t, 2H), 3.75 (s, 3H), 3.22 (t, 2H), 2.86 (s, 3H), 2.13 (t, 2H), 2.07 (s, 6H), 1.70-1.20 (m, 8H), 1.61 (m, 2H), 1.50/1.41 (s, 18H); HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₆ H ₅₄ FN ₄ O ₇ S: 705.3697, found: 705.3699.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[6-(dimethylamino)hexylamino]thiazol- 4-carboxylate

Using the General HFIP deprotection method, 650 mg (50%) of the desired product was obtained from the product from Step A.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.56 (t, 1H), 7.31 (d, 1H), 7.21 (d, 1H), 7.13 (t, 1H), 4.23 (br., 2H), 4.07 (t, 2H), 3.69 (s, 3H), 3.14 (m, 2H), 3.11 (t, 2H), 2.86 (br., 3H), 2.17 (m, 2H), 2.10 (s, 6H), 2.00 (quint., 2H), 1.50 (m, 2H), 1.41 (s, 9H), 1.37 (m, 2H), 1.34-1.21 (m, 2H), 1.34-1.21 (m, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 119.3, 115.4, 68.0, 60.6, 51.7, 45.6, 44.5, 38.6, 33.9, 30.6, 29.1, 28.5, 27.4, 27.0, 26.8, 23.3 ; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₁ H ₄₆ FN ₄ O ₅ S: 605.3173, found: 605.3160.

Stage C: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[6-(dimethylamino)hexyl-[5-methyl l-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product from Step B and the product from Synthesis 4a, 1.06 g (98%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.66 (s, 1H), 7.47 (d, 1H), 7.44 (td, 1H), 7.32 (d, 1H), 7.25 (td, 1H), 7.22 (d, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.37 (t, 2H), 4.20 (m, 2H), 4.15 (t, 2H), 3.77 (s, 3H), 3.72 (t, 2H), 3.26 ( t, 2H), 2.84 (s, 3H), 2.46 (s, 3H), 2.13 (m, 2H), 2.13 (m, 2H), 2.06 (s, 6H), 1.62-1.32 (m, 8H), 1.40 (s, 9H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 163.2, 129.1, 127.2, 123.4, 123.2, 119.2, 117.6, 115.5, 112.0, 79.5, 72.8, 68.4, 66.7, 59.5, 51.9, 46.8, 45.6, 38.6, 33.8, 31.0, 28.5, 23.1, 17.8, 17.7, -0.96; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₉ H ₆₈ FN ₈ O ₆ S ₂ Si: 975.4457, found: 975.4437.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[6-(dimethylamino)hexyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₇ H ₄₄ FN ₈ O ₃ S ₂ : 731.2962, found: 731.2968.

Example 200: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[3-(dimethylamino)propyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: methyl 2-[tert-butoxycarbonyl-[3-(dimethylamino)propyl]amino]-5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2 -fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from the product of Preparation 1b and 3-(dimethylamino)propan-1-ol, 1.40 g (quant., sample contained approx. 35 mol/mol % DIAD-2H) of the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.30 (dd, 1H), 7.21 (dm, 1H), 7.13 (t, 1H), 4.23 (s, 2H), 4.10 (t, 2H), 4.01 (t, 2H), 3.74 (s, 3H), 3.22 (t, 2H), 2.86 (s, 3H), 2.24 (t, 2H), 2.12 (s, 6H), 2.08 (m, 2H), 1.74 (m, 2H), 1.51/1.41 (s, 18H); HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₄₈ FN ₄ O ₇ S: 663.3228, found: 663.3218.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[3-(dimethylamino)propylamino]thiazol- 4-carboxylate

Using the General HFIP deprotection method, 0.95 g (80%) of the desired product was obtained from the product from Step A.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.57 (t, 1H), 7.31 (d, 1H), 7.21 (d, 1H), 7.13 (t, 1H), 4.23 (br., 2H), 4.07 (t, 2H), 3.69 (s, 3H), 3.17 (q, 2H), 3.12 (t, 2H), 2.86 (br., 3H), 2.24 (t, 2H), 2.11 (s, 6H), 2.00 (quint., 2H), 1.63 (m, 2H), 1.41 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 119.3, 115.4, 68, 57.0, 51.7, 45.6, 42.8, 38.6, 33.8, 30.6, 28.5, 27.0, 23.3; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₈ H ₄₀ FN ₄ O ₅ S: 563.2703, found: 563.2694.

Stage C: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[3-(dimethylamino)propyl-[5-methyl l-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product from Step B and the product from Synthesis 4a, 0.79 g (51%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.73 (s, 1H), 7.46 (dd, 1H), 7.43 (td, 1H), 7.31 (brd., 1H), 7.25 (td, 1H), 7.21 (d, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.35 (t, 2H), 4.20 (br., 2H), 4.15 (t, 2H), 3.76 (s, 3H), 3.72 (t, 2H), 3.27 (t, 2H), 2.84 (br., 3H), 2.45 (s, 3H), 2.32 (t, 2H), 2.18 (s, 6H), 2.13 (m, 2H), 1.86 (m, 2H), 1.40 (s, 9H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1 , 127.2, 123.4, 123.2, 119.3, 117.6, 115.4, 111.9, 72.8, 68.4, 66.7, 56.4, 51.9, 45.7, 45.5, 38.5, 33.8, 31.0, 28.5, 25.0, 23.1, 17.9, 17.8, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₆ H ₆₂ FN ₈ O ₆ S ₂ Si: 933.3987, found: 933.3990.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[3-(dimethylamino)propyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₃₄ H ₃₉ FN ₈ O ₃ S ₂ : 345.1280, found: 345.1265.

Example 201: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[2-(trimethylammonio)ethyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Using the General Alkylation, Deprotection, and Hydrolysis Procedure starting from the compound of Example 207, Step C, and iodomethane, the TFA salt of the desired product was obtained.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C34H39FN8O3S2: 345.1280, found: 345.1279.

Example 202: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[3-(trimethylammonio)propyl]amino]-5-[3-[2-fluoro -4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Using the General Alkylation, Deprotection, and Hydrolysis Procedure starting from the compound of Example 200, Step C, and iodomethane, the TFA salt of the desired product was obtained.

HR-ERI (m/z): [M+2H] ²⁺ , calculated for C ₃₅ H ₄₁ FN ₈ O ₃ S ₂ : 352.1358, found: 352.1365.

Example 203: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-(3-pyrrolidin-1-ylprop-1-ynyl)phenoxy]propyl]thiazole-4-carboxylic acid

Stage A: ethyl 5-[3-[2-fluoro-4-(3-pyrrolidin-1-ylprop-1-ynyl)phenoxy]propyl]-2-[methyl-[5-methyl-6-[(Z)-[3- (2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Alkylation Procedure, starting from Preparation 5g and Preparation 6 with the appropriate phenol, the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.83 (dm, 1H), 7.66 (q, 1H), 7.46 (dm, 1H), 7.43 (m, 1H), 7.31 (dd, 1H), 7.25 (m, 1H), 7.21 (dm, 1H), 7.15 (t, 1H), 5.85 (s, 2H), 4.25 (q, 2H), 4.14 (t, 2H), 3.77 (s, 3H), 3.72 (m, 2H), 3.64 (s, 2H), 3.26 (t, 2H), 2.64 (brm, 4H), 2.45 ( d, 3H), 2.12 (m, 2H), 1.72 (m, 4H), 1.29 (t, 3H), 0.92 (m, 2H), -0.11 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₅₁ FN ₇ O ₄ S ₂ Si: 816.3192, found: 816.3189.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-(3-pyrrolidin-1-ylprop-1-ynyl)phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate ethyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₃ FN ₇ O ₃ S ₂ : 658.2065, found: 658.2060.

Example 204: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-[3-(1-piperidyl)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: Ethyl 5-[3-[2-fluoro-4-[3-(1-piperidyl)prop-1-ynyl]phenoxy]propyl]-2-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazole-4-carboxylate

Using the General Alkylation Procedure, starting from Preparation 5g and Preparation 6d as the appropriate phenol, the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.83 (dm, 1H), 7.64 (q, 1H), 7.45 (dm, 1H), 7.43 (m, 1H), 7.30 (dd, 1H), 7.25 (m, 1H), 7.19 (dm, 1H), 7.14 (t, 1H), 5.85 (s, 2H), 4.25 (q, 2H), 4.14 (t, 2H), 3.76 (s, 3H), 3.71 (m, 2H), 3.39 (s, 2H), 3.25 (t, 2H), 2.44 (d, 3H), 2.42 ( brm, 4H), 2.12 (m, 2H), 1.50 (m, 4H), 1.35(m, 2H), 1.29 (t, 3H), 0.92 (m, 2H), -0.12 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₂ H ₅₃ FN ₇ O ₄ S ₂ Si: 830.3348, found: 830.3347.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-[3-(1-piperidyl)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate ethyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₅ FN ₇ O ₃ S ₂ : 672.2221, found: 672.2217.

Example 205: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-(dimethylamino)but-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Step A: Ethyl 5-[3-[4-[3-(dimethylamino)but-1-ynyl]-2-fluorophenoxy]propyl]-2-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazole-4-carboxylate

Using the General Alkylation Procedure, starting from Preparation 5g and Preparation 6f as the appropriate phenol, the desired product was obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-(dimethylamino)but-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate ethyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₂ H ₃₃ FN ₇ O ₃ S ₂ : 646.2065, found: 646.2057.

Example 206: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-((3R or 3S)-morpholinobut-1-ynyl)phenoxy]propyl]thiazole-4-carboxylic acid (enantiomer 2)

Step A: Ethyl 5-[3-[2-fluoro-4-((3R or 3S)-morpholinobut-1-ynyl)phenoxy]propyl]-2-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazole-4-carboxylate (enantiomer 2)

Using the General Alkylation Procedure, starting from Preparation 5g and Preparation 6h as the appropriate phenol, the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.66 (s, 1H), 7.46 (d, 1H), 7.43 (td, 1H), 7.29 (dd, 1H), 7.25 (td, 1H), 7.20 (dd, 1H), 7.15 (t, 1H), 5.86 (s, 2H), 4.26 (q, 2H), 4.14 (t, 2H), 3.77 (s, 3H), 3.72 (t, 2H), 3.66 (q, 1H), 3.59 (br., 4H), 3.27 (t, 2H), 2.57 /2.43 (m+m, 4H), 2.45 (s, 3H), 2.13 (quint, 2H), 1.30 (t, 3H), 1.28 (d, 3H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 129.0, 127.2, 123.4, 123.2, 119.2, 117.6, 115.5, 111.9, 88.1, 84.2, 72.8, 68.4, 66.7, 66.7, 60.7, 52.1, 49.5, 35.3, 31.1, 23.2, 19.3, 17.8, 17.8, 14.6, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₂ H ₅₃ FN ₇ O ₅ S ₂ Si: 846.3297, found: 846.3283.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-((3R or 3S)-morpholinobut-1-ynyl)phenoxy]propyl]thiazole-4-carboxylic acid (enantiomer 2)

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate ethyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₅ FN ₇ O ₄ S ₂ : 688.2176, found: 688.2171.

Example 207: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[2-(dimethylamino)ethyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[2-(dimethylamino)ethyl]amino]-5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from the product of Synthesis 1b and 2-(dimethylamino)ethanol, 0.90 g (70%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.30 (brd, 1H), 7.21 (dm, 1H), 7.13 (t, 1H), 4.22 (brs, 2H), 4.10 (t, 2H), 4.07 (t, 2H), 3.75 (s, 3H), 3.22 (t, 2H), 2.86 (brs, 3H), 2.46 (t, 2H), 2.17 (s, 6H), 2.08 (m, 2H), 1.50/1.41 (s, 18H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 129.1, 119.3, 115.4, 85.2, 82.4, 68.1, 57, 52.0, 46.0, 44.3, 38.6, 33.8, 30.5, 23.2; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₂ H ₄₆ FN ₄ O ₇ S: 649.3071, found: 649.3059.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[2-(dimethylamino)ethylamino]thiazol- 4-carboxylate

Using the General HFIP deprotection method, 0.68 g (89%) of the desired product was obtained from the product from Step A.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.50 (t, 1H), 7.31 (d, 1H), 7.21 (d, 1H), 7.13 (t, 1H), 4.23 (br., 2H), 4.07 (t, 2H), 3.69 (s, 3H), 3.26 (q, 2H), 3.11 (t, 2H), 2.86 (br., 3H), 2.37 (t, 2H), 2.15 (s, 6H), 2.00 (quint, 2H), 1.41 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 119.3, 115.4, 68.0, 58.2, 51.7, 45.7, 42.4, 38.6, 33.8, 30.6, 28.5, 23.3; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₇ H ₃₈ FN ₄ O ₅ S: 549.2547, found: 549.2543.

Stage C: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[2-(dimethylamino)ethyl-[5-methyl -6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product from Step B and the product from Synthesis 4a, 0.57 g (50%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.66 (s, 1H), 7.47 (dd, 1H), 7.44 (td, 1H), 7.31 (brd., 1H), 7.25 (t, 1H), 7.22 (d, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.46 (t, 2H), 4.20 (br., 2H), 4.15 (t, 2H), 3.77 (s, 3H), 3.72 (t, 2H), 3.26 (t, 2H), 2.84 (br., 3H), 2.56 (t, 2H), 2.45 (s, 3H), 2.23 (s, 6H), 2.12 (m, 2H), 1.40 (s, 9H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 163.1, 129.1, 127.2, 123.5, 123.2, 119.3, 117.8, 115.4, 112.0, 72.9, 68.4, 66.7, 56.6, 51.9, 46.1, 45.3, 38.6, 33.8, 31.0, 28.5, 23.1, 17.9, 17.8, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₅ H ₆₀ FN ₈ O ₆ S ₂ Si: 919.3831, found: 919.3829.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[2-(dimethylamino)ethyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₆ FN ₈ O ₃ S ₂ : 675.2336, found: 675.2323.

Example 208: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-((3S or 3R)-morpholinobut-1-ynyl)phenoxy]propyl]thiazole-4-carboxylic acid (enantiomer 1)

Step A: Ethyl 5-[3-[2-fluoro-4-((3S or 3R-morpholinobut-1-ynyl)phenoxy]propyl]-2-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazole-4-carboxylate (enantiomer 1)

Using the General Alkylation Procedure, starting from Preparation 5g and Preparation 6g as the appropriate phenol, the desired product was obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.66 (s, 1H), 7.46 (d, 1H), 7.43 (td, 1H), 7.29 (dd, 1H), 7.25 (td, 1H), 7.20 (dd, 1H), 7.15 (t, 1H), 5.86 (s, 2H), 4.26 (q, 2H), 4.14 (t, 2H), 3.77 (s, 3H), 3.72 (t, 2H), 3.66 (q, 1H), 3.59 (br., 4H), 3.27 (t, 2H), 2.57 /2.43 (m+m, 4H), 2.45 (s, 3H), 2.13 (quint, 2H), 1.30 (t, 3H), 1.28 (d, 3H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 129.0, 127.2, 123.4, 123.2, 119.2, 117.6, 115.5, 111.9, 88.1, 84.2, 72.8, 68.4, 66.7, 66.7, 60.7, 52.1, 49.5, 35.3, 31.1, 23.2, 19.3, 17.8, 17.8, 14.6, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₂ H ₅₃ FN ₇ O ₅ S ₂ Si: 846.3297, found: 846.3288.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-((3S or 3R-morpholinobut-1-ynyl)phenoxy]propyl]thiazole-4-carboxylic acid (enantiomer 1)

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step A as the appropriate ethyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₅ FN ₇ O ₄ S ₂ : 688.2170, found: 688.2166.

Example 209: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-(trifluoromethyl)pyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: Methyl 2-[[6-chloro-5-(trifluoromethyl)pyridazin-3-yl]methylamino]-5-[3-(2-fluoro-4-iodophenoxy)propyl]thiazole-4-carboxylate

A 50 mL oven-dried single-neck round-bottomed flask was fitted with a PTFE-lined magnetic stir bar and fitted with a reflux condenser. The flask was charged with 991 mg of Preparation 3s (2.20 mmol, 1.1 equiv) dissolved in 10 mL of dry THF, then the mixture was cooled to 0 °C and 96 mg of NaH (2.40 mmol, 1.2 equiv, 60% in mineral oil) was added portionwise over a period of 5 min. After stirring for 15 min at 0 °C, 434 mg of 3,6-dichloro-4-(trifluoromethyl)pyridazine (2 mmol, 1 equiv) was added in one portion and stirred at that temperature for 1 h, during which time the reaction reached complete conversion. The reaction mixture was quenched by addition of conc. _NH4Cl solution and extracted with EtOAc. The combined organic layers were dried over _Na2SO4 , filtered and concentrated under reduced pressure. The crude product was dissolved in DCM, then celite was added and the volatiles were removed under reduced pressure. The crude product was purified by flash column chromatography using heptane and EtOAc as eluents to give 500 mg ( ₃₉ %) of the desired product as a yellow solid.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 8.16 (s, 1H), 7.58 (dd, 1H), 7.45 (m, 1H), 6.98 (t, 1H), 4.09 (t, 2H), 3.87 (s, 3H), 3.80 (s, 3H), 3.28 (t, 2H), 2.11 (quin, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 162.7, 156.2, 155.3, 152.2, 147.0, 144.2, 143.2, 135.1, 134, 128.5, 124.9, 121.4, 117.9, 117.6, 82.4, 68.2, 52.1, 35.9, 30.6, 23.5; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₀ H ₁₇ ClF ₄ IN ₄ O ₃ S: 630.9685, found: 630.9679.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[6-chloro-5-(trifluoromethyl )pyridazin-3-yl]-methylamino]thiazol-4-carboxylate

A 12 mL oven-dried vessel equipped with a PTFE-lined magnetic stir bar was charged with 330 mg of the product from Step A (0.52 mmol, 1 equiv), 177 mg of tert-butyl N-methyl-N-prop-2-ynylcarbamate (1.04 mmol, 2 equiv), 2.5 mL of dry THF, and 0.5 mL of DIPA and then evacuated via the gas inlet. After addition _of 11.5 mg Pd( _PPh3 ) _2Cl2 (0.026 mmol, 0.05 equiv) and 4.98 mg CuI (0.026 mmol, 0.05 equiv), the reaction mixture was heated to 60 °C and stirred at this temperature for 1 h, during which the reaction reached complete conversion. Celite was added to the reaction mixture and the volatiles were removed under reduced pressure. Then, the crude product was purified by flash column chromatography using heptane and EtOAc to give 271 mg (69%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 8.15 (s, 1H), 7.31 (brd, 1H), 7.21 (dm, 1H), 7.14 (t, 1H), 4.23 (brs, 2H), 4.12 (t, 2H), 3.87 (s, 3H), 3.79 (s, 3H), 3.28 (t, 2H), 2.86 (brs, 3H), 2.12 (m, 2H), 1.41 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 144.2, 129.1, 121.6, 119.3, 117.8, 115.4, 85.2, 82.3, 68.2, 52.1, 38.6, 38.6, 35.8, 30.6, 28.5, 23.1; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₉ H ₃₁ ClF ₄ N ₅ O ₅ S: 672.1665, found: 672.1651.

