TW202535871A - Compounds for the treatment of kidney disease - Google Patents

Abstract

The disclosure provides polycystin-1 (PC1) correctors, pharmaceutical compositions containing at least one such corrector, methods of treating autosomal dominant polycystic kidney disease using such correctors and pharmaceutical compositions, and processes for making such correctors.

Description

Compounds used to treat kidney disease

without

Somatic dominant polycystic nephropathy (ADPKD) is a genetic disorder characterized by bilateral cysts in the kidneys. The cysts in ADPKD are non-cancerous, fluid-filled vesicles. Enlarged cysts can substantially increase kidney size, leading to compression, loss of surrounding kidney tissue, and a gradual decline in kidney function. The damage caused by enlarged cysts and increased kidney size ultimately leads to end-stage renal disease (ESKD), kidney failure, and premature death. ADPKD is a heterogeneous kidney disease with a wide range of symptoms, including hypertension, nocturia, polyuria, hematuria, palpable kidney, kidney stones, abdominal and peritoneal pain, recurrent urinary tract infections, intracranial aneurysm, vascular dissection, valvular heart disease, liver and/or pancreatic cysts, diverticulosis, and abdominal wall hernia. It affects approximately 1 in 400 to 1,000 people and is the most common hereditary kidney disease. Approximately 50% of ADPKD patients progress to end-stage renal disease (ESRD) by a median age of 58, making it the fourth leading cause of ESRD worldwide. However, cardiovascular and cerebrovascular complications are the leading cause of death in ADPKD patients. ( Cornec-Le Gall et al., Autosomal master polycystic kidney disease. Lancet. 2019;393(10174):919-35.)

ADPKD is a Mendelian disease, most commonly caused by a loss-of-germline mutation in either the PKD1 (encoding polycystin-1 (PC1)) or PKD2 (encoding polycystin-2 (PC2)) allele of the polycystin (PC) gene. A mutation in either gene results in reduced expression of the PC1-PC2 complex on the cell membrane. An analysis of over 1,100 ADPKD patients revealed that nearly 80% of ADPKD patients had a PKD1 germline mutation, and PKD1 mutations typically lead to more severe disease than PKD2 mutations. Heyer et al., Predicted Mutation Strength of Nontruncating PKD1 Mutations Aids Genotype-Phenotype Correlations in Autosomal Dominant Polycystic Kidney Disease. 2016; J Am Soc Nephrol 27(9): 2872-2884. Approximately one-third of these patients have nontruncated PKD1 mutations, which typically lead to ESKD around age 60-66. These nontruncated PKD1 mutations result in dysfunctional misfolded PC1 cells.

Mutations in PKD1 or PKD2 lead to reduced expression of the PC1-PC2 complex on the cell membrane. (Torres et al. , Autosomal dominant polycystic kidney disease. Lancet. 2007;369(9569):1287-301; Rastogi et al., Autosomal dominant polycystic kidney disease: updated perspectives. Ther Clin Risk Manag. 2019;15(1041-52).) Although the exact molecular function is unknown, decreased activity leads to renal epithelial cell proliferation, cyst formation, and fluid secretion into the cysts. Kidney survival data suggest that germline, non-truncated mutations targeting PKD1 result in low-content proteins reaching the membrane that retain some residual function. Hopp et al., Functional polycystin-1 dosage governs autosomal dominant polycystic kidney disease severity. J Clin Invest. 2012; 122(11):4257-73 . This can also occur in some truncated mutations. Rare case studies of patients carrying low-form PKD1 mutations have helped to inform the genetic dose-response model of ADPKD severity. Id . Although cyst growth depends on a range of PC1 doses with varying expression levels, existing data suggest that a critical threshold of 20-30% of WT/WT cell surface PC1 expression is required to prevent cyst development. Lanktree et al., Insights into Autosomal Dominant Polycystic Kidney Disease from Genetic Studies. Clinical Journal of the American Society of Nephrology. 2021;16(5):790-99; Gainullin et al., Polycystin-1 maturation requires polycystin-2 in a dose-dependent manner. J Clin Invest. 2015;125(2):607-20; and Ong and Harris, A polycystin-centric view of cyst formation and disease: the polycystins revisited. Kidney Int. 2015;88(4):699-710. Recently, two independent animal studies in adult-onset ADPKD mouse models have demonstrated that PKD1 gene reexpression has anti-cystic potential in a pre-existing cystic background ( Torres , Rastogi ).

Current treatments for ADPKD include medications aimed at slowing the growth rate of kidney cysts and thus reducing kidney function; medications aimed at controlling high blood pressure to delay disease progression and reduce kidney damage; medications for treating/controlling pain associated with polycystic kidney disease; medications for treating bladder and kidney infections; dialysis; kidney transplantation; and surgical or non-surgical interventions for aneurysms. All of these treatments are symptomatic and do not address the underlying cause of the disease. Therefore, it is crucial to address the root cause of the disease, restore PC1 function and translation, alleviate ADPKD symptoms, and slow or halt the decline in kidney function, cyst pain, and adverse cerebrovascular events.

The compounds of this invention can be used as PC1 regulators to increase the amount of PC1 on the surface of functional cells. These compounds can be administered to patients with non-truncated mutations in the PKD1 gene, and in some cases to patients with truncated mutations in the PKD1 gene, to reduce the symptoms of ADPKD and to alleviate or prevent renal function decline, cyst pain, and adverse cerebrovascular events.

The compounds of this invention include those of formula I: (Formula I) and tautomers or transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of those compounds, tautomers, transconjugates and deuterated derivatives, wherein: - It can be a single key or a double key, where when a single key is present, _x1 is... And x ₂ is And when a double key exists, _x1 is And x ₂ is - Each ^R1 is independently selected from hydrogen, _C1 - _C3 alkyl (substituted by 0 to 2 groups selected from lateral, hydroxyl, and amino groups), _C1 - _C3 alkoxy, halogen, and cyano; - Each ^R2 is independently selected from hydrogen and _C1 - _C3 alkyl; - ^R3 is selected from hydrogen, _C1 - _C3 alkyl, halogen, and cyano; - Each ^R4 and ^R5 is independently selected from hydrogen, _C1 - _C3 alkyl, and halogen; - ^R6 and ^R9 are independently selected from hydrogen, _C1 - _C3 alkyl, _C1 - _C3 alkoxy, halogen, and cyano; - ^R7 is selected from hydrogen, _C1 - _C3 alkyl, and halogen; and - ^R8 is selected from: ○ hydrogen, ○ C ₁ - _C8 alkyl, substituted by 0 to 5 independently selected groups of: ■ hydroxyl, ■ lateral group, ■ amino, ■ cyano, ■ halogen, ■ _C1 - _C3 alkoxy (substituted by 0 to 1 lateral group), ■ _C3 - _C6 cycloalkyl (substituted by 0 to 2 independently selected groups of hydroxyl, halogen, and _C1 - _C3 alkyl), ■ 3 to 7-membered heterocyclic (substituted by 0 to 3 independently selected groups of halogen, hydroxyl, lateral group, and _C1 - _C3 alkyl (substituted by 0 to 1 hydroxyl group), and ■ 5 to 6-membered heteroaryl (substituted by 0 to 3 independently selected groups of lateral group, _C1 - _C3 alkyl, and C3- _C6 alkyl). _{○ 6} -cycloalkyl group substitution); ○ _C3 - _C7 cycloalkyl, which is substituted by 0 to 3 independently selected from the following groups: ■ hydroxyl, ■ halogen, ■ _C1 - _C3 alkyl (which is substituted by 0 to 3 independently selected from hydroxyl and halogen), ■ _C1 - _C3 alkoxy; and ○ 5 to 9-membered heterocyclic, which is substituted by 0 to 3 independently selected from the following groups: ■ lateral oxy, ■ halogen ■ hydroxyl, and ■ _C1 - _C3 alkyl (which is substituted by 0 to 1 hydroxyl); and -Y is selected from ○ ^OR8 , ○ N( ^R8 ) ₂ , and ○ 3 to 10 member heterocyclic or 3 to 10 member heteroaryl, each substituted by 0 to 2 independently selected from the following groups: ■ N( ^R8 ) ₂ , ■ hydroxyl, ■ lateral group, ■ _C1 - _C3 alkoxy, and ■ _C1 - _C3 alkyl (substituted by 0 to 2 groups selected from amino, hydroxyl, _C3 - _C4 alkyl, lateral group and _C1 - _C3 alkoxy).

The compounds of this invention include compounds of formula Ia: (Formula Ia) and their tautomers or transisomers, deuterated derivatives of their compounds, tautomers and transisomers, and pharmaceutically acceptable salts and prodrugs of their compounds, tautomers, transisomers and deuterated derivatives, wherein: - each ^R1 is independently selected from hydrogen, _C1 - _C3 alkyl, _C1 - _C3 alkoxy, halogen and cyano; - each ^R2 is independently selected from hydrogen and _C1 - _C3 alkyl; - ^R3 is selected from hydrogen, _C1 - _C3 alkyl, halogen and cyano; - ^R4 and ^R5 are independently selected from hydrogen, _C1 -C3 alkyl and halogen; - ^R6 and ^R9 are independently selected from hydrogen, _C1 - _C3 alkyl and halogen. - _R7 is selected from hydrogen, _{C1 -C3 alkyl} , halogen, and cyano; and - ^R8 is selected from: ○ hydrogen, ○ _C1 - _C8 alkyl, which is substituted by 0 to 5 independently selected from the following groups: ■ hydroxyl, ■ lateral, ■ amino, ■ cyano, ■ halogen, ■ _C1 - ^C3 alkoxy (which is _substituted by 0 to 1 lateral), ■ _C3 - _C6 cycloalkyl (which is substituted by 0 to 2 independently selected from hydroxyl, halogen, and _C1 - _C3 alkyl), ■ 3 to 6-membered heterocyclic (which is substituted by 0 to 3 independently selected from halogen, hydroxyl, lateral, and _C1 - _C6 cycloalkyl). _{○ 3} -membered heterocyclic groups (substituted with 0 to 1 hydroxyl group), and ■ 5 to 6-membered heteroaryl groups (substituted with 0 to 3 independently selected from lateral oxygen, _C1 - _C3 alkyl and C3- _{C6 cycloalkyl} groups); ○ _C3 - _C7 cycloalkyl groups, substituted with 0 to 3 independently selected from the following groups: ■ hydroxyl, ■ halogen, ■ _C1 - _C3 alkyl groups (substituted with 0 to 3 independently selected from hydroxyl and halogen groups), ■ _C1 - _C3 alkoxy; and ○ 5 to 9-membered heterocyclic groups, substituted with 0 to 2 independently selected from the following groups: ■ lateral oxygen, ■ hydroxyl, and ■ _C1 - _C3 alkyl groups (substituted with 0 to 1 hydroxyl group).

The compounds of this invention also include compounds of formula Ib: (Formula Ib) and tautomers or transisomers of such compounds, deuterated derivatives of such compounds, tautomers and transisomers, and pharmaceutically acceptable salts and prodrugs of such compounds, tautomers, transisomers and deuterated derivatives, wherein: - each ^R1 is independently selected from hydrogen, _C1 - _{C3 alkyl (which is substituted by 0 to 2 groups selected from lateral, hydroxyl and amino), C1-C3 alkoxy, halogen and cyano; - each R2 is independently selected from hydrogen and C1-C3 alkyl; - R3 is selected from hydrogen, C1-C3 alkyl ,} ^halogen _{and cyano} ^; _{- each} ^R4 and ^R5 is independently selected from hydrogen, _C1 -C3 alkyl, halogen and cyano. _3. Alkyl and halogen; - ^R6 and ^R9 are independently selected from hydrogen, _C1 - _C3 alkyl, _C1 - _C3 alkoxy, halogen and cyano; - ^R7 is selected from hydrogen, _C1 - _C3 alkyl and halogen; and - ^R8 is selected from: ○ hydrogen, ○ _C1 - _C8 alkyl, which is substituted by 0 to 5 independently selected from the following groups: ■ hydroxyl, ■ lateral, ■ amino, ■ cyano, ■ halogen, ■ _C1 - _C3 alkoxy (which is substituted by 0 to 1 lateral), ■ _C3 - _C6 cycloalkyl (which is substituted by 0 to 2 independently selected from hydroxyl, halogen, _C1 - _C3 alkyl), ■ 3 to 6-membered heterocyclic groups (substituted by 0 to 3 independently selected groups selected from halogen, hydroxyl, lateral, and _C1 -C3 _alkyl groups (substituted by 0 to 1 hydroxyl), and ■ 5 to 6-membered heteroaryl groups (substituted by 0 to 3 independently selected groups selected from lateral, _C1 - _C3 alkyl, and _C3 - _C6 cycloalkyl); ○ _C3 - _C7 cycloalkyl groups, substituted by 0 to 3 independently selected groups of: ■ hydroxyl, ■ halogen, ■ _C1 - _C3 alkyl groups (substituted by 0 to 3 independently selected groups selected from hydroxyl and halogen), ■ _C1 - _C3 alkoxy; and ○ 5 to 9-membered heterocyclic groups, which are substituted by 0 to 2 independently selected groups of: ■ lateral group, ■ hydroxyl group, and ■ _C1 - _C3 alkyl group (which are substituted by 0 to 1 hydroxyl group); - Y is selected from ○ N( ^R8 ) ₂ and ○ 3 to 10-membered heterocyclic groups or 3 to 10-membered heteroaryl groups, each substituted by 0 to 2 independently selected groups of: ■ hydroxyl group, ■ lateral group, ■ _C1 - _C3 alkoxy group, and ■ _C1 - _C3 alkyl group (which are substituted by 0 to 2 groups selected from amino, hydroxyl, _C3 - _C4 alkyl, lateral group and _C1 - _C3 alkoxy group).

The compounds disclosed in this article also include compounds of formula II: (Formula II), and tautomers or transconjugates of such compounds, deuterated derivatives of such compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of such compounds, tautomers, transconjugates and deuterated derivatives, wherein: - each ^R1 is independently selected from hydrogen, _C1 - _C3 alkyl, _C1 -C3 alkoxy, halogen and cyano; - ^R6 is selected from _C1 - _C3 alkyl, halogen and cyano; - _R7 is selected from hydrogen, _C1 - _C3 ^alkyl and halogen; and - ^R8 is as defined in Formula Ia.

The compounds disclosed in this article also include compounds of formula IIa: (Formula IIa), and tautomers or transconjugates of such compounds, deuterated derivatives of such compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of such compounds, tautomers, transconjugates and deuterated derivatives, wherein: ^R1 is selected from hydrogen, _C1 - _C3 alkyl, _C1 - _C3 alkoxy, halogen and cyano; and all other variables are as defined in Formula II above.

The compounds disclosed in this article also include compounds of formula IIb: (Formula IIb), and tautomers or trans-isomers of such compounds, deuterated derivatives of such compounds, tautomers and trans-isomers, and pharmaceutically acceptable salts and prodrugs of such compounds, tautomers, trans-isomers and deuterated derivatives, wherein: - each ^R1 is independently selected from hydrogen and halogen; - ^R6 is selected from halogen; and - ^R8 is selected from: ○ _C1 - _C5 alkyl groups, which are substituted by 0 to 5 independently selected from the following groups: ■ hydroxyl, and ■ _C3 - _C6 cycloalkyl; ○ _C3 - _C6 cycloalkyl groups, which are substituted by 0 to 2 groups selected from hydroxyl and halogen; and ○ Five to six heterocyclic groups, which are either unsubstituted or substituted with _C1 -C3 _alkyl groups, wherein the _C1 - _C3 alkyl groups are substituted with 0 to 2 substituents selected from hydroxyl and halogen.

The compounds disclosed herein can be used in pharmaceutical compositions, such as in the manufacture of drugs. The compounds and pharmaceutical compositions of this invention can be administered to treat ADPKD.

This application asserts priority over U.S. Provisional Application No. 63/594,357, filed October 30, 2023, the contents of which are incorporated herein by reference in their entirety. Definitions

As used herein, the term "alkyl" refers to a saturated or partially saturated, branched or unbranched aliphatic hydrocarbon containing carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 carbon atoms), which may contain a double bond (alkenyl) or a triple bond (alkynyl) between one or more sets of adjacent carbon atoms. Alkyl groups may be substituted or unsubstituted. In some embodiments, the alkyl group contains 1 to 10 alkyl carbon atoms. In other embodiments, the alkyl group contains 1 to 8 alkyl carbon atoms. In still other embodiments, the alkyl group contains 1 to 6 alkyl carbon atoms, and in still other embodiments, the alkyl group contains 1 to 4 alkyl carbon atoms or 1 to 3 alkyl carbon atoms.

As used herein, the term "aliphatic" or "aliphatic group" refers to a fully saturated or branched, substituted or unsubstituted hydrocarbon chain containing one or more unsaturated units, or a fully saturated or bicyclic hydrocarbon (also referred to herein as "cycloaliphatic,""carbocyclic," or "cycloalkyl") containing one or more unsaturated units but not aromatic, having a single attachment site to the remainder of the molecule. Unless otherwise stated, an aliphatic group contains 1 to 20 aliphatic carbon atoms. In some embodiments, an aliphatic group contains 1 to 10 aliphatic carbon atoms. In other embodiments, an aliphatic group contains 1 to 8 aliphatic carbon atoms. In other embodiments, the aliphatic group contains 1 to 6 aliphatic carbon atoms, and in still other embodiments, the aliphatic group contains 1 to 4 aliphatic carbon atoms. In some embodiments, "cycloaliphatic" (or "carbocyclic" or "cycloalkyl") means a monocyclic _C3 - _C8 hydrocarbon or a bicyclic or tricyclic _C8 - _C14 hydrocarbon that is fully saturated or contains one or more unsaturated units but is not aromatic, having a single attachment site to the remainder of the molecule, wherein any single ring in the monocyclic, bicyclic or tricyclic system has 3 to 7 members. Suitable aliphatic groups include (but are not limited to) straight-chain or branched, substituted or unsubstituted alkyl, alkenyl or ynyl groups and mixtures thereof, such as (cycloalkyl)alkyl, (cycloalkenyl)alkyl and (cycloalkyl)alkenyl. Suitable cycloaliphatic groups include cycloalkyl, bicycloalkyl (e.g., decalin), crosslinked bicycloalkyl (e.g., norcamphenyl or [2.2.2]bicyclooctyl), and crosslinked tricyclic (e.g., adamantyl).

As used in this article, the term "unsaturated" refers to a part having one or more unsaturated units.

As used herein, the term "π bond" refers to a covalent bond formed by the p orbitals of adjacent atoms. π bonds exist when multiple bonds (i.e., double bonds or parabolic bonds) exist between two atoms. For example, a carbon-carbon double bond consists of one π bond, and a carbon-carbon parabolic bond consists of two π bonds.

As used in this article, the term "halogen" or "halogen" refers to F, Cl, Br, or I.

As used herein, the term "halogenated alkyl" refers to an alkyl group substituted with one or more halogen atoms, such as a fluoroalkyl group, which refers to an alkyl group substituted with one or more fluorine atoms. In some embodiments, the halogenated alkyl group contains 1 to 5 halogen atoms. In some embodiments, the halogenated alkyl group contains 1 to 3 halogen atoms. In some embodiments, the halogenated alkyl group contains 3 to 5 halogen atoms. In some embodiments, one carbon atom of the alkyl group is substituted with one or more halogen atoms. In some embodiments, each carbon atom of the alkyl group is substituted with one or more halogen atoms. In some embodiments, one or more carbon atoms of the alkyl group are all-halogenated carbon atoms (i.e., all hydrogen atoms of the alkyl group are substituted with halogen atoms). In some embodiments, each carbon atom of the alkyl group is all-halogenated carbon atoms. Non-limiting examples of halogens include _—CHF2 , _—CH2F , _—CF3 , _—CF2— and _perhalogens , such as _—CF2CF3 .

As used in this article, the terms "side oxygen" and "=O" refer to an oxygen substituent that is linked to another atom by a double bond.

As used herein, the term "alkoxy" refers to an alkyl or cycloalkyl group covalently bonded to an oxygen atom. Alkoxy groups may be substituted or unsubstituted.

As used herein, "cycloalkyl" refers to a monocyclic, bicyclic, tricyclic, or polycyclic non-aromatic hydrocarbon group having 3 to 12 carbon atoms (e.g., 3 to 10 carbon atoms), and may include one or more unsaturated bonds. In some embodiments, the cycloalkyl group contains 3 to 12 carbon ring atoms. In other embodiments, the cycloalkyl group contains 3 to 10 carbon ring atoms. In still other embodiments, the cycloalkyl group contains 3 to 9 carbon ring atoms, and in still other embodiments, the cycloalkyl group contains 3 to 8 carbon ring atoms, 3 to 7 carbon ring atoms, 3 to 6 carbon ring atoms, or 3 to 5 carbon ring atoms. "Cycloalkyl" encompasses monocyclic, bicyclic, tricyclic, bridged, fused, and spirocyclic compounds, including monospirocyclic and bispirocyclic compounds. Cycloalkyl compounds may be substituted or unsubstituted.

As used herein, the term "aryl" refers to a functional group or substituent derived from an aromatic ring, and encompasses monocyclic aromatic rings as well as bicyclic, tricyclic, and fused ring systems, wherein at least one ring in such a system is aromatic. Aryl groups may be substituted with one or more substituents, as appropriate.

The term "heteroatom" refers to one or more of oxygen, sulfur, nitrogen, phosphorus, or silicon (including any oxidized form of nitrogen, sulfur, phosphorus, or silicon; any quaternary ammonium form of basic nitrogen; and substituted nitrogen of heterocycles, such as N (e.g., in 3,4-dihydro-2H-pyrrole), NH (e.g., in pyrrolidone), or NR ⁺ (e.g., in N -substituted pyrrolidone). In some embodiments, the heteroatom is selected from oxygen, sulfur, and nitrogen.

As used herein, the term "aliphatic" refers to an aliphatic group in which one or two carbon atoms are independently replaced by one or more heteroatoms (e.g., oxygen, sulfur, nitrogen, phosphorus, or silicon). In some embodiments, the aliphatic group may be substituted with 1 to 5 heteroatoms. In some embodiments, the aliphatic group may be substituted with 1 to 3 heteroatoms. In some embodiments, the heteroatoms are selected from oxygen, sulfur, and nitrogen. In some embodiments, the aliphatic group may be substituted with 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen. In some embodiments, the aliphatic group may be substituted with 1 to 3 heteroatoms selected from oxygen, sulfur, and nitrogen. Aliphatic groups can be substituted or unsubstituted, branched or unbranched, cyclic or acyclic, and include "heterocyclic", "heterocyclic", "heterocyclic aliphatic" and "heterocyclic" groups.

As used herein, the term "hybrid aromatic ring" refers to an aromatic ring containing at least one ring atom (which is a heteroatom, such as O, N, S, P, or Si). In some embodiments, the heteroaryl ring contains at least one ring atom (which is a heteroatom selected from O, N, and S). The term heteroaryl encompasses monocyclic and bicyclic, tricyclic, bridged, fused, and spirocyclic systems (including monospirocyclic and bispirocyclic) having a total of 5 to 14 ring members, wherein at least one ring in the system is aromatic, at least one ring in the system contains one or more heteroatoms, and each ring in the system contains 3 to 7 ring members. In some embodiments, the heteroaryl ring may be substituted with 1 to 5 heteroatoms. In some embodiments, the heteroaryl ring may be substituted with 1 to 3 heteroatoms. In some embodiments, the heteroatoms in the heteroaryl ring are selected from oxygen, sulfur, and nitrogen. In some embodiments, the heteroaryl ring may be substituted with 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen. In some embodiments, the heteroaryl ring may be substituted with 1 to 3 heteroatoms selected from oxygen, sulfur, and nitrogen. The heteroaryl group may be substituted with one or more substituents, depending on the situation. In some embodiments, the term "heteroaryl ring" encompasses heteroaryl rings having various oxidation states, such as heteroaryl rings containing N -oxides and monoxides.

As used herein, the term "heterocyclic ring" refers to a non-aromatic hydrocarbon containing 3 to 12 atoms (e.g., 3 to 10 atoms) within a ring containing at least one ring atom (i.e., heteroatoms such as O, N, S, P, or Si), and may include one or more unsaturated bonds. "Heterocyclic" rings encompass monocyclic, bicyclic, tricyclic, polycyclic, bridged, fused, and spirocyclic rings, including monospirocyclic and dispirocyclic rings. In some embodiments, the heterocyclic ring has 1 to 5 heteroatoms. In some embodiments, the heterocyclic ring has 1 to 3 heteroatoms. In some embodiments, the heteroatoms in the heterocyclic ring are selected from oxygen, sulfur, and nitrogen. In some embodiments, the heterocyclic ring may be substituted with 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen. In some embodiments, the heterocyclic ring may be substituted with 1 to 3 heteroatoms selected from oxygen, sulfur, and nitrogen.

As used herein, in any chemical structure or formula, non-bold straight-link bonds, such as in compound 34: , indicates that the configuration of the center is chiral.

As used herein, in any chemical structure or formula, a non-bold tilde (e.g., "") at the center of the solid is a key-value pair of keys. (e.g., in compound 153): , indicates that the compound is isolated as a mixture of stereoisomers (e.g., a mixture of syn and/or anti isomers or a racemic mixture).

As used in this article, in any chemical structure or formula, a wavy line within one key ( This indicates the attachment point to the remaining portion of the compound. For example, when formula I... : When (Equation I) is a single key, _x1 is And x ₂ is It can be represented as For example, when equation I... : When (Equation I) is a two-key keyboard, _x1 is... And x ₂ is It can be represented as .

As used herein, in any chemical structure or formula, a bold or hashed wedge bond is attached to the stereocenter of the compound, such as in compound 60: , represents the absolute stereochemistry of the stereo center, and the relative stereochemistry of the stereo center relative to other stereo centers attached to the bold or hash wedge key.

As used herein, in any chemical structure or formula, a bold or hash linear link attached to the stereocenter of the compound, such as in compound 326: This indicates the relative stereochemistry of the stereo center relative to other stereo centers attached to the bold or hash direct chain.

As used herein, in any chemical structure or formula, the asterisk adjacent to the stereocenter of the compound, such as in compound 32: , indicates the presence of a stereocenter in the compound with an unknown absolute configuration. Compound 32 is a single stereoisomer.

As used herein, when used in conjunction with chiral compounds, the prefix " rac- " refers to a racemic mixture of the compound, such as in compound 157: In compounds prefixed with "racemic - ( rac- )," the ( R )- and ( S )- designations in the chemical name reflect the relative stereochemistry of the compound.

As used herein, when used in conjunction with chiral compounds, the prefix " rel- " refers to a single mirror isomer having an unknown absolute configuration. In compounds with the prefix " rel- ", the ( R )- and ( S )- designators in the chemical name reflect the relative stereochemistry of the compound, but not necessarily its absolute stereochemistry. If the relative stereochemistry of a given stereocenter is unknown, no stereochemistry designator is provided. In some cases, the absolute configuration of some stereocenters is known, while only the relative configuration of other stereocenters is known. In such cases, an asterisk ( ^* ) (e.g., ( R ^* )- and ( S ^* )- ) marks the stereochemical designation associated with the stereocenter of a known absolute configuration, while the stereochemical designation associated with the stereocenter of an unknown absolute configuration is not marked in this way. The unmarked stereochemical designation associated with the stereocenter of an unknown absolute configuration reflects the relative stereochemistry of those stereocenters relative to other stereocenters of the unknown absolute configuration, but does not necessarily reflect the relative stereochemistry relative to the stereocenter of a known absolute configuration.

Some compounds can exist in the form of steric isomers. It should be understood that some compounds of the present invention can exist in the form of isolated steric isomers and/or mixtures of such steric isomers, that is, stereoisomers produced by steric rotation around a single bond or chiral axis and which can be separated as individual chemical species.

Some of the compounds disclosed in this article can exist in tautomer forms, and it is expected that two tautomer forms will exist, even if only a single tautomer structure is described. For example, the description of compound X should be understood to include its tautomer compound Y (and vice versa) and mixtures thereof: Unless otherwise stated, all tautomer forms of the compounds of this invention fall within the scope of this invention.

"Level 3 (tert)" and "Level 3 ( t- )" are used interchangeably and both refer to Level 3.

The compounds described herein may, as appropriate, be substituted with one or more substituents, as generally described above, or as exemplified by specific types, subclasses, and species of the invention. It should be understood that the phrase “substitutically substituted” and the phrase “substituted or unsubstituted” are used interchangeably. “Substitutally substituted”, whether or not it is preceded by the term “substitutically,” indicates that at least one hydrogen atom of the “substitutally substituted” group is replaced by a substituent. Unless otherwise stated, the “substitutically substituted” group may have suitable substituents at each substituted position of the group, and the substituents at each position may be the same or different when more than one position in any given structure is substituted by more than one substituent selected from the specified group. The combinations of substituents contemplated in the invention are preferably combinations that result in the formation of stable or chemically viable compounds.

When referring to the compounds of this invention, the term "compound" means a collection of molecules with the same chemical structure, but there may be isotopic variations among the constituent atoms of the molecule.

As used herein, the term "stable" means a compound that is substantially unchanged when subjected to conditions that allow it to be produced, detected, and optimized for recovery, purification, and use to achieve one or more of the purposes disclosed herein.

As used herein, the term "stable compound" means a compound that is sufficiently stable to allow its manufacture, and that maintains its integrity for a period of time sufficient for the purposes detailed herein (e.g., formulation into therapeutic products, intermediates for the manufacture of therapeutic compounds, separable or storable intermediates, and/or treatment of diseases or conditions that respond to therapeutic agents).

In the compounds of this invention, any atom not expressly designated as a particular isotope is intended to represent any stable isotope of that atom. Unless otherwise stated, when a position is expressly designated as "H" or "hydrogen", that position should be understood to have hydrogen in its natural abundance isotopic composition.

As used herein, the term "derivative" refers to a collection of molecules having the same chemical structure as the compounds of the invention, but in which one or more atoms may have been substituted by another atom. Furthermore, unless otherwise stated, the structures described herein are intended to include compounds that differ only by the presence of one or more isotopically enriched atoms. For example, compounds having the structures of the invention fall within the scope of the invention, except for hydrogen replaced by deuterium or tritium, or carbon replaced by ^13C or ^14C . Such compounds can be used, for example, as analytical tools, probes in bioanalysis, or compounds with therapeutic profile improvements.

As used herein, "deuterated derivative" refers to a compound having the same chemical structure as the reference compound, wherein one or more hydrogen atoms are replaced by deuterium atoms. In some embodiments, the deuterated hydrogen atom is a part of an alkyl group. In some embodiments, the deuterated hydrogen atom is a part of a methyl group. In some embodiments, the deuterated hydrogen atom is a part of an aryl group. In some embodiments, the deuterated hydrogen atom is a part of a phenyl group. In the chemical structure, deuterium may be represented as "D" or " ^2H ".

In compounds identified as deuterated derivatives or containing "D" or " ^2H " substitutions, deuterium atoms are present in amounts exceeding their natural abundance; for example, the compound may have an isotopic enrichment factor of at least 3500 for each specified deuterium atom (52.5% deuterium inclusion at each specified deuterium atom). In some embodiments, if the substituent in the compound of the invention is represented as deuterium, then such compounds have an isotopic enrichment factor of at least 4000 (60% deuterium), at least 4500 (67.5% deuterium), at least 5000 (75% deuterium), at least 5500 (82.5% deuterium), at least 6000 (90% deuterium), at least 6333.3 (95% deuterium), at least 6466.7 (97% deuterium), at least 6600 (99% deuterium), or at least 6633.3 (99.5% deuterium) for each specified deuterium atom.

As used herein, when combined with quantities, volumes, reaction times, reaction temperatures, etc., the terms "about" and "approximately" refer to the acceptable error of a particular value as determined by a person generally skilled in the art, partly depending on the method of measurement or determination of that value. In some embodiments, the terms "about" and "approximately" refer to within 1, 2, 3, or 4 standard deviations. In some embodiments, the terms "about" and "approximately" refer to within 30%, 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, or 0.05% of a given value or range. In some embodiments, the terms "about" and "approximately" refer to within 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% of a given value or range. In some embodiments, the terms "about" and "approximately" refer to within 15% of the given value or range. In some embodiments, the terms "about" and "approximately" refer to within 10% of the given value. In some embodiments, the terms "about" and "approximately" refer to within 5% of the given value.

As used in this article, the symbol "~" that appears immediately before a numerical value has the same meaning as the terms "about" and "approximately".

The term "at least one" refers to one or more.

As used herein, the term "at least one compound selected from" means selecting one or more compounds from a specified group. "Selected from" and "chosen from" are used interchangeably in this document.

As used herein, the term "ambient conditions" refers to room temperature, open atmospheric conditions, and uncontrolled humidity conditions. As used herein, the term "room temperature" or "ambient temperature" refers to 15 ^° C to 30 ^° C.

As used in this article, the term "active pharmaceutical ingredient" or "therapeutic agent" ("API") refers to a bioactive compound.

The terms "patient" and "individual" are used interchangeably and refer to animals, including humans.

The terms “effective dose” and “effective amount” are used interchangeably in this document and refer to the amount of compound that produces the desired effect (e.g., providing a more potent PC1 protein, improving ADPKD or ADPKD symptoms, reducing the severity of ADPKD or ADPKD symptoms, or slowing the progression of ADPKD or ADPKD symptoms). The precise amount of effective dose will depend on the therapeutic purpose and will be determined by someone skilled in the art using known techniques (see, for example, Lloyd (1999) The Art, Science and Technology of Pharmaceutical Compounding).

As used herein, the terms "treatment" and "treating" generally refer to restoring functional PC1 function and improving one or more ADPKD symptoms, delaying the onset of one or more ADPKD symptoms, or reducing the severity of ADPKD or one or more ADPKD symptoms in an individual. Therefore, as used herein, "treatment" includes, but is not limited to, slowing or stopping the decline in renal function, cyst formation, cyst growth, cyst pain, and reducing the frequency, severity, or delaying the onset of adverse cerebrovascular/cardiovascular events. In some embodiments, "treatment" refers to slowing or stopping cyst formation. The improvement of any ADPKD symptoms or the reduction of its severity can be easily assessed using standard methods and techniques known in the field.

As used herein, when referring to two or more compounds, agents or additional active pharmaceutical ingredients, the term "with ~ combination" means administering two or more compounds, agents or active pharmaceutical ingredients to a patient before, at the same time as, or after each other.

The term "medically acceptable" refers to a component that, within the scope of reasonable medical judgment, is suitable for contact with human and other mammalian tissues without abnormal toxicity, irritation, or allergic reactions, and whose benefits/risks are commensurate.

As used herein, the term "medically acceptable salt" means any non-toxic salt that, when administered to a recipient, directly or indirectly provides the compound of the invention. Medicinally acceptable salts of the compounds of the invention include those derived from suitable inorganic and organic acids and inorganic and organic bases. "Medically acceptable relative ions" refers to the ionic portion of the salt that is non-toxic when released from the salt after administration to a recipient. Those skilled in the art will recognize that when the amount of "the compound or its pharmaceutically acceptable salt" is disclosed, the amount of the compound in its pharmaceutically acceptable salt form is an amount equivalent to the concentration of the free base of the compound.

The "free base" form of the compound does not contain an ionicly bonded salt. It should be noted that the amount of the compound or its pharmaceutically acceptable salt disclosed herein is based on its free base form. For example, "10 mg of at least one compound selected from compound I and its pharmaceutically acceptable salt" includes 10 mg of compound I and the concentration of a pharmaceutically acceptable salt of compound I equivalent to 10 mg of compound I.

Appropriate pharmaceutically acceptable salts are disclosed, for example, in J. Pharmaceutical Sciences , 1977, 66 , 1-19, by S.M. Berge et al. For instance, Table 1 of that article provides the following pharmaceutically acceptable salts: Table 1 by Berge et al .: Acetate iodide Benzathine benzenesulfonate Isethionate (hydroxyethyl sulfonate) Chloroprocaine Benzoate lactate choline Hydrogen carbonate Lactobionate diethanolamine Tartrate hydrochloride Apple acid salts ethylenediamine bromide Cisbutene diphosphate Meglumine Calcium edetate amygdalin Procaine Camphor sulfonate (Camsylate) Methsulfonate aluminum carbonates methyl bromide calcium chloride Methyl nitrate Lithium citrate Methyl sulfate Magnesium dichloride Mucate (galactoside) Potassium edetate Naphthalenesulfonate Sodium Succinate nitrates Zinc Estolate Pamoate (Embonate) Triethyliodine ethanesulfonate Pantothenic acid transbutenedioic acid Phosphate/Diphosphate Gluceptate Polygalacturonate Gluconate Salicylic acid glutamic acid salt Stearates Glycollylarsanilate hypoacetate Hexylresorcinate Succinate Hydrabamine sulfate Hydrobromate Tannate hydrochloride Tartrate Hydroxynaphthyl carboxylate Teociate

Non-limiting examples of pharmaceutically acceptable acid addition salts include: salts formed from inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, or perchloric acid; salts formed from organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid, or malonic acid; and salts formed by other methods used in the art, such as ion exchange. Non-limiting examples of pharmaceutically acceptable salts include adipic acid salts, alginate salts, ascorbic acid salts, aspartate salts, benzenesulfonate salts, benzoate salts, hydrogen sulfate salts, borate salts, butyrate salts, camphorate salts, camphorsulfonate salts, citrate salts, cyclopentanepropionate salts, diglucuronate salts, dodecyl sulfate salts, ethanesulfonate salts, formate salts, fumarate salts, glucoheponicate salts, glycerophosphate salts, glucuronate salts, hemisulfate salts, heptaate salts, hexanoate salts, hydroiodate salts, and 2-hydroxyethanesulfonic acid. Salts, lactobionates, lactates, laurates, lauryl sulfates, malates, maleates, malonic acids, methanesulfonates, 2-naphthalenesulfonates, nicotinates, nitrates, oleates, oxalates, palmitic acids, dihydroxynaphthalates, pectinates, persulfates, 3-phenylpropionates, phosphates, picrates, pivalates, propions, stearates, succinates, sulfates, tartrates, thiocyanates, p-toluenesulfonates, undecanoates, and valerates. Pharmaceutically acceptable salts derived from suitable alkalis include alkali metals, alkaline earth metals, ammonium, and N ⁺ ( _C1-4 alkyl) ₄ salts. The invention also contemplates quaternary ammoniation reactions of any basic nitrogen-containing group in the compounds disclosed herein. Suitable non-limiting examples of alkali metal and alkaline earth metal salts include sodium, lithium, potassium, calcium, and magnesium. Further non-limiting examples of pharmaceutically acceptable salts include ammonium, quaternary ammonium, and amine cations formed using relative ions such as halogens, hydroxides, carboxylates, sulfates, phosphates, nitrates, low-carbon alkyl sulfonates, and aryl sulfonates. Other suitable, non-limiting examples of pharmaceutically acceptable salts include besylates and glucosamine salts.

As used herein, the term "prodrug" refers to a compound that is converted in vivo into a compound according to any of the chemical formulas listed herein. Such conversion can be influenced by, for example, hydrolysis in the blood or enzymatic conversion of the prodrug form into the parent form in the blood or tissues. The prodrug of the present invention can be, for example, a amide. Animides that can be used as prodrugs of the present invention include phenylamides, aliphatic ( _C1 - _C24 ) amides, amide oxymethylamides, ureas, carbamates, and aminoamides. For example, the present invention compound containing an NH group can be amided at this position in its prodrug form. Other prodrug forms include esters, such as, for example, phenyl esters, aliphatic ( _C1 - _C24 ) esters, amide oxymethyl esters, carbonates, carbamates, and amino esters. A thorough discussion of prodrugs is provided in T. Higuchi and V. Stella, Pro-drugs as Novel Delivery Systems , Vol. 14, ACS Symposium Series, edited by Edward B. Roche, Bioreversible Carriers in Drug Design , American Pharmaceutical Association and Pergamon Press, 1987, and Judkins et al., Synthetic Communications 26(23):4351-4367, 1996, each of which is incorporated herein by reference in its entirety. In some embodiments, the invention is characterized as a prodrug of any of the chemical formulas or compounds listed herein.

In some embodiments, the compounds of the present invention are selected from compounds of formula I: (Formula I) and tautomers or transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of those compounds, tautomers, transconjugates and deuterated derivatives, wherein such variables are as defined in Formula I above.

Compounds of formula I include compounds of formula Ia: (Formula Ia) and tautomers or transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of those compounds, tautomers, transconjugates and deuterated derivatives, wherein such variables are as defined in Formula Ia above.

Compounds of formula I also include compounds of formula Ib: (Formula Ib) and tautomers or transconjugates of such compounds, deuterated derivatives of such compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of such compounds, tautomers, transconjugates and deuterated derivatives, wherein such variables are as defined in Formula Ib above.

In some embodiments of formulas I, Ia, and Ib, each ^R1 is independently selected from hydrogen, methyl, methoxy, fluorine, chlorine, and cyano. In some embodiments, ^R1 is fluorine. In some embodiments, there are two ^R1s , each of which is fluorine. In some embodiments, there are three ^R1s , each of which is fluorine. In some embodiments, ^R1 is chlorine. In some embodiments, there are two ^R1s , one of which is fluorine and the other of ^which is chlorine. In some embodiments, there are two ^R1s , one of ^which is ^fluorine and the other of ^which is methyl. In some embodiments, there are two ^R1s , one of which is ^fluorine and the other ^{of which} is cyano.

In some embodiments of formulas I, Ia, and Ib, at least one ^R1 is located adjacent to the attachment site of the benzylidene methylene group. In some embodiments, there is only one ^R1 , which is adjacent to the attachment site of the benzylidene methylene group. In some embodiments, there are two ^R1s , each adjacent to the attachment site of the benzylidene methylene group.

In some embodiments of formulas I, Ia, and Ib, there is an ^R1 located adjacent to the attachment site of a benylmethylene group selected from fluorine, chlorine, cyano, and methyl. In some embodiments, the ^R1 is fluorine. In some embodiments, the ^R1 is chlorine. In some embodiments, the ^R1 is cyano. In some embodiments, the ^R1 is methyl.

In some embodiments of formulas I, Ia, and Ib, there are two ^R1s , both located adjacent to the attachment site of the benzylidene group, and each ^R1 is independently selected from fluorine, chlorine, cyano, and methyl. In some embodiments, each ^R1 is fluorine. In some embodiments, each ^R1 is selected from fluorine and chlorine. In some embodiments, each ^R1 is selected from fluorine and cyano. In some embodiments, each ^R1 is selected from fluorine and methyl. In some embodiments, each ^R1 is chlorine.

In some embodiments of formulas I, Ia, and Ib, at least one ^R1 is located at a meta position at the attachment site of the benzyl methylene group. In some embodiments, there is an ^R1 located at a meta position at the attachment site of the benzyl methylene group. In some embodiments, the ^R1 is fluorine.

In some embodiments of formulas I, Ia, and Ib, there exists an ^R1 located at the para position of the attachment site of the benzyl methylene group. In some embodiments, the ^R1 is fluorine.

In some embodiments of formulas I, Ia, and Ib, there are three ^R1s , two of ^which are located adjacent to the attachment site of the benzylidene methyl group, and one of ^which is located meta-attached to the attachment site of the benzylidene methyl group. In some embodiments, all three ^R1s are fluorine.

In some embodiments of formulas I, Ia, and Ib, there are three ^R1s , two of ^which are located adjacent to the attachment site of the benzylidene methyl group, and one ^R1 is located para to the attachment site of the benzylidene methyl group. In some embodiments, all three ^R1s are fluorine.

In some embodiments of formulas I, Ia, and Ib, each ^R2 is independently selected from hydrogen and methyl. In some embodiments, each ^R2 is hydrogen. In some embodiments, each ^R2 is methyl. In some embodiments, one ^R2 is hydrogen and one ^R2 is methyl.

In some embodiments of formulas I, Ia, and Ib, ^R3 is selected from a _C1 - _C3 alkyl group. In some embodiments, ^R3 is a methyl group. In some embodiments, ^R3 is a cyano group.

In some embodiments of equations I, Ia, and Ib, ^R3 is hydrogen.

In some embodiments of Formulas I, Ia, and Ib, ^R4 and ^R5 are independently selected from hydrogen and methyl. In some embodiments, ^R4 is methyl. In some embodiments, ^R5 is methyl. In some embodiments, ^R4 is methyl and ^R5 is hydrogen. In some embodiments, ^R4 is hydrogen and ^R5 is methyl. In some embodiments, both ^R4 and ^R5 are hydrogen. In some embodiments of Formulas I, Ia, and Ib, ^R6 is selected from hydrogen, _C1 - _C3 alkyl, halogen, and cyano. In some embodiments, ^R6 is selected from methyl, ethyl, fluorine, chlorine, bromine, and cyano. In some embodiments, ^R6 is methyl. In some embodiments, ^R6 is fluorine. In some embodiments, ^R6 is chlorine. In some embodiments, ^R6 is bromine. In some embodiments, ^R6 is a cyano group.

In some embodiments of formulas I, Ia, and Ib, ^R7 is selected from hydrogen and methyl. In some embodiments, ^R7 is hydrogen. In some embodiments, ^R7 is methyl.

In some embodiments of formulas I, Ia, and Ib, ^R5 and ^R7 are independently selected from hydrogen and _C1 - _C3 alkyl groups. In some embodiments, ^R5 and ^R7 are independently selected from hydrogen and methyl groups. In some embodiments, both ^R5 and ^R7 are hydrogen. In some embodiments, ^R5 is hydrogen and ^R7 is methyl. In some embodiments, ^R5 is methyl and ^R7 is hydrogen. In some embodiments, both ^R5 and ^R7 are methyl groups.

In some embodiments of formulas I, Ia, and Ib, ^R6 is methyl and ^R7 is hydrogen. In some embodiments, ^R6 is fluorine and ^R7 is hydrogen. In some embodiments, ^R6 is fluorine and ^R7 is methyl. In some embodiments, ^R6 is chlorine and ^R7 is hydrogen. In some embodiments, ^R6 is chlorine and ^R7 is methyl. In some embodiments, ^R6 is bromine and ^R7 is hydrogen. In some embodiments, ^R6 is cyano and ^R7 is hydrogen.

In some embodiments of formulas I, Ia, and Ib, ^R5 is hydrogen, ^R6 is a halogen, and ^R7 is hydrogen. In some embodiments, ^R5 is hydrogen, ^R6 is fluorine, and ^R7 is hydrogen. In some embodiments, ^R5 is hydrogen, ^R6 is chlorine, and ^R7 is hydrogen. In some embodiments, ^R5 is hydrogen, ^R6 is bromine, and ^R7 is hydrogen.

In some embodiments of formulas I, Ia, and Ib, ^R5 is hydrogen, ^R6 is a _C1 - _C3 alkyl group, and ^R7 is hydrogen. In some embodiments, ^R5 is hydrogen, ^R6 is methyl, and ^R7 is hydrogen.

In some embodiments of formulas I, Ia and Ib, ^R5 is hydrogen, ^R6 is cyano, and ^R7 is hydrogen.

In some embodiments of formulas I, Ia, and Ib, ^R5 is hydrogen, ^R6 is a halogen, and ^R7 is a methyl group. In some embodiments, ^R5 is hydrogen, ^R6 is fluorine, and ^R7 is a methyl group. In some embodiments, ^R5 is hydrogen of formulas I, Ia, and Ib, ^R6 is chlorine, and ^R7 is a methyl group.

In some embodiments of formulas I, Ia, and Ib, ^R5 is methyl, ^R6 is halogen, and ^R7 is hydrogen. In some embodiments, ^R5 is methyl, ^R6 is chlorine, and ^R7 is hydrogen.

In some embodiments of formulas I, Ia, and Ib, ^R5 is methyl, ^R6 is halogen, and ^R7 is methyl. In some embodiments, ^R5 is methyl, ^R6 is chlorine, and ^R7 is methyl.

In some embodiments of formulas I, Ia, and Ib, ^R9 is selected from hydrogen, _C1 - _C3 alkyl, halogen, and cyano. In some embodiments, ^R9 is hydrogen.

In some embodiments of equations I, Ia, and Ib, ^R4 and ^R5 are both hydrogen. In some embodiments, ^R3 , ^R4 , and ^R5 are each hydrogen. In some embodiments, ^R2 , ^R3 , ^R4 , and ^R5 are each hydrogen. In some embodiments, ^R2 , ^R3 , ^R4 , ^R5 , and ^R7 are each hydrogen. In some embodiments, ^R2 , ^R3 , ^R4 , ^R5 , ^R7 , and ^R9 are each hydrogen.

In some embodiments, the compound of formula I or Ia is a compound of formula II: (Formula II), and tautomers or trans-isomers of those compounds, deuterated derivatives of those compounds, tautomers and trans-isomers, and pharmaceutically acceptable salts and prodrugs of those compounds, tautomers, trans-isomers and deuterated derivatives, wherein: each ^R1 is independently selected from hydrogen, _C1 - _C3 alkyl, _C1 - _C3 alkoxy, halogen and cyano; ^R6 is selected from _C1 - _C3 alkyl, halogen and cyano; ^R7 is selected from hydrogen, _C1 - _C3 alkyl and halogen; and ^R8 is selected from: ○ hydrogen, ○ _C1 - _C8 alkyl, which is substituted by 0 to 5 independently selected from the following groups: ■ hydroxyl, ■ lateral oxy, ■ amino, ■ Cyano, ■ Halogen, ■ _C1 - _C3 alkoxy (substituted with 0 to 1 lateral group), ■ _C3 - _C6 cycloalkyl (substituted with 0 to 2 groups independently selected from hydroxyl, halogen, and _C1 - _C3 alkyl), ■ 3 to 6 member heterocyclic (substituted with 0 to 3 groups independently selected from halogen, hydroxyl, lateral group, and _C1 - _C3 alkyl (substituted with 0 to 1 hydroxyl group), and ■ 5 to 6 member heteroaryl (substituted with 0 to 3 groups independently selected from lateral group, _C1 - _C3 alkyl, and _C3 - _C6 cycloalkyl); ○ _C3 - _C7 cycloalkyl, substituted with 0 to 3 groups independently selected from the following groups: ■ Hydroxyl, halogen, _C1 - _C3 alkyl (substituted by 0 to 3 groups independently selected from hydroxyl and halogen), _C1 - _C3 alkoxy; and 5 to 9-membered heterocyclic groups, substituted by 0 to 2 groups independently selected from: lateral oxy, hydroxyl, and C1- _{C3 alkyl} (substituted by 0 to 1 hydroxyl).

In some embodiments, the compound of formula I or Ia is a compound of formula IIa: (Formula IIa), and tautomers or transconjugates of such compounds, deuterated derivatives of such compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of such compounds, tautomers, transconjugates and deuterated derivatives, wherein: ^R1 is selected from hydrogen, _C1 - _C3 alkyl, _C1 - _C3 alkoxy, halogen and cyano; and all other variables are as defined in Formula II above.

In some embodiments of Formula II and IIa, each ^R1 is independently selected from hydrogen, fluorine, chlorine, cyano, and methyl. In some embodiments of Formula II and IIa, ^R6 is selected from methyl, fluorine, chlorine, bromine, and cyano. In some embodiments of Formula II and IIa, ^R7 is selected from hydrogen and methyl. In some embodiments of Formula II and IIa, each ^R1 is independently selected from hydrogen, fluorine, chlorine, cyano, and methyl; ^R6 is selected from methyl, fluorine, chlorine, and cyano; and ^R7 is selected from hydrogen and methyl. In some embodiments of formulas I, Ia, Ib, II and IIa, ^R8 is selected from hydrogen, _C1 - _C8 alkyl substituted with 0 to 5 groups, C3- _C7 cycloalkyl substituted with 0 to ₃ groups, and 5 to 9 heterocyclic groups substituted with 0 to 2 groups.

In some embodiments of equations I, Ia, Ib, II, and IIa, ^R8 is selected from:

In some embodiments of equations I, Ia, Ib, II, and IIa, ^R8 is selected from:

In some embodiments of formulas I, Ia, Ib, II and IIa, ^R8 is selected from _C1 - _C8 alkyl groups substituted with 0 to 5 groups.

In some embodiments of equations I, Ia, Ib, II, and IIa, ^R8 is selected from: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

In some embodiments of equations I, Ia, Ib, II, and IIa, ^R8 is selected from: , , , , , , , , , , , , , , , , ,and .

In some embodiments of equations I, Ia, Ib, II, and IIa, ^R8 is selected from: , , , , , , , , , , , , , , , , , and .

In some embodiments of equations I, Ia, Ib, II, and IIa, ^R8 is selected from: , , , , , , , , , , , , , , , and .

In some embodiments of formulas I, Ia, Ib, II and IIa, ^R8 is selected from _C3 - _C7 cycloalkyl groups substituted with 0 to 3 groups.

In some embodiments of equations I, Ia, Ib, II, and IIa, ^R8 is selected from:

In some embodiments of formulas I, Ia, Ib, II and IIa, ^R8 is selected from 5 to 9 member heterocyclic groups replaced by 0 to 2 groups.

In some embodiments of equations I, Ia, Ib, II, and IIa, ^R8 is selected from:

In some embodiments, the compound of formula I or Ia is a compound of formula IIb: (Formula IIb), and tautomers or trans-isomers of such compounds, deuterated derivatives of such compounds, tautomers and trans-isomers, and pharmaceutically acceptable salts and prodrugs of such compounds, tautomers, trans-isomers and deuterated derivatives, wherein: - each ^R1 is independently selected from hydrogen and halogen; - ^R6 is selected from halogen; and - ^R8 is selected from: ○ _C1 - _C5 alkyl groups, which are substituted by 0 to 5 independently selected from the following groups: ■ hydroxyl, and ■ _C3 - _C6 cycloalkyl; ○ _C3 - _C6 cycloalkyl groups, which are substituted by 0 to 2 groups selected from hydroxyl and halogen; and ○ Five to six heterocyclic groups, which are either unsubstituted or substituted with _C1 -C3 _alkyl groups, wherein the _C1 - _C3 alkyl groups are substituted with 0 to 2 substituents selected from hydroxyl and halogen.

In some embodiments of Formula IIb, each ^R1 is independently selected from hydrogen and fluorine. In some embodiments of Formula IIb, each ^R1 is hydrogen. In some embodiments of Formula IIb, one ^R1 is hydrogen and one ^R1 is fluorine. In some embodiments of Formula IIb, each ^R1 is fluorine.

In some embodiments of Formula IIb, ^R6 is selected from fluorine and chlorine. In some embodiments of Formula IIb, ^R6 is fluorine. In some embodiments of Formula IIb, ^R6 is chlorine.

In some embodiments of Formula IIb, ^R8 is selected from _C1 - _C5 alkyl groups, which are substituted with one to three independently selected groups selected from hydroxyl and _C3 - _C5 cycloalkyl groups. In some embodiments of Formula IIb, ^R8 is selected from _C1 - _C3 alkyl groups, which are substituted with one to three independently selected groups selected from hydroxyl and _C3 - _{C5 cycloalkyl} groups. In some embodiments of Formula IIb, ^R8 is selected from _{C1 - C3} alkyl groups, which are substituted with one to ^three independently _selected groups selected from hydroxyl and _C4 cycloalkyl groups. In some embodiments of formula IIb, ^R8 is selected from _C1 - _C3 alkyl groups, which are substituted by one to three independent groups selected from hydroxyl and _C5 cycloalkyl groups.

In some embodiments of Formula IIb, each ^R1 is independently selected ^{from hydrogen} and fluorine, and ^{R6 is} selected from fluorine and ^chlorine .

In some embodiments of Formula IIb, each ^R1 is fluorine, and ^R6 is selected from fluorine and chlorine. In some embodiments of Formula IIb, each ^R1 is fluorine, and ^R6 is fluorine. In some embodiments of Formula IIb, each ^R1 is fluorine, and ^R6 is chlorine.

In some embodiments of formula IIb, ^R6 is selected from fluorine and chlorine, and ^R8 is selected from a _C1 - _C5 alkyl group, which is substituted with one to three independently selected groups from hydroxyl and _C3 - _C5 cycloalkyl groups. In some embodiments of formula IIb, ^R6 is fluorine, and ^R8 is selected from a _C1 - _C5 alkyl group, which is substituted with one to three independently selected groups from hydroxyl and C3- _{C5 cycloalkyl} groups. In some embodiments of formula IIb, ^R6 is chlorine, and ^R8 is selected from a _C1 - _C5 alkyl group, which is substituted with one to three independently selected groups from hydroxyl and C3- _{C5 cycloalkyl} groups.

In some embodiments of Formula IIb, each ^R1 is independently selected from hydrogen and fluorine, ^R6 is selected from fluorine and chlorine, and ^R8 is selected from _C1 - _C5 alkyl groups, which are substituted by one to three independently selected hydroxyl and C3- _{C5 cycloalkyl} groups. In some embodiments of Formula IIb, each ^R1 is fluorine, ^R6 is fluorine, and ^R8 is selected from _C1 - _C5 alkyl groups, which are substituted by one to three independently selected hydroxyl and C3- _C5 cycloalkyl groups. In some embodiments of Formula IIb, each ^R1 is fluorine, ^R6 is chlorine, and ^R8 is selected from _C1 - _{C3 alkyl} groups, which are substituted by one to three independently selected hydroxyl and _C3 - _C5 cycloalkyl groups.

In some embodiments of formula IIb, ^R8 is selected from:

Compounds P1-P20 did not demonstrate detectable activity in the tests described herein; therefore, in some embodiments, compounds of formula I, Ia, Ib, II, or IIa are not: P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 P11 P12 P13 P14 P15 P16 P17 P18 P19 P20 Or tautomers or transconjugates of such compounds, deuterated derivatives of such compounds, tautomers or transconjugates, or pharmaceutically acceptable salts or prodrugs of such compounds, tautomers, transconjugates and deuterated derivatives.

In one embodiment, the compounds of the invention are selected from compounds 1 to 233 (Table 1), or their tautomers or transconjugates, or deuterated derivatives of such tautomers or transconjugates, or pharmaceutically acceptable salts or prodrugs of any of the foregoing. Table 1: Compounds 1 to 233

In some embodiments, the compounds of the present invention are selected from compounds 248 to 327 (Table 2), or their tautomers or transconjugates, or deuterated derivatives of such tautomers or transconjugates, or pharmaceutically acceptable salts or prodrugs of any of the foregoing. Table 2: Compounds 248 to 327 248 249 250 251 252 253 254 255 256 257 258 259 323 324 325 326 327

It should also be understood that compounds of formulas I, Ia, Ib, II, IIa, and IIb, including compounds 1 to 233 and compounds 248 to 327, may exist in their free form for therapeutic purposes or, when appropriate, in the form of their pharmaceutically acceptable derivatives or prodrugs. Pharmaceutically acceptable derivatives or prodrugs include, but are not limited to, pharmaceutically acceptable salts, esters, salts of such esters, or any other adducts or derivatives that, when administered to a patient in need, can directly or indirectly provide the compound as otherwise described herein, or its metabolites or residues. Examples of prodrugs and their uses are well known in the art (see, for example, SM Berge et al., J. Pharmaceutical Sciences , 1977, 66 , 1-19). Pharmaceutical Compositions

In some embodiments, the present invention provides a pharmaceutical composition comprising at least one compound selected from: compounds of formulas I, Ia, Ib, II, IIa, and IIb, tautomers and transisomers of those compounds, deuterated derivatives of those compounds, tautomers, and transisomers, and a pharmaceutically acceptable salt or prodrug of any of the foregoing. In some embodiments, the pharmaceutical composition may comprise compounds selected from: compounds 1 to 233 and compounds 248 to 327, tautomers and transisomers of those compounds, deuterated derivatives of those compounds, tautomers, and transisomers, and a pharmaceutically acceptable salt or prodrug of any of the foregoing.

It should also be understood that the pharmaceutical composition of the present invention can be used in combination therapies; that is, the pharmaceutical composition described herein further includes at least one other active agent. Alternatively, a pharmaceutical composition comprising at least one compound of formula I, Ia, Ib, II, IIa and IIb (including compounds 1 to 233 and compounds 248 to 327), tautomers and transconjugation isomers of those compounds, deuterated derivatives of those compounds, tautomers and transconjugation isomers, and a pharmaceutically acceptable salt or prodrug of any of the foregoing may be administered as a standalone composition, simultaneously, before or after a composition comprising at least one additional active agent.

In some embodiments, compounds of formulas I, Ia, Ib, II, IIa, and IIb (including compounds 1 to 233 and compounds 248 to 327), tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers, and transconjugates, and pharmaceutically acceptable salts or prodrugs of any of the foregoing, and additional active agents are prepared for administration in the same pharmaceutical composition. In some embodiments, compounds and additional active agents are prepared for administration in different pharmaceutical compositions. In some embodiments, compounds and additional active agents are prepared for simultaneous administration. In some embodiments, compounds of formulas I, Ia, Ib, II, IIa and IIb (including compounds 1 to 233 and compounds 248 to 327), tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts or prodrugs and additional active agents of any of the foregoing are prepared for sequential administration.

In some embodiments, more than one compound of formula I, Ia, Ib, II, IIa and IIb (including compounds 1 to 233 and compounds 248 to 327), tautomers and transconjugation isomers of those compounds, deuterated derivatives of those compounds, tautomers and transconjugation isomers, and pharmaceutically acceptable salts or prodrugs of any of the foregoing are provided in a method of treating ADPKD. In some embodiments, more than one compound of formula I, Ia, Ib, II, IIa and IIb (including compounds 1 to 233 and compounds 248 to 327), tautomers and transconjugation isomers of those compounds, deuterated derivatives of those compounds, tautomers and transconjugation isomers, and pharmaceutically acceptable salts or prodrugs of any of the foregoing are prepared for administration into the same pharmaceutical composition. In some embodiments, more than one compound of formula I, Ia, Ib, II, IIa and IIb (including compounds 1 to 233 and compounds 248 to 327), tautomers and transconjugation isomers of those compounds, deuterated derivatives of those compounds, tautomers and transconjugation isomers, and pharmaceutically acceptable salts or prodrugs of any of the foregoing are prepared for administration into various pharmaceutical compositions.

In some embodiments, the additional active agent is a drug that acts to slow the rate of growth of renal cysts and/or the rate of decline in renal function. In some embodiments, the additional active agent is a drug that acts to control hypertension or other adverse cardiovascular events. In some embodiments, the additional active agent is an angiotensin-converting enzyme (ACE) inhibitor or angiotensin-2 receptor blocker (ARB). In some embodiments, the additional active agent is a drug that helps slow the rate of growth of renal cysts. In some embodiments, the additional active agent is a vasopressin ( _V2 ) receptor blocker, such as tolvaptan. In some embodiments, the additional active agent is a medication for treating or controlling pain associated with polycystic kidney disease. In some embodiments, the additional active agent is acetaminophen. In some embodiments, the additional active agent is a medication for treating bladder and kidney infections. In some embodiments, the additional active agent is an antibiotic.

As described above, the pharmaceutical compositions disclosed herein may, where appropriate, further include at least one pharmaceutically acceptable carrier. The at least one pharmaceutically acceptable carrier may be selected from adjuvants and mediators. As used herein, at least one pharmaceutically acceptable carrier includes any and all of the following suitable for the desired specific dosage form: solvents, thinners, other liquid media, dispersants, suspending agents, surfactants, isotonics, thickeners, emulsifiers, preservatives, solid binders, and lubricants. Remington: The Science and Practice of Pharmacy , 21st Edition, 2005, edited by DB Troy, Lippincott Williams & Wilkins, Philadelphia, and Encyclopedia of Pharmaceutical Technology , edited by J. Swarbrick and JC Boylan, 1988–1999, Marcel Dekker, New York, disclose various carriers for the formulation of pharmaceutical compositions and known techniques for their preparation. The use of any carrier is within the scope of this invention unless, to date, any conventional carrier is incompatible with the compounds of this invention, such as by producing any undesirable biological effects or otherwise interacting in a harmful manner with any other component of the pharmaceutical composition. Non-limiting examples of suitable pharmaceutically acceptable carriers include, but are not limited to, mixtures of metaglycerides of ion exchangers, alumina, aluminum stearate, lecithin, serum proteins (such as human serum albumin), buffers (such as phosphates, glycine, sorbic acid, and potassium sorbate), saturated vegetable fatty acids, water, salts, and electrolytes (such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, and zinc salts), colloidal silica, magnesium trisilate, polyvinylpyrrolidone, polyacrylates, waxes, polyethylene-polyoxypropylene block polymers, lanolin, and sugars (such as lactose, glucose, and...). Sucrose), starch (such as corn starch and potato starch), cellulose and its derivatives (such as sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate), powdered tragali, malt, gelatin, talc, adjuvants (such as cocoa butter and suppository wax), oils (such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil and soybean oil), glycols (such as propylene glycol and polyethylene glycol), esters (such as ethyl oleate and ethyl laurate), agar, buffers (such as magnesium hydroxide and aluminum hydroxide), alginic acid, pyrogen-free water, isotropic brine, Ringer's solution. (solution), ethanol, phosphate buffer, non-toxic and compatible lubricants (such as sodium lauryl sulfate and magnesium stearate), colorants, releasing agents, coating agents, sweeteners, flavorings, aromatizers, preservatives and antioxidants.

In some embodiments, the compositions of the present invention comprise compounds of formulas I, Ia, Ib, II, IIa, and IIb (including compounds 1 to 233 and compounds 248 to 327), tautomers and transconjugated isomers of those compounds, deuterated derivatives of those compounds, tautomers, and transconjugated isomers, and pharmaceutically acceptable salts and prodrugs of any of the foregoing. The compositions may further comprise at least one additional pharmaceutical ingredient and/or at least one carrier. Treatment methods

In some embodiments, the present invention provides a method for treating ADPKD comprising administering to an individual in need at least one compound selected from: compounds of formulas I, Ia, Ib, II, IIa, and IIb (including compounds 1 to 233 and compounds 248 to 327), tautomers and transconjugating isomers of those compounds, deuterated derivatives of those compounds, tautomers, and transconjugating isomers, and pharmaceutically acceptable salts and prodrugs of any of the foregoing. In some embodiments, the individual in need carries a mutation in the PKD1 gene encoding polycystic protein-1 (PC1). In some embodiments, the PKD1 gene mutation in the individual in need is a non-truncated mutation. In some embodiments, the PKD1 gene mutation in the individual in need produces a misfolded, nonfunctional PC1 protein.

