RU2826000C1 - Proposed 3,4-dihydro-2,7-naphthyridine-1,6(2h,7h)-diones as mek inhibitors - Google Patents

Abstract

FIELD: organic chemistry.

SUBSTANCE: group of inventions includes a compound of formula I, a compound of formula II, 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione and pharmaceutically acceptable salts thereof, pharmaceutical compositions containing them, method of treatment and use based on 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. In formula I R¹ represents H, Br, C1-C6 alkyl or phenyl; R² is H, halogen or CH₃-; R³ is H, hydroxyC1-C6 alkyl-, hydroxyC1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl or (C3-C6 cycloalkyl)C1-C6 alkoxy-; R⁴ is phenyl substituted with 1, 2 or 3 substituents, independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl and C1-C6 alkyl-C(=O)-. In formula II, R¹ is H, Br, C1-C6 alkyl or phenyl; R² is H, halogen or CH₃-; R³ is H, hydroxyC1-C6 alkyl-, hydroxyC1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl or (C3-C6 cycloalkyl)C1-C6 alkoxy-; R^a and R^b are independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl and C1-C6 alkyl-C(=O)-.

EFFECT: derivatives of 3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, having MEK inhibitory activity.

36 cl, 5 dwg, 8 tbl, 77 ex

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

The present invention relates to novel 3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione compounds or pharmaceutically acceptable salts thereof that act as MEK inhibitors and can be used to treat abnormal cell growth, such as cancer, in patients. The present invention also relates to pharmaceutical compositions containing these compounds and to methods of using these compounds and compositions in treating abnormal cell growth, such as cancer, in a subject in need thereof. The present invention also relates to solid forms of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, to pharmaceutical compositions containing these solid forms, and to methods of using these solid forms and compositions thereof in the treatment of abnormal cell growth, such as cancer, in a subject in need thereof.

LEVEL OF TECHNOLOGY

MEK kinase (mitogen-activated protein kinase kinase (MAPKK)) is an important component of the Ras-RAF-MEK-ERK cell survival pathway. The Ras pathway is activated by the binding of growth factors, cytokines, and hormones to their cognate receptors. However, in cancer cells, this pathway is constitutively activated and leads to increased cancer cell survival, cell proliferation, angiogenesis, and metastasis. Tumors that exhibit constitutive activation of this pathway include, but are not limited to, colon, pancreas, breast, brain, ovary, lung, and skin tumors. Activation of Ras (either through upstream signaling or through activating point mutations in the Ras oncogene) results in the phosphorylation and activation of Raf kinase, which in turn phosphorylates and activates MEK1 and MEK2 (also called MAPKK1 and MAPKK2). MEK1 and MEK2 are dual-specific kinases that activate ERK1 and ERK2 by phosphorylating and activating ERK1/2 kinase (also called MAP kinase), which further phosphorylates and regulates the function of proteins such as Mcl-1, Bim, and Bad, which play active roles in cell survival and apoptosis. Activation of this phosphorylation-mediated pathway therefore results in increased cell proliferation, increased cell survival, and decreased cell death, which are necessary for the initiation and maintenance of the oncogenic phenotype. Inhibition of this pathway, in particular inhibition of MEK activity, is known to be beneficial in the treatment of hyperproliferative diseases. MEK inhibitors have shown varying levels of activity in several settings, including BRAF V600-mutated melanoma, NRAS-mutated melanoma, low-grade serous ovarian cancer, plexiform neurofibromas, thyroid cancer, and low-grade gliomas, with more limited responses in KRAS-mutated pancreatic cancer or lung cancer.

Cancers that frequently metastasize to the brain, such as melanoma and non-small cell lung cancer, are known to harbor alterations that activate the MAPK pathway, such as the BRAF V600E mutation and KRAS G12 (Cancer Genome Atlas N., Cell 2015; 161: 1681–96). Although activating mutations can occur at different levels of the canonical pathway, they all require mitogen/extracellular signal-regulated kinase (MEK) signaling to enhance proliferation and survival (Schubbert S, Shannon K, Bollag G., Nat Rev Cancer. 2007; 7:295–308). The general activation of the MAPK pathway in malignancies, as well as the central and downstream location of MEK, raise potential interest in the use of MEK inhibitors for the treatment of intracranial tumors.

The blood–brain interface comprises the endothelium of the cerebral microvessels, forming the blood–brain barrier (BBB), and the epithelium of the choroid plexus, forming the blood–cerebrospinal fluid barrier (BCSFB). The blood–brain barrier (BBB) is a highly selective physical, transport, and metabolic barrier separating the central nervous system (CNS) from the blood. The BBB can prevent specific drugs from entering brain tissue and is therefore a limiting factor in the delivery of many peripherally administered agents to the CNS. The efficacy of many molecularly targeted agents in central nervous system tumors is limited by penetration of the BBB, which consists of a monolayer of endothelial cells connected by tight junctions that serve as a physical barrier protecting the brain. In addition, these endothelial cells express multiple efflux transporters, including P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), which are known to efflux many anticancer drugs from the brain (Ohtsuki and Terasaki, 2007, Pharm Res 24:1745–1758; Agarwal et al., 2011, Pharm Res 24:1745–1758). Similar to the blood–brain barrier, the blood–cerebrospinal fluid barrier prevents most blood-borne substances from entering the brain, while allowing selective entry of specific substances into the brain and facilitating the clearance of brain metabolites and brain metabolites into the blood.

Therefore, there remains a need to develop drugs for the treatment of MEK-mediated tumors, including drugs that can penetrate BBB and/or BCSFB and target tumors in the CNS.

ESSENCE OF THE INVENTION

The invention provides, inter alia, compounds of formula I and formula II and pharmaceutically acceptable salts thereof. Such compounds can inhibit MEK activity, thereby affecting biological functions, and can be used to treat a subject having a MEK-associated tumor. In addition, the invention provides solid forms of 8-((2-fluoro-4-(methylthio)-phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Also provided are pharmaceutical compositions and medicinal products comprising compounds of any of the formulae described in the invention and pharmaceutically acceptable salts thereof, which can be used to treat a subject having a MEK-associated tumor, in the form of monotherapy or in combination with additional antitumor therapies. In addition, the invention provides methods for preparing compounds, their pharmaceutically acceptable salts and pharmaceutical compositions of any of the formulae described in the invention and their pharmaceutically acceptable salts, and methods for using them. This summary of the invention is provided to introduce in a simplified form a selection of concepts that are described in more detail below. It is not intended that this summary define key features or essential features of the claimed subject matter, and it is also not intended to be used alone as an aid in determining the scope of the claimed subject matter.

According to an embodiment of the invention, a compound of formula I is provided.

or a pharmaceutically acceptable salt thereof, wherein:

R ¹ is H, Br, C1-C6 alkyl or phenyl;

R ² is H, halogen or CH ₃ -;

R ³ is H, hydroxyC1-C6 alkyl-, hydroxyC1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl or (C3-C6 cycloalkyl)C1-C6 alkoxy-; and

R ⁴ is phenyl substituted with 1, 2 or 3 substituents independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl and C1-C6 alkyl-C(=O)-.

In addition, the invention provides a compound of formula II

or a pharmaceutically acceptable salt thereof, wherein:

R ¹ is H, Br, C1-C6 alkyl or phenyl;

R ² is H, halogen or CH ₃ -;

R ³ is H, hydroxyC1-C6 alkyl-, hydroxyC1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl or (C3-C6 cycloalkyl)C1-C6 alkoxy-; and

R ^a and R ^b are independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl, and C1-C6 alkyl-C(=O)-.

In one embodiment, the invention provides solid forms of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione.

In one embodiment, the invention provides a pharmaceutical composition comprising a compound of any of the formulae described in the invention or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or excipient. In some embodiments, the pharmaceutical composition comprises two or more pharmaceutically acceptable carriers and/or excipients.

In one embodiment, the invention provides therapeutic methods and uses comprising administering a compound of any of the formulae described herein or a pharmaceutically acceptable salt thereof to a subject.

In one embodiment, the invention provides a method of treating abnormal cell growth, such as a tumor, such as a MEK-associated tumor, in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound of any of the formulae described in the invention or a pharmaceutically acceptable salt thereof. The compounds of any of the formulae described in the invention may be administered as a monotherapy or may be administered in combination with one or more anticancer drugs.

In one embodiment, the invention provides a method of treating abnormal cell growth, such as a tumor, such as a MEK-associated tumor, in a subject in need thereof, comprising administering to the subject an amount of a compound of any of the formulae described herein or a pharmaceutically acceptable salt thereof in combination with an amount of an additional anticancer agent, wherein the combined amounts are effective in treating said abnormal cell growth.

In one embodiment, the invention provides a compound of any of the formulae described herein, or a pharmaceutically acceptable salt thereof, for use as a medicinal product.

In one embodiment, the invention provides a compound of any of the formulae described herein, or a pharmaceutically acceptable salt thereof, for use in the treatment of abnormal cell growth, such as a tumor, such as a MEK-associated tumor.

In one embodiment, the invention provides the use of a compound of any of the formulae described in the invention, or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for the treatment of abnormal cell growth, such as a tumor, such as a MEK-associated tumor, in a subject.

In one embodiment, the invention provides a pharmaceutical composition comprising a compound of any of the formulas described in the invention or a pharmaceutically acceptable salt thereof and at least one pharmaceutically acceptable carrier or excipient.

Each of the embodiments of the compounds of any of the formulas described in the invention can be combined with one or more other embodiments of the compounds of any of the formulas described in the invention that do not contradict the embodiment(s) with which they are combined.

It should be understood that both the foregoing general description and the following detailed description are provided by way of example and explanation only and are not intended to limit the invention as claimed in the claims.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 shows the powder X-ray diffraction pattern of crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 1.

Figure 2 shows the powder X-ray diffraction pattern of crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 2.

Figure 3 shows the powder X-ray diffraction pattern of crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 3.

Figure 4 shows the powder X-ray diffraction pattern of amorphous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 4.

Figure 5 shows the sorption isotherm of the crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 3.

DETAILED DESCRIPTION OF THE INVENTION

In one aspect, the invention provides a compound of formula I

or a pharmaceutically acceptable salt thereof, wherein:

R ¹ is H, Br, C1-C6 alkyl or phenyl;

R ² is H, halogen or CH ₃ -;

R ³ is H, hydroxyC1-C6 alkyl-, hydroxyC1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl or (C3-C6 cycloalkyl)C1-C6 alkoxy-; and

R ⁴ is phenyl substituted with 1, 2 or 3 substituents independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl and C1-C6 alkyl-C(=O)-.

As used herein, the singular forms of substituents include the plural forms unless otherwise indicated. For example, "a substituent" includes one or more substituents.

In the case of complex chemical names used in the invention, the substituent group is usually named before the group to which it is attached. For example, methoxyethyl includes an ethyl backbone with a methoxy substituent.

The term "halogen" denotes -F (sometimes referred to in the invention as "fluorine" or "fluorine atoms"), -Cl, -Br, and -I.

As used herein, the term "C1-C6 alkyl" refers to a saturated linear or branched monovalent hydrocarbon radical containing from one to six carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, 1-propyl, isopropyl, 1-butyl, isobutyl, sec-butyl, tert-butyl, 2-methyl-2-propyl, pentyl, neopentyl, and hexyl.

As used in the invention, the term "hydroxyC1-C6 alkyl-" refers to a C1-C6 alkyl radical as defined in the invention in which one of the hydrogen atoms is replaced by a hydroxyl group.

The term "hydroxy" refers to the -OH group.

The term "C3-C6 cycloalkyl" denotes a fully saturated carbocyclic ring having 3-6 ring carbon atoms. Examples include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

As used herein, the term "fluoroC1-C6 alkyl" refers to a C1-C6 alkyl radical as defined herein in which one, two, or three hydrogen atoms are replaced by one, two, or three fluorine atoms, respectively. Examples include, but are not limited to, fluoromethyl, difluoromethyl, trifluoromethyl, 2-fluoroethyl, 2,2-difluoroethyl, and 2,2,2-trifluoroethyl.

As used herein, the term "C1-C6 alkoxy" refers to a C1-C6 alkyl radical, as defined herein, that is attached by a single bond to an oxygen atom, wherein the radical is on the oxygen atom (i.e., C1-C6-O-). Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, and isopropoxy.

As used herein, the term "fluoroC1-C6 alkoxy" refers to C1-C6 alkoxy as defined herein, in which one, two or three hydrogen atoms are replaced by one, two or three fluorine atoms, respectively. An example includes, but is not limited to, trifluoromethoxy.

The term "(C3-C6 cycloalkyl)C1-C6 alkoxy-" refers to a C1-C6 alkoxy-, as defined herein, in which one of the hydrogen atoms is replaced by a C3-C6 cycloalkyl group, as defined herein.

As used herein, the term "C1-C6 alkylthio" refers to a radical (C1-C6 alkyl)S-, in which the C1-C6 alkyl moiety is defined herein.

As used herein, the term "fluoroC1-C6 alkylthio" refers to a C1-C6 alkylthio group as defined herein in which one, two or three hydrogen atoms are replaced by one, two or three fluorine atoms, respectively.

In one embodiment of formula I, R ¹ is H.

In one embodiment of formula I, R ¹ is Br.

In one embodiment of formula I, R ¹ is C1-C6 alkyl. In one embodiment of formula I, R ¹ is methyl.

In one embodiment of formula I, R ¹ is phenyl.

In one embodiment of formula I, R ² is H.

In one embodiment, R ² is halogen.

In one embodiment of Formula I, R ² is F.

In one embodiment of formula I, R ² is Cl.

In one embodiment of Formula I, R ² is Br.

In one embodiment of formula I, R ² is I.

In one embodiment of formula I, R ² is CH ₃ -.

In one embodiment of Formula I, R ¹ is H and R ² is H.

In one embodiment of formula I, R ³ is H.

In one embodiment of Formula I, R ³ is hydroxyC1-C6 alkyl-. Non-limiting examples include 2-hydroxyethyl.

In one embodiment of Formula I, R ³ is hydroxyC1-C6 alkoxy-. Non-limiting examples include 2-hydroxyethoxy and 2-hydroxypropoxy having the structures:

respectively.

In one embodiment of formula I, R ³ is C1-C6 alkoxy. Non-limiting examples include methoxy, ethoxy, 1-methylethoxy, and 2,2-dimethylethoxy.

In one embodiment of formula I, R ³ is fluoroC1-C6 alkoxy. A non-limiting example includes 2,2-difluoroethoxy.

In one embodiment of formula I, R ³ is C3-C6 cycloalkyl. A non-limiting example is cyclopropyl.

In one embodiment of Formula I, R ³ is (C3-C6 cycloalkyl)C1-C6 alkoxy-. A non-limiting example is cyclopropylmethoxy.

In one embodiment of formula I, R ⁴ is phenyl substituted with 1, 2 or 3 substituents independently selected from fluoro, chloro, bromo, iodino, ethyl, propyl, isopropyl, methylthio, difluoromethylthio, trifluoromethyl, methoxy, difluoromethoxy, cyclopropyl and C1-C6 alkyl-C(=O)-.

In one embodiment of formula I, R ⁴ is phenyl substituted with 1 or 2 substituents independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl, and C1-C6 alkyl-C(=O)-.

In one embodiment of formula I, R ⁴ is phenyl substituted with 1 or 2 substituents independently selected from fluoro, chloro, bromo, iodino, ethyl, propyl, isopropyl, methylthio, difluoromethylthio, trifluoromethyl, methoxy, difluoromethoxy, cyclopropyl, and C1-C6 alkyl-C(=O)-.

In one embodiment of formula I, R ⁴ is phenyl substituted with 1 substituent selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl, and C1-C6 alkyl-C(=O)-.

In one embodiment of formula I, R ⁴ is phenyl substituted with 1 substituent selected from fluoro, chloro, bromo, iodino, ethyl, propyl, isopropyl, methylthio, difluoromethylthio, trifluoromethyl, methoxy, difluoromethoxy, cyclopropyl, and C1-C6 alkyl-C(=O)-.

In one embodiment of formula I, R ⁴ is selected from the structures:

In one embodiment of formula I, R ⁴ is

In one embodiment of formula I, R ⁴ is

In one embodiment of formula I, R ⁴ is selected from the structures:

In one embodiment of formula I, R ⁴ is selected from the structures:

In one embodiment, R ⁴ has the structure:

wherein R ^a and R ^b are independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl and C1-C6 alkyl-C(=O)-. In one embodiment, wherein R ^a is halogen. In one embodiment, R ^b is halogen, C1-C6 alkyl, C1-C6 alkylthio or fluoroC1-C6 alkoxy. In one embodiment, wherein R ^a is halogen and R ^b is halogen, C1-C6 alkyl, C1-C6 alkylthio or fluoroC1-C6 alkoxy.

In one embodiment, the invention provides a compound of formula II:

or a pharmaceutically acceptable salt thereof, wherein:

R ¹ is H, Br, C1-C6 alkyl or phenyl;

R ² is H, halogen or CH ₃ -;

R ³ is H, hydroxyC1-C6 alkyl-, hydroxyC1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl or (C3-C6 cycloalkyl)C1-C6 alkoxy-; and

R ^a and R ^b are independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl, and C1-C6 alkyl-C(=O)-.

In one embodiment of Formula II, R ¹ is H.

In one embodiment of Formula II, R ¹ is Br.

In one embodiment of formula II, R ¹ is C1-C6 alkyl. In one embodiment of formula II, R ¹ is methyl.

In one embodiment of Formula II, R ¹ is phenyl.

In one embodiment of Formula II, R ² is H.

In one embodiment of formula II, R ² is halogen.

In one embodiment of Formula II, R ² is F.

In one embodiment of Formula II, R ² is Cl.

In one embodiment of Formula II, R ² is Br.

In one embodiment of Formula II, R ² is I.

In one embodiment of Formula II, R ² is CH ₃ -.

In one embodiment of formula II, R ² is H or CH ₃ -.

In one embodiment of Formula II, R ¹ is H and R ² is H or CH ₃ -.

In one embodiment of Formula II, R ¹ is H and R ² is H.

In one embodiment of Formula II, R ³ is H.

In one embodiment of Formula II, R ³ is hydroxyC1-C6 alkyl-. Non-limiting examples include 2-hydroxyethyl.

In one embodiment of Formula II, R ³ is hydroxyC1-C6 alkoxy-. Non-limiting examples include 2-hydroxyethoxy and 2-hydroxypropoxy having the structures:

respectively.

In one embodiment of formula II, R ³ is C1-C6 alkoxy. Non-limiting examples include methoxy, ethoxy, 1-methylethoxy, and 2,2-dimethylethoxy.

In one embodiment of formula II, R ³ is fluoroC1-C6 alkoxy. A non-limiting example includes 2,2-difluoroethoxy.

In one embodiment of Formula II, R ³ is C3-C6 cycloalkyl. A non-limiting example is cyclopropyl.

In one embodiment of Formula II, R ³ is (C3-C6 cycloalkyl)C1-C6 alkoxy-. A non-limiting example is cyclopropylmethoxy.

In one embodiment of formula II, R ³ is H or hydroxyC1-C6 alkoxy-.

In one embodiment of formula II, R ^a is halogen. In one embodiment of formula II, R ^a is fluorine or chlorine. In one embodiment of formula II, R ^a is fluorine.

In one embodiment of formula II, R ^b is fluorine, chlorine, bromine, iodine, ethyl, propyl, isopropyl, methylthio, difluoromethylthio, trifluoromethyl, methoxy, difluoromethoxy, cyclopropyl, or _CH3C (=O)-.

In one embodiment of formula II, R ^b is halogen, C1-C6 alkyl, C1-C6 alkylthio, or fluoroC1-C6 alkoxy.

In one embodiment of formula II, R ^b is bromine, iodine, ethyl, methylthio, or difluoromethoxy. In one embodiment of formula II, R ^b is methylthio.

In one embodiment of Formula II, R ^a is fluoro and R ^b is methylthio.

In one embodiment of formula II, R ^a is halogen and R ^b is halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl, or C1-C6 alkyl-C(=O)-.

In one embodiment of formula II, R ^a is halogen and R ^b is halogen, C1-C6 alkyl, C1-C6 alkylthio, or fluoroC1-C6 alkoxy.

In one embodiment of formula II, R ^a is halogen, and R ^b is halogen. In one embodiment of formula II, R ^a is halogen, R ^b is halogen, R ¹ is H, and R ² is H.

In one embodiment of formula II, R ^a is halogen, and R ^b is C1-C6 alkyl. In one embodiment of formula II, R ^a is halogen,

R ^b is C1-C6 alkyl, R ¹ is H, and R ² is H.

In one embodiment of formula II, R ^a is halogen, and R ^b is C1-C6 alkylthio. In one embodiment of formula II, R ^a is halogen, R ^b is C1-C6 alkylthio, R ¹ is H, and R ² is H.

In one embodiment of formula II, R ^a is halogen, and R ^b is fluoroC1-C6 alkylthio. In one embodiment of formula II, R ^a is halogen, R ^b is fluoroC1-C6 alkylthio, R ¹ is H, and R ² is H.

In one embodiment of formula II, R ^a is fluoro, R ^b is methylthio, R ¹ is H, and R ² is H.

In one embodiment of formula II, R ^a is halogen, and R ^b is fluoroC1-C6 alkyl. In one embodiment of formula II, R ^a is halogen, R ^b is fluoroC1-C6 alkyl, R ¹ is H, and R ² is H.

In one embodiment of formula II, R ^a is halogen, and R ^b is C1-C6 alkoxy. In one embodiment of formula II, R ^a is halogen, R ^b is C1-C6 alkoxy, R ¹ is H, and R ² is H.

In one embodiment of formula II, R ^a is halogen, and R ^b is fluoroC1-C6 alkoxy. In one embodiment of formula II, R ^a is halogen, R ^b is fluoroC1-C6 alkoxy, R ¹ is H, and R ² is H.

In one embodiment of formula II, R ^a is halogen, and R ^b is C3-C6 cycloalkyl. In one embodiment of formula II, R ^a is halogen, R ^b is C3-C6 cycloalkyl, R ¹ is H, and R ² is H.

In one embodiment of formula II, R ^a is halogen, and R ^b is C1-C6 alkyl-C(=O)-. In one embodiment of formula II, R ^a is halogen, R ^b is C1-C6 alkyl-C(=O)-, R ¹ is H, and R ² is H.

In one embodiment of formula II, R ¹ is H, R ² is H or CH ₃ -, R ³ is H or hydroxyC1-C6 alkoxy-, ^Ra is halogen, and R ^b is halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl, or C1-C6 alkyl-C(=O)-.

In one embodiment of formula II, R ¹ is H, R ² is H or CH ₃ -, R ³ is H or hydroxyC1-C6 alkoxy-, R ^a is halogen, and R ^b is halogen, C1-C6 alkyl, C1-C6 alkylthio, or fluoroC1-C6 alkoxy.

In one embodiment of any of the above-described embodiments of formula II, the group

choose from the structures:

As used herein, the term "compound" is intended to include all stereoisomers, geometric isomers, tautomers, and isotopes of the structures depicted. Compounds identified herein by use of the name or structure of one particular tautomeric form are intended to include other tautomeric forms unless otherwise indicated.

The compounds of the formulae given in the invention may have asymmetric carbon atoms. Carbon-carbon bonds in the compounds of the invention may be depicted in the invention using a solid line solid wedge-shaped line or a dotted wedge-shaped line The use of a solid line to depict bonds to asymmetric carbon atoms is intended to indicate that all possible stereoisomers (e.g., individual enantiomers, racemic mixtures, etc.) are included for that carbon atom. The use of a solid or dotted wedge-shaped line to depict bonds to asymmetric carbon atoms is intended to indicate that only the stereoisomer shown is to be included. However, it is possible that compounds of the invention may contain more than one asymmetric carbon atom. In these compounds, the use of a solid line to depict bonds to asymmetric carbon atoms is intended to indicate that all possible stereoisomers and the attached stereocenter are to be included. For example, unless otherwise indicated, it is intended that compounds of the invention may exist as enantiomers and diastereomers, or as racemates and mixtures thereof. The use of a solid line to represent bonds to one or more asymmetric carbon atoms in a compound of the invention and the use of a solid or dotted wedge-shaped line to represent bonds to other asymmetric carbon atoms in the same compound is intended to indicate that a mixture of diastereomers is present.

Compounds of the invention that have chiral centers may exist in the form of stereoisomers, such as racemates, enantiomers or diastereomers.

Stereoisomers of the compounds of the formulae given in the invention may include cis and trans isomers, optical isomers such as (R) and (S) enantiomers, diastereomers, geometric isomers, rotational isomers, atropisomers, conformational isomers and tautomers of the compounds of the invention, including compounds exhibiting more than one type of isomerism, and mixtures thereof (such as racemates and diastereoisomeric pairs).

Also included in the invention are acid addition salts or base addition salts in which the counterion is optically active, such as d-lactate or l-lysine, or racemic, such as dl-tartrate or dl-arginine.

When any racemate crystallizes, two different types of crystals may form. The first type is the racemic compound mentioned above (a true racemate), in which one homogeneous crystal form is formed, containing both enantiomers in equimolar amounts. The second type is a racemic mixture or conglomerate, in which two crystal forms are formed in equimolar amounts, each containing one enantiomer.

Traditional methods for the preparation/isolation of individual enantiomers include chiral synthesis from an appropriate optically pure precursor or resolution of the racemate (or racemate salt or racemate derivative) using, for example, chiral high-performance liquid chromatography (HPLC) or supercritical fluid chromatography (SFC).

Alternatively, the racemate (or racemic precursor) may be reacted with an appropriate optically active compound, such as an alcohol, or, in the case where the compound contains a moiety with acidic or basic properties, with an acid or base such as tartaric acid or 1-phenylethylamine. The resulting diastereomeric mixture may be separated by chromatography and/or fractional crystallization, and one or both diastereoisomers converted to the corresponding pure enantiomer(s) by methods well known to those skilled in the art.

The chiral compounds of the invention (and their chiral precursors) can be obtained in enantiomerically enriched form using chromatography, typically HPLC, on an asymmetric resin with a mobile phase consisting of a hydrocarbon, typically heptane or hexane, containing from 0 to 50% isopropanol, typically 2 to 20%, and from 0 to 5% alkylamine, typically 0.1% diethylamine. Concentration of the eluent gives the enriched mixture.

Stereoisomeric conglomerates can be separated by methods known to those skilled in the art; see, for example, the monograph "Stereochemistry of Organic Compounds" by E. L. Eliel (Wiley, New York, 1994), the entire contents of which are incorporated herein by reference.

The enantiomeric purity of the compounds described in the invention can be characterized by the enantiomeric excess (ee), which indicates the degree to which a sample contains one enantiomer in greater amounts than the other. A racemic mixture has an ee of 0%, while a single substantially pure enantiomer has an ee of 100%. Similarly, diastereomeric purity can be characterized by the diastereomeric excess (de).

The compounds of the invention may exhibit tautomerism and structural isomerism. For example, the compounds may exist in several tautomeric forms, including the enol and imine form, and the keto and enamine form, and as geometric isomers and mixtures thereof. All such tautomeric forms are included within the scope of the compounds of the invention. The tautomers exist as mixtures of tautomeric pairs in solution. In solid form, one tautomer usually predominates. Even if one tautomer can be described, the present invention includes all tautomers of the compounds of the formulae given. A tautomer of a compound of formula I may arise, for example, when R ³ is hydrogen, i.e.:

In addition, some of the compounds of the invention may form atropisomers (e.g., substituted biaryls). Atropisomers are conformational stereoisomers that arise when rotation about a single bond in a molecule is prevented or significantly slowed down by steric interactions with other parts of the molecule and the substituents at both ends of the single bond are asymmetric. The interconversion of atropisomers occurs slowly enough to allow their separation and isolation under given conditions. The energy barrier to thermal racemization can be determined by the steric hindrance to free rotation of one or more bonds forming the chiral axis.

The present invention also includes pharmaceutically acceptable isotopically labeled compounds that are identical to the compounds described in one of the formulae provided, except that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number commonly found in nature.

The isotopically labeled compounds of the invention can be prepared, in most cases, by conventional methods known to those skilled in the art or by processes analogous to the processes described in the invention, using an appropriate isotopically labeled reagent in place of the unlabeled reagent.

Examples of isotopes that can be incorporated into the compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, fluorine and chlorine, such as, but not limited to, ^2H , ^3H , ^13C , ^14C , ^15N , ^18O , ^17O , ^32P , ^35S , ^18F and ^36CI . Particular isotopically labeled compounds of the invention, for example, those into which radioactive isotopes such as ^2H , ^3H or ^14C have been incorporated, can be used in one or both of drug or substrate tissue distribution studies. Isotopes labeled with tritium, i.e., ^3H , and carbon 14, i.e., ^14C , are particularly preferred due to their ease of preparation and detectability. In addition, substitution with heavier isotopes such as deuterium, i.e., ² H, may provide specific therapeutic advantages due to higher metabolic stability, such as increased half-life in vivo or decreased dose requirements, and may therefore be advantageous in some circumstances. Substitution with positron-active isotopes such as ¹¹ C, ¹⁸ F, ¹⁵ O and ¹³ N may be used in positron emission tomography (PET) studies to assess the degree of receptor occupancy by substrate. Isotopically labeled compounds of the invention may be prepared, in most cases, using the procedures described in the Schemes and/or in the Examples and Syntheses below, by substituting an isotopically labeled reagent for an unlabeled reagent.

Pharmaceutically acceptable solvates of the invention include solvates in which the crystallization solvent may be isotopically substituted, for example, _D2O , ^d6 -acetone, ^d6 -DMSO.

Unless otherwise indicated, all references in the invention to the compounds being patented include references to their salts, solvates, hydrates and complexes, and to solvates, hydrates and complexes of their salts, including polymorphs, stereoisomers and isotopically labeled versions thereof.

The compounds of the invention may exist in the form of pharmaceutically acceptable salts, such as, for example, acid addition salts and base addition salts of the compounds of one of the formulae disclosed in the invention. As used herein, the term "pharmaceutically acceptable salt" refers to those salts that retain the biological effectiveness and properties of the parent compound. Unless otherwise specified, the phrase "pharmaceutically acceptable salt(s)" as used herein includes salts of groups with acidic or basic properties that may be present in the compounds of the formulae disclosed in the invention.

For example, the compounds of the invention which have basic properties are capable of forming a variety of salts with various inorganic and organic acids. Although such salts must be pharmaceutically acceptable for administration to animals, it is often desirable in practice to first isolate the compound of the present invention from the reaction mixture in the form of a pharmaceutically unacceptable salt and then simply convert this salt back to the compound in free base form by treatment with an alkaline reagent and then convert the resulting compound into a pharmaceutically acceptable acid addition salt. Acid addition salts of the compounds of the invention having basic properties can be prepared by treating the compound of basic properties with a substantially equivalent amount of the chosen inorganic or organic acid in an aqueous solvent medium or in an appropriate organic solvent such as methanol or ethanol. After evaporation of the solvent, the desired solid salt is obtained. The desired acid salt can also be precipitated from a solution of the compound in free base form in an organic solvent by adding to the solution an appropriate inorganic or organic acid.

Acids that can be used to prepare pharmaceutically acceptable acid addition salts of such compounds with basic properties from those that form non-toxic acid addition salts are salts containing pharmacologically acceptable anions, such as hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, isonicotinate, acetate, lactate, salicylate, citrate, acid citrate, tartrate, pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate, gluconate, glucuronate, saccharate, formate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate and pamoate salts.

Examples of salts include, but are not limited to, acetate, acrylate, benzenesulfonate, benzoate (such as chlorobenzoate, methyl benzoate, dinitrobenzoate, hydroxybenzoate, and methoxybenzoate), bicarbonate, bisulfate, bisulfite, bitartrate, borate, bromide, butyne-1,4-dioate, calcium ethylenediaminetetraacetate, camsylate, carbonate, chloride, caproate, caprylate, clavulanate, citrate, decanoate, dihydrochloride, dihydrogen phosphate, ethylenediaminetetraacetate, edisylate, estolate, esylate, ethylsuccinate, formate, fumarate, gluceptate, gluconate, glutamate, glycolate, glycol larsanilate, heptanoate, hexyl-1,6-dioate, hexylresorcinate, hydrabamine, hydrobromide, hydrochloride, hydroxybutyrate, iodide, isobutyrate, isethionate, lactate, lactobionate, laurate, malate, maleate, malonate, mandelate, mesylate, metaphosphate, methanesulfonate, methylsulfate, monohydrogenphosphate, mucate, napsylate, naphthalene-1-sulfonate, naphthalene-2-sulfonate, nitrate, oleate, oxalate, pamoate (embonate), palmitate, pantothenate, phenylacetate, phenylbutyrate, phenylpropionate, phthalate, phosphate/diphosphate, polygalacturonate, propanesulfonate, propionate, propiolate, pyrophosphate, pyrosulfate, salicylate, stearate, subacetate, suberate, succinate, sulfate, sulfonate, sulfite, tannate, tartrate, teoclate, tosylate and valerate salts.

Illustrative examples of suitable salts include organic salts formed from amino acids such as glycine and arginine, ammonia, primary, secondary and tertiary amines and cyclic amines such as piperidine, morpholine and piperazine, and inorganic salts formed with sodium, calcium, potassium, magnesium, manganese, iron, copper, zinc, aluminum and lithium.

Compounds of the invention which include a moiety with basic properties, such as an amino group, can form, in addition to the acids mentioned above, pharmaceutically acceptable salts with various amino acids.

Alternatively, the compounds used, which have acidic properties, are capable of forming base addition salts with various pharmacologically acceptable cations. Examples of such salts include alkali or alkaline earth metal salts and, in particular, sodium and potassium salts. All of these salts are prepared by conventional methods. The chemical bases used as reagents for preparing the pharmaceutically acceptable base addition salts according to this invention are bases that form non-toxic base addition salts with compounds having acidic properties. These salts can be prepared by any suitable method, for example, by treating the compound in the form of a free acid with an inorganic or organic base, such as an amine (primary, secondary or tertiary), an alkali metal hydroxide or an alkaline earth metal hydroxide, or other similar bases. These salts can also be prepared by treating the corresponding compounds with acidic properties with an aqueous solution containing the desired pharmacologically acceptable cations and then evaporating the resulting solution to dryness, preferably under reduced pressure. Alternatively, they can also be prepared by mixing solutions of acidic compounds in lower alcohols with the desired metal alkoxide and then evaporating the resulting solution to dryness in the same manner as above. In both cases, it is preferable to use stoichiometric amounts of the reactants in order to ensure completeness of the reaction and maximum yield of the desired end product.

Chemical bases that can be used as reagents for the preparation of pharmaceutically acceptable base addition salts of the compounds of the invention that have acidic properties are chemical bases that form non-toxic base addition salts with such compounds. Such non-toxic base addition salts include, but are not limited to, salts formed with such pharmacologically acceptable cations as alkali metal cations (e.g., potassium and sodium) and alkaline earth metal cations (e.g., calcium and magnesium), ammonium addition salts or a water-soluble amine such as N-methylglucamine (meglumine), and lower alkanolammonium and other addition salts of pharmaceutically acceptable organic amines.

Hemi-salts of acids and bases can also be formed, for example, hemisulfate and hemicalcium salts.

For a review of suitable salts, see Handbook of Pharmaceutical Salts: Properties, Selection, and Use by Stahl and Wermuth (Wiley VCH, 2002). Methods for preparing pharmaceutically acceptable salts of the compounds of the invention and for interconverting salt and free base forms are well known to one skilled in the art.

The salts of the present invention can be prepared by methods known to those skilled in the art. A pharmaceutically acceptable salt of the compounds of the invention can be readily prepared by mixing solutions of the compound and the desired acid or base, as appropriate. The salt can be precipitated from the solution and collected by filtration or can be recovered by evaporation of the solvent. The degree of dissociation of the salt can vary from complete dissociation to a substantially non-ionized state.

It will be apparent to those skilled in the art that the free base form of the compounds of the invention having a functional group with basic properties can be converted into acid addition salts by treatment with an appropriate acid in stoichiometric excess. Acid addition salts of the compounds of the invention can be converted back into the free base form of the compound by treatment with an appropriate base in stoichiometric excess, such as potassium carbonate or sodium hydroxide, typically in the presence of an aqueous solvent and at a temperature in the range of about 0°C to 100°C. The free base form of the compound can be isolated by conventional methods, such as extraction with an organic solvent. In addition, acid addition salts of the compounds of the invention can be interchanged by exploiting differential solubilities of the salts, volatility or acidity of the acids, or by treatment with a suitably loaded ion exchange resin. For example, the interchange can be achieved by reacting a salt of a compound of the invention with a slight stoichiometric excess of an acid having a lower pK value than the component with acidic properties of the starting salt. This transformation is typically carried out at a temperature in the range from about 0°C to the boiling point of the solvent used as the reaction medium. Similar exchanges are possible with base addition salts, usually via the intermediate formation of the compound in the free base form.

The compounds of the invention may exist in both unsolvated and solvated forms. In the case where the solvent or water is tightly bound, the complex will have a well-defined stoichiometry independent of humidity. However, when the solvent or water is loosely bound, as in channel solvates and hygroscopic compounds, the water/solvent content will depend on humidity and drying conditions. In such cases, deviation from stoichiometry will be normal. The term "solvate" is used in the invention to describe a molecular complex comprising a compound of the present invention and one or more molecules of a pharmaceutically acceptable solvent, for example, ethanol. The term "hydrate" is used when the solvent is water. Pharmaceutically acceptable solvates of the invention include hydrates and solvates in which the solvent of crystallization may be isotopically substituted, for example, D ₂ O, d ⁶ -acetone, d ⁶ -DMSO.

The invention also relates to prodrugs of the compounds of the formulae disclosed herein. For example, certain derivatives of the compounds of the invention, which in themselves may have little or no pharmacological activity, may, upon administration to a patient, be converted into the compounds of the invention, for example by hydrolytic cleavage. Such derivatives are called "prodrugs". Further information on the use of prodrugs can be found in the publications "Prodrugs as Novel Delivery Systems", Vol.14, ACS Symposium Series (T Higuchi and W Stella); "Bioreversible Carriers in Drug Design", Pergamon Press, 1987 (ed. E B Roche, American Pharmaceutical Association); Guarino, V.R; Stella, V.J.: Biotech Pharm. Aspects 2007 5 (Pt2) 133-187; and J. Rautio et al. Nature Reviews Drug Discovery, 17, 559-587 (2018), the entire contents of which are incorporated herein by reference.

Prodrugs of the invention can be prepared, for example, by replacing the corresponding functional groups present in the compounds of the invention with certain moieties known to those skilled in the art as "promoting groups" described, for example, in the monograph "Design of Prodrugs" by H Bundgaard (Elsevier, 1985), the entire contents of which are incorporated herein by reference.

Some non-limiting examples of prodrugs of the invention include:

(i) when the compound contains a carboxylic acid functional group (-COOH), the prodrug is formed in the form of its ester, for example, by replacing the hydrogen with (C1-C6)alkyl;

(ii) when the compound contains an alcohol functional group (-OH), the prodrug is formed in the form of its ether, for example, by replacing the hydrogen with a (C1-C6)alkanoyloxymethyl group or with a phosphate ether group; and

(iii) when the compound contains a primary or secondary amino group ( _NH2 or NHR, where R is not H), the prodrug is formed in the form of its amide, for example, by replacing one or both hydrogen atoms with a suitable metabolically labile group such as amide, carbamate, urea, phosphonate, sulfonate and other similar groups.

Further examples of substituent groups in accordance with the above examples and examples of other types of prodrugs can be found in the above references.

Finally, specific patentable compounds may themselves act as prodrugs of other patentable compounds.

Also included within the scope of the invention are metabolites of the compounds of the formulae described in the invention, i.e., compounds formed in vivo after administration of the drug, most often as a result of oxidation or dealkylation. Some examples of metabolites according to the invention include, but are not limited to,

(i) when the compound of the invention contains an alkyl group, the metabolite is a hydroxyalkyl derivative (-CH → -COH):

(ii) when the compound of the invention contains an alkoxy group, the metabolite is a hydroxy derivative (-OR → -OH);

(iii) when the compound of the invention contains a tertiary amino group, the metabolite is a secondary amino derivative (-NRR' → -NHR or -NHR');

(iv) when the compound of the invention contains a secondary amino group, the metabolite is a primary amino derivative (-NHR → -NH ₂ );

(v) when the compound of the invention contains a phenyl moiety, the metabolite is a phenol derivative (-Ph → -PhOH);

(vi) when the compound of the invention contains an amide group, the metabolite is a carboxylic acid derivative (-CONH ₂ → COOH); and

(vii) When a compound contains a hydroxyl group or a carboxylic acid group, the compound can be metabolized by conjugation, for example with glucuronic acid to form a glucuronide. There are also other pathways of conjugated metabolism. These pathways are often referred to as phase 2 metabolism and include, for example, sulfation or acetylation. Other functional groups, such as NH groups, can also be the subject of conjugation.

In one embodiment, the invention provides solid forms of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. In one embodiment, the solid form is a crystalline form. In one embodiment, the solid form is an amorphous form.

As used herein, the term "crystalline" means having a regularly repeating arrangement of molecules or facets of the outer surface. A single compound may form a variety of crystalline forms, each form having different and distinct physical properties in the solid state, such as different solubility profiles, dissolution rates, melting points, flow properties, and/or different X-ray diffraction peaks. Differences in physical properties may affect pharmaceutical properties such as shelf stability, compressibility, and density (which may be important in formulation and product manufacturing), and dissolution rate (which may be important in terms of bioavailability).

The term "amorphous" refers to a state in which a material lacks long-range order at the molecular level and, depending on temperature, may exhibit the physical properties of a solid or a liquid. Such materials typically do not produce characteristic X-ray patterns, and although they exhibit the properties of a solid, they are more formally described as a liquid. Upon heating, a transition from solid to liquid occurs, characterized by a change of state, usually of the second order ("vitrification").

There are a number of analytical techniques that can be used by the average solid state chemist to analyze solid forms. Powder X-ray diffraction can also be used to quantify the crystalline solid form (or forms) in a mixture. In powder X-ray diffraction, X-rays are directed at a crystalline powder and the intensity of the diffracted X-rays is measured as a function of the angle between the X-ray source and the beam diffracted by the sample. The intensity of these diffracted X-rays can be plotted graphically as peaks where the X-axis represents the angle (known as the "2-theta" angle) between the X-ray source and the diffracted X-rays, and the Y-axis represents the intensity of the diffracted X-rays. This graph is called a powder X-ray diffraction pattern or powder diffraction pattern. Different crystalline solid forms are characterized by different powder diffraction patterns, since the location of the peaks on the x-axis is a property of the solid structure of the crystal.

It is obvious to one skilled in the art that the typical accuracy of determining the 2-theta value on the X-axis of a peak in a powder diagram is on the order of plus or minus 0.2 degrees 2-theta (±0.2 degrees 2-theta). Therefore, for example, a diffraction peak that appears at "approximately 18.0 degrees 2-theta" means that the peak appears at 18.0 degrees ±0.2 degrees 2-theta, i.e., it may lie between 17.8 degrees 2-theta and 18.2 degrees 2-theta, when measured on most X-ray diffractometers under most conditions used. In addition, it is obvious to those skilled in the art that the relative peak intensities will be characterized by instrumental variability, as well as variability due to the degree of crystallinity, preferred orientation, sample surface preparation, and other factors known to those skilled in the art, and should be considered only as qualitative indicators. Accordingly, the term "essentially the same" as used herein with respect to X-ray powder diffraction peak positions means that typical variability in peak position and intensity is on the order of ±0.2 degrees 2-theta.

Powder X-ray diffraction is only one of several analytical techniques that can be used to characterize and/or identify crystalline solid forms. Spectroscopic techniques such as Raman spectroscopy (including microscopic Raman spectroscopy), infrared spectroscopy, and solid-state NMR spectroscopy can be used to characterize and/or identify crystalline solid forms. These techniques can also be used to quantify one or more crystalline solid forms in a mixture, and peak characterization values can be reported with the qualifier "approximately" preceding the peak characterization values.

As used herein, the term "anhydrous" refers to a crystalline form that does not contain any solvent or water molecules in the crystal lattice.

The term "hydrate" refers to a solvate comprising a compound and a stoichiometric or non-stoichiometric amount of water. The term "monohydrate" refers to a hydrate comprising one molecule of water per molecule of compound (i.e., a 1:1 stoichiometry of water to compound).

In one embodiment, the invention provides crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 1.

In one embodiment, crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 1 is characterized by a powder X-ray diffraction pattern (PXRD) of (2-theta).

Table X lists the PXRD peaks for crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 1 in degrees 2-theta (±0.2 degrees 2-theta).

In one embodiment, the invention provides crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 1, having an X-ray powder diffraction pattern comprising characteristic peaks at 5.0, 8.7, 9.3, 10.8, 14.5, 15.3, 18.8, and 20.5 degrees 2-theta (±0.2 degrees 2-theta).

In one embodiment, the invention provides crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 1, having an X-ray powder diffraction pattern comprising characteristic peaks at 2-theta angle values substantially the same as those shown in Figure 1.

In one embodiment, the invention provides crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2.

In one embodiment, crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2

characterized by a powder X-ray diffraction pattern (PXRD) (2-theta). In one embodiment, PXRD analysis of crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 2 is performed at 25°C and at a relative humidity below 10%, such as described in Example 77.

Table Y lists the PXRD peaks for crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 2 in degrees 2-theta (±0.2 degrees 2-theta).

In one embodiment, the invention provides crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2, having an X-ray powder diffraction pattern comprising characteristic peaks at 7.1, 9.4, 12.4, 12.8, 14.3, 15.6, 16.4, 17.4, 18.5, 18.9, 19.5, 19.9, 21.1, 21.4, 23.2, 23.7, 24.8, 25.6, 27.6, 30.3, 33.2, 33.5 and 37.5 degrees 2-theta (±0.2 degrees 2-theta).

In one embodiment, the invention provides crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2, having an X-ray powder diffraction pattern comprising characteristic peaks at 2-theta angle values substantially the same as those shown in Figure 2.

In one embodiment, the invention provides crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 3.

In one embodiment, crystalline 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione monohydrate, Form 3

characterized by a powder X-ray diffraction pattern (PXRD) (2-theta). In one embodiment, PXRD analysis of crystalline 8-((2-fluoro-4-(methylthio)phenyl)-amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 3 monohydrate is carried out at 25°C and at a relative humidity above 30%.

Table Z lists the PXRD peaks for crystalline 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione monohydrate, form 3 in degrees 2-theta (±0.2 degrees 2-theta).

In one embodiment, the invention provides a crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 3, having an X-ray powder diffraction pattern including characteristic peaks at 13.7, 18.0, and 18.3 degrees 2-theta (±0.2 degrees 2-theta).

In one embodiment, the invention provides a crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 3, having an X-ray powder diffraction pattern including characteristic peaks at 6.9, 9.1, 13.7, 18.0, and 18.3 degrees 2-theta (±0.2 degrees 2-theta).

In one embodiment, the invention provides a crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 3, having an X-ray powder diffraction pattern comprising characteristic peaks at 6.9, 9.1, 11.8, 12.0, 13.7, 14.0, 15.2, 15.8, 18, 0, 18.3, 19, 0, 19.3, 20.2, 20.9, 21.6, 22.6, 23.6, 24.0, 24.9, 25.2, 25.8, 27, 5, 28, 1, 28, 4, 29.8, 30.9, 31.7, 32.3 and 36.5 degrees 2-theta (±0.2 degrees 2-theta).

In one embodiment, the invention provides a crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 3, having an X-ray powder diffraction pattern comprising characteristic peaks at 2-theta angle values substantially the same as those shown in Figure 3.

In one embodiment, the invention provides amorphous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 4.

In one embodiment, amorphous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 4 is characterized by a powder X-ray diffraction (PXRD) pattern of (2-theta).

In one embodiment, the invention provides amorphous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 4, having an X-ray powder diffraction pattern comprising characteristic peaks at 2-theta angle values substantially the same as those shown in Figure 4.

The invention further provides therapeutic methods and uses comprising the administration of the compounds of the invention or pharmaceutically acceptable salts thereof in monotherapy or in combination with other therapeutic agents or palliatives.

The compounds of formula I and formula II, and their pharmaceutically acceptable salts, can be used to treat diseases and disorders that can be treated with a MEK kinase inhibitor, such as MEK-associated diseases and disorders, for example, for the treatment of abnormal cell growth, such as tumors, for example, MEK-associated tumors. The ability of the compounds of formula I and formula II, and their pharmaceutically acceptable salts to act as MEK inhibitors can be demonstrated by conducting the studies described in Example A. The IC ₅₀ values are provided in Table A.

Accordingly, in one embodiment, the invention provides a method of treating a tumor comprising administering to a subject in need thereof a therapeutically effective amount of a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the tumor is a MEK-associated tumor.

As used herein, the terms "MEK kinase inhibitor" and "MEK inhibitor" are used interchangeably and refer to a compound that inhibits the mitogen-activated protein kinase kinase enzymes MEK1 and/or MEK2.

The terms "MEK-associated" and "MEK-mediated" are used interchangeably and refer to a disease or disorder having constitutive activation of MEK kinase that can be treated with a MEK inhibitor. Examples include MEK-associated abnormal cell growth, such as MEK-associated tumors, e.g., MEK-associated cancers. In one embodiment, the term "MEK-associated" refers to a disease or disorder having dysregulation of MEK kinase expression or activity, or dysregulation of the BRAF gene or BRAF kinase.

The phrase "dysregulation of MEK kinase expression or activity" refers to gene amplification that results in overexpression of MEK protein, or to autocrine activity resulting from overexpression of the MEK gene in cells that results in a pathogenetic increase in the activity of the kinase domain of MEK protein (e.g., a constitutively active kinase domain of MEK protein) in the cell.

The phrase "dysregulation of the BRAF gene or BRAF kinase" refers to a genetic mutation (e.g., a translocation of the BRAF gene that results in the expression of a fusion protein, a deletion in the BRAF gene that results in the expression of a BRAF protein that includes a deletion of at least one amino acid compared to the wild-type BRAF protein, or a mutation in the BRAF gene that results in the expression of a BRAF protein with one or more point mutations compared to the wild-type BRAF protein). As another example, dysregulation of the BRAF gene, BRAF protein, or expression or activity, or the level of any of the processes mentioned, can be a mutation in the BRAF gene that encodes a BRAF protein that is constantly active or has increased activity compared to the protein encoded by the BRAF gene that does not include the mutation. For example, dysregulation of the BRAF gene, BRAF protein, or expression or activity or level of any of the above processes may result from a gene or chromosome translocation that results in the expression of a fusion protein that contains a first portion of BRAF that includes a functional kinase domain and a second portion of a partner protein (i.e., which is not BRAF).

In one embodiment, the MEK-associated disease or disorder has an activating BRAF mutation. In one embodiment, the MEK-associated disease or disorder is a MEK-associated cancer that has an activating BRAF mutation. Non-limiting examples of BRAF mutations include BRAF V600 mutations, such as V600E, V600D, V600K, V600R, and V600S. In one embodiment, the BRAF mutation is a V600E mutation. In one embodiment, the BRAF mutation is a V600K mutation.