Step C: methyl 2-[[6-(1,3-benzothiazol-2-ylamino)-5-(trifluoromethyl)pyridazin-3-yl]-methylamino]-5-[3-[4-[3-[tert -butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

A 4 mL oven-dried flask equipped with a PTFE-lined magnetic stir bar was charged with 130 mg of the product from Step B (0.19 mmol, 1 equiv), 87 mg of 1,3-benzothiazol-2-amine (0.58 mmol, 3 equiv), and 168 µL of DIPEA (125 mg, 0.96 mmol, 5 equiv) suspended in 1 mL of CyOH and then purged with argon. After 2 min of stirring under inert atmosphere, 18 mg of _Pd2 (dba) ₃ (0.019 mmol, 0.1 equiv) and 23 mg of XantPhos (0.038 mmol, 0.2 equiv) were added. The resulting mixture was then heated to 140 °C and stirred at that temperature for 4 h, during which time the reaction reached complete conversion. The reaction mixture was diluted with 1 mL DCM and purified by flash column chromatography using heptane and EtOAc as eluents to yield 85 mg (56%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 9.19 (br., 1H), 7.95 (s, 1H), 7.82 (d, 1H), 7.39 (t, 1H), 7.32 (d, 1H), 7.32 (d, 1H), 7.22 (d, 1H), 7.21 (t, 1H), 7.16 (t, 1H), 4.20 (br., 3H), 4.14 (t, 2H), 3.84 (s, 3H), 3.29 (t, 2H), 2.84 (br., 2H), 2.13 (quint., 2H), 1.40 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 163.0, 160.0, 156.8, 151.7, 151.1, 141.7, 137.0, 135.1, 129.1, 127.3, 126.6, 123.2, 122.9, 122.7, 119.1, 116.4, 115.5, 112.1, 68.3, 38.5, 35.6, 33.8, 30.9, 28.5, 23.1; HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₆ H ₃₆ F ₄ N ₇ O ₅ S ₂ : 786.2150, found: 786.2148.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-(trifluoromethyl)pyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, starting from the product from Step C as the appropriate methyl ester, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₀ H ₂₆ F ₄ N ₇ O ₃ S ₂ : 672.1469, found: 672.1458.

Example 210: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-(dimethylamino)butyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl-[4-(dimethylamino)butyl]amino]-5-[3-(2-fluoro-4-iodophenoxy)propyl]thiazole-4-carboxylate

Using the General Procedure for the Mitsunobu Reaction, starting from the product of Synthesis 1a and 4-(dimethylamino)butan-1-ol, 401 mg (quant.) of the target product were obtained.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.60 (dd, 1H), 7.47 (dm, 1H), 6.99 (t, 1H), 4.08 (t, 2H), 4.03 (t, 2H), 3.76 (s, 3H), 3.23 (t, 2H), 3.13 (t, 2H), 2.74 (s, 6H), 2.07 (m, 2H), 1.66 (m, 2H), 1.65 (m, 2H), 1.53 (s, 9H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm. 162.8, 152.7, 147.0, 143.6, 135.5, 134.1, 125.0, 117.7, 84.0, 82.4, 68.2, 56.8, 52.1, 46.0, 42.6, 30.5, 28.2, 25.2, 23.2, 21.7; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₅ H ₃₆ FIN ₃ O ₅ S: 636.1399, found: 636.1400.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[4-(dimethylamino)butylamino]thiazol- 4-carboxylate

Using the General HFIP deprotection method, starting from the product from Step A and performing concentration, crude methyl 2-[4-(dimethylamino)butylamino]-5-[3-(2-fluoro-4-iodophenoxy)propyl]thiazole-4-carboxylate was obtained (LC-ESI-MS (m/z): [M+H] ⁺ , calculated _{for C20H28FIN3O3S : 536.1} , found: 536.2), which was then reacted using the General Sonogashira reaction with tert-butyl N-methyl-N-prop-2-ynylcarbamate as the alkyne reagent to afford 240 mg (67%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.59 (t, 1H), 7.31 (d, 1H), 7.21 (d, 1H), 7.13 (t, 1H), 4.23 (br., 2H), 4.07 (t, 2H), 3.69 (s, 3H), 3.15 (q, 2H), 3.11 (t, 2H), 2.86 (br., 3H), 2.18 (t, 2H), 2.09 (s, 6H), 2.00 (quint., 2H), 1.50 (m, 2H), 1.43 (m, 2H), 1.41 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 119.3, 115.4, 68.0, 59.2, 51.7, 45.6, 44.5, 38.6, 33.9, 30.6, 28.5, 27.0, 24.9, 23.3; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₉ H ₄₂ FN ₄ O ₅ S: 577.2854, found: 577.2854.

Stage C: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[4-(dimethylamino)butyl-[5-methyl l-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting with 235 mg of the product from Step B (0.41 mmol, 1 equiv) and 249 mg of the product from Preparation 4a (0.61 mmol, 1.5 equiv) as the appropriate halide, 353 mg (90%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.73 (s, 1H), 7.47 (dm, 1H), 7.44 (t, 1H), 7.33 (brd, 1H), 7.26 (t, 1H), 7.22 (dm, 1H), 7.17 (t, 1H), 5.86 (s, 2H), 4.39 (br, 2H), 4.21 (br, 2H), 4.14 (t, 2H), 3.80 (s, 3H), 3.72 (t, 2H), 3.28 (t, 2H), 3.13 (br, 2H), 2.85 (brs, 3H), 2.70 (s, 6H), 2.47 (s, 3H), 2.14 (quin, 2H), 1.75 (brm, 4H), 1.42 (s, 9H), 0.92 (t, 2H), -0.10 (s, 9H); ¹ 3C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 163.1, 157.6, 155.3, 151.5, 147.6, 147.4, 141.5, 137.6, 137.5, 135.0, 129.1, 127.2, 123.5, 123.2, 119.4, 117.5, 115.5, 114.8, 112.0, 85.3, 82.3, 72.9, 68.5, 66.9, 56.5, 52.1, 46.2, 42.7, 38.4, 34.0, 31.1, 28.4, 24.5/21.5, 23.2, 17.9, 17.8, -1.1; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₇ H ₆₄ FN ₈ O ₆ S ₂ Si: 947.4138, found: 947.4144.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-(dimethylamino)butyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₅ H ₄₀ FN ₈ O ₃ S ₂ : 703.2649, found: 703.2637.

Example 211: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(trimethylammonio)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Stage A: [2-[tert-butyl(diphenyl)silyl]oxy-5-[[5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol- 2nd l]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]pentyl]-trimethylammonium

Using the General Procedure for Quaternary Salt Formation, starting from the product of Preparation 5b and N,N-dimethylmethanamine as the appropriate tertiary amine, the desired product was obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(trimethylammonio)pentyl]amino]-5-[3- [4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure for Deprotection of a Quaternary Salt, starting from the product from Step A as a quaternary salt, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₈ H ₄₆ FN ₈ O ₄ S ₂ : 761.3062, found: 761.3057.

Example 212: 3-[5-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-carboxy-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazol-2-yl]amino]pentyldimethylammonio]propane-1-sulfonate

Using the General Alkylation, Deprotection, and Hydrolysis Procedure starting from the compound of Example 213, Step C, and oxathiolane 2,2-dioxide, the TFA salt of the desired product was obtained.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₁ H ₇₂ FN ₈ O ₉ S ₃ Si: 839.2843, found: 839.2823.

Example 213: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-(dimethylamino)pentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: methyl 2-[tert-butoxycarbonyl-[5-(dimethylamino)pentyl]amino]-5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2 -fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from the product of Preparation 1b and 5-(dimethylamino)pentan-1-ol, 1.47 g (quant.) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.30 (d, 1H), 7.21 (d, 1H), 7.13 (t, 1H), 4.22 (m, 2H), 4.10 (t, 2H), 3.99 (t, 2H), 3.75 (s, 3H), 3.22 (m, 2H), 2.86 (bs, 3H), 2.35 (bs, 2H), 2.24 (bs, 6H), 2.08 (m, 2H), 1.62-1.13 (m, 6H), 1.51 (s, 9H), 1.42 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 119.2, 115.4, 85.2, 79.8, 68.1, 58.8, 52.0, 46.4, 45.0, 38.3, 33.8, 30.5, 28.5, 28.1, 23.2; HR-MSE (m/z): [M+H] ⁺ , calculated for C ₃₅ H ₅₂ FN ₄ O ₇ S: 691.3541, found: 691.3524.

Step B: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-(dimethylamino)pentylamino]thiazol- 4-carboxylate

Using the General HFIP deprotection method, 0.66 g (52%) of the desired product was obtained from the product from Step A.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.58 (t, 1H), 7.32 (brd., 1H), 7.21 (d, 1H), 7.13 (t, 1H), 4.23 (br., 2H), 4.07 (t, 2H), 3.69 (s, 3H) , 3.15 (m, 2H), 3.11 (t, 2H), 2.87 (br., 3H), 2.35 (br., 2H), 2.24 (brs., 6H), 2.00 (quint, 2H), 1.51 (m, 2H), 1.44 (m, 2H), 1.41 (s, 9H) , 1.30 (m, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ δ ppm 129.1, 119.3, 115.4, 68.0, 58.9, 51.7, 45.0, 44.4, 38.6, 33.8, 30.6, 28.9, 28.5, 26.4, 24.5, 23.3; HR-MS ERI (m/z): [M+H] ⁺ , calculated for C ₃₀ H ₄₄ FN ₄ O ₅ S: 591.3016, found: 591.3005.

Stage C: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-(dimethylamino)pentyl-[5-methyl l-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product from Step B and the product from Synthesis 4a, 0.43 g (40%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.69 (s, 1H), 7.47 (d, 1H), 7.44 (td, 1H), 7.32 (brd., 1H), 7.25 (td, 1H), 7.22 (d, 1H), 7.15 (t, 1H), 5.86 (s, 2H), 4.38 (t, 2H), 4.20 (br., 2H), 4.15 (t, 2H), 3.78 (s, 3H), 3.72 (t, 2H), 3.26 (t, 2H), 2.84 (br., 3H), 2.57 (br., 2H), 2.46 (s, 3H), 2.39 (br., 6H), 2.12 (m, 2H), 1.71 (m, 2H), 1.58 (m, 2H), 1.40 (s, 9H), 1.37 (m, 2H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 127.2, 123.5, 123.2, 119.3, 117.6, 115.5, 112, 72.9, 68.4, 66.7, 58.2, 52.0, 46.7, 44.2, 38.4, 33.8, 31.0, 28.5, 26.8, 25.4, 23.8, 23.2, 17.9, 17.8, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₈ H ₆₆ FN ₈ O ₆ S ₂ Si: 961.4300, found: 461.4293.

Step D: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-(dimethylamino)pentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₆ H ₄₂ FN ₈ O ₃ S ₂ : 717.2805, found: 717.2779.

Example 214: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-(dimethylamino)propyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Step A: ethyl 5-[3-[4-[3-(dimethylamino)propyl]-2-fluorophenoxy]propyl]-2-[methyl-[5-methyl-6-[(E)-[3-(2 -trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

A mixture of 59 mg of Example 50, Step A (0.075 mmol, 1 equiv.) and 6 mg of 10% palladium on charcoal (0.076 equiv.) in 5 mL of ethanol was heated under 4 bar hydrogen pressure at rt for 18 h. After filtration through celite, the product was concentrated to give 59 mg (99%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 9.30 (brs, 1H), 7.84 (dm, 1H), 7.68 (q, 1H), 7.48 (dm, 1H), 7.44 (m, 1H), 7.25 (m, 1H), 7.13 (dd, 1H), 7.10 (m, 1H), 6.97 (dm, 1H), 4.27 (q, 2H), 4.10 (t, 2H), 3.78 (s, 3H), 3.72 (m, 2H), 3.27 (t, 2H), 2.99 (m, 2H), 2.75 (d, 6H), 2.55 ( t, 2H), 2.46 (d, 3H), 2.12 (m, 2H), 1.88(m, 2H), 1.30 (t, 3H), 0.92 (m, 2H), -0.11 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₉ H ₅₃ FN ₇ O ₄ S ₂ Si: 794.3354 found: 794.3356.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-(dimethylamino)propyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

To a mixture of 59 mg of the product from Step A (0.076 mmol, 1 equiv.) in 5 mL of 1,4-dioxane was added 1.5 mL of 4 N HCl solution (6.0 mmol) and stirred at rt for 18 h. After addition of 510 mg of LiOH×H ₂ O (12.14 mmol, 160 equiv.), the mixture was stirred at 60 °C for 2 h. After concentration, the crude product was purified by flash column chromatography using DCM and MeOH (containing 1.2% NH ₃ ) as eluents and then by reversed-phase preparative chromatography (C18, 25 mM NH ₄ HCO ₃ in water: MeCN) to afford 3 mg (6%) of the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₁ H ₃₅ FN ₇ O ₃ S ₂ : 636.2226 found: 636.2221.

Example 215: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-5-quinuclidin-1-ium-1-ylpentyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Stage A: methyl 2-[[4-[tert-butyl(diphenyl)silyl]oxy-5-quinuclidin-1-ium-1-ylpentyl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl) -1.3-benzo otiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4-carboxylate

Using the General Procedure for Quaternary Salt Formation, starting from the product of Preparation 5b and quinuclidine as the appropriate tertiary amine, the desired product was obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-5-quinuclidin-1-ium-1-ylpentyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure for Deprotection of a Quaternary Salt, starting from the product from Step A as a quaternary salt, the desired product was obtained.

HR-ERI (m/z): [M+2H] ²⁺ , calculated for C ₄₂ H ₅₁ FN ₈ O ₄ S ₂ : 407.1724, found: 407.1724.

Example 216: 2-[[5-(1-Aza-4-azoniabicyclo[2.2.2]octan-4-yl)-4-hydroxypentyl]-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Stage A: methyl 2-[[5-(1-aza-4-azoniabicyclo[2.2.2]octan-4-yl)-4-[tert-butyl(diphenyl)silyl]oxypentyl]-[5-methyl-6-[(Z )-[3-(2-trimethylsilylethoxymethyl )-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl] thiazole-4-carboxylate

Using the General Procedure for Quaternary Salt Formation, starting from the product of Preparation 5b and 1,4-diazabicyclo[2.2.2]octane as the appropriate tertiary amine, the desired product was obtained.

Step_B_: 2-[[5-(1-aza-4-azoniabicyclo[2.2.2]octan-4-yl)-4-hydroxypentyl]-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure for Deprotection of a Quaternary Salt, starting from the product from Step A as a quaternary salt, the desired product was obtained.

HR-ERI (m/z): [M+2H] ²⁺ , calculated for C ₄₁ H ₅₀ FN ₉ O ₄ S ₂ : 407.6700, found: 407.6699.

Example 217: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(4-methylmorpholin-4-ium-4-yl)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Stage A: methyl 2-[[4-[tert-butyl(diphenyl)silyl]oxy-5-(4-methylmorpholin-4-ium-4-yl)pentyl]-[5-methyl-6-[(Z)-[3- (2-trimethylsilylethoxymethyl)-1,3-b enzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4-carboxylate

Using the General Procedure for Quaternary Salt Formation, starting from the product of Preparation 5b and 4-methylmorpholine as the appropriate tertiary amine, the desired product was obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(4-methylmorpholin-4-ium-4-yl)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure for Deprotection of a Quaternary Salt, starting from the product from Step A as a quaternary salt, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₀ H ₄₈ FN ₈ O ₅ S ₂ : 803.3168, found: 803.3165.

Example 218: 3-[2-[3-[4-[3-[2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-4-carboxythiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynylamino]ethyl dimethylammonio]propane-1-sulfonate

Step A: 3-[2-[tert-butoxycarbonyl-[3-[4-[3-[4-ethoxycarbonyl-2-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynyl]amino]ethyl dimethylammonio]propane-1-sulfonate

159 mg of the product of Synthesis 5h (0.17 mmol, 1 equiv) and 208 mg of oxathiolane 2,2-dioxide (1.70 mmol, 10 equiv) were mixed in acetonitrile (6 mL/mmol), and the reaction mixture was stirred at 60 °C for 2.5 h, during which time the conversion reached >90%. The mixture was concentrated on celite and purified by flash column chromatography using EtOAc and MeOH (1.2% NH ₃ ) as eluents to give 126 mg (70%) of the desired product as a yellow solid.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.67 (s, 1H), 7.46 (d, 1H), 7.44 (t, 1H), 7.35 (br., 1H), 7.25 (t, 1H), 7.25 (br., 1H) , 7.18 (t, 1H), 5.86 (s, 2H), 4.28 (br., 2H), 4.26 (q, 2H), 4.15 (t, 2H), 3.77 (s, 3H), 3.72 (t, 2H), 3.70 (brt., 2H), 3.46 (br., 2H) , 3.46 (br., 2H), 3.27 (t, 2H), 3.08 (brs., 6H), 2.46 (s, 3H), 2.46 (t, 2H), 2.13 (quint., 2H), 2.02 (br., 2H), 1.44 (brs., 9H), 1.29 (t, 3H), 0.92 (t, 2H) , -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 154.4, 129.2, 127.2, 123.4, 123.2, 119.3, 117.6, 115.5, 111.9, 72.8, 68.4, 66.7, 63.3, 60.7, 59.9, 50.7, 48.0, 40.7, 37.8, 35.3, 31.1, 28.3, 23.2, 19.4, 17.8, 17.8, 14.6, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₉ H ₆₈ FN ₈ O ₉ S ₃ Si: 1055.4019, found: 1055.4026.