In other embodiments, the present invention provides a method for increasing polycystic protein-1 (PC1) levels in an individual carrying a PKD1 gene mutation encoding PC1. In some embodiments, the individual's PKD1 gene mutation is a non-truncated mutation. In some embodiments, the individual's PKD1 gene mutation produces a misfolded, non-functional PC1 protein. In some embodiments, the individual's PKD1 gene mutation is a truncated mutation that produces PC1 protein that benefits from correction by the PC1 regulator disclosed herein.

As described above, the present invention also provides a pharmaceutical composition for treating ADPKD, wherein the pharmaceutical composition comprises at least one compound selected from: compounds of formula I, Ia, Ib, II, IIa, IIb, compounds 1 to 233, compounds 248 to 327, tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of any of the foregoing.

In some embodiments of methods for treating ADPKD or increasing the PC1 protein content in an individual, at least one of the following compounds is selected: compounds of formula I, Ia, Ib, II, IIa, IIb, compounds 1 to 233, compounds 248 to 327, tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of any of the foregoing, or a pharmaceutical composition containing at least one of the compounds, and is administered once daily. In some embodiments of methods for treating ADPKD or increasing PC1 protein levels in an individual, at least one of the following compounds is selected: Formula I or Formula II (including compounds 1 to 233), tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of any of the foregoing, or a pharmaceutical composition comprising at least one of the compounds, administered twice daily. In some embodiments of methods for treating ADPKD or increasing the PC1 protein content in an individual, at least one of the following compounds is selected: compounds of formula I, Ia, Ib, II, IIa, IIb, compounds 1 to 233, compounds 248 to 327, tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of any of the foregoing, or pharmaceutical compositions comprising at least one of the compounds, administered multiple times daily.

In some embodiments, the method of the present invention includes administering an additional active agent and a compound selected from: compounds of formulas I, Ia, Ib, II, IIa, IIb, compounds 1 to 233, compounds 248 to 327, tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of any of the foregoing, or a pharmaceutical composition comprising at least one of the compounds, to treat ADPKD. This method may include, in a single pharmaceutical composition or in a single pharmaceutical composition, the addition of an active ingredient and a compound selected from: compounds of formulas I, Ia, Ib, II, IIa, IIb, compounds 1 to 233, compounds 248 to 327, tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts or prodrugs of any of the foregoing. In some embodiments, the compound and the additional active ingredient are added simultaneously. In some embodiments, the compound and the additional active ingredient are added sequentially.

In some embodiments, a method of treating ADPKD includes administering at least one compound selected from: compounds of formulas I, Ia, Ib, II, IIa, IIb, compounds 1 to 233, compounds 248 to 327, tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of any of the foregoing, and an additional active agent that slows the growth rate of renal cysts and/or the decline in renal function. In some embodiments, the additional active agent is a vasopressin ( _V2 ) receptor blocker, such as tolvaptan. In some embodiments, the treatment of ADPKD includes administering at least one of the following compounds: compounds of formula I, Ia, Ib, II, IIa, IIb, compounds 1 to 233, compounds 248 to 327, tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of any of the foregoing, and additional active agents that control hypertension or other adverse cardiovascular events, such as angiotensin-converting enzyme (ACE) inhibitors or angiotensin-2 receptor blockers (ARBs).

In some embodiments, a method of treating ADPKD includes administering at least one of the following compounds: compounds of formula I, Ia, Ib, II, IIa, IIb, compounds 1 to 233, compounds 248 to 327, tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of any of the foregoing, and additional active agents for treating or controlling pain associated with polycystic kidney disease. In some embodiments, a method of treating ADPKD includes administering at least one compound selected from: compounds of formulas I, Ia, Ib, II, IIa, IIb, compounds 1 to 233, compounds 248 to 327, tautomers and transisomers of those compounds, deuterated derivatives of those compounds, tautomers and transisomers, and pharmaceutically acceptable salts and prodrugs of any of the foregoing, and additional active agents for treating bladder and kidney infections. In some embodiments, the additional active agent is an antibiotic.

In some embodiments, a method of treating ADPKD includes enteral administration of at least one compound selected from: compounds of formulas I, Ia, Ib, II, IIa, IIb, compounds 1 to 233, compounds 248 to 327, tautomers and transconjugated isomers of those compounds, deuterated derivatives of those compounds, tautomers and transconjugated isomers, and pharmaceutically acceptable salts and prodrugs of any of the foregoing. In some embodiments, the enteral administration route is selected as oral or rectal. In some embodiments, the enteral administration route is selected as nasogastric, nasoenteric, nasoduodenal, and nasojejunal.

In some embodiments, methods of treating ADPKD include non-enteral administration of at least one compound selected from: compounds of formulas I, Ia, Ib, II, IIa, IIb, compounds 1 to 233, compounds 248 to 327, tautomers and transconjugation isomers of those compounds, deuterated derivatives of those compounds, tautomers and transconjugation isomers, and pharmaceutically acceptable salts and prodrugs of any of the foregoing. In some embodiments, non-enteral administration routes are selected from intravenous, intraperitoneal, epidermal, transcutaneous, subcutaneous, intradermal, intramuscular, intranasal, intratracheal, intracranial, epidural, and intrathecal administration.

The present invention also provides compounds of formulas I, Ia, Ib, II, IIa and IIb (including compounds 1 to 233 and compounds 248 to 327), tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers and transconjugates, and pharmaceutically acceptable salts and prodrugs of any of the foregoing, for use in any of the methods described above.

In some embodiments, methods for treating ADPKD, reducing its severity, or alleviating its symptoms include administering to the patient an effective amount of compounds of formulas I, Ia, Ib, II, IIa, and IIb (including compounds 1 to 233 and compounds 248 to 327), tautomers and transconjugates of those compounds, deuterated derivatives of those compounds, tautomers, and transconjugates, and pharmaceutically acceptable salts and prodrugs of any of the foregoing. The synthesis of the compounds is also discussed.

All specific and general compounds, as well as the intermediates disclosed for the manufacture of those compounds, are considered part of this disclosure.

Those familiar with this field should understand that the methods described herein are generally applicable to other stereoisomers of the compounds described herein.

If the name of a compound conflicts with the structure of any compound described in this application, the structure shall prevail. I. Abbreviations

Unless otherwise indicated or the context otherwise suggests, the following abbreviations shall be understood to have the following meanings: abbreviation Meaning NMR Nuclear magnetic resonance ESI-MS Electron-mass spectrometry analysis LC/MS Liquid chromatography-mass spectrometry HPLC High performance liquid chromatography SFC Supercritical fluid chromatography ESI Electrophoretic ionization cm centimeters g gram mg mg L liter mL milliliters μL microliter mmol Momo h hour min minute mm millimeters μm micrometer MHz Million Hertz Hz Herz N Normal (concentration) M Mor (concentration) mM Milliliter (concentration) ppm One in a million % w/v % w/w Weight-volume concentration; Weight-weight concentration B ₂ pin ₂ BTEAC Bis(Phenanool)diboron benzyltriethylammonium chloride ^t Bu Grade III Butyl DCM dichloromethane DIPEA DIPA DMA DMAP N , N -Diisopropylethylamine, N , N -Diisopropylamine , N,N -Dimethylacetylamine, N , N -Dimethylpyridine-4-amine DMEM DMSO Duchenne modified Igerpec dimethyl monoxide DPBS EtOH Durham phosphate buffer salt solution ethanol EtOAc Ethyl acetate FBS G418 HEPES HEK293 Fetal bovine serum Geneticin™ 4-(2-hydroxyethyl)-1-piperazine ethanesulfonic acid from human embryonic kidney 293 cell line MeOH methanol MeCN Acetonitrile 2-MeTHF 2-Methyltetrahydrofuran NEAA NMP PBS PPTS SCX SEM SFC SPE STAB TBAF Non-essential amino acids N -methylpyrrolidone phosphate buffer solution p-toluenesulfonic acid pyridinium strong cation exchange 2-(trimethylsilyl)ethoxymethyl supercritical fluid chromatography solid phase extraction triethoxyborohydride tetrabutylammonium fluoride TBSCl Tertiary butyldimethylchlorosilane TFA TFAA Trifluoroacetic acid and trifluoroacetic anhydride THF TMA Tr Tetrahydrofuran trimethylaluminum triphenylmethyl TryplE™ RT rt Reagent (Catalogue No. 12604013) Ambient Temperature Duration approximately µ wave Approximately (approximately) microwave II. General Analytical Methods : NMR

NMR spectra were obtained using a Bruker Avance III 500 MHz NMR instrument equipped with a BBFO probe or a Bruker Avance III HD 400 MHz NMR instrument equipped with a BBFO probe. NMR spectra were obtained by dissolving the sample in a suitable deuterated solvent (such as dimethyl monoxide-d6 (DMSO-d6)). Analytical SFC

The Waters Acquity UPC ² instrument was used for analytical supercritical fluid chromatography (SFC) separation of various heterogeneous mixtures. This instrument includes a convergence manager, sample manager, binary solvent manager, column-30S, PDA detector, isocratic solvent manager, and QDa detector. Preparative SFC

The following instruments were used to perform preparative SFC separation of various heterogeneous mixtures: a) Waters Prep 100 SFC instrument, which includes a back pressure regulator, 2767 sample manager, 2545 quaternary gradient module, back pressure regulator, column oven, 2998 PDA detector, isocratic solvent manager, P200X pump, SFC flow splitter-100, three SFC heat exchangers-1000, III series LC pump and Qda detector. b) Berger Minigram SFC instrument, which is equipped with an ALS-3100 automatic sampler, column oven and UV detector. c) Shimadzu Nexera UC Prep instrument, including a _CO2 cooling unit, LC-40P SF solvent delivery module, LC-40D solvent delivery module, LC-20AP preparative liquid chromatography system, LC-20AR liquid chromatography system, CBM-40 system controller, SFC-40P back pressure regulator, HEX-40 heat exchanger, CTO-40C column oven, SPD-M40 PDA detector, FCV-20AH2 valve unit, FRS-40 sample and distillate collector, and LCMS-2020 LC mass spectrometer. UPLC

UPLC analysis was performed using a Waters Acquity UPLC-MS system, which includes a binary solvent manager, column manager, 2777 sample manager, PDA detector, SQD mass spectrometer, and evaporative light scattering detector (ELSD). Preparative HPLC was also performed.

Preparative reverse-phase HPLC was performed on a Waters automated purification HPLC-MS system equipped with a 2767 or 3767 sample manager, a 2545 binary gradient module, a system fluidizer, two 515 HPLC pumps, a flow splitter, a 2998 PDA detector, and a Qda detector. III. General LC/MS Methods

The compounds were analyzed by LC/MS according to one of the following methods, as shown in Table 3. Table 3: LC/MS Methods LC/MS method Method Description A Waters ^™ BEH C8 1.7 μm 2.1 x 50 mm, 2 to 98% MeCN aqueous solution (10 mM ammonium formate, pH 9), 45°C, flow rate 0.6 mL/min, for 5.0 minutes. B Waters ^™ BEH C18 2.5 μm 2.1 x 50 mm, 2 to 95% MeCN aqueous solution (0.1% _NH3 ), 40°C, flow rate 0.8 mL/min, for 1.4 minutes. C ^Kinetex® EVO C18 2.6 μm 2.1 x 50 mm, 2 to 98% MeCN aqueous solution (10 mM ammonium formate, pH 9), 45°C, flow rate 1.0 mL/min, for 1.5 minutes. D Waters ^™ BEH C18 1.7 μm 2.1 x 50 mm, 2 to 98% MeCN aqueous solution (0.1% formic acid), 35°C, flow rate 1.3 mL/min, for 4.0 minutes. E Waters ^™ CSH C18 1.7 μm 2.1 x 50 mm, 2 to 98% MeCN aqueous solution (0.1% TFA, pH 2), 45°C, flow rate 0.6 mL/min, for 5.0 minutes. F Waters ^™ CSH C18 1.7 μm 2.1 x 50 mm, 2 to 98% MeCN aqueous solution (0.1% TFA), 45°C, flow rate 1.0 mL/min, for 1.5 minutes. G Waters ^™ BEH C18 2.5 μm 2.1 x 50 mm, 2 to 50% MeCN aqueous solution (0.1% _NH3 ), 40°C, flow rate 0.8 mL/min, for 4.6 minutes. H Waters ^™ BEH C18 2.5 μm 2.1 x 50 mm, 2 to 95% MeCN aqueous solution (0.1% _NH3 ), 40°C, flow rate 0.8 mL/min, duration 4.6 min. I Waters ^™ CSH C18 1.7 μm 2.1 x 50 mm, 2 to 95% MeCN aqueous solution (0.1% formic acid), 40°C, flow rate 0.8 mL/min, for 1.4 minutes. J ^Kinetex® Polar C18 2.6 μm 3.0 x 50 mm, 5 to 95% MeCN aqueous solution (0.1% formic acid), flow rate 1.2 mL/min, for 3 minutes. K Waters ^™ BEH C18 2.5 μm 2.1 x 50 mm, 2 to 20% MeCN aqueous solution (0.1% _NH3 ), 40°C, flow rate 0.8 mL/min, for 2.0 minutes. L Waters ^™ BEH C18 1.7 μm 2.1 x 50 mm, 50 to 95% MeCN aqueous solution (0.1% _NH3 ), 40°C, flow rate 0.8 mL/min, for 1.4 minutes. M Waters ^™ BEH C18 2.5 μm 2.1 x 50 mm, 20 to 70% MeCN aqueous solution (0.1% _NH3 ), 40°C, flow rate 0.8 mL/min, for 4.6 minutes. N Waters ^™ BEH C8 1.7 μm 2.1 x 50 mm, 50 to 95% MeCN aqueous solution (0.1% _NH3 ), 40 °C, flow rate 0.8 mL/min, for 1.4 minutes. O Waters ^™ BEH C ₁₈ 1.7 μm 2.1 x 50 mm, 5 to 95% MeCN aqueous solution (5 mM ammonium acetate), flow rate 0.6 mL/min, for 4 minutes. P Waters ^™ BEH C ₁₈ 1.7 μm 2.1 x 100 mm, 10 to 90% MeCN aqueous solution (5 mM ammonium acetate), flow rate 0.3 mL/min, for 10 minutes. Q Waters ^™ Cortecs C ₁₈ 1.6 μm 3.0 x 30 mm, 3 to 98% MeCN aqueous solution (0.05% formic acid), flow rate 0.85 mL/min, for 2 minutes. R Waters ^™ CSH C18 1.7 μm 2.1 x 50 mm, 2 to 95% MeCN aqueous solution (0.1% formic acid), 40°C, flow rate 0.8 mL/min, for 1.4 minutes. S Waters ^™ CSH C18 1.7 μm 2.1 x 50 mm, 2 to 95% MeCN aqueous solution (0.1% formic acid), 40°C, flow rate 0.8 mL/min, for 4.6 minutes. IV. Synthesis of Starting Materials Starting Material 1: Synthesis of 1-(2-chlorobenzyl)-1,5-dihydro-4H-pyrazolo[4,3-c]pyridin-4-one (S1) Step 1 :

Under an argon atmosphere, with the temperature maintained between 15 and 25°C, KO ^t Bu (160 g, 1.426 mol) was added fractionally to a cooled DMSO (1.7 L) solution containing 4-chloro- 1H -pyrazolo[4,3- c ]pyridine (170 g, 1.107 mol). The resulting mixture was stirred further at ambient temperature for 25 minutes. 1-(bromomethyl)-2-chlorobenzene (292.86 g, 185 mL, 1.425 mol) was added dropwise, with the temperature maintained between 15 and 25°C, and the reaction mixture was stirred at ambient temperature for 30 minutes. Water (2 L) was added slowly, and the resulting slurry was stirred at ambient temperature for 1 hour. The solid was filtered and washed with water (1 L) and heptane (2 L). Purification by rapid chromatography ( _SiO₂ , 100% DCM) yielded a pale yellow solid. The solid was heated in ^iPrOH (300 mL) at 80°C. The mixture was cooled to ambient temperature. The slurry was filtered, washed with ^iPrOH (300 mL), and dried to give a white solid of 4-chloro-1-(2-chlorobenzyl) -1H -pyrazolo[4,3- c ]pyridine (S1, 160 g, 51%). ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 8.21 (s, ¹H), 8.16 (d, J = 6.1 Hz, ¹H), 7.42 (d, J = 7.6 Hz, ¹H), 7.28 - 7.24 (m, 2H), 7.19 (t, J = 7.6 Hz, 1H), 6.93 (d, J = 6.1 Hz, 1H), 5.69 (s, 2H) ppm. ESI-MS m/z calculated value 277.017, observed value 278.0 (M+1) ⁺ . Step 2 :

A solution of HCl containing 200 g (709.51 mmol) of 2-chloro-1-(2-chlorobenzyl) -1H -pyrazolo[4,3- c ]pyridine (14.0 mol) in 10 M aqueous solution was heated under reflux for 20 hours (1.4 L). The mixture was diluted with water (1.4 L) and cooled to ambient temperature. The solid was filtered, washed with water (500 mL), and dried in air to give 1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ( S1 , 182 g, 98%) as a pale yellow solid. ^1H NMR (400 MHz, DMSO - _d⁶ ) δ 11.07 (s, 1H), 8.08 (s, 1H), 7.49 (dd, J = 7.6, 1.5 Hz, 1H), 7.36 - 7.27 (m, 2H), 7.22 (m, 1H), 6.93 (dd, J = 7.6, 1.5 Hz, 1H), 6.64 (d, J = 6.9 Hz, 1H), 5.61 (s, 2H) ppm. ESI-MS m/z calculated value 259.051, observed value 260.0 (M+1) ⁺ .

The following starting materials were prepared using the method described in Starting Material 1, except that in step 1, different alkylating agents and/or 1H- pyrazolo[4,3- c ]pyridine were used instead of 1-(bromomethyl)-2-chlorobenzene and 4-chloro- 1H- pyrazolo[4,3- c ]pyridine. In the case of S18 , step 1 was performed using the conditions described in the synthesis of Starting Material 3. Table 4: Starting materials prepared using the method described in Starting Material 1 Starting material number Compound structure / compound name LC/MS NMR ( displacement in ppm ) S2 1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 243.081; observed value: 244.1 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 11.06 (s, 1H), 8.05 (s, 1H), 7.41-7.33 (m, 1H), 7.24 - 7.11 (m, 4H), 6.67 (d, J = 6.9 Hz, 1H), 5.57 (s, 2H)ppm. S4 1-(2-Chlorophenylmethyl)-6-methyl-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 273.067; observed value: 274.0 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 11.06 (br s, 1H), 8.01 (s, 1H), 7.50 (dd, J = 7.9, 1.2 Hz, 1H), 7.34 (td, J = 7.6, 1.7 Hz, 1H), 7.30 - 7.26 (m, 1H), 6.83 (dd, J = 7.6, 1.6 Hz, 1H), 6.44 (s, 1H), 5.54 (s, 2H), 2.20 (s, 3H) ppm. S7 1-(2,6-difluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 261.071; observed value: 262.0 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 11.05 (s, 1H), 7.99 (d, J = 0.8 Hz, 1H), 7.53 - 7.38 (m, 1H), 7.26 (dd, J = 7.3, 5.9 Hz, 1H), 7.20 - 7.06 (m, 2H), 6.71 (d, J = 7.2 Hz, 1H), 5.54 (s, 2H) ppm. S9 1-(2-chloro-6-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 277.042; observed value: 279.9 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 11.05 (d, J = 5.8 Hz, 1H), 7.99 (d, J = 0.8 Hz, 1H), 7.46 (td, J = 8.2, 6.1 Hz, 1H), 7.38 (dt, J = 8.1, 1.1 Hz, 1H), 7.34 - 7.23 (m, 2H), 6.74 (d, J = 7.2 Hz, 1H), 5.60 (d, J = 1.7 Hz, 2H) ppm. S12 1-(2-fluorobenzyl)-7-methyl-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 257.096; observed value: 258.2 (M+1) ⁺ . ^¹H NMR (400 MHz, methanol - _d⁴ ) δ 8.20 (s, 1H), 7.38–7.29 (m, 1H), 7.15 (br d, J = 1.0 Hz, 1H), 7.09 (t, J = 7.6 Hz, 1H), 6.98 (d, J = 1.1 Hz, 1H), 6.70 (s, 1H), 5.82 (s, 2H), 2.30 (d, J = 1.1 Hz, 3H) ppm; no interchangeable H was observed. S18 3-Chloro-1-(2,6-difluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 295.032; observed value: 296.2 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 11.23 (d, J = 4 Hz, 1H), 7.56 - 7.43 (m, 1H), 7.22 (t, J = 6 Hz, 1H), 7.15 (t, J = 8 Hz, 2H), 6.72 (d, J = 7.2 Hz, 1H), 5.52 (s, 2H) ppm.

The following starting materials were prepared using the method described in Starting Material 1, except that in step 1, 2-(chloromethyl)-1,3-difluorobenzene and 4-chloro-3-methyl- 1H- pyrazolo[4,3- c ]pyridine were used instead of 1-(bromomethyl)-2-chlorobenzene and 4-chloro- 1H- pyrazolo[4,3- c ]pyridine, and the reaction was carried out under the conditions described below:

2-(chloromethyl)-1,3-difluorobenzene (1.116 g, 6.865 mmol) and _K₂CO₃ (1.649 g, _11.931 mmol) were added to a stirred mixture containing 10 mL of DMF with 4-chloro-3-methyl- 1H -pyrazolo[4,3- c ]pyridine (1 g, 5.967 mmol), and the mixture was stirred at ambient temperature for 4 hours. The reaction mixture was poured into ice water, and the resulting solid was collected by filtration. Purification by reverse phase chromatography (80 g _C18 column, 50 to 80% MeCN aqueous solution containing 0.1% _NH4OH ) yielded 1.045 g (59%) of 4-chloro-1-(2,6-difluorobenzyl)-3-methyl- 1H- pyrazolo[4,3- c ]pyridine as a colorless solid. ^¹H NMR (400 MHz, methanol _-d⁴ ) δ 8.08 (d, J = 6.0 Hz, 1H), 7.60 (d, J = 6.0 Hz, 1H), 7.38 (tt, J = 8.4, 6.5 Hz, 1H), 6.99 (t, J = 8.0 Hz, 2H), 5.61 (s, 2H), 2.66 (s, 3H) ppm. ESI-MS m/z calculated value 293.053, observed value 294.1 (M+1) ⁺ . Table 5: Starting materials prepared using the method described in Starting Material 1. Starting material number Structure Name LC/MS NMR ( displacement in ppm ) S14 1-(2,6-Difluorobenzyl)-3-methyl-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 243.081; observed value: 244.1 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 11.06 (s, 1H), 8.05 (s, 1H), 7.41-7.33 (m, 1H), 7.24 - 7.11 (m, 4H), 6.67 (d, J = 6.9 Hz, 1H), 5.57 (s, 2H)ppm.

The following starting materials are prepared using the method described in Starting Material 1, except that in step 1, 2-(chloromethyl)-1,3-difluorobenzene and 4-chloro-3-iodo- 1H- pyrazolo[4,3- c ]pyridine are used instead of 1-(bromomethyl)-2-chlorobenzene and 4-chloro- 1H- pyrazolo[4,3- c ]pyridine, respectively, and the reaction is carried out under the conditions described for S14, wherein MeCN is used as the solvent instead of DMF. An additional cyanidation step is introduced between step 1 and step 2, as described below. In step 2, AcOH is used instead of 10 M HCl for the reaction:

Cyanidation step : CuCN (371 mg, 4.060 mmol) was added to a stirred solution of NMP (20 mL) containing 4-chloro-1-(2,6-difluorobenzyl)-3-iodo- 1H- pyrazolo[4,3- c ]pyridine (1.3 g, 2.109 mmol), and the reaction mixture was heated at 120°C for 12 hours. The reaction mixture was quenched by adding ice-cold water and extracted with EtOAc (2 x 200 mL). The combined organic layers were concentrated under vacuum. Purification by rapid chromatography (neutral alumina in hexane containing 30-40% EtOAc) yielded a grayish-white solid, 4-chloro-1-(2,6-difluorobenzyl)-3-iodo- 1H- pyrazolo[4,3- c ]pyridine (250 mg, 35%). ^¹H NMR (400 MHz, chloroform _-d³ ) δ 8.32 (d, J = 6.0 Hz, 1H), 7.51 (d, J = 6.0 Hz, 1H), 7.40–7.34 (m, 1H), 7.00–6.94 (m, 2H), 5.69 (m, 2H) ppm. ESI-MS m/z calculated value 304.033, observed value 305.1 (M+1) ⁺ . Table 6: Starting materials prepared using the method described in Starting Material 1 Starting material number Structure Name LC/MS NMR ( displacement in ppm ) S15 1-(2,6-difluorobenzyl)-4-sideoxy-4,5-dihydro- 1H- pyrazolo[4,3- c ]pyridine-3-carboxynitrile ESI-MS calculated m/z value: 286.067; observed value: 287.3 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 11.59 (br s, 1H), 7.55 - 7.51 (m, 1H), 7.44 (d, J = 7.6 Hz, 1H), 7.17 (t, J = 8.0 Hz, 2H), 6.85 (d, J = 7.2 Hz, 1H), 5.70 (s, 2H) ppm. Starting material 2: Synthesis of 5-(2,5-dichloropyridin-4-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (SB1) Step 1:

Under a nitrogen atmosphere, NaH (1.84 g, 60% mineral oil dispersion, 46.0 mmol) was added fractionally to a solution of 1,4-dimethyl alkylene (60 mL) containing 4-chloro- 1H- pyrazolo[4,3-c]pyridine (6 g, 39.07 mmol), and the reaction mixture was stirred at 0°C for 10 min. Triphenylmethyl chloride (12.2 g, 43.76 mmol) was added in one step, and the cooling bath was removed. The reaction mixture was stirred at ambient temperature for 3 days. The mixture was diluted with EtOAc and washed with 1 M NaOH. The organic layer was separated, dried ( _MgSO₄ ), and concentrated under vacuum to obtain 4-chloro-1-triphenylmethyl- 1H- pyrazolo[4,3- c ]pyridine (ESI-MS m/z calculated value 395.119, observed value 396.0 (M+1) ^＋ ) and 4-chloro-2-triphenylmethyl- 2H- pyrazolo[4,3- c ]pyridine (ESI-MS m/z calculated value 395.119, observed value 396.0 (M+1) ^＋ ) (7.41 g, 96%), which were used in the next step without further purification. Step 2:

In a microwave-safe reactor, KOH (6.2 g, 110.5 mmol) was added to a stirred mixture containing 1,4-dimethyl alkyl (15 mL) of 4-chloro-1-triphenylmethyl- 1H- pyrazolo[4,3- c ]pyridine and 4-chloro-2-triphenylmethyl- 2H- pyrazolo[4,3- c ]pyridine (5.54 g, 13.994 mmol) and water (5 mL), and the mixture was degassed (vacuum nitrogen cycle 3 times). _Pd₂ (dba) _₃ (640 mg, 0.699 mmol) and ^tBuXPhos (590 mg, 1.389 mmol) were added, and the mixture was degassed (vacuum nitrogen cycle 3 times) and stirred at 130°C under microwave irradiation for 90 minutes. After cooling to ambient temperature, the reactants were partially dissolved between EtOAc and water. The aqueous phase was separated and extracted with EtOAc. The combined organic extract was dried ( _{Na₂SO₄ )} , filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO₂ , containing heptane with 0 to 100% EtOAc) yielded a yellow solid mixture of 1-triphenylmethyl-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (ESI-MS m/z calculated value 377.153, observed value 376.0 (M⁻¹) ^- ) and 2-triphenylmethyl-2,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (ESI-MS m/z calculated value 377.1528, observed value 376.0 (M⁻¹) ^- ) (2.29 g, 44%), which was used in the next step without further purification. Step 3:

_Cs₂CO₃ (4.9 g, 15.04 mmol) was added under nitrogen atmosphere to a stirred _mixture containing 1-triphenylmethyl-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one and 2-triphenylmethyl-2,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (2.84 g, 7.524 mmol) and DMA (20 mL) containing 2,5-dichloro-4-fluoropyridine (1.6 g, 9.640 mmol), and the reaction mixture was heated at 105°C for 90 minutes. After cooling to ambient temperature, the mixture was partially dissolved in EtOAc and water and stirred vigorously for 30 minutes. The resulting suspension was filtered and washed with EtOAc to give 1.04 g of a pale yellow solid. The aqueous phase was separated and extracted with _EtOAc . The combined organic extract was washed with brine, dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO₂ , containing heptane with 0 to 50% EtOAc) yielded a pale yellow solid, which was combined with the original precipitate to give 5-(2,5-dichloropyridin-4-yl)-1-triphenylmethyl-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one. ^¹H NMR (500 MHz, DMSO - _d⁶ ) δ 8.75 (s, 1H), 8.30 (d, J = 0.8 Hz, 1H), 7.98 (s, 1H), 7.43–7.32 (m, 10H), 7.19 (d, J = 7.7 Hz, 1H), 7.16–7.10 (m, 5H), 5.34 (dd, A pale yellow solid mixture of 5-(2,5-dichloropyridin-4-yl)-2-triphenylmethyl-2,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (ESI-MS m/z calculated value 522.101, observed value ^{521.0 (M-1) - )} (3.4 g, 86%) was used in the next step without further purification. Step 4:

Under nitrogen atmosphere, Et ₃ SiH (2.6 mL, 16.28 mmol) and TFA (2.5 mL, 32.45 mmol) were added sequentially to a mixture of DCM (20 mL) containing 5-(2,5-dichloropyridin-4-yl)-1-triphenylmethyl-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one and 5-(2,5-dichloropyridin-4-yl)-2-triphenylmethyl-2,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (3.4 g, 6.496 mmol), and the mixture was stirred for 30 minutes at ambient temperature. The reactants were concentrated under vacuum, and the residue was azeotropically reacted with DCM (x 2) and then separately dissolved between EtOAc and a saturated _NaHCO3 solution. The precipitate was collected by filtration and washed with EtOAc. The aqueous phase was separated and extracted with EtOAc. The combined organic extract was dried ( _{Na2SO4 )} , filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO₂ , containing heptane with 0 to 100% EtOAc) followed by merging with the original precipitate 5-(2,5-dichloropyridin-4-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (SB1, 1.27 g, 70%) yielded a white solid. ^1H NMR (500 MHz, DMSO - _d⁶ ) δ 13.65 (s, 1H), 8.78 (s, 1H), 8.26 (s, 1H), 7.99 (s, 1H), 7.42 (d, J = 7.4 Hz, 1H), 6.74 (dd, J = 7.4, 0.9 Hz, 1H) ppm. ESI-MS m/z calculated value 279.992, observed value 281.0 (M+1) ⁺ . Starting material 3: Synthesis of 1-(2-chlorobenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (S3) Step 1 :

1-(bromomethyl)-2-chlorobenzene (316.60 mg, 0.2 mL, 1.541 mmol) was added to a suspension of MeCN (2 mL) containing 1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4- _one (200 mg, 1.444 mmol) and _K₂CO₃ (600 mg, 4.341 mmol), and the reaction mixture was stirred at ambient temperature for 16 hours. The reactants were then partially dissolved between water and EtOAc. The aqueous phase was separated and extracted with EtOAc. The combined organic extracts were washed with brine, dried ( _MgSO₄ ), filtered, and concentrated under vacuum. Purification from thermal ⁱ PrOH by recrystallization yielded a white solid, 1-(2-chlorobenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ( S3 , 120 mg, 29%). ^¹H NMR (400 MHz, chloroform- d ) δ 7.96 (s, 1H), 7.40 (dd, J = 7.6, 1.6 Hz, 1H), 7.29 - 7.21 (m, 2H), 6.93 - 6.90 (m, 1H), 5.40 (s, 3H), 3.58 (td, J = 6.9, 2.7 Hz, 2H), 2.90 (dt, J = 29.3, 6.9 Hz, 2H) ppm. ESI-MS m/z calculated value 261.067, observed value 262.0 (M+1) ⁺ . Synthesis of starting material 4: 3-fluoro-2-((4-sideoxy-4,5,6,7-tetrahydro- 1H- pyrazolo[4,3- c ]pyridin-1-yl)methyl)benzonitrile (S16) Step 1 :

AcOH (52.8 mg, 50 μL, 0.879 mmol) was added to a solution of EtOH (40 mL) containing 3-((dimethylamino)methylene)piperidine-2,4-dione (715 mg, 4.144 mmol) and (2-bromo-6-fluorobenzyl)hydrazine hydrochloride (2.219 g, 3.232 mmol), and the reaction mixture was heated to 80°C overnight. The mixture was then cooled to ambient temperature in an ice bath. The solid was collected by filtration to give a milky white solid of 1-(2-bromo-6-fluorobenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (948 mg, 91%). ^¹H NMR (400 MHz, chloroform- d ) δ 7.92 - 7.89 (m, 1H), 7.43 (d, J = 8.2 Hz, 1H), 7.28 - 7.20 (m, 1H, overlapped with solvent), 7.14 - 7.06 (m, 1H), 5.52 - 5.43 (m, 1H), 5.40 (d, J = 1.8 Hz, 2H), 3.66 - 3.57 (m, 2H), 3.02 (t, J = 6.9 Hz, 2H) ppm. ESI-MS m/z calculated value 323.007, observed value 324.1 (M+1) ⁺ . Step 2 :

A mixture of 1-(2-bromo-6-fluorobenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (8.5 g, 26.223 mmol), Zn(CN) _₂ (6.16 g, 52.463 mmol), and Pd( _PPh₃ ) _₄ (4.55 g, 3.938 mmol) was suspended in degassed DMF (80 mL), and the reaction mixture was stirred at 100°C under microwave irradiation for 30 min. Water was added, and the resulting solid was collected by filtration. The solid was then heated and filtered in a mixture of DCM and MeOH. The mother liquor was concentrated under vacuum to obtain a dark brown solid, 3-fluoro-2-((4-sideoxy-4,5,6,7-tetrahydro- 1H- pyrazolo[4,3- c ]pyridin-1-yl)methyl)benzonitrile ( S16 , 8.81 g, 99%). ^1H NMR (400 MHz, DMSO - _d⁶ ) δ 7.78 (br d, J = 6.1 Hz, 1H), 7.70 - 7.49 (m, 3H), 7.30 (br s, 1H), 5.45 (s, 2H), 3.50 - 3.37 (m, 2H), 3.03 (br t, J = 6.6 Hz, 2H) ppm. ESI-MS m/z calculated value 270.092, observed value 271.1 (M+1)+.

The following starting materials were prepared using the method described in Starting Material 4, except that step 2 was omitted. In step 1, different hydrazines and/or piperidine-2,4-diones were used instead of (2-bromo-6-fluorobenzyl)hydrazine hydrochloride and 3-((dimethylamino)methylene)piperidine-2,4-dione. Table 7: Starting materials prepared using the method described in Starting Material 4 Starting material number Structure Name LC/MS NMR ( displacement in ppm ) S5 1-(2-Fluorophenylmethyl)-1,5,6,7-Tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 245.096, observed value: 246.1 (M+1) ^{+ ¹H} NMR (400 MHz, chloroform- d ) δ 7.93 (s, 1H), 7.34–7.28 (m, 1H), 7.19–7.06 (m, 3H), 5.66 (s, 1H), 5.32 (s, 2H), 3.59 (td, J = 6.9, 2.3 Hz, 2H), 2.91 (t, J = 6.9 Hz, 2H) ppm. S6 rac -1-(2-fluorobenzyl)-6-methyl-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 259.112; observed value: 260.1 (M+1) ⁺ . ¹ H NMR (400 MHz, chloroform- d ) δ 7.69 (s, 1H), 7.42 - 7.32 (m, 1H), 7.30 -7.10 (m, 4H), 5.40 - 5.24 (m, 2H), 3.82 - 3.70 (m, 1H), 3.09 (dd, J = 16.0, 5.0 Hz, 1H), 2.57 (dd, J = 16.0, 10.1 Hz, 1H), 1.21 (d, J = 6.4 Hz, 3H) ppm. S8 1-(2,6-Difluorobenzyl)-1,5,6,7-Tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ESI-MS m/z calculated value: 263.087, observed value: 264.1 (M+1) ⁺ . ¹ H NMR (400 MHz, chloroform- d ) δ 7.61 (s, 1H), 7.49 - 7.38 (m, 1H), 7.24 (br s, 1H), 7.11 (t, J = 8.2 Hz, 2H), 5.30 (s, 2H), 3.39 (td, J = 6.9, 2.7 Hz, 2H), 2.93 (t, J = 6.9 Hz, 2H) ppm. S10 1-(2-fluoro-6-methylbenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 259.112; observed value: 260.1 (M+1) ⁺ . ¹ H NMR (400 MHz, chloroform- d ) δ 7.86 (s, 1H), 7.23 - 7.19 (m, 1H), 7.02 - 6.99 (m, 1H), 6.92 (t, J = 9.2 Hz, 1H), 5.62 (br s, 1H), 5.32 (d, J = 1.8 Hz, 2H), 3.56 (t, J = 6.9 Hz, 2H), 2.87 (t, J = 6.9 Hz, 2H), 2.44 (s, 3H) ppm. S11 1-(2-chloro-6-fluorobenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 279.058; observed value: 280.2 (M+1) ⁺ . ^¹H NMR (400 MHz, chloroform- d ) δ 7.63 (s, 1H), 7.48–7.42 (m, 1H), 7.37 (d, J = 8.0 Hz, 1H), 7.30–7.26 (m, 2H), 5.37 (s, 2H), 3.44–3.40 (m, 2H), 3.00 (t, J = 7.2 Hz, 2H) ppm. S17 rac -1-(1-(2-fluorophenyl)ethyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 259.112; observed value: 260.2 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 7.73 (s, 1H), 7.40 - 7.32 (m, 1H), 7.30 - 7.16 (m, 4H), 5.88 (q, J = 6.8 Hz, 1H), 3.4 - 3.33 (m, 2H), 3.06 - 2.96 (m, 1H), 2.69 - 2.59 (m, 1H), 1.81 (d, J = 7.0 Hz, 3H) ppm. SB3 5-(2,5-dichloropyridin-4-yl)-1-(2-fluorobenzyl)-6,6-dimethyl-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 418.076; observed value: 419.2 (M+1) ⁺ . ¹ H NMR (400 MHz, chloroform- d ) δ 8.51 (s, 1H), 7.96 (s, 1H), 7.38 - 7.31 (m, 1H), 7.29 - 7.22 (m, 2H), 7.19 - 7.13 (m, 1H), 7.10 (t, J = 9.2 Hz, 1H), 5.38 - 5.29 (m, 2H), 3.18 (d, J = 16.0 Hz, 1H), 2.94 (d, J = 16.0 Hz, 1H), 1.42 (s, 3H), 1.24 (s, 3H) ppm.

The following starting materials were prepared using the method described in Starting Material 4, except that step 2 was omitted. In step 1, different hydrazines and piperidine-2,4-diones were used instead of (2-bromo-6-fluorobenzyl)hydrazine hydrochloride and 3-((dimethylamino)methylene)piperidine-2,4-dione. An excess of TFA-containing DCM was used to perform the final Boc protection step at ambient temperature, conditions well known in the art. Table 8: Starting materials prepared using the method described in Starting Material 4 Starting material number Structure Name LC/MS NMR ( displacement in ppm ) S13 rac -1-(2-fluorobenzyl)-7-methyl-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ESI-MS calculated m/z value: 259.112; observed value: 260.1 (M+1) ⁺ . ¹ H NMR (400 MHz, chloroform- d ) δ 7.92 (s, 1H), 7.33 - 7.27 (m, 1H), 7.15 - 7.05 (m, 3H), 5.69 (s, 1H), 5.33 (s, 2H), 3.74 (dd, J = 12.4, 5.0 Hz, 1H), 3.27 (d, J = 11.9 Hz, 1H), 3.17 - 3.09 (m, 1H), 1.22 (d, J = 6.9 Hz, 3H) ppm. Starting material 5: Synthesis of 5-(2-chloro-5-fluoropyridin-4-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (SB2) Step 1 :

_K₂CO₃ (13 g, 89.359 mmol) and 1-(chloromethyl)-4-methoxybenzene (7.581 g, 7 _mL , 45.987 mmol) were added to a stirred solution containing ethyl 5-bromo- 1H -pyrazole-4-carboxylate (10 g, 43.372 mmol) in MeCN (100 mL), and the reaction mixture was stirred at ambient temperature for 16 hours. The reaction mixture was filtered through a ^Celite® mat and washed with EtOAc (500 mL). The mother liquor was concentrated under vacuum to give ethyl 5-bromo-1-(4-methoxybenzyl) -1H -pyrazole-4-carboxylate (14 g, 87%) as a white solid. ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ (s, ¹H), 7.30–7.26 (m, 2H), 6.94–6.90 (m, 2H), 5.25 (s, 2H), 4.25–4.18 (m, 2H), 3.73 (s, 3H), 1.28–1.24 (m, 3H) ppm. Step 2 :

CuBr (648 mg, 4.291 mmol), triphenylphosphine (592 mg, 2.144 mmol), LiBr (1.17 g, 12.799 mmol) and _Et3N (110.35 g, 160 mL, 1.036 mol) were added sequentially to a stirred solution containing ethyl 5-bromo-1-(4-methoxybenzyl) -1H -pyrazole-4-carboxylate (16 g, 42.893 mmol) in THF (160 mL). The mixture was then degassed by bubbling nitrogen through the solution for 10 minutes. Ethynyltrimethylsilane (23.574 g, 35 mL, 228.02 mmol) and Pd( _PPh3 ) ₄ (5.21 g, 4.283 mmol) were added sequentially, and the reaction mixture was stirred at 55°C for 72 hours. The mixture was diluted with water (200 mL) and extracted with EtOAc (2 x 200 mL). The combined organic layers were dried ( _{Na2SO4 )} , filtered, and concentrated under vacuum. Purification by rapid chromatography (300 g _SiO2 containing 40 to 50% DCM/hexane) yielded ethyl 1-(4-methoxybenzyl)-5-((trimethylsilyl)ethynyl) -1H -pyrazole-4-carboxylate (9 g, 33%) as a brown solid. ESI-MS m/z calculated value 356.156, observed value 357.3 (M+1) ⁺ . Step 3 :

2-Chloro-5-fluoropyridin-4-amine (181 mg, 1.173 mmol) and TMA (1.2 mL, 2 M toluene solution, 2.4 mmol) were added at 0°C to a stirred solution containing 1-(4-methoxybenzyl)-5-((trimethylsilyl)ethynyl) -1H -pyrazole-4-carboxylic acid ethyl ester (500 mg, 0.783 mmol) in toluene (5 mL), and the reaction mixture was stirred at 90°C for 16 hours. The reaction was quenched by adding saturated saline solution (10 mL) and extracted with EtOAc (2 x 50 mL). The combined organic phases were dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum to obtain _a grayish-white solid, N- (2-chloro-5-fluoropyridin-4-yl)-1-(4-methoxybenzyl)-5-((trimethylsilyl)ethynyl) -1H -pyrazole-4-methylamine (700 mg, 72%). ESI-MS m/z calculated value was 456.119, observed value was 457.2 (M+1) ⁺ . Step 4 :

TBAF (10.7 mL, 1 M THF solution, 10.700 mmol) was added at 0°C to a stirred solution containing N- (2-chloro-5-fluoropyridin-4-yl)-1-(4-methoxybenzyl)-5-((trimethylsilyl)ethynyl) -1H- pyrazol-4-methoxymethylamine (1.9 g, 2.136 mmol) in THF (19 mL), and the reaction mixture was stirred at ambient temperature for 16 hours. The reaction mixture was quenched by adding water (20 mL) and extracted with EtOAc (2 x 50 mL). The combined organic layers were dried ( _{Na₂SO₄ )} , filtered, and concentrated under vacuum. Purification by rapid chromatography (80 g SiO ₂ containing 30% EtOAc in hexane) yielded a white solid, 5-(2-chloro-5-fluoropyridin-4-yl)-1-(4-methoxybenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (850 mg, 95%). ^¹H NMR (400 MHz, chloroform- d ) δ 8.41 (d, J = 1.6 Hz, 1H), 8.12 (s, 1H), 7.43 (q, J = 1.6 Hz, 1H), 7.29 - 7.26 (m, 2H), 6.95 - 6.87 (m, 3H), 6.67 (d, J = 0.8 Hz, 1H), 5.39 (s, 2H), 3.81 (s, 3H) ppm. ESI-MS m/z calculated value 384.079, observed value 385.4 (M+1) ⁺ . Step 5 :

Trifluoromethanesulfonic acid (850 mg, 0.5 mL, 5.551 mmol) was added to a stirred solution of TFA (11 mL) containing 5-(2-chloro-5-fluoropyridin-4-yl)-1-(4-methoxybenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (1.1 g, 2.621 mmol) at 0°C, and the reaction mixture was stirred at ambient temperature for 16 hours. The mixture was then concentrated under vacuum to obtain a brown, gelatinous solid of 5-(2-chloro-5-fluoropyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ( SB2 , 900 mg, 82%), which was used in the next step without further purification. ESI-MS m/z calculated value 264.021, observed value 265.2 (M+1) ⁺ . Starting material 6: Synthesis of 1-(2,6-difluorobenzyl)-3-ethyl-1,5-dihydro-4- H- pyrazolo[4,3- c ]pyridin-4-one (S19) Step 1 :

_K₂CO₃ (1.2 g, 8.509 mmol) was added to _a stirred solution of MeCN (13 mL) containing 3-bromo- 1H -pyrazolo[4,3- c ]pyridine (840 mg, 4.157 mmol) and 2-(chloromethyl)-1,3-difluorobenzene (1.1 g, 6.631 mmol), and the reaction mixture was stirred at ambient temperature for 12 hours. The reaction mixture was quenched by adding water (150 mL) and extracted with _EtOAc (2 x 150 mL). The combined organic layers were dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum. Purification by rapid chromatography (40 g SiO ₂ containing 0 to 90% EtOAc in hexane) yielded 3-bromo-1-(2,6-difluorobenzyl) -1H -pyrazolo[4,3- c ]pyridine (860 mg, 60%) as a pale yellow solid. ^¹H NMR (400 MHz, chloroform- d ) δ 8.95 (s, ¹H), 8.49 (d, J = 6.0 Hz, ¹H), 7.42 (d, J = 6.0 Hz, ¹H), 7.34 - 7.26 (m, ¹H), 6.95 - 6.91 (m, 2H), 5.59 (s, 2H) ppm. ESI-MS m/z calculated value 322.987, observed value 324.0 (M+1) ⁺ . Step 2 :

_K₃PO₄ (1.2 g, 5.540 mmol) was added to _a stirred solution of 1,4-dimethyl alkylene (10.8 mL) containing 3-bromo-1-(2,6-difluorobenzyl) -1H -pyrazolo[4,3- c ]pyridine (720 mg, 2.086 mmol) and ethylboric acid (1.1 g, 14.590 mmol), and the mixture was degassed by passing nitrogen through it for 15 minutes. _PdCl₂ (dtbpf) (40 mg, 0.332 mmol) was added, and the reaction mixture was stirred at 90°C for 12 hours. The reaction mixture was cooled to ambient temperature, quenched with water (150 mL), and extracted with EtOAc (2 x 100 mL). The combined organic layers were dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum. Purification by rapid chromatography (40 g _SiO₂ containing 0 to 50% EtOAc in _hexane ) yielded a brown, viscous solid, 1-(2,6-difluorobenzyl)-3-ethyl- 1H -pyrazolo[4,3- c ]pyridine (590 mg, 99%). ^¹H NMR (400 MHz, chloroform- d ) δ 9.07 (s, 1H), 8.44 (d, J = 6.4 Hz, 1H), 7.42 (d, J = 6.0 Hz, 1H), 7.32 - 7.26 (m, 1H), 6.94 - 6.92 (m, 2H), 5.57 (s, 2H), 3.03 (q, J = 6.4 Hz, 2H), 1.40 (t, J = 7.6 Hz, 3H) ppm. ESI-MS m/z calculated value 273.108, observed value 274.2 (M+1) ⁺ . Step 3 :

m -CPBA (760 mg, 70% w/w, 3.083 mmol) was added to a stirred solution of DCM (8.4 mL) containing 1-(2,6-difluorobenzyl)-3-ethyl- 1H -pyrazolo[4,3- c ]pyridine (560 mg, 1.955 mmol) at 0°C, and the reaction mixture was stirred at ambient temperature for 12 hours. The reaction mixture was quenched by adding water (100 mL) and extracted with EtOAc (2 x 50 mL). The combined organic layer was washed with _NaHCO3 solution (100 mL), dried ( _Na2SO4 ), filtered, and concentrated under vacuum to obtain a brown solid, 1-(2,6- _{difluorobenzyl} )-3-ethyl- 1H -pyrazolo[4,3- c ]pyridine 5-oxide (460 mg, 65%). ^¹H NMR (400 MHz, chloroform- d ) δ 8.70 (s, 1H), 8.16 (dd, J = 7.2 Hz, J = 1.2 Hz, 1H), 7.39 (d, J = 7.2 Hz, 1H), 7.35 - 7.31 (m, 1H), 6.97 - 6.93 (m, 2H), 5.54 (s, 2H), 2.92 (q, J = 8.0 Hz, 2H), 1.35 (t, J = 7.6 Hz, 3H) ppm. ESI-MS m/z calculated value 289.103, observed value 290.2 (M+1) ⁺ . Step 4 :

A solution of _POCl₃ (13.160 g, 8 mL, 85.827 mmol) containing 1-(2,6-difluorobenzyl)-3-ethyl- 1H -pyrazolo[4,3- c ]pyridine 5-oxide (440 mg, 1.521 mmol) was stirred for 12 hours at 90°C. The reaction mixture was quenched by adding water (100 mL) and extracted with EtOAc (2 x 100 mL). The combined organic layers _were washed with _NaHCO₃ solution (100 mL), dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum. Purification by rapid chromatography (40 g SiO ₂ containing 0 to 20% EtOAc in hexane) yielded 200 mg (29%) of 4-chloro-1-(2,6-difluorobenzyl)-3-ethyl- 1H- pyrazolo[4,3- c ]pyridine, which was a brown solid. ^¹H NMR (400 MHz, chloroform- d ) δ 8.11 (d, J = 7.2 Hz, 1H), 7.36 - 7.36 (m, 2H), 6.94 - 6.90 (m, 2H), 5.54 (s, 2H), 3.18 - 3.12 (m, 2H), 1.40 - 1.36 (m, 3H) ppm. ESI-MS m/z calculated value 307.069, observed value 308.2 (M+1) ⁺ .

Steps 5 :

A solution containing 190 mg (0.413 mmol) of 4-chloro-1-(2,6-difluorobenzyl)-3-ethyl- 1H -pyrazolo[4,3- c ]pyridine in HCl (1.9 mL, 6 M aqueous solution) was stirred for 12 hours at 100°C. The reaction mixture was cooled to ambient temperature, diluted with water (100 mL), and extracted with EtOAc (2 x 50 mL). The combined organic layers were washed with _NaHCO3 solution (100 mL), dried ( _{Na2SO4 )} , filtered, and concentrated under vacuum. Purification by reverse-phase HPLC ( ^Inertsil® ODS-3 _C18 column, 20 to 99% MeCN aqueous solution containing 0.1% formic acid) yielded a grayish-white solid of 1-(2,6-difluorobenzyl)-3-ethyl-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one ( S19 , 74 mg, 61%). ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 10.93 (s, 1H), 7.49 - 7.41 (m, 1H), 7.21 - 718 (m, 1H), 7.16 - 7.09 (m, 2H), 6.60 (d, J = 7.2 Hz, 1H), 5.45 (s, 2H), 2.78 (q, J = 7.6 Hz, 2H), 1.16 (t, J = 2.8 Hz, 3H) ppm. ESI-MS m/z calculated value 289.103, observed value 290.3 (M+1) ⁺ . Starting material 7: Synthesis of 1-(2-phenylprop-2-yl)-1,5-dihydro- 4H- pyrazolo[4,3-c]pyridin-4-one (S20) Step 1 :

( E )-3-((dimethylamino)methylene)piperidine-2,4-dione (1.78 g, 10.054 mmol) and AcOH (300.96 mg, 285 μL, 5.012 mmol) were added sequentially to a solution of EtOH (30 mL) containing (2-phenylprop-2-yl)hydrazine dihydrochloride (2.23 g, 9.994 mmol), and the reaction mixture was heated to 80°C for 16 hours. The mixture was cooled to ambient temperature and concentrated under vacuum. The residue was then separated between water and EtOAc. The aqueous phase was separated and extracted with EtOAc (2x). The combined organic layers were washed with brine, dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO2 , containing 0 to 10% MeOH in DCM) yielded a pale yellow solid, 1-(2-phenylprop-2-yl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (521 mg, 19%). ^¹H NMR (400 MHz, chloroform- d ) δ 7.96 (s, 1H), 7.30–7.39 (m, 3H), 7.12–7.17 (m, 2H), 5.37 (br s, 1H), 3.26 (td, J = 6.8, 2.5 Hz, 2H), 2.26 (t, J = 6.8 Hz, 2H), 1.97–1.98 (m, 6H) ppm. ESI-MS m/z calculated value 255.137, observed value 256.1 (M+1) ⁺ . Step 2 :

Activated _MnO₂ (1.18 g, 13.573 mmol) was added to a solution containing 10 mL of toluene (200 mg, 0.682 mmol) of 1-(2-phenylprop-2-yl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (200 mg, 0.682 mmol), and the reaction mixture was stirred at 100°C for 48 hours. Additional activated _MnO₂ (592 mg, 6.810 mmol) was added, and the reaction mixture was stirred at 110°C for 24 hours. The mixture was cooled to ambient temperature, filtered through a ^Celite® mat, and the filter cake was washed with DCM (2 x 20 mL) and MeOH (1 x 20 mL). The filtrate was collected and concentrated under vacuum. Purification by rapid chromatography ( _SiO2 containing 20 to 50% EtOAc in heptane) yielded a brown solid, 1-(2-phenylprop-2-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ( S20 , 73 mg, 33%). ^¹H NMR (400 MHz, chloroform- d ) δ 8.22 (s, 1H), 7.32–7.35 (m, 3H), 7.19 (br d, J = 7.1 Hz, 2H), 6.75 (br d, J = 4.8 Hz, 1H), 5.55 (br d, J = 6.8 Hz, 1H), 2.01 (s, 6H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 253.122, observed value 254.1 (M+1) ⁺ . V. Synthesis of Intermediates Intermediate 1: Synthesis of 5-chloro-2,4-difluoro-3-methylpyridine (Int-P1) Step 1:

Under argon atmosphere, ^nBuLi (300 mL, 2.5 M hexane solution, 750.0 mmol) was added over 15 minutes to a stirred solution containing DIPA (75.810 g, 105 mL, 749.18 mmol) in THF (1 L), while maintaining the internal temperature below 0°C and cooling the reaction mixture to -60°C. A solution containing 5-chloro-2-fluoro-3-methylpyridine (100 g, 686.99 mmol) in THF (200 mL) was added dropwise, maintaining the internal temperature below -60°C and stirring the mixture at -60°C for 2 hours. A solution of THF (200 mL) containing iodine (200 g, 787.99 mmol) was added, the internal temperature was maintained below -60 _° C, and the resulting mixture was slowly heated to ambient temperature overnight, with the cooling bath kept in place _{. The reaction mixture was diluted with EtOAc (500 mL) and quenched by adding saturated Na₂S₂O₃ solution} (1 L). The organic layer was separated, washed with brine (300 mL), and concentrated under vacuum. The solid was slurried in MeOH (250 mL) and stirred at ambient temperature for 3 hours. The solid was filtered, washed with ice-cold MeOH (200 mL), and dried to obtain a grayish-white solid of 5-chloro-2-fluoro-4-iodo-3-methylpyridine (116 g, 61%). ^¹H NMR (400 MHz, chloroform- d ) δ 8.03 (s, 1H), 2.47 (s, 3H) ppm. Step 2:

CsF (350 mg, 2.304 mmol) was added to a stirred solution of DMSO (0.8 mL) containing 5-chloro-2-fluoro-4-iodo-3-methylpyridine (150 mg, 0.553 mmol), and the reaction mixture was heated at 150°C for 48 hours. The reaction mixture was cooled to ambient temperature to give a solution of 5-chloro-2,4-difluoro-3-methylpyridine ( Int-P1 ), which was used in the next step without further purification, assuming a 100% yield.

The following intermediates were prepared using the method described in Intermediate 1, except that in step 1, different pyridines and/or electrophiles were used instead of 5-chloro-2-fluoro-3-methylpyridine and iodine. Step 2 was omitted. Table 9: Intermediates prepared using the method described in Intermediate 1 Intermediate item number Compound structure / compound name LC/MS NMR ( displacement in ppm ) Int-P2 2-Chloro-4,5-difluoro-3-methylpyridine Ionization was not observed in ES+/- ^1H NMR (400 MHz, chloroform- d ) δ 8.18 (d, J = 8.7 Hz, 1H), 2.34 (s, 3H) ppm. Int-P3 5-Chloro-2-fluoro-4-iodo-3-methylpyridine Ionization was not observed in ES+/- ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.20 (dt, J = 1.4, 0.7 Hz, 1H), 3.31 (s, 3H) ppm. Intermediate 2: Synthesis of a mixture of 2-amino-2-(2,2-difluorocyclopropyl)ethane-1-ol as two non-mirror isomers (Int-Al). Step 1:

( R )-2-methylpropane-2-sulfinamide (525 mg, 4.332 mmol), PPTS (55 mg, 0.219 mmol), and _MgSO₄ (2.60 g, 21.6 mmol) were sequentially added to a stirred solution containing rac -2,2-difluorocyclopropane-1-carboxaldehyde (31.4 g, 1.6% w/w DCM solution, 4.737 mmol), and the reaction mixture was stirred at ambient temperature for 90 hours. The mixture was filtered, and an additional amount of _MgSO₄ (2.6 g, 21.6 mmol) was added. The reaction mixture was stirred at ambient temperature for 16 hours. The mixture was then filtered. The filtrate was washed sequentially with water (10 mL), saturated aqueous solution of _NH₄Cl (10 mL), and saturated aqueous solution of _NaHCO₃ (10 mL), dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum to obtain ( R ) -N -(( E )-(2,2- _{difluorocyclopropyl} )methylene)-2-methylpropane-2-sulfinamide (929 mg, 88%), a mixture of two non-mirror isomers, and appeared as a deep orange oil. ESI-MS m/z calculated value was 209.069, observed value was 210.1 (M+1) ⁺ . Step 2:

At -78°C, magnesium chloride (220 mL, 0.58 M THF solution, 127.60 mmol) was slowly added over 30 minutes to a solution of two nonmirror isomers of DCM (500 mL) containing ( R ) -N -(( E )-(2,2-difluorocyclopropyl)methylene)-2-methylpropane-2-sulfinamide (14 g, 63.558 mmol), and the reaction mixture was stirred at -78°C for 1 hour. The mixture was then heated to ambient temperature over 2 hours. The reaction mixture was dissolved in water. The organic layer was separated, dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum to give ( R ) -N- (1-(2,2- _{difluorocyclopropyl} )-2-(isopropoxydimethylsilyl)ethyl)-2-methylpropane-2-sulfinamide (21 g, 48%), a mixture of two non-mirror isomers, and presented as a brown oil. ^¹H NMR (400 MHz, chloroform- d ) δ 4.05–3.99 (m, 1H), 3.35–3.18 (m, 1H), 1.59–1.28 (m, 3H), 1.26–1.14 (m, 16H), 0.20–0.06 (m, 8H) ppm. Step 3:

At 0°C, KF (180 mg, 3.098 mmol) and _H₂O₂ (499.5 mg, 1.5 mL, 30% w/w aqueous solution, 4.405 mmol) were sequentially added to a solution containing _a mixture of two nonmirror isomers of ( R ) -N- (1-(2,2-difluorocyclopropyl)-2-(isopropoxydimethylsilyl)ethyl)-2-methylpropane-2-sulfinamide (1 g, 1.464 mmol) and a mixture of MeOH (4 mL) and THF (4 mL) containing _KHCO₃ (150 mg, 1.498 mmol). The reaction mixture was stirred at 45°C for 2 hours. The reaction mixture was cooled to ambient temperature and poured onto water. The mixture was extracted with EtOAc. The organic extract was dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO₂ , heptane containing 75% EtOAc) yielded ( _R ) -N- (1-(2,2-difluorocyclopropyl)-2-hydroxyethyl)-2-methylpropane-2-sulfinamide (0.5 g, 85%), a mixture of two nonmirror isomers. ^¹H NMR (400 MHz, methanol - _d⁴ ) δ 3.67–3.63 (m, ¹H), 3.59 (dd, J = 6.0, 1.8 Hz, ¹H), 3.01–2.93 (m, ¹H), 1.87–1.77 (m, ¹H), 1.54 (qt, J = 12.0, 4.0 Hz, ¹H), 1.39–1.30 (m, ¹H), 1.26–1.22 (m, 9H) ppm; no interchangeable H was observed. Step 4:

HCl (4 mL, 4 M, 16.0 mmol) was added to a stirred solution of ( R ) -N- (1-(2,2-difluorocyclopropyl)-2-hydroxyethyl)-2-methylpropane-2-sulfinamide (1.038 g, 3.630 mmol) in methanol (10 mL) containing a mixture of two nonmirror isomers, and the reaction mixture was stirred at ambient temperature for 2 hours. The reactants were then concentrated under vacuum. Purification by wet milling with a 1:5 mixture of EtOAc and _Et2O yielded 2-amino-2-(2,2-difluorocyclopropyl)ethane-1-ol hydrochloride ( Int-A1 , 860 mg, 96%), a mixture of two non-mirror isomers. ^¹H NMR (400 MHz, methanol - _d⁴ ) δ 3.79 (dd, J = 11.4, 3.7 Hz, 1H), 3.64 (q, J = 6.0 Hz, 1H), 3.03 (t, J = 5.3 Hz, 1H), 1.96–1.87 (m, 1H), 1.78–1.69 (m, 1H), 1.55–1.46 (m, 1H) ppm; no interchangeable H atoms were observed. Intermediate 3: Synthesis of rel- ( 2S ^* , 4R )-2-aminohexane-1,4-diol (Int-A6) and rel- (2S ^* , 4S )-2-aminohexane-1,4-diol (Int-A5). Step 1:

EtMgBr (1.2 mL, 3 M _Et₂O solution, 3.6 mmol) was added at -10°C to a stirred solution containing ( S )-2,2-dimethyl-4-(2-e-hydroxyethyl)azolidine-3-carboxylic acid tributyl ester (400 mg, 1.303 mmol) in THF (10 mL), and the reaction mixture was stirred at 0°C to ambient temperature for 4 hours. The reaction mixture was quenched by adding _NH₄Cl solution (20 mL) and extracted with EtOAc (3 x 50 mL). The combined organic extracts were washed with water (10 mL) and brine (10 mL), dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum _. Purification by rapid chromatography (alumina, 0 to 40% EtOAc in hexane solution) yielded:

First precipitate isomer: tributyl rel- ( S ^* )-4-(( R )-2-hydroxybutyl)-2,2-dimethylazolinidin-3-carboxylic acid (150 mg, 38%), as a colorless oil. ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 4.40 (d, J = 5.2Hz, 1H), 3.85 (t, J = 12Hz, 2H), 3.32 (s, 1H), 1.70 (s, 1H), 1.45 - 1.40 (m, 19H), 0.85 (t, J = 7.2Hz, 3H) ppm.

Second precipitate isomer: rel- ( S ^* )-4-(( S )-2-hydroxybutyl)-2,2-dimethylazolinidin-3-carboxylic acid tributyl ester (180 mg, 44%), appearing as a colorless oil. ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ ppm = 4.40 - 4.37 (m, 1H), 4.01 - 3.98 (m, 1H), 3.88 - 3.78 (m, 2H), 1.70 (s, 1H), 1.46 - 1.23 (m, 19H), 0.85 (t, J = 7.2Hz, 3H) ppm. Step 2:

HCl (1 mL, 4 M 1,4-dioxane solution, 4.0 mmol) was added to a stirred solution containing 5 mL of DCM with rel- ( S ^* )-4-(( R )-2-hydroxybutyl)-2,2-dimethylaminozolidine-3-carboxylic acid tributyl ester (150 mg, 0.497 mmol) at 0°C, and the reaction mixture was stirred for 3 hours. The mixture was concentrated under vacuum. Purification was performed by wet milling with _Et2O to obtain rel- ( 2S ^* , 4R )-2-aminohexane-1,4-diol hydrochloride ( Int-A6 , 80 mg, 90%) as a brown gel. ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 7.81 (s, 3H), 5.30 (br s, 1H), 4.70 (br s, 1H), 3.61 - 3.52 (m, 2H), 3.44 - 3.39 (m, 1H), 3.23 (d, J = 5.2 Hz, 1H), 1.59 - 1.56 (m, 1H), 1.49 - 1.33 (m, 3H), 0.85 (t, J = 7.2 Hz, 3H) ppm.

Treating rel- ( S ^* )-4-(( R )-2-hydroxybutyl)-2,2-dimethyl methazolidine-3-carboxylic acid tributyl ester (180 mg, 0.577 mmol) (second dissolution isomer) in the same manner as rel- ( S ^* )-4-(( S )-2-hydroxybutyl)-2,2-dimethyl methazolidine-3-carboxylic acid tributyl ester (180 mg, 0.577 mmol) yielded rel- (2S ^* , 4S )-2-aminohexane-1,4-diol hydrochloride ( Int-A5 , 91 mg, 85%) as a brown gel. ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 7.80 (br s, 3H), 5.26 (br s, 1H), 4.95 (br s, 1H), 3.60 (t, J = 11.2Hz, 1H), 3.47 (d, J = 4.4Hz, 2H), 3.23 (br s, 1H), 1.63 - 1.60 (m, 1H), 1.49 - 1.34 (m, 3H), 0.87 - 0.83 (m, 3H) ppm.

