Methods for making the Myt1 inhibitor 2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo-[2,3-b]pyridine-3-carboxamide

Abstract

Disclosed is a method for preparing enantiomerically enriched compound 1, which involves chiral salt resolution of compound 1, or intermediate INT 1f or intermediate INT 1g. Compound 1 is useful for treating diseases or conditions, such as cancer, particularly diseases or conditions dependent on the activity of membrane-bound tyrosine- and threonine-specific cdc2 inhibitory kinase (Myt1). JPEG2025542335000078.jpg43170

Description

[Technical Field]

[0001] The present invention relates to synthetic methods and intermediates used to prepare compounds or pharmaceutically acceptable salts thereof that are useful in the treatment of diseases or conditions, such as cancer, particularly diseases or conditions that depend on the activity of membrane-bound tyrosine- and threonine-specific cdc2 inhibitory kinase (Myt1). [Background technology]

[0002] DNA is constantly exposed to both endogenous damaging factors (e.g., stalled replication forks, reactive oxygen species) and exogenous damaging factors (UV, ionizing radiation, chemicals) that can cause DNA damage. As a result, cells have established sophisticated mechanisms to counter these harmful events, which would otherwise compromise genome integrity and lead to genome instability diseases such as cancer. These mechanisms are collectively referred to as the DNA damage response (DDR). One component of the overall DDR is the activation of various checkpoint pathways that regulate specific DNA repair mechanisms throughout various phases of the cell cycle, including the G1, S, G2, and mitotic checkpoints. Most cancer cells lose the G1 checkpoint due to p53 mutations and therefore rely on the G2 checkpoint to correct DNA damage before entering mitosis and dividing into two daughter cells.

[0003] There is a need for convenient synthetic methods that allow for the large-scale or commercial-scale production of anticancer therapeutics, such as anticancer therapeutics that utilize small molecules, particularly anticancer therapeutics that utilize therapies that enable targeted cancer treatment. These synthetic methods can provide useful alternatives to existing syntheses and can achieve higher yields, higher isomeric purity (e.g., enantiomeric enrichment), reduced economic costs, or reduced waste streams, or any combination thereof. Summary of the Invention

[0004] The present invention provides enantiomerically enriched compound 1:

[0005] [ka]

[0006] The present invention features methods and intermediates used to prepare In one aspect, the present invention provides a method for preparing enantiomerically enriched compound 1 or a salt thereof, comprising the step of:

[0007] [ka]

[0008] and converting the enantiomerically enriched chiral salt of compound INT 1f to compound 1 or a salt thereof. In some embodiments, the step of producing the enantiomerically enriched chiral salt comprises reacting compound INT 1f with an enantiomerically enriched chiral acid. In some embodiments, the enantiomerically enriched chiral acid is (S)-(+)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (R)-(-)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (1S)-(+)-3-bromocamphor-10-sulfonic acid hydrate, (1R)-(-)-10-camphorsulfonic acid, (1S)-(+)-10-camphor In some embodiments, the enantiomerically enriched chiral salt is the corresponding chiral acid addition salt of compound INT 1f. In some embodiments, the enantiomerically enriched chiral acid is (1R)-(-)-10-camphorsulfonic acid, and the enantiomerically enriched chiral salt is the (1R)-(-)-10-camphorsulfonic acid salt of compound INT 1f. In some embodiments, the step of reacting compound INT 1f with the enantiomerically enriched chiral acid comprises reactive crystallization from anisole.

[0009] In some embodiments, the converting step comprises hydrolyzing the enantiomerically enriched salt of compound INT 1f to produce enantiomerically enriched compound INT 1g:

[0010] [ka]

[0011] or a salt thereof. In some embodiments, the hydrolyzing step comprises reacting compound INT 1f with a strong Bronsted acid. In some embodiments, the strong Bronsted acid is methanesulfonic acid. In some embodiments, the converting step comprises deprotecting compound INT 1g or a salt thereof to produce compound 1 or a salt thereof. In some embodiments, the deprotecting step comprises reacting compound INT 1f with methionine.

[0012] In some embodiments, the compound INT 1g is the compound (S)-INT 1g:

[0013] [ka]

[0014] and the compound INT 1f is the compound (S)-INT 1f:

[0015] [ka]

[0016] and Compound 1 is (S)-Compound 1:

[0017] [ka]

[0018] is. In some embodiments, the step of converting the enantiomerically enriched chiral salt of compound INT 1f to compound 1 or a salt thereof comprises recrystallization. In some embodiments, the recrystallization is performed from a methanol / water solvent system.

[0019] In another aspect, the present invention provides a method for preparing enantiomerically enriched compound 1 or a salt thereof, the method comprising the steps of generating an enantiomerically enriched chiral salt of compound INT 1f and converting the enantiomerically enriched chiral salt of compound INT 1g to compound 1 or a salt thereof.

[0020] In some embodiments, the step of producing the enantiomerically enriched chiral salt comprises reacting compound INT 1g with an enantiomerically enriched chiral acid. In some embodiments, the enantiomerically enriched chiral acid is (S)-(+)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (R)-(-)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (1S)-(+)-3-bromocamphor-10-sulfonic acid hydrate, (1R)-(-)-10-camphorsulfonic acid, (1S)-(+)-10-camphor In some embodiments, the enantiomerically enriched chiral salt is the corresponding chiral acid addition salt of compound INT 1g. In some embodiments, the enantiomerically enriched chiral acid is (1R)-(-)-10-camphorsulfonic acid, (1R)-(-)-10-camphorsulfonic acid, and the enantiomerically enriched chiral salt is the (1R)-(-)-10-camphorsulfonic acid salt of compound INT 1g.

[0021] In some embodiments, the step of reacting compound INT 1g with an enantiomerically enriched chiral acid comprises reactive crystallization from anisole. In some embodiments, the converting step comprises deprotecting compound INT 1g, or a salt thereof, to produce compound 1, or a salt thereof. In some embodiments, the deprotecting step comprises reacting compound INT 1f with methionine. In some embodiments, compound INT 1g is compound (S)-INT 1g, and compound 1 is (S)-Compound 1.

[0022] In some embodiments, the step of converting the enantiomerically enriched chiral salt of compound INT 1g to compound 1 or a salt thereof comprises recrystallization. In some embodiments, the recrystallization is performed from a methanol / water solvent system.

[0023] In yet another aspect, the present invention provides a method for preparing enantiomerically enriched compound 1, the method comprising generating an enantiomerically enriched chiral salt of compound 1 and converting the enantiomerically enriched chiral salt of compound 1 to compound 1.

[0024] In some embodiments, the step of producing the enantiomerically enriched chiral salt comprises reacting compound 1 with an enantiomerically enriched chiral acid. In some embodiments, the enantiomerically enriched chiral acid is (S)-(+)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (R)-(-)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (1S)-(+)-3-bromocamphor-10-sulfonic acid hydrate, (1R)-(-)-10-camphorsulfonic acid, (1S)-(+)-10-camphorsulfonic acid, and the enantiomerically enriched chiral salt is the corresponding chiral acid addition salt of compound 1. In some embodiments, the enantiomerically enriched chiral acid is (1R)-(-)-10-camphorsulfonic acid, and the enantiomerically enriched chiral salt is the (1R)-(-)-10-camphorsulfonic acid salt of compound 1. In some embodiments, the step of reacting compound 1 with the enantiomerically enriched chiral acid comprises reactive crystallization from anisole.

[0025] In some embodiments, Compound 1 is (S)-Compound 1. In some embodiments, the step of converting the enantiomerically enriched chiral salt of Compound 1 to Compound 1 or a salt thereof comprises recrystallization. In some embodiments, the recrystallization is performed from a methanol / water solvent system.

[0026] In some embodiments of any of the above aspects, the enantiomerically enriched chiral acid is at least 90% ee (e.g., at least 95% ee, at least 96% ee, at least 97% ee, at least 98% ee, or at least 99% ee, maximally enantiopure). In some embodiments of any of the above aspects, the enantiomerically enriched compound 1 or a salt thereof is at least 90% ee (e.g., at least 95% ee, at least 96% ee, at least 97% ee, at least 98% ee, or at least 99% ee, maximally enantiopure). In some embodiments of any of the above aspects, the enantiomerically enriched salt of compound INT 1f is at least 90% ee (e.g., at least 95% ee, at least 96% ee, at least 97% ee, at least 98% ee, or at least 99% ee, maximally enantiopure) with respect to compound INT 1f. In some embodiments of any of the above aspects, the enantiomerically enriched salt of compound INT 1g is at least 90% ee (e.g., at least 95% ee, at least 96% ee, at least 97% ee, at least 98% ee, or at least 99% ee, up to enantiopure) with respect to compound INT 1g.

[0027] In another aspect, the present invention provides a chiral acid addition salt of compound INT 1f, wherein the chiral acid is (S)-(+)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (R)-(-)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (1S)-(+)-3-bromocamphor-10-sulfonic acid hydrate, (1R)-(-)-10-camphorsulfonic acid, (1S)-(+)-10-camphor and (R)-TRIP.

[0028] In some embodiments, the chiral acid is (1R)-(-)-10-camphorsulfonic acid. In some embodiments, the compound INT 1f is the compound (S)-INT 1f. In some embodiments, the enantioenrichment of the compound INT 1f is at least 90% ee (e.g., at least 95% ee, at least 96% ee, at least 97% ee, at least 98% ee, or at least 99% ee, up to enantiopure).

[0029] In another aspect, the present invention provides the compound INT Provided is 1 g of a chiral acid addition salt, wherein the chiral acid is (S)-(+)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (R)-(-)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (1S)-(+)-3-bromocamphor-10-sulfonic acid hydrate, (1R)-(-)-10-camphorsulfonic acid, (1S)-(+)-10-camphorsulfonic acid, (+)-2,3-dibenzoyl-D-tartaric acid, (-)-2,3-dibenzoyl-L-tartaric acid, (-)-O,O'-di-p-toluoyl-L-tartaric acid, (+)-O,O'-di-p-toluoyl-D-tartaric acid, (S)-TCYP, or (R)-TCYP. In some embodiments, the chiral acid is (1R)-(-)-10-camphorsulfonic acid.

[0030] In some embodiments, compound INT 1g is (S)-INT 1g. In some embodiments, the enantioenrichment of compound INT 1g is at least 90% ee (e.g., at least 95% ee, at least 96% ee, at least 97% ee, at least 98% ee, or at least 99% ee, up to enantiopure).

[0031] In another aspect, the present invention provides a chiral acid addition salt of Compound 1, wherein the chiral acid is (S)-(+)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (R)-(-)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (1S)-(+)-3-bromocamphor-10-sulfonic acid hydrate, (1R)-(-)-10-camphorsulfonic acid, or (1S)-(+)-10-camphorsulfonic acid. In some embodiments, the chiral acid is (1R)-(-)-10-camphorsulfonic acid.

[0032] In some embodiments, compound 1 is (S)-compound 1. In some embodiments, the enantioenrichment of compound INT 1f is at least 90% ee (e.g., at least 95% ee, at least 96% ee, at least 97% ee, at least 98% ee, or at least 99% ee, up to enantiopure). In some embodiments, the enantioenrichment of compound INT 1g is at least 90% ee (e.g., at least 95% ee, at least 96% ee, at least 97% ee, at least 98% ee, or at least 99% ee, up to enantiopure). In some embodiments, the enantioenrichment of compound 1 is at least 90% ee (e.g., at least 95% ee, at least 96% ee, at least 97% ee, at least 98% ee, or at least 99% ee, up to enantiopure).

[0033] definition As used herein, the term "acid addition salt" in reference to a compound (e.g., Compound 1, INT-1f, and INT 1g, or an enantiomer thereof, e.g., the (S) enantiomer thereof) refers to a salt (e.g., a pharmaceutically acceptable salt) of the compound in which the compound is protonated and positively charged and the counterion is the conjugate base of a Bronsted-Lowry acid (e.g., a chiral acid). Examples of chiral acids include, but are not limited to, the following acids or their isomers:

[0034] [ka]

[0035] The terms "CCNE1" and "cyclin E1," used interchangeably herein, refer to the G1 / S-specific cyclin E1 (gene name: CCNE1). A cell that overexpresses CCNE1 is one that exhibits higher CCNE1 activity than a cell that normally expresses CCNE1. For example, a CCNE1-overexpressing cell is one that exhibits a copy number of at least 3 compared to a diploid normal cell that has 2 copies. Thus, a cell with a CCNE1 copy number greater than 3 is a cell that overexpresses CCNE1. CCNE1 overexpression can be measured by determining the expression level of a gene product in a cell (e.g., CCNE1 mRNA transcript number or CCNE1 protein level).

[0036] As used herein, the term "Compound 1" refers to the compound having the structure shown below.