Step B: 3-[2-[3-[4-[3-[2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-4-carboxythiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynylamino]ethyl dimethylammonio]propane-1-sulfonate

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 25 mM NH ₄ HCO ₃ in water: MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₆ H ₄₂ FN ₈ O ₆ S ₃ : 797.2368, found: 797.2343.

Example 219: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-(trimethylammonio)pentyl]amino]-5-[3-[2-fluoro -4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Using the General Alkylation, Deprotection, and Hydrolysis Procedure starting from the compound of Example 213, Step C, and iodomethane, the TFA salt of the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₇ H ₄₄ FN ₈ O ₃ S ₂ : 731.2956, found: 731.2967.

Example 220: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(1-methylpiperidin-1-ium-1-yl)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Stage A: methyl 2-[[4-[tert-butyl(diphenyl)silyl]oxy-5-(1-methylpiperidin-1-ium-1-yl)pentyl]-[5-methyl-6-[(Z)-[3- (2-trimethylsilylethoxymethyl)-1,3- benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4-carboxylate

Using the General Procedure for Quaternary Salt Formation, starting from the product of Preparation 5b and 1-methylpiperidine as the appropriate tertiary amine, the desired product was obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(1-methylpiperidin-1-ium-1-yl)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure for Deprotection of a Quaternary Salt, starting from the product from Step A as a quaternary salt, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₅₀ FN ₈ O ₄ S ₂ : 801.3375, found: 801.3378.

Example 221: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-(1,4-dimethylpiperazin-1-yl-1-yl)-4-hydroxypentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Stage A: methyl 2-[[4-[tert-butyl(diphenyl)silyl]oxy-5-(1,4-dimethylpiperazin-1-yl-1-yl)pentyl]-[5-methyl-6-[(Z)-[ 3-(2-trimethylsilylethoxymethyl)-1, 3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazol-4- carboxylate

Using the General Procedure for Quaternary Salt Formation, starting from the product of Preparation 5b and 1,4-dimethylpiperazine as the appropriate tertiary amine, the desired product was obtained.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-(1,4-dimethylpiperazin-1-yl-1-yl)-4-hydroxypentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure for Deprotection of a Quaternary Salt, starting from the product from Step A as a quaternary salt, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₅₁ FN ₉ O ₄ S ₂ : 816.3484, found: 816.3489.

Example 222: 2-[3-[4-[3-[2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-4-carboxythiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynylamino]ethyltrimethylammonium

Step A: 2-[tert-butoxycarbonyl-[3-[4-[3-[4-ethoxycarbonyl-2-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynyl]amino]ethyltrimethylammonium

200 mg of Preparation 5h (0.21 mmol, 1 equiv) was dissolved in acetonitrile (4 mL/mmol), then 152 mg of iodomethane (1.07 mmol, 5 equiv) was added and stirred at rt for 1.5 h. The reaction did not progress further, so at this point the process was stopped, observing partial conversion. The volatiles were evaporated and the crude mixture (containing Preparation 5h and the desired product) was directly carried to the next step.

LC-MS-ESI (m/z): [M] ⁺ , calculated for C ₄₇ H ₆₄ FN ₈ O ₆ S ₂ Si: 947.4, found: 947.4.

Step B: 2-[3-[4-[3-[2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-4-carboxythiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynylamino]ethyltrimethylammonium

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed phase preparative chromatography (C 18, 25 mM NH ₄ HCO ₃ in water: MeCN), starting from the product from Step A, the desired product and Example 223 were separated and isolated.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₈ FN ₈ O ₃ S ₂ : 689.2487, found: 689.2481.

Example 223: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-[2-(dimethylamino)ethylamino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Example 223 was isolated as a by-product in the preparation of Example 222, Step B.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₆ FN ₈ O ₃ S ₂ : 675.2330, found: 675.2324.

Example 224: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[6-(trimethylammonio)hexyl]amino]-5-[3-[2-fluoro -4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Using the General Alkylation, Deprotection, and Hydrolysis Procedure starting from the compound of Example 199, Step C, and iodomethane, the TFA salt of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.90 (d, 1H), 7.64 (s, 1H), 7.53 (brd, 1H), 7.39 (t, 1H), 7.26 (dd, 1H), 7.21 (t, 1H), 7.18 (m, 1H), 7.15 (t, 1H), 4.37 (t, 2H), 4.13 (t, 2H), 3.44 (brs, 2H), 3.30 (t, 2H), 3.24 (t, 2H), 3.03 (s, 9H), 2.45 (s, 3H), 2.31 (s, 3H), 2.11 (quin, 2H), 1.72-1.39 (m, 8H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 151.5, 147.1, 128.8, 126.6, 122.6, 122.3, 119.1, 118.4, 117.0, 115.5, 88.5, 82.0, 69.0, 65.8, 52.6, 46.6, 40.3, 35.4, 31.2, 26.6-22.2, 23.2, 18.0; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₈ H ₄₄ FN ₈ O ₃ S ₂ : 745.3118, found: 745.3110.

Example 225: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[3-hydroxypropyl(dimethyl)ammonio]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Stage A: 5-[[5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]-[5-methyl-6-[( Z)-[3-(2-t rimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]pentyl-(3-hydroxypropyl)-dimethylammonium

Using the General Procedure of alkylation with an in situ generated tosylate followed by purification by reverse phase flash column chromatography (C18, 0.1% TFA in water:MeCN), starting from Preparation 5f and 3-(dimethylamino)propan-1-ol as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 10.35 (brs, 1H), 7.84 (dm, 1H), 7.72 (s, 1H), 7.48 (dd, 1H), 7.48 (dm, 1H), 7.46 (m, 1H), 7.35 (dm, 1H), 7.26 (m, 1H), 7.24 (t, 1H), 5.87 (s, 2H), 4.79 (brs, 1H), 4.42 (t, 2H), 4.29 (s, 2H), 4.19 (t, 2H), 3.79 (s, 3H), 3.73 (m, 2H), 3.46 (m, 2H), 3.30 (m, 2H), 3.27 (t, 2H), 3.25 (t, 2H), 3.00 (s, 6H), 2.86 (s, 6H), 2.47 (s, 3H), 2.14 (m, 2H), 1.8 (m, 2H), 1.76 (m, 2H), 1.75 (m, 2H ), 1.38 (m, 2H), 0.92 (m, 2H), -0.98 (s, 9H); HR-MSR (m/z): [M] ⁺ , calculated for C ₄₇ H ₆₆ FN ₈ O ₅ S ₂ Si: 933.4346, found: 933.4342.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[3-hydroxypropyl(dimethyl)ammonio]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₀ H ₅₀ FN ₈ O ₄ S ₂ : 789.3375, found: 789.3376.

Example 226: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-hydroxyethyl(dimethyl)ammonio]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Step A: 5-[[5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]pentyl-(2-hydroxyethyl)-dimethylammonium

Using the General Procedure of alkylation with an in situ generated tosylate followed by purification by reverse phase flash column chromatography (C18, 0.1% TFA in water:MeCN), starting from Preparation 5f and 2-(dimethylamino)ethanol as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.72 (s, 1H), 7.48 (d, 1H), 7.47 (dd, 1H), 7.45 (t, 1H), 7.35 (d, 1H), 7.26 (t, 1H), 7.24 (t, 1H), 5.87 (s, 2H), 5.29 (br., 1H), 4.42 (t, 2H), 4.28 (s, 2H), 4.19 (t, 2H), 3.81 (brt, 2H), 3.79 (s, 3H), 3.73 (t, 2H), 3.36 (m, 2H), 3.31 (m, 2H), 3.27 (t, 2H), 3.05 (s, 6H), 2.86 (s, 6H), 2.47 (s, 3H), 2.14 (m, 2H), 1.76 (m, 2H), 1.76 (m, 2H), 1.37 (m, 2H), 0.92 (t, 2H), - 0.10 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 129.6, 127.3, 123.5, 123.2, 119.7, 117.6, 115.5, 112.0, 72.9, 68.6, 66.8, 65.1, 64.4, 55.4, 52.0, 51.2, 46.9, 46.4, 42.2, 31.1, 26.7, 23.2, 23.2, 21.9, 17.9, 17.8, -0.9; HR-MSR (m/z): [M] ⁺ , calculated for C ₄₆ H ₆₄ FN ₈ O ₅ S ₂ Si: 919.4189, found: 919.4192.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-hydroxyethyl(dimethyl)ammonio]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-MSR (m/z): [M+2H] ²⁺ , calculated for C ₃₉ H ₄₉ FN ₈ O ₄ S ₂ : 388.16455, found: 388.1639.

Example 227: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[carboxymethyl(dimethyl)ammonio]pentyl]amino]-5-[3- [4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Step A: 5-[[5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]-[5-methyl-6-[(1)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]pentyl-(2-ethoxy-2-oxoethyl)-dimethylammonium

Using the General Procedure of alkylation with an in situ generated tosylate followed by purification by reverse phase flash column chromatography (C18, 0.1% TFA in water:MeCN), starting from the product of Preparation 5f and ethyl 2-(dimethylamino)acetate as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 10.33 (brs, 1H), 7.84 (dm, 1H), 7.72 (s, 1H), 7.48 (dd, 1H), 7.48 (dm, 1H), 7.46 (m, 1H), 7.35 (dm, 1H), 7.27 (m, 1H), 7.24 (t, 1H), 5.87 (s, 2H), 4.42 (t, 2H), 4.38 (s, 2H), 4.29 (s, 2H), 4.21 (q, 2H), 4.19 (t, 2H), 3.79 (s, 3H), 3.73 (m, 2H), 3.46 (m, 2H), 3.27 (t, 2H), 3.18 (s, 6H), 2.87 (s, 6H), 2.47 (s, 3H), 2.14 (m, 2H), 1.79 (m, 2H), 1.75 (m, 2H), 1.37 (m, 2H), 1.22 (t, 3H ), 0.92 (m, 2H), -0.10(s, 9H); HR-MSR (m/z): [M] ⁺ , calculated for C ₄₈ H ₆₆ FN ₈ O ₆ S ₂ Si: 961.4294, found: 961.4293 .

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[carboxymethyl(dimethyl)ammonio]pentyl]amino]-5-[3- [4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₉ H ₄₆ FN ₈ O ₅ S ₂ : 789.3011, found: 789.2995.

Example 228: 3-[[5-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-carboxy-5-[3-[2-fluoro-4-[(E)-3-oxoprop-1-enyl]phenoxy]propyl]thiazol-2-yl]amino]-2-hydroxypentyl]-dimethylammonio]propane-1-sulfonate

Example 228 was isolated as a by-product in the preparation of Example 146.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₈ H ₄₅ FN ₇ O ₈ S ₃ : 842.2470 found: 842.2494.

Example 229: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-hydroxyethyl(dimethyl)ammonio]pentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Step A: 5-[[5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]pentyl-(2-hydroxyethyl)-dimethylammonium

Using the General Procedure of alkylation with an in situ generated tosylate followed by purification by reverse phase flash column chromatography (C18, 0.1% TFA in water:MeCN), starting from the product of Preparation 5e and 2-(dimethylamino)ethanol as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.71 (s, 1H), 7.48 (dm, 1H), 7.45 (m, 1H), 7.33 (dd, 1H), 7.26 (m, 1H), 7.23 (dm, 1H), 7.17 (t, 1H), 5.87 (s, 2H), 5.28 (brs, 1H), 4.42 (t, 2H), 4.20 (brs, 2H), 4.16 (t, 2H), 3.81 (m, 2H), 3.78 (s, 3H), 3.73 (m, 2H), 3.36 ( t, 2H), 3.31 (t, 2H), 3.27 (t, 2H), 3.04(s, 6H), 2.84 (brs, 3H), 2.46 (s, 3H), 2.13 (m, 2H), 1.77 (m, 2H), 1.75 (m, 2H), 1.41 (s, 9H), 1.37 (m, 2H ), 0.92 (m, 2H), -0.11 (s, 9H); HR-MSR (m/z): [M] ⁺ , calculated for C ₅₀ H ₇₀ FN ₈ O ₇ S ₂ Si: 1005.4557, found: 1005.4554 .

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-hydroxyethyl(dimethyl)ammonio]pentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₈ H ₄₆ FN ₈ O ₄ S ₂ : 761.3062, found: 761.3057.

Example 230: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[3-hydroxypropyl(dimethyl)ammonio]pentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Stage A: 5-[[5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]-[5- methyl-6-[( Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]pentyl-(3-hydroxypropyl)-dimethylammonium

Using the General Procedure of alkylation with an in situ generated tosylate followed by purification by reverse phase flash column chromatography (C18, 0.1% TFA in water:MeCN), starting from the product of Preparation 5e and 3-(dimethylamino)propan-1-ol as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.71 (s, 1H), 7.48 (dm, 1H), 7.45 (m, 1H), 7.33 (dd, 1H), 7.26 (m, 1H), 7.23 (dm, 1H), 7.18 (t, 1H), 5.87 (s, 2H), 4.78 (brs, 1H), 4.42 (t, 2H), 4.21 (s, 2H), 4.15 (t, 2H), 3.78 (s, 3H), 3.72 (m, 2H), 3.46 (m, 2H), 3.30 ( t, 2H), 3.27 (t, 2H), 3.25 (t, 2H), 2.99(s) 6H), 2.85 (brs, 3H), 2.47 (s, 3H), 2.12 (m, 2H), 1.80 (m, 2H), 1.76 (m, 2H), 1.76 (m, 2H), 1.41 (s, 9H ), 1.38 (m, 2H), 0.92 (m, 2H), -0.11 (s, 9H); HR-MSR (m/z): [M] ⁺ , calculated for C ₅₁ H ₇₂ FN ₈ O ₇ S ₂ Si: 1019.4713, found: 1019.4713.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[3-hydroxypropyl(dimethyl)ammonio]pentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₉ H ₄₈ FN ₈ O ₄ S ₂ : 775.3218, found: 775.3213.

Example 231: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[carboxymethyl(dimethyl)ammonio]pentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Step A: 5-[[5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]pentyl-(2-ethoxy-2-oxoethyl)-dimethylammonium

Using the General Procedure of Alkylation with an In Situ Generated Tosylate followed by purification by reverse phase flash column chromatography (C18, 0.1% TFA in water:MeCN), starting from Preparation 5e and ethyl 2-(dimethylamino)acetate as the appropriate amine, the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.71 (q, 1H), 7.48 (dm, 1H), 7.44 (m, 1H), 7.33 (dd, 1H), 7.26 (m, 1H), 7.23 (dm, 1H), 7.17 (t, 1H), 5.87 (s, 2H), 4.42 (t, 2H), 4.37 (s, 2H), 4.21 (q, 2H), 4.21 (brs, 2H), 4.16 (t, 2H), 3.78 (s, 3H), 3.72 (m, 2H), 3.46 ( m, 2H), 3.27 (t, 2H), 3.18 (s, 6H), 2.84 (brs, 3H), 2.47 (d, 3H), 2.12 (m, 2H), 1.79 (m, 2H), 1.75 (m, 2H), 1.41 (s, 9H), 1.37 (m, 2H), 1.22 (t, 3H ), 0.92 (m, 2H), -0.10 (s, 9H); HR-MSR (m/z): [M] ⁺ , calculated for C ₅₂ H ₇₂ FN ₈ O ₈ S ₂ Si: 1047.4662, found: 1047.468 .

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[carboxymethyl(dimethyl)ammonio]pentyl]amino]-5-[3- [2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₈ H ₄₄ FN ₈ O ₅ S ₂ : 775.2855, found: 775.2857.

Example 232: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-(trimethylammonio)butyl]amino]-5-[3-[2-fluoro -4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Stage A: 4-[[5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]-[5- methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]butyltrimethylammonium

Using the General Procedure for Alkylation with an In Situ Generated Tosylate, starting from the product of Preparation 5c and N,N-dimethylmethanamine as the appropriate amine, the TFA salt of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.71 (s, 1H), 7.48 (d, 1H), 7.45 (t, 1H), 7.33 (brd, 1H), 7.26 (t, 1H), 7.22 (dm, 1H), 7.17 (t, 1H), 5.87 (s, 2H), 4.40 (t, 2), 4.20 (brs, 2H), 4.15 (t, 2H), 3.79 (s, 3H), 3.73 (t, 2H), 3.46 (t, 2H), 3.27 (t, 2H), 3.06 ( s, 9Н), 2.84 (brs, 3Н), 2.46 (s, 3Н), 2.12 (m, 2H), 1.82 (m, 2H), 1.75 (m, 2H), 1.40 (s, 9H), 0.92 (t, 2H), -0.10 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ m .d. 129.1, 127.2, 123.6, 123.2, 119.3, 117.5, 115.5, 112.1, 72.9, 68.4, 66.7, 65.4, 52.8, 52.1, 46.3, 38.8, 33.8, 31.0, 28.5, 24.4, 23.3, 19.8, 18.0, 17.8 , -1.0; HR-MSR (m/z): [M] ⁺ , calculated for C ₄₈ H ₆₆ FN ₈ O ₆ S ₂ Si: 961.4294, found: 961.4312.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-(trimethylammonio)butyl]amino]-5-[3-[2-fluoro -4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M] ⁺ , calculated for C ₃₆ H ₄₂ FN ₈ O ₃ S ₂ : 717.2800, found: 717.2800.

Example 233: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: ethyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]phenoxy]propyl]-2-[methyl-[5-methyl-6-[(Z)-[3-( 2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using the General Procedure for the Alkylation of Silyl-Protected Phenols, starting from 219 mg of Preparation 5g (0.30 mmol, 1 equiv) and 100 mg of Preparation 6j (0.30 mmol, 1 equiv) followed by purification by flash column chromatography using EtOAc and MeOH (containing 1.2% NH3) as eluents, 37 mg (12%) of the desired product was obtained as a dark yellow sticky substance.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.83 (dm, 1H), 7.66 (q, 1H), 7.47 (dm, 1H), 7.44 (m, 1H), 7.35 (m, 2H), 7.25 (m, 1H), 6.94 (m, 2H), 5.86 (s, 2H), 4.26 (q, 2H), 4.05 (t, 2H), 3.77 (s, 3H), 3.72 (m, 2H), 3.38 (s, 2H), 3.26 (m, 2H), 2.45 (d, 3H), 2.19 (s, 6H), 2.10 ( m, 2H), 1.30 (t, 3H), 0.92 (m, 2H), -0.11 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₉ H ₅₀ N ₇ O ₄ S ₂ Si: 772.3129, found: 772.3119.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₁ H ₃₂ N ₇ O ₃ S ₂ : 614.2002, found: 614.1998.