The following intermediates were prepared using the method described in Intermediate 3, except that in step 1, different starting materials and/or Grignard reagent were used instead of ( S )-2,2-dimethyl-4-(2-electro-ethyl)azolidine-3-carboxylate tributyl ester and EtMgBr. Table 10: Intermediates prepared using the method described in Intermediate 3 Intermediate item number Compound structure / compound name LC/MS NMR ( displacement in ppm ) Int-A7 (2R ) -2-aminohexane-1,4-diol is a mixture of two non-mirror isomers. No chromophores in the molecule ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 7.74 (s, 3H), 5.25 (d, J = 5.2 Hz, 1H), 4.88 (d, J = 4.4 Hz, 1H), 3.62 - 3.58 (m, 1H), 3.48 - 3.43 (m, 2H), 3.22 (br s, 1H), 1.62 - 1.59 (m, 1H), 1.47 - 1.41 (m, 3H), 0.87 - 0.83 (m, 3H) ppm. Int-A8 rel- ( 2S ^* , 4R )-2-aminopentane-1,4-diol No chromophores in the molecule ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 7.95 (br s, 3H), 5.45 (br s, 1H), 4.85 (br s, 1H), 3.83 - 3.80 (m, 1H), 3.79 - 3.60 (m, 1H), 3.58 - 3.38 (m, 1H), 3.20 - 3.16 (m, 1H), 1.60 - 1.46 (m, 2H), 1.07 (d, J = 6.4Hz, 3H) ppm. Int-A9 rel- ( 2S ^* ,4S ) -2-aminopentane-1,4-diol No chromophores in the molecule ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 7.79 (br s, 3H), 5.25 (t, J = 4.8 Hz, 1H), 4.93 (d, J = 3.2Hz, 1H), 3.75 (d, J = 2.8Hz, 1H), 3.61 - 3.57 (m, 1H), 3.47 - 3.44 (m, 1H), 3.20 (s, 1H), 1.59 - 1.57 (m, 1H), 1.51 - 1.47 (m, 1H), 1.07 (d, J = 6.4Hz, 3H) ppm. Int-A11 ( 2S )-2-aminopentane-1,4-diol is a mixture of two non-mirror isomers. No chromophores in the molecule ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 7.91 (br s, 3H), 5.27 (d, J = 4 Hz, 1H), 4.93 (br s, 1H), 3.95 - 3. 75 (m, 1H), 3.58 - 3.43 (m, 2H), 3.20 (s, 1H), 1.60 - 1.47 (m, 2H), 1.08 - 1.06 (m, 3H) ppm. Int-A19 ( 2S )-2-aminohexane-1,4-diol is a mixture of two non-mirror isomers. No chromophores in the molecule ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 7.78 (br s, 3H), 5.25 (s, 1H), 4.88 (d, J = 4.8 Hz, 1H), 3.88 - 3.84 (m, 2H), 3.49 - 3.45 (m, 2H), 1.76 - 1.73 (m, 2H), 1.38 - 1.33 (m, 2H), 0.88 - 0.83 (m, 3H) ppm. Int-A23 rel- ( 1R, 3S ) -3 -amino-1-cyclopropylbutane-1,4-diol No chromophores in the molecule ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 3.42 - 3.39 (m, ¹H), 3.27 - 3.24 (m, ¹H), 3.07 - 3.04 (m, 2H), 1.51 - 1.46 (m, 2H), 0.81 - 0.72 (m, ¹H), 0.36 - 0.32 (m, 2H), 0.23 - 0.22 (m, 2H) ppm; no interchangeable H was observed. Int-A24 rel- ( 1S, 3S ) -3 -amino-1-cyclopropylbutane-1,4-diol No chromophores in the molecule ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 4.51 (s, ¹H), 3.38 - 3.32 (m, ¹H), 3.27 - 3.22 (m, ¹H), 3.07 - 3.02 (m, ¹H), 2.92 - 2.90 (m, ¹H), 1.42 - 1.36 (m, 2H), 0.76 - 0.74 (m, ¹H), 0.34 - 0.31 (m, 2H), 0.23 - 0.14 (m, 2H); no interchangeable H₂ ppm were observed. Intermediate 4: Synthesis of rel- ( S) -5-(1-aminoethyl)pyridine-2( 1H )-one (Int-A14) Step 1:

( R )-2-methylpropane-2-sulfinamide (4.5 g, 37.128 mmol) and Ti(OEt) _₄ (19.584 g, 18 mL, 85.854 mmol) were added sequentially to a solution of 2-MeTHF (50 mL) containing 6-sideoxy-1,6-dihydropyridine-3-carboxaldehyde (4.15 g, 33.710 mmol), and the reaction mixture was stirred overnight at ambient temperature. The reaction mixture was quenched by adding methanol (30 mL) and _a saturated aqueous solution of NaHCO₃ (30 mL), and the mixture was stirred for 30 minutes at ambient temperature. The solid was filtered and washed with methanol (2 x 30 mL). The filtrate was partially dissolved between DCM and water, and the resulting suspension was filtered. The filtrate was concentrated under vacuum to remove DCM. The resulting suspension was filtered. The solid was washed with water (2 x 20 mL) and then dried under vacuum to give a white solid of ( R , E )-2-methyl- N -((6-sideoxy-1,6-dihydropyridin-3-yl)methylene)propane-2-sulfinamide (4.1 g, 48%). ^¹H NMR (400 MHz, chloroform- d ) δ 13.04 (br s, 1H), 8.38 (s, 1H), 8.10 (dd, J = 9.6, 4.0 Hz, 1H), 7.84 (d, J = 2.3 Hz, 1H), 6.69 (d, J = 9.6 Hz, 1H), 1.26 (s, 9H) ppm. ESI-MS m/z calculated value 226.078, observed value 227.1 (M+1) ⁺ . Step 2:

MeMgBr (18 mL, 3 M _Et₂O solution, 54.0 mmol) was slowly added under argon atmosphere to a stirred solution containing ( R,E )-2-methyl- N -((6-sideoxy-1,6-dihydropyridin-3-yl)methylene)propane-2-sulfinamide (4.1 g, 17.919 mmol) in 30 mL of 2-MeTHF, and the reaction mixture was stirred for 5 days at ambient temperature. The reaction mixture was quenched by adding water and concentrated under vacuum. Purification by reverse-phase chromatography (120 g _C18 column, 0 to 50% MeOH aqueous solution containing 0.1% ammonium hydroxide, followed by 120 g _C18 column, 0 to 40% MeCN aqueous solution containing 0.1% formic acid) yielded a pale yellow solid, rel- ( R ^* )-2-methyl- N -(( S )-1-(6-sideoxy-1,6-dihydropyridin-3-yl)ethyl)propane-2-sulfinamide (3.780 g, 87%). ^¹H NMR (400 MHz, methanol - _d⁴ ) δ 7.67 (dd, J = 9.4, 4.0 Hz, 1H), 7.40 (d, J = 2.6 Hz, 1H), 6.58 (d, J = 9.5 Hz, 1H), 4.36 (q, J = 6.7 Hz, 1H), 1.52 (d, J = 6.7 Hz, 3H), 1.23 (s, 9H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 242.109, observed value 243.0 (M+1) ^⁺ . Step 3:

A solution containing rel- ( R ^* )-2-methyl- N -(( S )-1-(6-sideoxy-1,6-dihydropyridin-3-yl)ethyl)propane-2-sulfinamide (660 mg, 2.685 mmol) in HCl (6.71 mL, 4 M 1,4-dimethylethane solution, 26.840 mmol) was stirred for 3 hours at ambient temperature. _Et₂O was added, and the solid was filtered to obtain a beige solid of rel- ( S )-5-(1-aminoethyl)pyridin-2( 1H )-ketohydrochloride ( Int-A14 , 447 mg, 93%). ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 8.32 (s, 3H), 7.61 (d, J = 9.2 Hz, 1H), 7.49 (s, 1H), 6.36 (d, J = 9.6 Hz, 1H), 4.19 (t, J = 6.0 Hz, 1H), 1.40 (d, J = 6.9 Hz, 3H) ppm; no interchangeable H was observed. ESI-MS m/z calculated 138.079, observed 139.0 (M+1) ^⁺ .

The following intermediates were prepared using the method described in Intermediate 4, except that in step 1, ( S )-2-methylpropane-2-sulfinamide was used instead of ( R )-2-methylpropane-2-sulfinamide. Table 11: Intermediates prepared using the method described in Intermediate 4 Intermediate item number Compound structure / compound name LC/MS NMR ( displacement in ppm ) Int-A15 rel- ( R )-5-(1-aminoethyl)pyridine-2( 1H )-one ESI-MS calculated m/z value: 138.079; observed value: 139.0 (M+1) ⁺ . ^¹H NMR (400 MHz, methanol - _d⁴ ) δ 8.02 (dd, J = 9.2, 2.7 Hz, 1H), 7.90 (d, J = 2.3 Hz, 1H), 6.91 (d, J = 9.2 Hz, 1H), 4.47 (q, J = 6.9 Hz, 1H), 1.62 (d, J = 6.9 Hz, 3H) ppm; no interchangeable H was observed. Intermediate 5: Synthesis of rel- ( R ^* )-6-(( S )-1-aminoethyl)-4-(4-methoxybenzyl) urin-3-one (Int-A17) and rel- ( R ^* )-6-(( R )-1-aminoethyl)-4-(4-methoxybenzyl) urin-3-one (Int-A18) Step 1:

(4-Methoxyphenyl)methylamine (31 g, 225.98 mmol) was added to a solution of DMSO (180 mL) containing ( R )-ethylene oxide-2-carboxylate (23 g, 225.29 mmol), and the reaction mixture was stirred at 45°C for 6 hours. The reaction mixture was cooled to ambient temperature and water was added to precipitate the solids. The solids were filtered, and the mother liquor was extracted with EtOAc (2 x). The combined organic extracts were washed with brine, dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum _. Purification by rapid chromatography ( _SiO2 , DCM solution of 7 to 93% MeOH) yielded methyl ( R )-2-hydroxy-3-((4-methoxybenzyl)amino)propionate (24.9 g, 39%), which was a yellow oil. ^¹H NMR (400 MHz, chloroform- d ) δ 7.22 - 7.17 (m, 2H), 6.85 (dt, J = 9.2, 2.4 Hz, 2H), 4.27 (dd, J = 5.7, 3.9 Hz, 1H), 3.81 - 3.79 (m, 3H), 3.77 (s, 3H), 3.75 - 3.68 (m, 2H), 2.99 (dd, J = 12.4, 4.1 Hz, 1H), 2.86 (q, J = 6.1 Hz, 1H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 239.116, observed value 240.12 (M+1) ⁺ . Step 2:

2-Chloroacetyl chloride (7.941 g, 5.6 mL, 70.308 mmol) was added dropwise to a solution of DCM (400 mL) containing ( R )-2-hydroxy-3-((4-methoxybenzyl)amino)propionate (15.68 g, 54.085 mmol) and triethylamine (10.890 g, 15 mL, 107.62 mmol). The mixture was stirred at 0°C for 15 min and then stirred to ambient temperature for 1 hour. The reaction mixture was quenched by adding saturated _NaHCO3 solution and extracted with DCM (x 3). The combined organic extracts were washed with brine, dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO2 , 30 to 100% heptane solution of EtOAc) yielded methyl ( R )-3-(2-chloro- N- (4-methoxybenzyl)acetamino)-2-hydroxypropionate (12.47 g, 69%), which was a yellow oil. ^¹H NMR (400 MHz, methanol - _d⁴ ) δ 7.12 - 7.29 (m, 2H), 6.75 - 7.03 (m, 2H), 4.66 - 4.82 (m, 1H), 4.47 - 4.61 (m, 1H), 4.22 - 4.46 (m, 2H), 4.08 - 4.16 (m, 1H), 3.77 - 3.84 (m, 3H), 3.72 - 3.77 (m, 3H), 3.38 - 3.71 (m, 2H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 315.087, observed value 316.1 (M+1) ⁺ . Step 3:

A solution of ^iPrOH (80 mL) containing KO t Bu (8.36 g, 74.502 mmol) was added dropwise to a stirred solution of ^iPrOH (170 mL) containing ( R )-3-(2-chloro- N- (4-methoxybenzyl)acetaminophen)-2-hydroxypropionate (12.47 g, 37.282 mmol), and the reaction mixture was stirred at 0°C for 4.5 hours. The reaction mixture was quenched at 0°C by adding HCl (500 mL, 1 M aqueous solution), and the reaction mixture was extracted with DCM (x 3). The combined organic extracts were washed with brine, dried ( _MgSO4 ), filtered, and vacuum concentrated to obtain ( R )-4-(4-methoxybenzyl)-5-sideoxy-2-carboxylic acid (9.5 g, 94%), which was a pale yellow solid. ^¹H NMR (400 MHz, methanol - _d⁴ ) δ 7.22–7.19 (m, 2H), 6.90–6.88 (m, 2H), 4.54 (s, 2H), 4.51–4.46 (dd, J = 8.2, 4.6 Hz, 1H), 4.40 (d, J = 16.9 Hz, 1H), 4.25 (d, J = 16.9 Hz, 1H), 3.76 (s, 3H), 3.58–3.42 (m, 2H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 265.095, observed value 264.1 (M⁻¹) ^– . Step 4:

Triethylamine (6.534 g, 9 mL, 64.572 mmol) was added to a stirred solution of DCM (150 mL) containing ( R )-4-(4-methoxybenzyl)-5-sideoxyphospholine-2-carboxylic acid (6.22 g, 19.392 mmol), N , O -dimethylhydroxylamine hydrochloride (2.2 g, 22.554 mmol), and T3P (15 mL, 50% w/v EtOAc solution, 23.571 mmol). The reaction mixture was stirred for 2 hours at ambient temperature to allow the reactants to partially dissolve between DCM and water. The organic layer was separated, dried ( _Na₂SO₄ ), filtered, and vacuum concentrated to obtain ( R ) -N -methoxy-4-(4-methoxybenzyl) -N -methyl-5-sideoxy-2-carbamate (6.3 _g , 95%), which was a yellow oily substance and solidified upon standing. ^¹H NMR (400 MHz, chloroform- d ) δ 7.20 (dt, J = 9.2, 2.4 Hz, 2H), 6.85 (dt, J = 9.2, 2.4 Hz, 2H), 4.66–4.60 (m, 2H), 4.48 (dd, J = 15.3, 8.5 Hz, 2H), 4.26 (d, J = 16.5 Hz, 1H), 3.78 (d, J = 6.0 Hz, 3H), 3.68 (s, 3H), 3.61–3.52 (m, 1H), 3.28–3.23 (m, 1H), 3.16 (s, 3H) ppm. ESI-MS Calculated m/z value: 308.137, Observed value: 309.0 (M+1) ⁺ . Step 5:

MeMgBr (6 mL, 3 M _Et₂O solution, 18.0 mmol) was added to a solution of ( R ) -N -methoxy-4-(4-methoxybenzyl) -N -methyl-5-sideoxycarboxylin-2-methoxyamine (2.75 g, 8.027 mmol) in 50 mL of THF at -78°C, and the reaction mixture was stirred under argon for 1 hour. The reaction mixture was quenched by adding water, heated to ambient temperature, and extracted with EtOAc. The organic layer was separated, dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum to give ( R )-6-acetyl- _4- (4-methoxybenzyl)carboxylin-3-one (2.35 g, 95%) as a yellow oil. ¹ H NMR (400 MHz, chloroform- d ) δ 7.19 (dt, J = 9.3, 2.5 Hz, 2H), 6.86 (dt, J = 9.2, 2.4 Hz, 2H), 4.61 (d, J = 14.7 Hz, 1H), 4.49 - 4.40 (m, 2H), 4.28 (d, J = 16.5 Hz, 1H), 4.14 - 4.08 (m, 1H), 3.79 (s, 3H), 3.36 (dd, J = 12.6, 3.4 Hz, 1H), 3.27 (dd, J = 12.5, 10.4 Hz, 1H), 2.23 (s, 3H) ppm. ESI-MS Calculated m/z value: 263.116, Observed value: 264.1 (M+1) ⁺ . Step 6:

(4-Methoxyphenyl)methylamine (2.5 g, 18.224 mmol) was added to a suspension of MeOH (30 mL) containing ( R )-6-acetyl-4-(4-methoxyphenylmethyl)trimoline-3-one (2.4 g, 7.748 mmol) and _MgSO₄ (1 g, 8.308 mmol), and the reaction mixture was stirred at ambient temperature for 4 hours. _NaBH₄ (0.7 g, 18.503 mmol) was added fractionally, and the reaction mixture was stirred at ambient temperature for 17 hours. The reaction mixture was quenched by adding water and extracted with EtOAc (2 x). The organic extract was dried ( _MgSO₄ ), filtered, and concentrated under vacuum. The non-mirror isomers were purified by rapid chromatography ( _SiO₂ , 0 to 5% MeOH in DCM solution) followed by reverse-phase chromatography (80 g _C₁₈ column, 20 to 80% MeCN aqueous solution containing 0.1% ammonium hydroxide) to obtain:

First dissolution isomer: rel- ( R ^* )-4-(4-methoxybenzyl)-6-(( S )-1-((4-methoxybenzyl)amino)ethyl)urin-3-one (1.01 g, 33%), a colorless oil. ¹ H NMR (400 MHz, methanol -d ₄ ) δ 7.21 - 7.18 (m, 2H), 7.15 (dd, J = 6.6, 2.1 Hz, 2H), 6.90 - 6.85 (m, 2H), 6.82 (td, J = 5.7, 3.2 Hz, 2H), 4.51 (dd, J = 33.7, 14.4 Hz, 2H), 4.19 (dd, J = 39.6, 16.7 Hz, 2H), 3.76 (s, 3H), 3.74 (s, 3H), 3.70 (d, J = 12.8 Hz, 1H), 3.65 (dt, J = 10.2, 4.4 Hz, 1H), 3.58 - 3.55 (m, 1H), 3.25 - 3.17 (m, 2H), 2.74 - 2.68 (m, 1H), 1.05 (d, J = 6.4 Hz, 3H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 384.205, observed value 385.3 (M+1) ⁺ .

Second precipitate isomer: rel- ( R ^* )-4-(4-methoxybenzyl)-6-(( R )-1-((4-methoxybenzyl)amino)ethyl) urin-3-one (0.7 g, 22%), a colorless oil. ^¹H NMR (400 MHz, methanol - _d⁴ ) δ 7.19 (td, J = 6.0, 2.9 Hz, 4H), 6.90 - 6.83 (m, 4H), 4.51 (q, J = 14.2 Hz, 2H), 4.26 - 4.16 (m, 2H), 3.76 (m, 7H), 3.58 - 3.52 (m, 2H), 3.23 - 3.18 (m, 2H), 2.70 (dt, J = 13.9, 6.5 Hz, 1H), 0.98 (d, J = 6.4 Hz, 3H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 384.205, observed value 385.3 (M+1) ⁺ . Step 7:

In a high-pressure autoclave, Pd(OH) _₂ (300 mg, 20% w/w on carbon, 0.427 mmol) was added to a stirred solution of methanol (30 mL) containing rel- ( R ^* )-4-(4-methoxybenzyl)-6-(( S )-1-((4-methoxybenzyl)amino)ethyl) urin-3-one (1.01 g, 2.550 mmol) (first precipitate isomer), and the reaction mixture was stirred for 18 hours under hydrogen (6 atm) at ambient temperature. The reaction mixture was filtered through a ^Celite® mat, and the filtrate was concentrated under vacuum. Purification by reverse phase chromatography ( _C18 column, 10 to 50% MeCN aqueous solution containing 0.1% ammonium hydroxide) yielded a colorless oily substance, rel- ( R ^* )-6-(( S )-1-aminoethyl)-4-(4-methoxybenzyl) urin-3-one ( Int-A17 , 325 mg, 48%). ¹ H NMR (400 MHz, methanol - _{d 4} ) δ 7.21 (dt, J = 9.2, 2.4 Hz, 2H), 6.88 (dt, J = 9.3, 2.5 Hz, 2H), 4.62 (d, J = 14.7 Hz, 1H), 4.44 (d, J = 14.2 Hz, 1H), 4.29 - 4.25 (m, 1H), 4.17 (d, J = 16.5 Hz, 1H), 3.76 (s, 3H), 3.55 - 3.50 (m, 1H), 3.26 - 3.20 (m, 2H), 2.94 - 2.88 (m, 1H), 1.06 (d, J = 6.4 Hz, 3H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 264.147, observed value 265.1 (M+1) ⁺ .

Rel- ( R ^* )-4-(4-methoxybenzyl)-6-(( S )-1-((4-methoxybenzyl)amino)ethyl)ratolin-3-one (0.7 g, 1.741 mmol) (second dissolution isomer) was treated in the same manner as rel- ( R ^* )-4-(4-methoxybenzyl)-6-(( R )-1-((4-methoxybenzyl)amino)ethyl)ratolin-3-one (Int-A18, 170 mg, 36%), which was a colorless oil, to obtain rel- ( R ^* )-6-(( R )-1-aminoethyl)-4-(4-methoxybenzyl)ratolin-3-one ( Int-A18 , 170 mg, 36%). ¹ H NMR (400 MHz, methanol - _{d 4} ) δ 7.22 - 7.19 (m, 2H), 6.88 (dt, J = 9.3, 2.5 Hz, 2H), 4.57 (d, J = 14.2 Hz, 1H), 4.49 (d, J = 14.2 Hz, 1H), 4.28 (d, J = 16.5 Hz, 1H), 4.16 (d, J = 16.5 Hz, 1H), 3.76 (s, 3H), 3.41 (q, J = 7.0 Hz, 1H), 3.19 (d, J = 7.3 Hz, 2H), 2.85 - 2.78 (m, 1H), 0.99 (d, J = 6.4 Hz, 3H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 264.147, observed value 265.1 (M+1) ⁺ .

The following intermediates are prepared using the method described in Intermediate 5, except that in step 1, ( S )-methyl ethylene oxide-2-carboxylate is used instead of ( R ) -methyl ethylene oxide-2-carboxylate. Table 12: Intermediates prepared using the method described in Intermediate 5 Intermediate item number Compound structure / compound name LC/MS NMR ( displacement in ppm ) Int-A20 rel- ( S ^* )-6-(( S )-1-aminoethyl)-4-(4-methoxybenzyl)urin-3-one ESI-MS calculated m/z value: 264.147; observed value: 265.1 (M+1) ⁺ . ¹ H NMR (400 MHz, methanol - _{d 4} ) δ 7.23 - 7.20 (m, 2H), 6.88 (dt, J = 9.3, 2.5 Hz, 2H), 4.62 (d, J = 14.2 Hz, 1H), 4.44 (d, J = 14.2 Hz, 1H), 4.22 (dd, J = 38.5, 16.5 Hz, 2H), 3.78 (d, J = 14.2 Hz, 3H), 3.58 - 3.50 (m, 1H), 3.33 - 3.21 (m, 2H), 2.91 (dt, J = 12.7, 6.1 Hz, 1H), 1.06 (d, J = 6.4 Hz, 3H ppm; no interchangeable H was observed. Intermediate 6: Synthesis of rac -2-amino-2-(2,2-dimethylcyclopropyl)ethanol-1-ol (Int-A22) Step 1:

TFA (725.2 mg, 0.5 mL, 6.233 mmol) and (diethoxyiodide)benzene (2 g, 6.085 mmol) were sequentially added to a stirred solution containing rac -1-(2,2-dimethylcyclopropyl)ethyl-1-one (500 mg, 3.119 mmol) in MeCN (12 mL) and water (3 mL) at 0°C, and the reaction mixture was stirred at 65°C for 3 hours. The reaction mixture was quenched by adding water and extracted with EtOAc (2 x 30 mL). The combined organic extracts were washed with a saturated solution _{of NaHCO3} and brine (20 mL), dried ( _Na2SO4 ), filtered, and concentrated under vacuum _. Purification by rapid chromatography (12 g _SiO₂ , 0 to 20% EtOAc in hexane solution) yielded rac -1-(2,2-dimethylcyclopropyl)-2-hydroxyethyl-1-one (150 mg, 26%) as a pale yellow oil. ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 5.07 (t, J = 6.0 Hz, 1H), 4.18–4.04 (m, 2H), 2.04–2.01 (m, 1H), 1.31 (s, 3H), 1.08–1.06 (m, 1H), 1.01 (s, 3H), 0.88–0.86 (m, 1H) ppm. Step 2:

Imidazole (75 mg, 1.080 mmol) and TBSCl (100 mg, 0.6502 mmol) were added sequentially to a stirred solution containing rac -1-(2,2-dimethylcyclopropyl)-2-hydroxyethyl-1-one (100 mg, 0.546 mmol) in DCM (3 mL), and the reaction mixture was stirred at ambient temperature for 16 hours. The reaction mixture was diluted with water (20 mL) and extracted with DCM (2 x 30 mL). The combined organic extracts were washed with water (20 mL) and brine (20 mL), dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum to obtain rac -2-((tert- _{butyldimethylsilyl} )oxy)-1-(2,2-dimethylcyclopropyl)ethyl-1-one (100 mg, 67%), which was a pale yellow oil. ^¹H NMR (400 MHz, chloroform- d ) δ 4.21 (dd, J = 20.4, 17.2 Hz, 2H), 2.15 (t, J = 5.6 Hz, 1H), 1.31 (q, J = 5.2 Hz, 1H), 1.21 (s, 3H), 1.09 (s, 3H), 0.93 (s, 9H), 0.88 (q, J = 3.6 Hz, 1H), 0.09 (s, 6H) ppm. Step 3:

Sodium acetate (185 mg, 2.2101 mmol) and hydroxylamine (290 mg, 1.766 mmol) were added sequentially to a stirred solution of EtOH (10 mL) containing rac -2-((tri-butyldimethylsilyl)oxy)-1-(2,2-dimethylcyclopropyl)ethyl-1-one (400 mg, 1.485 mmol), and the reaction mixture was stirred at ambient temperature for 16 hours. The reaction mixture was quenched by adding water and extracted with EtOAc (2 x 50 mL). The combined organic extracts were washed with brine (30 mL), dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum to obtain rac -2-((tri- _{butyldimethylsilyl} )oxy)-1-(2,2-dimethylcyclopropyl)ethyl-1-one oxime (300 mg, 77%), which was a grayish-white solid. ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 10.51 (s, 1H), 4.49 (d, J = 15.6 Hz, 1H), 4.30 (d, J = 15.6 Hz, 1H), 1.53 - 1.50 (m, 1H), 1.13 (s, 3H), 0.93 - 0.82 (m, 12H), 0.53 - 0.50 (m, 1H), 0.19 (s, 6H) ppm, 0.05 (m, 1H) ppm. Step 4:

_{NiCl₂· 6H₂O} (200 mg, 0.799 mmol) and _NaBH₄ (165 mg, 4.274 mmol) were added sequentially to a stirred solution of MeOH (5 mL) containing rac -2-((tri-butyldimethylsilyl)oxy)-1-(2,2-dimethylcyclopropyl)ethyl-1-one oxime (220 mg, 0.839 mmol) at 0°C, and the reaction mixture was stirred overnight at ambient temperature. The mixture was diluted with EtOAc (40 mL) and filtered through a ^Celite® mat. The filtrate was collected, washed with water (30 mL) and brine (30 mL), dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum to obtain rac -2-((tert- _{butyldimethylsilyl} )oxy)-1-(2,2-dimethylcyclopropyl)ethyl-1-amine (175 mg, 73%), which was a pale yellow oil. ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 3.58 (dd, J = 9.6, 3.6 Hz, 1H), 3.39 (dd, J = 9.6, 7.2 Hz, 1H), 2.33 - 2.31 (m, 1H), 1.09 (s, 3H), 1.01 (s, 3H), 0.88 (s, 9H), 0.85 - 0.83 (m, 1H), 0.40 - 0.38 (m, 1H), 0.33 - 0.28 (m, 1H), 0.04 (s, 6H) ppm; no interchangeable H was observed. Step 5:

HCl (2 mL, 2 M _Et₂O solution, 4.0 mmol) was added to a stirred solution containing rac -2-((tri-butyldimethylsilyl)oxy)-1-(2,2-dimethylcyclopropyl)ethyl-1-amine (160 mg, 0.559 mmol) in DCM (3 mL) at 0°C, and the reaction mixture was stirred at ambient temperature for 16 hours. The reactant was concentrated under vacuum. Purification by wet milling with _Et₂O yielded a grayish-white solid, rac -2-amino-2-(2,2-dimethylcyclopropyl)ethyl-1-ol hydrochloride ( Int-A22 , 90 mg, 93%). ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 7.88 (br s, 3H), 5.30 (t, J = 4.8 Hz, 1H), 3.64 - 3.59 (m, 1H), 3.52 - 3.46 (m, 1H), 2.67 (t, J = 1.6 Hz, 1H), 1.13 (s, 3H), 1.05 (s, 3H), 0.71 - 0.67 (m, 1H), 0.50 - 0.47 (m, 1H), 0.19 (t, J = 4.8 Hz, 1H) ppm. Intermediate 7: Synthesis of 2-amino-2-(cyclopropyl- _2,2,3,3 -d4 )ethane-1,1 - _d2-1 -ol (Int-A26) Step 1:

BTEAC (30.9 g, 136 mmol) was added to NaOH (436 g, 50 wt% aqueous solution, 5.45 mol) at 60°C with stirring. Immediately, a mixture of ethyl acetoacetate (35.3 g, 271 mmol) and 1,2-dibromoethane-1,1,2,2- d4 (52.5 g, 326 mmol) was added, and the resulting suspension was vigorously stirred at 60 _° C for 2 hours. The reaction mixture was cooled to ambient temperature. The mixture was diluted with deionized water (350 mL) and cooled to an internal temperature of 0°C. A concentrated HCl aqueous solution (500 mL) was added dropwise while maintaining an internal temperature below 20°C. The acidic mixture (pH 2–3) was extracted with _Et₂O (3 x 400 mL). The combined organic extracts were _dried ( _{Na₂SO₄ )} , filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO₂ , 10–50% hexane solution of EtOAc) yielded a colorless oily 1-acetylated cyclopropane-1-carboxylic acid-2,2,3,3 -d₄ acid (30.1 g, 67%). ^¹H NMR (400 MHz, chloroform- d ) δ 2.20 (s, 3H) ppm; no interchangeable H atoms were observed. Step 2:

Anhydrous LiCl (14.5 g, 0.342 mol) was added to 1-acetylated cyclopropane-1-carboxylic acid-2,2,3,3 - _d4 acid (30.1 g, 228 mmol), and the pure reaction mixture was stirred at 100°C for 2 hours. The mixture was cooled to ambient temperature, diluted with _Et2O (100 mL), filtered, and the filter cake was washed with _Et2O (2 x 50 mL). The mother liquor was collected and concentrated under reduced pressure at below 15°C to give 5-chloropentan-2-one-4,4,5,5- _d4 (10.62 g, 42% yield), which was a pale yellow oil. The remaining filter cake was dissolved in HCl (100 mL, 1 M aqueous solution) and extracted with _Et₂O (3 x 50 mL). The combined organic extracts were dried ( _{Na₂SO₄ )} , filtered, and concentrated under vacuum to give an additional amount of 5-chloropentan-2-one-4,4,5,5- _d₄ (16.1 g, 12%) as a pale yellow semi-solid. ^¹H NMR (400 MHz, chloroform- d₄ ) δ 2.17 (s, 3H), 2.62 (s, 2H) ppm. Step 3:

NaOH (20.43 g, 25% aqueous solution, 127.9 mmol) was added to 5-chloropentan-2-one-4,4,5,5- _d4 (10.6 g, 85.2 mmol), and the reaction mixture was stirred at 90°C for 2 hours. The reaction mixture was cooled to ambient temperature and saturated with NaCl. The mixture was extracted with _Et2O (3 x 30 mL). The combined organic extracts were dried ( _{Na2SO4 )} , filtered, and the volatiles were removed by fractionation at atmospheric pressure below 70°C to give 1-(cyclopropyl-2,2,3,3 _-d4 ) ethyl-1-one (5.58 g, 67.0%) as a pale yellow oil. ^¹H NMR (400 MHz, chloroform -d ) δ 1.90 (s, ¹H), 2.23 (s, ³H) ppm. Step 4:

At 0°C, _KMnO₄ (25.1 g, 158.8 mmol) was added over 10 minutes to a mixture containing 1-(cyclopropyl-2,2,3,3- _d₄ ) ethyl-1-one (7.00 g, 79.4 mmol), pyridine (18.84 g, 238.2 mmol), and KOH (5.35 g, 95.3 mmol) in 238 mL of deionized water. The reaction mixture was stirred at 60°C for 3 hours. The resulting suspension was filtered, and the filter cake was rinsed with warm (50°C) deionized water (3 x 50 mL). The combined mother liquor was concentrated under vacuum to obtain a pale yellow solid (20.9 g) composed of a mixture of 2-(cyclopropyl-2,2,3,3 - _d4 )-2-sideoxyacetic acid potassium (approximately 6.65 g, 54 wt%) and KOH (14.26 g, approximately 3.2 equivalents), which was used in the next step without further purification. ^¹H NMR (400 MHz, _D₂O ) δ 12.28 (s, ¹H) ppm; no interchangeable H atoms were observed. Step 5:

Ammonium formate (6.00 g, 96.0 mmol) was added to a stirred solution of MeOH (48 mL) containing 2-(cyclopropyl-2,2,3,3 - _d4 )-2-sideoxyacetic acid (approximately 3.00 g, 19.2 mmol) at ambient temperature, and the solution was degassed (vacuum nitrogen cycle x5). (Cp ^* _RhCl2 ) ₂ (29.7 mg, 48 μmol) was added, and the mixture was again degassed (vacuum nitrogen cycle x5). The reaction mixture was stirred and heated for 22 hours at 55°C under a _N2 atmosphere. The mixture was cooled to ambient temperature and concentrated under vacuum. The coarse yellow solid was wet-milled with _Et₂O (30 mL) to remove the catalyst and dissolved in deionized water (30 mL). Purification with an ion-exchange resin (15 g DOWEX 50WX8, 5% deionized aqueous solution of _NH₄OH ) yielded a grayish-white solid of 2-amino-2-(cyclopropyl-2,2,3,3 - _d₄ )acetic acid (1.82 g, 79%, in 2 steps). ^¹H NMR (400 MHz, _D₂O ) δ 3.07 (d, J = 9.6 Hz, 1H), 1.08 (d, J = 9.6 Hz, 1H) ppm; no interchangeable H atoms were observed. Step 6:

Under a _nitrogen atmosphere, _LiAlD4 (5.41 g, 129.0 mmol) was added over 5 minutes to a mixture containing 2-amino-2-(cyclopropyl-2,2,3,3 - _d4 )acetic acid (5.12 g, 43.0 mmol) and anhydrous THF (210 mL) at -78°C. The mixture was stirred at -78°C for 30 minutes, then at ambient temperature for 1 hour, and finally under reflux for 17 hours. The reaction mixture was then cooled to -78°C, and NaOH (20 mL, 5% by weight aqueous solution) was slowly added over 10 minutes. Remove the cold bath, stir the resulting suspension at ambient temperature for 1 hour, filter, and rinse the filter cake with Et ₂ O (5 x 60 mL). The combined organic extracts were dried (Na ₂ SO ₄ ), filtered, and concentrated under vacuum to obtain 2-amino-2-(cyclopropyl-2,2,3,3 -d ₄ ) ethyl-1,1- _d 2-1-ol ( Int-A26 , 3.35 g, 73%), which is a light yellow oil. ^¹H NMR (400 MHz, chloroform- d ) δ 1.90 – 2.50 (br s, 3H), 2.06 (d, J = 9.2 Hz, 1H), 0.67 (d, J = 8.8 Hz, 1H) ppm. Intermediate 8: Synthesis of rel- ( S ^* )-6-(( R )-1-amino-2-hydroxyethyl)-4-(4-methoxybenzyl) urin-3-one (Int-A27) Step 1:

^iPrMgCl (11.2 mL, 2 M THF solution, 22.4 mmol) was slowly added to a solution of THF (30 mL) containing iodomethyl iodide pivalate (4.519 g, 2.8 mL, 18.670 mmol), and the reaction mixture was stirred at -60°C for 1 hour. The resulting solution was then added dropwise to a solution of THF (30 mL) containing ( S ) -N -methoxy-4-(4-methoxybenzyl) -N -methyl-5-sideoxyphosphono-2-methoxyamine (2.5 g, 7.482 mmol). The reaction mixture was stirred at -78°C for 1 hour and quenched by adding saturated aqueous solution of _NH₄Cl . The mixture was warmed to ambient temperature and dissolved separately between EtOAc and water. The organic layer was separated, dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO2 , 20 to 100% heptane solution of EtOAc) yielded ( S )-2-(4-(4-methoxybenzyl)-5-sideoxy-2-yl)-2-sideoxyethylpentyl ester (1.793 g, 63%), a yellow oil. ^¹H NMR (400 MHz, chloroform-d) δ 7.20 (d, J = 8.7 Hz, 2H), 6.90 - 6.83 (m, 2H), 4.97 - 4.87 (m, 2H), 4.69 (d, J = 14.2 Hz, 1H), 4.47 - 4.39 (m, 2H), 4.37 - 4.24 (m, 2H), 3.81 (s, 3H), 3.38 (s, 1H), 3.37 (d, J = 2.3 Hz, 1H), 1.25 (s, 9H) ppm. ESI-MS m/z calculated value 363.168, observed value 364.2 (M+1) ⁺ . Step 2 :

A mixture containing ( S )-2-(4-(4-methoxybenzyl)-5-sideoxy-2-yl)-2-sideoxyethylpentanoic acid (1.65 g, 4.313 mmol), (4-methoxyphenyl)methylamine (1.187 g, 1.13 mL, 8.649 mmol), and 25 mL of DCM (4 Å molecular sieve) was stirred for 16 hours at ambient temperature. STAB (1.83 g, 8.634 mmol) was added, and the reaction mixture was stirred for an additional 4 hours. The mixture was separated with a saturated aqueous solution of _NaHCO3 . The aqueous phase was separated and extracted with DCM. The combined organic extracts were dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO2 , 10 to 100% EtOAc in heptane solution) yielded:

First dissolution isomer: Ethyl rel- ( S )-2-(( S ^* )-4-(4-methoxybenzyl)-5-sideoxy-2-yl)-2-((4-methoxybenzyl)amino)pentanoate (1.135 g, 52%), a pale yellow oil. ¹ H NMR (400 MHz, chloroform- d ) δ 7.16 (dd, J = 26.1, 8.2 Hz, 4H), 6.89 - 6.80 (m, 4H), 4.52 (s, 2H), 4.31 - 4.25 (m, 2H), 4.15 - 4.09 (m, 3H), 3.80 (s, 3H), 3.79 (s, 3H), 3.76 (s, 1H), 3.67 - 3.58 (m, 2H), 3.32 (dd, J = 12.4, 3.2 Hz, 1H), 3.19 (t, J = 11.2 Hz, 1H), 2.81 - 2.77 (m, 1H), 1.16 (d, J = 8.7 Hz, 9H) ppm. ESI-MS m/z calculated value 484.257, observed value 485.3 (M+1) ⁺ .

The second precipitate isomer: ethyl rel- ( R )-2-(( S ^* )-4-(4-methoxybenzyl)-5-sideoxy-2-yl)-2-((4-methoxybenzyl)amino)pentanoate (314 mg, 12%), which is a pale yellow oil and solidifies upon standing. ¹ H NMR (400 MHz, chloroform- d ) δ 7.19 - 7.15 (m, 4H), 6.87 - 6.82 (m, 4H), 4.53 (dd, J = 54.5, 14.7 Hz, 2H), 4.37 - 4.29 (m, 1H), 4.18 - 4.05 (m, 4H), 3.85 (d, J = 12.8 Hz, 1H), 3.80 (s, 3H), 3.79 (s, 3H), 3.77 - 3.69 (m, 1H), 3.64 (d, J = 13.3 Hz, 1H), 3.46 (t, J = 11.4 Hz, 1H), 2.97 (dd, J = 11.9, 3.2 Hz, 1H), 2.79 (q, J = 5.2 Hz, 1H), 1.16 - 1.11 (m, 9H) ppm. ESI-MS m/z calculated value 484.257, observed value 485.3 (M+1) ⁺ . Step 3 :

NaOMe (0.25 mL, 25% w/v MeOH solution, 1.157 mmol) was added to a solution of MeOH (3 mL) containing rel- ( R )-2-(( S ^* )-4-(4-methoxybenzyl)-5-sideoxy-2-yl)-2-((4-methoxybenzyl)amino)pentanoate ethyl ester (second precipitate isomer, 315 mg, 0.534 mmol), and the reaction mixture was stirred at ambient temperature for 2 hours. The mixture was poured over ice water and extracted with EtOAc (x 2). The combined organic phase was washed with brine, dried ( _MgSO4 ), filtered, and vacuum concentrated to obtain a pale yellow oily substance, rel- ( S ^* )-6-(( R )-2-hydroxy-1-((4-methoxybenzyl)amino)ethyl)-4-(4-methoxybenzyl)lin-3-one (286 mg, 91%), which solidified upon standing. ^¹H NMR (400 MHz, methanol- d⁴ ) δ 7.25–7.16 (m, 4H), 6.94–6.87 (m, 2H), 6.87–6.81 (m, 2H) _, 4.53 (q, J = 14.7 Hz, 2H), 4.33–4.12 (m, 2H), 3.85–3.75 (m, 8H), 3.69–3.49 (m, 3H), 3.40–3.33 (m, 1H), 3.14 (dd, J = 12.4, 2.7 Hz, 1H), 2.66–2.60 (m, 1H) ppm; no interchangeable H atoms were observed. ESI-MS m/z calculated value 400.200, observed value 399.2 (M⁻¹) ^- . Step 4 :

Pd(OH) _₂ (80 mg, 20% w/w, 0.114 mmol) was added to a solution of MeOH (20 mL) containing rel- ( S ^* )-6-(( R )-2-hydroxy-1-((4-methoxybenzyl)amino)ethyl)-4-(4-methoxybenzyl)lin-3-one (286 mg, 0.487 mmol), and the reaction mixture was stirred at 150 psi hydrogen for 16 hours. The reactants were filtered through a ^Celite® mat, and the filtrate was concentrated under vacuum. Purification was performed by reverse phase chromatography (12 g _C18 column, 0 to 50% MeCN aqueous solution containing 0.1% ammonium hydroxide), followed by rapid chromatography ( _SiO2 , 0 to 10% MeOH in DCM solution) to obtain a colorless oily substance, rel- ( S ^* )-6-(( R )-1-amino-2-hydroxyethyl)-4-(4-methoxybenzyl) urin-3-one ( Int-A27 , 63 mg, 45%), which solidified upon standing. ^¹H NMR (400 MHz, methanol _-d⁴ ) δ 7.22–7.20 (m, 2H), 6.90–6.87 (m, 2H), 4.53 (dd, J = 35.9, 14.4 Hz, 2H), 4.23 (dd, J = 41.7, 16.5 Hz, 2H), 3.76–3.70 (m, 4H), 3.51 (q, J = 5.6 Hz, 1H), 3.46–3.33 (m, 2H), 3.20 (dd, J = 12.1, 3.0 Hz, 1H), 2.75 (q, J = 5.6 Hz, 1H) ppm; no interchangeable H atoms were observed. ESI-MS calculated m/z value 280.142, observed value 281.1 (M+1) ⁺ . Intermediate 9: Synthesis of ( E )-1-(2,5-dichloropyridin-4-yl)-3-((dimethylamino)methylene)-6,6-dimethylpiperidin-2,4-dione (Int-P4) Step 1:

_Et3N (3.340 g, 4.6 mL, 33.003 mmol) was added to a solution of DMSO (50 mL) containing 2,5-dichloro-4-fluoropyridine (2.5 g, 15.062 mmol) and ethyl 3-amino-3-methylbutyrate hydrochloride (3.28 g, 18.056 mmol), and the reaction mixture was heated at 90°C for 20 hours. The reaction mixture was cooled to ambient temperature and quenched by adding water. The mixture was extracted with EtOAc (3 x). The combined organic matter was washed with water and brine, dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO₂ , 0 to 50% EtOAc in heptane solution) yielded ethyl 3-((2,5-dichloropyridin-4-yl)amino)-3-methylbutyrate (2.57 g, 58%) as a colorless oil. ^¹H NMR (400 MHz, chloroform- d ) δ 8.01 (s, 1H), 6.71 (s, 1H), 5.71 (br s, 1H), 4.15 (q, J = 7.2 Hz, 2H), 2.68 (s, 2H), 1.53 (s, 6H), 1.23 (t, J = 7.1 Hz, 3H) ppm. ESI-MS m/z calculated value 290.059, observed value 291.0 (M+1) ⁺ . Step 2 :

Ethyl 3-chloro-3-sideoxypropionate (2.623 g, 2.23 mL, 17.418 mmol) was added dropwise to a solution containing ethyl 3-((2,5-dichloropyridin-4-yl)amino)-3-methylbutyrate (2.56 g, 8.698 mmol) in 50 mL of toluene, and the reaction mixture was stirred under reflux for 20 hours. The reaction mixture was cooled to ambient temperature, quenched by adding _a saturated aqueous solution of NaHCO3, and extracted with DCM (3x). The combined organic layer was washed with brine, dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO2 , 0 to 50% EtOAc in heptane solution) yielded ethyl 3-( N- (2,5-dichloropyridin-4-yl)-3-ethoxy-3-sideoxypropionic acid)-3-methylbutyrate (1.58 g, 42%) as a colorless oil. ^¹H NMR (400 MHz, chloroform-d) δ 8.54 (s, 1H), 7.74 (s, 1H), 4.23 - 4.11 (m, 4H), 3.86 (d, J = 15.5 Hz, 1H), 3.04 (d, J = 15.7 Hz, 1H), 2.93 (d, J = 15.5 Hz, 1H), 2.67 (d, J = 15.5 Hz, 1H), 1.68 (s, 3H), 1.33 - 1.23 (m, 6H), 1.19 (s, 3H) ppm. ESI-MS m/z calculated value 404.091, observed value 405.2 (M+1) ⁺ . Step 3 :

Sodium (81 mg, 3.523 mmol) was added partically to EtOH (4 mL) at 0°C under argon atmosphere, and the mixture was stirred until the sodium was completely dissolved. The mixture was heated to ambient temperature and then added dropwise at 0°C to a stirred solution of EtOH (25 mL) containing ethyl 3-( N- (2,5-dichloropyridin-4-yl)-3-ethoxy-3-sideoxypropionic acid)-3-methylbutyrate (1.28 g, 2.948 mmol). The mixture was heated to ambient temperature and stirred for 20 hours. The reaction mixture was quenched by adding water and extracted with EtOAc. The EtOAc layer was separated and discarded. The aqueous layer was acidified to pH ~2 by adding 2 M HCl aqueous solution. The solid was filtered to obtain a white solid of ethyl 1-(2,5-dichloropyridin-4-yl)-6,6-dimethyl-2,4-dioxypiperidine-3-carboxylate (447 mg, 40%). The aqueous layer was further extracted with EtOAc (3x), and the combined organic layer was washed with brine, dried ( _MgSO4 ), filtered, and concentrated under vacuum to obtain an additional beige solid of ethyl 1-(2,5-dichloropyridin-4-yl)-6,6-dimethyl-2,4-dioxypiperidine-3-carboxylate (48 mg, 4%). ^¹H NMR (400 MHz, chloroform-d) δ 14.33 (s, 1H), 8.48 (s, 1H), 7.28 (s, 1H, overlapped with solvent), 4.30 - 4.42 (m, 2H), 3.11 (d, J = 16.8 Hz, 1H), 2.55 (d, J = 17.6 Hz, 1H), 1.53 (s, 3H), 1.37 (t, J = 7.25 Hz, 3H), 1.14 (s, 3H) ppm. ESI-MS m/z calculated value 358.049, observed value 359.1 (M+1) ⁺ . Step 4 :

A solution containing ethyl acetonitrile (3.6 mL) and water (36 μL) of 1-(2,5-dichloropyridin-4-yl)-6,6-dimethyl-2,4-dioxypiperidine-3-carboxylate (80 mg, 0.212 mmol) was stirred under reflux for 2 hours, followed by vacuum concentration. Purification by rapid chromatography ( _SiO₂ , 0 to 75% EtOAc in heptane) yielded a white solid of 1-(2,5-dichloropyridin-4-yl)-6,6-dimethylpiperidine-2,4-dione (29 mg, 45%). ^¹H NMR (400 MHz, chloroform- d ) δ 8.54 (s, 1H), 7.28 (s, 1H, overlapped with solvent), 3.42–3.62 (m, 2H), 2.96 (d, J = 15.3 Hz, 1H), 2.73 (d, J = 16.0 Hz, 1H), 1.49 (m, 3H), 1.23 (s, 3H) ppm. ESI-MS m/z calculated value 286.028, observed value 287.0 (M+1) ⁺ . Step 5 :

A mixture of DMF-DMA (179.4 mg, 0.2 mL, 1.506 mmol) containing 1-(2,5-dichloropyridin-4-yl)-6,6-dimethylpiperidin-2,4-dione (37 mg, 0.128 mmol) was heated at 100°C for 1 hour, and then cooled to ambient temperature. The solvent was decanted, and the resulting solid was wet-milled with Et ₂ O (2x) and then dried under vacuum to give a pale yellow solid of ( E )-1-(2,5-dichloropyridin-4-yl)-3-((dimethylamino)methylene)-6,6-dimethylpiperidin-2,4-dione ( Int-P4 , 37 mg, 81%). ^¹H NMR (400 MHz, chloroform- d ) δ 8.49 (s, 1H), 7.99 (s, 1H), 7.24 (s, 1H), 3.34 (s, 3H), 3.21 (s, 3H), 2.93 (d, J = 15.6 Hz, 1H), 2.49 (d, J = 16.0 Hz, 1H), 1.49 (s, 3H), 1.13 (s, 3H) ppm. ESI-MS m/z calculated value 341.070, observed value 342.1 (M+1) ⁺ . Intermediate 10: Synthesis of 5-chloro-4-fluoro-1-((2-(trimethylsilyl)ethoxy)methyl)pyridin-2( ¹H )-one (Int-P5) Step 1:

NaH (1.65 g, 60% mineral oil dispersion, 41.254 mmol) was added to a stirred solution containing 30 mL of THF with 2 g (13.556 mmol) of 5-chloro-4-fluoropyridin-2( 1H )-one (2 g, 13.556 mmol), and the reaction mixture was stirred at 0°C for 15 min. SEMCl (3.391 g, 3.6 mL, 20.341 mmol) was added, and the mixture was stirred at ambient temperature for 2 h. The reaction mixture was quenched by adding ice- _cold water (20 mL) and extracted with EtOAc (2 x 20 mL). The combined organic layers were washed with brine (20 mL), dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum. Purification by rapid chromatography (12 g SiO ₂ , 40 to 50% EtOAc in heptane solution) yielded a brown oily substance, 5-chloro-4-fluoro-1-((2-(trimethylsilyl)ethoxy)methyl)pyridin-2( 1H )-one ( Int-P5 , 2.3 g, 56%). ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 8.26 (d, J = 9.6 Hz, 1H), 6.52 (d, J = 11.6 Hz, 1H), 5.23 (s, 2H), 3.58 (t, J = 8.4 Hz, 2H), 0.86 (t, J = 8.0 Hz, 2H), -0.03 (s, 9H) ppm. ESI-MS m/z calculated value 277.070, observed value 278.0 (M+1) ⁺ . Intermediate 11: Synthesis of ( S )-1-(triphenylmethoxy)but-2-ol (Int-A28) Step 1:

_Et3N (726 mg, 1 mL, 7.175 mmol) and DMAP (43 mg, 0.352 mmol) were added sequentially to a solution of DCM (10 mL) containing ( S )-butane-1,2-diol (320 mg, 3.551 mmol) and TrCl (990 mg, 3.551 mmol), and the reaction mixture was stirred at ambient temperature for 20 hours. The mixture was diluted with HCl (1% aqueous solution) and extracted with DCM (3x). The combined organic layer was washed with brine, dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO2 , 0 to 25% heptane solution of EtOAc) yielded ( S )-1-(triphenylmethoxy)but-2-ol ( Int-A28 , 680 mg, 57%) as a colorless oil. ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 7.38 - 7.43 (m, 6H), 7.33 (t, J = 7.6 Hz, 6H), 7.22 - 7.28 (m, 3H), 4.64 (d, J = 5.4 Hz, 1H), 3.54 (dt, J = 7.5, 5.0 Hz, 1H), 2.93 (dd, J = 8.9, 5.6 Hz, 1H), 2.78 (dd, J = 8.9, 5.6 Hz, 1H), 1.47 - 1.60 (m, 1H), 1.28 - 1.37 (m, 1H), 0.79 (t, J = 7.4 Hz, 3H) ppm. ESI-MS The calculated m/z value is 332.178, and the observed value is 331.4 (M-1) ^- .

The following intermediates are prepared using the method described in Intermediate 11, except that in step 1, ( S )-3-methylbutane-1,2-diol is used instead of ( S )-butane-1,2-diol. Table 13: Intermediates prepared using the method described in Intermediate 11 Intermediate item number Compound structure / compound name LC/MS NMR ( displacement in ppm ) Int-A29 ( S )-3-methyl-1-(triphenylmethoxy)but-2-ol No chromophores in the molecule ¹ H NMR (400 MHz, chloroform- d ) δ 7.39 - 7.34 (m, 6H), 7.27 - 7.15 (m, 9H), 3.42 - 3.36 (br m, 1H), 3.18 (dd, J = 9.4, 3.3 Hz, 1H), 3.00 (dd, J = 9.4, 7.6 Hz, 1H), 2.21 (br s, 1H), 1.67 - 1.57 (m, 1H), 0.84 - 0.78 (d, J = 4.0 Hz, 3H), 0.69 (d, J = 6.8 Hz, 3H) ppm. VI. Synthetic Examples of Compounds 1: rel- 5-(5-chloro-2-((( 1S ) -2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (Compound 1), rel -5-(5-chloro-2-(( 1R )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4H-pyrazolo[4,3-c]pyridin-4-one (Compound 2), rel -5-(5-chloro-2-((1S)-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4- one Synthesis of rel -5-(5-chloro-2-(((1R)-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 3) and rel-5-(5-chloro-2-((( 1R )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 4) Step 1:

_Cs₂CO₃ (18.3 g, 56.17 mmol) was added to a solution of _DMA (80 mL) containing 2,5-dichloro-4-fluoropyridine (4.604 g, 27.74 mmol) and 1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one ( S₁ , 7.30 g, 28.11 mmol), and the reaction mixture was heated to 105°C for 1 hour. The reaction mixture was then diluted with water (300 mL). The solid was filtered, washed with heptane (100 mL), and dried under vacuum at 40°C to obtain a grayish-white solid of 1-(2-chlorobenzyl)-5-(2,5-dichloropyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (9.622 g, 86%). ^¹H NMR (500 MHz, DMSO - _d⁶ ) δ 8.78 (s, ¹H), 8.23 (d, J = 0.8 Hz, ¹H), 8.02 (s, ¹H), 7.55 (d, J = 7.5 Hz, ¹H), 7.53 - 7.50 (m, ¹H), 7.42 - 7.31 (m, 2H), 7.12 - 7.05 (m, 1H), 7.00 (dd, J = 7.6, 0.9 Hz, 1H), 5.75 - 5.63 (m, 2H) ppm. ESI-MS m/z calculated value 404.000, observed value 405.2 (M+1) ⁺ . Step 2:

DIPEA (159.4 mg, 214.8 μL, 1.233 mmol) was added to a stirred solution of DMSO (300 μL) containing 1-(2-chlorobenzyl)-5-(2,5-dichloropyridin-4-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (50 mg, 0.123 mmol) and rac -2-amino-2-(tetrahydrofuran-3-yl)ethanol-1-ol (80.87 mg, 0.617 mmol), and the reaction mixture was stirred at 150°C for 20 hours. The mixture was diluted with EtOAc (30 mL) and washed with water (30 mL). The aqueous layer was separated and extracted with EtOAc (2 x 30 mL). The combined organic extracts were dried ( _MgSO₄ ), filtered, and concentrated under vacuum. Purification by reverse-phase HPLC ( _C18 X-bridge column, 30-45% MeCN aqueous solution containing 1% _NH₄OH ) yielded rac -5-(5-chloro-2-((2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one. Step 3:

The isomers of rac -5-(5-chloro-2-((2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one were separated by chiral SFC using a ^Chiralpak® IB-3 column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 25% MeOH (topped with 20 mM ammonia), 75% _CO2 ; flow rate 100 mL/min). The results were as follows:

First dissolution isomer (rt = 7.62 min ) : rel -5-(5-chloro-2-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 1 , 2.6 mg, 19%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.20 (d, J = 0.8 Hz, 1H), 8.12 (s, 1H), 7.54 - 7.42 (m, 2H), 7.41 - 7.31 (m, 2H), 7.09 (dd, J = 7.4, 2.0 Hz, 1H), 6.95 (t, J = 8.7 Hz, 1H), 6.90 (dd, J = 7.5, 0.9 Hz, 1H), 6.65 (d, J = 1.5 Hz, 1H), 5.67 (d, J = 4.5 Hz, 2H), 4.77 - 4.74 (m, 1H), 4.01 - 3.98 (m, 1H), 3.84 - 3.76 (m, 1H), 3.75 - 3.66 (m, 1H), 3.63 - 3.55 (m, 1H), 3.50 - 3.36 (m, 3H), 2.49 - 2.42 (m, 1H), 1.96 - 1.92 (m, 1H), 1.72 - 1.59 (m, 1H) ppm. ESI-MS m/z calculated value 499.118, observed value 500.4 (M+1) ⁺ .

Second elution isomer (rt = 10.16 min ) : rel -5-(5-chloro-2-(( 1R )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3-c]pyridin-4-one (compound 2 , 1.6 mg, 11%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 (d, J = 0.8 Hz, 1H), 8.12 (s, 1H), 7.54 - 7.42 (m, 2H), 7.40 - 7.32 (m, 2H), 7.09 (dd, J = 7.5, 1.9 Hz, 1H), 6.96 - 6.87 (m, 2H), 6.64 (s, 1H), 5.67 (d, J = 4.5 Hz, 2H), 4.76 - 4.72 (m, 1H), 4.00 - 3.96 (m, 1H), 3.82 - 3.70 (m, 2H), 3.68 - 3.51 (m, 2H), 3.50 - 3.40 (m, 2H), 2.00 - 1.94 (m, 1H), 1.69 - 1.58 (m, 1H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 499.118, observed value 500.4 (M+1) ⁺ .

Third isomer (rt = 12.52 min ) : rel -5-(5-chloro-2-(( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 3 , 1.5 mg, 11%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 (d, J = 0.8 Hz, 1H), 8.12 (s, 1H), 7.54 - 7.41 (m, 2H), 7.41 - 7.30 (m, 2H), 7.09 (dd, J = 7.5, 1.9 Hz, 1H), 6.96 - 6.87 (m, 2H), 6.64 (s, 1H), 5.67 (d, J = 4.7 Hz, 2H), 4.76 - 4.72 (m, 1H), 3.98 (s, 1H), 3.76 (dtd, J = 18.6, 8.1, 3.8 Hz, 2H), 3.62 (td, J = 8.2, 7.0 Hz, 1H), 3.57 - 3.39 (m, 3H), 2.09 - 1.82 (m, 1H), 1.69 - 1.57 (m, 1H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 499.118, observed value 500.4 (M+1) ⁺ .

Fourth isomer (rt = 15.09 min ) : rel -5-(5-chloro-2-((( 1R )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3-c]pyridin-4-one (compound 4 , 1.4 mg, 10%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.20 (d, J = 0.8 Hz, 1H), 8.12 (s, 1H), 7.54 - 7.42 (m, 2H), 7.36 (dtd, J = 17.9, 7.4, 1.7 Hz, 2H), 7.09 (dd, J = 7.5, 1.9 Hz, 1H), 6.95 (t, J = 8.7 Hz, 1H), 6.90 (dd, J = 7.6, 0.9 Hz, 1H), 6.65 (d, J = 1.5 Hz, 1H), 5.67 (d, J = 4.5 Hz, 2H), 4.78 - 4.74 (m, 1H), 4.01 - 3.97 (m, 1H), 3.84 - 3.76 (m, 1H), 3.75 - 3.66 (m, 1H), 3.64 - 3.55 (m, 1H), 3.48 - 3.39 (m, 3H), 2.51 - 2.42 (m, 1H), 1.96 - 1.92 (m, 1H), 1.72 - 1.59 (m, 1H) ppm. ESI-MS m/z calculated value 499.118, observed value 500.4 (M+1) ⁺ . Example 2: Synthesis of ( S )-1-(2-chlorobenzyl)-5-(2-((1-hydroxypropyl-2-yl)amino)-5-methylpyridin-4-yl)-1,5-dihydro-4- H -pyrazolo[4,3 -c ]pyridin-4-one (compound 5) Step 1:

_Cs₂CO₃ (990 mg, 3.038 mmol) was added to _a stirred solution of DMA (6 mL) containing 1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one ( S₁ , 393 mg, 1.513 mmol) and 5-bromo-2-chloro-4-fluoropyridine (320 mg, 1.521 mmol), and the reaction mixture was stirred at 100°C for 30 min. The mixture was then partially dissolved between EtOAc (30 mL) and water (30 mL). The aqueous layer was separated and extracted with EtOAc (2 x 30 mL). The combined organic extracts were dried ( _MgSO4 ), filtered, and vacuum concentrated to give 5-(5-bromo-2-chloropyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (665 mg, 98%), which was used in the next step without further purification. ^¹H NMR (500 MHz, DMSO - _d⁶ ) δ 8.86 (s, ¹H), 8.23 (d, J = 0.8 Hz, ¹H), 7.99 (s, ¹H), 7.55 - 7.49 (m, 2H), 7.42 - 7.31 (m, 2H), 7.13 - 7.07 (m, 1H), 7.00 (dd, J = 7.6, 0.8 Hz, 1H), 5.77 - 5.63 (m, 2H) ppm. ESI-MS m/z calculated value 447.949, observed value 451.0 (M+1) ⁺ . Step 2:

_PdCl₂ ( _PPh₃ ) _₂ (7.9 mg, 0.011 mmol) was added to a stirred suspension containing 5-(5-bromo-2-chloropyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ] _{pyridin-4-one (50 mg, 0.111 mmol), Cs₂CO₃ (} 73 mg, 0.224 mmol), and 1,4-diane (500 μL) and water (50 μL) of trimethylcycloboroxane (80 μL, 50% w/v THF solution, 0.319 mmol). The mixture was degassed by bubbling nitrogen and the reaction mixture was heated to 100°C for 2 hours. The mixture was separately dissolved between EtOAc (30 mL) and water (30 mL). The aqueous layer was separated and extracted with EtOAc (2 x 30 mL). The combined organic extracts were dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO2 , 0 to 50% heptane solution of EtOAc) yielded a white solid of 5-(2-chloro-5-methylpyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (35 mg, 82%). ^¹H NMR (500 MHz, DMSO - _d⁶ ) δ 8.49 (d, J = 0.7 Hz, 1H), 8.22 (d, J = 0.8 Hz, 1H), 7.69 - 7.64 (m, 1H), 7.55 - 7.49 (m, 2H), 7.41 - 7.30 (m, 2H), 7.11 - 7.06 (m, 1H), 6.96 (dd, J = 7.5, 0.9 Hz, 1H), 5.74 - 5.63 (m, 2H), 2.06 (s, 3H) ppm. ESI-MS m/z calculated value 384.055, observed value 385.1 (M+1) ⁺ . Step 3:

A solution of DMSO (0.5 mL) containing 5-(2-chloro-5-methylpyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H- pyrazolo[4,3- c ]pyridin-4-one (35 mg, 0.091 mmol) and ( S )-2-aminoprop-1-ol (71 mg, 0.945 mmol) was heated to 150°C and stirred for 22 hours. Purification by reverse-phase HPLC ( _C18 X-bridge column, 30 to 45% MeCN aqueous solution containing 1% _NH4OH ) yielded a white solid ( S )-1-(2-chlorobenzyl)-5-(2-((1-hydroxypropyl-2-yl)amino)-5-methylpyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 5 , 3.1 mg, 8%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 0.9 Hz, 1H), 7.94 (s, 1H), 7.51 (dd, J = 7.8, 1.5 Hz, 1H), 7.44 - 7.30 (m, 4H), 7.08 (dd, J = 7.4, 1.9 Hz, 1H), 6.86 (dd, J = 7.6, 0.9 Hz, 1H), 6.39 (s, 1H), 6.30 (t, J = 7.4 Hz, 1H), 5.67 (d, J = 5.3 Hz, 2H), 4.72 - 4.68 (m, 1H), 3.95 - 3.89 (m, 1H), 3.50 - 3.46 (m, 1H), 1.83 (s, 3H), 1.12 (dd, J = 6.6, 5.0 Hz, 3H) ppm. ESI-MS m/z calculated value 423.146, observed value 424.4 (M+1) ⁺ . Example 3: Synthesis of 5-(5-chloro-2-((( 1r , 3r )-3-hydroxy-1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 6) and 5-(5-chloro-2-((( 1s , 3s )-3-hydroxy-1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 7). Step 1:

_Cs₂CO₃ (17.6 g, 54.02 mmol) was added to a solution of _DMA (80 mL) containing 2,5-dichloro-4-fluoropyridine (4.444 g, 26.77 mmol) and 1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one ( S₂ , 6.500 g, 26.72 mmol), and the reaction mixture was heated to 105°C for 1 hour. The reaction mixture was then diluted with water (300 mL) to precipitate the sediment. The solid was collected by filtration, washed with heptane (100 mL), and dried under vacuum at 40°C to obtain a grayish-white solid of 5-(2,5-dichloropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (8.51 g, 82%). ^¹H NMR (500 MHz, DMSO - _d⁶ ) δ 8.78 (s, ¹H), 8.20 (d, J = 0.8 Hz, ¹H), 8.01 (s, ¹H), 7.56 (d, J = 7.6 Hz, ¹H), 7.44 - 7.36 (m, ¹H), 7.31 - 7.17 (m, 3H), 7.02 (dt, J = 7.6, 0.8 Hz, 1H), 5.71 - 5.60 (m, 2H) ppm. ESI-MS m/z calculated value 388.029, observed value 389.0 (M+1) ⁺ . Step 2:

TFAA (3.5 mL, 25.18 mmol) was added to a solution of DCM (20 mL) containing urea hydrogen peroxide (2.4 g, 25.51 mmol) at 0 ^°C , and the mixture was stirred for 15 min. A solution of DCM (20 mL) containing 5-(2,5-dichloropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (1 g, 2.569 mmol) was added, and the reaction mixture was stirred at ambient temperature for 2 h. The mixture was diluted with DCM (15 mL) and neutralized by adding _NaHCO3 solution. The aqueous layer was separated and extracted with DCM (2 x 10 mL). The combined organic extracts were passed through a phase separator and concentrated under vacuum. Purification by rapid chromatography (12 g SiO2, 0 to 100% EtOAc in heptane, followed by 0 to 20% MeOH in EtOAc) yielded a white solid of 2,5-dichloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)pyridine 1-oxide (159 mg, 15%). ^1H NMR (500 MHz, DMSO - _d⁶ ) δ 9.07 (s, 1H), 8.31 (s, 1H), 8.20 (d, J = 0.8 Hz, 1H), 7.52 (d, J = 7.6 Hz, 1H), 7.44 - 7.32 (m, 1H), 7.30 - 7.14 (m, 3H), 7.06 - 6.78 (m, 1H), 5.67 (d, J = 15.5 Hz, 1H), 5.62 (d, J = 15.5 Hz, 1H) ppm. ESI-MS m/z calculated value 404.024, observed value 405.2 (M+1) ⁺ . Step 3:

A solution of MeOH (1 mL) containing 3-amino-3-(hydroxymethyl)cyclobut-1-ol hydrochloride (330 mg, a 1:1 mixture of nonmirror isomers, 2.148 mmol) was deposited onto an SCX cartridge that had been pre-washed with MeOH (10 mL). The amine was released by dissolving the cartridge in 2 N methanol-ammonia solution, and the resulting filtrate was concentrated under vacuum . The residue was dissolved in DMSO (2 mL) and added to 2,5-dichloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridine 1-oxide (150 mg, 0.370 mmol). The reaction mixture was heated and stirred at 125°C for 16 hours. _B2 pin ₂ (150 mg, 0.591 mmol) was added, and the mixture was stirred at 125°C for 1 hour. The reaction mixture was cooled to ambient temperature and concentrated under vacuum. Purification by reverse-phase HPLC ( _C18 X-bridge column, 23 to 38% MeCN aqueous solution containing 1% ammonium hydroxide) yielded 5-(5-chloro-2-((3-hydroxy-1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one, a mixture of two non-mirror isomers. Step 4:

The non-mirror isomer of 5-(5-chloro-2-((3-hydroxy-1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one was separated by chiral SFC using a ^Chiralpak® IG column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 50 to 60% MeOH (topped with 20 mM ammonia), 60 to 50% _CO2 ; flow rate 100 mL/min), yielding:

First elution isomer (rt = 2.63 min ) : 5-(5-chloro-2-((1r , 3r )-3-hydroxy-1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3-c]pyridin-4-one (compound 6 , 14.2 mg, 8%, by 2 steps) as a white solid. ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.9 Hz, 1H), 8.12 (s, 1H), 7.47 (d, J = 7.6 Hz, 1H), 7.42 - 7.36 (m, 1H), 7.31 - 7.16 (m, 3H), 7.04 (s, 1H), 6.91 (d, J = 7.5 Hz, 1H), 6.56 (s, 1H), 5.68 - 5.56 (m, 2H), 4.95 (br s, 1H), 4.81 (br s, 1H), 4.24 - 4.11 (m, 1H), 3.62 (d, J = 10.7 Hz, 1H), 3.56 (d, J = 10.7 Hz, 1H), 2.44 - 2.32 (m, 2H), 2.03 - 1.93 (m, 2H) ppm. ESI-MS m/z calculated value 469.132, observed value 468.1 (M-1) ^- .

