Process for synthesizing naphthyridine derivatives and intermediates thereof

Abstract

The present disclosure relates to Compound A, Compound E, Compound I, TIFF2024532339000121.tif37170, their salts and / or their stereoisomers are provided.

Description

[Background technology]

[0001] Naphthyridine derivatives and intermediates have been shown to be important in many biological applications. Large amounts of material are required to investigate their effectiveness. Therefore, there is a need for an efficient, cost-effective process for preparing naphthyridine derivatives that is suitable for large scale. Summary of the Invention [Means for solving the problem]

[0002] The present disclosure relates to compound A [ka] (In the formula, X 1 are independently NH, NR 1 , O, S or SO 2 and Y1 is -CN, -Cl, -CHO, -COOH, -CONHR 1 , -CON(R 1 )2 or -CO2R 1 ;Z 1 and Z 2 each is independently H, F, or C1-C6 alkyl; and each R 1 are independently C1-C6 alkyl. or a salt thereof, comprising the steps of: (a) Compound B [ka] (In the formula, Y 1A -CN, -Cl, -CONHR 1 , -CON(R 1 )2 or -CO2R 1 and R B is hydrogen or -COOR 4 and R 4 is C 1~6 (It is alkyl) with a first transition metal catalyst and a boron-containing compound to form R B is hydrogen, compound C [ka] (In the formula, R 2 and R 3 each is independently H or C1-C6 alkyl, or when taken together with the boron and oxygen atoms to which they are attached, forms a 5-, 6-, or 8-membered cyclic boronate. or R B -COOR 4 When the compound C' is [ka] and optionally isolating compound C or compound C'; (b) Compound C or compound C' is mixed with compound D [ka] (In the formula, X 1A is NR 7 , O or S, and R 7 is C1-C6 alkyl, benzyl or p-methoxybenzyl) and a second transition metal catalyst to form compound A or a salt thereof. and LG is a leaving group. 1 In embodiments where is CHO or COOH, the process further comprises the steps of: 1 , -CON(R 1 )2 or -CO2R 1 to CHO or COOH. 1 In embodiments where X is NH, the process further comprises: 1A to NH.

[0003] The present disclosure relates to compound E [ka] (In the formula, X 2 is NR 1 , O or S; R1 is C1-C6 alkyl; Y 2 is H, C1-C6 alkyl or C1-C6 haloalkyl; and Z 3 , Z 4 , Z 5 and Z 6 each is independently H, C1-C6 alkyl, or chloride. A process for preparing a compound F, its stereoisomer, a salt thereof or a salt of a stereoisomer thereof, comprising the steps of: [ka] or a salt thereof with an imine reductase (IRED) to form compound E, a stereoisomer thereof, a salt thereof, or a salt of a stereoisomer thereof.

[0004] The present disclosure relates to compound I [ka] , or a stereoisomer thereof, a salt thereof, or a salt of a stereoisomer thereof, comprising reacting compound A' or a salt thereof with compound E, or a stereoisomer thereof, a salt thereof, or a salt of a stereoisomer thereof, [ka] (In the formula, X 1 , NH, NR 1 , O, S or SO2; R 1 is C1-C6 alkyl; X 2 is NR 1 , O or S; Y 2 is H, C1-C6 alkyl or C1-C6 haloalkyl; Z 1 and Z 2 each is independently H, F, or C1-C6 alkyl; and Z 3 , Z 4 , Z 5 and Z 6 each is independently H, C1-C6 alkyl, or chloride. and a coupling agent to form compound I, a stereoisomer thereof, a salt thereof, or a salt of a stereoisomer thereof.

[0005] In this specification, [ka] Also provided is a compound having the structure: DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Provided herein are processes for preparing various compounds useful as active pharmaceutical ingredients (APIs) and / or synthetic intermediates thereof.

[0007] In some embodiments, the disclosed processes are carried out in batch mode (i.e., "batch chemistry" or "fed-batch mode"). In other embodiments, the disclosed processes are carried out using a continuous manufacturing process (i.e., "flow chemistry" or "continuous chemistry"). As used herein, continuous manufacturing refers to an integrated system of operational units with constant flow (steady or cyclic). The disclosed processes utilizing continuous chemistry can provide for the production of gram to metric ton quantities of active pharmaceutical ingredient (API). In some embodiments, the disclosed processes consist of a combination of steps carried out using batch chemistry and steps carried out using continuous chemistry.

[0008] In some embodiments, the present disclosure provides a process for preparing Compound A, or a salt thereof, as shown in Scheme 1 and described herein. Scheme 1A. Exemplary Process for Compound A or a Salt Thereof [ka] Scheme 1B. Exemplary Process for Compound A or a Salt Thereof [ka]

[0009] In some embodiments, the present disclosure provides a process for preparing compound E, a stereoisomer thereof, a salt thereof, or a salt of a stereoisomer thereof, as shown in Scheme 2 and described herein. Scheme 2. Exemplary Process for Compound E or a Salt Thereof [ka]

[0010] In some embodiments, the present disclosure provides a process for preparing compound I, a stereoisomer thereof, a salt thereof, or a salt of a stereoisomer thereof, as shown in Scheme 3 and described herein. Scheme 3. Exemplary Process for Compound I or a Salt Thereof [ka]

[0011] As described herein, the disclosure provides processes for preparing compound I and starting materials / intermediates (e.g., compounds A, A', A1, C, C', C1, C1-a, E, (S)-E and salts thereof, stereoisomers thereof and salts of stereoisomers thereof). In some embodiments, the disclosed processes advantageously provide compound E in as few as three steps from commercially available materials while utilizing enzymatic reactions. For example, the sequence of reactions converting compounds F / F' to compound E described herein includes enzymatic reduction, where the reduction catalyzed by an imine reductase (IRED) stereochemically controls the product (e.g., (S)-compound E). Chiral control by enzyme-mediated processes is often highly selective, and in this example, the disclosed processes provide the desired enantiomer with a stereochemical purity of greater than 99% enantiomeric excess (ee). Moreover, in some embodiments, the disclosed process advantageously provides compound A in two steps from commercially available raw materials in a process consisting of a very simple and efficient one-step iridium C-H insertion / boronation followed by a palladium-catalyzed Suzuki reaction.

[0012] The disclosed process advantageously provides compound A in a one-step procedure using a transition metal (e.g., iridium) / palladium catalyzed reaction. For example, in some embodiments, the use of an iridium C-H insertion / boronation reaction allows the process to begin with the cheaper and more readily available 5-aminopicolinonitrile rather than the methyl 5-amino-4-bromopicolinate used in other syntheses. The use of methyl 5-amino-4-bromopicolinate also reduces yields due to the need to isolate the boronate before the second Suzuki step. The disclosed process provides a one- or two-step process with improved yields, thereby increasing efficiency, shortening manufacturing schedules, and reducing costs considerably due to the difference in starting materials required.

[0013] Furthermore, the disclosed process is more cost-effective than conventional processes. For example, compound E requires a long lead time to be synthesized in large quantities in a multi-step process. In contrast, the disclosed process provides compound E much more efficiently, requiring only three steps from commercially available starting materials, two of which are carried out exclusively under aqueous conditions, making it more cost-effective.

[0014] In various embodiments, the disclosed process for compound E offers advantages over conventional processes that employ multiple steps, many of which are low yielding and require the use of expensive catalysts and chiral ligands as well as the use of high pressure. In contrast, the disclosed process consists of a biocatalytic reduction that can be carried out in water and at low temperatures (e.g., 20-50° C.), avoiding the need for high pressure. Furthermore, the biocatalytic process requires no extraction or distillation, and only minimal unit operations of pH adjustment and product filtration, resulting in short batch cycle times.

[0015] The term "halide" or "halo" refers to F, CI, Br, or I.

[0016] The term "alkyl" as used herein refers to a saturated straight or branched chain hydrocarbon. The term "cycloalkyl" refers to a saturated non-aromatic carbon-only ring system having 3 to 6 ring carbon atoms. Examples of C1-C6 alkyl groups include, but are not limited to, methyl, ethyl, isopropyl, n-propyl, isobutyl, n-butyl, sec-butyl, tert-butyl, isopentyl, n-pentyl, neopentyl, sec-pentyl, 3-pentyl, sec-isopentyl, active pentyl, isohexyl, n-hexyl, sec-hexyl, neohexyl, and tert-hexyl. Contemplated cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

[0017] The term "haloalkyl" refers to an alkyl substituted with one or more (e.g., 1, 2, 3, 4, 5, or 6) halogen atoms. This term includes perfluoroalkyl groups such as -CF3 and -CF2CF3.

[0018] Compound A In some embodiments, the present disclosure provides compound A [ka] (In the formula, X 1 are independently NH, NR 1 , O, S or SO2; Y 1 -CN, -Cl, -CHO, -COOH, -CONHR 1 , -CON(R 1 )2 or -CO2R 1 ;Z 1 and Z 2 each is independently H, F, or C1-C6 alkyl; and each R 1 are independently C1-C6 alkyl. or a process for preparing a salt thereof.

[0019] In some embodiments, in conjunction with any other embodiment above or below, X 1 is O.

[0020] In various embodiments, in conjunction with other embodiments described above or below, Y 1 is -CN, -Cl, or -CO2H. For example, in some embodiments, Y 1 is -CN, and in some embodiments, Y 1 is -CO2H. Further, in some embodiments, Y 1 is -Cl.

[0021] In some embodiments, in conjunction with any other embodiment above or below, Z 1 and Z 2 are H, respectively.

[0022] In some embodiments, in conjunction with other embodiments above or below, compound A is A': [ka] It has the structure:

[0023] In some embodiments, compound A' is CHO, CN, CONHR 1 or CON(R 1 )2 Y 1 In some embodiments, compound A' has the following structure: [ka] has.

[0024] In some embodiments, in conjunction with other embodiments above or below, compound A is selected from the group consisting of A1: [ka] It has the structure:

[0025] In some embodiments, in conjunction with other embodiments above or below, compound A is selected from the group consisting of A2: [ka] It has the structure:

[0026] Compound E In some embodiments, the present disclosure provides compound E [ka] (In the formula, X 2 is NR 1 , O or S; R 1 is C1-C6 alkyl; Y 2 is H, C1-C6 alkyl or C1-C6 haloalkyl; and Z 3 , Z 4 , Z 5 and Z 6 each is independently H, C1-C6 alkyl, or chlorine. The present invention provides a process for preparing a stereoisomer thereof, a salt thereof, or a salt of a stereoisomer thereof.

[0027] As described herein, in some embodiments, compound E is enriched in the (S)-stereoisomer. [ka] As used herein, "enriched in the (S)-stereoisomer" refers to the (S)-stereoisomer of the product having a higher stereochemical purity (measured by enantiomeric excess) than the starting material. In some embodiments, the enantiomeric excess of the product (S)-compound E can be 50% or more (e.g., 75%, 80%, 85%, 90% or 95% or more). In some embodiments, compound F is converted to (S)-compound E with an ee of greater than 99%. In some embodiments, compound E has the following structure: [ka] It is an (S)-compound having the formula:

[0028] In some embodiments, the (S)-compound E has the following structure: [ka] It is a salt having the formula:

[0029] Compound I In various embodiments, the present disclosure provides compound I [ka] (In the formula, X 1 , NH, NR 1 , O, S or SO2; X 2 is NR1, O or S; R 1 is C1-C6 alkyl; Y 2 is H, C1-C6 alkyl or C1-C6 haloalkyl; Z 1 and Z2 are each independently H, F, or C1-C6 alkyl; and Z 3 , Z 4 , Z 5 and Z 6 each is independently H, C1-C6 alkyl, or chloride. The present invention further provides a process for preparing the stereoisomer, a salt thereof, or a salt of the stereoisomer.

[0030] In some embodiments, compound (I) is the (S)-stereoisomer of compound I or a salt thereof. [ka]

[0031] In some embodiments, compound I has the following structure: [ka] or a salt thereof.

[0032] Compound B Compound B has the following structure: [ka] (In the formula, each Z 1 and Z 2is as defined for compound A, and R B is hydrogen or -COOR 4 and Y 1A -CN, -Cl, -CONHR 1 , CON(R 1 )2 or CO2R 1 and R 4 is C1-C6 alkyl In some embodiments, Y 1A is CN. In some embodiments, Y 1A is Cl. In some embodiments, R B is tert-butyloxycarbonyl (Boc).

[0033] In some embodiments, compound B has the structure [ka] has.

[0034] In some embodiments, compound B has the structure B1: [ka] In some embodiments, compound B has the formula B1': [ka] In some embodiments, compound B has the structure: [ka] It has the structure:

[0035] Compound C and Compound C' In some embodiments, compound C has the following structure: [ka] (In the formula, R 2 and R 3are each independently H or C1-C6 alkyl, or when taken together with the boron and oxygen atoms to which they are attached form a 5-, 6-, or 8-membered cyclic boronate; Y 1A -CN, -Cl, -CONHR 1 , -CON(R 1 )2 or -CO2R 1 R1 is C1-C6 alkyl, and Z 1 and Z 2 each is independently H, F, or C1-C6 alkyl. has.

[0036] In some embodiments, compound C is C1: [ka] It has the structure:

[0037] In some embodiments, compound C is C1-a: [ka] It has the structure:

[0038] In some embodiments, compound C' has the following structure: [ka] (In the formula, R 2 and R 3 are as defined for compound C, and R 4 is C1-C6 alkyl Optionally, compound C' has the following structure: [ka] has.

[0039] In some embodiments, compound C' is C'-2: [ka] It has the structure:

[0040] In some embodiments, compound C' has C'-3: [ka] It has the structure:

[0041] In some embodiments, compound C' has C'-4: [ka] It has the structure:

[0042] In some embodiments, compound C' is C'-5, C'-6 or C'-7: [ka] It has the structure:

[0043] Optionally, compound C' has the structure C'-5. Optionally, compound C' has the structure C'-6. Optionally, compound C' has the structure C'-7.

[0044] Compound D In some embodiments, compound D has the following structure: [ka] (In the formula, X 1A is NR 7 , O or S, and R 7 is C1-C6 alkyl, benzyl or p-methoxybenzyl, and LG is a leaving group. Compound A has X 1 is compound D's X 1A In an embodiment different from the above, the process further comprises: 1A X 1 For example, converting X of compound A to 1 In embodiments where X is NH, the process further comprises: 1Aconverting

[0045] The leaving group can be any suitable leaving group. Particularly contemplated leaving groups include, for example, sulfonate ester, sulfamate or halide. In some embodiments, the leaving group is tosyl, mesyl, nosyl or triflyl. In some embodiments, the leaving group is a halide (e.g., F, Cl, Br or I). Optionally, the halide leaving group is Cl, Br or I.

[0046] In some embodiments, compound D is D1: [ka] It has the structure:

[0047] Compound F In some embodiments, compound F has the following structure: [ka] (In the formula, X 2 , Y 2 , Z 3 , Z 4 , Z 5 and Z 6 each of which is as defined for compound E. has.

[0048] In some embodiments, compound F is F': [ka] (wherein PG is a protecting group). It has the structure:

[0049] The protecting group is any suitable protecting group for the amine nitrogen. In some embodiments, the protecting group is selected from the group consisting of tert-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz) and trimethylsilyl (TMS). In some embodiments, the leaving group is Boc. In some embodiments, the leaving group is Cbz. In some embodiments, the leaving group is TMS.

[0050] In some embodiments, compound F' has the following structure: [ka] has.

