Synthesis of ras inhibitors

Abstract

The present invention relates to Ras inhibitors and methods for making Ras inhibitors. The present invention relates to the synthesis of Ras inhibitors.

Description

[0001] This invention is a divisional application. The original application was filed on April 12, 2024, with application number 202480032559.4 and invention title "Synthesis of Ras Inhibitor". Background Technology

[0002] Most small molecule drugs work by binding to a functionally important pocket on a target protein, thereby modulating its activity. For example, cholesterol-lowering drugs called statins bind to the active site of HMG-CoA reductase, preventing the enzyme from binding to its substrate. In fact, many such drug / target interactions are known, which might mislead one into believing that, given a reasonable amount of time, effort, and resources, small molecule regulators targeting most (if not all) proteins could be discovered. But this is far from the truth. Currently, it is estimated that only about 10% of all human proteins are suitable targets for small molecules. (Bojadzic and Buchwald, Curr Top Med Chem 18: 674-699 (2019)). The remaining 90% are currently considered difficult to treat or manage with the aforementioned small molecule drugs. These targets are often referred to as “undruggable.” These undruggable targets comprise a large and largely unexplored library of medically important human proteins. Therefore, there is great interest in discovering novel molecular modalities that can modulate the function of such druggable targets.

[0003] The literature has well established that Ras proteins (K-Ras, H-Ras, and N-Ras) play crucial roles in various human cancers, thus making them suitable targets for anticancer therapies. In fact, approximately 30% of all human cancers in the United States are caused by Ras protein mutations, many of which are fatal. Dysregulation of Ras proteins caused by activating mutations, overexpression, or upstream activation is common in human tumors, and activating mutations of Ras are frequently found in human cancers. For example, an activating mutation at codon 12 in the Ras protein significantly biases the Ras mutant protein population towards the "on" (GTP-binding) state (Ras(ON)) by inhibiting GTPase activator protein (GAP) dependence and intrinsic GTP hydrolysis rate, leading to the action of oncogenic MAPK signaling. Notably, Ras exhibits a picomolar affinity for GTP, allowing it to be activated even in the presence of low concentrations of this nucleotide. Mutations at codons 13 (e.g., G13C) and 61 (e.g., Q61K) in Ras also cause oncogenic activity in some cancers.

[0004] Despite extensive drug discovery efforts targeting Ras over the past decades, only two agents targeting the K-Ras G12C mutant have been approved in the United States (sotorasib and adagrasib). Further efforts are needed to discover other drugs for cancers driven by various Ras mutations, and convenient, scalable synthetic methods remain essential. Summary of the Invention

[0005] The present invention is characterized by a method for preparing compound A, an intermediate that can be used to synthesize compound A, and a method for preparing said intermediate. Compound A is a RAS inhibitor having the following structure: Compound A In a first aspect, this disclosure provides a barium salt of compound 1: .

[0006] In some embodiments, the barium salt has a formic acid:barium ratio of 2:1. In some embodiments, the barium salt has the structure of compound 2: .

[0007] On the other hand, this disclosure provides compounds having the structure of compound 3: Compound 3, Or a salt thereof. In some embodiments, the compound or a salt thereof has the structure of compound 3a: Compound 3a, In another aspect, this disclosure provides a method for preparing compound 4a. The method includes contacting compound 4a with one or more ketone reductases: .

[0008] In some embodiments, compound 4a is formed in a yield of at least 85%. In some embodiments, the method further includes contacting compound 4 with glucose dehydrogenase. In some embodiments, the method further includes contacting compound 4 with glucose. In some embodiments, the method further includes contacting compound 4 with NADP. In some embodiments of the method for preparing compound 4a, the contact is carried out in the presence of a buffer solution. In some embodiments, the contact is carried out in the presence of dimethyl sulfoxide.

[0009] On the other hand, this disclosure provides a tetramethylethylenediamine (TMEDA) salt of compound 5: .

[0010] In some implementations, the TMEDA salt has a formic acid:TMEDA ratio of 2:1.

[0011] On the other hand, compound 5 is a 1,4-diazabicyclo[2.2.2]octane (DABCO) salt. In some embodiments, the DABCO salt has a formic acid:DABCO ratio of 2:1.

[0012] On the other hand, this disclosure provides a method for preparing compound 6: .

[0013] The method includes the following steps: a) Make compound 7 double N -Methylation to form compound 7c: ; b) Carboxylating compound 7c to form compound 7a: ; c) Protonate compound 7a to form compound 7b: ;as well as d) Protonate compound 7b to form compound 6: .

[0014] In some implementation schemes, dual N - The methylation step (a) involves contacting compound 7 with an alkylating agent and a reducing agent. In some embodiments, the alkylating agent is formaldehyde, and the reducing agent is sodium triacetoxyborohydride.

[0015] In some implementations, the protonation step (c) includes contacting compound 7a with acetic acid.

[0016] In some implementations, the protonation step (d) includes contacting compound 7b with hydrochloric acid.

[0017] In some embodiments, compound 7a or 7b is used directly in subsequent chemical steps without the need for protonation to form an HCl salt. In some embodiments, compound 6 is used directly in subsequent chemical steps without the need for separation or purification from the reaction mixture.

[0018] On the other hand, this disclosure provides a method for preparing compound 8: .

[0019] The method includes making compound 9 and compound 10: Contact occurs in the presence of acid and water. In some embodiments, the acid is sulfuric acid.

[0020] In some implementations, approximately 4 equivalents of sulfuric acid are used relative to the amount of compound 9.

[0021] On the other hand, this disclosure provides a method for preparing compound 8: .

[0022] The method includes the following steps: a) Couple compound 4b and compound 20 to form compound 21: ;as well as b) Contacting compound 21 and compound 10 to form compound 8: .

[0023] In some embodiments, the coupling step (a) includes reacting compound 4b with... i- PrMgCl•LiCl contact.

[0024] In some embodiments, contact step (b) further includes contacting compound 21 and compound 10 with sulfuric acid.

[0025] On the other hand, this disclosure provides a hemisulfate of compound 8 (compound 8: sulfate in a 2:1 ratio): Compound 8.

[0026] In some embodiments, this disclosure provides a method for preparing a hemisulfate of compound 8, the method comprising contacting a free base of compound 8 with sulfuric acid.

[0027] On the other hand, this disclosure provides a method for preparing compounds 11a and 11b. .

[0028] The method includes the following steps: a) Reduce compound 22 to form compound 23 as well as b) Alkylating compound 23 to form a mixture of compounds 11a and 11b. .

[0029] On the other hand, this disclosure provides a method for preparing compounds 11a and 11b. .

[0030] The method includes the following steps: a) Alkylating compound 22 to form compound 24 as well as b) Reduce compound 24 to form a mixture of compounds 11a and 11b. .

[0031] In some embodiments, the alkylation step (a) includes contacting compound 22 or compound 23 with diethyl sulfate.

[0032] In some embodiments, the reduction step (b) includes contacting compound 22 or compound 24 with sodium borohydride.

[0033] In another aspect, this disclosure provides a method for separating compound 11a and compound 11b: .

[0034] The method includes the following steps: a) Heating a mixture of compounds 11a and 11b in a solvent or a mixture of solvents for a period of time; b) A mixture forming a salt of compound 11a and a salt of compound 11b; and c) Separate a mixture of salts of compound 11a and salts of compound 11b.

[0035] In some implementations, the heating step (a) is carried out in a mixture of xylene.

[0036] In some embodiments, the salts of compounds 11a and 11b are hydrochloride salts of compounds 11a and 11b.

[0037] In some implementations, separation is performed as a flow process.

[0038] On the other hand, this disclosure provides a method for preparing compound 3a: .

[0039] The method includes the following steps: a) Deprotonation of compound 3b using a chiral base, thereby forming a diastereomer salt of compound 3b: ; b) Reduce the diastereomeric salt of compound 3b to form compound 3c: ; c) Couple compound 3c with compound 3d or its salt to form compound 3e; ;as well as d) Hydrolyze compound 3e to form compound 3a: .

[0040] In some implementations, the chiral base is compound 3f.

[0041] Compound 3f.

[0042] In some embodiments, the method includes protonating compound 3b prior to reduction step (b). In some embodiments, the protonation step includes contacting compound 3b with hydrochloric acid. In some embodiments, the hydrochloric acid is in an ether solution. In some embodiments, the hydrochloric acid is in a methyl-tert-butyl ether solution.

[0043] In some embodiments, reduction step (b) includes contacting compound 3b with hydrogen gas. In some embodiments, the hydrogen gas is at a pressure of about 4 bar. In some embodiments, reduction step (b) further includes contacting compound 3b with a rhodium catalyst. In some embodiments, reduction step (b) further includes contacting compound 3b with a chiral ligand. In some embodiments, the rhodium catalyst is Rh(COD)₂OTf. In some embodiments, the chiral ligand is ( S,S )-Et-DuPhos. In some embodiments, less than 0.25 mol% of rhodium catalyst is used relative to the amount of compound 3b.

[0044] In some embodiments, enzymatic chemistry can be used to obtain enantiomer-enriched compound 3a. In some embodiments, compound 3a is prepared by enzymatic chiral resolution. In some embodiments, compound 3a is prepared using a phenylamine lyase. In some embodiments, compound 3a is prepared using a lipase. In some embodiments, compound 3a is prepared using an amino acid dehydrogenase. The use of enzymatic chemistry can reduce the costs associated with asymmetric hydrogenation using a rhodium catalyst. Compared to asymmetric hydrogenation, the use of enzymatic chemistry also increases yield and / or reproducibility.

[0045] In one aspect, this disclosure provides a method for preparing compound A: .

[0046] The method includes the following steps: a) Couple compound 11a and compound 3a to form compound 12: ; b) Deprotecting compound 12 to form compound 13: ; c) Couple compound 13 to form compound 14: ; d) Deprotecting compound 14 to form compound 15: ;as well as e) Couple compound 15 and compound 2 to form compound A: .

[0047] In some embodiments, the method for preparing compound A further includes a step of purifying compound A by recrystallizing it. In some embodiments, recrystallization includes contacting compound A with one or more solvents selected from ethyl acetate, water, and diisopropylethylamine, or mixtures thereof. In some embodiments, recrystallization is carried out in a mixture of ethyl acetate and n-heptane.

[0048] In some embodiments, the coupling step (a) includes contacting compounds 11a and 3a with EDCI and HOBt. In some embodiments, the coupling step (c) is carried out in alumina-treated dioxane. In some embodiments, the coupling step (c) includes contacting compound 13 with a palladium catalyst. In some embodiments, the method further includes washing a solution of compound 15 with an aqueous alkaline solution. In some embodiments, compound 15 is not isolated or purified prior to the coupling step (e).

[0049] In one respect, this disclosure provides compounds having the structure of compound 12: Compound 12 Or its salt.

[0050] On the other hand, this disclosure provides compounds having the structure of compound 13: Compound 13 Or its salt.

[0051] Definitions and chemical terms In this application, unless the context clearly indicates otherwise, (i) the term “a (a)” means “one or more”; (ii) the term “or” is used to mean “and / or” unless explicitly indicated that the term refers to an alternative that is unique or that the alternatives are mutually exclusive, however, the definition supported by this disclosure refers to a unique alternative and “and / or”; (iii) the terms “comprising” and “including” should be understood to encompass the listed components or steps, whether presented alone or in combination with one or more additional components or steps; and (iv) when providing a scope, endpoints are included.

[0052] As used herein, the term "about" is used to indicate that a value includes the standard deviation of the error of the apparatus or method used to determine that value. In some embodiments, the term "about" refers to a range of values ​​in any direction (greater or less than) within 25%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or lower percentages of the value, unless otherwise specified or otherwise apparent from the context (e.g., when the figure would exceed 100% of the possible value).

[0053] As used herein, in the context of describing adjacent atoms, the term "adjacent" refers to divalent atoms directly connected by covalent bonds.

[0054] As used herein, “compounds of the present invention” and similar terms, whether explicitly indicated or not, refer to the Ras inhibitors described herein (e.g., compound A) and intermediates in their synthesis, as well as their salts (e.g., pharmaceutically acceptable salts), solvates, hydrates, stereoisomers (including transisomers) and tautomers.

[0055] Those skilled in the art will understand that some of the compounds described herein may exist in one or more different isomeric forms (e.g., stereoisomers, geometric isomers, transisomers, tautomers) or isotopic forms (e.g., one or more atoms are substituted with different isotopes of that atom, such as hydrogen substituted with deuterium). Unless otherwise indicated or clearly apparent from the context, the described structures are to be understood as representing any such isomeric or isotopic forms, individually or in combination.

[0056] The compounds described herein may be asymmetric (e.g., having one or more stereocenters). Unless otherwise indicated, all stereoisomers, such as enantiomers and diastereomers, are covered. Compounds of this disclosure containing asymmetrically substituted carbon atoms can be isolated in optically active or racemic forms. Methods for preparing optically active forms from optically active starting materials are known in the art, for example, by resolving racemic mixtures or by stereoselective synthesis. Many geometric isomers of alkenes, C=N double bonds, etc., may also be present in the compounds described herein, and all such stable isomers are covered in this disclosure. Cis and trans geometric isomers of the compounds of this disclosure are described and can be isolated in mixtures of isomers or in separate isomeric forms.

[0057] In some embodiments, one or more compounds illustrated herein may exist in different tautomer forms. As will be clear from the context, unless explicitly excluded, references to such compounds encompass all such tautomer forms. In some embodiments, the tautomer form is obtained by the exchange of a single bond with an adjacent double bond and the accompanying proton migration. In some embodiments, the tautomer form may be a proton-transfer tautomer, which is an isomer protonated state having the same empirical formula and total charge as the reference form. Examples of portions having a proton-transfer tautomer form include keto-enol pairs, amide-imine pairs, lactam-lactamimide pairs, amide-imine pairs, enamine-imine pairs, and cyclic forms where the proton can occupy two or more positions in a heterocyclic system, such as 1H-imidazolium and 3H-imidazolium, 1H-triazole, 2H-triazole and 4H-1,2,4-triazole, 1H-isoindole and 2H-isoindole, and 1H-pyrazole and 2H-pyrazole. In some embodiments, the tautomer form may be in equilibrium or spatially locked into one form through appropriate substitution. In some embodiments, the tautomer form is obtained by the interconversion of acetals.

[0058] Unless otherwise specified, the structures described herein also mean compounds that differ solely due to the presence of one or more isotopically enriched atoms. Exemplary isotopes that may be incorporated into the compounds of this invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, fluorine, chlorine, and iodine, for example... 2 H, 3 H, 11 C 13 C 14 C 13 N、 15 N、 15 O、 17 O、 18 O、 32 P, 33 P, 35 S,18 F, 36 Cl、 123 I and 125 I. Isotope-labeled compounds (e.g., labeled with...) 3 H and 14 Compounds of C can be used in the determination of the tissue distribution of compounds or substrates. Tritium (i.e., 3 H) and carbon-14 (i.e., ... 14 C) Isotopes are available because they are easy to prepare and detect. Alternatively, heavier isotopes, such as deuterium (i.e.,...), can be used. 2 H) substitution can provide certain therapeutic benefits due to increased metabolic stability (e.g., increased in vivo half-life or reduced dose requirement). In some embodiments, one or more hydrogen atoms are... 2 H or 3 H substitution, or one or more carbon atoms being... 13 C or 14 Carbon-enriched carbon substitution. Positron-emitting isotopes, such as... 15 O、 13 N、 11 C and 18 F can be used in positron emission tomography (PET) studies to examine substrate acceptor occupancy. The preparation of isotopically labeled compounds is known to those skilled in the art. For example, isotopically labeled compounds can generally be prepared by following a procedure similar to that disclosed for the compounds of the invention described herein, by replacing the unlabeled reagent with an isotopically labeled reagent.

[0059] As is known in the art, many chemical entities can be in a variety of different solid forms, such as amorphous or crystalline forms (e.g., polymorphs, hydrates, solvates). In some embodiments, the compounds of the present invention can be utilized in any of these forms, including any solid form. In some embodiments, the compounds described or depicted herein can be provided or utilized in hydrate or solvate form.

[0060] Throughout this specification, substituents of the compounds disclosed herein are disclosed by group or by range. Specifically, this disclosure is intended to include every individual combination of members of such groups and ranges. For example, specifically, the term "C1-C6 alkyl" is intended to individually disclose methyl, ethyl, C3 alkyl, C4 alkyl, C5 alkyl, and C6 alkyl. Furthermore, where a compound comprises multiple positions, and where substituents are disclosed by group or by range at said positions, unless otherwise indicated, this disclosure is intended to cover the individual compounds and groups of compounds (e.g., species and subclasses) containing every individual combination of members at each position.

[0061] The intended term “optionally substituted X” (e.g., “optionally substituted alkyl”) is equivalent to “X, wherein X is optionally substituted” (e.g., “alkyl, wherein the alkyl is optionally substituted”). It is not intended that the characteristic “X” (e.g., alkyl) itself is optional. As described herein, certain compounds of interest may contain one or more “optionally substituted” moieties. Generally, the term “substituted”, whether or not preceded by the term “optionally”, means that one or more hydrogens of the specified moiety are substituted by a suitable substituent, such as any of the substituents or groups described herein. Unless otherwise indicated, the “optionally substituted” group may have a suitable substituent at each substituted position of the group, and the substituents at each position may be the same or different when more than one position in any given structure can be substituted by more than one substituent selected from the specified group. For example, in the term “optionally substituted C1-C6 alkyl-C2-C9 heteroaryl,” the alkyl moiety, the heteroaryl moiety, or both may be optionally substituted. The combinations of substituents contemplated in this disclosure are preferably combinations of substituents that form stable or chemically viable compounds. As used herein, the term "stable" means that a compound remains substantially unchanged when subjected to conditions that allow it to be generated, detected, and, in some embodiments, recovered, purified, and used for one or more of the purposes disclosed herein.

[0062] The suitable monovalent substituents on the substituted carbon atoms of the "optionally substituted" group can be independently deuterium; halogen; -(CH2)0-4R°; -(CH2)0-4OR°; -O(CH2)0-4R o-O-(CH2)0-4C(O)OR°; -(CH2)0-4CH(OR°)2; -(CH2)0-4SR°; -(CH2)0-4Ph, which can be substituted by R°; -(CH2)0-4O(CH2)0-1Ph, which can be substituted by R°; -CH=CHPh, which can be substituted by R°; -(CH2)0-4O(CH2)0-1-pyridyl, which can be substituted by R°; 4-8 member saturated or unsaturated heterocyclic alkyl (e.g., pyridyl); 3-8 member saturated or unsaturated cycloalkyl (e.g., cyclopropyl, cyclobutyl, or cyclopentyl); -NO2; -CN; -N3; ​​-(CH2)0 -4N(R°)2; -(CH2)0-4N(R°)C(O)R°; -N(R°)C(S)R°; -(CH2)0-4N(R°)C(O)NR°2; -N(R°)C(S)NR°2; -(CH2)0-4N(R°)C(O)OR°; -N(R°) N(R°)C(O)R°; -N(R°)N(R°)C(O)NR°2; -N(R°)N(R°)C(O)OR°; -(CH2)0-4C(O)R°; -C(S)R°; -(CH2)0-4C(O)OR°; -(CH2)0-4-C(O)-N(R o )2;-(CH2)0-4-C(O)-N(R o )-S(O)2-R o ;-C(NCN)NR o 2;-(CH2)0-4C(O)SR o ;-(CH2)0-4C(O)OSiR o 3;-(CH2)0-4OC(O)R o ;-OC(O)(CH2)0-4SR o ;-SC(S)SR o ;-(CH2)0-4SC(O)R o ;-(CH2)0-4C(O)NR o 2; -C(S)NR o 2;-C(S)SR o ;-(CH2)0-4OC(O)NR o 2; -C(O)N(OR) o )R o ;-C(O)C(O)R o ;-C(O)CH2C(O)R o ;-C(NOR) o )R o ;-(CH2)0-4SSR o ;-(CH2)0-4S(O)2R o;-(CH2)0-4S(O)2OR o ;-(CH2)0-4OS(O)2R o ;-S(O)2NR o 2;-(CH2)0-4S(O)R o ;-N(R o )S(O)2NR o 2; -N(R) o )S(O)2R o ;-N(OR) o )R o ;-C(NOR) o )NR o 2;-C(NH)NR o 2; -P(O)2R o ;-P(O)R o 2; -P(O)(OR o )2;-OP(O)R o 2; -OP(O)(OR o )2;-OP(O)(OR o )R o -SiR o 3; -(C 1-4 (linear or branched alkylene)ON(R) o )2; or -(C 1-4 (straight-chain or branched alkylene)C(O)ON(R) o )2, where each R o It can be substituted and independently replaced by hydrogen, -C as defined below. 1-6 Aliphatic group, -CH2Ph, -O(CH2)0-1Ph, -CH2- (5-6 membered heteroaryl ring), or 3-6 membered saturated, partially unsaturated or aryl ring having 0-4 independent heteroatoms selected from nitrogen, oxygen or sulfur, or despite the above definitions, two independently occurring R groups. o Together with their inserted atoms, they form 3-12 saturated, partially unsaturated, or aryl monocyclic or bicyclic rings with 0-4 independent heteroatoms selected from nitrogen, oxygen, or sulfur, which may be substituted as defined below.