Second elution isomer (rt = 3.50 min ) : 5-(5-chloro-2-((1 s, 3 s )-3-hydroxy-1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (compound 7 , 25.2 mg, 14%, after 2 steps). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 0.8 Hz, 1H), 8.10 (s, 1H), 7.45 (d, J = 7.5 Hz, 1H), 7.44 - 7.36 (m, 1H), 7.30 - 7.14 (m, 4H), 6.91 (dd, J = 7.6, 0.7 Hz, 1H), 6.51 (s, 1H), 5.70 - 5.55 (m, 2H), 4.96 (d, J = 6.4 Hz, 1H), 4.84 (t, J = 5.7 Hz, 1H), 4.15 - 3.86 (m, 1H), 3.58 (dd, J = 10.9, 5.6 Hz, 1H), 3.50 (dd, J = 10.8, 5.6 Hz, 1H), 2.67 - 2.55 (m, 2H), 1.90 (dd, J = 12.3, 7.0 Hz, 2H) ppm. ESI-MS m/z calculated value 469.132, observed value 468.2 (M-1) ^- . Example 4: Synthesis of ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 8) Step 1:

Under nitrogen atmosphere, KO t Bu (40 mg, 0.357 mmol) was added in one step to a solution of NMP (1 mL) containing 5-(2,5-dichloropyridin-4-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one ( SB1 , 50 mg, 0.178 mmol) and 2-(bromomethyl)-1,3-difluorobenzene (70 mg, 0.338 mmol), and the reaction mixture was stirred for 3 hours at ambient temperature. The reaction mixture was quenched by adding water and concentrated under vacuum. Purification by reverse-phase HPLC ( _C18 X-bridge column, 38 to 53% MeCN aqueous solution containing 0.1% ammonium hydroxide) yielded 5-(2,5-dichloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (ESI-MS m/z calculated value 406.020, observed value 407.0 ((M+1) ⁺ ) and 5-(2,5-dichloropyridin-4-yl)-2-(2,6-difluorobenzyl)-2,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (ESI-MS m/z calculated value 406.020, observed value 407.0 (M+1) ⁺ ) (32) A 1:1 mixture of approximately 44% (mg, 44%) was used in the next step without further purification. Step 2:

( S )-2-amino-2-cyclopropyl ethanol-1-ol (50 mg, 0.494 mmol) and DIPEA (70 μL, 0.402 mmol) were added sequentially to an approximately 1:1 mixture of NMP (1 mL) containing 5-(2,5-dichloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one and 5-(2,5-dichloropyridin-4-yl)-2-(2,6-difluorobenzyl)-2,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (36 mg, 0.088 mmol), and the reaction mixture was stirred at 150 ^°C . The reactants were cooled to ambient temperature and concentrated under vacuum. Purification by reversed-phase HPLC ( _C18 X-bridge column, 30-45% MeCN aqueous solution containing 0.1% ammonium hydroxide) yielded a light brown solid. Regional isomers were separated by SFC using a DEAP column (5 µm particle size, 25 cm x 10 mm), purchased from Princeton Chromatography (mobile phase: 25% MeOH (topped with 20 mM ammonia), 75% _CO₂ ; flow rate 10 mL/min), yielding:

First elution isomer (rt = 2.50 min ) : ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-2-(2,6-difluorobenzyl)-2,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (6.2 mg, 30%) as a white solid. ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.53 (d, J = 4.3 Hz, 1H), 7.83 (s, 1H), 7.27 (tt, J = 8.4, 6.6 Hz, 1H), 6.98 - 6.89 (m, 3H), 6.63 (t, J = 6.8 Hz, 1H), 6.35 (d, J = 0.9 Hz, 1H), 6.32 (ddd, J = 7.5, 3.7, 0.8 Hz, 1H), 5.38 (s, 2H), 4.46 (d, J = 17.9 Hz, 1H), 3.33 - 3.24 (m, 3H), 0.76 (tq, J = 8.1, 4.8, 4.0 Hz, 1H), 0.26 - 0.03 (m, 3H), -0.00 (tt, J = 9.2, 4.3 Hz, 1H) ppm. ESI-MS m/z calculated value 471.127, observed value 472.0 (M+1) ⁺ .

Second elution isomer (rt = 3.35 min ) : ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (compound 8 , 7.02 mg, 33%), as a white solid. ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (dd, J = 2.0, 0.8 Hz, 1H), 8.10 (s, 1H), 7.53 - 7.46 (m, 2H), 7.21 - 7.14 (m, 2H), 6.95 (d, J = 7.5 Hz, 1H), 6.90 (t, J = 7.4 Hz, 1H), 6.63 (d, J = 1.1 Hz, 1H), 5.63 (s, 2H), 4.71 (dt, J = 17.9, 5.3 Hz, 1H), 3.59 - 3.49 (m, 3H), 1.16 - 0.95 (m, 1H), 0.55 - 0.29 (m, 3H), 0.25 (ddd, J = 8.7, 6.4, 4.6 Hz, 1H) ppm. ESI-MS m/z calculated value 471.127, observed value 472.0 (M+1) ⁺ . Example 5: Synthesis of ( S )-1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((1-hydroxybutyl-2-yl)amino)pyridin-4-yl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (compound 9). Step 1:

_Cs₂CO₃ (11.7 g, 35.91 mmol) was added to a stirred solution of _DMA (50 mL) containing 1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ( S₇ , 5.01 g, 18.60 mmol) and 2,4,5-trifluoropyridine (2.39 g, 17.96 mmol), and the reaction mixture was stirred at 50°C for 23 hours. The mixture was cooled to ambient temperature, quenched by adding water (200 mL), and stirred for 2 hours. The resulting solid was filtered and washed with water and heptane. Purification was carried out by wet milling with hot MeOH to obtain a beige solid of 1-(2,6-difluorobenzyl)-5-(2,5-difluoropyridin-4-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (5.99 g, 86%). ^1H NMR (400 MHz, DMSO - _d⁶ ) δ 8.51 (t, J = 1.4 Hz, 1H), 8.18 (d, J = 0.8 Hz, 1H), 7.75 - 7.65 (m, 2H), 7.50 (tt, J = 8.5, 6.7 Hz, 1H), 7.23 - 7.12 (m, 2H), 7.09 (d, J = 7.6 Hz, 1H), 5.65 (s, 2H) ppm. ESI-MS m/z calculated value 374.079, observed value 375.0 (M+1) ⁺ . Step 2:

A solution containing 0.7 mL of thionane (70 mg, 0.187 mmol) of 1-(2,6-difluorobenzyl)-5-(2,5-difluoropyridin-4- yl )-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (51 mg, 0.572 mmol) was sealed in a 4 mL screw-cap vial and stirred at 130 ^°C for 2.5 days. The mixture was cooled to ambient temperature, diluted with EtOAc (7 mL), and washed with a half-saturated saline solution (2 x 3 mL). The combined organic extracts were dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by reverse-phase HPLC ( _C18 Sunfire column, 23% to 38% MeCN aqueous solution containing 0.1% formic acid) yielded a white solid ( S )-1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((1-hydroxybutyl-2-yl)amino)pyridin-4-yl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (compound 9 , 21.2 mg, 25%). ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.14 (d, J = 0.8 Hz, 1H), 8.08 (d, J = 1.9 Hz, 1H), 7.61 (dd, J = 7.6, 0.6 Hz, 1H), 7.50 (ddd, J = 15.1, 8.5, 6.7 Hz, 1H), 7.17 (t, J = 8.1 Hz, 2H), 6.98 (d, J = 7.5 Hz, 1H), 6.60 (d, J = 5.0 Hz, 1H), 6.50 (d, J = 8.1 Hz, 1H), 5.63 (s, 2H), 4.64 (t, J = 5.5 Hz, 1H), 3.78 (d, J = 5.6 Hz, 1H), 3.50 (dt, J = 10.0, 4.9 Hz, 1H), 3.40 - 3.33 (m, 1H), 1.68 (dq, J = 13.9, 6.6 Hz, 1H), 1.45 (dq, J = 14.3, 7.6 Hz, 1H), 0.91 (t, J = 7.4 Hz, 3H) ppm. ESI-MS m/z calculated value 443.157, observed value 444.5 (M+1) ⁺ . Example 6: Synthesis of 5-(5-fluoro-2-((( S )-1-hydroxypropyl-2-yl)amino)-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 10) and 5-(5-fluoro-2-((( S )-1-hydroxypropyl-2-yl)amino)-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 11). Step 1:

_Cs₂CO₃ (4 g, 12.277 mmol) was added to _a stirred mixture of DMA (25 mL ) containing 2-chloro-4,5-difluoro-3-methylpyridine ( Int-P₂ , 1.689 mg, 6.764 mmol) and 1-(2-fluorobenzyl)-1,5-dihydro-4H-pyrazolo[4,3- c ]pyridin-4-one ( S₂ , 1.75 g, 7.195 mmol), and the reaction mixture was heated at 50°C for 1 hour. The reactants were partially dissolved between water and EtOAc. The aqueous layer was separated and extracted with EtOAc. The combined organic extracts were washed with brine, dried ( _MgSO₄ ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO₂ , 0 to 100% EtOAc in heptane) followed by reverse-phase chromatography (12 g _C₁₈ column, 20 to 80% MeCN aqueous solution containing 0.1% ammonium hydroxide) yielded a white solid, 5-(2-chloro-5-fluoro-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (1.871 g, 71%). ^¹H NMR (400 MHz, chloroform- d ) δ 8.31 (s, 1H), 8.24 (d, J = 0.9 Hz, 1H), 7.37 - 7.27 (m, 2H), 7.17 - 7.09 (m, 2H), 6.89 (dd, J = 7.6, 1.1 Hz, 1H), 6.59 (d, J = 7.8 Hz, 1H), 5.52 (s, 2H), 2.22 (s, 3H) ppm. ESI-MS m/z calculated value 386.075, observed value 387.1 (M+1) ⁺ . Step 2:

A stirred suspension of 5-(2-chloro-5-fluoro-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one (150 mg, 0.385 mmol) and CsF (351 mg, 2.311 mmol) in DMSO (3.5 mL) was heated to 150°C for 4 hours under microwave irradiation. The reaction mixture was poured onto a saturated solution of _NaHCO3 and extracted with EtOAc (x 3). The combined organic extracts were washed with brine, dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by reverse phase chromatography (12 g _C18 column, 50 to 100% MeCN aqueous solution containing 0.1% formic acid) yielded a light brown oily substance, 5-(2,5-difluoro-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (127 mg, 67%). ^¹H NMR (400 MHz, chloroform-d) δ 8.24 (s, 1H), 8.07 (s, 1H), 7.37 - 7.28 (m, 2H), 7.17 - 7.09 (m, 2H), 6.93 - 6.90 (m, 1H), 6.59 (d, J = 7.8 Hz, 1H), 5.52 (s, 2H), 2.12 (s, 3H) ppm. ESI-MS m/z calculated value 370.104, observed value 371.1 (M+1) ⁺ . Step 3:

DIPEA (200.34 mg, 0.27 mL, 1.550 mmol) was added to a stirred solution containing 5-(2,5-difluoro-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (127 mg, 0.260 mmol) and ( S )-2-aminoprop-1-ol (115.80 mg, 0.12 mL, 1.542 mmol) in 1.2 mL of DMSO. The reaction mixture was heated sequentially at 100°C, 120°C, and 130°C for 1 hour. The mixture was further heated at 150°C for 5 hours under microwave irradiation. The reaction mixture was quenched by adding water and extracted with EtOAc (x 3). The combined organic extracts were washed with brine, dried ( _MgSO₄ ), filtered, and concentrated under vacuum. Purification by reverse-phase chromatography (25 g _C18 column, 20-60% MeCN aqueous solution containing 0.1% formic acid) yielded:

First elution-resistant isomer (rt = 1.7 min ) : Further purification by reverse phase chromatography (12 g _C18 column, 20 to 37% MeCN aqueous solution containing 0.1% formic acid) yielded a white solid 5-(5-fluoro-2-((( S )-1-hydroxypropyl-2-yl)amino)-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (compound 10 , 6 mg, 5%). ^¹H NMR (400 MHz, chloroform- d ) δ 8.24 (s, 1H), 7.97 (s, 1H), 7.35 - 7.27 (m, 2H), 7.16 - 7.09 (m, 2H), 6.93 - 6.91 (m, 1H), 6.54 (d, J = 7.3 Hz, 1H), 5.51 (s, 2H), 4.23 (s, 2H), 3.81 (dd, J = 10.5, 2.3 Hz, 1H), 3.59 (dd, J = 10.5, 6.9 Hz, 1H), 1.89 (s, 3H), 1.27 (d, J = 6.0 Hz, 3H) ppm; no interchangeable H was observed. ESI-MS calculated m/z value: 425.166; observed value: 426.2 (M+1) ⁺ .

Second elution isomer (rt = 1.8 min ) : Further purification by rapid chromatography ( _SiO2 , 20 to 100% EtOAc in heptane solution) yielded a white solid 5-(5-fluoro-2-((( S )-1-hydroxypropyl-2-yl)amino)-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (compound 11 , 8 mg, 7%). ¹ H NMR (400 MHz, chloroform- d ) δ 8.24 (d, J = 0.9 Hz, 1H), 7.98 (s, 1H), 7.36-7.27 (m, 2H), 7.16-7.08 (m, 2H), 6.92 (dd, J = 7.6, 1.1 Hz, 1H), 6.53 (d, J = 7.3 Hz, 1H), 5.51 (s, 2H), 4.29 (d, J = 6.4 Hz, 1H), 4.20 (qd, J = 6.5, 3.0 Hz, 1H), 3.79 (d, J = 10.1 Hz, 1H), 3.68-3.61 (m, 2H), 1.89 (s, 3H), 1.29 (d, J = 6.9 Hz, 3H) ppm. ESI-MS m/z calculated value 425.166, observed value 426.2 (M+1) ⁺ . Example 7: Synthesis of rel- ( R ^* )-6-(( S )-1-((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)ethyl) thiolin-3-one (compound 12) Step 1:

A 4 mL screw-cap vial containing a stirred solution of DMSO (0.7 mL) containing 5-(2,5-dichloropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (70 mg, prepared using the method described in step 1 of Example 3, 0.180 mmol) and rel- ( R ^* )-6-(( S )-1-aminoethyl)-4-(4-methoxybenzyl) urin-3-one ( Int-A17 , 95 mg, 0.359 mmol) was sealed, and the reaction mixture was stirred at 150 ^°C for 48 hours. The reactants were cooled to ambient temperature, diluted with EtOAc (10 mL), and washed with a half-saturated saline solution (2 x 5 mL). The organic extract was dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by rapid chromatography (24 g _SiO2 , 0 to 5% MeOH in EtOAc solution) yielded a yellow, glassy solid, rel- ( R ^* )-6-(( S )-1-((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)ethyl)-4-(4-methoxybenzyl) thiolin-3-one (22 mg, 19%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (t, J = 0.8 Hz, 1H), 8.14 (d, J = 1.1 Hz, 1H), 7.45 (d, J = 7.5 Hz, 1H), 7.44 - 7.37 (m, 1H), 7.31 - 7.16 (m, 5H), 7.02 (dd, J = 14.5, 8.7 Hz, 1H), 6.95 - 6.87 (m, 3H), 6.60 (d, J = 3.1 Hz, 1H), 5.64 (s, 2H), 4.53 - 4.39 (m, 2H), 4.27 - 4.08 (m, 3H), 3.77 (dd, J = 13.7, 7.3 Hz, 4H), 3.28 - 3.23 (m, 2H), 1.17 - 1.13 (m, 3H) ppm. ESI-MS m/z calculated value 616.200, observed value 617.2 (M+1) ⁺ . Step 2:

A 4 mL screw-cap vial containing a stirred solution of TFA (500 μL, 6.490 mmol) of rel- ( R ^* )-6-(( S )-1-((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)ethyl)-4-(4-methoxybenzyl) thiolin-3-one (21 mg, 0.033 mmol) was sealed and the reaction mixture was stirred at 120 ^°C for 70 min, followed by stirring at 130 ^°C for 110 min. The reaction mixture was then cooled to ambient temperature and concentrated under vacuum. Purification by reverse-phase HPLC ( _C18 X-bridge column, 23 to 38% MeCN aqueous solution containing 0.1% ammonium hydroxide) yielded a white solid rel- ( R ^* )-6-(( S )-1-((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)ethyl) urin-3-one (compound 12 , 13 mg, 80%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (s, 2H), 7.97 (dd, J = 15.4, 3.8 Hz, 1H), 7.48 (dd, J = 7.5, 6.2 Hz, 1H), 7.40 (dddd, J = 8.3, 7.3, 5.4, 1.9 Hz, 1H), 7.31 - 7.19 (m, 3H), 7.08 - 7.01 (m, 1H), 6.93 (dt, J = 7.6, 0.7 Hz, 1H), 6.63 (d, J = 1.2 Hz, 1H), 5.64 (d, J = 3.3 Hz, 2H), 4.15 (s, 1H), 4.13 - 3.99 (m, 2H), 3.66 (dddd, J = 13.1, 9.9, 6.3, 3.7 Hz, 1H), 3.27 - 3.16 (m, 2H), 1.19 (t, J = 6.8 Hz, 3H) ppm. ESI-MS m/z calculated value 496.143, observed value 497.3 (M+1) ⁺ . Example 8: Synthesis of 5-(5-chloro-2-((1,3-dihydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-fluoro-6-methylbenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 13). Step 1:

2-Aminopropane-1,3-diol (746.8 mg, 8.197 mmol) was added to a stirred mixture containing 1 mL of DMSO containing 5-(2,5-dichloropyridin-4-yl)-1-triphenylmethyl-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one and 2.567 mmol of 5-(2,5-dichloropyridin-4-yl)-2-triphenylmethyl-2,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (1.344 g, prepared using the methods described in steps 1 to 3 of starting material 2). The reaction mixture was heated at 140°C for 2 hours. The reactants were cooled to ambient temperature and dissolved separately between saturated solutions of EtOAc and _NaHCO3 . The organic layer was separated, dried ( _MgSO4 ), and concentrated under vacuum to obtain a mixture of 5-(5-chloro-2-((1,3-dihydroxypropyl-2-yl)amino)pyridin-4-yl)-1-triphenylmethyl-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one and 5-(5-chloro-2-((1,3-dihydroxypropyl-2-yl)amino)pyridin-4-yl)-2-triphenylmethyl-2,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one, which was used in the next step without further purification. Step 2:

TFA (2.8 mL, 36.34 mmol) was added to a stirred mixture containing 10 mL of DCM containing 5-(5-chloro-2-((1,3-dihydroxypropyl-2-yl)amino)pyridin-4-yl)-1-triphenylmethyl-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one and 5-(5-chloro-2-((1,3-dihydroxypropyl-2-yl)amino)pyridin-4-yl)-2-triphenylmethyl-2,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one, and the reaction mixture was stirred at ambient temperature for 20 hours. The reaction mixture was then concentrated under vacuum. The residue was separately dissolved between saturated solutions of EtOAc and _NaHCO3 . The organic layer was separated, dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification was performed by rapid chromatography (24 g column, 0 to 100% heptane solution of 3:1 EtOAc:EtOH) to give 5-(5-chloro-2-((1,3-dihydroxypropyl-2-yl)amino)pyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (1.15 g, 100%, in 2 steps). ESI-MS m/z calculated value 335.079, observed value 336.1 (M+1) ⁺ . Step 3:

NaI (5.3 mg, 0.035 mmol) and KO t Bu (27.5 mg, 0.245 mmol) were added sequentially to a stirred mixture containing 5-(5-chloro-2-((1,3-dihydroxypropyl-2-yl)amino)pyridin-4-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (50 mg, 0.111 mmol) and 2-(bromomethyl)-1-fluoro-3-methylbenzene (27.4 mg, 0.135 mmol), and the reaction mixture was heated at 70 °C for 20 minutes. Purification by reverse-phase HPLC ( _C18 Sunfire column, 30 to 45% aqueous MeCN containing 0.1% TFA, followed by _C18 X-bridge column, 23 to 38% aqueous MeCN containing 0.1% ammonium hydroxide) yielded 5-(5-chloro-2-((1,3-dihydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-fluoro-6-methylbenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (compound 13 , 7.8 mg, 15%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (s, 1H), 8.11 (d, J = 0.8 Hz, 1H), 7.46 (d, J = 7.5 Hz, 1H), 7.30 (td, J = 8.0, 6.0 Hz, 1H), 7.10 (d, J = 7.6 Hz, 1H), 7.06 (d, J = 9.2 Hz, 1H), 6.92 (dt, J = 7.7, 0.8 Hz, 1H), 6.75 (d, J = 7.8 Hz, 1H), 6.68 (s, 1H), 5.58 (t, J = 1.7 Hz, 2H), 4.67 (dt, J = 11.0, 5.4 Hz, 2H), 3.91 (s, 1H), 3.59 - 3.46 (m, 4H), 2.43 (s, 3H) ppm. ESI-MS m/z calculated value 457.132, observed value 458.3 (M+1) ⁺ . Example 9: Synthesis of ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2,4,6-trifluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 14). Step 1:

DIPEA (200 μL, 1.148 mmol) was added to a stirred solution containing 5-(2,5-dichloropyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ( SB1 , 127 mg, 0.452 mmol) and ( 2S )-2-amino-2-cyclopropyl-ethanol (200 mg, 1.977 mmol), and the reaction mixture was heated at 150 ^° C for 16 hours. The mixture was then cooled to ambient temperature. Purification was performed by reverse-phase HPLC ( _C18 X-bridge column, 16 to 31% MeCN aqueous solution containing 0.1% ammonium hydroxide, followed by _C18 X-bridge column, 0 to 23% MeCN aqueous solution containing 0.05% TFA). After passing the collected fraction through an SPE bicarbonate box, it was precipitated by 3:1 MeCN/water and then lyophilized to obtain a white solid ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (25.54 mg, 16%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 13.33 (s, 1H), 7.97 (s, 1H), 7.84 (s, 1H), 7.06 (dd, J = 19.7, 7.4 Hz, 1H), 6.66 - 6.60 (m, 1H), 6.42 - 6.35 (m, 2H), 4.46 (d, J = 19.3 Hz, 1H), 3.28 (dtq, J = 12.3, 8.0, 4.4, 3.3 Hz, 3H), 0.76 (qt, J = 8.1, 5.0 Hz, 1H), 0.24 - 0.04 (m, 3H), 0.04 - -0.07 (m, 1H) ppm. ESI-MS m/z calculated value 345.099, observed value 346.0 (M+1) ⁺ . Step 2:

_K₂CO₃ (41.2 mg, 0.298 mmol) was added to _a stirred solution of DMSO (400 μL) containing 2-(bromomethyl)-1,3,5-trifluorobenzene (26.3 mg, 0.117 mmol) and ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1,5-dihydro-4- H- pyrazolo[4,3- c ]pyridin-4-one (40 mg, 0.116 mmol), and the reaction mixture was heated at 150 ^°C for 5 hours. The mixture was then cooled to ambient temperature. Purification by reverse-phase HPLC ( _C18 Sunfire column, 31 to 45% MeCN aqueous solution containing 0.1% trifluoroacetic acid) yielded ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2,4,6-trifluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 14 , 11.2 mg, 19%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 - 8.13 (m, 1H), 8.10 (s, 1H), 7.50 (dd, J = 17.9, 7.5 Hz, 1H), 7.32 - 7.24 (m, 2H), 7.13 - 7.07 (m, 1H), 6.96 (d, J = 7.5 Hz, 1H), 6.65 (d, J = 1.5 Hz, 1H), 5.59 (s, 2H), 3.90 (s, 1H), 3.61 - 3.45 (m, 3H), 1.01 (qt, J = 8.2, 5.0 Hz, 1H), 0.43 (dddd, J = 14.7, 9.5, 5.5, 3.3 Hz, 1H), 0.40 - 0.30 (m, 2H), 0.23 (td, J = 5.9, 3.6 Hz, 1H) ppm. ESI-MS m/z calculated value 489.118, observed value 490.2 (M+1) ⁺ . Example 10: Synthesis of rac -2-((5-chloro-4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)oxy)-2-cyclopropylacetamide (compound 248). Step 1:

In a screw-cap vial, NaH (14.79 mg, 60% mineral oil dispersion, 0.370 mmol) was added to a stirred solution containing 1,4-dimethyl ether (0.7 mL) of rac -2-cyclopropyl-2-hydroxyethyl ethyl acetate (53.33 mg, 0.370 mmol), and the mixture was stirred for 10 minutes at ambient temperature. 1-(2-chlorobenzyl)-5-(2,5-dichloropyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (50 mg, prepared using the method described in step 1 of Example 1, 0.123 mmol) was added to the reaction mixture, the vial was sealed, and the mixture was stirred for 90 minutes at 100 ^°C . The reaction mixture was cooled to ambient temperature and poured onto a 10 mL semi-saturated solution of _NH₄Cl . The aqueous layer was separated and extracted with EtOAc (10 mL). The organic extract was washed with a saturated brine solution, dried ( _MgSO₄ ), filtered, and concentrated under vacuum. Purification by rapid chromatography yielded ethyl rac -2-((5-chloro-4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)oxy)-2-cyclopropyl ethyl acetate (28 mg, 34%). ESI-MS m/z calculated value 512.102, observed value 513.2 (M+1) ⁺ . Step 2 :

In a screw-cap vial, ethyl rac -2-((5-chloro-4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)oxy)-2-cyclopropylacetate (12 mg, 0.023 mmol) was dissolved in methanol-ammonia (1 mL, 7 M MeOH solution, 7.0 mmol). The vial was sealed, and the reaction mixture was stirred at 60°C for 16 hours. The mixture was then cooled to ambient temperature and concentrated under vacuum. Purification by reverse-phase HPLC yielded rac -2-((5-chloro-4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)oxy)-2-cyclopropylacetamide (compound 248 , 5 mg, 44%), a white solid. ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.36 (d, J = 7.7 Hz, 1H), 8.23 (dd, J = 4.7, 0.8 Hz, 1H), 7.54 - 7.51 (m, 1H), 7.51 - 7.44 (m, 2H), 7.41 - 7.33 (m, 2H), 7.22 (d, J = 8.8 Hz, 1H), 7.17 - 7.09 (m, 2H), 6.95 (td, J = 7.4, 0.9 Hz, 1H), 5.69 (d, J = 3.5 Hz, 2H), 4.55 (t, J = 9.1 Hz, 1H), 1.27 (qt, J = 8.5, 4.8 Hz, 1H), 0.73 - 0.66 (m, 1H), 0.60 (ddd, J = 8.3, 3.5, 1.7 Hz, 2H), 0.49 - 0.38 (m, 1H) ppm. ESI-MS m/z calculated value 483.086, observed value 484.2 (M+1) ⁺ . Example 11: Synthesis of rac -5-(5-chloro-2-(1-cyclopropyl-2-hydroxyethoxy)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (compound 249). Step 1:

_LiBH4 (63 μL, 2 M THF solution, 0.126 mmol) was added to a solution containing 1 mL of THF containing rac -2-((5-chloro-4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)oxy)-2-cyclopropyl ethyl acetate (28 mg, prepared using the method described in step 1 of Example 10, starting with rac -2-cyclopropyl-2-hydroxyethyl ethyl acetate, 0.042 mmol), and the reaction mixture was stirred at ambient temperature for 16 hours. The reaction mixture was quenched by adding a half-saturated solution of _NH4Cl (5 mL). The aqueous layer was separated and extracted with EtOAc (10 mL). The organic extract was washed with saturated brine, dried ( _MgSO₄ ), filtered, and concentrated under vacuum. Purification by reverse-phase HPLC yielded a white solid, rac -5-(5-chloro-2-(1-cyclopropyl-2-hydroxyethoxy)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 249 , 10.6 mg, 53%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.37 (d, J = 2.1 Hz, 1H), 8.22 (d, J = 1.1 Hz, 1H), 7.55 - 7.46 (m, 2H), 7.41 - 7.33 (m, 2H), 7.13 - 7.08 (m, 2H), 6.94 (ddd, J = 7.6, 1.9, 0.9 Hz, 1H), 5.69 (d, J = 4.1 Hz, 2H), 4.84 (dt, J = 21.4, 5.6 Hz, 1H), 4.69 (p, J = 5.2, 4.7 Hz, 1H), 3.68 (tp, J = 11.7, 6.5, 5.8 Hz, 2H), 1.19 - 1.10 (m, 1H), 0.58 - 0.33 (m, 4H) ppm. ESI-MS m/z calculated value 470.091, observed value 471.2 (M+1) ⁺ . Example 12: Synthesis of 5-(5-chloro-2-((1,3-dihydroxypropyl-2-yl)oxy)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 250) Step 1:

NaH (15 mg, 60% mineral oil dispersion, 0.375 mmol) was added to a solution of 1,4-dimethylol (0.7 mL) containing 1,3-dimethyl-5-ol (39 mg, 0.375 mmol), and the mixture was stirred for 10 minutes at ambient temperature. 1-(2-chlorobenzyl)-5-(2,5-dichloropyridin-4-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (50 mg, prepared using the method described in step 1 of Example 1, 0.123 mmol) was added, and the reaction mixture was stirred at 100 ^°C for 8 hours. The mixture was cooled to ambient temperature and separately dissolved between EtOAc (10 mL) and a half-saturated saline solution (5 mL). The organic extract was separated, dried ( _MgSO₄ ), filtered, and concentrated under vacuum to give a yellow oily substance of 5-(2-((1,3-dialkyl-5-yl)oxy)-5-chloropyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (50 mg, 29%). ESI-MS m/z calculated value 472.071, observed value 473.1 (M+1) ⁺ . Step 2 :

A solution containing 5-(2-((1,3-diamino-5-yl)oxy)-5-chloropyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one (50 mg, 0.036 mmol) in HCl (1 mL, 4 M 1,4-diamino-4-yl) and water (22 μL, 1.221 mmol) was stirred for 16 hours at ambient temperature, followed by further stirring at 50°C for 75 minutes. The reaction mixture was then cooled to ambient temperature and concentrated under vacuum. Purification by reverse-phase HPLC yielded a pale yellow solid, 5-(5-chloro-2-((1,3-dihydroxypropyl-2-yl)oxy)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 250 , 12 mg, 20%). ¹ H NMR (500 MHz, methanol - _{d 4} ) δ 8.39 - 8.34 (m, 1H), 8.24 (d, J = 0.8 Hz, 1H), 7.49 (dd, J = 7.9, 1.3 Hz, 1H), 7.38 - 7.29 (m, 3H), 7.09 (dd, J = 7.6, 1.8 Hz, 1H), 7.06 - 7.02 (m, 1H), 6.86 (dd, J = 7.6, 0.9 Hz, 1H), 5.72 (d, J = 2.3 Hz, 2H), 4.47 (ddd, J = 11.0, 9.1, 4.3 Hz, 1H), 4.38 (ddd, J = 13.0, 11.1, 6.2 Hz, 1H), 4.05 - 3.96 (m, 1H), 3.72 - 3.60 (m, 2H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 460.071, observed value 461.3 (M+1) ⁺ . Example 13: Synthesis of 1-(2-chlorobenzyl)-5-(5-fluoro-2-((2S , 4S )-4-hydroxy-2-(hydroxymethyl)pyrrolidin-1-yl)pyridin-4-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 251). Step 1:

_K₂CO₃ (1.6 g, 10.998 mmol) and 1-chloro-2-(chloromethyl)benzene (393.30 mg, 0.3 mL, 2.320 mmol) were sequentially added to _a stirred solution of DMSO (9 mL) containing 5-(2-chloro-5-fluoropyridin-4-yl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one ( SB₂ , 900 mg, 2.142 mmol) at 0°C, and the reaction mixture was stirred for 16 hours at ambient temperature. The mixture was diluted with ice-cold water (50 mL). The aqueous phase was separated and extracted with EtOAc (2 x 50 mL). The combined organic extracts were washed with ice-cold water (2 x 100 mL), dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum . Purification by rapid chromatography (80 g SiO₂, 30% EtOAc in _hexane ) yielded a mixture of grayish-white solids of 5-(2-chloro-5-fluoropyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one and 5-(2-chloro-5-fluoropyridin-4-yl)-2-(2-chlorobenzyl)-2,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (844.2 mg, 100%). ESI-MS m/z calculated value 388.029, observed value 389.2 (M+1) ⁺ . Step 2 :

DIPEA (360 μL, 2.067 mmol) and ( 3S , 5S )-5-(hydroxymethyl)pyrrolidone-3-ol hydrochloride (136 mg, 0.885 mmol) were added sequentially to a DMSO mixture (300 µL) containing 5-(2-chloro-5-fluoropyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one and 5-(2-chloro-5-fluoropyridin-4-yl)-2-(2-chlorobenzyl)-2,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (98 mg, 0.252 mmol), and the reaction mixture was stirred at 150°C for 16 hours. The reactants were cooled to ambient temperature, diluted with DMSO (2 mL) and MeOH (2 mL), filtered, and purified by reverse-phase HPLC ( _C18 X-bridge column, 30% to 45% MeCN aqueous solution containing 1% TFA). Subsequently, the isomers were separated by chiral SFC using a ^Chiralcel® OJ-H column, 5 μm particle size, 25 cm x 20 mm, purchased from Daichel (mobile phase: 15% MeOH (topped with 20 mM ammonia), 85% _CO2 ; flow rate 100 mL/min), yielding:

First dissolution isomer (rt = 5.10 min ) : 1-(2-chlorobenzyl)-5-(5-fluoro-2-(( 2S , 4S )-4-hydroxy-2-(hydroxymethyl)pyrrolidin-1-yl)pyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 251 , 16 mg, 13%), as a grayish-white solid. ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.22 (d, J = 1.7 Hz, 1H), 8.21 (d, J = 0.8 Hz, 1H), 7.57 (d, J = 7.5 Hz, 1H), 7.52 (dd, J = 7.8, 1.5 Hz, 1H), 7.41 - 7.29 (m, 3H), 7.05 (dd, J = 7.6, 1.9 Hz, 1H), 6.93 (dd, J = 7.6, 1.0 Hz, 1H), 6.68 (d, J = 4.8 Hz, 1H), 5.68 (s, 2H), 5.20 (s, 1H), 4.99 (s, 1H), 4.35 (d, J = 5.3 Hz, 1H), 4.04 (s, 1H), 3.70 - 3.62 (m, 2H), 3.46 (dd, J = 11.2, 4.8 Hz, 1H), 3.35 (d, J = 11.4 Hz, 1H), 2.19 - 2.08 (m, 1H), 2.00 - 1.93 (m, 1H) ppm. ESI-MS m/z calculated value 469.132, observed value 470.3 (M+1) ⁺ .

Second precipitate isomer (rt = 6.93 min ) : 2-(2-chlorobenzyl)-5-(5-fluoro-2-(( 2S , 4S )-4-hydroxy-2-(hydroxymethyl)pyrrolidin-1-yl)pyridin-4-yl)-2,5-dihydro- 4H- pyrazolo[4,3-c]pyridin-4-one (18 mg, 15%) as a grayish-white solid. ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.77 (d, J = 0.8 Hz, 1H), 8.21 (d, J = 1.7 Hz, 1H), 7.52 (dd, J = 7.7, 1.5 Hz, 1H), 7.41 - 7.34 (m, 2H), 7.32 (d, J = 7.6 Hz, 1H), 7.19 (dd, J = 7.5, 1.9 Hz, 1H), 6.65 - 6.60 (m, 2H), 5.66 (s, 2H), 5.20 (s, 1H), 4.99 (s, 1H), 4.35 (d, J = 5.3 Hz, 1H), 4.03 (s, 1H), 3.71 - 3.60 (m, 2H), 3.46 (dd, J = 11.1, 4.8 Hz, 1H), 3.37 - 3.32 (m, 1H), 2.15 (ddd, J = 13.8, 9.0, 5.3 Hz, 1H), 1.96 (dq, J = 13.4, 1.7 Hz, 1H) ppm. ESI-MS m/z calculated value 469.132, observed value 470.3 (M+1) ⁺ . Example 14: Synthesis of rel -5-(5-chloro-2-(( 2S, 3R )-3-hydroxy-2-(hydroxymethyl)pyrrolidin-1-yl)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 252) and rel -5-(5-chloro-2-(( 2R , 3S )-3-hydroxy-2-(hydroxymethyl)pyrrolidin-1-yl)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 253). Step 1:

DIPEA (500 μL, 2.870 mmol) was added to a stirred solution containing 5-(2,5-dichloropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one (103 mg, prepared using the method described in step 1 of Example 3, 0.265 mmol) and rac- ( 2S , 3R )-2-(hydroxymethyl)pyrrolidone-3-ol hydrochloride (219 mg, 1.426 mmol), and the reaction mixture was stirred at 150°C for 20 hours. The mixture was diluted with EtOAc (30 mL) and washed with water (30 mL). The aqueous layer was separated and extracted with EtOAc (2 x 30 mL). The combined organic extracts were dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by reverse-phase HPLC ( _C18 X-bridge column, 24 to 38% MeCN aqueous solution containing 1% _NH4OH ) gave rac -5-(5-chloro-2-(( 2S , 3R )-3-hydroxy-2-(hydroxymethyl)pyrrolidin-1-yl)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (30 mg, 24%). ESI-MS m/z calculated value 469.132, observed value 470.0 (M+1) ⁺ . Step 2 :

The mirror isomer of rac -5-(5-chloro-2-(( 2S, 3R )-3-hydroxy-2-(hydroxymethyl)pyrrolidin-1-yl)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one was separated by chiral SFC using a ^Chiralcel® OJ-H column, 5 µm particle size, 25 cm x 10 mm, purchased from Daichel (mobile phase: 23% 1:1 MeOH:MeCN (supplemented with 0.2% DMIPA), 77% _CO2 ; flow rate 10 mL/min), and further separated by reverse-phase HPLC ( _C18 X-bridge column, 24 to 38% MeCN aqueous solution containing 1% NH4 ₊₎ . Further purification of OH) yields:

First dissolution isomer (rt = 3.77 min ) : rel -5-(5-chloro-2-(( 2S , 3R )-3-hydroxy-2-(hydroxymethyl)pyrrolidin-1-yl)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 252 , 10.6 mg, 8%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.25 (d, J = 1.5 Hz, 1H), 8.17 (dd, J = 1.7, 0.8 Hz, 1H), 7.47 (dd, J = 7.5, 1.8 Hz, 1H), 7.43 - 7.36 (m, 1H), 7.30 - 7.16 (m, 3H), 6.92 (dd, J = 7.6, 4.1 Hz, 1H), 6.69 (s, 1H), 5.64 (q, J = 15.5 Hz, 2H), 4.94 - 4.88 (m, 1H), 4.81 (t, J = 5.7 Hz, 1H), 4.28 (t, J = 3.6 Hz, 1H), 3.92 - 3.71 (m, 1H), 3.60 - 3.56 (m, 1H), 3.45 - 3.41 (m, 1H), 3.38 - 3.34 (m, 1H), 3.26 - 3.14 (m, 1H), 2.17 - 2.10 (m, 1H), 1.84 (dd, J = 13.0, 6.5 Hz, 1H) ppm. ESI-MS m/z calculated value 469.132, observed value 470.2 (M+1) ⁺ .

Second elution isomer (rt = 4.61 min ) : rel -5-(5-chloro-2-(( 2R , 3S )-3-hydroxy-2-(hydroxymethyl)pyrrolidin-1-yl)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3-c]pyridin-4-one (compound 253 , 9.0 mg, 7%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.25 (d, J = 1.5 Hz, 1H), 8.17 (dd, J = 1.7, 0.8 Hz, 1H), 7.47 (dd, J = 7.5, 1.8 Hz, 1H), 7.42 - 7.36 (m, 1H), 7.29 - 7.17 (m, 3H), 6.92 (dd, J = 7.6, 4.1 Hz, 1H), 6.69 (s, 1H), 5.64 (q, J = 15.4 Hz, 2H), 4.94 - 4.88 (m, 1H), 4.81 (t, J = 5.8 Hz, 1H), 4.28 (t, J = 3.5 Hz, 1H), 3.86 - 3.82 (m, 1H), 3.64 - 3.51 (m, 1H), 3.44 - 3.40 (m, 1H), 3.36 (s, 1H), 3.25 - 3.13 (m, 1H), 2.17 - 2.08 (m, 1H), 1.84 (dd, J = 12.8, 6.7 Hz, 1H) ppm. ESI-MS m/z calculated value 469.132, observed value 470.2 (M+1) ⁺ . Example 15: Synthesis of rel- ( R )-5-(5-chloro-2-((( S ^* )-1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-6-methyl-1,5,6,7-tetrahydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 254) and rel- ( S )-5-(5-chloro-2-((( S ^* )-1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-6-methyl-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 255). Step 1:

A stirred mixture of rac -1-(2-fluorobenzyl)-6-methyl-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3 -c ]pyridin-4-one ( S6 , 50 mg, 0.191 mmol), 5-chloro-2-fluoro-4-iodopyridine (58 mg, 0.225 mmol), XantPhos (12 mg, 0.021 mmol), and _Cs₂CO₃ (140 mg, 0.430 mmol) in 1,4-dimethyl _alkylene (1 mL) was degassed for 10 min using argon. _Pd₂ (dba) _₃ (11 mg, 0.012 mmol) was added, and the reaction mixture was heated overnight at 100°C. The reaction mixture was then cooled to ambient temperature and concentrated under vacuum. The residue was diluted with EtOAc, washed with water (2x), dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by reverse-phase chromatography (25 g _C18 column, 10 to 80% MeCN aqueous solution containing 0.1% ammonium hydroxide) yielded a pale yellow solid, rac -5-(5-chloro-2-fluoropyridin-4-yl)-1-(2-fluorobenzyl)-6-methyl-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (21.077 mg, 28%). ¹ H NMR (400 MHz, chloroform-d) δ 8.20 (s, 1H), 7.87 (s, 1H), 7.25 - 7.20 (m, 1H), 7.15 - 7.11 (m, 1H), 7.06 (d, J = 7.5 Hz, 1H), 7.03 - 6.96 (m, 1H), 6.91 (s, 1H), 5.23 (s, 2H), 4.18 - 4.10 (m, 1H), 3.29 (dd, J = 16.2, 7.3 Hz, 1H), 2.79 (dd, J = 16.2, 6.7 Hz, 1H), 1.12 (d, J = 6.6 Hz, 3H) ppm. ESI-MS Calculated m/z value: 388.090, Observed value: 389.0 (M+1) ⁺ . Step 2 :

( S )-2-aminoprop-1-ol (50 mg, 0.448 mmol) and DIPEA (96.460 mg, 0.13 mL, 0.746 mmol) were sequentially added to a stirred solution of DMSO (1.5 mL) containing rac -5-(5-chloro-2-fluoropyridin-4-yl)-1-(2-fluorobenzyl)-6-methyl-1,5,6,7-tetrahydro-4 -H- pyrazolo[4,3- c ]pyridin-4-one (51 mg, 0.122 mmol). The reaction mixture was heated at 150°C for 2 hours under microwave irradiation. The reaction mixture was diluted in EtOAc, washed with water (x 2), dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by reverse-phase chromatography (25 g _C18 column, 0 to 50% MeCN aqueous solution containing 0.1% formic acid, followed by 12 g _C18 column, 0 to 30% MeCN aqueous solution containing 0.1% formic acid) yielded 5-(5-chloro-2-(((S)-1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-6-methyl-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (11.9 mg, 22%), a mixture of non-mirror isomers, and a white solid. ¹ H NMR (400 MHz, methanol -d ₄ ) δ 8.07 (s, 1H), 7.90 (s, 1H), 7.43 - 7.37 (m, 1H), 7.28 - 7.15 (m, 3H), 6.58 (d, J = 0.8 Hz, 1H), 5.46 (d, J = 2.6 Hz, 2H), 4.23 (br, s, 1H), 4.03 - 3.97 (m, 1H), 3.62 - 3.53 (m, 2H), 3.46 (dd, J = 16.3, 7.2 Hz, 1H), 3.06 (dd, J = 16.4, 7.0 Hz, 1H), 1.27 (d, J = 6.5 Hz, 3H), 1.23 (d, J = 6.6 Hz, 3H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 443.152, observed value 444.2 (M+1) ⁺ . Step 3 :

The nonmirror isomer of 5-(5-chloro-2-((( S )-1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-6-methyl-1,5,6,7-tetrahydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one (15 mg, 0.034 mmol) was separated by chiral SFC using a ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 22% MeOH (topped with 20 mM ammonia), 78% _CO2 ; flow rate 100 mL/min). The result was:

First dissolution isomer (rt = 3.78 min ) : rel- ( R )-5-(5-chloro-2-((( S ^* )-1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-6-methyl-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 254 , 3.3 mg, 44%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.07 (s, 1H), 7.84 (s, 1H), 7.44 - 7.37 (m, 1H), 7.29 - 7.19 (m, 3H), 6.62 (s, 1H), 6.55 (s, 1H), 5.43 (s, 2H), 4.72 (t, J = 5.5 Hz, 1H), 4.11 (s, 1H), 3.91 (s, 1H), 3.48 (dt, J = 10.2, 5.0 Hz, 1H), 3.42 - 3.33 (m, 1H), 3.06 (d, J = 16.9 Hz, 1H), 1.15 (s, 3H), 1.12 (d, J = 6.6 Hz, 3H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 443.152, observed value 444.2 (M+1) ⁺ .

Second elution isomer (rt = 3.50 min ) : rel- ( S )-5-(5-chloro-2-((( S ^* )-1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-6-methyl-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 255 , 2.3 mg, 31%). ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.07 (s, 1H), 7.83 (s, 1H), 7.45 - 7.36 (m, 1H), 7.29 - 7.19 (m, 3H), 6.62 (s, 1H), 6.54 (s, 1H), 5.43 (s, 2H), 4.70 (t, J = 5.6 Hz, 1H), 4.11 (s, 1H), 3.91 (s, 1H), 3.47 (dt, J = 10.4, 5.2 Hz, 1H), 3.42 - 3.33 (m, 1H), 3.06 (d, J = 16.7 Hz, 1H), 1.15 (s, 3H), 1.13 (d, J = 6.6 Hz, 3H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 443.152, observed value 444.2 (M+1) ⁺ . Example 16: Synthesis of rac -5-(2-(3-(aminomethyl)piperidin-1-yl)-5-chloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound P13) Step 1:

_Cs₂CO₃ (28.2 g, 86.551 mmol) was added to a stirred _mixture containing 1-(2,6-difluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one ( S₇ , 11.3 g, 40.753 mmol) and 2,5-dichloro-4-fluoropyridine (7.25 g, 43.680 mmol), and the reaction mixture was stirred at ambient temperature for 22 hours. The reaction mixture was poured onto water (300 mL) to obtain a slurry. The solid was filtered, recrystallized from hot MeOH (1 L), and dried under vacuum at 40°C to give a white solid of 5-(2,5-dichloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (16.2 g, 94%). ^¹H NMR (400 MHz, chloroform- d ) δ 8.51 (s, 1H), 8.15 (s, 1H), 7.36 (s, 1H), 7.33 - 7.24 (m, 1H), 6.96 - 6.87 (m, 3H), 6.62 (d, J = 7.6 Hz, 1H), 5.46 (s, 2H) ppm. ESI-MS m/z calculated value 406.020, observed value 407.1 (M+1) ⁺ . Step 2 :

DIPEA (30 μL, 0.172 mmol) was added to a stirred solution containing 5-(2,5-dichloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (12 mg, 0.029 mmol) and rac- (piperidin-3-ylmethyl)aminocarbamate tributyl ester (21.43 mg, 0.1 mmol) in NMP (1 mL), and the reaction mixture was stirred overnight at 115°C. The reaction mixture was then cooled to ambient temperature and concentrated under vacuum. Purification by reverse-phase HPLC ( _C18 X-bridge column, MeCN aqueous solution containing 0.1% ammonium hydroxide) yielded tributyl rac -((1-(5-chloro-4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)piperidin-3-yl)methyl)aminocarbamate, which was used in the next step without further purification. Step 3 :

TFA (1 mL) was added to a stirred solution containing rac- (1-(5-chloro-4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)piperidin-3-yl)methyl)aminocarbamate tributyl ester (1 mL), and the reaction mixture was stirred for 1 hour at ambient temperature. The reaction mixture was concentrated under vacuum. The residue was dissolved in a mixture of MeCN and water and passed through an SPE bicarbonate chamber. The filtrate was collected and freeze-dried overnight to give rac -5-(2-(3-(aminomethyl)piperidin-1-yl)-5-chloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound P13 , 13.27 mg, 76%, by 2 steps) as a solid. ESI-MS calculated m/z 484.159, observed 485.0 (M+1) ⁺ . Example 17: Synthesis of rac -5-(5-chloro-2-(( 3S , 4R )-4-hydroxy-5,5-dimethylpyrrolidin-3-yl)oxy)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 257) and rac -5-(5-chloro-2-((( 3R , 4S )-4-hydroxy-2,2-dimethylpyrrolidin-3-yl)oxy)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 258) Step 1:

Me ₃ N.HCl (15 mg, 0.157 mmol) and Cs ₂ CO ₃ (200 mg, 0.614 mmol) were added sequentially to a stirred mixture containing rac- ( 3R , 4S )-2,2-dimethylpyrrolidone-3,4-diol hydrochloride (50 mg, 0.298 mmol) and 5-(2,5-dichloropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (50 mg, prepared using the method described in step 1 of Example 3, 0.129 mmol), and the reaction mixture was stirred at 130°C for 24 hours. Purification by reverse-phase HPLC ( _C18 X-bridge column, 0 to 100% MeCN aqueous solution containing 0.1% _NH4OH ), followed by freeze-drying, yielded rac -5-(5-chloro-2-((( 3S , 4R )-4-hydroxy-5,5-dimethylpyrrolidin-3-yl)oxy)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 257 , 8.7 mg, 10%) (ESI-MS m/z calculated 483.147, observed 484.3 (M+1) ⁺ ) and rac -5-(5-chloro-2-((3R , 4S ) -4-yl)-pyridin-4-one (compound 257, 8.7 mg, 10%) (ESI-MS m/z calculated 483.147, observed 484.3 (M+1)+). )-4-hydroxy-2,2-dimethylpyrrolidin-3-yl)oxy)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 258 , 3.2 mg, 4%) (ESI-MS m/z calculated 483.147, observed 482.2 (M-1) ^- ). Example 18: Synthesis of rac -2-((5-chloro-4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4,6,7-tetrahydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)-2-cyclopropylacetic acid (compound P14) Step 1:

After treating 1-(2,6-difluorobenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one ( S8 , 5 g, 18.99 mmol) and 5-chloro-2-fluoro-4-iodopyridine (5.52 g, 21.44 mmol) by rapid chromatography (80 g _SiO2 , 0 to 100% 3:1 EtOAc/EtOH in heptane), a brown solid 5-(5-chloro-2-fluoropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5,6,7-tetrahydro- 4H ,pyrazolo[4,3- c ]pyridin-4-one (5.120 g, 54%) was obtained. ^¹H NMR (500 MHz, DMSO - _d⁶ ) δ 8.44 (s, ¹H), 7.85 (s, ¹H), 7.60 - 7.37 (m, 2H), 7.32 - 6.95 (m, 2H), 5.42 (s, 2H), 4.19 - 3.91 (m, 2H), 3.26 (t, J = 6.6 Hz, 2H) ppm. ESI-MS m/z calculated value 392.065, observed 393.1 (M+1) ⁺ . Steps 2 and 3 :

A stirred solution of NMP (11 mL) containing 5-(5-chloro-2-fluoropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5,6,7-tetrahydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (1.97 g, 3.912 mmol) and rac -2-amino-2-cyclopropylacetic acid tributyl ester (2.58 g, 15.07 mmol) was heated to 140°C for 22 hours. The reactants were separately dissolved between EtOAc (100 mL) and water (100 mL). The aqueous layer was separated and extracted with EtOAc (2 x 100 mL). The combined organic extracts were dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by reverse-phase HPLC ( _C18 X-bridge column, 47 to 95% MeCN, containing 1% ammonium hydroxide) yielded rac -2-((5-chloro-4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4,6,7-tetrahydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)-2-cyclopropylacetic acid tributyl ester, which was used in the next step without further purification.