Example 234: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-5-[3-[4-[1-[(dimethylamino)methyl] -3-bicyclo[1.1.1]pentanyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: Ethyl 5-[3-[4-[1-[(dimethylamino)methyl]-3-bicyclo[1.1.1]pentanyl]phenoxy]propyl]-2-[methyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazole-4-carboxylate

Using the General Alkylation Procedure starting from 47 mg of Preparation 6i (0.22 mmol, 1 equiv) and 157 mg of Preparation 5g (0.22 mmol, 1 equiv) followed by purification by flash column chromatography using EtOAc and MeOH (containing 1.2% NH ₃ ) as eluents gave 130 mg (74%) of the desired product as a yellow solid.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 10.62 (brs, 1H), 7.83 (dm, 1H), 7.65 (q, 1H), 7.46 (dm, 1H), 7.43 (m, 1H), 7.25 (m, 1H), 7.11 (m, 2H), 6.89 (m, 2H), 5.85 (s, 2H), 4.26 (q, 2H), 4.01 (t, 2H), 3.76 (s, 3H), 3.72 (m, 2H), 3.24 (s, 2H), 3.24 (t, 2H), 2.74 (s, 6H), 2.44 ( d, 3H), 2.08 (m, 2H), 2.07 (s, 6H), 1.29 (t, 3H), 0.91 (m, 2H), -0.12 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₂ H ₅₆ N ₇ O ₄ S ₂ Si: 814.3599, found: 814.3592.

Step B: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[1-[(dimethylamino)methyl]-3-bicyclo[1.1.1]pentanyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure of Deprotection and Hydrolysis followed by repurification by reversed-phase preparative chromatography (C 18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step A.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₈ N ₇ O ₃ S ₂ : 656.2472, found: 656.2467.

Example 235: 3-[3-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-carboxy-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazol-2-yl]amino]propyl dimethylammonio]propane-1-sulfonate

The General Alkylation, Deprotection, and Hydrolysis Procedure was used starting from Example 200, Step C, and oxathiolane 2,2-dioxide. After alkylation, the sulfonated intermediate was isolated (HRMS-ESI (m/z): [M+H] ⁺ , calculated for C ₄₉ H ₆₈ FN ₈ O ₉ S ₃ Si: 1055.4025, found: 1055.4028), which was then reacted with HP×pyridine (HRMS-ESI (m/z): [M+H] ⁺ , calculated for C ₃₈ H ₄₅ FN ₈ O ₆ S ₃ : 825.2686, found: 825.2675) and finally hydrolyzed with LiOH×H ₂ O. Purification afforded the TFA salt of the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₇ H ₄₄ FN ₈ O ₆ S ₃ : 811.2530, found: 811.2525.

Example 236: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(2-fluoro-4-{3-[methyl({4-[3-(trifluoromethyl)-3H-diazirin-3-yl]phenyl}methyl)amino]prop-1-yn-1-yl}phenoxy)propyl]-1,3-thiazole-4-carboxylic acid

Step A: Ethyl 5-[3-(2-fluoro-4-{3-[methyl({4-[3-(trifluoromethyl)-3H-diazirin-3-yl]phenyl}methyl)amino]prop-1-yn-1-yl}phenoxy)propyl]-2-[methyl(5-methyl-6-{[(2Z)-3-{[2-(trimethylsilyl)ethoxy]methyl}-2,3-dihydro-1,3-benzothiazol-2-ylidene]amino}pyridazin-3-yl)amino]-1,3-thiazole-4-carboxylate

To a solution of Preparation 5j (20 mg, 25.8 μmol, 1 equiv) in dry dimethylformamide (1 mL) was added potassium carbonate (3.9 mg, 28.4 μmol, 1.1 equiv) followed by 3-[4-(bromomethyl)phenyl]-3-(trifluoromethyl)diazirine (7.9 mg, 28.4 μmol, 1.1 equiv) and the mixture was stirred for 16 h at ambient temperature. The reaction mixture was diluted with 5% aqueous ammonium hydroxide (10 mL), extracted with ethyl acetate (2×10 mL) and the combined organic extracts were washed successively with 5% aqueous ammonium hydrofluoride (10 mL) and brine (10 mL), dried (magnesium sulfate) and concentrated in vacuo. Purification by automated flash column chromatography (CombiFlash Rf, 4 g RediSep™ silica gel cartridge) eluting with a gradient of 0-50% ethyl acetate in isoheptane afforded the title product as a white solid (27.4 mg), which was used directly in the next step without further characterization.

Step B: Ethyl 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(2-fluoro-4-{3-[methyl({4-[3-(trifluoromethyl)-3H-diazirin-3-yl]phenyl}methyl)amino]prop-1-yn-1-yl}phenoxy)propyl]-1,3-thiazole-4-carboxylate

To a solution of the product from Step A (27.4 mg, 28 μmol, 1 equiv) in acetonitrile (1 mL) was added pyridinium polyfluoride (101 μL, 0.78 mmol, 28 equiv) and the mixture was heated at 60 °C for 20 h. The reaction mixture was diluted with 5% aqueous ammonium hydroxide solution (10 mL), extracted with ethyl acetate (2×10 mL), and the combined organic extracts were dried (magnesium sulfate) and concentrated in vacuo. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 5.5 g RediSep aq Gold column) eluting with a gradient of 5-95% acetonitrile in water afforded the desired product as a yellow solid (6.7 mg, 0.01 mmol, 28%).

LC/MS (C ₄₁ H ₃₇ F ₄ N ₉ O ₃ S ₂ ) 844 [M+H] ⁺ ; RT 1.64 (LCMS-V-B1)

Step C: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(2-fluoro-4-{3-[methyl({4-[3-(trifluoromethyl)-3H-diazirin-3-yl]phenyl}methyl)amino]prop-1-yn-1-yl}phenoxy)propyl]-1,3-thiazole-4-carboxylic acid

To a solution of the product from Step B (6.7 mg, 0.01 mmol, 1 equiv) in a 1:1 mixture of tetrahydrofuran/methanol (0.5 mL) was added 2 M aqueous sodium hydroxide solution (79.4 μL, 0.16 mmol, 20 equiv), and the mixture was stirred at ambient temperature for 4 h and then concentrated in vacuo. The residue was diluted with water (0.2 mL) and adjusted to pH 5 with 2 M aqueous hydrochloric acid. Purification by reversed-phase automated flash chromatography (CombiFlash Rf, C18 5.5 g RediSep aq Gold column) eluting with a gradient of 5 95% acetonitrile in water afforded the desired product as an orange/brown solid (3.5 mg, 4.29 μmol, 54%).

LC/MS (C ₃₉ H ₃₃ F ₄ N ₉ O ₃ S ₂ ) 816 [M+H] ⁺ ; RT 1.53 (LCMS-V-B1)

Example 237: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-phosphonopropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Step A: methyl 2-[tert-butoxycarbonyl(3-diethoxyphosphorylpropyl)amino]-5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl ]thiazole-4-carboxylate

Using the General Alkylation Procedure starting from 500 mg of Preparation 1b (0.87 mmol, 1 equiv) and 336 mg of 1-bromo-3-diethoxyphosphorylpropane (1.30 mmol, 1.5 equiv) as the appropriate halide, 517 mg (79%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.30 (dd, 1H), 7.21 (dm, 1H), 7.13 (t, 1H), 4.23 (brs, 2H), 4.10 (t, 2H), 4.04 (t, 2H), 4.03-3.90 (m, 4H) , 3.75 (s, 3H), 3.22 (t, 2H), 2.86 (brs, 3H), 2.08 (m, 2H), 1.83 (m, 2H), 1.73 (m, 2H), 1.51/1.41 (s, 18H), 1.2 (t, 6H); HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₅ H ₅₂ FN ₃ O ₁₀ PS: 756.3090, found: 756.3095.

Step B: Methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-(3-diethoxyphosphorylpropylamino)thiazole-4-carboxylate

Using the General HFIP deprotection method, starting from 512 mg of the product from Step A (0.68 mmol, 1 equiv) gave 210 mg (47%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.64 (brt, 1H), 7.31 (brd, 1H), 7.21 (dm, 1H), 7.13 (t, 1H), 4.23 (brs, 2H), 4.07 (t, 2H), 3.97 (m, 4H), 3.69 (s, 3H), 3.23 (m, 2H), 3.12 (t, 2H), 2.86 (brs, 3H), 2.00 (m, 2H), 1.84-1.63 (m, 4H), 1.41 (s, 3H), 1.21 (t, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 119.3, 115.4, 68.0, 61.4, 51.8, 44.7, 38.6, 33.8, 30.6, 28.5, 23.3, 16.7; HR-MSR (m/z ): [M+H] ⁺ , calculated for C ₃₀ H ₄₄ FN ₃ O ₈ PS: 656.2565, found: 656.2555.

Stage C: methyl 5-{3-{4-{3-{tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[3-diethoxyphosphorylpropyl-[5-meth yl-6-{(2)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting with 450 mg of the product from Step B (0.69 mmol, 1 equiv) and 363 mg of the product from Preparation 4a (0.89 mmol, 1.3 equiv) as the appropriate halide, 540 mg (77%) of the desired product were obtained.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₈ H ₆₆ FN ₇ O ₉ PS ₂ Si: 1026.3849, found: 1026.3849.

Step D: 2-{{6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-phosphonopropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Using the General Procedure for Deprotection and Hydrolysis of Phosphonic Acid Derivatives followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₂ H ₃₄ FN ₇ O ₆ PS ₂ : 726.1728, found: 726.1707.

Example 238: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-carboxypropyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Step A: Methyl 2-{tert-butoxycarbonyl-(4-ethoxy-4-oxobutyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl] thiazole-4-carboxylate

Using the General Alkylation Procedure, starting from the product of Preparation 1c and ethyl 4-bromobutanoate, 0.48 g (77%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.28 (dd, 1H), 7.20 (dm, 1H), 7.12 (t, 1H), 4.10 (t, 2H), 4.04 (t, 2H), 4.00 (q, 2H), 3.75 (s, 3H), 3.41 (s, 2H), 3.22 (t, 2H), 2.31 (t, 2H), 2.22 (s, 6H), 2.08 (m, 2H), 1.91 (m, 2H), 1.50 (s, 9H), 1.13 (t, 3H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 128.9, 119.2, 115.4, 68.1, 60.3, 52.1, 48.2, 46.0, 44.3, 31.2, 30.5, 28.0, 23.2, 23.2, 14.5; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₀ H ₄₁ FN ₃ O ₇ S: 606.2649, found: 606.2640.

Step B: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[(4-ethoxy-4-oxobutyl)amino]thiazol-4- carboxylate

Using the General HFIP deprotection method, 0.32 g (83%) of the desired product was obtained from the product from Step A.

¹ H NMR (400 MHz, DMSO-d ₆ ) δ ppm 7.61 (t, 1H), 7.30 (dd, 1H), 7.20 (dm, 1H), 7.12 (t, 1H), 4.07 (t, 2H), 4.04 (q, 2H), 3.69 (s, 3H), 3.42 (s, 2H), 3.12 (t, 2H), 3.118 (q, 2H), 2.35 (t, 2H), 2.23 (s, 6H), 2.00 (m, 2H), 1.76 (m, 2H), 1.17 (t, 3H); ¹³ C NMR (100 MHz, DMSO-d ₆ ) δ ppm 173.1, 164.6, 163, 128.9, 119.2, 115.4, 68.0, 60.3, 51.7, 48.2, 44.3, 43.7, 31.3, 30.6, 24.5, 23.3, 14.6; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₅ H ₃₃ FN ₃ O ₅ S: 506.2125, found: 506.2114.

Stage C: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[(4-ethoxy-4-oxobutyl)-[5-methyl-6-[( Z)-[ 3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product from Step B and the compound Synthesis 4a, 0.26 g (48%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.73 (s, 1H), 7.47 (dd, 1H), 7.44 (td, 1H), 7.30 (dd, 1H), 7.25 (td, 1H), 7.21 (dd, 1H), 7.15 (t, 1H), 5.86 (s, 2H), 4.38 (br., 2H), 4.14 (t, 2H), 4.02 (q, 2H), 3.78 (s, 3H), 3.72 (t, 2H), 3.38 (s, 2H), 3.26 (t, 2H), 2.46 (s, 3H), 2.44 (m, 2H), 2.19 (s, 6H), 2.13 (m, 2H), 1.97 (m, 2H), 1.14 (t, 3H), 0.92 (t, 2H), -0.11 (s, 9H); HR-ESI (m/z): [M+H] ⁺ , calculated for C ₄₃ H ₅₅ FN ₇ O ₆ S ₂ Si: 876.3409, found: 876.3403; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₄₂ H ₅₃ FN ₇ O ₆ S ₂ Si (double Me ester): 862.3252, found: 862.3237.

Step D: 2-({6-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-carboxypropyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₅ FN ₇ O ₅ S ₂ : 704.2125, found: 704.2116.

Example 239: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-phosphonopropyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl(3-diethoxyphosphorylpropyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Alkylation Procedure starting from the product of Preparation 1c and 1-bromo-3-diethoxyphosphorylpropane as the appropriate halide, 0.52 g (77%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.29 (dd, 1H), 7.20 (dm, 1H), 7.12 (t, 1H), 4.10 (t, 2H), 4.04 (t, 2H), 3.97 (m, 4H), 3.75 (s, 3H), 3.43 (s, 2H), 3.22 (t, 2H), 2.23 (s, 6H), 2.08 (m, 2H), 1.83 (m, 2H), 1.73 (m, 2H), 1.51 (s, 9H), 1.21 (t, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 156.5/153.0, 128.9, 119.2, 115.4, 68.1, 61.4, 52.1, 48.1, 46.9, 44.2, 30.5, 28.1, 23.2, 22.5, 21.3, 16.7; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₁ H ₄₆ FN ₃ O ₈ PS: 670.2727, found: 670.2716.

Step B: Methyl 2-(3-diethoxyphosphorylpropylamino)-5-{3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General HFIP deprotection method, 0.37 g (86%) of the desired product was obtained from the product from Step A.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.64 (t, 1H), 7.30 (dd, 1H), 7.21 (dm, 1H), 7.12 (t, 1H), 4.07 (t, 2H), 3.99/3.95 (m+m, 4H), 3.69 (s, 3H), 3.43 (s, 2H), 3.23 (m, 2H), 3.12 (t, 2H), 2.23 (s, 6H), 2.00 (m, 2H), 1.84-1.64 (m, 4H), 1.21 (t, 6H);

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₆ H ₃₈ FN ₃ O ₆ PS: 570.2203, found: 570.2183.

Stage C: methyl 2-[3-diethoxyphosphorylpropyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5 -[3-{4-{3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product from Step B and the product of Preparation 4a as the appropriate halide, 0.51 g (87%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.76 (s, 1H), 7.47 (dd, 1H), 7.44 (td, 1H), 7.30 (dd, 1H), 7.25 (td, 1H), 7.21 (dd, 1H), 7.15 (t, 1H), 5.86 (s, 2H), 4.40 (brt., 2H), 4.14 (t, 2H), 3.99 (m, 4H), 3.77 (s, 3H), 3.72 (t, 2H), 3.38 (br., 2H), 3.27 (t, 2H), 2.46 (s, 3H), 2.19 (s, 6H), 2.13 (m, 2H), 1.90(m, 2H), 1.89 (m, 2H), 1.20 (t, 6H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 163.1, 128.9, 127.2, 123.5, 123.2, 119.2, 117.4, 115.5, 112.0, 72.9, 68.5, 66.7, 61.5, 52.0, 48.1, 48.1, 44.2, 30.9, 23.1, 22.1, 20.5, 17.8, 17.8, 16.7, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₄ H ₆₀ FN ₇ O ₇ PS ₂ Si: 940.3487, found: 940.3471.

Step D: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-phosphonopropyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Using the General Procedure for Deprotection and Hydrolysis of Phosphonic Acid Derivatives followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₆ FN ₇ O ₆ PS: 740.1890, found: 740.1871.

Example 240: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-sulfopropyl)amino)-5-(3-{4-[3 -(dimethylamino)prop-1-in-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazol-4-carboxylic acid

Step A: 3-[tert-butoxycarbonyl-[5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]amino]propane-1-sulfonic acid

Using the General Alkylation Procedure starting from the product of Preparation 1c and sodium 3-bromopropane-1-sulfonate as the appropriate halide, 0.50 g (77%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.33 (dd, 1H), 7.23 (dm, 1H), 7.15 (t, 1H), 4.10 (t, 2H), 4.04 (t, 2H), 3.76 (s, 3H), 3.62 (s, 2H), 3.23 (t, 2H), 2.37 (s, 6H), 2.36 (m, 2H), 2.09 (m, 2H), 1.92 (m, 2H), 1.51 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 119.3, 115.4, 68.1, 52.0, 49.6, 47.9, 46.1, 43.8, 30.4, 28.1, 24.7, 23.1; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₂₇ H ₃₇ FN ₃ O ₈ S ₂ : 614.2006, found: 614.1993.

Step B: 3-{{5-{3-{4-{3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]amino]propane-1-sulfonic acid

Using the General HFIP deprotection method, 0.26 g (63%) of the desired product was obtained from the product from Step A.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.61 (t, 1H), 7.33 (dd, 1H), 7.24 (dd, 1H), 7.14 (t, 1H), 4.07 (t, 2H), 3.69 (s, 3H), 3.65 (s, 2H), 3.21 (q, 2H), 3.12 (t, 2H), 2.46 (t, 2H), 2.39 (s, 6H), 2.00 (qn, 2H), 1.80 (qn, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 164.7, 163.0, 151.5, 147.6, 136.9, 136.2, 129.1, 119.3, 115.5, 114.8, 85.2, 83.4, 68.1, 51.7, 49.6, 47.9, 44.1, 43.8, 30.6, 25.5, 23.3; HR-ERI (m/z) : [M+Na] ⁺ , calculated for C ₂₂ H ₂₈ FN ₃ NaO ₆ S ₂ : 536.1301, found: 536.1293.