[0063] Suitable monovalent substituents on R° (or a ring formed by two independently occurring R°s together with their inserted atoms) can be independently halogens, -(CH2)O-2R ● -(halogenated R) ● -(CH2)O-2OH, -(CH2)O-2OR ● -(CH2)0-2CH(OR) ● )2、-O(halogenated R ●), -CN, -N3, -(CH2)0-2C(O)R ● , -(CH2)0-2C(O)OH, -(CH2)0-2C(O)OR ● -(CH2)O-2SR ● , -(CH2)0-2SH, -(CH2)0-2NH2, -(CH2)0-2NHR ● -(CH2)0-2NR ● 2, -NO2, -SiR ● 3. -OSiR ● 3. -C(O)SR ● -(C1-4 straight-chain or branched alkylene)C(O)OR ● or -SSR ● , where each R ● It is either unsubstituted or, in the case of being preceded by "halogenated," substituted with only one or more halogens, and independently selected from C. 1-4 Aliphatic groups, -CH2Ph, -O(CH2)0-1Ph, or 5-6 member saturated, partially unsaturated, or aryl rings having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. Suitable divalent substituents on the saturated carbon atom of R° include =O and =S.

[0064] Suitable divalent substituents on the saturated carbon atom of the "optionally substituted" group include the following: =O, =S, =NNR. * 2、=NNHC(O)R * =NNHC(O)OR * =NNHS(O)2R * =NR * =NOR * -O(C(R) * 2))2-3O-or-S(C(R) * 2))2-3S-, where R * Each time it appears independently, it is selected from hydrogen, and C can be substituted as defined below. 1-6 An aliphatic group or an unsubstituted 5-6 member saturated, partially unsaturated, or aryl ring having 0-4 independent heteroatoms selected from nitrogen, oxygen, or sulfur. Suitable divalent substituents attached to the adjacent substituted carbon of the "optionally substituted" group include: -O(CR * 2)2-3O-, where R * Each time it appears independently, it is selected from hydrogen, and C can be substituted as defined below. 1-6 Aliphatic group or unsubstituted 5-6 member saturated, partially unsaturated or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen or sulfur.

[0065] R *Suitable substituents on aliphatic groups include halogens, -R ● -(halogenated R) ● -OH, -OR ● -O (halogenated R) ● -CN, -C(O)OH, -C(O)OR ● -NH2, -NHR ● -NR ● 2 or -NO2, where each R ● It is either unsubstituted or, in the case of being preceded by "halogenated," substituted with only one or more halogens, and independently C. 1-4 Aliphatic group, -CH2Ph, -O(CH2)0-1Ph or a 5-6 member saturated, partially unsaturated or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen or sulfur.

[0066] Suitable substituents on the substituted nitrogen of the "optionally substituted" group include -R -NR 2. -C(O)R -C(O)OR -C(O)C(O)R -C(O)CH2C(O)R -S(O)2R -S(O)2NR 2. -C(S)NR 2. -C(NH)NR 2 or -N(R) )S(O)2R ; where each R Independently hydrogen; can be substituted C as defined below. 1-6 Aliphatic group; unsubstituted -OPh; or unsubstituted 3-6 membered saturated, partially unsaturated, or aryl ring having 0-4 independently selected heteroatoms chosen from nitrogen, oxygen, or sulfur; or, despite the above definitions, two independently occurring R groups. Together with their inserted atoms, they form unsubstituted 3-12 saturated, partially unsaturated, or aryl monocyclic or bicyclic rings with 0-4 independent heteroatoms selected from nitrogen, oxygen, or sulfur.

[0067] R Suitable substituents on the aliphatic group are independently halogens, -R ● -(halogenated R) ● -OH, -OR ● -O (halogenated R) ● -CN, -C(O)OH, -C(O)OR ● -NH2, -NHR ●-NR ● 2 or -NO2, where each R ● It is either unsubstituted or, in the case of being preceded by "halogenated," substituted with only one or more halogens, and independently C. 1-4 Aliphatic group, -CH2Ph, -O(CH2)0-1Ph, or a 5-6 member saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. R Suitable divalent substituents on saturated carbon atoms include =O and =S.

[0068] As used herein, the term "acetyl" refers to the group -C(O)CH3.

[0069] As used herein, the term "alkoxy" refers to -O-Cl-C 20 Alkyl group, wherein the alkoxy group is attached to the remainder of the compound via an oxygen atom.

[0070] As used herein, the term "alkyl" refers to a saturated, straight-chain or branched monovalent hydrocarbon group containing 1 to 20 carbon atoms (e.g., 1 to 10 or 1 to 6). In some embodiments, the alkyl group is unbranched (i.e., straight-chain); in other embodiments, the alkyl group is branched. Alkyl groups include, but are not limited to, methyl, ethyl, n-propyl and isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl, and neopentyl.

[0071] As used herein, the term "alkylene" refers to a saturated divalent hydrocarbon group derived from a straight-chain or branched saturated hydrocarbon by removing two hydrogen atoms, and examples include methylene, ethylene, isopropylene, etc. The term "C" x -C y "Alkylene" indicates an alkylene having between x and y carbons. Indicative values ​​of x are 1, 2, 3, 4, 5, and 6, and exemplary values ​​of y are 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, or 20 (e.g., C1-C6, C1-C...). 10 C2-C 20 C2-C6, C2-C 10 Or C2-C 20 Alkylene). In some embodiments, the alkylene may be further substituted with one, two, three or four substituents as defined herein.

[0072] Unless otherwise specified, as used herein, the term "alkenyl" refers to a monovalent straight-chain or branched group having 2 to 20 carbons (e.g., 2 to 6 or 2 to 10 carbons) containing one or more carbon-carbon double bonds, and examples of alkenyl groups include vinyl, 1-propenyl, 2-propenyl, 2-methyl-1-propenyl, 1-butenyl, and 2-butenyl. Alkenyl groups include both cis and trans isomers. Unless otherwise specified, as used herein, the term "alkenylene" refers to a divalent straight-chain or branched group having 2 to 20 carbons (e.g., 2 to 6 or 2 to 10 carbons) containing one or more carbon-carbon double bonds.

[0073] As used herein, the term "alkynyl" refers to a monovalent straight-chain or branched group containing a carbon-carbon triple bond and having 2 to 20 carbons (e.g., 2 to 4, 2 to 6, or 2 to 10 carbons), and examples of such groups are ethynyl and 1-propynyl.

[0074] As used herein, the term "amino" signifies -N(R) )2, for example -NH2 and -N(CH3)2.

[0075] As used herein, the term "aminoalkyl" refers to an alkyl moiety that is substituted with one or more amino groups on one or more carbon atoms.

[0076] As used herein, the term "aryl" refers to a monovalent monocyclic, bicyclic, or polycyclic system formed of carbon atoms, wherein the ring attached to a side group is an aromatic ring. Examples of aryl groups are phenyl, naphthyl, phenanthryl, and anthracene. An aromatic ring may be attached to its side group at any heteroatom or carbocyclic atom that produces a stable structure, and unless otherwise specified, any ring atom may optionally be substituted.

[0077] The term "Boc" refers to a structure The tert-butoxycarbonyl or tert-butoxycarbonyl protecting group.

[0078] As used herein, the term “C0” signifies a bond. For example, a portion of the term -N(C(O)-(C0-C5 alkylene-H)- includes -N(C(O)-(C0 alkylene-H)-, which is also represented as -N(C(O)-H)-.

[0079] As used herein, the terms "carbocyclic" and "carbocyclic group" refer to a monovalent, optionally substituted C3-C group. 12A monocyclic, bicyclic, or tricyclic structure, which can be bridged, fused, or spirocyclic, wherein all rings are formed of carbon atoms and at least one ring is a non-aromatic ring. Carbocyclic structures include cycloalkyl, cycloalkenyl, and cycloynyl groups. Examples of carbocyclic groups are cyclohexyl, cyclohexenyl, cyclooctynyl, 1,2-dihydronaphthyl, 1,2,3,4-tetrahydronaphthyl, fluorenyl, indenyl, indenyl, decahydronaphthyl, etc. The carbocyclic ring can be attached to its side group at any ring atom that produces a stable structure, and unless otherwise specified, any ring atom may optionally be substituted.

[0080] As used herein, the term "carbonyl" refers to a C(O) group, which can also be represented as C=O.

[0081] As used herein, the term "carboxyl" refers to -CO2H, (C=O)(OH), COOH, or C(O)OH, or its unprotonated counterpart.

[0082] The term "Cbz" refers to a structure The benzyloxycarbonyl protecting group.

[0083] As used herein, the term "cyano" refers to the -CN group.

[0084] Unless otherwise specified, as used herein, the term "cycloalkyl" means a monovalent saturated cyclic hydrocarbon group having three to eight ring carbons, which may be bridged, fused or spirocyclic, and examples of which are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cycloheptyl.

[0085] Unless otherwise specified, as used herein, the term "cycloalkenyl" means a monovalent, non-aromatic, saturated cyclic hydrocarbon group having three to eight cyclic carbons and containing one or more carbon-carbon double bonds, which may be bridged, fused, or spirocyclic.

[0086] As used in this article, the term "diastereomer" refers to stereoisomers that are not mirror images of each other and cannot be superimposed on each other.

[0087] As used herein, the term "enantiomer" means each individual optically active form of the compound of the invention having at least 80% (i.e., at least 90% of one enantiomer and at most 10% of the other enantiomer), preferably at least 90% and more preferably at least 98% optical purity or enantiomer excess (as determined by standard methods in the art).

[0088] As used herein, the term "haloacetyl" refers to an acetyl group in which at least one hydrogen atom is replaced by a halogen.

[0089] As used herein, the term "haloalkyl" refers to an alkyl moiety substituted with one or more identical or different halogen moieties on one or more carbon atoms.

[0090] As used herein, the term "halogen" refers to a halogen selected from bromine, chlorine, iodine, or fluorine.

[0091] As used herein, the term "heteroalkyl" refers to an alkyl group as defined herein, in which at least one carbon atom is replaced by a heteroatom (e.g., O, N, or S atom). The heteroatom may be present in the middle or at the end of the group.

[0092] As used herein, the term "heteroaryl" refers to a monovalent monocyclic or polycyclic structure containing at least one fully aromatic ring: that is, it contains 4... n +2 π electrons and containing at least one cyclic heteroatom selected from N, O, or S in the aromatic ring. An illustrative unsubstituted heteroaryl group has 1 to 12 (e.g., 1 to 11, 1 to 10, 1 to 9, 2 to 12, 2 to 11, 2 to 10, or 2 to 9) carbons. The term "heteroaryl" includes bicyclic, tricyclic, and tetracyclic groups fused to any of the aforementioned heteroaromatic rings with one or more aromatic or carbocyclic rings, such as benzene or cyclohexane rings. Heteroaryl groups include, but are not limited to, pyridyl, pyrazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, imidazolyl, thiazolyl, quinolinyl, tetrahydroquinolinyl, and 4-azaindolyl. The heteroaryl ring may be attached to its side groups at any ring atom that produces a stable structure, and any ring atom may optionally be substituted unless otherwise specifically stated. In some embodiments, the heteroaryl group is substituted with one, two, three, or four substituents.

[0093] As used herein, the term "heterocyclic alkyl" refers to a monovalent monocyclic, bicyclic, or polycyclic system in which at least one ring is a non-aromatic ring and said non-aromatic ring contains one, two, three, or four heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur. This system may be bridged, fused, or spirocyclic. Five-membered rings have zero to two double bonds, and six- and seven-membered rings have zero to three double bonds. Illustrative unsubstituted heterocyclic alkyl groups have 1 to 12 (e.g., 1 to 11, 1 to 10, 1 to 9, 2 to 12, 2 to 11, 2 to 10, or 2 to 9) carbons. The term "heterocyclic alkyl" also refers to a heterocyclic compound having a bridged polycyclic structure, wherein one or more carbons or heteroatoms bridge a non-adjacent member of a monocyclic ring, such as a quinine cycloyl group. The term "heterocyclic alkyl" includes bicyclic, tricyclic, and tetracyclic groups fused with any of the aforementioned heterocycles and one or more aromatic, carbocyclic, heteroaromatic, or heterocyclic rings, such as aromatic, cyclohexane, cyclohexene, cyclopentane, cyclopentene, pyridine, or pyrrolidine rings. Examples of heterocyclic alkyl groups are pyrrolidinyl, piperidinyl, 1,2,3,4-tetrahydroquinolinyl, decahydroquinolinyl, dihydropyrrolopyridinyl, and decahydronaphthidyl. Heterocyclic alkyl rings may be attached to their side groups at any ring atom that produces a stable structure, and unless otherwise specified, any ring atom may optionally be substituted.

[0094] As used herein, the term "hydroxyl group" refers to the -OH group.

[0095] As used herein, the term "hydroxyalkyl" refers to an alkyl moiety that is substituted with one or more -OH moieties on one or more carbon atoms.

[0096] As used herein, the term "isomer" means any tautomer, stereoisomer, transisomer, enantiomer, or diastereomer of any compound of the present invention. It should be understood that the compounds of the present invention may have one or more chiral centers or double bonds, and thus exist in stereoisomeric form, such as double-bonded isomers (i.e., E / Z geometric isomers) or diastereomers (e.g., enantiomers (i.e., (+) or (-)) or cis / trans isomers). According to the present invention, the chemical structures described herein and therefore the compounds of the present invention cover all corresponding stereoisomers, i.e., stereoisomerically pure (e.g., geometrically pure, enantiomerically pure, or diastereomerically pure) forms and mixtures of enantiomers and stereoisomers, such as racemates. The enantiomers and stereoisomers of the compounds of the present invention can typically be resolved into their component enantiomers or stereoisomers by well-known methods, such as chiral gas chromatography, chiral high-performance liquid chromatography, crystallization of the compound as a chiral salt complex, or crystallization of the compound in a chiral solvent. The enantiomers and stereoisomers can also be obtained from stereoisomerically pure or enantiomerically pure intermediates, reagents, and catalysts via well-known asymmetric synthetic methods.

[0097] As used herein, the term "stereoisomer" refers to all possible different isomers and conformations that a compound (e.g., any compound of the formula described herein) may have, particularly all possible stereochemical and conformational isomers of the basic molecular structure, all diastereomers, enantiomers, or conformational isomers, including transisomers. Some compounds of the present invention may exist in different tautomer forms, all of which are included within the scope of the present invention.

[0098] As used herein, the term "sulfonyl" refers to the -S(O)2- group.

[0099] As used herein, the term "thiocarbonyl" refers to the -C(S)- group.

[0100] As used herein, the term "acetylenolone" refers to a group comprising the following structure: , where R is any chemically feasible substituent described in this paper.

[0101] Those skilled in the art who have read this disclosure will understand that certain compounds described herein may be provided or utilized in any of a variety of forms, such as salt forms, protective forms, prodrug forms, ester forms, isomer forms (e.g., optical or structural isomers), isotopic forms, etc. In some embodiments, reference to a specific compound may refer to a specific form of the compound. In some embodiments, reference to a specific compound may refer to the compound in any form. In some embodiments, for example, a formulation of a single stereoisomer of a compound may be considered as a form of the compound different from a racemic mixture of the compound; a specific salt of a compound may be considered as a form different from another salt form of the compound; a formulation of a conformational isomer ((Z) or (E)) containing a double bond may be considered as a form different from a formulation of another conformational isomer ((E) or (Z)) containing that double bond; a formulation in which one or more atoms are isotopes different from those present in a reference formulation may be considered as a different form. Attached Figure Description

[0102] Figure 1 A diagram illustrating the flow process used to separate compound 11b from the unwanted transisomer compound 11a. Detailed Implementation

[0103] This document provides synthetic methods and intermediates for the production of Ras inhibitor compound A or its salts. These methods and intermediates can be used to achieve higher yields, higher chemical purity and / or higher stereoisomer purity, and lower costs in preparing compound A. Further synthetic details are provided in the examples. The structure of compound A is shown below.

[0104] Compound A The compounds described herein can be prepared using the methods described herein and / or using known organic, inorganic, or enzymatic processes. Synthetic methods may employ commercially available starting materials or starting materials prepared by processes known to those skilled in the art of organic synthesis. These methods include (but are not limited to) those described in the following sections and in WO 2021 / 091982 and WO 2022 / 235864, the disclosure of each of which is incorporated herein by reference.

[0105] Synthesis method In another aspect, this disclosure provides a method for preparing compound 4a. The method includes contacting compound 4a with one or more ketone reductases: .

[0106] In some embodiments, compound 4a is formed in a yield of at least 85%. In some embodiments, the method further includes contacting compound 4 with glucose dehydrogenase. In some embodiments, the method further includes contacting compound 4 with glucose. In some embodiments, the method further includes contacting compound 4 with NADP. In some embodiments of the method for preparing compound 4a, the contact is carried out in the presence of a buffer solution. In some embodiments, the contact is carried out in the presence of dimethyl sulfoxide. In some embodiments, compound 4a is prepared according to the following scheme: On the other hand, this disclosure provides a method for preparing compound 6: .

[0107] The method includes the following steps: a) Make compound 7 double N -Methylation to form compound 7c: ; b) Carboxylating compound 7c to form compound 7a: ; c) Protonate compound 7a to form compound 7b: ;as well as d) Protonate compound 7b to form compound 6: .

[0108] In some implementation schemes, dual N - The methylation step (a) includes contacting compound 7 with an alkylating agent and a reducing agent. In some embodiments, the alkylating agent is formaldehyde, and the reducing agent is sodium triacetoxyborohydride. In some embodiments, the bis(hydroxymethyl)methyl( ... N - The methylation step (a) is carried out in a solvent (e.g., an ether solvent, such as in 2-methyltetrahydrofuran). In some embodiments, the bis... N - The methylation step (a) is performed according to the following protocol: In some embodiments, the carboxylation step (b) includes contacting compound 7c with a base. In some embodiments, the base is LiHMDS. In some embodiments, contacting compound 7c with the base is carried out below room temperature (e.g., below 20°C, below 10°C, below 0°C, below -10°C, below -20°C, below -30°C, below -40°C, below -50°C, or below -60°C). In some embodiments, contacting compound 7c with the base is carried out between -80°C and -65°C. In some embodiments, after contacting compound 7c with the base, compound 7c is then contacted with carbon dioxide (e.g., a carbon dioxide container or dry ice).

[0109] In some implementations, the carboxylation step (b) is performed according to the following scheme: In some embodiments, the protonation step (c) includes contacting compound 7a with acetic acid. In some embodiments, the protonation step (d) includes contacting compound 7b with hydrochloric acid. In some embodiments, compound 7a or 7b is used directly in subsequent chemical steps without the need for protonation to form an HCl salt. In some embodiments, compound 6 is used directly in subsequent chemical steps without the need for separation or purification from the reaction mixture.

[0110] In some implementations, the protonation step (d) and the protonation step (d) are performed according to the following scheme: On the other hand, this disclosure provides a method for preparing compound 8: .

[0111] The method includes making compound 9 and compound 10: Contact occurs in the presence of acid and water. In some embodiments, the acid is sulfuric acid. In some embodiments, approximately 4 equivalents of sulfuric acid are used relative to the amount of compound 9. In some embodiments, the contact between compound 9 and compound 10 is carried out at temperatures above room temperature (e.g., above 20°C, above 30°C, above 40°C, above 50°C, above 60°C, above 70°C, above 80°C, above 90°C, or at 100°C). In some embodiments, compound 8 is prepared according to the following scheme: On the other hand, this disclosure provides a method for preparing compound 8: .