TFA (438 μL, 5.685 mmol) was added to a solution containing 900 μL of DCM of tributyl rac -2-((5-chloro-4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4,6,7-tetrahydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)-2-cyclopropylacetate, and the reaction mixture was stirred at ambient temperature for 5 hours. The mixture was then concentrated under vacuum. Purification by reverse-phase HPLC ( _C18 X-bridge column, 0 to 23% MeCN aqueous solution containing 1% ammonium hydroxide) yielded rac -2-((5-chloro-4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4,6,7-tetrahydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)-2-cyclopropylacetic acid (compound P14 , 202 mg, 11%, in 2 steps). ^¹H NMR (500 MHz, DMSO - _d⁶ ) δ 8.00 (s, 1H), 7.80 (s, 1H), 7.50 (tt, J = 8.4, 6.6 Hz, 1H), 7.17 (t, J = 8.0 Hz, 2H), 7.06 (s, 1H), 6.67 (s, 1H), 5.40 (s, 2H), 3.89 (s, 2H), 3.77 (t, J = 7.4 Hz, 2H), 3.21 (s, 1H), 1.15 (qt, J = 8.1, 4.9 Hz, 1H), 0.61 - 0.20 (m, 4H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 487.122, observed value 488.3 (M+1) ⁺ . Example 19: Synthesis of a mixture of nonmirror isomers of 5-(5-chloro-2-((( S )-1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-7-methyl-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (compound 260). Step 1:

A stirred solution containing 15 mL of 5-chloro-2-fluoro-4-iodopyridine (287 mg, 1.115 mmol), rac - _1- (2-fluorobenzyl)-7-methyl-1,5,6,7-tetrahydro-4- H- pyrazolo[4,3- c ]pyridin-4-one ( S13 , 238 mg, 0.900 mmol), XantPhos (160 mg, 0.277 mmol), and _Cs₂CO₃ (440 mg, 1.350 mmol) was degassed for 20 min using argon. Pd(OAc) _₂ (18 mg, 0.080 mmol) was added, and the reaction mixture was heated at 100°C for 16 hours. The reaction mixture was cooled to ambient temperature and dissolved separately in water (25 mL) and EtOAc (20 mL). The aqueous phase was separated and extracted with EtOAc (20 mL). The combined organic extract was dried ( _{MgSO4), filtered, and concentrated under vacuum. Purification by reverse-phase chromatography (12 g C18 column, 20 to 80% MeCN aqueous solution containing 0.1% ammonium hydroxide) yielded a white solid, rac-5-(5-chloro-2-fluoropyridin-4 -} yl )-1-(2-fluorobenzyl)-7-methyl-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (200 mg, 57%). ^¹H NMR (400 MHz, methanol _-d⁴ ) δ 8.34 (s, ¹H), 7.92 (s, ¹H), 7.42 - 7.35 (m, ¹H), 7.25 (d, J = 1.8 Hz, ¹H), 7.22 - 7.14 (m, 3H), 5.50 - 5.46 (m, 2H), 4.47 - 4.38 (m, 1H), 3.66 - 3.58 (m, 1H), 3.51 - 3.42 (m, 1H), 1.36 (d, J = 7.0 Hz, 3H) ppm. ESI-MS m/z calculated value 388.090, observed value 389.2 (M+1) ⁺ . Step 2 :

( S )-2-aminoprop-1-ol (394.4 mg, 0.4 mL, 5.251 mmol) and rac -5-(5-chloro-2-fluoropyridin-4-yl)-1-(2-fluorobenzyl)-7-methyl-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (200 mg, 0.514 mmol) were treated by the method described in step 2 of Example 1, the difference being that DIPEA was not required. Purification by reverse-phase chromatography (12 g _C18 column, 20 to 80% MeCN aqueous solution containing 0.1% ammonium hydroxide) yielded 5-(5-chloro-2-((( S )-1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-7-methyl-1,5,6,7-tetrahydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 260 , 130 mg, 55%), a mixture of non-mirror isomers, and a white solid. ¹ H NMR (400 MHz, methanol -d ₄ ) δ 8.03 - 7.99 (m, 1H), 7.89 (s, 1H), 7.42 - 7.34 (m, 1H), 7.23 - 7.13 (m, 3H), 6.53 (s, 1H), 5.47 (s, 2H), 4.33 (dd, J = 12.3, 4.3 Hz, 1H), 4.03 - 3.94 (m, 1H), 3.62 - 3.47 (m, 3H), 3.47 - 3.39 (m, 1H), 1.35 (br d, J = 6.8 Hz, 3H), 1.21 (d, J = 6.6 Hz, 3H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 443.152, observed value 444.2 (M+1) ⁺ . Example 20: Synthesis of rac -5-(5-chloro-2-((5-sideoxypyrrolidin-3-yl)methoxy)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 261) Step 1:

^{KO t} Bu (29 mg, 0.258 mmol) was added to a stirred solution containing 1 mL of 1,4-dimethyl 4-(hydroxymethyl)pyrrolidin-2-one (29 mg, 0.252 mmol) and the reaction mixture was stirred for 5 minutes at ambient temperature. A solution of 0.5 mL of 1,4-dimethyl 5-(2,5-dichloropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (50 mg, 0.127 mmol, using the method described in step 1 of Example 3) was added dropwise, and the mixture was heated at 100°C for 20 hours. The reactants were cooled to ambient temperature, quenched with water, and extracted with DCM (3x). The combined organic layers were washed with brine, dried ( _MgSO₄ ), filtered, and concentrated under vacuum. Purification by reverse-phase chromatography (12 g _C18 column, 2 to 100% MeCN aqueous solution containing 0.1% _NH₄OH ) yielded a white solid, rac -5-(5-chloro-2-((5-sideoxypyrrolidin-3-yl)methoxy)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one (compound 261 , 10 mg, 17%). ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.45 (s, 1H), 8.19 (s, 1H), 7.59 (s, 1H), 7.51 (d, J = 7.6 Hz, 1H), 7.43 - 7.37 (m, 1H), 7.31 - 7.19 (m, 4H), 6.97 (d, J = 7.6 Hz, 1H), 5.65 (d, J = 3.2 Hz, 2H), 4.37 - 4.25 (m, 2H), 3.44 - 3.38 (m, 1H), 3.10 (dd, J = 9.8, 5.5 Hz, 1H), 2.93 - 2.83 (m, 1H), 2.33 (dd, J = 16.6, 9.0 Hz, 1H), 2.09 - 2.02 (m, 1H) ppm. ESI-MS m/z calculated value 467.116, observed value 468.2 (M+1) ⁺ . Example 21: Synthesis of 5-(5-chloro-2-(cyclopropylmethoxy)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3-c]pyridin-4-one (compound 262) Step 1:

_Cs₂CO₃ (2.15 g, 6.599 mmol) was added to a stirred solution of _DMA (5 mL) containing 1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one ( S₂ , 0.8 g, 3.289 mmol) and 5-chloro-4-fluoro-1-((2-(trimethylsilyl)ethoxy)methyl)pyridin-2( 1H )-one ( Int-P₅ , 1 g, 3.291 mmol), and the reaction mixture was stirred at 50°C for 1 hour. The reaction mixture was diluted with ice water (10 mL) and extracted with EtOAc (2 x 10 mL). The combined organic layers were washed with brine (10 mL), dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum. Purification by rapid chromatography (12 g _SiO₂ , 40 to 50% EtOAc in _heptane ) yielded a grayish-white solid of 5-(5-chloro-2-sideoxy-1-((2-(trimethylsilyl)ethoxy)methyl)-1,2-dihydropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (1.4 g, 70%). ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 8.20 (d, 2H), 7.51 (d, J = 7.6 Hz, 1H), 7.43 - 7.37 (m, 1H), 7.30 - 7.18 (m, 3H), 6.96 (d, J = 7.6 Hz, 1H), 6.78 (s, 1H), 5.70-5.58 (m, 2H), 5.34 - 5.28 (m, 2H), 3.65 (t, J = 8.0 Hz, 2H), 0.92 (t, J = 8.0 Hz, 2H), 0.009 (s, 9H) ppm. ESI-MS m/z calculated value 500.145, observed value 501.1 (M+1) ⁺ . Step 2 :

TBAF (10 mL, 1 M THF solution, 10 mmol) was added to a stirred solution containing 5 mL of THF with 5-(5-chloro-2-sideoxy-1-((2-(trimethylsilyl)ethoxy)methyl)-1,2-dihydropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (1.4 g, 2.295 mmol), and the reaction mixture was stirred at ambient temperature for 16 hours. The reaction was quenched by adding saturated _NH4Cl aqueous solution (20 mL) and extracted with EtOAc (3 x 20 mL). The combined organic extracts were washed with brine (20 mL), dried ( _{Na₂SO₄ )} , filtered, and concentrated under vacuum. Purification by rapid chromatography (12 g _SiO₂ , 15 to 20% MeOH/DCM) yielded a grayish-white solid of 5-(5-chloro-2-sideoxy-1,2-dihydropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (645 mg, 75%). ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 12.90 - 11.40 (br, s, 1H), 8.17 (s, 1H), 7.92 (s, 1H), 7.48 (d, J = 7.6 Hz, 1H), 7.43 - 7.35 (m, 1H), 7.29 - 7.16 (m, 3H), 6.94 (d, J = 7.2 Hz, 1H), 6.67 (s, 1H), 5.67 - 6.59 (m, 2H) ppm. ESI-MS m/z calculated value 370.063, observed value 371.2 (M+1) ⁺ . Step 3 :

_K₂CO₃ (38 mg, 0.275 mmol) was added to a stirred _mixture containing 5-(5-chloro-2-sideoxy-1,2-dihydropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (63 mg, 0.170 mmol) and (bromomethyl)cyclopropane (25 μL, 0.258 mmol), and the reaction mixture was stirred at 65°C for 24 hours. Purification by reverse-phase HPLC ( _C18 X-bridge column, 0 to 100% MeCN aqueous solution containing 0.1% _NH4OH ), followed by freeze-drying, yielded 5-(5-chloro-2-(cyclopropylmethoxy)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (compound 262 , 5.7 mg, 8%). ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 8.40 (d, 1H), 8.17 (d, 1H), 7.50 - 7.48 (d, 1H), 7.39 - 7.36 (m, 1H), 7.30 - 7.17 (m, 4H), 6.95 - 6.93 (m, 1H), 5.64 (m, 2H), 4.16 - 4.13 (d, 2H), 1.28 - 1.24 (m, 1H), 0.57 - 0.54 (m, 2H), 0.36 - 0.33 (m, 2H) ppm. ESI-MS m/z calculated value 424.110, observed value 425.4 (M+1) ⁺ . Example 22: Synthesis of (S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-phenylpropyl-2-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 263) Step 1:

2,5-Dichloro-4-fluoropyridine (38 mg, 0.229 mmol) was added to a stirred mixture containing 1-(2-phenylprop-2-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ] _pyridin -4-one ( S20 , 73 mg, 0.225 mmol) and _Cs₂CO₃ (154 mg, 0.473 mmol) in 2-MeTHF (3 mL), and the reaction mixture was heated at 70°C for 3.5 hours. The reaction mixture was cooled to ambient temperature and concentrated under vacuum. The residue was dissolved between DCM and water. The aqueous phase was separated and extracted with DCM (2x). The combined organic phase was dried ( _MgSO₄ ), filtered, and concentrated under vacuum. Purification by rapid chromatography (10 to 50% EtOAc in heptane solution) yielded a white solid 5-(2,5-dichloropyridin-4-yl)-1-(2-phenylprop-2-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (37 mg, 39%). ^¹H NMR (400 MHz, chloroform-d) δ 8.54 (s, 1H), 8.27 (s, 1H), 7.33 - 7.43 (m, 5H), 7.24 - 7.26 (m, 1H), 6.59 (d, J = 7.7 Hz, 1H), 5.63 (d, J = 7.6 Hz, 1H), 2.05 (s, 6H) ppm. ESI-MS m/z calculated value 398.070, observed value 399.1 (M+1) ⁺ . Step 2 :

CsF (20 mg, 0.132 mmol) was added to a stirred solution containing 1 mL of DMSO with 5-(2,5-dichloropyridin-4-yl)-1-(2-phenylprop-2-yl)-1,5-dihydro- 4H -pyrazolo[4,3 -c ]pyridin-4-one (37 mg, 0.088 mmol) and ( S )-2-amino-2-cyclopropylethanol-1-ol (45 mg, 0.445 mmol). The reaction mixture was heated at 150°C for 3 hours under microwave irradiation. Additional CsF (20 mg, 0.132 mmol) was added, and the reaction mixture was further heated at 150°C for 1 hour under microwave irradiation. The mixture was then partially dissolved between water and EtOAc and extracted with EtOAc (2x). The combined organic layer was washed with brine, dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by reverse-phase HPLC ( _C18 CSH column, 20 to 60% MeCN aqueous solution containing 0.1% formic acid) yielded a white solid ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-phenylpropyl-2-yl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (compound 263 , 13 mg, 32%). ¹ H NMR (400 MHz, methanol- d ₄ ) δ 8.20 (s, 1H), 8.03 (s, 1H), 7.36 - 7.42 (m, 2H), 7.30 - 7.35 (m, 1H), 7.27 (d, J = 7.2 Hz, 2H), 6.95 (t, J = 8.1 Hz, 1H), 6.55 (d, J = 0.9 Hz, 1H), 5.84 (d, J = 7.6 Hz, 1H), 3.70 - 3.78 (m, 1H), 3.60 - 3.68 (m, 1H), 3.34 - 3.44 (m, 1H), 2.04 (d, J = 3.2 Hz, 6H), 0.97 - 1.08 (m, 1H), 0.41 - 0.58 (m, 2H), 0.26 - 0.38 (m, 2H) ppm; no interchangeable H was observed. ESI-MS m/z calculated value 463.178, observed value 464.3 (M+1) ⁺ . Example 23: Synthesis of ( S )-5-(3-chloro-6-((1-cyclopropyl-2-hydroxyethyl)amino)-2-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one (compound 264) Step 1:

A mixture containing 2 mL of DMSO (212.04 mg, 0.781 mmol) and CsF (356 mg, 2.344 mmol) was stirred for 1 hour at 150°C under microwave irradiation. 1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3 _- c ]pyridin-4-one (200 mg, 0.781 mmol), _Cs₂CO₃ (763 mg, 2.342 mmol), and DMSO (4 mL) were added, and the reaction mixture was stirred for 3 hours at ambient temperature. The mixture was diluted with water (25 mL) and extracted with EtOAc (x 3). The combined organic extracts were washed with brine, dried ( _MgSO₄ ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO₂ , 10 to 80% EtOAc in heptane) yielded a white solid of 5-(3-chloro-6-fluoro-2-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3 -c ]pyridin-4-one (67 mg, 22%). ^¹H NMR (400 MHz, DMSO - _d⁶ ) δ 8.19 (s, ¹H), 7.53 (d, J = 2.3 Hz, ¹H), 7.51 (d, J = 7.6 Hz, ¹H), 7.36 - 7.43 (m, ¹H), 7.17 - 7.30 (m, 3H), 7.01 (d, J = 7.6 Hz, 1H), 5.65 (d, J = 7.0 Hz, 2H), 2.59 (s, 3H) ppm. ESI-MS m/z calculated value 386.075, observed value 387.1 (M+1) ⁺ . Step 2 :

A solution of DMSO (1 mL) containing 5-(3-chloro-6-fluoro-2-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (67 mg, 0.173 mmol) and ( S )-2-amino-2-cyclopropylethanol-1-ol (88 mg, 0.870 mmol) was heated for 2 hours at 150°C under microwave irradiation. The mixture was diluted with water (20 mL) and extracted with EtOAc (3 x 20 mL). The combined organic layers were washed with brine, dried ( _MgSO₄ ), filtered, and concentrated under vacuum. Purification by reverse-phase chromatography (25 g _C18 column, 10 to 50% MeCN aqueous solution containing 0.1% formic acid, followed by 12 g _C18 column, 10 to 50% MeCN aqueous solution containing 0.1% _NH4OH ) and then rapid chromatography ( _SiO2 , 20 to 100% EtOAc DCM solution) yielded a white solid ( S )-5-(3-chloro-6-((1-cyclopropyl-2-hydroxyethyl)amino)-2-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one (compound 264 , 29 mg, 36%). ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.16 (s, 1H), 7.41 - 7.46 (m, 1H), 7.36 - 7.41 (m, 1H), 7.23 - 7.30 (m, 2H), 7.21 (d, J = 6.5 Hz, 1H), 6.89 (d, J = 7.6 Hz, 1H), 6.74 (br dd, J = 7.8, 4.2 Hz, 1H), 6.46 (s, 1H), 5.63 (d, J = 3.4 Hz, 2H), 4.65 - 4.74 (m, 1H), 3.48 - 3.58 (m, 2H), 2.38 (s, 3H), 1.23 (br s, 1H), 0.93 - 1.04 (m, 1H), 0.28 - 0.47 (m, 3H), 0.15 - 0.27 (m, 1H) ppm. ESI-MS m/z calculated value 467.152, observed value 468.3 (M+1) ⁺ . Example 24 : Synthesis of rac -5-(5- chloro -2-((1-( cyclopropyl -2,2,3,3 -d4 )-2 _- hydroxyethyl -2,2 - _d2 ) amino ) pyridin -4 -yl )-1-((2,6 -difluorophenyl -3,4,5 _-d3 ) methyl _- d2 )-1,5- dihydro - 4H- pyrazolo [4,3- c ] pyridin -4 -one - 7- d ( compound 327) Step 1 :

Under a nitrogen atmosphere, at -78°C, ^nBuLi (2.5 M hexane solution, 1.15 equivalents) was added dropwise over 12 minutes to a stirred mixture containing 1,3-difluorobenzene-2,4,5,6- _d4 (1.00 equivalents) of THF (39 times the volume). The solution was stirred and heated to 0°C over 1.25 hours. The reaction mixture was cooled to -78°C, and the nitrogen inlet was switched to the _CO2 inlet. _CO2 (80 psi, 2.57 equivalents) was introduced into the stainless steel pressure chamber, and the _CO2 was slowly passed into the mixture over 7 minutes. The reaction mixture was gradually heated to ambient temperature over 5 hours. The mixture was cooled to -20°C and quenched by slowly adding 1 M HCl aqueous solution (39 times the volume) to pH 1 over 35 minutes, followed by heating to 0°C. The reaction mixture was extracted with _Et₂O (3 x 41 volumes). The combined organic phase was washed with a saturated NaCl aqueous solution (41 volumes), dried ( _Na₂SO₄ ), and concentrated under vacuum. Purification was carried out overnight by wet milling with hexane (20 _volumes ) at ambient temperature. After filtration, a grayish-white solid of 2,6-difluorobenzoic acid-3,4,5 - _d₃ acid was obtained.

Steps 2 :

In a sealed flask, _K₂CO₃ (1.30 equivalents) and MeI (4.00 equivalents) were added to a stirred solution of anhydrous MeCN (36 volumes) containing 2,6-difluorobenzoic acid-3,4,5- _d³ acid ( _1.00 equivalents). The flask was sealed, and the reaction mixture was stirred at 50°C for 48 hours. The mixture was separated with deionized water (38 volumes) and extracted with _Et₂O (3 x 38 volumes). The combined organic phase was washed with a saturated aqueous solution of NaCl (38 volumes), dried ( _{Na₂SO₄ )} , filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO2 , 100% _Et2O ) yielded methyl 2,6-difluorobenzoate-3,4,5- _d3 as an oily substance.

Steps 3 :

Under a nitrogen atmosphere, LiAD ₄ (1.00 equivalent) was slowly added to a stirred solution containing anhydrous THF (100 volumes) of methyl 2,6-difluorobenzoate-3,4,5- _d3 (1.00 equivalent) at -78°C. The suspension was stirred at -78°C for 1 hour and then at -20°C for 18 hours. The solution was cooled to -78°C and quenched by adding DCl (1 _MD₂O solution, 2.8 volumes). The reaction mixture was heated to 0°C and stirred for 20 minutes. The mixture was diluted with _D₂O (31 volumes) and extracted with _Et₂O (3 x 78 volumes). The combined organic phases were dried ( _Na₂SO₄ ), filtered, and concentrated under vacuum. Purification by rapid chromatography ( _SiO₂ , 10% EtOAc in _hexane solution) yielded an oily (2,6-difluorophenyl-3,4,5 - _d₃ )methane- _d₂ -ol.

Step 4 :

Under a nitrogen atmosphere, at 0°C, a solution of THF (17 times the volume) containing DIAD (1.20 equivalents) was added dropwise to a stirred solution of THF (34 times the volume) containing (2,6-difluorophenyl-3,4,5- _d3 )methane- _d2 -ol (1.20 equivalents), 4-chloro- 1H -pyrazolo[4,3- c ]pyridine (1.20 equivalents), and _PPh3 (1.20 equivalents). The cooling bath was removed, and the reaction mixture was stirred at 21°C for 18 hours. The mixture was then concentrated under vacuum at 30°C. Purification by rapid chromatography (a mixture of _SiO₂ , EtOAc, DCM and hexane in a 15:15:70 ratio) yielded a white solid, 4-chloro-1-((2,6-difluorophenyl-3,4,5 - _d₃ )methyl- _d₂ ) -1H- pyrazolo[4,3- c ]pyridine.

Steps 5 :

Concentrated DCl (35% by weight _D₂O solution, 17.5 equivalents) was added at 21°C to a stirred solution containing 10 times the volume of _D₂O with 1.00 equivalent of 4-chloro-1-((2,6-difluorophenyl-3,4,5 - _d₃ )methyl- _d₂ ) -1H- pyrazolo[4,3- c ]pyridine, and the reaction mixture was heated at 105°C for 27 hours. The turbid suspension was filtered, and the filter cake was washed with _D₂O (2 x 5 times the volume). The solid was vacuum dried to obtain a grayish-white solid, 1-((2,6-difluorophenyl-3,4,5 - _d3 )methyl- _d2 )-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one-5,7- _d2 .

Steps 6 :

_Cs₂CO₃ (2.00 equivalents) was added to a stirred _solution containing 1-((2,6-difluorophenyl-3,4,5 - _d₃ )methyl- _d₂ )-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one-5,7- _d₂ (1.00 equivalents) and 2,5-dichloro-4-fluoropyridine (1.20 equivalents) in THF (59 times the volume), and the suspension was stirred at 35°C for 24 hours. Purification was performed by rapid chromatography ( _SiO2 , 50% EtOAc in hexane solution, followed by 20% EtOAc in DCM solution), followed by grinding from n-hexane to obtain a white solid 5-(2,5-dichloropyridin-4-yl)-1-((2,6-difluorophenyl-3,4,5 _-d3 ) methyl- _d2 )-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one-7- d .

Steps 7 :

In a vial, a stirred solution containing 5-(2,5-dichloropyridin-4-yl)-1-((2,6-difluorophenyl-3,4,5 -d3 )methyl- _d2 )-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one-7- d (1 equivalent _{) and 2-amino-2-(cyclopropyl-2,2,3,3,d4 )} ethanol -1,1 - _d2-1 -ol ( Int-A26 , 4 equivalents) in thion (3 times the volume) was purged with nitrogen. The vial was sealed and heated at 150°C for 72 hours. The reaction mixture was then cooled to ambient temperature. The mixture was diluted with 2 M HCl (5 volumes) and extracted with EtOAc (6 volumes). The combined organic phases were washed with 2 M HCl (3 volumes). The combined aqueous layers were alkalized with 2 N NaOH (9 volumes). EtOH (3 volumes) was added, and the mixture was stirred overnight at ambient temperature. The resulting precipitate was filtered, washed with a 4:1 mixture of water and EtOH (3 x 2 volumes), and vacuum dried overnight at 50°C. The filtrate was transferred to a feed funnel and extracted with EtOAc (3 x 8 volumes). The combined organic extracts were washed with water (8 times the volume) and brine (8 times the volume), dried ( _MgSO4 ), filtered, and concentrated under vacuum. Purification by reverse-phase chromatography (60 g C18 _Sfar Duo column, 10 to 100% MeCN aqueous solution) yielded a second batch of solids. The solids from two batches were combined, recrystallized from EtOH (14 times volume) and heptane (28 times volume), and vacuum dried at 50°C for the entire week to give rac -5-(5-chloro-2-((1-(cyclopropyl-2,2,3,3 -d4 )-2-hydroxyethyl-2,2 -d2 ₎ amino)pyridin-4-yl)-1-((2,6-difluorophenyl- _{3,4,5 -d3} ) methyl- d2 )-1,5-dihydro- 4H -pyrazolo[4,3- _c ] pyridin-4-one-7- d (compound 327 ) .

The mirror isomer of rac -5-(5-chloro-2-((1-(cyclopropyl-2,2,3,3 -d4 )-2-hydroxyethyl-2,2 -d2 ₎ amino)pyridin-4-yl)-1 _- ((2,6-difluorophenyl- _3,4,5-d3 ) _methyl-d2 ) -1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one-7- d (compound 327 ) can be separated by chiral SFC using a method similar to that disclosed in this specification.

In step 1, _CO2 can be replaced by ¹³ _CO2 or ¹⁴ _CO2 .

