Synthetic processes and intermediates

Abstract

The present invention provides synthetic processes and synthetic intermediate compounds that can be used to prepare therapeutic conjugates.SOLUTION: To provide a method for preparing a compound of formula 1. The present invention also provides methods for treating HBV infection and / or HDV infection in humans by administering the therapeutic conjugates prepared by the synthetic methods of the present invention.SELECTED DRAWING: None

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims the benefit of priority to U.S. Application No. 62 / 951,836, filed December 20, 2019, which is incorporated herein by reference. [Background technology]

[0002] Hepatitis B virus (HBV) is a member of the hepadnavirus family. HBV infection in humans can cause an infectious, inflammatory disease of the liver. Infected individuals may not show symptoms for many years. It is estimated that approximately one-third of the world's population is infected at some point in their lifetime (including 350 million chronic carriers).

[0003] Hepatitis D virus (HDV) is a small, circular, enveloped RNA virus that can only replicate in the presence of hepatitis B virus (HBV). Specifically, HDV requires HBV surface antigen proteins to replicate. Infection with both HBV and HDV results in more serious complications than infection with HBV alone. When combined with hepatitis B virus, hepatitis D has the highest mortality rate of all hepatitis infections.

[0004] US Patent Application Publication No. 2009 / 0129994 describes, for example, conjugates useful for targeting siRNA suitable for treating HBV and / or HDV to the liver. Currently, there is a need for synthetic processes and synthetic intermediates that can be used to prepare such conjugates. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2018 / 191278 Summary of the Invention [Means for solving the problem]

[0006] In one aspect, the present invention provides synthetic processes and intermediate synthetic compounds that can be used to prepare therapeutic conjugates.

[0007] The present invention also provides methods for treating HBV and / or HDV infection in humans by administering a therapeutic conjugate prepared by the methods of the present invention.

[0008] The present invention also provides a method for treating HBV and / or HDV infection in a human subject, comprising administering to the human subject a therapeutically effective amount of a therapeutic conjugate prepared by the method of the present invention and a second therapeutic agent useful for treating HBV and / or HDV.

[0009] The present invention also provides compounds prepared by the methods of the present invention.

[0010] The present invention also provides a therapeutic conjugate prepared by the method of the present invention for use in medical treatment.

[0011] The present invention also provides therapeutic conjugates prepared by the methods of the invention for the prophylactic or therapeutic treatment of HBV and / or HDV, optionally in combination with another therapeutic agent.

[0012] The present invention also provides the use of a therapeutic conjugate prepared by the method of the present invention to prepare a medicament for the treatment of HBV and / or HDV, optionally in combination with another therapeutic agent. DETAILED DESCRIPTION OF THE INVENTION

[0013] Unless otherwise stated, the following definitions are used:

[0014] The term "alkyl" by itself or as part of another substituent means, unless otherwise specified, a straight or branched chain hydrocarbon radical having the specified number of carbon atoms (i.e., C1-8 means 1 to 8 carbons). Examples include (C1-C8) alkyl, (C2-C8) alkyl, (C1-C6) alkyl, (C2-C6) alkyl, and (C3-C6) alkyl. Examples of alkyl groups include methyl, ethyl, n-propyl, iso-propyl, n-butyl, t-butyl, iso-butyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and the larger homologs and isomers.

[0015] As used herein, the term "protecting group" refers to a substituent commonly used to block or protect a particular functional group on a compound. For example, an "amino-protecting group" is a substituent attached to an amino group that blocks or protects the amino functionality in the compound. Suitable amino-protecting groups include acetyl, trifluoroacetyl, t-butoxycarbonyl (BOC), benzyloxycarbonyl (CBZ), and 9-fluorenylmethyleneoxycarbonyl (Fmoc). Similarly, a "hydroxy-protecting group" refers to a substituent of a hydroxy group that blocks or protects the hydroxy functionality. Suitable protecting groups include acetyl and silyl. A "carboxy-protecting group" refers to a substituent of a carboxy group that blocks or protects the carboxy functionality. Common carboxy-protecting groups include phenylsulfonylethyl, cyanoethyl, 2-(trimethylsilyl)ethyl, 2-(trimethylsilyl)ethoxymethyl, 2-(p-toluenesulfonyl)ethyl, 2-(p-nitrophenylsulfenyl)ethyl, 2-(diphenylphosphino)-ethyl, nitroethyl, and the like. For a general description of protecting groups and their uses, see P.G.M.Wuts and T.W. Greene, "Greene's Protective Groups in Organic Synthesis" 4 th See, e.g., Wiley-Interscience, New York, 2006.

[0016] As used herein, a wavy line crossing a bond in a chemical structure TIFF2026016830000001.tif14115 shows the bond attachment point where the wave bond meets the rest of the molecule in the chemical structure.

[0017] When a bond in a compound of the formula herein is depicted in a non-stereochemical manner (e.g., flat), the atom to which the bond is attached includes all stereochemical possibilities. When a bond in a compound of the formula herein is depicted in a given stereochemical manner (e.g., bold, bold wedge, dashed line, or dashed wedge), the atom to which the stereochemical bond is attached should be understood to be enriched in the depicted absolute stereoisomer unless otherwise specified. In one embodiment, the compound may be at least 51% of the depicted absolute stereoisomer. In another embodiment, the compound may be at least 60% of the depicted absolute stereoisomer. In another embodiment, the compound may be at least 80% of the depicted absolute stereoisomer. In another embodiment, the compound may be at least 90% of the depicted absolute stereoisomer. In another embodiment, the compound may be at least 95% of the depicted absolute stereoisomer. In another embodiment, the compound may be at least 99% of the depicted absolute stereoisomer.

[0018] Capsid inhibitors As used herein, the term "capsid inhibitor" includes compounds capable of inhibiting, either directly or indirectly, the expression and / or function of capsid proteins. For example, capsid inhibitors may include, but are not limited to, any compound that inhibits capsid assembly, induces the formation of non-capsid polymers, promotes excessive or erroneous capsid assembly, adversely affects capsid stabilization, and / or inhibits RNA encapsulation. Capsid inhibitors also include any compound that inhibits capsid function at downstream event(s) within the replication process (e.g., viral DNA synthesis, transport of relaxed open circular DNA (rcDNA) into the nucleus, formation of covalently closed circular DNA (cccDNA), viral maturation, budding, and / or release, etc.). For example, in certain embodiments, an inhibitor detectably inhibits the expression level or biological activity of a capsid protein, e.g., as measured using an assay described herein. In certain embodiments, the inhibitor inhibits the levels of rcDNA and downstream products in the viral life cycle by at least 5%, at least 10%, at least 20%, at least 50%, at least 75%, or at least 90%.

[0019] The term "capsid inhibitor" includes the following compounds: [ka] and the like.

[0020] The term "capsid inhibitor" also includes the compounds Bay-41-4109 (see International Patent Application Publication No. WO / 2013 / 144129), AT-61 (see International Patent Application Publication No. WO / 1998 / 33501, and King, RW, et al., Antimicrob Agents Chemother., 1998, 42, 12, 3179-3186), DVR-01 and DVR-23 (see International Patent Application Publication No. WO2013 / 006394, and Campagna, MR, et al., J. of Virology, 2013, 87, 12, 6931), [ka] and pharmaceutically acceptable salts thereof.

[0021] The term "capsid inhibitor" also refers to [ka] and pharmaceutically acceptable salts thereof.

[0022] sAg secretion inhibitor / RNA destabilizer As used herein, the term "sAg secretion inhibitor" includes compounds capable of either directly or indirectly inhibiting the secretion of sAg (S, M, and / or L surface antigens) bearing subviral particles and / or DNA-containing viral particles from HBV-infected cells. As used herein, "sAg secretion inhibitors" are also known as "RNA destabilizing agents," and these terms are used interchangeably. For example, in certain embodiments, the inhibitor detectably inhibits sAg secretion, e.g., as measured using an assay well known in the art or described herein (e.g., an ELISA assay) or Western blot. In certain embodiments, the inhibitor inhibits sAg secretion by at least 5%, at least 10%, at least 20%, at least 50%, at least 75%, or at least 90%. In certain embodiments, the inhibitor reduces serum levels of sAg in a patient by at least 5%, at least 10%, at least 20%, at least 50%, at least 75%, or at least 90%.

[0023] The term "sAg secretion inhibitors" includes compounds described in U.S. Patent No. 8,921,381, as well as compounds described in U.S. Patent Application Publication Nos. 2015 / 0087659 and 2013 / 0303552. For example, this term includes the compounds PBHBV-001 and PBHBV-2-15, [ka] and pharmaceutically acceptable salts thereof.

[0024] Specific embodiments of the present invention are described below.

[0025] In one embodiment, the present invention provides a compound of formula 1: [ka] and a method for preparing a compound of formula 1-1: [ka] at a temperature of 40°C or higher, a compound of formula 1-2: [ka] to provide a compound of Formula 1. The reaction may be carried out neat or in the presence of one or more solvents. In one embodiment, the present invention is carried out in a polar aprotic solvent, such as, for example, tetrahydrofuran, 1,2-dichloroethene, methyltetrahydrofuran, toluene, acetonitrile, dimethoxyethane, or carbon tetrachloride. In one embodiment, the reaction is carried out at a temperature ranging from about 0°C to about 100°C. In another embodiment, the reaction is carried out at a temperature of 60°C or greater. In another embodiment, the reaction is carried out at a temperature ranging from about 60°C to about 80°C.

[0026] In one embodiment, the present invention provides compound 3: [ka] and a method for preparing a crystalline form of a compound of formula 1: [ka] to a crystalline form of compound 3 without the use of column chromatography during the conversion. In one embodiment, the compound may be crystallized from a solvent comprising dichloromethane or ethyl acetate. In another embodiment, the compound is crystallized from dichloromethane or ethyl acetate.

[0027] In one embodiment, the present invention provides compound 3: [ka] The present invention provides a crystalline form of

[0028] In one embodiment, the present invention provides a compound of formula 9: [ka] (In the formula, R 9 is an optionally substituted benzyloxycarbonyl group, by preparing a compound of formula 8: [ka] or a salt thereof to a compound of Formula 9. The conversion may be carried out at any suitable temperature, and may be carried out neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a polar or non-polar aprotic solvent, such as, for example, dichloromethane, chloroform, tetrahydrofuran, methyltetrahydrofuran, carbon tetrachloride, acetonitrile, pyridine, dimethylformamide, dimethylacetamide, or toluene. In one embodiment, the conversion is carried out at a temperature ranging from about 0° C. to about 100° C. In another embodiment, the conversion is carried out at a temperature ranging from about 15° C. to about 25° C. In one embodiment, R 9 is benzyloxycarbonyl or nitrobenzyloxycarbonyl. In one embodiment, the compound of formula 8 is converted to the compound of formula 9 by treating the compound of formula 8 with benzyloxycarbonyl chloride in the presence of a suitable base in a suitable solvent. In one embodiment, the base is an amine base such as trimethylamine, triethylamine, pyridine, dimethylaminopyridine, diisopropylethylamine, or tripropylamine.