Step C: 3-{{5-{3-{4-{3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]propane-1-sulfonic acid

Using General Procedure II for the Buchwald reaction, starting from the product from Step B and the product of Preparation 4a as the appropriate halide, 0.27 g (66%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.95 (s, 1H), 7.84 (d, 1H), 7.46 (d, 1H), 7.43 (t, 1H), 7.40 (dd, 1H), 7.28 (d, 1H), 7.25 (t, 1H), 7.19 (t, 1H), 5.86 (s, 2H), 4.48 (t, 2H), 4.16 (t, 2H), 3.90 (br., 2H), 3.78 (s, 3H), 3.72 (t, 2H), 3.27 (t, 2H), 2.57 (br., 6H), 2.53 (t, 2H), 2.45 (s, 3H), 2.14 (m, 2H), 2.00 (m, 2H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 163.2, 156.1, 134.9, 129.4, 127.2, 123.4, 123.2, 119.4, 117.8, 115.5, 111.9, 72.9, 68.5, 66.7, 52.0, 48.7, 47.3, 46.2, 42.9, 30.9, 23.6, 23.1, 17.9, 17.8, -0.9; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₀ H ₅₁ FN ₇ O ₇ S ₃ Si: 884.2765, found: 884.2757.

Step D: 2-({b-{(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-sulfopropyl)amino)-5-(3-{4-[3 -(dimethylamino)prop-1-in-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazol-4-carboxylic acid

Using the General Procedure of deprotection and hydrolysis followed by repurification by reversed-phase preparative chromatography (C18, 0.1% TFA in water:MeCN), the TFA salt of the desired product was obtained starting from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₃ H ₃₅ FN ₇ O ₆ S ₃ : 740.1795, found: 740.1786.

Example 241: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-sulfobutyl)amino)-5-(3-{4-[3 -(dimethylamino)prop-1-in-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazol-4-carboxylic acid

Step A: 4-[tert-butoxycarbonyl-[5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]amino]butane-1-sulfonic acid

Using the General Alkylation Procedure, starting from oxathiane 2,2-dioxide and the product of Preparation 1c, 0.29 g of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.34 (dd, 1H), 7.24 (dd, 1H), 7.14 (t, 1H), 4.10 (t, 2H), 3.98 (t, 2H), 3.75 (s, 3H), 3.74 (s, 2H), 3.22 (t, 2H), 2.46 (s, 6H), 2.42 (t, 2H), 2.09 (qn, 2H), 1.65 (qn, 2H), 1.56 (qn, 2H), 1.51 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 129.1, 119.3, 115.5, 68.2, 52.0, 51.7, 47.7, 46.4, 43.5, 30.4, 28.2, 27.4, 23.2, 22.9; HR-ESI (m/z): [M+Na] ⁺ , calculated for C ₂₈ H ₃₈ FN ₃ NaO ₈ S ₂ : 650.1982, found: 650.1974.

Step B: 4-{{5-{3-{4-{3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]amino]butane-1-sulfonic acid

Using the General HFIP deprotection method, 0.12 g of the desired product was obtained from the product from Step A.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₂₃ H ₃₁ FN ₃ O ₆ S ₂ : 528.1638, found: 528.1632.

Step C: 4-{{5-{3-{4-{3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-4-methoxycarbonylthiazol-2-yl]-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]butane-1-sulfonic acid

Using General Procedure II for the Buchwald reaction, starting from the product from Step B and the product from Synthesis 4a, 0.16 g of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.83 (d, 1H), 7.79 (s, 1H), 7.46 (d, 1H), 7.44 (t, 1H), 7.43 (dd, 1H), 7.31 (dm, 1H), 7.25 (td, 1H), 7.18 (t, 1H), 5.86 (s, 2H), 4.34 (t, 2H), 4.28 (s, 2H), 4.17 (t, 2H), 3.76 (s, 3H), 3.73 (t, 2H), 3.28 (t, 2H), 2.86 (s, 6H), 2.51 (m, 2H), 2.46 (s, 3H), 2.15 (m, 2H), 1.73 (m, 2H), 1.67 (m, 2H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.6, 127.2, 123.4, 123.2, 119.6, 117.8, 115.4, 111.9, 72.9, 68.4, 66.8, 51.9, 51.3, 47.0, 47.0, 42.2, 30.7, 26.2, 23.1, 22.9, 17.8, 17.8, -0.9; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₅₃ FN ₇ O ₇ S ₃ Si: 898.2922, found: 898.2907.

Step D: 2-({b-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-sulfobutyl)amino)-5-(3-{4-[3 -(dimethylamino)prop-1-in-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazol-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, 64 mg of the desired product was obtained from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₇ FN ₇ O ₆ S ₃ : 754.1951, found: 754.1930.

Example 242: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-phosphonobutyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Step A: Methyl 2-[tert-butoxycarbonyl(4-diethoxyphosphorylbutyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General Alkylation Procedure, starting from 1-bromo-4-diethoxyphosphorylbutane and the product of Preparation 1c, 1.28 g of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.29 (dd, 1H), 7.20 (dm, 1H), 7.13 (t, 1H), 4.10 (t, 2H), 4.01 (t, 2H), 3.93 (m, 4H), 3.75 (s, 3H), 3.42 (s, 2H), 3.22 (t, 2H), 2.23 (s, 6H), 2.08 (m, 2H), 1.78 (m, 2H), 1.71 (m, 2H), 1.51 (s, 9H), 1.45 (m, 2H), 1.18 (t, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 128.9, 119.2, 115.4, 68.1, 61.2, 52.0, 48.1, 45.9, 44.2, 30.5, 28.8, 28.0, 24.5, 23.2, 19.9, 16.7; HRMS -ERI (m/z): [M+H] ⁺ , calculated for C ₃₂ H ₄₈ FN ₃ O ₈ PS: 684.2884, found: 684.2859.

Step B: Methyl 2-(4-diethoxyphosphorylbutylamino)-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using the General HFIP deprotection method, 0.92 g of the desired product was obtained from the product from Step A.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.61 (t, 1H), 7.32 (dd, 1H), 7.22 (dm, 1H), 7.13 (t, 1H), 4.07 (t, 2H), 3.95 (m, 4H), 3.69 (s, 3H), 3.52 (brs., 2H), 3.17 (q, 2H), 3.12 (t, 2H), 2.30 (s, 6H), 2.00 (m, 2H), 1.73 (m, 2H), 1.58 (m, 2H), 1.50 (m, 2H), 1.21 (t, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 163.0, 129.0, 119.2, 115.4, 68.0, 61.2, 51.7, 48.0, 44.0, 43.8, 30.6, 29.8, 24.6, 23.3, 20.1, 16.8; HRMS -ERI (m/z): [M+H] ⁺ , calculated for C ₂₇ H ₄₀ FN ₃ O ₆ PS: 584.2359, found: 584.2340.

Stage C: methyl 2-[4-diethoxyphosphorylbutyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-5 -[3-{4-{3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product from Step B and the product from Synthesis 4a, 0.69 g of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.72 (s, 1H), 7.47 (dm, 1H), 7.44 (m, 1H), 7.31 (dd, 1H), 7.26 (m, 1H), 7.21 (dm, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.41 (t, 2H), 4.15 (t, 2H), 3.94/3.91 (m+m, 4H), 3.78 (s, 3H), 3.72 (m, 2H), 3.38 (s, 2H), 3.27 (t, 2H), 2.46 (s, 3H), 2.20 (s, 6H), 2.12 (m, 2H), 1.86 (m, 2H), 1.78 (m, 2H), 1.54 (m, 2H), 1.18 (t, 6H), 0.91 (m, 2H), -0.11 (s, 9H); HR-ESI (m/z): [M+H] ⁺ , calculated for C ₄₅ H ₆₂ FN ₇ O ₇ PS ₂ Si: 954.3643, found: 954.3627.

Step D: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-phosphonobutyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Using the General Procedure for Deprotection and Hydrolysis of Phosphonic Acid Derivatives, 288 mg of the desired product was obtained starting from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₈ FN ₇ O ₆ PS ₂ : 754.2047. found: 754.2036.

Example 243: 2-({6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-carboxybutyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Step A: methyl 2-[tert-butoxycarbonyl-(5-methoxy-5-oxopentyl)amino]-5-{3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl] thiazole-4-carboxylate

Using the General Alkylation Procedure, starting from methyl 5-bromopentanoate and the product of Preparation 1c, 0.99 g of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.28 (dd, 1H), 7.20 (dm. 1H), 7.13 (t, 1H), 4.10 (t, 2H), 4.00 (t, 2H), 3.75 (s, 3H), 3.56 (s, 3H), 3.41 (s, 2H), 3.22 (t, 2H), 2.37 (t. 2H). 2.22 (s. 6H), 2.08 (m, 2H), 1.63 (m, 2H), 1.51 (m, 2H), 1.51 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 128.9, 119.2, 115.4, 68.1, 52.1, 51.7, 48.2, 46.0, 44.3, 33.2, 30.5, 28.1, 27.3, 23.1, 22.0; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₀ H ₄₁ FN ₃ O ₇ S: 606.2649, found: 606.2644.

Step B: methyl 5-{3-{4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[(5-methoxy-5-oxopentyl)amino]thiazol-4- carboxylate

Using the General HFIP deprotection method, 0.72 g of the desired product was obtained from the product from Step A.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.59 (t, 1H), 7.29 (dd, 1H), 7.20 (dm, 1H), 7.12 (t, 1H), 4.07 (t, 2H), 3.69 (s, 3H), 3.58 (s, 3H), 3.41 (s, 2H), 3.16 (q, 2H), 3.12 (t, 2H), 2.33 (t, 2H), 2.22 (s, 6H), 2.00 (m, 2H), 1.56 (m, 2H), 1.51 (m, 2H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 173.7, 164.6, 163.0, 128.9, 119.2, 115.4, 85.1, 84.1, 68.0, 51.7, 51.7, 48.2, 44.3, 44.0, 33.4, 30.6, 28.5, 23.3, 22.4; HR-MSR (m/z): [M+ H] ⁺ , calculated for C ₂₅ H ₃₃ FN ₃ O ₅ S: 506.2125, found: 506.2123.

Step C: methyl 5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophen oxy]propyl]-2-[(5-methoxy-5-oxopentyl)-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino ]pyridazin-3-yl]amino]thiazol-4-carboxylate

Using General Procedure II for the Buchwald reaction, starting from the product from Step B and the product from Synthesis 4a, 0.79 g of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.83 (dm, 1H), 7.65 (s, 1H), 7.45 (dm, 1H), 7.43 (m, 1H), 7.30 (dd, 1H), 7.25 (m, 1H), 7.20 (dm, 1H), 7.15 (t, 1H), 5.85 (s, 2H), 4.37 (t, 2H), 4.14 (t, 2H), 3.77 (s, 3H), 3.71 (m, 2H), 3.56 (s, 3H), 3.39 (s, 2H), 3.26 (t, 2H), 2.45 (s, 3H), 2.43 (t, 2H), 2.20 (s, 6H), 2.12 (m, 2H), 1.71 (m, 2H), 1.60 (m, 2H), 0.91 (m, 2H), -0.11 (s, 9H); HR-ESI (m/z): [M+H] ⁺ , calculated for C ₄₃ H ₅₅ FN ₇ O ₆ S ₂ Si: 876.3409, found: 876.3378.

Step D: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-carboxybutyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure, 296 mg of the desired product was obtained from the product from Step C.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₅ H ₃₇ FN ₇ O ₅ S ₂ : 718.2282, found: 718.2263.

Example 244: 2-[(3-Aminopropyl){6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino]-5-(3-{2-fluoro- 4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazol-4-carboxylic acid

Example 245: 2-[(3-Azidopropyl){6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino]-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Example 246: 2-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino]-5-[3-(4-{3-[(dimethylamino)methyl]bicyclo[1.1.1]pentan-1-yl}-2-fluorophenoxy)propyl]-1,3-thiazole-4-carboxylic acid

Example 247: 6-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino]-3-(1-{[3-(2-{[(3S)-3,4-dihydroxybutyl]amino}ethoxy)-5,7-dimethyladamantan-1-yl]methyl}-5-methyl-1H-pyrazol-4-yl)pyridine-2-carboxylic acid

Using the General Procedure for an Amine Substitution and Hydrolysis Reaction, starting from the product of Preparation 14 and 2-[(4S)-2,2-dimethyl-1,3-dioxolan-4-yl]ethanamine as the appropriate amine, the desired product was obtained.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₂ H ₅₄ N ₉ O ₅ S: 796.3969. found: 796.3965.

Example 249: 6-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino]-3-[1-({3,5-dimethyl -7-[2-(methylamino)ethoxy]adamantan-1-yl}methyl)-5-methyl-1H-pyrazol-4-yl]pyridine-2-carboxylic acid

Example 250: 6-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino]-3-[1-({3-[2-(dimethylamino)ethoxy]-5,7-dimethyladamantan-1-yl}methyl)-5-methyl-1H-pyrazol-4-yl]pyridine-2-carboxylic acid

Using the General Procedure for Carrying Out an Amine Substitution and Hydrolysis Reaction starting from the product of Preparation 14 and dimethylamine as the appropriate amine, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₀ H ₅₀ N ₉ O ₃ S: 736.3757, found: 736.3751.

Example 251: 6-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino]-3-{1-[(3,5-dimethyl-7- {2-[(2-sulfoethyl)amino]ethoxy}adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}pyridine-2-carboxylic acid

Example 252: 6-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino]-3-{1-[(3,5-dimethyl-7-{2-[methyl(2-sulfoethyl)amino]ethoxy}adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}pyridine-2-carboxylic acid

Example 253: 2-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(pent-4-yn-1-yl)amino]-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Step A: Methyl 2-{tert-butoxycarbonyl(5-trimethylsilylpent-4-ynyl)amino]-5-[3-(2-fluoro-4-iodophenoxy)propyl]-1,3-thiazol-4-carboxylate

Using the General Procedure of Mitsunobu reaction, starting from the product of Preparation 1a (10 mmol) as the appropriate carbamate and 5-trimethylsilylpent-4-yn-1-ol (2 equiv.) as the appropriate alcohol, 6.0 g (89%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.91 (dm, 1H), 7.69 (s, 1H), 7.53 (dm, 1H), 7.39 (m, 1H), 7.34 (dd, 1H), 7.25 (dm, 1H), 7.21 (m, 1H), 7.19 (t, 1H), 4.38 (t, 2H), 4.16 (t, 2H), 3.87 (s, 2H), 3.27 (t, 2H), 2.88 (t, 1H), 2.51 (s, 3H), 2.46 (s, 3H), 2.31 (m, 2H), 2.14 (m, 2H), 1.91 (m, 2H); HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₃ FN ₇ O ₃ S ₂ : 670.2070, found: 670.2052.

Step B: Methyl 5-[3-(2-fluoro-4-iodophenoxy)propyl]-2-(5-trimethylsilylpent-4-ynylamino)-1,3-thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A (6.0 g, 8.9 mmol, 1 equiv) as the appropriate Boc-protected amine, 4.46 g (87%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.61 (t, 1H), 7.59 (dd, 1H), 7.45 (dm, 1H), 6.97 (t, 1H), 4.03 (t, 2H), 3.69 (s, 3H), 3.22 (m, 2H), 3.11 (t, 2H), 2.28 (t, 2H), 1.99 (m, 2H), 1.68 (m, 2H), 0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 134.0, 124.9, 117.6, 107.8, 85.1, 68.1, 51.7, 43.5, 30.6, 28.0, 23.3, 17.1, 0.6; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₂₂ H ₂₉ FIN ₂ O ₃ SSi: 575.0697, found: 575.0695.

Step C: methyl 5-{3-{4-{3-{tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-(5-trimethylsilylpent-4-ynylamino)- 1,3-thiazole-4-carboxylate

Using the General Sonogashira Reaction Procedure starting from the product from Step B (4.46 g, 7.76 mmol, 1 equiv) and tert-butyl N-methyl-N-prop-2-ynylcarbamate (2.62 g, 15.53 mmol, 2 equiv) as the appropriate acetylene, 4.44 g (93%) of the desired product was obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.61 (t, 1H), 7.30 (brd, 1H), 7.21 (dm, 1H), 7.12 (t, 1H), 4.23 (brs, 2H), 4.07 (t, 2H), 3.69 (s, 3H), 3.22 (m, 2H), 3.12 (t, 2H), 2.87 (brs, 3H), 2.28 (t, 2H), 2.00 (m, 2H), 1.68 (m, 2H), 1.41 (s, 9H), 0.11 (s, 9H); HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₁ H ₄₃ FN ₃ O ₅ SSi: 616.2677, found: 616.2659.

Stage D: methyl 5-{3-{4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[{5-methyl-6-{(Z)-{ 3-(2-trimethylsilyl ethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]-(5-trimethylsilylpent-4-ynyl)amino]-1,3-thiazol-4-carboxylate

Using General Procedure I for the Buchwald reaction, starting from the product from Step C (4.44 g, 7.2 mmol) and reacting in 1,4-dioxane at 120°C, 3.85 g (54%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.83 (d, 1H), 7.64 (s, 1H), 7.45 (dd, 1H), 7.42 (td, 1H), 7.31 (brd., 1H), 7.24 (td, 1H), 7.21 (d, 1H), 7.15 (t, 1H), 5.85 (s, 2H), 4.37 (t, 2H), 4.20 (br., 2H), 4.14 (t, 2H), 3.77 (s, 3H), 3.71 (t, 2H), 3.25 (t, 2H), 2.84 (br., 3H), 2.44 (s, 3H), 2.37 (t, 2H), 2.12 (m, 2H), 1.91(m, 2H), 1.4 (s, 9H), 0.91 (t, 2H), 0.09 (s, 9H), -0.12 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 163.1, 157.5, 155.2, 150.9, 137.6, 129.1, 127.2, 125.4, 123.4, 123.2, 119.3, 117.4, 115.4, 111.9, 107.5, 85.2, 72.9, 68.4, 66.7, 52.0, 46.5, 38.6, 33.8, 31.0, 28.5, 26.2, 23.2, 17.9, 17.8, 17.1, 0.5, -1.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₉ H ₆₅ FN ₇ O ₆ S ₂ Si ₂ : 986.3960, found: 986.3932.

Step E: 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-pent-4-ynylamino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]-1,3-thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure starting from the product from Step D followed by purification by reverse phase _{preparative chromatography (C18, 25 mM NH4HCO3 in} water:MeCN) gave the desired product.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₃ FN ₇ O ₃ S ₂ : 670.2070, found: 670.2052.