In one embodiment, the MEK-associated disease or disorder is a MEK-associated tumor having one or more BRAF fusions that cause constitutive activation and transforming kinase, including, but not limited to, KIAA11549-BRAF, MKRN1-BRAF, TRIM24-BRAF, AGAP3-BRAF, ZC3HAV1-BRAF, AKAP9-BRAF, CCDC6-BRAF, AGK-BRAF, EPS15-BRAF, NUP214-BRAF, ARMC10-BRAF, BTF3L4-BRAF, GHR-BRAF, ZC3HAV1-BRAF, ZNF767-BRAF, CCDC91-BRAF, DYNC112-BRAF, ZKSCAN1-BRAF, GTF2I-BRAF, MZT1-BRAF, RAD18-BRAF, CUX1-BRAF, SLC12A7-BRAF, MYRIP-BRAF, SND1-BRAF, NUB1-BRAF, KLHL7-BRAF, TANK-BRAF, RBMS3-BRAF, STRN3-BRAF, STK35-BRAF, ETFA-BRAF, SVOPL-BRAF, JHDM1D-BRAF or BCAP29-BRAF.

In one embodiment, the MEK-associated disease or disorder is a MEK-associated tumor that has a BRAF fusion protein, wherein the tumor is a breast carcinoma (e.g., infiltrating ductal carcinoma of the breast), a colorectal carcinoma (e.g., colon adenocarcinoma), an esophageal carcinoma (e.g., esophageal adenocarcinoma), a glioma (e.g., desmoplastic infantile ganglioglioma of the brain, pilocytic astrocytoma of the brain, pleomorphic xanthoastrocytoma of the brain, low-grade spinal cord glioma (NOS), anaplastic oligodendroglioma, anaplastic ganglioglioma), a head and neck carcinoma (e.g., head and neck neuroendocrine carcinoma), a lung carcinoma (e.g., lung adenocarcinoma, non-small cell lung cancer (NOS)), a melanoma (e.g., Spitzoid melanoma of the skin, non-Spitzoid melanoma of the mucous membranes, Spitzoid melanoma of the skin, melanoma of unknown primary, non-Spitzoid melanoma of the skin), pancreatic carcinoma (e.g., adenocarcinoma, acinar cell carcinoma of the pancreas), prostate carcinoma (e.g., acinar adenocarcinoma of the prostate), sarcoma (malignant solitary fibrous tumor), thyroid carcinoma (papillary thyroid carcinoma), carcinoma of unknown primary (e.g., adenocarcinoma of unknown primary), pleural mesothelioma, rectal adenocarcinoma, uterine endometrial carcinoma (e.g., uterine endometrial adenocarcinoma (NOS)) or ovarian serous carcinoma.

In one embodiment, the MEK-associated cancer is selected from the cancer types having BRAF fusion proteins described in Table 1 (J.S. Ross, et al., Int. J. Cancer: 138, 881-890 (2016)).

In one embodiment, the MEK-associated tumor is a BRAF wild-type tumor.

The term "wild type" describes a nucleic acid (e.g., BRAF gene or BRAF mRNA) that is typically found in a subject who does not have the disease or disorder associated with the reference nucleic acid or protein.

The term "wild-type BRAF" describes a BRAF nucleic acid (e.g., BRAF gene or BRAF mRNA) or BRAF protein that is found in a subject who does not have an activating BRAF mutation.

Unless otherwise specified, the term "abnormal cell growth" as used herein refers to cell growth that is independent of normal regulatory mechanisms (e.g., loss of contact inhibition), such as a tumor. Abnormal cell growth may be benign (non-cancerous) or malignant (cancerous).

The terms "cancer" or "cancerous" refer to any malignant and/or invasive growth or tumor caused by the abnormal growth of cells. Cancer includes primary cancer, which begins in a specific site in the body, metastatic cancer, which has spread from the site where it began to other parts of the body, recurrence of the original primary cancer after remission, and second primary cancer, which is a new primary cancer in a patient with a history of a previous cancer of a type different from the second primary cancer. Cancer includes solid tumors, named for the type of cells that form them, and cancers of the blood, bone marrow, or lymphatic system. A solid tumor is an abnormal growth or mass of tissue that usually does not contain protective membranes or fluid areas. Examples of solid tumors include sarcomas, carcinomas, and lymphomas. Leukemias (types of blood cancer) do not usually form solid tumors (National Cancer Institute, Dictionary of Cancer Terms).

As used herein, the terms "treat" or "treatment" refer to therapeutic or palliative measures. Beneficial or desired clinical results include, but are not limited to, relief, either partial or total, of symptoms associated with a disease or disorder or condition, reduction in the severity of a disease, stabilization (i.e., not worsening) of a disease, delay or slowing of disease progression, improvement or temporary alleviation of a disease (e.g., one or more symptoms of a disease), and remission (either partial or complete), whether detectable or undetectable.

As used herein, the term "treat" or "treatment" of cancer means administering a compound of the present invention to a subject having or diagnosed with cancer to achieve at least one beneficial therapeutic effect, such as, for example, reducing the number of cancer cells, reducing the size of a tumor, reducing the rate of infiltration of cancer cells into peripheral organs, or reducing the rate of tumor metastasis or tumor growth, reversing, reducing or inhibiting the progression of the disorder or condition to which such term applies, or one or more symptoms of such disorder or condition. As used herein, the term "treating", unless otherwise indicated, refers to the act of treating as immediately defined above. The term "treating" also includes adjuvant and neoadjuvant treatment of a subject.

For the purposes of the present invention, beneficial or desired clinical results include, but are not limited to, one or more of the following: reducing the proliferation (or eliminating) of tumor or cancer cells; inhibiting metastasis or slowing the growth of tumor cells; reducing tumor volume or size; increasing the period of remission in a subject (e.g., compared to one or more metric indicator(s) in a subject having a similar type of cancer but not receiving the given treatment or receiving a different treatment, or compared to one or more metric indicator(s) in the same subject before the start of treatment); alleviating symptoms associated with cancer; improving the quality of life of patients with cancer; reducing the dose of other drugs required to treat cancer; delaying the progression of cancer; curing cancer; overcoming one or more mechanisms of cancer resistance to treatment with anti-cancer drugs; and/or prolonging the survival of patients with cancer. Positive therapeutic effects in cancer treatment can be measured in several ways (see, for example, W. A. Weber, Assessing tumor response to therapy, J. Nucl. Med. 50 Suppl. 1:1 S-10S (2009). For example, with respect to tumor growth inhibition (TGI), according to the standards of the US National Cancer Institute (NCI), a TGI of less than or equal to 42% is considered minimal antitumor activity. A TGI of < 10% is considered high antitumor activity, where TGI (%) = median tumor volume in the treated case/median tumor volume in the control experiment × 100.

In one embodiment, the treatment outcome achieved by administering a compound of the invention is determined according to any of the following: partial response (PR), complete response (CR), overall response (OR), progression-free survival (PFS), disease-free survival (DFS), and overall survival (OS). PFS, also referred to as "time to tumor progression," refers to the length of time during and after treatment during which the tumor does not grow, and refers to the length of time during which patients were assessed by CR or PR, as well as the length of time during which patients were assessed by stable disease (SD). DFS refers to the length of time during and after treatment during which patients were disease-free. OS refers to the prolongation of average survival compared to unexposed or untreated subjects or patients. In one embodiment, the response to treatment with a compound of the invention is any of PR, CR, OR, PFS, DFS, or OS, as assessed using the Response Evaluation Criteria in Solid Tumors to Therapy (RECIST) 1.1 response criteria.

The treatment regimen using a compound of the invention that is effective for treating cancer in a patient may vary depending on factors such as the disease state, the age and body weight of the patient, and the ability of the therapy to achieve an anti-cancer response in the subject. Although an embodiment of any aspect of the invention may not be effective in achieving a positive therapeutic effect in every subject, it should nevertheless be able to achieve such an effect in a statistically significant number of subjects, as determined by any statistical test known in the art, such as the Student test, the chi-square test, the Mann-Whitney U test, the Kruskal-Wallis test (H test), the Jonckheere-Terpstra test, and the Wilcoxon test.

The terms "treatment regimen", "dosing protocol" and "dosing regimen" are used interchangeably to refer to the dose and timing of administration of a compound of the invention as monotherapy or in combination with another therapeutic agent.

"Improvement" means a reduction or improvement in one or more symptoms when treated with a combination of drugs described in the invention, compared to when the combination is not administered. "Improvement" also includes a reduction or decrease in the duration of the symptom.

As used herein, the term "subject" refers to any animal, including mammals such as humans. In one embodiment, the subject has experienced and/or exhibited at least one symptom of a disease or disorder to be treated and/or prevented. In one embodiment, the subject has been identified or diagnosed with a MEK-associated tumor (e.g., as determined using an assay or kit approved by a regulatory agency, such as the U.S. Food and Drug Administration

(FDA). In one embodiment, the subject has a MEK-associated tumor that is positive for a BRAF mutation (e.g., as determined using an assay or kit approved by a regulatory agency). The subject may be a subject whose tumors have a MEK mutation (e.g., if the tumor is identified as such using a kit or assay approved by a regulatory agency, such as one approved by the FDA). In one embodiment, the subject is suspected of having a MEK-associated tumor. In one embodiment, the subject has a medical history that indicates that the subject has a MEK-associated tumor with a BRAF mutation (and, optionally, the medical history indicates that the subject should be treated with any of the compositions of the invention). In one embodiment, the subject is a human. In one embodiment, the human being treated is a pediatric patient.

As used herein, the term "pediatric patient" refers to a subject under the age of 21 years at the time of diagnosis or treatment. The term "pediatric patient" may be further subdivided into various subgroups including: neonates (age from birth through the first month of life); infants (age 1 month through two years); children (age 2 years through 12 years); and adolescents (age 12 years through 21 years (up to but excluding birth at age twenty-two)). Berhman RE, Kliegman R, Arvin AM, Nelson WE, Nelson Textbook of Pediatrics, 15th Ed. Philadelphia: W.B. Saunders Company, 1996; Rudolph AM, et al. Rudolph's Pediatrics, 21st Ed. New York: McGraw-Hill, 2002; and Avery MD, First LR. Pediatric Medicine, 2nd Ed. Baltimore: Williams &Wilkins; 1994. In one embodiment, the pediatric patient is between the age of birth and the first 28 days of life, between the age of 29 days and less than two years, between the age of two years and less than 12 years, or between the age of 12 years and 21 years (up to, but not including, birth at twenty-two years). In one embodiment, the pediatric patient is between the age of birth and the first 28 days of life, between the age of 29 days and less than 1 year, between the age of one month and less than four months, between the age of three months and less than seven months, between the age of six months and less than 1 year, between the age of 1 year and less than 2 years, between the age of 2 years and less than 3 years, between the age of 2 years and less than seven years, between the age of 3 years and less than 5 years, between the age of 5 years and less than 10 years, between the age of 6 years and less than 13 years, between the age of 10 years and less than 15 years, or between the age of 15 years and less than 22 years.

In one embodiment, the invention provides a method of treating a tumor, the method comprising administering to a subject in need thereof, a therapeutically effective amount of a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the tumor is a MEK-associated tumor. In one embodiment, the MEK-associated tumor has a BRAF mutation. In one embodiment, the BRAF mutation is V600E and/or V600K and/or V600D and/or V600R and/or V600S. In one embodiment, the BRAF mutation is V600E. In one embodiment, the BRAF mutation is V600K. In one embodiment, the MEK-associated tumor has a BRAF fusion, such as a BRAF fusion described herein. In one embodiment, the MEK-associated tumor is a wild-type BRAF tumor.

In one embodiment of any of the methods of use described in the invention, the tumor is a solid tumor. In one embodiment of any of the methods described in the invention, the solid tumor is a MEK-associated tumor. In one embodiment, the tumor is intracranial. In one embodiment, the tumor is extracranial. In one embodiment of any of the methods of use described in the invention, the tumor (e.g., a MEK-associated tumor) is a malignant tumor (i.e., a cancer), e.g., a MEK-associated cancer. In one embodiment of any of the uses described herein, the MEK-associated cancer is melanoma, colon cancer, colorectal cancer, lung cancer (e.g., small cell lung carcinoma or non-small cell lung carcinoma), thyroid cancer (e.g., papillary thyroid cancer, medullary thyroid cancer, differentiated thyroid cancer, recurrent thyroid cancer, or refractory differentiated thyroid cancer), breast cancer, ovarian cancer, central nervous system (CNS) cancer, bone cancer, anal, anal canal, or anorectal cancer, eye cancer, bile duct cancer, ductal carcinoma in situ, liver, gallbladder, or pleural cancer, oral cancer, oral cavity cancer, lip cancer, oropharyngeal cancer, nasal, nasal cavity, or middle ear cancer, vulvar cancer, esophageal cancer, cervical cancer, gastrointestinal carcinoid tumor, hypopharyngeal cancer, kidney cancer, laryngeal cancer, liver cancer, lung cancer, melanoma, nasopharyngeal cancer, types of cancer of the peripheral nervous system (eg, neuroblastoma), ovarian cancer, pancreatic cancer, cancer of the peritoneal cavity, omentum and mesentery of the small intestine, pharyngeal cancer, prostate cancer, kidney cancer (eg, renal cell carcinoma (RCC)), small bowel cancer, soft tissue cancer, stomach cancer, testicular cancer, uterine cancer, ureteral cancer, or bladder cancer.

In one embodiment of any of the uses described herein, the MEK-associated cancer is an extracranial cancer (i.e., an extracranial tumor). In one embodiment, the extracranial cancer is selected from melanoma, colorectal cancer, thyroid cancer, non-small cell lung cancer, ovarian cancer, and neuroblastoma. In one embodiment, the MEK-associated cancer is melanoma. In one embodiment, the MEK-associated cancer is colorectal cancer. In one embodiment, the MEK-associated cancer is thyroid cancer. In one embodiment, the MEK-associated cancer is non-small cell lung cancer. In one embodiment, the MEK-associated cancer is ovarian cancer. In one embodiment, the MEK-associated cancer is neuroblastoma.

In one embodiment of any of the methods of use described in the invention, the MEK-associated cancer is a central nervous system (CNS) cancer.

In one embodiment of any of the methods of use described in the invention, the MEK-associated cancer is intracranial cancer (brain cancer).

In one embodiment of any of the methods of use described in the invention, the cancer is metastatic cancer.

The term "metastasis" is a term known in the art that refers to the spread of cancer cells from the site where they originally formed (the primary site) to one or more other sites in the subject's body (one or more secondary sites). In metastasis, cancer cells break away from the original (primary) tumor, travel through the blood or lymphatic system, and form a new tumor (metastatic tumor) in another organ or tissue in the body. The new metastatic tumor includes the same or similar cancer cells as the primary tumor. At the secondary site, the tumor cells may proliferate and begin to grow or form colonies of secondary tumor cells at that distant site.

As used herein, the term "metastatic cancer" (also known as "secondary cancer") refers to a type of cancer that begins in one type of tissue but then spreads to one or more tissues beyond the site of the (primary) cancer. Metastatic brain cancer refers to cancer in the brain, that is, cancer that begins in tissue other than the brain and has metastasized to the brain.

In one embodiment, the compounds of formula I or pharmaceutically acceptable salts thereof and the compounds of formula II or pharmaceutically acceptable salts thereof exhibit remarkable ability to penetrate the brain and/or CNS. Such compounds are able to cross the blood-brain barrier (BBB) and inhibit MEK kinase in the brain and/or other CNS structures. Accordingly, in one embodiment, the invention provides compounds that can be used to treat a CNS tumor, such as a CNS cancer.

In one embodiment, the MEK-associated tumor is a CNS cancer (i.e., a MEK-associated CNS cancer). In one embodiment, the MEK-associated CNS cancer has a BRAF mutation. In one embodiment, the MEK-associated CNS cancer has a BRAF V600 mutation. In one embodiment, the BRAF mutation is V600E and/or V600K and/or V600D and/or V600R and/or V600S. In one embodiment, the MEK-associated CNS cancer has a BRAF V600E mutation. In one embodiment, the MEK-associated CNS cancer has a BRAF V60 0K mutation. In one embodiment, the MEK-associated tumor has a BRAF fusion. In one embodiment, the MEK-associated tumor is a BRAF wild-type tumor.

As used interchangeably herein, the term "CNS cancer" or the term "central nervous system (CNS) cancer" refers to cancer (i.e., malignant tumor) of the CNS, including types of brain cancer (also known as intracranial tumors), types of spinal cord cancer, and types of cancer of the meninges surrounding the brain and spinal cord. Types of brain cancer include metastatic types of brain cancer (i.e., metastatic intracranial cancer types) and malignant primary brain tumors.

In one embodiment, the MEK-associated CNS cancer is MEK-associated metastatic brain cancer. The MEK-associated metastatic brain cancer can result from any cancer described herein wherein the subject has developed at least one brain metastasis. In one embodiment, the metastatic brain cancer is melanoma, colorectal cancer, thyroid cancer, non-small cell lung cancer, ovarian cancer, or neuroblastoma. In one embodiment, the MEK-associated metastatic brain cancer is metastatic melanoma, metastatic colorectal cancer, or metastatic non-small cell lung cancer. In one embodiment, the MEK-associated metastatic brain cancer is metastatic melanoma. In one embodiment, the MEK-associated metastatic brain cancer is metastatic colorectal cancer. In one embodiment, the MEK-associated metastatic brain cancer is metastatic non-small cell lung cancer. In one embodiment, the MEK-associated metastatic brain cancer is metastatic ovarian cancer. In one embodiment, the metastatic brain cancer is metastatic thyroid cancer. In one embodiment, the MEK-associated metastatic brain cancer is renal cell cancer. In one embodiment, the cancer is a MEK-associated metastatic cancer with at least one metastasis in the brain (i.e., metastatic brain cancer). In one embodiment, the cancer is a MEK-associated metastatic melanoma with at least one metastasis in the brain. In one embodiment, the cancer is a MEK-associated metastatic colorectal cancer with at least one metastasis in the brain. In one embodiment, the cancer is MEK-associated metastatic non-small cell lung cancer with at least one brain metastasis. In one embodiment, the cancer is MEK-associated metastatic ovarian cancer with at least one brain metastasis. In one embodiment, the cancer is MEK-associated metastatic thyroid cancer with at least one brain metastasis. In one embodiment, the cancer is MEK-associated neuroblastoma with at least one brain metastasis. In one embodiment of one of said types of MEK-associated metastatic brain cancer, the cancer has a BRAF mutation. In one embodiment, the cancer has a BRAF V600 mutation. In one embodiment, the BRAF mutation is V600E and/or V600K and/or V600D and/or V600R and/or V600S. In one embodiment, the cancer has a BRAF V600E mutation. In one embodiment, the cancer has a BRAF V600K mutation. In one embodiment, the MEK-associated tumor has a BRAF fusion. In one embodiment, the MEK-associated tumor is a BRAF wild-type tumor.

In one embodiment, the MEK-associated cancer is leptomeningeal metastases (leptomeningeal disease (LMD)). LMD is a collection of CNS metastases that grow in the meninges of the brain or spinal cord and/or in the cerebrospinal fluid (CSF), or meningeal carcinomatosis. In mammals, the meninges are the dura mater, arachnoid mater, and pia mater. Cerebrospinal fluid (CSF) is located in the subarachnoid space between the arachnoid mater and the pia mater. The arachnoid mater and pia mater together are sometimes referred to as the leptomeningeal disease (LMD). When leptomeningeal disease (LMD) occurs in the leptomeningeal disease and/or the cerebrospinal fluid (CSF) surrounding the spinal cord, it may be referred to as "extracranial LMD." When LMD occurs in the leptomeninges and/or cerebrospinal fluid of the brain, it may be referred to as "intracranial LMD." Because LMD cancer cells can be suspended in the CSF, they can rapidly disseminate throughout the central nervous system (CNS). As a result, leptomeningeal disease (LMD) has a poor prognosis with survival typically measured in months. In one embodiment, the metastatic cancer is LMD. In one embodiment, the metastatic cancer is MEK-associated LMD. In one embodiment, the metastatic cancer is MEK-associated intracranial LMD. In one embodiment, the metastatic cancer is MEK-associated extracranial LMD. In one embodiment, the MEK-associated LMD is LMD formed from melanoma metastases (i.e., the LMD is metastatic melanoma). In one embodiment, the MEK-associated LMD is LMD formed from metastases of colorectal cancer (i.e., the LMD is metastatic colorectal cancer). In one embodiment, the MEK-associated LMD is LMD formed from metastases of non-small cell lung cancer (i.e., the LMD is metastatic non-small cell lung cancer). In one embodiment of any of said MEK-associated leptomeningeal diseases (LMD), the LMD has a BRAF mutation. In one embodiment, the MEK-associated LMD has a BRAF V600 mutation. In one embodiment, the BRAF mutation is V600E and/or V600K and/or V600D and/or V600R and/or V600S. In one embodiment, the MEK-associated LMD has a BRAF V600E mutation. In one embodiment, the MEK-associated LMD has a BRAF V600K mutation. In one embodiment, the MEK-associated LMD has a BRAF fusion. In one embodiment, the MEK-associated LMD is a BRAF wild-type tumor.

In one embodiment, the MEK-associated tumor is a cancer with a high risk of metastasis. In one embodiment, the tumor with a high risk of metastasis is a cancer that has a BRAF V600E, V600D, V600K, V600R and/or V600S mutation. In one embodiment, the cancer with a high risk of metastasis has a BRAF fusion, such as any of the BRAF fusions described herein. In one embodiment, the cancer with a high risk of metastasis is a BRAF wild-type tumor. In one embodiment, the cancer with a high risk of metastasis is melanoma, colorectal cancer, thyroid cancer, non-small cell lung cancer, ovarian cancer, or neuroblastoma. In one embodiment, the cancer with a high risk of metastasis is melanoma, colorectal cancer, thyroid cancer, non-small cell lung cancer, ovarian cancer, or neuroblastoma. In one embodiment, the cancer with a high risk of metastasis is melanoma. In one embodiment, the cancer with a high risk of metastasis is melanoma having a BRAF V600E mutation or a BRAF V600K mutation. In one embodiment, the cancer with a high risk of metastasis is colorectal cancer. In one embodiment, the cancer with a high risk of metastasis is colorectal cancer having a BRAF V600E mutation or a BRAF V600K mutation. In one embodiment, the cancer with a high risk of metastasis is thyroid cancer. In one embodiment, the cancer with a high risk of metastasis is a thyroid cancer that has a BRAF V600E mutation or a BRAF V600K mutation. In one embodiment, the cancer with a high risk of metastasis is a non-small cell lung cancer. In one embodiment, the cancer with a high risk of metastasis is a non-small cell lung cancer that has a BRAF V600E mutation or a BRAF V600K mutation. In one embodiment, the cancer with a high risk of metastasis is ovarian cancer. In one embodiment, the cancer with a high risk of metastasis is ovarian cancer that has a BRAF V600E mutation or a BRAF V600K mutation. In one embodiment, the cancer with a high risk of metastasis is a neuroblastoma. In one embodiment, the cancer with a high risk of metastasis is a neuroblastoma that has a BRAF V600E mutation or a BRAF V600K mutation. In one embodiment, the cancer with a high risk of metastasis has a KIAA11549-BRAF fusion.

In one embodiment, the CNS tumor is a primary brain tumor. Primary brain tumors are tumors that arise in the brain and spinal cord, or collectively referred to as gliomas. The term "glioma" is used to describe tumors that arise in the glial cells present in the CNS. According to the WHO classification of brain tumors, gliomas are classified by cell activity and aggressiveness on a grade scale that includes grade I (benign CNS tumors) and grades II through IV (malignant CNS tumors):

Grade I glioma (pilocytic astrocytoma): usually occurs in the cerebellum or brainstem of a child, and rarely in the cerebral hemispheres, and is slow growing. Grade I glioma can occur in adults. Although these gliomas are benign (WHO grade I), the difficulty of treating this disease makes their growth pattern malignant with high morbidity rates (Rostami, Acta Neurochir (Wien). 2017; 159(11): 2217-2221).

Grade II glioma (low-grade gliomas): includes astrocytoma, oligodendroglioma, and mixed oligoastrocytoma. Grade II gliomas typically occur in young adults (e.g., 20-50 years of age) and are most often found in the cerebral hemispheres. Due to the infiltrative nature of these tumors, recurrence may occur. Some grade II gliomas recur and evolve into more aggressive tumors (grades III or IV).

Grade III glioma (malignant glioma): includes anaplastic astrocytoma, anaplastic oligodendroglioma, and anaplastic mixed oligoastrocytoma. Grade III tumors are aggressive, high-grade cancers that grow into nearby brain tissue via tentacle-like growths, making them difficult to completely remove surgically.

Grade IV gliomas: includes glioblastoma multiforme (GBM) and gliosarcoma; glioblastoma multiforme (GBM) is a malignant glioma. GBM is the most aggressive and most common primary brain tumor. Glioblastoma multiforme usually spreads rapidly and invades other parts of the brain through tentacle-like growths, making it more difficult to completely remove surgically. Gliosarcoma is a malignant type of cancer and is defined as a glioblastoma consisting of gliomatous and sarcomatous components.

In one embodiment, the primary brain tumor is a glioma. In one embodiment, the glioma is a low-grade glioma.

malignancy. In one embodiment, the glioma is a low-grade pediatric glioma.

In one embodiment, the primary brain tumor is a benign primary brain tumor. Benign primary brain tumors can cause severe pain, permanent brain damage, and death, and in some cases, become malignant. Non-limiting examples of benign primary brain tumors include grade I gliomas, papillary craniopharyngiomas, meningioma (including rhabdoid meningioma), atypical teratoid/rhabdoid tumors and dysembryoplastic neuroepithelial tumor (DNT), pilocytic astrocytoma, oligodendroglioma, mixed oligoastrocytoma, anaplastic astrocytoma, anaplastic oligodendroglioma, anaplastic mixed oligoastrocytoma, diffuse astrocytoma, ependymoma, pleomorphic quantum astrocytoma (QA), ganglioglioma, gliosarcoma, or anaplastic ganglioglioma.

In one embodiment, the cancer is a peripheral nervous system cancer. In one embodiment, the peripheral nervous system cancer is a neuroblastoma.

In one embodiment, the invention provides a method of treating a MEK-associated CNS tumor comprising administering (e.g., orally administering) a therapeutically effective amount of a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof, to a subject in need thereof. In one embodiment, the MEK-associated CNS tumor has a BRAF V600 mutation. In one embodiment, the MEK-associated CNS tumor has a BRAF V600E and/or V600K and/or V600D and/or V600R and/or V600S mutation. In one embodiment, the MEK-associated CNS tumor has a BRAF V600E mutation. In one embodiment, the MEK-associated CNS tumor has a BRAF V600K mutation. In one embodiment, the MEK-associated CNS tumor has a BRAF fusion, such as any of the BRAF fusions described herein, such as the KIAA11549-BRAF fusion. In one embodiment, the MEK-associated CNS tumor is a BRAF wild-type tumor. In one embodiment, the subject has been treated with one or more anti-cancer therapies independently selected from anti-cancer agents, surgery, and radiation therapy, prior to administration of a compound of Formula I, or a pharmaceutically acceptable salt thereof, or a compound of Formula II, or a pharmaceutically acceptable salt thereof, such as described herein below. In one embodiment, the subject is treated with a therapeutically effective amount of a compound of Formula I, or a pharmaceutically acceptable salt thereof, or a compound of Formula II, or a pharmaceutically acceptable salt thereof, in combination with one or more anti-cancer therapies independently selected from one or more anti-cancer agents, surgery, and/or radiation therapy, such as described herein below. In one embodiment, the subject is treated with one or more anticancer therapies independently selected from an anticancer agent, surgery, and radiation therapy, following administration of a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof, e.g., as described herein below. In one embodiment, the MEK-associated tumor is a CNS tumor. In one embodiment, the MEK-associated CNS tumor is a CNS malignancy (i.e., a CNS cancer). In one embodiment, the CNS malignancy is a metastatic CNS cancer. In one embodiment, the metastatic CNS cancer is selected from metastatic melanoma, metastatic colorectal cancer, metastatic non-small cell lung cancer, metastatic thyroid cancer, and metastatic ovarian cancer. In one embodiment, the metastatic CNS cancer is metastatic melanoma. In one embodiment, the metastatic CNS cancer is colorectal cancer. In one embodiment, the metastatic CNS cancer is metastatic non-small cell lung cancer. In one embodiment, the metastatic CNS cancer is metastatic thyroid cancer. In one embodiment, the metastatic CNS cancer is metastatic ovarian cancer. In one embodiment, the MEK-associated CNS cancer is leptomeningeal disease (LMD). In one embodiment, the LMD is intracranial. In one embodiment, the LMD is extracranial. In one embodiment, the LMD is metastatic melanoma. In one embodiment, the LMD is selected from metastatic melanoma, metastatic colorectal cancer, and metastatic non-small cell lung cancer. In one embodiment, the LMD is metastatic colorectal cancer. In one embodiment, the LMD is metastatic non-small cell lung cancer. In one embodiment, the MEK-associated CNS cancer is a primary brain tumor. In one embodiment, the primary brain tumor is a grade 2 glioma. In one embodiment, the primary brain tumor is a grade 3 glioma. In one embodiment, the primary brain tumor is a grade 4 glioma. In one embodiment, the MEK-associated CNS tumor is a benign tumor. In one embodiment, the benign CNS tumor is a papillary craniopharyngioma, a meningioma (including a rhabdoid meningioma), an atypical teratoid/rhabdoid tumor, or a dysembryoplastic neuroepithelial tumor (DNT). In one embodiment, the compound is a compound of Formula I, or a pharmaceutically acceptable salt thereof. In one embodiment, the compound is a compound of Formula II, or a pharmaceutically acceptable salt thereof. In one embodiment, the compound is selected from a compound of Examples 1-69, or a pharmaceutically acceptable salt thereof.

The suitability of a compound for the treatment of CNS cancer can be determined, for example, by determining whether the compound is a substrate of an efflux transporter, and/or by measuring cellular permeability, and/or by measuring the ratio of the free concentration of the compound in the blood to the free concentration of the compound in the plasma, as described in the invention.

In one embodiment, the compounds of formula I or pharmaceutically acceptable salts thereof, and the compounds of formula II or pharmaceutically acceptable salts thereof exhibit high cellular permeability. Methods for determining the permeability of a compound of the invention can be selected in accordance with the assay described in Example B, and the permeability coefficients are provided in Table B1.

The compounds of the invention are characterized by a low efflux value. In vitro methods for assessing whether the compounds of the invention are substrates for the efflux transporters P-glycoprotein (P-gp or multidrug resistance protein 1 (MDR1)) and breast cancer resistance protein (BCRP) are described in Example B, and the efflux coefficients of the compounds of the invention are given in Table B3.

In one embodiment, the compounds of the invention have moderate to high brain (unbound compound)/plasma (unbound compound) ratios (i.e., moderate to high free brain/free plasma compound ratios). The ability of a compound of the invention to penetrate the blood brain barrier (BBB) of a subject (e.g., a human) can be determined in an appropriate animal model (e.g., a rodent, such as a mouse). For example, the ability of particular compounds to penetrate the blood brain barrier (BBB) in mice is determined by assessing the ratio of unbound compound concentration in the brain to the concentration of unbound compound in the plasma (free B/P) in mice, e.g., as described in Example C, and the ratios of free brain to plasma compound concentrations are provided in Table C2. Calculation of the ratio of free compound concentration in the brain to the plasma concentration allows prediction of the effective concentrations required to achieve efficacy in the periphery and brain based on dose-response effects in animal models. These distribution data, along with associated pharmacokinetic data, can be used to model and predict the dose required to achieve efficacy in human patients.

Accordingly, in one embodiment, the methods of the present invention include methods of treating a MEK-associated CNS cancer in a subject in need thereof, comprising administering a compound of Formula II, or a pharmaceutically acceptable salt thereof, wherein at least a portion of the compound of Formula II penetrates the blood-brain barrier (BBB), as demonstrated in an appropriate animal model. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.3 following administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.35 following administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.4 following administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.45 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.5 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.55 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.6 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.65 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.7 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.75 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.8 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.85 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.9 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 0.95 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 1.0 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 1.1 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 1.2 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 1.3 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 1.4 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 1.5 after administration (e.g., oral or intravenous administration) to the subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 1.6 after administration (e.g., oral or intravenous administration) to a subject. In one embodiment, the brain/plasma ratio for the total amount of drug is at least about 1.7 after administration (e.g., oral or intravenous administration) to a subject. It should be noted that the percentage of the compound that penetrates the blood-brain barrier (BBB) is calculated based on the area under the concentration-time curve for a given period of time (AUC _0-t ) in the brain compared to plasma.

Accordingly, the percentages represent the ratio of concentrations. That is, if (AUC _0-24h ) for a compound is 20 ng/mL in the brain and 80 ng/mL in plasma, then the percentage of compound that crosses the blood-brain barrier (BBB) is 20% (20 ng/mL in the brain divided by the total concentration (equals 0.20). In one embodiment, the percentages are calculated based on the area under the concentration-time curve for the time period from t=0 (the dosing time) to the last time point of concentration quantification, that is (AUC _0-last ).

Cancers that frequently metastasize to the brain are known to harbor MAPK pathway activating alterations, such as BRAF mutations, including the BRAF mutations disclosed herein, or BRAF fusions, including the BRAF fusions disclosed herein. Although activating mutations may occur at different levels in the canonical pathway, they all require activation of the mitogen/extracellular signal-regulated kinase (MEK) signaling pathway to enhance proliferation and survival (Schubbert S, Shannon K, Bollag G. Nat Rev Cancer. 2007; 7:295-308). Mutations in the BRAF gene have been identified in malignant melanomas, papillary thyroid carcinomas, colorectal carcinomas, non-small cell lung carcinomas (NSCLC), and ovarian carcinomas and their metastatic tumors, and in primary brain tumors (Davies H., et al., Nature 417(6892):949-954, 2002). For example, BRAF mutations, such as BRAF V600 mutations, have been found in numerous metastatic CNS tumors, including melanoma brain metastases (Flaherty KT, et al., Nat Rev Cancer (2012) 12(5):349–61), colorectal cancer brain metastases and non-small cell lung cancer brain metastases (Berghoff, AS, Preusser M, Curr Opin Neurol (2014) 27(6):689–696), papillary thyroid cancer (Kim, WW et al., J Otolaryngol Head Neck Surg. 2018; 47:4, 1–6), and ovarian cancer (Grisham RN, et al., Cancer, 2013;119:548–554).

BRAF mutations, such as the BRAF mutations disclosed herein, and BRAF fusions, such as the BRAF fusions disclosed herein, have also been identified in malignant primary brain tumors, including grade IV gliomas, such as glioblastomas and gliosarcomas, anaplastic astrocytomas (high-grade tumors), and WHO grade III anaplastic gangliogliomas (Berghoff, A. S., Preusser M., Curr Opin Neurol (2014) 27(6):689-696); Schindler et al. (Acta Neuropathol 121 (3):397-405, 2011); Behling et al. (Diagn Pathol 11(1):55, 2016); K. C. Schreck, et al., Cancers, 2019, 11, 1262)) in pediatric and adult populations.

BRAF mutations, such as the BRAF mutations disclosed herein, and BRAF fusions, such as the BRAF fusions disclosed herein, have also been found in benign primary brain tumors, such as WHO grade II astrocytomas, WHO grade II pleomorphic xanthoastrocytomas (PXA), pleomorphic xanthoastrocytomas with anaplasia, pilocytic astrocytoma (PA), papillary

craniopharyngiomas, gangliogliomas, astroblastomas, piloid astrocytomas, atypical teratoid/rhabdoid tumors, rhabdoid meningiomas (Berghoff, AS, Preusser M, Curr Opin Neurol (2014) 27 (6):689-696; Schindler et al. (Acta Neuropathol 121 ( 3):397-405, 2011); (Behling et al., Diagn Pathol 11(1):55, 2016; Brastianos et al., Nat Genet 46 (2): 161-165, 2014; Dougherty et al., Neuro Oncol 12(7):621- 630, 2010; Lehman et al., Neuro Oncol 19(1):31–42, 2017; Mordechai et al., Pediatr Hematol Oncol 32 (3):207–211, 2015; Myung et al., Transl Oncol 5 ( 6): 430–436, 2012; Schindler et al., Acta Neuropathol 121 (3):397–405, 2011)), in populations of children and adults.

BRAF mutations have also been found in recurrent neuroblastoma (Eleveld, TF, et al., Nat Genet 47 (8):864-871, 2015). Neuroblastoma is a tumor of the peripheral nervous system in children. Most individuals with neuroblastoma have tumors that initially respond to chemotherapy, but a large proportion of individuals will experience therapy-resistant responses.

Accordingly, the invention also provides a method of treating a subject diagnosed with or identified as having a MEK-associated tumor, such as any of the exemplary MEK-associated tumors disclosed in the invention, comprising administering to the subject a therapeutically effective amount of a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, wherein the subject has been diagnosed with or identified as having a tumor having a BRAF mutation or BRAF fusion, such as by using a test or assay approved by a regulatory agency, such as the U.S. Food and Drug Administration (FDA), to identify a BRAF mutation or fusion in the subject or in a biopsy sample taken from the subject, or by performing any of the non-limiting examples of assays described in the invention. In one embodiment, the test or assay is provided as a kit. In one embodiment, the assay utilizes next generation sequencing, pyrosequencing, immunohistochemistry, fluorescence microscopy, FISH (fluorescence in situ hybridization) analysis, Southern blotting, Western blotting, FACS (fluorescence-activated cell sorting) analysis, Northern blotting, or PCR-based amplification (e.g., reverse transcription-PCR and real-time quantitative reverse transcription-PCR). In one embodiment, the assay is a regulatory agency-approved assay, such as an FDA-approved assay kit.

In one embodiment, the biopsy is a tumor biopsy (e.g., a tumor sample obtained by traditional surgery or stereotactic needle biopsy, such as computed tomography (CT)-guided or magnetic resonance imaging (MRI)-guided stereotactic needle biopsy). Tissue biopsy techniques can be used to detect overall tumor mass and/or BRAF mutation and/or BRAF fusion.

In one embodiment, a BRAF mutation or fusion can be identified using a liquid biopsy (otherwise referred to as a biological fluid biopsy or liquid phase biopsy). See, e.g., Karachialiou et al., "Realtime liquid biopsies become a reality in cancer treatment," Ann. Transl. Med., 3(3):36, 2016. Liquid biopsy techniques can be used to detect overall tumor mass and/or a BRAF mutation. Liquid biopsies can be performed on biological samples obtained relatively easily from a subject (e.g., by simply drawing blood), and are typically less invasive than traditional techniques used to detect tumor mass and/or a BRAF mutation. In one embodiment, liquid biopsies can be used to detect the presence of a BRAF mutation at an earlier stage than is possible using traditional techniques. In one embodiment, the biological sample to be used in the liquid biopsy may include cerebrospinal fluid (CSF), blood, plasma, urine, saliva, sputum, bronchoalveolar lavage, bile, lymphatic fluid, cyst fluid, stool, peritoneal effusions, and combinations thereof. In one embodiment, the liquid biopsy may be used to detect circulating tumor cells (CTCs). In one embodiment, the liquid biopsy may be used to detect cell-free DNA. In one embodiment, the cell-free DNA detected using the liquid biopsy is circulating tumor DNA (ctDNA), which is formed from tumor cells. ctDNA analysis (e.g., using sensitive detection methods such as, but not limited to, next-generation sequencing (NGS), conventional PCR, digital PCR, or microarray analysis) can be used to identify BRAF mutations or BRAF fusions.

In one embodiment, a BRAF mutation or BRAF fusion identified using a liquid biopsy is also present in a cancer cell that is present in the subject (e.g., a tumor). In one embodiment, any of the types of BRAF mutations or fusions can be detected using a liquid biopsy. In one embodiment, a genetic mutation identified using a liquid biopsy can be used to identify a subject as a candidate for a particular treatment.

"Tumor mass", also called "tumor burden", refers to the total amount of tumor material distributed in the body. Tumor mass refers to the total number of cancer cells or the total size of the tumor(s) in the body, including lymph nodes and bone marrow. Tumor mass can be determined by a variety of methods known in the art, such as, for example, measuring the size of the tumor(s) after removal from a subject, such as using calipers, or while in the body, using imaging techniques, such as magnetic resonance imaging (MRI), computed tomography (CT), multidetector computed tomography (MDCT), positron emission tomography (PET), x-rays, ultrasound, or bone scans.

The term "tumor size" refers to the total size of the tumor, which can be measured as the length and width of the tumor. Tumor size can be determined by a variety of methods known in the art, such as, for example, measuring the size of the tumor(s) after removal from a subject, such as using calipers, or while in the body, using imaging techniques, such as magnetic resonance imaging (MRI), bone scan, ultrasound, or computed tomography (CT).

Liquid biopsies can be performed multiple times during the diagnosis process, during monitoring, and/or during treatment to determine one or more clinically important parameters, including but not limited to disease progression or treatment efficacy, after treatment has been administered to a subject. For example, a first liquid biopsy can be performed at a first time point, and a second liquid biopsy can be performed at a second time point during the diagnosis process, during monitoring, and/or during treatment. In one embodiment, the first time point can be a time point before the disease is diagnosed in the subject (e.g., when the subject is healthy), and the second time point can be a time point after the disease has developed in the subject (e.g., the second time point can be used to diagnose the disease in the subject). In one embodiment, the first time point can be a time point before the disease is diagnosed in the subject (e.g., when the subject is healthy), after which the patient's health is monitored, and the second time point can be a time point after the patient's health is monitored. In one embodiment, the first time point may be a time point after the subject is diagnosed with a disease, after which the treatment is administered to the subject, and the second time point may be a time point after the treatment is administered; in such cases, the second time point may be used to assess the effectiveness of the treatment (e.g., if the genetic mutation(s) detected at the first time point are significantly reduced or undetectable).

A compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, may be used as a monotherapy or in combination with one or more different forms of therapy to treat a subject with abnormal cell growth, such as a MEK-associated tumor, for example, a MEK-associated cancer.

In one embodiment, a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, may be used in combination with one or more, such as one or more additional anti-cancer therapies, such as one or more therapies independently selected from surgery, radiation therapy, and the use of anti-cancer agents that have the same or a different mechanism of action. In one embodiment, treating a subject having a MEK-associated cancer with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, in combination with one or more, e.g., one or more additional therapies, e.g., independently selected from surgery, radiation therapy, and the use of anti-cancer agents (e.g., any of the anti-cancer agents described herein below, wherein the anti-cancer agent is not a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof), may have an increased therapeutic efficacy compared to treating the same or a similar subject with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, in monotherapy form. When a combination therapy is used and one or more, such as one, two or three anticancer therapies are independently selected from the use of one or more anticancer agents, such as any of the anticancer agents disclosed in the invention, the anticancer agent(s) may be administered simultaneously or separately at different set times and in any order with the compound of the invention and using different dosing regimens. In one embodiment, the anticancer agent(s) is(are) administered to the subject prior to administration of the compound of the invention. In another embodiment, the anticancer agent(s) is(are) administered to the subject after administration of the compound of the invention. In yet another embodiment, the anticancer agent(s) is(are) administered to the subject simultaneously with administration of the compound of the invention. In one embodiment, the compound of formula I or a pharmaceutically acceptable salt thereof, or the compound of formula II or a pharmaceutically acceptable salt thereof, is used in combination with one additional anticancer therapy, which is surgery, radiation therapy or an anticancer agent that has the same or a different mechanism of action.

Accordingly, in one embodiment, the invention provides methods of treating a subject having a MEK-associated tumor (e.g., any of the MEK-associated tumors described in the invention) that comprise administering to the subject a therapeutically effective amount of a compound of Formula I, or a pharmaceutically acceptable salt thereof, or a compound of Formula II, or a pharmaceutically acceptable salt thereof, in combination with one or more additional anti-cancer therapies. In one embodiment, the anti-cancer therapy is the use of one or more anti-cancer agents that are not a compound of Formula I, or a pharmaceutically acceptable salt thereof, or a compound of Formula II, or a pharmaceutically acceptable salt thereof. In one embodiment, the anti-cancer therapy is the use of a single anti-cancer agent that is not a compound of Formula I, or a pharmaceutically acceptable salt thereof, or a compound of Formula II, or a pharmaceutically acceptable salt thereof. In one embodiment, the additional anti-cancer therapy is surgery. In one embodiment, the additional anti-cancer therapy is radiation therapy.

Furthermore, the invention provides a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof for use in combination with one or more, for example, one or more anticancer therapies. In one embodiment, the additional anticancer therapy is independently selected from one or more therapies independently selected from surgery, radiation therapy and/or the use of one or more anticancer agents that have the same or a different mechanism of action.

The invention further provides one or more, for example one or more anticancer therapies for use in combination with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the additional anticancer therapy is independently selected from one or more therapies independently selected from surgery, radiation therapy and/or the use of one or more anticancer agents that have the same or a different mechanism of action.

Furthermore, the invention provides a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, for use in the treatment of a MEK-associated tumor in combination with one or more, for example, one or more additional anti-cancer therapies.

The invention further provides one or more, such as one or more additional anti-cancer therapies, for use in the treatment of a MEK-associated tumor by co-administration with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof.

In one embodiment, to treat a subject having a MEK-associated tumor, the subject is subjected to one or more anti-cancer therapies that are not the use of a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof, prior to administration of the compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the one or more anti-cancer therapies are selected from surgery, radiation therapy, and the use of an anti-cancer agent that has the same or a different mechanism of action. For example, in one embodiment, a subject in need of treatment may be subjected to at least partial resection of a tumor prior to administration of a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof. In one embodiment, treatment by at least partial resection of a tumor that reduces the size of the tumor (e.g., tumor mass) is performed prior to administration of one or more doses of a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof. In one embodiment, a subject in need of treatment may be treated with radiation therapy prior to administration of a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, a subject in need of treatment may be treated with one or more anticancer agents other than a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, prior to administration of a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has a cancer that is refractory or intolerant to a prior therapy or therapies.

Accordingly, in one embodiment, the invention provides methods of treating a subject having a MEK-associated tumor comprising (i) administering one or more, e.g., one or more anti-cancer therapies to said subject, and (ii) following step (i), administering (a) a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, in monotherapy form, or (b) a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, in combination with one or more, e.g., one or more, additional anti-cancer therapies. In one embodiment, the additional anti-cancer therapy is independently selected from one or more of surgery, radiation therapy, and/or the use of one or more anti-cancer agents that have the same or a different mechanism of action. In one embodiment, the additional anti-cancer therapy

is the use of one or more anticancer agents that have the same or different mechanism of action. In one embodiment, the additional anticancer therapy is the use of one anticancer agent that has the same or different mechanism of action. In one embodiment, the additional anticancer therapy is surgery. In one embodiment, the additional anticancer therapy is radiation therapy.

Non-limiting examples of additional anticancer agents that can be used in combination with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, in accordance with any of the combination therapies described in the invention include additional kinase inhibitors that are not a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, including MEK inhibitors, BRAF inhibitors, EGFR inhibitors, HER2 and/or HER3 inhibitors, SHP2 inhibitors, Axl inhibitors, PI3K inhibitors, SOS1 inhibitors, signal transduction pathway inhibitors, immune checkpoint inhibitors, apoptotic pathway modulators, cytotoxic chemotherapeutic agents, angiogenesis-targeted drugs, and immune system-targeted drugs, including immunotherapy.

In one embodiment, an anticancer agent that may be used in combination with a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof, in accordance with any of the combination therapies described in the invention, is a targeted therapeutic agent. As used herein, a "targeted therapeutic agent" refers to a molecule that blocks the growth of cancer cells by targeting specific target molecules required for carcinogenesis and tumor growth, rather than simply by targeting all rapidly dividing cells (e.g., as in the case of traditional cytotoxic chemotherapy), and includes, but is not limited to, therapeutic agents that target the receptor

tyrosine kinase, signal transduction pathway inhibitors (e.g., Ras-Raf-MEK-ERK pathway inhibitors, PI3K-Akt-mT0R-S6K pathway inhibitors ("PI3K inhibitors")), and apoptotic pathway modulators.

In one embodiment, an anticancer agent that may be used in combination with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, according to any of the combination therapies described in the invention, is a BRAF inhibitor. Non-limiting examples of other BRAF inhibitors include encorafenib, dabrafenib, vemurafenib, N-[3-(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-ylcarbonyl)-2,4-difluorophenyl]propane-1-sulfonamide (PLX4720), and (3R)-N-(3-[[5-(2-cyclopropyl-pyrimidin-5-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]carbonyl]-2,4-difluorophenyl)-3-fluoropyrrolidine-1-sulfonamide (PLX8394), and pharmaceutically acceptable salts thereof, the compounds disclosed in International Application No. PCT/IB2020/055992, published December 30, 2020 as PCT Publication No. WO 2020/261156 Al, including, for example, a compound selected from the following compounds:

N-(3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-2,4-difluorophenyl)propane-1-sulfonamide;

N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)-amino)phenyl)-3-fluoropropane-1-sulfonamide;

N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)-amino)-4,5-difluorophenyl)propane-1-sulfonamide;

N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)-amino)-4-fluorophenyl)propane-1-sulfonamide;

N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)-amino)-4-fluorophenyl)-3-fluoropropane-1-sulfonamide;

N-(2-chloro-4-fluoro-3-((5-methyl-3-(methyl-d3)-4-oxo-3,4-dihydro-quinazolin-6-yl)amino)phenyl)-3-fluoropropane-1-sulfonamide;

N-{2-chloro-3-[(3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)-oxy]-4-fluorophenyl}propane-1-sulfonamide;

N-(3-chloro-4-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)-oxy)-5-fluoropyridin-2-yl)propane-1-sulfonamide; and

N-{2-chloro-3-[(3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)-oxy]-4-fluorophenyl}-3-fluoropropane-1-sulfonamide; or a pharmaceutically acceptable salt thereof;

and compounds disclosed in PCT Publication No. WO 2021/250521, published December 16, 2021, including, for example, N-(2-chloro-4-fluoro-3-((5-fluoro-3-methyl-4-oxo-3,4-dihydro-quinazolin-6-yl)amino)phenyl)-2-azabicyclo[2.1.1]hexane-2-sulfonamide, (R)-N-(2-chloro-4-fluoro-3-((5-fluoro-3-methyl-4-oxo-3,4-dihydro-quinazolin-6-yl)amino)phenyl)-3-fluoropyrrolidine-1-sulfonamide and N-(2-chloro-3-((5-chloro-3-methyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-4-fluorophenyl)-3-fluoroazetidine-1-sulfonamide, or a pharmaceutically acceptable salt thereof.

In one embodiment, the BRAF inhibitor is selected from encorafenib or a pharmaceutically acceptable salt thereof, N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-4-fluorophenyl)-3-fluoropropane-1-sulfonamide or a pharmaceutically acceptable salt thereof, and N-(2-chloro-3-((5-chloro-3-methyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-4-fluorophenyl)-3-fluoroazetidine-1-sulfonamide or a pharmaceutically acceptable salt thereof.