[0037] [ka]

[0038] Compound 1 is sometimes referred to as 2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo-[2,3-b]pyridine-3-carboxamide. Compound 1 can exist as a mixture of both enantiomers, e.g., a racemic mixture, or as an enantiomerically enriched mixture of both enantiomers. The two enantiomers of Compound 1 are shown below.

[0039] [ka]

[0040] (S)-Compound 1 is also sometimes referred to as (S)-2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo-[2,3-b]pyridine-3-carboxamide. (R)-Compound 1 is also sometimes referred to as (R)-2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo-[2,3-b]pyridine-3-carboxamide.

[0041] The term "crystalline," as used herein, refers to a crystalline form of a compound (e.g., Compound 1, INT 1f, and INT 1g) characterized by an X-ray powder diffraction pattern (XRPD).

[0042] The term "Myt1," as used herein, refers to the membrane-bound tyrosine- and threonine-specific cdc2-inhibitory kinase (Myt1) (gene name PKMYT1). The term "Myt1 inhibitor," as used herein, refers to a compound that reduces the activity of the enzyme Myt1 upon contact with it, whether in vitro, in cell culture, or in an animal.

[0043] The term "pharmaceutical composition," as used herein, refers to a composition containing a compound described herein, formulated with pharmaceutically acceptable excipients, and manufactured or sold as part of a therapeutic regimen for the treatment of a disease in a mammal with the approval of a government regulatory agency. Pharmaceutical compositions can be formulated, for example, in unit dosage form for oral administration (e.g., a tablet, capsule, caplet, gel capsule, or syrup), for topical administration (e.g., as a cream, gel, lotion, or ointment), for intravenous administration (e.g., as a sterile solution free of particulate embolic agents and in a solvent system suitable for intravenous use), or any other formulation described herein.

[0044] The terms "pharmaceutically acceptable excipient" and "pharmaceutically acceptable carrier," as used interchangeably herein, refer to any ingredient other than the compounds described herein (e.g., a vehicle capable of suspending or dissolving an active compound) that is non-toxic and non-inflammatory in patients. Excipients can include, for example, anti-adherents, antioxidants, binders, coating agents, compression aids, disintegrants, dyes (colorants), emollients, emulsifiers, fillers (diluents), film-forming or coating agents, flavoring agents, fragrances, glidants (flow improvers), lubricants, preservatives, printing inks, adsorbents, suspending or dispersing agents, sweeteners, or hydration water. Exemplary excipients include, but are not limited to, butylated hydroxytoluene (BHT), calcium carbonate, calcium phosphate (dibasic), calcium stearate, croscarmellose, cross-linked polyvinylpyrrolidone, citric acid, crospovidone, cysteine, ethylcellulose, gelatin, hydroxypropyl cellulose, hydroxypropylmethylcellulose, lactose, magnesium stearate, maltitol, mannitol, methionine, methylcellulose, methylparaben, microcrystalline cellulose, polyethylene glycol, polyvinylpyrrolidone, povidone, pregelatinized starch, propylparaben, retinyl palmitate, shellac, silicon dioxide, sodium carboxymethylcellulose, sodium citrate, sodium starch glycolate, sorbitol, starch (corn), stearic acid, stearic acid, sucrose, talc, titanium dioxide, vitamin A, vitamin E, vitamin C, and xylitol.

[0045] The term "pharmaceutically acceptable salt," as used herein, refers to a salt that is, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and animals without undue toxicity, irritation, allergic response, and the like, and that is commensurate with a reasonable benefit / risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, pharmaceutically acceptable salts are described in Berge et al., J. Pharmaceutical Sciences 66:1-19, 1977 and Pharmaceutical Salts: Properties, Selection, and Use, (Eds. P.H. Stahl and C.G. Wermuth), Wiley-VCH, 2008. Salts can be prepared in situ during the final isolation and purification of the compounds described herein, or can be prepared separately by reacting the free base group with a suitable organic acid. Representative acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecyl sulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, and 2-hydroxyethanesulfonate. Examples of salts that can be used include lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate, and valerate.Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like, as well as non-toxic ammonium, quaternary ammonium, and amine cations, including, but not limited to, ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, and the like.

[0046] The term "tautomer" refers to structural isomers that readily interconvert, often via the migration of a proton. Tautomers are distinct chemical species that can be identified by distinct spectroscopic characteristics but generally cannot be individually isolated. Non-limiting examples of tautomers include ketone-enol, enamine-imine, amide-imidic acid, nitroso-oxime, ketene-ynol, and amino acid-ammonium carboxylate. [Brief explanation of the drawings]

[0047] [Figure 1] FIG. 1 is a graph showing the solubility of INT 1b in organic solvents including heptane, toluene, xylene, isopropyl acetate (IPAc), ethyl acetate (EtOAc), methyl ethyl ketone (MEK), methyl t-butyl ether (MTBE), dichloromethane (DCM), methanol (MeOH), ethanol (EtOH), isopropanol (iPrOH), acetonitrile (MeCN), water, 5M H2SO4, and 1M H2SO4. [Figure 2] 1 is an image showing the 1H NMR spectrum of INT 1b from Batch 1-INT 1b described in Example 2. [Figure 3] 1H NMR spectrum of INT 1c from the combination of batches 1 and 2-INT 1c described in Example 3. [Figure 4] 1H NMR spectrum of INT 1e derived from purified INT 1e described in Example 4. [Figure 5] 1H NMR spectrum of INT 1f from purified INT 1f described in Example 5. [Figure 6A] 1H NMR spectrum of INT 1f / acid d described in Example 7. [Figure 6B] 1H NMR spectrum of INT 1f / acid f described in Example 7. [Figure 6C] 1H NMR spectrum of INT 1f / acid h described in Example 7. [Figure 6D] 1H NMR spectrum of INT 1f / acid t described in Example 7. [Figure 6E] 1H NMR spectrum of INT 1f / acid v described in Example 7. [Figure 6F] 1H NMR spectrum of INT 1f / acid x described in Example 7. [Figure 6G] 1H NMR spectrum of INT 1f / acid y described in Example 7. [Figure 7A] 1H NMR spectrum of INT 1g / acid d described in Example 8. [Figure 7B] 1H NMR spectrum of INT 1g / acid f described in Example 8. [Figure 7C] 1H NMR spectrum of INT 1g / acid h described in Example 8. [Figure 7D] 1H NMR spectrum of INT 1g / acid t described in Example 8. [Figure 7E] 1H NMR spectrum of INT 1g / acid v described in Example 8. [Figure 8A] 1H NMR spectrum of compound 1 / acid d described in Example 9. [Figure 8B] 1H NMR spectrum of compound 1 / acid f described in Example 9. [Figure 8C] 1H NMR spectrum of compound 1 / acid h described in Example 9. [Figure 9A]Chiral HPLC of the solid recovered from reactive crystallization with (S)-CSA using anisole as the solvent as described in Example 10 (entry 10, Table 13). The earlier eluting peak at approximately 9.1 minutes corresponds to (S)-INT 1f, and the later eluting peak at approximately 10.7 minutes corresponds to (R)-INT 1f. [Figure 9B] Chiral HPLC of the mother liquor from reactive crystallization with (S)-CSA using anisole as the solvent as described in Example 10 (entry 10, Table 13). The earlier eluting peak at approximately 9.1 minutes corresponds to (S)-INT 1f, and the later eluting peak at approximately 10.7 minutes corresponds to (R)-INT 1f. [Figure 10] 1H NMR spectrum of INT 1f / (R)-CSA described in Example 12. [Figure 11] 1H NMR spectrum of INT 1f / (S)-CSA described in Example 12. [Figure 12] 1H NMR spectrum of (S)-Compound 1 from Batch 1-(S)-INT 1f / (R)-CSA described in Example 12. [Figure 13] 1 is a chiral HPLC of (S)-Compound 1 produced as described in Example 12. [Figure 14A] 1 is a chiral HPLC of (S)-Compound 1 from crystallized 1-(S)-INT 1f / (R)-CSA as described in Example 12. [Figure 14B] 1 is a chiral HPLC of (S)-Compound 1 from crystallized 2-(S)-INT 1f / (R)-CSA (2nd round, wet cake) as described in Example 12. [Figure 14C] 1 is a chiral HPLC of (S)-Compound 1 from crystallized 2-(S)-INT 1f / (R)-CSA (3rd round, dried solid) as described in Example 12. [Figure 15] 1H NMR spectrum of (S)-INT 1f / (R)-CSA from reactive crystallization-(S)-INT 1f / (R)-CSA described in Example 13 (entry 6 in Table 23). [Figure 16]1H NMR spectrum of (S)-INT 1f / (R)-CSA from recrystallized 1-(S)-INT 1f / (R)-CSA described in Example 13 (entry 2 in Table 24). [Figure 17A] 1H NMR spectrum of crude racemic INT 1f described in Example 13 (entry 1 in Table 27). [Figure 17B] 1H NMR spectrum of racemic INT 1f after recrystallization in chloroform as described in Example 13 (entry 2 in Table 27). [Figure 17C] FIG. 16 is a 1H NMR spectrum of racemic INT 1f after charcoal (DARCO®) treatment as described in Example 13 (entry 3 in Table 27). [Figure 18A] 2 is a graph showing X-ray powder diffraction (XRPD) patterns of the resulting solids from the racemic INT 1f solubility study described in Example 14 (Table 28). [Figure 18B] 1 is a graph showing the solubility profiles in anisole of racemic INT 1f and (S)-INT 1f / (R)-CSA described in Example 14 (Tables 28 and 29). [Figure 19] FIG. 16 shows X-ray powder diffraction (XRPD) patterns for a) racemic INT 1f, b) INT 1f recrystallized from anisole, c) (R)-INT 1f / (S)-CSA, d) (R)-INT 1f / (S)-CSA recrystallized from anisole (wet cake), e) (R)-INT 1f / (S)-CSA recrystallized from anisole (air dried), and f) (R)-INT 1f / (S)-CSA recrystallized from 1,3-dimethoxybenzene, as described in Example 14. [Figure 20A] 1 is an image of needle-like crystals of (R)-INT 1f / (S)-CSA recrystallized from anisole. [Figure 20B] 1 is an image of needle-like crystals of (R)-INT 1f / (S)-CSA recrystallized from 4-methylanisole. [Figure 20C]1 is an image of needle-like crystals of (R)-INT 1f / (S)-CSA recrystallized from 1,3-dimethoxybenzene. [Figure 20D] This is an image of needle-like crystals of (R)-INT 1f / (S)-CSA. [Figure 20E] This is an image of racemic INT 1f needle crystals. [Figure 20F] 1 is an image of needle-like crystals of INT 1f recrystallized from anisole. DETAILED DESCRIPTION OF THE INVENTION

[0048] The present invention features methods and compounds, or salts thereof, that may be useful for preparing compounds (e.g., synthesizing Compound 1) that are useful for treating diseases or conditions, such as cancer. Specifically, the diseases or conditions depend on the activity of membrane-bound tyrosine- and threonine-specific cdc2 inhibitory kinase (Myt1). Preferably, Compound 1 is (S)-Compound 1.

[0049] The methods and intermediates described herein may be useful for achieving higher yields, higher chemical purity, higher isomeric purity (e.g., enantiomeric enrichment), reduced economic costs, or reduced waste streams, or any combination thereof. The methods of the present invention may also enable reliable and economical commercial-scale synthesis of Compound 1 (e.g., (S)-Compound 1).

[0050] compound Where possible, the present invention includes individual diastereomers, enantiomers, epimers, and atropisomers of the compounds disclosed herein, as well as mixtures of diastereomers and / or enantiomers thereof, including racemic mixtures. While the specific stereochemistries disclosed herein are preferred, other stereoisomers, including diastereomers, enantiomers, epimers, atropisomers, and mixtures thereof, may also have utility in treating Myt1-mediated diseases. Inactive or less active diastereoisomers and enantiomers may also be useful, for example, for scientific studies of receptors and mechanisms of activation.

[0051] It is understood that a particular molecule can exist in more than one tautomeric form, and although only one tautomer may be shown in the examples, the invention includes all tautomers. The compounds and intermediates disclosed herein may contain, for example, one or more stereocenters and can exist as racemates, racemic mixtures, single enantiomers, individual diastereomers, and mixtures of diastereomers and / or enantiomers. The present invention includes all such isomeric forms of the compounds disclosed herein. All possible stereoisomers (e.g., enantiomers and / or diastereomers), in mixtures and as pure or partially purified compounds, are intended to be included within the scope of the present invention (i.e., all possible combinations of stereocenters, either as pure compounds or in mixtures).

[0052] Some of the compounds described herein (e.g., Compound 1, INT 1f, and INT 1g) may contain bonds with restricted rotation, such that two distinct rotamers or atropisomers can be separated and found to have different, potentially advantageous, biological activities. All possible atropisomers are intended to be included within the scope of the present invention.