[0112] The method includes the following steps: a) Couple compound 4b and compound 20 to form compound 21: ;as well as b) Contacting compound 21 and compound 10 to form compound 8: .

[0113] In some embodiments, the coupling step (a) includes reacting compound 4b with... i- PrMgCl•LiCl contact. In some embodiments, coupling step (a) includes a zinc source and a copper source. In some embodiments, the zinc source is ZnCl2. In some embodiments, the copper source is CuCl•2LiCl. In some embodiments, contact step (b) further includes contacting compound 21 and compound 10 with sulfuric acid. In some embodiments, contact step (b) is carried out at a temperature of 100°C ± 20°C. In some embodiments, compound 8 is prepared according to the following scheme: On the other hand, this disclosure provides a hemisulfate of compound 8 (compound 8: sulfate in a 2:1 ratio): Compound 8.

[0114] In some embodiments, this disclosure provides a method for preparing a hemisulfate of compound 8, the method comprising contacting the free base of compound 8 with sulfuric acid. In some embodiments, the contacting step is performed by heating at 80°C ± 15°C for five hours, followed by maintaining the temperature at 30°C ± 15°C for 16 hours.

[0115] On the other hand, this disclosure provides a method for preparing compounds 11a and 11b. .

[0116] The method includes the following steps: a) Reduce compound 22 to form compound 23 as well as b) Alkylating compound 23 to form a mixture of compounds 11a and 11b. .

[0117] In some embodiments, reduction step (a) includes a reducing agent. In some embodiments, the reducing agent is sodium borohydride. In some embodiments, reduction step (a) is maintained at a temperature of 25°C ± 10°C. In some embodiments, reduction step (a) is performed according to the following scheme: .

[0118] In some embodiments, the alkylation step (b) includes contacting compound 23 with diethyl sulfate (DES). In some embodiments, the alkylation step (b) includes precipitating compound 11 with an inorganic acid. In some embodiments, the alkylation step (b) is performed according to the following scheme: .

[0119] On the other hand, this disclosure provides a method for preparing compounds 11a and 11b. .

[0120] The method includes the following steps: b) Alkylate compound 22 to form compound 24 as well as b) Reduce compound 24 to form a mixture of compounds 11a and 11b. .

[0121] In some embodiments, the alkylation step (a) includes contacting compound 22 with diethyl sulfate. In some embodiments, the alkylation step (a) is performed according to the following scheme: In some embodiments, reduction step (b) includes contacting compound 24 with a reducing agent. In some embodiments, the reducing agent is sodium borohydride. In some embodiments, reduction step (b) includes precipitating compound 11 with an inorganic acid. In some embodiments, reduction step (b) is carried out according to the following scheme: .

[0122] In another aspect, this disclosure provides a method for separating compound 11a and compound 11b: .

[0123] The method includes the following steps: a) Heating a mixture of compounds 11a and 11b in a solvent or a mixture of solvents for a period of time; b) A mixture forming a salt of compound 11a and a salt of compound 11b; and c) Separate a mixture of salts of compound 11a and salts of compound 11b.

[0124] In some embodiments, the heating step (a) is carried out in a mixture of xylene. In some embodiments, the heating step (a) is carried out at a temperature above 50°C (e.g., above 75°C, above 100°C, above 125°C, or at 140°C). In some embodiments, two volumes of xylene are used. In some embodiments, the heating step (a) is carried out for more than about 1 hour (e.g., about 1 hour, about 2 hours, about 3 hours, or about 4 hours). In some embodiments, separation is carried out as a flow process.

[0125] In some embodiments, the salts of compounds 11a and 11b are hydrochloride salts of compounds 11a and 11b. In some embodiments, the hydrochloride salts of compounds 11a and 11b are formed in a solvent. In some embodiments, the solvent is an alcohol solvent (e.g., isopropanol).

[0126] In some embodiments, the method for separating compounds 11a and 11b further includes heating a mixture of salts of compounds 11a and 11b. In some embodiments, the heating of the salt mixture is carried out in a solvent (e.g., an alcohol solvent, such as isopropanol). In some embodiments, the heating of the salt mixture is carried out at a temperature above 50°C (e.g., above 60°C, above 70°C, or at about 80°C).

[0127] On the other hand, this disclosure provides a method for preparing compound 3a: .

[0128] The method includes the following steps: a) Deprotonation of compound 3b using a chiral base, thereby forming a diastereomer salt of compound 3b: ; b) Reduce the diastereomeric salt of compound 3b to form compound 3c: ; c) Couple compound 3c with compound 3d or its salt to form compound 3e; ;as well as d) Hydrolyze compound 3e to form compound 3a: .

[0129] In some implementations, the chiral base is compound 3f.

[0130] Compound 3f.

[0131] In some embodiments, the method includes protonating compound 3b prior to reduction step (b). In some embodiments, the protonation step includes contacting compound 3b with hydrochloric acid. In some embodiments, the hydrochloric acid is in an ether solution. In some embodiments, the hydrochloric acid is in a methyl-tert-butyl ether solution.

[0132] In some embodiments, reduction step (b) includes contacting compound 3b with hydrogen gas. In some embodiments, the hydrogen gas is at a pressure above 1 bar (e.g., above 2 bar, above 3 bar, about 2 bar, about 3 bar, or about 4 bar). In some embodiments, the hydrogen gas is at a pressure of about 4 bar. In some embodiments, reduction step (b) further includes contacting compound 3b with a rhodium catalyst. In some embodiments, reduction step (b) further includes contacting compound 3b with a chiral ligand. In some embodiments, the rhodium catalyst is Rh(COD)₂OTf. In some embodiments, the chiral ligand is ( S,S )-Et-DuPhos. In some embodiments, less than 10 mol% (e.g., less than 5 mol%, less than 2.5 mol%, less than 1 mol%, less than 0.75 mol%, less than 0.5 mol%, or less than 0.25 mol%) of rhodium catalyst is used relative to the amount of compound 3b. In some embodiments, less than 0.25 mol% (e.g., about 0.20 mol%, about 0.15 mol%, or about 0.10 mol%) of rhodium catalyst is used relative to the amount of compound 3b. In some embodiments, the reduction step (c) is carried out in a solvent (e.g., an alcohol solvent, such as methanol). In some embodiments, the reduction step (c) is carried out according to the following scheme: In some embodiments, the coupling step (d) includes contacting compounds 3c and 3d with a coupling agent (e.g., EDCI). In some embodiments, the coupling step (d) further includes contacting compounds 3c and 3d with HOBt.

[0133] In some implementations, the coupling step (d) is performed according to the following scheme: In some embodiments, the hydrolysis step (e) includes contacting compound 3e with a hydroxide salt. In some embodiments, the hydroxide salt is lithium hydroxide. In some embodiments, the hydrolysis step (e) is carried out according to the following scheme: In some embodiments, enzymatic chemistry can be used to obtain enantiomer-enriched compound 3a. In some embodiments, compound 3a is prepared by enzymatic chiral resolution. In some embodiments, compound 3a is prepared using a phenylamine lyase. In some embodiments, compound 3a is prepared using a lipase. In some embodiments, compound 3a is prepared using an amino acid dehydrogenase. The use of enzymatic chemistry can reduce the costs associated with asymmetric hydrogenation using a rhodium catalyst. Compared to asymmetric hydrogenation, the use of enzymatic chemistry also increases yield and / or reproducibility.

[0134] In one aspect, this disclosure provides a method for preparing compound A: .

[0135] The method includes the following steps: a) Couple compound 11a and compound 3a to form compound 12: ; b) Deprotecting compound 12 to form compound 13: ; c) Couple compound 13 to form compound 14: ; e) Deprotecting compound 14 to form compound 15: ;as well as e) Couple compound 15 and compound 2 to form compound A: .

[0136] In some embodiments, coupling step (a) includes contacting compounds 11a and 3a with EDCI and HOBt. In some embodiments, coupling step (a) further includes contacting compounds 11a and 3a with one or more bases. In some embodiments, coupling step (a) includes contacting compounds 11a and 3a with DIPEA. In some embodiments, coupling step (a) includes contacting compounds 11a and 3a with DMAP. In some embodiments, coupling step (a) is performed according to the following scheme: In some embodiments, the deprotection step (b) includes contacting compound 12 with an acid. In some embodiments, the acid is hydrochloric acid.

[0137] In some implementations, the deprotection step (b) is performed according to the following scheme: In some embodiments, the coupling step (c) is carried out in alumina-treated dioxane. In some embodiments, the coupling step (c) includes contacting compound 13 with a palladium catalyst. In some embodiments, the coupling step (c) includes contacting compound 13 with a base (e.g., a carbonate base, such as cesium carbonate). In some embodiments, the coupling step (c) is carried out in a solvent (e.g., an ether solvent, such as 1,4-dioxane). In some embodiments, the coupling step (c) is carried out at temperatures above room temperature (e.g., above 50°C, above 60°C, above 70°C, or above 80°C). In some embodiments, the coupling step (c) is carried out between 80°C and 90°C. In some embodiments, the coupling step (c) is carried out according to the following scheme: In some embodiments, the deprotection step (d) includes contacting compound 14 with hydrogen gas. In some embodiments, the hydrogen gas is at a pressure above 1 atm (e.g., above 2 atm, above 3 atm, above 4 atm). In some embodiments, the hydrogen gas is at a pressure of about 5 atm. In some embodiments, the deprotection step (d) further includes contacting compound 14 with a palladium catalyst. In some embodiments, the palladium catalyst is palladium / carbon. In some embodiments, the method further includes washing a solution of compound 15 with an aqueous alkaline solution (e.g., an aqueous carbonate solution, such as sodium carbonate). In some embodiments, compound 15 is not isolated or purified prior to the coupling step (e).

[0138] In some implementations, the deprotection step (d) is performed according to the following scheme: .

[0139] In some embodiments, the coupling step (e) includes contacting compounds 15 and 2 with a coupling agent (e.g., BOP or PyBOP). In some embodiments, the coupling step (e) includes contacting compounds 15 and 2 with a base (e.g., DIPEA). In some embodiments, the coupling step (e) is performed according to the following scheme: In some embodiments, the method for preparing compound A further includes a step of purifying compound A by recrystallizing it. In some embodiments, recrystallization includes contacting compound A with one or more solvents selected from ethyl acetate, water, and diisopropylethylamine, or mixtures thereof. In some embodiments, recrystallization is carried out in a mixture of ethyl acetate and n-heptane.

[0140] Compounds and intermediates In one respect, this disclosure provides a barium salt of compound 1: .

[0141] In some embodiments, the barium salt has a formic acid:barium ratio of 2:1. In some embodiments, the barium salt has the structure of compound 2: .

[0142] On the other hand, this disclosure provides compounds having the structure of compound 3: Compound 3, Or its salts. In some embodiments, the compound or its salts have the structure of compound 3a: Compound 3a, On the other hand, this disclosure provides a tetramethylethylenediamine (TMEDA) salt of compound 5: .

[0143] In some implementations, the TMEDA salt has a formic acid:TMEDA ratio of 2:1.

[0144] On the other hand, compound 5 is a 1,4-diazabicyclo[2.2.2]octane (DABCO) salt. In some embodiments, the DABCO salt has a formic acid:DABCO ratio of 2:1.

[0145] On the other hand, this disclosure provides a hemisulfate of compound 8 (compound 8: sulfate in a 2:1 ratio): Compound 8.

[0146] In one respect, this disclosure provides compounds having the structure of compound 12: Compound 12 Or its salt.

[0147] On the other hand, this disclosure provides compounds having the structure of compound 13: Compound 13 Or its salt.

[0148] Example This disclosure will be further illustrated by the following examples and synthetic embodiments, which should not be construed as limiting the scope or spirit of this disclosure to the specific procedures described herein. It should be understood that the embodiments are provided to illustrate certain implementations and are not intended to limit the scope of this disclosure. It should be further understood that various other implementations, modifications, and equivalents that may be conceived by those skilled in the art may be employed without departing from the spirit of this disclosure or the scope of the appended claims.

[0149] Example 1. Synthetic procedure for compound 4b-(S)-3-bromo-2-(1-methoxyethyl)pyridine.

[0150] The general synthetic procedure for compound 4a-(S)-3-bromo-2-(1-methoxyethyl)pyridine is described in detail below.

[0151] Synthesis of compound 4b-(S)-3-bromo-2-(1-methoxyethyl)pyridine.

[0152] Synthesis of part 1 - compound 4-1-(3-bromopyridin-2-yl)ethyl-1-one.

[0153] Toluene (2,100 L, 7 V) and 3-bromopyridinecarboxylon (300 kg, 1,639 mol, 1 equivalent) were charged into the reactor. The resulting mixture was cooled to and maintained at -20 °C. MeMgCl (3 M solution in THF, 601 L, 1,803 mol, 1.1 equivalent) was then charged into the reactor. The resulting mixture was heated to and maintained at 10-20 °C for 16 hours, at which point HPLC analysis indicated that the reaction was complete.

[0154] The reaction mixture was loaded into a pre-cooled (-10 to 0°C) 4 M HCl aqueous solution (1,070 L, 2.6 equivalents) at -10 to 10°C, and the resulting mixture was maintained at 15–25°C for 30 minutes. The phases were separated, and the aqueous phase was extracted with toluene (600 L × 5, 2V × 5). The combined organic layers were washed with a saturated NaHCO3 aqueous solution (100 L, 0.3 V), and then concentrated (50–60°C, -0.08 MPa) to about 200 L (0.7 V) to give crude 1-(3-bromopyridin-2-yl)ethyl-1-one (compound 4a) as a brown oil (346 kg, 93.7% a / a purity, 83.4% w / w determination, 88% yield), which was used directly in the next step.

[0155] Table 1. HPLC method used for part 1 of Example 1 HPLC method: LRMS (ESI+) 1 H NMR (400 MHz, DMSO- d 6, 25℃) δ 8.66 (dd, J = 4.6, 1.3 Hz, 1H), 8.22 (dd, J = 8.2, 1.3 Hz, 1H), 7.52(dd, J = 8.2, 4.6 Hz, 1H), 2.61 (s, 3H).

[0156] Synthesis of part of the 2-compound 4a-(S)-1-(3-bromopyridin-2-yl)ethanol-1-ol.

[0157] At 25–30 °C, add a solution of potassium phosphate buffer (0.2 M, pH = 6–8–7.2, 2,000 L, 10 V), glucose (594 kg, 3,297 mol, 3.3 equivalents), GDH (4 kg, 2% w / w), NADP (2 kg, 1% w / w), KRED (2 kg, 1% w / w), and 1-(3-bromopyridin-2-yl)ethyl-1-one (compound 4) (200 kg, 999.83 mol, 1 equivalent) in DMSO (200 L, 1 V). Note: Maintain the pH at 6–5–7 using 2 M NaOH aqueous solution as needed. Maintain the reaction mixture at 28–32 °C for 6 hours, at which point HPLC analysis indicates the reaction is complete.

[0158] Diatomaceous earth (40 kg, 20% w / w) and MTBE (800 L, 4 V) were added to the reaction mixture. The resulting mixture was filtered, and the filter cake was washed with MTBE (200 L, 1 V). The resulting phases were separated, and the aqueous phase was extracted again with MTBE (500 L × 3, 2.5 V × 3). The combined organic phases were washed with brine (100 L, 0.5 V) and concentrated (45-55 °C, -0.08 MPa) to give (S)-1-(3-bromopyridin-2-yl)ethanol-1-ol (compound 4a) (204 kg, 97.8% a / a purity, 89.6% w / w determination, 90% yield).

[0159] Substitutional synthesis of some 3-compound 4a-(S)-1-(3-bromopyridin-2-yl)ethanol-1-ol.

[0160] Triethylamine (47 kg, 464.46 mol, 2.8 equivalents) was charged into the reactor. It was cooled to and maintained at 0–10 °C. Formic acid (19 kg, 412.82 mol, 2.5 equivalents) and RuCl (p-isopropyltoluene) [(S,S)-Ts-DPEN] (0.55 kg, 864.49 mmol, 0.005 equivalents) were charged into the reactor. The resulting mixture was heated to and maintained at 30–35 °C. 1-(3-bromopyridin-2-yl)ethyl-1-one (compound 4) (36.7 kg, 165.12 mol, 1 equivalent) was charged into the reactor, and the charging port was flushed with additional triethylamine (2 kg, 19.76 mol, 0.12 equivalents). The reaction mixture was maintained at 30–35 °C for 6 hours, at which point HPLC analysis indicated the reaction was complete.

[0161] The reaction mixture was concentrated (30-35°C) to remove triethylamine. Water (170 kg) and EtOAc (310 kg) were added to the resulting mixture at 15-25°C. The phases were separated, and the aqueous phase was extracted with EtOAc (160 kg × 2). The combined organic phases were washed with brine (158 kg × 2), dried over anhydrous Na₂SO₄, filtered, and the waste desiccant filter cake was washed with EtOAc (40 kg). The combined filtrate was cooled to and maintained at 0-10°C, and MeOH (55 kg, 3.2 equivalents) containing 35% w / w HCl was added. The resulting mixture was maintained at 0-10°C for 12 hours, then filtered, and the product was washed with EtOAc (40 kg). The product was dissolved in water (66 kg) and EtOAc (170 kg), and the resulting solution was cooled to and maintained at 5-15°C. A solution of NaHCO3 (33 kg) in water (170 kg) was added. The phases were separated, and the aqueous phase was extracted with EtOAc (170 kg × 3). The combined organic phases were washed with brine (158 kg × 2), dried over anhydrous Na2SO4, filtered, and the waste desiccant filter cake was washed with EtOAc (120 kg). The filtrate was concentrated (40-45 °C) to give (S)-1-(3-bromopyridin-2-yl)ethanol-1-ol (compound 4a) (30.0 kg, >99.9% a / a purity, 95% w / w determination, 86% yield), which is a dark brown oil.

[0162] Table 2. HPLC methods used for portions 2 and 3 of Example 1 HPLC method: LRMS (ESI+) 1 H NMR (400 MHz, DMSO- d 6, 25℃) δ 8.56 (dd, J = 4.6, 1.4 Hz, 1H), 8.02 (dd, J = 8.0, 1.4 Hz, 1H), 7.26(dd, J = 8.0, 4.6 Hz, 1H), 5.13 - 5.04 (m, 2H), 1.37 (d, J = 6.0 Hz, 3H).

[0163] Synthesis of part of the 4-compound 4b-(S)-3-bromo-2-(1-methoxyethyl)pyridine.

[0164] THF (2,025 L, 5 V) was added to the reactor and t -BuONa (231 kg, 2,404 mol, 1.2 equivalents). Cool the resulting mixture to and maintain it at 0–10 °C. Add (S)-1-(3-bromopyridin-2-yl)ethanol-1-ol (405 kg, 2,004 mol, 1 equivalent) to a solution of THF (800 L, 2 V) and MeI (340 kg, 2,395 mol, 1.2 equivalents). Maintain the resulting reaction mixture at 0–10 °C for 16 hours, at which point HPLC analysis indicates the reaction is complete.

[0165] At 0–10 °C, a 7.5% w / w aqueous solution of NH3 (520 L, 1.3 V) and MTBE (1,200 L, 3 V) were added to the reaction mixture. The phases were separated, and the aqueous layer was extracted with MTBE (1,200 L, 3 V). The combined organic phases were washed with brine (200 L, 0.5 V) and concentrated (50–60 °C, -0.08 MPa) to give crude (S)-3-bromo-2-(1-methoxyethyl)pyridine (compound 4b). The crude (S)-3-bromo-2-(1-methoxyethyl)pyridine was distilled (120 °C, 600 Pa) to give (S)-3-bromo-2-(1-methoxyethyl)pyridine as a colorless solid (445 kg, 99.3% a / a purity, 90.2% w / w determination, 93% yield) (cured after packaging).

[0166] Table 3. HPLC method used for part 4 of Example 1 HPLC method: LRMS (ESI+) 1 ¹H NMR (400 MHz, CDCl₃, 25 °C) δ 8.61 (d, J = 3.2 Hz, 1H), 7.83 (q, J = 1.6, 6.8 Hz, 1H), 7.08 (q, J =3.6, 4.8 Hz, 1H), 4. 92 (q, J = 6.4 Hz, 1H), 3.31 (s, 3H), 1.48 (d, J = 6.8 Hz, 3H).