In one embodiment, the BRAF inhibitor is encorafenib or a pharmaceutically acceptable salt thereof. In one embodiment, the BRAF inhibitor is N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-4-fluoro-phenyl)-3-fluoropropane-1-sulfonamide or a pharmaceutically acceptable salt thereof. In one embodiment, the BRAF inhibitor is N-(2-chloro-3-((5-chloro-3-methyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-4-fluorophenyl)-3-fluoroazetidine-1-sulfonamide or a pharmaceutically acceptable salt thereof.

Additional examples of BRAF inhibitors are known in the field.

In one embodiment, an anti-cancer agent that may be used in combination with a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof, according to any of the combination therapies described herein, is an EGFR inhibitor. Non-limiting examples of EGFR inhibitors include cetuximab (Erbitux®), panitumumab (Vectibix®), osimertinib (merelektinib, Tagrisso®), erlotinib (Tarceva®), gefinitib (Iressa®), necitumumab (Portrazza™), neratinib (Nerlinx®), lapatinib (Tykerb®), vandetanib (Caprelsa®), brigatinib (Alunbrig®), and the EGFR inhibitors disclosed in PCT Publication Nos. WO 2019/071351 and WO 2017/117680. Further examples of EGFR inhibitors are known in the art.

In one embodiment, an anticancer agent that may be used in combination with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, according to any of the combination therapies described in the invention, is an SHP2 inhibitor. Non-limiting examples of SHP2 inhibitors include 6-(4-amino-4-methylpiperidin-1-yl)-3-(2,3-dichlorophenyl)pyrazin-2-amine (SHP099), [3-[(3S,4S)-4-amino-3-methyl-2-oxa-8-azaspiro[4.5]decan-8-yl]-6-(2,3-dichlorophenyl)-5-methyl-pyrazin-2-yl]methanol (RMC-4550), RMC-4630, TN0155, and the compounds disclosed in patent documents WO 2020/081848, WO 2020/201991, WO 2015/107493, WO 2015/107494, WO 2015/107495, and WO 2019/075265. In one embodiment, the SHP2 inhibitor is a compound disclosed in patent document WO 2020/201991. In one embodiment, the SHP2 inhibitor is (S)-1'-(6-((2-amino-3-chloropyridin-4-yl)thio)-1,2,4-triazin-3-yl)-1,3-dihydro-spiro[indene-2,4'-piperidine]-1-amine or a pharmaceutically acceptable salt thereof.

In one embodiment, an anticancer agent that may be used in combination with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, according to any of the combination therapies described in the invention, is a PI3K inhibitor. Non-limiting examples include buparlisib (VKM120), alpelisib (BYL719), samatolisib (LY3023414), 8-[(1R)-1-[(3,5-difluorophenyl)amino]ethyl]-N,N-dimethyl-2-(morpholin-4-yl)-4-oxo-4H-chromene-6-carboxamide (AZD8186), tenalisib (RP6530), voxtalisib hydrochloride (SAR-245409), gedatolisib (PF-05212384), panulisib (P-7170), taselisib (GDC-0032), trans-2-amino-8-[4-(2-hydroxyethoxy)cyclohexyl]-6-(6-methoxypyridin-3-yl)-4-methyl-pyrido[2,3-d]pyrimidin-7(8H)-one (PF-04691502), duvelisib (ABBV-954), N2-[4-oxo-4-[4-(4-oxo-8-phenyl-4H-1-benzopyran-2-yl)morpholin-4-ium-4-ylmethoxy]butyryl]-L-arginyl-glycyl-L-aspartyl-L-serine acetate (SF-1126), pictilisib (GDC-0941), 2-methyl-1-[2-methyl-3-(trifluoromethyl)benzyl]-6-(morpholin-4-yl)-1H-benzimidazole-4-carboxylic acid (GSK2636771), idelalisib (GS-1101), umbralisib tosylate (TGR-1202), pictilisib (GDC-0941), copanlisib hydrochloride (BAY 84-1236), dostolisib (BEZ-235), 1-(4-[5-[5-amino-6-(5-tert-butyl-1,3,4-oxadiazol-2-yl)pyrazin-2-yl]-1-ethyl-1H-1,2,4-triazol-3-yl]-piperidin-1-yl)-3-hydroxy-propan-1-one (AZD-8835), 5-[6,6-dimethyl-4-(morpholin-4-yl)-8,9-dihydro-6H-[1,4]oxazino[4,3-e]purin-2-yl]-pyrimidin-2-amine (GDC-0084), everolimus, rapamycin, perifosine, sirolimus, and temsirolimus.

In one embodiment, an anticancer agent that may be used in combination with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, according to any of the combination therapies described in the invention, is an immunotherapeutic agent. The term "immunotherapeutic agent" refers to an agent that has a modulating effect on the immune system. In one embodiment, an immunotherapeutic agent may increase the expression and/or activity of a regulator of the immune system. In one embodiment, an immunotherapeutic agent may decrease the expression and/or activity of a regulator of the immune system. In one embodiment, an immunotherapeutic agent may recruit immune cells and/or enhance the activity of immune cells.

In one embodiment, an immunotherapeutic agent that may be used in combination with a compound of formula I or a pharmaceutically acceptable salt thereof or a compound of formula II or a pharmaceutically acceptable salt thereof in accordance with any of the combination therapies described in the invention is an antibody (e.g., a monoclonal antibody, a conjugated antibody). In one embodiment, the antibody is bevacizumab (Mvasti™, Avastin®), trastuzumab (Herceptin®), rituximab (MabThera™, Rituxan®), edrecolomab (Panorex), daratumuab (Darzalex®), olaratumab (Lartruvo™), ofatumumab (Arzerra®), alemtuzumab (Campath®), cetuximab (Erbitux®), oregovomab, pembrolizumab (Keytruda®), dinutiximab (Unituxin®), obinutuzumab (Gazyva®), tremelimumab (CP-675.206), ramucirumab (Cyramza®), ublituximab (TG-1101), panitumumab (Vectibix®), elotuzumab (Emplicity™), necitumumab (Porrazza™), cirmtuzumab (UC-961), ibritumomab (Zevalin®), isatuximab (SAR650984), nimotuzumab, fresolimumab (GC1008), lirilumab (INN), mogamulizumab (Poteligeo®), ficlatuzumab (AV-299), denosumab (ec sjiva®), ganitumab, urelumab, pidilizumab, amatuximab, blinatumomab (AMG103; Blincyto®) or midostaurin (Ridapt). In one embodiment, an immunotherapeutic agent that may be used in combination with a compound of Formula I or a pharmaceutically acceptable salt thereof or a compound of Formula II or a pharmaceutically acceptable salt thereof in accordance with any of the combination therapies described herein is an immune checkpoint inhibitor. In one embodiment, the immunotherapeutic agent comprises one or more, such as one or two, immune checkpoint inhibitors. In one embodiment, the immune checkpoint inhibitor is a CTLA-4 inhibitor, a PD-1 inhibitor, or a PD-L1 inhibitor. In one embodiment, the CTLA-4 inhibitor is ipilimumab (Yervoy®) or tremelimumab (CP-675,206). In one embodiment, the PD-1 inhibitor is pembrolizumab (Keytruda®), nivolumab (Opdivo®), and sasanlimab (RN888). In one embodiment, the PD-L1 inhibitor is atezolizumab (Tecentriq®) or durvalumab (Imfinzi™).

In one embodiment, the anti-cancer therapy that may be used in combination with a compound of formula I or a pharmaceutically acceptable salt thereof or a compound of formula II or a pharmaceutically acceptable salt thereof in accordance with any of the combination therapies described in the invention is radiation therapy.

Non-limiting examples of radiation therapy include external beam radiation therapy (e.g., external beam radiation therapy using kilovoltage x-rays or megavoltage x-rays) or internal beam radiation therapy. Internal beam radiation therapy (also called brachytherapy) may include the use of, for example, low-dose internal beam radiation therapy or high-dose internal beam radiation therapy. Low-dose internal beam radiation therapy includes, for example, the introduction of small radioactive pellets into or in close proximity to cancerous tissue in a subject. High-dose internal beam radiation therapy includes, for example, the introduction of a thin tube (e.g., a catheter) or implant into or in close proximity to cancerous tissue in a subject and the delivery of a high dose of radiation into the thin tube or implant using a radiation machine. Methods of delivering beam radiation therapy to a subject having cancer are well known in the art. In embodiments where the tumor is a CNS tumor, radiation therapy may include whole brain radiation therapy (WBRT) or stereotactic radiosurgery (SRS) such as CyberKnife®, XKnife®, Gamma Knife®, or the Exactrac® System.

In one embodiment, an anticancer therapy that can be used in combination with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, according to any of the combination therapy methods described in the invention, is a surgical intervention. Non-limiting examples of surgical intervention include, for example, open surgery or minimally invasive surgery. Surgery can include, for example, at least a partial resection of a tumor, a complete removal of a tumor, a cytoreductive removal of a tumor, or removal of a tumor that causes pain or pressure in a subject. Methods for performing open surgery and minimally invasive surgery on a subject having cancer are known in the art.

In one embodiment, the invention provides a method of treating a MEK-associated tumor (e.g., any of the MEK-associated tumors described in the invention) comprising administering to a subject in need thereof, therapeutically effective amounts of a compound of Formula I, or a pharmaceutically acceptable salt thereof, or a compound of Formula II, or a pharmaceutically acceptable salt thereof, and a BRAF inhibitor (e.g., any of the BRAF inhibitors disclosed in the invention), in any order, together or separately. In one embodiment, the compound of Formula I is a compound selected from the compounds of Examples 1-69, or a pharmaceutically acceptable salt thereof.

In one embodiment, the invention provides a method of treating a MEK-associated tumor (e.g., any of the MEK-associated tumors described in the invention) comprising administering to a subject in need thereof, therapeutically effective amounts of a compound of formula I, or a pharmaceutically acceptable salt thereof, or a compound of formula II, or a pharmaceutically acceptable salt thereof, and an EGFR inhibitor (e.g., any of the EGFR inhibitors disclosed in the invention), in any order, together or separately. In one embodiment, the compound of formula I is a compound selected from the compounds of examples 1-69, or a pharmaceutically acceptable salt thereof.

In one embodiment, the invention provides a method of treating a MEK-associated tumor (e.g., any of the MEK-associated tumors described in the invention) comprising administering to a subject in need thereof, therapeutically effective amounts of a compound of Formula I, or a pharmaceutically acceptable salt thereof, or a compound of Formula II, or a pharmaceutically acceptable salt thereof, and a SHP2 inhibitor (e.g., any of the SHP2 inhibitors disclosed in the invention), in any order, together or separately. In one embodiment, the compound of Formula I is a compound selected from the compounds of Examples 1-69, or a pharmaceutically acceptable salt thereof.

In one embodiment, the invention provides a method of treating a MEK-associated tumor (e.g., any of the MEK-associated tumors described in the invention), comprising administering to a subject in need thereof, therapeutically effective amounts of a compound of formula I, or a pharmaceutically acceptable salt thereof, or a compound of formula II, or a pharmaceutically acceptable salt thereof, and an immune checkpoint inhibitor (e.g., any of the immune checkpoint inhibitors disclosed in the invention), in any order, together or separately. In one embodiment, the compound of formula I is a compound selected from the compounds of examples 1-69, or a pharmaceutically acceptable salt thereof.

The invention further provides (i) a pharmaceutical combination for the treatment of a MEK-associated tumor in a subject in need thereof, comprising (a) a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, and (b) at least one additional anti-cancer agent (e.g., any of the exemplary additional anti-cancer agents described herein or known in the art), wherein the compound of formula I or a pharmaceutically acceptable salt thereof, or the compound of formula II or a pharmaceutically acceptable salt thereof, and the one or more, e.g., one or more, additional anti-cancer agents are formulated separately for simultaneous or separate use in the treatment of the tumor, wherein the amounts of the compound of formula I or a pharmaceutically acceptable salt thereof, or the compound of formula II or a pharmaceutically acceptable salt thereof and the additional anti-cancer agent(s) are together effective in treating the tumor; (ii) the use of such a combination for the preparation of a medicament for the treatment of the tumor; and (iii) and a commercial package or product comprising such a combination as a combination preparation for simultaneous, separate or sequential use; and for a method of treating a tumor in a subject in need thereof.

As used herein, the term "pharmaceutical combination" refers to a non-fixed combination of active ingredients. The term "non-fixed combination" means that a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, and one or more, for example one or more additional anticancer agents, are formulated in separate compositions or doses such that they can be administered to a subject in need thereof simultaneously or separately at different defined time intervals and in any order, where such administration allows achieving effective concentrations of the two or more compounds in the subject's body. The above also applies to cocktail therapies, for example the administration of three or more active ingredients. Likewise, the term "combination" when applied to a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof when used in combination with one or more anticancer agents, refers to a non-fixed combination.

Accordingly, the invention further provides a method of treating a MEK-associated tumor, comprising administering to a subject in need thereof a pharmaceutical combination for treating said tumor, which comprises (a) a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, and (b) one or more, such as one or more additional anticancer agents, for simultaneous, separate or sequential use in treating the tumor, wherein the amounts of the compound of formula I or a pharmaceutically acceptable salt thereof, or the compound of formula II or a pharmaceutically acceptable salt thereof and the additional anticancer agent(s) are together effective in treating the tumor.

In one embodiment, the invention provides a method of treating a MEK-associated tumor (e.g., a benign, malignant, or metastatic tumor) comprising administering to a subject in need thereof a therapeutically effective amount of a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, wherein the subject has not been treated with an anti-cancer therapy prior to administration of said compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof, wherein the anti-cancer therapy is selected from one or more, e.g., one or more anti-cancer therapies independently selected from surgery, radiation therapy, and the use of an anti-cancer agent that has the same or a different mechanism of action. In one embodiment, the patient has not been treated with an anti-cancer agent prior to administration of said compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the patient has not been treated with surgery prior to administration of said compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the patient has not been treated with radiation therapy prior to administration of said compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof.

In one embodiment, the invention provides a method of treating a subject having a MEK-associated tumor (e.g., a benign, malignant, or metastatic tumor) comprising administering a therapeutically effective amount of a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof, wherein the subject has not undergone prior therapy or standard therapy (e.g., treatment with one or more anticancer agents that are not a compound of Formula I or a pharmaceutically acceptable salt thereof, and/or radiation therapy and/or surgery), wherein the MEK-associated tumor has become refractory or intolerant to said prior therapy. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed in the invention, the subject having metastatic melanoma (e.g., metastatic melanoma having a BRAF V600 mutation or a BRAF fusion) has been treated with a BRAF inhibitor prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from encorafenib, dabrafenib, vemurafenib, N-[3-(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-ylcarbonyl)-2,4-difluorophenyl]-propane-1-sulfonamide, (3R)-N-(3-[[5-(2-cyclopropylpyrimidin-5-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]carbonyl]-2,4-difluorophenyl)-3-fluoro-pyrrolidine-1-sulfonamide (PLX8394). In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from encorafenib, dabrafenib, and vemurafenib. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed in the invention, the subject having metastatic melanoma (e.g., metastatic melanoma having a BRAF V600 mutation or a BRAF fusion) has been treated with a BRAF inhibitor and a MEK inhibitor prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from encorafenib, dabrafenib, vemurafenib, N-[3-(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-ylcarbonyl)-2,4-difluorophenyl]propane-1-sulfonamide, and (3R)-N-(3-[[5-(2-cyclopropylpyrimidin-5-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]carbonyl]-2,4-difluorophenyl)-3-fluoropyrrolidine-1-sulfonamide (PLX8394), and a MEK inhibitor selected from binimetinib, trametinib, cobimetinib, selumetinib, pimasertib, refametinib, N-[2(R),3-dihydroxypropoxy]-3,4-difluoro-2-(2-fluoro-4-iodophenylamino)benzamide (PD-325901), 2-(2-chloro-4-iodophenylamino)-N-(cyclopropylmethoxy)-3,4-difluorobenzamide (CI-1040), and 3-[2(R),3-dihydroxypropyl]-6-fluoro-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione (TAK-733). In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from encorafenib, dabrafenib, and vemurafenib, and a MEK inhibitor selected from binimetinib, trametinib, and cobimetinib. In one embodiment, the subject has been previously treated with encorafenib and binimetinib. In one embodiment, the subject has been previously treated with dabrafenib and trametinib. In one embodiment, the subject has been previously treated with vemurafenib and cobimetinib. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject having metastatic melanoma (e.g., metastatic melanoma having a BRAF V600 mutation or a BRAF fusion) has been treated with one or more, such as one or two, immune checkpoint inhibitors (e.g., any of the immune checkpoint inhibitors disclosed herein, such as a CTLA-4 inhibitor, a PD-1 inhibitor, and/or a PD-L1 inhibitor) prior to treatment with a compound of Formula I or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has previously been treated with one or more, such as one or two, immune checkpoint inhibitors independently selected from ipilimumab, nivolumab, and pembrolizumab. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed in the invention, the subject having metastatic melanoma (e.g., metastatic melanoma having a BRAF V600 mutation or a BRAF fusion) has been treated with one or more, e.g., one or two, PI3K inhibitors prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with one or more, such as one or two, PI3K inhibitors selected from buparlisib (BKM120), alpelisib (BYL719), samatolisib (LY3023414), 8-[(1R)-1-[(3,5-difluorophenyl)amino]ethyl]-N,N-dimethyl-2-(morpholin-4-yl)-4-oxo-4H-chromene-6-carboxamide (AZD8186), tenalisib (RP6530), voxtalisib hydrochloride (SAR-245409), gedatolisib (PF-05212384), panulisib (P-7170), taselisib (GDC-0032), trans-2-amino-8-[4-(2-hydroxyethoxy)cyclohexyl]-6-(6-methoxypyridin-3-yl)-4-methyl-pyrido[2,3-d]pyrimidin-7(8H)-one (PF-04691502), duvelisib (ABBV-954), N2-[4-oxo-4-[4-(4-oxo-8-phenyl-4H-1-benzopyran-2-yl)-morpholin-4-ium-4-ylmethoxy]butyryl]-L-arginyl-glycyl-L-aspartyl-L-serine acetate (SF-1126), pictilisib (GDC-0941), 2-methyl-1-[2-methyl-3-(trifluoromethyl)benzyl]-6-(morpholin-4-yl)-1H-benzimidazole-4-carboxylic acid (GSK2636771), idelalisib (GS-1101), umbralisib tosylate (TGR-1202), pictilisib (GDC-0941), copanlisib hydrochloride (BAY 84-1236), dostolisib (BEZ-235), 1-(4-[5-[5-amino-6-(5-tert-butyl-1,3,4-oxadi azol-2-yl)pyrazin-2-yl]-1-ethyl-1H-1,2,4-triazol-3-yl]-piperidin-1-yl)-3-hydroxypropan-1-one (AZD-8835), 5-[6,6-Dimethyl-4-(morpholin-4-yl)-8,9-dihydro-6H-[1,4]-oxazino[4,3-e]-purin-2-yl]pyrimidin-2-amine (GDC-0084) everolimus, rapamycin, perifosine, sirolimus, and temsirolimus. In one embodiment, the subject has been previously treated with buparlisib or alpelisib, alone or in combination. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject having metastatic melanoma (e.g., metastatic melanoma having a BRAF V600 mutation or a BRAF fusion) has been treated with a BRAF inhibitor and one or more, e.g., one or two, immune checkpoint inhibitors (e.g., any of the immune checkpoint inhibitors disclosed herein, e.g., a CTLA-4 inhibitor, a PD-1 inhibitor, and/or a PD-L1 inhibitor), prior to treatment with a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has previously been treated with a BRAF inhibitor selected from encorafenib, dabrafenib, vemurafenib, N-[3-(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-yl-carbonyl)-2,4-difluorophenyl]-propane-1-sulfonamide, and (3R)-N-(3-[[5-(2-cyclopropylpyrimidin-5-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]carbonyl]-2,4-difluorophenyl)-3-fluoropyrrolidine-1-sulfonamide

(PLX8394), and one or more, such as one or two, immune checkpoint inhibitors independently selected from ipilimumab, nivolumab, and pembrolizumab. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the disclosed method of treating a subject having a MEK-associated tumor, the subject having metastatic melanoma (e.g., metastatic melanoma having a BRAF V600 mutation or a BRAF fusion) has been treated with a BRAF inhibitor, a MEK inhibitor, and one or more, e.g., one or two, immune checkpoint inhibitors (e.g., any of the immune checkpoint inhibitors disclosed herein, e.g., a CTLA-4 inhibitor, a PD-1 inhibitor, and/or a PD-L1 inhibitor) prior to treatment with a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from encorafenib, dabrafenib, vemurafenib, N-[3-(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-ylcarbonyl)-2,4-difluorophenyl]propane-1-sulfonamide (PLX4720) and (3R)-N-(3-[[5-(2-cyclopropylpyrimidin-5-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]-carbonyl]-2,4-difluorophenyl)-3-fluoro-pyrrolidine-1-sulfonamide (PLX8394), a MEK inhibitor selected from binimetinib, trametinib, cobimetinib, selumetinib, pimasertib, refametinib, N-[2(R),3-dihydroxypropoxy]-3,4-difluoro-2-(2-fluoro-4-iodophenylamino)benzamide (PD-325901), 2-(2-chloro-4-iodophenylamino)-N-(cyclopropylmethoxy)-3,4-difluorobenzamide

(CI-1040) and 3-[2(R),3-dihydroxypropyl]-6-fluoro-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione (TAK-733), and one or more immune checkpoint inhibitors (e.g., any of the immune checkpoint inhibitors disclosed in the invention, e.g., a CTLA-4 inhibitor, a PD-1 inhibitor, and/or a PD-L1 inhibitor). In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from encorafenib, dabrafenib, and vemurafenib, a MEK inhibitor selected from binimetinib, trametinib, and cobimetinib, and one or more, such as one or two, immune checkpoint inhibitors independently selected from ipilimumab, nivolumab, and pembrolizumab. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject having metastatic melanoma (e.g., metastatic melanoma having a BRAF V600 mutation or a BRAF fusion) has been treated with one or more, e.g., one or two, alkylating agents prior to treatment with a compound of Formula I, or a pharmaceutically acceptable salt thereof, or a compound of Formula II, or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with alkylating agents selected from temozolomide, fotemustine, lomustine, and carmustine. In one embodiment, the subject has been previously treated with temozolomide. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject having metastatic colorectal cancer (e.g., metastatic colorectal cancer having a BRAF V600 mutation or a BRAF fusion) has been treated with a MEK inhibitor and one or more, e.g., one or two, immune checkpoint inhibitors (e.g., any of the immune checkpoint inhibitors disclosed herein, e.g., a CTLA-4 inhibitor, a PD-1 inhibitor, and/or a PD-L1 inhibitor) prior to treatment with a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has previously been treated with a MEK inhibitor selected from binimetinib, trametinib, cobimetinib, selumetinib, pimasertib, refametinib, N-[2(R),3-dihydroxypropoxy]-3,4-difluoro-2-(2-fluoro-4-iodophenylamino)benzamide (PD-325901), 2-(2-chloro-4-iodophenylamino)-N-(cyclopropylmethoxy)-3,4-difluorobenzamide (CI-1040), and 3-[2(R),3-dihydroxypropyl]-6-fluoro-5-(2-fluoro-4-iodophenylamino)-8-methyl-pyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione (TAK-733), and one or more control inhibitors immune checkpoint inhibitors (e.g., any of the immune checkpoint inhibitors disclosed herein, e.g., a CTLA-4 inhibitor, a PD-1 inhibitor, and/or a PD-L1 inhibitor). In one embodiment, the subject has been previously treated with a MEK inhibitor selected from binimetinib, trametinib, and cobimetinib, and one or more, e.g., one or two, immune checkpoint inhibitors independently selected from ipilimumab, nivolumab, and pembrolizumab. In one embodiment, the subject has been previously treated with a MEK inhibitor that is binimetinib and an immune checkpoint inhibitor that is nivolumab, ipilimumab, or pembrolizumab. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject having metastatic colorectal cancer (e.g., metastatic colorectal cancer having a BRAF V600 mutation or a BRAF fusion) has been treated with one or more, such as one or two, immune checkpoint inhibitors (e.g., any of the immune checkpoint inhibitors disclosed herein, such as a CTLA-4 inhibitor, a PD-1 inhibitor, and/or a PD-L1 inhibitor) prior to treatment with a compound of Formula I, or a pharmaceutically acceptable salt thereof, or a compound of Formula II, or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has previously been treated with one or more, such as one or two, immune checkpoint inhibitors independently selected from ipilimumab, nivolumab, pembrolizumab, and sasanlimab. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject having metastatic colorectal cancer (e.g., mutant metastatic colorectal cancer having a BRAF V600 mutation or a BRAF fusion) has been treated with one or more cytotoxic chemotherapeutic agents prior to treatment with a compound of Formula I, or a pharmaceutically acceptable salt thereof, or a compound of Formula II, or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been treated with oxaliplatin, irinotecan, a FOLFOXIRI combination (oxaliplatin, irinotecan, and fluorouracil), a FOLFIRI combination (folinic acid, fluorouracil, and irinotecan), or a CAPEOX combination (capecitabine and oxaliplatin) prior to treatment with a compound of Formula I, or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed in the invention, the subject having metastatic colorectal cancer (e.g., metastatic colorectal cancer having a BRAF V600 mutation or a BRAF fusion) has been treated with an EGFR inhibitor, a BRAF inhibitor, and one or more cytotoxic chemotherapeutic agents prior to treatment with a compound of Formula I or a pharmaceutically acceptable salt thereof, or a compound of Formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject having metastatic colorectal cancer has been previously treated with an EGFR inhibitor selected from cetuximab, panitumumab, osimertinib, erlotinib, gefinitib, necitumumab, neratinib, lapatinib, vandetanib, and brigatinib, a BRAF inhibitor selected from encorafenib, dabrafenib, vemurafenib, N-[3-(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-ylcarbonyl)-2,4-difluoro-phenyl]-propane-1-sulfonamide (PLX4720), and (3R)-N-(3-[[5-(2-cyclopropylpyrimidin-5-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]carbonyl]-2,4-difluorophenyl)-3-fluoropyrrolidine-1-sulfonamide (PLX8394), and one or more cytotoxic chemotherapeutic agents. In one embodiment, the subject has been previously treated with an EGFR inhibitor selected from cetuximab and panitumumab, a BRAF inhibitor that is vemurafenib, and a cytotoxic chemotherapeutic agent that is irinotecan. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject having metastatic colorectal cancer (e.g., metastatic colorectal cancer having a BRAF V600 mutation or a BRAF fusion) has been treated with an EGFR inhibitor and one or more cytotoxic chemotherapeutic agents prior to treatment with a compound of Formula I, or a pharmaceutically acceptable salt thereof, or a compound of Formula II, or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has previously been treated with an EGFR inhibitor selected from cetuximab, panitumumab, osimertinib, erlotinib, gefinitib, necitumumab, neratinib, lapatinib, vandetanib, and brigatinib, and one or more chemotherapeutic agents. In one embodiment, the subject has previously been treated with an EGFR inhibitor selected from cetuximab and panitumumab and a cytotoxic chemotherapeutic agent that is irinotecan or a combination of FOLFIRI (folinic acid, fluorouracil and irinotecan). In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject having metastatic non-small cell lung cancer (e.g., metastatic non-small cell lung cancer having a BRAF V600 mutation or a BRAF fusion) has been treated with one or more, e.g., one or two, EGFR inhibitors prior to treatment with a compound of Formula I, or a pharmaceutically acceptable salt thereof, or a compound of Formula II, or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with one or more, e.g., one or two, EGFR inhibitors independently selected from cetuximab, panitumumab, osimertinib, erlotinib, gefinitib, necitumumab, neratinib, lapatinib, vandetanib, and brigatinib. In one embodiment, the subject has been previously treated with erlotinib. In one embodiment, the subject has been previously treated with gefinitib. In one embodiment, the subject has been previously treated with erlotinib and gefinitib. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject having metastatic non-small cell lung cancer (e.g., metastatic non-small cell lung cancer that has a BRAF mutation) has previously been treated with a BRAF inhibitor selected from encorafenib, dabrafenib, vemurafenib, N-[3-(5-chloro-1H-pyrrolo-[2,3-b]pyridin-3-ylcarbonyl)-2,4-difluorophenyl]propane-1-sulfonamide (PLX4720) and (3R)-N-(3-[[5-(2-cyclo-propylpyrimidin-5-yl)-1H-pyrrolo-[2,3-b]pyridin-3-yl]carbonyl]-2,4-difluorophenyl)-3-fluoropyrrolidine-1-sulfonamide (PLX8394), a MEK inhibitor selected from binimetinib, trametinib, cobimetinib, selumetinib, pimasertib, refametinib, N-[2(R),3-dihydroxypropoxy]-3,4-difluoro-2-(2-fluoro-4-iodophenylamino)benzamide (PD-325901), 2-(2-chloro-4-iodophenylamino)-N-(cyclopropylmethoxy)-3,4-difluorobenzamide (CI-1040), and 3-[2(R),3-dihydroxypropyl]-6-fluoro-5-(2-fluoro-4-iodophenylamino)-8-methyl-pyrido[2,3-d]-pyrimidine-4,7(3H,8H)-dione (TAK-733), and an EGFR inhibitor selected from cetuximab, panitumumab, osimertinib, erlotinib, gefinitib, necitumumab, neratinib, lapatinib, vandetanib, and brigatinib, prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from vemurafenib, dabrafenib, and encorafenib, and an EGFR inhibitor selected from cetuximab and panitumumab, prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed in the invention, the subject having metastatic thyroid cancer (e.g., metastatic thyroid cancer having a BRAF V600 mutation or a BRAF fusion) has been previously treated with a BRAF inhibitor selected from encorafenib, dabrafenib, vemurafenib, N-[3-(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-ylcarbonyl)-2,4-difluorophenyl]propane-1-sulfonamide (PLX4720) and (3R)-N-(3-[[5-(2-cyclopropylpyrimidin-5-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]carbonyl]-2,4-difluorophenyl)-3-fluoro-pyrrolidine-1-sulfonamide (PLX8394), a MEK inhibitor selected from binimetinib, trametinib, cobimetinib, selumetinib, pimasertib, refametinib, N-[2(R),3-dihydroxypropoxy]-3,4-difluoro-2-(2-fluoro-4-iodophenylamino)benzamide (PD-325901), 2-(2-chloro-4-iodophenylamino)-N-(cyclopropylmethoxy)-3,4-difluorobenzamide (CI-1040) and 3-[2(R),3-dihydroxypropyl]-6-fluoro-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione (TAK-733), and an EGFR inhibitor selected from cetuximab, panitumumab, osimertinib, erlotinib, gefinitib, necitumumab, neratinib, lapatinib, vandetanib and brigatinib, prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has previously been treated with a BRAF inhibitor selected from vemurafenib, dabrafenib and encorafenib, prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the subject has developed brain metastases during said prior treatment.

In one embodiment of the disclosed method of treating a subject having a MEK-associated tumor, the subject has leptomeningeal disease (LMD) and has previously been treated with a BRAF inhibitor and one or more, such as one or two, immune checkpoint inhibitors (e.g., any of the immune checkpoint inhibitors disclosed herein, such as a CTLA-4 inhibitor, a PD-1 inhibitor, and/or a PD-L1 inhibitor) prior to treatment with a compound of Formula I or a pharmaceutically acceptable salt thereof, a compound of Formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has previously been treated with a BRAF inhibitor selected from encorafenib, dabrafenib, vemurafenib, N-[3-(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-ylcarbonyl)-2,4-difluorophenyl]propane-1-sulfonamide (PLX4720) and (3R)-N-(3-[[5-(2-cyclopropylpyrimidin-5-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]carbonyl]-2,4-difluorophenyl)-3-fluoropyrrolidine-1-sulfonamide (PLX8394), and one or more, such as one or two, immune checkpoint inhibitors independently selected from ipilimumab, nivolumab and pembrolizumab. In one embodiment, the subject has become refractory to said prior treatment.

In one embodiment of the disclosed method of treating a subject having a MEK-associated tumor, the subject has leptomeningeal disease (LMD) and has previously been treated with a BRAF inhibitor, a MEK inhibitor, and one or more, such as one or two, immune checkpoint inhibitors (e.g., any of the immune checkpoint inhibitors disclosed herein, such as a CTLA-4 inhibitor, a PD-1 inhibitor, and/or a PD-L1 inhibitor) prior to treatment with a compound of Formula I or a pharmaceutically acceptable salt thereof, a compound of Formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from encorafenib, dabrafenib, vemurafenib, N-[3-(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-ylcarbonyl)-2,4-difluorophenyl]propane-1-sulfonamide (PLX4720) and (3R)-N-(3-[[5-(2-cyclopropylpyrimidin-5-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]-carbonyl]-2,4-difluorophenyl)-3-fluoropyrrolidine-1-sulfonamide (PLX8394), a MEK inhibitor selected from binimetinib, trametinib, cobimetinib, selumetinib, pimasertib, refametinib, N-[2(R),3-dihydroxypropoxy]-3,4-difluoro-2-(2-fluoro-4-iodophenylamino)benzamide (PD-325901), 2-(2-chloro-4-iodophenylamino)-N-(cyclopropylmethoxy)-3,4-difluorobenzamide (CI-1040) and 3-[2(R),3-dihydroxypropyl]-6-fluoro-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione (TAK-733), and an immune checkpoint inhibitor (e.g., any of the immune checkpoint inhibitors disclosed in the invention, e.g., a CTLA-4 inhibitor, a PD-1 inhibitor and/or a PD-L1 inhibitor). In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from encorafenib, dabrafenib, and vemurafenib, a MEK inhibitor selected from binimetinib, trametinib, and cobimetinib, and one or more, such as one or two, immune checkpoint inhibitors independently selected from ipilimumab, nivolumab, and pembrolizumab. In one embodiment, the subject has become refractory to said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject has leptomeningeal disease (LMD) and has been previously treated with one or more, such as one or two, immune checkpoint inhibitors (e.g., any of the immune checkpoint inhibitors disclosed herein, such as a CTLA-4 inhibitor, a PD-1 inhibitor, and/or a PD-L1 inhibitor) prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with one or more, such as one or two, immune checkpoint inhibitors independently selected from ipilimumab, nivolumab, and pembrolizumab. In one embodiment, the subject has become refractory to said prior treatment.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed in the invention, the subject has a glioma and has previously been treated by undergoing surgery prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the glioma is a grade 2, grade 3, or grade 4 glioma.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject has a glioma and has been previously treated with radiation therapy (e.g., whole brain radiation therapy or stereotactic radiosurgery) prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the glioma is a grade 2, grade 3, or grade 4 glioma.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject has a glioma and has been previously treated with one or more cytotoxic chemotherapeutic agents prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with one or more cytotoxic chemotherapeutic agents independently selected from cisplatin, pemetrexed, vinorelbine, and paclitaxel. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the glioma is a grade 2, grade 3, or grade 4 glioma.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject has a MEK-associated glioma and has been previously treated with an ornithine decarboxylase inhibitor prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with an ornithine decarboxylase inhibitor that is eflornithine (as a racemate, or the D or L enantiomer). In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the glioma is a grade 2, grade 3, or grade 4 glioma.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject has a MEK-associated glioma and has been previously treated with an alkylating agent prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with an alkylating agent selected from temozolomide, lomustine, and carmustine. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the glioma is a grade 2, grade 3, or grade 4 glioma.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject has a MEK-associated glioma and has been previously treated with an alkylating agent and an ornithine decarboxylase inhibitor prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with an alkylating agent selected from temozolomide, lomustine, and carmustine, and an ornithine decarboxylase inhibitor that is eflornithine (as a racemate, or the D or L enantiomer). In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the glioma is a grade 2, grade 3, or grade 4 glioma.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject has a MEK-associated glioma and has been previously treated with radiation therapy (e.g., whole brain radiation therapy or stereotactic radiosurgery) and an alkylating agent prior to treatment with a compound of Formula I, or a pharmaceutically acceptable salt thereof, a compound of Formula II, or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with radiation therapy (e.g., whole brain radiation therapy or stereotactic radiosurgery) and an alkylating agent selected from temozolomide, lomustine, and carmustine. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the glioma is a grade 2, grade 3, or grade 4 glioma.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject has a MEK-associated glioma and has been previously treated with antibody therapy prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with antibody therapy, wherein the antibody is bevacizumab. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the glioma is a grade 2, grade 3, or grade 4 glioma.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed in the invention, the subject has a MEK-associated glioma and has previously been treated with surgery and radiation therapy prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the glioma is a grade 2, grade 3, or grade 4 glioma.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed herein, the subject has a MEK-associated glioma and has been previously treated with surgery, radiation therapy, and an alkylating agent prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with surgery, radiation therapy (e.g., whole brain radiation therapy or stereotactic radiosurgery), and an alkylating agent selected from temozolomide, lomustine, and carmustine. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the glioma is a grade 2, grade 3, or grade 4 glioma.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed in the invention, the subject has a MEK-associated glioma and has previously been treated with a BRAF inhibitor prior to treatment with a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from N-[3-(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-yl-carbonyl)-2,4-difluorophenyl]propane-1-sulfonamide (PLX4720), vemurafenib, dabrafenib, encorafenib, and (3R)-N-(3-[[5-(2-cyclopropylpyrimidin-5-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]-carbonyl]-2,4-difluorophenyl)-3-fluoropyrrolidine-1-sulfonamide (PLX8394). In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the glioma is a grade 2, grade 3, or grade 4 glioma.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed in the invention, the subject has a MEK-associated glioma and has previously been treated with a BRAF inhibitor and a MEK inhibitor prior to treatment with a compound of formula I or a pharmaceutically acceptable salt, solvate, or polymorph thereof, or a compound of formula II or a pharmaceutically acceptable salt, solvate, or polymorph thereof. In one embodiment, the subject has previously been treated with a BRAF inhibitor selected from N-[3-(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-ylcarbonyl)-2,4-difluorophenyl]propane-1-sulfonamide (PLX4720), vemurafenib, dabrafenib, encorafenib, and (3R)-N-(3-[[5-(2-cyclopropylpyrimidin-5-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]-carbonyl]-2,4-difluorophenyl)-3-fluoropyrrolidine-1-sulfonamide (PLX8394), and a MEK inhibitor selected from binimetinib, trametinib, cobimetinib, selumetinib, pimasertib, refametinib, N-[2(R),3-dihydroxypropoxy]-3,4-difluoro-2-(2-fluoro-4-iodophenylamino)benzamide (PD-325901), 2-(2-chloro-4-iodophenylamino)-N-(cyclopropylmethoxy)-3,4-difluorobenzamide (CI-1040), and 3-[2(R),3-dihydroxypropyl]-6-fluoro-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione (TAK-733). In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from encorafenib, dabrafenib, and vemurafenib, and a MEK inhibitor selected from binimetinib, trametinib, and cobimetinib. In one embodiment, the subject has become refractory to said prior treatment. In one embodiment, the glioma is a grade 2, grade 3, or grade 4 glioma.

In one embodiment of the method of treating a subject having a MEK-associated tumor disclosed in the invention, the subject has a MEK-associated brainstem ganglioglioma and has previously been treated with a BRAF inhibitor prior to treatment with a compound of formula I or a pharmaceutically acceptable salt thereof, a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from encorafenib, dabrafenib, vemurafenib, N-[3-(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-ylcarbonyl)-2,4-difluorophenyl]-propane-1-sulfonamide (PLX4720), and (3R)-N-(3-[[5-(2-cyclopropyl-pyrimidin-5-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]-carbonyl]-2,4-difluorophenyl)-3-fluoropyrrolidine-1-sulfonamide (PLX8394). In one embodiment, the subject has been previously treated with a BRAF inhibitor selected from encorafenib, dabrafenib, and vemurafenib. In one embodiment, the subject has become refractory to said prior treatment.

Although the genetic basis of tumorigenesis may differ depending on the type of cancer, the cellular and molecular mechanisms required for metastasis appear to be similar in all types of solid tumors. During the metastatic cascade, cancer cells lose growth inhibitory responses, undergo changes in their adhesiveness, and produce enzymes that can degrade extracellular matrix components. This leads to tumor cell detachment from the original tumor, entry into the bloodstream through newly formed vasculature, migration, and extravasation of tumor cells to favorable distant sites where they can form colonies. A number of genes have been identified as promoters or suppressors of metastasis.

Accordingly, the invention further provides methods for treating, inhibiting, preventing, promoting the prevention of, or reducing the metastasis of a MEK-associated tumor in a subject in need thereof, wherein the method comprises administering to the subject a therapeutically effective amount of a compound of formula I or a pharmaceutically acceptable salt thereof, or a compound of formula II or a pharmaceutically acceptable salt thereof. In one embodiment, the compound of formula I or a pharmaceutically acceptable salt thereof is used in combination with one or more anti-cancer therapies independently selected from surgery (e.g., at least partial resection of the tumor), radiation therapy, and the use of an anti-cancer agent.

As used herein, the term "treating metastasis" means reducing the size, progression, and/or further spread of one or more metastases.

As used herein, the term "inhibiting metastasis" means reducing the occurrence (or reoccurrence) of one or more metastases, preventing the occurrence (or reoccurrence) of one or more metastases, or reducing the spread of one or more metastases.

In one embodiment, a subject treated according to any of the methods disclosed herein may be assessed according to one or more standard objective response criteria known in the art, including RECIST.

(Response Evaluation Criteria in Solid Tumors, such as RECIST version 1.0, RECIST version 1.1, and modified RECIST 1.1 (mRECIST 1.1)), RANO-BM (Objective Response Criteria in Metastatic Brain Tumors), Macdonald, RANO-LMD, and NANO (Neurological Rating Scale in Neuro-Oncology). In one embodiment of any of these criteria, the tumor is assessed by tumor imaging (e.g., magnetic resonance imaging (MRI), computed tomography (CT), multidetector computed tomography (MDCT), or positron emission tomography (PET)). In one embodiment, the objective response to treatment is assessed in accordance with RECIST version 1.1, where: a complete response (CR) is defined as a complete disappearance of all tumor lesions; a partial response (PR) is defined as a decrease in the sum of tumor size measurements by at least 30%; disease progression (PD) is defined as an increase of at least 20% in the sum of tumor dimensions (where the appearance of new lesions or significant progression of non-target tumor lesions is also defined as PD), where an increase of at least 5 mm from the baseline value is assessed as PD; and stable disease (SD) is defined as the absence of a significant decrease in tumor size, in order to assess the status as PR, and the absence of a significant increase in tumor size, in order to assess the status as PD, using the smallest sum of tumor diameters during treatment for comparison. In one embodiment, the assessments include intracranial response (assessed according to a modified RECIST using gadolinium-enhanced MRI), extracranial response, objective global response rate, tumor control rate (DCR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS).

As used herein, the term "effective dose" or "effective amount" of a drug, compound or pharmaceutical composition refers to an amount sufficient to produce any one or more effects, beneficial or desired, including on the biochemical, histological and/or behavioral symptoms of a disease, its complications and intermediate pathological phenotypes manifested during the development of the disease. In terms of use for therapeutic purposes, a "therapeutically effective amount" refers to the amount of the administered compound that alleviates, to some extent, one or more of the symptoms of the disease being treated. In the context of treating cancer, a therapeutically effective amount refers to an amount that has the effect of (1) reducing the size of a tumor, (2) inhibiting (i.e., slowing, to some extent, preferably stopping) tumor metastasis, (3) inhibiting (i.e., slowing, to some extent, preferably stopping) tumor growth or tumor invasiveness, (4) alleviating, to some extent (or, preferably, eliminating) one or more signs or symptoms associated with cancer, (5) reducing the dosage of other drugs required to treat the disease, and/or (6) enhancing the effect of another drug, and/or (7) slowing the progression of the disease in a patient.

An effective dose may be administered in one or more administrations. For the purposes of this invention, an effective dose of a drug, compound or pharmaceutical composition is a dose sufficient to effect prophylactic or therapeutic treatment, either directly or indirectly. It should be understood that in a clinical context, an effective dose of a drug, compound or pharmaceutical composition may or may not be achieved in combination with another drug, compound or pharmaceutical composition.

"Pharmaceutical composition" refers to a mixture of one or more compounds of the invention or pharmaceutically acceptable salts, solvates, hydrates or prodrugs thereof as an active ingredient, and at least one pharmaceutically acceptable carrier or excipient. In one embodiment, the pharmaceutical composition includes two or more pharmaceutically acceptable carriers and/or excipients.

In one embodiment, the invention provides a pharmaceutical composition comprising a compound of the invention or a pharmaceutically acceptable salt thereof and at least one pharmaceutically acceptable carrier or excipient. In one embodiment, the pharmaceutical composition comprises two or more pharmaceutically acceptable carriers and/or excipients.

Accordingly, in one embodiment, the invention provides a pharmaceutical composition for use in the treatment of abnormal cell growth in a subject in need thereof, wherein the pharmaceutical composition comprises a compound of the invention or a pharmaceutically acceptable salt thereof and at least one pharmaceutically acceptable carrier or excipient.

As used in the invention, a "pharmaceutically acceptable carrier" refers to a carrier or diluent that does not cause significant irritant effects on the body and does not adversely affect the biological activity and properties of the administered compound.

A pharmaceutically acceptable carrier may include any conventional pharmaceutical carrier or excipient. The choice of carrier and/or excipient will depend to a large extent on such factors as the particular route of administration, the effect of the carrier or

excipients for solubility and stability, and the properties of the dosage form.

Suitable pharmaceutical carriers include inert diluents or fillers, water and various organic solvents (such as those that form hydrates and solvates). Pharmaceutical compositions may, if desired, contain additional ingredients such as substances that correct the taste and smell of the drug, binders, excipients and other similar ingredients.

The term "excipient" is used in the invention to describe any ingredient that is not a compound(s) of the invention. The choice of excipient will depend to a large extent on such factors as the particular route of administration, the effect of the excipient on solubility and stability, and the properties of the dosage form.

The "excipient" used in the invention includes all kinds of solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption-retarding substances, carriers, diluents and other similar auxiliary substances that are physiologically compatible. Examples of auxiliary substances include one or more substances such as water, physiological saline, phosphate-buffered saline, dextrose, glycerol, ethanol and other similar substances, as well as combinations thereof, and can include isotonic agents in the compositions, for example, sugars, sodium chloride or polyalcohols such as mannitol or sorbitol. Examples of auxiliary substances also include various organic solvents (such as hydrate-forming and solvate-forming substances). The pharmaceutical compositions may, if required, contain additional auxiliary substances such as substances that modify the taste and smell of the drug, binders, lubricants, disintegrants, sweeteners or flavoring agents, coloring agents or dyes, and other similar auxiliary substances. For example, for oral administration, tablets containing various auxiliary substances such as citric acid can be used, together with various disintegrants such as starch, alginic acid and specific complex silicates, and with binders such as sucrose, gelatin and acacia. Non-limiting examples of auxiliary substances include calcium carbonate, calcium phosphate, various sugars and types of starch, cellulose derivatives, gelatin, vegetable oils and polyethylene glycols. Thus, for example, for oral administration, tablets containing various

auxiliary substances such as citric acid, together with various disintegrants such as starch, alginic acid and certain complex silicates, as well as with binders such as sucrose, gelatin and acacia. Non-limiting examples of auxiliary substances include calcium carbonate, calcium phosphate, various sugars and types of starch, cellulose derivatives, gelatin, vegetable oils and polyethylene glycols. In addition, lubricating substances such as magnesium stearate, sodium lauryl sulfate and talc are often used for tabletting. Solid compositions of a similar type can also be used in soft and hard-filled gelatin capsules. Therefore, non-limiting examples of materials include lactose or milk sugar and high molecular weight polyethylene glycols. When aqueous suspensions or elixirs are desired for oral administration, the active compound contained therein can be combined with various sweetening or flavoring agents, coloring agents or dyes and, if desired, emulsifying or suspending agents, together with diluents such as water, ethanol, propylene glycol, glycerol or combinations thereof.

Examples of excipients also include pharmaceutically acceptable substances such as wetting agents, or minor amounts of excipients such as humectants or emulsifiers, preservatives, or buffers that enhance the shelf life or potency of the compound.

The pharmaceutical composition may, for example, be in a form suitable for oral administration, in the form of a tablet, capsule, pill, powder, sustained release formulations, suspension solution, liquid solutions (e.g. injection and infusion solutions), suitable for parenteral injection in the form of a sterile solution, suspension or emulsion, suitable for topical application in the form of an ointment or cream, powders, liposomes and suppositories (e.g. for rectal administration in the form of suppositories). Typical forms for parenteral administration include solutions or suspensions of the active compounds in sterile aqueous solutions, for example, aqueous propylene glycol or dextrose solutions. If desired, such dosage forms can be suitably buffered. The dosage form depends on the intended route of administration and therapeutic use.

The pharmaceutical composition may be in a single dose dosage form used for single administration of precisely measured doses.

The compounds of the invention can be administered orally. Oral administration can involve swallowing, whereby the compound enters the gastrointestinal tract, or buccal or sublingual administration can be used, whereby the compound enters the bloodstream directly from the oral cavity. Dosage forms useful for oral administration include solid forms such as tablets, capsules containing solid particles, liquids or powders, lozenges (including liquid-filled), chewable lozenges, multiparticulates and nanoparticles, gels, solid solution, liposomes, films (including mucoadhesive), suppositories, sprays and liquid dosage forms. Such capsules or tablets can include controlled-release forms. In the case of capsules, tablets and pills, the dosage forms can also contain buffering agents or can be prepared with enteric coatings.

Liquid forms include suspensions, solutions, syrups and elixirs. Such forms may be used as fillers in soft or hard capsules and typically include a carrier or excipient such as one or more wetting agents, emulsifiers, suspending agents, flavoring agents (e.g. sweeteners) or flavoring agents, such as water, ethanol, polyethylene glycol, propylene glycol, methylcellulose or a suitable oil, and one or more emulsifiers and/or suspending agents. Liquid forms may also be prepared by dissolving a solid, such as from a powder to prepare a solution.

The compounds of the invention can be used in rapidly dissolving, rapidly disintegrating dosage forms, such as the dosage forms described in Expert Opinion in Therapeutic Patents, 11 (6), 981986 by Liang and Chen (2001), the entire contents of which are incorporated herein by reference.