[0053] Some of the compounds described herein may contain olefinic double bonds, and unless specified otherwise, are meant to include both E and Z geometric isomers. Some of the compounds described herein may exist with different points of hydrogen attachment, called tautomers. One example is a ketone and its enol form, known as keto-enol tautomers. The individual tautomers and mixtures thereof are encompassed by the present invention.

[0054] Compounds disclosed herein that possess one or more asymmetric centers can be separated into diastereoisomers, enantiomers, etc. by methods well known in the art (e.g., chiral supercritical fluid chromatography (SFC) and / or recrystallization).

[0055] Alternatively, enantiomers and other compounds containing chiral centers may be synthesized by stereospecific synthesis using enantiomerically pure starting materials and / or reagents of known configuration.

[0056] Acid addition salts of Compound 1, INT 1f, and INT 1g Compounds 1, INT 1f, and INT 1g contain bonds with restricted rotation such that the two distinct atropisomers can be separated. The methods of the present invention include techniques for resolving the enantiomers of these compounds by generating a chiral acid addition salt of one or more of compounds 1, INT 1g, and INT 1f. Preferably, resolution can be achieved by generating a chiral acid addition salt of INT 1f.

[0057] Recrystallization of the chiral acid addition salt of INT 1f from a solvent system improves the enantiomeric ratio of INT 1f. Alternatively, when generating an acid addition salt of INT 1f, reactive crystallization techniques may be used to improve the enantiomeric ratio of INT 1f.

[0058] Preferably, the methods of the present invention are directed to the synthesis of (S)-Compound 1 and employ the use of (S)-INT 1f and (S)-INT 1g. Chiral acids that can be used to resolve any one of Compound 1, INT 1f, and INT 1g include, but are not limited to, the following:

[0059] [ka]

[0060] Myt1 The compounds described herein can be Myt1 inhibitors (e.g., Compound 1) or intermediates useful for synthesizing Myt1 inhibitors (e.g., INT 1f and INT 1g). These compounds can be used to inhibit Myt1 in cells, e.g., cells of a subject, or to synthesize compounds useful for inhibiting Myt1. The subject can be in need of treatment for a disease or condition, e.g., a disease or condition with symptoms of cellular hyperproliferation, e.g., cancer. The Myt1 inhibitory activity of the compounds disclosed herein can be useful in treating a subject in need of treatment for cancer.

[0061] Myt1 is a cell cycle-regulating kinase primarily localized in the endoplasmic reticulum and Golgi complex. It is part of the Wee family of kinases, which also includes Wee1 and Wee1b. It is involved in the negative regulation of the CDK1-cyclin B complex, which promotes cell progression from the G2 phase of the cell cycle to mitosis (M phase). During DNA damage, Myt1 drives the phosphorylation of CDK1 (both Tyr15 and Thr14 of CDK1) in G2, maintaining the kinase complex in an inactive state as part of the G2 checkpoint response, along with Wee1 (which mediates only Tyr15 phosphorylation), preventing entry into mitosis until the damage is repaired. In addition, Myt1 has been proposed to directly interact with CDK1 complexes in the cytoplasm, preventing their nuclear translocation and thus inhibiting cell cycle progression.

[0062] Myt1 is essential in many cancer cells and has therefore been implicated as a potentially important cancer target. Overexpression of Myt1 has been observed in various cancers, including hepatocellular carcinoma and clear cell renal cell carcinoma. Myt1 downregulation plays a minor role in unperturbed cells but a more prominent role in cells exposed to DNA damage. Furthermore, cells that exhibit high levels of replication stress in addition to defective G1 checkpoint regulation may be particularly susceptible to loss of Myt1 function, as they tend to enter mitosis earlier than normal with compromised genomic material, leading to mitotic cell death. [Example]

[0063] The following examples are intended to illustrate the invention. They are not intended to limit the invention in any way. NMR, HPLC, LC / MS NMR data were collected on a 400 MHz Bruker Avance III HD instrument equipped with a 5 mm broadband autotunable multinuclear probe with z-axis gradient.

[0064] A schematic achiral HPLC method is shown below.

[0065] [Table 1]

[0066] Impurities elute before 17 min. All intermediates are well separated. The 90% MPB% does not need to be maintained for 5 min; it can be shortened to 1 min. The final equilibration time (22.1–27 min MPB 10%) can be reduced to 2 or 3 min.

[0067] The diluents and recommended sample concentrations for each intermediate in the examples are listed below.

[0068] [Table 2]

[0069] A schematic chiral HPLC method for INT 1f is shown below.

[0070] [Table 3]

[0071] A schematic chiral HPLC method for INT 1g is shown below.

[0072] [Table 4]

[0073] A schematic chiral HPLC method for compound 1 is shown below.

[0074] [Table 5]

[0075] A schematic LC / MS method is shown below.

[0076] [Table 6]

[0077] abbreviation Abbreviations and terms commonly used in the fields of organic chemistry, medicinal chemistry, pharmacology, and medicine and well known to those skilled in the art are used herein. Representative abbreviations and definitions are provided below.

[0078] [Table 7]

[0079] Example 1. Preparation of (S)-Compound 1 Scheme 1

[0080] [ka]

[0081] INT 1f, INT 1g, and compound 1 are atropisomers. The desired enantiomer of compound 1 was isolated by chiral SFC (Scheme 1) as the (S) enantiomer. While resolution by chiral SFC is suitable for isolating gram quantities of the desired enantiomer, it is inefficient for obtaining multi-kilogram quantities of material.

[0082] Therefore, a chiral salt resolution method for the late intermediate INT 1f was developed. From the 25 chiral acids screened, seven were carried forward for further evaluation based on whether or not a salt was formed. INT 1f is a weak base, resulting in the formation of a chiral salt of the pyridine 4H proton (0.5-0.6 ppm downfield) and the methyl proton on the pyridine ring (0.2-0.3 ppm downfield). 1 Salts were formed with chiral sulfonic acids, as determined by the chemical shifts of the H NMR signals. Other salts selected were based on the observation that some degree of separation of proton signals was observed in the corresponding spectra. Of the seven acids screened, it was found that the enriched salt formed from INT 1f and (R)-CSA, when processed downstream, yielded enantiomerically enriched (S)-compound 1 without loss of chirality. The salt of INT 1f with (R)-CSA was prepared by reactive crystallization of molar equivalent amounts of INT 1f and (R)-CSA in anisole to give the enantiomerically enriched salt (85:15 er) in 37% yield (74% recovery of the available enantiomers). Recrystallization from anisole afforded a further enriched salt (95:5 er) in an overall yield of 30% for the two-step process.

[0083] Example 2. Preparation of INT 1b Scheme 2

[0084] [ka]

[0085] Diazotization of INT 1a gave INT 1b. Initial conditions involved adding concentrated H2SO4 to a suspension of INT 1a in water. This was highly exothermic, and subsequent addition of NaNO2 resulted in vigorous gas evolution. The reaction was made more manageable for scale-up by adding solid INT 1a to a pre-made 1 M H2SO4 solution. This was not exothermic, and the rate of gas evolution was controlled by slow addition of aqueous NaNO2. INT 1a was initially soluble in the acidic solution at 10 °C, but solids began to precipitate immediately upon addition of NaNO2.

[0086] INT 1b has low solubility in most organic solvents (see Figure 1). As a result, the reaction was quenched with 2M K2HPO4 to precipitate INT 1b. The reaction was carried out at Kilo Lab on a 300 g scale in a 20 L reactor (Batch 1 - INT 1b). After addition of NaNO and aging at 10-20 °C for 1 h, the reaction was judged complete (no INT 1a detected by HPLC). The suspension was quenched with 2 M aqueous KHPO, and the solid was filtered and washed with HO to give INT 1b.

[0087] Batch 1 - INT 1b: A 20 L jacketed reactor equipped with a stir bearing, thermocouple, N2 inlet, and NaOH scrubber was charged with aqueous H2SO4 (1 M, 1.50 L, 1.53 kg). To this was charged INT 1a (299.2 g, 1.49 mol) as a solid. The suspension was diluted with aqueous H2SO4 (1 M, 1.50 L, 1.62 kg) and cooled to 0-5 °C. Aqueous NaNO2 (100 mg / mL, 1.34 L, 1411.8 g) was charged dropwise via an addition funnel over 2 h, and the temperature was maintained at 0°C. 内部The temperature was maintained at ≦10°C. The reactor was warmed to 10-20°C. The suspension was aged at 10-20°C for 1 hour, at which point the reaction was complete by HPLC analysis (no INT 1a was detected). The reactor was cooled to 0-5°C. The reaction was quenched by the dropwise addition of aqueous KHPO (2 M, 3.0 L, 4022.2 g) until pH = 6. The solid was filtered under vacuum (the reactor was emptied by filtrate swish) and slurry washed with HO (2 x 3.0 L). The solid was dried on the filter overnight, then transferred to a drying tray and dried overnight in a hood with airflow, then under vacuum at 40°C for 2 days to give INT 1b as a tan solid (270.3 g, 97.6 area %, 96.4 wt% = 260.6 g, 1.29 mol) in 86.4% isolated yield. 1 The 1 H NMR spectrum is shown in Figure 2.

[0088] Example 3. Preparation of INT 1c Scheme 3

[0089] [ka]

[0090] INT 1b was first reacted with POBr3 in sulfolane at 105° C. The reaction required at least 2.5 mol equivalents of POBr3 to reach near completion in 8 h (Table 1).

[0091] [Table 8]

[0092] The reaction was carried out in dimethylformamide (DMF) using POBr3 in xylene rather than solid POBr3. Addition of POBr3 in xylene to a DMF solution of INT 1b over 1 h resulted in the formation of a black sludge that was difficult to analyze. Therefore, various solvents were investigated for this reaction (Table 2). In aprotic solvents such as DMF or dimethylacetamide (DMAc), the reaction proceeded to completion (less than 0.2 area % INT 1b). However, numerous by-products were observed. In ethereal solvents such as THF and dioxane, the reaction did not go to completion. When the reaction was carried out in pure xylene, the reaction profile was much cleaner compared to the other solvents, and INT 1c was obtained at 89.7 area %.

[0093] [Table 9]

[0094] Reactions in xylene yielded cleaner reactions compared to other solvents, but the reaction did not go to completion. Addition rates of POBr3 over 2 hours (slow addition) and 0.5 hours (fast addition) were investigated (Table 3). The addition rate did not significantly affect reaction conversion. INT 1b went into solution at 90 °C in xylene and 70 °C in toluene, becoming a homogeneous solution before the addition of POBr3. Therefore, mixtures of solvents were investigated in an attempt to improve the reaction profile and drive the reaction to completion (Table 4). Of the solvent systems screened, bromination in DMF / toluene yielded the best results in terms of completion (less than 0.2 area % INT 1b) and reaction profile, resulting in INT 1c with 72 area % purity.

[0095] [Table 10]

[0096] [Table 11]

[0097] Using the improved conditions, the reaction was run twice at a 100 g batch scale (Batch 1-INT 1c and Batch 2-INT 1c). Batch 1-INT 1c produced INT 1c in 84.5% isolated yield, and Batch 2-INT 1c produced INT 1c in 70.8% isolated yield. The two batches were combined and recrystallized from TBME / heptane (Batch 1 and 2 combined - INT 1c), and INT 1c was isolated as a tan solid in 84.0% recovery.

[0098] Batch 1 - INT 1c: DMF (150 mL) was charged to a three-neck 2 L round-bottom flask equipped with an overhead stirrer, thermocouple, nitrogen inlet, and NaOH scrubber. INT 1b (103.7 g, Lot 094-153) was charged to the solvent. The suspension was diluted with DMF (150 mL) and heated to 90 °C. Toluene (500 mL) was charged to the solution. POBr3 (379 g, 56.5 wt % solution in xylene) was charged to the solution over 90 minutes (solids formed at the addition point and on the sides of the flask). The reaction was heated with vigorous stirring at 90 °C for 16 hours, at which point it was complete by HPLC analysis (no INT 1b was detected and 96.4 area % INT 1c). The crude reaction mass was cooled to ambient temperature and then poured in portions into two 2 L round-bottom flasks, each containing 1.0 L of water, and cooled in an ice / water bath. The reaction vessel was washed with water (500 mL), which was added to the quench vessel. Each quench was performed by: (1) extracting the aqueous layer with TBME (3 × 500 mL), (2) combining the organic components and washing with aqueous NaOH (0.5 N, 500 mL) and water (500 mL), and (3) drying the organic components with NaSO (100 g). The organic components from both extractions were combined by filtration into a 2 L round-bottom flask. The NaSO was washed with TBME (100 mL). The filtrate was concentrated to dryness under reduced pressure to give crude INT 1c as an orange solid (124.8 g, 97.5 area %, 88.8 wt % = 110.8 assay g by HPLC relative to the working standard, 418.3 mmol) in 84.5% recovery.