[0051] Compound G In some embodiments, the disclosed process includes forming compound F or compound F' by combining compound G or a salt thereof, compound H and an organometallic reagent or magnesium metal. In some embodiments, compound G has the following structure: [ka] (In the formula, X 2 is as defined for compound E, and PG is a protecting group as defined for compound F'. In some embodiments, the protecting group of compound G is Boc.

[0052] In some embodiments, compound G has the following structure: [ka] has.

[0053] Compound H In some embodiments, compound H has the following structure: [ka] (In the formula, Y 2 And Z 3 , Z 4, Z 5 and Z 6 are as defined for compound E, and X h is Cl, Br or I. has.

[0054] In some embodiments, X h is I. In some embodiments, X h is Br. In some embodiments, Y 2 is CF3. In some embodiments, Z 3 , Z 4 , Z 5 and Z 6 Each of is H.

[0055] In some embodiments, compound H has the following structure: [ka] has.

[0056] Process for preparing compounds A and B The disclosed process for preparing compound A or a salt thereof includes (a) mixing compound B with a first transition metal catalyst and a boron-containing compound to form compound C, and (b) mixing compound C with compound D and a second transition metal catalyst to form compound A or a salt thereof. In some embodiments, compound C is compound C1 or C1-a.

[0057] Compound B is mixed with an appropriate amount of a first transition metal catalyst and a boron-containing compound to form compound C. In some embodiments, compound B is mixed with less than 1 equivalent (eq) of a boron-containing compound (e.g., 0.5 eq of a boron-containing compound) to form compound C.

[0058] Compound C is mixed with an appropriate amount of compound D and a second transition metal catalyst to form compound A or a salt thereof. In some embodiments, compound C is mixed with at least one equivalent of compound D (e.g., 1.0, 1.1, 1.2, 1.3, 1.4, or 1.5 eq or more of compound D). In some embodiments, X 1A X 1 is converted to

[0059] In some embodiments, the process further comprises isolating compound C (e.g., by crystallization or chromatography). In some embodiments, the process for preparing compound A or a salt thereof is carried out in a vessel without isolating compound C (e.g., a "one-pot" process). In such cases, compound C proceeds directly to step (b) without isolation.

[0060] In some embodiments, the disclosed process further comprises preparing compound B (e.g., compound B1) or a salt thereof using a biocatalytic reaction (e.g., biocatalytic reduction). Aspects of the disclosed process are described in Bornadel et al. "Process Development and Protein Engineering Enhanced Nitroreductase-Catalyzed Reduction of 2-Methyl-5-nitropyridine." Org. Process Res. Dev. 25, 3, (2021): 648-653, the disclosure of which is incorporated herein by reference.

[0061] In some embodiments, the disclosed process comprises 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine. [ka] or a salt thereof to prepare compound B1 or compound B1'.

[0062] By way of example, some embodiments of the disclosed process include combining 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine or a salt thereof with a nitroreductase in a solvent to form Compound B1 or Compound B1′ or a salt thereof.

[0063] The nitroreductase may be any suitable nitroreductase capable of converting 2-cyano-5-nitropyridine, 2-chloro-5-nitropyridine or a salt thereof to Compound B1 or a salt thereof. Suitable nitroreductases are commercially available (e.g., Johnson Matthey, London, UK). Suitable non-limiting examples of nitroreductases include NR-17, NR-X4-mut2, NR-X4-mut10, NR-X18, NR-X27, NR-X30, NR-X32, NR-X36, NR-X39, NR-X41, NR-X53, NR-X54, and combinations thereof, available from Johnson Matthey. In some embodiments, the nitroreductase is NR-17 or NR-X36.

[0064] In the disclosed process, an appropriate amount of nitroreductase is employed to provide Compound B1 or Compound B1' or a salt thereof. If too little NR-17 or NR-X36 is present, the enzymatic reaction may not proceed at an appropriate rate. In contrast, if too much NR-17 or NR-X36 is present, the reaction may not be cost-effective and may produce undesirable by-products. In some embodiments, NR-17 is present in an amount of 0.1 to 10% by weight based on 2-cyano-5-nitropyridine (e.g., 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9 or 10 wt.% of NR-17). Thus, NR-17 or NR-X36 may be present in an amount between and including any of the aforementioned values ​​based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine, for example, 0.1-10, 0.2-9.9, 0.3-9.8, 0.4-9.7, 0.5-9.6, 0.6-9.5, 0.7-9.4, 0.8-9.3, 0.9-9.2, or 1-9.1% by weight (e.g., 1-10, 1-9, 2-9, 2-8, 3-8, 3-7, 4-7, 4-6, 5-6% by weight based on 2-cyano-5-nitropyridine). In some embodiments, NR-17 or NR-36 is present in an amount of 5-7% by weight based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine.

[0065] In some embodiments, the biocatalytic reduction of 2-cyano-5-nitropyridine, 2-chloro-5-nitropyridine or a salt thereof in the disclosed process further comprises mixing 2-cyano-5-nitropyridine, 2-chloro-5-nitropyridine or a salt thereof and a nitroreductase in the presence of one or more of glucose dehydrogenase (GDH), a third transition metal catalyst, a cofactor, a reducing agent, or a buffer. In some embodiments, the disclosed process comprises mixing 2-cyano-5-nitropyridine, 2-chloro-5-nitropyridine or a salt thereof and a nitroreductase in the presence of glucose dehydrogenase (GDH), a third transition metal catalyst, a cofactor, a reducing agent, and a buffer. In embodiments including a cofactor, a reducing agent, and GDH, the cofactor (e.g., NADPH) is regenerated via catalytic oxidation of the reducing agent (e.g., glucose) by GDH.

[0066] Third transition metal catalyst As described herein, some embodiments of the disclosed process include mixing 2-cyano-5-nitropyridine, 2-chloro-5-nitropyridine or a salt thereof with a nitroreductase in the presence of a third transition metal catalyst. In some embodiments, the third transition metal catalyst includes vanadium, iron, copper, or a combination thereof. In some embodiments, the third transition metal catalyst includes vanadium. A suitable form of vanadium is ammonium metavanadate (NH4VO3) or vanadium(V) oxide (e.g., vanadium(IV) oxide and / or vanadium(V) oxide). In some embodiments, the third transition metal catalyst is ammonium metavanadate (NH4VO3) or vanadium pentoxide (VO5).

[0067] The disclosed process employs an appropriate amount of third transition metal catalyst. If too little third transition metal catalyst is present, the enzymatic reaction may not proceed at an adequate rate or may produce undesirable by-products. In contrast, if too much third transition metal catalyst is present, the reaction may be less cost-effective and may produce undesirable by-products. In some embodiments, the third transition metal catalyst is present in an amount of 0.01 to 2 eq based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine (e.g., 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2 eq based on 2-cyano-5-nitropyridine). In some embodiments, the third transition metal catalyst is present in an amount of 0.05 to 0.2 eq based on the 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine (e.g., 0.05, 0.08, 0.1, 0.15, or 0.2 eq of third transition metal catalyst based on the 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine). Thus, the third transition metal catalyst may be present in an amount between and including any of the aforementioned values ​​(e.g., 0.01-2, 0.1-1.9, 0.2-1.8, 0.3-1.7, 0.4-1.6, 0.5-1.5, 0.6-1.4, 0.7-1.3, 0.8-1.2, or 0.9-1.1 eq based on 2-cyano-5-nitropyridine, or 0.05-0.2, 0.08-0.15 eq based on 2-cyano-5-nitropyridine). In some embodiments, the third transition metal catalyst is present in an amount of 0.1 eq based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine. In some embodiments, the third transition metal catalyst is present in an amount of 2 eq based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine.

[0068] Glucose dehydrogenase (GDH) As described herein, some embodiments of the disclosed processes include combining 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine with a nitroreductase in the presence of glucose dehydrogenase (GDH), which is present in some embodiments of the disclosed processes to facilitate cofactor regeneration.

[0069] Suitable glucose dehydrogenases are commercially available (e.g., from Johnson Matthey (London, UK) and Codexis (Redwood City, CA)). Suitable non-limiting examples of glucose dehydrogenases include GDH-5, GDH-8, GDH-101, GDH-105, CDX-901, and combinations thereof. In some embodiments, the glucose dehydrogenase is GDH-101. By way of example, GDH-101 is commercially available from Johnson Matthey, and GDH-105 and CDX-901 are commercially available from Codexis.

[0070] In the disclosed process, an appropriate amount of glucose dehydrogenase is employed. If too little glucose dehydrogenase is present, the enzymatic reaction may not proceed at an adequate rate. In contrast, if too much glucose dehydrogenase is present, the reaction may be less cost-effective and may produce undesirable by-products. In some embodiments, glucose dehydrogenase is present in an amount of 0.1 to 25% by weight based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine (e.g., 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25% by weight based on 2-cyano-5-nitropyridine). Thus, glucose dehydrogenase can be present in an amount between and including any of the aforementioned values ​​(e.g., 0.1-25, 0.5-25, 1-24, 2-23, 3-22, 4-21, 5-20, 6-19, 7-18, 8-17, 9-16, 10-15, 11-14, or 12-13% by weight based on 2-cyano-5-nitropyridine). In some embodiments, glucose dehydrogenase is present in an amount of 1% by weight based on 2-cyano-5-nitropyridine.

[0071] cofactor As described herein, some embodiments of the disclosed process include mixing 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine with a nitroreductase in the presence of a cofactor. As will be appreciated, the cofactor facilitates the biocatalytic reduction reaction catalyzed by the nitroreductase. Suitable non-limiting examples of cofactors include nicotinamide adenine dinucleotide (NAD+), dihydronicotinamide adenine dinucleotide (NADH), nicotinamide adenine dinucleotide phosphate (NADP+), dihydronicotinamide adenine dinucleotide phosphate (NADPH), salts of NADPH, and combinations thereof. In some embodiments, the cofactor is NADP+.

[0072] The disclosed process employs an appropriate amount of cofactor. If too little cofactor is present, the enzymatic reaction may not proceed at an adequate rate. In contrast, if too much cofactor is present, the reaction may be less cost-effective and may produce undesirable by-products. In some embodiments, the cofactor is present in an amount of 0.5 to 20% by weight based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine (e.g., 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20% by weight based on 2-cyano-5-nitropyridine). Thus, the cofactor can be present in an amount between and including any of the aforementioned values ​​(e.g., 0.5-20, 0.6-19, 0.7-18, 0.8-17, 0.9-16, 1-15, 2-14, 3-13, 4-12, 5-11, 6-10, or 7-9% by weight of the cofactor based on 2-cyano-5-nitropyridine). In some embodiments, the cofactor is present in an amount of 0.7% by weight based on 2-cyano-5-nitropyridine.

[0073] Reducing Agent As described herein, some embodiments of the disclosed process include combining 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine with a nitroreductase in the presence of a reducing agent. The reducing agent facilitates regeneration of the cofactor. In some embodiments, the reducing agent is glucose.

[0074] In the disclosed process, an appropriate amount of reducing agent is employed. If too little reducing agent is present, the enzymatic reaction may not proceed at an adequate rate. In contrast, if too much reducing agent is present, the reaction may be less cost-effective and may produce undesirable by-products. In some embodiments, the reducing agent is present in an amount of 3 to 5 eq based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine (e.g., 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, or 5.0 eq based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine). Thus, the reducing agent may be present in an amount between and including any of the aforementioned values ​​(e.g., 3.0-5.0, 3.5-4.5, or 3.0-4.0 eq of reducing agent based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine). In some embodiments, the reducing agent is present in an amount of 3.1 eq based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine.

[0075] Buffer for preparing compound B In some embodiments, the disclosed process is carried out in the presence of a suitable buffer. Suitable buffers include those capable of maintaining a pH of 7 to 8 (e.g., 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, or 8.0). In some embodiments, the buffer maintains a pH of 7.2 to 7.5. In some embodiments, the buffer comprises a tricine buffer, a potassium phosphate buffer, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), tris(hydroxymethyl)aminomethane (Tris), or a combination thereof. In some embodiments, the buffer is a potassium phosphate buffer.

[0076] The buffering agent is present in any suitable amount. If the amount of buffering agent is too low, the pH of the reaction will not be properly maintained (e.g., pH 7-8). In contrast, if the amount of buffering agent is too high, the reaction may be less cost-effective and may produce undesirable by-products. In some embodiments, the buffering agent is present in an amount of 80-95% (v / w) (e.g., 80-90%, 80-85%, 85-95%, 85-90% or 90-95% (v / w)). In some embodiments, the buffering agent is present in an amount of 92% (v / w). In some embodiments, the buffering agent is present in an amount of 100-250 mM (e.g., 100, 125, 150, 175, 200, 225 or 250 mM).

[0077] Solvent for preparing compound B The process of preparing compound B disclosed herein is carried out in a suitable solvent. Suitable non-limiting examples of organic co-solvents include ethanol, isopropyl alcohol, tert-butyl alcohol, tetrahydrofuran, 2-methyltetrahydrofuran, methyl tert-butyl ether (MTBE), toluene, isoamyl acetate, tert-butyl acetate, cyclopentyl methyl ether, dimethylacetamide, acetone, dimethylcarbonate, acetonitrile, and combinations thereof. In some embodiments, the mixing of 2-cyano-5-nitropyridine or a salt thereof with nitroreductase is carried out in a solvent comprising water, dimethylsulfoxide (DMSO), toluene, MTBE, isopropyl alcohol, isopropyl acetate, or a combination thereof. In some embodiments, the mixing of 2-cyano-5-nitropyridine or a salt thereof with nitroreductase is carried out in a solvent comprising water, dimethylsulfoxide (DMSO), or a combination thereof. In some embodiments, the solvent comprises DMSO. Without wishing to be bound by a particular theory, DMSO functions as an organic co-solvent. Typically, DMSO can be present in an amount of 0.5 to 20 volumes (e.g., 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 volumes based on 2-cyano-5-nitropyridine). In some embodiments, the solvent comprises 0.5 volumes of DMSO based on 2-cyano-5-nitropyridine.

[0078] temperature The process for preparing compound B disclosed herein is carried out at a suitable temperature, typically a temperature between 20 and 50° C. In some embodiments, 2-cyano-5-nitropyridine or a salt thereof is mixed with a nitroreductase at a temperature between 32 and 38° C. (e.g., 35 and 38° C.).

[0079] Fed-batch mode In some embodiments, the disclosed process for preparing compound B is carried out in fed-batch mode. In an exemplary embodiment carried out in fed-batch mode, 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine can be added to the reaction mixture containing other components via continuous addition (e.g., syringe pump at constant flow rate). By carrying out the disclosed process in fed-batch mode, advantages can be obtained, such as reducing the required amount of nitroreductase, third transition metal catalyst, cofactor and solvent required to carry out the reaction. For example, in some embodiments, the amount of total enzyme (NR and GDH) required is reduced by about 70%; the amount of third transition metal catalyst (e.g., NH4VO3) required is reduced by about 88%; the amount of cofactor (e.g., NADPH) required is reduced by about 95%; and / or the amount of solvent required is reduced by about 97%.

[0080] The process for preparing Compound A or a salt thereof may be carried out in batch or continuous mode.