[0029] In one embodiment, the present invention provides a compound of formula 10: [ka] (In the formula, R 9 is an optionally substituted benzyloxycarbonyl group), by preparing the corresponding compound of formula 9: [ka] to a compound of Formula 10. The conversion may be carried out at any suitable temperature, either neat or in the presence of one or more solvents. In one embodiment, the conversion provides a compound of Formula 10 as at least about 85%, 90%, or 95% β-isomer. In one embodiment of the present invention, the conversion is carried out in a non-polar aprotic solvent such as, for example, dichloroethane, dichloromethane, acetonitrile, methyltetrahydrofuran, tetrahydrofuran, dimethoxyethane, or toluene. In one embodiment, the conversion is carried out at a temperature ranging from about 0° C. to about 100° C. In another embodiment, the conversion is carried out at a temperature ranging from about 80° C. to about 85° C. In another embodiment, the conversion is carried out at a temperature ranging from about 35° C. to about 45° C. In another embodiment, the conversion is carried out at a temperature ranging from about 45° C. to about 55° C. In another embodiment, the conversion is carried out at a temperature ranging from about 55° C. to about 65° C. In another embodiment, the conversion is carried out at a temperature that optimizes the β:α ratio of the products. 9 is benzyloxycarbonyl or nitrobenzyloxycarbonyl. In one embodiment, the compound of formula 9 can be prepared by reacting the compound of formula 7: [ka] to the compound of formula 10. In one embodiment, the catalyst is Sc(OTf) 3 , trimethylsilyl trifluoromethanesulfonate, zinc chloride, or 4A molecular sieves.

[0030] In one embodiment, the present invention provides a compound of formula 10: [ka] (In the formula, R 9 is an optionally substituted benzyloxycarbonyl group, by preparing a compound of formula 8: [ka] or a salt thereof, with the corresponding compound of formula 9: [ka] and subsequently converting the corresponding compound of formula 9 to a compound of formula 10 without chromatographic purification of the compound of formula 9.

[0031] In one embodiment, the present invention provides a salt of formula 11: [ka] and a method for preparing a compound of formula 10: [ka] (In the formula, R 9 is an optionally substituted benzyloxycarbonyl group) with hydrogen and trifluoroacetic acid in the presence of a suitable catalyst and in the presence of a suitable solvent. In one embodiment, a suitable catalyst comprises palladium on carbon. In one embodiment, a suitable solvent comprises tetrahydrofuran. The reaction may be carried out at any suitable temperature. In one embodiment, the reaction is carried out at a temperature ranging from about 0° C. to about 50° C. In another embodiment, the reaction is carried out at a temperature ranging from about 20° C. to about 25° C. In one embodiment, R 9 is benzyloxycarbonyl or nitrobenzyloxycarbonyl.

[0032] In one embodiment, the present invention provides a compound of formula 15D: [ka] or a salt thereof, comprising a compound of formula 15C: [ka] (Wherein, each R 15is (C1-C6) alkyl) to a compound of Formula 15D, or a salt thereof. The conversion may be carried out at any suitable temperature, and may be carried out neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a polar protic solvent, such as, for example, methanol, ethanol, tetrahydrofuran, and / or water. In one embodiment, the conversion is carried out at a temperature ranging from about 0°C to about 100°C. In another embodiment, the conversion is carried out at a temperature ranging from about 15°C to about 25°C. In one embodiment, the conversion is carried out in the presence of a suitable base, such as, for example, sodium hydroxide, lithium hydroxide, or potassium hydroxide.

[0033] In one embodiment, the present invention provides a compound of formula 15C: [ka] (Wherein, each R 15 is (C1-C6) alkyl), providing a method for preparing a compound of formula 15A: [ka] or a salt thereof, with the corresponding compound of formula 15B: [ka] or a salt thereof to provide a compound of Formula 15C. The reaction may be carried out at any suitable temperature, and may be carried out neat or in the presence of one or more solvents. In one embodiment of the present invention, the reaction is carried out in a polar aprotic solvent, such as, for example, dimethylformamide, dichloromethane, 1,2-dichloroethane, or dimethylacetamide. In one embodiment, the reaction is carried out at a temperature ranging from about 0° C. to about 50° C. In another embodiment, the reaction is carried out at a temperature ranging from about 5° C. to about 10° C. In one embodiment, the reaction is carried out in the presence of a suitable base. In one embodiment, the base is a hindered amine base, such as, for example, diisopropylethylamine, trimethylamine, pyridine, or dimethylaminopyridine. In one embodiment, the reaction is carried out in the presence of a suitable coupling agent, such as 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide EDC, N,N′-dicyclohexyl-carbodiimide DCC, (1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate HATU, (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HBTU, or propanephosphonic anhydride T3P).

[0034] In one embodiment, the present invention provides a compound of formula 13A: [ka] (Wherein, each R 15 is (C1-C6) alkyl), and the corresponding compound of formula 15C: [ka] (Wherein, each R 15is (C1-C6) alkyl) to a compound of Formula 13A. The conversion may be carried out at any suitable temperature, and may be carried out neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a polar protic solvent, such as, for example, methanol, ethyl acetate, tetrahydrofuran, methyltetrahydrofuran, or ethanol. In one embodiment, the conversion is carried out at a temperature ranging from about 0°C to about 100°C. In another embodiment, the conversion is carried out at a temperature ranging from about 15°C to about 25°C. In one embodiment, the conversion is carried out in the presence of a suitable catalyst, such as, for example, palladium on carbon or Pd(OH).

[0035] In one embodiment, the present invention provides a compound of formula 13B: [ka] (Wherein, each R 15 is (C1-C6) alkyl and T is an optionally substituted triphenylmethyl group, to prepare the corresponding compound of formula 13A: [ka] to a compound of Formula 13B. The conversion may be carried out at any suitable temperature, and may be carried out neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a non-polar aprotic solvent, such as, for example, dichloromethane, 1,2-dichloroethane, dimethylformamide, or dimethylacetamide. In one embodiment, the conversion is carried out at a temperature ranging from about −78° C. to about 100° C. In another embodiment, the conversion is carried out at a temperature ranging from about 0° C. to about 30° C. In one embodiment, the conversion is carried out in the presence of a suitable coupling agent such as 1-ethyl-3-(3-dimethylamino-propyl)carbodiimide EDC, N,N′-dicyclohexylcarbodiimide DCC, (1-[bis(dimethylamino)-methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate HATU, (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HBTU, or propanephosphonic anhydride T3P). In one embodiment, the compound of Formula 13A can be prepared by reacting the compound of Formula 13A with the corresponding compound of Formula 6: [ka] or a salt thereof, wherein DMTr is 4,4-dimethoxytriphenylmethyl. In one embodiment, the compound of formula 13A is converted to a compound of formula 13B by treatment with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide in dichloromethane at a temperature ranging from about 0° C. to about 30° C. [ka] is processed.

[0036] In one embodiment, the present invention provides a compound of formula 13C: [ka] and a method for preparing a compound of formula 13B: [ka] (Wherein, each R 15 is (C1-C6) alkyl, and T is an optionally substituted triphenylmethyl group, to a compound of formula 13C. The conversion may be carried out at any suitable temperature, neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a polar protic solvent, such as, for example, methanol, ethanol, tetrahydrofuran, and / or water. In one embodiment, the conversion is carried out at a temperature ranging from about 0°C to about 100°C. In another embodiment, the conversion is carried out at a temperature ranging from about 20°C to about 40°C. In one embodiment, the conversion is carried out in the presence of a suitable base, such as, for example, potassium hydroxide, lithium hydroxide, or sodium hydroxide. In one embodiment, a compound of formula 13B is converted to a compound of formula 13C by treatment with potassium hydroxide in a solvent comprising methanol and water.

[0037] In one embodiment, the present invention provides a compound of formula 13CC: [ka] The present invention provides a method for preparing the crystalline potassium salt of the compound of formula 13CC, comprising treating the compound of formula 13CC or a salt thereof with potassium hydroxide in methanol. In one embodiment, the crystalline potassium salt of the compound of formula 13CC can be prepared as described in Example 30.

[0038] In one embodiment, the present invention provides a compound of formula 11B: [ka] and a method for preparing a compound of formula 11A: [ka] or a salt thereof to a compound of Formula 11B. The conversion may be carried out at any suitable temperature, and may be carried out neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a non-polar aprotic solvent, such as, for example, dichloromethane, 1,2-dichloroethane, methyltetrahydrofuran, tetrahydrofuran, dimethylformamide, or dimethylacetamide. In one embodiment, the conversion is carried out at a temperature ranging from about 0° C. to about 100° C. In another embodiment, the conversion is carried out at a temperature ranging from about 5° C. to about 30° C. In one embodiment, the compound of formula 11A is converted to the compound of formula 11B by treating the compound of formula 11A, or a salt thereof, with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide EDC, N,N′-dicyclohexylcarbodiimide DCC, (1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate HATU, (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HBTU, or propanephosphonic anhydride T3P) in dichloromethane.

[0039] In one embodiment, the present invention provides a compound of formula 12: [ka] and a method for preparing a compound of formula 11B: [ka] to a compound of formula 12. The conversion may be carried out at any suitable temperature, neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a non-polar aprotic solvent, such as, for example, dichloromethane, 1,2-dichloroethane, methyltetrahydrofuran, tetrahydrofuran, dimethylformamide, or dimethylacetamide. In one embodiment, the conversion is carried out at a temperature ranging from about 0° C. to about 50° C. In another embodiment, the conversion is carried out at a temperature ranging from about 0° C. to about 30° C. In one embodiment, the conversion is carried out in the presence of a suitable base. In one embodiment, the base is a hindered amine base, such as, for example, diisopropylethylamine, trimethylamine, dimethylaminopyridine, or pyridine. In one embodiment, a compound of formula 11B can be prepared by converting a compound of formula 11B to a compound of formula 11: [ka] or a salt thereof to give a compound of formula 12. In one embodiment, a compound of formula 11B can be converted to a compound of formula 11 by treating a compound of formula 11B with a solvent comprising diisopropylethylamine and dichloromethane to give a compound of formula 11: [ka] This is converted to a compound of formula 12 by treatment with the trifluoroacetate salt of

[0040] In one embodiment, the present invention provides a compound of formula 13: [ka] or a salt thereof, comprising a compound of formula 12: [ka] to provide a compound of formula 13 or a salt thereof. The reduction may be carried out at any suitable temperature, and may be carried out neat or in the presence of one or more solvents. In one embodiment of the present invention, the reduction is carried out in a polar aprotic solvent, such as, for example, tetrahydrofuran, methyltetrahydrofuran, or ethyl acetate. In one embodiment, the reduction is carried out at a temperature ranging from about 0°C to about 50°C. In another embodiment, the reduction is carried out at a temperature ranging from about 0°C to about 30°C. In one embodiment, the reduction is carried out in the presence of a suitable catalyst, such as, for example, palladium on carbon. In one embodiment, the compound of formula 13 or a salt thereof is prepared by the trifluoroacetate salt of the following formula: [ka] is.