[0099] Batch 2 - INT 1c: This procedure was repeated on the same scale (103.7 g of INT 1b, Lot 094-153). At 16 hours, the reaction was complete by HPLC analysis (no INT 1b detected, 95.9 area % INT 1c). Aqueous workup gave INT 1c as an orange solid (126.2 g, 94.4 area %, 73.6 wt % by HPLC vs. working standard = 92.9 assay g, 350.6 mmol) in 70.8% isolated yield.

[0100] Combined Batches 1 and 2 - INT 1c: A suspension of INT 1c (Lot 094-188: 124.8 g, 97.5 area %, 88.8 wt % by HPLC vs. working standard = 110.8 assay g, 418.3 mmol combined with Lot 094-191: 126.2 g, 94.4 area %, 73.6 wt % by HPLC vs. working standard = 92.9 assay g, 350.6 mmol combined) in TBME (1.0 L, 4 vol) was heated to approximately 60° C. to dissolve most of the solids. Heptane (750 mL, 3 vol) was charged and the suspension was allowed to cool slowly to ambient temperature, then concentrated under reduced pressure to approximately 1.65 vol over 3 hours. The solid was collected by filtration, washed with heptane (250 mL), and dried to constant weight on the filter under nitrogen to give INT 1c as a tan solid (214.3 g, 99.3 area %, relative to 1,3,5-trimethoxybenzene internal standard). 1 The purified INT 1c was obtained in 84.0% recovery (98.4 wt% = 210.9 assay g, 796.0 mmol) by H NMR. 1 The 1 H NMR spectrum is shown in Figure 3.

[0101] Example 4. Preparation of INT 1e Scheme 4

[0102] [ka]

[0103] Reaction conditions including Pd(OAc)2, xantphos, Cs2CO3, and DME at 95 °C were investigated. Reaction screening was performed on a small scale (100 mg of INT 1d) at reflux temperature, resulting in some loss of solvent. Therefore, accurate assay yields were difficult to obtain because the final reaction volume was unknown; therefore, reactions were compared by area % of INT 1e rather than solution assay yield. Using rac-BINAP instead of xantphos resulted in incomplete conversion. Varying the solvent, temperature, and base did not result in any significant improvement over the current conditions (Table 5).

[0104] [Table 12]

[0105] Substituting Pd(OAc) for Pd(dba) improved the reaction, with INT 1c completely consumed and a small amount of INT 1d remaining (Table 6, entry 2). Considering the possibility that INT 1c was being consumed and forming a side reaction product (i.e., desbromortidine), we increased the amount of INT 1c added and observed further improvement (Table 6, entry 3).

[0106] [Table 13]

[0107] The two best conditions (entries 3 and 4) were scaled up to compare solution assay yields. These reactions were carried out using 0.50 g of INT 1d (1.0 equiv.) and 0.96 g of INT 1c (1.1 equiv.) in DME (10 vol.) at 85 °C with 10 mol% Xantphos as the ligand. Between 4.5 and 5 h, both reactions were complete and filtered for solution assay yield. The reaction mixture contained 10 mol% Pd(OAc)2 and 3.0 mol equiv. NaO. tThe reaction with Bu gave INT 1e in 68% yield, whereas the reaction with 5 mol% Pd2(dba)3 and 4.0 mol equivalents of Cs2CO3 gave an 86% yield. Based on these results, the reaction was scaled up using Pd2(dba)3 and Cs2CO3 with 20.2 g of INT 1d and 43.1 g of INT 1c (Batch 1-INT 1e). After 15 hours of heating at reflux, the reaction was judged complete (less than 1.5 area % of INT 1d remained). Workup afforded INT 1e in 87.6% isolated yield. The batch was recrystallized from 2-isopropanol (Recrystallization 1-INT 1e), and INT 1e was isolated as a yellow solid in 95.1% recovery.

[0108] Batch 1 - INT 1e: A three-necked, 1 L round-bottom flask equipped with an overhead stirrer, thermocouple, nitrogen inlet, and reflux condenser was charged with DME (200 mL, sparged before use) and INT 1d (20.18 g, 99.1 wt% by QNMR against a mesitylene standard, 20.0 assay g, 132.3 mmol). The resulting solution was charged with INT 1c (combined batches 1 and 2 - INT 1c, 43.07 g, 89.5 wt% by HPLC against a working standard, 36.6 assay g, 145.5 mmol), Cs2CO3 (172.4 g, 529.1 mmol), Xantphos (7.65 g, 13.2 mmol), and Pd2(dba)3 (6.06 g, 6.61 mmol). The suspension was diluted with DME (200 mL, sparged before use). The headspace was purged with nitrogen and the reaction was heated to reflux (approximately 85 °C). At 15 h, the reaction was cooled to ambient temperature and filtered through a plug of Solka-Floc using 500 mL of EtOAc. The Solka-Floc was washed with 200 mL of EtOAc. Solution assay yield = 83.9%. The filtrate and washings were passed through a 0.45 μm polished filter and concentrated to a low volume (approximately 1-2 volumes). Heptane (80 mL) was added dropwise, and the mixture was stirred at 0-10 °C for 1 h. The solid was filtered, washed with cold 5% EtOAc / heptane (60 mL), and dried on the filter under N overnight to afford INT 1e as a tan solid (51.45 g, 75.9 area %, 75.5 wt % by HPLC relative to working standard = 38.8 assay g, 115.7 mmol) in 88% yield.

[0109] Purified INT 1e: A suspension of INT 1e (batch 1-INT 1e, 51.45 g, 75.9 area %, 75.5 wt % = 38.8 assay g, 115.7 mmol) in 2-isopropanol (310 mL, 8 vol) was heated to reflux (approximately 81° C.) for 30 minutes to dissolve the solids and then slowly cooled to give a suspension. After stirring at ambient temperature for approximately 1 hour, the solids were collected by filtration, washed with cold 2-isopropanol (58 mL), and dried overnight on the funnel under a nitrogen atmosphere. INT 1e was obtained as a yellow solid (36.88 g, 96.3 area %, relative to 1,3,5-trimethoxybenzene internal standard). 1 Purified INT 1e was isolated from INT 1d in 90.3% recovery and 78.8% assay yield (95.0 wt % = 35.0 assay g, 104.5 mmol) by H NMR. 1 The 1 H NMR spectrum is shown in Figure 4.

[0110] Example 5. Preparation of INT 1f (racemic) Scheme 5

[0111] [ka]

[0112] When azaindole formation was performed on 1.0 g of INT 1e (purified INT 1e), only minimal formation of INT 1f was observed after 5 hours of reflux (87 area % INT 1e, 5.3 area % INT 1f). Overnight reflux did not significantly improve conversion (8.7 area % INT 1f). To determine if the slow reaction was due to the presence of water, a KF titration was performed on the reagents. NaO t Bu solid (fresh bottle, 1 day after opening) had the highest water content (Table 7). Therefore, azaindole formation for 1.0 g scale INT 1e was evaluated using NaO t A Bu solution (2 M in THF) was used to test the reaction. After 5 h at reflux, the reaction was at >50% conversion (15 area % of INT 1e, 69 area % of INT 1f).

[0113] [Table 14]

[0114] NaO t The use of a 2 M solution of Bu in THF worked well and was used for the subsequent preparation of INT 1f (Batch 1-INT 1f) on a 34.4 g scale with INT 1e. After 16 h of reflux, the reaction was judged complete (1.5 area % INT 1e remaining). Extractive workup afforded INT 1f in 71.8% isolated yield. To obtain highly pure material for chiral salt screening, INT 1f was recrystallized from CHCl3 as an off-white solid (2:1 INT 1f / CHCl3 solvate) in 95.1% recovery.

[0115] Batch 1-INT 1f: A four-necked, 1 L round-bottom flask equipped with an overhead stirrer, reflux condenser, addition funnel, thermocouple, and nitrogen inlet was charged with malononitrile (13.55 g, 205.12 mmol, 2.08 equiv) and 1,2-dimethoxyethane (sparged with nitrogen for 2 h, 495 mL, 15 vol). The solution was cooled to 0-5 °C in an ice-water bath and placed under a nitrogen atmosphere. NaO t Bu solution (2 M in THF, 0.71 wt% HO by KF titration, 98 mL, 196.86 mmol, 2.0 equiv.) was added dropwise over 15 min, and T 内部The temperature was maintained at ≤10°C. The ice bath was removed, and the solution was allowed to stir at ambient temperature for 30 minutes. INT 1e (purified INT 1e, 34.39 g, 95.0 wt% = 33.0 assay g, 98.43 mmol, 1.0 equiv.) and Pd(dppf)Cl2·CHCl2 (5.83 g, 7.14 mmol, 0.0725 equiv.) were charged to the reaction mixture in one portion. The headspace was purged with nitrogen, and the reaction was refluxed overnight (T = 80–85°C). At 16 hours, the reaction was complete by HPLC analysis (1.5 area % INT 1e remaining, 87.9 area % INT 1f). The reaction was cooled to ambient temperature and filtered through a plug of silica gel (approximately 66 g) with EtOAc (595 mL). The filtrate was extracted with water (3 × 100 mL), dried over NaSO (approximately 35 g), and filtered. The NaSO was washed with EtOAc (165 mL). The organic components were combined and concentrated under reduced pressure to a low volume (approximately 2 volumes). The suspension was stirred at ambient temperature for 1 h, then the solid was filtered and washed with cold EtOAc (50 mL) to afford INT 1f as a light brown solid (27.86 g, 98.5 area %, 81.3 wt % by HPLC as the free base vs. working standard = 22.65 assay g, 70.70 mmol) in 71.8% isolated yield.

[0116] Purified INT 1f: A suspension of INT 1f (batch 1-INT 1f, 27.86 g, 98.5 area %, 81.3 wt % as free base = 22.65 assay g, 70.70 mmol) was suspended in CHCl3 (113 mL), stirred for 15 min, and then concentrated to a low volume (approximately 1 volume) under reduced pressure. The slurry was then cooled in an ice bath for 1 h. The solid was filtered, washed with cold CHCl3 (22 mL), and dried on the funnel overnight under a nitrogen atmosphere to give INT 1f as an off-white solid (25.52 g, 99.3 area %, relative to 1,3,5-trimethoxybenzene internal standard). 1 84.6 wt% by H NMR = 21.58 assay g, 67.37 mmol; 100 wt% as 2:1 INT 1f / CHCl3 solvate, yield 95.1%. Liquid and wash losses = 4.6%. Purified INT 1f 1 The 1 H NMR spectrum is shown in Figure 5.

[0117] Example 6. Preparation of chiral acid salts of INT 1f, INT 1g, and Compound 1 INT 1f, INT 1g, and compound 1 exhibited atropisomerism, and the desired enantiomer of compound 1 was isolated by chiral supercritical fluid chromatography (SFC) as the (S) enantiomer. While resolution by chiral supercritical fluid chromatography (SFC) is suitable for isolating gram quantities of the desired enantiomer, it is inefficient for obtaining multi-kilogram quantities of material. To overcome this, chiral salt resolution of either INT 1f, INT 1g, or compound 1 was investigated. Salt resolution of INT 1f was likely the desired resolution point.

[0118] For the resolution of INT 1f, 25 commercially available chiral acids (Scheme 6) were screened to determine whether salt formation occurred. For each acid, INT 1f (1.0 equiv.) and the chiral acid (0.5 or 1.0 equiv.) were dissolved (DCM, ACN, or ACN / HO) and then concentrated to give a residue. 1 The acids were analyzed by H NMR (CDCl3). Several of the acids screened showed a significant difference between the pyridine 4H protons (0.5-0.6 ppm downfield) and the methyl protons on the pyridine ring (0.2-0.3 ppm downfield). 1 H NMR signal shifts were observed, suggesting salt formation. In some cases, no signal shifts were observed, but signal separation was obtained, also suggesting salt formation. For most of the chiral acids screened, no signal shifts or separations were observed, suggesting that salt formation did not occur.

[0119] Scheme 6

[0120] [ka]

[0121] Example 7. Crystallization of the chiral acid salt of INT 1f Scheme 7

[0122] [ka]

[0123] Salts formed from INT 1f with acids d, f, h, t, v, x, and y (Table 8) were subjected to crystallization screening.

[0124] [Table 15]

[0125] Example 8. Crystallization of INT 1g of chiral acid salt Scheme 8

[0126] [ka]

[0127] Salts formed with INT 1g and acids d, f, h, t, and v were subjected to crystallization screening (Table 9).

[0128] [Table 16]

[0129] Example 9. Crystallization of chiral acid salt of compound 1 Scheme 9

[0130] [ka]

[0131] Salts formed between compound 1 and acids d, f, and h were subjected to crystallization screening (Table 10).