For tablet dosage forms, depending on the dose, the drug content may range from 1% to 80% by weight of the dosage form, most commonly from 5% to 60% by weight of the dosage form. In addition to the drug, tablets typically contain a disintegrant. Examples of disintegrants include sodium starch glycolate, sodium carboxymethylcellulose, calcium carboxymethylcellulose, sodium croscarmellose, crospovidone, polyvinylpyrrolidone, methylcellulose, microcrystalline cellulose, lower alkyl-substituted hydroxypropyl cellulose, starch, pregelatinized starch, and sodium alginate. Typically, the disintegrant will comprise from 1% to 25% by weight, preferably from 5% to 20% by weight of the dosage form. Binders are typically used to impart cohesive properties to the tablet. Suitable binders include microcrystalline cellulose, gelatin, sugars, polyethylene glycol, natural and synthetic gums, polyvinylpyrrolidone, pregelatinized starch, hydroxypropyl cellulose and hydroxypropyl methylcellulose. The tablets may also contain diluents such as lactose (monohydrate, spray-dried monohydrate, anhydrous and other similar forms), mannitol, xylitol, dextrose, sucrose, sorbitol, microcrystalline cellulose, starch and dibasic calcium phosphate dihydrate. The tablets may also optionally include surfactants such as sodium lauryl sulfate and polysorbate 80, and glidants such as silicon dioxide and talc. When present, the surfactants typically comprise from 0.2% to 5% by weight of the tablet, and the glidants typically comprise from 0.2% to 1% by weight of the tablet. Tablets also typically contain lubricating agents such as magnesium stearate, calcium stearate, zinc stearate, sodium stearyl fumarate, and mixtures of magnesium stearate with sodium lauryl sulfate. Lubricants are typically present in amounts of 0.25% to 10% by weight, preferably 0.5% to 3% by weight, based on the weight of the tablet. Other conventional ingredients include antioxidants, coloring agents, flavoring agents, preservatives, and flavoring agents. The tablet mixtures may be directly compressed or rolled to form tablets. The tablet mixtures or portions of the mixtures may optionally be moistened, dried, or melt granulated, melt solidified, or extruded prior to tableting. The finished form may comprise one or more layers and may be coated or uncoated, or may be encapsulated. Solid dosage forms for oral administration may be prepared for immediate release and/or modified release.

Modified release dosage forms include delayed release, sustained release, pulsed release, controlled release, targeted release and programmed release.

For oral administration, compositions in the form of tablets or capsules containing 0.01, 0.05, 0.1, 0.25, 0.5, 1, 0.2, 5, 5, 0.10, 0.15, 0.25, 0.50, 0.75, 0 or 100 milligrams of the active ingredient can be provided for symptomatic dose adjustment for the patient. The drug typically contains from about 0.01 mg to about 100 mg of the active ingredient. In another embodiment, the drug contains from about 0.01 to 0.25 mg of the active ingredient. In another embodiment, the drug contains about 0.25, 0.5, 1.0, 5.0, 15 or 25 mg of the active ingredient.

The compounds of the invention may also be administered directly into the blood stream, into a muscle, or into an internal organ.

Suitable routes of parenteral administration include intravenous, intraarterial, intraperitoneal, intrathecal, intraventricular, intraurethral, intrasternal, intracranial, intramuscular and subcutaneous. Suitable devices for parenteral administration include needle (including microneedle) syringes, needleless syringes and infusion devices. Injectable forms of preparations (i.e., sterile injectable aqueous or oily suspensions) can be prepared by methods known in the art using one or more suitable dispersing, wetting or suspending agents. Parenteral forms are usually aqueous solutions which may contain auxiliary substances such as salts, carbohydrates and buffering substances (preferably with a pH value from 3 to 9), but, in the case of some applications, they are more conveniently prepared in the form of a sterile non-aqueous solution or in dried form, which will be used in combination with a suitable vehicle, such as sterile pyrogen-free water. The preparation of parenteral forms under sterile conditions, for example, by lyophilization, can be readily accomplished using standard pharmaceutical techniques well known to those skilled in the art. The solubility of the compounds of the invention used for the preparation of parenteral solutions can be increased by the use of appropriate preparation techniques, such as the introduction of solubility enhancing agents.

Dosage forms for parenteral administration can be prepared for immediate release and/or modified release. Dosage forms for modified release include delayed release, sustained release, pulsed release, controlled release, targeted release and programmed release. For example, the compounds of the invention can be prepared in the form of a solid, semi-solid or thixotropic liquid for administration in the form of an implanted depot providing modified release of the active compound. Examples of such dosage forms include stents and microspheres made of poly(lactic-co-glycolic acid) with a drug applied thereto.

The compounds of the invention can also be applied topically to the skin or mucous membrane, i.e., dermally or transdermally, for example, using transdermal patches or iontophoretic devices, for intraocular administration or intranasal or inhalation administration. The dosage form for topical administration can include a compound that enhances the absorption or penetration of the active ingredient through the skin or other affected areas. When the compounds of this invention are administered using a transdermal device, the administration will be carried out using a patch, either of the reservoir type and the porous membrane type, or of the various solid matrix type. Typical dosage forms for topical administration include gels, hydrogels, lotions, solutions, creams, ointments, powders, dressings, foams, films, transdermal patches, capsules, implants, sponges, fibers, bandages and microemulsions. Liposomes can also be used. Typical carriers include alcohol, water, mineral oil, petrolatum, white petrolatum, glycerin, polyethylene glycol, and propylene glycol. Penetration enhancers may be included. Other methods of topical administration include drug delivery by electroporation, iontophoresis, phonophoresis, sonophoresis, and microneedle or needle-free (e.g., Powderject™, Bioject™, etc.) injection.

Dosage forms that can be used for topical administration to the eye include, for example, eye drops in which the compound of the present invention is dissolved or suspended in a suitable excipient. A typical form suitable for ocular or aural administration may be drops of a micronized suspension or a solution in isotonic sterile physiological solution with an adjusted pH value. Other forms suitable for ocular and aural administration include ointments, biodegradable (i.e., absorbable gel sponges, collagen) and non-biodegradable (i.e., silicone) implants, capsules, lenses and dispersed or vesicular systems such as niosomes or liposomes. A polymer such as cross-linked polyacrylic acid, polyvinyl alcohol, hyaluronic acid, a cellulose polymer such as hydroxypropyl methylcellulose, hydroxyethylcellulose or methylcellulose, or a heteropolysaccharide polymer such as gellan gum may be incorporated into the dosage form together with a preservative such as benzalkonium chloride. Such formulations may also be delivered using iontophoresis.

Dosage forms for topical use may be prepared in such a way that they can perform immediate and/or modified release. Modified release forms include delayed, sustained, pulsed, controlled, targeted and programmed release.

The compounds of the invention may also be administered intranasally or by inhalation, typically in the form of a dry powder (either alone or in the form of a mixture, for example in a dry mixture with lactose, or in the form of a mixture with particles, for example a mixture with phospholipids such as phosphatidylcholine), from a dry powder inhaler or in the form of an atomized aerosol from a pressurized container, pump, spray, nebulizer (preferably an atomizer using electrohydrodynamics to create a fine mist) or sprayer, with or without a suitable propellant, such as 1,1,1,2-tetrafluoroethane or 1,1,1,2,3,3,3-heptafluoropropane. In the case of intranasal administration, the powder may include a bioadhesive substance, for example chitosan or cyclodextrin. The pressurized container, pump, spray, aerosol inhaler or nebulizer contains a solution or suspension of the compound(s) of the invention, containing, for example, ethanol, an aqueous solution of ethanol or a suitable alternative substance for dispersing, solubilizing or prolonging the release of the active compound, a propellant(s) as a solvent and an optional surfactant such as sorbitan trioleate, oleic acid or oligolactic acid. Before use in the form of a dry powder or suspension, the drug may be micronized to a particle size suitable for delivery by inhalation (typically less than 5 microns). This may be achieved by any suitable fine milling method, such as spiral jet milling, fluidized bed jet milling, supercritical fluid processing to form nanoparticles, high pressure homogenization or spray drying.

Capsules (made, for example, from gelatin or hydroxypropyl methylcellulose (HPMC)), blisters and cartridges for use in an inhaler or insufflator may be formulated to contain a powder mix of the compound of the invention, a suitable powder base such as lactose or starch and a potency modifier such as leucine, mannitol or magnesium stearate. Lactose may be anhydrous or in the form of a monohydrate, preferably in the form of a monohydrate. Other suitable excipients include dextran, glucose, maltose, sorbitol, xylitol, fructose, sucrose and trehalose.

Suitable flavoring agents such as menthol and levomenthol, or sweeteners such as saccharin or sodium saccharin may be added to the dosage forms of the present invention intended for inhalation/intranasal administration.

The compounds of the invention can be administered rectally or vaginally, for example in the form of a suppository, pessary or enema. A traditional suppository base is cocoa butter, but various alternative bases can be used depending on the particular case.

Rectal/vaginal dosage forms may be prepared in instant and/or modified release forms. Modified release forms include delayed, sustained, pulsed, controlled, targeted and programmed release.

The compounds of the invention can also be administered directly to the eye or ear, typically in the form of drops of a micronized suspension or solution in isotonic, sterile, pH-adjusted saline. Other forms suitable for ocular and aural administration include ointments, biodegradable (i.e., absorbable gel sponges, collagen) and non-biodegradable (i.e., silicone) implants, capsules, lenses, and dispersed or vesicular systems such as niosomes or liposomes. A polymer such as cross-linked polyacrylic acid, polyvinyl alcohol, hyaluronic acid, a cellulose polymer such as hydroxypropyl methylcellulose, hydroxyethylcellulose or methylcellulose, or a heteropolysaccharide polymer such as gellan gum can be incorporated into the dosage form together with a preservative such as benzalkonium chloride. Such formulations can also be delivered using iontophoresis.

Dosage forms for administration to the eye/ear may be prepared in such a way that they can provide immediate and/or modified release. Modified release forms include delayed, sustained, pulsed, controlled, targeted and programmed release.

In addition, other excipients and routes of administration known in the pharmaceutical art may be used. The pharmaceutical compositions of the invention may be prepared by any of the methods well known in the pharmaceutical art, such as methods for preparing effective dosage forms and methods for effective administration. The above considerations regarding effective dosage forms and methods for effective administration are well known in the art and are described in well-known textbooks. The preparation of dosage forms is discussed, for example, in the monographs and manuals of Hoover, John E., Remington's Pharmaceutical Sciences, Mack Publishing Co., Easton, Pennsylvania, 1975; Liberman et al., Eds., Pharmaceutical Dosage Forms, Marcel Decker, New York, N.Y., 1980; and Kibbe et al., Eds., Handbook of Pharmaceutical Excipients (3rd Ed.), American Pharmaceutical Association, Washington, 1999.

Acceptable excipients are nontoxic to subjects at the dosages and concentrations employed and may include one or more of the following excipients: 1) buffers, such as phosphate, citrate, or other organic acids; 2) salts, such as sodium chloride; 3) antioxidants, such as ascorbic acid or methionine; 4) preservatives, such as octadecyldimethylbenzylammonium chloride, hexamethonium chloride, benzalkonium chloride, benzethonium chloride, phenol, butyl or benzyl alcohol; 5) alkyl parabens, such as methyl or propyl paraben, catechin, resorcinol, cyclohexanol, 3-pentanol, or m-cresol; 6) low molecular weight (less than about 10 residues) polypeptides; 7) proteins, such as serum albumin, gelatin, or immunoglobulins; 8) hydrophilic polymers such as polyvinylpyrrolidone; 9) amino acids such as glycine, glutamine, asparagine, histidine, arginine or lysine; 10) monosaccharides, disaccharides or other carbohydrates including glucose, mannose or dextrins; 11) chelating agents such as ethylenediaminetetraacetic acid (EDTA); 12) sugars such as sucrose, mannitol, trehalose or sorbitol; 13) salt-forming counterions such as sodium, metal complexes (e.g. Zn-protein complexes) or 14) nonionic surfactants such as polysorbates (e.g. polysorbate 20 or polysorbate 80), poloxamers or polyethyleneglycol (PEG).

A liposome containing the compounds of the invention can be prepared by methods known in the art (see, for example, Chang, H.I.; Yen, M.K.; Clinical development of liposome-based drugs: formulation, characterization, and therapeutic efficacy; Int J Nanomedicine 2012; 7; 49-60). In particular, liposomes suitable for the purposes of the invention can be prepared by a reverse-phase evaporation method using a lipid composition comprising phosphatidylcholine, cholesterol, and PEG-derivatized phosphatidylethanolamine (PEG-PE). The liposomes are extruded through filters with a certain pore size to obtain liposomes of the desired diameter.

The compounds of the invention can also be incorporated into microcapsules prepared, for example, by coacervation or interfacial polymerization techniques, for example, in hydroxymethylcellulose or gelatin microcapsules and polymethylmethacrylate microcapsules, respectively, in colloidal drug delivery systems (e.g. liposomes, albumin microspheres, microemulsions, nanoparticles and nanocapsules) or in macroemulsions. Such techniques are disclosed in Remington, The Science and Practice of Pharmacy, 20th Ed., Mack Publishing (2000).

Sustained release preparations may be used. Suitable examples of sustained release preparations include semipermeable matrices of solid hydrophobic polymers containing a compound of the invention, these matrices being in the form of shaped articles, for example films or microcapsules. Examples of sustained release matrices include polyesters, hydrogels (for example poly(2-hydroxyethyl methacrylate) or polyvinyl alcohol), polylactides, copolymers of L-glutamic acid and 7-ethyl-L-glutamate, non-degradable ethylene-vinyl acetate copolymer, degradable copolymers of lactic and glycolic acids, such as the copolymers used to form a depot suspension of leuprolide acetate (injectable microspheres consisting of a copolymer of lactic and glycolic acids and leuprolide acetate), sucrose acetate isobutyrate and poly-D-(-)-3-hydroxybutyric acid.

Dosage forms used for intravenous administration must be sterile. This is easily achieved, for example, by filtration through sterilizing filter membranes. The compounds of the invention are typically placed in a container having a sterile entry port, for example, in a bag or vial for intravenous solution having a stopper pierced by a hypodermic needle.

Suitable emulsions can be prepared using commercially available fat emulsions such as lipid emulsions containing soybean oil, intravenous fat emulsion (e.g. containing safflower oil, soybean oil, egg phosphatides and glycerol in water), emulsions containing soybean oil and medium chain triglycerides and cottonseed oil lipid emulsions. The active ingredient can either be dissolved in a premixed emulsion composition or, alternatively, it can be dissolved in an oil (e.g. soybean oil, safflower oil, cottonseed oil, sesame oil, corn oil or almond oil) to form an emulsion when mixed with a phospholipid (e.g. egg phospholipids, soy phospholipids or soy lecithin) and water. It should be noted that other ingredients, such as glycerol or glucose, may be added to adjust the tonicity of the emulsion. Suitable emulsions typically contain up to 20% oil, such as 5 to 20%. A fat emulsion may contain fat droplets of 0.1 to 1.0 µm, in particular 0.1 to 0.5 µm, and have a pH in the range of 5.5 to 8.0.

For example, emulsion compositions may be emulsions prepared by mixing the compound of the invention with lipid emulsions containing soybean oil or its components (soybean oil, egg phospholipids, glycerol and water).

A drug product intermediate (DPI) is a partially processed material that must undergo subsequent processing steps before it becomes a bulk dosage form of a drug. The compounds of the invention can be formulated as a drug product intermediate comprising the ingredient in a form with a higher free energy than the crystalline form. One reason for using a DPI is the need to improve oral absorption characteristics, which are deficient due to low solubility, slow dissolution, improved mass transfer across the mucus layer adjacent to epithelial cells, and, in some cases, limitations due to biological barriers such as metabolism and transporters. Other reasons may include the need to improve solid state stability and improve processability of subsequent processing steps. In one embodiment, the drug product intermediate comprises a compound of the invention isolated and stabilized in an amorphous state (e.g., in the form of amorphous solid dispersions (ASDs)). Many methods are known in the art for preparing dispersions of amorphous solids that produce a material suitable for integration into a bulk dosage form, such as spray dried dispersions (SDDs), melt extrudates (often referred to as NMEs), co-precipitated precipitates, amorphous drug nanoparticles, and nanoadsorbates. In one embodiment, the amorphous solid dispersions comprise a compound of the invention and a polymeric excipient. Other excipients, as well as concentrations of said excipients, and the compound of the invention are well known in the art and are described in well-known textbooks. See, for example, "Amorphous Solid Dispersions Theory and Practice" by Navnit Shah et al.

In another aspect, the invention provides a compound of the invention or a pharmaceutically acceptable salt thereof for use as a medicament, in particular a medicament for the treatment of abnormal cell growth.

In another aspect, the invention provides the use of a compound of the invention or a pharmaceutically acceptable salt thereof for the manufacture of a medicament for the treatment of abnormal cell growth in a subject, such as a tumor, such as a MEK-associated tumor, in a subject.

In another aspect, the invention provides a compound of any of the formulae described herein, or a pharmaceutically acceptable salt thereof, for use in the treatment of abnormal cell growth, such as a tumor, such as a MEK-associated tumor.

The compounds of the invention may be administered by any route that delivers the compounds to the site of action. These routes include oral administration, intraduodenal routes of administration, parenteral injection (including intravenous, subcutaneous, intramuscular, intravascular or infusion), topical and rectal administration.

The dosage regimens can be adjusted to achieve the optimum desired response. For example, a single dose can be administered, several divided doses can be administered over a specific period of time, or the dose can be proportionally reduced or increased depending on the requirements of the therapeutic situation. Parenteral compositions are especially advantageously prepared in unit dose form from the standpoint of ease of administration and consistency of dosage. The unit dose form used in the invention refers to physically discrete units suitable as unitary doses for the mammals to be treated; each unit contains a predetermined quantity of the active compound calculated to achieve the desired therapeutic effect, in association with the required pharmaceutical carrier. The requirements for the unit dose dosage forms of the invention are conditioned by and directly depend on (a) the unique characteristics of the compound being administered and the specific therapeutic or prophylactic effect to be achieved, and (b) the limitations that exist in formulating such active compound for the treatment of diseases in individuals.

For example, it will be obvious to a person skilled in the art, after reading the description of the present invention, that the dose and the dosing regimen are adjusted using methods well known in the field of therapy. That is, the maximum tolerated dose can be easily established, and an effective amount can be determined that allows achieving a detectable positive therapeutic effect in a patient, and, in addition, the time requirements for the administration of each drug can be determined to achieve a detectable positive therapeutic effect in a patient. Accordingly, despite the fact that the invention provides specific doses and administration regimens as examples, nevertheless, these examples in no way limit the doses and administration regimen that can be offered to a patient when applying the present invention in practice.

It should be understood that the dosage values may vary depending on the type and severity of the disease state to be relieved, and may include single or multiple doses. It should also be understood that for any particular subject, specific dosage regimens should be adjusted over time according to the individual's needs and the professional judgment of the person administering or supervising the administration of the compositions, and that the dosage ranges provided in the invention are examples only and in no way limit the variety or practical application of the claimed composition. For example, dosages may be adjusted based on pharmacokinetic or pharmacodynamic parameters, which may include clinical effects such as toxic effects and/or laboratory test data. Thus, for example, the present invention includes the possibility of increasing the individual dose for a patient determined by a person skilled in the art. Determining appropriate doses and administration schedules for a chemotherapeutic agent is well known in the art and it will be appreciated that, having been taught the teachings of the present invention, it will not be particularly difficult for one skilled in the art to determine appropriate doses and administration schedules. In one embodiment, an effective dose is typically in the range of about 0.001 to about 100 mg per kg of body weight per day, and often about 0.01 to about 35 mg/kg/day, in a single dose or in divided doses. For a 70 kg male, this would be about 0.07 mg/day to about 7000 mg/day, most often about 10 mg/day to about 1000 mg/day. Sometimes, the dose is approximately 10, 20, 30, 40, 50, 60, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700, 750, 800, 900 or 1000 mg/day. Sometimes, the dose is from about 10 mg/day to about 1000 mg/day, from about 10 mg/day to about 750 mg/day, from about 10 mg/day to about 600 mg/day, from about 10 mg/day to about 300 mg/day, from about 10 mg/day to about 150 mg/day, from about 20 mg/day to about 750 mg/day, from about 20 mg/day to about 600 mg/day, from about 20 mg/day to about 300 mg/day, from about 20 mg/day to about 150 mg/day, from about 50 mg/day to about 750 mg/day, from about 50 mg/day to about 600 mg/day, from about 50 mg/day to about 300 mg/day, from about 50 mg/day to about 150 mg/day, from about 75 mg/day to about 750 mg/day, from about 75 mg/day to about 600 mg/day, from about 75 mg/day to about 300 mg/day, or from about 75 mg/day to about 150 mg/day. In some cases, dosage levels below the lower end of the above range may be more than sufficient, while in other cases, even higher doses may be used without causing any harmful side effects, with such high doses typically being divided into several smaller doses for administration throughout the day. In one embodiment, the subject is administered about 50 mg/day.

In cases where it may be desirable to administer a combination of active compounds for the treatment of a particular disease or condition, it is within the scope of the present invention that two or more pharmaceutical compositions, at least one of which contains a compound of the invention, are conveniently combined in the form of a kit for use in administering the compositions together. For example, a kit of the invention comprises two or more separate pharmaceutical compositions, at least one of which contains a compound of the invention, and means for separately storing said compositions, such as a container, a divided vessel or a divided foil pouch. An example of such a kit is the well-known blister pack used for packaging tablets, capsules and other similar dosage forms.

The kit of the invention is particularly useful for administering different dosage forms, such as oral and parenteral, for administering separate compositions at different dosing intervals, or for titrating separate compositions against each other. To facilitate compliance with the prescribed therapy regimen, the kit typically includes instructions for use and may be provided with a memory aid. In some embodiments, the kit includes a compound or pharmaceutical composition thereof and a diagnostic agent. In other embodiments, the kit includes a compound or pharmaceutical composition thereof and one or more therapeutic agents, such as a BRAF inhibitor, such as a BRAF inhibitor selected from N-(3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-2,4-difluorophenyl)propane-1-sulfonamide; N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydro-quinazolin-6-yl)amino)phenyl)-3-fluoropropane-1-sulfonamide; N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-4,5-difluorophenyl)propane-1-sulfonamide; N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydro-quinazolin-6-yl)amino)-4-fluorophenyl)propane-1-sulfonamide; N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-4-fluorophenyl)-3-fluoropropane-1-sulfonamide; N-(2-chloro-4-fluoro-3-((5-methyl-3-(methyl-d3)-4-oxo-3,4-dihydroquinazolin-6-yl)amino)phenyl)-3-fluoropropane-1-sulfonamide; N-{2-chloro-3-[(3,5-dimethyl-4-oxo-3,4-dihydro-quinazolin-6-yl)oxy]-4-fluorophenyl}propane-1-sulfonamide; N-(3-chloro-4-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)oxy)-5-fluoropyridin-2-yl)propane-1-sulfonamide; N-{2-chloro-3-[(3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)oxy]-4-fluorophenyl}-3-fluoropropane-1-sulfonamide; N-(2-chloro-4-fluoro-3-((5-fluoro-3-methyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)phenyl)-2-azabicyclo[2.1.1]hexane-2-sulfonamide, (R)-N-(2-chloro-4-fluoro-3-((5-fluoro-3-methyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)phenyl)-3-fluoropyrrolidine-1-sulfonamide and N-(2-chloro-3-((5-chloro-3-methyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-4-fluorophenyl)-3-fluoro-azetidine-1-sulfonamide or pharmaceutically acceptable salts thereof;

The following schemes and descriptions provide general detailed information regarding the preparation of the compounds of the invention.

The compounds of the invention can be prepared by any method known in the art for preparing compounds of similar structure. In particular, the compounds of the invention can be prepared using the procedures described with reference to the reaction schemes below, or using the specific methods described in the examples, or using processes analogous thereto.

It will be apparent to those skilled in the art that the experimental conditions shown in the following schemes illustrate suitable conditions for carrying out the transformations shown, and that it may be necessary or desirable to vary the precise conditions used to prepare compounds of formula I and compounds falling within formula I, such as compounds of formula II and other similar compounds.

It will further be apparent to one skilled in the art that at any stage in the synthesis of the compounds of the invention it may be necessary or desirable to protect one or more reactive groups in order to prevent undesirable side reactions. In particular, it may be necessary or desirable to protect amino groups or alcohol groups. The protecting groups (PGs) used in the preparation of the compounds of the invention can be used in conventional manner. See, for example, the protecting groups described in Greene's Protective Groups in Organic Synthesis by Theodora W Greene and Peter G M Wuts, third edition, (John Wiley and Sons, 1999), in particular Chapter 7 ("Protection for the Amino Group") and Chapter 2 ("Protection for the Hydroxyl Group, Including 1,2- and 1,3-Diols"), the entire contents of which are hereby incorporated by reference, which also describes methods for removing such groups.

Scheme 1 describes a general method for the preparation of compound 8, which is a compound of formula I wherein R ¹ is H, R ² is H, R ³ is C3-C6 cycloalkyl, and R ⁴ is as defined for formula I. Commercially available 2,6-dichloro-4-methylnicotinic acid (compound 1) can be converted to its ester analog 2 upon treatment with (trimethylsilyl)diazomethane. Compound 2 can be converted to the dimethylaminovinyl intermediate 3 upon treatment with N,N-dimethylformamide dimethyl acetal. Compound 3 can be converted to the aldehyde intermediate 4 upon treatment with an appropriate acid, such as hydrochloric acid, in a suitable solvent, such as ether. Cyclization of compound 4 can be accomplished by reacting compound 4 with a reagent having the formula ^R3NH2 , where ^R3 is _C3 -C6 cycloalkyl, in the presence of a reducing agent (e.g. sodium cyanoborohydride), in a suitable solvent such as methanol to afford compound 5. Compound 5 can be converted to compound 6 by treatment with trimethylsilyl iodide in a suitable solvent such as acetonitrile. Compound 6 can be methylated by treatment with methyl iodide in the presence of an appropriate base such as an alkali metal carbonate such as potassium carbonate in the presence of an appropriate solvent such as THF to provide compound 7. Compound 7 can undergo nucleophilic aromatic substitution by treatment with a reagent having the formula R ⁴ NH ₂ where R ⁴ is as defined for formula I, in the presence of a strong base such as lithium hexamethyldisilazide in a suitable solvent such as THF to provide compound 8.

Scheme 2 describes a general method for the preparation of compound 17, which is a compound of formula I wherein R ¹ is H, R ² is H, R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy-, and R ⁴ is as defined for formula I. Commercially available 4-bromo-2,6-dichloropyridine can be lithiated with a reagent such as lithium diisopropylamide and treated with carbon dioxide to provide carboxylic acid 10. Compound 10 can be converted to compound 11 by refluxing in an aqueous solution of a base such as 4 M sodium hydroxide. Compound 11 can be methylated by treatment with methyl iodide in the presence of an appropriate base such as an alkali metal carbonate such as potassium carbonate in the presence of an appropriate solvent such as DMF to give compound 12. Compound 12 can be converted to the vinyl ether intermediate 13 by carrying out a Suzuki reaction with (E)-2-(2-ethoxyvinyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (compound (1)), using a catalyst such as methanesulfonato(2-dicyclohexylphosphino-2',6'-diisopropoxy-1,1'-biphenyl)(2-amino-1,1'-biphenyl-2-yl)palladium(II) and an alkali metal base (e.g. an alkali metal carbonate, e.g. aqueous potassium carbonate) in a suitable solvent such as 1,4-dioxane. Compound 13 can be subjected to an oximine formation reaction by treatment with a reagent of the formula R ^3a -NH ₂ HCl, where R ^3a is P ¹ O-C1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy-, and P ¹ is an alcohol protecting group such as tert-butyl, benzyl, or tert-butyldimethylsilyl, using triethylamine and HCl and heating in a suitable solvent such as 1,4-dioxane to provide compound 14. Compound 14 can be reduced to an alkoxyamine intermediate 15 using an appropriate reducing agent such as sodium cyanoborohydride in a suitable solvent such as isopropanol. Compound 15 can be subjected to nucleophilic aromatic substitution by treatment with a reagent having the formula ^R4NH2 , wherein _R4 is as defined for formula ^I , in the presence of a strong base such as lithium hexamethyldisilazide, in a suitable solvent such as THF, and suitably cyclized, followed by optional deprotection if compound 16 contains a ^P1 protecting group (using standard alcohol deprotection conditions known to those skilled in the art such as phosphoric acid, trifluoroacetic acid, or tetrabutylammonium fluoride) to provide compound 17, wherein ^R3 is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy-.

Scheme 3 describes a general method for the preparation of compound 20, which is a compound of formula I wherein R ¹ is H, R ² is CH ₃ -, R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy-, and R ⁴ is as defined for formula I. Compound 15, prepared as described in Scheme 2, wherein R ^3a is P ¹ O-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy-, and P ¹ is an alcohol protecting group such as tert-butyl, benzyl, or tert-butyldimethylsilyl, and wherein R ⁴ is as defined for formula I, can be cyclized by treatment with a reagent having the formula R ⁴ NH ₂ , wherein R ⁴ is as defined for formula I, in the presence of a strong base such as lithium hexamethyldisilazide, in a suitable solvent such as THF to afford compound 16. Compound 16 can be iodinated using n-iodosuccinimide and p-toluenesulfonic acid, in a suitable solvent such as 1:1 MeOH:THF, to afford compound 18. Compound 18 can be subjected to a Negishi coupling reaction with methylzinc(II) chloride using a catalyst, for example a palladium catalyst such as bis(tritert-butylphosphine), then optionally deprotected if compound 19 contains a protecting group (using standard alcohol deprotection conditions known to those skilled in the art, such as phosphoric acid, trifluoroacetic acid or tetrabutylammonium fluoride) to obtain compound 20, where R ³ is hydroxy-C1-C6 alkoxy, C1-C6 alkoxy, fluoro-C1-C6 alkoxy, or (C3-C6 cycloalkyl)-C1-C6 alkoxy.

Scheme 4 describes a general method for the preparation of compound 24, which is a compound of formula I wherein R ¹ is H, R ² is H, R ³ is H, and R ⁴ is as defined for formula I. Compound 13, prepared as described in Scheme 2, can be subjected to nucleophilic aromatic substitution by treatment with a reagent having the formula R ⁴ NH ₂ , wherein R ⁴ is as defined for formula I, in the presence of a strong base such as lithium hexamethyldisilazide, in a suitable solvent such as THF, to afford compound 21. Compound 21 can be hydrolyzed to form an aldehyde intermediate 22 under acidic conditions using an acid such as trifluoroacetic acid in a suitable solvent such as dichloromethane. Compound 22 can be cyclized by treatment with a reagent having the formula ^P2 - _NH2 , where ^P2 is an amino protecting group such as benzyl, p-methoxybenzyl, or 2,4-dimethoxybenzyl, using a reducing agent such as sodium triacetoxyborohydride in a suitable solvent such as dichloroethane to provide compound 23. Removal of the protecting group from compound 23 can be achieved by using standard deprotection conditions known to those skilled in the art, such as heating with trifluoroacetic acid or hydrochloric acid, to provide compound 24.

Scheme 5 describes a general method for the preparation of compound 27, which is a compound of formula I wherein R ¹ is H, R ² is H, R ³ is hydroxyC1-C6 alkyl, and R ⁴ is as defined for formula I. Compound 13, prepared as described in Scheme 2, can be hydrolyzed to the aldehyde intermediate 25 using an appropriate acid such as trifluoroacetic acid. Compound 25 can be reacted with a reagent of the formula P ¹ O-(C1-C6 alkyl)-ONH ₂ HCl, where P ¹ is an alcohol protecting group such as tert-butyldimethylsilyl, using an appropriate reducing agent such as sodium triacetoxyborohydride and acetic acid in a suitable solvent such as dichloroethane at 60 °C to afford the cyclized and deprotected compound 26. Compound 26 can undergo nucleophilic aromatic substitution by treatment with a reagent having the formula R ⁴ NH ₂ , where R ⁴ is as defined for formula I, in the presence of a strong base such as lithium hexamethyldisilazide, in a suitable solvent such as THF to afford compound 27.

Scheme 6 describes an alternative general method for the preparation of compound 17, which is a compound of formula I wherein R ¹ is H, R ² is H, R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy, and R ⁴ is as defined for formula I. Compound 28, prepared by a method similar to that described for compound 13, can undergo nucleophilic aromatic substitution by treatment with a reagent having the formula R ⁴ NH ₂ , wherein R ⁴ is as defined for formula I, in the presence of a strong base such as lithium hexamethyldisilazide, in a suitable solvent such as THF, to provide compound 29. Compound 29 can undergo an oximine formation reaction by treatment with a reagent of the formula R ^3a NH ₂ HCl, where R ^3a is P ¹ O-C1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, and P ¹ is an alcohol protecting group such as tert-butyl, benzyl, or tert-butyldimethylsilyl, using triethylamine and HCl and heating, in a suitable solvent such as 1,4-dioxane, to provide compound 30. Compound 30 can be cyclized with an appropriate reducing agent such as sodium cyanoborohydride and acetic acid in a suitable solvent such as isopropanol, and then optionally deprotected if compound 30 contains the protecting group P ¹ (using standard alcohol deprotection conditions known to those skilled in the art such as phosphoric acid, trifluoroacetic acid, or tetrabutylammonium fluoride) to provide compound 17, where R ³ is hydroxy-C1-C6 alkoxy, C1-C6 alkoxy, fluoro-C1-C6 alkoxy or (C3-C6 cycloalkyl)-C1-C6 alkoxy.

Scheme 7 describes an alternative general method for the preparation of compound 17, which is a compound of formula I wherein R ¹ is H, R ² is H, R ³ is hydroxyC1-C6 alkoxy, and R ⁴ is as defined for formula I. Compound 28 can be subjected to an oximine formation reaction by treatment with a reagent of the formula TBSO-(C1-C6 alkyl)-ONH ₂ HCl using triethylamine and HCl and heating, in a suitable solvent such as 1,4-dioxane, to afford compound 32. Compound 32 can be protected with an appropriate protecting group for the alcohol group P ¹ , such as tert-butyldimethylsilyl, using tert-butyldimethylsilyl chloride and an appropriate base such as imidazole, in a suitable solvent such as DMF, to afford compound 14. Compound 14 can be reduced to the intermediate compound alkoxyamine 15, using an appropriate reducing agent such as sodium cyanoborohydride, in a suitable solvent such as _isopropanol . Compound 15 can undergo nucleophilic aromatic substitution by treatment with a reagent having the formula ^R4NH2 , wherein ^R4 is as defined for formula I, in the presence of a strong base such as lithium hexamethyldisilazide, in a suitable solvent such as THF, to provide compound 16. Compound 16 can be deprotected using standard alcohol deprotection conditions known to those skilled in the art, such as phosphoric acid, trifluoroacetic acid, or tetrabutylammonium fluoride, to provide compound 17.

Scheme 8 describes an alternative general method for the preparation of compound 20, which is a compound of formula I wherein R ¹ is H, R ² is CH3-, R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy, and R ⁴ is as defined for formula I. Compound 28 can undergo nucleophilic aromatic substitution by treatment with a reagent having the formula R ⁴ NH ₂ , wherein R ⁴ is as defined for formula I, in the presence of a strong base such as lithium hexamethyldisilazide, in a suitable solvent such as THF, to provide compound 29. Compound 29 can be hydrolyzed to an aldehyde intermediate 22 using an appropriate acid such as trifluoroacetic acid. Compound 22 can be reacted with a reagent of the formula R ^3a NH ₂ HCl, where R ^3a is P ¹ O-C1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy, and P ¹ is an alcohol protecting group such as tert-butyl, benzyl, or tert-butyldimethylsilyl, using an appropriate reducing agent such as sodium triacetoxyborohydride and acetic acid in a solvent such as dichloroethane at 60°C to provide cyclized compound 16. Compound 16 can be iodinated using p-iodosuccinimide and p-toluenesulfonic acid in a suitable solvent such as 1:1 MeOH:THF to provide compound 18. Compound 18 can be subjected to a Negishi coupling reaction with methyl zinc(II) chloride using a catalyst such as bis(tritert-butylphosphine)palladium(0) in a suitable solvent such as THF, followed by optional deprotection if compound 18 contains a protecting group R ¹ (using standard alcohol deprotection conditions known to those skilled in the art such as phosphoric acid, trifluoroacetic acid, or tetrabutylammonium fluoride) to afford compound 20, wherein R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy.

Scheme 9 describes a general method for the synthesis of compound 35, which is a compound of formula I wherein R ¹ is H, R ² is halogen, R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy, and R ⁴ is as defined for formula I. Compound 12 can undergo nucleophilic aromatic substitution by treatment with a reagent having the formula R ⁴ NH ₂ , wherein R ⁴ is as defined for formula I, in the presence of a strong base such as lithium hexamethyldisilazide, in a suitable solvent such as THF, to afford compound 33. Compound 33 can be converted to vinyl ether intermediate 21 by a Suzuki reaction with (E)-2-(2-ethoxyvinyl)-4,4,5,5-tetramethyl-1,3,2-dioxa-borolane using a catalyst, for example a palladium catalyst such as methanesulfonato(2-dicyclohexylphosphino-2',6'-diisopropoxy-1,1'-biphenyl)(2-amino-1,1'-biphenyl-2-yl)palladium(II), and an alkali metal base, for example an alkali metal carbonate such as an aqueous solution of potassium carbonate, in a suitable solvent such as 1,4-dioxane. Compound 21 can be subjected to an oximine formation reaction by treatment with a reagent of the formula R ³ aNH ₂ HCl, where R ^3a is P ¹ O-C1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy, and P ¹ is an alcohol protecting group such as tert-butyl, benzyl, or tert-butyldimethylsilyl, using triethylamine and HCl and heating, in a suitable solvent such as 1,4-dioxane, to afford compound 30. Compound 30 can be treated with an appropriate reducing agent such as sodium cyanoborohydride and acetic acid in a suitable solvent such as isopropanol to afford cyclized compound 31. Compound 31 can be subjected to halogenation using conditions such as treatment with N-iodosuccinimide and p-toluenesulfonic acid in 1:1 THF/MeOH, or with N-bromosuccinimide in a suitable solvent such as DMF, or with N-chlorosuccinimide in a suitable solvent such as DMF, or with the electrophilic fluorinating reagent Selectfluor in a suitable solvent such as acetonitrile, then optionally removing the protecting group if compound 31 has a P ¹ protecting group (such as phosphoric acid, trifluoroacetic acid, or tetrabutylammonium fluoride) to afford compound 35, wherein R ² is iodine, bromine, chlorine, or fluorine, respectively, and R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy

Scheme 10 describes an alternative general method for the preparation of compound 17, which is a compound of formula I wherein R ¹ is H, R ² is H, R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy, and R ⁴ is as defined for formula I. Compound 12 can undergo nucleophilic aromatic substitution by treatment with a reagent having the formula R ⁴ NH ₂ , wherein R ⁴ is as defined for formula I, in the presence of an appropriate base such as potassium tert-butoxide, in a suitable solvent such as THF, to afford compound 36. Compound 36 can be converted to vinyl ether intermediate 29 by a Suzuki reaction with (Z)-2-(2-ethoxyvinyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane using a catalyst, for example a palladium catalyst, such as methanesulfonato(2-dicyclohexylphosphino-2',6'-diisopropoxy-1,1'-biphenyl)(2-amino-1,1'-biphenyl-2-yl)palladium(II), and an appropriate base, such as an alkali metal base, for example an alkali metal carbonate, for example an aqueous solution of potassium carbonate, in a solvent such as 2-methyltetrahydrofuran. Compound 29 can be reacted with a reagent of the formula R ^3a NH ₂ HCl, where R ^3a is P ¹ O-C1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy, and P ¹ is an alcohol protecting group such as tert-butyl, benzyl, or tert-butyldimethylsilyl, using triethylamine and hydrochloric acid in a suitable solvent such as 1,4-dioxane, then treated with an appropriate reducing agent such as pyridineborane and hydrochloric acid and heated at 60°C, then optionally deprotected if compound 29 has a P ¹ protecting group (such as phosphoric acid, trifluoroacetic acid, or tetrabutylammonium fluoride) to obtain compound 17, where R ³ is hydroxy-C1-C6 alkoxy, C1-C6 alkoxy, fluoro-C1-C6 alkoxy, or (C3-C6 cycloalkyl)-C1-C6 alkoxy.

Scheme 11 describes a method for preparing compound 43, which is a compound of formula I wherein R ¹ is phenyl, R ² is hydrogen, R ³ is hydrogen, and R ⁴ is described for formula I. Commercially available 2,6-dichloro-4-iodopyridine can be lithiated with a reagent such as lithium diisopropylamide and treated with carbon dioxide to give compound 37. Compound 37 can be converted to compound 38 by refluxing in an aqueous solution of a base such as 4 M sodium hydroxide. Compound 3 8 can be methylated by treatment with methyl iodide in the presence of an appropriate base such as an alkali metal carbonate such as potassium carbonate in the presence of an appropriate solvent such as DMF to give compound 39. Compound 3 9 can be converted to the vinyl ether intermediate 4 0 by a Suzuki reaction with 4,4,5,5-tetramethyl-2-(1-phenylvinyl)-1,3,2-dioxaborolane using an appropriate catalyst such as a palladium catalyst (e.g. Pd(dppf)Cl ₂ ) and a base such as an alkali metal carbonate (e.g. aqueous potassium carbonate) in a suitable solvent such as 1,4-dioxane. Compound 40 can undergo nucleophilic aromatic substitution by treatment with a reagent having the formula ^R4NH2 , wherein _R4 is defined for formula ^I , in the presence of a strong base such as lithium hexamethyldisilazide, in a suitable solvent such as THF, to give compound 41. Compound 41 can be cyclized with (2,4-dimethoxyphenyl)methanamine in the presence of a Lewis acid such as trimethylaluminum by heating in a suitable solvent such as toluene, to give compound 42. Compound 42 can undergo a deprotection reaction by heating with a suitable acid such as TFA, to give compound 43.

Scheme 12 describes a method for the preparation of compound 51, which is a compound of formula I wherein R ¹ is methyl, R ² is hydrogen, R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy, and R ⁴ is as defined for formula I. Compound 44 can be treated with NH ₃ , Fe(NO ₃ ) ₃ ⋅ 9H ₂ O, and NaNH ₂ at low temperature, then treated with methyl iodide to provide compound 45. Compound 45 can be heated together with benzo[d][1, 3, 2]dioxaborolane in a suitable solvent such as toluene with a catalyst such as NiCl ₂ (dppe) to provide compound 46. Compound 46 can be converted to compound 47 by reaction with compound 39 using Suzuki reaction conditions, for example, in the presence of a catalyst, for example a palladium catalyst such as Pd(dppf) _Cl2 , and a base such as _{K3PO4 , K2CO3 ,} KOtBu, _Cs2CO3 , NaOH or triethylamine, in a suitable solvent, for example a solvent mixture _such as toluene/THF. Compound 47 can be subjected to an oximine formation reaction by treatment with a reagent of the formula R ^3a NH ₂ HCl, where R ^3a is P ¹ O-C1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, or (C3-C6 cycloalkyl)C1-C6 alkoxy, and P ¹ is an alcohol protecting group such as tert-butyl, benzyl, or tert-butyldimethylsilyl, using triethylamine and HCl and heating, in a suitable solvent such as 1,4-dioxane, to afford compound 48. Compound 48 can be treated with an appropriate reducing agent such as sodium cyanoborohydride and acetic acid in a suitable solvent such as isopropanol to afford the cyclized product 49. Compound 49 can be subjected to nucleophilic aromatic substitution by treatment with a reagent having the formula ^R4NH2 , wherein _R4 is as defined for formula ^I , in the presence of a strong base such as lithium hexamethyldisilazide, in a suitable solvent such as THF, then optionally deprotecting if compound 49 contains a ^P1 protecting group (using standard alcohol deprotection conditions known to those skilled in the art such as phosphoric acid, trifluoroacetic acid or tetrabutylammonium fluoride) to afford compound 51, wherein ^R3 is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy or (C3-C6 cycloalkyl)C1-C6 alkoxy.

As used herein, the term "amino protecting group" refers to a derivative of groups that are commonly used to block or protect an amino group while reactions involving other functional groups on the compound are carried out. Examples of suitable protecting groups for use in any of the synthetic methods described herein include carbamates, amides, alkyl and aryl groups, imines, as well as many N-heteroatom derivatives that can be removed to regenerate the desired amino group. Non-limiting examples of amino protecting groups include tert-butyloxycarbonyl ("Boc"), 2-trimethylsilylethoxymethyl (SEM), and p-methoxybenzyl (PMB). Additional examples of these groups and other protecting groups can be found in T. W. Greene, et al., Greene's Protective Groups in Organic Synthesis. New York: Wiley Interscience, 2006.

As used herein, the term "alcohol protecting group" refers to a derivative of groups commonly used to block a hydroxyl group while reactions involving other functional groups on the compound are carried out. Examples of suitable protecting groups for use in any of the methods described herein include benzyl, trityl, silyl ethers, and other similar protecting groups.

Intermediates 7, 15, 18, 22, 26, 29, 30 and 31 shown in the above schemes are also novel intermediates useful for preparing compounds of formula I and are offered as further embodiments of the invention.

In one embodiment, the invention provides a method for preparing compounds of formula I, comprising:

(a) for a compound of formula I wherein R ¹ is H, R ² is H, R ³ is C3-C6 cycloalkyl, and R ⁴ is as defined for formula I, reacting a compound of formula 7

with a reagent having the formula R ⁴ NH ₂ , where R ⁴ is as defined for formula I, in the presence of a strong base; or

(b) for a compound of formula I where R ¹ is H, R ² is H, R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy or (C3-C6 cycloalkyl)C1-C6 alkoxy-, and R ⁴ is defined for formula I, cyclization of a compound of formula 15

where R ^3a is P ¹ O-C1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy or (C3-C6 cycloalkyl)C1-C6 alkoxy-, and P ¹ is an alcohol protecting group, in the presence of a reagent having the formula R ⁴ NH ₂ , where R ⁴ is as defined for formula I, in the presence of a strong base, then optionally removing the alcohol protecting group, if present; or

(c) for a compound of formula I wherein R ¹ is H, R ² is CH ₃ -, R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy or (C3-C6 cycloalkyl)C1-C6 alkoxy-, and R ⁴ is defined for formula I, treating a compound of formula 18

where R ^3a is P ¹ O-C1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy or (C3-C6 cycloalkyl)C1-C6 alkoxy, P ¹ is an alcohol protecting group, and R ⁴ is defined for formula I, with methyl zinc(II) chloride in the presence of a palladium catalyst, then removing the alcohol protecting group, if present; or

(d) for a compound of formula I where R ¹ is H, R ² is H, R ³ is H, and R ⁴ is as defined for formula I, cyclization of a compound of formula 22

where R ⁴ is defined for formula I, in the presence of a reagent having the formula P ² -NH ₂ , where P ² is an amino protecting group, then removing the amino protecting group; or

(e) for a compound of formula I wherein R ¹ is H, R ² is H, R ³ is hydroxyC1-C6 alkyl, and R ⁴ is as defined for formula I, reacting the compound of formula 26

In the presence of a reagent having the formula R ⁴ NH ₂ , in the presence of a strong base, where R ⁴ is defined for formula I; or

(f) for a compound of formula I where R ¹ is H, R ² is H, R ³ is hydroxyC1-C6 alkyl, and R ⁴ is as defined for formula I, cyclization of a compound having formula 30

where R ¹ is a protecting group for the alcohol group, and R ⁴ is defined for formula I, in the presence of a reducing agent, then removing the protecting group for the alcohol group; or

(d) for a compound of formula I where R ¹ is H, R ² is halogen, R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy or (C3-C6 cycloalkyl)C1-C6 alkoxy-, and R ⁴ is defined for formula I, halogenating a compound of formula 31

where R ⁴ is defined for formula I, R ^3a is P ¹ O-C1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy or (C3-C6 cycloalkyl)C1-C6 alkoxy-, and P ¹ is an alcohol protecting group, then removing the alcohol protecting group if present; or

(h) for a compound of formula I wherein R ¹ is H, R ² is H, R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy or (C3-C6 cycloalkyl)C1-C6 alkoxy-, and R ⁴ is defined for formula I, reacting the compound of formula 29

where R ⁴ is defined for formula I, with a reagent of formula P ¹ O-(C1-C6 alkyl)-ONH2HCl, where P ¹ is an alcohol protecting group, in the presence of triethylamine and hydrochloric acid, then removing the alcohol protecting group; or

(i) for a compound of formula I wherein R ¹ is phenyl, R ² is hydrogen, R ³ is hydrogen, and R ⁴ is as described for formula I, cyclization of a compound having formula 41

where R ⁴ is defined for formula I, with (2,4-dimethoxyphenyl)methanamine in the presence of a Lewis acid at elevated temperature to give a compound having formula 42:

then treating compound 42 with acid; or

(j) for a compound of formula I wherein R ¹ is methyl, R ² is hydrogen, R ³ is hydroxy-C1-C6 alkoxy-, C1-C6 alkoxy, fluoro-C1-C6 alkoxy or (C3-C6 cycloalkyl)C1-C6 alkoxy, and R ⁴ is defined for formula I, reacting a compound having formula 49

where R ^3a is P ¹ O-C1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy or (C3-C6 cycloalkyl)C1-C6 alkoxy-, and P ¹ is a protecting group for an alcohol group, with a reagent having the formula R ⁴ NH ₂ , where R ⁴ is defined for formula I, in the presence of a strong base, then removing the protecting group P ¹ , if present; and, optionally, converting the compound of formula I into a pharmaceutically acceptable salt thereof.

In addition, it is believed that synthetic intermediates 3, 4, 5, 6, 7, 13, 14, 15, 16, 18, 21, 22, 23, 25, 26, 28, 29, 30, 32, 33, 36, 37, 38, 39, 40, 41, 42, 47, 48 and 49 are novel and represent additional embodiments of this invention.

For a more thorough understanding of the present invention, the following is a detailed description of embodiments of the invention and examples included in the present invention. It should be understood that the present invention is not limited to specific examples of synthesis of compounds, which, of course, can be changed. It should also be understood that the terminology used in the invention serves only to describe specific embodiments and does not limit the invention in any way.

E1. Compound of formula I:

or a pharmaceutically acceptable salt thereof, wherein:

R ¹ is H, Br, C1-C6 alkyl or phenyl;

R ² is H, halogen or CH ₃ -;

R ³ is H, hydroxyC1-C6 alkyl-, hydroxyC1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl or (C3-C6 cycloalkyl)C1-C6 alkoxy-; and

R ⁴ is phenyl substituted with 1, 2 or 3 substituents independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl and C1-C6 alkyl-C(=O)-.

E2. The compound of embodiment E1 or a pharmaceutically acceptable salt thereof, wherein R ¹ is H.

E3. A compound according to embodiment E1 or E2, or a pharmaceutically acceptable salt thereof, wherein R ² is H.

E4. A compound according to embodiment E1 or E2, or a pharmaceutically acceptable salt thereof, wherein R ² is CH ₃ -.

E5. A compound according to any one of embodiments E1-E4, or a pharmaceutically acceptable salt thereof, wherein ^R3 is hydroxyC1-C6 alkyl-.

E6. A compound according to any one of embodiments E1 to E5, or a pharmaceutically acceptable salt thereof, wherein ^R4 is phenyl substituted with 1 or 2 substituents independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl, and C1-C6 alkyl-C(=O)-.

E7. A compound according to any one of embodiments E1 to E6, or a pharmaceutically acceptable salt thereof, wherein ^R4 is phenyl substituted with 1 or 2 substituents independently selected from halogen and C1-C6 alkylthio.

E8. Compound of formula II:

or a pharmaceutically acceptable salt thereof, wherein

R ¹ is H, Br, C1-C6 alkyl or phenyl;

R ² is H, halogen or CH ₃ -;

R ³ is H, hydroxyC1-C6 alkyl-, hydroxyC1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl or (C3-C6 cycloalkyl)C1-C6 alkoxy-; and

R ^a and R ^b are independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl, and C1-C6 alkyl-C(=O)-.