[0041] In one embodiment, the present invention provides a compound of formula 14: [ka] and a method for preparing a compound of formula 13: [ka] or a salt thereof to a compound of Formula 14. The conversion may be carried out at any suitable temperature, either neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a non-polar aprotic solvent, such as dichloromethane, 1,2-dichloroethane, methyltetrahydrofuran, tetrahydrofuran, dimethylformamide, or dimethylacetamide. In one embodiment, the conversion is carried out at a temperature ranging from about −78° C. to about 25° C. In another embodiment, the conversion is carried out at a temperature ranging from about −25° C. to about 30° C. In one embodiment, the conversion is carried out in the presence of a suitable base. In one embodiment, the base is an amine base, such as trimethylamine, triethylamine, diisopropylethylamine, dimethylaminopyridine, pyridine, or tripropylamine. In one embodiment, the conversion is carried out in the presence of a suitable coupling reagent, such as propanephosphonic anhydride. In one embodiment, the compound of Formula 13 can be prepared by coupling a compound of Formula 13 with a compound of Formula 14 in the presence of a coupling agent such as 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide EDC, (1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate HATU, (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HBTU, or propanephosphonic anhydride T3P) in a solvent comprising dichloromethane at a temperature ranging from about −15° C. to about 15° C. [ka] or a salt thereof to be converted to a compound of formula 14.

[0042] In one embodiment, the present invention provides a compound of formula 16: [ka] (In the formula, R 16 is an amine protecting group), to provide a compound of formula 13: [ka] or a salt thereof to a compound of Formula 16. The conversion may be carried out at any suitable temperature, either neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a non-polar aprotic solvent, such as dichloromethane, 1,2-dichloroethane, methyltetrahydrofuran, tetrahydrofuran, dimethylformamide, or dimethylacetamide. In one embodiment, the conversion is carried out at a temperature ranging from about −78° C. to about 50° C. In another embodiment, the conversion is carried out at a temperature ranging from about −25° C. to about 50° C. In one embodiment, the conversion is carried out in the presence of a suitable base. In one embodiment, the base is an amine base, such as trimethylamine, triethylamine, or tripropylamine, diisopropylethylamine, dimethylaminopyridine, or pyridine. In one embodiment, the conversion is carried out in the presence of a suitable coupling reagent such as, for example, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide EDC, (1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate HATU, (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HBTU, or propanephosphonic anhydride T3P. In one embodiment, a compound of Formula 13, or a salt thereof, can be prepared by reacting a compound of Formula 13 under suitable coupling conditions to give the corresponding compound of Formula 15DD: [ka] (In the formula, R 16 is an amine protecting group) or a salt thereof to give a compound of formula 16. In one embodiment, the compound of formula 13 is the trifluoroacetate salt: [ka] can be converted under suitable coupling conditions into a compound of formula 15D, where R 16is benzyloxycarbonyl), [ka] to give a compound of formula 16, 16 is benzyloxycarbonyl. In one embodiment, a compound of formula 13 is treated with a compound of formula 15D or 15DD in the presence of propanephosphonic anhydride, trimethylamine, and a solvent comprising dichloromethane to provide a compound of formula 16.

[0043] In one embodiment, the present invention provides a compound of formula 18: [ka] (In the formula, R 18 is a suitable protecting group), to provide a compound of formula 13: [ka] or a salt thereof to a compound of Formula 18. The conversion may be carried out at any suitable temperature, and may be carried out neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a non-polar aprotic solvent, such as, for example, dichloromethane, 1,2-dichloroethane, methyltetrahydrofuran, tetrahydrofuran, dimethylformamide, or dimethylacetamide. In one embodiment, the conversion is carried out at a temperature ranging from about −78° C. to about 50° C. In another embodiment, the conversion is carried out at a temperature ranging from about −25° C. to about 50° C. In one embodiment, the conversion is carried out in the presence of a suitable base. In one embodiment, the base is an amine base, such as, for example, trimethylamine, triethylamine, or tripropylamine, diisopropylethylamine, dimethylaminopyridine, or pyridine. In one embodiment, the conversion is carried out in the presence of a suitable coupling reagent such as, for example, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide EDC, (1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate HATU, (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HBTU, or propanephosphonic anhydride T3P. In one embodiment, a compound of Formula 13 or a salt thereof can be prepared by coupling a compound of Formula 13 or a salt thereof under suitable coupling conditions to a compound of Formula 13CCC: [ka] (In the formula, R 18 is a suitable protecting group) or a salt thereof to provide a compound of formula 18. In one embodiment, the compound of formula 13 is the trifluoroacetate salt: [ka] can be converted under suitable coupling conditions into a compound of formula 13CCC, where R 18 is 4,4-dimethoxytriphenylmethyl) to give a compound of formula 18: [ka] (In the formula, R 18 is 4,4-dimethoxytriphenylmethyl. In one embodiment, a compound of formula 13 is treated with a compound of formula 13CCC in the presence of propanephosphonic anhydride, trimethylamine, and a solvent comprising dichloromethane to provide a compound of formula 18.

[0044] In one embodiment, the present invention provides a compound of formula 16-2: [ka] and a method for preparing a compound of formula 16-1: [ka] or a salt thereof to a compound of formula 16-2. The conversion may be carried out at any suitable temperature, either neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a non-polar aprotic solvent, such as, for example, dichloromethane, 1,2-dichloroethane, chloroform, or carbon tetrachloride. In one embodiment, the conversion is carried out at a temperature ranging from about −78° C. to about 100° C. In another embodiment, the conversion is carried out at a temperature ranging from about −0° C. to about 30° C. In one embodiment, the conversion is carried out by activating the carboxylic acid group in a compound of formula 16-1, for example, by treating the compound of formula 16-1 with oxalyl chloride, and treating the resulting carboxylic acid chloride group with tert-butanol to provide a compound of formula 16-2.

[0045] In one embodiment, the present invention provides a compound of formula 16-3: [ka] and a method for preparing a compound of formula 16-2: [ka] to a compound of formula 16-3. The conversion may be carried out at any suitable temperature, neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a polar protic solvent, such as, for example, methanol or ethanol. In one embodiment, the reaction is carried out at a temperature ranging from about -78°C to about 50°C. In another embodiment, the conversion is carried out at a temperature ranging from about -0°C to about 50°C. In one embodiment, the conversion is carried out in the presence of a suitable catalyst, such as, for example, palladium on carbon.

[0046] In one embodiment, the present invention provides a compound of formula 16-4: [ka] and a method for preparing a compound of formula 16-3: [ka] to a compound of formula 16-4. The conversion may be carried out at any suitable temperature, neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a non-polar aprotic solvent, such as, for example, dichloromethane, 1,2-dichloroethane, methyltetrahydrofuran, tetrahydrofuran, dimethylformamide, or dimethylacetamide. In one embodiment, the conversion is carried out at a temperature ranging from about −78° C. to about 50° C. In another embodiment, the conversion is carried out at a temperature ranging from about −0° C. to about 50° C. In one embodiment, the conversion is carried out in the presence of a suitable base. In one embodiment, the base is an amine base, such as, for example, trimethylamine, triethylamine, or tripropylamine, diisopropylethylamine, dimethylaminopyridine, or pyridine. In one embodiment, the conversion is carried out in the presence of a suitable coupling reagent, such as 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide EDC, (1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate HATU, (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HBTU, or propanephosphonic anhydride T3P.

[0047] In one embodiment, the present invention provides a compound of formula 16-5: [ka] or a salt thereof, comprising a compound of formula 16-4: [ka] to a compound of formula 16-5. The conversion may be carried out at any suitable temperature, neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a polar protic solvent, such as, for example, methanol, ethanol, tetrahydrofuran, or ethyl acetate. In one embodiment, the conversion is carried out at a temperature ranging from about −78° C. to about 50° C. In another embodiment, the conversion is carried out at a temperature ranging from about −0° C. to about 50° C. In one embodiment, the conversion is carried out in the presence of a suitable catalyst, such as, for example, palladium on carbon.

[0048] In one embodiment, the present invention provides a compound of formula 16D: [ka] or a salt thereof, comprising a compound of formula 16-5: [ka] to a compound of Formula 16D. The conversion may be carried out at any suitable temperature, and may be carried out neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a non-polar aprotic solvent, such as, for example, dichloromethane, 1,2-dichloroethane, methyltetrahydrofuran, tetrahydrofuran, dimethylformamide, or dimethylacetamide. In one embodiment, the conversion is carried out at a temperature ranging from about −78° C. to about 50° C. In another embodiment, the conversion is carried out at a temperature ranging from about 0° C. to about 50° C. In one embodiment, the conversion is carried out in the presence of a suitable base. In one embodiment, the base is an amine base, such as, for example, trimethylamine, triethylamine, or tripropylamine, diisopropylethylamine, dimethylaminopyridine, or pyridine. In one embodiment, the conversion is carried out in the presence of a suitable coupling reagent such as 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide EDC, (1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate HATU, (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HBTU, or propanephosphonic anhydride T3P.

[0049] In one embodiment, the present invention provides a compound of formula 16E: [ka] or a salt thereof, comprising a compound of formula 16D: [ka] or a salt thereof to a compound of Formula 16E. The conversion may be carried out at any suitable temperature, and may be carried out neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a non-polar aprotic solvent such as, for example, dichloromethane, chloroform, or carbon tetrachloride. In one embodiment, the conversion is carried out at a temperature ranging from about −25° C. to about 50° C. In another embodiment, the conversion is carried out at a temperature ranging from about 0° C. to about 50° C. In one embodiment, the conversion is carried out in the presence of a suitable acid. In one embodiment, the acid is trifluoroacetic acid.

[0050] In one embodiment, the present invention provides a compound of formula 16: [ka] or a salt thereof, comprising a compound of formula 16E: [ka] or a salt thereof to a compound of Formula 16. The conversion may be carried out at any suitable temperature, and may be carried out neat or in the presence of one or more solvents. In one embodiment of the present invention, the conversion is carried out in a polar aprotic solvent, such as, for example, dimethylformamide, dichloromethane, or dimethylaminopyridine. In one embodiment, the conversion is carried out at a temperature ranging from about −25° C. to about 25° C. In another embodiment, the conversion is carried out at a temperature ranging from about 0° C. to about 10° C. In one embodiment, the conversion is carried out in the presence of a suitable base. In one embodiment, the base is a hindered amine base, such as, for example, diisopropylethylamine, trimethylamine, dimethylaminopyridine, or pyridine. In one embodiment, the conversion is carried out in the presence of a suitable coupling agent, such as, for example, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide EDC. In one embodiment, the conversion is carried out in the presence of a suitable hydroxybenzotriazole, N,N'-dicyclohexylcarbodiimide DCC, (1-[bis(dimethylamino)-methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate HATU, or propanephosphonic anhydride T3P). In one embodiment, a compound of Formula 16E or a salt thereof can be prepared by coupling a compound of Formula 16E or a salt thereof under suitable coupling conditions to a compound of Formula 11: [ka] or a salt thereof to give a compound of formula 16 or a salt thereof.

[0051] Compounds of Formula 16 and Formula 18 may be used to prepare therapeutic conjugates, including the corresponding therapeutic conjugates described in International Patent Application Publication No. WO2018 / 191278.