[0132] [Table 17]

[0133] Example 10. Crystallization of INT 1f Chiral Salt INT 1f salt (50-60 mg) was weighed into 4 mL vials. Solvent (approximately 0.2-1.0 mL) was added to each vial, and the vials were stirred at ambient temperature for 3 days. Additional solvent was added to vials with thick slurries, and additional salt was added to vials with clear solutions. The results are summarized in Tables 11-17 below.

[0134] No enantioenrichment was observed for salts with acids d (Table 11), f (Table 12), t (Table 14), v (Table 15), x (Table 16), or y (Table 17).

[0135] [Table 18]

[0136] [Table 19]

[0137] [Table 20]

[0138] [Table 21]

[0139] [Table 22]

[0140] [Table 23]

[0141] [Table 24]

[0142] Entry 10 in Table 13 (anisole solvent, acid h ((S)-CSA)) demonstrated very good chiral purity of 15:85 in the recovered solid (see Figure 9A). The chiral purity of the mother liquor was determined to be 81:19 (Figure 9B). This suggests that use of the enantiomer of acid h (i.e., acid g; (R)-CSA) in the method described above can produce enantiomerically enriched solids of (S)-INT 1f / (R)-CSA).

[0143] Example 11. Crystallization of INT 1f Chiral Salts - Aromatic Solvent Screening Following the promising results of using anisole as the solvent and switching to (R)-CSA to obtain the desired diastereomer, the following common aromatic solvents were screened: 1,3-dimethoxybenzene, 2-, 3-, and 4-methianisole, o-, m-, and p-xylene, and α,α,α-trifluorotoluene (Table 18). Of the nine solvent systems, the INT 1f / (R)-CSA salt exhibited high solubility in 1,3-dimethoxybenzene and anisole, and good solubility in 2-, 3-, and 4-methianisole upon heating, but poor solubility in the other solvents. In addition to anisole, 4-methylanisole and 1,3-dimethoxybenzene also yielded enantiomerically enriched crystalline solids with enantiomeric ratios (er) of 90:10 and 87:13, respectively. However, the highest er was obtained with anisole (92:8).

[0144] [Table 25-1]

[0145] [Table 25-2]

[0146] The solids obtained from anisole, 4-methylanisole, and 1,3-dimethoxybenzene were slurried at 40-45°C over the weekend to determine their effect on er (Table 19). Anisole showed the highest increase in er, with an increase from 92:8 to 95:5. Anisole was selected as the solvent for further development.

[0147] [Table 26]

[0148] Example 12. Development of INT 1f Chiral Salt Resolution Process - Synthesis of (S)-Compound 1 from (S)-INT 1f / (R)-CSA Initial development work focused on the (S)-CSA salt of INT 1f. To determine which enantiomer of camphorsulfonic acid (CSA) would yield (S)-Compound 1, the (R)- and (S)-camphorsulfonic acid salts of INT 1f were prepared by concentrating a 1:1 solution of INT 1f and chiral acid to give a residue to yield approximately 6 g of each salt. Salt formation was monitored by: 1 The pyridine proton chemical shift and proton decoupling in the H NMR spectrum were determined. 1 The H NMR spectrum is shown in Figure 10. 1 The 1 H NMR spectrum is shown in Figure 11.

[0149] Both salts were concentrated by crystallization from anisole (40 vol) at 45 °C for approximately 16-18 hours. Each racemic salt was concentrated to an approximately 9:1 ratio and then converted to the corresponding atropisomer of compound 1. It was found that the salt derived from (1S)-(+)-10-camphorsulfonic acid gave (R)-compound 1, and the salt derived from (1R)-(-)-10-camphorsulfonic acid gave the desired (S)-compound 1 (Scheme 10).

[0150] Scheme 10

[0151] [ka]

[0152] Batch 1—(S)-INT 1f / (R)-CSA:(S)-INT 1f / (R)-CSA (0.37 g, 99.1 area %, 82.5 wt % = 0.31 assay g, 0.55 mmol, 91.0:9.0 er) was used for the one-pot synthesis of (S)-Compound 1. Heating with methanesulfonic acid (1.43 mL, 40.0 equiv.) and HO (30.5 μL, 4.0 equiv.) at 40 °C for 1 h resulted in almost complete conversion to (S)-INT 1g (5.8 area % (S)-INT 1f, Table 20). The solution was cooled to ambient temperature and charged with DL-methionine (0.33 g, 4.0 equiv.). After heating overnight at 70-72 °C, the reaction was nearly complete (3.0 area % (S)-INT 1 g, 86.6 area % (S)-Compound 1). The reaction was quenched with aqueous ammonia (28 wt %) to pH = 9. The solid was isolated by filtration and dried under vacuum overnight to give a yellow solid (0.177 g, 93.6 area %, relative to 1,3,5-trimethoxybenzene internal standard). 1 H NMR yielded 79.6 wt% (0.141 assay g, 0.43 mmol) in 79.2% isolated yield with an er ratio of 91.1:8.9. This confirms that (S)-INT 1f / (R)-CSA affords (S)-Compound 1 without loss of chirality (Table 20). 1 The H NMR spectrum is shown in Figure 12. The chiral HPLC of (S)-Compound 1 produced by this method is shown in Figure 13.

[0153] [Table 27]

[0154] After identifying which enantiomer of camphorsulfonic acid was required, we then investigated how to develop a process that could yield enantiomerically enriched (S)-INT 1f. Enantiomerically enriched (S)-INT 1f / (R)-CSA could be crystallized from a preformed racemic salt or prepared in situ via reactive crystallization from racemic INT 1f and (1R)-(-)-10-camphorsulfonic acid. In both methods, the initial crystallization (40 volumes of anisole, 40-45°C, approximately 16 hours) yielded an enantiomeric ratio (er) of approximately 90:10. After isolation, further recrystallization rounds of (S)-INT 1f / (R)-CSA resulted in enrichment from 90:10 er to 97:3 er (second round) and further to 99:1 er (third round, Table 21). The chiral HPLC spectra associated with each entry in Table 21 are shown in Figures 14A-14C.

[0155] [Table 28]

[0156] When the enantiomerically enriched salt was not isolated after the first crystallization but instead subjected to temperature cycling to improve er, little improvement in er was observed, regardless of the amount of solvent used (Table 22). For the isolation of (S)-INT 1f / (R)-CSA, the recovery improved significantly from 51.0% to 89.6% by cooling the recrystallization before filtration.

[0157] [Table 29]

[0158] Among the potential approaches mentioned above, it was thought that initial crystallization followed by recrystallization from anisole could be a suitable process for further development. Therefore, a process was investigated to form concentrated (S)-INT 1f by reactive crystallization followed by recrystallization to obtain (S)-INT 1f in an approximately 95:5 er ratio.

[0159] Example 13. Two-Step Crystallization Process and Final Process Development For the following development studies, yields are expressed as percent recovery relative to the available chiral INT 1f free base. For example, in the reactive crystallization - (S)-INT 1f / (R)-CSA study, the corrected total INT 1f charge is 5.00 g, but the percent recovery is based on 2.50 g of INT 1f with the correct configuration.

[0160] Step 1. Reactive crystallization - (S)-INT 1f / (R)-CSA Reactive crystallization of INT 1f (purified INT 1f, 5.91 g, 99.3 area%, 84.6 wt% = 5.00 g, racemic) with (1R)-(-)-10-camphorsulfonic acid (1.0 equiv.) was performed in anisole (34.5 volumes relative to the free base, 20 volumes relative to the salt) to determine whether seeding with a 99:1 er ratio could improve enantioselectivity during the first crystallization. Neither equilibration at ambient temperature after seeding (Table 23, entry 2) nor equilibration at 45-50 °C (entry 4) showed an improvement in er over the typically observed er. Cooling to 0-10 °C prior to isolation by filtration reduced liquid loss from 17 to 7 mg / mL without damaging er. (S)-INT 1f / (R)-CSA was isolated by filtration and dried overnight at 50 °C in a vacuum oven to give the salt (3.73 g, 99.1 area %, 98.6 wt % = 3.68 assay g) containing traces of anisole in an er of 85.3:14.7, 74% recovery. 1 The 1 H NMR spectrum is shown in Figure 15.

[0161] [Table 30]

[0162] Step 2. Recrystallization of 1‐(S)-INT 1f / (R)-CSA (S)-INT 1f / (R)-CSA (reaction crystallization-(S)-INT 1f / (R)-CSA, 3.73 g, 99.1 area %, 98.6 wt % = 3.68 assay g, 85.3:13.7 er) was dissolved in anisole (20 volumes relative to salt) at 80 °C, cooled to 45-50 °C, and the slurry was aged overnight at 45-50 °C, at which point enantioenrichment had occurred (95.5:4.5 er, Table 24). The suspension was cooled to ambient temperature and stirred over the weekend to give (S)-INT 1f / (1R)-(-)-10-camphorsulfonic acid (2.84 g, 98.5 area %, relative to 1,3,5-trimethoxybenzene internal standard). 1 97.2 wt% = 2.76 assay g, 94.5:5.5 er) was obtained in 83% recovery by H NMR. (S)-INT 1f / (R)-CSA (entry 2, Table 24) 1 The 1 H NMR spectrum is shown in Figure 16.

[0163] [Table 31]

[0164] The influence of the molar equivalents (mol equiv) of acid used was investigated to determine whether this could affect the er. Reactive crystallization of racemic INT 1f with (R)-CSA in anisole was performed at ratios of 1:0.5, 1:1, 1:1.5, and 1:2. Interestingly, resolution was observed only at the 1:1 ratio, with a typical er of 83:17 observed for the isolated solid. To determine what ratios of INT 1f to (R)-CSA would be acceptable, free base / acid ratios of 0.90, 0.95, 1.05, and 1.10 equivalents of acid were investigated. All four ratios yielded an er of approximately 87:13 after equilibration overnight at 45–50°C (Table 25), which is consistent with reactive crystallization using a 1:1 free base / acid ratio.

[0165] [Table 32]

[0166] Because recrystallization of INT 1f from CHCl3 is undesirable for scale-up, reactive crystallization of crude racemic INT 1f was investigated. However, this crystallization failed to yield concentrated INT 1f. In fact, the recovered material contained not only the racemic material but also a 10:1 mix of CSA and INT 1f.

[0167] If recrystallization of crude INT 1f is not performed, the charcoal treatment used in the previous isolation step is likely critical to successful resolution. Thus, charcoal (DARCO) treatment of crude INT 1f from the same batch as above (15.10 g, 88.0 wt% = 13.29 g) gave racemic INT 1f (8.81 g, 99.2 area %, 99.6 wt% = 8.77 assay g) in 66% yield. This material successfully underwent reactive crystallization with (R)-CSA to give the corresponding salt in an er of 88.3:11.7. Addition of charcoal-treated INT 1f to 11 wt% water (Table 26) also resulted in successful reactive crystallization, giving the salt in an er of 89.6:10.4. The failure of reactive crystallization of INT 1f may be due to the presence of an unidentified impurity ( 1 This may be due to the presence of a singlet at 2.01 ppm in the 1 H NMR (Table 27).

[0168] [Table 33]

[0169] [Table 34]

[0170] From the seven acids screened, it was found that enriched salts formed from INT 1f and (R)-CSA, when processed downstream, yielded enantiomerically enriched (S)-compound 1 without loss of chirality. The salt was prepared by reactive crystallization of molar equivalent amounts of INT 1f with (R)-CSA in anisole to give the enantiomerically enriched salt (85:15 er) in 37% yield (74% recovery of the available enantiomer). Recrystallization from anisole afforded further enriched salt (95:5 er) in 30% overall yield in a two-step process. The process could tolerate 10% more or less acid input and significant amounts of water, up to 11%. Purification of racemic INT 1f by recrystallization from a suitable solvent, such as chloroform, or by charcoal treatment for successful reactive crystallization in anisole.

[0171] Example 14. Physical properties of INT 1f and (S)-INT 1f / (R)-CSA Some important physical parameters of INT 1f and (S)-INT 1f / (R)-CSA were investigated.

[0172] The solubility of racemic INT 1f (recrystallized from anisole) in anisole at various temperatures was investigated (Table 28). The XRPD spectrum of each INT 1f sample in Table 28 is shown in Figure 18A.

[0173] [Table 35]

[0174] The solubility of the (S)-INT 1f / (R)-CSA salt in anisole at various temperatures was also investigated (Table 29).

[0175] [Table 36]

[0176] The solubility comparison (Figure 20B) suggests that INT 1f is unlikely to crystallize prior to the CSA salt form in a reactive crystallization process. The crystalline forms and morphologies of INT 1f and (R)-INT 1f / (S)-CSA from anisole and 1,3-dimethoxybenzene were investigated (Figure 19, Figure 20A, Figure 20B, Figure 20C, Figure 20D, Figure 20E, and Figure 20F). From anisole, a potential weak solvate was initially isolated (form P1), which then collapsed to form P2 upon drying in anisole. From 1,3-dimethoxybenzene, form P2 was obtained.