E9. The compound of embodiment E8 or a pharmaceutically acceptable salt thereof, wherein R ¹ is H.

E10. A compound according to embodiment E8 or E9, or a pharmaceutically acceptable salt thereof, wherein R ² is H.

E11. A compound according to embodiment E8 or E9, or a pharmaceutically acceptable salt thereof, wherein R ² is CH ₃ -.

E12. A compound according to any one of embodiments E8 to E11, or a pharmaceutically acceptable salt thereof, wherein ^R3 is hydroxyC1-C6 alkyl-.

E13. A compound according to any one of embodiments E8 to E11, or a pharmaceutically acceptable salt thereof, wherein R ³ is H.

E14 A compound according to any one of embodiments E8 to E13, or a pharmaceutically acceptable salt thereof, wherein R ^a is halogen.

E15. A compound according to any one of embodiments E8 to E14, or a pharmaceutically acceptable salt thereof, wherein R ^b is halogen, C1-C6 alkyl, C1-C6 alkylthio, or fluoroC1-C6 alkoxy.

E16. The compound of embodiment E15 or a pharmaceutically acceptable salt thereof, wherein R ^b is C1-C6 alkylthio.

E17. A compound according to embodiment E1, selected from the following compounds:

8-((4-bromo-2-fluorophenyl)amino)-2-cyclopropyl-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-2-(cyclopropylmethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-2-ethoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

2-cyclopropyl-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

2-cyclopropyl-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-chloro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-chlorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2,3-difluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-3-chloro-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-(trifluoromethyl)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-ethyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-cyclopropyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-methoxyphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-((trifluoromethyl)thio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-isopropylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-chloro-4-cyclopropylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-acetyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-chloro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-chloro-4-ethylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-(trifluoromethoxy)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-((difluoromethyl)thio)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-2-isopropoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-iodophenyl)amino)-2-isopropoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

2-ethoxy-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-iodophenyl)amino)-2-methoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

2-(tert-butoxy)-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

(S)-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

(R)-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

(S)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

(R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

(R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-5-chloro-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

5-chloro-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-5-fluoro-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

5-bromo-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

4-bromo-8-((2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-ethyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-cyclopropyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-iodophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-iodo-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-ethyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-cyclopropyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-propylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-(methylthio)phenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-ethyl-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-cyclopropyl-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-chlorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

2-(2,2-difluoroethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-7-methyl-4-phenyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-4-phenyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-(methylthio)phenyl)amino)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione;

or a pharmaceutically acceptable salt thereof.

E18. A compound which is 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, having the structure:

or a pharmaceutically acceptable salt thereof.

E19. A compound which is 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, having the structure:

E20. Crystal containing 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione.

E21. Crystalline anhydrous 8-((2-fluoro-4-(methylthio)-phenyl)-amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 1.

E22. Crystalline anhydrous 8-((2-fluoro-4-(methylthio)-phenyl)-amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 1 according to embodiment E21, having an X-ray powder diffraction pattern comprising characteristic peaks at 5.0, 8.7, 9.3, 10.8, 14.5, 15.3, 18.8 and 20.5 degrees 2-theta (±0.2 degrees 2-theta).

E23. Crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 1 according to embodiment E21, having a powder X-ray diffraction pattern comprising characteristic peaks at 2-theta angle values substantially the same as those shown in Figure 1.

E24. Crystalline anhydrous 8-((2-fluoro-4-(methylthio)-phenyl)-amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 2.

E25. Crystalline anhydrous 8-((2-fluoro-4-(methylthio)-phenyl)-amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2 according to embodiment E24, having an X-ray powder diffraction pattern comprising characteristic peaks at 7.1, 9.4, 12.4, 12.8, 14.3, 15.6, 16.4, 17.4, 18.5, 18.9, 19.5, 19.9, 21.1, 21.4, 23.2, 23.7, 24.8, 25.6, 27.6, 30.3, 33.2, 33.5 and 37.5 degrees 2-theta (±0.2 degrees 2-theta).

E26. Crystalline anhydrous 8-((2-fluoro-4-(methylthio)-phenyl)-amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2 according to embodiment E24, having an X-ray powder diffraction pattern comprising characteristic peaks at 2-theta angle values substantially the same as those shown in Figure 2.

E27. Crystalline anhydrous 8-((2-fluoro-4-(methylthio)-phenyl)-amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2 according to embodiment E25 or E26, wherein the powder X-ray diffraction pattern is obtained by performing powder X-ray diffraction analysis at 25°C and at a relative humidity below 10%.

E28. Crystalline monohydrate of 8-((2-fluoro-4-(methylthio)-phenyl)-amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 3.

E29. Crystalline monohydrate of 8-((2-fluoro-4-(methylthio)-phenyl)-amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 3 according to embodiment E28, having peaks in the powder X-ray diffraction pattern at 13.7, 18.0 and 18.3 degrees 2-theta (±0.2 degrees 2-theta).

E30. Crystalline monohydrate of 8-((2-fluoro-4-(methylthio)-phenyl)-amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 3 according to embodiment E2 8, having peaks in the powder X-ray diffraction pattern at 6.9, 9.1, 13.7, 18.0 and 18.3 degrees 2-theta (±0.2 degrees 2-theta).

E31. Crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 3 according to embodiment E2 8, having peaks in the powder X-ray diffraction pattern at 2-theta angle values of 6.9, 9.1, 11.8, 12.0, 13.7, 14.0, 15.2, 15.8, 18.0, 18.3, 19.0, 19.3, 20.2, 20.9, 21.6, 22.6, 23.6, 24.0, 24.9, 25.2, 25.8, 27.5, 28.1, 28.4, 29.8, 30.9, 31.7, 32.3 and 36.5 degrees 2-theta (±0.2 degrees 2-theta).

E32. Crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 3 according to embodiment E28, having a powder X-ray diffraction pattern comprising characteristic peaks at 2-theta angle values substantially the same as those shown in Figure 3.

E33. Crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 3 according to any one of embodiments E29 to E32, wherein the powder X-ray diffraction pattern is obtained by performing powder X-ray diffraction analysis at 25°C and at a relative humidity above 35%.

E34. Amorphous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 4.

E35. Amorphous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 4 of embodiment E34, having an X-ray powder diffraction pattern comprising characteristic peaks at 2-theta angle values substantially the same as those shown in Figure 4.

E36. A pharmaceutical composition comprising a compound according to any one of embodiments E1 to E35 or a pharmaceutically acceptable salt thereof and at least one pharmaceutically acceptable excipient.

E37. A method for treating a MEK-associated tumor, comprising administering to a subject in need thereof a therapeutically effective amount of a compound according to any one of embodiments E1 to E35 or a pharmaceutically acceptable salt thereof.

E38. The method of embodiment E37, wherein the tumor has a BRAF V600 mutation selected from V600E, V600K, V600D, V600R, and V600S.

E39. The method according to embodiment E37 or E38, wherein the tumor has a BRAF V600 mutation.

E40. The method according to any one of embodiments E37 - E39, wherein the tumor is an extracranial tumor.

E41. The method according to embodiment E40, wherein the extracranial tumor is selected from melanoma, colorectal cancer, thyroid cancer, non-small cell lung cancer, ovarian cancer, and neuroblastoma.

E42. The method according to any one of embodiments E37 - E39, wherein the tumor is a CNS tumor.

E43. The method according to embodiment E42, wherein the CNS tumor is an intracranial tumor.

E44. The method according to embodiment E43, wherein the intracranial tumor is brain cancer.

E45. The method according to embodiment E44, wherein the brain cancer is metastatic brain cancer.

E46. The method according to embodiment E45, wherein the metastatic brain cancer is selected from metastatic melanoma, metastatic colorectal cancer, metastatic non-small cell lung cancer, metastatic thyroid cancer, and metastatic ovarian cancer.

E47. The method according to embodiment E42, wherein the CNS tumor is intracranial leptomeningeal disease (LMD) or extracranial leptomeningeal disease (LMD).

E48. The method according to embodiment E47, wherein the LMD is selected from metastatic melanoma, metastatic colorectal cancer and metastatic non-small cell lung cancer.

E49. The method according to embodiment E43, wherein the intracranial tumor is a primary tumor.

E50. The method according to embodiment E49, wherein the primary brain tumor is a malignant tumor.

E51. The method according to embodiment E50, wherein the primary brain tumor is a grade 2 glioma, a grade 3 glioma, or a grade 4 glioma.

E52. The method according to embodiment E49, wherein the primary brain tumor is a benign tumor.

E53. The method of embodiment E37, wherein the tumor has a BRAF fusion.

E54. The method of embodiment E53, wherein the tumor has a BRAF fusion selected from KIAA11549-BRAF, MKRN1-BRAF, TRIM24-BRAF, AGAP3-BRAF, ZC3H7AV1-BRAF, AKAP9-BRAF, CCDC6-BRAF, AGK-BRAF, EPS15-BRAF, NUP214-BRAF, ARMC10-BRAF, BTF3L4-BRAF, GHR-BRAF, ZC3HAV1-BRAF, ZNF767-BRAF, CCDC91-BRAF, DYNC112-BRAF, ZKSCAN1-BRAF, GTF2I-BRAF, MZT1-BRAF, RAD18-BRAF, CUX1-BRAF, SLC12A7-BRAF, MYRIP-BRAF, SND1-BRAF, NUB1-BRAF, KLHL7-BRAF, TANK-BRAF, RBMS3-BRAF, STRN3-BRAF, STK35-BRAF, ETFA-BRAF, SVOPL-BRAF and JHDM1D-BRAF.

E55. The method of embodiment E54, wherein the tumor is a breast carcinoma (e.g., invasive ductal breast carcinoma), a colorectal carcinoma (e.g., colon adenocarcinoma), an esophageal carcinoma (e.g., esophageal adenocarcinoma), a glioma (e.g., desmoplastic infantile ganglioglioma of the brain, pilocytic astrocytoma of the brain, pleomorphic xanthoastrocytoma of the brain, low-grade spinal cord glioma (NOS), anaplastic oligodendroglioma, anaplastic ganglioglioma), a head and neck carcinoma (e.g., neuroendocrine carcinoma of the head and neck), a lung carcinoma (e.g., adenocarcinoma of the lung, non-small cell lung cancer (NOS)), a melanoma (e.g., spitzoid melanoma of the skin, non-spitzoid melanoma of the mucous membranes, spitzoid melanoma of the skin, melanoma of unknown primary, non-Spitzoid melanoma of the skin), pancreatic carcinoma (e.g., adenocarcinoma, acinar cell carcinoma of the pancreas), prostate carcinoma (e.g., acinar adenocarcinoma of the prostate), sarcoma (malignant solitary fibrous tumor), thyroid carcinoma (papillary thyroid carcinoma), carcinoma of unknown primary (e.g., adenocarcinoma of unknown primary), pleural mesothelioma, rectal adenocarcinoma, uterine endometrial carcinoma (e.g., uterine endometrial adenocarcinoma (NOS)) or ovarian serous carcinoma.

E56. The method according to embodiment E37, wherein the tumor is a tumor with a non-mutant type (wild type) BRAF.

E57. The method according to any one of embodiments E37 to E56, wherein the method further comprises administering one or more anti-cancer therapies.

E58. The method according to embodiment E57, wherein the one or more additional anti-cancer therapies are independently selected from surgery, radiation therapy, and the use of anti-cancer agents.

E59. The method according to embodiment E58, wherein the additional anticancer therapy is selected from the use of one or more anticancer agents.

E60. The method according to embodiment E59, wherein the anticancer agent is selected from MEK inhibitors, BRAF inhibitors, EGFR inhibitors, HER ² and/or HER ³ inhibitors, SHP2 inhibitors, Axl inhibitors, PI3K inhibitors, SOS1 inhibitors, signal transduction pathway inhibitors, immune checkpoint inhibitors, apoptotic pathway modulators, cytotoxic chemotherapeutic agents, angiogenesis-targeted therapeutic agents, and immune system-targeted drugs, including immunotherapy.

E61. The method according to embodiment E60, wherein the anticancer agent is a BRAF inhibitor.

E62. The method according to embodiment E61, wherein the BRAF inhibitor is encorafenib or a pharmaceutically acceptable salt thereof.

E63. The method according to embodiment E61, wherein the BRAF inhibitor is selected from the following compounds:

N-(3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-2,4-difluorophenyl)propane-1-sulfonamide;

N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)phenyl)-3-fluoropropane-1-sulfonamide;

N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-4,5-difluorophenyl)propane-1-sulfonamide;

N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-4-fluorophenyl)propane-1-sulfonamide;

N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-4-fluorophenyl)-3-fluoropropane-1-sulfonamide;

N-(2-chloro-4-fluoro-3-((5-methyl-3-(methyl-d3)-4-oxo-3,4-dihydroquinazolin-6-yl)amino)phenyl)-3-fluoropropane-1-sulfonamide;

N-{2-chloro-3-[(3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)-oxy]-4-fluorophenyl}propane-1-sulfonamide;

N-(3-chloro-4-((3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)oxy)-5-fluoropyridin-2-yl)propane-1-sulfonamide; and

N-{2-chloro-3-[(3,5-dimethyl-4-oxo-3,4-dihydroquinazolin-6-yl)-oxy]-4-fluorophenyl}-3-fluoropropane-1-sulfonamide;

or a pharmaceutically acceptable salt thereof.

E64. The method according to embodiment E63, wherein the BRAF inhibitor is N-(2-chloro-3-((3,5-dimethyl-4-oxo-3,4-dihydro-quinazolin-6-yl)amino)-4-fluorophenyl)-3-fluoropropane-1-sulfonamide or a pharmaceutically acceptable salt thereof.

E65. The method according to embodiment E61, wherein the BRAF inhibitor is selected from the following compounds:

N-(2-chloro-4-fluoro-3-((5-fluoro-3-methyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)phenyl)-2-azabicyclo[2.1.1]hexane-2-sulfonamide,

(R)-N-(2-chloro-4-fluoro-3-((5-fluoro-3-methyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)phenyl)-3-fluoropyrrolidine-1-sulfonamide and

N-(2-chloro-3-((5-chloro-3-methyl-4-oxo-3,4-dihydroquinazolin-6-yl)amino)-4-fluorophenyl)-3-fluoroazetidine-1-sulfonamide,

or a pharmaceutically acceptable salt thereof.

E66. The method according to embodiment E65, wherein the BRAF inhibitor is N-(2-chloro-3-((5-chloro-3-methyl-4-oxo-3,4-dihydro-quinazolin-6-yl)amino)-4-fluorophenyl)-3-fluoroazetidine-1-sulfonamide or a pharmaceutically acceptable salt thereof.

E67. The method according to embodiment E60, wherein the anticancer agent is an SHP2 inhibitor.

E68. The method according to embodiment E67, wherein the SHP2 inhibitor is (S)-1'-(6-((2-amino-3-chloropyridin-4-yl)thio)-1,2,4-triazin-3-yl)-1,3-dihydrospiro[indene-2,4'-piperidine]-1-amine or a pharmaceutically acceptable salt thereof

E69. The method according to any one of embodiments E37 to E68, wherein the compound is 8-((2-fluoro-4-(methylthio)-phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione and wherein the subject is administered 50 mg of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione once daily.

E70. A compound according to any one of embodiments E1 to E35 or a pharmaceutically acceptable salt thereof for use as a medicinal product.

E71. A compound according to one of embodiments E1-E35 or a pharmaceutically acceptable salt thereof for use in the treatment of a MEK-associated tumor.

E72. Use of a compound according to any one of embodiments E1 to E35, or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for the treatment of a MEK-associated tumor in a subject.

For a more thorough understanding of this invention, examples are provided below. These examples are provided in the invention for illustrative purposes only and do not limit the scope of the invention in any way.

The compounds and intermediates described below have been named using the naming convention of ChemDraw, Version 20.1.1.125 (Perkin Elmer Informatics). The naming convention of ChemDraw, Version 20.1.1.125, is well known to those skilled in the art and is believed to be generally consistent with the IUPAC (International Union of Pure and Applied Chemistry) nomenclature of organic compounds and the CAS (Chemical Abstracts Service) naming convention. Unless otherwise noted, all chemical reagents were purchased from the manufacturers without further purification or were synthesized using methods known in the literature.

EXAMPLES

Examples of biological activity studies

Example A

Cellular Phospho-p44/42 MAPK (Erk1/2) (Thr202/Tyr204) Assay

Inhibition of ERK1/2(Thr202/Tyr204) phosphorylation was determined using the following cell-based assay, which involves incubating cells with compound for 1 hour and quantifying the pERK signal using In-Cell Western on fixed cells and normalizing to the GAPDH signal. A375 cells were obtained from the American Type Culture Collection (ATCC) and grown in DMEM supplemented with 10% fetal bovine serum, penicillin/streptomycin, Glutamax©, non-essential amino acids, and sodium pyruvate. Cells were seeded in 96-well plates at 30,000 cells per well and allowed to attach overnight at 37°C/5% CO ₂ . Cells were treated with compounds prepared as serial 1:3 dilutions to yield 10 concentrations (range: 20 μM - 0.05 nM; maximum concentration varied from 20 μM to 1 μM) with a final DMSO concentration of 0.5%. Control wells contained either 0.5% DMSO only (no inhibition control) or 1 μM of a potent control compound (complete inhibition control). After incubation for 1 h, cells were fixed in 3.7% formaldehyde in dPBS (Dulbecco's phosphate-buffered saline) at room temperature for 20 min. Cells were then washed with dPBS and permeabilized in 100% MeOH at room temperature for 10 min. After permeabilization, cells were washed with dPBS and incubated in LI-COR blocking buffer (LI-COR Biosciences, Cat # 927-40000) for 1 hour or more. Plates were then incubated with an antibody specific for the MEK-dependent ERK1/2 phosphorylation sites, threonine 202 and tyrosine 204 (Cell Signaling Technologies; Cat # 9101), located downstream of MEK in the MAP kinase signaling pathway, and GAPDH (Millipore; Cat # MAB374). pErk1/2 (Thr202/Tyr204) antibody was diluted 1:250 in LI-COR blocking buffer containing 0.05% Tween-20; GAPDH was diluted 1:2500. Plates were incubated overnight at 4°C. After washing with PBS/0.05% Tween-20, cells were incubated with fluorescently labeled secondary antibodies (Anti-rabbit-Alexa Flour680, Invitrogen Cat # A21109; Anti-mouse-IRDye800CW, LI-COR Biosciences Cat # 926-32210, both at 1:1000 dilution) for 1 h. Cells were then washed as above and fluorescence was analyzed at 680 and 800 nm using an Odyssey CLx Infrared Imaging System (LI-COR Biosciences). Phosphorylated Erk1/2 (Thr202/Tyr204) signal was normalized to GAPDH signal for each well. IC ₅₀ values were calculated from the normalized values using the 4-parameter fit in BioAssay software and are presented in Table A.

Example B

MDR ¹ LLC-PK1 and BCRP MDCKII permeability assay

LLC-PK1 cells, both LLC-PK1 and ^MDR1 -transfected, were cultured and plated according to the manufacturer's recommendations, except that the passage medium contained only 2% fetal bovine serum to extend the passage time to seven days.

A canine P-gp knockout cell line transfected with BCRP was cultured and seeded according to the manufacturer's recommendations.

To assess the functionality of P-gp or BCRP efflux, both positive and negative controls were used in the assays. Stock solutions for controls and test drug were prepared in DMSO to final assay concentrations of 10 and 1 μM, respectively. The final concentration of organics in the assay was 1%. All dosing solutions contained 10 μM Lucifer Yellow to monitor the integrity of the LLC PK1 or MDCKII cell monolayer.

For the apical-basolateral (A to B) determination, 75 μl of test sample in transfer buffer was added to the apical side of individual transwells, and 250 μl of basolateral medium without compound or Lucifer Yellow was added to each well. For the basolateral to apical (B to A) determination, 250 μl of test sample in transfer buffer was added to each well, and 75 μl of transfer buffer without compound or Lucifer Yellow was added to each transwell. All assays were performed in triplicate, and each compound was tested for both apical-to-basolateral and basolateral-to-apical transfer. Plates were incubated for 2 h on a Lab-Line Instruments Titer Orbital Shaker (VWR, West Chester, PA) at 50 rpm and 37°C with 5% CO ₂ . All culture plates were removed from the incubator, and 50 μl of medium was removed from the apical and basolateral portions of each well and added to 150 μl of 1 μM labetalol in a 2:1 v/v mixture of acetonitrile:H ₂ O.

Plates were read using a Molecular Devices (Sunnyvale, CA) Gemini fluorescence reader to assess Lucifer Yellow concentrations at 425/535 nm excitation/emission wavelengths. Values were considered acceptable when they were found to be less than 2% for apical-basolateral flux and 5% for basolateral-apical flux across monolayers of MDR1-transfected LLC-PK1 cells or BCRP-transfected MDCKII cells. Plates were sealed and the contents of each well were analyzed by liquid chromatography tandem mass spectrometry (LC MS/MS). Compound concentrations were determined as the peak area ratios of the compound to the internal standard (labetalol) compared to the dosing solution.

Liquid chromatography mass spectrometry (LC-MS) analysis

The liquid chromatography-tandem mass spectrometry (LC-MS/MS) system consisted of an HTS-PAL autosampler (Leap Technologies, Carrboro, NC), an HP1200 HPLC (Agilent, Palo Alto, CA), and an MDS Sciex 4000 Q Trap ion trap system (Applied Biosystems, Foster City, CA). Chromatographic separation of the analyte and internal standard was achieved at room temperature using a C18 column (Kinetics®, 50 × 300 mm, 2.6 μm particle size, Phenomenex, Torrance, CA) coupled with gradient conditions using mobile phases A (water containing 1% isopropyl alcohol and 0.1% formic acid) and B (0.1% formic acid in acetonitrile). The total chromatogram recording time, including re-equilibration, for a single injected sample was 1.2 minutes. Mass spectrometric detection of analytes was achieved using electrospray ionization in positive ion mode. Analyte responses were measured by multiple reaction monitoring (MRM) of transitions unique to each compound (protonated precursor ion and selected product ions for each test sample and m/z 329 to m/z 162 for labetalol, the internal standard).

The permeability coefficient (P _{a p p} ) is calculated using the following equation:

P _app =[((C _d × V × (1×10 ⁶ ))/(t × 0.12 cm ² × C)]

where _Cd , V, t and _C0 represent the detection concentration (µM), the volume on the dosing side (mL), the incubation time (sec) and the initial dosing concentration (µM), respectively. Calculations for _Papp were performed for each of the replicate experiments and then averaged. The permeability coefficients of the compounds of formula I are given in Table B1. In this assay, a compound is defined as having high permeability if its permeability is greater than 8× ^10-6 cm/sec, a compound is defined as having medium permeability if its permeability is between 2× ^10-6 cm/sec and 8× ^10-6 cm/sec, and a compound is defined as having low permeability if its permeability is less than 2× ^10-6 cm/sec.

The efflux coefficient is calculated from the average values of the P _app data for permeability from the apical membrane to the basolateral membrane (A-B) and the P _app data from the basolateral membrane to the apical membrane (B-A):

Efflux coefficient = P _arr (B-A) / P _arr (A-B)

The efflux coefficient is calculated from the average values of the P _app data for permeability from the apical membrane to the basolateral membrane (A-B) and the P _app data from the basolateral membrane to the apical membrane (B-A):

Efflux coefficient = P _arr (B-A) / P _arr (A-B)

Table B2 provides the efflux coefficients for compounds of formula I when tested in this assay.

N/A: no data available

Example C

Pharmacokinetics (ratio of free compound concentration in brain to free compound concentration in plasma) (in mice)

The ability of representative compounds to penetrate the blood–brain barrier (BBB) in mice was determined by assessing the ratio of unbound compound concentration in the brain to the unbound compound concentration in plasma (also referred to as the ratio of free compound concentration in the brain to free compound concentration in plasma) in male CD-I mice.

Brain concentrations of compounds were determined by oral administration of compounds to mice for pharmacokinetic (PK) studies, with typical sampling time points of 2, 4, 8, 12, and 24 h after oral gavage of 10 mg/kg. Brain samples were stored at -20 ± 5°C until analysis. Test compound concentrations in mouse brain homogenate were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) after acetonitrile protein precipitation. A 12-point calibration curve was constructed over the range 0.5 to 10,000 ng/mL in duplicate. A 400 μg/mL solution of test compound in dimethyl sulfoxide (DMSO) was serially diluted (three-fold) in 100% DMSO, and 2.5 μL of each standard solution was then added to 100 μL of brain homogenate from naïve male CD-I mice. To simulate extraction in the standard curve, 2.5 μL of DMSO was added to all test samples. Calibrator and test samples of brain homogenate were supplemented with 10 μL of IS (1 μg/mL structural analog). Brain homogenate was prepared by adding 0.75 mL of water : MeOH 4:1 to each brain sample, followed by homogenization for 1 min with tubular bead mills at 6 m/sec using an MP Fast Prep-24®. Proteins were precipitated from 100 μl of brain homogenate sample by adding 300 μl of acetonitrile. Samples were vortexed for 5 min and centrifuged in an Allegra X-12R centrifuge (Beckman Coulter, Fullerton, CA; SX4750A rotor) for 15 min at approximately 1500 g at 4°C. A 100 μl aliquot of each supernatant was transferred using a 550 μl personal pipette (Apricot Designs, Monrovia, CA) into 96-well plates and diluted 1:1 with HPLC-grade water. The resulting plates were sealed with aluminum foil for LC-MS/MS analysis.

Brain:plasma ratios were calculated using the compound concentration measured in the brain divided by the compound concentration measured in plasma. Brain:plasma ratios were always calculated for a single animal and at a single time point. The ratio of free compound concentration in the brain to free compound concentration in plasma was calculated by multiplying the ratio of free compound concentration in the brain to free compound concentration in plasma by the free fraction of the in vitro brain homogenate divided by the free fraction of the in vitro plasma using the following equation: (B/P)*(Bfu/Pfu).

Table C provides ratios of free compound concentration in the brain to free compound concentration in the plasma for representative compounds of Examples 6, 7, 8, 14, 22, 36 and 46 disclosed in the invention.

Examples of synthesis

Intermediate connection 1

Methyl (E)-2,6-dichloro-4-(2-(dimethylamino)vinyl)nicotinate

Step 1. Preparation of methyl 2,6-dichloro-4-methylnicotinate. To a solution of 2,6-dichloro-4-methylnicotinic acid (1.0 g, 4.9 mmol) in 1:1 MeOH:dioxane (10 mL) at 0 °C was added (trimethylsilyl)diazomethane (3.3 mL, 2 M in hexanes, 6.6 mmol). The mixture was removed from the ice bath and stirred for 10 min, then concentrated to half the volume and partitioned between water (20 mL) and EtOAc (20 mL). The aqueous layer was extracted with EtOAc (2×20 mL), and the combined organic layers were washed with brine (10 mL), dried over Na ₂ SO ₄ , filtered, and carefully concentrated. The residue was purified by column chromatography eluting with 0-15% EtOAc/petroleum ether to give methyl 2,6-dichloro-4-methylnicotinate (0.81 g, 76%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.2 (s, 1H), 4.0 (s, 3H), 2.3 (s, 3H) ppm.

Step 2. Preparation of methyl (E)-2,6-dichloro-4-(2-(dimethylamino)vinyl)nicotinate. To a solution of methyl 2,6-dichloro-4-methylnicotinate (810 mg, 3.68 mmol) in DMF (5 mL) was added N,N-dimethylformamide dimethyl acetal (978 mL, 7.36 mmol), and the mixture was stirred at 100 °C for 16 h. The cooled mixture was treated with water (40 mL), stirred for 10 min, and then the solids were collected by filtration, washed with water, and dried under vacuum to give methyl (E)-2,6-dichloro-4-(2-(dimethylamino)vinyl)nicotinate (764 mg, 75%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.3 (s, 1H), 7.1 (d, 1H), 4.8 (d, 1H), 3.1 (s, 3H), 2.9 (s, 6H) ppm.

Intermediate connection 2

Methyl 4-bromo-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate

Step 1. Preparation of 4-bromo-2,6-dichloronicotinic acid. A solution of 4-bromo-2,6-dichloropyridine (100 g, 440.7 mmol) in THF (1000 mL) was cooled to -78 °C. LDA (2 M in THF, 242.4 mL, 484.8 mmol) was added dropwise at -78 °C and stirring was continued for 1 h at -78 °C. Solid CO ₂ (155.1 g, 3.53 mol) was added portionwise to the reaction mixture and stirring was continued for 2 h at -78 °C. The reaction was quenched by adding 1 M Na ₂ CO ₃ (1600 mL) followed by water (500 mL) and stirring for 10 min. The aqueous layer was extracted with EtOAc (300 mL). The pH of the aqueous solution was adjusted with 2N HCl to obtain a solution with pH 2. The aqueous solution was then extracted with _EtOAc (3×300 mL). The combined organic layers were dried over _Na2SO4 , filtered and concentrated to give 4-bromo-2,6-dichloronicotinic acid (540 g, 75%). ¹ H NMR (400 MHz, DMSO- _d6 ) δ 15.51-12.87 (m, 1H), 8.13 (s, 1H) ppm.

Step 2. Preparation of 4-bromo-2-chloro-6-oxo-1,6-dihydropyridine-3-carboxylic acid. A solution of NaOH (4 M, 1.62 L, 6.46 mol) was heated to 110 °C, and 4-bromo-2,6-dichloronicotinic acid (70 g, 258.4 mmol) was added in one portion. The mixture was stirred for 8 h, then cooled to 0 °C. The pH of the reaction mixture was adjusted to 1 with HCl (6 M) and stirred for 30 min. The solids were collected by filtration and dried under vacuum to give 4-bromo-2-chloro-6-oxo-1,6-dihydropyridine-3-carboxylic acid (calculated 100%).

Step 3. Preparation of methyl 4-bromo-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. To a mixture of 4-bromo-2-chloro-6-oxo-1,6-dihydropyridine-3-carboxylic acid (100 g, 396 mmol) in DMF (800 mL) were added methyl iodide (168.6 g, 1.19 mol, 73.98 mL) and K ₂ CO ₃ (164.2 g, 1.19 mol) in one portion. The mixture was stirred at 25 °C for 3 h, then poured into saturated aqueous NH ₄ Cl (1800 mL), and the aqueous phase was extracted with EtOAc (2×500 mL). The combined organic layers were washed with brine (400 mL), dried over Na ₂ SO ₄ , filtered and concentrated. The combined residues (5 batches) were purified by column chromatography eluting with 2-100% EtOAc/petroleum ether to give methyl 4-bromo-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (from 5 batches, 141.83 g, 24.7%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 6.86 (s, 1H), 3.94 (s, 3H), 3.69-3.66 (m, 3H); MS (atmospheric pressure chemical ionization (apci), m/z) = 280.0, 282.0 (M+H).

Intermediate connection 3

Methyl (Z)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate

Methyl 4-bromo-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (20.0 g, 71.3 mmol, methanesulfonato(2-dicyclohexylphosphino-2',6'-diisopropoxy-1,1'-biphenyl)(2-amino-1,1'-biphenyl-2-yl)palladium(II) (5.96 g, 7.13 mmol) and (Z)-2-(2-ethoxyvinyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (14.8 g, 74.9 mmol) were suspended in 1,4-dioxane (700 mL) and K ₂ CO ₃ (53.5 mL, 107 mmol) (2 N aqueous solution) was added. The mixture was stirred at 60 °C for 6 h, then at ambient temperature for 12 h under argon. The reaction mixture was partitioned between water (1500 mL) and EtOAc (500 mL). The aqueous layer was extracted with EtOAc (2 x 400 mL), and the combined organic layers were washed with brine (500 mL), dried over Na ₂ SO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-40-60% EtOAc/heptanes to give methyl (Z)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (13.3 g, 68%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.23 (s, 1H), 6.45 (d, 1H), 4.86 (d, 1H), 4.40 (qt, 2H), 3.89 (s, 3H), 3.67 (s, 3H), 1.35 (t, 3H); MS (atmospheric pressure chemical ionization (apci), m/z)=272.0 (M+H).

Intermediate connection 4

Methyl 4-(2-((2-(tert-butoxy)ethoxy)amino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate

Step 1. Preparation of methyl (E/Z)-4-(2-((2-(tertbutoxy)-ethoxy)imino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate Methyl (Z)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (0.95 g, 3.50 mmol) and O-(2-(tertbutoxy)ethyl)hydroxylamine hydrochloride (593 mg, 3.50 mmol) were combined in 1,4-dioxane (10 mL). Et ₃ N (487 mL, 3.50 mmol) and HCl (1.75 mL, 6.99 mmol) (4N/dioxane) were added. The suspension was heated to 60°C for 1 h, then cooled and filtered. The filtrate was concentrated to give methyl (E/Z)-4-(2-((2-(tert-butoxy)-ethoxy)imino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (calculated 100%) as a 1:1 mixture of isomers. MS (atmospheric pressure chemical ionization (apci), m/z)=359.1 (M+H).

Step 2. Preparation of methyl 4-(2-((2-(tertbutoxy)ethoxy)amino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. To a solution of methyl (E/Z)-4-(2-((2-(tertbutoxy)ethoxy)imino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (1.25 g, 3.48 mmol) in IPA (20 mL) was added sodium cyanoborohydride (1.09 g, 17.4 mmol), then acetic acid (1.0 mL, 17.4 mmol). The mixture was stirred at ambient temperature for 16 h, then partitioned between saturated _NaHCO3 solution (50 mL) and EtOAc (50 mL). The aqueous layer was extracted with EtOAc (2×30 mL), and the combined organic layers were washed with brine (30 mL), then dried over _Na2SO4 , filtered and concentrated. The residue was purified by column chromatography eluting with 0-80% _EtOAc /DCM to give methyl 4-(2-((2-(tertbutoxy)ethoxy)amino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (0.66 g, 53%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 6.43 (s, 1H), 3.90 (s, 3H), 3.78 (t, 2H), 3.68 (s, 3H), 3.50 (t, 2H), 3.10 (t, 2H), 2.71 (t, 2H), 1.20 (s, 9H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=361.1, 363.1 (M+H).

Intermediate connection 5

2-Chloro-4-ethylaniline

Step 1. Preparation of N-(4-ethylphenyl)acetamide. 4-Ethyl aniline (513 µL, 4.13 mmol) was dissolved in DCM (10.3 mL). After addition of triethylamine (690 µL, 4.95 mmol) and cooling to 0 °C, acetic anhydride (467 µL, 4.95 mmol) was added dropwise. After 30 min, the reaction was quenched by addition of saturated aqueous NaHCO ₃ (50 mL). The organic layers were separated, and the aqueous layer was extracted with DCM (2×25 mL). The combined organic layers were dried over Na ₂ SO ₄ , filtered, and concentrated. The residue was triturated with hexanes, and the solids were collected by filtration to afford N-(4-ethylphenyl)acetamide (600 mg, 89%). ^1H NMR (400 MHz, CDCl ₃ ) δ 7.40-7.38 (d, 2H), 7.16-7.14 (d, 2H), 7.07 (br.s, 1H), 2.64-2.58 (qt, 2H), 2.16 (s, 3H), 1.23-1.20 (t, 3H) ppm.

Step 2. Preparation of N-(2-chloro-4-ethylphenyl)acetamide. N-(4-ethylphenyl)acetamide (50 mg, 0.31 mmol) was dissolved in DMF (613 μL). After addition of N-chlorosuccinimide (65 mg, 0.49 mmol), the solution was heated to 70 °C for 6 h, then cooled to ambient temperature over 16 h. The reaction mixture was poured into 2N HCl (4 mL) and stirred for 15 min. The mixture was extracted with EtOAc (10 mL). The organic layers were washed with water (3×10 mL), dried over Na ₂ SO ₄ , filtered, and concentrated. The residue was purified by column chromatography, eluting with 0-25% EtOAc/hexanes to give N-(2-chloro-4-ethylphenyl)acetamide (36 mg, 59%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 8.23-8.21 (d, 1H), 7.51 (br.s, 1H), 7.20-7.19 (d, 1H), 7.11-7.08 (dd, 1H), 2.63-2.57 (qt, 2H), 2.23 (s, 3H), 23-1, 20 (t, 3H) ppm.

Step 3. Preparation of 2-chloro-4-ethylaniline. N-(2-chloro-4-ethylphenyl)acetamide (36 mg, 0.18 mmol) was dissolved in EtOH (0.5 mL) and 12N HCl (0.5 mL, 6.0 mmol) was added. The mixture was stirred for 2 h at 120 °C. The reaction mixture was cooled to ambient temperature, adjusted to pH 10 with 6N NaOH, then extracted with MTBE (3×25 mL). The combined organic layers were dried over Na ₂ SO ₄ , filtered, and concentrated to give 2-chloro-4-ethylaniline (26 mg, 92%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.09-7.08 (d, 1H), 6.91-6.88 (dd, 1H), 6.71-6.69 (d, 1H), 2.55-2.49 (qt, 2H), 1.20-1.16 (t, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=156.1 (M+H).

Intermediate connection 6

4-((Difluoromethyl)thio)-2-fluoroaniline

_LiBF4 (196 mg, 2.10 mmol) and LiH (17.5 mg, 2.10 mmol) were combined in DMF (8.8 mL, 1.75 mmol). 4-Amino-3-fluorobenzenethiol (250 mg, 1.75 mmol) was added and the mixture was stirred for 5 min at ambient temperature. (Trifluoromethyl)-trimethylsilane (0.644 mL, 4.37 mmol) was added quickly and then the solution was stirred for 10 min at the same temperature. TBAF (6 mL, 1N/THF, 6.00 mmol) was added quickly and then the solution was stirred for 10 min at the same temperature. The reaction mixture was quenched with water (50 mL). The mixture was extracted with EtOAc (2 x 25 mL) and the combined organic layers were washed with water (3 x 50 mL) and brine (50 mL), then dried over Na ₂ SO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-15% EtOAc/hexanes to give 4-((difluoromethyl)thio)-2-fluoroaniline (56 mg, 17%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.25-7.22 (dd, 1H), 7.19-7.16 (ddd, 1H), 6.86-6.58 (t, 1H), 6.77-6.73 (dd, 1H), 3.95 (br s, 1H) ppm.

Intermediate connection 7

2-Chloro-4-(methylthio)aniline

2-Chloro-4-iodoaniline (250 mg, 0.986 mmol), NiBr ₂ (22 mg, 0.099 mmol), Zn powder (129 mg, 1.97 mmol) and 2,2'-bipyridine (15 mg, 0.099 mmol) were dissolved in THF (1.6 mL) under Ar atmosphere. 1,2-Dimethyldisulfane (44 μL, 0.493 mmol) was added and the mixture was sealed and heated to 65 °C for 16 h. The reaction mixture was diluted with EtOAc (50 mL) and washed with concentrated NH ₄ OH solution (50 mL) then 10% citric acid solution (50 mL). The combined organic layers were dried over Na ₂ SO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-15% EtOAc/hexanes to give 2-chloro-4-(methylthio)aniline (116 mg, 68%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.27-7.26 (m, 1H), 7.09-7.06 (dd, 1H), 6.71-6.69 (d, 1H), 4.02 (br s, 2H), 2.41 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z) = 174.0 (M+H).

Intermediate connection 8

Methyl (E)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate

Methyl 4-bromo-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (1.0 g, 3.565 mmol), methanesulfonato(2-dicyclohexylphosphino-2',6'-diisopropoxy-1,1'-biphenyl)(2-amino-1,1'-biphenyl-2-yl)palladium(II) (0.2982 g, 0.3565 mmol) and (E)-2-(2-ethoxyvinyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.7414 g, 3.743 mmol) were suspended in 1,4-dioxane (35.65 mL) and potassium carbonate (2.674 mL, 2N aqueous solution, 5.35 mmol). After degassing with argon, the mixture was stirred at 60 °C for 4 h. The cooled reaction mixture was partitioned between water (150 mL) and EtOAc (50 mL). The aqueous layer was washed with EtOAc (2 x 40 mL). The combined organic layers were washed with brine (150 mL), dried over sodium sulfate, filtered and concentrated. The residue was purified by column chromatography eluting with 0-40% EtOAc/heptane to give methyl (E)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (379 mg, 39%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.27 (s, 1H), 7.03 (d, 1H), 6.43 (s, 1H), 5.53 (d, 1H), 3.95-3.83 (m, 5H), 3.67 (s, 3H), 1.34 (t, 2H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=272.1 (M+H).

Example 1

8-((4-bromo-2-fluorophenyl)amino)-2-cyclopropyl-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of methyl 2,6-dichloro-4-(2-oxoethyl)nicotinate. A suspension of methyl (E)-2,6-dichloro-4-(2-(dimethylamino)vinyl)nicotinate (0.797 g, 2.90 mmol) in Et ₂ O (30 mL) and 1 N HCl (30 mL) was stirred vigorously at ambient temperature for 1 h. The resulting solution was treated with brine (20 mL) and extracted with Et ₂ O (3×10 mL). The combined organic layers were washed with brine (10 mL), dried over MgSO ₄ , filtered, and carefully concentrated to give methyl 2,6-dichloro-4-(2-oxoethyl)nicotinate (calculated 100%), which was used immediately.

Step 2. Preparation of 8-chloro-2-cyclopropyl-6-methoxy-3,4-dihydro-2,7-naphthyridine-1(2H)-one. To a solution of methyl 2,6-dichloro-4-(2-oxoethyl)nicotinate (0.719 g, 2.90 mmol) in 1:1 IPA:MeOH (20 mL) at 0 °C was added cyclopropylamine (201 mL, 2.90 mmol). The mixture was stirred at ambient temperature for 10 min, then sodium cyanoborohydride (546 mg, 8.70 mmol) and acetic acid (498 mL, 8.70 mmol) were added. After stirring at ambient temperature for 16 h, the mixture was partitioned between saturated _NaHCO3 (50 mL) and EtOAc (20 mL), and the aqueous layer was extracted with EtOAc (2 x 20 mL). The combined organic layers were washed with brine (10 mL), dried over _{Na2SO4 ,} filtered, and concentrated. The residue was dissolved in methanol (10 mL), treated with aqueous 1N NaOH (3.33 mL, 3.33 mmol), and stirred at ambient temperature for 1 h. The mixture was concentrated to half the volume, then partitioned between water (20 mL) and DCM (20 mL). The aqueous layer was extracted with DCM (2 x 10 mL), and the combined organic layers were washed with brine (10 mL), dried over _Na2SO4 , filtered _, and concentrated. The residue was purified by column chromatography, eluting with 0-10% (20% MeOH/DCM)/DCM to give 8-chloro-2-cyclopropyl-6-methoxy-3,4-dihydro-2,7-naphthyridin-1(2H)-one (310 mg, 42%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 6.5 (s, 1H), 4.0 (s, 3H), 3.5 (t, 2H), 2.9 (m, 3H), 0.9 (m, 2H), 0.7 (m, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=253.1, 255.1 (M+H).

Step 3. Preparation of 8-chloro-2-cyclopropyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 8-chloro-2-cyclopropyl-6-methoxy-3,4-dihydro-2,7-naphthyridine-1(2H)-one (99 mg, 0.39 mmol) in acetonitrile (2 mL) was added trimethylsilyl iodide (2.94 mL, 1.96 mmol). The mixture was stirred at ambient temperature for 48 h and then concentrated. The residue was purified by column chromatography eluting with 0-15-20% (20% MeOH/DCM)/DCM to give 8-chloro-2-cyclopropyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (calculated 100%), which was used immediately. MS (atmospheric pressure chemical ionization (apci), m/z) = 239.0 (M+H).

Step 4. Preparation of 8-chloro-2-cyclopropyl-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 8-chloro-2-cyclopropyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (93 mg, 0.39 mmol) in THF (2 mL) was added K ₂ CO ₃ (110 mg, 0.78 mmol) followed by methyl iodide (29 mL, 0.47 mmol). The mixture was stirred at ambient temperature for 2 h, then treated with additional methyl iodide (50 mL, 0.84 mmol) and stirred for an additional 16 h. The mixture was filtered, washed with 4:1 DCM/MeOH (10 mL), and the filtrate was concentrated. The residue was purified by column chromatography, eluting with 0-15% (20% MeOH/DCM)/DCM to give 8-chloro-2-cyclopropyl-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (31 mg, 31%). ^1H NMR (400 MHz, CDCl ₃ ) δ 6.29 (s, 1H), 3.73 (s, 3H), 3.45 (t, 2H), 2.87-2.81 (m, 1H), 2.77 (t, 2H), 0.94-0.89 (m, 2H), 0.72-0.68 (m, 2H pp) m; MS (atmospheric pressure chemical ionization (apci), m/z)=253.1 (M+H).

Step 5. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-cyclopropyl-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 4-bromo-2-fluoroaniline (24 mg, 0.12 mmol) in THF (1 mL) at -78 °C under N ₂ was added LiHMDS (1.84 mL, 1.0 M/THF, 0.184 mmol). The mixture was stirred for 4 5 min, then a suspension of 8-chloro-2-cyclopropyl-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (31 mg, 0.13 mmol) in THF (2 mL) was added. The mixture was stirred at -78 °C for 20 min, then quenched with saturated aqueous NH ₄ Cl (10 mL), stirred at ambient temperature for 10 min, then extracted with EtOAc (3 x 10 mL). The combined organic layers were washed with brine (10 mL), dried over Na ₂ SO ₄ , filtered, and concentrated. The residue was purified by column chromatography eluting with 0-80% EtOAc/hexanes to give 8-((4-bromo-2-fluorophenyl)amino)-2-cyclopropyl-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (24.9 mg, 50%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.6 (s, 1H), 7.29 (dd, 1H), 7.19 (ddd, 1H), 6.71 (t, 1H), 5.99 (s, 1H), 3.50 (t, 2H), 3.20 (s, 3H), 2.77 (t, 2H), 2.74-2.70 (m, 1H), 0.93-0.87 (m, 2H), 0.72-0.67 (m, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=406.0, 408.0 (M+H).

Example 2

8-((4-bromo-2-fluorophenyl)amino)-2-(cyclopropylmethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same method as in Example 1, except using O-(cyclopropylmethyl)hydroxylamine hydrochloride instead of cyclopropylamine in step 2, to give 8-((4-bromo-2-fluorophenyl)amino)-2-(cyclopropylmethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (20 mg, 57%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.32 (s, 1H), 7.30 (dd, 1H), 7.21 (m, 1H), 6.72 (t, 1H), 6.00 (s, 1H), 3.85 (d, 2H), 3.77 (t, 2H), 3.18 (s, 3H), 2 .98 (t, 2H), 1.22-1.14 (m, 1H), 0.64-0.59 (m, 2H), 0.36-0.31 (m, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=436.0, 438.0 (M+H).

Example 3

8-((4-bromo-2-fluorophenyl)amino)-2-ethoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same method as in Example 1, except using O-ethylhydroxylamine hydrochloride instead of cyclopropylamine in step 2, to give 8-((4-bromo-2-fluorophenyl)amino)-2-ethoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (22 mg, 55%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.34 (s, 1H), 7.30 (dd, 1H), 7.21 (m, 1H), 6.72 (t, 1H), 5.99 (s, 1H), 4.08 (qt, 2H), 3.73 (t, 2H), 3.19 (s, 3H), 2.99 (t, 2H), 1.32 (t, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=410.0, 412.0 (M+H).

Example 4

2-cyclopropyl-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same method as in Example 1, except using 2-fluoro-4-(methylthio)aniline instead of 4-bromo-2-fluoroaniline in Step 5, to give 2-cyclopropyl-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (50.4 mg, 66%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.62 (s, 1H), 7.01 (dd, 1H), 6.95 (dd, 1H), 6.79 (t, 1H), 5.95 (s, 1H), 3.49 (t, 2H), 3.18 (s, 3H), 2.80-2.68 (m, 3H), 2.47 (s, 3H), 0.93-0.87 (m, 2H), 0.72-0.67 (m, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=374.1 (M+H).

Example 5

2-cyclopropyl-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same method as in Example 1, except using 2-fluoro-4-iodoaniline instead of 4-bromo-2-fluoroaniline in step 5, to give 2-cyclopropyl-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (46.7 mg, 52%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.60 (s, 1H), 7.46 (dd, 1H), 7.37 (dt, 1H), 6.55 (t, 1H), 6.00 (s, 1H), 3.50 (t, 2H), 3.21 (s, 3H), 2.81-2.69 (m, 3H), 0.93-0.87 (m, 2H), 0.72-0.67 (m, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=454.0 (M+H).

Example 6

8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

8-((2-Fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione was prepared by either Method A or Method B.

Method A.

Step 1. Preparation of 4-bromo-2,6-dichloronicotinic acid. A solution of 4-bromo-2,6-dichloropyridine (100 g, 440.7 mmol) in THF (1000 mL) was cooled to -78 °C. LDA (242.4 mL, 2M/THF, 484.8 mmol) was added dropwise at -78 °C and stirring was continued for 1 h at -78 °C. Solid CO ₂ (155.1 g, 3.53 mol) was added portionwise to the reaction mixture and stirring was continued for 2 h at -78 °C. The reaction was quenched by adding 1 M Na ₂ CO ₃ (1600 mL) followed by water (500 mL) and stirring for 10 min. The aqueous layer was extracted with EtOAc (300 mL). The pH of the aqueous solution was adjusted with _2N HCl to obtain a solution with pH 2. The aqueous solution was then extracted with EtOAc (3×300 mL). The combined organic layers were dried over _Na2SO4 , filtered and concentrated to give 4-bromo-2,6-dichloronicotinic acid (540 g, 75%). ¹ H NMR (400 MHz, DMSO- _d6 ) δ 15.51-12.87 (m, 1H), 8.13 (s, 1H) ppm.

Step 2. Preparation of 4-bromo-2-chloro-6-oxo-1,6-dihydropyridine-3-carboxylic acid. A solution of NaOH (1.62 L, 4 M, 6.46 mol) was heated to 110 °C and 4-bromo-2,6-dichloronicotinic acid (70 g, 258, 4 mmol) from step 1 was added in one portion. The mixture was stirred for 8 h, then cooled to 0 °C. The pH of the reaction mixture was adjusted to 1 with HCl (6 M) and stirred for 30 min. The solids were collected by filtration and dried under vacuum to give 4-bromo-2-chloro-6-oxo-1,6-dihydropyridine-3-carboxylic acid (calculated 100%).

Step 3. Preparation of methyl 4-bromo-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. To a mixture of 4-bromo-2-chloro-6-oxo-1,6-dihydropyridine-3-carboxylic acid (100 g, 396 mmol) in DMF (800 mL) were added methyl iodide (168.6 g, 1.19 mol, 73.98 mL) and K ₂ CO ₃ (164.2 g, 1.19 mol) in one portion. The mixture was stirred at 25 °C for 3 h, then poured into saturated aqueous NH ₄ Cl (1800 mL), and the aqueous phase was extracted with EtOAc (2×500 mL). The combined organic layers were washed with brine (400 mL), dried over Na ₂ SO ₄ , filtered and concentrated. The combined residues (5 batches) were purified by column chromatography eluting with 2-100% EtOAc/petroleum ether to give methyl 4-bromo-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (from 5 batches, 141.83 g, 24.7%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 6.86 (s, 1H), 3.94 (s, 3H), 3.69-3.66 (m, 3H); MS (atmospheric pressure chemical ionization (apci), m/z) = 280.0, 282.0 (M+H).