[0052] The invention will now be described with reference to the following non-limiting examples. [Example]

[0053] Scheme 1 [ka]

[0054] In compounds 1-6, the bold wedge bond indicates the cis isomer rather than absolute stereochemistry. The present invention provides compounds 1-6 having both cis configurations. When compounds 1-6 are incorporated into other compounds herein, the bold wedge bond in compounds 1-6 indicates the cis configuration, while any other bold, bold wedge, dashed, or dashed wedge bond therein indicates absolute stereochemistry.

[0055] Example 1. Synthesis of Compound 3 [ka] To a solution of compound 1-1 (200 g, 1.58 mol) in 2-MeTHF (2.4 L) was added trifluoroacetic acid (TFA) (5.4 g, 4.7 mmol). The reaction mixture was heated to 65-70 °C, and compound 1-2 (414 g, 1.74 mol) was slowly added while maintaining the reaction temperature at 65-70 °C. After the addition was complete, the reaction mixture was heated at 65-70 °C for ≥2 h until the reaction was complete as confirmed by UPLC (disappearance of compound 1-1). The reaction mixture was then cooled to -5-0 °C. Red-Al (1.6 kg, 4.75 mol, 60-70% solution in toluene) was slowly added while maintaining the temperature below -5-0 °C. The reaction mixture was then warmed to 25-30 °C and stirred for ≥12 h until the reaction was complete as confirmed by UPLC (disappearance of compound 1-2). A separate reaction vessel-2, containing 10% NaOH solution (4.0 L), was cooled to 0°C. The reaction mixture was quenched by transferring it to a cooled 10% NaOH solution while maintaining the temperature below 30°C. After the transfer was complete, the quenched mixture was stirred for 3 hours and then the layers were separated. The organic layer was separated. The organic layer was washed with water (2.0 L) and 15% brine (2.0 L) and then evaporated to dryness. The crude residue of compound 2 (424 g) (pale yellow oil) was used directly in the next step.

[0056] Compound 2 (424 g, 1.7 mol) was transferred into MeOH (1.7 L). Activated carbon (42.4 g, 0.10 wt / wt) was added and heated to 40–45°C for 2 h. The hot solution was filtered through a pad of hyflo and washed with MeOH (424 mL). The filtrate was transferred to a hydrogenation autoclave flask and degassed and purged with N2 twice. 10 wt% Pd / C (50% wet, 42.4 g) was charged, and the mixture was degassed and purged with H2 twice. The reaction mixture was stirred under a H2 atmosphere (100 psi) for 20 h or more until completion was confirmed by UPLC. The mixture was degassed and purged with N2 and filtered through a Celite pad. The filtrate was evaporated to near dryness, co-distilled with ethyl acetate (2 x 848 mL), and triturated with ethyl acetate (424 mL) at 25-30°C for 3 hours. The solid was filtered, washed with chilled ethyl acetate (212 mL), and dried under reduced pressure at <30°C. Compound 3 (180.0 g, 71%) was obtained as an off-white solid. m / z 160.11 [M+H] + . 1 H NMR (400 MHz, DMSO-d6) δ 4.18 (s, 2H), 3.34 (s, 2H), 3.25 (d, J = 10.5 Hz, 2H), 2.80 (d, J = 10.6 Hz, 2H), 2.44 (d, J = 10.5 Hz, 2H), 0.88 (d, J = 1.7 Hz, 6H).

[0057] Example 2. Synthesis of Compound 4 [ka] To a solution of methyl sebacate (135.0 g, 848 mmol) in DCM (1350 mL), thionyl chloride (100.9 g, 848 mmol) and DMF (1.0 g) were sequentially charged with stirring while maintaining an internal temperature of 20-30 °C. The mixture was stirred at 20-30 °C for 2 h or more until completion of the reaction was confirmed by the disappearance of the methyl sebacate using UPLC. The mixture was evaporated to dryness, and the residue was co-distilled with DCM (675 mL) to generate the acid chloride in solution in DCM (675 mL). In a separate flask, a mixture of compound 3 in DCM (675 mL), water (1350 mL), and K2CO3 (239.0 g, 2544 mmol) was cooled to 0-5 °C. To this cooled mixture, a solution of the acid chloride in DCM was slowly added dropwise with stirring in four portions at 15-minute intervals, maintaining the temperature below 5°C. The reaction mixture was then warmed to 25-30°C and stirred for 12 hours or more until the reaction was complete as determined by UPLC. The mixture was diluted with ethyl acetate (1500 mL), and the organic layer was separated, washed with water (1350 mL), brine (675 mL), dried over Na2SO4 (135 g), and evaporated to dryness under reduced pressure at <45°C to give compound 4 (260 g, 86%) as a pale yellow liquid. m / z 358.18 [M+H] + . 1 H NMR (400 MHz, DMSO-d6) δ 4.66 (ddd, J = 13.8, 6.1, 3.8 Hz, 2H), 3.51 (dd, J = 10.2, 2.2 Hz, 1H), 3.41 - 3.32 (m, 1H), 3.31 (tt, J = 7.6, 3.8 Hz, 4H), 3.09 (dd, J = 10.3, 2.3 Hz, 1H), 2.99 (dd, J = 11.9, 2.4 Hz, 1H), 2.49 (d, J = 1.7 Hz, 1H), 2.27 (td, J = 7.4, 2.4 Hz, 2H), 2.14 (t, J = 7.6 Hz, 2H), 1.55 - 1.40 (m, 4H), 1.26 - 1.21 (m, 8H), 1.01 - 0.90 (m, 6H).

[0058] Example 3. Synthesis of Compound 5 [ka] To a solution of compound 4 (35.0 g, 9.8 mmol) in DCM (350 mL) was added trimethylamine TEA (14.87 g, 14.7 mmol) and DMAP (1.2 g, 1.0 mmol) at 20-30 °C. The mixture was cooled to 0-5 °C, and then DMTrCl (33.2 g, 9.8 mmol) was added. The reaction mixture was stirred at the same temperature for 2 h or more until completion was confirmed by UPLC. Water (350 mL) was added, and the mixture was warmed to 20-30 °C and stirred for 30 min. The aqueous layer was separated and extracted with DCM (70 mL). The organic layers were pooled, washed with aqueous NaHCO (350 mL), brine (350 mL), dried over NaSO (35.0 g), filtered, and evaporated to dryness. The crude residue was purified by silica gel column chromatography (15-60% EA / hexane) to give pure compound 5 (35.0 g, 54.1%) as a pale yellow oil. m / z 660.58 [M+H] + . 1 H NMR (400 MHz, chloroform-d) δ 7.40 (d, J = 8.1 Hz, 2H), 7.34 - 7.17 (m, 9H), 6.83 (dd, J = 8.8, 2.6 Hz, 4H), 3.80 (s, 6H), 3.67 (s, 3H), 3.56 (d, J = 12.3 Hz, 1H), 3.49 - 3.18 (m, 3H), 3.12 (d, J = 9.9 Hz, 1H), 3.04 (s, 1H), 2.29 (td, J = 7.7, 3.8 Hz, 2H), 2.17 (q, J = 6.2, 4.8Hz, 2H), 2.08 - 2.02 (m, 1H), 1.30 (s, 12H), 1.18 (d, J = 23.3 Hz, 3H), 1.03 (d, J = 4.8 Hz, 3H).

[0059] Example 4. Synthesis of Compound 6 [ka] A solution of compound 5 (35.0 g, 5.3 mmol) in MeOH / water (1:1, 700 mL) was cooled to 0 °C. LiOH.HO (4.86 g, 11.6 mmol) was added, and the mixture was stirred for at least 1 h until the reaction was complete as confirmed by UPLC. The methanol was evaporated, water was added, and the mixture was cooled to 0–5 °C. The mixture was neutralized to approximately pH 7.0 with sodium dihydrogen phosphate solution and then acidified to pH 6–6.5 with acetic acid, maintaining the temperature below 5 °C. The aqueous mixture was extracted with DCM (2 × 350 mL), evaporated to dryness, and then further dried in a vacuum oven at 45 °C. Compound 6 (28.3 g, 82%) was obtained as an off-white solid. m / z 646.54 [M+H] + . 1 H NMR (400 MHz, DMSO-d6) δ 11.96 (s, 1H), 7.32 (p, J = 7.6 Hz, 4H), 7.21 (t, J = 7.6 Hz, 5H), 6.87 (d, J = 8.2 Hz, 4H), 4.60 - 4.48 (m, 1H), 3.72 (s, 6H), 3.46 (dd, J = 30.2, 11.0 Hz, 1H), 3.20 (dd, J = 25.3, 11.0 Hz, 1H), 3.13 - 2.83 (m, 5H), 2.12 (dq, J = 31.7, 7.6 Hz, 4H), 1.49 - 1.41 (m, 4H), 1.22 (d, J = 10.2 Hz, 10H), 1.11 - 0.99 (m, 4H).

[0060] Scheme 2 [ka]

[0061] Example 5. Synthesis of Compound 9 [ka] A 500 mL reaction vessel was charged with 19.0 g (1.0 equiv.) of compound 8 (after azeotropic concentration with toluene to remove all water) and 190 mL (10 V) of DCM. After cooling to -20 °C, 20.6 g (0.95 equiv.) of Cbz-Cl was slowly charged using a syringe pump at -20 to -10 °C over 2 hours. Next, 14.2 g (1.10 equiv.) of TEA was slowly charged using a syringe pump at -20 to -7 °C over 2 hours. The reaction mixture was stirred at room temperature for 17 hours to complete the reaction. The contents were washed sequentially with 95 mL (5 V) of 1 N HCl, 95 mL (5 V) of 8 wt% NaHCO3, and 95 mL (5 V) of brine. Next, 38 mL (2 V) of purified water was added to the organic layer, and the contents were concentrated using a water bath at 65 °C under 20 Torr. The process of azeotropic concentration with water (distillation with water removes impurities) was repeated twice. After azeotropic concentration, the concentrate was diluted with 57 mL (3 V) of DCM and treated with 19 g (1 S) of Na2SO4. The contents were filtered, and the waste solution was washed with 38 mL (2 V) of DCM. The filtrate was concentrated using a water bath at 65 °C under 20 Torr, then dried under full vacuum at 50 °C over the weekend to give the product compound 9 (185 g, 97% yield) as a colorless oil. m / z 284.2 [M+H] + . 1 H NMR (600 MHz, DMSO-d6) δ 7.39 - 7.28 (m, 3H), 7.32 - 7.22 (m, 2H), 5.73 (s, 1H), 5.00 (s, 3H), 4.56 (t, J = 5.5 Hz, 2H), 3.47 (t, J = 5.3 Hz, 4H), 3.40 (td, J = 5.6, 5.2, 2.2 Hz, 7H), 3.33 (s, 1H), 3.14 (q, J = 6.0 Hz, 4H)

[0062] Example 6. Synthesis of Compound 10 [ka] To a solution of compound 9 (10 g, 35.3 mmol) in DCE (100 mL) was added compound 7 (16.5 g, 42.4 mmol) and TMSOTf (0.6 mL, 3.5 mmol). The mixture was stirred at 60-65 °C for 3 h or more until the reaction was complete as confirmed by UPLC. The mixture was cooled to 20-25 °C and washed successively with 8 wt% aqueous NaHCO (2 × 60 mL), 1 N HCl (120 mL), and brine (120 mL), dried over NaSO (120 g), and evaporated to dryness to give compound 10 (22.7 g, quantitative yield) as a pale yellow syrup. m / z 613.3 [M+H] + . 1 H NMR (600 MHz, DMSO-d6) δ 7.78 (d, J = 9.2 Hz, 1H), 7.38 - 7.26 (m, 5H), 7.29 - 7.22 (m, 1H), 5.20 (d, J = 3.4 Hz, 1H), 5.01 - 4.93 (m, 3H), 4.54 (d, J = 8.5 Hz, 1H), 4.01 (m, 3H), 3.86 (m, 1H), 3.76 (m, 1H), 3.60 - 3.51 (m, 1H), 3.54 - 3.43 (m, 6H), 3.39 (t, J = 6.0 Hz, 2H), 3.13 (q, J = 6.0 Hz, 2H), 2.08 (s, 3H), 1.98 (s, 3H), 1.87 (s, 3H), 1.75 (s, 3H).