[0081] The disclosed process provides compound A or a salt thereof in a suitable yield. In some embodiments, compound A or a salt thereof is prepared in an overall yield of 40% or more based on compound B (e.g., in a yield of 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90 or 95% or more based on compound B). In some embodiments where compound C is isolated prior to reaction with compound D (e.g., a "two-pot" process), compound A or a salt thereof is obtained in an overall yield of at least 40% or more based on compound B, e.g., 40-60%, 45-60%, 50-60%, 50-55% or 55-60%. In some embodiments where compound C is not isolated prior to reaction with compound D (e.g., a "one-pot" process), compound A is obtained in an overall yield of 50% or more, e.g., 60% or more. In some embodiments, compound A is obtained in an overall yield of 60-95%, 60-80%, or 60-70% from the one-pot process.

[0082] In some embodiments, compound A1 or a salt thereof is converted to compound A' or a salt thereof. In these embodiments, compound A1 is converted to compound A' using any suitable reaction conditions to convert the -CN functional group of compound A1 to the -CO2H functional group of compound A'. In some embodiments, the conversion of compound A1 to compound A' is carried out using basic conditions to hydrolyze the -CN functional group. In some embodiments, compound A1 or a salt thereof is converted to compound A' or a salt thereof in a chemical yield of 90% or more (e.g., 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more). In some embodiments, compound A1 is converted to compound A' using basic hydrolysis conditions.

[0083] Solvent and temperature for forming compound C or compound C' The compound B is mixed with the first transition metal catalyst and the boron-containing compound in a suitable solvent. Optionally, the solvent is an aprotic solvent. Exemplary aprotic solvents include, for example, tetrahydrofuran, 1,4-dioxane, 2-methyltetrahydrofuran, cyclopentyl methyl ether (CPME) and toluene. In some embodiments, the solvent is tetrahydrofuran (THF).

[0084] The mixing of compound B with the first transition metal catalyst and the boron-containing compound is carried out at a suitable temperature. Optionally, the reaction is carried out at a temperature of about 50-100°C (e.g., 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100°C). In some embodiments, the temperature is 55-95°C, 60-90°C, 65-85°C, 70-80°C, or 75°C. For example, in some embodiments, compound B is mixed with the first transition metal catalyst and the boron-containing compound at about 65°C. In some embodiments, compound B, the first transition metal catalyst, and the boron-containing compound are added together in a reaction vessel at a low temperature (e.g., 25-35°C) and then mixed at a high temperature (e.g., 60-65°C). In some embodiments, the reaction mixture is cooled to a low temperature (e.g., 40-45°C) before the reaction mixture is quenched.

[0085] Boron-Containing Compounds The boron-containing compound is any suitable boron compound compatible with the desired boronation reaction under the desired reaction conditions. In some embodiments, the boron-containing compound is 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane) or 4,4,5,5-tetramethyl-1,3,2-dioxaborolane.

[0086] The first transition metal catalyst The first transition metal catalyst is any suitable transition metal catalyst capable of affecting the desired conversion of boronation. Thus, the first transition metal catalyst is any suitable transition metal catalyst capable of catalyzing the conversion of compound B to compound C or C'. Contemplated first transition metal catalysts include iridium. In some embodiments, the first transition metal catalyst is [Ir(OMe)(COD)]2 or [Ir(Cl)(COD)]2. As will be appreciated, these iridium catalysts are used with organic ligands to promote the desired reactivity. Suitable ligands include, for example, 4,4'di-tert-butyl-2,2'-bipyridine (diby), 3,4,7,8-tetramethyl-1,10-phenanthroline, and 1,10-phenanthroline.

[0087] The first transition metal catalyst is used in an appropriate amount. If too little catalyst is used, the desired reaction rate may not be obtained. Conversely, if too much catalyst is used, undesirable by-products may be obtained and / or the cost of the reaction may be unnecessarily high. In some embodiments, the first transition metal catalyst is present in an amount of 0.3 to 5 mol % based on compound B (e.g., 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75, 4, 4.25, 4.5, 4.75 or 5 mol % based on compound B). In some embodiments, the first transition metal catalyst is present in an amount of 1.5 mol % based on compound B (as a dimer complex). As will be appreciated, the metal catalyst without a ligand may be present as a dimer, such that after adding the ligand, the first transition metal-ligand catalyst is present in an amount of 3 mol % based on compound B. In some embodiments, the first transition metal catalyst is 1.5 mol % [Ir(OMe)(cod)]2-3%dibpy. In some embodiments, the first transition metal catalyst is prepared by mixing a solution of a boron-containing compound (e.g., bis(pinacolato)diboron) (0.5 eq dimer; 1 eq borane), a ligand (0.03 eq) and an iridium-containing compound (0.015 eq). In some embodiments, an excess of the boron-containing compound is used. For example, in some embodiments, 1.5 eq pinacolborane is added to form an N-boronate derivative, followed by the addition of the first transition metal catalyst and bis(pinacolato)diborane. In some embodiments, 2 eq or more of pinacolborane is added, followed by the addition of the first transition metal catalyst. Typically, in embodiments where 2 eq or more of pinacolborane is added, bis(pinacolato)diboron does not need to be added to the reaction mixture. In some embodiments, compound B is added as a solution of the first transition metal-ligand catalyst and the boron-containing compound.

[0088] Second transition metal catalyst As described herein, the disclosed process for preparing compound A also includes mixing compound C or C' with compound D and a second transition metal catalyst. In some embodiments, mixing compound C or C' with compound D and a second transition metal catalyst is carried out in a solvent including a mixture of an organic solvent (e.g., THF) and water. Similar to the first transition metal catalyst, the second transition metal catalyst is any suitable catalyst that can affect the coupling of compound C or C' with compound D under desired conditions. Contemplated second transition metal catalysts include palladium catalysts or nickel catalysts. In some embodiments, the second transition metal catalyst is dichloro[9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene]palladium(II). In some embodiments, the second transition metal catalyst is 1,4-bis(diphenylphosphino)butane-palladium(II) chloride, bis(1,5-cyclooctadiene)nickel(0) with tri-n-butylphosphonium tetrafluoroborate or [(N,N,N',N'-tetramethylethane-1,2-diamine)nickel(ortho-tolyl)chloride] complex. In some embodiments, the second transition metal catalyst is chloro(2-methylphenyl)(N,N,N',N'-tetramethyl-1,2-ethylenediamine)nickel(II) with tri-n-butylphosphine. In some embodiments, a reducing additive such as n-hexylmagnesium chloride, methylmagnesium chloride, manganese or zinc is added.

[0089] Similar to the first transition metal catalyst, the second transition metal catalyst is used in an appropriate amount. In some embodiments, the second transition metal catalyst is present in an amount of 1-10 or 1-5 mol % based on compound B. In some embodiments, the second transition metal catalyst is prepared by mixing the phosphine ligand and the Pd catalyst in an organic solvent.

[0090] Alternative synthesis scheme for compound C' [ka] Compound C' may be prepared generally as outlined in the scheme above.

[0091] Compound B is first mixed with a metal-amide base (e.g., the metal is methylmagnesium chloride, ethylmagnesium chloride, isopropylmagnesium chloride, n-hexylmagnesium chloride, methylmagnesium bromide, ethylmagnesium bromide, isopropylmagnesium bromide, n-hexylmagnesium bromide, n-butyllithium or tert-butyllithium; the amide is 2,2,6,6-tetramethylpiperidine, diisopropylamine), then a boron-containing compound (trimethylborate, triethylborate, triisopropylborate, 2-methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane or 2-ethoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane), and then optionally with water or a diol (diethanolamine) or a diacid (methyliminodiacetic acid) to form compound C'. Compound C' can be isolated or used directly in the next step. The preparation of compound C' in this manner, using a metal-amide base to promote this transformation (instead of a precious metal catalyst), offers many advantages including cost and sustainability. Furthermore, isolation of crystalline boronic esters can provide better purity and yield.

[0092] In some embodiments, the preparation of compound C' includes using methylmagnesium chloride (2.0-5.0 molar equivalents; or more specifically, 3.6 molar equivalents) and / or 2,2,6,6-tetramethylpiperidine (1.0-4.0 molar equivalents; or more specifically, 3.6 molar equivalents) and / or triethylborate (2.0-5.0 molar equivalents; or more specifically, 3.8 molar equivalents). Optionally, the reaction of compound B to form compound C' is carried out in a solvent such as an ether-containing solvent (tetrahydrofuran, 2-methyltetrahydrofuran, 1,2-dimethoxyethane, tert-butyl methyl ether, isopropyl ether). Optionally, 7.5 L / kg of tetrahydrofuran and 12.5 L / kg of 1,2-dimethoxyethane are used. Optionally, treatment with a diol such as diethanolamine to form compound C'-6 is also contemplated.

[0093] Optionally, compound C' is prepared as shown in the following scheme. [ka]

[0094] As shown in the above scheme, compound C' can be prepared by mixing a dichloro-pyridyl compound with a metal catalyst to form a cyano-pyridyl chloride compound. For example, 1.5% molar equivalent of (tris)dibenzylideneacetonepalladium(0) and 3.0% molar equivalent of 1,1'-bis(di-tert-butylphosphino)ferrocene and 0.65 molar equivalent of zinc(II) cyanide or potassium ferrocyanide can be mixed with the dichloro-pyridyl compound in the presence of 20 molar equivalents of zinc metal in a solvent such as N,N-dimethylacetamide (e.g., 9 L / kg) and tetrahydrofuran (e.g., 1 L / kg) at 70° C. to form the cyano-chloro-pyridyl compound shown above. The cyano-chloro-pyridyl compound can then be mixed with palladium(II) acetate (e.g., 2.5% molar equivalents) and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (also known as SPhos, e.g., 5.0 molar equivalents) in the presence of a boron source such as bis(pinacolato)diboron (e.g., 1.2 molar equivalents) and in the presence of a base (e.g., 2 molar equivalents of potassium acetate) in an ether solvent (e.g., 2-methyltetrahydrofuran) at, e.g., 70°C to form compound C'.

[0095] Solvent and temperature for forming compound A The mixing of compound C or C' with compound D is carried out in a suitable solvent. As will be appreciated, if the process is a "one-pot" process, the solvent may comprise the solvent of step (a). In some embodiments, the solvent may be different from the solvent of step (a). In some embodiments, the mixing of compound C or C' with compound D is carried out in a solvent comprising THF and water.

[0096] Process for preparing compound E The disclosed process for preparing compound E, its stereoisomers, its salts, or its stereoisomers includes mixing compound F or its salts with an imine reductase (IRED) to form compound E, its stereoisomers, its salts, or its stereoisomers. In some embodiments, compound E is the (S)-stereoisomer of compound E or is enriched in the (S)-stereoisomer of compound E. By way of example, in various embodiments, in conjunction with other embodiments described above or below, the (S)-compound E produced according to the disclosed process has an enantiomeric excess of 95% or greater (e.g., 95, 96, 97, 98, 99, 99.5, 99.6, 99.7, 99.8, or 99.9% or greater).

[0097] In various embodiments, in conjunction with other embodiments above or below, compound E, its stereoisomer, salt thereof, or salt of a stereoisomer thereof is prepared in an overall yield of 75% or greater based on compound F. In some embodiments, compound E, its stereoisomer, salt thereof, or salt of a stereoisomer thereof is prepared in a stereochemical purity of greater than 99% ee in a yield of 80-90% based on compound F. In some embodiments, compound E, its stereoisomer, salt thereof, or salt of a stereoisomer thereof is prepared in a stereochemical purity of greater than 99% ee in a yield of 80-90% based on compound F. [ka] In some embodiments, (S)-compound E is prepared in 91% yield and +99% ee by chiral HPLC from (S)-compound E in 90% yield or higher and high stereochemical purity (e.g., 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% yield or higher; +99% ee by chiral HPLC).

[0098] The IRED enzyme can be any suitable IRED. IREDs are commercially available (e.g., from Prozomix Limited, Northumberland, UK). In some embodiments, the IRED used is IRED-155, which may alternatively be referred to as IRED-0712-C.

[0099] The IRED is present in a suitable amount. For example, in some embodiments, the IRED is present in an amount of 5-10% by weight based on compound F. In some embodiments, the IRED is present in an amount of 10% by weight based on compound F. For example, in some embodiments, the IRED is present in an amount of 5% by weight based on compound F.

[0100] In some embodiments, the enzymatic reduction is carried out in an aqueous buffer solution. Desirably, the enzymatic reduction is carried out at a pH of 6-9 (e.g., a pH of 6-8 or 7-8). Suitable buffers include, for example, 2-amino-2-(hydroxymethyl)-1,3-propanediol (Tris) and phosphate buffers. In some embodiments, the buffer is potassium phosphate buffer (pH 7.4) present in an amount of 30 volumes. In some embodiments, the buffer is potassium phosphate buffer (pH 7.4) present in an amount of 15 volumes.

[0101] The enzyme reaction mixture includes any suitable reducing agent, oxidizing agent, and / or cofactor capable of maintaining the desired rate of enzyme activity. By way of example, in some embodiments, the mixing of compound F or a salt thereof with the IRED is carried out using nicotinamide adenine dinucleotide phosphate (NADP+) (3 wt%), glucose dehydrogenase (GDH) (1.5-3 wt%), and glucose (reducing agent). In some embodiments, a slight excess of NADP+ (1.01 mmol) based on the substrate is used. Similarly, an excess of reducing agent can be used (e.g., 1.1 eq, 1.2 eq, 1.3 eq, 1.4 eq, or 1.5 eq of reducing agent). In some embodiments, the enzyme reaction mixture includes 1.4 eq of D-(+)-glucose.

[0102] The mixing of compound F or a salt thereof with the IRED is carried out at a suitable temperature. In various cases, the mixing reaction is carried out at a temperature of less than 50° C. (e.g., 45° C.). For example, in some embodiments, the mixing of compound F or a salt thereof with the imine reductase is carried out at 20-45° C., 20-40° C., 20-35° C., or 30-35° C.

[0103] As described herein, in various embodiments, in conjunction with other embodiments described above or below, the disclosed process further includes combining compound G or a salt thereof with compound H and an organometallic reagent or magnesium metal to form compound F'. In these embodiments, compound F' containing an amine protecting group is converted to compound F by removing (e.g., deprotecting) the protecting group from the amine group. In some embodiments, the protecting group of compound F' is Boc, which can be removed, for example, using an aqueous acidic solution (e.g., HCl). An exemplary embodiment showing the conversion of compound F' to compound F and then to compound E is shown in Scheme 4. Scheme 4 [ka]

[0104] In some embodiments, compound F, e.g., [ka] is isolated prior to conversion to compound E.

[0105] The process for preparing compound F can be carried out in batch or continuous mode.

[0106] In various cases, compound F is prepared in a yield of 40% or more based on compound G (e.g., 40, 45, 50, 55, 60, 65, 70, 75, 80, or 85% or more based on compound G). In some embodiments, where compound G is mixed with a mixture comprising compound H and an organometallic reagent or magnesium metal in a batch mode, the yield of compound F is 45-65%. In some embodiments, compound F is prepared in a continuous mode in a yield of 67-82%, where compound G is mixed with a mixture comprising compound H and an organometallic reagent or magnesium metal, and the mixture comprising compound H and an organometallic reagent is prepared in a continuous mode.

[0107] The organometallic reagent for mixing with compound H is any suitable organometallic reagent. Non-limiting suitable organometallic reagents include Grignard reagents. In some embodiments, the organometallic reagent is isopropylmagnesium chloride (iPrMgCl). In some cases, an excess of organometallic reagent is used. For example, in some embodiments, 1.5 eq of iPrMgCl is used relative to compound H. In some embodiments, compound G is the limiting reagent, i.e., less than 1 eq of compound G (e.g., 0.95, 0.9, 0.85, or 0.8 eq) relative to compound H is present in the reaction. For example, in some embodiments, 0.85 eq of compound G is added to the Grignard reagent formed from compound H and iPrMgCl. In some embodiments, the organometallic reagent is replaced with magnesium metal in the reaction, i.e., compound G is mixed with a mixture containing compound H and magnesium metal to form compound F.