Step 4. Obtaining methyl (Z)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. Methyl 4-bromo-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (20.0 g, 71.3 mmol) obtained in step 3, methanesulfonato(2-dicyclohexylphosphino-2',6'-diisopropoxy-1,1'-biphenyl)(2-amino-1,1'-biphenyl-2-yl)palladium(II) (5.96 g, 7.13 mmol) and (Z)-2-(2-ethoxyvinyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (14.8 g, 74.9 mmol) were suspended in 1,4-dioxane (700 mL) and K ₂ CO ₃ (53.5 mL, 2N aqueous solution, 107 mmol) was added. The mixture was stirred at 60 °C for 6 h, then at ambient temperature for 12 h under argon. The reaction mixture was partitioned between water (1500 mL) and EtOAc (500 mL). The aqueous layer was extracted with EtOAc (2 x 400 mL), and the combined organic layers were washed with brine (500 mL), dried over Na ₂ SO ₄ , filtered, and concentrated. The residue was purified by column chromatography eluting with 0-40-60% EtOAc/heptanes to give methyl (Z)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (13.3 g, 68%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.23 (s, 1H), 6.45 (d, 1H), 4.86 (d, 1H), 4.40 (qt, 2H), 3.89 (s, 3H), 3.67 (s, 3H), 1.35 (t, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=272.0 (M+H).

Step 5. Preparation of methyl (E/Z)-4-(2-((2-(tertbutoxy)-ethoxy)imino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate Methyl (Z)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (0.95 g, 3.50 mmol) from step 4 and O-(2-(tertbutoxy)ethyl)hydroxylamine hydrochloride (593 mg, 3.50 mmol) were combined in 1,4-dioxane (10 mL). Et ₃ N (487 mL, 3.50 mmol) and HCl (1.75 mL, 4N/dioxane, 6.99 mmol) were added. The suspension was heated to 60°C for 1 h, then cooled and filtered. The filtrate was concentrated to give methyl (E/Z)-4-(2-((2-(tert-butoxy)ethoxy)imino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (calculated 100%) as a 1:1 mixture of isomers. MS (atmospheric pressure chemical ionization (apci), m/z)=359.1 (M+H).

Step 6. Preparation of methyl 4-(2-((2-(tertbutoxy)-ethoxy)amino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. To a solution of methyl (E/Z)-4-(2-((2-(tertbutoxy)-ethoxy)imino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (1.25 g, 3.48 mmol) in IPA (20 mL) from Step 5 was added sodium cyanoborohydride (1.09 g, 17.4 mmol), followed by acetic acid (1.0 mL, 17.4 mmol). The mixture was stirred at ambient temperature for 16 h, then partitioned between saturated _NaHCO3 solution (50 mL) and EtOAc (50 mL). The aqueous layer was extracted with EtOAc (2×30 mL), and the combined organic layers were washed with brine (30 mL), then dried over _Na2SO4 , filtered and concentrated. The residue was purified by column chromatography eluting with 0-80% _EtOAc /DCM to give methyl 4-(2-((2-(tertbutoxy)ethoxy)amino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (0.66 g, 53%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 6.43 (s, 1H), 3.90 (s, 3H), 3.78 (t, 2H), 3.68 (s, 3H), 3.50 (t, 2H), 3.10 (t, 2H), 2.71 (t, 2H), 1.20 (s, 9H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=361.1, 363.1 (M+H).

Step 7. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. 2-Fluoro-4-(methylthio)aniline (114 mg, 0.73 mmol) was dissolved in THF (5.0 mL, 0.69 mmol) and cooled to -78 °C under N ₂ . LiHMDS (1.39 mL, 1.0 m /THF, 1.39 mmol) was added dropwise, and the mixture was stirred for 45 min. Then, a solution of methyl 4-(2-((2-(tert-butoxy)ethoxy)amino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (250 mg, 0.69 mmol) from step 6 in THF (5.0 mL) was added dropwise. After stirring for 10 min, additional LiHMDS (1.0 mL, 1.0 mmol) was added and stirring was continued at -78 °C for 1 h. The reaction mixture was quenched with saturated aqueous NH ₄ Cl (20 mL) then extracted with EtOAc (3×10 mL). The combined organic layers were dried over Na ₂ SO ₄ , filtered, and concentrated. The residue was purified by column chromatography eluting with 0-15% (20% MeOH/DCM)/DCM to give 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (111 mg, 36%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.35 (s, 1H), 7.02-6.99 (dd, 1H), 6.97-6.94 (m, 1H), 6.82-6.77 (t, 1H), 5.95 (s, 1H), 4.16-4.14 (m, 2H), 3.80-3.77 (t, 2H), 3.62-3.60 (m, 2H), 3.17 (s, 3H), 2.99-2.95 (t, 2H), 2.47 (s, 3H), 1.21 (s, 9H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=450.2 (M+H).

Step 8. Preparation of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione To a solution of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (111 mg, 0.247 mmol) obtained in step 7 in acetonitrile (2.0 mL) was added H ₃ PO ₄ (2.0 mL, 38.5 mmol). The solution was heated to 60 °C for 15 min, then cooled and quenched with saturated aqueous NaHCO ₃ (20 mL). The mixture was extracted with EtOAc (3 x 10 mL), and the combined organic layers were dried over Na ₂ SO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-20% (20% MeOH/DCM)/DCM followed by reverse phase HPLC (5-95% acetonitrile/water/0.1% TFA over 30 min). Fractions containing purified desired product were pooled and the product was converted to the free base form with DCM/NaHCO ₃ to give 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (62 mg, 64%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.17 (s, 1H), 7.03-6.97 (m, 2H), 6.85 (t, 1H), 5.95 (s, 1H), 4.03 (t, 2H), 3.74-3.70 (m, 4H), 3.16 (s, 3H), 2.98 (t, 2H), 2.48 (s, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z) = 394.1 (M+H). Powder X-ray diffraction (PXRD) analysis was performed as described in Example 77. The powder X-ray diffraction pattern, which is shown in Figure 4, confirmed that the obtained material is amorphous. On this basis, the material was named as amorphous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 4.

Method B.

Step 1. Preparation of methyl 4-bromo-2-((2-fluoro-4-(methylthio)-phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. To a solution of methyl 4-bromo-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (prepared according to any of the methods described in the invention; 50.0 g, 87.2%, 155 mmol) and 2-fluoro-4-(methylthio)aniline (24.4 g, 55 mmol) in THF (50 mL) at 0 °C was added potassium tert-butoxide (34.9 g, 311 mL, 1.0 molar solution, 311 mmol) over 40 minutes. The reaction mixture was heated at 0 °C for 50 min, then diluted with saturated aqueous NH ₄ Cl (600 mL) and EtOAc (500 mL). Water was added to dissolve the solids, and the layers were separated. The aqueous layer was extracted with EtOAc (2 x 300 mL), and the combined organic layers were washed with water (500 mL) and brine (500 mL), then dried over Na ₂ SO ₄ , filtered, and concentrated. The residue was suspended in MeOH (57 mL) and sonicated briefly, then heated to 60 °C for 10 min. The mixture was slowly cooled to ambient temperature, then cooled to 0 °C over 30 min. The solids were filtered and collected to give methyl 4-bromo-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (40.14 g, 64.4%). ¹ H NMR CDCl ₃ δ 9.03 (s, 1H), 7.04 (dd, 1H), 6.96 (m, 1H), 6.71-6.65 (m, 2H), 3.85 (s, 3H), 3.24 (s, 3H), 2.47 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=401.0, 403.0 (M+H).

Step 2. Obtaining methyl (Z)-4-(2-ethoxyvinyl)-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. (Z)-2-(2-Ethoxyvinyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (80.25 g, 82.3 mL, 405.17 mmol) was added to a stirred solution of methyl 4-bromo-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (130.06 g, 324.14 mmol), prepared according to the procedure used in step 1, K ₂ CO ₃ (67.2 g, 243.10 mL, 2 M, 486.21 mmol) and methanesulfonato(2-dicyclohexylphosphino-2',6'-diisopropoxy-1,1'-biphenyl)'2-amino-1,1'-biphenyl-2-yl)palladium(II) (6.78 g, 8.10 mmol) in 2-methyltetrahydrofuran (860 mL) at ambient temperature under argon. Argon was bubbled through the reaction mixture for 30 min. The reaction mixture was heated to 60 °C and stirred for 13 h, then stirred at ambient temperature for 6 h. The reaction mixture was diluted with water (1800 mL) and EtOAc (1100 mL), then filtered through GF/F filter paper. The filtrate layers were separated, and the aqueous layer was extracted with EtOAc (2 x 650 mL). The combined organic layers were washed with brine (1500 mL), dried over Na ₂ SO ₄ , filtered and concentrated. The residue was treated with MTBE (30 mL), concentrated and dried under vacuum. The residue was suspended in MTBE (330 mL) and stirred at 60 °C for 1 h. The mixture was slowly cooled to ambient temperature, then stirred at 0 °C for 40 min. The solids were filtered, washed with cold MTBE (110 mL), then with cold MTBE:heptane (1:1 mixture, 150 mL), and dried under vacuum to give methyl (Z)-4-(2-ethoxyvinyl)-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (98.54 g, 77.46%). 1H NMR _CDCl3 δ 8.65 (s, 1H), 7.04 (dd, 1H), 6.97 (s, 1H), 6.92 (m, 1H), 6.56 (t, 1H), 6.37 (d, 1H), 5.36 (d, 1H), 4.01 (qt, 2H), 3.79 (s, 3H), 3.31 (s, 3H), 2.46 (s, 3H), 1.35 (t, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=393.1 (M+H).

Step 3. Obtaining 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Triethylamine (2.84 g, 3.91 mL, 28.0 mmol) was added to a stirred solution of methyl (Z)-4-(2-ethoxyvinyl)-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (10.0 g, 25.5 mmol), prepared according to the procedure used in Step 2, and O-(2-(tert-butoxy)ethyl)hydroxylamine hydrochloride (4.95 g, 96%, 28.0 mmol) in 1,4-dioxane (255 mL). The reaction mixture was placed in a cold water bath, flushed with Ar, and HCl (2.04 g, 14.0 mL, 4 M/dioxane, 56.1 mmol) was added dropwise via an addition funnel. The mixture was heated at 60 °C for 1 h, then cooled to ambient temperature using a cold water bath. Pyridineborane (4.74 g, 5.42 mL, 51.0 mmol) was added slowly, and the mixture was stirred for 10 min at ambient temperature. HCl (1.11 g, 7.64 mL, 4 M/dioxane, 30.6 mmol) was added over 5 min, and stirring was continued for 20 min. The reaction mixture was heated at 60 °C for 21 h, then cooled to ambient temperature. The cooled mixture was neutralized to approximately pH 7 by slowly adding saturated aqueous _NaHCO3 (140 mL), then diluted with EtOAc (400 mL) and _H2O (300 mL). The layers were separated and the aqueous layer was extracted with EtOAc (2×150 mL). The combined organic layers were washed with brine ( ₆₀₀ mL), dried over _Na2SO4 , filtered, and concentrated. The residue was dissolved in a minimum amount of DCM and filtered through a 12.7 cm pad of silica gel, eluting with 3% MeOH:DCM (1 L). The filtrate was concentrated to give 2-(2-(tert-butoxy)-ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (calculated 100%), which was used without further purification. MS (atmospheric pressure chemical ionization (apci), m/z) = 450.2 (M+H).

Step 4. Preparation of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 2-(2-(tert-butoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (14.18 g, 31.54 mmol), prepared according to the procedure used in Step 3, in acetonitrile (63.09 mL, 31.54 mmol) at ambient temperature was added phosphoric acid (36.36 g, 21.60 mL, 85%, 315.4 mmol) dropwise over 20 min. The reaction mixture was heated to 60 °C for 4 h, then slowly cooled to ambient temperature. The reaction mixture was slowly poured into cold potassium phosphate solution (66.95 g, 157.7 mL, 2 M, 315.4 mmol) in an ice bath with vigorous stirring. After stirring for 10 min, EtOAc (300 mL) was added and the layers were separated. The organic layer was washed with brine (300 mL), then the aqueous layer was extracted with EtOAc ( ₁₀₀ mL). The combined organic layers were dried over _Na2SO4 , filtered and concentrated. The residue was purified by column chromatography eluting with 0-40% (20% MeOH/DCM)/MTBE to give 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (9.48 g, 76.4%). Powder X-ray diffraction (PXRD) analysis confirmed that the obtained material is amorphous: ¹ H NMR CDCl ₃ δ 11.19 (s, 1H), 7.06-6.93 (m, 2H), 6.91-6.76 (m, 1H), 5.95 (t, 1H), 4.44 (s, 1H), 4.21-3.87 (m, 2H), 3.84-3.54 (m, 4H), 3.16 (s, 3H), 2.98 (td, 2H), 2.48 (s, 3H). MS (atmospheric pressure chemical ionization (apci), m/z)=394.1 (M+H).

Example 7

8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same procedure as in Example 6, Method A, except using 4-bromo-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline in Step 7, to give 8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (15 mg, 63%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.14 (s, 1H), 7.33 (dd, 1H), 7.24 (m, 1H), 6.78 (t, 1H), 5.99 (s, 1H), 4.38 (t, 1H), 4.05-4.01 (m, 2H), 3.75-3.7 0 (m, 4H), 3.17 (s, 3H), 3.00 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=426.0, 428.0 (M+H).

Example 8

8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same procedure as in Example 6, Method A, except using 4-iodo-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline in Step 7, to give 8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (12 mg, 74%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.11 (s, 1H), 7.49 (dd, 1H), 7.42 (m, 1H), 6.63 (t, 1H), 6.00 (s, 1H), 4.42-4.33 (m, 1H), 4.05-4.00 (m, 2H), 3.7 6-3.69 (m, 4H), 3.18 (s, 3H), 2.99 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=474.0 (M+H).

Example 9

8-((2-chloro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same procedure as in Example 6, Method A, except using 2-chloro-4-iodoaniline instead of 2-fluoro-4-(methylthio)aniline in Step 7, to give 8-((2-chloro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (6.4 mg, 50%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.09 (s, 1H), 7.79 (s, 1H), 7.48 (d, 1H), 6.46 (d, 1H), 6.02 (s, 1H), 4.03 (t, 2H), 3.78-3.70 (m, 4H), 3.14 (s, 3 H), 3.00 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=490.0 (M+H).

Example 10

8-((4-bromo-2-chlorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same procedure as in Example 6, Method A, except using 4-bromo-2-chloroaniline instead of 2-fluoro-4-(methylthio)aniline in Step 7, to give 8-((4-bromo-2-chlorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (7.9 mg, 52%). ¹ H NMR 11.10 (s, 1H), 7.62 (d, 1H), 7.31 (dd, 1H), 6.61 (d, 1H), 6.02 (s, 1H), 4.03 (t, 2H), 3.77-3.68 (m, 4H), 3.14 (s, 3H), 3.00 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=442.0, 444.0 (M+H).

Example 11

8-((4-bromo-2,3-difluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same procedure as in Example 6, Method A, except using 4-bromo-2,3-difluoroaniline instead of 2-fluoro-4-(methylthio)aniline in Step 7, to give 8-((4-bromo-2,3-difluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (12.2 mg, 75%). ¹ H NMR 11.17 (s, 1H), 7.30-7.22 (m, 1H), 6.65 (dt, 1H), 6.04 (s, 1H), 4.32 (br s, 1H), 4.04 (t, 2H), 3.78-3.69 (m, 4H), 3.21 (s, 3H), 3.01 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=444.0 (M+H).

Example 12

8-((4-bromo-3-chloro-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same procedure as in Example 6, Method A, except using 4-bromo-3-chloro-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline in Step 7, to give 8-((4-bromo-3-chloro-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (10.6 mg, 68%). ¹ H NMR 11.17 (s, 1H), 7.37 (d, 1H), 6.68 (t, 1H), 6.04 (s, 1H), 4.06-4.00 (m, 2H), 3.77-3.69 (m, 4H), 3.20 (s, 3H), 3.01 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=460.0, 462.0 (M+H).

Example 13

8-((2-fluoro-4-(trifluoromethyl)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(trifluoromethyl)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared in the same manner as Example 6, Step 7 in Method A, except using 2-fluoro-4-(trifluoromethyl)aniline instead of 2-fluoro-4-(methylthio)aniline to give 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(trifluoromethyl)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (11 mg, 22%). MS (atmospheric pressure chemical ionization (apci), m/z)=472.2 (M+H).

Step 2. Obtaining 8-((2-fluoro-4-(trifluoromethyl)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same method as in Example 6, Step 8 in Method A, except using 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(trifluoromethyl)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione instead of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, to give 8-((2-fluoro-4-(trifluoromethyl)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (6 mg, 62%) ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.18 (s, 1H), 7.44-7.41 (dd, 1H), 7.38-7.36 (d, 1H), 6.92-6.88 (t, 1H), 6.08 (s, 1H), 4.05-4.03 (m, 2H), 3.76-3.72 (m, 4H), 3.23 (s, 3H), 3.03-3.00 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=416.1 (M+H).

Example 14

8-((4-ethyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((4-ethyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same procedure as Example 6, Step 7 in Method A, except using 4-ethyl-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline to give 2-(2-(tertbutoxy)ethoxy)-8-((4-ethyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (19 mg, 42%). MS (atmospheric pressure chemical ionization (apci), m/z)=432.2 (M+H).

Step 2. Preparation of 8-((4-ethyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same method as in Example 6, Step 8 in Method A, except that 2-(2-(tertbutoxy)ethoxy)-8-((4-ethyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione was used instead of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, to give 8-((4-ethyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (10 mg, 61%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.17 (s, 1H), 7.00-6.91 (m, 2H), 6.87-6.83 (t, 1H), 5.93 (s, 1H), 4.03-4.01 (m, 2H), 3.74-3.70 (m, 4H), 3.15 (s , 3H), 3.00-2.97 (t, 2H), 2.66-2.61 (qt, 2H), 1.25-1.21 (t, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=376.2 (M+H).

Example 15

8-((4-cyclopropyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((4-cyclopropyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same procedure as Example 6, Step 7 in Method A, except using 4-cyclopropyl-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline to give 2-(2-(tertbutoxy)ethoxy)-8-((4-cyclopropyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (32 mg, 52%). MS (atmospheric pressure chemical ionization (apci), m/z)=444.2 (M+H).

Step 2. Preparation of 8-((4-cyclopropyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same method as in Example 6, Step 8 in Method A, except that 2-(2-(tertbutoxy)ethoxy)-8-((4-cyclopropyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione was used instead of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione to give 8-((4-cyclopropyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (19 mg, 68%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.18 (s, 1H), 6.83-6.78 (m, 3H), 5.92 (s, 1H), 4.49 (br. s, 1H), 4.03-4.01 (m, 2H), 3.74-3.69 (m, 4H), 3.13 (s, 3 H), 3.0-2.96 (t, 2H), 1.90-1.84 (m, 1H), 1.03-0.98 (m, 2H), 0.69-0.65 (m, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=388.1 (M+H).

Example 16

8-((2-fluoro-4-methoxyphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-methoxyphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same procedure as Example 6, Step 7 in Method A, except using 2-fluoro-4-methoxyaniline instead of 2-fluoro-4-(methylthio)aniline to give 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-methoxyphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (8 mg, 17%). MS (atmospheric pressure chemical ionization (apci), m/z)=434.2 (M+H).

Step 2. Preparation of 8-((2-fluoro-4-methoxyphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same method as in Example 6, Step 8 in Method A, except that 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-methoxyphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione was used instead of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, to give 8-((2-fluoro-4-methoxyphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (3 mg, 43%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.18 (s, 1H), 6.94-6.90 (t, 1H), 6.07-6.64 (m, 2H), 5.91 (s, 1H), 4.04-4.01 (m, 2H), 3.80 (s, 3H), 3.75-3.69 (m , 4H), 3.12 (s, 3H), 3.00-2.96 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=378.1 (M+H).

Example 17

8-((2-fluoro-4-((trifluoromethyl)thio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-((trifluoromethyl)thio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same procedure as Example 6, Step 7 in Method A, except using 2-fluoro-4-((trifluoromethyl)thio)aniline instead of 2-fluoro-4-(methylthio)aniline to give 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-((trifluoromethyl)thio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (17 mg, 31%). MS (atmospheric pressure chemical ionization (apci), m/z)=504.1 (M+H).

Step 2. Preparation of 8-((2-fluoro-4-((trifluoromethyl)thio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same method as in Example 6, Step 8 in Method A, except that 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-((trifluoromethyl)thio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione was used instead of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, to give 8-((2-fluoro-4-((trifluoromethyl)thio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (10 mg, 66%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.16 (s, 1H), 7.49-7.46 (dd, 1H), 7.40-7.38 (d, 1H), 6.86-6.82 (t, 1H), 6.06 (s, 1H), 4.31 (br s, 1H), 4.05-4.02 (t, 2H), 3.76-3.72 (m, 4H), 3.23 (s, 3H), 3.03-3.00 (t, 2H); MS (atmospheric pressure chemical ionization (apci), m/z)=448.1 (M+H).

Example 18

8-((2-fluoro-4-isopropylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-isopropylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same procedure as in Example 6, Step 7 of Method A, except using 2-fluoro-4-isopropylaniline instead of 2-fluoro-4-(methylthio)aniline to give 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-isopropylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (17 mg, 34%). MS (atmospheric pressure chemical ionization (apci), m/z)=446.2 (M+H).

Step 2. Preparation of 8-((2-fluoro-4-isopropylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared in the same manner as Example 6, Step 8 in Method A, except using 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-isopropylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione instead of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione to give 8-((2-fluoro-4-isopropylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (10 mg, 67%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.16 (s, 1H), 7.00-6.93 (m, 2H), 6.97-6.83 (t, 1H), 5.93 (s, 1H), 4.51-4.48 (t, 1H), 4.03-4.01 (t, 2H), 3.75-3 .69 (m, 4H), 3.14 (s, 3H), 3.00-2.96 (t, 2H), 2.92-2.85 (m, 1H), 1.24-1.22 (d, 6H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=390.2 (M+H).

Example 19

8-((2-chloro-4-cyclopropylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-chloro-4-cyclopropylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same procedure as Example 6, Step 7 in Method A, except using 2-chloro-4-cyclopropylaniline instead of 2-fluoro-4-(methylthio)aniline to give 2-(2-(tertbutoxy)ethoxy)-8-((2-chloro-4-cyclopropylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (21 mg, 41%). MS (atmospheric pressure chemical ionization (apci), m/z)=460.2 (M+H).

Step 2. Preparation of 8-((2-chloro-4-cyclopropylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same method as in Example 6, Step 8 in Method A, except that 2-(2-(tertbutoxy)ethoxy)-8-((2-chloro-4-cyclopropylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione was used instead of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, to give 8-((2-chloro-4-cyclopropylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (12 mg, 65%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.13 (s, 1H), 7.14 (d, 1H), 6.91-6.88 (dd, 1H), 6.69-6.67 (d, 1H), 5.95 (s, 1H), 4.47-4.44 (t, 1H), 4.04-4.01 ( t, 2H), 3.75-3.69 (m, 4H), 3.09 (s, 3H), 3.01-2.98 (t, 2H), 1.89-1.82 (m, 1H), 1.02-0.97 (m, 2H), 0.69-0.65 (m, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=404.1 (M+H).

Example 20

8-((4-acetyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((4-ethynyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione 2-Fluoro-4-((trimethylsilyl)ethynyl)aniline (30.2 mg, 0.145 mmol) was dissolved in THF (1.0 mL, 0.139 mmol) and cooled to -78 °C under N ₂ . LiHMDS (0.277 mL, 1N/THF, 0.277 mmol) was added dropwise, and the mixture was stirred for 45 min at the same temperature. Methyl 4-(2-((2-(tert-butoxy)ethoxy)amino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (50 mg, 0.139 mmol) was dissolved in THF (1.0 mL, 0.139 mmol) and added dropwise to the reaction mixture. After stirring for 10 min, LiHMDS (0.160 mL, 1N/THF, 0.160 mmol) was added and the reaction mixture was stirred for 1 h at the same temperature. The reaction mixture was quenched with saturated aqueous NH ₄ Cl (25 mL) then extracted with EtOAc (3×25 mL). The combined organic layers were dried over Na ₂ SO ₄ , filtered and concentrated. The material was dissolved in THF (1.0 mL, 0.139 mmol) and treated with TBAF (0.1 mL, 1N/THF, 0.100 mmol) at ambient temperature for 30 min. The mixture was partitioned between EtOAc (25 mL) and saturated aqueous NH ₄ Cl (25 mL). The organic layer was removed and the aqueous layer was washed with EtOAc (2×25 mL). The combined organic layers were dried over Na ₂ SO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-15% (20% MeOH/DCM)/DCM to give 2-(2-(tertbutoxy)ethoxy)-8-((4-ethynyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (19 mg, 32%). MS (atmospheric pressure chemical ionization (apci), m/z)=428.2 (M+H).

Step 2. Preparation of 8-((4-acetyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared in the same manner as Example 6, Step 8 of Method A, except using 2-(2-(tertbutoxy)ethoxy)-8-((4-ethynyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione instead of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, to give 8-((4-acetyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (11 mg, 64%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.19 (s, 1H), 7.76-7.73 (dd, 1H), 7.71-7.69 (dd, 1H), 6.87-6.83 (t, 1H), 6.07 (s, 1H), 4.31 (br s, 1H), 4.05-4.03 (m, 2H), 3.76-3.73 (m, 4H), 3.24 (s, 3H), 3.03-3.00 (t, 2H), 2.58 (s, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=390.1 (M+H).

Example 21

8-((2-chloro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-chloro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same procedure as Example 6, Step 7 in Method A, except using 2-chloro-4-(methylthio)aniline instead of 2-fluoro-4-(methylthio)aniline to give 2-(2-(tertbutoxy)ethoxy)-8-((2-chloro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (15 mg, 29%). MS (atmospheric pressure chemical ionization (apci), m/z)=466.1 (M+H).

Step 2. Obtaining 8-((2-chloro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same method as in Example 6, Step 8 in Method A, except that 2-(2-(tert-butoxy)-ethoxy)-8-((2-chloro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione was used instead of 2-(2-(tert-butoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione to give 8-((2-chloro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (9 mg, 68%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.15 (s, 1H), 7.33 (d, 1H), 7.09-7.06 (dd, 1H), 6.71-6.69 (d, 1H), 5.97 (s, 1H), 4.42 (br s, 1H), 4.04-4.02 (t, 2H), 3.75-3.71 (m, 4H), 3.12 (s, 3H), 3.01-2.98 (t, 2H), 2.48 (s, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=410.1 (M+H).

Example 22

8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same procedure as in Example 6, Step 7 of Method A, except using 4-(difluoromethoxy)-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline to give 2-(2-(tertbutoxy)ethoxy)-8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (17 mg, 33%). MS (atmospheric pressure chemical ionization (apci), m/z)=470.2 (M+H).

Step 2. 8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H, 7H)-dione. Prepared by the same method as in Example 6, Step 8 in Method A, except that 2-(2-(tert-butoxy)-ethoxy)-8-((4-(difluoromethoxy)-2-fluorophenyl)amino was used. )-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione instead of 2-(2-(tert-butoxy)-ethoxy)-8-((2-fluoro-4 -(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione to obtain 8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)- dione (10 mg, 67%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.18 (s, 1H), 7.00-6.91 (m, 3H), 6.68-6.31 (t, 1H), 5.98 ( s, 1H), 4.43-4.40 (t, 1H), 4.04-4.02 (t, 2H), 3.75-3.71 (m, 4H), 3.16 (s, 3H), 3.01-2.98 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=414.1 (M+H).

Example 23

8-((2-chloro-4-ethylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-chloro-4-ethylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same procedure as Example 6, Step 7 of Method A, except using 2-chloro-4-ethylaniline instead of 2-fluoro-4-(methylthio)aniline to give 2-(2-(tertbutoxy)ethoxy)-8-((2-chloro-4-ethylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (9 mg, 14%). MS (atmospheric pressure chemical ionization (apci), m/z)=448.2 (M+H).

Step 2. Preparation of 8-((2-chloro-4-ethylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same method as in Example 6, Step 8 in Method A, except that 2-(2-(tertbutoxy)ethoxy)-8-((2-chloro-4-ethylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione was used instead of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, to give 8-((2-chloro-4-ethylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (6 mg, 80%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.13 (s, 1H), 7.29 (d, 1H), 7.02-7.00 (dd, 1H), 6.72-6.70 (d, 1H), 5.95 (s, 1H), 4.46 (br s, 1H), 4.04-4.01 (m, 2H), 3.75-3.70 (m, 4H), 3.10 (s, 3H), 3.01-2.97 (t, 2H), 2.65-2.59 (qt, 2H), 1.24-1.21 (t, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=392.1 (M+H).

Example 24

8-((2-fluoro-4-(trifluoromethoxy)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(trifluoromethoxy)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same procedure as Example 6, Step 7 in Method A, except using 2-fluoro-4-(trifluoromethoxy)aniline instead of 2-fluoro-4-(methylthio)aniline to give 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(trifluoromethoxy)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (22 mg, 41%). MS (atmospheric pressure chemical ionization (apci), m/z)=488.2 (M+H).

Step 2. Preparation of 8-((2-fluoro-4-(trifluoromethoxy)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same method as in Example 6, Step 8 in Method A, except that 2-(2-(tertbutoxy)-ethoxy)-8-((2-fluoro-4-(trifluoromethoxy)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione was used instead of 2-(2-(tertbutoxy)-ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione to give 8-((2-fluoro-4-(trifluoromethoxy)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (13 mg, 67%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.17 (s, 1H), 7.08-7.06 (d, 1H), 7.02-6.99 (d, 1H), 6, 94-6, 90 (t, 1H), 6.01 (s, 1H), 4.40-4.36 (t, 1H), 4.05-4.02 (t, 2H), 3.75-3.72 (t, 4H), 3.18 (s, 3H), 3.02-2.99 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=432.1 (M+H).

Example 25

8-((4-((difluoromethyl)thio)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((4-((difluoromethyl)thio)-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same procedure as Example 6, Step 7 in Method A, except using 4-((difluoromethyl)thio)-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline to give 2-(2-(tertbutoxy)ethoxy)-8-((4-((difluoromethyl)thio)-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (19 mg, 35%). δ 11.31 (s, 1H), 7.40-7.37 (dd, 1H), 7.30-7.28 (m, 1H), 6.94-6.66 (t, 1H), 6.80-6.76 (t, 1H), 6.04 (s, 1H), 4.17-4.14 (m, 2H), 3.82-3.79 (t, 2H), 3.62-3.59 (m, 2H), 3.24 (s, 3H), 3.01-2.97 (t, 2H), 1.21 (s, 9H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=486.2 (M+H).

Step 2. Preparation of 8-((4-((difluoromethyl)thio)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same method as in Example 6, Step 8 in Method A, except that 2-(2-(tertbutoxy)ethoxy)-8-((4-((difluoromethyl)thio)-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione was used instead of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, to give 8-((4-((difluoromethyl)thio)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (11 mg, 57%). 1H NMR (400 MHz, _CDCl3 ) δ 11.16 (s, 1H), 7.42-7.39 (dd, 1H), 7.33-7.32 (d, 1H), 6.96-6.68 (t, 1H), 6.87-6.82 (t, 1H), 6.04 (s, 1H), 4.37-4.33 (t, 1H), 4.05-4.02 (t, 2H), 3.75-3.72 (t, 4H), 3.22 (s, 3H), 3.03-2.99 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=430.1 (M+H).

Example 26

8-((4-bromo-2-fluorophenyl)amino)-2-isopropoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same method as in Example 6, steps 1-7 in Method A, except using O-isopropylhydroxylamine hydrochloride instead of O-(2-(tert-butoxy)ethyl)hydroxylamine hydrochloride in step 5, and 4-bromo-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline in step 7, to give 8-((4-bromo-2-fluorophenyl)amino)-2-isopropoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (10.3 mg, 14%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.37 (s, 1H), 7.30 (dd, 1H), 7.21 (dq, 1H), 6.73 (t, 1H), 6.00 (s, 1H), 4.33 (m, 1H), 3.68 (t, 2H), 3.18 (s, 3H), 2.99 (t, 2H), 1.30 (d, 6H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=424.1, 426.1 (M+H).

Example 27

8-((2-fluoro-4-iodophenyl)amino)-2-isopropoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same method as in Example 6, steps 1-7 in Method A, except using O-isopropylhydroxylamine hydrochloride instead of O-(2-(tert-butoxy)ethyl)hydroxylamine hydrochloride in step 5, and 2-fluoro-4-iodoaniline instead of 2-fluoro-4-(methylthio)aniline in step 7, to give 8-((2-fluoro-4-iodophenyl)amino)-2-isopropoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (15.2 mg, 23%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.36 (s, 1H), 7.46 (dd, 1H), 7.38 (dt, 1H), 6.58 (t, 1H), 6.00 (s, 1H), 4.33 (m, 1H), 3.68 (t, 2H), 3.19 (s, 3H), 2.99 (t, 2H), 1.30 (d, 6H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=472.1 (M+H).

Example 28

2-ethoxy-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same method as in Example 6, steps 1-7 in Method A, except using O-ethylhydroxylamine hydrochloride instead of O-(2-(tert-butoxy)ethyl)hydroxylamine hydrochloride in step 5, and 2-fluoro-4-iodoaniline instead of 2-fluoro-4-(methylthio)aniline in step 7, to give 2-ethoxy-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (24.3 mg, 25%). ¹ H NMR 11.33 (s, 1H), 7.46 (d, 1H), 7.38 (d, 1H), 6.57 (t, 1H), 6.00 (s, 1H), 4.07 (qt, 2H), 3.72 (t, 2H), 3.19 (s, 3H), 2.99 (t, 2H), 1.31 (t, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=458.0 (M+H).

Example 2 9

8-((2-fluoro-4-iodophenyl)amino)-2-methoxy-7-methyl-3,4-dihydro-2, 7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same method as in Example 6, steps 1-7 in Method A, except using O-methylhydroxylamine hydrochloride instead of O-(2-(tert-butoxy)ethyl)hydroxylamine hydrochloride in step 5, and 2-fluoro-4-iodoaniline instead of 2-fluoro-4-(methylthio)aniline in step 7, to give 8-((2-fluoro-4-iodophenyl)amino)-2-methoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (16.7 mg, 33%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.32 (s, 1H), 7.47 (d, 1H), 7.39 (d, 1H), 6.58 (t, 1H), 6.00 (s, 1H), 3.84 (s, 3H), 3.73 (t, 2H), 3.19 (s, 3H), 3.00 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=444.0 (M+H).

Example 30

2-(tert-butoxy)-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Steps 1-7. Preparation of methyl 4-(2-(tert-butoxyamino)ethyl)-2-((2-fluoro-4-iodophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. Prepared by the same method as Example 6, steps 1-7, except using O-(tert-butyl)hydroxylamine hydrochloride instead of O-(2-(tert-butoxy)ethyl)hydroxylamine hydrochloride in step 5, and 2-fluoro-4-iodoaniline instead of 2-fluoro-4-(methylthio)aniline in step 7, to give methyl 4-(2-(tert-butoxyamino)ethyl)-2-((2-fluoro-4-iodophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (40.3 mg, 62%). MS (atmospheric pressure chemical ionization (apci), m/z)=518.1 (M+H).

Step 8. Preparation of 2-(tertbutoxy)-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. A solution of methyl 4-(2-(tertbutoxyamino)ethyl)-2-((2-fluoro-4-iodophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (40.3 mg, 0.078 mmol) in THF (1 mL) was treated with Et ₃ N (10.9 μL, 0.078 mmol). The reaction mixture was heated to 50 °C for 1 h. _Et3N (10.9 µL, 0.078 mmol) was added to the reaction mixture and stirring was continued at 50 °C for another hour. An additional aliquot of _Et3N (10.9 µL, 0.078 mmol) was added and the reaction mixture was stirred at 50 °C for 5 days. The reaction mixture was partitioned between water (40 mL) and EtOAc (20 mL). The aqueous layer was washed with EtOAc (2×15 mL). The combined organic layers were washed with brine (25 mL), dried over sodium sulfate, filtered and concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/water/0.1% TFA over 20 min) and the pure fractions were combined, washed with saturated sodium bicarbonate solution and extracted with EtOAc (3×15 mL). The combined organic layers were washed with saturated sodium bicarbonate solution (20 mL) and brine (25 mL), dried over sodium sulfate, filtered and concentrated in vacuo to give 2-(tert-butoxy)-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (16.5 mg, 43%). 1H NMR (400 MHz, _CDCl3 ) δ 11.49 (s, 1H), 7.46 (dd, 1H), 7.39 (td, 1H), 6.59 (t, 1H), 5.99 (s, 1H), 3.70-3.60 (m, 2H), 3.18 (s, 3H), 3.10-2.87 (m, 2H), 1.34 (s, 9H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=486.1 (M+H).

Example 31

(S)-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of methyl (S,E)-2-chloro-4-(2-((2-hydroxypropoxy)imino)ethyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate Methyl (Z)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (200 mg, 0.736 mmol) and (S)-O-(2-((tert-butyldimethylsilyl)oxy)propyl)hydroxylamine (151 mg, 0.736) were taken up in 1,4-dioxane (5 mL), TEA (103 μL, 0.736 mmol) and HCl (368 μL, 4N/dioxane, 1.47 mmol) was added. The suspension was heated to 60 °C for 3 h. The reaction mixture was filtered and concentrated. The residue was purified by column chromatography eluting with 0-80% EtOAc/hexanes to give methyl (S,E)-2-chloro-4-(2-((2-hydroxypropoxy)imino)ethyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (66.6 mg, 29%). MS (atmospheric pressure chemical ionization (apci), m/z)=317.1 (M+H).

Step 2. Preparation of methyl (S,E)-2-chloro-1-methyl-6-oxo-4-(6,8,8,9,9-pentamethyl-4,7-dioxa-3-aza-8-siladec-2-en-1-yl)-1,6-dihydropyridine-3-carboxylate Methyl (S,E)-2-chloro-4-(2-((2-hydroxypropoxy)imino)ethyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (66.6 mg, 0.210 mmol) and imidazole (0.043 g, 0.631 mmol) were dissolved in DMF (2 mL) and cooled to 0 °C. TBS-C1 (63.4 mg, 0.421 mmol) was then added and the reaction mixture was warmed to room temperature for 2 h. The reaction mixture was diluted with water (40 mL) and EtOAc (20 mL). The aqueous layer was washed with EtOAc (2 x 15 mL). The combined organic layers were washed with water (5 x 20 mL) and brine (25 mL), dried over sodium sulfate, filtered, and concentrated. The residue was purified by column chromatography eluting with 0-40% EtOAc/hexanes to give methyl (S,E)-2-chloro-1-methyl-6-oxo-4-(6,8,8,9,9-pentamethyl-4,7-dioxa-3-aza-8-siladec-2-en-1-yl)-1,6-dihydropyridine-3-carboxylate (63.4 mg, 70%). MS (atmospheric pressure chemical ionization (apci), m/z)=431.2 (M+H).

Step 3. Preparation of methyl (S)-2-chloro-1-methyl-6-oxo-4-(6,8,8,9,9-pentamethyl-4,7-dioxa-3-aza-8-siladecyl)-1,6-dihydropyridine-3-carboxylate Methyl (S,E)-2-chloro-1-methyl-6-oxo-4-(6,8,8,9,9-pentamethyl-4,7-dioxa-3-aza-8-siladec-2-en-1-yl)-1,6-dihydropyridine-3-carboxylate (63.4 mg, 0.147 mmol) was dissolved in 2-propanol (1 mL). Sodium cyanoborohydride (46.2 mg, 0.735 mmol) and acetic acid (42.1 μL, 0.735 mmol) were added. The mixture was stirred at room temperature for 16 h. The reaction mixture was partitioned between saturated aqueous sodium bicarbonate (30 mL) and EtOAc (20 mL). The aqueous layer was washed with EtOAc (2×15 mL). The combined organic layers were washed with brine (20 mL), dried over sodium sulfate, filtered, and concentrated. The residue was purified by column chromatography eluting with 0-40% EtOAc/hexanes to give methyl (S)-2-chloro-1-methyl-6-oxo-4-(6,8,8,9,9-pentamethyl-4,7-dioxa-3-aza-8-siladecyl)-1,6-dihydropyridine-3-carboxylate (30.6 mg, 48%). MS (atmospheric pressure chemical ionization (apci), m/z)=433.2 (M+H).

Step 4. Preparation of (S)-2-(2-((tert-butyldimethylsilyl)oxy)propoxy)-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 2-fluoro-4-iodoaniline (16.9 mg, 0.071 mmol) in anhydrous THF (1 mL) at -78 °C under N ₂ was added LiHMDS (0.141 mL, 1M/THF, 0.141 mmol). The mixture was stirred for 45 min, then a solution of methyl (S)-2-chloro-1-methyl-6-oxo-4-(6,8,8,9,9-pentamethyl-4,7-dioxa-3-aza-8-siladecyl)-1,6-dihydropyridine-3-carboxylate (30.6 mg, 0.071 mmol) in THF (0.5 mL) was added. The mixture was stirred at -78 °C for 10 min. The mixture was quenched with saturated aqueous NH4Cl (30 mL), stirred at ambient temperature for 10 min, then extracted with EtOAc (3×10 mL). The combined organic layers were washed with brine (20 mL), dried over sodium sulfate, filtered, and concentrated. The residue was purified by column chromatography eluting with 0-50% EtOAc/hexanes to give (S)-2-(2-((tert-butyldimethylsilyl)oxy)propoxy)-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (15.2 mg, 36%). MS (atmospheric pressure chemical ionization (apci), m/z)=602.2 (M+H).

Step 5. Preparation of (S)-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (S)-2-(2-((tert-butyldimethylsilyl)oxy)propoxy)-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (15.2 mg, 0.025 mmol) was dissolved in MeOH (0.5 mL). The reaction mixture was treated with HCl (12.6 μL, 4N/dioxane, 0.051 mmol) and stirred for 1 h. The reaction mixture was concentrated and the residue was purified by reverse phase HPLC (5-95% acetonitrile/water/0.1% TFA over 20 min) and the pure fractions were combined, washed with saturated aqueous sodium bicarbonate and extracted with EtOAc (3×20 mL). The combined organic layers were washed with saturated aqueous sodium bicarbonate (15 mL) and brine (15 mL), dried over sodium sulfate, filtered and concentrated to give (S)-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (6.8 mg, 55%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.16 (s, 1H), 7.48 (dd, 1H), 7.42 (dt, 1H), 6.62 (t, 1H), 6.00 (s, 1H), 4.05-3.91 (m, 2H), 3.78-3.60 (m, 3H), 3.17 (s, 3H), 3.10-2.90 (m, 2H), 1.15 (d, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=488.0 (M+H).

Example 32

(R)-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as in Example 31, except using (R)-O-(2-((tert-butyldimethylsilyl)oxy)propyl)hydroxylamine instead of (S)-O-(2-((tert-butyldimethylsilyl)oxy)propyl)hydroxylamine in step 1, to give (R)-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (8.6 mg, 49%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.16 (s, 1H), 7.48 (dd, 1H), 7.42 (dt, 1H), 6.62 (t, 1H), 5.99 (s, 1H), 4.05-3.91 (m, 2H), 3.78-3.60 (m, 3H), 3.17 (s, 3H), 3.09-2.90 (m, 2H), 1.15 (d, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=488.0 (M+H).

Example 33

(S)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same method as in Example 31, except using 4-bromo-2-fluoroaniline instead of 2-fluoro-4-iodoaniline in step 4, to give (S)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (9.2 mg, 55%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.16 (s, 1H), 7.32 (dd, 1H), 7.26-7.22 (m, 1H), 6.78 (t, 1H), 5.99 (s, 1H), 4.05-3.92 (m, 2H), 3.78-3.60 (m, 3H), 3.17 (s, 3H), 3.10-2.90 (m, 2H), 1.15 (d, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=440.1, 442.1 (M+H).

Example 34

(R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as in Example 31, except using (R)-O-(2-((tert-butyldimethylsilyl)oxy)propyl)hydroxylamine instead of (S)-O-(2-((tert-butyldimethylsilyl)oxy)propyl)hydroxylamine in step 1, and 4-bromo-2-fluoroaniline instead of 2-fluoro-4-iodoaniline in step 4 to give (R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (9.2 mg, 55%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.17 (s, 1H), 7.32 (dd, 1H), 7.24 (dt, 1H), 6.78 (t, 1H), 5.99 (s, 1H), 4.06-3.91 (m, 2H), 3.78-3.60 (m, 3H), 3.17 (s, 3H), 3.10-2.90 (m, 2H), 1.15 (d, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=440.0 (M+H).

Example 35

(R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Steps 1-4: Preparation of (R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-((tert-butyldimethylsilyl)oxy)propoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared by the same method as Example 31 in steps 1-4 except using (R)-O-(2-((tert-butyldimethylsilyl)oxy)propyl)hydroxylamine instead of (S)-O-(2-((tert-butyldimethylsilyl)oxy)propyl)hydroxylamine in step 1 to give (R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-((tert-butyldimethylsilyl)oxy)propoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (63.5 mg, 62%). MS (atmospheric pressure chemical ionization (apci), m/z)=554.1 (M+H).

Step 5. Preparation of (R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. (R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-((tert-butyldimethylsilyl)oxy)propoxy)-7-methyl-3,4-dihydro-2, 7-naphthyridine-1,6(2H,7H)-dione (42.3 mg, 0.076 mmol) was dissolved in THF (1 mL) and MeOH (1 mL). p-Toluenesulfonic acid monohydrate (21.8 mg, 0.114 mmol) was added. After 5 min, N-iodosuccinimide (17.2 mg, 0.076 mmol) was added and stirred for 30 min. The reaction mixture was partitioned between EtOAc (15 mL) and saturated aqueous sodium bicarbonate (30 mL), and the aqueous layer was extracted with EtOAc (2×10 mL). The combined organic layers were washed with brine (25 mL), dried over sodium sulfate, filtered, and concentrated. The residue was purified by column chromatography eluting with 0-50% EtOAc/heptane to give (R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (23.8 mg, 54%). MS (atmospheric pressure chemical ionization (apci), m/z)=566.0 (M+H).

Step 6. Preparation of (R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of (R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (21.7 mg, 0.038 mmol) in THF (400 μL) at 0 °C was added Pd(Pt-Bu ₃ ) ₂ (1.96 mg, 0.004 mmol), followed by methylzinc(II) chloride (19.4 μL, 0.039 mmol). The mixture was removed from the ice bath and stirred for 5 min. The mixture was partitioned between saturated aqueous NH ₄ Cl (20 mL) and EtOAc (15 mL). The aqueous layer was extracted with EtOAc (2×10 mL). The combined organic layers were washed with brine (20 mL), dried over sodium sulfate, filtered, and concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/water/0.1% TFA over 20 min), and the pure fractions were combined, washed with saturated aqueous sodium bicarbonate, and extracted with EtOAc (3×10 mL). The combined organic layers were washed with saturated aqueous sodium bicarbonate (25 mL) and brine (30 mL), dried over sodium sulfate, filtered, and concentrated to give (R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (7.5 mg, 43%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 10.97 (s, 1H), 7.30 (dd, 1H), 7.19 (dt, 1H), 6.68 (t, 1H), 4.05-3.91 (m, 2H), 3.71 (m, 2H), 3.64 (m, 1H), 3.22 (s, 3H), 3.13-3.04 (m, 1H), 3.03-2.92 (m, 1H), 2.08 (s, 3H), 1.14 (d, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=454.1 (M+H).

Example 36

8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 4-bromo-2-fluoroaniline (88 mg, 0.47 mmol) in anhydrous THF (5 mL) at -78°C under _N2 was added LiHMDS (694 mL, 1.0 M/THF, 0.694 mmol). The mixture was stirred for 45 min, then a solution of methyl 4-(2-((2-(tertbutoxy)ethoxy)amino)ethyl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (167 mg, 0.46 mmol) in THF (2 mL) was added. Stirring was continued at -78 °C for 10 min, then LiHMDS (300 mL, 1.0 M/THF, 0.300 mmol) was added. After stirring for another 10 min at -78 °C, LiHMDS (100 mL, 1.0 M/THF, 0.100 mmol) was added and stirring was continued for 10 min. The mixture was quenched with saturated aqueous NH ₄ Cl (10 mL), stirred at ambient temperature for 10 min, then extracted with EtOAc (3×10 mL). The combined organic layers were washed with brine (10 mL), dried over Na ₂ SO ₄ , filtered, and concentrated. The residue was purified by column chromatography eluting with 0-15% (20% MeOH/DCM)/DCM to give 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (78 mg, 35%). MS (atmospheric pressure chemical ionization (apci), m/z) = 482.1 (M+H).

Step 2. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (78 mg, 0.16 mmol) in THF (2 mL) and MeOH (2 mL) was added p-toluenesulfonic acid monohydrate (46 mg, 0.24 mmol). After 5 min, N-iodosuccinimide (36 mg, 0.16 mmol) was added. After stirring at ambient temperature for 30 min, the reaction mixture was partitioned between EtOAc (10 mL) and saturated aqueous NaHCO ₃ (10 mL). The aqueous solution was extracted with EtOAc (2×10 mL), and the combined organic layers were washed with brine (10 mL), dried over Na ₂ SO ₄ , filtered, and concentrated. The residue was purified by column chromatography eluting with 0-30% EtOAc/hexanes to give 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tert-butoxy)ethoxy)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (62 mg, 63%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.54 (s, 1H), 7.31 (dd, 1H), 7.22 (m, 1H), 6.73 (t, 1H), 4.17-4.13 (m, 2H), 3.80 (t, 2H), 3.63-3.59 (m, 2H), 3.2 7 (s, 3H), 3.17 (t, 2H), 1.22 (s, 9H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=608.0 (M+H).

Step 3. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tert-butoxy)ethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (62 mg, 0.10 mmol) in anhydrous THF (2 mL) at 0 °C was added Pd(Pt-Bu ₃ ) ₂ (5 mg, 0.01 mmol), followed by methylzinc(II) chloride (61 mL, 2M/THF, 0.12 mmol). The mixture was removed from the ice bath and stirred for 5 min, then partitioned between saturated aqueous NH ₄ Cl (10 mL) and EtOAc (10 mL). The aqueous layer was extracted with EtOAc (2×10 mL), and the combined organic layers were washed with brine (10 mL), dried over _{Na2SO4 ,} filtered, and concentrated. The residue was purified by column chromatography eluting with 0-60% EtOAc/hexanes to give 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tert-butoxy)ethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (39 mg, 77%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.11 (s, 1H), 7.28 (dd, 1H), 7.16 (dt, 1H), 6.61 (t, 1H), 4.17-4.13 (m, 2H), 3.78 (t, 2H), 3.64-3.59 (m, 2H), 3.25 (s, 3H), 3.02 (t, 2H), 2.09 (s, 3H), 1.22 (s, 9H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=496.1 (M+H).