[0063] Example 7. Synthesis of Compound 11 [ka] To a solution of compound 10 (110 g, 179 mmol) in THF (100 mL) was added TFA (20.5 g, 179 mmol). The mixture was degassed and purged with N2 twice. 10 wt% Pd / C (11 g) was charged, and the mixture was degassed and purged with H2 twice. The mixture was stirred under H2 atmosphere (70 psi) for 3 hours or more until the reaction was complete as confirmed by UPLC. The mixture was degassed and purged with N2 and filtered through a Celite pad. The filtrate was evaporated to dryness to give compound 11 (106 g, quantitative yield) as a pale yellow foamy solid. m / z 479.2 [M+H] + . 1 H NMR (600 MHz, DMSO-d6) δ 7.93 (dd, J = 12.4, 5.3 Hz, 4H), 5.20 (d, J = 3.4 Hz, 1H), 4.96 (dd, J = 11.2, 3.4 Hz, 1H), 4.54 (d, J = 8.5 Hz, 1H), 4.06 - 3.96 (m, 3H), 3.88 (dt, J = 11.1, 8.8 Hz, 1H), 3.78 (m, 1H), 3.58 (t, J = 5.2 Hz, 3H), 3.58 - 3.45 (m, 6H), 2.96 (h, J = 5.6 Hz, 2H), 2.08 (s, 3H), 1.98 (s, 3H), 1.87 (s, 3H), 1.76 (s, 3H).

[0064] Scheme 3 [ka]

[0065] Example 8. Synthesis of Compound 15C [ka] A solution of DMF (1000 mL) and DIPEA (275.3 g, 2.13 mmol) was cooled to 0-5 °C. While maintaining the temperature at 0-5 °C, compound 15-A (100 g, 0.35 mol), EDC.HCl (217.1 g, 1.13 mol), and HOBt monohydrate (173.9 g, 1.13 mol) were sequentially charged. After stirring for 10 min, compound 15-B (163.4 g, 1.17 mol) was added. The reaction mixture was warmed to 25-30 °C and stirred for ≥16 h until completion was confirmed by UPLC. The reaction mixture was diluted by slowly adding ethanol (1000 mL) followed by water (4500 mL) and stirred at 25-30 °C for ≥4 h. The precipitate formed was filtered, washed with water (1000 mL), and the solid was dried under reduced pressure at <50 °C. Compound 15C (134.0 g, 83% yield) was obtained as a white solid. m / z 452.21 [M+H] + .

[0066] Example 9. Synthesis of Compound 15D [ka] To a solution of compound 15C (50 g, 11.1 mmol) in MeOH / water (1:1, 500 mL) was slowly added a solution of NaOH (9.8 g, 24.4 mmol) in water (250 mL) at 25°C to 35°C. The reaction mixture was stirred for 6 hours or more until completion was confirmed by UPLC. MeOH was evaporated. The aqueous solution was acidified to pH 1-2 by adding 6.0 N HCl solution and saturated with NaCl. The aqueous layer was extracted with ethyl acetate (3 x 750 mL). The ethyl acetate layers were pooled, dried over Na-SO4 (100 g), and evaporated to dryness. The crude residue was triturated with hexane (250 mL), filtered, washed with hexane (100 mL), and dried under reduced pressure at 45°C. Compound 15D (20.0 g, 49%) was obtained as a white solid. m / z 396.11 [M+H] + .

[0067] Scheme 4 [ka]

[0068] Example 10. Synthesis of Compound 13A [ka] A solution of compound 15C (80.0 g, 0.17 mol) in THF (2800 mL) was degassed and purged with N2 twice. 10 wt% Pd / C (50% wet, 8.0 g) was charged, and the mixture was degassed and purged with H2 twice. The mixture was stirred under H2 atmosphere (100 psi) for 6 hours or more until the reaction was complete as confirmed by UPLC. The mixture was degassed and purged with N2 and filtered through a Celite pad. The filtrate was evaporated, and the solvent was exchanged with ethyl acetate (2 × 400 mL). The residue was dissolved in ethyl acetate (400 mL) at 45 °C, and n-heptane (320 mL) was slowly added. The mixture was stirred at 45 °C for 1 hour, followed by 0–5 °C for 1 hour. The solid was filtered, washed with a cold solution of ethyl acetate / n-heptane (1:2, 160 mL), and dried in a vacuum oven at 25-30 °C to give compound 13A (46.2 g, 82% yield) as a white solid. m / z 318.14 [M+H] + .

[0069] Example 11. Synthesis of Compound 13B [ka] A solution of DCM and DIPEA (5.9 g, 46.4 mmol) was cooled to 0-5 °C. Compound 6 (15.0 g, 23.2 mmol), EDC.HCl (5.1 g, 26.7 mmol), and HOBt monohydrate (4.1 g, 26.7 mmol) were sequentially charged while maintaining the temperature at 0-5 °C. The mixture was stirred for 10 min, then compound 13A (7.74 g, 24.3 mmol) was charged. The mixture was stirred at 0-5 °C for 21 h or more until the reaction was complete as confirmed by UPLC. Purified water (150 mL) was added while maintaining the temperature below 30 °C. The organic layer was separated and washed with aqueous NaHCO3 (2 × 105 mL) and 10% aqueous NaCl. The organic layer was evaporated and the solvent was exchanged twice with ethyl acetate (300 mL and 150 mL). When the total volume reached 4 V, n-heptane was added and the mixture was heated at 50-55°C for 1 hour, then cooled to 0-5°C for 1 hour. The solid was filtered, washed with the mother liquor and n-heptane (30 mL), and dried under reduced pressure at 40-45°C to give compound 13B (17.9 g, 81%) as a white solid. m / z 946.05 [M+H] + .

[0070] Example 12. Synthesis of Compound 13C [ka] A solution of compound 13B (10.0 g, 10.6 mmol) in THF (100 mL) was cooled to 0-5 °C. KOH solution (1.5 g, 26.4 mmol in 50 mL of water) was added below 5 °C. The reaction mixture was warmed to 25-30 °C and stirred for at least 4 h until completion was confirmed by UPLC. The mixture was cooled to 0-5 °C and the pH was adjusted to approximately 7.0 with aqueous sodium dihydrogen phosphate, maintaining the temperature below 10 °C. 2-Methyltetrahydrofuran (150 mL) was added. The pH was adjusted to 4-5 using 1 N HCl, maintaining the temperature below 10 °C. The mixture was stirred at 25-30 °C for 20 min. The organic layer was separated, and the aqueous layer was backwashed with 2-methyltetrahydrofuran. The organic layers were pooled and washed with 10% aqueous NaCl (50 mL). The organic layer was added with triethylamine (4.3 g, 42.4 mmol) and stirred for 1 h, then evaporated and solvent exchanged with tetrahydrofuran (20 mL), then evaporated to dryness and further dried in a vacuum oven to give compound 13C (TEA salt) (9.0 g, 84%) as a white hygroscopic solid. m / z 889.13 [M+H] +.

[0071] Scheme 5 [ka]

[0072] Example 13. Synthesis of Compound 12 [ka] To a solution of compound 16-1 (41.5 g, 196.6 mmol) in DCM (415 mL) was added N-hydroxysuccinimide (49.7 g, 432.4 mmol) and EDC.HCl (82.9 g, 432.4 mmol). The reaction mixture was stirred at 25-30 °C for 16 h or more until the reaction was complete and compound 11B was formed, as confirmed by TLC. The reaction mixture was evaporated to 2-3 V, water (415 mL) was added, and the solid was stirred at 25-30 °C for 1 h. The solid was filtered and washed with water (415 mL), and the hydrous solid was triturated with aqueous NaHCO3 (415 mL) at 25-30 °C for 1 h. The solid was filtered again, washed with water (415 mL), MTBE (210 mL), and dried under reduced pressure below 45° C. to give compound 11B (45.0 g, 56% yield) as a white solid.

[0073] A solution of compound 11 (110.0 g, 185.64 mmol) in DCM (1100 mL) was cooled to 0-5 °C. Compound 11B (33.85 g, 83.54 mmol) and DIPEA (47.9 g, 371.3 mmol) were charged below 10 °C and stirred at 20-25 °C for 3 h or more until the reaction was complete as confirmed by UPLC. Water (1100 mL) was added to the mixture below 30 °C and stirred for 45 min. The organic layer was separated and washed with aqueous NaHCO (1100 mL), 1 N HCl (1100 mL), and 15% aqueous NaCl (1100 mL). The organic layer was evaporated, solvent exchanged with MTBE (500 mL), dissolved in MTBE (500 mL), and stirred at 25-30 °C for 3 h. The resulting solid was filtered, washed with MTBE (250 mL), and dried under reduced pressure at <50° C. Compound 12 (90.0 g, 86% yield) was obtained as a pale yellow foamy solid. m / z 1132.5 [M+H] + .

[0074] Example 14. Synthesis of Compound 13 [ka] A solution of compound 12 (39 g, 34.45 mmol) in THF (240 mL) was degassed and purged with N2 twice. 10 wt% Pd / C (3.9 g) was charged, and the mixture was degassed and purged with H2 twice. The reaction mixture was stirred under an H2 atmosphere for 4 hours or more until the reaction was complete as determined by UPLC. The mixture was degassed and purged with N2 and filtered through a pad of Celite (39 g). The filtrate was evaporated to dryness to give compound 13 (36.4 g, 95% yield) as a gray foamy solid. m / z 1102.5 [M+H] + .

[0075] Example 15. Synthesis of Compound 14 [ka] A solution of compound 13 (30 g, 22.72 mmol) and N-carbobenzoxyglycine (7.97 g, 38.11 mmol) in DCM (150 mL) was cooled to 0-5 °C, and TEA (7.6 mL, 54.44 mmol) and T3P (29.2 mL, 49 mmol, 50% solution in ethyl acetate) were sequentially charged with stirring below 5 °C. The reaction mixture was stirred at 0-5 °C for ≥3 h until completion was confirmed by UPLC. The reaction mixture was washed successively with water (110 mL), saturated aqueous NaHCO3 (110 mL), and brine (110 mL), then dried over Na2SO4 (60 g), and evaporated to dryness to give compound 14 (32 g, 91% yield) as a gray foamy solid. m / z 1293.6 [M+H] + .