[0177] Example 15. Overview of chiral acid salts of INT 1g and Compound 1 This example summarizes the resolution of INT 1g and Compound 1 via chiral salts. Solid-state characterization is shown in Table 30. The solubility and enantiomeric ratios of the acid salts are shown in Tables 31-38.

[0178] Scheme 11

[0179] [ka]

[0180] [Table 37]

[0181] [Table 38]

[0182] [Table 39]

[0183] [Table 40]

[0184] [Table 41]

[0185] [Table 42]

[0186] [Table 43]

[0187] [Table 44]

[0188] [Table 45]

[0189] In contrast to the results observed for INT 1f in Example 10, no measurable enantioenrichment was observed for any salt of INT 1g with a chiral acid, either in the recovered solid or in the mother liquor. The highest enantioenrichment found for the INT 1g chiral acid salt was an isomer ratio of 60:40 observed in the mother liquor of the combination of INT 1g with acid h, using either anisole or EtOAc as the solvent (Table 33, entries 2 and 10). In addition, no measurable enantioenrichment was observed for any salt of compound 1 with a chiral acid, either in the recovered solid or in the mother liquor. The highest enantioenrichment found for the compound 1 chiral acid salt was an isomer ratio of 26:74 observed in the mother liquor of the combination of compound 1 with acid d, using 1,4-dioxane as the solvent (Table 36, entry 6).

[0190] Example 16. Procedure for the synthesis of (S)-2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo-[2,3-b]pyridine-3-carboxamide ((S)-Compound 1) This example describes a batch procedure for the synthesis of (S)-2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo-[2,3-b]pyridine-3-carboxamide ((S)-Compound 1).

[0191] The synthetic route starts from 2,6-dimethyl-4-methoxyaniline (INT 2a) and 2,3-dibromo-5,6-dimethylpyridine (INT 2b) and involves four chemical transformations (see Scheme 12).

[0192] The first step involves the Buchwald-Hartwig coupling of INT 2a with INT 2b, yielding 3-bromo-N-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethylpyridin-2-amine (INT 1e). This intermediate is reacted with malononitrile to give racemic 2-amino-1-(3-methoxy-2,6-dimethyl-phenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]pyridine-3-carbonitrile (INT 1f). The (S)-INT 1f / (R)-CSA salt can be crystallized in situ from INT 1f and (R)-CSA with chiral purity of approximately 85%. Additional rounds of slurrying can improve this to over 95%. The intermediate salt (S)-INT 1f / (R)-CSA is converted to crude (S)-compound 1, which is recrystallized to give the final product.

[0193] Scheme 12

[0194] [ka]

[0195] Raw Materials: All critical raw materials, reagents, solvents, and process chemicals were used as received from commercial suppliers. Step 1: Synthesis of 3-bromo-N-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethylpyridin-2-amine (INT 1e) A mixture of 3-methoxy-2,6-dimethylaniline (INT 2a, 95.0 g, 0.628 mol), 2,3-dibromo-5,6-dimethylpyridine (INT 2b, 182 g, 0.685 mol), CsCO (409 g, 1.26 mol), Xantphos (21.8 g, 37.7 mmol), Pd(OAc) (2.82 g, 12.6 mmol), and DME (1.9 L) was stirred at reflux for 16 h. After completion of the reaction, the mixture was cooled to ambient temperature and filtered through a pad of diatomaceous earth (47.5 g). The filter cake was washed with EtOAc (3 × 250 mL). The combined filtrate and washings were stirred with activated carbon (95.0 g) at ambient temperature for 1.5 h. The decolorized solution was filtered, and the filter cake was washed with EtOAc (240 mL). The combined filtrate and washings are concentrated under vacuum to approximately 700 mL, followed by a solvent exchange to EtOH by repeatedly adding EtOH (715 mL) and concentrating to 700 mL. Additional EtOH (425 mL) is then added, and the resulting mixture is heated to reflux for approximately 30 minutes, cooled to ambient temperature, stirred overnight, and filtered. The filter cake is washed with EtOH (240 mL) and dried under vacuum at 50° C. to afford INT 1e as a yellow-green solid (163 g) in 77% yield. 1 H NMR(400MHz,DMSO)δ 7.57(s,1H),7.26(s,1H),7.03(d,J=8.0Hz,1H),6.77(d,J=8.3Hz,1H),3.76(s,3H),2.06(s,3H),2.03(s,6H),1.94(s,3H). 13 C NMR(101MHz,DMSO)δ 156.14,153.90,151.45,141.56,139.05,128.28,127.24,124.64,121.57,108.46,101.20,55.87,22.25,18.37,17.59,11.83. Step 2: Synthesis of 2-amino-1-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]-pyridine-3-carbonitrile (INT 1f) To a solution of malononitrile (644 g, 9.74 mol) in DME (32 L) is added NaO-t-Bu (895 g, 9.31 mol) in small portions at 0 °C. This is followed by the addition of INT 1e (1.57 kg, 4.68 mol) and Pd(dppf)Cl2·CHCl2 (204.1 g, 0.250 mol) at ambient temperature. The resulting mixture is heated to reflux for 18 h. After completion of the reaction, the reaction mass is cooled to 35 °C and filtered through a pad of diatomaceous earth (1.57 kg). The filter cake is washed with DME (3 × 3.0 L). The combined filtrate and washings are stirred with activated carbon (1.75 kg) at 60 °C for 2 h. The decolorized solution is filtered, and the filter cake is washed with EtOAc (2 × 5.2 L). The decolorization procedure is repeated once. The combined filtrate and washings are concentrated under vacuum to 11 L, followed by a solvent switch to i-PrOH by repeated addition of i-PrOH (10 L) and concentration to 11 L. The resulting mixture is heated to reflux for approximately 30 min, cooled to ambient temperature, stirred overnight, and filtered. The filter cake is washed with i-PrOH (4.0 L) and dried under vacuum at 50 °C to give INT 1f as a pale yellow solid (1.13 kg) in 76% yield. 1 H NMR(400MHz,DMSO)δ 7.39(s,1H),7.22(d,J=8.5Hz,1H),7.07(d,J=8.5Hz,1H),6.78(s,2H),3.84(s,3H),2.25(d,J=5.1Hz,6H),1.79(s,3H),1.70(s,3H). 13 C NMR(101MHz,DMSO)δ 156.53,153.19,147.39,143.51,132.59,129.06,128.60,126.18,125.25, 124.53,119.06,117.58,112.00,59.05,56.09,22.31,19.20,17.32,11.29. Step 3: Synthesis of (S)-2-ammonium-1-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]-pyridine-3-carbonitrile / (R)-CSA ((S)-INT 1f / (R)-CSA) A mixture of INT 1f (1.12 kg, 3.50 mol), (R)-CSA (818 g, 3.52 mol), and anisole (32 L) was heated to 85°C for 1 hour, cooled to 50°C, and then seed crystals (2.2 g, 7.0 mmol) were added. The mixture was stirred at 50°C for 14 hours, cooled to 10°C over 5 hours, aged at this temperature for 16 hours, and filtered. The filter cake was washed with anisole (2.25 L) and dried on a centrifuge for 1 hour to give crude wet (S)-INT 1f / (R)-CSA (1.46 kg). A suspension of crude (S)-INT 1f / (R)-CSA in anisole (16 L) was heated to 85°C for 2 hours, cooled to 10°C over several hours, aged at this temperature for 16 hours, and filtered. The filter cake is washed with anisole (1.8 L) and dried under vacuum at 50° C. to give (S)-INT 1f / (R)-CSA of 97.5% chiral purity as an off-white solid (758 g) in 39% yield. 1 H NMR(400MHz,DMSO)δ 7.55(s,1H),7.25(d,J=8.5Hz,1H),7.11(d,J=8.5Hz,1H),3.85(s,3H), 2.95(d,J=14.7Hz,1H),2.68-2.55(m,1H),2.48-2.51(m,1H),2.28(d,J= 4.7Hz,6H),2.25-2.18(m,1H),1.96(t,J=4.5Hz,1H),1.91-1.82(m,2H) ,1.79(s,3H),1.71(s,3H),1.39-1.23(m,2H),1.04(s,3H),0.75(s,3H). 13C NMR(101MHz,DMSO)δ 216.42,156.61,153.38,146.07,142.02,131.90,129.03,128.82,126.27,125.98,125.78,119.94,117.10,112 .37,59.38,58.57,56.14,47.60,47.36,42.68,42.60,26.84,24.64,21.28,20.48,19.97,18.98,17.24,11.27. Step 4: Synthesis of (S)-2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]pyridine-3-carboxamide ((S)-Compound 1) To a mixture of methanesulfonic acid (3.5 L) and water (65.6 mL, total water content 1.60 w / w%), (S)-INT 1f / (R)-CSA (750 g, 1.36 mol) is added portionwise at 45° C. Stirring is continued at this temperature for 4 hours. After completion of the reaction, the resulting mass is cooled to ambient temperature, and DL-methionine (810 g, 5.43 mol) is added. The reaction mixture is stirred at 75° C. for 18 hours, cooled to ambient temperature, and quenched by dropwise addition to cold water (15 L), while maintaining the temperature below 20° C. The quenched mixture is diluted with water (5.6 L) and stirred with activated carbon (75.0 g) at ambient temperature for 3 hours. The decolorized solution is filtered through a pad of diatomaceous earth (375 g), and the filter cake is washed with water (7.5 L). 2-MeTHF (3.3 L) is then added to the combined filtrate and washings. The pH of the biphasic system is adjusted to 8-9 with aqueous NaOH (30 w / w%, approximately 6 L). The resulting suspension is heated to 55 °C for 30 min, cooled to ambient temperature, stirred for 10 h, and filtered. The filter cake is washed with water (3 × 2.3 L) and dried under vacuum at 50 °C to give crude (S)-Compound 1 as a light brown solid (410 g, chemical purity 98.8 area %, chiral purity 97.4%) in 93% yield.

[0196] Crude (S)-Compound 1 (270 g, 0.832 mol) is dissolved in methanol (3.4 L) at 65° C., and the resulting mixture is cooled to 55° C. and filtered (warm) to remove insoluble material. The filter cake is washed with methanol (680 mL). Water (270 mL) is added to the filtrate at 55° C., which is then cooled to 0° C. Seed crystals (16 mg as a suspension in 1:1 v / v methanol / water (270 mL)) are added, and the resulting mixture is stirred at 0° C. for 3 hours. Water (3.8 L) is added over several hours, and then stirring is continued at 0° C. for 10 hours. The resulting suspension is filtered. The filter cake is washed with methanol / water (1:1 v / v, 405 mL) and dried under vacuum at 50 °C to give (S)-Compound 1 (217 g) as a light brown solid (217 g, chemical purity 99.6 area%, chiral purity 99.9%) in 80% yield from crude (S)-Compound 1. 1 H NMR(400MHz,DMSO)δ 9.48(s,1H),7.83(s,1H),7.05(d,J=8.1Hz,1H),6.91(d,J=8.1Hz,1H),6 .71(s,2H),6.65(s,2H),2.25(d,J=8.1Hz,6H),1.75(s,3H),1.67(s,3H). 13 C NMR(101MHz,DMSO)δ 168.91,154.62,152.27,145.59,143.95,133.10,128.26,127.52,125. 67,124.47,124.11,116.59,115.97,83.56,22.22,19.34,17.38,11.35. Example 17. Alternative Procedure for the Synthesis of (S)-2-Amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo-[2,3-b]pyridine-3-carboxamide ((S)-Compound 1) This example describes a batch procedure for the synthesis of (S)-2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo-[2,3-b]pyridine-3-carboxamide ((S)-Compound 1).

[0197] The synthetic route starts from 2,6-dimethyl-4-methoxyaniline (INT 2a) and 2,3-dibromo-5,6-dimethylpyridine (INT 2b) and involves four chemical transformations (see Scheme 13).

[0198] The first step involves the Buchwald-Hartwig coupling of INT 2a with INT 2b, yielding 3-bromo-N-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethylpyridin-2-amine (INT 1e). This intermediate is reacted with malononitrile to give racemic 2-amino-1-(3-methoxy-2,6-dimethyl-phenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]pyridine-3-carbonitrile (INT 1f). The (S)-INT 1f / (R)-CSA salt can be crystallized in situ from INT 1f and (R)-CSA, followed by an additional round of slurrying with chiral purity exceeding 97%. The intermediate salt (S)-INT 1f / (R)-CSA is converted to crude (S)-compound 1, which is recrystallized to give the final product.