The following compounds were prepared using methods similar to those disclosed in this specification. Table 14: Compounds prepared using similar methods Compound number Compound structure / Compound name Starting materials SFC conditions (if applicable) LC/MS NMR (displacement in ppm) 15 5-(5-chloro-2-((1,3-dihydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 459.086; observed value: 460.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.20 (d, J = 0.8 Hz, 1H), 8.14 (s, 1H), 7.54 - 7.49 (m, 1H), 7.44 (d, J = 7.5 Hz, 1H), 7.41 - 7.30 (m, 2H), 7.12 - 7.06 (m, 1H), 6.90 (dd, J = 7.6, 0.9 Hz, 1H), 6.75 (d, J = 7.9 Hz, 1H), 6.69 (s, 1H), 5.73 - 5.61 (m, 2H), 4.71 - 4.62 (m, 2H), 3.93 - 3.89 (m, 1H), 3.58 - 3.44 (m, 4H) ppm. 16 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 469.107; observed value: 470.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.20 (dd, J = 1.9, 0.8 Hz, 1H), 8.10 (s, 1H), 7.55 - 7.42 (m, 2H), 7.42 - 7.31 (m, 2H), 7.10 (dd, J = 7.5, 2.0 Hz, 1H), 6.93 - 6.86 (m, 2H), 6.63 (d, J = 1.2 Hz, 1H), 5.68 (d, J = 5.1 Hz, 2H), 4.70 (dt, J = 19.2, 5.4 Hz, 1H), 3.60 - 3.47 (m, 2H), 1.06 - 0.96 (m, 1H), 0.52 - 0.07 (m, 4H) ppm; no interchangeable H was observed. 17 5-(5-chloro-2-((2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 429.076; observed value: 430.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 (d, J = 0.8 Hz, 1H), 8.15 (s, 1H), 7.54 - 7.49 (m, 1H), 7.44 (d, J = 7.5 Hz, 1H), 7.41 - 7.30 (m, 2H), 7.11 - 7.05 (m, 1H), 7.03 (t, J = 5.7 Hz, 1H), 6.89 (dd, J = 7.5, 0.9 Hz, 1H), 6.63 (s, 1H), 5.73 - 5.61 (m, 2H), 4.72 (t, J = 5.4 Hz, 1H), 3.57 - 3.48 (m, 2H), 3.40 - 3.31 (m, 2H) ppm. 18 rac -5-(5-chloro-2-((4,4-difluoro-1-hydroxybutyl-2-yl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 493.088; observed value: 494.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.23 - 8.15 (m, 2H), 7.55 - 7.49 (m, 1H), 7.45 (dd, J = 7.5, 0.6 Hz, 1H), 7.41 - 7.30 (m, 2H), 7.09 (dd, J = 7.4, 1.9 Hz, 1H), 7.01 (t, J = 8.1 Hz, 1H), 6.90 (ddd, J = 7.6, 3.8, 0.9 Hz, 1H), 6.62 (d, J = 5.8 Hz, 1H), 6.30 - 5.92 (m, 1H), 5.67 (d, J = 4.7 Hz, 2H), 4.98 - 4.89 (m, 1H), 4.16 - 4.12 (m, 1H), 3.56 - 3.49 (m, 1H), 3.45 - 3.31 (m, 1H), 2.26 - 2.00 (m, 2H) ppm. 19 5-(5-chloro-2-(((1-methyl- 1H- 1,2,3-triazol-5-yl)methyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 480.098; observed value: 481.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.23 (s, 1H), 8.19 (d, J = 0.8 Hz, 1H), 7.59 (s, 1H), 7.57 - 7.48 (m, 2H), 7.46 (d, J = 7.6 Hz, 1H), 7.41 - 7.30 (m, 2H), 7.11 - 7.05 (m, 1H), 6.91 (dd, J = 7.5, 0.9 Hz, 1H), 6.70 (s, 1H), 5.67 (d, J = 6.3 Hz, 2H), 4.61 (qd, J = 15.8, 5.7 Hz, 2H), 4.03 (s, 3H) ppm. 20 Reverse rac -5-(5-chloro-2-((( 1S, 2S )-2-hydroxycyclobutyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 455.092; observed value: 456.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 (d, J = 0.8 Hz, 1H), 8.15 (s, 1H), 7.52 (dd, J = 7.7, 1.5 Hz, 1H), 7.44 (dd, J = 7.5, 3.7 Hz, 1H), 7.40 - 7.31 (m, 3H), 7.11 - 7.06 (m, 1H), 6.90 (dd, J = 7.5, 0.9 Hz, 1H), 6.58 (s, 1H), 5.73 - 5.61 (m, 2H), 5.28 (dd, J = 12.7, 7.1 Hz, 1H), 4.01 - 3.97 (m, 1H), 3.87 (p, J = 7.6 Hz, 1H), 2.04 - 1.92 (m, 2H), 1.42 (p, J = 10.0 Hz, 1H), 1.25 - 1.16 (m, 1H) ppm. twenty one rac -5-(5-chloro-2-(((5-sideoxypyrrolidin-3-yl)methyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 482.102; observed value: 483.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 (d, J = 0.8 Hz, 1H), 8.17 (s, 1H), 7.54 - 7.48 (m, 2H), 7.46 (d, J = 7.4 Hz, 1H), 7.41 - 7.30 (m, 2H), 7.25 - 7.19 (m, 1H), 7.11 - 7.06 (m, 1H), 6.90 (dd, J = 7.6, 0.9 Hz, 1H), 6.61 (s, 1H), 5.73 - 5.61 (m, 2H), 3.37 - 3.23 (m, 3H), 3.04 - 2.97 (m, 1H), 2.69 - 2.64 (m, 1H), 2.31 - 2.22 (m, 1H), 1.95 (ddd, J = 16.7, 6.1, 1.7 Hz, 1H ppm. twenty two rac -3-((5-chloro-4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)pentanilonitrile S1 ESI-MS calculated m/z value: 466.108; observed value: 467.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.21 - 8.19 (m, 1H), 7.55 - 7.45 (m, 2H), 7.41 - 7.30 (m, 2H), 7.26 - 7.20 (m, 1H), 7.10 (dd, J = 7.5, 1.9 Hz, 1H), 6.91 (dt, J = 7.5, 1.1 Hz, 1H), 6.69 (s, 1H), 6.61 (s, 1H), 5.73 - 5.62 (m, 2H), 4.10 - 3.94 (m, 1H), 2.93 - 2.82 (m, 1H), 2.80 - 2.70 (m, 1H), 1.71 - 1.59 (m, 2H), 0.98 - 0.91 (m, 3H) ppm. twenty three ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 453.137; observed value: 454.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (dd, J = 2.0, 0.8 Hz, 1H), 8.08 (s, 1H), 7.51 - 7.35 (m, 2H), 7.31 - 7.17 (m, 3H), 6.94 - 6.85 (m, 2H), 6.62 (d, J = 1.0 Hz, 1H), 5.63 (d, J = 3.8 Hz, 2H), 4.69 (dt, J = 18.4, 5.3 Hz, 1H), 3.57 - 3.45 (m, 2H), 1.00 (s, 1H), 0.52 - 0.11 (m, 4H) ppm. twenty four 5-(5-bromo-2-((1,3-dihydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 503.036; observed value: 506.0 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.21 (s, 1H), 8.19 (d, J = 0.8 Hz, 1H), 7.54 - 7.49 (m, 1H), 7.44 - 7.30 (m, 3H), 7.13 - 7.07 (m, 1H), 6.89 (dd, J = 7.6, 0.9 Hz, 1H), 6.77 (d, J = 7.9 Hz, 1H), 6.69 (s, 1H), 5.73 - 5.61 (m, 2H), 4.67 (dt, J = 13.1, 5.5 Hz, 2H), 3.93 - 3.89 (m, 1H), 3.58 - 3.44 (m, 4H) ppm. 25 ( S )-5-(5-chloro-2-((1-hydroxybutyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 441.137; observed value: 442.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 0.8 Hz, 1H), 8.12 (s, 1H), 7.47 (t, J = 7.6 Hz, 1H), 7.43 - 7.36 (m, 1H), 7.31 - 7.17 (m, 3H), 6.91 (d, J = 7.6 Hz, 1H), 6.77 (t, J = 7.4 Hz, 1H), 6.61 (d, J = 1.1 Hz, 1H), 5.64 (s, 1H), 5.63 (s, 1H), 4.66 (dt, J = 13.8, 5.5 Hz, 1H), 3.83 - 3.79 (m, 1H), 3.52 - 3.44 (m, 1H), 3.42 - 3.31 (m, 1H), 1.74 - 1.61 (m, 1H), 1.50 - 1.37 (m, 1H), 0.90 (td, J = 7.4, 3.1 Hz, 3H) ppm. 26 ( S )-1-(2-chlorobenzyl)-5-(2-((1-cyclopropyl-2-hydroxyethyl)amino)-5-fluoropyridin-4-yl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 453.137; observed value: 454.4 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 7.97 (s, 1H), 7.81 (d, J = 1.8 Hz, 1H), 7.38 - 7.22 (m, 2H), 7.12 (dtd, J = 19.7, 7.4, 1.6 Hz, 2H), 6.83 (dd, J = 7.5, 1.9 Hz, 1H), 6.68 (d, J = 7.6 Hz, 1H), 6.43 - 6.29 (m, 2H), 5.44 (s, 2H), 4.44 (d, J = 8.9 Hz, 1H), 3.39 - 3.17 (m, 3H), 0.29 - 0.10 (m, 5H) ppm. 27 ( R )-5-(5-chloro-2-((1-(1-methyl- 1H- 1,2,3-triazol-5-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS m/z calculated value: 478.143, observed value: 479.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.21 (d, J = 1.2 Hz, 1H), 8.16 (dd, J = 1.8, 0.8 Hz, 1H), 7.66 (d, J = 4.8 Hz, 1H), 7.54 - 7.36 (m, 3H), 7.31 - 7.15 (m, 3H), 6.92 (d, J = 7.5 Hz, 1H), 6.63 (d, J = 1.2 Hz, 1H), 5.63 (s, 2H), 5.33 (q, J = 6.7 Hz, 1H), 4.01 (s, 3H), 1.52 (dd, J = 6.8, 5.0 Hz, 3H) ppm. 28 rac -6-(((5-chloro-4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)methyl) 3-oxoline-3-one S1 ESI-MS m/z calculated value: 498.097, observed value: 499.3 (M+1) ⁺ . 29 5-(5-chloro-2-(((6-sideoxy-1,6-dihydropyridin-3-yl)methyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS m/z calculated value: 492.087, observed value: 493.3 (M+1) ⁺ . 30 Peak 1 rel- ( R )-5-(5-chloro-2-((4,4-difluoro-1-hydroxybutyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralcel® OD-H column, 5 µm particle size, 25 cm x 10 mm, purchased from Daicel (mobile phase: 45% MeOH (topped with 20 mM ammonia), 55% _CO2 ; flow rate 10 mL/min); rt = 3.84 min. ESI-MS calculated m/z value: 477.118; observed value: 478.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 - 8.14 (m, 2H), 7.46 (dd, J = 7.6, 0.8 Hz, 1H), 7.44 - 7.36 (m, 1H), 7.31 - 7.17 (m, 3H), 7.02 (t, J = 8.2 Hz, 1H), 6.92 (dd, J = 7.6, 3.1 Hz, 1H), 6.62 (s, 1H), 6.29 - 5.92 (m, 1H), 5.63 (d, J = 3.5 Hz, 2H), 4.93 (dt, J = 14.9, 5.5 Hz, 1H), 4.16 - 4.12 (m, 1H), 3.56 - 3.49 (m, 1H), 3.45 - 3.33 (m, 1H), 2.25 - 2.16 (m, 1H), 2.11 - 1.95 (m, 1H) ppm. 31 Peak 2 rel- ( S )-5-(5-chloro-2-((4,4-difluoro-1-hydroxybutyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralcel® OD-H column, 5 µm particle size, 25 cm x 10 mm, purchased from Daicel (mobile phase: 45% MeOH (topped with 20 mM ammonia), 55% _CO2 ; flow rate 10 mL/min); rt = 4.88 min. ESI-MS calculated m/z value: 477.118; observed value: 478.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 - 8.15 (m, 2H), 7.46 (dd, J = 7.5, 0.8 Hz, 1H), 7.44 - 7.36 (m, 1H), 7.31 - 7.17 (m, 3H), 7.01 (t, J = 8.3 Hz, 1H), 6.92 (dd, J = 7.6, 3.1 Hz, 1H), 6.62 (s, 1H), 6.27 - 5.97 (m, 1H), 5.63 (d, J = 3.5 Hz, 2H), 4.93 (dt, J = 14.8, 5.5 Hz, 1H), 4.16 - 4.12 (m, 1H), 3.55 - 3.49 (m, 1H), 3.45 - 3.33 (m, 1H), 2.25 - 2.14 (m, 1H), 2.10 - 1.94 (m, 1H) ppm. 32 Peak 1: Forward or Reverse rel- 5-(5-chloro-2-((3-(hydroxymethyl)tetrahydro- 2H- piperan-4-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 25% MeOH (topped with 20 mM ammonia), 75% _CO2 ; flow rate 100 mL/min); rt = 5.64 min. ESI-MS calculated m/z value: 483.147; observed value: 484.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.8 Hz, 2H), 7.48 (dd, J = 8.9, 7.5 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.30 - 7.18 (m, 3H), 7.03 (dd, J 3.82 - 3.71 (m, 2H), 3.54 - 3.46 (m, 4H), 2.03 - 1.99 (m, 1H), 1.65 - 1.61 (m, 2H) ppm. 33 Peak 2: Reverse or forward rel- 5-(5-chloro-2-((3-(hydroxymethyl)tetrahydro- 2H- piperan-4-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 25% MeOH (topped with 20 mM ammonia), 75% _CO2 ; flow rate 100 mL/min); rt = 8.73 min. ESI-MS calculated m/z value: 483.147; observed value: 484.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.9 Hz, 2H), 7.48 (dd, J = 8.9, 7.5 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.31 - 7.17 (m, 3H), 7.03 (dd, J = 7.8, 3.6 Hz, 1H), 6.92 (d, J = 7.6 Hz, 1H), 6.69 (s, 1H), 5.64 (d, J = 2.5 Hz, 2H), 4.51 - 4.47 (m, 1H), 4.22 - 4.18 (m, 1H), 3.82 - 3.75 (m, 2H), 3.54 - 3.46 (m, 4H), 2.04 - 1.98 (m, 1H), 1.66 - 1.60 (m, 2H) ppm. 34 5-(5-chloro-2-((4-(hydroxymethyl)tetrahydro- 2H- piperan-4-yl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 499.118; observed value: 500.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.20 (d, J = 0.8 Hz, 1H), 8.10 (s, 1H), 7.52 (dd, J = 7.6, 1.6 Hz, 1H), 7.46 (d, J = 7.5 Hz, 1H), 7.41 - 7.31 (m, 2H), 7.09 (dd, J = 7.5, 1.9 Hz, 1H), 6.91 (dd, J = 7.5, 0.9 Hz, 1H), 6.76 (s, 1H), 6.60 (s, 1H), 5.67 (d, J = 2.2 Hz, 2H), 4.80 (t, J = 5.6 Hz, 1H), 3.74 (dd, J = 10.7, 5.5 Hz, 1H), 3.67 - 3.61 (m, 3H), 3.60 - 3.52 (m, 2H), 2.19 (d, J = 13.8 Hz, 1H), 2.10 (d, J = 13.9 Hz, 1H), 1.71 - 1.65 (m, 2H) ppm. 35 rac -5-(5-chloro-2-((1-cyclopropyl-2-hydroxypropyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 467.152; observed value: 468.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (dd, J = 3.0, 0.8 Hz, 1H), 8.07 (d, J = 7.5 Hz, 1H), 7.51 - 7.44 (m, 1H), 7.43 - 7.37 (m, 1H), 7.30 - 7.19 (m, 3H), 6.92 (d, J = 7.5 Hz, 1H), 6.85 (t, J = 7.8 Hz, 0.8H), 6.75 (d, J = 9.0 Hz, 0.2H), 6.70 (d, J = 1.8 Hz, 0.2H), 6.66 (d, J = 2.2 Hz, 0.8H), 5.64 (d, J = 3.0 Hz, 2H), 4.73 - 4.63 (m, 1H), 3.80 (ddt, J = 16.2, 10.9, 5.7 Hz, 1H), 3.45 (s, 1H), 1.22 - 1.00 (m, 4H), 0.54 - 0.40 (m, 1H), 0.37 - 0.30 (m, 1H), 0.29 - 0.18 (m, 2H) ppm. 36 rel- ( S ^* )-6-(( R )-1-((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)-2-hydroxyethyl) 3-oxoline-3-one S2 ESI-MS calculated m/z value: 512.138; observed value: 513.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (dd, J = 7.3, 6.4 Hz, 2H), 8.09 (d, J = 4.1 Hz, 0.2H), 8.00 - 7.92 (m, 0.8H), 7.52 - 7.45 (m, 1H), 7.40 (tdd, J = 7.5, 5.4, 1.9 Hz, 1H), 7.32 - 7.18 (m, 3H), 7.13 - 7.07 (m, 0.2H), 7.00 (t, J = 7.4 Hz, 0.8H), 6.93 (d, J = 7.5 Hz, 1H), 6.70 (d, J = 1.3 Hz, 0.7H), 6.68 (d, J = 1.7 Hz, 0.3H), 5.64 (d, J = 3.4 Hz, 2H), 4.91 - 4.78 (m, 1H), 4.17 (s, 1H), 4.12 - 3.93 (m, 2H), 3.87 - 3.77 (m, 1H), 3.64 (d, J = 9.0 Hz, 1H), 3.60 - 3.51 (m, 1H), 3.47 - 3.34 (m, 1H), 3.29 - 3.18 (m, 1H) ppm. 37 ( S )-5-(5-chloro-2-(((5-sideoxypyrrolidin-3-yl)methyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 482.102; observed value: 483.2 (M+1) ⁺ . ¹ H NMR (500 MHz, methanol - _{d 4} ) δ 8.23 (d, J = 0.9 Hz, 1H), 8.16 (s, 1H), 7.49 (dd, J = 7.9, 1.4 Hz, 1H), 7.38 - 7.29 (m, 3H), 7.08 (dd, J = 7.6, 1.8 Hz, 1H), 6.83 (dd, J = 7.5, 0.9 Hz, 1H), 6.64 (s, 1H), 5.71 (d, J = 3.7 Hz, 2H), 3.54 (dd, J = 10.1, 7.8 Hz, 1H), 3.48 - 3.43 (m, 2H), 3.22 (dd, J = 10.2, 5.3 Hz, 1H), 2.86 (dp, J = 14.3, 7.3 Hz, 1H), 2.49 (ddd, J = 17.1, 8.9, 2.5 Hz, 1H), 2.19 (dd, J = 17.1, 6.3 Hz, 1H) ppm; no interchangeable H was observed. 38 ( R )-5-(5-chloro-2-(((5-sideoxypyrrolidin-3-yl)methyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 482.102; observed value: 483.2 (M+1) ⁺ . ¹ H NMR (500 MHz, methanol - _{d 4} ) δ 8.23 (d, J = 0.8 Hz, 1H), 8.16 (s, 1H), 7.49 (dd, J = 7.9, 1.4 Hz, 1H), 7.38 - 7.28 (m, 3H), 7.08 (dd, J = 7.6, 1.8 Hz, 1H), 6.83 (dd, J = 7.5, 0.9 Hz, 1H), 6.64 (d, J = 0.5 Hz, 1H), 5.71 (d, J = 3.7 Hz, 2H), 3.54 (dd, J = 10.1, 7.9 Hz, 1H), 3.48 - 3.42 (m, 2H), 3.22 (dd, J = 10.2, 5.3 Hz, 1H), 2.92 - 2.81 (m, J = 7.1 Hz, 1H), 2.49 (ddd, J = 17.0, 8.8, 2.5 Hz, 1H), 2.18 (dd, J = 17.1, 6.3 Hz, 1H) ppm; no interchangeable H was observed. 39 Peak 1 rel- 5-(5-chloro-2-((( 3R, 4S) -4-(hydroxymethyl)tetrahydrofuran-3-yl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S1 ^Chiralcel® OJ column, 5 µm particle size, 25 cm x 10 mm, purchased from Daicel (mobile phase: 33% 1:1 MeOH: ⁱ PrOH (added with 20 mM ammonia), 67% _CO2 ; flow rate 10 mL/min); rt = 4.08 min. ESI-MS calculated m/z value: 485.102; observed value: 486.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.22 - 8.15 (m, 2H), 7.52 (dd, J = 7.7, 1.5 Hz, 1H), 7.46 (dd, J = 7.5, 1.3 Hz, 1H), 7.41 - 7.28 (m, 3H), 7.09 (dd, J = 7.5, 1.9 Hz, 1H), 6.90 (dt, J = 7.6, 1.0 Hz, 1H), 6.62 (d, J = 1.1 Hz, 1H), 5.73 - 5.62 (m, 2H), 4.80 - 4.77 (m, 1H), 4.13 - 4.09 (m, 1H), 3.97 - 3.90 (m, 2H), 3.58 - 3.45 (m, 2H), 3.44 - 3.39 (m, 1H), 2.33 - 2.22 (m, 1H) ppm; no interchangeable H was observed. 40 Peak 2 rel- 5-(5-chloro-2-((( 3S , 4R ) -4- (hydroxymethyl)tetrahydrofuran-3-yl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S1 ^Chiralcel® OJ column, 5 µm particle size, 25 cm x 10 mm, purchased from Daicel (mobile phase: 33% 1:1 MeOH: ⁱ PrOH (added with 20 mM ammonia), 67% _CO2 ; flow rate 10 mL/min); rt = 4.82 min. ESI-MS calculated m/z value: 485.102; observed value: 486.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.20 (d, J = 0.8 Hz, 1H), 8.18 (s, 1H), 7.52 (dd, J = 7.7, 1.5 Hz, 1H), 7.46 (dd, J = 7.5, 1.3 Hz, 1H), 7.41 - 7.28 (m, 3H), 7.09 (dd, J = 7.5, 1.9 Hz, 1H), 6.90 (dt, J = 7.5, 1.0 Hz, 1H), 6.62 (d, J = 1.1 Hz, 1H), 5.73 - 5.62 (m, 2H), 4.80 - 4.77 (m, 1H), 4.13 - 4.08 (m, 1H), 3.97 - 3.90 (m, 2H), 3.58 - 3.45 (m, 2H), 3.44 - 3.37 (m, 1H), 2.31 - 2.23 (m, 1H) ppm; no interchangeable H was observed. 41 rac -5-(5-chloro-2-((3,4-dihydroxybutyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 473.102; observed value: 474.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 (d, J = 0.9 Hz, 1H), 8.15 (s, 1H), 7.51 (dd, J = 7.8, 1.4 Hz, 1H), 7.45 (dd, J = 7.5, 1.9 Hz, 1H), 7.41 - 7.30 (m, 2H), 7.08 (dd, J = 7.6, 1.9 Hz, 1H), 6.98 (t, J = 5.5 Hz, 1H), 6.92 - 6.87 (m, 1H), 6.58 (s, 1H), 5.73 - 5.61 (m, 2H), 4.55 - 4.46 (m, 2H), 3.55 - 3.49 (m, 1H), 3.39 - 3.35 (m, 1H), 3.29 - 3.22 (m, 1H), 1.78 - 1.71 (m, 1H), 1.50 - 1.42 (m, 1H) ppm; no interchangeable H was observed. 42 Peak 1 rel- 5-(5-chloro-2-(( 1S , 2S )-2-hydroxycyclobutyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ( R , R ) - Whelk- ^O® 1 column, 5 µm particle size, 25 cm x 21.1 mm, purchased from Regis Technologies (mobile phase: 40% 1:1 MeOH: ⁱ PrOH (supplemented with 20 mM ammonia), 60% _CO2 ; flow rate 100 mL/min); rt = 4.91 min ESI-MS calculated m/z value: 455.092; observed value: 456.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 (d, J = 0.8 Hz, 1H), 8.15 (s, 1H), 7.52 (dd, J = 7.7, 1.5 Hz, 1H), 7.44 (dd, J = 7.5, 3.7 Hz, 1H), 7.40 - 7.30 (m, 3H), 7.08 (dd, J = 7.3, 1.9 Hz, 1H), 6.90 (dd, J = 7.5, 0.8 Hz, 1H), 6.58 (s, 1H), 5.73 - 5.61 (m, 2H), 5.30 - 5.26 (m, 1H), 4.01 - 3.97 (m, 1H), 3.91 - 3.82 (m, 1H), 2.04 - 1.92 (m, 2H), 1.48 - 1.36 (m, 1H), 1.27 - 1.10 (m, 1H) ppm. 43 Peak 2 rel- 5-(5-chloro-2-((( 1R , 2R ) -2 -hydroxycyclobutyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ( R , R ) - Whelk- ^O® 1 column, 5 µm particle size, 25 cm x 21.1 mm, purchased from Regis Technologies (mobile phase: 40% 1:1 MeOH: ⁱ PrOH (supplemented with 20 mM ammonia), 60% _CO2 ; flow rate 100 mL/min); rt = 5.87 min ESI-MS calculated m/z value: 455.092; observed value: 456.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 (d, J = 0.8 Hz, 1H), 8.15 (s, 1H), 7.52 (dd, J = 7.8, 1.5 Hz, 1H), 7.44 (dd, J = 7.5, 3.6 Hz, 1H), 7.40 - 7.30 (m, 3H), 7.08 (dd, J = 7.5, 1.9 Hz, 1H), 6.90 (dd, J = 7.6, 0.9 Hz, 1H), 6.58 (s, 1H), 5.73 - 5.61 (m, 2H), 4.01 - 3.97 (m, 1H), 3.87 (q, J = 7.8 Hz, 1H), 2.03 - 1.94 (m, 2H), 1.48 - 1.36 (m, 1H), 1.23 - 1.19 (m, 1H) ppm; no interchangeable H was observed. 44 ( S )-2-((5-(5-chloro-2-((1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-4-sideoxy-4,5-dihydro- 1H- pyrazolo[4,3- c ]pyridin-1-yl)methyl)benzonitrile SB1 ESI-MS calculated m/z value: 434.126; observed value: 435.0 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (s, 1H), 8.14 (s, 1H), 7.88 (dd, J = 7.8, 1.3 Hz, 1H), 7.71 (td, J = 7.7, 1.4 Hz, 1H), 7.59 - 7.50 (m, 1H), 7.40 (d, J = 7.5 Hz, 1H), 7.33 (d, J = 7.9 Hz, 1H), 6.89 (dd, J = 7.6, 0.9 Hz, 1H), 6.63 (s, 1H), 6.52 (d, J = 7.8 Hz, 1H), 5.76 (s, 2H), 4.47 (s, 1H), 3.96 (hept, J = 6.3 Hz, 1H), 3.56 - 3.47 (m, 1H), 3.42 - 3.36 (m, 1H), 1.17 (d, J = 6.5 Hz, 3H) ppm. 45 5-(5-chloro-2-(((1 s ,3 s )-3-hydroxy-1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 485.102; observed value: 486.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 (d, J = 0.8 Hz, 1H), 8.10 (s, 1H), 7.52 (dd, J = 7.7, 1.5 Hz, 1H), 7.44 (d, J = 7.5 Hz, 1H), 7.40 - 7.29 (m, 2H), 7.17 (s, 1H), 7.09 (dd, J = 7.4, 1.9 Hz, 1H), 6.89 (dd, J = 7.6, 0.9 Hz, 1H), 6.52 (s, 1H), 5.69 (d, J = 15.8 Hz, 1H), 5.65 (d, J = 15.8 Hz, 1H), 4.97 (s, 1H), 4.84 (s, 1H), 4.00 - 3.91 (m, 1H), 3.58 (d, J = 10.8 Hz, 1H), 3.51 (d, J = 10.8 Hz, 1H), 2.65 - 2.56 (m, 2H), 1.94 - 1.86 (m, 2H) ppm. 46 ( R )-5-(5-chloro-2-((1,3-dihydroxy-3-methylbut-2-yl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 487.118; observed value: 488.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.20 (s, 1H), 8.10 (s, 1H), 7.52 (dd, J = 7.7, 1.5 Hz, 1H), 7.45 (dd, J = 16.5, 7.5 Hz, 1H), 7.42 - 7.29 (m, 2H), 7.11 - 7.06 (m, 1H), 6.90 (d, J = 7.5 Hz, 1H), 6.75 (s, 1H), 6.71 - 6.61 (m, 1H), 5.77 - 5.60 (m, 2H), 4.60 (d, J = 32.6 Hz, 1H), 4.51 (d, J = 15.3 Hz, 1H), 3.98 (s, 1H), 3.83 - 3.67 (m, 1H), 3.62 - 3.46 (m, 1H), 1.17 (d, J = 5.1 Hz, 3H), 1.11 (d, J = 5.9 Hz, 3H) ppm. 47 5-(5-chloro-2-((( 1r , 3r )-3-hydroxy-1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 485.102; observed value: 486.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.20 (d, J = 0.8 Hz, 1H), 8.13 (s, 1H), 7.52 (dd, J = 7.7, 1.5 Hz, 1H), 7.46 (d, J = 7.5 Hz, 1H), 7.38 (td, J = 7.6, 2.0 Hz, 1H), 7.35 - 7.30 (m, 1H), 7.09 (dd, J = 7.5, 1.9 Hz, 1H), 7.04 (s, 1H), 6.89 (dd, J = 7.6, 0.9 Hz, 1H), 6.56 (s, 1H), 5.72 - 5.66 (m, 1H), 5.69 - 5.62 (m, 1H), 4.94 (d, J = 5.9 Hz, 1H), 4.80 (t, J = 5.7 Hz, 1H), 4.20 - 4.14 (m, 1H), 3.63 (dd, J = 10.7, 5.6 Hz, 1H), 3.56 (dd, J = 10.7, 5.6 Hz, 1H), 2.42 - 2.34 (m, 2H), 2.04 - 1.95 (m, 2H) ppm. 48 5-(5-chloro-2-((3-hydroxypropyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS m/z calculated value: 427.121, observed value: 426.1 (M⁻¹) ^- . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 - 8.12 (m, 2H), 7.46 (d, J = 7.5 Hz, 1H), 7.43 - 7.35 (m, 1H), 7.30 - 7.16 (m, 4H), 7.00 (t, J = 5.6 Hz, 1H), 6.91 (dt, J = 7.6, 0.6 Hz, 1H), 6.57 (s, 1H), 5.63 (d, J = 5.2 Hz, 2H), 4.46 (t, J = 5.2 Hz, 1H), 3.52 - 3.44 (m, 2H), 3.30 - 3.27 (m, 1H), 1.73 - 1.64 (m, 2H) ppm. 49 5-(5-chloro-2-((( 2R , 3R )-1,3-dihydroxybutyl-2-yl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 473.102; observed value: 474.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.20 (d, J = 0.8 Hz, 1H), 8.11 (s, 1H), 7.52 (dd, J = 7.7, 1.6 Hz, 1H), 7.46 (dd, J = 10.9, 7.5 Hz, 1H), 7.36 (dtd, J = 17.5, 7.5, 1.7 Hz, 2H), 7.12 - 7.06 (m, 1H), 6.89 (dd, J = 7.6, 0.9 Hz, 1H), 6.76 (d, J = 1.2 Hz, 1H), 6.59 (d, J = 8.3 Hz, 1H), 5.73 - 5.62 (m, 2H), 4.68 (dd, J = 7.2, 4.6 Hz, 1H), 4.65 - 4.58 (m, 1H), 4.03 - 3.99 (m, 1H), 3.94 - 3.78 (m, 1H), 3.57 - 3.39 (m, 2H), 1.08 (t, J = 6.1 Hz, 3H) ppm. 50 Peak 1 rel- 5-(5-chloro-2-((( 3S , 4R ) -4- (hydroxymethyl)tetrahydrofuran-3-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralcel® OJ column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 17% MeOH (topped with 20 mM ammonia), 83% _CO2 ; flow rate 100 mL/min); rt = 5.30 min. ESI-MS calculated m/z value: 469.132; observed value: 470.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 - 8.14 (m, 2H), 7.47 (dd, J = 7.5, 1.3 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.33 - 7.17 (m, 4H), 6.92 (d, J = 7.5 Hz, 1H), 6.61 (d, J = 1.1 Hz, 1H), 5.63 (d, J = 3.7 Hz, 2H), 4.80 - 4.76 (m, 1H), 4.13 - 4.09 (m, 1H), 3.97 - 3.89 (m, 2H), 3.61 - 3.45 (m, 3H), 3.44 - 3.37 (m, 1H), 2.33 - 2.22 (m, 1H) ppm. 51 Peak 2 rel- 5-(5-chloro-2-((( 3R , 4S ) -4- (hydroxymethyl)tetrahydrofuran-3-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralcel® OJ column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 17% MeOH (topped with 20 mM ammonia), 83% _CO2 ; flow rate 100 mL/min); rt = 6.59 min. ESI-MS calculated m/z value: 469.132; observed value: 470.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 - 8.14 (m, 2H), 7.47 (dd, J = 7.5, 1.3 Hz, 1H), 7.43 - 7.36 (m, 1H), 7.33 - 7.17 (m, 4H), 6.92 (d, J = 7.4 Hz, 1H), 6.61 (d, J = 1.0 Hz, 1H), 5.63 (d, J = 3.7 Hz, 2H), 4.80 - 4.76 (m, 1H), 4.13 - 4.09 (m, 1H), 3.97 - 3.89 (m, 2H), 3.58 - 3.45 (m, 3H), 3.41 (s, 1H), 2.33 - 2.22 (m, 1H) ppm. 52 Peak 1 rel- 5-(5-chloro-2-((( 3S , 4S )-4-(hydroxymethyl)tetrahydrofuran-3-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ( R , R )-Whelk- ^O® 1 column, 5 µm particle size, 25 cm x 21.1 mm, purchased from Regis Technologies (mobile phase: 32% MeOH (topped with 20 mM ammonia), 68% _CO2 ; flow rate 100 mL/min); rt = 5.63 min. ESI-MS calculated m/z value: 469.132; observed value: 470.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 1.7 Hz, 1H), 8.17 (d, J = 0.8 Hz, 1H), 7.47 (dd, J = 12.1, 7.5 Hz, 1H), 7.40 (dddd, J = 8.3, 7.3, 5.4, 1.9 Hz, 1H), 7.30 - 7.18 (m, 3H), 7.10 (d, J = 7.8 Hz, 1H), 6.92 (dt, J = 7.6, 0.7 Hz, 1H), 6.68 (d, J = 1.1 Hz, 1H), 5.64 (d, J = 2.8 Hz, 2H), 4.63 - 4.47 (m, 2H), 3.96 - 3.85 (m, 2H), 3.67 (dd, J = 8.4, 7.6 Hz, 1H), 3.63 - 3.50 (m, 2H), 3.44 - 3.35 (m, 1H), 2.59 - 2.51 (m, 1H) ppm. 53 Peak 2 rel- 5-(5-chloro-2-((( 3R , 4R ) -4- (hydroxymethyl)tetrahydrofuran-3-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ( R , R )-Whelk- ^O® 1 column, 5 µm particle size, 25 cm x 21.1 mm, purchased from Regis Technologies (mobile phase: 32% MeOH (topped with 20 mM ammonia), 68% _CO2 ; flow rate 100 mL/min); rt = 7.55 min. ESI-MS calculated m/z value: 469.132; observed value: 470.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 1.7 Hz, 1H), 8.17 (d, J = 0.9 Hz, 1H), 7.51 - 7.43 (m, 1H), 7.44 - 7.35 (m, 1H), 7.31 - 7.15 (m, 3H), 7.10 (d, J = 7.8 Hz, 1H), 6.95 - 6.90 (m, 1H), 6.68 (d, J = 1.1 Hz, 1H), 5.64 (d, J = 2.8 Hz, 2H), 4.65 - 4.46 (m, 2H), 3.96 - 3.85 (m, 2H), 3.67 (dd, J = 8.5, 7.6 Hz, 1H), 3.63 - 3.49 (m, 2H), 3.40 (t, J = 9.6 Hz, 1H), 2.59 - 2.50 (m, 1H) ppm. 54 Peak 1 rel- ( R )-5-(5-chloro-2-((1,4-dihydroxybutyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 Chiral Art Amylose-SA column, 5 µm particle size, 25 cm x 20 mm, purchased from YMC Europe GmbH (mobile phase: 40% 1:1 ⁱ PrOH:MeCN (added with 20 mM ammonia), 60% _CO2 ; flow rate 100 mL/min); rt = 3.72 min. ESI-MS calculated m/z value: 457.132; observed value: 458.3 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 0.8 Hz, 1H), 8.12 (s, 1H), 7.50 - 7.34 (m, 2H), 7.32 - 7.15 (m, 3H), 6.91 (d, J = 7.5 Hz, 1H), 6.80 (t, J = 7.4 Hz, 1H), 6.61 (s, 1H), 5.63 (d, J = 2.6 Hz, 2H), 4.75 - 4.64 (m, 1H), 4.49 - 4.39 (m, 1H), 4.00 - 3.95 (m, 1H), 3.53 - 3.33 (m, 2H), 1.81 (s, 1H), 1.65 - 1.54 (m, 1H) ppm; no interchangeable H was observed. 55 Peak 2 rel- ( S )-5-(5-chloro-2-((1,4-dihydroxybutyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 Chiral Art Amylose-SA column, 5 µm particle size, 25 cm x 20 mm, purchased from YMC Europe GmbH (mobile phase: 40% 1:1 ⁱ PrOH:MeCN (added with 20 mM ammonia), 60% _CO2 ; flow rate 100 mL/min); rt = 3.72 min. ESI-MS calculated m/z value: 457.132; observed value: 458.3 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 0.8 Hz, 1H), 8.12 (s, 1H), 7.50 - 7.34 (m, 2H), 7.32 - 7.15 (m, 3H), 6.91 (d, J = 7.5 Hz, 1H), 6.80 (t, J = 7.3 Hz, 1H), 6.61 (s, 1H), 5.66 - 5.60 (m, 2H), 4.75 - 4.66 (m, 1H), 4.49 - 4.39 (m, 1H), 4.07 - 3.89 (m, 1H), 3.56 - 3.34 (m, 3H), 1.85 - 1.76 (m, 1H), 1.65 - 1.52 (m, 1H) ppm; no interchangeable H was observed. 56 ( R )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 453.137; observed value: 454.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (dd, J = 2.0, 0.8 Hz, 1H), 8.08 (s, 1H), 7.51 - 7.35 (m, 3H), 7.31 - 7.17 (m, 4H), 6.98 - 6.85 (m, 2H), 6.62 (d, J = 1.1 Hz, 1H), 5.63 (d, J = 3.9 Hz, 2H), 4.69 (dt, J = 18.8, 5.3 Hz, 1H), 3.60 - 3.45 (m, 2H), 1.00 (m, 1H), 0.50 - 0.19 (m, 4H) ppm. 57 ( R )-5-(5-fluoro-2-((1-(1-methyl- 1H- 1,2,3-triazol-5-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 462.173; observed value: 463.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.8 Hz, 1H), 8.15 (d, J = 1.9 Hz, 1H), 7.64 (d, J = 0.6 Hz, 1H), 7.57 (dd, J = 7.6, 0.6 Hz, 1H), 7.39 (dddd, J = 8.3, 7.2, 5.4, 2.0 Hz, 1H), 7.27 - 7.17 (m, 4H), 6.95 (dt, J = 7.7, 0.6 Hz, 1H), 6.60 (d, J = 5.0 Hz, 1H), 5.64 (s, 2H), 5.28 (p, J = 7.0 Hz, 1H), 4.01 (s, 3H), 1.51 (d, J = 6.9 Hz, 3H) ppm. 58 5-(5-chloro-2-((1,5-dihydroxypentan-3-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 471.147; observed value: 472.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 0.8 Hz, 1H), 8.12 (s, 1H), 7.47 (d, J = 7.5 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.30 - 7.16 (m, 3H), 6.94 - 6.88 (m, 1H), 6.82 (d, J = 8.4 Hz, 1H), 6.57 (s, 1H), 5.63 (d, J = 2.8 Hz, 2H), 4.40 (dt, J = 10.1, 5.1 Hz, 2H), 4.07 - 4.03 (m, 1H), 3.46 (q, J = 5.8 Hz, 4H), 1.71 - 1.61 (m, 4H) ppm. 59 ( S )-1-benzyl-5-(5-chloro-2-((1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one SB1 ESI-MS calculated m/z value: 409.131; observed value: 410.0 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 0.8 Hz, 1H), 8.14 (s, 1H), 7.44 (d, J = 7.5 Hz, 1H), 7.40 - 7.34 (m, 2H), 7.33 - 7.28 (m, 3H), 6.93 (dd, J = 7.6, 0.8 Hz, 1H), 6.81 (t, J = 7.8 Hz, 1H), 6.59 (s, 1H), 5.62 (d, J = 15.5 Hz, 1H), 5.57 (d, J = 15.5 Hz, 1H), 4.73 (dt, J = 11.0, 5.5 Hz, 1H), 3.94 (d, J = 9.7 Hz, 1H), 3.58 - 3.41 (m, 1H), 1.14 (t, J = 6.4 Hz, 3H) ppm; no interchangeable H was observed. 60 ( S )-5-(5-chloro-2-((1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(4-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one SB1 ESI-MS calculated m/z value: 427.121; observed value: 428.0 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 0.8 Hz, 1H), 8.14 (s, 1H), 7.45 (d, J = 7.4 Hz, 1H), 7.42 - 7.30 (m, 2H), 7.25 - 7.14 (m, 2H), 7.07 - 6.92 (m, 1H), 6.82 (t, J = 7.8 Hz, 1H), 6.59 (s, 1H), 5.61 (d, J = 15.8 Hz, 1H), 5.56 (d, J = 15.8 Hz, 1H), 4.73 (dt, J = 11.0, 5.5 Hz, 1H), 4.00 - 3.84 (m, 1H), 3.48 (dt, J = 10.3, 5.2 Hz, 1H), 1.14 (t, J = 6.4 Hz, 3H) ppm. 61 Peak 1 rel- 5-(5-chloro-2-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IB-3 column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 25% MeOH (topped with 20 mM ammonia), 75% _CO2 ; flow rate 100 mL/min); rt = 5.16 min. ESI-MS calculated m/z value: 483.147; observed value: 484.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 0.9 Hz, 1H), 8.12 (s, 1H), 7.47 (dd, J = 15.5, 7.5 Hz, 1H), 7.43 - 7.36 (m, 1H), 7.31 - 7.17 (m, 3H), 6.99 - 6.89 (m, 2H), 6.64 (d, J = 1.3 Hz, 1H), 5.63 (d, J = 2.9 Hz, 2H), 4.80 - 4.65 (m, 1H), 4.06 - 3.92 (m, 1H), 3.84 - 3.76 (m, 1H), 3.75 - 3.66 (m, 1H), 3.64 - 3.55 (m, 1H), 3.47 - 3.36 (m, 3H), 2.51 - 2.42 (m, 1H), 2.00 - 1.88 (m, 1H), 1.72 - 1.59 (m, 1H ppm. 62 Peak 2 rel- 5-(5-chloro-2-((( 1R )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IB-3 column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 25% MeOH (topped with 20 mM ammonia), 75% _CO2 ; flow rate 100 mL/min); rt = 6.71 min. ESI-MS calculated m/z value: 483.147; observed value: 484.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (s, 1H), 8.12 (s, 1H), 7.47 (dd, J = 18.3, 7.5 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.31 - 7.16 (m, 3H), 6.96 - 6.89 (m, 2H), 6.63 (s, 1H), 5.63 (d, J = 2.9 Hz, 2H), 4.76 - 4.72 (m, 1H), 4.00 - 3.96 (m, 1H), 3.82 - 3.70 (m, 2H), 3.67 - 3.58 (m, 1H), 3.56 - 3.40 (m, 3H), 2.02 - 1.92 (m, 1H), 1.69 - 1.57 (m, 1H) ppm; no interchangeable H was observed. 63 Peak 3 rel- 5-(5-chloro-2-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IB-3 column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 25% MeOH (topped with 20 mM ammonia), 75% _CO2 ; flow rate 100 mL/min); rt = 8.29 min. ESI-MS calculated m/z value: 483.147; observed value: 484.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (s, 1H), 8.12 (s, 1H), 7.47 (dd, J = 18.2, 7.5 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.31 - 7.17 (m, 3H), 6.96 - 6.88 (m, 2H), 6.63 (s, 1H), 5.63 (d, J = 2.9 Hz, 2H), 4.77 - 4.73 (m, 1H), 4.00 - 3.96 (m, 1H), 3.82 - 3.70 (m, 2H), 3.67 - 3.58 (m, 1H), 3.58 - 3.39 (m, 3H), 2.02 - 1.92 (m, 1H), 1.69 - 1.57 (m, 1H) ppm; no interchangeable H was observed. 64 Peak 4 rel- 5-(5-chloro-2-((( 1R )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IB-3 column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 25% MeOH (topped with 20 mM ammonia), 75% _CO2 ; flow rate 100 mL/min); rt = 9.59 min. ESI-MS calculated m/z value: 483.147; observed value: 484.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 0.8 Hz, 1H), 8.12 (s, 1H), 7.47 (dd, J = 15.5, 7.5 Hz, 1H), 7.43 - 7.36 (m, 1H), 7.31 - 7.17 (m, 3H), 6.96 (t, J = 8.7 Hz, 1H), 6.93 - 6.89 (m, 1H), 6.64 (d, J = 1.3 Hz, 1H), 5.63 (d, J = 2.9 Hz, 2H), 4.78 - 4.74 (m, 1H), 4.04 - 3.92 (m, 1H), 3.84 - 3.74 (m, 1H), 3.75 - 3.66 (m, 1H), 3.64 - 3.55 (m, 1H), 3.50 - 3.35 (m, 3H), 2.51 - 2.42 (m, 1H), 2.00 - 1.88 (m, 1H), 1.72 - 1.59 (m, 1H) ppm. 65 5-(5-chloro-2-((3-hydroxy-2-(hydroxymethyl)propyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3-c]pyridin-4-one S2 ESI-MS calculated m/z value: 457.132; observed value: 458.2 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 0.8 Hz, 1H), 8.14 (s, 1H), 7.46 (d, J = 7.5 Hz, 1H), 7.43 - 7.36 (m, 1H), 7.31 - 7.16 (m, 3H), 3.52 - 3.38 (m, 4H), 3.26 (t, J = 6.2 Hz, 2H), 1.85 - 1.75 (m, 1H) ppm. 66 rac -5-(5-chloro-2-((1-hydroxy-4-methoxybut-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS m/z calculated value: 471.147, observed value: 470.2 (M⁻¹) ^- . 67 Peak 1 rel- 5-(5-chloro-2-((1-(2,2-difluorocyclopropyl)-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralcel® OD-H column, 5 µm particle size, 25 cm x 10 mm, purchased from Daicel (mobile phase: 65% MeOH (topped with 20 mM ammonia), 35% _CO2 ; flow rate 10 mL/min); rt = 2.75 min. ESI-MS calculated m/z value: 489.118; observed value: 490.3 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.17 (s, 1H), 8.13 (s, 1H), 7.51 - 7.35 (m, 2H), 7.29 - 7.08 (m, 4H), 6.92 (d, J = 7.5 Hz, 1H), 6.66 (d, J = 1.5 Hz, 1H), 5.63 (d, J = 2.7 Hz, 2H), 5.02 - 4.97 (m, 1H), 3.97 - 3.92 (m, 1H), 3.57 - 3.52 (m, 2H), 2.00 - 1.84 (m, 1H), 1.59 (s, 1H), 1.41 - 1.36 (m, 1H) ppm. 68 Peak 2 rel- 5-(5-chloro-2-((1-(2,2-difluorocyclopropyl)-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralcel® OD-H column, 5 µm particle size, 25 cm x 10 mm, purchased from Daicel (mobile phase: 65% MeOH (topped with 20 mM ammonia), 35% _CO2 ; flow rate 10 mL/min); rt = 3.89 min. ESI-MS calculated m/z value: 489.118; observed value: 490.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.8 Hz, 1H), 8.14 (s, 1H), 7.47 (dd, J = 12.3, 7.5 Hz, 1H), 7.45 - 7.35 (m, 1H), 7.32 - 7.14 (m, 4H), 6.93 (d, J = 7.5 Hz, 1H), 6.67 (d, J = 1.9 Hz, 1H), 5.64 (d, J = 4.1 Hz, 2H), 5.03 - 4.99 (m, 1H), 3.97 - 3.93 (m, 1H), 3.57 - 3.50 (m, 2H), 2.00 - 1.87 (m, 1H), 1.65 - 1.54 (m, 1H), 1.47 - 1.32 (m, 1H) ppm. 69 5-(5-chloro-2-((2-(hydroxymethyl)spiro[3.3]hept-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 493.168; observed value: 494.3 (M+1) ⁺ . 70 Peak 1 rel- ( R )-6-(((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)methyl) pyrolin-3-one S2 ^Chiralcel® OJ column, 5 µm particle size, 25 cm x 10 mm, purchased from Daicel (mobile phase: 40% 1:1 MeOH:MeCN (supplemented with 0.2% DMIPA), 60% _CO2 ; flow rate 10 mL/min); rt = 3.43 min. ESI-MS calculated m/z value: 482.127; observed value: 483.2 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.18 (s, 1H), 8.17 (d, J = 0.8 Hz, 1H), 7.98 (s, 1H), 7.47 (dd, J = 7.5, 1.0 Hz, 1H), 7.44 - 7.36 (m, 1H), 7.31 - 7.25 (m, 1H), 7.22 (td, J = 7.4, 6.2 Hz, 2H), 6.93 (d, J = 7.5 Hz, 1H), 6.67 (s, 1H), 5.64 (d, J = 3.4 Hz, 2H), 4.11 - 3.97 (m, 2H), 3.86 (s, 1H), 3.49 (s, 1H), 3.44 (s, 1H), 3.25 (d, J = 13.7 Hz, 1H), 3.13 (t, J = 10.4 Hz, 1H) ppm; no interchangeable H was observed. 71 Peak 2 rel- ( S )-6-(((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)methyl) pyrolin-3-one S2 ^Chiralcel® OJ column, 5 µm particle size, 25 cm x 10 mm, purchased from Daicel (mobile phase: 40% 1:1 MeOH:MeCN (supplemented with 0.2% DMIPA), 60% _CO2 ; flow rate 10 mL/min); rt = 4.32 min. ESI-MS calculated m/z value: 482.127; observed value: 483.2 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.18 (s, 1H), 8.17 (d, J = 0.8 Hz, 1H), 7.98 (s, 1H), 7.47 (dd, J = 7.6, 1.0 Hz, 1H), 7.44 - 7.36 (m, 1H), 7.31 - 7.25 (m, 1H), 7.25 - 7.18 (m, 2H), 6.93 (d, J = 7.6 Hz, 1H), 6.67 (s, 1H), 5.69 - 5.59 (m, 2H), 4.10 - 3.98 (m, 2H), 3.85 (d, J = 5.4 Hz, 1H), 3.46 (d, J = 23.4 Hz, 2H), 3.25 (d, J = 12.6 Hz, 1H), 3.13 (t, J = 11.3 Hz, 1H) ppm. 72 5-(5-chloro-2-(((1 s ,3 s )-3-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 453.137; observed value: 454.3 (M+1) ⁺ . ¹ H NMR (500 MHz, methanol - _{d 4} ) δ 8.20 (d, J = 0.9 Hz, 1H), 8.12 (s, 1H), 7.39 (tdd, J = 7.5, 5.3, 1.8 Hz, 1H), 7.33 (d, J = 7.5 Hz, 1H), 7.27 (td, J = 7.6, 1.8 Hz, 1H), 7.22 - 7.13 (m, 2H), 6.88 (dt, J = 7.5, 0.8 Hz, 1H), 6.56 (s, 1H), 5.65 (d, J = 3.2 Hz, 2H), 4.19 (p, J = 8.1 Hz, 1H), 3.54 (d, J = 6.1 Hz, 2H), 2.52 (ddddd, J = 11.6, 9.1, 7.3, 5.4, 2.7 Hz, 2H), 2.29 - 2.18 (m, 1H), 1.69 (q, J = 9.6 Hz, 2H) ppm; no interchangeable H was observed. 73 5-(5-chloro-2-(((1-methyl- 1H- 1,2,3-triazol-5-yl)methyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 464.128; observed value: 465.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.23 (s, 1H), 8.16 (d, J = 0.8 Hz, 1H), 7.59 (s, 1H), 7.55 (t, J = 5.8 Hz, 1H), 7.47 (d, J = 7.5 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.31 - 7.16 (m, 3H), 6.95 - 6.90 (m, 1H), 6.69 (s, 1H), 5.69 - 5.58 (m, 2H), 4.71 - 4.51 (m, 2H), 4.03 (s, 3H)ppm. 74 Peak 1 rel- ( R )-5-(5-chloro-2-((2-hydroxy-1-(1-methyl- 1H -pyrazol-5-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 (R,R ) - Whelk- ^O® 1 column, 5 µm particle size, 25 cm x 21.1 mm, purchased from Regis Technologies (mobile phase: 32% MeOH (supplemented with 20 mM ammonia), 68% _CO2 ; flow rate 100 mL/min); rt = 4.97 min ESI-MS calculated m/z value: 493.143; observed value: 494.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 (d, J = 1.2 Hz, 1H), 8.16 (dd, J = 4.3, 0.8 Hz, 1H), 7.46 (dd, J = 7.5, 2.6 Hz, 1H), 7.42 - 7.36 (m, 2H), 7.32 - 7.16 (m, 4H), 6.92 (dd, J = 7.6, 4.0 Hz, 1H), 6.68 (d, J = 0.9 Hz, 1H), 6.23 (d, J = 1.9 Hz, 1H), 5.63 (d, J = 2.9 Hz, 2H), 5.36 - 5.20 (m, 1H), 5.09 - 5.05 (m, 1H), 3.83 (d, J = 2.3 Hz, 3H), 3.78 - 3.62 (m, 2H) ppm. 75 Peak 2 rel- ( S )-5-(5-chloro-2-((2-hydroxy-1-(1-methyl- 1H -pyrazol-5-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 (R,R ) - Whelk- ^O® 1 column, 5 µm particle size, 25 cm x 21.1 mm, purchased from Regis Technologies (mobile phase: 32% MeOH (supplemented with 20 mM ammonia), 68% _CO2 ; flow rate 100 mL/min); rt = 6.50 min ESI-MS calculated m/z value: 493.143; observed value: 494.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 (d, J = 1.2 Hz, 1H), 8.16 (dd, J = 4.3, 0.8 Hz, 1H), 7.46 (dd, J = 7.5, 2.6 Hz, 1H), 7.42 - 7.34 (m, 2H), 7.32 - 7.16 (m, 4H), 6.92 (dd, J = 7.6, 4.0 Hz, 1H), 6.68 (d, J = 1.0 Hz, 1H), 6.23 (d, J = 1.9 Hz, 1H), 5.63 (d, J = 3.0 Hz, 2H), 5.31 - 5.20 (m, 1H), 5.09 - 5.05 (m, 1H), 3.83 (d, J = 2.4 Hz, 3H), 3.75 - 3.71 (m, 1H), 3.70 - 3.62 (m, 1H) ppm. 76 Peak 1 rel- 5-(5-chloro-2-(((( 3S , 4S ) -4-hydroxytetrahydrofuran-3-yl)methyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 Lux ^™ Cellulose-3 column, 5 µm particle size, 25 cm x 10 mm, purchased from Phenomenex Corporation (mobile phase: 30% MeOH (topped with 20 mM ammonia), 70% _CO₂ ; flow rate 10 mL/min); rt = 3.68 min. ESI-MS calculated m/z value: 469.132; observed value: 470.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (s, 1H), 8.17 (d, J = 0.8 Hz, 1H), 7.47 (dd, J = 7.5, 1.6 Hz, 1H), 7.40 (dddd, J = 8.2, 7.3, 5.4, 1.9 Hz, 1H), 7.30 - 7.24 (m, 2H), 7.24 - 7.19 (m, 1H), 7.03 (d, J = 6.3 Hz, 1H), 6.92 (d, J = 7.5 Hz, 1H), 6.62 (s, 1H), 5.68 - 5.60 (m, 2H), 5.00 (t, J = 4.7 Hz, 1H), 4.23 (s, 1H), 3.86 - 3.78 (m, 2H), 3.60 (dd, J = 9.3, 1.5 Hz, 1H), 3.51 - 3.41 (m, 2H), 3.37 - 3.32 (m, 1H), 2.41 - 2.34 (m, 1H)ppm. 77 Peak 2 rel- 5-(5-chloro-2-(((( 3R , 4R ) -4-hydroxytetrahydrofuran-3-yl)methyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 Lux ^™ Cellulose-3 column, 5 µm particle size, 25 cm x 10 mm, purchased from Phenomenex Corporation (mobile phase: 30% MeOH (topped with 20 mM ammonia), 70% _CO₂ ; flow rate 10 mL/min); rt = 4.56 min. ESI-MS calculated m/z value: 469.132; observed value: 470.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (s, 1H), 8.17 (d, J = 0.9 Hz, 1H), 7.47 (dd, J = 7.5, 1.6 Hz, 1H), 7.40 (dddd, J = 8.2, 7.3, 5.4, 1.9 Hz, 1H), 7.31 - 7.18 (m, 3H), 7.06 - 7.01 (m, 1H), 6.95 - 6.90 (m, 1H), 6.62 (s, 1H), 5.70 - 5.59 (m, 2H), 5.00 (t, J = 4.7 Hz, 1H), 4.23 (s, 1H), 3.86 - 3.78 (m, 2H), 3.60 (dd, J = 9.3, 1.5 Hz, 1H), 3.51 - 3.41 (m, 2H), 3.34 (d, J = 5.1 Hz, 1H), 2.40 - 2.33 (m, 1H) ppm. 78 Peak 1 rel- 5-(5-fluoro-2-((( 1R , 2R )-2-hydroxycyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralcel® IG column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% 1:1 MeOH:MeCN (supplemented with 0.2% DMIPA), 70% _CO2 ; flow rate 100 mL/min); rt = 5.82 min. ESI-MS calculated m/z value: 423.151; observed value: 424.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.8 Hz, 1H), 8.10 (d, J = 1.8 Hz, 1H), 7.55 (d, J = 7.5 Hz, 1H), 7.39 (tdd, J = 7.4, 5.3, 2.0 Hz, 1H), 7.28 - 7.17 (m, 3H), 7.05 (d, J = 7.4 Hz, 1H), 6.94 (d, J = 7.5 Hz, 1H), 6.54 (d, J = 5.0 Hz, 1H), 5.64 (s, 2H), 3.99 - 3.90 (m, 1H), 3.85 (q, J = 7.8 Hz, 1H), 2.03 - 1.94 (m, 2H), 1.80 - 1.74 (m, 1H), 1.41 (tt, J = 10.5, 8.9 Hz, 1H), 1.25 - 1.15 (m, 1H) ppm. 79 Peak 2 rel- 5-(5-fluoro-2-((( 1S , 2S )-2-hydroxycyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 Chiralcel® IG column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% 1:1 MeOH:MeCN (supplemented with 0.2% DMIPA), 70% _CO2 ; flow rate 100 mL/min); rt = 7.26 min. ESI-MS calculated m/z value: 423.151; observed value: 424.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 0.8 Hz, 1H), 8.11 (d, J = 1.8 Hz, 1H), 7.56 (d, J = 7.5 Hz, 1H), 7.44 - 7.36 (m, 1H), 7.28 - 7.18 (m, 3H), 7.06 (d, J = 7.4 Hz, 1H), 6.95 (d, J = 7.6 Hz, 1H), 6.55 (d, J = 5.0 Hz, 1H), 5.65 (s, 2H), 3.95 (t, J = 8.0 Hz, 1H), 3.86 (q, J = 7.8 Hz, 1H), 2.03 - 1.94 (m, 2H), 1.78 - 1.74 (m, 1H), 1.42 (tt, J = 10.5, 9.0 Hz, 1H), 1.25 - 1.17 (m, 1H) ppm. 80 5-(5-chloro-2-((3,3-difluoropropyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 447.107; observed value: 448.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.20 (s, 1H), 8.16 (d, J = 0.8 Hz, 1H), 7.46 (d, J = 7.5 Hz, 1H), 7.42 - 7.35 (m, 1H), 7.31 - 7.12 (m, 4H), 6.95 - 6.89 (m, 1H), 6.61 (s, 1H), 6.16 (tt, J = 56.6, 4.5 Hz, 1H), 5.69 - 5.58 (m, 2H), 3.46 - 3.38 (m, 2H), 2.19 - 2.04 (m, 2H) ppm. 81 rac -5-(5-chloro-2-((1-cyclobutyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 467.152; observed value: 468.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.8 Hz, 1H), 8.12 (s, 1H), 7.47 (dd, J = 18.2, 7.5 Hz, 1H), 7.43 - 7.37 (m, 1H), 7.30 - 7.18 (m, 3H), 6.92 (d, J = 7.5 Hz, 1H), 6.73 (t, J = 8.8 Hz, 1H), 6.65 (d, J = 1.9 Hz, 1H), 5.64 (d, J = 3.1 Hz, 2H), 4.56 (dt, J = 21.3, 5.4 Hz, 1H), 3.98 (s, 1H), 3.45 - 3.36 (m, 2H), 2.57 (q, J = 8.2 Hz, 1H), 1.94 (q, J = 7.5 Hz, 2H), 1.85 - 1.71 (m, 4H) ppm. 82 5-(5-fluoro-2-(((1 s ,3 s )-3-hydroxy-1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 453.161; observed value: 454.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 0.8 Hz, 1H), 8.06 (d, J = 1.9 Hz, 1H), 7.55 (dd, J = 7.6, 0.6 Hz, 1H), 7.40 (dddd, J = 8.2, 7.4, 5.4, 1.9 Hz, 1H), 7.28 - 7.23 (m, 2H), 7.23 - 7.17 (m, 1H), 6.96 - 6.92 (m, 1H), 6.89 (s, 1H), 6.50 (d, J = 5.1 Hz, 1H), 5.64 (s, 2H), 4.96 (d, J = 6.3 Hz, 1H), 4.84 (t, J = 5.6 Hz, 1H), 3.97 (h, J = 7.1 Hz, 1H), 3.54 (d, J = 5.5 Hz, 2H), 2.60 (ddd, J = 9.9, 7.2, 2.8 Hz, 2H), 1.94 - 1.84 (m, 2H) ppm. 83 rac -6-((2-cyclopropyl-1-hydroxypropyl-2-yl)amino)-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro-5 -H -pyrazolo[4,3- c ]pyridin-5-yl)nicotinamide S2 ESI-MS calculated m/z value: 458.187; observed value: 459.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.49 (s, 1H), 8.20 (d, J = 0.8 Hz, 1H), 7.57 (d, J = 7.5 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.33 - 7.17 (m, 4H), 6.97 (dt, J = 7.7, 0.6 Hz, 1H), 6.73 (s, 1H), 5.65 (s, 2H), 4.91 (t, J = 5.7 Hz, 1H), 3.80 - 3.76 (m, 1H), 3.69 - 3.65 (m, 1H), 1.51 (p, J = 7.6 Hz, 1H), 1.04 (s, 3H), 0.47 - 0.31 (m, 4H) ppm. 84 Peak 1 rel- 5-(2-((1-(2,2-difluorocyclopropyl)-2-hydroxyethyl)amino)-5-fluoropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 23% MeOH (topped with 20 mM ammonia), 77% _CO2 ; flow rate 2 mL/min); rt = 4.82 min. ESI-MS calculated m/z value: 473.147; observed value: 474.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 0.9 Hz, 1H), 8.08 (d, J = 1.9 Hz, 1H), 7.57 (d, J = 7.5 Hz, 1H), 7.44 - 7.36 (m, 1H), 7.25 (tdd, J = 9.6, 7.6, 1.5 Hz, 2H), 7.20 (td, J = 7.4, 1.2 Hz, 1H), 6.95 (d, J = 7.6 Hz, 1H), 6.90 (d, J = 8.4 Hz, 1H), 6.63 (d, J = 5.0 Hz, 1H), 5.65 (s, 2H), 4.97 (s, 1H), 3.91 (s, 1H), 3.54 (t, J = 4.0 Hz, 2H), 1.92 (dtd, J = 14.6, 10.9, 7.8 Hz, 1H), 1.58 (dh, J = 11.9, 3.8 Hz, 1H), 1.45 - 1.33 (m, 1H) ppm. 85 Peak 2 rel- 5-(2-((1-(2,2-difluorocyclopropyl)-2-hydroxyethyl)amino)-5-fluoropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 23% MeOH (topped with 20 mM ammonia), 77% _CO2 ; flow rate 2 mL/min); rt = 8.09 min. ESI-MS calculated m/z value: 473.147; observed value: 474.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 0.8 Hz, 1H), 8.08 (d, J = 1.8 Hz, 1H), 7.57 (d, J = 7.6 Hz, 1H), 7.40 (tdd, J = 7.6, 5.4, 1.9 Hz, 1H), 7.28 - 7.22 (m, 2H), 7.20 (td, J = 7.4, 1.2 Hz, 1H), 6.95 (d, J = 7.5 Hz, 1H), 6.91 (d, J = 8.5 Hz, 1H), 6.64 (d, J = 5.0 Hz, 1H), 5.65 (s, 2H), 4.99 (s, 1H), 3.91 (s, 1H), 3.54 (dd, J = 5.0, 2.9 Hz, 2H), 1.97 - 1.87 (m, 1H), 1.57 (dq, J = 12.2, 4.8 Hz, 1H), 1.43 - 1.35 (m, 1H) ppm. 86 5-(5-chloro-2-(((1 s ,3 s )-1-(hydroxymethyl)-3-methoxycyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 483.147; observed value: 484.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.9 Hz, 1H), 8.12 (s, 1H), 7.46 (d, J = 7.5 Hz, 1H), 7.40 (dddd, J = 8.2, 7.3, 5.4, 1.9 Hz, 1H), 7.30 - 7.24 (m, 2H), 7.24 - 7.18 (m, 2H), 6.95 - 6.90 (m, 1H), 6.53 (s, 1H), 5.64 (d, J = 3.8 Hz, 2H), 4.92 (t, J = 5.6 Hz, 1H), 3.74 (p, J = 6.8 Hz, 1H), 3.62 (dd, J = 10.8, 5.2 Hz, 1H), 3.54 (dd, J = 10.8, 5.2 Hz, 1H), 3.12 (s, 3H), 2.66 - 2.57 (m, 2H), 1.97 - 1.90 (m, 2H) ppm. 87 rac -6-((4,4-difluoro-1-hydroxy-2-methylbut-2-yl)amino)-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl) nicotinamide S2 ESI-MS calculated m/z value: 482.168; observed value: 483.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.54 (s, 1H), 8.20 (d, J = 0.8 Hz, 1H), 7.55 (d, J = 7.6 Hz, 1H), 7.46 (s, 1H), 7.44 - 7.35 (m, 1H), 7.32 - 7.16 (m, 3H), 6.99 (dt, J = 7.6, 0.7 Hz, 1H), 6.72 (d, J = 0.5 Hz, 1H), 6.11 (tt, J = 56.1, 4.8 Hz, 1H), 5.64 (s, 2H), 5.10 (t, J = 5.6 Hz, 1H), 3.74 - 3.58 (m, 2H), 2.69 (d, J = 17.8 Hz, 1H), 2.44 - 2.24 (m, 1H), 1.39 (s, 3H) ppm. 88 5-(5-chloro-2-((1,3-dihydroxy-2-methylpropyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 457.132; observed value: 458.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 0.8 Hz, 1H), 8.12 (s, 1H), 7.45 (d, J = 7.5 Hz, 1H), 7.40 (dddd, J = 9.1, 7.3, 5.4, 1.9 Hz, 1H), 7.33 - 7.26 (m, 1H), 7.26 - 7.17 (m, 2H), 6.92 (d, J = 7.5 Hz, 1H), 6.76 (s, 1H), 6.45 (s, 1H), 5.64 (d, J = 1.7 Hz, 2H), 4.89 (dt, J = 8.8, 5.7 Hz, 2H), 3.71 - 3.53 (m, 4H), 1.28 (s, 3H) ppm. 89 Rotation-resistant isomer 1 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-6-methyl-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S4 ESI-MS calculated m/z value: 483.123, observed value: 484.3 (M+1) ^{+ 1} H NMR (500 MHz, methanol - _{d 4} ) δ 8.17 (d, 1H), 8.12 (d, 1H), 7.50-7.48 (dd, 1H), 7.35-7.30 (m, 2H), 7.00-6.98 (dd, 1H), 6.74 (d, 1H), 6.60 (d, 1H), 5.67 (m, 2H), 3.81-3.79 (m, 1H), 3.70-67 (m, 1H), 3.47-3.45 (m, 1H), 2.12 (d, 3H), 1.09-1.01 (m, 1H), 0.60-0.51 (m, 2H), 0.43-0.32 (m, 2H) ppm; no interchangeable H was observed. 90 Rotation-resistant isomer 2 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-6-methyl-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S4 ESI-MS calculated m/z value: 483.123, observed value: 484.3 (M+1) ^{+ 1} H NMR (500 MHz, methanol - _{d 4} ) δ 8.17 (d, 1H), 8.12 (d, 1H), 7.50-7.48 (dd, 1H), 7.35-7.30 (m, 2H), 7.00-6.98 (dd, 1H), 6.74 (d, 1H), 6.60 (d, 1H), 5.67 (m, 2H), 3.81-3.79 (m, 1H), 3.70-67 (m, 1H), 3.42-3.38 (m, 1H), 2.12 (d, 3H), 1.09-1.01 (m, 1H), 0.58-0.48 (m, 2H), 0.39-0.32 (m, 2H) ppm; no interchangeable H was observed. 91 5-(2-((( 1H- pyrazol-4-yl)methyl)amino)-5-chloropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 449.117; observed value: 450.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 12.62 (s, 1H), 8.20 (s, 1H), 8.16 (d, J = 0.8 Hz, 1H), 7.57 (s, 2H), 7.45 (d, J = 7.5 Hz, 1H), 7.42 - 7.36 (m, 1H), 7.30 - 7.16 (m, 4H), 6.91 (d, J = 7.6 Hz, 1H), 6.62 (s, 1H), 5.69 - 5.58 (m, 2H), 4.33 (d, J = 5.6 Hz, 2H) ppm. 92 5-(2-(((1,2,3-thiadiazol-5-yl)methyl)amino)-5-chloropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 467.073; observed value: 468.0 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.91 (s, 1H), 8.30 (s, 1H), 8.17 (d, J = 0.8 Hz, 1H), 7.84 (t, J = 6.0 Hz, 1H), 7.48 (d, J = 7.5 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.30 - 7.16 (m, 3H), 6.93 (d, J = 7.6 Hz, 1H), 6.73 (s, 1H), 5.69 - 5.58 (m, 2H), 4.97 - 4.85 (m, 2H) ppm. 93 5-(5-chloro-2-(((3-methylisoazol-4-yl)methyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 464.116; observed value: 465.1 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.71 (s, 1H), 8.22 (s, 1H), 8.16 (d, J = 0.8 Hz, 1H), 7.46 (d, J = 7.5 Hz, 1H), 7.45 - 7.32 (m, 2H), 7.32 - 7.15 (m, 3H), 6.92 (d, J = 7.6 Hz, 1H), 6.65 (s, 1H), 5.63 (d, J = 3.1 Hz, 2H), 4.30 (t, J = 5.3 Hz, 2H), 2.26 (s, 3H) ppm. 94 Peak 1 rel- ( R )-5-(5-chloro-2-((4,4-difluoro-1-hydroxypentan-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 26% MeOH (topped with 20 mM ammonia), 74% _CO2 ; flow rate 100 mL/min); rt = 3.68 min. ESI-MS calculated m/z value: 491.134; observed value: 492.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (s, 1H), 7.47 (dd, J = 7.5, 5.9 Hz, 1H), 7.43 - 7.36 (m, 1H), 7.31 - 7.16 (m, 3H), 7.00 - 6.89 (m, 2H), 6.60 (s, 1H), 5.63 (d, J = 3.4 Hz, 2H), 4.94 - 4.90 (m, 1H), 4.24 - 4.20 (m, 1H), 3.50 - 3.46 (m, 1H), 3.37 - 3.26 (m, 1H), 2.29 (s, 1H), 2.15 - 1.91 (m, 1H), 1.62 (td, J = 19.2, 2.9 Hz, 3H) ppm; no interchangeable H was observed. 95 Peak 2 rel- ( S )-5-(5-chloro-2-((4,4-difluoro-1-hydroxypentan-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 26% MeOH (topped with 20 mM ammonia), 74% _CO2 ; flow rate 100 mL/min); rt = 6.22 min. ESI-MS calculated m/z value: 491.134; observed value: 492.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 1.5 Hz, 2H), 7.47 (dd, J = 7.5, 5.9 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.31 - 7.17 (m, 3H), 6.96 (t, J = 9.1 Hz, 1H), 6.91 (d, J = 7.5 Hz, 1H), 6.60 (s, 1H), 5.63 (d, J = 3.4 Hz, 2H), 4.93 - 4.89 (m, 1H), 4.24 - 4.21 (m, 1H), 3.49 - 3.46 (m, 1H), 3.30 - 3.27 (m, 1H), 2.36 - 2.23 (m, 1H), 2.16 - 1.93 (m, 1H), 1.68 - 1.56 (m, 3H) ppm. 96 rac -5-(2-((2-cyclopropyl-1-hydroxypropyl-2-yl)amino)-5-fluoropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 451.182; observed value: 452.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 0.8 Hz, 1H), 8.06 (d, J = 1.9 Hz, 1H), 7.57 (d, J = 7.5 Hz, 1H), 7.40 (tdd, J = 7.7, 5.4, 2.0 Hz, 1H), 7.25 (tdd, J = 9.5, 7.4, 1.5 Hz, 2H), 7.20 (td, J = 7.4, 1.2 Hz, 1H), 6.95 (d, J = 7.5 Hz, 1H), 6.73 (d, J = 5.1 Hz, 1H), 6.23 (s, 1H), 5.65 (s, 2H), 5.09 (t, J = 5.7 Hz, 1H), 3.71 (dd, J = 10.7, 5.7 Hz, 1H), 3.61 (dd, J = 10.7, 5.8 Hz, 1H), 1.41 (tt, J = 8.1, 5.8 Hz, 1H), 1.01 (s, 3H), 0.45 - 0.40 (m, 1H), 0.39 - 0.31 (m, 3H) ppm. 97 rac -5-(5-fluoro-2-((3-hydroxy-1-(hydroxymethyl)spiro[3.3]hept-1-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 493.193; observed value: 494.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 0.8 Hz, 1H), 8.08 (t, J = 1.8 Hz, 1H), 7.57 (d, J = 7.5 Hz, 1H), 7.40 (tdd, J = 7.5, 5.3, 2.0 Hz, 1H), 7.28 - 7.23 (m, 2H), 7.23 - 7.18 (m, 1H), 6.95 (d, J = 7.5 Hz, 1H), 6.73 (d, J = 5.1 Hz, 0.5H), 6.62 - 6.57 (m, 1H), 6.19 (s, 0.5H), 5.65 (s, 2H), 5.01 (dd, J = 14.4, 6.0 Hz, 1H), 4.65 (t, J = 5.0 Hz, 0.5H), 4.55 (t, J = 5.4 Hz, 0.5H), 4.02 - 3.95 (m, 1H), 3.87 - 3.77 (m, 1H), 3.67 (dd, J = 10.7, 5.1 Hz, 0.5H), 3.37 - 3.33 (m, 0.5H), 2.62 (d, J = 9.2 Hz, 0.5H), 2.39 (d, J = 7.6 Hz, 0.5H), 2.27 (q, J = 9.6 Hz, 0.5H), 2.22 - 2.13 (m, 0.5H), 2.11 - 2.04 (m, 0.5H), 1.85 (q, J = 9.2 Hz, 0.5H), 1.73 (dd, J = 12.0, 5.5 Hz, 1H), 1.66 (dt, J = 8.6, 4.6 Hz, 1.5H), 1.51 (dd, J = 11.2, 8.2 Hz, 0.5H) ppm; no interchangeable H was observed. 98 rac -5-(5-chloro-2-((1-hydroxy-2-methylbut-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 455.152; observed value: 456.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 0.8 Hz, 1H), 8.10 (s, 1H), 7.46 (dd, J = 7.5, 3.5 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.31 - 7.16 (m, 3H), 6.91 (d, J = 7.5 Hz, 1H), 6.69 (d, J = 1.2 Hz, 1H), 6.44 (s, 1H), 5.63 (s, 2H), 4.92 (t, J = 5.7 Hz, 1H), 3.70 - 3.39 (m, 2H), 1.99 - 1.84 (m, 1H), 1.73 - 1.60 (m, 1H), 1.25 (d, J = 4.6 Hz, 3H), 0.80 (td, J = 7.5, 3.2 Hz, 3H) ppm. 99 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-chloro-6-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one SB1 ESI-MS calculated m/z value: 487.098; observed value: 488.0 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.12 (dd, J = 1.9, 0.8 Hz, 1H), 8.10 (s, 1H), 7.55 - 7.45 (m, 2H), 7.41 (dt, J = 8.2, 1.0 Hz, 1H), 7.32 (ddd, J = 9.6, 8.3, 1.2 Hz, 1H), 6.98 (d, J = 7.6 Hz, 1H), 6.89 (t, J = 7.5 Hz, 1H), 6.63 (d, J = 1.0 Hz, 1H), 5.67 (d, J = 1.5 Hz, 2H), 4.71 (dt, J = 18.2, 5.3 Hz, 1H), 3.66 - 3.44 (m, 3H), 1.01 (dtd, J = 13.0, 8.0, 4.9 Hz, 1H), 0.47 - 0.28 (m, 3H), 0.28 - 0.21 (m, 1H) ppm. 100 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2,6-dichlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one SB1 ESI-MS calculated m/z value: 503.068; observed value: 504.0 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.23 - 8.03 (m, 2H), 7.57 (d, J = 0.8 Hz, 1H), 7.56 (s, 1H), 7.54 - 7.43 (m, 2H), 6.98 (dd, J = 7.5, 0.9 Hz, 1H), 6.89 (t, J = 7.4 Hz, 1H), 6.64 (d, J = 0.9 Hz, 1H), 5.75 (s, 2H), 4.71 (dt, J = 18.2, 5.3 Hz, 1H), 3.63 - 3.44 (m, 3H), 1.06 - 0.96 (m, 1H), 0.49 - 0.28 (m, 3H), 0.24 (td, J = 5.4, 3.4 Hz, 1H) ppm. 101 4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-6-((1-hydroxy-2-methylprop-2-yl)amino)nicotinamide S2 ESI-MS calculated m/z value: 432.171; observed value: 432.9 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.50 (s, 1H), 8.20 (d, J = 0.8 Hz, 1H), 7.56 (d, J = 7.5 Hz, 1H), 7.44 - 7.35 (m, 2H), 7.32 - 7.16 (m, 3H), 7.00 - 6.94 (m, 1H), 6.69 - 6.65 (m, 1H), 5.64 (s, 2H), 4.93 (t, J = 5.7 Hz, 1H), 3.58 (d, J = 5.7 Hz, 2H), 1.35 (s, 6H) ppm. 102 Peak 1 rel- 6-((1-(2,2-difluorocyclopropyl)-2-hydroxyethyl)amino)-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro-5- H -pyrazolo[4,3- c ]pyridin-5-yl)nicotinamide S2 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 25 to 35% MeOH (topped with 20 mM ammonia), 75 to 65% _CO₂ ; flow rate 100 mL/min); rt = 3.96 min. ESI-MS calculated m/z value: 480.152; observed value: 481.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.51 (s, 1H), 8.20 (d, J = 0.9 Hz, 1H), 8.06 (s, 1H), 7.57 (d, J = 7.6 Hz, 1H), 7.40 (s, 1H), 7.32 - 7.17 (m, 3H), 7.01 - 6.95 (m, 1H), 6.68 - 6.64 (m, 1H), 5.65 (s, 2H), 5.12 - 5.08 (m, 1H), 4.13 - 4.09 (m, 1H), 3.56 (d, J = 4.8 Hz, 2H), 2.03 - 1.90 (m, 1H), 1.67 - 1.56 (m, 1H), 1.42 - 1.35 (m, 1H) ppm. 103 Peak 2 rel- 6-((1-(2,2-difluorocyclopropyl)-2-hydroxyethyl)amino)-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro-5- H -pyrazolo[4,3- c ]pyridin-5-yl)nicotinamide S2 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 25 to 35% MeOH (topped with 20 mM ammonia), 75 to 65% _CO₂ ; flow rate 100 mL/min); rt = 7.05 min. ESI-MS calculated m/z value: 480.152; observed value: 481.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.51 (s, 1H), 8.20 (d, J = 0.8 Hz, 1H), 8.10 (s, 1H), 7.57 (d, J = 7.5 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.32 - 7.17 (m, 3H), 7.00 - 6.93 (m, 1H), 6.66 (s, 1H), 5.65 (s, 2H), 5.20 - 5.16 (m, 1H), 4.13 - 4.09 (m, 1H), 3.56 (d, J = 4.9 Hz, 2H), 2.03 - 1.90 (m, 1H), 1.67 - 1.56 (m, 1H), 1.41 - 1.37 (m, 1H) ppm. 104 rac -5-(5-fluoro-2-((2-hydroxy-1-(1-methylcyclopropyl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 451.182; observed value: 453.2 (M+1) ⁺ . ¹ H NMR (500 MHz, methanol - _{d 4} ) δ 7.95 (d, 1H), 7.75 (d, 1H), 7.20 - 7.19 (d, 1H), 7.15 - 7.13 (m, 1H), 7.01- 6.99 (m, 1H), 6.95 - 6.90 (m, 2H), 6.64 - 6.63 (d, 1H), 6.42 - 6.41 (d, 1H), 5.40 (s, 2H), 3.56 - 3.53 (m, 1H), 3.44 - 3.40 (m, 1H), 3.32 - 3.30 (m, 1H), 0.87 (s, 3H), 0.38 - 0.36 (m, 1H), 0.31 - 0.29 (m, 1H), 0.12 - 0.08 (m, 1H), 0.02 - 0.00 (m, 1H) ppm; no interchangeable H was observed. 105 5-(5-chloro-2-((1,3-dihydroxy-2-methylpropyl-2-yl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 473.102; observed value: 474.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.21 (d, J = 0.8 Hz, 1H), 8.12 (s, 1H), 7.52 (dd, J = 7.7, 1.6 Hz, 1H), 7.45 (d, J = 7.5 Hz, 1H), 7.36 (dtd, J = 17.5, 7.4, 1.7 Hz, 2H), 7.10 (dd, J = 7.5, 1.9 Hz, 1H), 6.90 (dd, J = 7.6, 0.9 Hz, 1H), 6.77 (s, 1H), 6.45 (s, 1H), 5.68 (d, J = 3.0 Hz, 2H), 4.89 (d, J = 7.5 Hz, 2H), 3.69 - 3.55 (m, 4H), 1.28 (s, 3H) ppm. 106 4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-6-((1-hydroxy-2-methylprop-2-yl)amino)nicotinamide S1 ESI-MS calculated m/z value: 448.141; observed value: 448.9 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.51 (s, 1H), 8.23 (d, J = 0.8 Hz, 1H), 7.55 (d, J = 7.5 Hz, 1H), 7.51 (dd, J = 7.7, 1.5 Hz, 1H), 7.41 - 7.30 (m, 3H), 7.10 (dd, J = 7.5, 1.9 Hz, 1H), 6.96 (dd, J = 7.6, 0.9 Hz, 1H), 6.68 (s, 1H), 5.68 (s, 2H), 4.94 (t, J = 5.6 Hz, 1H), 3.60 - 3.56 (m, 2H), 1.35 (s, 6H) ppm. 107 rac -5-(5-fluoro-2-((1-hydroxy-3,3-dimethylbut-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 453.198; observed value: 454.4 (M+1) ⁺ . ^¹H NMR (500 MHz, methanol - _d⁴ ) δ 8.20 (d, 1H), 7.99 (d, 1H), 7.45 - 7.43 (dd, 1H), 7.39 - 7.38 (m, 1H), 7.27 - 7.24 (m, 1H), 7.20 - 7.14 (m, 2H), 6.89 - 6.87 (d, 1H), 6.68 - 6.67 (d, 1H), 5.64 (s, 2H), 3.94 - 3.92 (m, 1H), 3.89 - 3.86 (dd, 1H), 3.57 - 3.54 (m, 1H), 1.02 (s, 9H) ppm; no interchangeable H was observed. 108 Forward and reverse mixtures 5-(5-fluoro-2-((1-(hydroxymethyl)-3-methylcyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 451.182; observed value: 452.3 (M+1) ⁺ . 109 5-(5-fluoro-2-((1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 437.166; observed value: 438.3 (M+1) ⁺ . 110 rac -5-(5-chloro-2-((1,4-dihydroxy-2-methylbut-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 471.147; observed value: 472.2 (M+1) ⁺ . ¹ H NMR (500 MHz, methanol -d ₄ ) δ 8.20 (s, 1H), 8.13 (s, 1H), 7.39 (tdd, J = 7.4, 5.2, 1.7 Hz, 1H), 7.33 (dd, J = 7.6, 2.2 Hz, 1H), 7.27 (td, J = 7.5, 1.8 Hz, 1H), 7.23 - 7.14 (m, 2H), 6.88 (d, J = 7.5 Hz, 1H), 6.67 (s, 1H), 5.65 (d, J = 3.1 Hz, 2H), 3.90 - 3.55 (m, 4H), 2.29 - 2.15 (m, 1H), 2.10 - 1.96 (m, 1H), 1.38 (s, 3H) ppm; no interchangeable H was observed. 111 Peak 1: Forward or Reverse 5-(5-chloro-2-((4-hydroxy-1-(hydroxymethyl)cyclohexyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 497.163; observed value: 498.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.8 Hz, 1H), 8.08 (s, 1H), 7.47 (d, J = 7.5 Hz, 1H), 7.40 (dddd, J = 8.2, 7.2, 5.4, 1.9 Hz, 1H), 7.30 - 7.17 (m, 4H), 6.96 - 6.88 (m, 1H), 6.76 (s, 1H), 5.63 (s, 2H), 4.74 (t, J = 5.6 Hz, 1H), 4.45 (d, J = 4.4 Hz, 1H), 3.67 (dd, J = 10.6, 5.7 Hz, 1H), 3.57 (dd, J = 10.5, 5.6 Hz, 1H), 3.37 (dt, J = 10.2, 5.3 Hz, 1H), 2.32 (d, J = 11.9 Hz, 1H), 2.24 (d, J = 11.8 Hz, 1H), 1.58 (d, J = 12.1 Hz, 3H), 1.46 - 1.30 (m, 3H) ppm. 112 Peak 2: Reverse or forward 5-(5-chloro-2-((4-hydroxy-1-(hydroxymethyl)cyclohexyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 497.163; observed value: 498.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 0.8 Hz, 1H), 8.08 (s, 1H), 7.45 (d, J = 7.5 Hz, 1H), 7.40 (dddd, J = 8.7, 7.3, 5.4, 1.9 Hz, 1H), 7.30 - 7.14 (m, 4H), 6.91 (d, J = 7.6 Hz, 1H), 6.72 (s, 1H), 5.63 (s, 2H), 4.80 (t, J = 5.7 Hz, 1H), 4.33 (d, J = 3.5 Hz, 1H), 3.76 - 3.68 (m, 1H), 3.67 (q, J = 2.9 Hz, 1H), 3.65 - 3.59 (m, 1H), 1.90 - 1.84 (m, 4H), 1.63 (s, 2H), 1.44 - 1.34 (m, 2H) ppm. 113 5-(2-((3,3-difluoro-1-(hydroxymethyl)cyclobutyl)amino)-5-fluoropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 473.147; observed value: 474.3 (M+1) ⁺ . 114 Rotation-resistant isomer 1 5-(5-chloro-2-((( S )-1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-6-methyl-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S4 ESI-MS calculated m/z value: 457.107; observed value: 458.2 (M+1) ⁺ . 115 Peak 1 rel- 4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-6-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)nicotinamide S1 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% 1:1 MeOH:MeCN (added with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 5.37 min. ESI-MS calculated m/z value: 490.152; observed value: 491.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.50 (s, 1H), 8.23 (d, J = 0.8 Hz, 1H), 7.86 (d, J = 8.6 Hz, 1H), 7.58 (d, J = 7.5 Hz, 1H), 7.52 (dd, J = 7.7, 1.5 Hz, 1H), 7.41 - 7.30 (m, 2H), 7.12 - 7.07 (m, 1H), 6.96 (dd, J = 7.6, 0.9 Hz, 1H), 6.63 (s, 1H), 5.68 (s, 2H), 4.85 - 4.82 (m, 1H), 4.22 - 4.18 (m, 1H), 3.80 (t, J = 8.0 Hz, 1H), 3.74 - 3.67 (m, 1H), 3.60 (q, J = 7.8 Hz, 1H), 3.49 - 3.37 (m, 4H), 1.99 - 1.89 (m, 1H), 1.68 - 1.57 (m, 1H) ppm. 116 Peak 2 rel- 4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-6-((( 1R )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)nicotinamide S1 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% 1:1 MeOH:MeCN (added with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 7.92 min. ESI-MS calculated m/z value: 490.152; observed value: 491.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.50 (s, 1H), 8.23 (d, J = 0.8 Hz, 1H), 7.84 (d, J = 8.5 Hz, 1H), 7.57 (d, J = 7.5 Hz, 1H), 7.54 - 7.49 (m, 1H), 7.41 - 7.30 (m, 2H), 7.10 (d, J = 7.5 Hz, 1H), 6.96 (dd, J = 7.6, 0.9 Hz, 1H), 6.62 (s, 1H), 5.68 (s, 2H), 4.85 - 4.81 (m, 1H), 4.21 - 4.18 (m, 1H), 3.80 - 3.71 (m, 2H), 3.63 (q, J = 7.8 Hz, 1H), 3.59 - 3.45 (m, 3H), 3.41 (t, J = 8.0 Hz, 1H), 2.00 - 1.96 (m, 1H), 1.67 - 1.59 (m, 1H) ppm. 117 Peak 3 rel- 4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-6-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)nicotinamide S1 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% 1:1 MeOH:MeCN (added with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 9.32 min. ESI-MS calculated m/z value: 490.152; observed value: 491.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.50 (s, 1H), 8.23 (d, J = 0.8 Hz, 1H), 7.84 (d, J = 8.6 Hz, 1H), 7.57 (d, J = 7.6 Hz, 1H), 7.52 (dd, J = 7.7, 1.5 Hz, 1H), 7.41 - 7.30 (m, 2H), 7.10 (d, J = 7.4 Hz, 1H), 6.96 (dd, J = 7.6, 0.9 Hz, 1H), 6.62 (s, 1H), 5.68 (s, 2H), 4.85 - 4.81 (m, 1H), 4.21 - 4.18 (m, 1H), 3.80 - 3.71 (m, 2H), 3.63 (q, J = 7.9 Hz, 1H), 3.58 - 3.46 (m, 3H), 3.42 (t, J = 8.1 Hz, 1H), 2.01 - 1.96 (m, 1H), 1.65 - 1.61 (m, 1H) ppm. 118 Peak 4 rel- 4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-6-((( 1R )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)nicotinamide S1 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% 1:1 MeOH:MeCN (added with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 11.33 min. ESI-MS calculated m/z value: 490.152; observed value: 491.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.51 (s, 1H), 8.23 (d, J = 0.9 Hz, 1H), 7.88 - 7.84 (m, 1H), 7.58 (d, J = 7.5 Hz, 1H), 7.52 (dd, J = 7.8, 1.5 Hz, 1H), 7.41 - 7.31 (m, 2H), 7.10 (d, J = 7.4 Hz, 1H), 6.96 (d, J = 7.6 Hz, 1H), 6.63 (s, 1H), 5.68 (s, 2H), 4.84 (m, 1H), 4.20 (m, 1H), 3.80 (t, J = 8.1 Hz, 1H), 3.74 - 3.67 (m, 1H), 3.60 (q, J = 7.8 Hz, 1H), 3.53 - 3.37 (m, 4H), 2.01 - 1.88 (m, 1H), 1.68 - 1.57 (m, 1H) ppm. 119 Peak 1 rel- ( R )-4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-6-((1,4-dihydroxybutyl-2-yl)amino)nicotinamide S1 Lux ^™ Cellulose-2 column, 5 µm particle size, 15 cm x 30 mm, purchased from Phenomenex, Inc. (mobile phase: 30% MeOH (topped with 20 mM ammonia), 70% _CO₂ ; flow rate 100 mL/min); rt = 12.42 min. ESI-MS calculated m/z value: 464.136; observed value: 465.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.51 (s, 1H), 8.23 (d, J = 0.8 Hz, 1H), 7.73 (s, 1H), 7.56 (d, J = 7.5 Hz, 1H), 7.52 (dd, J = 7.8, 1.5 Hz, 1H), 7.41 - 7.30 (m, 2H), 7.09 (d, J = 7.4 Hz, 1H), 6.96 (dd, J = 7.6, 0.9 Hz, 1H), 6.61 (s, 1H), 5.68 (s, 2H), 4.81 - 4.78 (m, 1H), 4.48 - 4.45 (m, 1H), 4.25 - 4.21 (m, 1H), 3.50 - 3.43 (m, 4H), 1.83 - 1.80 (m, 1H), 1.66 - 1.60 (m, 1H) ppm. 120 Peak 2 rel- ( S )-4-(1-(2-chlorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-6-((1,4-dihydroxybutyl-2-yl)amino)nicotinamide S1 Lux ^™ Cellulose-2 column, 5 µm particle size, 15 cm x 30 mm, purchased from Phenomenex Corporation (mobile phase: 30% MeOH (topped with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 14.86 min. ESI-MS calculated m/z value: 464.136; observed value: 465.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.50 (s, 1H), 8.23 (d, J = 0.8 Hz, 1H), 7.73 (s, 1H), 7.56 (d, J = 7.6 Hz, 1H), 7.52 (dd, J = 7.8, 1.5 Hz, 1H), 7.41 - 7.30 (m, 2H), 7.09 (d, J = 7.6 Hz, 1H), 6.96 (dd, J = 7.5, 0.9 Hz, 1H), 6.61 (s, 1H), 5.68 (s, 2H), 4.81 - 4.78 (m, 1H), 4.48 - 4.45 (m, 1H), 4.25 - 4.21 (m, 1H), 3.51 - 3.44 (m, 4H), 1.83 - 1.80 (m, 1H), 1.66 - 1.59 (m, 1H) ppm. 121 rel- 5-(5-chloro-2-((( 2S ^* , 4S )-1,4-dihydroxyhexyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 485.163; observed value: 486.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 1.0 Hz, 1H), 8.13 (d, J = 1.3 Hz, 1H), 7.50 - 7.44 (m, 1H), 7.43 - 7.37 (m, 1H), 7.31 - 7.18 (m, 3H), 6.92 (d, J = 7.6 Hz, 1H), 6.81 (t, J = 7.9 Hz, 1H), 6.61 (s, 1H), 5.64 (d, J = 3.9 Hz, 2H), 4.68 (dt, J = 13.9, 5.4 Hz, 1H), 4.39 (dd, J = 10.7, 5.5 Hz, 1H), 4.04 (s, 1H), 3.55 - 3.37 (m, 3H), 1.77 - 1.69 (m, 1H), 1.60 - 1.41 (m, 2H), 1.36 - 1.28 (m, 1H), 0.86 (tt, J = 7.5, 2.1 Hz, 3H)ppm. 122 rel- 5-(5-chloro-2-((( 2S ^* , 4R ) -1,4 -dihydroxyhexyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 485.163; observed value: 486.3 (M+1) ⁺ . 123 rel- 5-(5-chloro-2-(( 2R ^* , 4S )-1,4-dihydroxyhexyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 485.163; observed value: 486.2 (M+1) ⁺ . 124 rel- 5-(5-chloro-2-(((2R ^* , 4R )-1,4-dihydroxyhexyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 485.163; observed value: 486.3 (M+1) ⁺ . 125 rel- 5-(5-chloro-2-((( 2S ^* , 4R )-1,4-dihydroxypentan-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 471.147; observed value: 472.2 (M+1) ⁺ . 126 rel- 5-(5-chloro-2-(((2S ^* , 4S )-1,4-dihydroxypentan-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 471.147; observed value: 472.3 (M+1) ⁺ . 127 ( S )-5-(5-chloro-2-((1,4-dihydroxy-4-methylpentan-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 485.163; observed value: 486.3 (M+1) ⁺ . 128 Peak 1 5-(5-chloro-2-(((( 1r , 3r )-1,3-dihydroxycyclobutyl)methyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 469.132; observed value: 470.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.9 Hz, 1H), 8.14 (s, 1H), 7.46 (d, J = 7.5 Hz, 1H), 7.40 (dddd, J = 8.3, 7.3, 5.4, 1.9 Hz, 1H), 7.32 - 7.17 (m, 3H), 6.95 - 6.91 (m, 1H), 6.87 (t, J = 5.8 Hz, 1H), 6.72 (s, 1H), 5.69 - 5.58 (m, 2H), 4.98 (s, 1H), 4.87 (d, J = 5.4 Hz, 1H), 4.28 (ddt, J = 13.1, 7.3, 5.9 Hz, 1H), 3.40 (t, J = 4.5 Hz, 2H), 2.18 - 2.11 (m, 2H), 1.90 (ddd, J = 12.8, 6.0, 1.8 Hz, 2H) ppm. 129 Peak 2 5-(5-chloro-2-((((1 s ,3 s )-1,3-dihydroxycyclobutyl)methyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 469.132; observed value: 470.3 (M+1) ⁺ . ¹ H NMR (500 MHz, methanol - _{d 4} ) δ 8.20 (d, J = 0.8 Hz, 1H), 8.13 (d, J = 0.5 Hz, 1H), 7.42 - 7.36 (m, 1H), 7.35 (s, 1H), 7.27 (td, J = 7.6, 1.8 Hz, 1H), 7.22 - 7.14 (m, 2H), 6.88 (dt, J = 7.6, 0.8 Hz, 1H), 6.71 (d, J = 0.5 Hz, 1H), 5.65 (d, J = 3.4 Hz, 2H), 3.94 (p, J = 7.2 Hz, 1H), 3.43 (s, 2H), 2.60 - 2.54 (m, 2H), 1.99 (dd, J = 12.3, 7.2 Hz, 2H) ppm; no interchangeable H was observed. 130 ( S )-5-(2-((1-cyclopropyl-2-hydroxyethyl)amino)-5-fluoropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 455.157; observed value: 456.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 7.89 (d, J = 0.8 Hz, 1H), 7.80 (d, J = 1.8 Hz, 1H), 7.36 (d, J = 7.7 Hz, 1H), 7.25 (tt, J = 8.4, 6.6 Hz, 1H), 6.97 - 6.87 (m, 2H), 6.76 - 6.71 (m, 1H), 6.38 - 6.30 (m, 2H), 5.39 (s, 2H), 4.43 (t, J = 5.4 Hz, 1H), 3.35 - 3.25 (m, J = 5.2 Hz, 2H), 3.22 (tt, J = 8.2, 5.0 Hz, 1H), 0.76 (qt, J = 8.2, 5.0 Hz, 1H), 0.24 - 0.04 (m, 3H), -0.01 (dtd, J = 9.1, 5.3, 3.8 Hz, 1H) ppm. 131 ( S )-6-((1-cyclopropyl-2-hydroxyethyl)amino)-4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4-dihydro-5 -H -pyrazolo[4,3-c]pyridin-5-yl)nicotinamide S7 ESI-MS calculated m/z value: 462.162; observed value: 463.4 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.47 (s, 1H), 8.15 (d, J = 0.8 Hz, 1H), 7.85 (s, 1H), 7.60 (d, J = 7.5 Hz, 1H), 7.55 - 7.43 (m, 1H), 7.21 - 7.11 (m, 2H), 7.00 (d, J = 7.6 Hz, 1H), 6.62 (s, 1H), 5.63 (s, 2H), 4.80 (s, 1H), 3.71 - 3.50 (m, 3H), 1.06 - 1.00 (m, 1H), 0.50 - 0.37 (m, 2H), 0.36 - 0.18 (m, 2H) ppm. 132 4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)-6-((1-hydroxy-2-methylprop-2-yl)amino)nicotinamide S7 ESI-MS calculated m/z value: 450.162; observed value: 451.0 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.51 (s, 1H), 8.15 (d, J = 0.8 Hz, 1H), 7.59 (d, J = 7.5 Hz, 1H), 7.54 - 7.44 (m, 1H), 7.40 (s, 1H), 7.20 - 7.12 (m, 2H), 7.00 (dd, J = 7.5, 0.8 Hz, 1H), 6.68 (d, J = 0.5 Hz, 1H), 5.63 (s, 2H), 4.93 (t, J = 5.6 Hz, 1H), 3.58 (s, 2H), 1.35 (s, 6H)ppm. 133 Peak 1 rel- 1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 Chiral Art Amylose-SA column, 5 µm particle size, 25 cm x 20 mm, purchased from YMC Europe GmbH (mobile phase: 35 to 50% 1: ⁱ PrOH:MeCN (supplemented with 0.2% DMIPA), 65 to 50% _CO2 ; flow rate 100 mL/min); rt = 4.38 min. ESI-MS calculated m/z value: 485.167; observed value: 486.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (d, J = 0.8 Hz, 1H), 8.08 (d, J = 1.8 Hz, 1H), 7.61 (dd, J = 7.6, 0.6 Hz, 1H), 7.49 (tt, J = 8.5, 6.7 Hz, 1H), 7.21 - 7.12 (m, 2H), 6.98 (d, J = 7.5 Hz, 1H), 6.67 (d, J = 8.8 Hz, 1H), 6.62 (d, J = 5.0 Hz, 1H), 5.63 (s, 2H), 4.70 (t, J = 5.4 Hz, 1H), 4.01 - 3.90 (m, 1H), 3.81 (t, J = 8.0 Hz, 1H), 3.71 (td, J = 8.2, 4.3 Hz, 1H), 3.60 (td, J = 8.1, 7.1 Hz, 1H), 3.46 - 3.39 (m, 3H), 1.99 - 1.90 (m, 1H), 1.67 (dq, J = 12.3, 8.2 Hz, 1H) ppm; no interchangeable H was observed. 134 Peak 2 rel- 1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((( 1R )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3-c]pyridin-4-one S7 Chiral Art Amylose-SA column, 5 µm particle size, 25 cm x 20 mm, purchased from YMC Europe GmbH (mobile phase: 35 to 50% 1: ⁱ PrOH:MeCN (supplemented with 0.2% DMIPA), 65 to 50% _CO2 ; flow rate 100 mL/min); rt = 5.07 min. ESI-MS calculated m/z value: 485.167; observed value: 487.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (d, J = 0.8 Hz, 1H), 8.08 (d, J = 1.8 Hz, 1H), 7.61 (d, J = 7.7 Hz, 1H), 7.49 (tt, J = 8.4, 6.6 Hz, 1H), 7.21 - 7.12 (m, 2H), 6.98 (d, J = 7.5 Hz, 1H), 6.67 (s, 1H), 6.63 (d, J = 5.0 Hz, 1H), 5.63 (s, 2H), 3.94 (s, 2H), 3.82 - 3.71 (m, 2H), 3.63 (td, J = 8.2, 7.0 Hz, 1H), 3.56 - 3.40 (m, 3H), 2.03 - 1.93 (m, 1H), 1.64 (dq, J = 12.1, 8.3 Hz, 1H) ppm; no interchangeable H was observed. 135 Peak 3 rel- 1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((( 1R )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 Chiral Art Amylose-SA column, 5 µm particle size, 25 cm x 20 mm, purchased from YMC Europe GmbH (mobile phase: 35 to 50% 1: ⁱ PrOH:MeCN (supplemented with 0.2% DMIPA), 65 to 50% _CO2 ; flow rate 100 mL/min); rt = 5.61 min. ESI-MS calculated m/z value: 485.167; observed value: 486.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (d, J = 0.8 Hz, 1H), 8.08 (d, J = 1.8 Hz, 1H), 7.61 (dd, J = 7.6, 0.6 Hz, 1H), 7.49 (tt, J = 8.4, 6.6 Hz, 1H), 7.21 - 7.12 (m, 2H), 6.98 (d, J = 7.5 Hz, 1H), 6.67 (d, J = 8.8 Hz, 1H), 6.62 (d, J = 5.0 Hz, 1H), 5.63 (s, 2H), 4.71 (t, J = 5.4 Hz, 1H), 3.96 (s, 1H), 3.81 (t, J = 8.0 Hz, 1H), 3.71 (td, J = 8.2, 4.3 Hz, 1H), 3.60 (td, J = 8.1, 7.0 Hz, 1H), 3.42 (dt, J = 10.8, 7.5 Hz, 3H), 2.50 - 2.43 (m, 1H), 2.00 - 1.90 (m, 1H), 1.67 (dq, J = 12.1, 8.2 Hz, 1H) ppm. 136 Peak 4 rel- 1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 Chiral Art Amylose-SA column, 5 µm particle size, 25 cm x 20 mm, purchased from YMC Europe GmbH (mobile phase: 35 to 50% 1: ⁱ PrOH:MeCN (supplemented with 0.2% DMIPA), 65 to 50% _CO2 ; flow rate 100 mL/min); rt = 8.39 min. ESI-MS calculated m/z value: 485.167; observed value: 486.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (d, J = 0.8 Hz, 1H), 8.08 (d, J = 1.8 Hz, 1H), 7.61 (dd, J = 7.6, 0.6 Hz, 1H), 7.49 (tt, J = 8.4, 6.6 Hz, 1H), 7.21 - 7.12 (m, 2H), 6.98 (d, J = 7.5 Hz, 1H), 6.67 - 6.59 (m, 2H), 5.63 (s, 2H), 4.69 (t, J = 5.3 Hz, 1H), 3.98 - 3.92 (m, 1H), 3.79 (t, J = 8.1 Hz, 1H), 3.75 (dt, J = 8.2, 4.1 Hz, 1H), 3.63 (td, J = 8.2, 7.1 Hz, 1H), 3.56 - 3.41 (m, 3H), 1.97 (dtd, J = 12.1, 7.7, 4.1 Hz, 1H), 1.64 (dq, J = 12.2, 8.3 Hz, 1H), 1.04 (d, J = 6.1 Hz, 1H) ppm. 137 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-fluoro-6-methylbenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one SB1 ESI-MS calculated m/z value: 467.152; observed value: 468.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.12 - 8.10 (m, 1H), 8.10 (s, 1H), 7.47 (dd, J = 18.0, 7.5 Hz, 1H), 7.30 (td, J = 7.9, 6.0 Hz, 1H), 7.13 - 7.02 (m, 2H), 6.93 (d, J = 7.5 Hz, 2H), 6.65 (d, J = 1.5 Hz, 1H), 5.63 - 5.53 (m, 2H), 3.60 - 3.41 (m, 3H), 2.43 (s, 3H), 1.00 (qt, J = 8.2, 5.0 Hz, 1H), 0.44 (qd, J = 5.5, 2.7 Hz, 1H), 0.41 - 0.26 (m, 2H), 0.26 - 0.18 (m, 1H) ppm; no interchangeable H was observed. 138 rac -5-(2-((1,1-difluoro-3-hydroxy-2-methylpropyl-2-yl)amino)-5-fluoropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 461.147; observed value: 462.2 (M+1) ⁺ . 139 Rotation-resistant isomer 1 5-(5-chloro-2-((( S )-1-cyclopropyl-2-hydroxyethyl)amino)-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 467.152; observed value: 468.1 (M+1) ⁺ . ^¹H NMR (400 MHz, methanol - _d⁴ ) δ 8.18 (s, 1H), 7.99 (s, 1H), 7.38–7.33 (m, 1H), 7.28–7.25 (m, 1H), 7.21–7.11 (m, 3H), 6.90 (d, J = 7.8 Hz, 1H), 5.69 (d, J = 7.3 Hz, 1H), 5.63 (s, 2H), 3.80–3.70 (m, 2H), 3.66–3.60 (m, 1H), 1.87 (s, 3H), 1.14–1.05 (m, 1H), 0.58–0.28 (m, 4H) ppm; no interchangeable H was observed. 140 Rotation-resistant isomer 2 5-(5-chloro-2-((( S )-1-cyclopropyl-2-hydroxyethyl)amino)-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 467.152; observed value: 468.1 (M+1) ⁺ . ¹ H NMR (400 MHz, methanol -d ₄ ) δ 8.18 (d, J = 0.9 Hz, 1H), 7.99 (s, 1H), 7.39-7.33 (m, 1H), 7.29-7.23 (m, 2H), 7.18-7.12 (m, 2H), 6.90 (d, J = 7.3 Hz, 1H), 5.69 (d, J = 7.8 Hz, 0.5H), 5.63 (s, 2H), 3.78 (dd, J = 11.0, 4.6 Hz, 1H), 3.72 (dd, J = 10.8, 4.8 Hz, 1H), 3.65-3.58 (m, 1H), 1.88 (s, 3H), 1.15–1.06 (m, 1H), 0.58–0.27 (m, 4H) ppm; no interchangeable H was observed. 141 5-(2-(((1,2,3-thiadiazol-5-yl)methyl)amino)-5-chloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 485.064; observed value: 486.0 (M+1) ⁺ . 142 5-(5-chloro-2-((1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 471.127; observed value: 472.0 (M+1) ⁺ . 143 Forward rac -1-(2,6-difluorobenzyl)-5-(5-fluoro-2-(( 3S , 4R )-3-(hydroxymethyl)tetrahydro- 2H- piperan-4-yl)amino)pyridin-4-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 485.167; observed value: 486.3 (M+1) ⁺ . 144 rac -6-((4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-5-fluoropyridin-2-yl)amino)methyl) 3-oxoline-3-one S7 ESI-MS calculated m/z value: 484.147; observed value: 485.3 (M+1) ⁺ . 