[0076] Example 16. Synthesis of Compound 15 [ka] A solution of compound 14 (68 g, 52.78 mmol) in THF (400 mL) was degassed and purged with N2 twice. 10 wt% Pd / C (6.8 g) and TFA (4.4 mL, 57.84 mmol) were charged, and the mixture was degassed and purged with H2 twice. The reaction mixture was stirred under an H2 atmosphere for 4 hours or more until the reaction was complete as determined by UPLC. The mixture was degassed and purged with N2 and filtered through a pad of Celite (68 g). The filtrate was evaporated to dryness to give compound 15 (63 g, 95% yield) as a gray foamy solid. m / z 1159.6 [M+H] + (free base).

[0077] Scheme 6 [ka]

[0078] Example 17. Synthesis of Compound 16-2 [ka] To a suspension of compound 16-1 (50 g, 236 mmol) in DCM (500 mL) was sequentially charged with oxalyl chloride (69 g, 543 mmol) and DMF (172 mg, 2.3 mmol) while maintaining the internal temperature at 20–30 °C. The mixture was stirred at 20–30 °C for 12 h or more until the completion of the reaction was confirmed by the disappearance of compound 16-1 using UPLC. The mixture was evaporated to dryness, and the residue was dissolved in toluene. t-BuOH (52.5 g, 708 mmol) and DMAP (66.3 g, 543 mmol) were charged to the toluene solution. The mixture was stirred at 20–25 °C for 4 h or more until the completion of the reaction was confirmed by UPLC. The mixture was filtered, and the filtrate was washed with 5% aqueous citric acid (500 mL), brine (500 mL), dried over NaSO (100 g), and evaporated. The residue was azeotroped with n-hexane (250 mL) and evaporated to dryness to give compound 16-2 (73 g, 95% yield) as an off-white solid. m / z 341.2 [M+H] + . 1H NMR (400 MHz, chloroform-d) δ 8.92 (s, 2H), 8.87 (s, 1H), 1.64 (s, 18H).

[0079] Example 18. Synthesis of compound 16-3 [ka] A solution of compound 16-2 (30 g, 92.3 mmol) in MeOH (360 mL) was degassed and purged with N2 twice. 10 wt% Pd / C (3 g) was charged, and the mixture was degassed and purged with H2 twice. The mixture was stirred under an H2 atmosphere for 6 hours or more until the reaction was complete as confirmed by UPLC. The mixture was degassed and purged with N2 and filtered through a Celite pad. The filtrate was evaporated to dryness to give compound 16-3 (26 g, 95% yield) as an off-white solid. m / z 294.2 [M+H] + . 1 H NMR (400 MHz, chloroform-d) δ 7.96 (d, J = 1.7 Hz, 1H), 7.45 (d, J = 1.5 Hz, 2H), 3.92 (s, 2H), 1.59 (s, 18H).

[0080] Example 19. Synthesis of Compound 16-4 [ka] To a solution of compound 16-3 (23.7 g, 80.7 mmol) in DCM (355 mL), the following was sequentially charged with stirring at 15-25 °C: N-carbobenzoxyglycine (23.7 g, 113 mmol), TEA (16.3 g, 161 mmol), and T3P (92.3 g, 145 mmol, 50% solution in ethyl acetate). The mixture was stirred at 15-25 °C for 2 h or more until completion of the reaction was confirmed by UPLC. The mixture was washed successively with water (240 mL), saturated aqueous NaHCO3 (240 mL), and brine (240 mL), then dried over Na2SO4 (48 g), and evaporated to dryness to give compound 16-4 (46.2 g, 118% yield) as a pale yellow solid. m / z 484.2 [M+H] + . 1 H NMR (400 MHz, chloroform-d) δ 8.95 (s, 1H), 8.34 (s, 2H), 8.29 (s, 1H), 7.36–7.27 (m, 5H), 5.99 (s, 1H), 5.16 (s, 2H), 4.12 (d, J = 5.6 Hz, 2H), 1.57 (s, 18H).

[0081] Example 20. Synthesis of Compound 16-5 [ka] A solution of compound 16-4 (46.2 g, 95.3 mmol) in MeOH (1150 mL) was degassed and purged with N2 twice. 10 wt% Pd / C (4.6 g) was charged, and the mixture was degassed and purged with H2 twice. The mixture was stirred under an H2 atmosphere for 3 hours or more until the reaction was complete as confirmed by UPLC. The mixture was degassed and purged with N2 and filtered through a Celite pad. The filtrate was evaporated, and the residue was dissolved in methylene chloride (500 mL) and evaporated to dryness to give compound 16-5 (32.4 g, 97% yield) as a pale yellow solid. m / z 351.2 [M+H] + . 1H NMR (600 MHz, chloroform-d) δ 9.63 (s, 1H), 8.37 (d, J = 1.6 Hz, 2H), 8.31 (t, J = 1.5 Hz, 1H), 3.49 (d, J = 18.7 Hz, 4H), 1.59 (s, 18H).

[0082] Example 21. Synthesis of Compound 16D [ka] To a solution of compound 16-5 (32.5 g, 92.7 mmol) in methylene chloride (455 mL) was added compound 15A (11.7 g, 41.7 mmol) and HBTU (52.7 g, 139 mmol). While maintaining the internal temperature at 15°C to 25°C, TEA (28.1 g, 278 mmol) was added to the mixture. The reaction mixture was stirred at the same temperature for 6 hours or more until completion was confirmed by UPLC. The reaction mixture was washed successively with water (320 mL), aqueous NaHCO3 (320 mL), and brine (320 mL), dried over Na2SO4, and evaporated to dryness. The crude residue was purified by column chromatography (30% to 100% EA / hexane) to give compound 16D (45.2 g, 51% yield) as a white solid. m / z 946.5 [M+H] + . 1 H NMR (600 MHz, DMSO-d6) δ 8.39 (d, J = 15.5 Hz, 5H), 8.22 (t, J = 5.7 Hz, 1H), 8.05 (s, 2H), 7.35 - 7.24 (m, 5H), 5.06 (t, J = 9.3 Hz, 2H), 4.05 (q, J = 7.1 Hz, 1H), 3.98 - 3.87 (m, 4H), 2.28 (hept, J = 7.9, 7.1 Hz, 2H), 1.96 (dt, J = 18.0, 6.7 Hz, 1H), 1.82 (dd, J = 14.5, 7.2 Hz, 1H), 1.53 (d, J = 3.5 Hz, 36H).

[0083] Example 22. Synthesis of Compound 16E [ka] To a solution of compound 16D (30.0 g, 31.7 mmol) in methylene chloride (600 mL) was added TFA (108.4 g, 951 mmol) while maintaining an internal temperature of 15°C to 25°C. 1 The reaction mixture was stirred at 20-25°C for ≥12 h until confirmed by H NMR. The mixture was evaporated to dryness, and the residue was dissolved in methylene chloride (300 mL) and evaporated to dryness again. The resulting residue was partitioned between methylene chloride (300 mL) and 8 wt% aqueous NaHCO3. The organic layer was separated, and the aqueous layer was washed again with methylene chloride (300 mL). The methylene chloride layer was discarded. The aqueous layer was acidified with 3N HCl (approximately 600 mL) to adjust the pH to 3-4. The solid formed was filtered, washed with water, and dried at 45°C for ≥12 h to give compound 16E (16.4 g, 95% yield) as a white solid. m / z 722.2 [M+H] + . 1 H NMR (600 MHz, DMSO-d6) δ 10.31 (s, 1H), 10.11 (s, 1H), 8.48 - 8.38 (m, 5H), 8.30 (s, 0H), 8.25 (t, J = 5.8 Hz, 1H), 8.15 (dt, J = 3.4, 1.6 Hz, 2H), 7.67 (d, J = 6.9 Hz, 1H), 7.37 - 7.24 (m, 5H), 5.12 - 5.01 (m, 2H), 4.03 (q, J = 7.1 Hz, 1H), 3.91 (dd, J = 21.2, 6.1 Hz, 4H), 2.49 (s, 0H), 2.35 - 2.22 (m, 2H), 1.95 (ddt, J = 15.0, 9.0, 5.9 Hz, 1H), 1.87 - 1.79 (m, 1H).

[0084] Example 23. Synthesis of Compound 16 [ka] To a solution of compound 15 (40 g, 31.82 mmol) in DMF (400 mL) was added compound 15A (4.0 g, 14.32 mmol) and HBTU (14.5 g, 38.18 mmol). The reaction mixture was cooled to 10-15 °C, and then TEA (10.6 mL, 76.36 mmol) was added while maintaining the internal temperature at 10-15 °C. The reaction mixture was warmed to 20-25 °C and stirred for 3 h or more until completion was confirmed by UPLC. The reaction mixture was quenched by adding water (400 mL) and ethyl acetate (400 mL). The aqueous layer was separated and extracted with DCM (3 × 400 mL). The DCM layers were pooled, washed with water (5 × 200 mL), dried over NaSO, filtered, and evaporated to dryness. Compound 16 (31.7 g, 87% yield) was obtained as a pale yellow foamy solid. m / z 2563.9 [M+H] +

[0085] Example 24. Synthesis of Compound 16 [ka] To a solution of compound 11 (1.0 g, 1.74 mmol) in anhydrous DMF (9 mL), compound 16E (0.21 g, 0.29 mmol), EDC (333 mg, 1.74 mmol), and HOBt (265 mg, 1.74 mmol) were added sequentially, and the mixture was cooled to 0-5 °C. DIPEA (450 mg, 3.48 mmol) was added while maintaining the internal temperature at 0-5 °C, and the mixture was stirred at the same temperature for 24 h or more until the reaction was complete as confirmed by UPLC. The reaction mixture was diluted with water (11 mL) and then extracted with methylene chloride (50 mL). The methylene chloride layer was washed with water (2 × 5 mL), dried over NaSO, and evaporated to dryness. The residue was purified by column chromatography (2-15% MeOH / DCM) to give pure compound 16 (360 mg, 49.5% yield) as a foamy solid.

[0086] Example 25. Synthesis of Compound 16 [ka] A solution of compound 15D (1.6 g, 4.08 mmol) and compound 13 (10 g, 9.07 mmol) in DCM (100 mL) was cooled to 0-10 °C. TEA (1.84 g, 18.14 mmol) and T3P (10.34 mL, 16.3 mmol, 50% solution in ethyl acetate) were sequentially charged with stirring at 0-10 °C. The reaction mixture was stirred at 25-35 °C for 6 h or more until completion was confirmed by UPLC. The reaction was quenched by adding water (200 mL). The aqueous layer was separated and extracted with DCM (50 mL). The DCM layers were pooled and washed successively with saturated aqueous NaHCO3 (200 mL), 1.0 N HCl (200 mL), and 10% aqueous NaCl (200 mL), then dried over Na2SO4 (25 g), and evaporated to approximately 20 g. MTBE (50 mL) was added, evaporated to dryness, and further dried under reduced pressure at 45° C. Compound 16 (10.3 g, 89% yield) was obtained as a pale yellow solid.