[0199] Scheme 13

[0200] [ka]

[0201] Raw Materials: All critical raw materials, reagents, solvents, and process chemicals were used as received from commercial suppliers. Step 1: Synthesis of 3-bromo-N-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethylpyridin-2-amine (INT 1e) A mixture of 3-methoxy-2,6-dimethylaniline (INT 2a, 80.0 g, 0.529 mol) in 1,2-dimethoxyethane (DME, 1.38 L) was stirred at 20-30 °C for 5-10 min, after which 2,3-dibromo-5,6-dimethylpyridine (INT 2b, 152.8 g, 0.576 mol), CsCO (258.6 g, 0.794 mol), Xantphos (18.4 g, 31.7 mmol), and Pd(OAc) (2.4 g, 11 mmol) were added under nitrogen. The resulting mixture was stirred at 80-85 °C for 20-24 h, cooled to 20-30 °C, and filtered through a pad of diatomaceous earth (20.0 g, 0.25 rel. wt.). The filter cake is washed with DME (2 x 460 mL, then 276 mL). The combined filtrate and washes are concentrated under vacuum at 40-50 °C to 600 mL (7-8 relative volumes), and then water (240 mL) is added at 60-75 °C. The resulting mixture is cooled to 20-30 °C, aged for 10-15 hours, and filtered. The filter cake is washed with a mixture of DME (276 mL) and water (120 mL) and dried under nitrogen protection at 20-30 °C for 30-60 minutes to give crude INT 1e as a yellow solid (164.2 g, 93% yield).

[0202] A mixture of crude INT 1e (164.2 g) in ethanol (800 mL) is heated at 75-78 °C for 1-2 h, then cooled to 20-30 °C, aged for 10-15 h, and filtered. The filter cake is washed with ethanol (200 mL) and dried under vacuum at 45-55 °C to give INT 1e as a yellow solid (145.2 g, 82% yield).

[0203] Step 2: Synthesis of 2-amino-1-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]-pyridine-3-carbonitrile (INT 1f) A solution of malononitrile (53.2 g, 0.805 mol) in DME (4.5 L) under nitrogen was stirred at 20–30 °C for 5–10 min, then cooled to 0–10 °C (target temperature: 5 °C). Sodium tert-butoxide (96.8 g, 1.01 mmol) was added in five portions at 0–10 °C. The reactor mixture was warmed up to 20–30 °C and aged at that temperature for 30–40 min. INT 1e (225.0 g, 0.671 mol), 1,1'-bis(diphenylphosphino)ferrocene (dppf; 7.44 g, 0.0134 mol), and Pd(dppf)Cl2·CHCl2 (10.96 g, 13.4 mmol) were then added. The resulting mixture is heated at 83-87°C for 18-24 hours, cooled to 30-50°C, and filtered through a pad of diatomaceous earth (112.5 g). The filter cake is washed with DME (2 x 1.3 L). The combined filtrate and washings are concentrated under vacuum at 40-50°C to approximately 1,700 mL (7-8 rel. vol), after which water (675 mL) is added. The resulting suspension is heated at 60-75°C for 1-2 hours, then cooled to 20-30°C, aged for 10-15 hours, and filtered. The filter cake is washed with a mixture of DME (620 mL) and water (270 mL) and dried under nitrogen protection at 20-30 °C for 30-60 min to give crude INT 1f as an off-white solid (189.5 g), which is suspended in 2-propanol (2.02 L) and heated at 80-83 °C for 30-45 min. The mixture is cooled to 18-28 °C, aged for 2-4 h, and filtered. The filter cake is washed with 2-propanol (572 mL) and dried under vacuum at 45-55 °C to give INT 1f as a white solid (153.0 g, 74% yield).

[0204] Step 3: Synthesis of (S)-2-ammonium-1-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]-pyridine-3-carbonitrile / (R)-CSA ((S)-INT 1f / (R)-CSA) A mixture of INT 1f (148 g, 0.462 mol), (R)-CSA (107.3 g, 0.462 mol), and anisole (2.97 L) was heated to 85°C for 1 h, cooled to 45-50°C, and then seed crystals (296 mg, 0.536 mmol) were added. The mixture was stirred at 48-52°C for 4-6 h, cooled to 7-13°C at a cooling rate of 5-10°C / h, and aged at this temperature for approximately 16 h. The suspension was filtered, and the filter cake was washed with anisole (297 mL) and either dried on the filter or centrifuged for 1 h to obtain wet crude (S)-INT 1f / (R)-CSA. A suspension of crude (S)-INT 1f / (R)-CSA in anisole (2.05 L) is stirred at 20-30 °C for 5-10 min, heated at 80-85 °C for 1-2 h, cooled to 7-13 °C, and then aged at this temperature for 16 h. The suspension is filtered, and the filter cake is washed with anisole (296 g, 2.0 rel. wt.) and dried under vacuum at 45-55 °C to give (S)-INT 1f / (R)-CSA as an off-white solid (106.2 g, 42% yield) with 97.4% chiral purity.

[0205] Step 4: Synthesis of (S)-2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]pyridine-3-carboxamide ((S)-Compound 1) To a mixture of methanesulfonic acid (657.4 g) and water (6.11 mL, total water content 1.60 w / w%), (S)-INT 1f / (R)-CSA (95.0 g, 0.172 mol) is added in 16 portions at 40-48 °C. Stirring is continued at this temperature for 8 h, after which the reaction mixture is cooled to 15-25 °C and DL-methionine (102.6 g, 0.688 mol) is added. The resulting mixture is heated at 70-78 °C for 18-24 h, cooled to 15-25 °C, and then slowly added to pre-cooled (0-10 °C) water (2.38 kg). The quenched mixture is diluted with water (475 mL) and 2-MeTHF (334 mL). The pH is adjusted to 7-9 by adding aqueous NaOH (approximately 30 w / w%). The suspension is aged at 30-35°C for 20-60 min and at 15-25°C for 10-15 h, then filtered. The filter cake is washed with water (3 x 475 mL) and dried under vacuum at 45-55°C to give a brown solid (54.2 g, 91% yield). A suspension of the above solid (53.0 g) in THF (425 mL) is heated at 65-70°C for 20-40 min, then cooled to -3-3°C, aged for 20-24 h, and filtered. The filter cake is washed with THF (2 x 53 mL) and dried under vacuum at 45-55°C to give crude (S)-Compound 1 as a light brown solid (57.5 g, 108% yield).

[0206] Activated carbon (5.83 g) was added to crude (S)-compound 1 (58.3 g, 0.180 mol) in methanol (736 mL). The suspension was stirred at 20-30°C for 5-10 minutes and at 60-66°C for 1-2 hours, cooled to 50-55°C, and filtered to remove insoluble material. The filter cake was washed with methanol (147 mL). Water (29.2 mL) was slowly added to the combined filtrate and washings at 50-55°C. The resulting mixture was cooled to 3-7°C and then charged with a suspension of seed crystals (0.58 g, 1.8 mmol) in MeOH / water (4:5 v / v, 58 mL). Stirring was continued at 3-7°C for 3 hours, followed by the addition of water (857 mL) over 4-9 hours at 3-7°C. The resulting suspension was aged at this temperature for 8-12 hours and filtered. The filter cake is washed twice with a mixture of MeOH (49 mL) and water (43.7 mL) and dried under vacuum at 45-55 °C to give (S)-compound 1 as a yellowish to off-white solid (44.3 g, 76% yield) with a purity of >99.9% and a chiral purity of 99.7%.

[0207] Example 18. Procedure for the synthesis of (S)-2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo-[2,3-b]pyridine-3-carboxamide ((S)-Compound 1) This example describes a procedure for the GMP manufacture of (S)-2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo-[2,3-b]pyridine-3-carboxamide ((S)-Compound 1).

[0208] The GMP production of (S)-2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]pyridine-3-carboxamide (1) involves four chemical transformations starting from 2,6-dimethyl-4-methoxyaniline (2) and 2,3-dibromo-5,6-dimethylpyridine (3) (see Scheme 14).

[0209] The first step involves the Buchwald-Hartwig coupling of 2 with 3, resulting in 3-bromo-N-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethylpyridin-2-amine (4). This intermediate is reacted with malononitrile to give racemic 2-amino-1-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]pyridine-3-carbonitrile (INT 1f). (S)-2-Ammonium-1-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]pyridine-3-carbonitrile / (R)-CSA ((S)-INT 1f / (R)-CSA) can be crystallized in situ from INT 1f and (R)-CSA with chiral purity of approximately 85%. Additional rounds of slurrying can improve this to over 95%. The intermediate salt (S)-INT 1f / (R)-CSA is converted to crude (S)-Compound 1, which is recrystallized to give the final product.

[0210] Scheme 14

[0211] [ka]

[0212] Raw Materials: All critical raw materials, reagents, solvents, and process chemicals were used as received from commercial suppliers. Step 1: Synthesis of 3-bromo-N-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethylpyridin-2-amine (INT 1e) A mixture of 3-methoxy-2,6-dimethylaniline (INT 2a, 8.08 kg, 53.4 mol), 2,3-dibromo-5,6-dimethylpyridine (INT 2b, 15.5 kg, 58.5 mol), CsCO (35.0 kg, 107 mol), Xantphos (1.86 kg, 3.21 mol), Pd(OAc) (243 g, 1.08 mol), and DME (160 L) was stirred at reflux for 16 h. After completion of the reaction, the mixture was cooled to ambient temperature and filtered through a pad of diatomaceous earth (4.1 kg). The filter cake was washed with EtOAc (3 × 65 L). The combined filtrate and washings were stirred with activated carbon (8.1 kg) at ambient temperature for 2 h. The decolorized solution was filtered, and the filter cake was washed with EtOAc (61 L). The combined filtrate and washings are concentrated under vacuum to approximately 60 L, followed by a solvent switch to EtOH by repeated addition of EtOH (61 L) and concentration to 60 L. Additional EtOH (36 L) is then added, and the resulting mixture is heated to reflux for approximately 30 minutes, cooled to ambient temperature, stirred overnight, and filtered. The filter cake is washed with EtOH (20 L) and dried under vacuum at 50° C. to afford INT 1e as a pale yellow solid (13.3 kg) in 74% yield.

[0213] Step 2: Synthesis of 2-amino-1-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]-pyridine-3-carbonitrile (INT 1f) To a solution of malononitrile (12.8 kg, 194 mol) in DME (620 L) is added NaO-t-Bu (17.6 kg, 183 mol) in small portions at 0 °C. This is followed by the addition of INT 1e (30.9 kg, 92.2 mol) and Pd(dppf)Cl2·CHCl2 (4.01 kg, 4.91 mol) at ambient temperature. The resulting mixture is heated to reflux for 18 h. After completion of the reaction, the reaction mass is cooled to 35 °C and filtered through a pad of diatomaceous earth (30.9 kg). The filter cake is washed with DME (3 × 180 L). The combined filtrate and washings are stirred with activated carbon (30.9 kg) at 60 °C for 1.5 h. The decolorized solution is filtered, and the filter cake is washed with DME (2 × 10 L). The combined filtrate and washes are subjected to a second decolorization treatment with activated carbon (30.9 kg) at 60 °C, but this time the filter cake is washed with EtOAc (2 × 10 L). The combined filtrate and washes are concentrated under vacuum to 240 L, followed by a solvent switch to i-PrOH by repeated addition of i-PrOH (197 L) and concentration to 240 L. The resulting mixture is heated to reflux for approximately 30 min, cooled to ambient temperature, stirred overnight, and filtered. The filter cake is washed with i-PrOH (79 L) and dried under vacuum at 50 °C to afford INT 1f as a pale yellow solid (21.3 kg) in 72% yield.

[0214] Step 3: Synthesis of (S)-2-ammonium-1-(3-methoxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]-pyridine-3-carbonitrile / (R)-CSA ((S)-INT 1f / (R)-CSA) A mixture of INT 1f (21.0 kg, 65.7 mol), (R)-CSA (15.4 kg, 66.3 mol), and anisole (612 L) is heated to 85°C for 1 hour, cooled to 50°C, and then seed crystals (42 g, 0.13 mol) are added. The mixture is stirred at 50°C for 14 hours, cooled to 10°C over 6 hours, aged at this temperature for 16 hours, and filtered. The filter cake is washed with anisole (53 L) and dried on a centrifuge for 1 hour to give crude wet (S)-INT 1f / (R)-CSA (17.2 kg). A suspension of crude (S)-INT 1f / (R)-CSA in anisole (302 L) is heated to 85°C for 2 hours, cooled to 10°C over 10 hours, aged at this temperature for 16 hours, and filtered. The filter cake is washed with anisole (43 L) and dried under vacuum at 50° C. to give (S)-INT 1f / (R)-CSA of 97.2% chiral purity as an off-white solid (14.4 kg) in 40% yield.