Step 4. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (39 mg, 0.079 mmol) in acetonitrile (0.5 mL) was added phosphoric acid (0.5 mL). The mixture was heated to 60°C for 1 h, then cooled to ambient temperature. The mixture was stirred with saturated aqueous _NaHCO3 (10 mL) and EtOAc (10 mL) for 10 min and the layers were separated. The aqueous layer was extracted with EtOAc (2×10 mL) and the combined organic layers were washed with brine (10 mL), dried over _{Na2SO4 ,} filtered and concentrated. The residue was purified by reverse phase HPLC (0-95% acetonitrile/water/0.1% TFA over 20 min) and the purified fractions were triturated with saturated aqueous _NaHCO3 /EtOAc to give 8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (18 mg, 52%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 10.96 (s, 1H), 7.31 (dd, 1H), 7.20 (dt, 1H), 6.68 (t, 1H), 4.05-4.01 (m, 2H), 3.75-3.69 (m, 4H), 3.23 (s, 3H), 3.03 (t, 2H), 2.08 (s, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=440.0 (M+H).

Example 37

8-((4-bromo-2-fluorophenyl)amino)-5-chloro-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione Prepared by the same procedure as Example 6, steps 1-7 in Method A, except using 4-bromo-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline in Step 7, to give 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (28 mg, 35%). MS (atmospheric pressure chemical ionization (apci), m/z)=482.1 (M+H).

Step 2. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-5-chloro-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (28 mg, 0.058 mmol) in DMF (0.5 mL) was added NCS (8 mg, 0.058 mmol). The mixture was stirred at ambient temperature for 1 h, then at 50 °C for 2 h. The cooled mixture was partitioned between saturated _NaHCO3 solution (10 mL) and EtOAc (10 mL), and the aqueous layer was extracted with EtOAc (2×10 mL). The combined organic layers were washed with water (5×10 mL) and brine (10 mL), then dried over _Na2SO4 , filtered and concentrated. The residue was purified by column chromatography eluting with 0-50% _EtOAc /hexanes to give 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-5-chloro-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (14 mg, 47%). MS (atmospheric pressure chemical ionization (apci), m/z)=516.0 (M+H).

Step 3. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-5-chloro-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-5-chloro-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (14 mg, 0.027 mmol) in acetonitrile (0.5 mL) was added phosphoric acid (0.5 mL). The mixture was heated to 60°C for 30 min, then cooled to ambient temperature. The mixture was stirred with saturated aqueous _NaHCO3 (10 mL) and EtOAc (10 mL) for 10 min and the layers were separated. The aqueous layer was extracted with EtOAc (2×10 mL) and the combined organic layers were washed with brine (10 mL), dried over _{Na2SO4 ,} filtered and concentrated. The residue was purified by column chromatography eluting with 0-15% (20% MeOH/DCM)/DCM to give 8-((4-bromo-2-fluorophenyl)amino)-5-chloro-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (11 mg, 88%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.22 (s, 1H), 7.33 (dd, 1H), 7.26 (dt, 1H), 6.78 (t, 1H), 4.07-4.02 (m, 2H), 3.78-3.70 (m, 4H), 3.25 (s, 3H), 3.22 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=460.0 (M+H).

Example 38

5-chloro-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same method as in Example 37, except using 4-iodo-2-fluoroaniline instead of 4-bromo-2-fluoroaniline in step 1, to give 5-chloro-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (10 mg, 93%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.21 (s, 1H), 7.49 (dd, 1H), 7.43 (dt, 1H), 6.63 (t, 1H), 4.25-4.17 (m, 1H), 4.07-4.02 (m, 2H), 3.79-3.70 (m, 4H), 3.25 (s, 3H), 3.22 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=508.0 (M+H).

Example 39

8-((4-bromo-2-fluorophenyl)amino)-5-fluoro-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tert-butoxy)ethoxy)-5-fluoro-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. A solution of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (77 mg, 0.16 mmol) and 1-(chloromethyl)-4-fluoro-1,4-diazabicyclo[2.2.2]octan-1,4-dium tetrafluoroborate (57 mg, 0.16 mmol) in acetonitrile (9.0 mL) was stirred at 0 °C for 1 h. The reaction mixture was diluted with EtOAc (50 mL) and washed with water (25 mL) then brine (25 mL). The organic phase was dried over Na ₂ SO ₄ , filtered and concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/water/0.1% TFA over 20 min). Fractions containing the desired product were combined and diluted with saturated aqueous _NaHCO3 ( ₁₅ mL) then extracted with EtOAc (2×25 mL). The organic phases were combined and dried over _Na2SO4 , filtered and concentrated to give 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-5-fluoro-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (10 mg, 13%). MS (atmospheric pressure chemical ionization (apci), m/z)=500.1 (M+H).

Step 2. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-5-fluoro-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione A solution of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-5-fluoro-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (13 mg, 0.026 mmol) and concentrated H ₃ PO ₄ (0.20 mL, 3.0 mmol) in acetonitrile (1.0 mL) was stirred at 60°C for 1 h. The reaction mixture was concentrated, then diluted with _K3PO4 solution (1 M in water, 3.0 mL, 3.0 mmol). The aqueous phase was extracted with EtOAc (2× ₁₅ mL), and the organic phases were combined, dried over _Na2SO4 , filtered, and concentrated. The residue was purified by HPLC (10-95% _acetonitrile /water/0.1% TFA). Fractions containing the desired product were combined and diluted with saturated aqueous _NaHCO3 (15 mL). The aqueous solution was extracted with EtOAc (2×15 mL) and the organic phases were combined, _dried over _Na2SO4 , filtered and concentrated to give 8-((4-bromo-2-fluorophenyl)amino)-5-fluoro-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (5.0 mg, 43%). 1H NMR (400 MHz, CDCl ₃ ) δ 10.79 (s, 1H), 7.34-7.30 (m, 1H), 7.25-7.21 (m, 1H), 6.72 (t, 1H), 4.23 (t, 1H), 4.06-4.02 (m, 2H), 3, 80-3, (m, 4H), 3.25 (s, 3H), 3.17-3.12 (m, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=444.0 (M+H).

Example 40

8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Obtaining 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-iodophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. 8-((4-Bromo-2-fluorophenyl)amino)-2-(2-(tert-butoxy)ethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (prepared in the same manner as in Example 36, steps 1-3; 65 mg, 0.13 mmol), copper(I) iodide (6.2 mg, 0.033 mmol), sodium iodide (39 mg, 0.26 mmol) and (1S,2S)-N1,N2-dimethylcyclohexane-1,2-diamine (9.3 mg, 0.065 mmol) were combined in 1,4-dioxane (1 ml) and sparged with argon. The mixture was heated at 110 °C for 18 h, then at ambient temperature for 48 h. The mixture was partitioned between EtOAc (20 mL) and ammonium hydroxide solution (10 mL/water 10 mL). The organic phase was separated and the aqueous phase was extracted with EtOAc (2 x 10 mL). The combined organic phases were washed with brine (10 mL), dried over Na ₂ SO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-80% EtOAc/heptane to give 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-iodophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (49 mg, 69%). MS (atmospheric pressure chemical ionization (apci), m/z)=544.1 (M+H).

Step 2. Preparation of 8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-iodophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (49 mg, 0.09 mmol) in acetonitrile (1 mL) was added phosphoric acid (0.5 mL). The mixture was heated to 60°C for 1 h, then cooled to ambient temperature. The mixture was stirred with saturated aqueous NaHCO ₃ (10 mL) and EtOAc (10 mL) for 10 min, and the layers were separated. The aqueous layer was extracted with EtOAc (2×10 mL), and the combined organic layers were washed with brine (10 mL), dried over Na ₂ SO ₄ , filtered, and concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/ _H2O /0, 1% TFA over 20 min) and the purified fractions were triturated with EtOAc/saturated aqueous _NaHCO3 to give 8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (23 mg, 52%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 10.95 (s, 1H), 7.47 (dd, 1H), 7.37 (dt, 1H), 6.52 (t, 1H), 4.05-4.02 (m, 2H), 3.75-3.65 (m, 4H), 3.24 (s, 3H), 3.03 (t, 2H), 3.02 (s, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=488.0 (M+H).

Example 41

8-((2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of methyl 4-bromo-2-((2-fluorophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. To a solution of 2-fluoroaniline (100 mg, 0.90 mmol) in anhydrous THF (5 mL) at -78 °C under N ₂ was added LiHMDS (1.34 mL, 1.0 M/THF, 1.34 mmol). The mixture was stirred for 45 min, then a solution of methyl 4-bromo-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (250 mg, 0.89 mmol) in THF (5 mL) was added. The mixture was stirred at -78 °C for 50 min. Additional LiHMDS (0.5 mL, 1.0 M/THF, 0.5 mmol) was added and stirring was continued for an additional 10 min. The mixture was quenched with saturated aqueous _NH4Cl (20 mL), stirred at ambient temperature for 10 min, then extracted with EtOAc (3×20 mL). The combined organic layers were washed with brine (10 mL), dried over sodium sulfate, filtered, and concentrated to give methyl 4-bromo-2-((2-fluorophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (291 mg, 92%). MS (atmospheric pressure chemical ionization (apci), m/z) = 355.0 (M+H).

Step 2. Obtaining methyl (E)-4-(2-ethoxyvinyl)-2-((2-fluorophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. Methyl 4-bromo-2-((2-fluorophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (188 mg, 0.529 mmol), methanesulfonato(2-dicyclohexylphosphino-2',6'-diisopropoxy-1,1'-biphenyl)'2-amino-1,1'-biphenyl-2-yl)palladium(II) (44.3 g, 0.053 mmol) and (E)-2-(2-ethoxyvinyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (123 μL, 0.582 mmol) were suspended in 1,4-dioxane (5 mL) and potassium carbonate (0.397 mL, 2N aqueous solution, 0.794 mmol) was added. After degassing with argon, the mixture was stirred at ambient temperature for 2-3 h. The reaction mixture was partitioned between water (40 mL) and EtOAc (30 mL). The aqueous layer was washed with EtOAc (2×15 mL). The combined organic layers were washed with brine (40 mL), dried over sodium sulfate, and concentrated. The residue was purified by column chromatography eluting with 0-50% EtOAc/hexanes to give methyl (E)-4-(2-ethoxyvinyl)-2-((2-fluorophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (91.5 mg, 50%). MS (atmospheric pressure chemical ionization (apci), m/z) = 347.1 (M+H).

Step 3. Preparation of methyl (E)-4-(2-((2-(tertbutoxy)-ethoxy)imino)ethyl)-2-((2-fluorophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate Methyl (E)-4-(2-ethoxyvinyl)-2-((2-fluorophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (91.5 mg, 0.264 mmol) and O-(2-(tertbutoxy)ethyl)hydroxylamine hydrochloride (44.8 mg, 0.264 mmol) were taken up in 1,4-dioxane (2 mL). TEA (36.8 μL, 0.264 mmol) and HCl (66 μL, 4N/dioxane, 0.264 mmol) were added. The suspension was heated to 60 °C. After 2 h, additional HCl (66 μL, 4N/dioxane, 0.264 mmol) was added and stirring was continued at 60 °C for another 2 h. The reaction mixture was filtered and concentrated. The residue was purified by column chromatography eluting with 0-40% EtOAc/hexanes to give methyl (E)-4-(2-((2-(tertbutoxy)ethoxy)imino)ethyl)-2-((2-fluorophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (67.6 mg, 59%). MS (atmospheric pressure chemical ionization (apci), m/z)=434.2 (M+H).

Step 4. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione Methyl (E)-4-(2-((2-(tertbutoxy)ethoxy)imino)ethyl)-2-((2-fluorophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (67.6 mg, 0.156 mmol) was dissolved in MeOH (1.0 mL) and 2-propanol (1.0 mL). Sodium cyanoborohydride (49 mg, 0.780 mmol) and acetic acid (44.6 μL, 0.780 mmol) were added and the mixture was stirred at ambient temperature for 16 h. The reaction mixture was heated at 40 °C for 16 h. The reaction mixture was partitioned between saturated aqueous sodium bicarbonate (20 mL) and EtOAc (10 mL). The aqueous layer was washed with EtOAc (2×10 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated. The residue was purified by column chromatography eluting with 0-80% EtOAc/hexanes to give 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (37.8 mg, 60%). MS (atmospheric pressure chemical ionization (apci), m/z)=404.2 (M+H).

Step 5. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (19 mg, 0.047 mmol) was dissolved in THF (0.5 mL) and MeOH (0.5 mL). p-Toluenesulfonic acid monohydrate (13 mg, 0.071 mmol) was added. After 5 min, N-iodosuccinimide (11 mg, 0.047 mmol) was added and the mixture was stirred for 1 h. The reaction mixture was partitioned between EtOAc (20 mL) and saturated aqueous sodium bicarbonate (40 mL). The aqueous layer was washed with EtOAc (2×15 mL). The combined organic layers were washed with brine (20 mL), dried over sodium sulfate, filtered, and concentrated. The residue was purified by column chromatography eluting with 0–30% EtOAc/hexanes to give 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (9.9 mg, 40%). MS (atmospheric pressure chemical ionization (apci), m/z) = 530.1 (M+H).

Step 6. Preparation of 8-((2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (9.9 mg, 0.019 mmol) was dissolved in acetonitrile (0.5 mL) and phosphoric acid (0.5 mL) was added. The solution was heated to 60 °C for 1 h. The reaction mixture was partitioned between saturated aqueous sodium bicarbonate (15 mL) and EtOAc (10 mL). The aqueous layer was washed with EtOAc (2×8 mL). The combined organic layers were washed with brine (15 mL), dried over sodium sulfate, filtered, and concentrated. The residue was purified by reverse-phase HPLC (5-95% acetonitrile/water/0.1% TFA over 20 min), and the pure fractions were combined, washed with saturated aqueous sodium bicarbonate, and extracted with EtOAc (3×10 mL). The combined organic layers were washed with saturated aqueous sodium bicarbonate (20 mL) and brine (20 mL), dried over sodium sulfate, filtered and concentrated to give (8-((2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (4.5 mg, 51%). ¹ H NMR (400 MHz, _CDCl3 ) δ 11.41 (s, 1H), 7.21-7.08 (m, 3H), 6.94 (t, 1H), 4.04 (t, 2H), 3.76-3.69 (m, 4H), 3.25 (s, 3H), 3.19 (t, 2H) ppm; MS (chemical atmospheric pressure ionization (APCI), m/z)=474.0 (M+H).

Example 42

5-bromo-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as in Example 41, except using 4-bromo-2-fluoroaniline instead of 2-fluoroaniline in step 1, and N-bromosuccinimide in step 5, to give 5-bromo-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (6.5 mg, 29%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.28 (s, 1H), 7.33 (dd, 1H), 7.25 (m, 1H), 6.80 (t, 1H), 4.05 (t, 2H), 3.78-3.70 (m, 4H), 3.25 (s, 3H), 3.22 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=504.0 (M+H).

Example 4 3

4-bromo-8-((2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (75 mg, 0.14 mmol) in anhydrous THF (5 mL) at ambient temperature was added methylzinc(II) chloride (140 mL, 2 M, 0.14 mmol). After stirring for 5 min, the mixture was concentrated. The residue was purified by column chromatography eluting with 0-80% EtOAc/hexanes to give 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (38 mg, 64%). MS (atmospheric pressure chemical ionization (apci), m/z)=418.2 (M+H).

Step 2. Preparation of 4-bromo-2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (38 mg, 0.09 mmol) in anhydrous DMF (1 mL) was added NBS (17 mg, 0.09 mmol). The mixture was stirred at ambient temperature for 2 h, then partitioned between saturated NaHCO ₃ solution (10 mL) and EtOAc (10 mL). The aqueous layer was extracted with EtOAc (2×10 mL) and the combined organic layers were washed with water (5×10 mL) and brine (10 mL), then dried over _Na2SO4 , filtered and concentrated. The residue was purified by column chromatography eluting with 0-60% _EtOAc /hexanes to give 4-bromo-2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (30 mg, 66%). MS (atmospheric pressure chemical ionization (apci), m/z) = 496.2 (M+H).

Step 3. Preparation of 4-bromo-8-((2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-

4-bromo-8-((2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (75 mg, 0.14 mmol) in anhydrous THF (5 mL) at ambient temperature was added methylzinc(II) chloride (140 mL, 2 M, 0.14 mmol). After stirring for 5 min, the mixture was concentrated. The residue was purified by column chromatography eluting with 0-80% EtOAc/hexanes to give 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (38 mg, 64%). MS (atmospheric pressure chemical ionization (apci), m/z)=418.2 (M+H).

Step 2. Preparation of 4-bromo-2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (38 mg, 0.09 mmol) in anhydrous DMF (1 mL) was added NBS (17 mg, 0.09 mmol). The mixture was stirred at ambient temperature for 2 h, then partitioned between saturated NaHCO ₃ solution (10 mL) and EtOAc (10 mL). The aqueous layer was extracted with EtOAc (2×10 mL) and the combined organic layers were washed with water (5×10 mL) and brine (10 mL), then dried over _Na2SO4 , filtered and concentrated. The residue was purified by column chromatography eluting with 0-60% _EtOAc /hexanes to give 4-bromo-2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (30 mg, 66%). MS (atmospheric pressure chemical ionization (apci), m/z) = 496.2 (M+H).

Step 3. Preparation of 4-bromo-8-((2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Phosphoric acid (0.5 mL) was added to a solution of 4-bromo-2-(2-(tertbutoxy)ethoxy)-8-((2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (30 mg, 0.060 mmol) in acetonitrile (0.5 mL). The mixture was heated to 60 °C for 1 h, then cooled and stirred with saturated aqueous NaHCO ₃ (10 mL) and EtOAc (10 mL) for 10 min. The layers were separated and the aqueous layer was extracted with EtOAc (2 x 10 mL). The combined organic layers were washed with brine (10 mL), dried over Na ₂ SO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-15% (20% MeOH/DCM)/DCM to give 4-bromo-8-((2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (10 mg, 38%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.08 (s, 1H), 7.15-7.05 (m, 2H), 6.86 (t, 1H), 5.36 (t, 1H), 4.17-4.04 (m, 3H), 3.99-3.92 (m, 1H), 3.88 (dd, 1H), 3.68 (dt, 1H), 3.21 (s, 3H), 2.17 (s, 3H), 1.26 (t, 1H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=440.1 (M+H).

Example 44

8-((4-ethyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of methyl (Z)-4-(2-ethoxyvinyl)-2-((4-ethyl-2-fluorophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. To a solution of 4-ethyl-2-fluoroaniline (155 mg, 1.12 mmol) in anhydrous THF (2 mL) at -78 °C under N ₂ was added LiHMDS (2.21 mL, 1 M/THF, 2.21 mmol). The mixture was stirred for 40 min, then a solution of methyl (Z)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (300 mg, 1.10 mmol) in THF (1 mL) was added via syringe. The mixture was stirred at -78 °C for 45 min. The mixture was quenched with saturated aqueous NH ₄ Cl (35 mL), stirred at ambient temperature for 5 min, then extracted with EtOAc (3 x 15 mL). The combined organic layers were washed with brine (30 mL), dried over sodium sulfate, filtered, and concentrated. The residue was purified by column chromatography eluting with 0-50% EtOAc/heptane to give methyl (Z)-4-(2-ethoxyvinyl)-2-((4-ethyl-2-fluorophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (298 mg, 72%). MS (atmospheric pressure chemical ionization (apci), m/z) = 375.2 (M+H).

Step 2. Preparation of methyl 2-((4-ethyl-2-fluorophenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate. Methyl (Z)-4-(2-ethoxyvinyl)-2-((4-ethyl-2-fluorophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (298 mg, 0.797 mmol) was dissolved in DCM (800 μL) and TFA (921 μL, 11.9 mmol) was added. The reaction mixture was stirred at ambient temperature for 16 h. The mixture was partitioned between DCM (20 mL) and saturated aqueous sodium bicarbonate (35 mL). The aqueous layer was washed with DCM (2×15 mL). The combined organic layers were washed with saturated aqueous sodium bicarbonate (30 mL), dried over sodium sulfate, filtered and concentrated to give methyl 2-((4-ethyl-2-fluorophenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate (276 mg, 100%). MS (atmospheric pressure chemical ionization (APCI), m/z)=347.1 (M+H).

Step 3. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((4-ethyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione Methyl 2-((4-ethyl-2-fluorophenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate (276 mg, 0.797 mmol), O-(2-(tertbutoxy)ethyl)hydroxylamine hydrochloride (117 mg, 0.876 mmol), sodium triacetoxyhydroborate (203 mg, 0.956 mmol), and acetic acid (45.6 μL, 0.797 mmol) were taken up in DCE (8 mL). The reaction mixture was stirred at ambient temperature for 1 h. The reaction mixture was heated to 55 °C for 20 min. To the reaction mixture was added more sodium triacetoxyhydroborate (400 mg) and acetic acid (90 μL), and stirred at ambient temperature for 16 h. To the reaction mixture was added sodium cyanoborohydride (250 mg, 3.98 mmol) and acetic acid (250 μL), and stirred at ambient temperature for 3 h. The solution was partitioned between DCM (40 mL) and saturated aqueous sodium bicarbonate (70 mL). The aqueous layer was washed with DCM (2 x 20 mL). The combined organic layers were washed with brine (50 mL), dried over sodium sulfate, filtered, and concentrated. The residue was purified by column chromatography eluting with 0-100% EtOAc/heptane to give 2-(2-(tertbutoxy)ethoxy)-8-((4-ethyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (137 mg, 40%). MS (atmospheric pressure chemical ionization (apci), m/z)=432.2 (M+H).

Step 4. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((4-ethyl-2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. 2-(2-(tertbutoxy)ethoxy)-8-((4-ethyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (137 mg, 0.317 mmol) was dissolved in THF (1 mL)/MeOH (1 mL). p-Toluenesulfonic acid monohydrate (90.4 mg, 0.475 mmol) was added. After 5 min, N-iodosuccinimide (71.3 mg, 0.317 mmol) was added and stirred for 30 min. The reaction mixture was partitioned between EtOAc (20 mL) and saturated aqueous sodium bicarbonate (30 mL), and the aqueous layer was extracted with EtOAc (2×10 mL). The combined organic layers were washed with brine (25 mL), dried over sodium sulfate, filtered, and concentrated to give 2-(2-(tertbutoxy)ethoxy)-8-((4-ethyl-2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (143 mg, 81%). MS (atmospheric pressure chemical ionization (apci), m/z) = 558.1 (M+H).

Step 5. Preparation of 2-(2-(tert-butoxy)ethoxy)-8-((4-ethyl-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 2-(2-(tertbutoxy)ethoxy)-8-((4-ethyl-2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (143 mg, 0.256 mmol) in THF (2.5 mL, 0.256 mmol) at 0 °C was added Pd(Pt-Bu ₃ ) ₂ (13.1 mg, 0.026 mmol), followed by methylzinc(II) chloride (130 μL, 0.259 mmol). The mixture was removed from the ice bath and stirred for 45 min. The mixture was partitioned between saturated aqueous NH ₄ Cl (50 mL) and EtOAc (20 mL), and the aqueous layer was extracted with EtOAc (2×15 mL). The combined organic layers were washed with brine (40 mL), dried over sodium sulfate, filtered and concentrated. The residue was purified by column chromatography eluting with 0-50% EtOAc/heptane to give 2-(2-(tertbutoxy)ethoxy)-8-((4-ethyl-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (53.7 mg, 47%). MS (atmospheric pressure chemical ionization (apci), m/z) = 446.2 (M+H).

Step 6. Preparation of 8-((4-ethyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione 2-(2-(tert-butoxy)ethoxy)-8-((4-ethyl-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (53.7 mg, 0.121 mmol) was dissolved in acetonitrile (0.75 mL) and phosphoric acid (0.75 mL) was added. The reaction mixture was heated to 60 °C for 60 min. The reaction mixture was partitioned between saturated aqueous sodium bicarbonate (40 mL) and EtOAc (20 mL). The aqueous layer was washed with EtOAc (2×10 mL). The combined organic layers were washed with saturated aqueous sodium bicarbonate (30 mL) and brine (25 mL), dried over sodium sulfate, filtered and concentrated. The residue was purified by column chromatography eluting with 0-100% EtOAc/heptane to give 8-((4-ethyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (40.6 mg, 87%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.01 (s, 1H), 6.95 (dd, 1H), 6.89 (dd, 1H), 6.77 (t, 1H), 4.53 (t, 1H), 4.02 (t, 2H), 3.75-3.67 (m, 4H), 3.20 (s, 3H), 3.02 (t, 2H), 2.62 (qt, 2H), 2.08 (s, 3H), 1.22 (t, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=390.2 (M+H).

Example 45

8-((4-cyclopropyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as in Example 44 except using 4-cyclopropyl-2-fluoroaniline instead of 4-ethyl-2-fluoroaniline in step 1 to give 8-((4-cyclopropyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (30.7 mg, 75%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.00 (s, 1H), 6.81-6.71 (m, 3H), 4.52 (t, 1H), 4.02 (m, 2H), 3.75-3.66 (m, 4H), 3.19 (s, 3H), 3.02 (t, 2H), 2.07 (s, 3H), 1.86 (m, 1H), 1.02-0.95 (m, 2H), 0.69-0.63 (m, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=402.2 (M+H).

Example 46

8-((4-bromo-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione trifluoroacetate

Step 1. Preparation of methyl (E)-2-((4-bromo-2-fluorophenyl)amino)-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate 4-Bromo-2-fluoroaniline (492 mg, 2.59 mmol) and methyl (E)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (670 mg, 2.47 mmol) were dissolved in THF (12.3 mL, 0.2 M) and cooled to -78°C under nitrogen atmosphere. LiHMDS (4.9 mL, 1.0 M/THF, 4.9 mmol) was added dropwise, then the mixture was warmed from -78 °C to ambient temperature over 1 h. The reaction mixture was quenched with saturated aqueous NH ₄ Cl (15 mL), then extracted with EtOAc (2 x 10 mL). The combined organic layers were dried over MgSO ₄ , filtered, and concentrated. The residue was purified by column chromatography eluting with 0-100% EtOAc/heptane to give methyl (E)-2-((4-bromo-2-fluorophenyl)amino)-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (810 mg, 77%). MS (atmospheric pressure chemical ionization (apci), m/z)=425.0 (M+H).

Step 2. Preparation of methyl 2-((4-bromo-2-fluorophenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate. To a solution of methyl (E)-2-((4-bromo-2-fluorophenyl)amino)-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (810 mg, 1.90 mmol) in DCM (5.0 mL) was added TFA (5.0 mL). The solution was stirred at ambient temperature for 16 h, then concentrated. The crude mixture was then diluted with DCM (10 mL) and washed with saturated aqueous NaHCO ₃ (10 mL). The organic phase was dried over _MgSO4 , filtered and concentrated to give methyl 2-((4-bromo-2-fluorophenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate, which was used without further purification (751 mg, 99%). MS (atmospheric pressure chemical ionization (apci), m/z)=397.0, 399.0 (M+H).

Step 3. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-(4-methoxybenzyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione Methyl 2-((4-bromo-2-fluorophenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate (751 mg, 1.89 mmol), (4-methoxyphenyl)methanamine (272 mg, 1.99 mmol), sodium triacetoxyborohydride (441 mg, 2.08 mmol), and acetic acid (11.4 mg, 0.189 mmol) were dissolved in DCE (19 mL) and stirred at ambient temperature for 1 h. The reaction mixture was warmed to 60 °C and stirred for 1 h. The reaction mixture was then cooled to ambient temperature, diluted with DCM (10 mL) and washed with saturated aqueous NaHCO ₃ (15 mL). The organic phase was dried over MgSO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-100% EtOAc/heptane to give 8-((4-bromo-2-fluorophenyl)amino)-2-(4-methoxybenzyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (630 mg, 69%). MS (atmospheric pressure chemical ionization (apci), m/z) = 486.0 (M+H).

Step 4. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione trifluoroacetate. 8-((4-bromo-2-fluorophenyl)amino)-2-(4-methoxybenzyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (630 mg, 1.30 mmol) was dissolved in TFA (8.0 mL) and heated to 80 °C for 16 h. The reaction mixture was cooled to ambient temperature and concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/H ₂ O/0.1% TFA). Fractions containing purified desired product were lyophilized to give 8-((4-bromo-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione trifluoroacetate (226 mg, 48%). ¹ H NMR (400 MHz, _CDCl3 ) δ 11.28 (s, 1H), 7.32-7.29 (m, 1H), 7.23-7.20 (m, 1H), 6.74 (t, 1H), 6.05 (s, 1H), 5.62 (s, 1H), 3.51-3.47 (m, 2H), 3.20 (s, 3H), 2.84 (t, 2H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=366.0, 368.0 (M+H).

Example 47

8-((4-Bromo-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. 8-((4-bromo-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (prepared in the same manner as in Example 46; 41 mg, 0.11 mmol) and p-toluenesulfonic acid (29 mg, 0.17 mmol) were dissolved in 1 mL of 1:1 THF/MeOH. After 5 min, NIS (25 mg, 0.11 mmol) was added. The reaction mixture was stirred at ambient temperature for 30 min. The crude reaction mixture was then partitioned between EtOAc (10 mL) and saturated aqueous NaHCO ₃ (15 mL) and extracted with EtOAc (2×5 mL). The combined organic layers were dried over MgSO ₄ , filtered and concentrated to give 8-((4-bromo-2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione which was used without further purification (55 mg, 100%). MS (atmospheric pressure chemical ionization (apci), m/z) = 493.9 (M+H).

Step 2. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione 8-((4-bromo-2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (55 mg, 0.112 mmol) and bis(tritert-butylphosphine)palladium(0) (5.71 mg, 0.0112 mmol) were dissolved in THF (1.1 mL) and methylzinc(II) chloride (55.9 μL, 2M/THF, 0.112 mmol) was added dropwise. The reaction mixture was stirred at ambient temperature for 1 h. The reaction mixture was quenched with saturated aqueous _NaHCO3 (2 mL) then extracted with EtOAc (2×5 mL). The combined organic layers were dried over _MgSO4 , filtered and concentrated. The residue was purified by reverse phase liquid chromatography eluting with 5-95% acetonitrile/H2O to give 8-((4-bromo-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (24 mg, 56%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.08 (s, 1H), 7.30-7.27 (m, 1H), 7.18-7.15 (m, 1H), 6.63 (t, 1H), 5.72 (s, 1H), 3.50-3.46 (m, 2H), 3.26 (s, 3H), 2.88 (t, 2H), 2.11 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=380.0 (M+H).

Example 48

8-((2-Fluoro-4-iodophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

8-((4-bromo-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (prepared in the same manner as in Example 46; 20 mg, 0.053 mmol), copper(I) iodide (2.5 mg, 0.013 mmol), sodium iodide (16 mg, 0.11 mmol), and (1S,2S)-N1,N2-dimethylcyclohexane-1,2-diamine (3.7 mg, 0.026 mmol) were combined in 1,4-dioxane (0.5 mL). The reaction mixture was heated to 120°C for 16 h. The reaction mixture was then cooled to ambient temperature, quenched with saturated aqueous _NH4Cl (2 mL), then extracted with EtOAc (2×5 mL). The combined organic layers were dried over _MgSO4 , filtered, and concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/ _H2O /0.1% TFA). Fractions containing purified desired product were combined, and the product was converted to the free base form with DCM/ _NaHCO3 to give 8-((2-fluoro-4-iodophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (5.0 mg, 22%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.07 (s, 1H), 7.46-7.43 (m, 1H), 7.36-7.33 (m, 1H), 6.48 (t, 1H), 5.82 (s, 1H), 3.50-3.46 (m, 2H), 3.27 (s, 3H), 2.88 (t, 2H), 2.11 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=428.10 (M+H).

Example 49

8-((4-Iodo-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione trifluoroacetate

Step 1. Preparation of methyl (E)-4-(2-ethoxyvinyl)-2-((2-fluoro-4-iodophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. 4-Iodo-2-fluoroaniline (266 mg, 1.12 mmol) and methyl (E)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (290 mg, 0.920 mmol) were dissolved in THF (9.2 mL) and cooled to -78 °C under N ₂ . LiHMDS (2.1 mL, 1.0 M/THF, 2.1 mmol) was added dropwise, and the mixture was then warmed from -78 °C to ambient temperature over 1 h. The reaction mixture was quenched with saturated aqueous _NH4Cl (10 mL) then extracted with EtOAc (2×10 mL). The combined organic layers were dried over _MgSO4 , filtered and concentrated. The residue was purified by column chromatography eluting with 0-100% EtOAc/heptane to give methyl (E)-4-(2-ethoxyvinyl)-2-((2-fluoro-4-iodophenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (389 mg, 77%). MS (atmospheric pressure chemical ionization (apci), m/z) = 473.1 (M+H).

Step 2. Preparation of methyl 2-((4-iodo-2-fluorophenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate. To a solution of methyl (E)-2-((4-iodo-2-fluorophenyl)amino)-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (389 mg, 0.824 mmol) in DCM (4.0 mL) was added TFA (4.0 mL). The solution was stirred at ambient temperature for 16 h, then concentrated. The crude mixture was then diluted with DCM (10 mL) and washed with saturated aqueous NaHCO ₃ (10 mL). The organic phase was dried over _MgSO4 , filtered and concentrated to give methyl 2-((4-iodo-2-fluorophenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate, which was used directly in the next step without further purification (351 mg, 96%). MS (atmospheric pressure chemical ionization (apci), m/z)=445.0 (M+H).

Step 3. Preparation of 8-((4-iodo-2-fluorophenyl)amino)-2-(4-methoxybenzyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione Methyl 2-((4-iodo-2-fluorophenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate (351 mg, 0.790 mmol), (4-methoxyphenyl)methanamine (114 mg, 0.830 mmol), sodium triacetoxyborohydride (184 mg, 0.869 mmol), and acetic acid (4.8 mg, 0.079 mmol) were dissolved in DCE (10 mL) and stirred at ambient temperature for 1 h. After this, the reaction mixture was warmed to 60 °C and stirred for 1 h. The reaction mixture was then cooled to ambient temperature, diluted with DCM (5 mL) and washed with saturated aqueous NaHCO ₃ (10 mL). The organic phase was dried over MgSO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-100% EtOAc/heptane to give 8-((4-iodo-2-fluorophenyl)amino)-2-(4-methoxybenzyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (321 mg, 76%). MS (atmospheric pressure chemical ionization (apci), m/z) = 534.1 (M+H).

Step 4. Preparation of 8-((4-iodo-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione trifluoroacetate. 8-((4-iodo-2-fluorophenyl)amino)-2-(4-methoxybenzyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (321 mg, 0.602 mmol) was dissolved in TFA (6.0 mL) and heated to 60 °C for 16 h. The reaction mixture was then cooled to ambient temperature and concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/H ₂ O/0.1% TFA). Fractions containing purified desired product were lyophilized to give 8-((4-iodo-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione trifluoroacetate (102 mg, 41%). ¹ H NMR (400 MHz, _CDCl3 ) δ 11.27 (s, 1H), 7.48-7.45 (m, 1H), 7.40-7.38 (m, 1H), 6.58 (t, 1H), 6.05 (s, 1H), 5.84 (s, 1H), 3.51-3.47 (m, 2H), 3.20 (s, 3H), 2.84 (t, 2H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=414.0 (M+H).

Example 50

8-((2-Fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione trifluoroacetate

Step 1. Preparation of methyl (E)-4-(2-ethoxyvinyl)-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate Methyl (E)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (400 mg, 1.47 mmol) and 2-fluoro-4-(methylthio)aniline (243 mg, 1.55 mmol) were dissolved in THF (9.8 mL) and cooled to -78°C under N ₂ . LiHMDS (2.9 mL, 1.0 M/THF, 2.9 mmol) was added dropwise, then the mixture was warmed from -78 °C to ambient temperature over 1 h. The reaction mixture was quenched with saturated aqueous NH ₄ Cl (10 mL), then extracted with EtOAc (2 x 10 mL). The combined organic layers were dried over MgSO ₄ , filtered, and concentrated. The residue was purified by column chromatography eluting with 0-100% EtOAc/heptane to give methyl (E)-4-(2-ethoxyvinyl)-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (495 mg, 86%). MS (atmospheric pressure chemical ionization (apci), m/z)=393.1 (M+H).

Step 2. Preparation of methyl 2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate. To a solution of methyl (E)-4-(2-ethoxyvinyl)-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (495 mg, 1.26 mmol) in DCM (4.0 mL) was added TFA (4.0 mL). The solution was stirred at ambient temperature overnight, then concentrated. The crude mixture was then diluted with DCM (10 mL) and washed with saturated aqueous NaHCO ₃ (10 mL). The organic phase was dried over _MgSO4 , filtered and concentrated to give methyl 2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate, which was used without further purification (391 mg, 85%). MS (atmospheric pressure chemical ionization (apci), m/z)=365.1 (M+H).

Step 3. Preparation of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(4-methoxybenzyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione Methyl 2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-4-(2-oxo-ethyl)-1,6-dihydropyridine-3-carboxylate (391 mg, 1.07 mmol), (4-methoxyphenyl)methanamine (155 mg, 1.13 mmol), sodium triacetoxyborohydride (250 mg, 1.18 mmol), and acetic acid (6.4 mg, 0.079 mmol) were dissolved in DCE (11 mL) and stirred at ambient temperature for 1 h. After this, the reaction mixture was warmed to 60 °C and stirred for 1 h. The reaction mixture was then cooled to ambient temperature, diluted with DCM (5 mL) and washed with saturated aqueous NaHCO ₃ (10 mL). The organic phase was dried over MgSO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-100% EtOAc/heptane to give 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(4-methoxybenzyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (401 mg, 82%). MS (atmospheric pressure chemical ionization (apci), m/z) = 454.1 (M+H).

Step 4. Preparation of 8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione trifluoroacetate. 8-((2-Fluoro-4-(methylthio)phenyl)amino)-2-(4-methoxybenzyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (401 mg, 0.884 mmol) was dissolved in TFA (8.0 mL) and heated to 60 °C for 16 h. The reaction mixture was then cooled to ambient temperature and concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/H ₂ O/0.1% TFA). Fractions containing purified desired product were pooled and lyophilized to give 8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione trifluoroacetate (131 mg, 44%). ¹ H NMR (400 MHz, _CDCl3 ) δ 11.10 (s, 1H), 7.04-6.96 (m, 2H), 6.84 (t, 1H), 6.49 (s, 1H), 6.11 (s, 1H), 3.53-3.49 (m, 2H), 3.20 (s, 3H), 2.85 (t, 2H), 2.48 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=334.1 (M+H).

Example 51

8-((4-Ethyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as Example 50 except using 4-ethyl-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline in step 1 to give 8-((4-ethyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (14.9 mg, 47%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.25 (s, 1H), 6.95 (m, 1H), 6.90 (m, 1H), 6.81 (t, 1H), 6.06 (s, 1H), 5.99 (s, 1H), 3.48 (m, 2H), 3.17 (s, 3H), 2.82 (t, 2H), 2.62 (qt, 2H), 1.22 (t, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=316.1 (M+H).

Example 52

8-((4-Cyclopropyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as in Example 50 except using 4-cyclopropyl-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline in step 1 to give 8-((4-cyclopropyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (5.8 mg, 17%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.24 (s, 1H), 6.83-6.75 (m, 3H), 5.99 (s, 1H), 5.94 (s, 1H), 3.48 (dt, 2H), 3.16 (s, 3H), 2.82 (t, 2H), 1.86 (m, 1H), 1.02-0.95 (m, 2H), 0.69-0.62 (m, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=328.1 (M+H).

Example 53

8-((4-(Difluoromethoxy)-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as in Example 50 except using 4-(difluoromethoxy)-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline in step 1 to give 8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (30.6 mg, 47%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.29 (s, 1H), 6.97 (m, 1H), 6.91-6.84 (m, 2H), 6.49 (t, 1H), 6.03 (s, 1H), 5.79 (s, 1H), 3.49 (dt, 2H), 3.19 (s, 3H), 2.84 (t, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=354.1 (M+H).

Example 54

8-((2-Fluoro-4-propylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Steps 1-4. Preparation of 8-((4-allyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared in the same manner as in Example 50 except using 4-allyl-2-fluoroaniline instead of 2-fluoro-4-(methylthio)aniline in Step 1 to give 8-((4-allyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (3.8 mg, 10%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.27 (s, 1H), 7.09 (dd, 1H), 7.01 (dd, 1H), 6.80 (t, 1H), 6.35-6.28 (m, 1H), 6.25-6.15 (m, 1H), 6.01 (s, 1H), 5.85 (s, 1H), 3.49 (dt, 2H), 3.19 (s, 3H), 2.83 (t, 2H), 1.88 (dd, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=328.1 (M+H).

Step 5. Preparation of 8-((2-fluoro-4-propylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. A stirred mixture of 8-((4-allyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (3.8 mg, 0.012 mmol) and Pd/C (5% Degussa type, 1 mg, 0.009 mmol) in MeOH (0.5 mL) was degassed and stirred under H2 for 24 h. The reaction mixture was diluted with DCM, filtered, and the filtrate was concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/water/0.1% TFA over 20 min) and the pure fractions were combined, washed with saturated aqueous sodium bicarbonate, and extracted with EtOAc (3×10 mL). The combined organic layers were washed with saturated aqueous sodium bicarbonate (30 mL) and brine (30 mL), dried over sodium sulfate, filtered, and concentrated to give 8-((2-fluoro-4-propylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (2.5 mg, 65%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.22 (s, 1H), 6.93 (dd, 1H), 6.88 (m, 1H), 6.81 (t, 1H), 5.99 (s, 1H), 5.81 (s, 1H), 3.48 (dt, 2H), 3.17 (s, 3H), 2.83 (t, 2H), 2.55 (t, 2H), 1.62 (m, 2H), 0.92 (t, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=330.1 (M+H).

Example 55

8-((2-Fluoro-4-(methylthio)phenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. 8-((2-Fluoro-4-(methylthio)phenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. 8-((2-Fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (41.2 mg, 0.124 mmol) and p-toluenesulfonic acid (31.9 mg, 0.185 mmol) were dissolved in 1 mL of 1:1 THF/MeOH. After 5 min, NIS (27.8 mg, 0.124 mmol) was added. The reaction mixture was stirred at ambient temperature for 30 min. The crude reaction mixture was then partitioned between EtOAc (10 mL) and saturated aqueous NaHCO ₃ (15 mL) and extracted with EtOAc (2×5 mL). The combined organic layers were dried over MgSO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 10-80% EtOAc/heptane to give 8-((4-bromo-2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (37 mg, 65%). MS (atmospheric pressure chemical ionization (apci), m/z) = 460.0 (M+H).

Step 2. Preparation of 8-((2-fluoro-4-(methylthio)phenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione 8-((2-fluoro-4-(methylthio)phenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (37.0 mg, 0.0806 mmol) and bis(tritert-butylphosphine)palladium(0) (4.12 mg, 0.00806 mmol) were dissolved in THF (0.8 mL) and methylzinc(II) chloride (80.6 μL, 2M/THF, 0.161 mmol) was added dropwise. The reaction mixture was stirred at ambient temperature for 1 h. The reaction mixture was quenched with saturated aqueous _NH4Cl (2 mL) then extracted with EtOAc (2×5 mL). The combined organic layers were dried over _MgSO4 , filtered and concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/ _H2O /0.1% TFA). Fractions containing purified desired product were combined and the product was converted to the free base form with DCM/ _NaHCO3 to give 8-((2-fluoro-4-(methylthio)phenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (15.5 mg, 55%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.10 (s, 1H), 7.04-7.01 (m, 1H), 6.95-6.93 (m, 1H), 6.71 (t, 1H), 5.96 (s, 1H), 3.49-3.46 (m, 2H), 3.25 (s, 3H), 2.87 (t, 2H), 2.46 (s, 3H), 2.11 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=348.1 (M+H).

Example 56

8-((4-ethyl-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as in Example 55 except using 8-((4-ethyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (prepared in the same manner as in Example 51) instead of 8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione in step 1 to give 8-((4-ethyl-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (6.7 mg, 62%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.06 (s, 1H), 6.94 (dd, 1H), 6.86 (dd, 1H), 6.72 (t, 1H), 5.87 (s, 1H), 3.47 (dt, 2H), 3.23 (s, 3H), 2.87 (t, 2H), 2.61 (qt, 2H), 2.11 (s, 3H), 1.21(t, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=330.2 (M+H).

Example 57

8-((4-cyclopropyl-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as in Example 55 except using 8-((4-cyclopropyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (prepared in the same manner as in Example 52) instead of 8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione in step 1 to give 8-((4-cyclopropyl-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (2.3 mg, 47%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.05 (s, 1H), 6.80-6.75 (m, 2H), 6.69 (t, 1H), 5.80 (s, 1H), 3.47 (dt, 2H), 3.22 (s, 3H), 2.87 (t, 2H), 2.10 (s, 3H), 1.85 (m, 1H), 1.00-0.94 (m, 2H), 0.67-0.61 (m, 2H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=342.2 (M+H).

Example 58

8-((4-(Difluoromethoxy)-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as in Example 55 except using 8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (prepared in the same manner as in Example 53) instead of 8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione in step 1 to give 8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (9.5 mg, 41%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.09 (s, 1H), 6.96 (dd, 1H), 6.87-6.82 (m, 1H), 6.76 (t, 1H), 6.47 (t, 1H), 6.01 (s, 1H), 3.48 (dt, 2H), 3.25 (s, 3H), 2.88 (t, 2H), 2.11 (s, 3H) ppm; MS (atmospheric pressure chemical ionization (apci), m/z)=368.1 (M+H).

Example 59

8-((4-Bromo-2-chlorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of methyl (E)-2-((4-bromo-2-chlorophenyl)amino)-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate Methyl (E)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (140 mg, 0.515 mmol) and 4-bromo-2-chloroaniline (108 mg, 0.520 mmol) were dissolved in THF (5.2 mL) and cooled to -78 °C under N ₂ . LiHMDS (1.0 mL, 1.0 M/THF, 1.0 mmol) was added dropwise, and the mixture was warmed from -78 °C to ambient temperature over 1 h. The reaction mixture was quenched with saturated aqueous _NH4Cl (5 mL) then extracted with EtOAc (2×5 mL). The combined organic layers were dried over _MgSO4 , filtered and concentrated. The residue was purified by column chromatography eluting with 0-100% EtOAc/heptane to give methyl (E)-2-((4-bromo-2-chlorophenyl)amino)-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (145 mg, 64%). MS (atmospheric pressure chemical ionization (apci), m/z)=441.0, 443.0 (M+H).

Step 2. Preparation of methyl 2-((4-bromo-2-chlorophenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate. To a solution of methyl (E)-2-((4-bromo-2-chlorophenyl)amino)-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (145 mg, 0.328 mmol) in DCM (2.0 mL) was added TFA (2.0 mL). The solution was stirred at ambient temperature overnight, then concentrated. The crude mixture was then diluted with DCM (5 mL) and washed with saturated aqueous NaHCO ₃ (5 mL). The organic phase was dried over _MgSO4 , filtered and concentrated to give methyl 2-((4-bromo-2-chlorophenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate, which was used without further purification (136 mg, 100%). MS (atmospheric pressure chemical ionization (apci), m/z)=415.2 (M+H).

Step 3. Preparation of 8-((4-bromo-2-chlorophenyl)amino)-2-(4-methoxybenzyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione Methyl 2-((4-bromo-2-chlorophenyl)amino)-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate (136 mg, 0.329 mmol), (4-methoxyphenyl)methanamine (47.4 mg, 0.345 mmol), sodium triacetoxyborohydride (76.6 mg, 0.362 mmol), and acetic acid (2.0 mg, 0.033 mmol) were dissolved in DCE (3.3 mL) and stirred at ambient temperature for 1 h. After this, the reaction mixture was warmed to 60 °C and stirred for 1 h. The reaction mixture was then cooled to ambient temperature, diluted with DCM (5 mL) and washed with saturated aqueous NaHCO ₃ (10 mL). The organic phase was dried over MgSO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-100% EtOAc/heptane to give 8-((4-bromo-2-chlorophenyl)amino)-2-(4-methoxybenzyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (104 mg, 63%). MS (atmospheric pressure chemical ionization (apci), m/z) = 502.1, 504.1 (M+H).

Step 4. Preparation of 8-((4-bromo-2-chlorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. 8-((4-bromo-2-chlorophenyl)amino)-2-(4-methoxybenzyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (79.1 mg, 0.207 mmol) was dissolved in TFA (3.0 mL) and heated to 60 °C for 16 h. The reaction mixture was then cooled to ambient temperature and concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/H ₂ O/0.1% TFA). Fractions containing purified desired product were pooled and the product was converted to the free base form with DCM/NaHCO ₃ to give 8-((4-bromo-2-chlorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (28 mg, 35%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.27 (s, 1H), 7.61 (d, 1H), 7.31-7.28 (m, 1H), 6.60-6.57 (m, 1H), 6.07 (t, 1H), 5.63 (s, 1H), 3.52-3.48 (m, 2H), 3.17 (s, 3H), 2.85 (t, 2H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=382.0, 384.0 (M+H).

Example 60

8-((4-Bromo-2-fluorophenyl)amino)-2-(2-hydroxyethyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione trifluoroacetate

Step 1. Preparation of methyl 2-chloro-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate. To a solution of methyl (E)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (331 mg, 1.22 mmol) in DCM (5.0 mL) was added TFA (5.0 mL). The solution was stirred at ambient temperature for 16 h, then concentrated. The crude mixture was then diluted with DCM (10 mL) and washed with saturated aqueous NaHCO ₃ (10 mL). The organic phase was dried over _MgSO4 , filtered and concentrated to give methyl 2-chloro-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate, which was used without further purification (236 mg, 80%). MS (atmospheric pressure chemical ionization (APCI), m/z)=244.1 (M+H).

Step 2. Preparation of 8-chloro-2-(2-hydroxyethyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione Methyl 2-chloro-1-methyl-6-oxo-4-(2-oxoethyl)-1,6-dihydropyridine-3-carboxylate (122 mg, 0.501 mmol), 2-((tert-butyldimethylsilyl)oxy)ethan-1-amine (105 mg, 0.601 mmol), sodium triacetoxyborohydride (127 mg, 0.601 mmol), and acetic acid (6.0 mg, 0.10 mmol) were dissolved in DCE (5 mL) and stirred at ambient temperature for 2 h. The reaction mixture was warmed to 60 °C and stirred for 16 h. The reaction mixture was then cooled to ambient temperature, diluted with DCM (10 mL) and washed with saturated aqueous _NaHCO3 (15 mL). The organic phase was dried over _MgSO4 , filtered and concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/ _H2O /0.1% TFA). Fractions containing purified desired product were combined and the product was converted to the free base form with DCM/ _NaHCO3 to give 8-chloro-2-(2-hydroxyethyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (20 mg, 16%). MS (atmospheric pressure chemical ionization (apci), m/z) = 257.0 (M+H).