Example 254: 2-[(4-Aminobutyl){6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino]-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Example 255: 2-[(4-Azidobutyl){6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino]-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Example 256: 2-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(hex-5-yn-1-yl)amino]-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Example 257: 2-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(pent-4-yn-1-yl)amino]-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Example 258: 2-[(3-Azidopropyl){6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino]-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Example 259: 2-[(3-Aminopropyl){6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino]-5-(3-{4-[3 -(dimethylamino)prop-1-in-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazol-4-carboxylic acid

Example 260: 2-[(4-Aminobutyl){6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino]-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Example 261: 2-[(4-Azidobutyl){6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino]-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Example 262: 2-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(hex-5-yn-1-yl)amino]-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Example 263: 2-[(4-Aminobutyl){6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino]-5-(3-{2-fluoro-4-[3-(methylamino)propyl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Example 264: 2-[(4-Azidobutyl){6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}amino]-5-(3-{2-fluoro-4-[3-(methylamino)propyl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Example 265: 2-[{6-[(1,3-Benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(hex-5-yn-1-yl)amino]-5-(3-{2-fluoro-4-[3-(methylamino)propyl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid

Example 266: 5-[3-[4-[3-[tert-Butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[[5-methyl-6-[(Z)-[ 3-(2-tr imethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]-pent-4-ynylamino]thiazol-4-carboxylic acid acid

A mixture of 500 mg of the product from Example 253, Step D, and 106 mg (2.5 mmol, 5 equiv) of LiOH*H ₂ O in a mixture of 5 mL of THF and 2 mL of water was stirred at 40 °C for 16 h and then purified by crystallization from Et ₂ O to give 356 mg (78%) of the desired product.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₄₅ H ₅₅ FN ₇ O ₆ S ₂ Si: 900.3409, found: 900.3383

Example 267: 2-[5-Azidopentyl-[6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]-1,3-thiazole-4-carboxylic acid

Step A: methyl 2-[tert-butoxycarbonyl-[5-[tert-butyl(dimethyl)silyl]oxypentyl]amino]-5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop- 1-ynyl]-2-fluorophenoxy]propyl]-1,3-thiazol-4-carboxylate

Using the Obito Mitsunobu reaction procedure, starting from the product of Preparation 1b (0.7 mmol) as the appropriate carbamate and 5-[tert-butyl(dimethyl)silyl]oxypentan-1-ol (1.5 equiv) as the appropriate alcohol, 494 mg (91%) of the desired product were obtained.

LC/MS (C ₃₉ H ₆₀ FN ₃ O ₈ SSiNa) 800 [M+Na] ⁺ .

Step B: methyl 5-{3-{4-{3-{tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-[tert-butyl(dimethyl) silyl]oxypentylamino]-1,3-thiazole-4-carboxylate

Using the General HFIP deprotection procedure, starting from the product from Step A (490 mg, 0.63 mmol, 1 equiv) as the appropriate Boc-protected amine, 240 mg (56%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.57 (br., 1H), 7.31 (d, 1H), 7.21 (d, 1H), 7.12 (t, 1H), 4.23 (br., 2H), 4.07 (t, 2H), 3.69 (s, 3H), 3.56 (t, 2H), 3.14 (m, 2H), 3.11 (t, 2H), 2.86 (br., 3H), 2.00 (quint., 2H), 1.51 (m, 2H), 1.45 (m, 2H), 1.41 (s, 9H), 1.33 (m, 2H), 0.84 (s, 9H), 0 (s, 6H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 119.3, 115.4, 68.0, 62.8, 51.7, 44.5, 38.6, 33.8, 32.4, 30.6, 28.9, 28.5, 26.3, 23.3, 23.2, -4.9; HR-ESI (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₅₃ FN ₃ O ₆ SSi: 678.3408, found: 678.3393.

Stage C: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-{tert-butyl(dimethyl)silyl]oxypentyl- [ 5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-1,3-thiazol-4-carboxylate

Using General Procedure I for the Buchwald reaction, starting from the product from Step B (235 mg) and reacting in 1,4-dioxane at 120°C, 220 mg (60%) of the desired product were obtained.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.81 (dd, 1H), 7.62 (s, 1H), 7.45 (dd, 1H), 7.42 (m, 1H), 7.28 (dd, 1H), 7.24 (m, 1H), 7.19 (m, 1H), 7.15 (t, 1H), 5.84 (s, 2H), 4.38 (t, 2H), 4.20 (s, 2H), 4.16 (t, 2H), 3.78 (s, 3H), 3.73 (t, 2H), 3.55 (t, 2H), 3.26 (t, 2H), 2.85 (s, 3H), 2.44 (s, 3H), 2.13 (m, 2H), 1.71 (m, 2H), 1.51 (m, 2H), 1.41 (s, 9H), 1.40 (m, 2H), 0.92 (t, 2H), 0.80 (s, 9H), -0.04 (s, 6H), -0.10 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm. 163.2, 147.5, 137.6, 129, 127.1, 123.5, 123.1, 119.3, 117.7, 115.7, 111.9, 73.0, 68.6, 66.8, 62.7, 51.8, 47.0, 38.6, 33.8, 32.4, 31.0, 28.5, 27.1, 26.2, 23.1, 23.0, 17.9, 17.8, -1.0, -5.0; HR-MSR (m/z): [M+H] ⁺ , calculated for C ₅₂ H ₇₅ FN ₇ O ₇ S ₂ Si ₂ : 1048.4692, found: 1048.4692.

Stage D: methyl 5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-2-[5-hydroxypentyl-[5-methyl-6-[ (Z)-{3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl]amino]-1,3-thiazol-4-carboxylate

A mixture of the product from Step C (0.3 mmol) and 18 mg of camphorsulfonic acid (0.07 mmol, 0.25 equiv) in 2 mL of a 1:1 mixture of DCM and MeOH was stirred at 60 °C for 1.5 h. The product was purified by flash column chromatography using heptane and EtOAc as eluents to give 195 mg (66%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (d, 1H), 7.66 (s, 1H), 7.46 (d, 1H), 7.43 (t, 1H), 7.32 (d, 1H), 7.25 (t, 1H), 7.22 (d, 1H), 7.16 (t, 1H), 5.86 (s, 2H), 4.36 (t, 2H), 4.20 (s, 2H), 4.15 (t, 2H), 3.78 (s, 3H), 3.72 (t, 2H), 3.40 (t, 2H), 3.26 (t, 2H), 2.84 (s, 3H), 2.46 (s, 3H), 2.12 (qn, 2H), 1.69 (qn, 2H), 1.49 (m, 2H), 1.40 (s, 9H), 1.4 (qn, 2H), 0.92 (t, 2H), -0.11 (s, 9H); ¹³ C NMR (125 MHz, DMSO-d ₆ ) δ ppm 129.1, 127.2, 123.4, 123.2, 119.3, 117.6, 115.5, 112.0, 72.9, 68.4, 66.7, 61.0, 52.0, 47.0, 38.5, 33.9, 32.5, 31.0, 28.5, 27.1, 23.2, 23.1, 17.9, 17.8, -1.0; HR-MSR (m/z): [M+Na] ⁺ , calculated for C ₄₆ H ₆₀ FN ₇ NaO ₇ S ₂ SiNa: 956.3641, found: 956.3646.

Stage E: methyl 2-[5-azidopentyl-[5-methyl-6-[(Z)-[3-(2-trimethylsilylethoxymethyl)-1,3-benzothiazol-2-ylidene]amino]pyridazin-3-yl] amino]-5-[3-[4-[3-[tert-butoxycarbonyl(methyl)amino]prop-1-ynyl]-2-fluorophenoxy]propyl]-1,3-thiazol-4-carboxylate

A mixture of 158 mg of the product from Step D, 70 µL of triethylamine (0.50 mmol, 3 equiv), and 83 mg of p-tolylsulfonyl 4-methylbenzenesulfonate (0.25 mmol, 1.5 equiv) in 1 mL of DCM was stirred for 5 h. After concentration, the residue was dissolved in 1 mL of acetonitrile and 133 mg of sodium azide (2.0 mmol, 12 equiv) was added, and the resulting mixture was stirred at 80 °C for 0.5 h. The product was purified by flash column chromatography using heptane and EtOAc as eluents to afford 120 mg (73%) of the desired product.

¹ H NMR (500 MHz, DMSO-d ₆ ) δ ppm 7.84 (dm, 1H), 7.69 (s, 1H), 7.47 (dm, 1H), 7.44 (m, 1H), 7.32 (brd, 1H), 7.26 (m, 1H), 7.22 (dm, 1H), 7.17 (t, 1H), 5.86 (s, 2H), 4.37 (t, 2H), 4.20 (brs, 2H), 4.15 (t, 2H), 3.78 (s, 3H), 3.72 (m, 2H), 3.36 (t, 2H), 3.27 (t, 2H), 2.84 (brs, 3H), 2.46 (s, 3H), 2.13 (m, 2H), 1.72(m, 2H), 1.64 (m, 2H), 1.43 (m, 2H), 1.40 (s, 9H), 0.92 (m, 2H), -0.11 (s, 9H); HR-ESI (m/z): [M+H] ⁺ , calculated for C ₄₆ H ₆₀ FN ₁₀ O ₆ S ₂ Si: 959.3892, found: 959.3892.

Step F: 2-[5-adipopentyl-[6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl]amino]-5-{3-[2-fluoro-4-{3-(methylamino)prop-1-ynyl]phenoxy]propyl]-1,3-thiazole-4-carboxylic acid

Using the General Deprotection and Hydrolysis Procedure starting from the product from Step E followed by purification by reverse phase preparative chromatography (C18, 0.1% TFA in water:MeCN) gave the desired product.

HR-MSR (m/z): [M+H] ⁺ , calculated for C ₃₄ H ₃₆ FN ₁₀ O ₃ S ₂ : 715.2397, found: 715.2391.

Example 268: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3-[2-(3-hydroxypropylamino)ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Using the General Procedure for Carrying Out an Amine Substitution and Hydrolysis Reaction, starting from the product of Preparation 14 and 3-aminopropan-1-ol as the appropriate amine, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₅₂ N ₉ O ₄ S: 766.3863, found: 766.3860.

Example 269: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3-[2-(3-methoxypropylamino)ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Using the General Procedure for Carrying Out an Amine Substitution and Hydrolysis Reaction, starting from the product of Preparation 14 and 3-methoxypropan-1-amine as the appropriate amine, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₂ H ₅₄ N ₉ O ₄ S: 780.4019, found: 780.4019.

Example 270: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3,5-dimethyl-7-(2-morpholinoethoxy)-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Using the General Procedure for Carrying Out an Amine Substitution and Hydrolysis Reaction, starting from the product of Preparation 14 and morpholine as the appropriate amine, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₂ H ₅₂ N ₉ O ₄ S: 778.3863, found: 778.3858.

Example 271: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3-[2-(2-carboxyethylamino)ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Using the General Procedure for an Amine Substitution and Hydrolysis Reaction, starting from the product of Preparation 14, 3-aminopropanoic acid as the appropriate amine and 10 equiv. K ₂ CO ₃ as the base, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₁ H ₅₀ N ₉ O ₅ S: 780.3656, found: 780.3658.

Example 272: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3-[2-[(3-hydroxyphenyl)methylamino]ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Using the General Procedure for Carrying Out an Amine Substitution and Hydrolysis Reaction, starting from the product of Preparation 14 and 3-(aminomethyl)phenol as the appropriate amine, the desired product was obtained.

HR-ERI (m/z): [M+H] ⁺ , calculated for C ₄₅ H ₅₂ N ₉ O ₄ S: 814.3863, found: 814.3861.

The following Examples 273-280 were synthesized using the General Procedure for an Amine Substitution and Hydrolysis Reaction starting from the product of Preparation 14 and the appropriate amine.

Example 273: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3,5-dimethyl-7-(2-pyrrolidin-1-ylethoxy)-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Example 274: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamine]-3-[1-[[3,5-dimethyl-7-[2-(4-methylpiperazin-1-yl)ethoxy]-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Example 275: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3-[2-(4-hydroxybutylamino)ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Example 276: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamine]-3-[1-[[3,5-dimethyl-7-(2-piperazin-1-ylethoxy)-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Example 277: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3-[2-[3-hydroxypropyl(methyl)amino]ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Example 278: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamine]-3-[1-[[3-[2-[4-hydroxybutyl(methyl)amino]ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Example 279: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3-[2-[[3-hydroxy-2-(hydroxymethyl)propyl]amino]ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Example 280: 6-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamine]-3-[1-[[3-[2-[bis(3-hydroxypropyl)amino]ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid

Example 281: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamine]-5-[3-[2-fluoro-4-(3-piperazin-1-ylprop-1-ynyl)phenoxy]propyl]thiazole-4-carboxylic acid

Example 282: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-[3-(4-methylpiperazin-1-yl)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Example 283: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamine]-5-[3-[2-fluoro-4-[3-[3-hydroxypropyl(methyl)amino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Example 284: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-[[(3S)-3,4-dihydroxybutyl]methylamino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Example 285: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-[3-(3-hydroxypropylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Example 286: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamine]-5-[3-[4-[3-[[(3S)-3,4-dihydroxybutyl]amino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Example 287: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-[3-[4-hydroxybutyl(methyl)amino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Example 288: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamine]-5-[3-[4-[3-[[(3R)-3,4-dihydroxybutyl]methylamine]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

Example 289: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-[3-(4-hydroxybutylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid

Example 290: 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-[[(3R)-3,4-dihydroxybutyl]amino]prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid

PHARMACOLOGICAL STUDY

EXAMPLE A: Fluorescence polarization analysis data

Fluorescence polarization measures the rotation of fluorescent molecules in solution, with the larger the molecule, the more polarized the fluorescence emission.

The fluorescent PUMA (UniProtKB®, main accession number Q9BXH1 - SEQ ID:01) fluorescein-betaAla-Ahx-AREIGAQLRRMADDLNAQY-OH probe from Biopeptides binds to GST(1-218)-(FACTOR_XA)-hsBCLXL(2-209) having the amino acid sequence (SEQ ID:02):

which results in an increase in anisotropy. If a compound is added that competitively binds to the same site as the probe, thereby releasing it, the anisotropy decreases due to the increase in the amount of free probe.

Eleven-point serial dilutions of each compound were prepared in DMSO, with the final buffer containing 10 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid [HEPES], 150 mM NaCl, 0.05% Tween 20, pH 7.4, and 5% DMSO. The final protein concentration in the assay was 20 nM with the fluorescent probe present at 10 nM. Samples were incubated for 2 h at 23°C, after which fluorescence polarization was measured on a Biotek SynergyNeo plate reader (excitation 485 nm, emission 525 nm, parallel and perpendicular readings). Dose-response curves were then constructed with XL-Fit software using a 4-parameter logistic model (sigmoidal dose-response model), and inhibitory concentrations that resulted in a 50% increase in fluorescence intensity (IC ₅₀ ) were determined. K _I values were determined from IC ₅₀ values according to Cer et al., Nucleic Acids Res, 2009, Jul 1; 37(WebServer issue): W441–W445.

The results are summarized in Table 1. They show that the compounds of the present invention inhibit the interaction between the Bcl-xL protein and the fluorescent peptide described above.

EXAMPLE B: AlphaLISA analysis data

The AlphaLISA assay measures the increase in alpha signal upon binding of biotinylated GST(1-218)-(FACTOR XA)-hsBCLXL(2-209) (SEQ ID:02 - GST UniProtKB® Primary Accession Number P08515, and BCLXL UniProtKB® Primary Accession Number Q07817-1) attached to a streptavidin-labeled alpha donor bead to an N-terminally labeled BIM-derived peptide (fluorescein-betaAla-Ahx- SEQ ID:05, where SEQ ID:05 is DMRPEIWIAQELRRIGDEANAYYARR) attached to an anti-FTIC AlphaLISA acceptor bead.

GST(1-218)-(FACTOR_XA)-hsBCLXL(2-209) was biotinylated in 50 mM phosphate buffer using a 20-fold excess of EZ Link NHS-LC-biotin (thermoFisher, cat. no. 21336) overnight at 4°C.

Addition of a compound that competitively binds to the same site as the peptide will result in a decrease in the alpha signal of the available donor granule-protein-peptide-acceptor granule complex due to displacement of the peptide.

Eleven-point serial dilutions of each compound were prepared in DMSO, with the final buffer being 10 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid [HEPES], 150 mM NaCl, 0.05% Tween 20, pH 7.4, and 4% DMSO. The final protein concentration for the assay was 20 pM with peptide present at 1 nM. Alpha beads were used at a final concentration of 5 μg/mL. Samples were incubated overnight at 23°C after addition of acceptor beads. Finally, donor beads were added and incubated for 2 h at 23°C, after which the alpha signal (excitation 680 nm, emission 615 nm) was measured on a Biotek Synergy2 plate reader. Dose-response curves were then constructed using XL-Fit software using a 4-parameter logistic model (sigmoidal dose-response model), and inhibitory concentrations that resulted in a 50% increase in fluorescence intensity (IC ₅₀ ) were determined.

The results are summarized in Table 2.

EXAMPLE C: Extinction Analysis Data

The fluorescence quenching assay measures the change in fluorescence intensity of the C-terminally Cy5-tagged BCL-xL protein His-(EK)-hsBCLXL(2-197)[N197C] (UniProtKB®, main accession number Q07817-1), which has the amino acid sequence (SEQ ID: 03):

which is linked at the C-terminal end to amino acid X, which corresponds to cysteine labeled on sulfur with Sulfo-Cyanine5 from Lumiprobe GmbH, catalog number 13380,

upon binding to a C-terminal-labeled peptide derived from PUMA (UniProtKB®, main accession number Q9BXH1) having the amino acid sequence (SEQ ID: 04): [QWAREIGAQLRRMADDLNAQY], which is linked at the C-terminal region to the amino acid X', where X' is a cysteine labeled on sulfur with TQ5WS from AAT Bioquest, catalog number 2079.

Addition of a compound that competitively binds to the same site as the peptide will result in an increase in the fluorescence intensity of the protein due to displacement of the fluorescence quencher.

Eleven-point serial dilutions of each compound were prepared in DMSO, with the final buffer containing 10 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid [HEPES], 150 mM NaCl, 0.05% Tween 20, pH 7.4, and 5% DMSO. The final protein concentration in the assay was 1 nM with peptide present at 400 nM. Samples were incubated for 2 h at 23°C, after which fluorescence intensity was measured on a Biotek SynergyNeo plate reader (excitation 620 nm, emission 680 nm). Dose-response curves were then constructed with XL-Fit software using a 4-parameter logistic model (sigmoidal dose-response model), and inhibitory concentrations that resulted in a 50% increase in fluorescence intensity (IC ₅₀ ) were determined. K _I values were determined from IC ₅₀ values according to Cer et al., Nucleic Acids Res, 2009, Jul 1; 37(WebServer issue): W441–W445.