[0087] Example 26. Synthesis of Compound 17 [ka] A solution of compound 16 (2.7 g, 1.05 mmol) in MeOH (27 mL) was degassed and purged with N2 twice. 10 wt% Pd / C (0.27 g) and TFA (156 mg, 1.37 mmol) were charged, and the mixture was purged with H2. The reaction mixture was stirred under an H2 atmosphere for 3 hours or more until the reaction was complete as determined by UPLC. The mixture was degassed and purged with N2 and filtered through a Celite pad. The filtrate was evaporated, and the residue was dissolved in methylene chloride (25 mL) and evaporated to dryness to give compound 17 (2.4 g, 90% yield) as a gray foamy solid. m / z 2428.9 [M+H] + . 1H NMR (600 MHz, DMSO-d6) δ 8.54 (q, J = 5.2 Hz, 1H), 8.21 (d, J = 5.3 Hz, 1H), 8.14 (t, J = 1.8 Hz, 1H), 7.95 (d, J = 8.7 Hz, 1H), 7.80 (d, J = 9.2 Hz, 1H), 5.19 (d, J = 3.4 Hz, 1H), 4.95 (dd, J = 11.2, 3.4 Hz, 1H), 4.52 (d, J = 8.5 Hz, 1H), 4.07 - 3.97 (m, 3H), 3.94 - 3.82 (m, 2H), 3.76 (m, 1H), 3.59 - 3.47 (m, 8H), 3.44 (m, 3H), 2.38 (t, J = 7.8 Hz, 1H), 2.08 (s, 3H), 1.98 (s, 3H), 1.87 (s, 3H), 1.75 (s, 3H).

[0088] Example 27. Synthesis of Compound 18 [ka] To a solution of compound 17 (1.0 g, 0.39 mmol) in DCM (25 mL), compound 6 (0.29 g, 0.44 mmol) and HBTU (186 mg, 0.49 mmol) were added, and the mixture was cooled to 15-25 °C. DIPEA (151 mg, 1.17 mmol) was added while maintaining the internal temperature at 15-25 °C, and the mixture was then stirred at 20-25 °C for 2.5 h or more until the reaction was complete as confirmed by UPLC. The reaction mixture was diluted with DCM (5 mL), washed with water (10 mL), aqueous NaHCO (3 × 8 mL), and brine (10 mL), dried over NaSO, and evaporated to dryness. The residue was purified by column chromatography (2-18% MeOH / DCM) to give pure compound 18 (860 mg, 72.5% yield) as an off-white foamy solid. m / z (z=2) 1378.5 [M-DMTr+2H] 2+ .

[0089] Example 28. Synthesis of Compound 18 [ka] A solution of compound 13C (39.8 g, 40.2 mmol) and compound 13 (93 g, 84.39 mmol) in THF (800 mL) was cooled to 0–10 °C. TEA (0.5 mL, 3.6 mmol) and T3P (20.3 g, 200.9 mmol, 50% solution in ethyl acetate) were sequentially charged with stirring at 0–10 °C. The reaction mixture was stirred at 25–35 °C for 18 h or more until completion was confirmed by UPLC. The reaction mixture was quenched by adding saturated aqueous NaHCO3 (800 mL) (10 mL) and 2-MeTHF (800 mL). The aqueous layer was separated. The organic layer was washed successively with 5% NaH2PO4 (800 mL) and 10% aqueous NaCl (800 mL), then dried over Na2SO4 and evaporated. The solvent was exchanged with MTBE (400 mL), stirred for 3-4 h, evaporated to dryness, and further dried under reduced pressure at 45 °C to obtain crude compound 18 (120 g) as a solid. The crude material was purified by column chromatography to a purity of ≥97% and used in the next step. m / z (z=2) 1378.5 [M-DMTr+2H] 2+ .

[0090] Example 29. Synthesis of Compound 19 [ka] To a solution of compound 18 (1.1 kg, 163.6 mmol) in DCM (1.1 L) was slowly charged TEA (126 g, 1260 mmol) while maintaining the temperature at 25 °C. Compound 18A (126 g, 1260 mmol) was then charged in small portions while maintaining the temperature at 25 °C. The resulting mixture was stirred at 40-45 °C for 72 hours or more until the reaction was complete as confirmed by UPLC. The reaction mixture was cooled to 20-25 °C, washed with aqueous NaHCO (2 × 5 L), dried over NaSO, filtered, and evaporated to dryness to obtain compound 19 (1.0 kg) as an off-white solid. For the free acid: m / z (z=2) 1428.5 [M-DMTr+2H] 2+ .

[0091] Example 30. Synthesis of crystalline potassium salt of compound of formula 13CC: [ka] A 100 mL reaction vessel was charged with 5.0 g (1.0 equiv.) of compound 13BB and 25 mL (5 V) of MeOH. After dissolution, the contents were adjusted to 0-5°C. In a separate reaction vessel, 653 mg (2.2 equiv.) of KOH was dissolved in 25 mL (5 V) of MeOH. The KOH in MeOH was slowly charged to the contents, and the reaction mixture was slowly adjusted to 40°C. The reaction mixture was stirred until the reaction was complete. After concentrating to a minimum volume, 10 V of CPME was added, and the contents were stirred at 50-60°C. A pale yellow slurry formed during stirring. The slurry was concentrated to a minimum volume under reduced pressure. After adding 10 V of heptane, the slurry was stirred at 50-60°C for 1 hour and slowly adjusted to 0-5°C. After stirring for 1 hour, the contents were filtered through a filter paper, and the wet cake was washed with 2 V of heptane. 5.2 g of product was obtained as an off-white solid.

[0092] All publications, patents, and patent documents are incorporated by reference herein, as if individually incorporated by reference. The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications can be made while remaining within the spirit and scope of the invention.

[0093] Finally, preferred embodiments of the present invention are described in sections.

[0094] [Embodiment 1] Compounds of Formula 1: [ka] 1. A method for preparing Compound of Formula 1-1: [ka] with a compound of formula 1-2: [ka] and reacting at a temperature of 40°C or higher.

[0095] [Embodiment 2] 2. The process of embodiment 1, wherein the compound of formula 1-1 is reacted with the compound of formula 1-2 in a solvent comprising tetrahydrofuran.

[0096] [Embodiment 3] The method of embodiment 1 or embodiment 2, wherein the compound of formula 1-1 is reacted with the compound of formula 1-2 in a solvent comprising tetrahydrofuran at a temperature of 60° C. or greater.

[0097] [Embodiment 4] Compound 3: [ka] 1. A method for preparing a crystalline form of Compounds of Formula 1: [ka] to a crystalline form of compound 3 without the use of column chromatography during the conversion.

[0098] [Embodiment 5] Compound 3: [ka] Crystalline form of.

[0099] [Embodiment 6] Compound of Formula 9: [ka] (In the formula, R 9 is an optionally substituted benzyloxycarbonyl group. 1. A method for preparing Compound of Formula 8: [ka] or a salt thereof to the compound of formula 9.

[0100] [Embodiment 7] R 9 is benzyloxycarbonyl or nitrobenzyloxycarbonyl.

[0101] [Embodiment 8] 7. The method of embodiment 6, wherein the compound of formula 8 is converted to the compound of formula 9 by treating the compound of formula 8 with benzyloxycarbonyl chloride in the presence of a suitable base in a suitable solvent.

[0102] [Embodiment 9] Compound of Formula 10: [ka] (In the formula, R 9 is an optionally substituted benzyloxycarbonyl group. 1. A method for preparing The corresponding compound of formula 9: [ka] to the compound of formula 10.

[0103] [Embodiment 10] The compound of formula 9 can be prepared by reacting a compound of formula 7: [ka] 10. The method of embodiment 9, wherein the compound of formula 10 is converted to the compound of formula 10 by treatment with

[0104] [Embodiment 11] 11. The method of claim 10, wherein the catalyst is Sc(OTf)3 and the suitable solvent comprises dichloroethane.

[0105] [Embodiment 12] Compound of Formula 10: [ka] (In the formula, R 9 is an optionally substituted benzyloxycarbonyl group. 1. A method for preparing Compound of Formula 8: [ka] or a salt thereof, with the corresponding compound of formula 9: [ka] To convert into and subsequently converting the corresponding compound of formula 9 to the compound of formula 10 without chromatographic purification of the compound of formula 9; Including, The method.

[0106] [Embodiment 13] Compound of Formula 10: [ka] (In the formula, R 9 is an optionally substituted benzyloxycarbonyl group. with hydrogen and trifluoroacetic acid in the presence of a suitable catalyst and in the presence of a suitable solvent, Salt of Formula 11: [ka] A method for preparing

[0107] [Embodiment 14] 14. The method of claim 13, wherein the suitable catalyst comprises palladium on carbon and the suitable solvent comprises tetrahydrofuran.

[0108] [Embodiment 15] Compound of Formula 15D: [ka] or a salt thereof, comprising: Compound of Formula 15C: [ka] (Wherein, each R 15 is (C1-C6) alkyl) into the compound of formula 15D or a salt thereof, The method.

[0109] [Embodiment 16] Compound of Formula 15C: [ka] (Wherein, each R 15 is (C1-C6) alkyl) 1. A method for preparing Compound of Formula 15A: [ka] or a salt thereof, with the corresponding compound of formula 15B: [ka] or a salt thereof to provide the compound of formula 15C.

[0110] [Embodiment 17] Compound of Formula 13A: [ka] (Wherein, each R 15 is (C1-C6) alkyl) 1. A method for preparing The corresponding compound of formula 15C: [ka] (Wherein, each R 15 is (C1-C6) alkyl) to the compound of formula 13A.

[0111] [Embodiment 18] Compound of Formula 13B: [ka] (Wherein, each R 15 is (C1-C6) alkyl and T is an optionally substituted triphenylmethyl group. 1. A method for preparing The corresponding compound of formula 13A: [ka] to the compound of formula 13B.

[0112] [Embodiment 19] The compound of formula 13A can be converted under suitable amide forming conditions to the corresponding compound of formula 6: [ka] or a salt thereof, whereby the compound of formula 13A is converted to the compound of formula 13B.

[0113] [Embodiment 20] Compounds of formula 13CC: [ka] 1. A method for preparing Compound of formula 13BB: [ka] (Wherein, each R 15 is (C1-C6) alkyl) to said compound of formula 13CC.

[0114] [Embodiment 21] 21. The method of embodiment 20, wherein the compound of formula 13BB is converted to the compound of formula 13CC by treatment with lithium hydroxide in a suitable solvent.

[0115] [Embodiment 22] Compounds of formula 13CC: [ka] 1. A process for preparing the potassium salt of The process comprising treating a compound of formula 13CC or a salt thereof with potassium carbonate in a suitable solvent to provide said potassium salt of said compound of formula 13CC.

[0116] [Embodiment 23] Compound of Formula 11B: [ka] 1. A method for preparing Compound of Formula 11A: [ka] or a salt thereof to the compound of formula 11B.

[0117] [Embodiment 24] 24. The method of embodiment 23, wherein the compound of formula 11A is converted to the compound of formula 11B by treating the compound of formula 11A or the salt thereof with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide in a suitable solvent.