[0167] Example 2. Synthesis procedure of 3,3-dimethyldihydro-2H-pyran-2,6(3H)-dione.

[0168] The general synthetic procedure for 3,3-dimethyldihydro-2H-pyran-2,6(3H)-dione is described in detail below.

[0169] Synthesis of part of 1,4,4-dimethyl-5-oxopentanonilonitrile.

[0170] 1,4-Dioxane (1,552 L, 5 V), hydroquinone (1.55 kg, 14.1 mol, 0.0033 equivalents), and 5% w / w NaOH aqueous solution (341.4 kg, 426.78 mol, 0.1 equivalents) were charged into the reactor. The resulting mixture was heated to and maintained at 70–75 °C. After 8 hours, isobutyraldehyde (310.6 kg, 4,307.3 mol, 1 equivalent) and acrylonitrile (2) (285.7 kg, 5,384.5 mol, 1.25 equivalents) were charged into the reactor. The reaction mixture was maintained at 70–75 °C for 8 hours, at which point GC analysis indicated that the reaction was complete.

[0171] The reaction mixture was then cooled to and maintained at 20–25°C. The pH was adjusted to 5–6 with a 3.5% w / w HCl aqueous solution (172.5 kg required) and concentrated (45°C, approximately 0.03 atm) until no organic solvent distilled off. The remaining residue was cooled to and maintained at 20–25°C. DCM (1,552 L, 5 V) and water (620 L, 2 V) were added. The phases were separated, and the organic phase was concentrated (45°C, approximately 0.03 atm) until no solvent distilled off, yielding crude 4,4-dimethyl-5-oxopentanonitrile (626.6 kg, 70.8% a / a purity, 43.5% w / w determination, 51% yield) as a brown oil.

[0172] Table 4. GC method for part 1 of Example 2 GC methods: LRMS (ESI+) 1 ¹H NMR (400 MHz, CDCl₃, 25 °C) δ 9.37 (s, 1H), 2.30 - 2.19 (m, 2H), 1.88 - 1.77 (m, 2H), 1.06 (s, 6H).

[0173] Synthesis of part of 2-crude 3,3-dimethyldihydro-2H-pyran-2,6(3H)-dione.

[0174] Water (1,115 kg, 5 V), KH₂PO₄ (13.8 kg, 101.4 mol, 0.057 equivalents), DMSO (164.0 kg, 2,099.1 mol, 1.2 equivalents), and crude 4,4-dimethyl-5-oxopentanonitrile (455.3 kg, 49.0% w / w determination, 1,782.3 mol, 1 equivalent) were added to the reactor. The resulting mixture was cooled to and maintained at 10–20 °C. After 20 hours, a 20% w / w NaClO₂ aqueous solution (1,185.0 kg, 2,620.5 mol, 1.5 equivalents) was added. The reaction mixture was then maintained at 10–20 °C for 1 hour, at which point GC analysis indicated the reaction was complete. This yielded crude 4-cyano-2,2-dimethylbutyric acid, which was used directly in the next step.

[0175] A mixture of crude 4-cyano-2,2-dimethylbutyric acid was charged with KOH (361.5 kg, 6,442.7 mol, 3.6 equivalents). The resulting mixture was extracted with MTBE (800 kg × 2, 4.9 V × 2). The aqueous phase was then heated to and maintained at 90–100 °C for 15 hours, at which point GC analysis indicated that the reaction was complete.

[0176] Cool the reaction mixture to and maintain it at 15–25 °C. Adjust the pH to 1–2 with 30% w / w HCl aqueous solution (requires 1,058 kg, 4.9 equivalents). Extract the resulting mixture with MTBE (1,058 kg × 2, 6.4 V × 2). Wash the combined organic phases with 5% w / w NaCl aqueous solution (378 kg × 2, 1.7 V × 2) and concentrate (40–45 °C, approximately 0.03 atm) to 670 L (3 V) to give crude 2,2-dimethylglutaric acid, which is used directly in the next step.

[0177] Ac₂O (614.6 kg, 6,020.1 mol, 3.4 equivalents) was charged into a mixture of crude 2,2-dimethylglutaric acid at 40–45 °C. The resulting mixture was concentrated (40–45 °C, approximately 0.03 atm) to remove MTBE. The reaction mixture was heated to and maintained at 80–85 °C for 2 hours, at which point GC analysis indicated that the reaction was complete.

[0178] The reaction mixture was then concentrated (70-75 °C, approximately 0.03 atm) to remove AcOH and Ac2O until no solvent was distilled off. This yielded crude 3,3-dimethyldihydro-2H-pyran-2,6(3H)-dione (390.5 kg, 86.3% a / a purity, 69.3% w / w determination, 107% crude yield), which was used directly in the next step.

[0179] Synthesis of part of 3,3,3-dimethyldihydro-2H-pyran-2,6(3H)-dione .

[0180] Heptane (574.0 kg, 1.86 V, crude weight) was charged into the reactor. It was cooled to and maintained at -10 to -5 °C. After 10 hours, a solution of crude 3,3-dimethyldihydro-2H-pyran-2,6(3H)-dione (454.0 kg, 84.1% w / w determined) in MTBE (667.2, 2 V, crude weight) was charged into the reactor. The resulting mixture was maintained at -10 to -5 °C for 1.5 hours and then filtered.

[0181] Dissolve the filter cake in MTBE (572 kg, 2 V, determined weight). Add activated carbon (19.1 kg, 0.05% w / w, determined weight) to the resulting solution. Maintain it at 15–25 °C for 8 hours. Then filter the resulting solution and wash the waste carbon filter cake with MTBE (18 kg, 0.05 V). After 9 hours, add the filtrate to pre-cooled (-10 to -5 °C) n-heptane (518.4 kg, 2 V, determined weight). Maintain the resulting mixture at -10 to -5 °C for 2 hours. Then filter it at -10 to -5 °C. The product was dried (25-30℃, about 0.03 atm) for 16 hours to obtain 3,3-dimethyldihydro-2H-pyran-2,6(3H)-dione as a grayish-white solid (212.0 kg, 100% a / a purity, 98.3% w / w determination, 55% yield).

[0182] Substitutional synthesis of some 4-3,3-dimethyldihydro-2H-pyran-2,6(3H)-dione.

[0183] Ac₂O (5.4 L) and 2,2-dimethylglutaric acid (2,573 g, 98.8% w / w and 506 g, 90.9% w / w, 18.74 mol, 1 equivalent) were charged into the reactor. The resulting reaction mixture was heated to and maintained at 110 °C for 1 hour, at which point GC analysis indicated that the reaction was complete.

[0184] The reaction mixture was concentrated (70°C, about 0.03 atm) to remove AcOH and Ac2O until no solvent was distilled off. The residue was combined with another batch (2,2-dimethylglutaric acid (6,610 g, 90.8% w / w determination)) and distilled (110–120°C, about 0.005 atm) until no product was distilled off. The resulting fraction was wet-milled with n-heptane (35 L), filtered, and the product was dried (25°C, about 0.005 atm) to give 3,3-dimethyldihydro-2H-pyran-2,6(3H)-dione as a grayish-white solid (6.66 kg, 99.6% a / a purity, 98.56% w / w determination, 82% yield).

[0185] Table 5. GC methods used for parts 2, 3, and 4 of Example 2 GC methods: LRMS (ESI+) 1 ¹H NMR (300 MHz, CDCl₃, 25 °C) δ 2.82 (t, J = 7.0 Hz, 2H), 1.85 (t, J = 7.0 Hz, 2H), 1.35 (s, 6H).

[0186] Partial substitution synthesis of 5-2,2-dimethylglutaric acid.

[0187] A 65% w / w aqueous solution of HNO3 (3.3 L) and concentrated H2SO4 (500 mL) were charged into the reactor at 25 °C. The resulting mixture was heated to and maintained at 70–80 °C. 4,4-Dimethyl-5-oxopentanilonitrile (2.21 kg, 90.5% w / w determination, 15.98 mol, 1 equivalent) was then added fractionally over 24 hours. The reaction mixture was then maintained at 70–75 °C for 1 hour, at which point GC analysis indicated the reaction was complete.

[0188] The reaction mixture was cooled to 25°C and then placed in ice-cold water (10 kg), during which time a solid precipitate formed. The resulting mixture was extracted with MTBE (10 L × 1, then 5 L × 2). The combined organic phases were washed with water (2 L × 1), then with brine (2 L × 1), dried over anhydrous Na₂SO₄, filtered, and then concentrated (45°C, about 0.03 atm) until no solvent was distilled off. This yielded 2,2-dimethylglutaric acid as a white solid (2.6 kg, 98.8% w / w determination, 100% yield).

[0189] Table 6. GC method for part 5 of Example 2 GC methods: LRMS (ESI-) 1 ¹H NMR (400 MHz, CDCl₃, 25 °C) δ 2.42 (t, J = 7.5 Hz, 2H), 1.92 (t, J = 7.5 Hz, 2H), 1.23 (s, 6H).

[0190] Example 3. Synthesis procedure of compound 5.

[0191] Part 1 - Compound 5 TMEDA salt THF (445 L, 6 V), crude 4-fluoropiperidine-1,4-dicarboxylic acid 1-tert-butyl 4-ethyl ester (74.0 kg, 268.8 mol, 1.0 equivalent, corrected by assay), and MeOH (370 L, 5 V) were added to a 3000 L glass-lined reactor at 20 ± 5 °C, and the mixture was stirred at 20 ± 5 °C for 15 min. A solution of LiOH∙H₂O (22.6 kg, 538.6 mol, 2.0 equivalent) in H₂O (225 L, 3 V) was added dropwise (slightly exothermic) to the reaction mixture over 30 min at 20 ± 5 °C, and the mixture was heated to 45 °C and stirred for 10 h. HPLC analysis indicated the reaction was complete. The reaction mixture was cooled to 20 ± 5 °C and diluted with H₂O (740 L, 10 V). The mixture was washed continuously with IPAc (740 L, 10 V) and DCM (740 L × 2, 10 V × 2), and then partitioned with EtOAc (740 L, 10 V). The pH of the resulting two-phase mixture was adjusted to pH 3 with 7% w / w HCl aqueous solution (185 kg). The phases were separated, and the lower aqueous-lean phase was extracted with EtOAc (740 L, 10 V). The combined organic phase (1398.8 kg) was washed with 5% w / w brine (370 L, 5 V), dried over MgSO4 (84.6 kg), and filtered. The spent desiccant filter cake was washed with EtOAc (190.6 kg).

[0192] Two batches of organic-rich layers (74.0 kg, corrected by assay, × 2) were combined and concentrated to 4 V at 45 ± 5 °C under reduced pressure (approximately 0.03 atm). TMEDA (28.1 kg, 241.9 mol, 0.45 equivalents) was added at 45 ± 5 °C, and the mixture was stirred at 45 ± 5 °C for 16 h. The mixture was slowly cooled to -10 to -15 °C over 6 h and stirred again for 16 h. The slurry was filtered at -10 °C, and the product was washed with cold EtOAc (80 L, -10 °C) to give a wet compound 5½ TMEDA salt. The wet product was wet-milled at 25 °C with EtOAc / n-heptane (1 / 1, 170 L, 2 V) for 2 h and filtered. The product was washed with EtOAc / n-heptane (1 / 1, 42.5 L, 0.5 V) and dried in an oven at 45 ± 5 °C under vacuum (approximately 0.005 atm) for 12 hours (drying standard: LOD < 1.0%) to give compound 5½TMEDA salt (80.0 kg, 99.8% a / a purity (TFA method), 99.6% a / a purity (H3PO4 method), 98.2% w / w determination, 47.9% determination corrected yield).

[0193] LRMS (ESI-) 1 H NMR (300 MHz, d6-DMSO, 24℃) δ 3.80 (bd, 4H), 2.98 (bs, 4H), 2.78 (s, 4H), 2.42 (s, 12H), 1.07-1 / 79(m, 4H), 1.77-1.71 (m, 4H), 1.41 (s, 18H) Partial 2-compound 5 DABCO salt THF (200 mL, 1V) and crude 4-fluoropiperidine-1,4-dicarboxylic acid 1-tert-butyl 4-ethyl ester (164.2 g, 0.669 mmol, 1.0 equivalent, corrected by assay) were added to a 5 L round-bottom flask. A solution of NaOH(s) (53.52 g, 1.338 mmol, 2.0 equivalent) in water (600 mL, 3V) was added to the mixture at 25 ± 5 °C (internal temperature). The resulting mixture was stirred at 25 ± 5 °C for 2 hours. HPLC analysis indicated the reaction was complete. The reaction mixture was diluted with water (2.00 L, 10V) and washed twice with 2-MeTHF (1.00 L × 2, 5V × 2). The mixture was partitioned with EtOAc (1.00 L, 5V) and the pH was adjusted to 2–3 with 3N HCl aqueous solution. The phases were separated, and the lower acid-poor aqueous layer was extracted with EtOAc (1.00 L, 5V). The combined organic layers were concentrated under reduced pressure (approximately 0.1 MPa) at 40 ± 5 °C (jacket temperature) to give crude compound 5 as a yellow solid (160.0 g, 81.33% a / a purity, 86.8% w / w determination, 94.2% corrected yield).

[0194] Crude compound 5 (150.0 g (130.2 g, corrected by assay, 0.53 mol, 1.0 equivalent)) and 2-MeTHF (750 mL, 5 V) were charged into a 5 L round-bottom flask. The mixture was heated to 50 ± 5 °C and a solution of DABCO (56.45 g, 0.53 mol, 1.0 equivalent) in 2-MeTHF (750 mL, 5 V) was added. The mixture was stirred at 50 ± 5 °C for 16 hours, cooled to 20–25 °C, and stirred for another 2 hours, then filtered. The resulting filter cake was slurried in THF (750 mL, 5 V) at 50 ± 5 °C and separated by filtration, then dried under vacuum at 40–50 °C to give compound 5 DABCO salt as a white solid (121.1 g, 99.62% a / a purity, 63.9% yield).

[0195] 1 ¹H NMR (400 MHz, D₂O, 23 °C) δ 3.90 (bd, 2H), 3.13 (s, 12H), 2.96 (t, 2H), 1.97-1.59 (m, 4H), 1.35(s, 9H) Example 4. Synthesis procedure of compound 6.

[0196] 2-MeTHF (568.0 kg, 20 V) and compound 7 (33.4 kg, 72.2 wt%, 289.3 mol, (assay corrected), 1.0 equivalent) were charged into a 2000 L glass-lined reactor (reactor A) under positive nitrogen pressure. The mixture was stirred at 100 RPM for 10 minutes and then cooled to 0–10 °C. CH2O (37 wt% aqueous solution, 163.6 kg, 2016 mol, 7.0 equivalent) was added dropwise to the cold solution at a rate of 1.6 kg / min while maintaining the internal temperature at 0–10 °C. The reaction mixture was stirred at 0–10 °C for 10 minutes. NaBH(OAc)3 (188.0 kg, 887 mol, 3.1 equivalent) was added to the reactor in nineteen portions over eight hours via a solid feeder while maintaining the temperature at 0–10 °C. The reaction mixture was heated to 20-30°C over 3 hours, and then stirred for 10 hours. GC analysis indicated that the reaction was complete, with compound 7 having an area of ​​<1.0%.

[0197] Transfer the reaction mixture to a 3000 L glass-lined reactor (Reactor B) at 0 - 20 °C. Charge 15 wt% Na2CO3 (aqueous solution) (1960.0 kg, 57.8 w / w.) into the reactor over 90 minutes at 0 - 10 °C with agitation (100 RPM). Warm the biphasic mixture to 10 - 20 °C and stir for an additional 20 minutes. Separate the layers; return the lower water-lean layer to the 3000 L Reactor B and transfer the upper organic-rich layer to a 2000 L Reactor A. Extract the aqueous layer twice with 2-MeTHF (284.0 kg, 10 V). Wash the combined organic layers in Reactor A successively with 10 w% NaCl (aqueous solution) (334.0 kg × 2) and dry over Na2SO4 (100.0 kg, 3.0 w / w), and stir (100 RPM) at 10 - 20 °C for 3 hours. Filter the mixture under reduced pressure. Rinse the spent desiccant with 2-MeTHF (57.0 kg, 1.7 w / w). Transfer the filtrate to Reactor A and cool to 10 - 20 °C. Slowly charge 4 Å molecular sieves (200.0 kg, 6.0 w / w) into the solution over three hours at 10 - 20 °C. Warm the mixture to 20 - 30 °C and hold at 20 - 30 °C under a slight N2 pressure for 12 hours with periodic agitation at only 30 RPM for 1 minute per hour. Filter the mixture and wash the spent molecular sieves twice with 2-MeTHF (28.0 kg, 2 V). Distribute the filtrate into eight 200 L HDPE drums, 140 kg filtrate per drum. Slowly charge 4 Å molecular sieves (10.0 kg, ~7 wt% relative to the 2-MeTHF solution) into each drum. Hold the filtrate at 20 - 35 °C for 72 hours (12 - 120 hours). The KF determination of the 2-MeTHF solution of Compound 7c meets the standard of ≤ 1000 ppm.

[0198] A solution of compound 7c in 2M THF (568.0 kg, 2.68 wt% determined, 1.0 equivalent) was charged into a 1000 L stainless steel reactor under nitrogen pressure and vacuum. Note that an in-line filter was used to separate the molecular sieve contained in the feed drum. The solution was cooled to -80°C to -75°C with agitation (100 RPM). LiHMDS (190.8 kg, 1M THF solution, 1.6 equivalent) was added dropwise (approximately 1.5 kg / min) while maintaining the temperature at -80°C to -65°C. The reaction mixture was further stirred under nitrogen at -80°C to -65°C for six hours. CO2 (g) (60 kg) was added to the reaction mixture at a rate of 80–100 g / min at -65°C to -45°C until the reaction mixture was saturated. Saturation was determined when a large amount of gas was observed in the exhaust gas through a bubbler. The reaction mixture was further stirred at -62°C to -45°C for eight hours. The reaction was indicated by HPLC determination of 7c < 5.0% area. The reaction mixture was gradually heated to 20-30°C over 10-20 hours to release dissolved CO2 gas. The reaction mixture was transferred to a 2000 L glass-lined reactor and concentrated under reduced pressure at 10-20 bar and 40-50°C to a target volume of 50-60 L. 45.0 kg (66 L) of n-heptane was added to the reactor, and the mixture was concentrated again to 50-60 L. The separation process was repeated twice with n-heptane (2 × 45.0, 66 L) to achieve a final volume of 50-60 L. 107.3 kg (120 L) of EtOAc was added to the reactor. The mixture was stirred at 20-30°C for three hours to dissolve the solids. 246.0 kg (360 L) of n-heptane was added to the reactor. The slurry was further stirred at 20-30°C for three hours and then filtered. The resulting solid was washed twice with n-heptane (2 × 45.0 kg, 66 L) and dried under reduced pressure (10-15 mbar) at 40-45°C for 20 hours to give 24.7 kg of compound 7a (lithium salt), with a purity of 89% by HPLC and a yield of 53.8 wt% by qNMR, as a white solid with a yield of 61.3%.

[0199] AcOH (630.0 kg, 5.24 w / w) was charged into a 3000 L glass-lined reactor. After 90 minutes, 10 portions (10-15 kg each) of compound 7a (120.0 kg) were added, while maintaining the temperature at 20-25 °C. The mixture was stirred at 20-25 °C for six hours to obtain a clear solution. EtOAc (2160.0 kg, 18 w / w) was added to the solution over 30 minutes. The mixture was stirred at 20-25 °C for 12 hours. The resulting solid was separated by centrifugation and washed twice with EtOAc (2 × 270.0 kg, 2.25 w / w) to obtain 116.2 kg of wet product, compound 7bAcOH salt.