The results are summarized in Table 3.

The results of Tables 1-3 show that the compounds of the present invention are potent inhibitors of Bcl-xL protein.

EXAMPLE D: Study of the effect of Bcl-xL inhibitors on the survival of MOLT-4 or H146 cells using the MTT assay

The MTT colorimetric assay is based on the mitochondrial reduction of tetrazolium salt by living cells. The number of viable cells is proportional to the production of formazan salts, which can be read spectrophotometrically at 540 nm.

MOLT-4 and H146 cells were purchased from ATCC and cultured in RPMI 1640 supplemented with 10% heat-inactivated fetal bovine serum, penicillin (100 IU/ml), streptomycin (100 mg/ml), and L-glutamine (2 mM). Cells were cultured at 37°C in a humidified atmosphere containing 5% CO ₂ . Cells were seeded in 96-microwell plates (150 μl/well) and exposed to compounds for 48 h (3.16-fold serially diluted; 9 concentrations of each, in triplicate). After the incubation time, 15 μl of MTT solution (5 mg/ml) were added per well and the cells were incubated for another 4 h. Then 100 μl of 10% sodium dodecyl sulfate (SDS)/10 mM HCl were added per well and the plate was incubated overnight before the absorbance was measured at 540 nm. IC ₅₀ values were calculated using a standard four-parameter curve fit. The IC ₅₀ value is defined as the concentration of compound at which the MTT signal is reduced to 50% of the signal measured for the control. Results are the average of at least 2 independent experiments and are presented in Table 4 below.

These data show that most of these compounds are active in cells and can induce a dose-dependent decrease in the survival of H146 and Molt-4 cell lines.

EXAMPLE E: Study of pharmacodynamics and tumor regression

Therapeutic and pharmacodynamic effects of small molecules targeting Bcl-xL in vivo were determined in the MOLT-4 T-cell acute lymphoblastic leukemia (T-ALL) model administered intravenously (i.v.). Test compounds were formulated with 20% hydroxypropyl-β-cyclodextrin/25 mM hydrogen chloride (HPBCD/HCl).

Materials and methods

MOLT-4 cells (ATCC #CRL-1582) were cultured in RPMI supplemented with 10% FBS. Cells were resuspended in 50% Matrigel (BD Biosciences), and 0.1 ml of the suspension containing 5 × 10 ⁶ cells was inoculated subcutaneously into the right flank of female NOD SCID mice (Charles River). For efficacy studies, after tumors reached an appropriate volume, mice were randomized (8 animals per group) using Easy stat software. Vehicle control (HPBCD/HCl), Example 73 (3.75 or 7.5 mg/kg), or Example 100 (3.75 mg/kg) were administered i.v. (twice weekly for 3 weeks - Q3D6). Mice body weight was monitored three times per week and tumor size was measured using an electronic caliper. Tumor volume was estimated by measuring the minimum and maximum tumor diameters and calculating using the formula: (minimum diameter) ² (maximum diameter)/2. At the end of the treatment cycle (day 17), tumor growth inhibition was calculated using the formula:

The response was assessed as follows: CR (complete response) if the tumor size was ≤25 ^mm3 for at least three consecutive measurements, PR (partial response) if the tumor size was between 25 ^mm3 and half the initial size for at least three consecutive measurements. Mice were sacrificed at the first measurement in which the tumor volume exceeded 2000 ^mm3 or at the first sign of deterioration in the health of the animals.

For pharmacodynamic studies, after tumors reached an appropriate volume, mice were randomized (3 animals per group) using Easy stat software. Vehicle control (HPBCD/HCl) or small molecules targeting Bcl-xL were administered i.v. (once daily - QD) at a dose of 7.5 mg/kg. Tumor samples were collected 6 h post-dose and lysed (10 mM HEPES pH 7.4, 142.5 mM KCl, 5 mM _MgCl2 , 1 mM EDTA, 1% NP40, protease and phosphatase inhibitor cocktails - Calbiochem). Cleared lysates were prepared for immunodetection of cleaved PARP and cleaved caspase 3 using the MSD apoptosis panel whole cell lysate kit (MSD) in 96-well plates according to the manufacturer's instructions and analyzed on a QuickPlex SQ 120 instrument. Whole blood samples were analyzed on a Hematology Analyzer Coulter Ac⋅T diff instrument (Beckman Coulter).

All experiments were carried out in accordance with current French regulations after approval by the Ethics Committee of the Servier Research Institute (IdRS). NOD SCID mice were maintained in accordance with established regulations.

Results

The efficacy of Example 73 and Example 100 on MOLT-4 xenografts is shown in Table 5. Treatment was started 12 days after inoculation with tumor cells (mean size: 214 ^mm3 ). Vehicle (HPBCD/HCl), Example 73 (3.75 and 7.5 mg/kg), or Example 100 (3.75 mg/kg) were dosed intravenously every 3 days for a total of 6 administrations.

On day 17 after the start of treatment, the tumor growth inhibition (%TGI) for Example 73 was 56.9% at the dose of 3.75 mg/kg and 83.3% at the dose of 7.5 mg/kg (p<0.05), as shown in Table 5. At the same time point, the %TGI induced by Example 100 at the dose of 3.75 mg/kg was 64.6% (p<0.05).

No clinically significant weight loss was observed as a result of treatment.

The effects of small molecules targeting Bcl-xL on apoptosis induction in MOLT-4 tumor cells and circulating platelet counts are shown in Table 6. Treatment was started 18 days after tumor cell inoculation (mean size: 349 mm). Vehicle (HPBCD/HCl), Example 74, Example 76, and Example 73 (7.5 mg/kg) were dosed once i.v. and samples were collected 6 hours later. All compounds showed induction of apoptosis markers, namely cleaved PARP (14.2- to 26.6-fold range compared to control) and cleaved caspase 3 (4.7- to 5.1-fold range compared to control). Furthermore, given the well-described role of Bcl-xL in regulating platelet lifespan, all tested compounds caused a significant reduction in platelet counts (to 2-4% of control values).

In conclusion, this study shows that the small molecules targeting Bcl-xL described in Examples 73, 74, 76, and 100 are active in vivo following intravenous administration. Tumor regression, induction of apoptosis in tumor cells, and a strong reduction in circulating platelet numbers were observed, consistent with the previously described role of Bcl-xL in controlling apoptosis and regulating platelet survival (Youle and Strasser, Nat. Rev. Mol. Cell Biol. 2008 Jan; 9(1):47-59; Zhang et al., Cell Death Differ. 2007 May; 14(5):943-51; Mason et al., Cell 2007 Mar 23; 128(6): 1173-86). Furthermore, no clinically significant weight loss was observed at effective doses, and platelet loss was restored after treatment cessation (data not shown). Overall, these data indicate that there is an acceptable therapeutic window for the use of these Bcl-xL-targeted small molecules in the treatment of cancer.

EXAMPLE F: In vivo pharmacodynamic profile of compounds of formula (I)

The pharmacokinetic profile of compounds of formula (I) was evaluated in rodents (mice, rats) after administration by the p.o. and/or i.v. The formulation was selected based on the physicochemical properties of the test drug and the route of administration. A single dose of the drug (<5 mg/kg) prepared in an adapted formulation was administered to animals by the i.v. (bolus or 10-minute infusion) or p.o. (stomach tube) route (3 animals/route). Blood samples from each animal (up to 6 samples/animal) were collected for 24 h after dosing, and plasma concentrations of the test compound were determined by extraction followed by liquid chromatography coupled with tandem mass spectrometric detection (LC/MS-MS).

In some cases, the following experimental protocol was used to determine the pharmacokinetic profile of the compounds of the present invention in Wistar rats:

The drug was prepared as a mixture of polyethyleneglycol 300/anhydrous ethanol/NaCl 0.9% (40/10/50 v/v/v). The drug was administered intravenously to male Wistar rats (3 animals) at a dose of 0.75 mg/kg (10 min infusion, 5 ml/kg). Blood samples were collected from each animal at the following time points: completion of infusion (10 min), 0.5 h, 1 h, 3 h, 6 h, and 24 h after dosing. Plasma concentrations of the test compound were determined by extraction followed by liquid chromatography coupled with tandem mass spectrometric detection (LC/MS-MS).

The lower limit of quantification was 2.5 ng/mL.

The results allow ranking the compounds of the present invention based on their plasma concentration, elimination rate constant, clearance and volume of distribution in order to assess the therapeutic range of these compounds in an animal model.

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<---

Claims (181)