Step 3. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione trifluoroacetate 4-Bromo-2-fluoroaniline (17.7 mg, 0.093 mmol) and 8-chloro-2-(2-hydroxyethyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (20 mg, 0.077 mmol) were dissolved in THF (0.7 mL) and cooled to -78°C under N ₂ . LiHMDS (233 µL, 1.0 M/THF, 0.233 mmol) was added dropwise, then the mixture was warmed from -78 °C to ambient temperature over 1 h. The reaction mixture was quenched with saturated aqueous NH ₄ Cl (5 mL), then extracted with EtOAc (3 x 5 mL). The combined organic layers were dried over MgSO ₄ , filtered, and concentrated. The residue was purified by reverse phase HPLC (5-95% acetonitrile/H ₂ O/0.1% TFA). Purified fractions were lyophilized to give 8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione trifluoroacetate (10.1 mg, 32%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.36 (s, 1H), 7.32-7.29 (m, 1H), 7.22-7.19 (m, 1H), 6.70 (t, 1H), 6.06 (s, 1H), 3.85 (t, 2H), 3.67 (t, 2H), (t, 2H), 3.22 (s, 3H), 2.86 (t, 2H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=410.1, 412.1 (M+H).

Example 61

8-((2-Fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as in Example 44 except using 2-fluoro-4-(methylthio)aniline instead of 4-ethyl-2-fluoroaniline in step 1 to give 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (2.1 mg, 21%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.01 (s, 1H), 7.02 (dd, 1H), 6.95 (m, 1H), 6.77 (m, 1), 4.48 (t, 1H), 4.03 (t, 2H), 3.76-3.67 (m, 4H), 3.21 (s, 3H), 3.02 (t, 2H), 2.47 (s, 3H), 2.08 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=408.1 (M+H).

Example 62

8-((4-(Difluoromethoxy)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Steps 1-5. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. Prepared in the same manner as in Example 41, steps 1-5, except using 4-(difluoromethoxy)-2-fluoroaniline instead of 2-fluoroaniline in step 1, to give 2-(2-(tertbutoxy)ethoxy)-8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (156 mg, 94%). MS (atmospheric pressure chemical ionization (apci), m/z)=596.1 (M+H).

Step 6. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 2-(2-(tertbutoxy)ethoxy)-8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (156 mg, 0.262 mmol) in THF (2.5 mL) at 0 °C was added Pd(Pt-Bu ₃ ) ₂ (13.4 mg, 0.026 mmol), followed by methylzinc(II) chloride (132 μL, 0.265 mmol). The mixture was removed from the ice bath and stirred for 10 min. The reaction mixture was partitioned between saturated aqueous NH ₄ Cl (40 mL) and EtOAc (20 mL), and the aqueous layer was extracted with EtOAc (2×10 mL). The combined organic layers were washed with brine (30 mL), dried over sodium sulfate, filtered and concentrated. The residue was purified by column chromatography eluting with 0-50% EtOAc/heptane to give 2-(2-(tertbutoxy)ethoxy)-8-((4-(difluoro-methoxy)-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (89.9 mg, 71%). MS (atmospheric pressure chemical ionization (apci), m/z) = 484.2 (M+H).

Step 7. Preparation of 8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione 2-(2-(tertbutoxy)ethoxy)-8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (89.9 mg, 0.186 mmol) was dissolved in ACN (750 μL) and phosphoric acid (750 μL) was added. The reaction mixture was heated to 60 °C for 30 min. The reaction mixture was partitioned between saturated aqueous sodium bicarbonate (50 mL) and EtOAc (20 mL). The aqueous layer was washed with EtOAc (2×15 mL). The combined organic layers were washed with saturated aqueous sodium bicarbonate (25 mL), brine (25 mL), dried over sodium sulfate, filtered and concentrated. The residue was purified by column chromatography eluting with 0-100% EtOAc/heptane to give 8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (65.9 mg, 83%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 11.00 (s, 1H), 6.97 (dd, 1H), 6.90-6.79 (m, 2H), 6.48 (t, 1H), 4.44 (t, 1H), 4.03 (m, 2H), 3.76-3.68 (m, 4H), 3.22 (s, 3H), 3.03 (t, 2H), 2.09 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=428.1 (M+H).

Example 63

2-(2,2-Difluoroethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of methyl (Z)-4-(2-ethoxyvinyl)-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. Prepared in the same manner as Example 44, step 1, except using 2-fluoro-4-(methylthio)aniline instead of 4-ethyl-2-fluoroaniline to give methyl (Z)-4-(2-ethoxyvinyl)-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (0.373 g, 69%). MS (atmospheric pressure chemical ionization (apci), m/z)=393.1 (M+H).

Step 2. Obtaining methyl (E)-4-(2-((2,2-difluoroethoxy)-imino)ethyl)-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. Prepared by the same method as in Example 6, step 5, except that methyl (Z)-4-(2-ethoxyvinyl)-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate was used instead of methyl (Z)-2-chloro-4-(2-ethoxyvinyl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate and O-(2,2-difluoroethyl)hydroxylamine hydrochloride was used instead of O-(2-(tert-butoxy)ethyl)hydroxylamine hydrochloride to give methyl (E)-4-(2-((2,2-difluoroethoxy)imino)ethyl)-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (calculated 100%). MS (atmospheric pressure chemical ionization (apci), m/z)=444.1 (M+H).

Step 3. Obtaining 2-(2,2-difluoroethoxy)-8-((2-fluoro-4-(methyl-thio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of methyl (E)-4-(2-((2,2-difluoro-ethoxyimino)ethyl)-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydro-pyridine-3-carboxylate (36 mg, 0.081 mmol) in MeOH (0.8 mL) were added sodium cyanoborohydride (26 mg, 0.406 mmol) and acetic acid (23 μL, 0.406 mmol). The mixture was stirred at 45 °C for 2 h, then at ambient temperature for 72 h. The mixture was diluted with saturated aqueous NaHCO ₃ (25 mL) and EtOAc (25 mL). The organic phase was separated, dried over Na ₂ SO ₄ , filtered and concentrated. The residue was purified by column chromatography, eluting with 5-100% EtOAc/heptane to give 2-(2,2-difluoroethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (11.8 mg, 35.2%). ^1H NMR (400 MHz, CDCl ₃ ) δ 11.26 (s, 1H), 7.08-6.94 (m, 2H), 6.91-6.76 (m, 1H), 6.51-5.64 (m, 2H), 4.22 (td, 2H), 3.73 (t, 2H), 3.16 (s, 3H ), 3.04-2.97 (m, 2H), 2.48 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=414.1 (M+H).

Example 64

8-((4-Bromo-2-fluorophenyl)amino)-7-methyl-4-phenyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 2,6-dichloro-4-iodonicotinic acid. A solution of 2,6-dichloro-4-iodopyridine (4.0 g, 14.6 mmol) in THF (30 mL) was cooled to -78 °C. LDA (10.95 mL, 2 M, 21.9 mmol) was added dropwise to the solution at -78 °C and stirred for 2 h at -78 °C. Excess CO ₂ was bubbled through the reaction solution for 20 min at -78 °C. The reaction mixture was then poured onto dry ice (10 g) and quenched with water (30 mL). The pH of the reaction mixture was adjusted to pH 3-4 using 2N HCl and extracted with EtOAc (3×100 mL). The organic layers were combined and dried over sodium sulfate, filtered and concentrated to give 2,6-dichloro-4-iodonicotinic acid (3.0 g, 64.6%). MS (atmospheric pressure chemical ionization (APCI), m/z)=317.9, 319.8 (M+H).

Step 2. Preparation of 2-chloro-4-iodo-6-oxo-1,6-dihydropyridine-3-carboxylic acid. A solution of NaOH (100 mL, 4 M, 236 mmol) was heated to 110 °C and then 2,6-dichloro-4-iodonicotinic acid (3.0 g, 9.44 mmol) was added in one portion and stirred for 8 h. The pH of the reaction mixture was adjusted to pH 1 with HCl (6 M) at 0 °C and stirred for 30 min. The resulting solids were collected by filtration and dried under vacuum to give 2-chloro-4-iodo-6-oxo-1,6-dihydropyridine-3-carboxylic acid (3.0 g, assumed 100%), which was used without further purification. MS (atmospheric pressure chemical ionization (apci), m/z)=299.9, 301.9 (M+H).

Step 3. Preparation of methyl 2-chloro-4-iodo-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. To a mixture of 2-chloro-4-iodo-6-oxo-1,6-dihydropyridine-3-carboxylic acid (3.0 g, 10.02 mmol) in DMF (30 mL) were added MeI (4.27 g, 30.06 mmol) and K ₂ CO ₃ (4.15 g, 30.06 mmol) in one portion at 25 °C. After stirring for 3 h, the reaction mixture was poured into saturated aqueous NH ₄ Cl (10 mL), and the aqueous phase was extracted with ethyl acetate (3×50 mL). The combined organic layers were washed with brine (100 mL), dried over Na ₂ SO ₄ , filtered, and concentrated. The residue was purified by column chromatography eluting with 2-100% EtOAc/petroleum ether to give methyl 2-chloro-4-iodo-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (850 mg, 25.9%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.16 (s, 1H), 3.93 (s, 3H), 3.65 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z) = 327.9 (M+H).

Step 4. Preparation of methyl 2-chloro-1-methyl-6-oxo-4-(1-phenylvinyl)-1,6-dihydropyridine-3-carboxylate. To a solution of methyl 2-chloro-4-iodo-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (0.2 g, 0.611 mmol) in 1,4-dioxane (10 mL) and water (1 mL) were added 4,4,5,5-tetramethyl-2-(1-phenylvinyl)-1,3,2-dioxaborolane (0.148 g, 0.641 mmol), Pd(dppf)Cl ₂ (50 mg, 0.061 mmol), Na ₂ CO ₃ (0.194 g, 1.83 mmol), and H ₂ O (1 mL). The mixture was then degassed 3 times and stirred at 80 °C for 3 h. 4,4,5,5-tetramethyl-2-(1-phenylvinyl)-1,3,2-dioxaborolane (37 mg, 0.153 mmol) and Pd(dppf) _Cl2 (50 mg, 0.061 mmol) were added. The mixture was degassed 3 times and stirred at 80 °C for another 1.5 h. The cooled mixture was filtered and the filtrate was concentrated. The residue was purified by column chromatography eluting with 0-20% EtOAc/petroleum ether to give methyl 2-chloro-1-methyl-6-oxo-4-(1-phenylvinyl)-1,6-dihydropyridine-3-carboxylate (95 mg, 51%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.33-7.32 (m, 3H), 7.32-7.25 (m, 2H), 6.58 (s, 1H), 5.62 (s, 1H), 5.42 (s, 1H), 3.75 (s, 3H), 3.36 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=303.7 (M+H).

Step 5. Preparation of methyl 2-((4-bromo-2-fluorophenyl)amino)-1-methyl-6-oxo-4-(1-phenylvinyl)-1,6-dihydropyridine-3-carboxylate. To a solution of 4-bromo-2-fluoroaniline (56 mg, 0.29 mmol) in THF (5 mL) was added LiHMDS (0.74 mL, 1.0 M, 0.74 mmol) at -78 °C and stirred for 0.5 h at -78 °C. Then, a solution of methyl 2-chloro-1-methyl-6-oxo-4-(1-phenylvinyl)-1,6-dihydropyridine-3-carboxylate (90 mg, 0.296 mmol) in THF (0.5 mL) was added, and the mixture was stirred at -78 °C for 30 min. The mixture was quenched with saturated aqueous _NH4Cl (5 mL) and extracted with EtOAc (3×50 mL). The combined organic layers were washed with brine (5 mL), dried over _Na2SO4 , filtered and concentrated. The residue was purified by column chromatography eluting with 0-20% _EtOAc /petroleum ether to give methyl 2-((4-bromo-2-fluorophenyl)amino)-1-methyl-6-oxo-4-(1-phenylvinyl)-1,6-dihydropyridine-3-carboxylate (120 mg, 89%). MS (atmospheric pressure chemical ionization (apci), m/z) = 459.2 (M+H).

Step 6. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-(2,4-dimethoxybenzyl)-7-methyl-4-phenyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione To a solution of methyl 2-((4-bromo-2-fluorophenyl)amino)-1-methyl-6-oxo-4-(1-phenylvinyl)-1,6-dihydropyridine-3-carboxylate (120 mg, 0.29 mmol) in toluene (10 mL) were added DMB-NH2 (43.8 mg, 0.26 mmol) and AlMe3 (0.4 mL, 2.0 M, 0.79 mmol) at 25 °C under N ₂ atmosphere, and the mixture was stirred at 80 °C for 48 h. The mixture was quenched with saturated aqueous NH ₄ Cl (5 mL) and filtered. The filtrate was extracted with EtOAc (3×10 mL), and the organic layer was washed with brine (10 mL), dried over Na ₂ SO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-50% EtOAc/petroleum ether to give 8-((4-bromo-2-fluorophenyl)amino)-2-(2,4-dimethoxybenzyl)-7-methyl-4-phenyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (80.0 mg, 52%). MS (atmospheric pressure chemical ionization (apci), m/z) = 594.2 (M+H).

Step 7. 8-((4-Bromo-2-fluorophenyl)amino)-7-methyl-4-phenyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. A mixture of 8-((4-bromo-2-fluorophenyl)amino)-2-(2,4-dimethoxybenzyl)-7-methyl-4-phenyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (80 mg, 0.14 mmol) in TFA (5 mL) was stirred for 1 h at 80 °C. The cooled mixture was concentrated and the residue was dissolved in MeOH (5 mL). Solid NaHCO ₃ (~1 g) was added and the mixture was stirred for 15 min, then treated with DCM (20 mL) and filtered. The filtrate was concentrated and purified by preparative HPLC (preparative HPLC conditions: column: Boston Prime C18 150×25 mm×5 μm; mobile phase: water (0.225% ammonium hydroxide by volume)-ACN; B%: 40%-70%, flow rate (ml/min): 25). The fractions were lyophilized to obtain 8-((4-bromo-2-fluorophenyl)amino)-7-methyl-4-phenyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (5.49 mg, 9%). ¹ H NMR (400 MHz, MeOD) δ 7.49 (d, 1H), 7.40-7.32 (m, 6H), 6.93 (t, 1H), 5.76 (s, 1H), 4.19 (t, 1H), 3.66 (d, 2H), 3.24 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=442.2, 444.1 (M+H).

Example 65

8-((2-Fluoro-4-(methylthio)phenyl)amino)-7-methyl-4-phenyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same method as in Example 64, except using 2-fluoro-4-(methylthio)aniline instead of 4-bromo-2-fluoroaniline in Step 5, to give 8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-4-phenyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (21 mg, 29%). ¹ H NMR (400 MHz, d ₆ -DMSO) δ 11.71 (s, 1H), 8.15 (s, 1H), 7.40-7.25 (m, 6H), 7.08 (d, 1H), 6.97 (t, 1H), 5.59 (s, 1H), 4.13 (t, 1H), 3.54 (br s, 2H), 3.30 (s, 3H), 3.05 (s, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=410.1 (M+H).

Example 66

8-((4-Bromo-2-fluorophenyl)amino)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as in Example 64 except using 4,4,5,5-tetramethyl-2-(prop-1-en-2-yl)-1,3,2-dioxaborolane instead of 4,4,5,5-tetramethyl-2-(1-phenylvinyl)-1,3,2-dioxaborolane in Step 4 to give 8-((4-bromo-2-fluorophenyl)amino)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (3 mg, 13%). ¹ H NMR (400 MHz, MeOD) δ 7.48 (d, 1H), 7.35 (d, 1H), 6.88 (t, 1H), 6.15 (s, 1H), 3.51 (dd, 1H), 3.21 (s, 3H), 3.20-3.15 (m, 1H), 2.99-2.86 (m, 1H), 1.33 (d, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=380.0, 382.2 (M+H).

Example 67

8-((2-Fluoro-4-(methylthio)phenyl)amino)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared in the same manner as in Example 64, except using 4,4,5,5-tetramethyl-2-(prop-1-en-2-yl)-1,3,2-dioxaborolane instead of 4,4,5,5-tetramethyl-2-(1-phenylvinyl)-1,3,2-dioxaborolane in step 4, and 2-fluoro-4-(methylthio)aniline instead of 4-bromo-2-fluoroaniline in step 5, to give 8-((2-fluoro-4-(methylthio)phenyl)amino)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (3.8 mg, 22%). ¹ H NMR (400 MHz, MeOD) δ 7.16 (d, 1H), 7.09 (d, 1H), 6.92 (t, 1H), 6.09 (s, 1H), 3.51 (dd, 1H), 3.19 (s, 3H), 3.17-3.15 (m, 1H), 2.99-2.94 (m, 1H), 2.51 (s, 3H), 1.33 (d, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=348.1 (M+H).

Example 68

8-((4-Bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Step 1. Preparation of 1-ethoxyprop-1-yne. Anhydrous _NH3 (300 mL) _{was condensed at -70°C in a reaction flask and crushed Fe(NO3)3⋅9H2O ( 252} mg, 0.625 mmol) was added with slow stirring. Solid _NaNH2 (34.14 g, 0.875 mol) was added at -60 to -40°C over 10 min, then 2-chloro-1,1-diethoxyethane (38.15 g, 0.25 mol) was added dropwise at this temperature over 30 min. The reaction mixture was heated under reflux at -30 °C for 1 h, then MeI (177.42 g, 1.25 mol) was added dropwise over 30 min. The reaction mixture was stirred vigorously for 90 min at this temperature, then carefully quenched by the dropwise addition of cooled aqueous saturated NH ₄ Cl (40 mL), followed by Et ₂ O (100 mL), and additional aqueous saturated NH ₄ Cl (50 mL). The cooling bath was removed and the reaction mixture was warmed to 15 °C. Water (50 mL) was added, and the organic layer was separated and washed with water (50 mL) and brine (50 mL). The combined aqueous solutions were extracted with _Et2O (50 mL), and the combined organic layers _were dried over _Na2SO4 and filtered to give ~1.3 M ether solution of 1-ethoxyprop-1-yne (100 mL, 52%). ¹ H NMR (400 MHz, _CDCl3 ) δ 3.99 (q, 2H), 1.73 (s, 3H), 1.32 (t, 3H) ppm.

Step 2. Preparation of (Z)-2-(1-ethoxyprop-1-en-2-yl)benzo[d]-[1,3,2]dioxaborolane. To a solution of benzo[d][1,3,2]-dioxaborolane (1.43 g, 11.89 mmol) in toluene (50 mL) were added 1-ethoxyprop-1-yne (7.7 mL, 1.3 M/Et ₂ O, 11.89 mmol) and NiCl ₂ (dppe) (314 mg, 0.59 mmol) under N ₂ atmosphere. The reaction mixture was degassed three times and stirred at 50 °C for 3 h. The mixture was filtered to give a toluene solution of (Z)-2-(1-ethoxyprop-1-en-2-yl)benzo[d][1,3,2]dioxaborolane (1.5 g, 62%), which was used without further purification.

Step 3. Obtaining methyl (E)-2-chloro-4-(1-ethoxyprop-1-en-2-yl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. To a solution of (Z)-2-(1-ethoxyprop-1-en-2-yl)benzo[d][1,3,2]dioxaborolane (1.5 g, 7.33 mmol) in toluene (50 mL) and THF (30 mL) were added methyl 2-chloro-4-iodo-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (1.2 g, 3.66 mmol), Pd(dppf)Cl ₂ (299 mg, 0.37 mmol), K ₃ PO ₄ (2.33 g, 10.99 mmol), and H ₂ O (3 mL). The mixture was degassed 3 times and stirred at 75 °C for 3 h. The cooled mixture was filtered. The filtrate was diluted with EtOAc (50 mL), then washed with water (3 x 10 mL) and brine (10 mL), dried over Na ₂ SO ₄ , filtered and concentrated. The residue was purified by column chromatography eluting with 0-40% EtOAc/petroleum ether to give methyl (E)-2-chloro-4-(1-ethoxyprop-1-en-2-yl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (650 mg, 62%). MS (atmospheric pressure chemical ionization (apci), m/z) = 286, O (M+H).

Step 4. Preparation of methyl (E/Z)-4-(1-((2-(tertbutoxy)-ethoxy)imino)propan-2-yl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate. To a solution of methyl (E)-2-chloro-4-(1-ethoxyprop-1-en-2-yl)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (600 mg, 2.1 mmol) and O-(2-(tert-butoxy)ethyl)hydroxylamine hydrochloride (356 mg, 2.1 mmol) in dioxane (10 mL) were added TEA (212 mg, 2.1 mmol) and HCl (1 mL, 4 M/dioxane, 4.2 mmol). The mixture was heated to 60 °C and stirred for 2 h. 1,4-Dioxane (20 mL) was added and the mixture was filtered and concentrated to give methyl (E/Z)-4-(1-((2-(tert-butoxy)ethoxy)imino)propan-2-yl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (780 mg, 99.6%), which was used without further purification. MS (atmospheric pressure chemical ionization (apci), m/z) = 317.1 (M+H - t-Bu).

Step 5. Preparation of 2-(2-(tertbutoxy)ethoxy)-8-chloro-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of methyl (E/Z)-4-(1-((2-(tertbutoxy)ethoxy)imino)propan-2-yl)-2-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (780 mg, 2.09 mmol) in IPA (10 mL) were added NaCNBH ₃ (657 mg, 10.46 mmol) and AcOH (628 mg, 10.46 mmol). The mixture was stirred at 20 °C for 48 h. EtOAc (100 mL) was added and the mixture was washed with saturated aqueous _NaHCO3 (10 mL) and brine (10 mL), dried over _MgSO4 , filtered and concentrated. The residue was purified by column chromatography eluting with 0-40% EtOAc/petroleum ether to give 2-(2-(tert-butoxy)-ethoxy)-8-chloro-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (200 mg, 28%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 6.31 (s, 1H), 4.10-4.06 (m, 2H), 3.84 (dd, 1H), 3.70 (s, 3H), 3.59-3.53 (m, 3H), 3.06-3.05 (m, 1H), 1.31 (d, 3H), 1.15 (s, 9H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=343.1 (M+H).

Step 6. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. To a solution of 4-bromo-2-fluoroaniline (55 mg, 0.29 mmol) in THF (8 mL) was added dropwise LiHMDS (0.73 mL, 1 M, 0.73 mmol) at -78°C under N ₂ atmosphere. The mixture was stirred at -78 °C for 30 min, then a solution of 2-(2-(tertbutoxy)ethoxy)-8-chloro-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (100 mg, 0.29 mmol) in THF (2 mL) was added dropwise and stirring was continued at -78 °C for 30 min. The mixture was treated with saturated aqueous NH ₄ Cl (5 mL) and extracted with EtOAc (2×30 mL). The combined organic layers were washed with brine (5 mL), dried over MgSO ₄ , filtered and concentrated to give 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tert-butoxy)ethoxy)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (144.8 mg, 100%), which was used without further purification. MS (atmospheric pressure chemical ionization (apci), m/z) = 496.2 (M+H).

Step 7. Preparation of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. A mixture of 8-((4-bromo-2-fluorophenyl)amino)-2-(2-(tertbutoxy)ethoxy)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (144.8 mg, 0.292 mmol) in TFA (5 mL) was stirred for 2 h at 25 °C. The mixture was concentrated, dissolved in MeOH (10 mL), and treated with solid NaHCO ₃ (73 mg, 0.876 mmol). After stirring for 30 min, DCM (50 mL) was added. The mixture was filtered, concentrated and purified by preparative HPLC (preparative HPLC conditions: column: Waters XBridge 150×25 mm 10 μm; mobile phase: water (0.05% ammonium hydroxide v/v)-ACN; B%: 24%-64%, flow rate (mL/min): 25). The purified fractions were lyophilized to give 8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (34.8 mg, 27%). ¹ H NMR (400 MHz, MeOD) δ 7.38 (d, 1H), 7.26 (d, 1H), 6.82 (t, 1H), 6.02 (s, 1H), 3.98 (t, 2H), 3.82 (dd, 1H), 3.66 (t, 2H), 3.64-3.50 (m, 1H), 3.12 (s, 3H), 3.09-3.08 (m, 1H), 1.29 (d, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=440.1 (M+H).

Example 69

8-((2-Fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione

Prepared by the same method as in Example 68, except using 2-fluoro-4-(methylthio)aniline instead of 4-bromo-2-fluoroaniline in Step 6, to give 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione (27.5 mg, 23%). ¹ H NMR (400 MHz, MeOD) δ 7.16 (d, 1H), 7.10 (d, 1H), 6.99 (t, 1H), 6.07 (s, 1H), 4.05 (t, 2H), 3.91 (dd, 1H), 3.76 (t, 2H), 3.60 (dd, 1H), 3.21 (s, 3H), 3.19-3.15 (m, 1H), 2.50 (s, 3H), 1.40 (d, 3H) ppm. MS (atmospheric pressure chemical ionization (apci), m/z)=408.2 (M+H).

Example 70

Preparation of anhydrous crystalline 8-((2-fluoro-4-(methylthio)-phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 1

Phosphoric acid (37.4 g, 25.8 mL, 14.8 molar solution, 50 equiv, 382 mmol) was added to a stirred solution of 2-(2-(tertbutoxy)ethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, which can be prepared by any of the methods described in the invention (3.43 g, 1 equiv, 7.63 mmol), in acetonitrile (ACN) in air. The mixture was warmed to 60 °C and stirred for 15 min, after which LCMS analysis indicated the reaction was complete. The reaction mixture was cooled to 0 °C and treated with K ₃ PO ₄ (382 mL, 1 M, 382 mmol). The mixture was extracted with ethyl acetate (3 x 100 mL). The combined organic layers were washed with brine (50 mL), dried over sodium sulfate, filtered and concentrated in vacuo to give a bright yellow foam. The crude residue was purified on an 80 g silica gel cartridge eluting with a gradient of 0% to 15% methanol in dichloromethane (DCM) first, then increasing the concentration of methanol in DCM to 20% to give the product as a bright yellow foam (2.17 g). This product was dissolved in DCM (50 mL), treated with Norit CA1 activated carbon (600 mg) and stirred for 15 min. The mixture was filtered through GF filter paper and the residue concentrated to give a bright yellow foam. This procedure was repeated using Darco G-60 activated carbon to give the product as a pale pink foam. This material was treated with 2-propanol (20 mL) and DCM (5 mL) was added to completely solubilize it. The mixture was concentrated during which time solids began to form, but the material became an oil after complete concentration. The residue was treated with 2-propane (10 mL) and warmed to 40 °C, at which point a thick precipitate formed. The mixture was cooled to room temperature and diluted with standard 2-propanol (5 mL) to facilitate stirring. The mixture was then filtered and 15 mL of cold 2-propanol was used to rinse and wash it to give crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 1 (1.61 g, 4.09 mmol, 53.6%) as a yellowish-white solid after drying under vacuum. Figure 1 shows the powder X-ray diffraction pattern of crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 1, prepared by this method, wherein powder X-ray diffraction (PXRD) analysis was performed using the instrumental methods described in Example 77.

Example 71

Preparation of seed crystals of crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 2

Step 1. Methyl 4-bromo-2-((2-fluoro-4-(methylthio)phenyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (prepared by any of the methods described herein) (1.0 equiv, 7.5 kg), XPhos (0.075 equiv), and MeThF (10 vol) were added to the reactor and the reaction mixture was degassed. Pd(II) acetate (0.015 equiv) was charged to the reactor and the reaction mixture was degassed. (Z)-2-(2-ethoxyvinyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.8 equiv) was charged to the reactor and 45 wt % KOH solution (4 equiv) was poured into the reactor. The reaction mixture was heated at 50 °C for 1 h, then (Z)-2-(2-ethoxyvinyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.3 equiv) was added and heating was continued for another h. The reaction mixture was washed with water (2 volumes) then 1 M acetic acid (2 equiv), then stirred with SiliaMetS® thiol (SiliCycle Inc., Quebec City, Quebec, Canada) (0.3 g/g) at 50 °C for 18 h before filtration. The filter cake was washed with MeTHF (5 volumes). The organic layer was concentrated to 3 volumes and a small portion was removed and cooled to form seeds. The seed crystals were loaded back into the reactor and stirred for 1 hour at 50 °C, then slowly cooled to 30 °C. MeTHF/heptane 1:4 (5 vol) was then slowly loaded into the reactor and the mixture was stirred for 1 hour. The mixture was then slowly cooled to 10 °C and stirred for 18 hours, then filtered. The filter cake was washed with MeTHF/heptane 1:1 (5 vol). The solids were then oven dried to give methyl 4-[(Z)-2-ethoxyethenyl]-2-[2-fluoro-4-(methylsulfanyl)anilino]-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate

Step 2. Methyl 4-[(Z)-2-ethoxyethenyl]-2-[2-fluoro-4-(methylsulfanyl)anilino]-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate (5.0 g, 12.5 mmol) was combined with 2-methyltetrahydrofuran (20 vol) and O-(2-(tertbutoxy)ethyl)hydroxylamine hydrochloride (1.3 equiv, 16.3 mmol) and heated to ∼75 °C. The resulting mixture was cooled to 20 °C. Borane-pyridine complex (2.0 equiv, 25.0 mmol) was added, as was HCl in cyclopentyl methyl ether (CPME) (3 M, 1.3 equiv, 16.3 mmol). The resulting mixture was stirred at 20 °C for 45 min, then heated to 60 °C. After stirring overnight, the mixture was cooled to 20 °C and quenched with HCl (1 M, 30 mL). During this time, some effervescence and heat evolution were observed. After the effervescence ceased (~5 min), the organic layer was separated, washed with water (8 vol), and concentrated to ∼6 vol by distillation under reduced pressure. Phosphoric acid (14.6 M, 15 equiv, 187 mmol) was then added, and the mixture was stirred at 20 °C and diluted with 2-methyltetrahydrofuran (7 vol). Potassium hydroxide solution (11.5 M, 20 equiv) was added slowly. After stirring for ∼10 min, the layers were separated. The organic phase was washed with water (10 volumes) then concentrated to approximately 5 volumes by distillation under reduced pressure to give a solution of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione in 2-methyltetrahydrofuran. Cyclopentyl methyl ether (2 volumes) was warmed to approximately 40°C and then added to a solution of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione. The mixture was stirred for 1 hour. A solid precipitated during stirring. The solvent was exchanged to CPME (approximately 8 volumes) by distillation under reduced pressure and the resulting suspension was stirred at 15°C for 2 hours. The resulting solid was collected and dried at 45°C under vacuum to give crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 2. The crystalline form was confirmed by powder X-ray diffraction (PXRD) analysis using the instrumental methods described in Example 77.

Example 72

Preparation of crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 2

Methyl 4-[(Z)-2-ethoxyethenyl]-2-[2-fluoro-4-(methylsulfanyl)anilino]-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate, prepared as described in Example 71, step 1 (2.0 g, 5.0 mmol), was combined with 2-methyltetrahydrofuran (20 vol) and heated to approximately 75 °C. To the mixture was added O-(2-(tert-butoxy)ethyl)hydroxylamine hydrochloride (1.3 equiv, 6.50 mmol), and the resulting mixture was cooled to 20 °C. Borane-pyridine complex (2.0 equiv, 10.0 mmol) was added, as well as HCl in cyclopentyl methyl ether (CPME) (3 M, 1.3 equiv, 6.5 mmol). The resulting mixture was stirred at 60 °C. After stirring overnight, the mixture was cooled to 20 °C and quenched with HCl (1 M, 12 mL). Some bubbling and exotherm was observed during this time. After completion of the reaction (~5 min), the organic layer was separated, washed with water (8 vol), and concentrated to ∼6 vol by distillation under reduced pressure. Phosphoric acid (14.6 M, 15 equiv, 75.0 mmol) was then added and the mixture was stirred at 65 °C. After stirring overnight, the mixture was cooled to 20 °C and diluted with 2-methyltetrahydrofuran (7 vol). Potassium hydroxide solution (11.5 M, 20 equiv) was added slowly. After stirring for ∼10 min, the layers were separated. The organic phase was washed with water (10 ml) and then concentrated to approximately 5 volumes by distillation under reduced pressure. The mixture was then heated to 50 °C and cyclopentyl methyl ether (2 volumes) was added. Seeds of crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2 (prepared as described in Example 71) were then added and the resulting suspension was cooled to 30 °C. The solvent was exchanged into cyclopentyl methyl ether (approximately 9 volumes) by distillation under reduced pressure and the resulting suspension was stirred at 40 °C for 1 hour. The mixture was cooled to 20 °C and stirred overnight. The resulting solid was collected and washed with cyclopentyl methyl ether (4 vol) and dried at 45°C under vacuum to give crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2. Figure 2 shows the powder X-ray diffraction pattern of crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2 prepared by this method, wherein powder X-ray diffraction (PXRD) analysis was performed using the instrumental methods described in Example 77.

Example 73

Preparation of seed crystals of crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 3

The reactor was charged with 2-methyltetrahydrofuran (20 volumes) containing methyl 4-[(Z)-2-ethoxyethenyl]-2-[2-fluoro-4-(methylsulfanyl)anilino]-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate, prepared as described in Example 71, step 1 (5.0 kg; limiting reagent - all subsequent charges are based on this amount) and O-(2-(tertbutoxy)ethyl)hydroxylamine hydrochloride (2.89 kg). The mixture was then heated to 70 °C. After completion of the reaction, the mixture was cooled to 20 °C and borane-pyridine complex (8 M, 3.3 L) and HCl in CPME (3 M, 5.95 L) were added. The mixture was stirred at 20 °C. After completion of the reduction reaction, the mixture was heated to 65 °C until the cyclization reaction was complete. The reaction mixture was cooled to 25 °C, quenched with 1 M HCl (6 vol), and washed with water (8 vol). The organic layer was concentrated to approximately 7 vol. Phosphoric acid (13.1 L) was charged and the resulting mixture was heated to 60 °C until the deprotection reaction was complete. The reaction mixture was quenched with aqueous 45 wt % potassium hydroxide solution (22.8 L) (7 vol) and then washed with water (10 vol). The organic layer was then filtered through a filter. At the reaction temperature of 45 °C, the organic layer was concentrated to approximately 5 vol and the water content was determined by the KF Karl Fischer method and corrected to 5% water content. Approximately 5% of the reaction mixture was removed and cooled to 20 °C to give a slurry that was charged back to the reactor to seed the entire contents of the reactor. After stirring at 45°C for three hours, the solvent was exchanged with CPME (8 vol), leaving approximately 5%-10% 2-MeTHF and at least 0.5% Karl Fischer water. The reaction mixture was then cooled to 15°C over 3 hours and granulated for 8 hours. The solids were collected and washed with CPME (4 vol). The solids were dried under vacuum to remove residual solvent. The drying process allowed dehydration of the solid form to crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2. The resulting crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2 was then rehydrated in an oven (without vacuum) at 25-40°C using traces of water. The final solids were rehydrated to give crystalline 8-((2-fluoro-4-(methyl-thio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione monohydrate, form 3, based on the results of Karl Fischer analysis of water and powder X-ray diffraction (PXRD) analysis, where the PXRD analysis was performed using the instrumental methods described in Example 77.

Example 74

Preparation of crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 3 by seeded crystallization

The reactor was charged with 2-MeTHF (6 volumes, 19 L) and water (0.27 volumes, 0.87 L). Amorphous 8-((2-fluoro-4-(methylthio)-phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, prepared in the same manner as in Example 6, Method A or B (3.22 kg), was added and the mixture was heated to 65°C. During this time, the solid dissolved to give a solution. The mixture was cooled to 45°C and seeded with crystalline 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione monohydrate, Form 3, prepared in Example 73. The mixture was stirred for approximately 2 hours, then heptane (4 vol) was slowly charged over 3 hours. The mixture was cooled to 15°C over 4 hours and stirred for at least 2 hours. The solids were then collected and washed with 50:50 heptane/2-MeTHF (4 vol, 13 L). The solids were dried under vacuum to remove residual solvent. The drying process resulted in dehydration of the solid form to form crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2. The resulting crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2 was then rehydrated in an oven (without vacuum) at 25-40°C using traces of water. After standing in an oven for 8-24 h, the solid rehydrated to form crystalline 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione monohydrate, form 3, as confirmed by Karl Fischer water analysis and powder X-ray diffraction (PXRD) analysis.

Example 75

Alternative preparation of crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 3

Amorphous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, prepared in the same manner as in Example 6, Method A or B (404.88 mg), was combined with 2-propanol (1.50 mL, 3.7 vol) under magnetic stirring. The mixture was heated to 60°C. During this time, the mixture became homogeneous, dark red in color, and all solids had dissolved. Water (2.5 mL, 6.2 vol) was added, and the mixture was cooled to room temperature and stirred for 2 h. During this time, solids precipitated and the mixture became quite thick. A larger magnetic stirrer was then used. An aliquot was removed for powder X-ray diffraction (PXRD) analysis and the mixture was stirred at room temperature. After stirring overnight, the solid was collected and washed with 9:12-propanol:water (2 x 1.00 mL). Dry in a preheated oven at 50 °C with a water cuvette for 3 h, then left overnight without a lid in place. 371 mg, 91% recovery. The isolated material was determined by PXRD analysis to be crystalline 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione monohydrate, Form 3. Figure 3 shows the powder X-ray diffraction pattern of crystalline 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione monohydrate, Form 3, obtained by this method, wherein the PXRD analysis was performed using the instrumental methods described in Example 77.

Example 76

Moisture absorption analysis of crystalline monohydrate of 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 3

Water sorption and desorption studies were performed on an automated vapor sorption analyzer (TA instruments Q5000 SA). The microbalance was calibrated using a 100 mg standard weight. The relative humidity sensor was calibrated at relative humidity (RH) of 5.0, 11.3, 32.8, 52.8, 75.3 and 84.3% (25 °C) using saturated salt solutions. Approximately 10-20 mg of crystalline 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione monohydrate, form 3 was placed in a quartz sample holder and dried at a relative humidity (RH) ≤ 3% at 25 °C. The RH value was then gradually increased from 0% to 40% RH in 5% increments, then decreased to a final RH value of 0% RH in 5% increments. A maximum equilibration time of 120 minutes was used for all stages. The mass increment for each % RH stage was determined relative to the mass after the initial drying stage at 0% RH. The mass change of the sample was not used to assess whether equilibrium had been reached, and instead all stages were programmed to last 120 minutes. After data collection was complete, the data were analyzed using TA's general-purpose data analysis software and Microsoft Excel.

Figure 5 shows the sorption isotherm for crystalline 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione monohydrate, Form 3. As shown in Figure 5, crystalline 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione monohydrate, Form 3 dehydrates to crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 2 at 15% RH and 25°C, confirmed by PXRD analysis. Crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2 rehydrates to crystalline 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione monohydrate, Form 3 at 25% RH at 25°C, as confirmed by PXRD analysis. Based on this analysis, crystalline anhydrous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 2 is stable at RH below 10% at 25°C, and crystalline monohydrate 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, Form 3 is stable at RH above 30% at 25°C.

Example 77

General methods for the analysis of solid forms by powder X-ray diffraction (PXRD)

Instrumental methods

Powder X-ray diffraction analysis of anhydrous crystalline 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 1, anhydrous crystalline 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, form 2 and amorphous 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione form 4 was performed on a diffractometer A Rigaku MiniFlex 6G equipped with a Cu radiation source was used. The sample was prepared using a zero-background silicon sample holder (2 mm × 0.5 mm well). The diffracted radiation was recorded using a D/teX Ultra2 detector. The X-ray tube voltage and current were set to 40 kV and 15 mA, respectively. Data were collected in a Miniflex goniometer at a Cu wavelength of 3.0 to 45.0° 2-theta using a step size of 0.02° and a step speed of 2.00°/min. The primary slit was set to 1.25° and the slit length was set to 10 mm. The sample was rotated at 10 rpm during data collection. Data were exported to a *txt file using Rigaku's SmartLab Studio II software and data analysis was performed using EVA diffract plus software. As demonstrated in Example 76, anhydrous Form 2 rehydrates to monohydrate Form 3 at 25% RH at 25°C. Therefore, PXRD analysis of anhydrous Form 2 was performed at approximately 25°C and a relative humidity below 10%.

Powder X-ray diffraction analysis of crystalline 8-((2-fluoro-4-(methylthio)phenyl)-amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione monohydrate, form 3 was performed on a Bruker AXS D8 Endeavor diffractometer equipped with a Cu radiation source. The divergence slit was set to 10 mm with constant illumination. Diffracted radiation was recorded with a PSD-Lynx Eye detector, while the PSD detector opening was set to 4.11 degrees. The voltage and current on the X-ray tube were set to 40 kV and 40 mA, respectively. Data were collected at a Cu wavelength in a Theta-Theta goniometer from 3.0 to 40.0 degrees 2-theta. A step size of 0.02 degrees and a time step of 0.3 seconds were used. The anti-scatter screen was fixed at 1.5 mm. Samples were rotated during data acquisition. Samples were prepared by placing them in a zero-background silicon sample holder and rotating them during data acquisition. Data were acquired using Bruker DIFFRAC Plus software and analyzed using EVA diffract plus. The PXRD data file was not processed prior to peak searching. Using the peak searching algorithm in EVA, peaks selected with a threshold of 1 were used for preliminary peak assignments. To ensure reliability, corrections were made manually; the output of the automatic assignments was inspected visually and peak locations were corrected for peak maximum. Peaks with a relative intensity ≥3% were typically selected. Typically, peaks that were not resolved or were comparable to noise were not selected. The typical error associated with the position of a peak in a powder X-ray diffraction pattern officially accepted by the United States Pharmacopeia (USP) is +/- 0.2° 2-theta (USP-941). As shown in Example 76, Form 3 monohydrate dehydrates to anhydrous Form 2 at 15% RH and 25°C. Accordingly, PXRD analysis of Form 3 monohydrate was performed at approximately 25°C and a relative humidity above 30%.

PXRD Peak Selection Parameter

Using the peak-finding algorithm in EVA, peaks selected with a threshold of 1 were used for preliminary peak assignments. To ensure reliability, corrections were made manually; the output of the automatic assignments was inspected visually and peak locations were adjusted to the peak maximum. Peaks with a relative intensity ≥3% were typically selected. Peaks that were unresolved or comparable to noise were not selected. The typical error associated with peak position in powder X-ray diffraction patterns officially accepted by the United States Pharmacopeia (USP) is +/- 0.2° 2-theta (USP-941).

It is obvious to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope or spirit of the invention. After reading the description and practicing the invention, it is obvious to those skilled in the art that there are other embodiments of the invention. It is intended that the description and examples serve only for illustration, and the true scope and spirit of the invention are defined by the claims below.

The entire contents of all literature cited in the invention, including patents, patent applications, articles, textbooks and other similar publications, as well as the contents of publications cited in these sources, are incorporated into the present invention by reference. In the event that the defined terms, the use of terms, the described methods and other similar definitions in the literature cited in the invention differ from or contradict those set forth in the present invention, the present invention has priority.

The entire contents of U.S. Provisional Patent Application No. 63/168,456, filed March 31, 2021, and U.S. Provisional Patent Application No. 63/309,346, filed February 11, 2022, are incorporated herein by reference.

Claims (121)

1. Compound of formula I or a pharmaceutically acceptable salt thereof, where R ¹ is H, Br, C1-C6 alkyl or phenyl; R ² is H, halogen or CH ₃ -; R ³ is H, hydroxyC1-C6 alkyl-, hydroxyC1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl or (C3-C6 cycloalkyl)C1-C6 alkoxy-; and R ⁴ is phenyl substituted with 1, 2 or 3 substituents independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl and C1-C6 alkyl-C(=O)-. 2. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, wherein R ¹ is H. 3. The compound according to claim 1 or 2 or a pharmaceutically acceptable salt thereof, wherein R ² is H. 4. The compound according to claim 1 or 2 or a pharmaceutically acceptable salt thereof, wherein R ² is CH ₃ -. 5. A compound according to any one of claims 1-4 or a pharmaceutically acceptable salt thereof, wherein R ³ is hydroxyC1-C6 alkyl-. 6. A compound according to any one of claims 1 to 5, or a pharmaceutically acceptable salt thereof, wherein R ⁴ is phenyl substituted with 1 or 2 substituents independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl and C1-C6 alkyl-C(=O)-. 7. A compound according to any one of claims 1 to 5 or a pharmaceutically acceptable salt thereof, wherein R ⁴ is phenyl substituted with 1 or 2 substituents independently selected from halogen and C1-C6 alkylthio. 8. Compound of formula II or a pharmaceutically acceptable salt thereof, where R ¹ is H, Br, C1-C6 alkyl or phenyl; R ² is H, halogen or CH ₃ -; R ³ is H, hydroxyC1-C6 alkyl-, hydroxyC1-C6 alkoxy-, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl or (C3-C6 cycloalkyl)C1-C6 alkoxy-; and R ^a and R ^b are independently selected from halogen, C1-C6 alkyl, C1-C6 alkylthio, fluoroC1-C6 alkylthio, fluoroC1-C6 alkyl, C1-C6 alkoxy, fluoroC1-C6 alkoxy, C3-C6 cycloalkyl, and C1-C6 alkyl-C(=O)-. 9. The compound according to claim 8 or a pharmaceutically acceptable salt thereof, wherein R ^a is halogen. 10. The compound according to claim 8 or 9 or a pharmaceutically acceptable salt thereof, wherein R ^b is halogen, C1-C6 alkyl, C1-C6 alkylthio or fluoroC1-C6 alkoxy. 11. The compound according to item 1, selected from the following compounds: 8-((4-bromo-2-fluorophenyl)amino)-2-cyclopropyl-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-2-(cyclopropylmethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-2-ethoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 2-cyclopropyl-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 2-cyclopropyl-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-chloro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-chlorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2,3-difluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-3-chloro-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-(trifluoromethyl)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-ethyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-cyclopropyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-methoxyphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-((trifluoromethyl)thio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-isopropylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-chloro-4-cyclopropylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-acetyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-chloro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-chloro-4-ethylphenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-(trifluoromethoxy)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-((difluoromethyl)thio)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-2-isopropoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-iodophenyl)amino)-2-isopropoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 2-ethoxy-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-iodophenyl)amino)-2-methoxy-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 2-(tert-butoxy)-8-((2-fluoro-4-iodophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; (S)-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; (R)-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; (S)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; (R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; (R)-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxypropoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-5-chloro-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 5-chloro-8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-5-fluoro-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-iodophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5-iodo-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 5-bromo-8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 4-bromo-8-((2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-ethyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-cyclopropyl-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-iodophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-iodo-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-ethyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-cyclopropyl-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-propylphenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-(methylthio)phenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-ethyl-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-cyclopropyl-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-chlorophenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethyl)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-(difluoromethoxy)-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-5,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 2-(2,2-difluoroethoxy)-8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-7-methyl-4-phenyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-(methylthio)phenyl)amino)-7-methyl-4-phenyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-(methylthio)phenyl)amino)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((4-bromo-2-fluorophenyl)amino)-2-(2-hydroxyethoxy)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-4,7-dimethyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione; or a pharmaceutically acceptable salt thereof. 12. A compound which is 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, having the structure or a pharmaceutically acceptable salt thereof. 13. A compound which is 8-((2-fluoro-4-(methylthio)phenyl)amino)-2-(2-hydroxyethoxy)-7-methyl-3,4-dihydro-2,7-naphthyridine-1,6(2H,7H)-dione, having the structure 14. A pharmaceutical composition having MEK inhibitory activity, comprising an effective amount of a compound according to any one of claims 1-13 or a pharmaceutically acceptable salt thereof and at least one pharmaceutically acceptable excipient. 15. A method for treating a MEK-associated tumor, comprising administering to a subject in need thereof a therapeutically effective amount of a compound according to claim 12. 16. The method of claim 15, wherein the tumor has a BRAF V600 mutation selected from V600E, V600K, V600D, V600R, and V600S. 17. The method according to claim 15 or 16, wherein the tumor has a BRAF V600 mutation. 18. The method according to any one of claims 15-17, wherein the tumor is a CNS tumor. 19. The method according to claim 18, wherein the CNS tumor is an intracranial tumor. 20. The method according to claim 19, wherein the intracranial tumor is brain cancer. 21. The method of claim 20, wherein the brain cancer is metastatic brain cancer. 22. The method according to claim 21, wherein the metastatic brain cancer is selected from metastatic melanoma, metastatic colorectal cancer, metastatic non-small cell lung cancer, metastatic thyroid cancer, and metastatic ovarian cancer. 23. The method of claim 18, wherein the CNS tumor is intracranial leptomeningeal disease (LMD) or extracranial leptomeningeal disease (LMD). 24. The method of claim 23, wherein the leptomeningeal disease (LMD) is selected from metastatic melanoma, metastatic colorectal cancer, and metastatic non-small cell lung cancer. 25. The method of claim 19, wherein the intracranial tumor is a primary tumor. 26. The method according to claim 25, wherein the primary brain tumor is a malignant tumor. 27. The method of claim 26, wherein the primary brain tumor is a grade 2, grade 3, or grade 4 glioma. 28. The method according to claim 27, wherein the primary brain tumor is a benign tumor. 29. The method of claim 15, wherein the tumor has BRAF fusion. 30. The method of claim 29, wherein the tumor has a BRAF fusion selected from KIAA1154 9-BRAF, MKRN1-BRAF, TRIM24-BRAF, AGAP3-BRAF, ZC3HAV1-BRAF, AKAP9-BRAF, CCDC6-BRAF, AGK-BRAF, EPS15-BRAF, NUP214-BRAF, ARMC10-BRAF, BTF3L4-BRAF, GHR-BRAF, ZC3HAV1-BRAF, ZNF767-BRAF, CCDC91-BRAF, DYNC112-BRAF, ZKSCAN1-BRAF, GTF2I-BRAF, MZT1-BRAF, RAD18-BRAF, CUX1-BRAF, SLC12A7-BRAF, MYRIP-BRAF, SND1-BRAF, NUB1-BRAF, KLHL7-BRAF, TANK-BRAF, RBMS3-BRAF, STRN3-BRAF, STK35-BRAF, ETFA-BRAF, SVOPL-BRAF and JHDM1D-BRAF. 31. The method of claim 30, wherein the tumor is breast carcinoma, colorectal carcinoma, esophageal carcinoma, glioma, head and neck carcinoma, lung carcinoma, melanoma, pancreatic carcinoma, prostate carcinoma, sarcoma, thyroid carcinoma, carcinoma of unknown primary site, pleural mesothelioma, rectal adenocarcinoma, uterine endometrial carcinoma, or ovarian serous carcinoma. 32. The method according to claim 15, wherein the tumor is a tumor with a non-mutant type (wild type) BRAF. 33. The method according to any one of paragraphs 15-32, wherein the subject is a human. 34. A compound according to any one of claims 1-13 or a pharmaceutically acceptable salt thereof for use as a medicinal product for the treatment of a MEK-associated tumor. 35. A compound according to any one of claims 1-13 or a pharmaceutically acceptable salt thereof for use in the treatment of a MEK-associated tumor. 36. Use of a compound according to claim 12 or a pharmaceutically acceptable salt thereof for the manufacture of a medicinal product for the treatment of a MEK-associated tumor in a subject.

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