[0108] Compound I The present disclosure provides a process for preparing compound I, its stereoisomers, its salts, or its stereoisomer salts using the disclosed processes. In some embodiments, the disclosed processes include preparing compound A′(Y 1 is -COH) or a salt thereof with compound E, a salt thereof, or a salt of a stereoisomer thereof, and a coupling agent to form compound I, a stereoisomer thereof, a salt thereof, or a salt of a stereoisomer thereof.

[0109] The disclosed processes provide compound I in suitable yields. In some embodiments, compound I is formed from the disclosed processes in a chemical yield of 70% or more (e.g., 75%, 80%, 85%, or 90% or more) relative to compound A. Furthermore, the stereochemical purity of compound I is not decreased during the reaction of compound A1 with (S)-compound E.

[0110] The coupling agent can be any suitable coupling agent capable of forming an amide bond between Compound A' and Compound E, as in Compound I. Suitable coupling agents include, for example, phosphonium salts and uronium salts. In some embodiments, the coupling agent is chloro-N,N,N',N'-tetramethylformamidinium hexafluorophosphate (TCFH), O-[(ethoxycarbonyl)cyanomethyleneamino]-N,N,N',N'-tetramethyluronium tetrafluoroborate (TOTU), 1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate (COMU), 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU), N-[(1H-benzotriazol-1-yl)-(diamino)methyl]-1H-benzotriazol-1-yl ... methylamino)methylene]-N-methylmethanaminium hexafluorophosphate N-oxide (HBTU), O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TBTU), propanephosphonic anhydride (T3P), bis(2-oxo-3-oxazolidinyl)phosphinic chloride (BOPCl), 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT), 1,1'-carbonyldiimidazole (CDI) and 1-cyano-2-ethoxy-2-oxoethylideneaminooxy-tris-pyrrolidino-phosphonium hexafluorophosphate (PyOxim). In some embodiments, the coupling agent is TBTU or CDI or chloro-N,N,N',N'-tetramethylformamidinium hexafluorophosphate (TCFH). Additionally, in some embodiments, the coupling agent is TBTU. In some embodiments, the coupling agent is TCFH. In some embodiments, the coupling agent is CDI.

[0111] In some embodiments, in conjunction with other embodiments above or below, the mixing of compound A' and compound E is carried out in the presence of an additive. The presence of an additive may facilitate the coupling reaction (e.g., improve the chemical yield and / or improve the stereochemical purity). Suitable non-limiting examples of additives include N-methylimidazole and alkylamine bases (e.g., trimethylamine and diisopropylethylamine). In some embodiments, the additive is triethylamine. In some embodiments, the additive is N-methylimidazole (NMI), trimethylamine, diisopropylethylamine, or a mixture thereof. Suitable non-limiting examples of additives include organic acids (e.g., trifluoromethanesulfonic acid, trifluoroacetic acid, acetic acid) and mineral acids (e.g., hydrochloric acid, hydrobromic acid). In some embodiments, the additive is trifluoromethanesulfonic acid. In some embodiments, the additive is hydrochloric acid.

[0112] In some embodiments, the process for preparing compound I, its stereoisomer, its salt, or its stereoisomer salt further comprises purifying compound I. For example, in some embodiments, the process further comprises crystallizing compound I, its stereoisomer, its salt, or its stereoisomer salt. In some embodiments, compound I is recrystallized from an organic solvent comprising acetone. In some embodiments, the organic solvent further comprises an anti-solvent, such as, for example, a hydrocarbon solvent (e.g., heptane).

[0113] It should be understood that the disclosed processes for preparing Compound A and Compound E are useful for preparing Compound I. For example, in various embodiments, in conjunction with other embodiments described above or below, the disclosed process for preparing Compound I includes preparing Compound E according to the processes disclosed herein. 1 In some cases, the process disclosed herein comprises reacting compound A with Y 1 For example, Y may further include converting Y to COH (i.e., compound A'). 1When Y is an ester or amide, the ester or amide is hydrolyzed to the acid. 1 If Y is an aldehyde, the aldehyde is oxidized to an acid. 1 If Y is a nitrile, the nitrile is converted to an acid. 1 When is a halide (eg, chloride), the halide is converted to an acid.

[0114] In some cases, Y 1 When is a halide (eg, Cl), compound I is prepared as shown in the following scheme. [ka]

[0115] In some embodiments, Y 1 Compound (A) where =Cl is a mixture of 0.5% to 5.0% molar metal catalyst (including, but not limited to, palladium(II) acetate, palladium(II) chloride, and [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II)) and 0.5% to 10% molar ligand (including, but not limited to, [1,1'-bis(diphenylphosphino)ferrocene], 1,3-bis(diphenylphosphino)propane bis(tetrafluoroborate), and 1,3-bis(dicyclohexylphosphino)propane bis(tetrafluoroborate)) and carbon monoxide (20 to 100 pounds per square inch). or more specifically 50 pounds per square inch) and 2.0 to 10.0 molar equivalents of an inorganic or organic base or mixtures thereof (potassium acetate, potassium bicarbonate, potassium carbonate, 1,8-diazabicyclo[5.4.0]undec-7-ene (also known as DBU), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (also known as TBD), 1,5-diazabicyclo[4.3.0]non-5-ene (also known as DBN; potassium carbonate and DBU in the exact embodiment) and 1.0 to 15.0 molar equivalents of a nucleophile to form the desired product (nucleophile: R of product). 7 ):(Water:OR 7 =OH; ethanol:OR7 =OCH2CH3;Methanol:OR 7 =OCH3;Phenyl:OR 7 =OPh; Compound (E): The product is Compound I) is formed in a solvent (e.g., 1-methylpyrrolidine, dimethylsulfoxide, methanol, acetonitrile, acetic acid) at 85°C.

[0116] Y 1 When is a halide (eg, Cl), prior to preparing compound I, the halide is first converted to a CN group. [ka]

[0117] Compound A(Y 1 =Cl) is mixed with 1% to 10 molar equivalents of a metal catalyst (including but not limited to bis(1,5-cyclooctadiene)nickel(0) or palladium(II) acetate or palladium(II) chloride) having 1% to 10 molar equivalents of a ligand (4,5-bis(diphenylphosphino)9,9-dimethylxanthene, 1,1'-bis(diphenylphosphino)ferrocene, bis(2-dicyclohexylphosphinophenyl)ether) with 0.5 to 1.5 molar equivalents of zinc(II) cyanide, and 1.0 to 1.5 molar equivalents of an additive 4-dimethylaminopyridine, and 0.1 to 1.0 molar equivalents of zinc, and a solvent (including but not limited to dimethylsulfoxide, N,N-dimethylacetamide) at, for example, 80°C, 1 Compound A, in which is CN, is formed at 80°C.

[0118] Embodiment 1. Compound A [ka] (In the formula, X 1 , NH, NR 1 , O, S or SO2; Y 1 -CN, -Cl, -CHO, -COOH, -CONHR 1, -CON(R 1 )2 or -CO2R 1 and; Z 1 and Z 2 each is independently H, F, or C1-C6 alkyl; and Each R 1 are independently C1-C6 alkyl. or a salt thereof, comprising the steps of: (a) Compound B [ka] with a first transition metal catalyst and a boron-containing compound to form R B is hydrogen to form compound C, or R B is -COOR4, forming compound C', and optionally compound C or compound C' [ka] (In the formula, R B is hydrogen or -COOR 4 and R 2 and R 3 are each independently H or C1-C6 alkyl, or when taken together with the boron and oxygen atoms to which they are attached form a 5-, 6-, or 8-membered cyclic boronate; R 4 is C1-C6 alkyl; Y 1A -CN, -Cl, -CONHR 1 , -CON(R 1 )2 or -CO2R 1 is) and isolating (b) Compound C or compound C' is mixed with compound D [ka] (In the formula, X 1A is NR 7 , O or S, and R 7 is C1-C6 alkyl, benzyl or p-methoxybenzyl, and LG is a leaving group. and a second transition metal catalyst to form compound A or a salt thereof. A process including. 2.X 1 The process of embodiment 1, wherein 3.Y 1 The process of embodiment 1 or 2, wherein is -CN. 4.Y 1 The process of embodiment 1 or 2, wherein 5. Compound A Y 1 is CHO or COOH, -CN, -CONHR 1 , -CON(R 1 )2 or CO2R 1 3. The process of embodiment 1 or 2, further comprising converting 6. X of Compound A 1 is NH, and the process is 1A 6. The process of any one of embodiments 1 to 5, further comprising converting 7.Z 1 and Z 2 The process of any one of embodiments 1 to 6, wherein each of 8. Compound A is A1: [ka] The process according to any one of embodiments 1 to 7, wherein the process has the structure: 9. Compound A is A2: [ka] The process according to any one of embodiments 1 to 7, wherein the process has the structure: 10. The process of any one of embodiments 1 to 9, wherein the first transition metal catalyst comprises iridium. 11. The process of embodiment 10, wherein the first transition metal catalyst is selected from the group consisting of: [Ir(OMe)(cod)]2, [Ir(Cl)(cod)]2. 12. The process of any one of the preceding embodiments, wherein the first transition catalyst is present in an amount of 1 to 5 mol % or wt % based on compound B. 13. The process of any one of the preceding embodiments, wherein the boron-containing compound is 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane) or 4,4,5,5-tetramethyl-1,3,2-dioxaborolane. 14. The process of embodiment 13, wherein the boron-containing compound is 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane). 15. Compound C is C1: [ka] 15. The process according to any one of embodiments 1 to 14, wherein the process has the structure: 16. Compound C' is C'-2: [ka] 15. The process according to any one of embodiments 1 to 14, wherein the process has the structure: 17. Compound C' is C'-3: [ka] 15. The process according to any one of embodiments 1 to 14, wherein the process has the structure: 18. Compound C' is selected from the group consisting of C'-4, C'-5, C'-6 and C'-7: [ka] 15. The process according to any one of embodiments 1 to 14, wherein the process has the structure: 19. The process according to any one of the preceding embodiments, wherein LG of compound D is a sulfonate ester, a sulfamate or a halide. 20. The process of embodiment 19, wherein the sulfonate ester is tosyl, mesyl, nosyl, or triflyl. 21. Compound D is D1: [ka] 21. The process according to any one of embodiments 1 to 20, wherein the process has the structure: 22. The process of any one of the preceding embodiments, wherein the second transition metal catalyst comprises a palladium catalyst or a nickel catalyst. 23. The process of embodiment 22, wherein the second transition metal catalyst is dichloro[9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene]palladium(II). 24. The process of any one of the preceding embodiments, wherein the second transition metal catalyst is present in an amount of 1 to 5 mol % or wt % based on compound B. 25. The process according to any one of embodiments 1 to 24, wherein the process is carried out in a vessel without isolating compound C or compound C'. 26. The process according to any one of embodiments 1 to 25, wherein compound C or compound C' is isolated. 27. Compound C is C1-a: [ka] 27. The process of embodiment 26, having the structure: 28. Compound C' is selected from the group consisting of C'-5, C'-6 and C'-7: [ka] 27. The process of embodiment 26, having the structure: 29. The process according to any one of embodiments 1 to 28, wherein compound A is prepared in an overall yield of 50% or greater based on compound B. 30. Compound E: [ka] (In the formula, X 2 is NR 1 , O or S; R 1 is C1-C6 alkyl; Y 2is H, C1-C6 alkyl or C1-C6 haloalkyl; and Z 3 , Z 4 , Z 5 and Z 6 each is independently H, C1-C6 alkyl, or chloride. A process for preparing a compound F, its stereoisomer, a salt thereof or a salt of a stereoisomer thereof, comprising the steps of: [ka] or a salt thereof with an imine reductase (IRED) to form compound E, a stereoisomer thereof, a salt thereof, or a salt of a stereoisomer thereof. 31.X 2 The process of embodiment 30, wherein 32.Y 2 32. The process of embodiment 30 or 31, wherein is CF3. 33.Z 3 , Z 4 , Z 5 and Z 6 The process of any one of embodiments 30 to 32, wherein each of is H. 34. Compound E is the (S)-stereoisomer: [ka] 34. The process of any one of embodiments 30 to 33, wherein the process is enriched in 35. The process of embodiment 34, wherein compound E has an enantiomeric excess of 95% or greater. 36. The process of embodiment 35, wherein compound E has an enantiomeric excess of 98% or greater. 37. The process of embodiment 36, wherein compound E has an enantiomeric excess of 99% or greater. 38. The process of embodiment 37, wherein compound E has an enantiomeric excess of 99.9% or greater. 39. The process according to any one of embodiments 30 to 38, wherein the mixing is carried out at a temperature of 20 to 50° C. 40. The process of embodiment 39, wherein the temperature is 20 to 35° C. 41. The process of embodiment 1, wherein the temperature is 30 to 35°C. 42. Compound G or a salt thereof is mixed with compound H and an organometallic reagent or magnesium metal to obtain compound F' [ka] (wherein PG is a protecting group and X h is Cl, Br or I. 42. The process of any one of embodiments 30 to 41, further comprising forming 43.X h The process of embodiment 42, wherein: 44.X h 43. The process of embodiment 42, wherein 45.Y 2 The process of embodiment 42 or 44, wherein is CF3. 46.Z 3 , Z 4 , Z 5 and Z 6 The process of any one of embodiments 42-45, wherein each of is H. 47. The process according to any one of embodiments 42 to 46, wherein the organometallic reagent is iPrMgCl. 48. The process according to any one of embodiments 42 to 47, wherein the protecting group is selected from the group consisting of tert-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz) and trimethylsilyl (TMS). 49. The process according to embodiment 48, wherein the protecting group is Boc. 50. The process of any one of embodiments 30 to 49, which is carried out in batch mode. 51. The process of any one of embodiments 30 to 49, carried out in a continuous mode. 52. The process according to any one of embodiments 30 to 51, further comprising deprotecting compound F' to form compound F or a salt thereof. 53. The process according to any one of embodiments 30-51, wherein compound E, its stereoisomer, its salt, or its stereoisomer salt is prepared in an overall yield of 75% or more based on compound F. 54. Compound I: [ka] A process for preparing compound I, its stereoisomer, its salt or its salt of a stereoisomer, comprising mixing compound A' or a salt thereof with compound E, its stereoisomer, its salt or its salt of a stereoisomer and a coupling agent to obtain compound I, its stereoisomer, its salt or its salt of a stereoisomer. [ka] (In the formula, X 1 , NH, NR 1 , O, S or SO2; X 2 is NR 1 , O or S; Each R 1 is independently C1-C6 alkyl; Y 2 is H, C1-C6 alkyl or C1-C6 haloalkyl; Z 1 and Z 2 each is independently H, F, or C1-C6 alkyl; and Z 3 , Z 4 , Z 5 and Z 6 each is independently H, C1-C6 alkyl, or chloride. The process includes forming a 55. Compound I is the (S)-stereoisomer [ka] 55. The process of embodiment 54, wherein 56.X 1 and X 2 are O; Y 2 is -CF3; and Z 1 , Z2 , Z 3 , Z 4 , Z 5 and Z 6 56. The process of embodiment 55, wherein each of is H. 57. Coupling agents include chloro-N,N,N',N'-tetramethylformamidinium hexafluorophosphate (TCFH), O-[(ethoxycarbonyl)cyanomethyleneamino]-N,N,N',N'-tetramethyluronium tetrafluoroborate (TOTU), 1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate (COMU), 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU), N-[(1H-benzotriazol-1-yl)-(dimethylamino)methylene]-N-methyl 57. The process of any one of embodiments 54 to 56, wherein the aryl group is selected from the group consisting of methanaminium hexafluorophosphate N-oxide (HBTU), O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TBTU), propanephosphonic anhydride (T3P), bis(2-oxo-3-oxazolidinyl)phosphinic chloride (BOPCl), 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT), 1,1'-carbonyldiimidazole (CDI) and 1-cyano-2-ethoxy-2-oxoethylideneaminooxy-tris-pyrrolidino-phosphonium hexafluorophosphate (PyOxim). 58. The process according to any one of embodiments 54 to 57, wherein the coupling agent is O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TBTU). 59. The process of embodiment 57, wherein the coupling agent is CDI. 60. The process of any one of embodiments 54 to 59, wherein the mixing is carried out in the presence of an additive. 61. The process of embodiment 60, wherein the additive is N-methylimidazole (NMI) or triethylamine. 62. The process of embodiment 60, wherein the additive is trifluoromethanesulfonic acid, hydrochloric acid, hydrobromic acid, or hydroiodic acid. 63. The process according to any one of embodiments 54 to 62, further comprising crystallizing compound I, its stereoisomer, its salt or its stereoisomer salt. 64. The process according to any one of embodiments 54-63, wherein compound E is prepared according to the process according to any one of embodiments 30-53. 65. The process according to any one of embodiments 54 to 64, wherein the process further comprises converting compound A to compound A', and compound A is prepared according to the process according to any one of embodiments 1 to 29. 66. The process according to any one of embodiments 54 to 65, wherein compound I is (4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)-[(3S)-3-[4-(trifluoromethyl)phenyl]morpholin-4-yl]methanone. 67. The process according to embodiment 66, wherein compound I is enriched in the (S)-stereoisomer. 68. Compound I has the structure: [ka] 67. The process of embodiment 66, comprising: 69. Compound B is B1 [ka] (Compound B1) or B1' [ka] (Compound B1') The process according to any one of embodiments 1 to 28 and 65 to 67, wherein the process has the structure: 70. 2-Cyano-5-nitropyridine in solvent [ka] or 2-chloro-5-nitropyridine [ka] 70. The process of embodiment 69, further comprising combining Compound B1, Compound B1', or a salt thereof with a nitroreductase to form Compound B1, Compound B1', or a salt thereof. 71. The process of embodiment 70, wherein the nitroreductase is selected from the group consisting of NR-17, NR-X4-mut2, NR-X4-mut10, NR-X18, NR-X27, NR-X30, NR-X32, NR-X36, NR-X39, NR-X41, NR-X53, NR-X54 and combinations thereof. 72. The process according to embodiment 70 or 71, wherein the nitroreductase is NR-17 or NR-X36. 73. The process of embodiment 72, wherein NR-17 or NR-36 is present in an amount of 0.1 to 10% by weight based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine. 74. The process of embodiment 73, wherein NR-17 or NR-36 is present in an amount of 5 to 7% by weight based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine. 75. The process according to any one of embodiments 70 to 74, further comprising mixing 2-cyano-5-nitropyridine, 2-chloro-5-nitropyridine or a salt thereof with a nitroreductase in the presence of one or more of glucose dehydrogenase (GDH), a third transition metal catalyst, a cofactor, a reducing agent or a buffering agent. 76. The process of embodiment 75, wherein the third transition metal catalyst comprises vanadium, iron, copper, or a combination thereof. 77. The process of embodiment 75 or 76, wherein the vanadium is vanadium oxide. 78. The process of any one of embodiments 75-77, wherein the vanadium oxide is vanadium(IV) oxide or vanadium(V) oxide. 79. The process of any one of embodiments 75-78, wherein the third transition metal catalyst is ammonium metavanadate (NH4VO3) or vanadium pentoxide (V2O5). 80. The process of any one of embodiments 73-77, wherein the third transition metal catalyst is present in an amount of 0.01 to 2.5 eq based on the 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine. 81. The process of embodiment 80, wherein the third transition metal catalyst is present in an amount of 0.1 eq based on the 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine. 82. The process of embodiment 80, wherein the third transition metal catalyst is present in an amount of 2 eq based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine. 83. The process according to any one of embodiments 75 to 82, wherein the glucose dehydrogenase is selected from the group consisting of GDH-101, GDH-105, CDX-901, and combinations thereof. 84. The process of any one of embodiments 75 to 83, wherein the glucose dehydrogenase is GDH-101. 85. The process according to any one of embodiments 75 to 84, wherein the glucose dehydrogenase is present in an amount of 0.1 to 25% by weight based on the 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine. 86. The process of embodiment 85, wherein the glucose dehydrogenase is present in an amount of 1% by weight based on the 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine. 87. The process of any one of embodiments 75-86, wherein the cofactor is selected from the group consisting of nicotinamide adenine dinucleotide (NAD+), dihydronicotinamide adenine dinucleotide (NADH), nicotinamide adenine dinucleotide phosphate (NADP+), dihydronicotinamide adenine dinucleotide phosphate (NADPH), a salt of NADPH, and combinations thereof. 88. The process of any one of embodiments 75-87, wherein the cofactor is nicotinamide adenine dinucleotide phosphate (NADP+). 89. The process of any one of embodiments 75-88, wherein the cofactor is present in an amount of 0.5 to 20% by weight based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine. 90. The process of embodiment 89, wherein the cofactor is present in an amount of 0.7% by weight based on 2-cyano-5-nitropyridine. 91. The process of any one of embodiments 75-90, wherein the reducing agent is glucose. 92. The process of any one of embodiments 75-91, wherein the reducing agent is present in an amount of 3 to 5 eq based on the 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine. 93. The process of embodiment 92, wherein the reducing agent is present in an amount of 3.1 eq based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine. 94. The process of any one of embodiments 75-93, wherein the buffer comprises tricine buffer, potassium phosphate buffer, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), tris(hydroxymethyl)aminomethane (Tris), or a combination thereof. 95. The process of any one of embodiments 75-94, wherein the buffer is a potassium phosphate buffer. 96. The process of any one of embodiments 75-95, wherein the buffer maintains a pH of 6-9. 97. The process of embodiment 96, wherein the buffer maintains a pH of 7.2 to 7.5. 98. The process of any one of embodiments 75-97, wherein the buffering agent is present in an amount of 100-250 mM. 99. The process of embodiment 98, wherein the buffering agent is present in an amount of 80-95% (v / w). 100. The process of embodiment 99, wherein the buffering agent is present in an amount of 92% (v / w). 101. The process according to any one of embodiments 70 to 100, wherein the mixing of 2-cyano-5-nitropyridine, 2-chloro-5-nitropyridine or a salt thereof with the nitroreductase is carried out in a solvent comprising water, dimethylsulfoxide (DMSO), toluene, methyl tert-butyl ether (MTBE), isopropyl acetate or a combination thereof. 102. The process of any one of embodiments 70 to 101, wherein the solvent comprises DMSO. 103. The process of embodiment 102, wherein the solvent comprises 0.5 to 20 volumes of DMSO based on 2-cyano-5-nitropyridine. 104. The process of embodiment 103, wherein the solvent comprises 0.5 volumes of DMSO based on 2-cyano-5-nitropyridine. 105. The process according to any one of embodiments 70 to 104, wherein the mixing of 2-cyano-5-nitropyridine, 2-chloro-5-nitropyridine or a salt thereof with the nitroreductase is carried out at a temperature of 20 to 50°C. 106. The process of embodiment 105, wherein the temperature is 32 to 38°C. 107. The process according to any one of embodiments 70 to 106, wherein the mixing of 2-cyano-5-nitropyridine, 2-chloro-5-nitropyridine or a salt thereof with the nitroreductase is carried out in fed-batch mode. EXAMPLES