1. Compound of formula (I) wherein R ₁ and R ₂ independently of one another represent a group selected from hydrogen; linear or branched C ₁ -C ₆ alkyl optionally substituted with hydroxy or C ₁ -C ₆ alkoxy group; C ₃ -C ₆ cycloalkyl; trifluoromethyl; linear or branched C ₁ -C ₆ alkylene heterocycloalkyl, wherein the heterocycloalkyl group is optionally substituted with a linear or branched C ₁ -C ₆ alkyl group; or R ₁ and R ₂ together with the carbon atoms that carry them form a C ₃ -C ₆ cycloalkylene group, R ₃ is a group selected from hydrogen; C ₃ -C ₆ cycloalkyl; linear or branched C ₁ -C ₆ alkyl; -X ₁ -NR _a R _b ; -X ₁ -N ⁺ R _a R _b R _c ; -X ₁ -OR _c ; -X ₁ -COOR _c ; -X ₁ -PO(OH) ₂ ; -X ₁ -SO ₂ (OH); -X ₁ -N ₃ and R _a and R _b independently of one another represent a group selected from hydrogen; heterocycloalkyl; linear or branched C ₁ -C ₆ alkyl optionally substituted with one or two hydroxyl groups; C ₁ -C ₆ alkylene-SO ₂ OH; C ₁ -C ₆ alkylene-SO ₂ O ^- ; C ₁ -C ₆ alkylene-COOH; C ₁ -C ₆ alkylene-PO(OH) ₂ ; _Cl -C ₆ alkylene-NR _d R _e ; C ₁ -C ₆ alkylene-N ⁺ R _d R _e R _f ; groups or R _a and R _b together with the nitrogen atom carrying them form the B ₁ cycle; or R _a , R _b and R _c together with the nitrogen atom carrying them form a bridging C ₃ -C ₈ heterocycloalkyl, R _c , R _d , R _e , R _f independently of each other represent hydrogen or a linear or branched C ₁ -C ₆ alkyl group, or R _d and R _e together with the nitrogen atom carrying them form the B ₂ cycle, or R _d , R _e and R _f together with the nitrogen atom carrying them form a bridging C ₃ -C ₈ heterocycloalkyl, Het ₁ is a group selected from Het ₂ is a group selected from A ₁ means S, A ₂ means CH, G is selected from the group consisting of -C(O)OR _G3 , -C(O)NR _G1 R _G2 , -C(O)R _G2 , -NR _G1 C(O)R _G2 , where R _G1 and R _G2 are each independently selected from the group consisting of hydrogen, C ₁ -C ₆ alkyl optionally substituted with 1-3 halogen atoms, C ₂ -C ₆ alkenyl, C ₂ -C ₆ alkynyl, C ₃ -C ₆ cycloalkyl, phenyl and -(CH ₂ ) _1-4 -phenyl; R _G3 is selected from the group consisting of C ₁ -C ₆ alkyl optionally substituted with 1-3 halogen atoms, C ₂ -C ₆ alkenyl, C ₂ -C ₆ alkynyl, C ₃ -C ₆ cycloalkyl, phenyl and -(CH ₂ ) _1-4 -phenyl; or R _G1 and R _G2, together with the atom to which each is attached, are combined to form a C ₃ -C ₈ heterocycloalkyl; or alternatively, G is selected from the group consisting of where R _G4 is selected from C ₁ -C ₆ alkyl optionally substituted with 1-3 halogen atoms, C ₂ -C ₆ alkenyl, C ₂ -C ₆ alkynyl and C ₃ -C ₆ cycloalkyl, R ₄ represents a fluorine, chlorine or bromine atom, a methyl, hydroxyl or methoxy group, R ₆ is a group selected from: hydrogen; -C ₂ -C ₆ alkenyl; -X ₂ -OR ₇ ; -X ₂ -NSO ₂ -R ₇ ; -C=C(R ₉ )-Y ₁ -OR ₇ ; _C3 - _C6 cycloalkyl; _C3 - _C6 heterocycloalkyl, optionally substituted with hydroxyl group; C ₃ -C ₆ cycloalkylene-Y ₂ -R ₇ ; groups C ₃ -C ₆ heterocycloalkylene-Y ₂ -R ₇ , heteroarylene-R ₇ groups, optionally substituted by a linear or branched C ₁ -C ₆ alkyl group, R ₇ is a group selected from a linear or branched C ₁ -C ₆ alkyl group; (C ₃ -C ₆ )cycloalkylene-R ₈ ; or where Cy is C ₃ -C ₈ cycloalkyl, R ₈ is a group selected from hydrogen; linear or branched C ₁ -C ₆ alkyl, -NR' _a R'_b;-NR' _a -CO-OR'_c;-NR' _a -CO-R'_c; -N ⁺ R' _a R' _b R'_c;-O-R'_c;-NH-X' ₂ -N ⁺ R' _a R' _b R'_c;-O-X' ₂ -NR' _a R' _b , -X' ₂ -NR' _a R' _b , -NR' _c -X' ₂ -N ₃ and R ₉ is a group selected from linear or branched C ₁ -C ₆ alkyl, trifluoromethyl, hydroxyl, halogen, C ₁ -C ₆ alkoxy, R ₁₀ is a group selected from hydrogen, fluorine, chlorine, bromine, -CF ₃ and methyl, R ₁₁ is a group selected from hydrogen, C ₁ -C ₃ alkylene-R ₈ , -O-C ₁ -C ₃ alkylene-R ₈ , -CO-NR _h R _i and -CH=CH-C ₁ -C ₄ alkylene-NR _h R _i , -CH=CH-CHO, C ₃ -C ₈ cycloalkylene-CH ₂ -R ₈ , C ₃ -C ₈ heterocycloalkylene-CH ₂ -R ₈ , R ₁₂ and R ₁₃ independently of each other represent a hydrogen atom or a methyl group, R ₁₄ and R ₁₅ independently of each other represent hydrogen or a methyl group, or R ₁₄ and R ₁₅ together with the carbon atom carrying them form cyclohexyl, R _h and R _i independently of each other represent hydrogen or a linear or branched C ₁ -C ₆ alkyl group, X ₁ and X ₂ independently of each other represent a linear or branched C ₁ -C ₆ alkylene group optionally substituted with one or two groups selected from trifluoromethyl, hydroxyl, halogen, C ₁ -C ₆ alkoxy, X' ₂ is a linear or branched C ₁ -C ₆ alkylene, R' _a and R' _b independently of one another represent a group selected from hydrogen; heterocycloalkyl; -SO ₂ -phenyl, wherein phenyl may be substituted with linear or branched C ₁ -C ₆ alkyl; linear or branched C ₁ -C ₆ alkyl optionally substituted with one or two hydroxyl or C ₁ -C ₆ alkoxy groups; C ₁ -C ₆ alkylene-SO ₂ OH; C ₁ -C ₆ alkylene-SO ₂ O ^- ; C ₁ -C ₆ alkylene-COOH; C ₁ -C ₆ alkylene-PO(OH) ₂ ; C ₁ -C ₆ alkylene-NR' _d R'_e; C ₁ -C ₆ alkylene-N ⁺ R' _d R' _e R'_f; C ₁ -C ₆ alkylene-O-C ₁ -C ₆ alkylene-OH; C ₁ -C ₆ alkylenephenyl, wherein phenyl may be substituted by hydroxyl or C ₁ -C ₆ alkoxy group; groups or R' _a and R' _b together with the nitrogen atom carrying them form the B ₃ cycle, or R' _a , R' _b and R' _c together with the nitrogen atom carrying them form a bridging C ₃ -C ₈ heterocycloalkyl, R' _c , R' _d , R' _e , R' _f independently of each other represent hydrogen or a linear or branched C ₁ -C ₆ alkyl group, or R' _d and R' _e together with the nitrogen atom carrying them form the B ₄ cycle, or R' _d , R' _e and R' _f together with the nitrogen atom carrying them form a bridging C ₃ -C ₈ heterocycloalkyl, Y ₁ is a linear or branched C ₁ -C ₄ alkylene, Y ₂ is a bond, -O-, -O-CH ₂ -, -O-CO-, -O-SO ₂ -, -CH ₂ -, -CH ₂ -O, -CH ₂ -CO-, -CH ₂ -SO ₂ -, -C ₂ H ₅ -, -CO-, -CO-O-, -CO-CH ₂ -, -CO-NH-CH ₂ -, -SO ₂ -, -SO ₂ -CH ₂ -, -NH-CO-, -NH-SO ₂ -, m=0, 1 or 2, p=1, 2, 3 or 4, _B1 , _B2 , _B3 and _B4 independently of one another represent a _C3 - _C8 heterocycloalkyl group which: (i) may be a mono- or bicyclic group, wherein the bicyclic group comprises a fused, bridged or spiro ring system, (ii) may contain, in addition to the nitrogen atom, one or two heteroatoms independently selected from oxygen, sulfur and nitrogen, (iii) may be substituted with one or two groups selected from fluorine, bromine, chlorine, linear or branched _C1 - _C6 alkyl, hydroxyl, _-NH2 , oxo or piperidinyl, its enantiomers and diastereoisomers and their addition salts with a pharmaceutically acceptable acid or base, where heterocycloalkylene means a divalent heterocycloalkyl, where heterocycloalkyl means a mono- or bicyclic non-aromatic carbocyclic group consisting of 3-10 ring members and containing from 1 to 3 heteroatoms selected from oxygen, sulfur, SO, _SO2 and nitrogen, wherein the bicyclic group can be of a condensed or spiro ring type, heteroarylene means a divalent heteroaryl, where heteroaryl means a mono- or bicyclic group consisting of 5 to 10 ring members, having at least one aromatic moiety and containing from 1 to 4 heteroatoms selected from oxygen, sulfur and nitrogen. 2. The compound according to claim 1, wherein Het ₁ is 3. The compound according to claim 1 or 2, wherein R ₁ is a methyl group and R ₂ is a hydrogen atom. 4. The compound according to claim 1 or 2, wherein each of R ₁ and R ₂ represents a methyl group or a hydrogen atom. 5. A compound according to claim 1 or 2, wherein R ₁ or R ₂ is a linear or branched C ₁ -C ₆ alkyl, optionally substituted with a hydroxyl or C ₁ -C ₆ alkoxy group. 6. The compound according to claim 5, wherein R ₁ or R ₂ is a group selected from methyl, methoxymethyl, hydroxymethyl, ethyl and prop-2-yl. 7. The compound according to claim 1 or 2, wherein R ₁ or R ₂ is a C ₃ -C ₆ cycloalkyl group. 8. The compound according to claim 7, wherein R ₁ or R ₂ is a cyclopropyl group. 9. The compound according to claim 1 or 2, wherein R ₁ is a trifluoromethyl group. 10. The compound according to claim 1 or 2, wherein R ₂ is a linear or branched C ₁ -C ₆ alkylene heterocycloalkyl group. 11. The compound according to claim 10, wherein R ₂ is a (4-methylpiperazin-1-yl)propyl group. 12. A compound according to claim 1 or 2, wherein R ₁ and R ₂ together with the carbon atoms carrying them form a cyclohexene or cyclopentene group. 13. A compound according to any one of claims 1 to 12, wherein R ₃ represents a hydrogen atom or a methyl group. 14. A compound according to any one of claims 1 to 12, wherein R ₃ is -X ₁ -PO(OH) ₂ , -X ₁ -SO ₂ (OH), -X ₁ -NR _a R _b ; -X ₁ -N ⁺ R _a R _b R _c , where R _a or R _b or both of them are a group selected from C ₁ -C ₆ alkylene-SO ₂ OH, C ₁ -C ₆ alkylene-SO ₂ O ^- and C ₁ -C ₆ alkylene-PO(OH) ₂ . 15. A compound according to any one of claims 1 to 12, wherein R ₈ is -NR' _a R'_b; -N ⁺ R' _a R' _b R'_c;-NH-X' ₂ -N ⁺ R' _a R' _b R' _c , wherein R' _a and R' _b or both of them are a group selected from C ₁ -C ₆ alkylene-SO ₂ OH and C ₁ -C ₆ alkylene-PO(OH) ₂ . 16. A compound according to any one of claims 1 to 12, wherein R ₃ is a group selected from ethyl, propyl; 2-methoxyethyl, 2-(morpholin-4-yl)ethyl, 3-(morpholin-4-yl)propyl, 3-diethylaminopropyl, 3-methoxypropyl, 3-hydroxypropyl, 3,4-dihydroxybutyl, 4-methoxy-3-hydroxybutyl, 4-hydroxy-3-methoxybutyl, 2,3-dihydroxypropyl, 4,5-dihydroxypentyl, 4-hydroxybutyl, 3-hydroxy-2-morpholinopropyl, 5-hydroxy-4-methoxypentyl, 5-morpholino-4-hydroxypentyl, 3-hydroxy-2-methoxypropyl, 5-[2-(dimethylamino)ethylmethylamino]-4-hydroxypentyl, 5-hydroxypentyl, 5-methoxy-4-hydroxypentyl, 5-(dimethylamino)-4-hydroxypentyl, 4-hydroxy-5-(trimethylammonio)pentyl, 5-[3-sulfonatepropyldimethylammonio]-4-hydroxypentyl, 4-hydroxy-5-(methylamino)pentyl, 3-carboxypropyl, 5-[methyl(4-piperidyl)amino]pentyl, 5-(2-morpholinoethylamino)pentyl, 5-[2-(4-methylpiperazin-1-yl)ethylamino]pentyl, 4-[2-(4-methylpiperazin-1-yl)ethylamino]butyl, 4-hydroxy-5-[methyl-[2-(methylamino)ethyl]amino]pentyl, 5-[2-(diethylamino)ethylamino]-4-hydroxypentyl, 5-(4-amino-1-piperidyl)-4-hydroxypentyl, 4-hydroxy-5-piperazin-1-ylpentyl, 5-[2-(1-piperidyl)ethylamino]pentyl, 4-(4-amino-1-piperidyl)butyl, 4-[2-(diethylamino)ethylamino]butyl, 5-(4-amino-1-piperidyl)pentyl, 4-[methyl-[2-(methylamino)ethyl]amino]butyl, 4-(2-morpholinoethylamino)butyl, 4-[2-(4-methylpiperazin-1-yl)ethylamino]butyl, 4-[(1-methyl-4-piperidyl)amino]butyl, 5-[2-(diethylamino)ethylamino]pentyl, 4-piperazin-1-ylbutyl, 4-(methylamino)butyl, 5-piperazin-1-ylpentyl, 5-methyl-2-(methylamino)ethyl, 5-aminopentyl, 4-aminobutyl, 5-(methylamino)pentyl, 5-[3-(4-methylpiperazin-1-yl)propylamino]pentyl, 4-hydroxy-5-[methyl(2-phosphonoethyl)amino]pentyl, 6-(dimethylamino)hexyl, 3-(dimethylamino)propyl, 2-(trimethylammonio)ethyl, 3-(trimethylammonio)propyl, 2-(dimethylamino)ethyl, 4-(dimethylamino)butyl, 5-[3-sulfonatepropyldimethylammonio]pentyl, 4-(trimethylammonio)butyl, 4-hydroxy-5-quinuclidin-1-ium-1-ylpentyl, 4-hydroxy-5-(1-aza-4-azoniabicyclo[2.2.2]octan-4-yl)pentyl, 4-hydroxy-5-(4-methylmorpholin-4-ium-4-yl)pentyl, 5-(trimethylammonio)pentyl, 4-hydroxy-5-(1-methylpiperidin-1-ium-1-yl)pentyl, 5-(1,4-dimethylpiperazin-1-ium-1-yl)-4-hydroxypentyl, 6-(trimethylammonio)hexyl, 5-[3-hydroxypropyl(dimethyl)ammonio]pentyl, 5-[2-hydroxyethyl(dimethyl)ammonio]pentyl, 5-[carboxymethyl(dimethyl)ammonio]pentyl, 5-[carboxymethyl(dimethyl)ammonio]pentyl, 3-phosphonopropyl, 3-[3-sulfonatepropyldimethylammonio]propyl, 3-sulfopropyl, 4-sulfobutyl, 4-phosphonobutyl, 4-carboxybutyl, 3-aminopropyl, 3-azidopropyl, pent-4-yn-1-yl, 4-aminobutyl, 4-azidobutyl, hex-5-yn-1-yl, 5-azidopentyl. 17. A compound according to any one of claims 1 to 16, wherein Het ₂ is 18. A compound according to any one of claims 1 to 16, wherein Het ₂ is 19. The compound according to claim 17 or 18, wherein R ₆ is a hydrogen atom. 20. The compound according to claim 17, wherein R ₆ is a group -X ₂ -OR ₇ , where X ₂ is a propylene group. 21. The compound according to claim 20, wherein R ₇ represents the following group: 22. The compound according to claim 20, wherein R ₇ represents the following group: 23. The compound of claim 21 or 22, wherein R ₈ is a group selected from dimethylamino, methylamino, methylethylamino, diethylamino, methyl[2-(methylamino)ethyl]amino, (2-hydroxyethyl)(methyl)amino, 4-morpholinyl, pyrrolidin-1-yl, 1-piperidyl, [( tert -butoxy)carbonyl](methyl)amino, hydroxyl, bis(3-sulfopropyl)amino, 3-sulfopropylamino, methyl(3-sulfopropyl)amino, methyl( p -tolylsulfonyl)amino, (4-methoxyphenyl)methylmethylamino, 2-(dimethylamino)ethylamino and 24. The compound according to claim 21 or 22, wherein R ₈ is a group selected from 3-piperazin-1-yl, 4-methylpiperazin-1-yl, 3-hydroxypropyl(methyl)amino, [(3S)-3,4-dihydroxybutyl]methylamino, 3-hydroxypropylamino, [(3S)-3,4-dihydroxybutyl]amino, 4-hydroxybutyl(methyl)amino, [(3R)-3,4-dihydroxybutyl]methylamino, 4-hydroxybutylamino, [(3R)-3,4-dihydroxybutyl]amino. 25. The compound according to claim 20, wherein R ₇ is where R ₁₁ is selected from dimethylcarbamoyl, 3-(dimethylamino)propyl, 3-(methylamino)propyl, 3-(methylamino)propyl. 26. The compound according to claim 17, wherein R ₆ is a C ₃ -C ₆ heterocycloalkylene-Y ₂ -R ₇ group, wherein the heterocycloalkylene group is selected from 27. The compound according to claim 26, wherein R ₇ is selected from methyl, methylethyl, tert -butyl, 2-methylpropyl and phenyl. 28. The compound according to claim 27, wherein R ₇ is phenyl. 29. The compound according to claim 17 or 18, wherein R ₆ is -C=C(R ₉ )-Y ₁ -OR ₇ , where Y ₁ is a methylene group. 30. The compound according to claim 17 or 18, wherein R ₆ is 31. The compound of claim 30, wherein R ₇ is a group selected from where R ₈ is a group selected from hydrogen, 2-(methylamino)ethoxy and 32. The compound of claim 30, wherein R ₇ is a group selected from where R ₈ is a group selected from 2-(dimethylamino)ethoxy, 2-[(2-sulfoethyl)amino]ethoxy, 2-[methyl(2-sulfoethyl)amino]ethoxy, 2-(3-hydroxypropylamino)ethoxy, 2-(3-methoxypropylamino)ethoxy, 2-morpholinoethoxy, 2-(2-carboxyethylamino)ethoxy, 2-[(3-hydroxyphenyl)methylamino]ethoxy, 2-(methylamino)ethoxy, 2-pyrrolidin-1-ylethoxy, 2-(4-methylpiperazin-1-yl)ethoxy, 2-(4-hydroxybutylamino)ethoxy, 2-piperazin-1-ylethoxy, 2-[3-hydroxypropyl(methyl)amino]ethoxy, 2-[4-hydroxybutyl(methyl)amino]ethoxy; 2-[[3-hydroxy-2-(hydroxymethyl)propyl]amino]ethoxy; 2-[bis(3-hydroxypropyl)amino]ethoxy. 33. The compound according to item 1, selected from the following group of compounds: 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-hydroxybutyl)amino)-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid, 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxy-4-methoxybutyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(2,3-dihydroxypropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4,5-dihydroxypentyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3,4-dihydroxybutyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxypropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(trimethylammonio)pentyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate, 3-[[5-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-carboxy-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazol-2-yl]amino]-2-hydroxypentyl]-dimethylammonio]propane-1-sulfonate, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxybutyl)amino]-5-[3-[2-fluoro-4-[3-[methyl(3-sulfopropyl)amino]prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid, 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid, 5-{1-[(adamantan-1-yl)methyl]-5-methyl-1H-pyrazol-4-yl}-2-({6-[(1,3-benzothiazol-2-yl)amino]-5-cyclopropylpyridazin-3-yl}(methyl)amino)-1,3-thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(diethylamino)ethylamino]-4-hydroxypentyl]amino]-5-[3 -[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-(4-methylpiperazin-1-yl)ethylamino]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(4-hydroxy-5-piperazin-1-ylpentyl)amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid, 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[(2S)-3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}-2-methylpropyl]-1,3-thiazole-4-carboxylic acid, 2-[4-aminobutyl-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid, 2-[5-aminopentyl-[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[3-(dimethylamino)propyl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-methylamino]-5-[3-[4-[3-(dimethylamino)but-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(trimethylammonio)pentyl]amino]-5-[3-[4- [3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate, 3-[2-[3-[4-[3-[2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-4-carboxythiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynylamino]ethyl dimethylammonio]propane-1-sulfonate, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-hydroxy-5-(4-methylmorpholin-4-ium-4-yl)pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate, 2-[3-[4-[3-[2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-4-carboxythiazol-5-yl]propoxy]-3-fluorophenyl]prop-2-ynylamino]ethyltrimethylammonium, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[6-(trimethylammonio)hexyl]amino]-5-[3-[2-fluoro-4- [3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylate, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[2-hydroxyethyl(dimethyl)ammonio]pentyl]amino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[5-[carboxymethyl(dimethyl)ammonio]pentyl]amino]-5-[3-[4- [3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylate, 3-[[5-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-[4-carboxy-5-[3-[2-fluoro-4-[(E)-3-oxoprop-1-enyl]phenoxy]propyl]thiazol-2-yl]amino]-2-hydroxypentyl]-dimethylammonio]propane-1-sulfonate, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-Benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[1-[(dimethylamino)methyl]-3-bicyclo [1.1.1]pentanyl]phenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-phosphonopropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid, 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-carboxypropyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid, 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-phosphonopropyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid, 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(3-sulfopropyl)amino)-5-(3-{4-[3-(dimethylamino )prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazol-4-carboxylic acid, 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-sulfobutyl)amino)-5-(3-{4-[3-(dimethylamino )prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazol-4-carboxylic acid, 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-phosphonobutyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid, 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(4-carboxybutyl)amino)-5-(3-{4-[3-(dimethylamino)prop-1-yn-1-yl]-2-fluorophenoxy}propyl)-1,3-thiazole-4-carboxylic acid, 2-[{6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(pent-4-yn-1-yl)amino]-5-(3-{2-fluoro-4-[3-(methylamino)prop-1-yn-1-yl]phenoxy}propyl)-1,3-thiazole-4-carboxylic acid, 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-[2-fluoro-4-(3-{methyl[2-(methylamino)ethyl]amino}prop-1-yn-1-yl)phenoxy]propyl}-1,3-thiazole-4-carboxylic acid, 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-[3-(2-fluoro-4-{3-[(2-hydroxyethyl)(methyl)amino]prop-1-yn-1-yl}phenoxy)propyl]-1,3-thiazole-4-carboxylic acid, 2-({6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino)-5-{3-[2-fluoro-4-(3-hydroxyprop-1-yn-1-yl)phenoxy]propyl}-1,3-thiazole-4-carboxylic acid, 2-[5-azidopentyl-[6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl]amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]-1,3-thiazole-4-carboxylic acid, its enantiomers and diastereoisomers and their addition salts with a pharmaceutically acceptable acid or base. 34. The compound according to claim 1, selected from the following group of compounds: 6-[{6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino]-3-[1-({3-[2-(dimethylamino)ethoxy]-5,7-dimethyladamantan-1-yl}methyl)-5-methyl-1H-pyrazol-4-yl]pyridine-2-carboxylic acid, 6-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3-[2-(3-hydroxypropylamino)ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid, 6-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3-[2-(3-methoxypropylamino)ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid, 6-[{6-[(1,3-benzothiazol-2-yl)amino]-5-methylpyridazin-3-yl}(methyl)amino]-3-(1-{[3-(2-{[(3S)-3,4-dihydroxybutyl]amino}ethoxy)-5,7-dimethyladamantan-1-yl]methyl}-5-methyl-1H-pyrazol-4-yl)pyridine-2-carboxylic acid, 6-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3,5-dimethyl-7-(2-morpholinoethoxy)-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid, 6-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3-[2-(2-carboxyethylamino)ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid, 6-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-3-[1-[[3-[2-[(3-hydroxyphenyl)methylamino]ethoxy]-5,7-dimethyl-1-adamantyl]methyl]-5-methylpyrazol-4-yl]pyridine-2-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[4-[3-(dimethylamino)prop-1-ynyl]-2-fluorophenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]-(3-hydroxypropyl)amino]-5-[3-[2-fluoro-4-[3-(methylamino)prop-1-ynyl]phenoxy]propyl]thiazole-4-carboxylic acid, 2-[[6-(1,3-benzothiazol-2-ylamino)-5-methylpyridazin-3-yl]methylamino]-5-[3-[2-fluoro-4-(3-pyrrolidin-1-ylprop-1-ynyl)phenoxy]propyl]thiazole-4-carboxylic acid, its enantiomers and diastereoisomers and their addition salts with a pharmaceutically acceptable acid or base. 35. A pharmaceutical composition having inhibitory activity against the Bcl-xL protein, comprising a compound according to any one of claims 1-34 or an addition salt thereof with a pharmaceutically acceptable acid or base in combination with one or more pharmaceutically acceptable excipients. 36. The pharmaceutical composition according to claim 35 for use as pro-apoptotic agents. 37. The pharmaceutical composition according to claim 35 for use in the treatment of malignant neoplasms, autoimmune diseases or diseases of the immune system. 38. The pharmaceutical composition according to claim 37, wherein the malignant neoplasm is a hematological malignant tumor or a solid tumor. 39. The pharmaceutical composition of claim 38, wherein the hematological malignancy is myeloma, in particular multiple myeloma, lymphoma, in particular non-Hodgkin's lymphoma (NHL), or leukemia, in particular chronic lymphocytic leukemia (CLL), T-cell acute lymphoblastic leukemia (T-ALL), B-cell acute lymphoblastic leukemia (B-ALL) and acute myelocytic leukemia (AML). 40. The pharmaceutical composition according to claim 38, wherein the solid tumor is selected from bladder cancer, brain cancer, breast cancer, uterine cancer, esophageal cancer, liver cancer, colorectal cancer, kidney cancer, melanoma, ovarian cancer, prostate cancer, pancreatic cancer, and lung cancer. 41. A compound according to any one of claims 1 to 34, or an addition salt thereof with a pharmaceutically acceptable acid or base, for use in the treatment of a malignant neoplasm selected from myeloma, especially multiple myeloma, lymphoma, especially non-Hodgkin's lymphoma (NHL), or leukemia, especially chronic lymphocytic leukemia (CLL), T-cell acute lymphoblastic leukemia (T-ALL), B-cell acute lymphoblastic leukemia (B-ALL) and acute myelocytic leukemia (AML), cancer of the bladder, brain, breast, uterus, esophagus and liver, colorectal cancer, kidney cancer, melanoma, ovarian cancer, prostate cancer, pancreatic cancer and lung cancer, especially non-small cell lung cancer and small cell lung cancer. 42. A compound according to any one of claims 1-34 for use in the treatment of malignant neoplasms requiring radiotherapy. 43. A pharmaceutical composition according to claim 35 for use in the treatment of diseases or conditions characterized by excessive or deregulated platelet activity, in particular prothrombotic conditions. 44. An intermediate compound in the synthesis which is where R ₄ and m are as defined for general formula (I) according to claim 1. 45. An intermediate compound of the synthesis according to claim 44, wherein R ₄ is a hydrogen atom.