[0200] The wet product (116.2 kg) and EtOAc (2160.0 kg, 18 w / w) were charged into a 5000 L glass-lined reactor. A solution of 4 M HCl in EtOAc (240 kg, 2 w / w) was added to the resulting suspension at 20–25 °C for 25 minutes (approximately 10 kg / min). The resulting suspension was stirred at 20–25 °C for 12 hours. The resulting solid was separated by centrifugation, washed twice with EtOAc (2 × 130.0 kg, 1.1 w / w), and dried under reduced pressure at 35–40 °C for 40 hours to give 63.5 kg of compound 6, with a purity of 96.2% by HPLC, 1757 ppm AcOH residue by HS-GC, and 97.7 wt% by qNMR, as a white solid with an 85.3% corrected yield.

[0201] LRMS (ESI+) 1 H NMR (400 MHz, d6-DMSO) δ 2.78 (s, 6H), 1.70 (s, 6H) Example 5. Synthesis procedure of compound 11b.

[0202] Part 1 - Compound 9-(S)-5-(2-(1-methoxyethyl)pyridin-3-yl)-2,2-dimethyl-5-oxo Synthesis of valeric acid THF (1,200 L, at 10.0 times the volume, 70 L / min) and (S)-3-bromo-2-(1-methoxyethyl)pyridine (compound 4b, 120 kg, 20 kg / min) were charged into a 3,000 L Hastelloy-lined jacketed reactor at 15–25 °C under N2. The resulting mixture was then cooled to -15 to -10 °C.

[0203] i-PrMgCl·LiCl (448 L, 3.74 times the volume, 1.05 equivalents) was added dropwise to the reactor at -25 to -15 °C. The reaction mixture was stirred at -15 to -5 °C for 1 hour under N2.

[0204] A solution of 82.9 kg of 3,3-dimethyldihydro-2H-pyran-2,6(3H)-dione in THF (360 L, 3.00 L by volume) was charged into a reactor at -15 to -5 °C under N2. The reaction mixture was stirred at -8 to -12 °C for 12 hours.

[0205] The reaction mixture was quenched by adding water (360 L, 3.00 times by volume) under N2 at 0-10°C, and then concentrated to 500-600 L. A mixture of AcOH (60.0 L, 0.50 times by volume) and water (1,200 L, 10.0 times by volume) was added to the concentrated mixture. The two-phase mixture was extracted twice with EtOAc (1,200 L, 10.0 times by volume). The combined organic phases were concentrated to 400-500 L.

[0206] Add 1,205 L of n-heptane (3.00 times by volume) to the concentrated solution and concentrate the resulting mixture to about 400-500 L. Repeat this unit operation twice more. Add 1,205 L of MTBE:n-heptane = 1:1 solution (3.00 times by volume) to the concentrated solution. Stir the resulting slurry at 15-20°C under N2 for 16 hours. Separate the solid by filtration and dry at 35-40°C under N2 for 12-24 hours to obtain compound 9 as a grayish-white solid (57.5% separation yield, 99.2% w / w determination, 100% ee, 99.5% purity).

[0207] 1 H NMR (400 MHz, DMSO- d 6, 25℃) δ 12.20 (s, 1H), 8.60 (d, J =3.2 Hz, 1H), 7.89 (dd, J=15.6, 1.2 Hz, 1H)7.39 (dd, J =7.6, 4.8 Hz, 1H), 4.55 (q, J =6.4Hz, 1H), 3.11 (s, 3H), 2.80 (dd, J =16.0, 8.0 Hz, 2H), 1.80 (dd, J =16.0, 8.0 Hz, 2H), 1.42 (d, J =6.4 Hz, 3H), 1.12(s, 6H) Part of the 2-compound 8-(S)-3-(5-bromo-2-(2-(1-methoxyethyl)pyridin-3-yl)-1H-indole-3- Synthesis of 2,2-dimethylpropionic acid Water (1,565 L, 5.00 times by volume), H₂SO₄ (440 kg, 1.40 times by weight, 4.00 equivalents), compound 9 (313 kg, 1 equivalent), and compound 10 (250 kg, 0.80 times by weight, 1.00 equivalent) were charged into a 5,000 L glass-lined reactor at 10-20 °C under N₂. The mixture was heated to 95-100 °C and stirred for 18 hours.

[0208] The reaction mixture was cooled to 50–60 °C under N2 and neutralized to pH 4–5 by adding 20% ​​wt. NaOH aqueous solution (1,800 L). Compound 8 was precipitated by further adjusting the pH to 6.2–6.8 using K2HPO4 aqueous solution (about 65 L). The solid was separated by centrifugation, washed with water (1,290 L, 5.00 times by volume), and dried at 45–50 °C under N2 for 24 h to obtain compound 8 as a brown solid (456 kg, 80.6% determined corrected yield, 85.0% area purity).

[0209] Analytical data for compound 8: 1 H NMR (400 MHz, DMSO- d 6, 25℃) δ 12.14 (bs, 1 H), 11.42 (s, 1 H), 8.71 (dd, J =4.4, 1.2 Hz, 1H), 7.45(dd, J =8.0, 4.8 Hz, 1H), 7.31 (d, J =8.8 Hz, 1H) 7.21 (d, J= 8.4 Hz, 1 H), 4.18(q, J =6.4 Hz, 1 H), 2.93 - 2.77 (m, 5 H), 1.36 (d, J = 6.0 Hz, 3 H), 0.88 (d, J =6.4 Hz, 6 H) Part of compound 3, 16-(S)-3-(5-bromo-1-ethyl-2-(2-(1-methoxyethyl)pyridin-3-yl)-1H- Synthesis of ethyl indole-3-yl)-2,2-dimethylpropionate DMF (973 L, 7.00 times by volume) and Compound 8 (139 kg, 1 equivalent) were charged into a 5,000 L glass-lined reactor at 10–20 °C under N2. The mixture was stirred at ambient temperature to obtain a clear solution, which was then cooled to 0–5 °C.

[0210] Add 32.2 kg of NaOH (0.24 times by weight, 2.50 equivalent) and 126 kg of EtI (0.91 times by weight, 2.50 equivalent) to the mixture. Heat the reaction mixture to 15-20°C and stir for 6 hours.

[0211] The reaction was quenched with water (1,390 L, 10.0 times by volume) at 0–20 °C. The resulting mixture was extracted twice with MTBE (5–10 times by volume). The combined organic layers were concentrated at 35–45 °C. The concentrated mixture was diluted with THF (278 L, 2.00 times by volume) and further concentrated under reduced pressure at 35–45 °C to about 2 v (about 150 L). The preceding unit operation was repeated until the MTBE content in the THF solution was less than 1% w / w. The resulting THF solution of compound 16, in the form of a 1:1 diastereomer mixture, was used directly in the next step (385 kg, 33.5% w / w HPLC determination, 96.3% separation yield, determination: 129 kg).

[0212] Part 4 - Compound 11 - (S)-3-(5-bromo-1-ethyl-2-(2-(1-methoxyethyl)pyridin-3-yl)- Synthesis of 1H-indol-3-yl)-2,2-dimethylprop-1-ol A THF solution of compound 16 (661.8 kg, determination of compound 16: 205.3 kg) was charged into a 1,000 L glass-lined reactor at 15–20 °C under N2. LiBH4 (2 M solution in THF, 1.20 equivalents) was then added to the mixture at 50–60 °C, followed by stirring at N2 for 12 hours at 50–60 °C.

[0213] The reaction was quenched with 0.50 M HCl (aqueous solution) (1,455 L, 7.08 times by volume). The pH of the mixture was adjusted to 4–5 with 0.50 M HCl (aqueous solution). The resulting mixture was extracted with EtOAc (1,810 L, 8.80 times by volume). The phases were separated. The organic layer was washed with brine (743 L, 3.61 times by volume) and concentrated to 1300 L to obtain EtOAc solutions of compounds 11a and 11b in the form of a 1:1 diastereomer mixture (1,484 kg EtOAc solution, 93.12 area % purity, 97.6% corrected yield, 11a + 11b determination: 183 kg).

[0214] Part 5 - Separation of 11b from a mixture of compounds 11a and 11b In a 5,000 L glass-lined reactor, EtOAc solutions of compounds 11a and 11b were concentrated to 1.2–1.5 V, and xylene (2.29 times by volume) was added. The mixture was stirred at 90–100 °C for 2 hours to evaporate residual EtOAc, then heated to 135–140 °C and held for 4 hours to allow the diastereomer mixture to equilibrate to a ratio of less than 1:1.6 (11a:11b). The reaction mixture was then cooled to 20–25 °C, concentrated to 1.2–1.5 V, and diluted with IPA (3.87 times by volume) at 40–45 °C. The solution was further cooled to 20–25 °C, diluted with additional IPA (4.77 times by volume), and treated with a solution of HCl in IPA (5 mol / L, 1.32 times by volume). The resulting suspension was stirred at 20–25 °C for 16–24 hours and then filtered. The mixture was stirred at 70-75°C for 4 hours, and then at 20-25°C for 10 hours to dissolve the resulting wet filter cake in IPA (5.00 times by volume). The solid was separated by filtration and dried under N2 at 35-40°C for 24 hours to give the first batch of compound 11b (388 kg, 99.0% area purity, 99.7% chiral purity, 46% yield) as a pale yellow solid.

[0215] The product-rich filtrates were combined and concentrated to near dryness. The resulting brown oily substance was purified by silica gel chromatography (column height: 250 mm, diameter: 100 mm, 100-200 mesh silica gel, n-heptane / ethyl acetate = 5 / 1 to 0 / 1) to give an eluent containing a mixture of product-rich compounds 11a and 11b. This mixture was equilibrated again as described above to give compound 11b as a pale yellow solid (151 kg, 98.7% area purity, 99.7% chiral purity, 15% yield).

[0216] 1 H NMR (400 MHz, DMSO- d 6, 25℃) δ 8.93 (d, J =4.0 Hz, 1H), 8.35 (d, J =7.6 Hz, 1H), 7.89-7.92 (m, 2H),7.52 (d, J =8.8 Hz, 1H), 7.32 (dd, J =8.4, 1.6 Hz, 1H), 4.02-4.15 (m, 2H), 3.75-3.85 (m, 1H), 2.93-3.04 (m, 5H), 2.67 (d, J =14Hz, 1H), 2.12 (d, J =14Hz, 1H), 1.44 (d, J =6 Hz, 3H), 1.11 (t, J =6.8 Hz, 3H), 0.64 (s, 3H), 0.60 (s, 3H) Example 6. Alternative synthesis of compound 11b This embodiment illustrates the alternative synthesis of compound 11b. This method utilizes an acyl chloride derivative of 3,3-dimethyldihydro-2H-pyran-2,6(3H)-dione to prepare compound 9. An additional method via compound 22 improves the initial ratio of the desired transisomer compound 11b to the unwanted compound 11a. This method has the advantage of utilizing more readily available and cost-effective substrates.

[0217] One advantage of using stepwise alkylation is that indole alkylation has higher diastereoselectivity, thus providing the desired compound 11b in a ratio greater than 5:1, instead of the unwanted compound 11a.

[0218] Preparation of compound 20 500 g of 2,2-dimethylglutaric anhydride, methanol (8 V), and sulfuric acid (0.13 equivalents) were charged into a reaction vessel. The mixture was stirred at 55 °C for 24 h. The solvent was distilled under vacuum at 50 °C. The residue was partitioned with water (3 V) and MTBE (7 V). The organic layer was washed with water and brine and distilled under vacuum to give an oily diester compound 18. The crude diester, methanol (8 V), and potassium hydroxide (1.2 equivalents) were stirred at room temperature for 14 h and then heated to reflux for 2 h. The mixture was cooled to room temperature, concentrated under reduced pressure, acidified with 1 M HCl (aqueous solution), and partitioned with brine and MTBE. The organic phase was concentrated to give a solid carboxylic acid compound 19. Compound 19, toluene (5 V), and DMF (1 wt%) were charged into a reactor. Thionyl chloride (1.5 equivalents) was slowly added while maintaining the temperature at 0–10 °C. The reaction mixture was stirred at room temperature for 14 h. The solvent was removed by vacuum distillation at 50-55℃, and the product was separated by high-vacuum distillation to obtain compound 20, which is in the form of oil.

[0219] Preparation of compound 21 Step 1a: Under nitrogen protection, add THF (100 mL, 1.0 vol.) to reactor R1. Incubate the reactor at 20-30°C. i A PrMgCl·LiCl THF solution (374 mL, 1.05 equivalents) was added to the mixture. The temperature was adjusted to between -10°C and 0°C. THF containing compound 4b (100 g, 1.0 equivalents) was added dropwise to the reaction mixture at -10 to 0°C (200 mL, 2 vol.). The mixture was stirred at -10 to 0°C for 2 hours, and then samples were taken for IPC (HPLC purity: 95.0 A% of compound 4b-2 and 0.2 A% of compound 4b).

[0220] Step 1b: Under nitrogen protection, 2-MeTHF (300 mL, 3 vol.) and ZnCl2 (72.3 g, 1.15 equivalents) were charged into reactor R2. The temperature was adjusted to between -10°C and 0°C. The reaction mixture from R1 was added dropwise to R2 over 1 hour at -10°C to 0°C. THF (50 mL, 0.5 vol.), CuCl (4.6 g, 0.1 equivalents), and LiCl (3.9 g, 0.2 equivalents) were charged into reactor R3 and stirred over 1 hour at 20°C to 30°C. The reaction mixture from R3 was added dropwise to R2 over -10°C to 0°C. Compound 20 (107 g, 1.2 equivalents) was added dropwise to R2 over -10°C to 0°C. The mixture was stirred at -10 to 0 °C for 16 hours, and then sampled for IPC (HPLC purity: 92.7 A% for compound 21 and 0.6 A% for compound 4b-2). The reaction mixture was heated to 25 °C–30 °C. Toluene (500 mL, 5 vol.), AcOH (83.3 g, 3.0 equivalent), and H₂O (300 mL, 3.0 vol.) were added to the reaction mixture and stirred for 0.5 hours. The organic phase was separated, and the aqueous phase was extracted with toluene (300 mL, 3 vol.). The combined organic phases were washed with 10% ammonium hydroxide (300 mL × 2, 3 vol. × 2). The organic phase was concentrated under vacuum to 1–1.5 vol. 158 g of compound 21 as a brown oil was obtained, with 96.2% HPLC purity and 89% uncorrected yield.

[0221] Step 1c: Add water (5 vol) to the crude product and stir for 15 minutes. Cool the reaction mixture to 5 ± 5 °C. Slowly add lithium hydroxide (2 equivalents) at 5 ± 5 °C. Raise the temperature to 25 ± 5 °C and stir for 14–16 hours. Monitor the progress of the reaction by HPLC (limit: compound 21: NMT 1.0%). After the reaction is complete, wash the reaction mixture with MTBE (2 × 5 vol) and adjust the pH to 5–6 with 50% acetic acid solution (1 vol) (solid precipitation occurs). Stir the resulting mixture for 3–4 hours, filter the solid and wash with water (5 vol), then with heptane (5 vol). Dry the product under vacuum at 50 °C.

[0222] Purity: NLT: 95%, Yield range: 65-70% Preparation of compound 8 hemisulfate This procedure reduces debromination impurities and allows for efficient recycling of the flow chemistry of the compound 11a / compound 11b mixture (see below).

[0223] Under nitrogen protection, reactor R1 was charged with H2O (50 mL, 2.5 vol.) and concentrated H2SO4 (13.4 g, 1.0 equivalent). Compound 21 (20.0 g, 1.0 equivalent) and compound 10 (16.0 g, 1.05 equivalent) were added to the mixture at 20–30 °C. The temperature was adjusted to 90–100 °C. The mixture was stirred at 90–100 °C for 48 hours, and then samples were taken for IPC (HPLC purity: 84.2 A% of compound 8, 0.2 A% of compound 21, and 1.1 A% of compound 21a). The mixture was cooled to 60–65 °C, and H2O (110 mL, 5.5 vol.) was added to the mixture at 60–65 °C. Then, NaOH (5.5 g, 2.0 equivalent) was added to the mixture at 60–65 °C, and the mixture was stirred at 60–65 °C for 2 hours. The mixture was cooled to 20–25 °C and stirred for 2 hours. The mixture was filtered, and the filter cake was washed with H₂O (40 mL, 2.0 vol.). The wet filter cake was dried at 50–55 °C under reduced pressure (-0.95 MPa) for 14 hours. 26.9 g of compound 8½H₂SO₄ as a grayish-yellow solid was obtained, with a purity of 96.2% by HPLC and a corrected yield of 78%.

[0224] Alternative experimental procedures for the preparation of compound 8 hemisulfate Sulfuric acid (238 kg, 2.0 equivalents) was added dropwise to water (807.7 L) under N2 while maintaining the temperature at 20 °C ± 20 °C. Compound 9 (340 kg, assay corrected) and Compound 10 (299.18 kg, 1.1 equivalents) were charged at 20 ± 10 °C. The reaction mixture was stirred at 70 - 75 °C for at least 30 minutes and further stirred at 95 ± 10 °C for 32 hours. The reaction was monitored by HPLC, showing completion of the reaction with < / = 1% of Compound 9 detected. The reaction mixture was cooled to 60 - 65 °C. Water (1871.5 kg) and 30 wt% NaOH (aqueous solution) (298.5 kg, 1.9 equivalents) were charged, and the mixture was stirred for at least five hours. The slurry was cooled to 25 ± 5 °C over four hours, further stirred at 25 ± 5 °C for 2 hours, and filtered. The resulting solid was washed with water (1020 kg) to give 538.95 kg of a wet filter cake. At 80 °C - 85 °C, the wet filter cake was reslurried in a mixture of water (1619 kg) and H2SO4 (85.04 kg) for five hours and further stirred at 25 °C - 30 °C for 16 hours. The solid was separated by filtration, washed with water (1020 L), and vacuum dried at 50 ± 5 °C for 36 hours to give 446 kg of Compound 8 - ½H2SO4 as a yellow solid in the form of a hemisulfate.

[0225] Preparation of compound 22 Compound 8 ½ H2SO4 (2.0 kg, 1.0 equivalent) and EtOH (7V) were charged to reactor R1 under nitrogen protection at 20 - 25 °C. DMF (1.0% w / w) was charged to the reactor to form a suspension. SOCl2 (1.0 equivalent) was added dropwise to the suspension with stirring over 1 hour at 0 - 10 °C to give a clear homogeneous solution. The reaction mixture was heated to an internal temperature of 60 °C - 65 °C and stirred for 16 hours. Samples showed completion of the reaction by IPC (Compound 8 < 2.5%; samples were diluted with ethanol). The reaction mixture was cooled to 20 °C - 25 °C and the pH was adjusted to approximately 7.0 by adding saturated NaHCO3 aqueous solution (approx. 10V). After completion of neutralization, the reaction mixture was further stirred at 20 °C - 25 °C for 1 hour. The mixture was filtered and the filter cake was washed with water (2V). The wet filter cake was then reslurried in water (7V) for 5 hours. The slurry was then filtered and the filter cake was washed with water (2V). The filter cake was further dried under high vacuum at < 50 °C to give Compound 22 (1,756 g; purity 9​​Alternatively, the carboxylic acid can be activated into a mixed anhydride (e.g., by using isobutyl chloroformate) before reduction in the next step, or the carboxylic acid can be directly reduced to a primary alcohol in the next step.

[0227] Preparation of compounds 11a and 11b Compound 22 (100.0 g, 1.0 equivalent), EtOH (500 mL, 5.0 vol.), and CaCl2 (24.2 g, 1.0 equivalent) were charged into the reactor. The mixture was stirred at 25–30 °C for 30 minutes. NaBH4 (20.6 g, 2.5 equivalent) was added to the mixture in portions at 25–30 °C. The mixture was stirred at 25–30 °C for 16 hours, and then samples were taken for IPC (HPLC purity: 97.2 A% for compound 23 and 0.92 A% for compound 22). The reaction mixture was adjusted to pH 1–2 with 3 M HCl (approximately 2.4 V) at 20–30 °C (internal temperature). The mixture was stirred at 20–30 °C for 30 minutes. The reaction mixture was adjusted to pH 4.5–5.0 with 30% NaOH aqueous solution (approximately 2.5 V) at 20–30 °C (internal temperature). The mixture was stirred at 20–30 °C for 30 minutes. Water (500 mL, 5.0 vol.) was added to the mixture at 25–30 °C. The mixture was stirred at 20–30 °C for 14 hours. The mixture was filtered, and the filter cake was washed with water (200 mL, 2.0 vol.). The wet filter cake was dried at 55–60 °C under reduced pressure (-0.95 MPa) for 14 hours. 89 g of compound 23 as a grayish-white solid was obtained, with a purity of 97.6% by HPLC and an uncorrected yield of 95%.