[0119] The following examples further illustrate the disclosed process but, of course, should not be construed as in any way limiting its scope.

[0120] The following abbreviations are used herein: NMR means nuclear magnetic resonance; SFC means supercritical fluid chromatography; DIPEA means diisopropylethylamine; DMF means dimethylformamide; PyBroP means benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate; NaHCO3 means sodium bicarbonate; EtOAc means ethyl acetate; EtOH means ethanol; DCM means dichloromethane; TEA means trimethylamine; ESI means electrospray ionization; DMSO means dimethylsulfoxide; nd means not detected; V or vol means volume (L / kg); GC means gas chromatography.

[0121] Comparison process example Comparative Example 1 - (4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)(2-(4-(trifluoromethyl)phenyl)piperidin-1-yl)methanone [ka] To a solution of 2-(4-(trifluoromethyl)phenyl)piperidine (0.100 g, 0.436 mmol, Arch Corporations, NJ), 4-((2,4-dimethoxybenzyl)amino)-1,3-dihydrofuro[3,4-c][1,7]naphthyridine-8-carboxylic acid hydrochloride (0.273 g, 0.654 mmol) and 1,1'-dimethyltriethylamine (0.564 g, 0.762 mL, 4.36 mmol, Sigma-Aldrich Corporation) in DMA (4 mL) was added bromotripyrrolidinophosphonium hexafluorophosphate (0.203 g, 0.436 mmol, Sigma-Aldrich Corporation) and the resulting mixture was heated at 50° C. for 30 min. The reaction was brought to room temperature, diluted with water, saturated NaHCO3 and extracted with EtOAc (3×). The combined organic layers were dried over Na2SO4, filtered and concentrated. The residue was chromatographed on silica gel using 0-50% (3:1 EtOAc / EtOH) in heptane to give (4-((2,4-dimethoxybenzyl)amino)-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)(2-(4-(trifluoromethyl)phenyl)piperidin-1-yl)methanone as a pale yellow solid. m / z(ESI): 593(M+H). + .

[0122] To a solution of (4-((2,4-dimethoxybenzyl)amino)-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)(2-(4-(trifluoromethyl)phenyl)piperidin-1-yl)methanone in DCM (2 mL) was added TFA (14.80 g, 10 mL, 130 mmol, Aldrich) and the resulting mixture was heated at 50° C. for 1 h. The reaction was concentrated, washed with 10% Na2CO3, and extracted with DCM. The combined organic layers were concentrated and chromatographed on silica gel with 0-50% (3:1 EtOAc / EtOH) to give (4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)(2-(4-(trifluoromethyl)phenyl)piperidin-1-yl)methanone (0.042 g, 0.095 mmol, 21.76% yield) as an off-white solid. m / z (ESI): 443 (M+H). + .

[0123] The compound was purified by preparative SFC using a Chiral Technologies AS column (250×21 mm, 5 mm) with 75% liquid CO2 and 25% MeOH (with 0.2% TEA) as the mobile phase using a flow rate of 80 mL / min to yield 13.5 mg of peak 1 (ee >99%) and 13 mg of peak 2 (ee >99%), stereochemistry arbitrarily assigned. Peak 1: (S)-(4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)(2-(4-(trifluoromethyl)phenyl)piperidin-1-yl)methanone (0.013 g, 0.029 mmol). White solid. m / z(ESI): 443 (M+H). + . 1H NMR(400MHz,DMSO-d6)δ ppm 8.69-8.99(m,1H),7.73-7.86(m,3H),7.57-7.67(m,2H),7.03(br s,2H),5.38(br s,2H),5.05(br s, 2H), 3.64-3.91(m, 1H), 2.35-2.46(m, 2H), 1.86-2.01(m, 1H), 1.29-1.72(m, 5H). Peak 2: 3415634#1(R)-(4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)(2-(4-(trifluoromethyl)phenyl)piperidin-1-yl)methanone (0.011 g, 0.025 mmol). White solid. 126773-15-2 m / z(ESI): 443(M+H) + . 1 H NMR(400MHz,DMSO-d6)δ ppm 8.81-8.98(m,1H),7.74-7.84(m,3H),7.62(br d,J=7.9Hz,2H),7.03(br s,2H),5.39(br d,J=2.9Hz,2H),5.05(br s,2H),3.72-3.87(m,1H),2.36-2.45(m,2H),1.85-2.04(m,1H),1.31-1.72(m,5H).

[0124] (4-Amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)-[3-[4-(trifluoromethyl)phenyl]morpholin-4-yl]methanone was prepared in a similar manner as above. The enantiomers were separated as outlined in Table 1.

[0125] [Table 1]

[0126] Example 1. Synthesis of Compound A1 - 4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridine-8-carbonitrile [ka] Potassium 4-cyano-2,5-dihydrofuran-3-oleate [ka] Synthesis 1 To a solution of potassium tert-butoxide (124.5 g, 1.1 moles, 1.0 eq) in tetrahydrofuran (3.0 L, 30 V), a solution of methyl 2-hydroxyacetate (100 g, 1.1 moles, 1.0 eq) in tetrahydrofuran (500 mL, 5.0 V) was added using an addition funnel at 0-10° C. over a period of 30-45 minutes. Other suitable bases include potassium carbonate, sodium carbonate and sodium bicarbonate. The resulting solution was stirred for another 15-20 minutes at 0-10° C. Then, a solution of acrylonitrile (88.3 g, 1.7 moles, 1.5 eq) in tetrahydrofuran (1.0 L, 10 V) was slowly added to the above reaction mass over a period of 3.5-4 hours at 5-10° C. Other suitable solvents include MTBE. After stirring at 5-10 °C for 1 h, the reaction mixture was quenched with water (20 mL, 1.1 mol, 1.0 eq), stirred at 5-10 °C for 30 min, the resulting slurry was filtered, and the resulting solid was washed with THF (200 mL, 2.0 V) to give the desired product, potassium 4-cyano-2,5-dihydrofuran-3-olate. Analytical data: 1 H NMR(400MHz,DMSO-d6):4.51(t,J=2.0Hz,2H),3.70(t,J=2.0Hz,2H).

[0127] Synthesis 2 To a solution of potassium tert-butoxide (18.7 g, 167 mmol, 1.0 eq) in 2-methyltetrahydrofuran (450 mL, 30 L / kg) was added a solution of methyl 2-hydroxyacetate (15.0 g, 167 mmol, 1.0 eq) in 2-methyltetrahydrofuran (75.0 mL, 5.0 L / kg) over 30 min at 0-10° C. A solution of acrylonitrile (19.4 g, 366 mmol, 2.2 eq) in tetrahydrofuran (150 mL, 10 L / kg) was added slowly over 4 h at 5-10° C. After stirring at 5-10 °C for 1 h, the reaction mixture was quenched with water (3.0 mL, 167 mmol, 1.0 eq) and the slurry was stirred at 5-10 °C for 30 min, filtered and washed with 2-MeTHF (30 mL, 2.0 L / kg) to yield the desired product, potassium 4-cyano-2,5-dihydrofuran-3-olate. Analytical data: 1 H NMR(400MHz,DMSO-d6):4.51(t,J=2.0Hz,2H),3.70(t,J=2.0Hz,2H).