145 ( S )-2-((5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-4-sideoxy-4,5-dihydro- 1H- pyrazolo[4,3- c ]pyridin-1-yl)methyl)-3-fluorobenzonitrile SB1 ESI-MS calculated m/z value: 478.132; observed value: 479.32 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.15 (s, 1H), 8.09 (s, 1H), 7.86 - 7.78 (m, 1H), 7.66 (dd, J = 8.2, 4.0 Hz, 2H), 7.52 (dd, J = 14.6, 7.5 Hz, 1H), 7.00 (d, J = 7.6 Hz, 1H), 6.90 (t, J = 6.5 Hz, 1H), 6.63 (s, 1H), 5.74 (s, 2H), 4.72 (s, 1H), 3.51 (d, J = 11.6 Hz, 3H), 1.01 (d, J = 9.4 Hz, 1H), 0.48 - 0.27 (m, 3H), 0.24 (s, 1H) ppm. 146 4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)-6-((1-(hydroxymethyl)cyclobutyl)amino)nicotinamide S7 ESI-MS calculated m/z value: 462.162; observed value: 463.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.48 (d, J = 0.4 Hz, 1H), 8.15 (d, J = 0.8 Hz, 1H), 7.99 (s, 1H), 7.59 (d, J = 7.5 Hz, 1H), 7.54 - 7.44 (m, 1H), 7.21 - 7.12 (m, 2H), 7.00 (dd, J = 7.6, 0.9 Hz, 1H), 6.56 (s, 1H), 5.63 (s, 2H), 4.91 (t, J = 5.5 Hz, 1H), 3.70 (s, 2H), 2.25 - 2.10 (m, 4H), 1.91 - 1.71 (m, 2H) ppm. 147 Peak 1 rel- ( S )-5-(5-chloro-2-((1-(6-sideoxy-1,6-dihydropyridin-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 490.132; observed value: 491.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 11.40 (s, 1H), 8.17 (t, J = 1.2 Hz, 2H), 7.50 (dt, J = 9.5, 2.9 Hz, 1H), 7.46 (dd, J = 12.4, 7.5 Hz, 1H), 7.44 - 7.38 (m, 1H), 7.36 (d, J = 7.9 Hz, 1H), 7.31 - 7.18 (m, 4H), 6.92 (d, J = 7.5 Hz, 1H), 6.61 (d, J = 4.3 Hz, 1H), 6.32 (d, J = 9.5 Hz, 1H), 5.64 (d, J = 3.9 Hz, 2H), 4.83 (d, J = 9.7 Hz, 1H), 1.39 (dd, J = 6.9, 4.6 Hz, 3H) ppm. 148 Peak 2 rel- ( R )-5-(5-chloro-2-((1-(6-sideoxy-1,6-dihydropyridin-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 490.132; observed value: 491.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 11.40 (s, 1H), 8.17 (t, J = 1.2 Hz, 2H), 7.50 (dt, J = 9.5, 2.9 Hz, 1H), 7.46 (dd, J = 12.4, 7.5 Hz, 1H), 7.40 (tdd, J = 7.5, 5.2, 1.8 Hz, 1H), 7.36 (d, J = 7.9 Hz, 1H), 7.31 - 7.18 (m, 4H), 6.92 (d, J = 7.5 Hz, 1H), 6.61 (d, J = 4.3 Hz, 1H), 6.32 (d, J = 9.4 Hz, 1H), 5.64 (d, J = 3.8 Hz, 2H), 4.83 (s, 1H), 1.39 (dd, J = 6.9, 4.6 Hz, 3H) ppm. 149 Peak 1 rel- 5-(5-chloro-2-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% 1:1 MeOH: ⁱ PrOH (added with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 5.78 min. ESI-MS calculated m/z value: 501.138; observed value: 502.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (d, J = 1.6 Hz, 2H), 7.55 - 7.45 (m, 2H), 7.21 - 7.13 (m, 2H), 6.96 (d, J = 7.6 Hz, 2H), 6.65 (d, J = 1.4 Hz, 1H), 5.63 (s, 2H), 4.74 (dt, J = 20.9, 5.4 Hz, 1H), 4.01 (s, 1H), 3.81 (td, J = 8.3, 1.9 Hz, 1H), 3.71 (ddt, J = 8.1, 4.3, 1.9 Hz, 1H), 3.64 - 3.56 (m, 1H), 3.51 - 3.37 (m, 3H), 2.47 (d, J = 8.0 Hz, 1H), 1.95 (dtt, J = 12.0, 8.1, 4.1 Hz, 1H), 1.65 (dq, J = 12.3, 7.9 Hz, 1H) ppm. 150 Peak 2 rel- 5-(5-chloro-2-((( 1R )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% 1:1 MeOH: ⁱ PrOH (added with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 7.95 min. ESI-MS calculated m/z value: 501.138; observed value: 502.3 (M+1) ⁺ . ¹ H NMR (500 MHz, methanol - _{d 4} ) δ 8.14 (d, J = 0.8 Hz, 1H), 8.13 (s, 1H), 7.45 (tt, J = 8.5, 6.5 Hz, 1H), 7.37 (dd, J = 14.2, 7.5 Hz, 1H), 7.10 - 7.02 (m, 2H), 6.97 (d, J = 7.5 Hz, 1H), 6.66 (d, J = 1.9 Hz, 1H), 5.66 (s, 2H), 4.07 (s, 1H), 3.96 - 3.88 (m, 2H), 3.82 - 3.71 (m, 2H), 3.68 - 3.58 (m, 2H), 2.67 - 2.57 (m, 1H), 2.12 (dd, J = 7.2, 2.8 Hz, 1H), 1.83 - 1.72 (m, 1H) ppm; no interchangeable H was observed. 151 Peak 3 rel- 5-(5-chloro-2-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% 1:1 MeOH: ⁱ PrOH (added with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 10.06 min. ESI-MS calculated m/z value: 501.138; observed value: 502.3 (M+1) ⁺ . ¹ H NMR (500 MHz, methanol -d ₄ ) δ 8.14 (s, 1H), 8.13 (s, 1H), 7.45 (tt, J = 8.4, 6.5 Hz, 1H), 7.37 (dd, J = 14.3, 7.5 Hz, 1H), 7.10 - 7.02 (m, 2H), 6.97 (d, J = 7.5 Hz, 1H), 6.66 (d, J = 1.9 Hz, 1H), 5.66 (s, 2H), 4.07 (s, 1H), 3.96 - 3.88 (m, 2H), 3.82 - 3.71 (m, 2H), 3.68 - 3.58 (m, 2H), 2.62 (qd, J = 8.1, 4.4 Hz, 1H), 2.13 (ddt, J = 12.0, 7.8, 4.0 Hz, 1H), 1.83 - 1.72 (m, 1H) ppm; no interchangeable H was observed. 152 Peak 4 rel- 5-(5-chloro-2-((( 1R )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% 1:1 MeOH: ⁱ PrOH (added with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 12.67 min. ESI-MS calculated m/z value: 501.138; observed value: 502.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (d, J = 1.3 Hz, 2H), 7.55 - 7.45 (m, 2H), 7.21 - 7.13 (m, 2H), 6.96 (t, J = 8.8 Hz, 2H), 6.65 (d, J = 1.4 Hz, 1H), 5.63 (s, 2H), 4.74 (d, J = 20.4 Hz, 1H), 4.01 (s, 1H), 3.81 (td, J = 8.0, 1.9 Hz, 1H), 3.75 - 3.67 (m, 1H), 3.64 - 3.56 (m, 1H), 3.50 - 3.37 (m, 3H), 2.47 (d, J = 8.1 Hz, 1H), 1.94 (ddd, J = 12.1, 8.5, 4.8 Hz, 1H), 1.72 - 1.60 (m, 1H) ppm. 153 rac -5-(5-chloro-2-((2-cyclopropyl-1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 485.143; observed value: 486.0 (M+1) ⁺ . 154 5-(5-chloro-2-((4-(hydroxymethyl)tetrahydro- 2H- piperan-4-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 501.138; observed value: 502.4 (M+1) ⁺ . 155 rac -5-(2-((2-cyclopropyl-1-hydroxypropyl-2-yl)amino)-5-fluoropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 469.173; observed value: 470.0 (M+1) ⁺ . 156 1-(2,6-Difluorobenzyl)-5-(5-fluoro-2-((1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 455.157; observed value: 456.3 (M+1) ⁺ . 157 rac -5-(5-chloro-2-((( 1R , 2R , 4R )-2,4-dihydroxycyclopentyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 469.132; observed value: 470.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 - 8.15 (m, 2H), 7.47 (dd, J = 7.5, 4.1 Hz, 1H), 7.44 - 7.36 (m, 1H), 7.32 - 7.17 (m, 3H), 7.02 (d, J = 6.6 Hz, 1H), 6.93 (d, J = 7.5 Hz, 1H), 6.60 (d, J = 2.1 Hz, 1H), 5.70 - 5.59 (m, 2H), 4.95 (dd, J = 9.5, 4.9 Hz, 1H), 4.62 (dd, J = 4.5, 2.6 Hz, 1H), 4.12 (s, 1H), 4.02 (s, 1H), 3.83 (q, J = 5.0 Hz, 1H), 2.25 (dt, J = 13.8, 7.1 Hz, 1H), 1.99 (tdd, J = 12.0, 7.5, 4.0 Hz, 1H), 1.63 (dq, J = 13.8, 7.0 Hz, 1H), 1.43 (dt, J = 12.9, 6.2 Hz, 1H) ppm. 158 1-(2,6-difluorobenzyl)-5-(5-fluoro-2-(((1 s ,3 s )-3-hydroxycyclobutyl)amino)pyridin-4-yl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 441.141; observed value: 443.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.12 (d, J = 0.8 Hz, 1H), 8.09 (d, J = 1.8 Hz, 1H), 7.59 (dd, J = 7.6, 0.6 Hz, 1H), 7.49 (tt, J = 8.4, 6.6 Hz, 1H), 7.20 - 7.11 (m, 2H), 7.00 - 6.93 (m, 2H), 6.48 (d, J = 5.0 Hz, 1H), 5.62 (s, 2H), 5.04 (d, J = 6.0 Hz, 1H), 3.89 - 3.78 (m, 1H), 3.75 - 3.64 (m, 1H), 2.67 - 2.58 (m, 2H), 1.76 - 1.65 (m, 2H) ppm. 159 ( S )-4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-6-((4,4,4-trifluoro-1-hydroxybutyl-2-yl)amino)nicotinamide S7 ESI-MS calculated m/z value: 504.133; observed value: 505.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.56 (s, 1H), 8.15 (d, J = 0.8 Hz, 1H), 7.96 (d, J = 7.8 Hz, 1H), 7.61 (d, J = 7.5 Hz, 1H), 7.54 - 7.44 (m, 1H), 7.21 - 7.12 (m, 2H), 7.01 (dd, J = 7.5, 0.8 Hz, 1H), 6.63 (s, 1H), 5.63 (s, 2H), 5.14 (s, 1H), 4.54 (s, 1H), 3.54 (s, 1H), 3.46 - 3.37 (m, 1H), 2.72 - 2.64 (m, 1H) ppm; no interchangeable H was observed. 160 5-(2-((3,3-bis(hydroxymethyl)cyclobutyl)amino)-5-chloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 501.138; observed value: 502.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.14 (s, 1H), 8.12 (d, J = 0.8 Hz, 1H), 7.54 - 7.44 (m, 2H), 7.21 (d, J = 7.0 Hz, 1H), 7.21 - 7.12 (m, 2H), 6.94 (dd, J = 7.6, 0.8 Hz, 1H), 6.52 (s, 1H), 5.62 (s, 2H), 4.54 (t, J = 5.5 Hz, 1H), 4.49 (t, J = 5.3 Hz, 1H), 4.19 (s, 1H), 3.43 (d, J = 5.5 Hz, 2H), 3.32 (d, J = 5.3 Hz, 2H), 2.15 - 2.05 (m, 2H), 1.76 - 1.68 (m, 2H) ppm. 161 Peak 1 rel- 1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((( 1R , 2R )-2-hydroxycyclobutyl)amino)pyridin-4-yl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralpak® IC column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 33% MeOH (topped with 20 mM ammonia), 67% _CO2 ; flow rate 100 mL/min); rt = 5.00 min. ESI-MS calculated m/z value: 441.141; observed value: 442.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.11 (dd, J = 10.9, 1.3 Hz, 2H), 7.59 (dd, J = 7.6, 0.6 Hz, 1H), 7.53 - 7.44 (m, 1H), 7.20 - 7.11 (m, 2H), 7.05 (d, J = 7.5 Hz, 1H), 7.00 - 6.95 (m, 1H), 6.55 (d, J = 4.9 Hz, 1H), 5.62 (s, 2H), 5.28 (s, 1H), 3.94 (q, J = 8.0 Hz, 1H), 3.85 (q, J = 7.7 Hz, 1H), 2.04 - 1.92 (m, 2H), 1.47 - 1.36 (m, 1H), 1.23 - 1.14 (m, 1H) ppm. 162 Peak 2 rel- 1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((( 1S , 2S )-2-hydroxycyclobutyl)amino)pyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralpak® IC column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 33% MeOH (topped with 20 mM ammonia), 67% _CO2 ; flow rate 100 mL/min); rt = 6.02 min. ESI-MS calculated m/z value: 441.141; observed value: 442.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.12 (d, J = 0.8 Hz, 1H), 8.10 (d, J = 1.8 Hz, 1H), 7.59 (dd, J = 7.6, 0.6 Hz, 1H), 7.53 - 7.44 (m, 1H), 7.20 - 7.11 (m, 2H), 7.05 (d, J = 7.4 Hz, 1H), 7.00 - 6.95 (m, 1H), 6.55 (d, J = 4.9 Hz, 1H), 5.62 (s, 2H), 5.27 (s, 1H), 3.98 - 3.90 (m, 1H), 3.89 - 3.81 (m, 1H), 2.03 - 1.92 (m, 2H), 1.47 - 1.36 (m, 1H), 1.27 - 1.14 (m, 1H) ppm. 163 rac -6-((2-cyclopropyl-1-hydroxypropyl-2-yl)amino)-4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4-dihydro-5- H -pyrazolo[4,3- c ]pyridin-5-yl)nicotinamide S7 ESI-MS calculated m/z value: 476.177; observed value: 477.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.49 (s, 1H), 8.16 (d, J = 0.8 Hz, 1H), 7.60 (d, J = 7.5 Hz, 1H), 7.54 - 7.44 (m, 1H), 7.32 (s, 1H), 7.21 - 7.12 (m, 2H), 7.03 - 6.98 (m, 1H), 6.74 (s, 1H), 5.63 (s, 2H), 4.91 (s, 1H), 3.80 - 3.76 (m, 1H), 3.69 - 3.66 (m, 1H), 1.54 - 1.48 (m, 1H), 1.04 (s, 3H), 0.47 - 0.38 (m, 1H), 0.41 - 0.32 (m, 3H) ppm. 164 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2,3,6-trifluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one SB1 ESI-MS calculated m/z value: 489.118; observed value: 490.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.14 (dd, J = 2.0, 0.8 Hz, 1H), 8.09 (s, 1H), 7.56 (dd, J = 9.6, 5.1 Hz, 1H), 7.54 - 7.48 (m, 1H), 7.22 (dddt, J = 9.3, 5.7, 3.6, 2.0 Hz, 1H), 6.96 (d, J = 7.6 Hz, 1H), 6.91 (dd, J = 8.2, 5.2 Hz, 1H), 6.62 (d, J = 1.2 Hz, 1H), 5.69 - 5.63 (m, 2H), 4.73 (s, 1H), 3.59 - 3.46 (m, 3H), 1.00 (qt, J = 8.1, 5.0 Hz, 1H), 0.43 (dtt, J = 9.2, 7.0, 2.9 Hz, 1H), 0.40 - 0.27 (m, 2H), 0.23 (dtdd, J = 9.0, 7.0, 4.8, 2.1 Hz, 1H) ppm. 165 Peak 1 rel- 5-(5-chloro-2-(((2S ^* , 4R )-1,4-dihydroxypentan-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 Lux ^™ Cellulose-2 column, 5 µm particle size, 15 cm x 30 mm, purchased from Phenomenex Corporation (mobile phase: 33% MeOH (topped with 20 mM ammonia), 67% _CO₂ ; flow rate 100 mL/min); rt = 5.27 min. ESI-MS calculated m/z value: 489.138; observed value: 490.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.14 - 8.12 (m, 2H), 7.54 - 7.45 (m, 2H), 7.21 - 7.13 (m, 2H), 6.95 (d, J = 7.5 Hz, 1H), 6.80 (t, J = 8.8 Hz, 1H), 6.62 (d, J = 1.0 Hz, 1H), 5.63 (s, 2H), 4.70 (d, J = 12.9 Hz, 1H), 4.54 - 4.46 (m, 1H), 4.04 (s, 1H), 3.72 (s, 1H), 3.50 - 3.44 (m, 1H), 3.43 - 3.33 (m, 1H), 1.68 - 1.58 (m, 1H), 1.48 (ddd, J = 13.5, 9.8, 3.3 Hz, 1H), 1.09 (d, J = 6.2 Hz, 3H) ppm. 166 Peak 2 rel- 5-(5-chloro-2-(((2S ^* , 4S )-1,4-dihydroxypentan-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 Lux ^™ Cellulose-2 column, 5 µm particle size, 15 cm x 30 mm, purchased from Phenomenex Corporation (mobile phase: 33% MeOH (topped with 20 mM ammonia), 67% _CO₂ ; flow rate 100 mL/min); rt = 7.42 min. ESI-MS calculated m/z value: 489.138; observed value: 490.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (d, J = 1.2 Hz, 2H), 7.54 - 7.45 (m, 2H), 7.21 - 7.13 (m, 2H), 6.95 (d, J = 7.5 Hz, 1H), 6.81 (t, J = 7.7 Hz, 1H), 6.62 (s, 1H), 5.63 (s, 2H), 4.70 (d, J = 12.6 Hz, 1H), 4.45 (dd, J = 10.4, 4.8 Hz, 1H), 4.02 (s, 1H), 3.74 (d, J = 9.3 Hz, 1H), 3.50 (d, J = 10.5 Hz, 1H), 3.45 - 3.34 (m, 1H), 1.71 - 1.53 (m, 2H), 1.08 (dd, J = 6.1, 4.0 Hz, 3H) ppm. 167 Peak 1 rel- 1-(2,6-difluorobenzyl)-5-(2-(((2S ^* , 4R )-1,4-dihydroxypentan-2-yl)amino)-5-fluoropyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 Lux ^™ Cellulose-2 column, 5 µm particle size, 15 cm x 30 mm, purchased from Phenomenex Corporation (mobile phase: 30% MeOH (topped with 20 mM ammonia), 70% _CO₂ ; flow rate 100 mL/min); rt = 4.69 min. ESI-MS calculated m/z value: 473.167; observed value: 474.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (d, J = 0.8 Hz, 1H), 8.08 (d, J = 1.9 Hz, 1H), 7.60 (d, J = 7.6 Hz, 1H), 7.49 (tt, J = 8.4, 6.6 Hz, 1H), 7.21 - 7.12 (m, 2H), 6.98 (d, J = 7.6 Hz, 1H), 6.59 (d, J = 5.0 Hz, 1H), 6.52 (d, J = 8.0 Hz, 1H), 5.63 (s, 2H), 4.67 (t, J = 5.4 Hz, 1H), 4.52 (d, J = 4.8 Hz, 1H), 3.99 (s, 1H), 3.80 - 3.66 (m, 1H), 3.47 (dt, J = 9.9, 4.7 Hz, 1H), 3.38 (dt, J = 10.9, 5.7 Hz, 1H), 1.62 (ddd, J = 13.5, 9.4, 3.8 Hz, 1H), 1.46 (ddd, J = 13.5, 9.7, 3.2 Hz, 1H), 1.09 (d, J = 6.2 Hz, 3H) ppm. 168 Peak 2 rel- 1-(2,6-difluorobenzyl)-5-(2-(((2S ^* , 4S )-1,4-dihydroxypentan-2-yl)amino)-5-fluoropyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 Lux ^™ Cellulose-2 column, 5 µm particle size, 15 cm x 30 mm, purchased from Phenomenex Corporation (mobile phase: 30% MeOH (topped with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 5.84 min. ESI-MS calculated m/z value: 473.167; observed value: 474.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (d, J = 0.9 Hz, 1H), 8.08 (d, J = 1.9 Hz, 1H), 7.60 (d, J = 7.5 Hz, 1H), 7.49 (tt, J = 8.4, 6.6 Hz, 1H), 7.21 - 7.12 (m, 2H), 6.98 (d, J = 7.6 Hz, 1H), 6.59 (d, J = 5.0 Hz, 1H), 6.52 (d, J = 8.2 Hz, 1H), 5.63 (s, 2H), 4.67 (t, J = 5.5 Hz, 1H), 4.44 (d, J = 4.8 Hz, 1H), 3.97 (d, J = 7.7 Hz, 1H), 3.75 (dt, J = 12.0, 6.1 Hz, 1H), 3.50 (dt, J = 9.8, 4.7 Hz, 1H), 3.39 (dt, J = 10.7, 5.5 Hz, 1H), 1.66 (dt, J = 12.7, 6.2 Hz, 1H), 1.57 (dt, J = 13.5, 7.4 Hz, 1H), 1.08 (d, J = 6.1 Hz, 3H) ppm. 169 Peak 1 rel- 1-(2-chloro-6-fluorobenzyl)-5-(2-(((2S ^* , 4R )-1,4-dihydroxypentan-2-yl)amino)-5-fluoropyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S9 Lux ^™ Cellulose-2 column, 5 µm particle size, 15 cm x 30 mm, purchased from Phenomenex Corporation (mobile phase: 33% MeOH (topped with 20 mM ammonia), 67% _CO₂ ; flow rate 100 mL/min); rt = 6.16 min. ESI-MS calculated m/z value: 489.138; observed value: 490.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.12 (d, J = 0.8 Hz, 1H), 8.08 (d, J = 1.9 Hz, 1H), 7.59 (dd, J = 7.5, 0.6 Hz, 1H), 7.49 (td, J = 8.2, 6.1 Hz, 1H), 7.41 (dt, J = 8.0, 1.0 Hz, 1H), 7.31 (ddd, J = 9.5, 8.3, 1.2 Hz, 1H), 7.01 (dd, J = 7.6, 0.8 Hz, 1H), 6.60 (d, J = 5.0 Hz, 1H), 6.51 (d, J = 8.1 Hz, 1H), 5.67 (d, J = 1.5 Hz, 2H), 4.67 (t, J = 5.5 Hz, 1H), 4.52 (d, J = 4.7 Hz, 1H), 3.99 (s, 1H), 3.77 - 3.68 (m, 1H), 3.47 (dt, J = 10.1, 4.9 Hz, 1H), 3.38 (dt, J = 10.5, 5.9 Hz, 1H), 1.62 (ddd, J = 13.5, 9.4, 3.8 Hz, 1H), 1.46 (ddd, J = 13.4, 9.7, 3.2 Hz, 1H), 1.09 (d, J = 6.2 Hz, 3H) ppm. 170 Peak 2 rel- 1-(2-chloro-6-fluorobenzyl)-5-(2-(((2S ^* , 4S )-1,4-dihydroxypentan-2-yl)amino)-5-fluoropyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S9 Lux ^™ Cellulose-2 column, 5 µm particle size, 15 cm x 30 mm, purchased from Phenomenex Corporation (mobile phase: 33% MeOH (topped with 20 mM ammonia), 67% _CO₂ ; flow rate 100 mL/min); rt = 7.83 min. ESI-MS calculated m/z value: 489.138; observed value: 490.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.12 (d, J = 0.8 Hz, 1H), 8.08 (d, J = 1.9 Hz, 1H), 7.60 (d, J = 7.6 Hz, 1H), 7.49 (td, J = 8.2, 6.1 Hz, 1H), 7.41 (dt, J = 8.0, 1.0 Hz, 1H), 7.31 (ddd, J = 9.6, 8.3, 1.2 Hz, 1H), 7.01 (d, J = 7.6 Hz, 1H), 6.59 (d, J = 5.0 Hz, 1H), 6.51 (d, J = 8.2 Hz, 1H), 5.67 (d, J = 1.6 Hz, 2H), 4.67 (t, J = 5.5 Hz, 1H), 4.44 (d, J = 4.9 Hz, 1H), 3.96 (d, J = 9.5 Hz, 1H), 3.75 (dt, J = 11.9, 6.1 Hz, 1H), 3.54 - 3.46 (m, 1H), 3.39 (dt, J = 10.9, 5.6 Hz, 1H), 1.66 (dt, J = 13.6, 6.2 Hz, 1H), 1.57 (dt, J = 13.6, 7.4 Hz, 1H), 1.08 (d, J = 6.1 Hz, 3H)ppm. 171 rac -1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((4,4,4-trifluoro-3-hydroxy-3-methylbutyl)amino)pyridin-4-yl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 511.144; observed value: 512.3 (M+1) ⁺ . 172 Peak 1 rel- 1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((( 1R , 2S )-2-hydroxycyclobutyl)amino)pyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralpak® IG column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% 1:1 MeOH:MeCN (added with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 9.65 min. ESI-MS calculated m/z value: 441.141; observed value: 442.3 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.13 (d, J = 0.8 Hz, 1H), 8.09 (d, J = 1.9 Hz, 1H), 7.57 (d, J = 7.6 Hz, 1H), 7.53 - 7.43 (m, 1H), 7.21 - 7.10 (m, 2H), 6.98 (d, J = 7.5 Hz, 1H), 6.68 (d, J = 5.0 Hz, 1H), 6.62 (d, J = 6.9 Hz, 1H), 5.63 (s, 2H), 5.19 - 5.14 (m, 1H), 4.36 - 4.32 (m, 1H), 4.27 - 4.23 (m, 1H), 2.09 - 2.00 (m, 2H), 1.90 - 1.73 (m, 2H) ppm. 173 Peak 2 rel- 1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((( 1S , 2R )-2-hydroxycyclobutyl)amino)pyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralpak® IG column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% 1:1 MeOH: MeCN (added with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 13.22 min. ESI-MS calculated m/z value: 441.141; observed value: 442.3 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.13 (d, J = 0.8 Hz, 1H), 8.10 (d, J = 1.9 Hz, 1H), 7.61 - 7.55 (m, 1H), 7.55 - 7.43 (m, 1H), 7.17 (t, J = 8.0 Hz, 2H), 6.98 (d, J = 7.5 Hz, 1H), 6.69 (d, J = 5.0 Hz, 1H), 6.63 (d, J = 6.9 Hz, 1H), 5.63 (s, 2H), 5.16 (d, J = 4.7 Hz, 1H), 4.37 - 4.33 (m, 1H), 4.28 - 4.24 (m, 1H), 2.10 - 1.99 (m, 2H), 1.91 - 1.73 (m, 2H) ppm. 174 5-(5-chloro-2-((R)-1-(( R )-5-sideoxypyrrolidin-3-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 480.148; observed value: 481.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.8 Hz, 1H), 8.16 (s, 1H), 7.54 - 7.46 (m, 2H), 7.40 (dddd, J = 8.3, 7.3, 5.4, 1.9 Hz, 1H), 7.31 - 7.24 (m, 2H), 7.24 - 7.18 (m, 1H), 7.01 (d, J = 8.4 Hz, 1H), 6.92 (d, J = 7.6 Hz, 1H), 6.59 (d, J = 1.5 Hz, 1H), 5.64 (d, J = 2.6 Hz, 2H), 4.05 (s, 1H), 3.33 - 3.26 (m, 1H), 3.03 (dt, J = 9.7, 6.3 Hz, 1H), 2.58 (dt, J = 14.9, 7.7 Hz, 1H), 2.21 (ddd, J = 16.9, 9.1, 7.9 Hz, 1H), 2.04 (dd, J = 16.7, 8.3 Hz, 1H), 1.10 (dd, J = 9.6, 6.5 Hz, 3H) ppm. 175 5-(5-chloro-2-(((1 s ,3 s )-3-hydroxycyclobutyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 457.112; observed value: 458.0 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.14 (s, 1H), 8.12 (d, J = 0.8 Hz, 1H), 7.49 (dd, J = 7.1, 5.6 Hz, 2H), 7.24 (d, J = 7.0 Hz, 1H), 7.20 - 7.12 (m, 2H), 6.94 (d, J = 7.5 Hz, 1H), 6.51 (s, 1H), 5.62 (s, 2H), 5.06 (d, J = 6.0 Hz, 1H), 3.91 - 3.64 (m, 2H), 2.66 - 2.59 (m, 2H), 1.73 (s, 2H) ppm. 176 rac -5-(5-chloro-2-((1,4-dihydroxy-3-methylbut-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 489.138; observed value: 490.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 - 8.11 (m, 2H), 7.54 - 7.46 (m, 2H), 7.17 (t, J = 8.0 Hz, 2H), 6.96 (d, J = 7.5 Hz, 1H), 6.73 (t, J = 10.1 Hz, 1H), 6.69 (d, J = 1.1 Hz, 1H), 5.63 (s, 2H), 4.74 - 4.64 (m, 1H), 4.57 (dt, J = 9.3, 5.5 Hz, 1H), 4.08 (s, 1H), 3.52 (tt, J = 10.7, 5.6 Hz, 1H), 3.45 (td, J = 11.0, 5.7 Hz, 0.5H), 3.37 (dq, J = 10.4, 5.4 Hz, 0.5H), 1.94 (dt, J = 12.2, 6.2 Hz, 1H), 0.94 (d, J = 7.3 Hz, 1H), 0.87 (dd, J = 6.9, 1.2 Hz, 2H) ppm; no interchangeable H was observed. 177 Peak 1 rel- 5-(5-chloro-2-(((2S ^* , 4S )-1,4-dihydroxyhexyl-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 Palmar Art Amylose-SA column, 5 µm particle size, 25 cm x 20 mm, purchased from YMC Europe GmbH (mobile phase: 20% MeOH (topped with 20 mM ammonia), 80% _CO2 ; flow rate 100 mL/min); rt = 6.31 min. ESI-MS calculated m/z value: 503.154; observed value: 504.2 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.13 (q, J = 1.0 Hz, 2H), 7.56 - 7.44 (m, 2H), 7.17 (t, J = 8.0 Hz, 2H), 6.95 (d, J = 7.5 Hz, 1H), 6.81 (t, J = 7.7 Hz, 1H), 6.62 (s, 1H), 5.63 (s, 2H), 4.68 (dt, J = 10.8, 5.4 Hz, 1H), 4.39 (dd, J = 8.2, 5.5 Hz, 1H), 4.04 (s, 1H), 3.56 - 3.38 (m, 3H), 1.78 - 1.70 (m, 1H), 1.56 - 1.39 (m, 2H), 1.31 (dt, J = 13.7, 7.1 Hz, 1H), 0.86 (t, J = 7.3 Hz, 3H) ppm. 178 rel- ( R ^* )-6-(( R ) -1 -((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)ethyl) 3-one S2 ESI-MS calculated m/z value: 496.143; observed value: 497.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 - 8.16 (m, 1H), 8.15 (d, J = 2.1 Hz, 1H), 7.96 (d, J = 2.9 Hz, 1H), 7.49 (dd, J = 14.4, 7.5 Hz, 1H), 7.40 (dddd, J = 8.3, 7.3, 5.4, 1.9 Hz, 1H), 7.31 - 7.18 (m, 3H), 7.01 - 6.97 (m, 1H), 6.93 (d, J = 7.4 Hz, 1H), 6.66 (d, J = 3.6 Hz, 1H), 5.64 (d, J = 2.7 Hz, 2H), 4.28 (s, 1H), 4.10 (dd, J = 16.4, 2.0 Hz, 1H), 4.02 (d, J = 16.4 Hz, 1H), 3.76 (dq, J = 9.1, 4.5 Hz, 1H), 3.23 - 3.15 (m, 2H), 1.18 (dd, J = 9.5, 6.8 Hz, 3H) ppm. 179 5-(5-chloro-2-(((1 s ,3 s )-1-(hydroxymethyl)-3-methoxycyclobutyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 501.138; observed value: 502.1 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.14 - 8.09 (m, 2H), 7.55 - 7.43 (m, 2H), 7.17 (dd, J = 16.2, 8.2 Hz, 3H), 6.95 (d, J = 7.5 Hz, 1H), 6.53 (s, 1H), 5.62 (s, 2H), 4.91 (t, J = 5.6 Hz, 1H), 3.77 - 3.69 (m, 1H), 3.64 - 3.49 (m, 2H), 3.12 (s, 3H), 2.66 - 2.57 (m, 2H), 1.97 - 1.88 (m, 2H) ppm. 180 Peak 1: Forward or Reverse 5-(5-chloro-2-((3-hydroxy-3-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralpak® ID column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% MeOH (topped with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 7.42 min. ESI-MS calculated m/z value: 487.122; observed value: 488.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (s, 1H), 8.11 (d, J = 0.8 Hz, 1H), 7.54 - 7.44 (m, 2H), 7.21 (d, J = 6.5 Hz, 1H), 7.21 - 7.12 (m, 2H), 6.97 - 6.92 (m, 1H), 6.52 (s, 1H), 5.62 (s, 2H), 4.80 (s, 1H), 4.68 - 4.64 (m, 1H), 4.36 - 4.32 (m, 1H), 3.26 (s, 2H), 2.20 - 2.11 (m, 2H), 2.07 - 1.98 (m, 2H) ppm. 181 Peak 2: Reverse or forward 5-(5-chloro-2-((3-hydroxy-3-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralpak® ID column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% MeOH (topped with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 9.06 min. ESI-MS calculated m/z value: 487.122; observed value: 488.2 (M+1) ⁺ . ^¹H NMR (500 MHz, methanol - _d⁴ ) δ 8.12 (dd, J = 3.1, 0.6 Hz, 2H), 7.48 - 7.39 (m, 1H), 7.35 (d, J = 7.6 Hz, 1H), 7.09 - 7.00 (m, 2H), 6.95 (dd, J = 7.6, 0.8 Hz, 1H), 6.56 (d, J = 0.5 Hz, 1H), 5.64 (s, 2H), 3.91 - 3.81 (m, 1H), 3.52 (s, 2H), 2.71 - 2.61 (m, 2H), 1.97 - 1.89 (m, 2H) ppm; no interchangeable H was observed. 182 Forward rac -5-(5-chloro-2-((( 3S , 6S )-6-(hydroxymethyl)tetrahydro- 2H- piperan-3-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 501.138; observed value: 502.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.15 (s, 1H), 8.12 (d, J = 0.7 Hz, 1H), 7.54 - 7.44 (m, 2H), 7.21 - 7.12 (m, 2H), 7.08 (d, J = 7.3 Hz, 1H), 6.95 (d, J = 7.5 Hz, 1H), 6.77 (d, J = 2.4 Hz, 1H), 5.62 (s, 2H), 4.57 (q, J = 5.4 Hz, 1H), 3.95 - 3.91 (m, 1H), 3.91 - 3.83 (m, 1H), 3.61 - 3.54 (m, 1H), 3.46 - 3.39 (m, 1H), 3.38 - 3.27 (m, 2H), 1.94 - 1.84 (m, 1H), 1.81 - 1.70 (m, 1H), 1.59 - 1.44 (m, 2H) ppm. 183 Peak 1: Forward or Reverse 5-(5-chloro-2-((3-hydroxy-3-(trifluoromethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 525.099; observed value: 526.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.20 (s, 1H), 8.12 (d, J = 0.8 Hz, 1H), 7.54 - 7.43 (m, 3H), 7.21 - 7.12 (m, 2H), 6.95 (d, J = 7.5 Hz, 1H), 6.56 (s, 1H), 6.47 (s, 1H), 5.62 (s, 2H), 4.54 (q, J = 7.8 Hz, 1H), 2.47 - 2.38 (m, 2H), 2.28 - 2.19 (m, 2H) ppm. 184 Peak 2: Reverse or forward 5-(5-chloro-2-((3-hydroxy-3-(trifluoromethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 525.099; observed value: 526.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.19 (s, 1H), 8.12 (s, 1H), 7.54 - 7.44 (m, 3H), 7.20 - 7.12 (m, 2H), 6.95 (d, J = 7.6 Hz, 1H), 6.62 (s, 1H), 6.58 (s, 1H), 5.62 (d, J = 1.9 Hz, 2H), 4.04 - 3.98 (m, 1H), 2.90 - 2.80 (m, 2H), 2.20 - 2.11 (m, 2H) ppm. 185 Peak 1 rel- 1-(2,6-difluorobenzyl)-5-(2-(((2S ^* , 4S )-1,4-dihydroxyhexyl-2-yl)amino)-5-fluoropyridin-4-yl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralcel® OJ column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 10% MeOH (topped with 20 mM ammonia), 90% _CO2 ; flow rate 100 mL/min); rt = 5.53 min. ESI-MS calculated m/z value: 487.183; observed value: 488.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (d, J = 0.8 Hz, 1H), 8.08 (d, J = 1.8 Hz, 1H), 7.59 (d, J = 7.5 Hz, 1H), 7.49 (tt, J = 8.4, 6.6 Hz, 1H), 7.16 (t, J = 8.0 Hz, 2H), 6.98 (d, J = 7.6 Hz, 1H), 6.59 (d, J = 5.0 Hz, 1H), 6.51 (d, J = 8.1 Hz, 1H), 5.63 (s, 2H), 4.66 (t, J = 5.4 Hz, 1H), 4.39 (d, J = 5.4 Hz, 1H), 3.98 (s, 1H), 3.51 (dt, J = 10.3, 4.8 Hz, 2H), 3.42 (dt, J = 10.6, 5.4 Hz, 1H), 1.74 (dt, J = 13.7, 6.0 Hz, 1H), 1.54 - 1.39 (m, 2H), 1.32 (dq, J = 13.9, 7.3 Hz, 1H), 0.86 (t, J = 7.4 Hz, 3H) ppm. 186 Peak 2 rel- 5-(5-chloro-2-(((2S ^* , 4R )-1,4-dihydroxyhexyl-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 Palmar Art Amylose-SA column, 5 µm particle size, 25 cm x 20 mm, purchased from YMC Europe GmbH (mobile phase: 20% MeOH (topped with 20 mM ammonia), 80% _CO2 ; flow rate 100 mL/min); rt = 9.71 min. ESI-MS calculated m/z value: 503.154; observed value: 504.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.13 (q, J = 1.2 Hz, 2H), 7.54 - 7.45 (m, 2H), 7.17 (t, J = 8.0 Hz, 2H), 6.95 (d, J = 7.5 Hz, 1H), 6.81 (t, J = 8.1 Hz, 1H), 6.62 (s, 1H), 5.63 (s, 2H), 4.70 (s, 1H), 4.39 (s, 1H), 4.04 (s, 1H), 3.50 (s, 3H), 1.79 - 1.70 (m, 1H), 1.55 - 1.39 (m, 2H), 1.32 (dt, J = 14.0, 7.2 Hz, 1H), 0.86 (t, J = 7.3 Hz, 3H) ppm. 187 5-(5-chloro-2-(((1 s ,3 s )-3-hydroxy-3-methylcyclobutyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 471.127; observed value: 472.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.15 (s, 1H), 8.12 (d, J = 0.8 Hz, 1H), 7.54 - 7.44 (m, 2H), 7.23 (d, J = 6.7 Hz, 1H), 7.20 - 7.12 (m, 2H), 6.94 (d, J = 7.5 Hz, 1H), 6.54 (s, 1H), 5.62 (d, J = 2.5 Hz, 2H), 4.96 (s, 1H), 3.80 (m, 1H), 2.42 - 2.32 (m, 2H), 1.96 - 1.88 (m, 2H), 1.25 (s, 3H) ppm. 188 rel- ( S ^* )-6-(( S )-1-((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro-5 H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)ethyl) succinyl-3-one S2 ESI-MS calculated m/z value: 496.143; observed value: 497.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (s, 2H), 7.97 (dd, J = 15.4, 3.8 Hz, 1H), 7.48 (dd, J = 7.5, 6.2 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.30 - 7.19 (m, 3H), 7.05 (t, J = 7.6 Hz, 1H), 6.93 (d, J = 7.6 Hz, 1H), 6.63 (d, J = 1.2 Hz, 1H), 5.64 (d, J = 3.2 Hz, 2H), 4.15 (s, 1H), 4.13 - 4.00 (m, 2H), 3.66 (dddd, J = 13.2, 9.9, 6.3, 3.7 Hz, 1H), 3.27 - 3.16 (m, 2H), 1.19 (t, J = 6.8 Hz, 3H) ppm. 189 Peak 1 rel- 5-(5-chloro-2-((( 2R )-1,4-dihydroxy-3-methylbut-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 20% MeOH (topped with 20 mM ammonia), 80% _CO2 ; flow rate 100 mL/min); rt = 7.13 min. ESI-MS calculated m/z value: 489.138; observed value: 490.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.15 - 8.11 (m, 2H), 7.55 - 7.45 (m, 2H), 7.21 - 7.13 (m, 2H), 6.96 (d, J = 7.6 Hz, 1H), 6.73 (t, J = 10.0 Hz, 1H), 6.69 (d, J = 1.1 Hz, 1H), 5.63 (s, 2H), 4.68 (dt, J = 16.4, 5.4 Hz, 1H), 4.57 (ddd, J = 9.2, 6.0, 5.0 Hz, 1H), 4.07 (s, 1H), 3.51 - 3.48 (m, 2H), 3.36 (td, J = 10.8, 4.8 Hz, 1H), 3.30 - 3.26 (m, 1H), 1.95 (dq, J = 13.0, 6.7 Hz, 1H), 0.87 (dd, J = 6.9, 1.2 Hz, 3H) ppm. 190 Peaks 2 and 3 rac -5-(5-chloro-2-((1,4-dihydroxy-3-methylbut-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 20% MeOH (topped with 20 mM ammonia), 80% _CO2 ; flow rate 100 mL/min); rt = 10.12 min. ESI-MS calculated m/z value: 489.138; observed value: 490.2 (M+1) ⁺ . 191 Peak 4 rel- 5-(5-chloro-2-((( 2S )-1,4-dihydroxy-3-methylbut-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 20% MeOH (topped with 20 mM ammonia), 80% _CO2 ; flow rate 100 mL/min); rt = 12.01 min. ESI-MS calculated m/z value: 489.138; observed value: 490.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.15 - 8.09 (m, 2H), 7.55 - 7.45 (m, 2H), 7.17 (t, J = 8.0 Hz, 2H), 6.96 (d, J = 7.5 Hz, 1H), 6.74 (t, J = 9.4 Hz, 1H), 6.69 (d, J = 1.1 Hz, 1H), 5.63 (s, 2H), 4.69 (s, 1H), 4.58 (s, 1H), 4.07 (s, 1H), 3.55 - 3.42 (m, 2H), 3.36 (dt, J = 10.8, 5.6 Hz, 1H), 1.94 (dt, J = 13.0, 6.5 Hz, 1H), 0.87 (dd, J = 6.9, 1.2 Hz, 3H) ppm; no interchangeable H was observed. 192 Rotation-resistant isomer 1 rel- 5-(5-chloro-2-(((2S ^* , 4S )-1,4-dihydroxyhexyl-2-yl)amino)-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 499.179; observed value: 500.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.8 Hz, 1H), 8.07 (d, J = 0.7 Hz, 1H), 7.44 - 7.35 (m, 2H), 7.33 - 7.18 (m, 3H), 6.98 - 6.93 (m, 1H), 5.97 (d, J = 7.2 Hz, 1H), 5.69 - 5.59 (m, 2H), 4.64 (t, J = 5.7 Hz, 1H), 4.50 (d, J = 5.3 Hz, 1H), 4.25 - 4.15 (m, 1H), 3.63 - 3.55 (m, 1H), 3.55 - 3.46 (m, 1H), 3.44 - 3.36 (m, 1H), 1.86 - 1.76 (m, 4H), 1.64 - 1.55 (m, 1H), 1.51 - 1.40 (m, 1H), 1.40 - 1.28 (m, 1H), 0.86 (t, J = 7.4 Hz, 3H) ppm. 193 Rotation-resistant isomer 2 rel- 5-(5-chloro-2-(((2S ^* , 4S )-1,4-dihydroxyhexyl-2-yl)amino)-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 499.179; observed value: 500.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.8 Hz, 1H), 8.07 (d, J = 0.7 Hz, 1H), 7.44 - 7.36 (m, 2H), 7.33 - 7.17 (m, 3H), 6.98 - 6.93 (m, 1H), 5.94 (d, J = 7.5 Hz, 1H), 5.64 (s, 2H), 4.68 (t, J = 5.7 Hz, 1H), 4.44 (d, J = 5.3 Hz, 1H), 4.26 - 4.16 (m, 1H), 3.61 - 3.51 (m, 1H), 3.54 - 3.39 (m, 2H), 1.85 - 1.76 (m, 4H), 1.63 - 1.53 (m, 1H), 1.50 - 1.39 (m, 1H), 1.39 - 1.27 (m, 1H), 0.86 (t, J = 7.4 Hz, 3H) ppm. 194 ( S )-4-(1-(2-chloro-6-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-6-((1-cyclopropyl-2-hydroxyethyl)amino)nicotinamide S9 ESI-MS calculated m/z value: 478.132; observed value: 479.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.47 (s, 1H), 8.14 (d, J = 0.8 Hz, 1H), 7.85 (s, 1H), 7.60 (d, J = 7.6 Hz, 1H), 7.52 - 7.44 (m, 1H), 7.43 - 7.38 (m, 1H), 7.35 - 7.27 (m, 1H), 7.03 (d, J = 7.6 Hz, 1H), 6.63 (s, 1H), 5.68 (s, 2H), 4.81 - 4.78 (m, 1H), 3.73 - 3.51 (m, 3H), 1.06 - 1.01 (m, 1H), 0.52 - 0.36 (m, 2H), 0.35 - 0.13 (m, 2H) ppm. 195 rac -5-(5-chloro-2-((( S )-1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(1-(2,6-difluorophenyl)ethyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one SB1 ESI-MS calculated m/z value: 485.143; observed value: 486.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 2.1 Hz, 1H), 8.08 (d, J = 4.7 Hz, 1H), 7.50 - 7.38 (m, 2H), 7.13 (td, J = 8.6, 1.9 Hz, 2H), 6.95 0.99 (qt, J = 8.9, 4.3 Hz, 1H), 0.44 (dt, J = 9.3, 3.9 Hz, 1H), 0.41 - 0.29 (m, 2H), 0.22 (dq, J = 9.5, 3.8 Hz, 1H) ppm; no interchangeable H was observed. 196 Peak 1 rel- 5-(5-chloro-2-((( 1R )-3-hydroxy-1-(hydroxymethyl)cyclopentyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 Lux ^™ i-Amilose-1 column, 5 µm particle size, 25 cm x 21.2 mm, purchased from Phenomenex Corporation (mobile phase: 35% MeOH (supplemented with 0.2% ammonia), 65% _CO₂ ; flow rate 50 mL/min); rt = 7.30 min. ESI-MS calculated m/z value: 483.147; observed value: 484.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.8 Hz, 1H), 8.11 (s, 1H), 7.47 (dd, J = 7.5, 1.4 Hz, 1H), 7.44 - 7.36 (m, 1H), 7.32 - 7.17 (m, 3H), 6.92 (d, J = 7.6 Hz, 1H), 6.84 (s, 1H), 6.69 (d, J = 2.7 Hz, 1H), 5.64 (d, J = 1.8 Hz, 2H), 4.91 (td, J = 5.6, 2.5 Hz, 1H), 4.80 (d, J = 4.9 Hz, 1H), 4.09 (q, J = 5.5 Hz, 1H), 3.63 - 3.44 (m, 2H), 2.10 (dt, J = 13.6, 6.6 Hz, 1H), 2.06 - 1.94 (m, 1H), 1.79 (d, J = 14.0 Hz, 2H), 1.72 (dt, J = 12.4, 6.0 Hz, 1H), 1.61 (dt, J = 12.7, 6.3 Hz, 1H) ppm. 197 Peak 2 rel- 5-(5-chloro-2-((( 1S )-3-hydroxy-1-(hydroxymethyl)cyclopentyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 Lux ^™ i-Amilose-1 column, 5 µm particle size, 25 cm x 21.2 mm, purchased from Phenomenex Corporation (mobile phase: 35% MeOH (supplemented with 0.2% ammonia), 65% _CO₂ ; flow rate 50 mL/min); rt = 8.70 min. ESI-MS calculated m/z value: 483.147; observed value: 484.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.8 Hz, 1H), 8.11 (s, 1H), 7.47 (dd, J = 7.6, 1.4 Hz, 1H), 7.40 (dddd, J = 9.1, 7.3, 5.4, 1.9 Hz, 1H), 7.32 - 7.19 (m, 3H), 6.92 (d, J = 7.6 Hz, 1H), 6.84 (d, J = 2.0 Hz, 1H), 6.69 (d, J = 2.7 Hz, 1H), 5.64 (d, J = 1.9 Hz, 2H), 4.91 (td, J = 5.6, 2.5 Hz, 1H), 4.80 (d, J = 4.8 Hz, 1H), 4.09 (q, J = 5.4 Hz, 1H), 3.64 - 3.45 (m, 2H), 2.10 (dt, J = 13.6, 6.6 Hz, 1H), 2.00 (td, J = 12.7, 6.3 Hz, 1H), 1.85 - 1.76 (m, 2H), 1.72 (dq, J = 13.3, 6.6 Hz, 1H), 1.61 (dt, J = 12.7, 6.4 Hz, 1H) ppm. 198 ( S )-1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((1-hydroxy-3-methylbut-2-yl)amino)pyridin-4-yl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 457.173; observed value: 458.5 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.14 (d, J = 0.8 Hz, 1H), 8.07 (d, J = 1.9 Hz, 1H), 7.61 (d, J = 7.6 Hz, 1H), 7.50 (tt, J = 8.4, 6.7 Hz, 1H), 7.17 (t, J = 8.0 Hz, 2H), 6.98 (d, J = 7.5 Hz, 1H), 6.65 (d, J = 5.0 Hz, 1H), 6.45 (d, J = 8.7 Hz, 1H), 5.63 (s, 2H), 4.57 (t, J = 5.3 Hz, 1H), 3.80 (dd, J = 8.7, 5.7 Hz, 1H), 3.55 - 3.40 (m, J = 5.2 Hz, 2H), 1.98 (dq, J = 13.6, 6.9 Hz, 1H), 0.93 (dd, J = 6.8, 1.9 Hz, 6H) ppm. 199 rac -5-(2-((1-cyclobutyl-2-hydroxyethyl)amino)-5-fluoropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 469.173; observed value: 470.5 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.14 (d, J = 0.8 Hz, 1H), 8.07 (d, J = 1.9 Hz, 1H), 7.65 - 7.58 (m, 1H), 7.50 (tt, J = 8.5, 6.7 Hz, 1H), 7.17 (t, J = 8.0 Hz, 2H), 6.98 (d, J = 7.6 Hz, 1H), 6.63 (d, J = 5.1 Hz, 1H), 6.44 (d, J = 8.6 Hz, 1H), 5.63 (s, 2H), 4.54 (t, J = 5.4 Hz, 1H), 3.94 (dt, J = 8.6, 4.1 Hz, 1H), 3.38 (q, J = 4.1 Hz, 2H), 2.57 (q, J = 8.4 Hz, 1H), 1.98 - 1.90 (m, 2H), 1.89 - 1.70 (m, 4H) ppm. 200 Peak 1 rel- ( R )-5-(5-chloro-2-((3-(hydroxymethyl)tetrahydrofuran-3-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 Lux ^™ Cellulose-4 column, 5 µm particle size, 25 cm x 21.2 mm, purchased from Phenomenex Corporation (mobile phase: 33% MeOH (topped with 20 mM ammonia), 67% _CO₂ ; flow rate 100 mL/min); rt = 7.40 min. ESI-MS calculated m/z value: 487.122; observed value: 488.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.14 (d, J = 2.9 Hz, 1H), 8.13 (d, J = 0.8 Hz, 1H), 7.49 (ddd, J = 9.4, 7.9, 6.1 Hz, 2H), 7.21 - 7.11 (m, 3H), 6.96 (d, J = 7.6 Hz, 1H), 6.66 (s, 1H), 5.63 (s, 2H), 4.99 (s, 1H), 3.91 - 3.63 (m, 6H), 2.18 - 2.05 (m, 2H) ppm. 201 Peak 2 rel- ( S )-5-(5-chloro-2-((3-(hydroxymethyl)tetrahydrofuran-3-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 Lux ^™ Cellulose-4 column, 5 µm particle size, 25 cm x 21.2 mm, purchased from Phenomenex Corporation (mobile phase: 33% MeOH (topped with 20 mM ammonia), 67% _CO₂ ; flow rate 100 mL/min); rt = 8.73 min. ESI-MS calculated m/z value: 487.122; observed value: 488.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.14 (d, J = 2.9 Hz, 1H), 8.13 (d, J = 0.8 Hz, 1H), 7.54 - 7.45 (m, 2H), 7.21 - 7.11 (m, 3H), 6.96 (d, J = 7.6 Hz, 1H), 6.66 (s, 1H), 5.63 (s, 2H), 5.00 (s, 1H), 3.90 - 3.63 (m, 6H), 2.19 - 2.04 (m, 2H) ppm. 202 rac -2-((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)propionylamine S2 ESI-MS calculated m/z value: 440.116; observed value: 441.3 (M+1) ⁺ . 203 rac -3-((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)butyramine S2 ESI-MS calculated m/z value: 454.132; observed value: 455.3 (M+1) ⁺ . 204 rac -5-(5-chloro- ₂ -((1-(cyclopropyl-2,2,3,3 -d4 )-2-hydroxyethyl-2,2 _-d2 ) amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 459.174; observed value: 460.2 (M+1) ⁺ . 205 rac -5-(5-chloro-2-((1-(2,2-dimethylcyclopropyl)-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 481.168; observed value: 482.3 (M+1) ⁺ . 206 rel- 5-(5-chloro-2-((( 2S ^* , 4R )-4-cyclopropyl-1,4-dihydroxybutyl-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 515.154; observed value: 516.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 12 (dd, J = 2.8, 0.8 Hz, 2H), 7.54 - 7.45 (m, 2H), 7.21 - 7.13 (m, 2H), 6.95 (d, J = 7.5 Hz, 1H), 6.77 (t, J = 8.8 Hz, 1H), 6.61 (s, 1H), 5.63 (s, 2H), 4.68 (s, 1H), 4.54 - 4.45 (m, 1H), 4.07 (s, 1H), 3.51 - 3.36 (m, 2H), 2.99 (d, J = 12.6 Hz, 1H), 1.73 (ddt, J = 13.9, 9.4, 4.1 Hz, 1H), 1.65 (td, J = 10.3, 3.2 Hz, 1H), 0.81 (p, J = 5.1 Hz, 1H), 0.34 (ddt, J = 8.8, 6.2, 3.6 Hz, 2H), 0.25 (t, J = 4.9 Hz, 1H), 0.20 - 0.14 (m, 1H) ppm. 207 rel- 5-(5-chloro-2-((( 2S ^* , 4S )-4-cyclopropyl-1,4-dihydroxybutyl-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 515.154; observed value: 516.4 (M+1) ⁺ . 208 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-7-methyl-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S12 ESI-MS calculated m/z value: 467.152; observed value: 468.2 (M+1) ⁺ . ¹ H NMR (400 MHz, methanol -d ₄ ) δ 8.26 (s, 1H), 8.08 (s, 1H), 7.41 - 7.34 (m, 1H), 7.23 - 7.07 (m, 3H), 6.85 - 6.79 (m, 1H), 6.64 (s, 1H), 5.87 (d, J = 5.4 Hz, 2H), 3.77 (s, 1H), 3.71 - 3.65 (m, 1H), 3.49 - 3.39 (m, 1H), 2.38 - 2.34 (m, 3H), 1.05 (br d, J = 4.6 Hz, 1H), 0.56 (br d, J = 3.8 Hz, 1H), 0.49 (br d, J = 4.4 Hz, 1H), 0.43 - 0.29 (m, 2H) ppm; no interchangeable H was observed. 209 rac -5-(2-(((1,4-oxazolyl-6-yl)methyl)amino)-5-chloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 500.154; observed value: 501.0 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 1.1 Hz, 1H), 8.12 (d, J = 0.8 Hz, 1H), 7.54 - 7.45 (m, 2H), 7.27 - 7.07 (m, 3H), 6.95 (d, J = 7.6 Hz, 1H), 6.60 (s, 1H), 5.63 (s, 2H), 3.80 (dd, J = 12.3, 5.0 Hz, 1H), 3.60 (d, J = 5.0 Hz, 2H), 3.52 (ddd, J = 12.3, 6.8, 3.0 Hz, 1H), 3.16 (t, J = 6.3 Hz, 2H), 3.05 - 2.95 (m, 1H), 2.89 - 2.75 (m, 2H), 2.64 (p, J = 1.9 Hz, 1H), 2.15 (d, J = 6.5 Hz, 1H) ppm; no interchangeable H was observed. 210 rac -5-(5-chloro-2-((2-sideoxy-3-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3-c]pyridin-4-one S2 ESI-MS calculated m/z value: 480.148; observed value: 481.3 (M+1) ⁺ . 211 Peak 1: Forward or Reverse rac -5-(5-chloro-2-((4-methyl-2-epoxypiperidin-3-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 480.148; observed value: 481.3 (M+1) ⁺ . 212 Peak 2: Reverse or forward rac -5-(5-chloro-2-((4-methyl-2-epoxypiperidin-3-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 480.148; observed value: 481.3 (M+1) ⁺ . 213 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(phenylmethyl _- d2 )-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one SB1 ESI-MS calculated m/z value: 437.159; observed value: 438.3 (M+1) ⁺ . ¹ H NMR (500 MHz, methanol -d ₄ ) δ 8.20 (s, 1H), 8.12 (s, 1H), 7.41 - 7.25 (m, 6H), 7.02 (d, J = 3.6 Hz, 1H), 6.86 (d, J = 7.5 Hz, 1H), 3.85 (dd, J = 11.2, 3.8 Hz, 1H), 3.69 (ddd, J = 11.1, 6.7, 2.1 Hz, 1H), 3.33 (d, J = 8.7 Hz, 1H), 1.11 - 1.00 (m, 1H), 0.66 - 0.60 (m, 1H), 0.57 (qd, J = 9.4, 5.2 Hz, 1H), 0.38 (dq, J = 9.0, 5.7 Hz, 2H) ppm; no interchangeable H was observed. 214 Rotation-resistant isomer 1 5-(5-chloro-2-((( S )-1-hydroxypropyl-2-yl)amino)-3-methylpyridin-4-yl)-1-(2-chlorobenzyl)-6-methyl-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S4 ESI-MS calculated m/z value: 471.123; observed value: 472.2 (M+1) ⁺ . ^¹H NMR (400 MHz, methanol - _d⁴ ) δ 8.17 (d, J = 0.6 Hz, 1H), 8.08 (s, 1H), 7.49 - 7.45 (m, 1H), 7.36 - 7.26 (m, 2H), 7.02 - 6.98 (m, 1H), 6.78 (s, 1H), 5.66 (s, 2H), 4.34 - 4.25 (m, 1H), 3.64 (s, 2H), 2.05 - 2.01 (m, 3H), 1.86 (s, 3H), 1.27 (d, J = 6.6 Hz, 3H) ppm; no interchangeable H was observed. 215 5-(2-amino-5-chloropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4H-pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 369.079, observed value: 370.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 0.8 Hz, 1H), 8.10 (s, 1H), 7.46 (d, J = 7.5 Hz, 1H), 7.40 (dddd, J = 8.3, 7.3, 5.4, 1.9 Hz, 1H), 7.30 - 7.18 (m, 3H), 6.95 - 6.90 (m, 1H), 6.53 (s, 1H), 6.45 (s, 2H), 5.64 (d, J = 3.2 Hz, 2H) ppm. 216 5-(2-amino-5-chloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 387.070; observed value: 387.9 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.12 (d, J = 0.8 Hz, 1H), 8.10 (s, 1H), 7.54 - 7.44 (m, 2H), 7.21 - 7.12 (m, 2H), 6.95 (d, J = 7.4 Hz, 1H), 6.53 (s, 1H), 6.45 (s, 2H), 5.62 (s, 2H) ppm. 217 ( R )-5-(5-chloro-2-((2-hydroxypropyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4H-pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 455.112; observed value: 446.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.14 (s, 1H), 8.12 (d, J = 0.8 Hz, 1H), 7.53 - 7.45 (m, 2H), 7.16 (t, J = 8.0 Hz, 2H), 7.03 - 6.97 (m, 1H), 3.26 (ddd, J = 13.3, 7.6, 5.7 Hz, 1H), 3.21 - 3.10 (m, 1H), 1.09 (dd, J = 6.3, 1.2 Hz, 3H) ppm. 218 Peak 2 rel- 5-(5-fluoro-2-((3-(hydroxymethyl)tetrahydro- 2H- piperan-4-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralcel® OJ column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 18% MeOH (topped with 20 mM ammonia), 82% _CO2 ; flow rate 100 mL/min); rt = 4.92 min. ESI-MS calculated m/z value: 467.177; observed value: 468.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (d, J = 0.8 Hz, 1H), 8.12 (d, J = 1.9 Hz, 1H), 7.59 (dd, J = 7.6, 0.6 Hz, 1H), 7.40 (dddd, J = 8.2, 7.2, 5.4, 2.0 Hz, 1H), 7.29 - 7.17 (m, 3H), 6.95 (dt, J = 7.7, 0.6 Hz, 1H), 6.79 (d, J = 7.7 Hz, 1H), 6.66 (d, J = 5.0 Hz, 1H), 5.65 (s, 2H), 4.49 (t, J = 5.1 Hz, 1H), 4.18 (p, J = 6.5 Hz, 1H), 3.79 (dt, J = 11.5, 5.8 Hz, 2H), 3.54 - 3.46 (m, 4H), 2.01 (q, J = 7.9 Hz, 1H), 1.63 (q, J = 6.0 Hz, 2H)ppm. 219 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-3-methyl-1,5-dihydro-4H-pyrazolo[4,3- c ]pyridin-4-one S14 ESI-MS calculated m/z value: 485.143; observed value: 486.26 (M+1) ⁺ . ¹ H NMR (400 MHz, DMSO- d ₆ ) δ 8.05 (s, 1H), 7.51 - 7.33 (m, 2H), 7.12 (t, J = 8.0 Hz, 2H), 6.88 - 6.78 (m, 2H), 6.57 (d, J = 0.9 Hz, 1H), 5.48 (s, 2H), 4.70 (br s, 1H), 3.48 (br s, 3H), 2.36 (s, 3H), 1.03 - 0.90 (m, 1H), 0.46 - 0.14 (m, 4H) ppm. 220 5-(5-chloro-2-((1,1,1-trifluoro-3-hydroxy-2-(hydroxymethyl)propyl-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H- pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 529.094; observed value: 530.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO- d ₆ ) δ 8.24 (s, 1H), 8.14 (d, J = 0.9 Hz, 1H), 7.54 (d, J = 7.5 Hz, 1H), 7.53 - 7.45 (m, 1H), 7.17 (t, J = 8.0 Hz, 2H), 7.01 - 6.96 (m, 1H), 6.86 (s, 1H), 6.54 (s, 1H), 5.63 (s, 2H), 5.48 (q, J = 6.0 Hz, 2H), 4.02 (dd, J = 11.7, 6.3 Hz, 1H), 3.96 (dd, J = 11.6, 6.1 Hz, 1H), 3.91 (s, 2H) ppm. 221 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-4-sideoxy-4,5-dihydro- 1H- pyrazolo[4,3- c ]pyridin-3-carboxynitrile S15 ESI-MS calculated m/z value: 496.123; observed value: 497.4 (M+1) ⁺ . 222 rac -5-(5-chloro-2-(((2-sideoxypiperidin-3-yl)methyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 496.118; observed value: 497.3 (M+1) ⁺ . 223 5-(5-chloro-2-(((2-methyl- 2H- 1,2,3-triazol-4-yl)methyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 480.098; observed value: 481.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.20 (s, 1H), 8.19 (d, J = 0.8 Hz, 1H), 7.62 (s, 1H), 7.51 (dd, J = 7.8, 1.5 Hz, 1H), 7.49 (t, J = 5.8 Hz, 1H), 7.45 (d, J = 7.5 Hz, 1H), 7.41 - 7.30 (m, 2H), 7.08 (dd, J = 7.5, 1.9 Hz, 1H), 6.90 (dd, J = 7.6, 0.9 Hz, 1H), 6.66 (s, 1H), 6.02 - 5.33 (m, 2H), 4.53 (d, J = 5.8 Hz, 2H), 4.10 (s, 3H) ppm. 224 5-(5-chloro-2-(((2,5-dimethylamino)pyridin-4-yl)methyl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 494.102; observed value: 495.5 (M+1) ⁺ . 225 5-(5-chloro-2-((2-(2-(2-oxyimidazolidine-1-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 481.143; observed value: 482.2 (M+1) ⁺ . 226 Non-mirror isomer 1 Peak 2 rel- 5-(5-chloro-2-((( 3R )-4-(hydroxymethyl)tetrahydro- 2H- piperan-3-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 30% MeOH (topped with 20 mM ammonia), 70% _CO2 ; flow rate 100 mL/min); rt = 6.88 min. ESI-MS calculated m/z value: 483.147; observed value: 484.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.16 (d, J = 0.9 Hz, 1H), 8.15 (d, J = 0.9 Hz, 1H), 7.47 (dd, J = 7.5, 3.2 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.31 - 7.16 (m, 3H), 6.96 - 6.88 (m, 2H), 6.59 (s, 1H), 5.63 (d, J = 3.2 Hz, 2H), 4.49 (d, J = 20.6 Hz, 1H), 3.97 - 3.83 (m, 2H), 3.79 - 3.75 (m, 1H), 3.57 - 3.51 (m, 1H), 3.41 - 3.32 (m, 1H), 3.34 - 3.30 (m, 1H), 2.98 - 2.89 (m, 1H), 1.82 - 1.76 (m, 1H), 1.65 - 1.61 (m, 1H), 1.53 - 1.39 (m, 1H) ppm. 227 rac -5-(5-chloro-2-((6-sideoxy-5-azaspiro[3.5]non-9-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 506.163; observed value: 507.3 (M+1) ⁺ . 228 5-(5-chloro-2-((1-(2-hydroxyethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 467.152; observed value: 468.3 (M+1) ⁺ . 229 rac -5-(5-chloro-2-((2-hydroxy-1-(1-methyl- 1H- 1,2,3-triazol-5-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 494.138; observed value: 495.3 (M+1) ⁺ . ^¹H NMR (500 MHz, DMSO - _d⁶ ) δ 8.44 (s, 1H), 8.17 (d, J = 0.8 Hz, 1H), 7.66 (d, J = 4.3 Hz, 1H), 7.48 (dd, J = 7.6, 1.4 Hz, 1H), 7.44 - 7.35 (m, 1H), 7.30 - 7.17 (m, 4H), 6.96 (dd, J = 7.7, 2.3 Hz, 1H), 5.70 - 5.58 (m, 2H), 4.52 - 4.36 (m, 3H), 4.05 (s, 3H) ppm; no interchangeable H was observed. 230 3:1 mixture of mirror isomers ( S )-2-((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)-2-cyclopropylacetic acid S2 ESI-MS calculated m/z value: 467.116; observed value: 468.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 (dd, J = 3.5, 0.8 Hz, 1H), 8.12 (d, J = 1.3 Hz, 1H), 7.48 (dd, J = 7.5, 0.8 Hz, 1H), 7.44 - 7.37 (m, 1H), 7.31 - 7.18 (m, 3H), 6.93 (d, J = 7.6 Hz, 1H), 6.72 (s, 1H), 5.64 (d, J = 3.3 Hz, 2H), 3.79 (q, J = 8.5 Hz, 1H), 1.16 (dtt, J = 8.0, 5.7, 2.8 Hz, 1H), 0.56 - 0.33 (m, 5H) ppm; no interchangeable H was observed. 231 5-(2-((( 1H- 1,2,4-triazol-5-yl)methyl)amino)-5-chloropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 450.112; observed value: 451.1 (M+1) ⁺ . ^¹H NMR (500 MHz, DMSO - _d⁶ ) δ 13.82 (s, 1H), 8.17 (s, 1H), 8.17 (d, J = 0.9 Hz, 1H), 7.53 (s, 1H), 7.47 - 7.35 (m, 2H), 7.30 - 7.17 (m, 3H), 6.92 (d, J = 7.6 Hz, 1H), 6.72 (s, 1H), 5.69 - 5.58 (m, 2H), 4.59 - 4.55 (m, 2H) ppm; no interchangeable H was observed. 232 Peak 1 rel- ( R )-2-((5-chloro-4-(1-(2-fluorobenzyl)-4-sideoxy-1,4-dihydro- 5H -pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)amino)-2-cyclopropylacetic acid S2 ( R , R )-Whelk- ^O® 1 column, 5 µm particle size, 25 cm x 21.1 mm, purchased from Regis Technologies (mobile phase: 32% MeOH (topped with 20 mM ammonia), 68% _CO2 ; flow rate 100 mL/min); rt = 4.00 min ESI-MS calculated m/z value: 467.116; observed value: 468.2 (M+1) ⁺ . ^¹H NMR (500 MHz, DMSO - _d⁶ ) δ 8.18 (dd, J = 3.5, 0.8 Hz, 1H), 8.12 (d, J = 1.7 Hz, 1H), 7.48 (dd, J = 7.5, 1.4 Hz, 1H), 7.43 - 7.37 (m, 1H), 7.30 - 7.25 (m, 2H), 7.25 - 7.18 (m, 1H), 6.93 (d, J = 7.5 Hz), 0.58 - 0.31 (m, 4H) ppm; no interchangeable H was observed. 233 rac -1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((4-hydroxy-4-methylpentan-2-yl)amino)pyridin-4-yl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 471.188; observed value: 472.2 (M+1) ⁺ . 265 rac -5-(5-chloro-2-((1-hydroxypropyl-2-yl)oxy)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 444.076; observed value: 445.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.42 (s, 1H), 8.22 (d, J = 0.8 Hz, 1H), 7.54 - 7.47 (m, 2H), 7.41 - 7.32 (m, 2H), 7.13 - 7.08 (m, 2H), 3.60 (dt, J = 11.4, 5.7 Hz, 1H), 3.53 (tt, J = 10.9, 5.2 Hz, 1H), 1.28 (t, J = 6.5 Hz, 3H) ppm. 266 ( S )-5-(5-chloro-2-(2-(hydroxymethyl)acetate-1-yl)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3-c]pyridin-4-one S2 ESI-MS calculated m/z value: 439.121; observed value: 440.5 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.25 (d, J = 1.4 Hz, 1H), 8.16 (s, 1H), 7.46 - 7.35 (m, 2H), 7.29 - 7.16 (m, 3H), 6.92 (dd, J = 7.5, 2.2 Hz, 1H), 6.75 (d, J = 3.5 Hz, 1H), 5.70 - 5.54 (m, 2H), 4.95 (q, J = 5.0 Hz, 1H), 4.29 - 4.25 (m, 1H), 3.92 - 3.76 (m, 2H), 3.74 - 3.61 (m, 2H), 2.32 - 2.28 (m, 1H), 2.22 - 2.15 (m, 1H) ppm. 267 5-(2-(bis(2-hydroxyethyl)amino)-5-chloropyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 457.132; observed value: 458.5 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.22 (s, 1H), 8.18 - 8.13 (m, 1H), 7.48 - 7.43 (m, 1H), 7.42 - 7.36 (m, 1H), 7.30 - 7.16 (m, 3H), 6.91 (dd, J = 7.6, 0.7 Hz, 1H), 6.85 (s, 1H), 5.71 - 5.57 (m, 2H), 4.75 - 4.68 (m, 2H), 3.62 - 3.49 (m, 8H) ppm. 268 5-(5-chloro-2-(( 2S , 4S )-4-hydroxy-2-(hydroxymethyl)pyrrolidin-1-yl)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 485.102; observed value: 486.1 (M+1) ⁺ . 269 rac -5-(5-chloro-2-(3-hydroxy-3-(hydroxymethyl)pyrrolidin-1-yl)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 485.102; observed value: 486.1 (M+1) ⁺ . ¹ H NMR (500 MHz, acetonitrile- d ₃ ) δ 8.21 (s, 1H), 8.11 (d, J = 0.8 Hz, 1H), 7.48 (dd, J = 7.9, 1.4 Hz, 1H), 7.32 (s, 2H), 7.19 (d, J = 7.5 Hz, 1H), 7.08 - 7.02 (m, 1H), 6.65 (dd, J = 7.5, 0.9 Hz, 1H), 6.51 (d, J = 3.0 Hz, 1H), 5.61 (s, 2H), 3.57 - 3.50 (m, 3H), 3.49 - 3.42 (m, 1H), 3.40 - 3.36 (m, 1H), 3.17 - 3.13 (m, 1H), 3.06 - 3.02 (m, 1H), 2.10 - 2.01 (m, 1H), 1.93 - 1.87 (m, 1H) ppm; no interchangeable H was observed. 270 5-(5-chloro-2-(( 3R , 5S )-3,5-dihydroxypiperidin-1-yl)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 485.102; observed value: 486.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.26 (s, 1H), 8.19 (d, J = 0.8 Hz, 1H), 7.52 (dd, J = 7.8, 1.5 Hz, 1H), 7.45 (d, J = 7.5 Hz, 1H), 7.41 - 7.30 (m, 2H), 7.09 - 7.03 (m, 2H), 6.90 (dd, J = 7.6, 0.9 Hz, 1H), 5.68 (q, J = 15.9 Hz, 2H), 4.94 (d, J = 5.0 Hz, 2H), 4.29 (t, J = 11.7 Hz, 2H), 3.50 - 3.40 (m, 2H), 2.58 - 2.50 (m, 2H), 2.21 - 2.15 (m, 1H), 1.28 (q, J = 11.0 Hz, 1H) ppm. 271 Forward rac -5-(5-chloro-2- ( (( 3S , 4R )-4-fluoropyrrolidin-3-yl)oxy)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 473.082; observed value: 474.1 (M+1) ⁺ . ^¹H NMR (500 MHz, DMSO - _d⁶ ) δ 8.47 (d, J = 2.4 Hz, 1H), 8.24 - 8.19 (m, 1H), 7.56 - 7.47 (m, 2H), 7.42 - 7.31 (m, 2H), 7.26 (d, J = 1.3 Hz, 1H), 7.11 (dd, J = 7.5, 1.9 Hz, 1H), 6.95 (dd, J = 7.6, 1.1 Hz, 1H), 5.69 (d, J = 4.7 Hz, 2H), 5.36 - 5.14 (m, 2H), 3.30 - 3.21 (m, 2H, overlapping with water), 3.03 - 2.90 (m, 1H), 2.87 - 2.78 (m, 1H), 2.60 - 2.40 (m, 1H, overlapping with solvent) ppm. 272 rac -5-(5-chloro-2-(o-lin-3-ylmethoxy)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 485.102; observed value: 486.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.44 (d, J = 0.3 Hz, 1H), 8.22 (d, J = 0.8 Hz, 1H), 7.55 - 7.48 (m, 2H), 7.41 - 7.33 (m, 2H), 7.19 (s, 1H), 7.12 - 7.07 (m, 1H), 6.95 (dd, J = 7.6, 0.9 Hz, 1H), 5.74 - 5.63 (m, 2H), 4.25 - 4.13 (m, 2H), 3.80 (dd, J = 10.8, 3.0 Hz, 1H), 3.66 (dt, J = 10.9, 2.8 Hz, 1H), 3.43 - 3.36 (m, 1H), 3.23 (dd, J = 10.8, 9.3 Hz, 1H), 3.07 (d, J = 8.2 Hz, 1H), 2.76 (dt, J = 22.2, 12.0 Hz, 2H) ppm; no interchangeable H was observed. 273 rac -5-(5-chloro-2-((5-sideoxypyrrolidin-3-yl)methoxy)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 ESI-MS calculated m/z value: 483.086; observed value: 484.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.45 (s, 1H), 8.22 (d, J = 0.8 Hz, 1H), 7.58 (s, 1H), 7.54 - 7.51 (m, 1H), 7.50 (d, J = 7.6 Hz, 1H), 7.41 - 7.33 (m, 2H), 7.21 (s, 1H), 7.12 - 7.08 (m, 1H), 6.95 (dd, J = 7.6, 0.9 Hz, 1H), 5.73 - 5.64 (m, 2H), 4.36 - 4.26 (m, 2H), 3.41 (m, 1H), 3.11 (m, 1H), 2.88 (m, 1H), 2.33 (dd, J = 16.7, 9.1 Hz, 1H), 2.05 (dd, J = 16.7, 6.7 Hz, 1H) ppm 274 Peak 1 rel- ( R )-5-(5-chloro-2-((5-sideoxypyrrolidin-3-yl)methoxy)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 Chiralcel® ^OJ -H column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 20% MeOH (topped with 20 mM ammonia), 80% _CO2 ; flow rate 2 mL/min); rt = 5.32 min. ESI-MS calculated m/z value: 483.086; observed value: 484.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.45 (s, 1H), 8.22 (d, J = 0.8 Hz, 1H), 7.58 (s, 1H), 7.53 (dd, J = 7.8, 1.5 Hz, 1H), 7.50 (d, J = 7.5 Hz, 1H), 7.41 - 7.33 (m, 2H), 7.21 (s, 1H), 7.12 - 7.08 (m, 1H), 6.95 (dd, J = 7.6, 0.9 Hz, 1H), 5.73 - 5.64 (m, 2H), 4.35 - 4.27 (m, 2H), 3.41 (ddd, J = 9.7, 7.9, 0.9 Hz, 1H), 3.11 (dd, J = 9.7, 5.6 Hz, 1H), 2.88 (p, J = 7.3 Hz, 1H), 2.33 (dd, J = 16.7, 9.0 Hz, 1H), 2.09 - 2.02 (m, 1H) ppm. 275 Peak 2 rel- ( S )-5-(5-chloro-2-((5-sideoxypyrrolidin-3-yl)methoxy)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S1 Chiralcel® ^OJ -H column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 20% MeOH (topped with 20 mM ammonia), 80% _CO2 ; flow rate 2 mL/min); rt = 6.14 min. ESI-MS calculated m/z value: 483.086; observed value: 484.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.45 (s, 1H), 8.22 (d, J = 0.8 Hz, 1H), 7.58 (s, 1H), 7.53 (dd, J = 7.8, 1.5 Hz, 1H), 7.50 (d, J = 7.5 Hz, 1H), 7.37 (dtd, J = 18.6, 7.4, 1.7 Hz, 2H), 7.21 (s, 1H), 7.10 (dd, J = 7.5, 1.9 Hz, 1H), 6.95 (dd, J = 7.6, 0.9 Hz, 1H), 5.74 - 5.64 (m, 2H), 4.35 - 4.26 (m, 2H), 3.41 (dd, J = 9.7, 8.1 Hz, 1H), 3.11 (dd, J = 9.8, 5.6 Hz, 1H), 2.88 (p, J = 7.3 Hz, 1H), 2.33 (dd, J = 16.7, 9.0 Hz, 1H), 2.09 - 2.01 (m, 1H) ppm. 276 5-(5-chloro-2- ( ( 2S , 4R )-4-hydroxy-2-(hydroxymethyl)pyrrolidin-1-yl)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 469.132; observed value: 470.3 (M+1) ⁺ . 277 ( R )-5-(5-chloro-2-(1-(1-methyl- 1H- 1,2,3-triazol-5-yl)ethoxy)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS m/z calculated value: 479.127, observed value: 480.2 [M+1] ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.48 (d, J = 2.4 Hz, 1H), 8.18 (dd, J = 4.0, 0.8 Hz, 1H), 7.85 (d, J = 5.1 Hz, 1H), 7.51 (dd, J = 7.5, 4.7 Hz, 1H), 7.43 - 7.36 (m, 1H), 7.31 - 7.18 (m, 4H), 6.97 (dd, J = 7.6, 4.0 Hz, 1H), 6.39 (p, J = 6.4 Hz, 1H), 5.70 - 5.58 (m, 2H), 4.08 (d, J = 3.7 Hz, 3H), 1.72 (dd, J = 6.6, 4.3 Hz, 3H) ppm. 278 rac -5-(5-chloro-2-(2-(hydroxymethyl)-1,4-oxoazirheptan-4-yl)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 501.138; observed value: 502.0 (M+1) ⁺ . 279 5-(5-chloro-2-((1,3-dihydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-chlorobenzyl)-1,5,6,7-tetrahydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one S3 ESI-MS calculated m/z value: 461.102; observed value: 462.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.03 (s, 1H), 7.86 (s, 1H), 7.54 - 7.48 (m, 1H), 7.42 - 7.32 (m, 2H), 7.14 - 7.08 (m, 1H), 6.62 (s, 1H), 6.52 (d, J = 7.9 Hz, 1H), 5.45 (s, 2H), 4.63 (t, J = 5.5 Hz, 2H), 3.94 - 3.75 (m, 3H), 3.55 - 3.43 (m, 4H), 3.14 (t, J = 6.7 Hz, 2H) ppm. 280 Forward rac -5-(5-chloro-2- ( ( 4aR , 7aR )-2-sideoxyoctahydro- 6H- pyrrolo[3,4- b ]pyridin-6-yl)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 492.148; observed value: 493.3 (M+1) ⁺ . 281 5-(5-chloro-2-(3-(hydroxymethyl)-6,7-dihydro-[1,2,3]triazolo[1,5- a ]pyridine-5( 4H )-yl)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 506.138; observed value: 507.0 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.41 (s, 1H), 8.19 (d, J = 0.8 Hz, 1H), 7.51 (d, J = 7.5 Hz, 1H), 7.41 (dddd, J = 8.2, 7.2, 5.5, 2.0 Hz, 1H), 7.35 (s, 1H), 7.29 - 7.16 (m, 3H), 6.96 (dt, J = 7.6, 0.7 Hz, 1H), 5.70 (d, J = 15.5 Hz, 1H), 5.63 (d, J = 15.5 Hz, 1H), 5.14 (t, J = 5.7 Hz, 1H), 4.95 (d, J = 16.8 Hz, 1H), 4.87 (d, J = 16.8 Hz, 1H), 4.57 (d, J = 5.5 Hz, 2H), 4.47 - 4.42 (m, 2H), 4.14 (t, J = 5.5 Hz, 2H) ppm. 282 ( S )-5-(5-fluoro-2-((1-hydroxybutyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S5 ESI-MS calculated m/z value: 427.182; observed value: 428.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 7.94 (d, J = 2.7 Hz, 1H), 7.86 (s, 1H), 7.41 (dddd, J = 8.2, 7.3, 5.4, 2.0 Hz, 1H), 7.35 - 7.15 (m, 3H), 6.56 (d, J = 5.2 Hz, 1H), 5.43 (s, 2H), 3.97 (t, J = 6.6 Hz, 2H), 3.73 (d, J = 8.1 Hz, 1H), 3.46 (dd, J = 10.6, 4.8 Hz, 1H), 3.35 (dd, J = 10.6, 5.9 Hz, 2H), 3.16 (d, J = 13.2 Hz, 3H), 1.74 - 1.59 (m, 1H), 1.41 (dq, J = 13.6, 7.5 Hz, 1H), 0.89 (t, J = 7.4 Hz, 3H) ppm. 283 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S5 ESI-MS calculated m/z value: 455.152; observed value: 456.1 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 7.97 (s, 1H), 7.83 (s, 1H), 7.45 - 7.36 (m, 1H), 7.31 - 7.18 (m, 3H), 6.65 (d, J = 8.0 Hz, 1H), 6.55 (s, 1H), 5.42 (s, 2H), 4.65 (t, J = 5.4 Hz, 1H), 3.96 - 3.79 (m, 2H), 3.57 - 3.41 (m, 3H), 3.19 - 3.13 (m, 2H), 1.03 - 0.93 (m, 1H), 0.46 - 0.25 (m, 3H), 0.23 - 0.10 (m, 1H) ppm. 284 5-(2-(( 2R , 5S )-2,5 - bis(hydroxymethyl)pyrrolidin-1-yl)-5-chloropyridin-4-yl)-1-(2-fluorobenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S5 ESI-MS calculated m/z value: 485.163; observed value: 486.0 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.15 (s, 1H), 7.84 (s, 1H), 7.45 - 7.36 (m, 1H), 7.30 - 7.18 (m, 3H), 6.72 (s, 1H), 5.43 (s, 2H), 4.82 - 4.75 (m, 2H), 4.02 - 3.79 (m, 4H), 3.58 - 3.50 (m, 2H), 3.42 - 3.34 (m, 2H), 3.20 - 3.15 (m, 2H), 1.98 - 1.86 (m, 4H) ppm. 285 Resistive isomer 1 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S5 ESI-MS calculated m/z value: 469.168; observed value: 469.9 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 7.93 (d, J = 0.7 Hz, 1H), 7.83 (s, 1H), 7.45 - 7.36 (m, 1H), 7.33 - 7.21 (m, 3H), 5.78 (d, J = 8.1 Hz, 1H), 5.42 (s, 2H), 4.59 (t, J = 5.7 Hz, 1H), 3.84 - 3.67 (m, 2H), 3.68 - 3.59 (m, 1H), 3.56 (t, J = 5.6 Hz, 2H), 3.20 (t, J = 6.8 Hz, 2H), 1.96 (s, 3H), 1.10 - 0.99 (m, 1H), 0.43 (s, 1H), 0.39 - 0.32 (m, 2H), 0.27 - 0.18 (m, 1H) ppm. 286 Rotation-resistant isomer 2 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S5 ESI-MS calculated m/z value: 469.168; observed value: 470.0 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 7.93 (d, J = 0.7 Hz, 1H), 7.83 (s, 1H), 7.45 - 7.36 (m, 1H), 7.33 - 7.18 (m, 3H), 5.76 (d, J = 8.1 Hz, 1H), 5.42 (s, 2H), 4.64 (t, J = 5.7 Hz, 1H), 3.86 - 3.69 (m, 2H), 3.68 - 3.59 (m, 1H), 3.57 (t, J = 5.6 Hz, 2H), 3.20 (t, J = 6.8 Hz, 2H), 1.96 (d, J = 0.6 Hz, 3H), 1.10 - 1.00 (m, 1H), 0.47 - 0.38 (m, 1H), 0.36 - 0.28 (m, 2H), 0.26 - 0.18 (m, 1H) ppm. 287 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S8 ESI-MS calculated m/z value: 473.143; observed value: 474.3 (M+1) ⁺ . ¹ H NMR (500 MHz, methanol -d ₄ ) δ 8.00 (s, 1H), 7.84 (s, 1H), 7.46 (tt, J = 8.4, 6.5 Hz, 1H), 7.15 - 6.92 (m, 2H), 6.61 (s, 1H), 5.46 (d, J = 0.9 Hz, 2H), 3.99 (t, J = 6.7 Hz, 2H), 3.79 - 3.64 (m, 2H), 3.41 - 3.37 (m, 1H), 3.30 (t, J = 6.7 Hz, 2H), 1.04 (qt, J = 8.2, 5.0 Hz, 1H), 0.59 - 0.45 (m, 2H), 0.41 - 0.29 (m, 2H) ppm; no interchangeable H was observed. 288 rac -5-(5-chloro-2-((2-cyclopropyl-1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S8 ESI-MS calculated m/z value: 487.159; observed value: 488.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.01 (s, 1H), 7.80 (s, 1H), 7.50 (tt, J = 8.4, 6.6 Hz, 1H), 7.30 - 7.11 (m, 2H), 6.71 (s, 1H), 6.29 (s, 1H), 5.40 (s, 2H), 5.12 (t, J = 5.8 Hz, 1H), 4.09 (q, J = 5.3 Hz, 2H), 3.89 (s, 2H), 3.70 (dd, J = 10.7, 5.7 Hz, 1H), 3.59 (dd, J = 10.7, 5.8 Hz, 1H), 1.40 (ddd, J = 14.0, 8.1, 6.0 Hz, 1H), 0.99 (s, 3H), 0.50 - 0.12 (m, 4H) ppm. 289 4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4,6,7-tetrahydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-6-((1-hydroxy-2-methylprop-2-yl)amino)nicotinamide S8 ESI-MS calculated m/z value: 452.177; observed value: 451.1 (M⁻¹) ^- . ¹ H NMR (400 MHz, DMSO -d ₆ ) δ 8.34 (s, 1H), 7.82 (s, 1H), 7.55 - 7.43 (m, 1H), 7.22 - 7.11 (m, 3H), 6.61 - 6.57 (m, 1H), 5.40 (s, 2H), 4.93 (t, J = 5.7 Hz, 1H), 3.98 (t, J = 6.6 Hz, 2H), 3.55 (d, J = 5.7 Hz, 2H), 3.22 (t, J = 6.5 Hz, 2H), 1.32 (s, 6H) ppm. 290 rac -5-(5-chloro-2-((1-hydroxy-2-methylbut-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S8 ESI-MS calculated m/z value: 475.159; observed value: 476.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.00 (s, 1H), 7.79 (s, 1H), 7.50 (tt, J = 8.5, 6.7 Hz, 1H), 7.25 - 7.10 (m, 2H), 6.65 (s, 1H), 6.26 (s, 1H), 5.40 (s, 2H), 4.99 (t, J = 5.7 Hz, 1H), 4.09 (q, J = 5.3 Hz, 1H), 3.88 (s, 2H), 3.67 - 3.46 (m, 2H), 3.27 - 3.12 (m, 3H), 1.90 (dq, J = 14.7, 7.4 Hz, 2H), 1.75 - 1.52 (m, 1H), 0.79 (t, J = 7.4 Hz, 3H) ppm. 291 Forward rac -1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((( 3R , 4S )-3-(hydroxymethyl)tetrahydro- 2H- piperan-4-yl)amino)pyridin-4-yl)-1,5,6,7-tetrahydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S8 ESI-MS calculated m/z value: 487.183; observed value: 489.5 (M+1) ⁺ . 292 4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4,6,7-tetrahydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)-6-((1,3-dihydroxy-2-methylpropyl-2-yl)amino)nicotinamide S8 ESI-MS calculated m/z value: 468.172; observed value: 469.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.33 (s, 1H), 7.83 (s, 1H), 7.54 - 7.44 (m, 1H), 7.21 - 7.12 (m, 2H), 6.97 (s, 1H), 6.67 (d, J = 0.5 Hz, 1H), 5.40 (s, 2H), 4.85 (t, J = 5.7 Hz, 2H), 3.98 (t, J = 6.5 Hz, 2H), 3.64 (dd, J = 10.7, 5.7 Hz, 2H), 3.58 (dd, J = 10.7, 5.8 Hz, 2H), 3.22 (t, J = 6.6 Hz, 2H), 1.27 (s, 3H) ppm. 293 ( S )-5-(5-chloro-2-((1-hydroxy-3-methylbut-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S8 ESI-MS calculated m/z value: 475.159; observed value: 474.1 (M⁻¹) ^- . 294 1-(2,6-Difluorobenzyl)-5-(5-fluoro-2-((1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S8 ESI-MS calculated m/z value: 457.173; observed value: 458.3 (M+1) ⁺ . 295 rac -5-(5-chloro-2-((( S )-1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(1-(2-fluorophenyl)ethyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S17 ESI-MS calculated m/z value: 469.168; observed value: 470.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 7.97 (s, 1H), 7.87 (s, 1H), 7.38 (q, J = 6.9 Hz, 2H), 7.22 (dd, J = 12.0, 7.8 Hz, 2H), 6.65 (d, J = 7.9 Hz, 1H), 6.54 (s, 1H), 5.94 (q, J = 6.9 Hz, 1H), 4.66 (s, 1H), 3.97 - 3.63 (m, 2H), 3.60 - 3.42 (m, 3H), 3.26 (dt, J = 16.8, 6.3 Hz, 1H), 2.90 (dt, J = 15.7, 7.3 Hz, 1H), 1.85 (d, J = 6.9 Hz, 3H), 1.06 - 0.84 (m, 1H), 0.51 - 0.10 (m, 4H) ppm. 296 rac -5-(5-chloro-2-((2-cyclobutyl-1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S8 ESI-MS calculated m/z value: 501.174; observed value: 502.2 (M+1) ⁺ . 297 rac -5-(5-chloro-2-((3-(hydroxymethyl)tetrahydrofuran-3-yl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S8 ESI-MS calculated m/z value: 489.138; observed value: 490.2 (M+1) ⁺ . 298 Peak 1 rel- 1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S8 Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 35% ⁱ PrOH (topped with 20 mM ammonia), 65% _CO2 ; flow rate 100 mL/min); rt = 7.34 min. ESI-MS calculated m/z value: 487.183; observed value: 488.3 (M+1) ⁺ . 299 Peak 3 rel- 1-(2,6-difluorobenzyl)-5-(5-fluoro-2-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S8 Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 35% ⁱ PrOH (topped with 20 mM ammonia), 65% _CO2 ; flow rate 100 mL/min); rt = 13.07 min. ESI-MS calculated m/z value: 487.183; observed value: 488.3 (M+1) ⁺ . 300 Peak 1 rel- 5-(5-chloro-2-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S8 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 33% MeOH (topped with 20 mM ammonia), 67% _CO2 ; flow rate 100 mL/min); rt = 4.84 min. ESI-MS calculated m/z value: 503.154; observed value: 504.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.02 (s, 1H), 7.79 (s, 1H), 7.50 (tt, J = 8.4, 6.7 Hz, 1H), 7.22 - 7.13 (m, 2H), 6.75 (d, J = 8.8 Hz, 1H), 6.59 (s, 1H), 5.40 (s, 2H), 4.71 (s, 1H), 3.96 (s, 2H), 3.90 (s, 1H), 3.80 (t, J = 8.0 Hz, 1H), 3.70 (td, J = 8.2, 4.3 Hz, 1H), 3.59 (td, J = 8.1, 7.0 Hz, 1H), 3.46 - 3.36 (m, 3H), 3.22 (s, 1H), 2.46 (p, J = 8.1 Hz, 2H), 1.98 - 1.88 (m, 1H), 1.65 (dq, J = 12.2, 8.2 Hz, 1H) ppm; no interchangeable H was observed. 301 Peak 3 rel- 5-(5-chloro-2-((( 1S )-2-hydroxy-1-(tetrahydrofuran-3-yl)ethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S8 ^Chiralpak® IB column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 33% MeOH (topped with 20 mM ammonia), 67% _CO2 ; flow rate 100 mL/min); rt = 9.06 min. ESI-MS calculated m/z value: 503.154; observed value: 504.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.02 (s, 1H), 7.79 (s, 1H), 7.50 (tt, J = 8.5, 6.7 Hz, 1H), 7.22 - 7.13 (m, 2H), 6.71 (d, J = 8.9 Hz, 1H), 6.59 (s, 1H), 5.40 (s, 2H), 4.70 (s, 1H), 3.95 (s, 1H), 3.89 (s, 1H), 3.81 - 3.70 (m, 3H), 3.62 (td, J = 8.2, 7.0 Hz, 1H), 3.53 - 3.40 (m, 2H), 3.22 (s, 1H), 2.48 (d, J = 8.2 Hz, 1H), 2.01 - 1.92 (m, 2H), 1.63 (dq, J = 12.2, 8.3 Hz, 2H) ppm. 302 ( R )-5-(5-fluoro-2-((1-(1-methyl- 1H- 1,2,3-triazol-5-yl)ethyl)amino)pyridin-4-yl)-1-(2-fluoro-6-methylbenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S10 ESI-MS calculated m/z value: 478.204; observed value: 479.3 (M+1) ⁺ . 303 Reverse rac -5-(5-fluoro-2-((( 1S , 2S )-2-hydroxycyclobutyl)amino)pyridin-4-yl)-1-(2-fluoro-6-methylbenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S10 ESI-MS calculated m/z value: 439.182; observed value: 440.3 (M+1) ⁺ . 304 5-(5-chloro-2-(4-(2-methoxyethyl)piperazine-1-yl)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 514.170; observed value: 515.0 (M+1) ⁺ . 305 N- (1-(5-chloro-4-(1-(2,6-difluorobenzyl)-4-sideoxy-1,4-dihydro- 5H- pyrazolo[4,3- c ]pyridin-5-yl)pyridin-2-yl)piperidin-4-yl)acetamide S7 ESI-MS calculated m/z value: 512.154; observed value: 513.3 (M+1) ⁺ . 306 ( S )-5-(5-chloro-2-((1-hydroxybutyl-2-yl)oxy)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 442.121; observed value: 441.1 (M⁻¹) ^- . ¹ H NMR (400 MHz, methanol -d ₄ ) δ 8.30 (s, 1H), 8.17 (s, 1H), 7.38 - 7.32 (m, 2H), 7.26 - 7.22 (m, 1H), 7.17 - 7.10 (m, 2H), 6.96 (d, J = 4.6 Hz, 1H), 6.88-6.86 (m, 1H), 5.62 (s, 2H), 5.16 (sixt, J = 5.6 Hz, 1H), 3.78 - 3.65 (m, 2H), 1.78-1.69 (m, 2H), 0.97 (td, J = 7.4, 2.1 Hz, 3H) ppm; no interchangeable H was observed. 307 rac -5-(5-chloro-2-(hexahydropyrrolo[1,2- a ]pyridine-2( 1H )-yl)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 496.159; observed value: 497.0 (M+1) ⁺ . 308 rac -5-(2-(3-amino-3-methylpiperidin-1-yl)-5-chloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4 -H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 484.159; observed value: 485.0 (M+1) ⁺ . 309 5-(5-chloro-2-(4-propylopyr-1-yl)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 512.154; observed value: 513.2 (M+1) ⁺ . 310 Resistive isomer 1 5-(2-(( 2R , 5S )-2,5-bis(hydroxymethyl)pyrrolidin-1-yl)-5-chloro-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 497.163; observed value: 496.1 (M⁻¹) ^- . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.27 (d, J = 0.7 Hz, 1H), 8.18 (d, J = 0.8 Hz, 1H), 7.45 - 7.36 (m, 2H), 7.33 - 7.18 (m, 3H), 7.00 (d, J = 7.6 Hz, 1H), 5.65 (s, 2H), 4.69 - 4.65 (m, 2H), 4.20 - 4.11 (m, 1H), 4.06 - 3.98 (m, 1H), 3.59 - 3.48 (m, 2H), 3.28 (m, 2H), 2.02 (s, 3H), 1.92 - 1.73 (m, 4H) ppm. 311 Rotation-resistant isomer 2 5-(2-(( 2R , 5S )-2,5-bis(hydroxymethyl)pyrrolidin-1-yl)-5-chloro-3-methylpyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 497.163; observed value: 496.2 (M⁻¹) ^- . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.27 (d, J = 0.7 Hz, 1H), 8.18 (d, J = 0.8 Hz, 1H), 7.45 - 7.36 (m, 2H), 7.33 - 7.18 (m, 3H), 7.00 (d, J = 7.5 Hz, 1H), 5.65 (s, 2H), 4.70 - 4.64 (m, 2H), 4.20 - 4.11 (m, 1H), 4.06 - 3.98 (m, 1H), 3.58 - 3.48 (m, 2H), 3.30 - 3.16 (m, 2H), 2.02 (s, 3H), 1.92 - 1.85 (m, 3H), 1.87 - 1.77 (m, 1H) ppm. 312 5-(5-chloro-2-(7-oxa-1-azaspiro[3.5]nonane-1-yl)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 497.143; observed value: 498.0 (M+1) ⁺ . 313 5-(2-(( 2R , 4S )-2,4-bis(hydroxymethyl)acetate-1-yl)-5-chloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 487.122; observed value: 488.0 (M+1) ⁺ . 314 5-(5-chloro-2-((1-(hydroxymethyl)cyclobutyl)amino)pyridin-4-yl)-1-(2-fluoro-6-methylbenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S10 ESI-MS calculated m/z value: 469.168; observed value: 470.3 (M+1) ⁺ . 315 rac -5-(5-chloro-2-((1,4-dihydroxybutyl-2-yl)amino)pyridin-4-yl)-1-(2-fluoro-6-methylbenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S10 ESI-MS calculated m/z value: 473.163; observed value: 474.3 (M+1) ⁺ . 316 ( R )-5-(5-chloro-2-((1,4-dihydroxybutyl-2-yl)amino)pyridin-4-yl)-1-(2-fluoro-6-methylbenzyl)-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S10 ESI-MS calculated m/z value: 473.163; observed value: 474.3 (M+1) ⁺ . 317 Peak 1: Forward or Reverse 5-(5-chloro-2-((3-hydroxycyclobutyl)(methyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 471.127; observed value: 472.2 (M+1) ⁺ . ¹ H NMR (500 MHz, acetonitrile - _{d 3} ) δ 8.22 (s, 1H), 8.03 (d, J = 0.9 Hz, 1H), 7.48 - 7.38 (m, 1H), 7.21 (d, J = 7.6 Hz, 1H), 7.09 - 7.00 (m, 2H), 6.79 - 6.74 (m, 1H), 6.67 (s, 1H), 5.54 (d, J = 1.2 Hz, 2H), 4.26 - 4.16 (m, 1H), 3.97 - 3.87 (m, 1H), 3.14 (d, J = 6.5 Hz, 1H), 2.99 (s, 3H), 2.66 - 2.55 (m, 2H), 2.05 - 1.97 (m, 2H) ppm. 318 Peak 2: Reverse or forward 5-(5-chloro-2-((3-hydroxycyclobutyl)(methyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro- 4-H -pyrazolo[4,3- c ]pyridin-4-one S7 ESI-MS calculated m/z value: 471.127; observed value: 472.4 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.27 (s, 1H), 8.11 (d, J = 0.8 Hz, 1H), 7.54 - 7.44 (m, 2H), 7.21 - 7.12 (m, 2H), 6.95 (d, J = 7.5 Hz, 1H), 6.81 (s, 1H), 5.68 - 5.57 (m, 2H), 5.16 - 5.06 (m, 1H), 5.03 - 5.00 (m, 1H), 4.26 - 4.20 (m, 1H), 2.96 (s, 3H), 2.43 - 2.32 (m, 2H), 2.16 - 2.05 (m, 2H) ppm. 319 5-(2-amino-5-chloropyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S8 ESI-MS calculated m/z value: 389.085; observed value: 390.2 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 7.99 (s, 1H), 7.79 (s, 1H), 7.50 (tt, J = 8.4, 6.7 Hz, 1H), 7.25 - 7.08 (m, 2H), 6.49 (s, 1H), 6.24 (s, 2H), 5.40 (s, 2H), 3.89 (s, 2H), 3.27 - 3.14 (m, 2H) ppm. 320 rel- 1-(2-chloro-6-fluorobenzyl)-5-(2-((( 2S ^* , 4R )-1,4-dihydroxypentan-2-yl)amino)-5-fluoropyridin-4-yl)-1,5,6,7-tetrahydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S11 ESI-MS calculated m/z value: 491.154; observed value: 492.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 7.91 (d, J = 2.6 Hz, 1H), 7.79 (s, 1H), 7.48 (td, J = 8.2, 6.1 Hz, 1H), 7.40 (dt, J = 8.0, 1.0 Hz, 2H), 7.31 (ddd, J = 9.5, 8.3, 1.2 Hz, 2H), 6.52 (d, J = 5.2 Hz, 1H), 6.27 (d, J = 8.0 Hz, 1H), 5.44 (d, J = 1.4 Hz, 2H), 4.65 (t, J = 5.5 Hz, 1H), 4.58 (d, J = 4.6 Hz, 1H), 3.98 (t, J = 6.6 Hz, 2H), 3.71 (d, J = 4.7 Hz, 1H), 3.45 (dt, J = 10.2, 5.0 Hz, 1H), 3.24 (t, J = 6.6 Hz, 2H), 1.60 (ddd, J = 13.4, 9.4, 3.7 Hz, 1H), 1.43 (ddd, J = 13.3, 9.7, 3.2 Hz, 1H), 1.08 (d, J = 6.2 Hz, 3H) ppm. 321 Rotation-resistant isomer 1 ( S )-5-(5-chloro-2-((1-hydroxypropyl-2-yl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-6,6-dimethyl-1,5,6,7-tetrahydro-4- H -pyrazolo[4,3- c ]pyridin-4-one SB3 ESI-MS calculated m/z value: 457.168; observed value: 458.3 (M+1) ⁺ . ^¹H NMR (400 MHz, methanol - _d⁴ ) δ 8.03 (s, 1H), 7.85 (s, 1H), 7.39 - 7.34 (m, 1H), 7.23 - 7.11 (m, 3H), 6.54 (s, 1H), 5.47 - 5.38 (m, 2H), 4.03 - 3.95 (m, 1H), 3.60 - 3.51 (m, 2H), 3.18 (s, 2H), 1.41 (s, 3H), 1.27 (s, 3H), 1.19 (d, J = 6.9 Hz, 3H) ppm; no interchangeable H was observed. 322 ( S )-5-(5-chloro-2-((1-hydroxy-3-methylbut-2-yl)oxy)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S2 ESI-MS calculated m/z value: 456.136; observed value: 457.2 (M+1) ⁺ . ¹ H NMR (400 MHz, methanol -d ₄ ) δ 8.29 (d, J = 1.4 Hz, 1H), 8.17 (s, 1H), 7.39 - 7.30 (m, 2H), 7.27 - 7.21 (m, 1H), 7.17 - 7.10 (m, 2H), 6.97 (d, J = 6.0 Hz, 1H), 6.87 (dd, J = 7.8, 2.3 Hz, 1H), 5.62 (s, 2H), 5.13 - 5.07 (m, 1H), 3.80 - 3.71 (m, 2H), 2.17 - 2.08 (m, 1H), 1.00 - 0.97 (m, 6H) ppm; no interchangeable H was observed. 323 ( S )-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-4-sideoxy-4,5-dihydro- 1H- pyrazolo[4,3- c ]pyridin-3-carboxynitrile S15 ESI-MS calculated m/z value: 496.123; observed value: 497.4 (M+1) ⁺ . 324 ( S )-3-chloro-5-(5-chloro-2-((1-cyclopropyl-2-hydroxyethyl)amino)pyridin-4-yl)-1-(2,6-difluorobenzyl)-1,5-dihydro-4- H -pyrazolo[4,3- c ]pyridin-4-one S18 ESI-MS calculated m/z value: 505.088; observed value: 506.1 (M+1) ⁺ . 325 Peak 1 rel- 5-(5-chloro-2-(((( 3S , 4R ) -4-hydroxytetrahydrofuran-3-yl)methyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IC column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 40% MeOH (topped with 20 mM ammonia), 60% _CO2 ; flow rate 100 mL/min); rt = 5.08 min. ESI-MS calculated m/z value: 469.132; observed value: 470.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.17 (d, J = 2.8 Hz, 1H), 7.47 (dd, J = 7.5, 1.4 Hz, 1H), 7.40 (tdd, J = 7.5, 5.4, 1.9 Hz, 1H), 7.31 - 7.24 (m, 2H), 7.24 - 7.17 (m, 2H), 6.93 (d, J = 7.6 Hz, 1H), 6.60 (s, 1H), 5.69 - 5.60 (m, 2H), 5.00 (s, 1H), 4.06 (dq, J = 5.1, 2.5 Hz, 1H), 3.87 (ddd, J = 8.3, 6.4, 1.6 Hz, 1H), 3.83 (dd, J = 9.3, 4.9 Hz, 1H), 3.51 (dd, J = 8.6, 3.9 Hz, 1H), 3.48 (dd, J = 9.3, 2.7 Hz, 1H), 3.26 (q, J = 7.1 Hz, 1H), 3.16 (tt, J = 13.4, 6.1 Hz, 1H), 2.32 (d, J = 8.1 Hz, 1H) ppm; no interchangeable H was observed. 326 Peak 2 rel- 5-(5-chloro-2-(((( 3R , 4S ) -4-hydroxytetrahydrofuran-3-yl)methyl)amino)pyridin-4-yl)-1-(2-fluorobenzyl)-1,5-dihydro- 4H- pyrazolo[4,3- c ]pyridin-4-one S2 ^Chiralpak® IC column, 5 µm particle size, 25 cm x 20 mm, purchased from Daicel (mobile phase: 40% MeOH (topped with 20 mM ammonia), 60% _CO2 ; flow rate 100 mL/min); rt = 6.59 min. ESI-MS calculated m/z value: 469.132; observed value: 470.3 (M+1) ⁺ . ¹ H NMR (500 MHz, DMSO -d ₆ ) δ 8.18 - 8.16 (m, 1H), 7.47 (dd, J = 7.5, 1.4 Hz, 1H), 7.40 (dddd, J = 9.0, 7.3, 5.4, 1.9 Hz, 1H), 7.30 - 7.24 (m, 2H), 7.24 - 7.15 (m, 2H), 6.93 (d, J = 7.6 Hz, 1H), 6.60 (s, 1H), 5.69 - 5.58 (m, 2H), 5.00 (s, 1H), 4.06 (dq, J = 5.2, 2.6 Hz, 1H), 3.87 (ddd, J = 8.3, 6.4, 1.6 Hz, 1H), 3.83 (dd, J = 9.2, 4.9 Hz, 1H), 3.54 - 3.49 (m, 1H), 3.48 (dd, J = 9.2, 2.7 Hz, 1H), 3.26 (q, J = 7.1 Hz, 1H), 3.15 (dq, J = 13.4, 6.2 Hz, 1H), 2.36 - 2.28 (m, 1H) ppm; no interchangeable H was observed. Bioactivity data