[0215] Step 4: Synthesis of (S)-2-amino-1-(3-hydroxy-2,6-dimethylphenyl)-5,6-dimethyl-1H-pyrrolo[2,3-b]pyridine-3-carboxamide ((S)-Compound 1) To a mixture of methanesulfonic acid (32 L) and water (0.48 L, total water content 1.60 w / w%), (S)-INT 1f / (R)-CSA (6.76 kg, 24.6 mol) is added in portions at 45° C. Stirring is continued at this temperature for 4 hours. After completion of the reaction, the resulting mass is cooled to ambient temperature, and DL-methionine (14.8 kg, 99.2 mol) is added. The reaction mixture is stirred at 75° C. for 18 hours, cooled to ambient temperature, and quenched by dropwise addition to cold water (141 L), while maintaining the temperature below 20° C. The quenched mixture is diluted with water (51 L) and stirred with activated carbon (0.70 kg) at ambient temperature for 3 hours. The decolorized solution is filtered through a pad of diatomaceous earth (3.4 kg), and the filter cake is washed with water (69 L). 2-MeTHF (30 L) is then added to the combined filtrate and washings. The pH of the biphasic system is adjusted to 8-9 with aqueous NaOH (30 w / w%, approximately 50 L). The resulting suspension is heated to 55 °C for 30 min, cooled to ambient temperature, stirred for 10 h, and filtered. The filter cake is washed with water (3 × 20 L) and dried under vacuum at 50 °C to give crude (S)-Compound 1 as a light brown solid (3.75 kg, chemical purity 98.8 area%, chiral purity 97.3%) in 94% yield.

[0216] Crude (S)-Compound 1 (7.40 kg, 22.8 mol) is dissolved in methanol (93 L) at 65° C., and the resulting mixture is cooled to 55° C. and filtered (warm) to remove insoluble material. The filter cake is washed with methanol (19 L). Water (3.7 L) is added to the filtrate at 55° C., which is then cooled to 5° C. Seed crystals (74 g as a 1:1 v / v suspension in methanol / water (8 L)) are added, and the resulting mixture is stirred at 0° C. for 3 hours. Water (109 L) is added over several hours, and then stirring is continued at 0° C. for 10 hours. The resulting suspension is filtered. The filter cake is washed with methanol / water (1:1 v / v, 6 L) and dried under vacuum at 50 °C to give (S)-Compound 1 as a pale yellow solid (6.11 kg, chemical purity 99.6 area%, chiral purity 99.8%) in 83% yield from crude (S)-Compound 1.

[0217] Other embodiments Various modifications and variations of the described invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications to the description of the detailed description that are obvious to those skilled in the art are intended to be within the scope of the present invention.

[0218] Other embodiments are within the scope of the following claims.

Claims

1. Enantiomerically enriched compound 1: 【Chemistry 1】 or a salt thereof, comprising the steps of: (a) Compound INT 1f: 【Chemistry 2】 and forming an enantiomerically enriched chiral salt of (b) converting the enantiomerically enriched chiral salt of compound INT 1f to compound 1 or a salt thereof; The method comprising:

2. 10. The method of claim 1, wherein step (a) comprises reacting compound INT 1f with an enantiomerically enriched chiral acid.

3. The enantiomerically enriched chiral acid is (S)-(+)-1,1′-binaphthyl-2,2′-diyl hydrogen phosphate, (R)-(−)-1,1′-binaphthyl-2,2′-diyl hydrogen phosphate, (1S)-(+)-3-bromocamphor-10-sulfonic acid hydrate, (1R)-(−)-10-camphorsulfonic acid, (1S)-(+)-10-camphorsulfone 3. The method of claim 2, wherein the acid is (+)-2,3-dibenzoyl-D-tartaric acid, (-)-2,3-dibenzoyl-L-tartaric acid, (-)-O,O'-di-p-toluoyl-L-tartaric acid, (+)-O,O'-di-p-toluoyl-D-tartaric acid, (S)-TCYP, (R)-TCYP, (S)-TRIP, or (R)-TRIP, and the enantiomerically enriched chiral salt is the corresponding chiral acid addition salt of compound INT 1f.

4. 4. The method of claim 3, wherein the enantiomerically enriched chiral acid is (1R)-(-)-10-camphorsulfonic acid and the enantiomerically enriched chiral salt is the (1R)-(-)-10-camphorsulfonic acid salt of compound INT 1f.

5. 5. The method of any one of claims 2 to 4, wherein step (a) comprises reactive crystallization from anisole.

6. Step (b) hydrolyzing the enantiomerically enriched salt of compound INT 1f to obtain enantiomerically enriched compound INT 1g: 【Transformation 3】 6. The method of claim 1, comprising producing a compound selected from the group consisting of methyl methylcellulose, ...

7. 7. The method of claim 6, wherein the hydrolyzing step comprises reacting compound INT 1f with a strong Bronsted acid.

8. 8. The method of claim 7, wherein the strong Bronsted acid is methanesulfonic acid.

9. 9. The method of any one of claims 6 to 8, wherein step (b) comprises deprotecting compound INT 1g or a salt thereof to produce compound 1 or a salt thereof.

10. 10. The method of claim 9, wherein the deprotecting step comprises reacting compound INT 1f with methionine.

11. INT 1g is (S)-INT 1g: 【Chemistry 4】 and INT 1f is (S)-INT 1f: 【Transformation 5】 and Compound 1 is (S)-Compound 1: 【Transformation 6】 The method according to any one of claims 6 to 10, wherein

12. 12. The method of any one of claims 1 to 11, wherein the enantiomerically enriched chiral acid is at least 90% ee.

13. 13. The method of any one of claims 1 to 12, wherein the enantiomerically enriched compound 1 or a salt thereof is at least 98% ee.

14. 14. The method of any one of claims 1 to 13, wherein step (b) comprises recrystallization.

15. 15. The method of claim 14, wherein the recrystallization is carried out from a methanol / water solvent system.

16. 1. A method for preparing enantiomerically enriched Compound 1 or a salt thereof, comprising: (a) producing an enantiomerically enriched chiral salt of 1 g of compound INT; (b) converting the enantiomerically enriched chiral salt of compound INT 1g to compound 1 or a salt thereof; The method comprising:

17. 17. The method of claim 16, wherein step (a) comprises reacting compound INT 1g with an enantiomerically enriched chiral acid.

18. The enantiomerically enriched chiral acid is (S)-(+)-1,1′-binaphthyl-2,2′-diyl hydrogen phosphate, (R)-(−)-1,1′-binaphthyl-2,2′-diyl hydrogen phosphate, (1S)-(+)-3-bromocamphor-10-sulfonic acid hydrate, (1R)-(−)-10-camphorsulfonic acid, (1S)-(+)-10-camphorsulfone 18. The method of claim 17, wherein the acid is (+)-2,3-dibenzoyl-D-tartaric acid, (-)-2,3-dibenzoyl-L-tartaric acid, (-)-O,O'-di-p-toluoyl-L-tartaric acid, (+)-O,O'-di-p-toluoyl-D-tartaric acid, (S)-TCYP, (R)-TCYP, (S)-TRIP, or (R)-TRIP, and the enantiomerically enriched chiral salt is the corresponding chiral acid addition salt of compound INT 1g.

19. 19. The method of claim 18, wherein the enantiomerically enriched chiral acid is (1R)-(-)-10-camphorsulfonic acid and the enantiomerically enriched chiral salt is the (1R)-(-)-10-camphorsulfonic acid salt of compound INT 1g.

20. 20. The method of any one of claims 17 to 19, wherein step (a) comprises reactive crystallization from anisole.

21. 21. The method of any one of claims 16 to 20, wherein step (b) comprises deprotecting compound INT 1g or a salt thereof to produce compound 1 or a salt thereof.

22. 22. The method of claim 21, wherein the deprotecting step comprises reacting compound INT 1g with methionine.

23. 23. The method of any one of claims 16 to 22, wherein INT 1g is (S)-INT 1g and Compound 1 is (S)-Compound 1.

24. 24. The method of any one of claims 16 to 23, wherein the enantiomerically enriched chiral acid is at least 90% ee.

25. 25. The method of any one of claims 16 to 24, wherein the enantiomerically enriched compound 1 or salt thereof is at least 90% ee.

26. 26. The method of any one of claims 16 to 25, wherein the step of converting the enantiomerically enriched chiral salt of compound INT 1g to compound 1 or a salt thereof comprises recrystallization.

27. 27. The method of claim 26, wherein the recrystallization is from a methanol / water solvent system.

28. 1. A method for preparing enantiomerically enriched compound 1, comprising: (a) forming an enantiomerically enriched chiral salt of Compound 1; (b) converting the enantiomerically enriched chiral salt of Compound 1 to Compound 1; The method comprising:

29. 29. The method of claim 28, wherein step (a) comprises reacting compound 1 with an enantiomerically enriched chiral acid.

30. The enantiomerically enriched chiral acid is (S)-(+)-1,1′-binaphthyl-2,2′-diyl hydrogen phosphate, (R)-(−)-1,1′-binaphthyl-2,2′-diyl hydrogen phosphate, (1S)-(+)-3-bromocamphor-10-sulfonic acid hydrate, (1R)-(−)-10-camphorsulfonic acid, (1S)-(+)-10-camphorsulfonic acid, (+)-2,3-dibenzyl 30. The method of claim 29, wherein the enantiomerically enriched chiral salt is compound 1, selected from the group consisting of (S)-TCYP, (R)-TCYP, (S)-TRIP, and (R)-TRIP, and the enantiomerically enriched chiral salt is the corresponding chiral acid addition salt of compound 1.

31. 31. The method of claim 30, wherein the enantiomerically enriched chiral acid is (1R)-(-)-10-camphorsulfonic acid and the enantiomerically enriched chiral salt is the (1R)-(-)-10-camphorsulfonic acid salt of compound 1.

32. 32. The method of any one of claims 29 to 31, wherein step (a) comprises reactive crystallization from anisole.

33. 33. The method of any one of claims 28 to 32, wherein Compound 1 is (S)-Compound 1.

34. 34. The method of any one of claims 28 to 33, wherein the enantiomerically enriched chiral acid is at least 90% ee.

35. 35. The method of any one of claims 28 to 34, wherein the enantiomerically enriched compound 1 or salt thereof is at least 90% ee.

36. 36. The method of any one of claims 28 to 35, wherein step (b) comprises recrystallization.

37. 37. The method of claim 36, wherein the recrystallization is from a methanol / water solvent system.

38. Chiral acid addition salts of compound INT 1f, wherein the chiral acid is (S)-(+)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (R)-(-)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (1S)-(+)-3-bromocamphor-10-sulfonic acid hydrate, (1R)-(-)-10-camphorsulfonic acid, (1S)-(+)-10 (S)-TCYP, (R)-TCYP, (S)-TRIP, or (R)-TRIP.

39. 39. The chiral acid addition salt of claim 38, wherein the chiral acid is (1R)-(-)-10-camphorsulfonic acid.

40. 40. The chiral acid addition salt of claim 38 or 39, wherein the compound INT 1f is the compound (S)-INT 1f.

41. 41. The chiral acid addition salt of any one of claims 38 to 40, wherein the enantioenrichment of compound INT 1f is at least 90% ee.

42. A chiral acid addition salt of the compound INT 1g, wherein the chiral acid is (S)-(+)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (R)-(-)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (1S)-(+)-3-bromocamphor-10-sulfonic acid hydrate, (1R)-(-)-10-camphorsulfonic acid, (1S)-(+)-10-camphorsulfonic acid, (+)-2,3-dibenzoyl-D-tartaric acid, (-)-2,3-dibenzoyl-L-tartaric acid, (-)-O,O'-di-p-toluoyl-L-tartaric acid, (+)-O,O'-di-p-toluoyl-D-tartaric acid, (S)-TCYP, or (R)-TCYP.

43. 43. The chiral acid addition salt of claim 42, wherein the chiral acid is (1R)-(-)-10-camphorsulfonic acid.

44. 44. The chiral acid addition salt of claim 42 or 43, wherein the compound INT 1g is (S)-INT 1g.

45. 45. The chiral acid addition salt of any one of claims 42 to 44, wherein the enantioenrichment of compound INT 1g is at least 90% ee.

46. A chiral acid addition salt of Compound 1, wherein the chiral acid is (S)-(+)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (R)-(-)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate, (1S)-(+)-3-bromocamphor-10-sulfonic acid hydrate, (1R)-(-)-10-camphorsulfonic acid, or (1S)-(+)-10-camphorsulfonic acid.

47. 47. The chiral acid addition salt of claim 46, wherein the chiral acid is (1R)-(-)-10-camphorsulfonic acid.

48. 48. The chiral acid addition salt of claim 46 or 47, wherein Compound 1 is (S)-Compound 1.

49. 49. The chiral acid addition salt of any one of claims 46 to 48, wherein the enantioenrichment of compound 1 is at least 90% ee.

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