[0128] Compound D - (4-cyano-2,5-dihydrofuran-3-yl) 4-methylbenzenesulfonate [ka] Synthesis 1 To a slurry of potassium 4-cyano-2,5-dihydrofuran-3-olate (3.0 g, 20.1 mmol, 1.0 eq, 88.0% w / w) in 2-MeTHF (30 mL, 10.0 V), potassium carbonate (2.8 g, 20 mmol, 1 eq) and tosyl chloride (3.9 g, 20 mmol, 1 eq) were added sequentially at 20-25 °C, and the resulting slurry was stirred for 2-3 h at 20-25 °C. The reaction was monitored by gas chromatography (GC). The reaction mixture was filtered and the filtrate was washed with 1.5 N aqueous HCl (5 V) followed by 10% aqueous sodium bicarbonate (5 V). The organic phase was separated and concentrated under reduced pressure to give the product. Analytical data: 1H NMR(400MHz, CDCl3):2.50(s,3H),4.72(t,J=4.8Hz,2H),4.85(t,J=4.8Hz,2H),7.46(d,J=8.4Hz,1H),7.90(d,J=8.4Hz,1H).

[0129] Synthesis 2 To a solution of potassium 4-cyano-2,5-dihydrofuran-3-olate (4.6 g active, 31.5 mmol; total mass 6.6 g) in acetonitrile (35 mL, 7.6 L / kg) was added potassium carbonate (8.0 g, 58 mmol, 1.8 equiv), p-toluenesulfonyl chloride (9.3 g, 49 mmol, 1.5 equiv) and 4-dimethylaminopyridine (770 mg, 6.3 mmol, 0.20 equiv) at 20° C. Other suitable bases include amine bases such as diisopropylethylamine, diisopropylamine, pyridine, 2,6-lutidine, 2,4,6-collidine as well as carbonates such as sodium carbonate, sodium bicarbonate. The reaction mixture was stirred at 20° C. for 2-3 h. The reaction mixture was filtered and the solid was washed with MeCN (10 mL, 2.2 L / kg). Other suitable solvents include tetrahydrofuran, 2-methyltetrahydrofuran, methyl tert-butyl ether and isopropyl acetate. The MeCN solution was added dropwise to a stirred sample of water (96 mL, 21 L / kg) and the mixture was then stirred for 1 hour. The product was filtered and washed with water (15 mL, 3 L / kg). The product was dried under nitrogen at ambient temperature to yield (4-cyano-2,5-dihydrofuran-3-yl) 4-methylbenzenesulfonate. Analytical data: 1 H NMR(400MHz, CDCl3):2.50(s,3H),4.72(t,J=4.8Hz,2H),4.85(t,J=4.8Hz,2H),7.46(d,J=8.4Hz,1H),7.90(d,J=8.4Hz,1H).

[0130] Synthesis 3 To a solution of potassium tert-butoxide (12.4 g, 167 mmol, 1.0 equiv) in 2-methyltetrahydrofuran (300 mL, 30 L / kg) was added a solution of methyl 2-hydroxyacetate (10.0 g, 111 mmol, 1.0 equiv) in 2-methyltetrahydrofuran (50.0 mL, 5.0 L / kg) over 30 min at 0-10 °C. A solution of acrylonitrile (12.7 g, 244 mmol, 2.2 equiv) in 2-methyltetrahydrofuran (100 mL, 10 L / kg) was added slowly over 4 h at 5-10 °C. After stirring for 1 h at 5-10 °C, the reaction mixture was filtered and washed with 2-MeTHF (30 mL, 2.0 L / kg). To the resulting solution was added p-toluenesulfonyl chloride (21.2 g, 111 mmol, 1.0 equiv.) and 4-dimethylaminopyridine (2.7 g, 22.2 mmol, 0.20 equiv.). After stirring at 20° C. for 18 h, the reaction mixture was quenched with 10% w / w aqueous sodium bicarbonate (50 mL, 5.0 L / kg) and the layers were separated. The organic layer was then washed with water (20 mL, 2.0 L / kg) and the layers were separated. The combined organic layers were distilled to a total volume of 30 mL to remove water and heptane (80 mL, 8.0 L / kg) was added slowly. The product was filtered and washed with 10% 2-MeTHF / heptane (20 mL, 2.0 L / kg). The cake was dried under nitrogen at ambient temperature to yield (4-cyano-2,5-dihydrofuran-3-yl) 4-methylbenzenesulfonate. Analytical data: 1 H NMR(400MHz, CDCl3):2.50(s,3H),4.72(t,J=4.8Hz,2H),4.85(t,J=4.8Hz,2H),7.46(d,J=8.4Hz,1H),7.90(d,J=8.4Hz,1H).

[0131] Compound A1 - 4-Amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridine-8-carbonitrile [ka] To a solution of 5-amino-2-pyridinecarbonitrile (800 g, 6.7 mol, 1 eq) in THF (6.4 L, 8 V) in a 30 L jacketed glass reactor at 40-45° C., 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.3 kg, 9.9 mol, 1.5 eq) was added over 25 min under nitrogen atmosphere while maintaining the internal temperature below about 50° C. The reaction mixture was heated to 50° C. for 1 h and then cooled to 20-25° C. To the cooled solution was added bis(pinacolato)diboron (854 g, 3.3 moles, 0.5 eq), 4,4'-di-tert-butyl-2-2'-dipyridyl (54.3 g, 0.2 moles, 0.03 eq), and a solution of [Ir(OMe)(cod)]2 (67 g, 0.10 moles, 0.015 eq) in THF (3.2 L, 4 V) over 20 min while maintaining the temperature at 25-35 °C. The reaction was heated to 60-65 °C for 2-3 h, then cooled to 40-45 °C and quenched by the addition of isopropyl alcohol (800 mL, 1 V) at 40-45 °C over 30 min and stirred at the same temperature for an additional 20 min. The reaction was cooled to 20-25 °C and purged with nitrogen gas for 1 h. A degassed solution of K3PO4 (4.7 kg, 20.1 moles, 3 eq) in water (8 L, 10 V) was added followed by PdCl2(Xantphos) (250 g, 3.3 moles, 0.05 eq) and (4-cyano-2,5-dihydrofuran-3-yl) 4-methylbenzenesulfonate (1782 g, 6.72 moles, 1 eq) at 25-30 °C under nitrogen atmosphere. The reaction was heated to 60-65 °C for 2 h. Completion of the reaction was confirmed by HPLC and the reaction was cooled to 20-25 °C. Acetonitrile (4 L, 5 V) was added slowly, stirred for 2-3 h and the slurry was filtered through a Büchner funnel. The resulting cake was washed with water (8 L, 10 V) followed by dimethylacetamide (DMAc) (4 L, 5 V) and dried under vacuum for 4-5 h. The crude material and DMAc (9.6 L, 12V) were transferred to a 30 L glass reactor, followed by the addition of 1,2-bis(diphenylphosphino)ethane (136 g, 0.341 mol, 0.05 eq) at 20-25° C., and the resulting mixture was heated to 60-65° C. for 5-6 h.The reaction mass was cooled to 20-25°C, stirred at the same temperature for 1 h, filtered and the solid obtained was washed with DMAc (9.6 L, 12 V), water (8 L, 10 V) and n-heptane (2.5 L, 3 V) and dried to give 977 g of product. The isolated material (977 g) and IPA (9.5 L, 12 V) were added to a 30 L reactor, heated to 55-60°C for 2 h, cooled to 20-30°C, stirred for 30 min, filtered and dried to give the product. 1 H NMR(400MHz,TFA-d):9.40(s,1H),8.30(s,1H),5.76(d,J=3.2Hz,2H),5.59(s,2H).LCMS:213.1(M+H) + .

[0132] Example 2. Synthesis of Compound A' - 4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridine-8-carboxylic acid [ka] 4-Amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridine-8-carbonitrile (2.0 kg, 1.0 equiv.) was charged to a clean, dry, 100 L jacketed reactor followed by water (20.0 L). NaOH (10 N, 4.2 equiv., 4.0 L) was charged followed by an additional amount of water (16.1 L). The mixture was heated to 85±5° C. and stirred for >17 hours. The mixture was then cooled to 20±5° C. and discharged into a carboy. The reactor was washed with water and the process stream was polish-filtered back into the reactor. The reaction was heated to 55±5° C., followed by the addition of HCl (37 wt. %, 2.2 equiv., 1.7 L) while maintaining the temperature below about 60° C. Additional HCl (37 wt%, 3.0 equiv, 2.3 L) was added to the mixture over about 2 h while maintaining the temperature below about 60° C. The product slurry was aged at 55±5° C. for about 0.5 h, cooled to 20±5° C. over about 2 h, and aged an additional 1.0 h. The product slurry was filtered and the cake washed twice with water (2×4.0 L) followed by two washes with isopropanol (2×4.0 L). The product cake was dried under vacuum under a stream of nitrogen to give the product. LCMS: 232.08 (M+H). + .1 H NMR (400 MHz, 1:1 TFA-d / toluene-d): 9.30 (s, 1H), 8.29 (s, 1H), 5.11 (app s, 4H).

[0133] Example 3. Synthesis of (S)-compound - E-(3S)-3-[4-(trifluoromethyl)phenyl]morpholine [ka] Compound F' - tert-butyl (2-(2-oxo-2-(4-(trifluoromethyl)phenyl)ethoxy)ethyl)carbamate [ka] To a solution of 1-iodo-4-(trifluoromethyl)benzene (5.0 g, 18.4 mmol, 1.0 equiv) (compound H) in toluene (20 mL, 4V) cooled to 0° C., a solution of isopropylmagnesium chloride (13.8 mL, 27.6 mmol, 1.5 equiv) in 2M THF was added. The solution was stirred for 2 h and then cooled to −20° C. A solution of tert-butyl 3-oxomorpholine-4-carboxylate (3.2 g, 15.6 mmol, 0.85 equiv) (compound G) in toluene (15 mL, 3V) was then slowly added and stirred at −20° C. for 2 h. The reaction was quenched and purified by slurrying twice in DCM / heptane (1:40) to give the title compound, tert-butyl (2-(2-oxo-2-(4-(trifluoromethyl)phenyl)ethoxy)ethyl)carbamate (compound F′). LCMS: 248 (M+H-Boc) + .

[0134] 5-(4-(trifluoromethyl)phenyl)-3,6-dihydro-2H-1,4-oxazine [ka] Synthesis 1 To a 2M aqueous solution of hydrochloric acid (137 mL, 274 mmol, 2.5 equiv.), tert-butyl (2-(2-oxo-2-(4-(trifluoromethyl)phenyl)ethoxy)ethyl)carbamate (38.2 g, 111.3 mmol, 1.0 equiv.) (compound F') was added at room temperature. The resulting reaction mass was stirred and heated to 50 °C for 2.5-3.5 h until complete deprotection of Boc group was observed by HPLC analysis. The reaction was cooled to room temperature and polish filtered. In a separate vessel, potassium carbonate (36.89 g, 266.9 mmol, 2.4 equiv.) was added to water (380 mL, 10 V) and stirred until a clear solution was obtained. A solution of the intermediate 2-(2-aminoethoxy)-1-(4-(trifluoromethyl)phenyl)ethan-1-one in aqueous hydrochloric acid was slowly added to the aqueous potassium carbonate solution over 15 minutes. After addition, the reaction slurry was stirred for 5-10 minutes and filtered. The cake was washed with water (190 mL, 5V) and immediately dried under vacuum with a nitrogen purge to give 5-(4-(trifluoromethyl)phenyl)-3,6-dihydro-2H-1,4-oxazine. LCMS: 248.02 (M+H+H2O). + . 1 H NMR (400MHz, CDCl3):7.81(d,J=8.29Hz,2H),7.67(d,J=8.29Hz,2H),4.65(t,J=2.49Hz,2H),3.93(m,2H),3.80(m,2H).

[0135] Synthesis 2 The reactor was charged with dimethylsulfoxide (600 mL, 3 L / kg) and tert-butyl (2-(2-oxo-2-(4-(trifluoromethyl)phenyl)ethoxy)ethyl)carbamate (200 g, 576 mmol). Other suitable solvents include polar aprotic solvents including, for example, N-methylpyrrolidinone, N,N-dimethylacetamide, or 1,3-dimethyl-2-imidazolidinone. The mixture was heated to 40° C. to dissolve the batch. 1N hydrochloric acid (2.59 L, 4.5 equiv.) was added slowly to the resulting solution. Other suitable mineral acids include phosphoric acid, sulfuric acid; and organic acids including trifluoroacetic acid. The reaction mixture was heated to 60° C. for 2.5 hours, then cooled to 20° C. and polish filtered. The reaction mixture was added slowly to a sparged, premixed solution of sodium carbonate (183 g, 3.0 equiv.) in water (2.0 L, 10 L / kg). Other suitable inorganic bases include sodium hydroxide and potassium carbonate. After stirring for 30 minutes at 20° C., the batch was filtered. The solid was washed with 10% DMSO / water (600 mL, 3 L / kg) and then twice with water (600 mL, 3 L / kg). The cake was dried under a stream of nitrogen at ambient temperature to give 5-(4-(trifluoromethyl)phenyl)-3,6-dihydro-2H-1,4-oxazine. 1 H NMR (400MHz, CDCl3):7.81(d,J=8.29Hz,2H),7.67(d,J=8.29Hz,2H),4.65(t,J=2.49Hz,2H),3.93(m,2H),3.80(m,2H).

[0136] (S)-Compound E [ka] Synthesis 1 β-Nicotinamide adenine dinucleotide phosphate (NADP +) (753.4 mg, 1.013 mmol, 3 wt%), D-(+)-glucose (26.1 g, 145 mmol, 1.4 equiv.) and GDH-101 (754.8 mg, 3 wt%) were charged into 100 mM potassium phosphate buffer at pH 7.4 (750 mL, 30 V) and stirred for approximately 10-15 min until all solids were dissolved. IRED-155 (also called IRED-0712-C) (Prozomix) (2.533 g, 10 wt%) was charged and the reaction mass was stirred for 10-15 min until all solids were in solution. The solution was heated to 30 °C and 5-(4-(trifluoromethyl)phenyl)-3,6-dihydro-2H-1,4-oxazine (23.5 g, 102.4 mmol, 1.0 equiv.) was charged and the reaction was stirred for 18 h. The reaction was cooled to 20° C. 6N aqueous hydrochloric acid (61.0 mL, 2.6 V) was added over about 15 minutes until the pH was less than about 1.0. The reaction mass was stirred for 2 hours. A filter agent (0.75 eq. wt.) was added to the reaction mass and the mixture was stirred for 1 hour. The mixture was filtered over a pad of filter aid (0.25 eq. wt.) and washed with water. The filtrate was charged to the reactor and 10N aqueous sodium hydroxide (51.6 mL, 2.2 eq.) was added over 15 minutes until the pH was 11. After stirring for about 30 minutes, the mixture was filtered and dried under vacuum with a nitrogen purge to give (S)-3-(4-(trifluoromethyl)phenyl)morpholine ((S)-Compound E). (Analytical Data: (+99% ee by chiral HPLC, LCMS: 232.08 (M+H) + . 1 H NMR(400MHz,DMSO-d6):7.68(d,J=8Hz,2H),7.65(d,J=8Hz,2H),3.89(dd,J=9.95,2.9Hz,1H),3.74(m,2H),3.47(m,1H),3.15(t,J=10.4Hz,1H),2.95(br s,1H)2.88(m,2H).