[0228] 2-MeTHF (270 mL, 9.0 vol.), 1,4-dioxane (90 mL, 3.0 vol.), and compound 23 (30.0 g, 1.0 equivalent) were charged into the reactor. KOH (7.3 g, 1.8 equivalent) was added in portions to the mixture at 15–30 °C (internal temperature). Diethyl sulfate (DES) (17.7 g, 1.6 equivalent) was added dropwise to the mixture at 25–30 °C (internal temperature). The mixture was stirred at 25–30 °C for 16 hours, and then sampled for IPC [HPLC purity: 96.4 A% for compound 11b (7.05 ratio of compound 11b / compound 11a) and compound 23 was not detected]. The mixture was stirred at 20–30 °C for 30 minutes. Water (90 mL, 3.0 vol.) was added to the mixture at 25–30 °C and stirred for 30 minutes to separate the organic phase. 2-MeTHF (60 mL, 2.0 vol.) was added to the aqueous phase at 20–30 °C and stirred for 30 min, separating the aqueous phase. The combined organic phases were concentrated and replaced with THF (300 mL, 10.0 vol.). 6 M HCl (10.8 mL, 0.9 equivalents) was added dropwise to the mixture at 20–30 °C. The mixture was stirred at 20–30 °C for 13 h. The mixture was filtered, and the filter cake was washed with THF (60 mL, 2.0 vol.). The wet filter cake was dried under reduced pressure (-0.95 MPa) at 50–55 °C for 14 h. 26.0 g of compound 11b-HCl as a grayish-yellow solid was obtained, with a purity of 97.9% HPLC and an uncorrected yield of 74%.

[0229] Substitutional synthesis using the intermediate of compound 24 2-MeTHF (150 mL, 5.0 vol.), 1,4-dioxane (150 mL, 5.0 vol.), and compound 22 (30.0 g, 1.0 equivalent) were charged into the reactor. KOH (6.6 g, 1.8 equivalent) was added in portions to the mixture at 20–30 °C. The mixture was cooled to -5 to 0 °C, and diethyl sulfate (DES) (16.1 g, 1.6 equivalent) was added dropwise to the mixture at -5 to 0 °C. The mixture was stirred at -5 to 5 °C for 24 hours, and then samples were taken for IPC [HPLC purity: 99.0 A% of compound 24 and 0.7 A% of compound 22 (desired / undesired transisomers in a 5.3:1 ratio)]. HOAc (7.1 g, 1.8 equivalence) was added dropwise to the reactor and stirred for 0.5 h. The reaction mixture was then heated to 20–30 °C, and 10% NaCl aqueous solution (90 mL, 3.0 vol.) was added to the mixture at 20–30 °C. The mixture was stirred for 30 min. The aqueous phase was separated. The organic phase was washed with 10 wt% NaCl aqueous solution (90 mL, 3.0 vol.), concentrated under reduced pressure at 30–40 °C, and replaced with EtOH (150 mL, 5.0 vol.) to give compound 24 in solution form, with 97.0% HPLC purity and 97% corrected yield.

[0230] At 20–30 °C, 142 g of an EtOH solution of compound 24 (equivalent to 30.9 g of pure compound 24, 1.0 equivalent) was added to the reactor. At 25–30 °C, 7.1 g of CaCl2 (1.0 equivalent) was added to the mixture. The mixture was stirred at 25–30 °C for 1 hour. At 25–30 °C, 6.0 g of NaBH4 (2.5 equivalent) was added in portions. The mixture was stirred at 25–30 °C for 24 hours, and then a sample was taken for IPC (HPLC purity: 98.2 A% of compound 11 and 0.3 A% of compound 24). At 25–30 °C, 90 mL of 3M HCl aqueous solution (3.0 vol.) was added dropwise to adjust the pH to 1–2 and stirred for 0.5 hours. H2O (150 mL, 5.0 vol.) was added and stirred for 0.5 hours. Add 30 wt% NaOH aqueous solution (14.5 mL, 0.46 vol.) dropwise at 25-30 °C to adjust the pH to 4.5-5.0 and stir for 0.5 h. Add AcONa (3.1 g, 0.6 equivalent) in portions at 25-30 °C. Heat the mixture to 60-65 °C and stir for 2 h. Cool the mixture to 25-30 °C and stir for 2 h. Filter the mixture and wash the filter cake with H2O (45 mL, 1.5 vol.). Dry the wet filter cake under reduced pressure at 50-55 °C for 14 h. Obtain 26.2 g of a mixture of compounds 11a and 11b as a grayish-white solid, with 99.3% HPLC purity (including the unwanted transisomer: 16.6 A) and 93% uncorrected yield. A mixture of compounds 11a and 11b (26.2 g) was charged into a reactor, and THF (260 mL, 10 vol.) was added to the reactor. 6M HCl (9.5 mL, 0.9 equivalence) was added dropwise to the mixture at 20–30 °C. The mixture was stirred at 20–30 °C for 13 hours. The mixture was filtered, and the filter cake was washed with THF (60 mL, 2.0 vol.). The wet filter cake was dried under reduced pressure at 50–55 °C for 14 hours. 21.3 g of compound 11b as a grayish-yellow solid was obtained, with a HPLC purity of 99.5% (excluding unwanted products) and an uncorrected yield of 75%.

[0231] Example 7. Separation of compounds 11a and 11b in flow A mixture of compounds 11a and 11b (free base) and THF (10 V) was charged into a reactor. The mixture was stirred at 25 ± 5 °C for two hours, then filtered through diatomaceous earth (2.5 wt%). The filtrate was pumped through a flow reactor at 220 °C for 240 seconds, then rapidly cooled to 0 °C for 120 seconds. The effluent, consisting of a >1.58:1 mixture as a transisomer, was collected in the reactor. Compound 11b HCl seed crystals (0.05 wt%) were charged into the reactor. IPA containing HCl (0.25 equivalents, about 0.15 V) was charged into the reactor over a period of not less than five hours, while maintaining the temperature at 25 ± 5 °C. The mixture was further stirred at 25 ± 5 °C for four hours. Additional IPA containing HCl (0.25 equivalents, about 0.15 V) was charged into the reactor over a period of not less than five hours, while maintaining the temperature at 25 ± 5 °C. The mixture was further stirred at 25±5℃ for four hours. The solid was separated by centrifugation and washed with THF (0.5V) to give compound 11b HCl. The separated solid was slurried in IPA (8V) at 60-70℃ for at least five hours. The slurry was cooled to 10-20℃ over at least five hours, stirred further for two hours, and filtered. The separated solid was washed with IPA (2×2.5V) and dried under vacuum at 40±5℃.

[0232] The filtrate from the centrifuge is passed through a chloride ion exchange column to obtain a mixture of compounds 11a / 11b (free base), which can be isomerized in the same manner as described above.

[0233] A schematic diagram of the flow process used to separate compound 11b from compound 11b is shown in Figure 1 middle.

[0234] Example 8. Synthesis procedure of compound 3a.

[0235] Part 1 - Synthesis of compound 3h-(R)-2-formylmorpholine-4-carboxylic acid tert-butyl ester A 3000 L glass-lined reactor (A) was charged with tert-butyl (R)-2-(hydroxymethyl)morpholine-4-carboxylate (compound 3i) (104 kg, 478.7 mol, 1.0 equivalent) and EtOAc (1032 kg, 11 v), followed by a solution of NaHCO3 (120.6 kg, 1436.1 mol, 3.0 equivalent) and TEMPO (0.75 kg, 4.787 mol, 0.01 equivalent) in EtOAc (94 kg, 1 v). The resulting mixture was purged three times with N2 and cooled to -15 to -10 °C.

[0236] Charge 2000 L reactor (B) with TCCA (100.1 kg, 430.8 mol, 0.9 eq) and EtOAc (938 kg, 10 V). Stir the mixture until a clear solution is obtained. Purge the resulting solution three times with N2 and cool to -10 to -5 °C. Then charge the mixture into a 3000 L glass-lined reactor (A) while maintaining the temperature at -10 to 0 °C. Stir the resulting mixture at -5 to 0 °C for 1 hour, at which point GC monitoring shows the reaction is complete.

[0237] Quench the reaction mixture by adding an aqueous solution of Na2S2O3 (prepared by dissolving 520 kg of Na2S2O3 in 832 kg of water) at 0 - 15 °C and stir at <= 15 °C for 30 minutes. Separate the phases and wash the organic-rich phase with water. Extract the combined aqueous phases with EtOAc (703 kg × 4, 7.5 v × 4). Then wash the combined organics with 20 wt% brine (520 kg × 2, 5 V × 2). Then concentrate the organic phase at 15 - 35 °C under reduced pressure (-0.85 to -0.9 MPa) to 4 - 5 v to obtain an EtOAc solution of compound 3h.

[0238] 1 1H NMR (400 MHz, CDCl3, 25 °C) δ 9.69 (s, 1H), 3.98 - 3.65 (m, 5H), 3.16 - 3.03 (m, 2H), 1.52 (s, 9H).

[0239] Table 7. GC method for Example 6, part 1 Part of the 2-compound 3g-(S,Z)-2-(2-(((benzyloxy)carbonyl)amino)-3-methoxy-3-oxo- Synthesis of tert-butyl propionate (1-en-1-yl)morpholino-4-carboxylate Charge a 3000 L reactor with an EtOAc solution of compound 3h (763 kg, containing 675 kg EtOAc and 82.4 kg 51, 382.8 mol, 1.0 eq), methyl 2 - (((benzyloxy)carbonyl)amino)-2-(dimethoxyphosphoryl)acetate (139.4 kg, 421.1 mol, 1.1 eq) and EtOAc (437 kg, 15 v). Purge the mixture three times with N2 and cool to -5 to 0 °C. Then add tetramethylguanidine (110.2 kg, 957 mol, 2.5 eq) dropwise at -5 to 5 °C and stir the reaction mixture for 0.5 hour. Monitor the reaction by GC, showing the reaction is complete.

[0240] The reaction mixture was charged into a 5000 L reactor containing H2O (824 kg, 10 v) and cooled to -5–5 °C. The resulting mixture was stirred for 0.5 h. The organic phase was separated, and the aqueous phase was extracted with EtOAc (400 kg × 2, 5 v × 2). The combined organic phases were washed sequentially with 20 wt% brine (400 kg × 2, 5 v × 2) containing 5 wt% citric acid, 5 wt% NaHCO3 aqueous solution (400 kg × 3, 5 v × 3), and 20 wt% brine (400 kg × 1, 5 v × 1), respectively. The resulting organic layer was concentrated under reduced pressure to about 1.5–2 v at 40–45 °C. THF (371 kg, 5 v) was added to the residue and the mixture was further concentrated under reduced pressure to 1.5–2 v at 40–45 °C. The preceding unit operation was repeated once more to obtain 3g of the compound in the form of a THF solution. The corrected yield and 100% ee were determined by chiral HPLC at 91% HPLC.

[0241] 1 H NMR (400 MHz, CDCl3, 25℃) δ 7.33-7.27 (m, 5H), 7.03 (s, 1H), 6.05(d, J = 4.0 Hz, 1H), 5.10(dd, J = 20, 12 Hz, 2H), 4.20-3.80 (m, 7H), 3.50-3.40(m, 1H), 2.97-2.80 (m, 2H), 1.42 (s, 9H).

[0242] Table 8. GC method used for reactor monitoring in Part 2 of Example 6 Table 9. HPLC method used in Part 2 of Example 6 Table 10. Chiral HPLC methods used in Part 2 of Example 6 Part 3 - Synthesis of compound 3b salt from compound 3f - (S,Z)-2-(((benzyloxy)carbonyl)amino)-3-(4- (tert-butoxycarbonyl)morpholin-2-yl)acrylic acid,(R)-1-phenylethyl-1-amine salt A 204.5 kg solution of the compound in THF (containing 106.3 kg of 52,252.9 mol, 1.0 equivalent and 109 L THF) and THF (380 kg to 532 L, 5 V) were charged into a 2000 L reactor. The mixture was stirred at ambient temperature to obtain a clear solution, which was then cooled to 0–10 °C. An aqueous solution of LiOH monohydrate (15 kg, 354.1 mol, 1.4 equivalent) in water (266 L, 2.5 V) was added to the cold solution over 3.5 hours at ≤10 °C. After the addition was complete, the mixture was heated to 10–15 °C and stirred for another 1 hour at 10–15 °C. The reaction was monitored by HPLC and the reaction was confirmed to be complete.

[0243] Add 0.1 M HCl aqueous solution (106 L, 1 v) to the crude reaction mixture. Concentrate the reaction mixture under reduced pressure to 400 L at 35–40 °C. Add water (532 L, 5 v) to the mixture and extract the mixture twice with MTBE (390 kg × 2, 5 v × 2). Cool the aqueous phase to 0–10 °C and add 1 M HCl aqueous solution (307 kg) dropwise to achieve pH 2–3. Extract the resulting aqueous phase twice further with MTBE (550 kg × 1, 7 v × 1, 390 kg × 1, 5 v × 1). Wash the combined organic phases with brine (500 kg × 2, 5 v × 2) and heat to 20–30 °C, then treat with Na₂SO₄ (100 kg, 1 w) and activated carbon (21 kg, 20 wt%). Stir the mixture at 20–30 °C for 1 hour and filter. The waste solids were rinsed twice with MTBE (150 kg × 2, 1.5 v × 2).

[0244] Compound 3f(() was subjected to treatment at 10-25℃ for 30 minutes. R (30.6 kg, 252.8 mol, 1.0 equivalent) of 1-(+)-1-phenylethylamine was added dropwise to the filtrate solution. The mixture was stirred at 10–25 °C for 18 hours. The resulting solid was separated by filtration and washed twice with MTBE (150 kg × 2, 1.5 v × 2). The wet filter cake was dried under reduced pressure at 40–45 °C to give 108 kg of compound 3b salt as a white solid, with a corrected yield of 77.3% and an ee of 100%.

[0245] 1 H NMR (400 MHz, CDCl3, 25℃) δ 8.01 (brs, 2H), 7.37-7.27 (m, 10H), 5.77 (d, J= 8.0 Hz, 1H), 5.08 (dd, J = 20, 12 Hz, 2H), 4.24-4.20 (m, 2H), 4.09-3.80 (m, 3H), 3.53-3.26 (m, 1H), 2.97-2.80 (m, 1H), 2.70-2.60 (m, 1H), 1.52-1.47 (m, 12H).

[0246] Table 11. HPLC methods used for reaction monitoring in Part 3 of Example 6 Table 12. HPLC purity methods for the salt of compound 3b Table 13. Chiral HPLC methods for the salt of compound 3b Part of the 4a-compound 3c-(S)-2-(((benzyloxy)carbonyl)amino)-3-((S)-4-(tert-butoxycarbonyl) Synthesis of morpholino-2-yl)propionic acid Compound 3b salt (100 kg, 95.37 wt% qNMR), MTBE (740 kg, 10 v), and water (500 kg, 5 v) were charged into a 3000 L reactor. The mixture was stirred for 10 min and then cooled to 0–5 °C. The pH of the mixture was adjusted to pH 2 using 1 M HCl (aqueous solution) (containing 270 kg water and 36 kg 30% HCl aqueous solution) at ≤10 °C. The mixture was stirred for 10 min. The phases were separated. The separated aqueous phase was further adjusted to pH 3.5 using 1 M HCl (aqueous solution) and extracted with MTBE (370 kg, 5 v). The combined organic layers were washed continuously with HCl aqueous solution (0.05 M, containing 100 kg water and 0.5 kg 30% HCl, 1 v) and brine (200 kg, 2 v × 3). The washed organic phase was heated to 15–25 °C and treated with Na₂SO₄ (100 kg, 1 w) and activated carbon (10 kg, 10 wt%). The mixture was stirred at 15–25 °C for 1 hour and filtered through a diatomaceous earth mat (20 kg, 0.2 w). The waste solids were washed twice with MTBE (150 kg × 2, 1.5 v × 2). The combined organic filtrate was further filtered through an organic membrane and concentrated under reduced pressure to about 2 v (200 L) at 35–40 °C. MeOH (400 kg, 5 v) was added to the resulting residue; the solution was again concentrated under reduced pressure to about 2 v (about 200 L) at 35–40 °C. The operation was repeated twice more to give compound 3b (301.5 kg, 25.5 wt% by HPLC, containing 77 kg of 52a) in the form of a MeOH solution.

[0247] The MeOH solution of compound 3b was transferred to a 1000 L pressure reactor and diluted with MeOH (160 kg, 2.4 v, total 6 v). The mixture was purged three times with N2 and further degassed by bubbling N2 at a rate of 8.5 L / min for 2 hours at 15–25 °C. The solution was prepared in a glove box under reduced pressure. S,S A solution of 207.5 g (0.287 mol, 0.152 mol%) of Et-DuPhos-Rh in degassed MeOH (1.8 L) was loaded into a pressure reactor. The reactor was then purged three times with N2 and three times with H2. The reaction solution was stirred at 35-40 °C while maintaining the H2 pressure at 4-10 atm for 5 hours. The reaction was monitored by HPLC, indicating completion. The pressure in the reactor was released and the reactor was purged with N2.

[0248] A saturated aqueous solution of NaHCO3 (200 kg, 2.5 v, containing 180 kg water and 20 kg NaHCO3) was added to the reaction mixture. The reaction mixture was concentrated to 3–4 v under reduced pressure at 45–50 °C, and then diluted with water (200 kg, 2.5 v). The pH was adjusted with an aqueous solution of Na2CO3 (42 kg water and 18 kg Na2CO3). The mixture was stirred for 30 minutes. The phases were separated. The aqueous phase was washed with MTBE (185 kg × 3, 2.5 v × 3). The washed aqueous phase was partitioned again with MTBE (370 kg, 5 v) and the pH was adjusted to pH 2 with 1 M HCl (aqueous solution) (450 kg water and 61.3 kg 30% HCl) at ≤10 °C. The phases were separated, and the pH of the aqueous phase was further adjusted to 2–4 with 1 M HCl (aqueous solution). The acidic aqueous phase was then extracted with MTBE (370 kg × 2, 5 v × 2). The combined organic layers were washed with brine (230 kg × 2, 3 v × 2) and treated with Na₂SO₄ (100 kg, 1 w) and activated carbon (3.9 kg, 5 wt%) for 1 hour at 15–25 °C. The mixture was stirred and then filtered through a diatomaceous earth mat (15 kg, 0.2 w). The waste desiccant and carbon were washed with MTBE (150 kg × 2, 2 v × 2). The combined filtrate was concentrated under reduced pressure to about 2 v (about 150 L) at 35–45 °C, and DCM (500 kg, 5 v) was added to the residue. The mixture was further concentrated under reduced pressure to about 2 v (about 150 L) at 35–45 °C. The preceding unit operation was repeated twice to give compound 3c (221.2 kg, 32.1 wt% by HPLC, containing 71 kg of 57) as a pale yellow DCM solution, with a corrected yield of 96% based on the salt of compound 3b.

[0249] 1 H NMR (400 MHz, CDCl3, 25℃) δ 8.68 (brs, 1H), 7.36-7.28 (m, 5H), 6.05 (app s, 1H), 5.13(dd, J = 20, 12 Hz, 2H), 4.59 (app s, 1H), 3.86-3.45 (m,5H), 3.00-2.80 (m, 1H), 2.60-2.50 (m, 1H), 2.00-1.90 (m, 2H), 1.47 (s, 9H).

[0250] Table 14. HPLC methods used for reaction monitoring in step 4b Table 15. HPLC purity methods for compound 3c Table 1. Chiral HPLC methods for compound 3c Substitutional synthesis of some 4b-compound 3c Alternatively, compound 3b can be directly hydrogenated into a salt without the need for the initial formation of a free base of compound 3b.