Compounds of formulas I, Ia, Ib, II, IIa, and IIb can be used as PC1 regulators to increase PC1 on the surface of functional cells. These compounds are active, as detected by the _EC50 / _Emax assessment using the combinations described below in the test below. Compounds of formulas I, Ia, Ib, II, IIa, or IIb demonstrating detectable activity exhibit an _Emax value ≥ 3.0. _Emax can be calculated using any method known in the art.

In some embodiments, compounds of formulas I, Ia, Ib, II, IIa, and IIb are active if, as detected in the following tests, their EC ₅₀ is ≤ 1.0 μM, or based on a combination of EC ₅₀ > 1.0 μM and E _max ≥ 3.0. In some embodiments, compounds of formulas I, Ia, Ib, II, IIa, and IIb are active if their EC ₅₀ is ≤ 0.05 μM, > 0.05 μM but ≤ 0.2 μM, > 0.2 μM but ≤ 1.0 μM, or based on a combination of EC ₅₀ > 1.0 μM and E _max ≥ 3.0, as detected in the following tests. In some embodiments, compounds of formulas I, Ia, Ib, II, IIa, and IIb with an EC ₅₀ value ≤ 1.0 μM are included, as detected in the following tests. In some embodiments, compounds of formulas I, Ia, Ib, II, IIa, and IIb that are inactive in the following tests evaluated using the above combination of EC ₅₀ /E _max are excluded from this invention. I. Tests Overview of the assay for measuring PC1 on the cell surface in HEK293 cell line with overexpressing the PC1 mutant

To routinely evaluate the effects of compounds on the transport of the mutant PC1, a whole-well luminescence assay based on HEK293 cells was developed. A cell line stably overexpressing L2816P PKD (modified at the N-terminus with an 11-amino acid HiBiT ^™ epitope tag) and overexpressing WT PKD2 from a random locus via lentiviral integration was established. The expression of the two polycystic proteins was validated using Western ink dot assays and cell surface assays. At baseline, L2816P was primarily misfolded and not transported to the cell surface, resulting in low luminescence signals in cells detected using the Nano-Glo HiBiT extracellular detection system. Rapid culturing at low temperatures leads to an increase in PC1 content on the cell surface, as indicated by increased fluorescence. Reagents

DMEM, HEPES, NEAA, G418, purine, cypermethrin, TryplE, PBS, and deoxyhydroxytetracycline were purchased from Thermo Fisher (Loughborough, UK). FBS was purchased from Life Technologies (Paisley, UK). The Nano-Glo® HiBiT test kit (N2422, batch 0000523864) was purchased from Promega (Southampton, UK). The Jump-In™ T-Rex™ HEK293 kit (A15008) was purchased from Thermo Fisher (Loughborough, UK). The BioTek washer/dispenser (EL406) was purchased from Agilent (Wokingham, UK). The PHERAstar reader was purchased from BMG LABTECH (Aylesbury, UK). Test protocol .

HEK293 cells expressing HiBiT-labeled L2816P PKD1 were maintained in Duchenne modified iogel medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 1X non-essential amino acids (NEAA), 1X (4-(2-hydroxyethyl)-1-piperazine ethanesulfonic acid) (HEPES), 500 μg/mL G418, 10 μg/mL purine, 5 μg/mL methomyl, and 1 μg/mL deoxyhydroxytetracycline. Twenty-four hours prior to analysis, cells were washed with 1X Duchenne phosphate-buffered saline (DPBS) and then dissolved in TrypE solution. Cells were harvested and seeded at a density of 5000 cells per well (25 μL) in Corning 384-well discs containing 125 nL of pre-split compound. Concentration response data were generated at 10 sites in duplicate at final experimental concentrations ranging from 0.00320 μM to 50.0 μM. The discs were incubated at 37°C/5% _CO2 for 24 hours, followed by 7 washes with DPBS, and then the assay reagent was added. The LgBiT™ peptide contained in the assay reagent binds with high affinity to any HiBiT-labeled PC1 L2816P on the cell surface, generating a luminescent signal. The discs were read on a luminescent reader after the assay reagent was added. The raw data were transformed into a multiple of the baseline by dividing the signal by the mean of the neutral control ( _{Emax ,} DMSO-treated cells). The normalized data were then fitted with a 3-parameter Hill model ( _EC50 , Hill slope, Sinf). Modifications and variations to the embodiments described herein will be apparent to those skilled in the art without departing from the scope of the invention. The specific embodiments described herein are provided by way of example only. II. Activity Data

The table below shows the ADPKD/PC1 activities of representative compounds of the present invention obtained using the tests disclosed above, where "++++" indicates an EC ₅₀ value ≤ 0.05 μM; "+++" indicates an EC ₅₀ value > 0.05 μM but ≤ 0.2 μM; "++" indicates an EC ₅₀ value > 0.2 μM but ≤ 1.0 μM; and "+" indicates that the compound is confirmed to have detectable activity based on the combination of EC ₅₀ value > 1.0 μM and E _max score ≥ 3.0. "ND" indicates that the ADPKD/PC1 activity of compound 327 was not tested as of the date of this application, but is expected to have detectable activity in the above tests. Table 15. Bioactivity data of compounds 1 to 233 and 248 to 327 Compound number Detectable activity Compound number Detectable activity 1 ++++ 50 ++ 2 ++ 51 ++ 3 +++ 52 ++ 4 ++ 53 ++ 5 + 54 +++ 6 +++ 55 ++ 7 ++++ 56 +++ 8 ++++ 57 ++ 9 ++++ 58 ++ 10 ++ 59 +++ 11 + 60 ++ 12 +++ 61 +++ 13 ++ 62 ++ 14 +++ 63 +++ 15 +++ 64 ++ 16 ++++ 65 ++ 17 ++ 66 ++ 18 +++ 67 ++++ 19 ++ 68 +++ 20 +++ 69 + twenty one ++ 70 ++ twenty two + 71 ++ twenty three +++ 72 ++ twenty four ++ 73 ++ 25 +++ 74 + 26 +++ 75 +++ 27 +++ 76 ++ 28 ++ 77 ++ 29 ++ 78 ++ 30 +++ 79 ++ 31 ++ 80 ++ 32 +++ 81 ++ 33 ++ 82 +++ 34 ++ 83 +++ 35 + 84 ++++ 36 + 85 +++ 37 ++ 86 +++ 38 ++ 87 ++ 39 ++ 88 +++ 40 ++ 89 ++ 41 ++ 90 + 42 ++ 91 ++ 43 ++ 92 +++ 44 ++ 93 ++ 45 ++++ 94 +++ 46 ++ 95 ++ 47 +++ 96 +++ 48 ++ 97 ++ 49 ++ 98 +++ 99 ++++ 150 ++ 100 ++++ 151 +++ 101 ++ 152 ++ 102 +++ 153 ++++ 103 + 154 +++ 104 ++ 155 +++ 105 +++ 156 ++++ 106 +++ 157 + 107 ++ 158 +++ 108 +++ 159 ++ 109 +++ 160 +++ 110 +++ 161 +++ 111 ++ 162 ++ 112 ++ 163 ++++ 113 ++ 164 +++ 114 ++ 165 +++ 115 ++ 166 ++++ 116 + 167 +++ 117 + 168 +++ 118 ++ 169 +++ 119 ++ 170 +++ 120 + 171 +++ 121 +++ 172 +++ 122 ++ 173 + 123 ++ 174 ++ 124 + 175 +++ 125 ++ 176 +++ 126 +++ 177 ++++ 127 +++ 178 ++ 128 ++ 179 +++ 129 ++ 180 ++ 130 ++++ 181 +++ 131 ++++ 182 ++ 132 +++ 183 ++ 133 +++ 184 ++++ 134 ++ 185 +++ 135 ++ 186 ++ 136 +++ 187 ++++ 137 ++++ 188 ++ 138 ++ 189 +++ 139 ++++ 190 +++ 140 + 191 ++ 141 +++ 192 ++++ 142 ++++ 193 + 143 +++ 194 +++ 144 ++ 195 +++ 145 ++ 196 +++ 146 ++++ 197 +++ 147 ++ 198 +++ 148 ++ 199 ++ 149 ++++ 200 ++++ 201 ++ 266 + 202 +++ 267 ++ 203 ++ 268 +++ 204 ++++ 269 ++ 205 +++ 270 + 206 +++ 271 + 207 ++++ 272 + 208 + 273 + 209 +++ 274 + 210 ++ 275 + 211 +++ 276 ++ 212 +++ 277 ++ 213 ++ 278 ++ 214 ++++ 279 ++ 215 +++ 280 + 216 +++ 281 + 217 ++++ 282 ++ 218 +++ 283 ++ 219 +++ 284 ++++ 220 +++ 285 ++++ 221 +++ 286 + 222 +++ 287 +++ 223 +++ 288 ++++ 224 + 289 ++ 225 ++ 290 +++ 226 +++ 291 +++ 227 +++ 292 ++ 228 ++++ 293 +++ 229 ++ 294 ++ 230 +++ 295 + 231 ++ 296 ++++ 232 +++ 297 ++++ 233 ++ 298 +++ 248 + 299 +++ 249 + 300 +++ 250 + 301 +++ 251 +++ 302 + 252 ++ 303 ++ 253 + 304 + 254 + 305 ++ 255 ++ 306 ++ 256 ++ 307 ++ 257 ++ 308 ++ 258 ++ 309 ++ 259 ++ 310 ++ 260 ++ 311 + 261 + 312 ++ 262 ++ 313 ++ 263 ++ 314 +++ 264 + 315 +++ 265 + 316 ++ 317 ++ 323 ++ 318 ++ 324 + 319 ++ 325 ++ 320 ++ 326 +++ 321 + 327 ND 322 ++ Other Implementation Examples

All disclosures and patents mentioned in this disclosure are incorporated herein by full reference as if each individual disclosure or patent application were specifically and separately stated to be incorporated by full reference. In the event of any conflict between the meaning of a term in any of the patents or disclosures incorporated by reference and the usage of terms in this disclosure, the meaning of the term as defined in this disclosure shall prevail.

The foregoing description merely discloses and describes exemplary embodiments of the invention. Those skilled in the art will readily recognize, based on such description and the appended claims, that various changes, modifications, and alterations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.

Claims (35)

A compound of formula I: (Formula I) its tautomer or transtransfer isomer, a deuterated derivative of the compound, tautomer or transtransfer isomer, or a pharmaceutically acceptable salt or prodrug of the compound, tautomer, transtransfer isomer or deuterated derivative, wherein: - It can be a single key or a double key, where when a single key is present, _x1 is... And x ₂ is And when a double key exists, _x1 is And x ₂ is - Each ^R1 is independently selected from hydrogen, _C1 - _C3 alkyl (substituted by 0 to 2 groups selected from lateral, hydroxyl, and amino groups), _C1 - _C3 alkoxy, halogen, and cyano; - Each ^R2 is independently selected from hydrogen and _C1 - _C3 alkyl; - ^R3 is selected from hydrogen, _C1 - _C3 alkyl, halogen, and cyano; - Each ^R4 and ^R5 is independently selected from hydrogen, _C1 - _C3 alkyl, and halogen; - ^R6 and ^R9 are independently selected from hydrogen, _C1 - _C3 alkyl, _C1 - _C3 alkoxy, halogen, and cyano; - ^R7 is selected from hydrogen, _C1 - _C3 alkyl, and halogen; and - ^R8 is selected from: ○ hydrogen, ○ C ₁ - _C8 alkyl, substituted by 0 to 5 independently selected groups of: ■ hydroxyl, ■ lateral group, ■ amino, ■ cyano, ■ halogen, ■ _C1 - _C3 alkoxy (substituted by 0 to 1 lateral group), ■ _C3 - _C6 cycloalkyl (substituted by 0 to 2 independently selected groups of hydroxyl, halogen, and _C1 - _C3 alkyl), ■ 3 to 7-membered heterocyclic (substituted by 0 to 3 independently selected groups of halogen, hydroxyl, lateral group, and _C1 - _C3 alkyl (substituted by 0 to 1 hydroxyl group), and ■ 5 to 6-membered heteroaryl (substituted by 0 to 3 independently selected groups of lateral group, _C1 - _C3 alkyl, and C3- _C6 alkyl). _{○ 6} -cycloalkyl group substitution); ○ _C3 - _C7 cycloalkyl, which is substituted by 0 to 3 independently selected from the following groups: ■ hydroxyl, ■ halogen, ■ _C1 - _C3 alkyl (which is substituted by 0 to 3 independently selected from hydroxyl and halogen), ■ _C1 - _C3 alkoxy; and ○ 5 to 9-membered heterocyclic, which is substituted by 0 to 3 independently selected from the following groups: ■ lateral oxy, ■ halogen ■ hydroxyl, and ■ _C1 - _C3 alkyl (which is substituted by 0 to 1 hydroxyl); and -Y is selected from ○ ^OR8 , ○ N( ^R8 ) ₂ , and ○ 3 to 10 member heterocyclic or 3 to 10 member heteroaryl, each substituted by 0 to 2 independently selected from the following groups: ■ N( ^R8 ) ₂ , ■ hydroxyl, ■ lateral group, ■ _C1 - _C3 alkoxy, and ■ _C1 - _C3 alkyl (substituted by 0 to 2 groups selected from amino, hydroxyl, _C3 - _C4 alkyl, lateral group and _C1 - _C3 alkoxy). If the compound, tautomer, transconjugated isomer, deuterated derivative, or pharmaceutically acceptable salt of claim 1 is selected from compound of formula Ia: (Formula Ia), or its tautomer or trans-isomer, a deuterated derivative of such tautomer or trans-isomer, or a pharmaceutically acceptable salt or prodrug of any of the foregoing, wherein: - each ^R1 is independently selected from hydrogen, _C1 - _C3 alkyl, _C1 - _C3 alkoxy, halogen, and cyano; - each ^R2 is independently selected from hydrogen and _C1 - _C3 alkyl; - ^R3 is selected from hydrogen, _C1 - _C3 alkyl, halogen, and cyano; - ^R4 and ^R5 are independently selected from hydrogen, _C1 - _C3 alkyl, and halogen; - ^R6 and ^R9 are independently selected from hydrogen, _C1 - _C3 alkyl, halogen, and cyano; - ^R7 is selected from hydrogen, _C1 -C3 alkyl, halogen, and cyano. ₃ alkyl and halogen; and ^-R8 is selected from: ○ hydrogen, ○ _C1 - _C8 alkyl, which is substituted by 0 to 5 independently selected from the following groups: ■ hydroxyl, ■ lateral oxygen, ■ amino, ■ cyano, ■ halogen, ■ _C1 - _C3 alkoxy (which is substituted by 0 to 1 lateral oxygen), ■ _C3 - _C6 cycloalkyl (which is substituted by 0 to 2 independently selected from hydroxyl, halogen, and _C1 - _C3 alkyl groups), ■ 3 to 6-membered heterocyclic (which is substituted by 0 to 3 independently selected from halogen, hydroxyl, lateral oxygen, and _C1 - _C3 alkyl (which is substituted by 0 to 1 hydroxyl group), and ■ 5 to 6 member heteroaryl groups (substituted by 0 to 3 independently selected groups selected from lateral oxygen, _C1 - _C3 alkyl and _C3 - _C6 cycloalkyl); ○ _C3 - _C7 cycloalkyl groups, substituted by 0 to 3 independently selected groups selected from: ■ hydroxyl, ■ halogen, ■ _C1 - _C3 alkyl groups (substituted by 0 to 3 independently selected groups selected from hydroxyl and halogen), ■ _C1 - _C3 alkoxy; and ○ 5 to 9 member heterocyclic groups, substituted by 0 to 2 independently selected groups selected from: ■ lateral oxygen, ■ hydroxyl, and ■ _C1 - _C3 alkyl groups (substituted by 0 to 1 hydroxyl). If the compound, tautomer, transconjugated isomer, deuterated derivative, or pharmaceutically acceptable salt of claim 1 is selected from compound of formula Ib: (Formula Ib) its tautomer or transisomer, a deuterated derivative of the compound, tautomer or transisomer, or a pharmaceutically acceptable salt or prodrug of the compound, tautomer, transisomer or deuterated derivative, wherein: - each ^R1 is independently selected from hydrogen, a C1-C3 alkyl group (substituted by 0 to 2 groups selected from lateral, hydroxyl and amino groups), a C1-C3 alkoxy group, a halogen, and a cyano group; - each R2 _{is independently selected from} ^hydrogen and a _C1 - _C3 alkyl group; - ^R3 is selected from hydrogen, a _C1 - _C3 alkyl group, a halogen, and a cyano group; - each ^R4 and ^R5 is independently selected from hydrogen, a _C1 - _C3 alkyl group, and a halogen; - ^R6 and ^R9 are independently selected from hydrogen, _C1 - _C3 alkyl, _C1 - _C3 alkoxy, halogen, and cyano; - ^R7 is selected from hydrogen, _C1 - _C3 alkyl, and halogen; and - ^R8 is selected from: ○ hydrogen, ○ _C1 - _C8 alkyl, which is substituted by 0 to 5 independently selected from the following groups: ■ hydroxyl, ■ lateral, ■ amino, ■ cyano, ■ halogen, ■ _C1 - _C3 alkoxy (which is substituted by 0 to 1 lateral), ■ _C3 - _C6 cycloalkyl (which is substituted by 0 to 2 independently selected from hydroxyl, halogen, and _C1 - _C3 alkyl), ■ 3 to 6-membered heterocyclic groups (substituted by 0 to 3 independently selected groups selected from halogen, hydroxyl, lateral, and _C1 -C3 _alkyl groups (substituted by 0 to 1 hydroxyl), and ■ 5 to 6-membered heteroaryl groups (substituted by 0 to 3 independently selected groups selected from lateral, _C1 - _C3 alkyl, and _C3 - _C6 cycloalkyl); ○ _C3 - _C7 cycloalkyl groups, substituted by 0 to 3 independently selected groups of: ■ hydroxyl, ■ halogen, ■ _C1 - _C3 alkyl groups (substituted by 0 to 3 independently selected groups selected from hydroxyl and halogen), ■ _C1 - _C3 alkoxy; and ○ 5 to 9-membered heterocyclic groups, which are substituted by 0 to 2 independently selected groups of: ■ lateral group, ■ hydroxyl group, and ■ _C1 - _C3 alkyl group (which are substituted by 0 to 1 hydroxyl group); and -Y is selected from ○ N( ^R8 ) ₂ and ○ 3 to 10-membered heterocyclic groups or 3 to 10-membered heteroaryl groups, each substituted by 0 to 2 independently selected groups of: ■ hydroxyl group, ■ lateral group, ■ _C1 - _C3 alkoxy group, and ■ _C1 - _C3 alkyl group (which are substituted by 0 to 2 groups selected from amino, hydroxyl, _C3 - _C4 alkyl, lateral group and _C1 - _C3 alkoxy group). The compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug of any of claims 1 to 3, wherein each ^R1 is independently selected from hydrogen, methyl, methoxy, fluorine, chlorine, and cyano. The compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug of any of claims 1 to 4, wherein ^R2 is independently selected from hydrogen and methyl. The compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug of any of claims 1 to 5, wherein R ³ is selected from hydrogen, methyl, and cyano. The compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug of any of claims 1 to 6, wherein ^R4 and ^R5 are independently selected from hydrogen and methyl. The compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug of any of claims 1 to 7, wherein R ⁶ is selected from hydrogen, methyl, ethyl, fluorine, chlorine, bromine, and cyano. The compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug of any of Examples 1 to 8, wherein R ⁷ is selected from hydrogen and fluorine. If the compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug of claim 1 is selected from compound of formula II: (Formula II), tautomers or trans-isomers of the compounds, deuterated derivatives of the compounds, tautomers and trans-isomers, and pharmaceutically acceptable salts and prodrugs of the compounds, tautomers, trans-isomers and deuterated derivatives, wherein: - each ^R1 is independently selected from hydrogen, _C1 - _C3 alkyl, _C1 - _C3 alkoxy, halogen and cyano; - ^R6 is selected from _C1 - _C3 alkyl, halogen and cyano; - ^R7 is selected from hydrogen, _C1 - _C3 alkyl and halogen; and - ^R8 is selected from: ○ hydrogen, ○ _C1 - _C8 alkyl, which is substituted by 0 to 5 independently selected groups of: ■ hydroxyl, ■ lateral oxy, ■ Amino, cyano, halogen, _C1 - _C3 alkoxy (substituted with 0 to 1 lateral alkyl group), _C3 - _C6 cycloalkyl (substituted with 0 to 2 independently selected groups from hydroxyl, halogen, and _C1 - _C3 alkyl), 3 to 6 member heterocyclic (substituted with 0 to 3 independently selected groups from halogen, hydroxyl, lateral alkyl, and _C1 - _C3 alkyl (substituted with 0 to 1 hydroxyl group), and 5 to 6 member heteroaryl (substituted with 0 to 3 independently selected groups from lateral alkyl, _C1 - _C3 alkyl, and _C3 - _C6 cycloalkyl); ○ _C3 -C ₇ -Cycloalkyl group, which is substituted by 0 to 3 independently selected from the following groups: ■ hydroxyl, ■ halogen, ■ _C1 - _C3 alkyl group (which is substituted by 0 to 3 independently selected from hydroxyl and halogen), ■ _C1 - _C3 alkoxy group; and 0.5 to 9-membered heterocyclic group, which is substituted by 0 to 2 independently selected from the following groups: ■ syloxy group, ■ hydroxyl group, and ■ _C1 - _C3 alkyl group (which is substituted by 0 to 1 hydroxyl group). If the compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug is selected from compound of formula IIa, as described in claim 1: (Formula IIa), tautomers or transisomers of those compounds, deuterated derivatives of those compounds, tautomers and transisomers, and pharmaceutically acceptable salts and prodrugs of those compounds, tautomers, transisomers and deuterated derivatives, wherein: - ^R1 is selected from hydrogen, _C1 - _C3 alkyl, _C1 - _C3 alkoxy, halogen and cyano; - ^R6 is selected from _C1 - _C3 alkyl, halogen and cyano; - ^R7 is selected from hydrogen, _C1 - _C3 alkyl and halogen; and - ^R8 is selected from: ○ hydrogen, ○ _C1 - _C8 alkyl, which is substituted by 0 to 5 independently selected from the following groups: ■ hydroxyl, ■ serooxy, ■ amino, ■ Cyano, ■ Halogen, ■ _C1 - _C3 alkoxy (substituted with 0 to 1 lateral group), ■ _C3 - _C6 cycloalkyl (substituted with 0 to 2 groups independently selected from hydroxyl, halogen, and _C1 - _C3 alkyl), ■ 3 to 6-membered heterocyclic (substituted with 0 to 3 groups independently selected from halogen, hydroxyl, lateral group, and _C1 - _C3 alkyl (substituted with 0 to 1 hydroxyl group), and ■ 5 to 6-membered heteroaryl (substituted with 0 to 3 groups independently selected from lateral group, _C1 - _C3 alkyl, and _C3 - _C6 cycloalkyl); ○ _C3 - _C7 cycloalkyl, substituted with 0 to 3 groups independently selected from the following groups: ■ Hydroxyl, halogen, _C1 - _C3 alkyl (substituted by 0 to 3 groups independently selected from hydroxyl and halogen), _C1 - _C3 alkoxy; and 5 to 9-membered heterocyclic groups, substituted by 0 to 2 groups independently selected from: lateral oxy, hydroxyl, and C1- _{C3 alkyl} (substituted by 0 to 1 hydroxyl). Compounds, tautomers, transconjugation isomers, deuterated derivatives, or pharmaceutically acceptable salts or prodrugs from any of the claims 1 to 11, wherein R ⁸ is selected from: , , , , , , , ,and . The compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug of any of claims 1 to 12, wherein ^R8 is selected from a _C1 - _C8 alkyl group substituted with 0 to 5 groups. Compounds, tautomers, transconjugation isomers, deuterated derivatives, or pharmaceutically acceptable salts or prodrugs from any of claims 1 to 13, wherein R ⁸ is selected from: Compounds, tautomers, transconjugation isomers, deuterated derivatives, or pharmaceutically acceptable salts or prodrugs from any of claims 1 to 13, wherein R ⁸ is selected from: , , , , , , , , , , , , , , , , ,and . Compounds, tautomers, transconjugation isomers, deuterated derivatives, or pharmaceutically acceptable salts or prodrugs from any of claims 1 to 13, wherein R ⁸ is selected from: , , , , , , , , , , , , , , , , , and . Compounds, tautomers, transconjugation isomers, deuterated derivatives, or pharmaceutically acceptable salts or prodrugs from any of claims 1 to 13, wherein R ⁸ is selected from: , , , , , , , , , , , , and , , ,and . The compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug of any of claims 1 to 12, wherein ^R8 is selected from a _C3 - _C7 cycloalkyl group substituted with 0 to 3 groups. Such as the compounds, tautomers, transconjugation isomers, deuterated derivatives, or pharmaceutically acceptable salts or prodrugs mentioned in claim 18, wherein R ⁸ is selected from: The compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug of any of claims 1 to 12, wherein ^R8 is selected from a 5 to 9-membered heterocyclic group substituted with 0 to 2 groups. Such as the compounds, tautomers, transconjugation isomers, deuterated derivatives, or pharmaceutically acceptable salts or prodrugs mentioned in claim 20, wherein R ⁸ is selected from: A compound selected from compounds 1-233 of Table 1 and compounds 248-327 of Table 2, their tautomers or transconjugates, deuterated derivatives of their tautomers or transconjugates, and any of the foregoing as a pharmaceutically acceptable salt and prodrug. If the compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug is selected from compound of formula IIb, then: (Formula IIb), tautomers or trans-isomers of those compounds, deuterated derivatives of those compounds, tautomers and trans-isomers, and pharmaceutically acceptable salts and prodrugs of those compounds, tautomers, trans-isomers and deuterated derivatives, wherein: - each ^R1 is independently selected from hydrogen and halogen; - ^R6 is selected from halogen; and - ^R8 is selected from: ○ _C1 - _C5 alkyl, which is substituted by 0 to 5 independently selected from: ■ hydroxyl, and ■ _C3 - _C6 cycloalkyl; ○ _C3 - _C6 cycloalkyl, which is substituted by 0 to 2 selected from hydroxyl and halogen; and ○ Five to six heterocyclic groups, which are either unsubstituted or substituted with _C1 -C3 _alkyl groups, wherein the _C1 - _C3 alkyl groups are substituted with 0 to 2 substituents selected from hydroxyl and halogen. Such as the compounds, tautomers, transconjugation isomers, deuterated derivatives, or pharmaceutically acceptable salts or prodrugs mentioned in claim 23, wherein R ⁸ is selected from: A compound selected from: Compound 7 Compound 8 Compound 23 Or its tautomers or transtransfer isomers, or deuterated derivatives of such tautomers or transtransfer isomers, or pharmaceutically acceptable salts or prodrugs of any of the foregoing. A compound having the following formula: (Compound 7). A compound having the following formula: (Compound 8). A compound having the following formula: (Compound 23). A compound having the following formula: (Compound 27). A compound having the following formula: (Compound 149). A compound having the following formula: (Compound 201). A pharmaceutical composition comprising a compound, a tautomer, a transconjugation isomer, a deuterated derivative or a pharmaceutically acceptable salt or prodrug, and a pharmaceutical carrier, as described in any of claims 1 to 31. A method for treating a patient with autosomal dominant polycystic kidney disease (ADPKD) using a compound, tautomer, transtransfer isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug, or a pharmaceutical composition, as described in any of claims 1 to 31, or claim 32. Use of any compound, tautomer, transconjugation isomer, deuterated derivative, or pharmaceutically acceptable salt or prodrug as claimed in any of claims 1 to 31, for the manufacture of a medicament for the treatment of patients with somatic dominant polycystic kidney disease (ADPKD). A compound, tautomer, transtransfer inhibitor, deuterated derivative, or pharmaceutically acceptable salt or prodrug, or a pharmaceutical composition as described in claim 32, for the treatment of patients with autosomal dominant polycystic kidney disease (ADPKD) in need.