[0137] Synthesis 2 The reactor was charged with 0.1 M potassium phosphate buffer (pH 6.4, 1.62 L, 13.5 L / kg) and D-glucose (132 g, 1.4 equivalents). Nicotinamide adenine dinucleotide phosphate, monosodium salt (NADP, 1.8 g, 1.5 wt%), glucose dehydrogenase (GDH, 1.8 g, 1.5 wt%) and imine reductase (IRED, 6 g, 5 wt%) were all charged in sequence, followed by 5-(4-(trifluoromethyl)phenyl)-3,6-dihydro-2H-1,4-oxazine (120 g) as a solid. Suitable IREDs include, for example, IRED-155 (also called IRED-0712-C) (Prozomix). Suitable GDHs include, for example, GDH-101. The disodium salt of NADP is also suitable. The reactor was heated to 30° C. The pH was continuously monitored and potassium hydroxide (2M) was used to maintain the pH. NADP was added slowly during the course of the reaction (1.8 g (1.5 wt%) NADP in 60 mL (0.5 L / kg) buffer). After 24 h, the reaction mixture was diluted with acetonitrile (1.14 L, 9.5 L / kg) and aged with stirring for 10 min. 2-Methyltetrahydrofuran (900 mL, 7.5 L / kg) was then charged and after phase separation the aqueous layer was drained. The organic layer was washed with 20% w / w aqueous sodium chloride (600 mL, 5 L / kg) and then distilled under vacuum to 360 mL. Isopropyl alcohol (1.44 L, 12 L / kg) was added and the mixture was distilled to 360 mL. Isopropyl alcohol (1.20 L, 10 L / kg) was added and the solution was finish filtered. Distilled under vacuum to 480 mL. Separately, acetyl chloride (45 mL, 1.2 equiv.) was added dropwise to isopropanol (240 mL, 2 L / kg) at 0° C., the mixture was heated to 20° C. and aged for 15 min. Alternatively, HCl in a solvent (e.g., isopropanol, ethanol, or 2-methyltetrahydrofuran) could be added. The product / isopropanol mixture was heated to 60° C. and the HCl / isopropanol solution was charged slowly. The slurry was cooled to 20° C. Heptane (1.44 L, 12 L / kg) was charged over 2 h. Other suitable solvents include methyl ethyl ketone.The solid product was filtered and washed twice with premixed 2:1 heptane:isopropanol (2×480 mL, 2×4 L / kg). The cake was dried under vacuum under a stream of nitrogen to yield (S)-3-(4-(trifluoromethyl)phenyl)morpholine hydrochloride (>99.8% chiral purity). 1 H NMR(400MHz,DMSO-d6):Δ 9.80-10.99(m,2H),7.95(d,2H),7.83(d,2H),4.61(m,1H),4.02(m,2H),3.86(m,2H),3.24-3.32(m,2H);mp 198℃.

[0138] Example 4. Synthesis of Compound I - (4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)-[(3S)-3-[4-(trifluoromethyl)phenyl]morpholin-4-yl]methanone [ka] Reaction scale 1 4-Amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridine-8-carboxylic acid (1.0 kg, 4.3 moles, 1.0 equiv.), (3S)-3-[4-(trifluoromethyl)phenyl]morpholine (1.2 kg, 5.2 mmol, 1.2 equiv.) and DMF (6.6 kg, 7.0 V) were charged to a clean, dry reactor. Triethylamine (1.1 Kg, 13.8 moles, 2.6 equiv.) was added to the mixture. The mixture was cooled to 10±5° C. and O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate (TBTU) (1.67 kg, 5.2 moles, 1.2 equiv.) was added slowly. An additional amount of DMF (0.94 Kg, 1 V) was then added. The reaction mixture was warmed to 25±5° C. and stirred for 18 hours. Water (1.0 kg, 1V) was charged followed by MeCN (1.6 kg, 2V) and the reaction mass was warmed to 45° C. Then water (7.0 kg, 7V) was added over 30 minutes. A seed lot of 4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)-[(3S)-3-[4-(trifluoromethyl)phenyl]morpholin-4-yl]methanone (10 g, 22 mmol, 0.01 equiv.) was charged and the mixture was stirred at 45° C. for 2 hours before being cooled to 20° C. over 10 hours. Water (12.0 kg, 12V) was added over 2 hours at 20° C. and stirred for a further 4 hours more before being filtered. The reactor was rinsed with a mixture of 10% DMF in water (9.83 kg, 10V) and the resulting rinse mixture was used to wash the cake. The reactor was rinsed with a mixture of water (10.0 kg, 10V) and the resulting rinse mixture was used to wash the cake. This rinse and wash protocol was repeated one more time with water (10.0 kg, 10V). The cake was dried under vacuum using a stream of nitrogen to give (4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)-[(3S)-3-[4-(trifluoromethyl)phenyl]morpholin-4-yl]methanone. LCMS: 445.20 1H NMR(400MHz,130℃におけるDMSO-d6):8.87(s,1H),7.80(s,1H),7.73(d,J=8.7Hz,2H),7.71(d,J=8.7Hz,2H),6.58(br s,2H),5.72(br s,1H),5.38(m,2H),5.09(t,J=3.5Hz,2H),4.44(br d,J=12.3Hz,1H),4.08(br d,J=13.4Hz,1H),3.96(dd,J=12.3,3.7Hz,1H),3.86(br dd,J=11.4,3.0Hz,1H),3.66(td,J=11.4,3.0Hz,1H),3.28(m,1H).

[0139] Reaction スケール2 4-Amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridine-8-carboxylic acid (85.0 g, 352.2 mmol, 1.0 equiv), (3S)-3-[4-(trifluoromethyl)phenyl]morpholine (99.6 g, 422.6 mmol, 1.2 equiv), and DMF (674 mL, 8.7 moles, 7.9 V) were charged to a clean, dry 5 L reactor. 1-Methylimidazole (75.2 g, 916.2 mmol, 2.6 equiv) was added to the mixture. The mixture was cooled to 0° C. and N,N,N′,N′-tetramethylchloroformamidinium hexafluorophosphate (TCFH) (118.6 g, 422.6 mmol, 1.2 equiv) was added slowly. An additional amount of DMF (170 mL, 2V) was then added at 0° C. The reaction mixture was warmed to 25° C. and stirred overnight. The reaction mass was then warmed to 45° C. and 2-methyltetrahydrofuran (169.2 mL, 2V) was added followed by water (850 mL, 10V) slowly added via addition funnel over 30 minutes. A seed lot of 4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)-[(3S)-3-[4-(trifluoromethyl)phenyl]morpholin-4-yl]methanone (1.6 g, 3.5 mmol, 0.1 equiv) was charged as a slurry in 1:1 v / v DMF and water (31.3 mL) and the mixture was stirred at 45° C. for about 12 hours. Water (510 mL, 6V) was added via addition funnel over 1 h 10 min and the mixture was further stirred at 45° C. for 30 min before being filtered. The reactor was rinsed with water (340 mL, 4V) and the resulting rinse mixture was used to wash the cake. This rinse and wash protocol was repeated two more times. The cake was dried under vacuum using a stream of nitrogen to give (4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)-[(3S)-3-[4-(trifluoromethyl)phenyl]morpholin-4-yl]methanone. LCMS: 445.20 1H NMR (DMSO-d6 at 400MHz, 130℃): 8.87(s,1H),7.80(s,1H),7.73(d,J=8.7Hz,2H),7.71(d,J=8.7Hz,2H),6.58(br s,2H),5.72(br s,1H),5.38(m,2H),5.09(t,J=3.5Hz,2H),4.44(br d,J=12.3Hz,1H),4.08(br d,J=13.4Hz,1H),3.96(dd,J=12.3,3.7Hz,1H),3.86(br dd,J=11.4,3.0Hz,1H),3.66(td,J=11.4,3.0Hz,1H),3.28(m,1H).

[0140] Reaction scale 3 4-Amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridine-8-carboxylic acid (compound A') (20.0 g, 86.5 mmol, 1.0 equiv.) was added to dimethyl sulfoxide (400 mL) at 20° C. 1,1'-carbonyldiimidazole (15.4 g, 95.2 mmol, 1.1 equiv.) was added to the mixture and the mixture was heated to 60° C. for 1 h. A solution of (S)-3-(4-(trifluoromethyl)phenyl)morpholin-4-ium chloride (25.5 g, 95.2 mmol, 1.1 equiv.) and dimethyl sulfoxide (40 mL) was added and the mixture was heated to 80° C. for 11 h. The reaction mixture was cooled to 35° C., water (265 mL) was added, and the batch was cooled to 20° C. The reaction was filtered and washed with 40% water:DMSO (80 mL) followed by water (100 mL). The cake was dried under vacuum using a stream of nitrogen to give (4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)-[(3S)-3-[4-(trifluoromethyl)phenyl]morpholin-4-yl]methanone (compound I). LCMS: 445.20 1H NMR (DMSO-d6 at 400MHz, 130℃): 8.87(s,1H),7.80(s,1H),7.73(d,J=8.7Hz,2H),7.71(d,J=8.7Hz,2H),6.58(br s,2H),5.72(br s,1H),5.38(m,2H),5.09(t,J=3.5Hz,2H),4.44(br d,J=12.3Hz,1H),4.08(br d,J=13.4Hz,1H),3.96(dd,J=12.3,3.7Hz,1H),3.86(br dd,J=11.4,3.0Hz,1H),3.66(td,J=11.4,3.0Hz,1H),3.28(m,1H).

[0141] Recrystallization of Compound I A clean, dry 5 L reactor was charged with (4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)-[(3S)-3-[4-(trifluoromethyl)phenyl]morpholin-4-yl]methanone (279.7 g, 0.6 moles, 1.0 equiv.) followed by acetone (6.2 L, 22 V). The mixture was stirred at 40° C. for 15 minutes and then cooled to 25° C. The reaction was drained into a flask, the reactor was washed with acetone, and the process stream was polish filtered and returned to the reactor. The reactor jacket was set to 65° C. and the reaction volume was reduced to approximately 6 V by distillation at atmospheric pressure, at which point crystallization was observed. The reaction temperature was cooled to 20° C. over 2 hours. Heptane (2.8 L, 10 V) was added over 2 hours. The slurry was filtered and the cake washed twice with a 4:1 heptane / acetone mixture (750 mL, 3 V each) and dried under vacuum with a nitrogen purge to give (4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-8-yl)-[(3S)-3-[4-(trifluoromethyl)phenyl]morpholin-4-yl]methanone.

[0142] Example 5. Synthesis of Compound B1 This example illustrates a process for preparing compound B1 according to an embodiment of the present disclosure.

[0143] 2-Cyano-5-nitropyridine was mixed with nitroreductase NR-17, glucose dehydrogenase GDH-101, NH4VO3 as the third transition metal catalyst, NADP as the cofactor, glucose as the reducing agent, and a buffer under reaction conditions A or B as shown below and in Table 2. [ka]

[0144] [Table 2]

[0145] Reaction condition A was as follows: 10 mg of 2-cyano-5-nitropyridine; NR-17 (1 wt%); NH4VO3 (1 eq); NADP+ (14 wt%); GDH (19 wt%); glucose (4 eq); DMSO (19 V); Tricine buffer (170 V; pH 8); 35° C.; and reaction time 2 hours.

[0146] Reaction condition B (fed-batch) was as follows: 2 g of 2-cyano-5-nitropyridine in DMSO at 0.7 V added over 63 h; NR-17 (7 wt%); NH4VO3 (16 mol%); NADP+ (1 wt%); GDH (1 wt%); glucose (3 eq); KPi buffer (9 V; pH 7.2); 35 °C and reaction time 18 to 56 h.

[0147] Example 6. Synthesis of Compound B1 [ka] This example illustrates the synthesis of compound B1 according to an embodiment of the disclosed process.

[0148] To a slurry of nitroreductase (NR-17; 250 mg, 5 mg / mL%), glucose dehydrogenase (GDH-105; 50 mg, 1 mg / mL%), cofactor (NADP; 36 mg, 1 mM), and third transition metal catalyst (NH4VO3; 468 mg, 0.12 eq) in a buffer (KPi Buffer; 30 mL, 100 mM) at a pH of about 7.5 and a temperature of 20-25°C, a reducing agent (D-glucose; 18.2 g, 3.05 eq) was added at a temperature of 20-25°C. The reaction mixture was mixed for 10-15 minutes. The pH of the reaction mixture was maintained at about 7.5 using a base (e.g., 40% NaOH solution). The reaction mixture was heated to a temperature of 35-38°C (internal temperature). To this heated mixture was added a solution of 2-cyano-5-nitropyridine (5 g, 33.5 mmol, 100% by weight) in DMSO (2.5 mL, 0.5 V) (total solution volume 5.5 mL) over 6 h while maintaining the pH of the mixture at 7-8 with a base (e.g., 40% NaOH solution) (e.g., using a syringe pump at a flow rate of 0.015 mL / min).

[0149] The reaction mass was stirred for 16 hours at a temperature of 35-38°C. The progress of the reaction was monitored by HPLC. IPC by HPLC: starting material = 4.1%, product = 86%. The reaction was cooled to a temperature of 20-25°C, quenched with water (30V) and stirred for 10-15 minutes. The pH of the reaction mixture was adjusted to about 10. The reaction mixture was filtered to remove undissolved particles (solid weight: 0.3 g). The aqueous filtrate was extracted with an organic solvent (e.g., 3 x 10V 2-methyltetrahydrofuran). The combined organic layers were all washed with water (10V), dried over sodium sulfate and concentrated under vacuum at 40-45°C to give 2.5 g of compound B1 (free base).

[0150] Example 7 – Synthesis of Compound B2 [ka] The reactor was charged with solid di-tert-butyl carbonate (8.1 g, 1.2 equiv.) and solid 6-chloropyridin-3-amine (4.0 g, 31 mmol). After purging with nitrogen, isopropanol (20 mL, 5.0 L / kg) was added and the mixture was heated to 55-60°C. Other suitable solvents include tert-butanol or tert-amyl alcohol. After 19 hours, the reaction mixture was diluted with water (35 mL, 8.75 L / kg) and the mixture was held at 60°C for 1 hour. The reaction mixture was slowly cooled to 20°C, aged for 2 hours, filtered, and then displacement washed with 35% i-PrOH / water (24 mL, 6 L / kg). The solid was dried at ambient temperature under a nitrogen sweep to give tert-butyl (6-chloropyridin-3-yl)carbamate. 1 H NMR (400MHz, CDCl3): Δ 8.28(d,1H),7.97(bs,1H),7.28(d,1H),6.79(bs,1H),1.53(s,9H);mp 128℃.

[0151] Example 8 - Synthesis of compound C'-6 tert-butyl (6-chloro-4-(1,3,6,2-dioxazaborocan-2-yl)pyridin-3-yl)carbamate [ka] A mixture of tert-butyl (6-chloropyridin-3-yl)carbamate (3.0 g, 13.1 mmol, 1.0 equiv.), methylmagnesium chloride (3.0 M in tetrahydrofuran, 47.2 mmol, 3.6 equiv.), 2,2,6,6-tetramethylpiperidine (6.66 g, 47.2 mmol, 3.6 equiv.), lithium chloride (665 mg, 15.7 mmol, 1.2 equiv.), tetrahydrofuran (7 mL) and 1,2-dimethoxyethane (38 mL) was stirred at 25° C. for over 24 h until the reaction was complete. A solution of triethylborate (7.27 g, 49.8 mmol, 3.8 equiv.) in tetrahydrofuran (9 mL) was added. The reaction mixture was poured into 60 mL of aqueous sodium potassium tartrate and 2-methyltetrahydrofuran and the layers were separated. The organic layer was washed with water and distilled to remove 1,2-dimethoxyethane and tetrahydrofuran. To the product stream in 2-methyltetrahydrofuran (approximately 30 mL) was added a solution of diethanolamine (1.52 g, 1.44 mmol, 1.1 equiv) in isopropanol (15 mL). Heptane (30 mL) was added and the reaction mixture was filtered. The product cake was washed with 50% 2-methyltetrahydrofuran / heptane (30 mL) and dried at ambient temperature under a nitrogen sweep to give the product tert-butyl (6-chloro-4-(1,3,6,2-dioxazaborocan-2-yl)pyridin-3-yl)carbamate (compound C'-6). 1 H NMR(400MHz,DMSO-d6):9.51(s,1H),8.77(s,1H),7.50(bs,1H),7.25(bs,1H),3.70-3.95(m,4H),3.17-3.23(m,2H),3.02-3.09(m,2H),1.46(s,9H).