[0251] In this procedure, 150 kg of compound 3b salt and 420 kg of MeOH (3.5 v) are charged into the reactor. The reactor and contents are purged three times with N2. The solution is cooled to between -5 and 5 °C and slowly treated with MsOH (26.78 kg, 0.98 equivalents) while maintaining the temperature between -5 and 5 °C. The solution is then heated to 10 to 20 °C and transferred to a hydrogenation reactor. The reactor and contents are purged three times with N2, and then treated with ( S , SThe reaction mixture was treated with a solution of 308.2 g (0.15 mol%) in MeOH (1.5 L). The reaction mixture was purged three times with N2 and then three times with hydrogen. The reaction mixture was stirred at 35-40 °C under 10 atm H2 for five hours. The reaction was monitored by HPLC, indicating completion, and compound 3b was detected to be ≤0.3%. The reaction mixture was cooled to 15-25 °C, purged with N2, transferred to a reactor, diluted with 5 wt% NaHCO3 aqueous solution (600 kg), and concentrated to 5-6 V at 45-50 °C under reduced pressure (-0.0955 MPa to -0.0968 MPa). The concentrate was diluted with water (150 kg, 1 V), adjusted to pH 9-10 with 20 wt% Na2CO3 aqueous solution (180 kg), and partitioned with MTBE (222 kg, 2 V). The aqueous layer was washed twice with MTBE (2 × 222 kg), partitioned with MTBE (390 kg, 3.5 v), and adjusted to pH 1–3 with 1.5 M HCl (669 kg) at 0–10 °C. The phases were separated, and the aqueous layer was further extracted twice with MTBE (2 × 333 kg). The combined organic layer was washed with 0.05 M HCl aqueous solution (301.5 kg) and twice with 20 wt% brine (2 × 300 kg). The organic layer was treated with Na₂SO₄ (150 kg, 1 wt%) and activated carbon (7.6 kg, 5 wt%), stirred at 15–25 °C for 1 hour, and filtered through diatomaceous earth (7.5 kg, 0.05 wt%). The filter aid was washed three times with MTBE (3 × 112 kg). The combined filtrates were solvent-exchanged under reduced pressure at 35–45 °C using a total of 7 V of dichloromethane to give a pale yellow solution of 422.3 g (25 wt%) of compound 3c.

[0252] Part of the 5-compound 3e-(S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-3-((S)-3-(methoxy) Synthesis of tert-butyl morpholine-4-carboxylic acid (tert-butyl ester) of tetrahydropyridazine-1(2H)-yl)-3-oxopropyl)morpholine-4-carboxylic acid A DCM solution containing compound 3d (172 kg, 26.4 wt%, net weight: 45.4 kg, 1.2 equivalents) and DCM (940 kg, 10 v) was charged into a 2000 L glass-lined reactor. The reactor was then purged twice with N2 and cooled to 0–5 °C. The mixture was then allowed to stand at 0–5 °C for 10 minutes. N-Methylmorpholine (31.6 kg, 1.8 equivalents) was added to the mixture, followed by a DCM solution of compound 3c (221 kg, 32.1 wt%, net weight: 70.9 kg, 1.0 equivalents) at 0–5 °C. The mixture was stirred at 0–5 °C for 10 minutes. HOBt (470 g, 0.02 equivalents) and EDCI (46.6 kg, 1.4 equivalents) were then added to the mixture at 0–5 °C. The reaction mixture was stirred at 0–5 °C for 2 hours. The reaction was monitored by HPLC, indicating completion.

[0253] The crude reaction mixture was washed three times consecutively with water (710 kg × 3, 10 v × 3) and once with brine (910 kg, 10 v). The organic solvent portion was concentrated under reduced pressure to about 200 L, and then MeOH (168 kg) was added. The mixture was further concentrated under reduced pressure to about 200 L. The preceding unit operation was repeated once more to give compound 3e (319 kg solution) in the form of MeOH solution, which was used in the next step without further purification.

[0254] 1 H NMR (400 MHz, CDCl3, 25℃) N / A Table 27. HPLC method used for reaction monitoring in Part 5 of Example 6 Table 38. HPLC purity methods for compound 3e Part of the 6-compound 3a-(S)-1-((S)-2-(((benzyloxy)carbonyl)amino)-3-((S)-4-(tert-butyl) Synthesis of hexahydropyridazine-3-carboxylic acid (oxycarbonyl)morpholino-2-yl)propionyl)hexahydropyridazine-3-carboxylic acid A 2000 L glass-lined reactor was charged with MeOH (319 kg, 29.1 wt%, net weight: 92.9 kg, 1.0 equivalent) and MeOH (514 kg, 7 v) containing compound 3e. The reactor was purged twice with N2 and cooled to 3–4 °C. In a 1000 L glass-lined reactor, an aqueous LiOH solution was prepared by dissolving 11 kg of LiOH·H₂O (1.5 equivalent) in 650 kg of water (7 v). The alkaline solution was added to the initial mixture over a 2-hour period at 0–5 °C. The mixture was stirred at 0–5 °C for 2 hours. HPLC monitoring showed the reaction was complete.

[0255] The reaction mixture was neutralized to pH 6-7 at 0-15°C using a 1 M HCl aqueous solution and concentrated under reduced pressure to remove most of the organic solvent. After concentration, MTBE (688 kg, 10 v) was added to the residue, and the pH of the mixture was adjusted to pH 3-4 at or below 15°C using a 1 M HCl aqueous solution. After pH adjustment, solid NaCl (28 kg, 0.3 wt) was added, and the mixture was stirred for 1 hour. The phases were separated. The organic phase was washed with a 20 wt% NaCl aqueous solution (930 kg, 10 v), treated with seed crystals of compound 3a (1.4 kg, 1.5 wt%), and stirred at 15-25°C for 20 hours. Then, n-heptane (635 kg, 10 v) was added to the resulting slurry over a 5-hour period at 15-25°C. The slurry was cooled to 0-5°C and stirred for another 2 hours. The solid was separated by filtration, washed with 1:1 (v / v) MTBE / n-heptane (130 kg × 2) and dried at 45–55 °C under high vacuum (4–7 mbar) for 18 h to give compound 3a (84 kg) as a white solid, determined by qNMR, 98.9 wt%, with a two-step corrected yield of 90.3% based on compound 3c.

[0256] 1 H NMR (400 MHz, DMSO- d 6, 25℃) δ 12.73 (brs, 1H), 7.38-7.31 (m, 5H),7.12 (d, J = 12 Hz, 1H), 5.07-4.95 (m, 4H), 4.05 (d, J = 12 Hz, 1H), 3.74-3.65 (m, 3H), 3.35-3.20 (m, 3H, with DMSO- d (Residual water peaks in 6 overlap), 2.90-2.75 (m, 2H), 2.50 (app brs, 1H), 1.85-1.75 (m, 1H), 1.54-1.52 (m, 2H), 1.50-1.45 (m, 3H), 1.39 (s, 9H).

[0257] Table 4. HPLC methods used for reaction monitoring in Part 6 of Example 6 Table 20. HPLC purity methods for compound 3a Table 21.5 Chiral HPLC methods for compound 3a Example 9. Synthesis procedure of compound 2.

[0258] Compound 17 can be prepared as described, for example, in WO 2021 / 091982.

[0259] Synthesis of Part 1 - Compound 2 (Barium Salt) MTBE (270.35 kg, 8 V) and water (451.00 kg, 10 V) were charged into the reactor at 25 ± 5 °C. Compound 17 maleate (45.65 kg, 1.0 equivalent) and Na₂CO₃ (18.9 kg, 2.1 equivalent (2.08–2.12 equivalent)) were continuously charged into the reactor at 25 ± 5 °C. Additional MTBE (66.65 kg, 2 V) was charged into the reactor at 25 ± 5 °C. The mixture was stirred at 25 ± 5 °C until all solids dissolved. The phases were separated. The separated lower, water-poor layer was extracted once with MTBE (166.40 kg, 5 V). The combined organic layers were washed with 9 wt% NaCl (aqueous solution) (225.0 L, 5 V) and concentrated under reduced pressure to 2–4 V. MTBE was exchanged with THF (3 × 200.6 kg (5V)) by vacuum distillation to approximately 160 L (2–4 V). GC analysis of the solution indicated that it met the standard of MTBE ≤ 1% by area.

[0260] THF (109.15 kg, 2.5 V) and water (13.00 kg, 0.3 V) were charged into the reactor, followed by Ba(OH)₂·8H₂O (13.95 kg, 0.52 equivalents (0.515-0.525 equivalents)). The reaction mixture was stirred at 42 ± 5 °C for 30 hours. The reaction mixture was cooled to 25 ± 5 °C and determined by HPLC. The result for compound 17, 2.4 area % did not meet the standard of ≤2.0 area % . Ba(OH)₂·8H₂O (0.36 kg, 0.01 equivalents) was charged into the reactor at 25 ± 5 °C. The temperature was adjusted, and the reaction mixture was stirred at 42 ± 5 °C for three hours, followed by cooling to 25 ± 5 °C. The HPLC analysis of the reaction met the standard of ≤2.0 area % for compound 17. The reaction mixture was concentrated to 140 L (2–4 V) and then azeotropically dried with THF (7 × 200.25 kg, 5 V) to a final volume of 100 L (2–4 V). The reaction met the KF endpoint of ≤0.5 wt%. Heptane (460.60 kg, 15 V) was added to a second reactor. The THF solution of compound 2 was added dropwise to the heptane. The resulting slurry was stirred for 30 min and then concentrated to 295 L (6–7 V). Additional heptane (91.50 kg, 3 V) was added to the reactor. GC analysis of the reaction indicated that it met the standard of THF ≤ 5 area %. The temperature was adjusted to 25 ± 5 °C and the reaction mixture was stirred for five hours. The solid was separated by centrifugation, washed once with heptane (62.05 kg, 2 V), and dried at 40 ± 5 °C to give 39.96 kg (85.91 mol) of off-white solid.

[0261] 1 H NMR (400 MHz, d6-DMSO, 25℃) δ 4.36 (dd, J=10.4, 2.4 Hz, 1H), 4.08-4.22 (m, 2H), 3.40-3.51 (m, 1H), 3.01-3.07 (m, 2H), 2.76 (d, J =4.8 Hz, 3H), 2.21 (s, 6H), 1.84-2.21 (m, 4H), 1.36 (s, 6H), 0.94-0.98 (m, 3H), 0.71-0.77 (m, 3H) Partial substitution synthesis of compound 2 (barium salt) MTBE (7.0 V, 246.55 kg), water (10 V, 476.5 kg), compound 17 maleate (1.0 equivalent, 47.56 kg), and Na₂CO₃ (2.1 equivalent, 20.15 kg) were charged into a reactor at 20 ± 5 °C. Additional MTBE (1.0 V, 35.25 kg) was added as a wash solution to the same reactor. The mixture was stirred under nitrogen until all solids were dissolved. The phases were separated. The lower, water-poor layer was extracted with MTBE (5 V, 176.35 kg), and the layers were separated. The combined organic layers were washed with 9 wt% NaCl (aqueous solution) (5 V, 265.9 kg) and concentrated under reduced pressure to 2–4 V. MTBE was exchanged with THF (3 × approximately 214 kg (5V)) under reduced pressure distillation to 2–4 V. THF (3.0 V, 112.20 kg), water (0.3 V, 14.25 kg), and Ba(OH)₂·8H₂O (0.52 equivalents, 13.80 kg) were added to the reactor. The reaction mixture was stirred at 42 ± 5 °C for 36 hours, cooled to 25 ± 5 °C, and analyzed by HPLC. The reaction did not meet the standard of ≤1.0 area % for compound 17. Ba(OH)₂·8H₂O (0.05 equivalents, 1501.7 kg) was added to the reactor at 25 ± 5 °C. The reaction mixture was stirred at 42 ± 5 °C for 18 hours, cooled to 25 ± 5 °C, and analyzed by HPLC. The reaction met the standard of ≤1.0 area % for compound 17. 1M HCl (aqueous solution) (0.08 equivalents, 7.21 kg) was added at 20 ± 5 °C. THF was added dropwise to the reaction mixture. The reaction mixture was further stirred at 20 ± 5 °C for 30 min. THF was replaced with toluene (2 × 204 kg (5 V)) and further concentrated to 2–4 V. The mixture met the KF standard of <0.5%. Heptane (322.85 kg, 10 V) was added dropwise at 20 ± 5 °C and the mixture was concentrated to 6–7 V. Additional heptane (100.25 kg, 3 V) was added to the reactor. The reaction mixture was stirred at 20 ± 5 °C for another 5 h. The solid was separated by filtration, washed twice with heptane (33 kg, 1 V), and dried at 45 ± 10 °C for 28 h to give 40.76 kg of white solid, 93.0% yield and 98.5% area purity.

[0262] 1 H NMR (400 MHz, d6-DMSO, 23℃) δ4.37 (d, J=9.2 Hz, 1H), 4.08-4.22 (m, 2H), 3.44-3.50 (m, 1H), 3.00-3.10 (m, 2H), 2.69-2.76 (m, 3H), 1.84-2.30 (m, 4H), 2.21 (s, 6H), 1.36 (d, J =4.0 Hz, 6H), 0.94-0.98 (m, 3H), 0.71-0.77 (m, 3H) Synthesis of part 3-compound 2 (free acid) The barium salt of compound 2 can be converted into a free acid form or various amine salts. Free acids and / or amine salts can provide the ability to improve the purity and / or reactivity of compound 2.

[0263] To prepare the free acid of compound 2, 1.0 equivalent of compound 2 was added at 20±5℃. 1 2% Ba and 4% water were charged into the reactor. Then, an aqueous solution of H₂SO₄ (1M, 0.53 equivalents) was added to the reactor. The resulting mixture was stirred at 20±5°C for 2 hours, and then filtered to remove BaSO₄ through diatomaceous earth. The filtrate was concentrated to 4-5% V. Solvent exchange was performed eight times with toluene (5.0% V). The mixture was concentrated to dryness to obtain a viscous oil. The oil and 10% MTBE were added to the reactor and stirred at 20±5°C for 6 hours for filtration.

[0264] As described in Example 8 below, the free acid of compound 2 can couple with compound 15. Other salts of compound 2 can be formed using maleic acid, tartaric acid, and chiral amine (non-racemic) bases (including cinchonidine, quinine, and (S)-cyclohexylethylamine). These may offer advantages in separation, purification, stability, or coupling.

[0265] Example 10. Synthesis procedure of compound A.

[0266] Part 1 - Compound 12 - (1 2 M)-(S)-2-((S)-2-(((benzoxy)carbonyl)amino)-3-((S)-3- ((3-(5-bromo-1-ethyl-2-(2-((S)-1-methoxyethyl)pyridin-3-yl)-1H-indol-3-yl)-2,2-dimethylpropyl Synthesis of tert-butyl morpholino-4-carboxylate (oxy)carbonyl)tetrahydropyridazine-1(2H)-yl)-3-oxopropyl)morpholino-4-carboxylate Compound 11a hydrochloride (8.60 kg, 1 equivalent) and EtOAc (79 kg, 10 v) were charged into a 500 L glass-lined reactor. The mixture was cooled to 10–20 °C under nitrogen and treated with an aqueous solution of K₂CO₃ (46 kg, 6.5 wt%, 1.1 equivalent). The mixture was stirred at 10–20 °C for 0.5 h. The phases were separated, and the organic phase was washed twice with water (46 kg × 2) and once with brine (46 kg, 25 wt%). The resulting organic layer was concentrated to give compound 11a in the form of an EtOAc solution, which was used directly in step 1.

[0267] Compound 3a (10.6 kg, 1.15 equivalents), HOBt (2.4 kg, 1.0 equivalents), DMAP (1.1 kg, 0.5 equivalents), and EtOAc (112 kg) were charged into a concentrated solution of compound 11a in EtOAc. The mixture was stirred under nitrogen at 15–25 °C and then fractionally charged with DIPEA (9.2 kg, 4.0 equivalents) over 3 hours. EDCI (5.3 kg, 1.5 equivalents) was then fractionally charged over 8 hours at 15–25 °C with stirring. The reaction was monitored by HPLC and the reaction was confirmed to be complete.

[0268] The crude reaction mixture was washed consecutively with 10 wt% citric acid aqueous solution (70 kg × 2), 5 wt% NaHCO3 aqueous solution (70 kg × 2), and brine (58 kg). The crude organic solution was concentrated under reduced pressure at NMT 40 °C to give compound 12 (102 kg, 19.0 wt%) in EtOAc solution form, which was used in the next step without further purification.

[0269] LRMS (ESI+) C 48 H 64 BrN6O9(M+H + The calculated value is: 947.38 Experimental values: 946.1; 948.1 Part 2 - Compound 13 - (S)-1-((S)-2-(((benzyloxy)carbonyl)amino)-3-((S)-morpholine-2- (1) propionyl) hexahydropyridazine-3-carboxylic acid (1) 2 M)-3-(5-bromo-1-ethyl-2-(2-((S)-1-methoxyethyl)pyridine-3- Synthesis of 1H-indole-3-yl)-2,2-dimethylpropyl ester A solution of compound 12EtOAc (102 kg, 19 wt%, 1.0 equivalent) was charged into a 500 L glass-lined reactor and cooled to -10 to 0 °C under nitrogen. A solution of EtOAc in HCl (100 kg, 4 M) was then added to the reactor over 2 hours at -10 to 0 °C under nitrogen. The mixture was stirred for 10–16 hours at -10 to 0 °C under nitrogen. Reaction monitoring indicated completion.

[0270] EtOAc (37 kg) was added to the reaction mixture, and excess HCl was removed by purging the mixture with nitrogen at -10 to 0 °C for 2–4 hours. The slurry was filtered, and the wet filter cake was washed with EtOAc (35 kg). The crude solids were slurried with EtOAc (167 kg) and cooled to -10 to 10 °C under nitrogen. NaHCO3 aqueous solution (168 kg, 7 wt%) was slowly added while maintaining the temperature at -10 to 10 °C. The mixture was heated to 15–25 °C and stirred for 2 hours. The phases were separated, and the organic layer was washed continuously with NaHCO3 aqueous solution (168 kg, 7 wt%) and brine (168 kg, 25 wt%). The crude organic solution was concentrated under reduced pressure at NMT 40 °C to obtain a solution of the crude product in EtOAc. It was then purified by crystallization from a mixture of EtOAc and cyclohexane to give compound 13 as a solid (12.35 kg, 85.2 wt%, 80% corrected yield by two-step determination). C 43 H 56 BrN6O7(M+H + The calculated value is: 847.33 Experimental values: 846.0, 848.0 Part of 3a-compound 14- ((2 2 S,6 3 S,4S)-1 1 -Ethyl-1 2 -(2-((S)-1-methoxyethyl)pyridine- 3-yl)-10,10-dimethyl-5,7-dioxo-6 1 ,6 2 ,6 3 ,6 4 ,6 5 ,6 6 -hexahydro-1 1 H-8-oxa-2(4,2)-morpholine (1)-1(5,3)-indolyl-6(1,3)-pyridazine-hexacycloundecan-4-yl)carbamic acid (1) 2 Synthesis of M)-Benzyl ester Compound 13 (10 kg, 1.0 equivalent), Cs₂CO₃ (11.5 kg, 3.0 equivalent), water (1.00 kg), and 1,4-dioxane (383 kg, 35 v) were charged into a 1000 L reactor. The mixture was stirred for 30 minutes and then degassed by bubbling nitrogen under stirring for 4 hours. P(t-Bu)₃HBF₄ (0.26 kg, 0.08 equivalent) and P(t-Bu)₃PdG₃ (0.51 kg, 0.08 equivalent) were added to the reactor and the reaction mixture was further degassed by bubbling nitrogen for 2 hours. The reaction mixture was stirred at 80–88 °C for 4–7 hours. The reaction was monitored by HPLC, indicating completion.