[0152] Example 9 – Synthesis of 8-chloro-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-4-amine (A2) [ka] A sample of tert-butyl (6-chloro-4-(1,3,6,2-dioxazaborocan-2-yl)pyridin-3-yl)carbamate (compound C'-6) (2.0 g, 5.85 mmol, 1.0 equiv.) was combined with 2-methyltetrahydrofuran (36 mL) and 4-cyano-2,5-dihydrofuran-3-yl 4-methylbenzenesulfonate (compound D) (2.33 g, 8.78 mmol, 1.5 equiv.) was added. The mixture was washed twice with 2.5% aqueous acetic acid (18 mL). To the organic product layer was added bis(1,5-cyclooctadiene)nickel(0) (57 mg, 0.176 mmol, 3 mol%), tributylphosphonium tetrafluoroborate (153 mg, 0.527 mmol, 9 mol%), triethylamine (59 mg, 0.585 mmol, 0.1 equiv), water (10 mL) and potassium phosphate (2.5 g, 11.7 mmol, 2.0 equiv). The reaction was heated to 60° C. The batch was filtered and washed with water (10 mL), isopropanol (10 mL) and tert-butyl methyl ether (10 mL). The product cake was then dried under vacuum under a stream of nitrogen to give the product, 8-chloro-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-4-amine (compound A2). 1 H NMR (400 MHz, acetonitrile-d3): 8.69 (s, 1H), 7.47 (s, 1H), 6.52 (br s, 2H), 5.27 (br t, J = 3.66 Hz, 2H), 5.03 (br t, J = 3.66 Hz, 2H).

[0153] Example 10 - Synthesis of Compound A' - 4-Amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridine-8-carboxylic acid [ka] 8-Chloro-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-4-amine (compound A2) (20.0 g, 90.2 mmol, 1.0 equiv.), dimethylsulfoxide (900 mL), palladium(II) acetate (506 mg, 2.26 mmol, 2.5 mol %), 1,3-bis(dicyclohexylphosphino)propane bis(tetrafluoroborate) (1.38 g, 2.26 mmol, 2.5 mol %), water (24 mL), phenol (25.5 g, 271 mmol, 3.0 equiv.) and potassium carbonate (62.3 g, 451 mmol, 5.0 equiv.) were combined under 50 psi of carbon monoxide and heated to 85° C. for 21 hours. The mixture was cooled and a nitrogen atmosphere was introduced. The batch was diluted with water (450 mL), filtered, and washed with 33% water:DMSO (100 mL). To the resulting product solid was added water (700 mL) at 48° C., followed by hydrochloric acid (6N, 100 mL). The batch was cooled to 20° C., filtered, and washed with water (100 mL), isopropanol (100 mL), and tert-butyl methyl ether (100 mL). The product cake was then dried under vacuum under a stream of nitrogen to give the product 4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridine-8-carboxylic acid (compound A′). LCMS: 232.08 (M+H). + . 1 H NMR (400 MHz, 1:1 TFA-d / toluene-d8): 9.30 (s, 1H), 8.29 (s, 1H), 5.11 (app s, 4H).

[0154] Example 11 - Compound A1 - 4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridine-8-carbonitrile [ka] A mixture of bis(1,5-cyclooctadiene)nickel(0) (62 mg, 0.23 mmol, 5 mol%) and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos, 130 mg, 0.23 mmol, 5 mol%) in tetrahydrofuran (20 mL) was stirred at 20° C. for 20 min. 8-Chloro-1,3-dihydrofuro[3,4-c][1,7]naphthyridin-4-amine (compound A2) (1.0 g, 4.51 mmol, 1.0 equiv.) and tetrahydrofuran (5 mL) were added and the solvent was stripped off. The batch was diluted with dimethyl sulfoxide (30 mL) and 4-dimethylaminopyridine (550 mg, 4.51 mmol, 1.0 equiv.) was added. To this batch was added zinc cyanide (425 mg, 3.61 mmol, 0.8 equiv) and zinc dust (88 mg, 1.35 mmol, 0.3 equiv). The reaction was heated to 80° C. for 16 h. The reaction was cooled to ambient temperature, filtered, and diluted with 2-methyltetrahydrofuran. The mixture was washed with aqueous ammonium hydroxide, then water, and the solvent was stripped. The residue was dissolved in N,N-dimethylacetamide (10 mL) and heptane (10 mL) was added. The slurry was filtered and washed with isopropanol (10 mL) to give the product, compound A1, 4-amino-1,3-dihydrofuro[3,4-c][1,7]naphthyridine-8-carbonitrile. 1 H NMR(400MHz,TFA-d):9.40(s,1H),8.30(s,1H),5.76(d,J=3.2Hz,2H),5.59(s,2H).LCMS:213.1(M+H) + .

[0155] All references cited herein (e.g., publications, patent applications, and patents) are hereby incorporated by reference to the same extent as if each reference was individually and specifically indicated to be incorporated by reference and was set forth in its entirety herein.

[0156] The recitation of ranges of values ​​herein, unless otherwise stated herein, is merely intended to serve as a shorthand method of referring individually to each of the separate values ​​falling within that range, and each of the endpoints, and each separate value and endpoint is incorporated herein as if it were individually recited herein.

[0157] The use of the terms "a" and "an" as well as "the" and similar referents in describing the invention (especially in relation to the claims which follow) should be construed to encompass both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The term "at least one" followed by a list of one or more items (e.g., "at least one of A and B") should be construed to mean one item (A or B) selected from the listed items or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms "comprise," "have," "include," and "contain" should be construed as open-ended terms (i.e., meaning "including, but not limited to"), unless otherwise indicated herein or clearly contradicted by context. The recitation of ranges of values ​​herein is intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated herein as if it were individually recited herein. All methods described herein may be performed in any suitable order, unless otherwise indicated herein or clearly contradicted by context. The use of any examples or exemplary language (e.g., "etc.") provided herein is intended merely to further clarify the invention and does not impose limitations on the scope of the invention unless otherwise asserted. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

Claims

1. Compound A: 【Chemical 1】 (In the formula, X １ , NH, NR １ , O, S or SO ２ and Y １ is -CN, -Cl, -CHO, -COOH, -CONHR １ , -CON(R １ ) ２ or -CO ２ R １ and Z １ and Z ２ each independently represents H, F, or C １ ~C ６ is alkyl; and Each R １ are independently １ ~C ６ alkyl) or a salt thereof, comprising: (a) mixing compound B with a first transition metal catalyst and a boron-containing compound to form R Ｂ is hydrogen to form compound C, or R Ｂ Ga-COOR ４ and optionally forming Compound C or Compound C': 【Chemistry 2】 (In the formula, R Ｂ is hydrogen or -COOR ４ and R ２ and R ３ each independently represents H or C １ ~C ６ alkyl, or when taken together with the boron and oxygen atoms to which they are attached, form a 5-, 6-, or 8-membered cyclic boronate; R ４ is C １ ~C ６ is alkyl; Y １Ａ is -CN, -Cl, -CONHR １ , -CON(R １ ) ２ or -CO ２ R １ is) and isolating (b) Compound C or Compound C' is converted into Compound D 【Chemistry 3】 (In the formula, X １Ａ is NR ７ , O or S, and R ７ is C １ ~C ６ alkyl, benzyl, or p-methoxybenzyl, and LG is a leaving group. and a second transition metal catalyst to form Compound A or a salt thereof. A process involving:

2. Compound A is A1 or A2: 【Chemistry 4】 2. The process of claim 1 having the structure:

3. 3. The process of claim 1 or 2, wherein the first transition metal catalyst comprises iridium.

4. 3. The process of claim 1 or 2, wherein the boron-containing compound is 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane) or 4,4,5,5-tetramethyl-1,3,2-dioxaborolane.

5. Compound C' is C'-4, C'-5, C'-6 or C'-7: 【Chemistry 5】 3. The process of claim 1 or 2, having the structure:

6. Compound D is D1: 【Chemistry 6】 3. The process of claim 1 or 2, having the structure:

7. 3. The process of claim 1 or 2, wherein the second transition metal catalyst is present in an amount of 1 to 5 mole % or weight % based on compound B, and comprises a palladium catalyst or a nickel catalyst.

8. Compound E: 【Chemistry 7】 (In the formula, X ２ is NR １ , O or S, and R １ is C １ ~C ６ is alkyl; Y ２ is H, C １ ~C ６ Alkyl or C １ ~C ６ haloalkyl; and Z ３ , Z ４ , Z ５ and Z ６ each independently represents H, C １ ~C ６ alkyl or chloride) , its stereoisomer, a salt thereof or a salt of a stereoisomer thereof, comprising: 【Chemistry 8】 or a salt thereof with an imine reductase (IRED) to form Compound E, a stereoisomer thereof, a salt thereof, or a salt of a stereoisomer thereof.

9. X ２ is O and Y ２ is CF ３ and Z ３ , Z ４ , Z ５ and Z ６ 9. The process of claim 8, wherein each of

10. Compound E is the (S)-stereoisomer: 【Chemistry 9】 and compound E has an enantiomeric excess of 95% or greater.

11. Compound G or a salt thereof is mixed with compound H and an organometallic reagent or magnesium metal to form compound F' 【Chemistry 10】 wherein PG is a protecting group and X ｈ is Cl, Br or I 10. The process of claim 8 or 9, further comprising forming

12. 12. The process of claim 11, wherein the organometallic reagent is iPrMgCl and the protecting group is selected from the group consisting of tert-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz) and trimethylsilyl (TMS).

13. 12. The process of claim 11, further comprising deprotecting compound F' to form compound F or a salt thereof.

14. Compound I 【Chemistry 11】 , its stereoisomer, a salt thereof or a salt of a stereoisomer thereof, comprising reacting compound A′ or a salt thereof with compound E, its stereoisomer, a salt thereof or a salt of a stereoisomer thereof. 【Chemistry 12】 (In the formula, X １ , NH, NR １ , O, S or SO ２ and X ２ is NR １ , O or S; Each R １ are independently １ ~C ６ is alkyl; Y ２ is H, C １ ~C ６ Alkyl or C １ ~C ６ haloalkyl; Z １ and Z ２ each independently represents H, F, or C １ ~C ６ is alkyl; and Z ３ , Z ４ , Z ５ and Z ６ each independently represents H, C １ ~C ６ alkyl or chloride) and mixing with a coupling agent to form Compound I, a stereoisomer thereof, a salt thereof, or a salt of a stereoisomer thereof.

15. X １ and X ２ are each O; Y ２ is -CF ３ and Z １ , Z ２ , Z ３ , Z ４ , Z ５ and Z ６ 15. The process of claim 14, wherein each of

16. The coupling agent may be chloro-N,N,N',N'-tetramethylformamidinium hexafluorophosphate (TCFH), O-[(ethoxycarbonyl)cyanomethyleneamino]-N,N,N',N'-tetramethyluronium tetrafluoroborate (TOTU), 1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate (COMU), 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU), N-[(1H-benzotriazol-1-yl)-(dimethylamino)methylene]-N 16. The process of claim 14 or 15, wherein the phosphonium hexafluorophosphate N-oxide (HBTU), O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TBTU), propanephosphonic anhydride (T3P), bis(2-oxo-3-oxazolidinyl)phosphinic chloride (BOPCl), 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT), 1,1'-carbonyldiimidazole (CDI), and 1-cyano-2-ethoxy-2-oxoethylideneaminooxy-tris-pyrrolidino-phosphonium hexafluorophosphate (PyOxim).

17. 17. The process of claim 16, wherein the coupling agent is O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TBTU).

18. 17. The process of claim 16, wherein the coupling agent is CDI.

19. 16. The process of claim 14 or 15, wherein the mixing is carried out in the presence of an additive.

20. 20. The process of claim 19, wherein the additive is N-methylimidazole (NMI) or triethylamine.

21. 20. The process of claim 19, wherein the additive is trifluoromethanesulfonic acid, hydrochloric acid, hydrobromic acid, or hydroiodic acid.

22. 16. The process of claim 14 or 15, further comprising crystallizing Compound I, a stereoisomer thereof, a salt thereof, or a salt of a stereoisomer thereof.

23. Compound I has the structure: 【Chemistry 13】 16. The process of claim 14 or 15, comprising:

24. Compound B is B1 【Chemistry 14】 (Compound B1) or B1' 【Chemistry 15】 (Compound B1') 2. The process of claim 1 having the structure:

25. 2-cyano-5-nitropyridine in a solvent 【Chemistry 16】 Or 2-chloro-5-nitropyridine 【Chemistry 17】 25. The process of claim 24, further comprising combining Compound B1, Compound B1', or a salt thereof with a nitroreductase to form Compound B1, Compound B1', or a salt thereof.

26. 26. The process of claim 25, wherein the nitroreductase is NR-17 or NR-36 and is present in an amount of 5 to 7% by weight based on 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine.

27. 27. The process of claim 25 or 26, further comprising combining 2-cyano-5-nitropyridine, 2-chloro-5-nitropyridine or a salt thereof with the nitroreductase in the presence of one or more of glucose dehydrogenase (GDH), a third transition metal catalyst, a cofactor, a reducing agent, or a buffer.

28. 28. The process of claim 27, wherein the third transition metal catalyst comprises vanadium, iron, copper, or a combination thereof.

29. The third transition metal catalyst is ammonium metavanadate (NH ４ VO ３ ) or vanadium pentoxide (V ２ O ５ 29. The process of claim 28, wherein

30. 28. The process of claim 27, wherein the third transition metal catalyst is present in an amount of 0.01 to 2.5 eq based on the 2-cyano-5-nitropyridine or 2-chloro-5-nitropyridine.

31. 28. The process of claim 27, wherein the glucose dehydrogenase is selected from the group consisting of GDH-101, GDH-105, CDX-901, and combinations thereof.

32. 28. The process of claim 27, wherein the reducing agent is glucose.

33. 28. The process of claim 27, wherein the buffer comprises tricine buffer, potassium phosphate buffer, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), tris(hydroxymethyl)aminomethane (Tris), or a combination thereof.

34. 26. The process of claim 25, wherein the mixing of 2-cyano-5-nitropyridine, 2-chloro-5-nitropyridine, or a salt thereof with the nitroreductase is carried out in a solvent comprising water, dimethyl sulfoxide (DMSO), toluene, methyl tert-butyl ether (MTBE), isopropyl acetate, or a combination thereof.

35. 35. The process of claim 34, wherein the solvent comprises 0.5 to 20 volumes of DMSO based on 2-cyano-5-nitropyridine.

36. 26. The process of claim 25, wherein the combining of 2-cyano-5-nitropyridine, 2-chloro-5-nitropyridine or a salt thereof with the nitroreductase is carried out at a temperature of 32 to 38°C.

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