[0271] The crude reaction mixture was cooled to 15–35 °C, and then EtOAc (42 kg) and water (48 kg) were added. The mixture was stirred at 15–25 °C for 60 min. The phases were separated. The organic phase was washed with brine (53 kg, 25 wt%) and concentrated under reduced pressure at 50 °C using NMT to obtain a concentrated solution (65 kg). The concentrated solution was added to water (55 kg) with stirring. The resulting slurry was stirred at 15–25 °C for 4 h and filtered. The solid was washed with water and recrystallized from the mixture of MeOH and water to give compound 14 as a solid (3.35 kg, 40% corrected yield). 1 H NMR (400 MHz, d6-DMSO, 25℃) δ 8.75 (d, J=4 Hz, 1H), 7.81 (d, J=4 Hz, 1H), 7.42 (d, J =8 Hz, 1H),7.29-7.35 (m, 5H), 7.18 (d, J =8 Hz, 1H), 6.99-7.05 (m, 2H), 7.50 (dd, J =8, 4Hz, 1 H). 5.30 (bd, J =4 Hz, 2 H), 4.99 (q, J =12 Hz, 2 H), 4.10-4.30 (m, 3 H), 3.82-3.95 (m, 2H), 3.58-3.76 (m, 5H), 3.43 (d, J =12 Hz, 1H), 3.22 (d, J=12 Hz,1H), 3.05 (s, 3H), 2.65-2.85 (m, 4H), 1.99 (d, J =4 Hz, 2H), 1.81 (d, J =Hz, 2H), 1.50-1.70 (m, 2H), 1.40 (d, J =4 Hz, 3H), 0.97 (bs, 3H), 0.68 (bs, 3H), 0.57 (bs, 3H) Alternative methods for the synthesis of compound 14 (partial 3b) The following alternative synthesis of compound 14 uses a less expensive, more readily available substrate and a more robust process.

[0272] Under an inert atmosphere, a 1000 mL three-necked round-bottom flask was charged with ground Cs₂CO₃ (23.06 g, 3.0 equivalents), anisole (300 mL, 15V), bis(tri-tert-butylphosphine)palladium(0) (1.2 g, 2.36 mmol, 0.1 equivalents), and water (1.3 mL, 3.0 equivalents). The reaction mixture was sprayed under an inert gas for 10–15 minutes and heated to 85 °C (84–87 °C). A solution of compound 13 (20 g) in anisole (10V) was added over an inert atmosphere for 4–5 hours. After another hour, the reaction was monitored by HPLC to indicate completion. The reaction mixture was cooled to 50 °C and filtered through a Solka-Floc® cellulose filter aid to remove insoluble solids. The reactor and filter aid were washed with anisole (2V).

[0273] A portion of the filtrate (9.33 V = 1 / 3 of the total volume), water (112 mL, 5.6 V), and seed crystals (1 wt%) were charged into the reactor to achieve a 62.5:37.5 ratio of anisole to water. The slurry was aged at room temperature with moderate to vigorous agitation for at least 12 hours. After one hour, the filtrate (4.6 V = 1 / 6 of the total original volume) and water (2.8 V) were simultaneously added to the resulting slurry at the same rate. The mixture was concentrated to 15 V under reduced pressure at 50 °C. A portion of the filtrate (4.6 V = 1 / 6 of the total original volume) and water (2.8 V) were added simultaneously, and the mixture was concentrated, repeated three times. The resulting concentrated slurry was aged at 50 °C for at least 12 hours and further concentrated to 10 V under reduced pressure at 50 °C. If necessary, additional water was added to achieve an 8:2 ratio of anisole / water. The slurry was further concentrated to 7 V under reduced pressure at 50 °C. If necessary, add additional water to achieve a 9:1 anisole / water ratio. Age the slurry at 50°C for three hours, cool to 10°C for six hours, and age at 10°C for at least 12 hours. Separate the solids by filtration, wash seven times with heptane (1V), and dry under reduced pressure at 40°C.

[0274] Part 4 - Compound 15 - (1 2 M)-(2 2 S,6 3 S,4S)-4-amino-1 1 -Ethyl-1 2 -(2-((S)-1-methoxy (Ethyl)pyridin-3-yl)-10,10-dimethyl-6 1 ,6 2 ,6 3 ,6 4 ,6 5 ,6 6 -hexahydro-1 1 H-8-oxa-2(4,2)-morpholina-1 Synthesis of (5,3)-indolaza-6(1,3)-pyridazine-hexacyclic undecaban-5,7-dione Compound 14 (2.26 kg, 1.0 equivalent), 10% Pd / C (0.32 kg), THF (10.0 kg, 5 v), and MeOH (4.5 kg, 2.5 v) were charged into a 50 L pressure reactor. The reactor was stirred at 5 atm H2 and 30–40 °C. During the reaction, the atmosphere was exchanged by venting and refilling with fresh H2 several times.

[0275] After the reaction was monitored by HPLC, the atmosphere was exchanged with N2, and the reaction mixture was filtered through a diatomaceous earth pad. The waste filter aid was washed with a mixture of THF and MeOH. The combined filtrate was then concentrated under reduced pressure at NMT 40°C and diluted with EtOAc (186 kg). The mixture was further concentrated under reduced pressure at NMT 30°C to approximately 67–146 L. EtOAc was added, and the concentration was repeated twice more to remove THF and MeOH. The resulting crude production solution in EtOAc was stirred with SiliaMetSThiol® (0.732 kg) at 15–25°C for 15 hours. After filtration, the crude product in EtOAc was concentrated under reduced pressure at NMT 30°C and then crystallized from the mixture of EtOAc and n-heptane to give compound 15 as a solid.

[0276] HRMS (ESI+) C 35 H 49 Calculated value of N6O5(M+H): 633.37 Experimental value: 633.1 1H NMR (400 MHz, d6-DMSO, 24℃) δ 8.74 (d, J =4 Hz, 1H), 7.78 (d, J =8 Hz, 1H), 7.50 (dd, J =4, 4 Hz, 1H), 7.43 (d, J =8 Hz, 1H), 7.04 (d, J =8 Hz, 1H), 7.00 (s, 1H), 5.14 (bd, J =12 Hz, 1H), 4.51 (bt, J =4 Hz, 1H), 4.36 (bd, J =12 Hz, 1H), 4.25-4.16 (m, 2H), 4.06-3.93 (m, 3H), 3.74-3.56 (m, 5H), 3.45 (d, J =12 Hz, 1H), 3.25 (d, J =12 Hz, 1H),3.14 (s, 3H), 2.78-2.65 (m, 4H), 2.03 (bd, J =12 Hz, 1H), 1.99 (s, 1H), 1.84-1.51 (m, 5H), 1.39 (d, J= 4 Hz, 3H), 1.18 (t, J = 8Hz, 1 H), 0.90 - 0.84 (m, 3 H), 0.72 (bs, 3H), 0.43 (bs, 3H) Part 5 - Compound A - (1 2 M)-1-(4-(dimethylamino)-4-methylpentan-2-ynyl)-N-((2S)- 1-(((2 2 S,6 3 S,4S)-1 1 -Ethyl-12-(2-((S)-1-methoxyethyl)pyridin-3-yl)-10,10-dimethyl-5,7- Dioxo-6 1 ,6 2 ,6 3 ,6 4 ,6 5 [[ID=Z4]] ,6 6 -hexahydro-1 1 H-8-oxa-2(4,2)-morpholina-1(5,3)-indola-6(1,3)- pyridazine heterocyclic undecano-4-yl)amino)-3-methyl-1-oxobutyl-2-yl)-4-fluoro-N-methylpiperidine-4-carboxamide synthesis Charge the compound 15 (1.91 kg, 1.0 equivalent) and DMF (13.9 kg) into a 50 L glass reactor. Stir the mixture at 20 - 30 °C until all solids are dissolved. Charge the compound 2 (1.70 kg, 1.2 equivalents) and DMF (3.8 kg). Stir the mixture at 20 - 30 °C until all solids are dissolved. Charge DIPEA (2.20 kg, 5.50 equivalents) at 20 - 30 °C and cool the mixture to -20 to -10 °C with stirring. Charge ethyl cyanoacetohydroxamate - 2 - oxime (Oxyma) (0.48 kg, 1.1 equivalents) into the reactor and stir the reaction mixture at -20 to -10 °C for 30 minutes. At -20 to -10 °C, charge PyBOP as a DMF solution (1.89 kg dissolved in 3.62 kg DMF, 1.2 equivalents) into the reactor within <= 1 hour. Stir the reaction mixture at -20 to -10 °C for 1 - 3 hours. Monitor the reaction by HPLC, showing that the reaction is complete. <0001Z25>The crude reaction mixture was diluted with EtOAc (3.6 kg) and partitioned with a mixture of EtOAc (65 kg) and brine (25 wt%, 132 kg). The two-phase mixture was stirred at 20–30 °C for 1 hour and filtered through a diatomaceous earth mat. The reactor and spent filter aid wet cake were rinsed with EtOAc (11 kg). The combined filtrates were allowed to stand for 1 hour, and then the phases were separated. The organic layer was washed once with brine (25 wt%, 90 kg × 2). HCl (0.6 M aqueous solution, 71 kg) was added to the separated organic layer at 5–20 °C. The two-phase mixture was stirred at 10–20 °C for 1 hour. The phases were separated, and the upper organic-lean phase was extracted with HCl (0.6 M aqueous solution, 30 kg). The combined aqueous-rich phase was washed three times with EtOAc (34 kg × 3). Add EtOAc (34 kg) to the washed aqueous phase and adjust the pH to 9-10 by adding Na2CO3 aqueous solution (30 wt%) at 10-20°C. Stir the mixture at 10-20°C for 1 hour and separate the phases. Extract the aqueous-lean phase with EtOAc (34 kg) and wash the combined organic-rich phases twice with brine (25 wt%, 90 kg × 2). Then wash the resulting organic layers with acetic acid in brine (prepared by dissolving 0.23 kg glacial acetic acid and 8 kg 25 wt% brine in 115 kg water) (39 kg × 2), Na2CO3 in brine (prepared by dissolving 1.3 kg Na2CO3 and 8 kg 25 wt% brine in 31 kg water) (40 kg), and brine (25 wt%, 92 kg). The crude organic solution was then treated with CUNO® by filtration through a filter cartridge, and the filtrate was concentrated under reduced pressure to approximately 30 L at NMT 40°C. The crude residue was then crystallized by adding seed crystals (0.040 kg) to n-heptane (57 kg).

[0278] The crude product was then further purified by recrystallization from a mixture of EtOAc and n-heptane to obtain purified compound A as a white solid.

[0279] HRMS (ESI+) C 55 H 78 Calculated value of FN9O8(M+H): 1012.6036 Experimental value: 1012.6065 1H NMR (400 MHz, CD3OD, 23℃) δ 8.71 (dd J = 4.8, 1.6 Hz, 1H), 7.83 (d,J = 7.2 Hz, 1H), 7.50 (dd, J =8.0, 4.8 Hz, 1H), 7.39 (d, J = 8.0 Hz, 1H), 7.11 (s, 1H), 7.07 (dd, J = 9.0, 2.0Hz, 1H), 5.67 (d, J = 8.8 Hz, 1H), 4.62 and 4.52 (d, J = 10.0 Hz, 1H (as a rotational isomer), 4.46 (d, J = 12.4 Hz, 1H), 4.28-4.37 (m, 2 H), 4.24 (q ( J = 6.4 Hz, 1H),4.12-4.17 (m, 1H), 3.50-4.00 (m, 9H), 3.28 (d, J = 10.8 Hz, 1H), 3.10-3.20 and 2.90-3.00 (m, 8H, as a rotational isomer), 2.60-2.80 (m, 4H), 2.35 (s, 3H), 2.34 (s, 3H), 2.05-2.35 (m, 7H), 1.85-1.95 (m, 2H), 1.60-1.73 (m, 2H), 1.46 (s, 3H), 1.45 (s, 3H), 1.44 (s, 3H), 0.96 and 1.02 (d, J = 6.4 Hz, 3H (as a rotatory isomer), 1.00–1.10 (m, 3H), 0.83 and 0.87 (dd, J = 6.8, 2.0 Hz, 3H (as a rotational isomer), (0.77 (bs, 3H), 0.64 (bs, 3H) Part 6 - Direct synthesis of compound A without separating compound 15 Alternatively, compound A can be prepared in a condensation process that avoids the separation and characterization of compound 15. This process allows for a more robust and cost-effective approach.

[0280] Compound 14 (34.8 kg), 10% Pd / C, water wetting (0.20X), THF (5V), and iPrOH (3V) were charged into a pressure reactor. The mixture was stirred at 30–40°C for 32 hours under hydrogen (0.5 MPa). After the reaction was completed as monitored by HPLC, the atmosphere was exchanged with N2, and the reaction mixture was filtered through a diatomaceous earth pad to remove the spent Pd / C catalyst. The spent filter aid was washed with a mixture of THF and iPrOH. The combined filtrate was mixed with a silica-thiol scavenger (0.1X) at 20–30°C for 14 hours to reduce residual palladium. The mixture was filtered and the spent scavenger was washed with a mixture of THF and iPrOH. The filtrate was concentrated to 3V under reduced pressure and diluted with DMF (3V).

[0281] Compound 2 (0.60 equivalents), DIPEA (5.5 equivalents), and DMF (9V) were added to a concentrated solution of compound 15. The mixture was cooled to between -50°C and -10°C. Oxyma (1.1 equivalents) and PyBOP (1.2 equivalents) were rapidly and continuously added to a solution of DMF (2V) at -40°C to -30°C over a period not exceeding 30 minutes. The reaction mixture was stirred at -20°C to -10°C for 3 hours. The reaction was monitored by HPLC to indicate completion.

[0282] The crude reaction mixture was added dropwise to a mixture of EtOAc (20 kg) and 25 wt% brine (30 V) over one hour. The two-phase mixture was stirred at 20–30 °C for 1 hour and filtered through diatomaceous earth (0.5 ×). The waste filter aid was washed with EtOAc (1 V). The combined organic phases were washed twice with 25 wt% brine (20 V) and partitioned with 0.6 M HCl (aqueous solution) (18 V) at 10–20 °C. The organic-lean layer was extracted with 0.6 M HCl (aqueous solution) (8 V). The combined aqueous phases were washed three times with EtOAc (10 V), partitioned with EtOAc (10 V), and neutralized to pH 9.0–10.0 with 30 wt% Na₂CO₃ (aqueous solution) (approximately 7.2 ×) at 10–20 °C. The aqueous-lean layer was washed with EtOAc (10 V). The combined organic layers were washed twice with 25 wt% brine (20 V), twice with water containing 0.2 wt% AcOH and 3 wt% NaCl (10 V), once with water containing 3 wt% Na2CO3 and 5 wt% NaCl (10 V), once with 25 wt% brine (20 V), and filtered through a carbon filter. The reactor and filter were rinsed with EtOAc. The combined filtrate was concentrated to 7-8 V under reduced pressure at <40 °C and loaded into a mixture of n-heptane (21.6 V) and seed crystals (0.7 wt%) at 25-35 °C. The resulting slurry was cooled to between 15 and 25 °C for four hours, aged for eight hours, and filtered. The solid was washed with a 3:1 mixture of n-heptane and EtOAc (2.0 X) and dried under reduced pressure at 40-50 °C for 30 hours to obtain crude compound A as a white solid.

[0283] Part 7 - Purification of Compound A Crude compound A was dissolved in EtOAc (4.0V) and treated with water (0.08X) and DIPEA (0.015X). The solution was stirred at 35-45°C for 30 minutes. Heptane (4.0V) was added at 35-45°C for 30 minutes. Seed crystals (1 wt%) were added at 35-45°C. The mixture was stirred at 35-45°C for eight hours. The resulting slurry was cooled to between 20°C and 30°C over six hours, aged with stirring for 30 minutes, then heated to 35-45°C over one hour and aged for 30 minutes. This temperature cycle was repeated once or twice. A mixture of 10.5:1 v / v heptane / EtOAc (6.1X) was added after six hours. The slurry was cooled to between 5°C and 15°C over eight hours, aged for eight hours, and then filtered. The solid was washed twice with a mixture of 2.5:1 v / v n-heptane / EtOAc (2.0V) and dried under reduced pressure at 50°C to give compound A as a white solid.

[0284] Other implementation plans Although the invention has been described in conjunction with specific embodiments thereof, it should be understood that the invention is capable of further modifications, and this application is intended to cover any variations, uses or adaptations of the invention that deviate from the disclosure of this invention and are generally followed in accordance with the principles of the invention and included within the scope of known or customary practices in the field to which this invention pertains, and may be applied to the essential features described herein.

[0285] All publications, patents and patent applications are incorporated herein by reference in their entirety as if each individual publication, patent or patent application were specifically and individually incorporated in its entirety.

Claims

1. A method for preparing compound 4a: The method includes contacting compound 4 with one or more ketone reductases to produce compound 4a: 。 2. The method of claim 1, further comprising combining compound 4a with a methyl source to produce compound 4b: 。 3. The method of claim 2, wherein compound 4a is combined with a methyl source and a base to produce compound 4b.

4. The method according to claim 3, wherein the base is a tert-butoxide.

5. The method according to any one of claims 1-4, wherein compound 4 is contacted with NADP and one or more ketone reductases in the presence of a buffer to produce compound 4a, and compound 4a is formed in a yield of at least 85%.

6. The method according to any one of claims 2-4, wherein the methyl source is MeI.

7. A method for preparing compound 8 or a salt thereof: The method includes: a) Couple compound 4b and compound 20 to form compound 21: ； as well as b) Contacting compound 21 and compound 10 to form compound 8: 。 8. The method according to claim 7, wherein the coupling in step a) is performed in the presence of a zinc source and a copper source.

9. The method of claim 7, wherein the contact in step b) is carried out in the presence of sulfuric acid.

10. The method according to claim 7, wherein the coupling in step a) is carried out in the presence of PrMgCl•LiCl, ZnCl2 and CuCl•2LiCl; and the contact in step b) is carried out in the presence of sulfuric acid.

11. The method according to any one of claims 7 to 10, wherein the method prepares the hemisulfate of compound 8.

12. A method for preparing compound 6: The method includes: a) Make compound 7 double N -Methylation to form compound 7c: ； b) Carboxylating compound 7c to form compound 7a: ； c) Protonate compound 7a to form compound 7b: ； as well as d) Protonate compound 7b to form compound 6: 。 13. The method according to claim 12, wherein the double... N -Methylation includes contacting compound 7 with an alkylating agent and a reducing agent; and carboxylation in step b) includes contacting compound 7 with a base.

14. A method for separating compound 11a and compound 11b: The method includes: a) Heating a mixture of compounds 11a and 11b in a solvent or a mixture of solvents for a period of time; b) A mixture forming a salt of compound 11a and a salt of compound 11b; and c) Separate a mixture of salts of compound 11a and salts of compound 11b.

15. The method of claim 14, wherein the salt is a hydrochloride salt.

16. The method according to claim 14 or 15, wherein the salt is formed in an alcohol solvent.

17. The method according to claim 14 or 15, wherein the mixture of compound 11a and compound 11b forms compound 11. Compound 11 was prepared by reducing compound 24: 。 18. The method of claim 17, wherein the reduction comprises contacting compound 24 with sodium borohydride in the presence of calcium chloride.

19. A method for preparing compound 3a: ， The method includes: a) Deprotonation of compound 3b using a chiral base, thereby forming a diastereomer salt of compound 3b: ； b) Reduce the diastereomeric salt of compound 3b to form compound 3c: ； c) Couple compound 3c with compound 3d or its salt to form compound 3e; ； as well as d) Hydrolyze compound 3e to form compound 3a: 。 20. The method according to claim 19, wherein the chiral base in step a) is compound 3f: 。 21. The method of claim 19, wherein compound 3b is prepared by hydrolyzing compound 3g to produce compound 3b: 。 22. The method according to any one of claims 19 to 21, wherein: The reduction in step b) involves contacting compound 3b with hydrogen gas in the presence of a rhodium catalyst and a chiral ligand. The coupling in step c) is carried out in the presence of a coupling reagent; and The hydrolysis in step d) is carried out in the presence of hydroxide salt.

23. A method for preparing compound A: Compound A The method includes: a) Couple compound 11a and compound 3a to form compound 12: ； b) Deprotecting compound 12 to form compound 13: ； c) Couple compound 13 to form compound 14: ； d) Deprotecting compound 14 to form compound 15: ;as well as e) Couple compound 15 and compound 2 to form compound A: 。 24. The method of claim 23, wherein the coupling in step a) comprises contacting compounds 11a and 3a with HOBt, EDCl and a base.

25. The method of claim 23, wherein the removal of the protecting group in step b) is carried out in the presence of an acid; and the removal of the protecting group in step d) is carried out in the presence of hydrogen and a palladium catalyst.

26. The method according to any one of claims 23 to 25, wherein the coupling in step c) is carried out in the presence of a carbonate base and a palladium catalyst, and the coupling in step e) is carried out in the presence of a coupling agent and a base.

27. A compound having the structure of compound 12: Or its salt.

28. A compound having the structure of compound 13: Or its salt.

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