[0118] [Embodiment 25] Compound of Formula 12: [ka] 1. A method for preparing Compound of Formula 11B: [ka] to the compound of formula 12.

[0119] [Embodiment 26] The compound of formula 11B can be prepared by reacting the compound of formula 11B in the presence of a suitable base and a suitable solvent to obtain a compound of formula 11: [ka] or a salt thereof to the compound of formula 12.

[0120] [Embodiment 27] Compound of Formula 13: [ka] or a salt thereof, comprising: Compound of Formula 12: [ka] to provide the compound of formula 13 or the salt thereof.

[0121] [Embodiment 28] The compound of formula 13 or a salt thereof may be a trifluoroacetate salt of the formula: [ka] 28. The method of embodiment 27, wherein

[0122] [Embodiment 29] Compound of Formula 14: [ka] 1. A method for preparing Compound of Formula 13: [ka] or a salt thereof to the compound of formula 14.

[0123] [Embodiment 30] The compound of formula 13 can be prepared by coupling the compound of formula 13 under suitable coupling conditions to a compound of formula: [ka] or a salt thereof to the compound of formula 14.

[0124] [Embodiment 31] Compound of Formula 16: [ka] (In the formula, R 16 is an amine protecting group) 1. A method for preparing Compound of Formula 13: [ka] or a salt thereof to the compound of formula 16.

[0125] [Embodiment 32] The compound of formula 13 or the salt thereof can be prepared by coupling the compound of formula 13 under suitable coupling conditions to give a compound of formula 15DD: [ka] (In the formula, R 16 is an amine protecting group) or a salt thereof to the compound of formula 16.

[0126] [Embodiment 33] The trifluoroacetate salt of the compound of formula 13: [ka] under suitable coupling conditions to give a compound of formula 15D: [ka] to give a compound of formula 16: [ka] (In the formula, R 16 is benzyloxycarbonyl) 32. The method of embodiment 31, wherein

[0127] [Embodiment 34]

[0037] Embodiment 34. The method of any one of embodiments 31 to 33, wherein the compound of formula 13 is treated with the compound of formula 15D or 15DD in the presence of propanephosphonic anhydride and a solvent comprising dichloromethane to provide the compound of formula 16.

[0128] [Embodiment 35] Compound of Formula 18: [ka] (In the formula, R 18 is a suitable protecting group) 1. A method for preparing Compound of Formula 13: [ka] or a salt thereof to the compound of formula 18.

[0129] [Embodiment 36] The compound of formula 13 or the salt thereof can be prepared by coupling the compound of formula 13 under suitable coupling conditions to give a compound of formula 13CCC: [ka] (In the formula, R 18 is a suitable protecting group) or a salt thereof to the compound of formula 18.

[0130] [Embodiment 37] The trifluoroacetate salt of the compound of formula 13: [ka] can be converted under suitable coupling conditions into a compound of formula 13CCC, where R 18 is 4,4-dimethoxytriphenylmethyl) to give a compound of formula 18: [ka] (In the formula, R 18 is 4,4-dimethoxytriphenylmethyl) 36. The method of embodiment 35, wherein

[0131] [Embodiment 38]

[0037] Embodiment 38. The method of any of embodiments 35 to 37, wherein the compound of formula 13 is treated with the compound of formula 13CCC in the presence of propanephosphonic anhydride and a solvent comprising dichloromethane to provide the compound of formula 18.

[0132] [Embodiment 39] Compounds of Formula 16-2: [ka] 1. A method for preparing Compounds of Formula 16-1: [ka] or a salt thereof to the compound of formula 16-2.

[0133] [Embodiment 40] Compounds of Formula 16-3: [ka] 1. A method for preparing Compounds of Formula 16-2: [ka] to the compound of formula 16-3.

[0134] [Embodiment 41] Compounds of formula 16-4: [ka] 1. A method for preparing Compounds of Formula 16-3: [ka] to the compound of formula 16-4.

[0135] [Embodiment 42] Compounds of Formula 16-5: [ka] or a salt thereof, comprising: Compounds of formula 16-4: [ka] to the compound of formula 16-5.

[0136] [Embodiment 43] Compound of Formula 16D: [ka] or a salt thereof, comprising: Compounds of Formula 16-5: [ka] to the compound of formula 16D.

[0137] [Embodiment 44] Compound of Formula 16E: [ka] or a salt thereof, comprising: Compound of Formula 16D: [ka] or a salt thereof to the compound of formula 16E.

[0138] [Embodiment 45] Compound of Formula 16: [ka] or a salt thereof, comprising: Compound of Formula 16E: [ka] or a salt thereof to the compound of formula 16.

[0139] [Embodiment 46] The compound of formula 16E or the salt thereof can be prepared by coupling the compound of formula 16E or the salt thereof under suitable coupling conditions to give a compound of formula 11: [ka] or a salt thereof.

[0140] [Embodiment 47] [ka] [ka] or a salt thereof (wherein each R 15 is (C1-C6) alkyl and each T is an optionally substituted triphenylmethyl group).

[0141] [Embodiment 48] [ka] [ka] or a salt thereof (wherein each R 15 is (C1-C6) alkyl).

[0142] [Embodiment 49] The following salts: [ka]

[0143] [Embodiment 50] The compound of formula 18 can be reacted with a compound of formula 19: [ka] (In the formula, R 19 is a group containing siRNA suitable for treating HBV and / or HDV

[0037] Embodiment 39. The method of any one of embodiments 35 to 38, further comprising converting

[0144] [Embodiment 51] The compound of formula 19 may be a compound of formula 20: [ka] wherein the siRNA is suitable for treating HBV and / or HDV. 51. The method of embodiment 50, wherein

[0145] [Embodiment 52] A method for treating HBV and / or HDV infection in a human subject, comprising administering to the human subject a therapeutically effective amount of a compound of Formula 19 or Formula 20 prepared as described in embodiment 50 or embodiment 51, and a second therapeutic agent useful for treating HBV and / or HDV.

[0146] [Embodiment 53] 53. The method of embodiment 52, wherein the second therapeutic agent is an HBV encapsidation inhibitor or an HBV RNA destabilizing agent.

[0147] [Embodiment 54] The method of embodiment 53, wherein the HBV RNA destabilizing agent is an HBV surface antigen inhibitor.

[0148] [Embodiment 55] Embodiment 55. The method of any one of embodiments 52 to 54, wherein the compound of Formula 19 or Formula 20 and the second therapeutic agent are administered separately.

Claims

1. 1. A method for preparing a compound of formula 1, comprising: 【Chemistry 1】 Compound of Formula 1-1: 【Chemistry 2】 with a compound of formula 1-2: 【Transformation 3】 and reacting at a temperature of 40°C or higher.

2. 2. The method of claim 1, wherein the compound of formula 1-1 is reacted with the compound of formula 1-2 in a solvent comprising tetrahydrofuran.

3. 3. The method according to claim 1, wherein the compound of formula 1-1 is reacted with the compound of formula 1-2 in a solvent containing tetrahydrofuran at a temperature of 60° C. or higher.

4. A process for preparing a crystalline form of Compound 3, comprising: 【Chemistry 4】 Compound of Formula 1: 【Transformation 5】 to the crystalline form of compound 3 without the use of column chromatography during the conversion.

5. Crystalline form of Compound 3. 【Transformation 6】

6. A process for preparing a compound of formula 9, comprising: 【Transformation 7】 (In the formula, R ９ is an optionally substituted benzyloxycarbonyl group. Compound of Formula 8: 【Transformation 8】 or a salt thereof, to a compound of formula 9:

7. R ９ The method of claim 6, wherein is benzyloxycarbonyl or nitrobenzyloxycarbonyl.

8. 7. The method of claim 6, wherein the compound of formula 8 is converted to the compound of formula 9 by treating the compound of formula 8 with benzyloxycarbonyl chloride in the presence of a suitable base in a suitable solvent.

9. A process for preparing a compound of formula 10, comprising: 【Chemistry 9】 (In the formula, R ９ is an optionally substituted benzyloxycarbonyl group. The corresponding compound of formula 9: 【Chemistry 10】 to a compound of formula 10.

10. in the presence of a suitable catalyst and a suitable solvent, a compound of formula 7: 【Chemistry 11】 10. The method of claim 9, wherein the compound of formula 9 is converted to the compound of formula 10 by treatment with

11. The catalyst is Sc(OTf) ３ and the suitable solvent comprises dichloroethane.

12. A process for preparing a compound of formula 10, comprising: 【Chemistry 12】 (In the formula, R ９ is an optionally substituted benzyloxycarbonyl group. Compound of Formula 8: 【Chemistry 13】 or a salt thereof, to the corresponding compound of formula 9: 【Chemistry 14】 Converting it into and subsequently converting the corresponding compound of formula 9 to a compound of formula 10 without chromatographically purifying the compound of formula 9; A method comprising:

13. 1. A process for preparing a salt of formula 11, comprising: 【Chemistry 15】 Compound of Formula 10: 【Chemistry 16】 (In the formula, R ９ is an optionally substituted benzyloxycarbonyl group. with hydrogen and trifluoroacetic acid in the presence of a suitable catalyst and in the presence of a suitable solvent.

14. 14. The method of claim 13, wherein the suitable catalyst comprises palladium on carbon and the suitable solvent comprises tetrahydrofuran.

15. 1. A process for preparing a compound of formula 15D or a salt thereof, comprising: 【Chemistry 17】 Compound of Formula 15C: [Chemistry 18] (Wherein, each R １５ (C １ -C ６ ) alkyl) to a compound of formula 15D or a salt thereof.

16. A process for preparing a compound of formula 15C, comprising: 【Chemistry 19】 (Wherein, each R １５ (C １ -C ６ ) alkyl) Compound of Formula 15A: 【Chemistry 20】 or a salt thereof, with the corresponding compound of formula 15B: 【Chemistry 21】 or a salt thereof to provide a compound of formula 15C.

17. A process for preparing a compound of formula 13A, comprising: 【Chemistry 22】 (Wherein, each R １５ (C １ -C ６ ) alkyl) The corresponding compound of formula 15C: 【Chemistry 23】 (Wherein, each R １５ (C １ -C ６ ) alkyl) to a compound of formula 13A.

18. A process for preparing a compound of formula 13B, comprising: 【Chemistry 24】 (Wherein, each R １５ (C １ -C ６ ) alkyl and T is an optionally substituted triphenylmethyl group. The corresponding compound of formula 13A: 【Chemistry 25】 to a compound of formula 13B.

19. Compounds of formula 13A can be converted under suitable amide forming conditions to the corresponding compounds of formula 6: 【Chemistry 26】 or a salt thereof to convert the compound of formula 13A to a compound of formula 13B.

20. A process for preparing a compound of formula 13CC, comprising: 【Chemistry 27】 Compound of Formula 13BB: 【Chemistry 28】 (Wherein, each R １５ (C １ -C ６ ) alkyl) to a compound of formula 13CC.

21. 21. The method of claim 20, wherein the compound of formula 13BB is converted to the compound of formula 13CC by treatment with lithium hydroxide in a suitable solvent.

22. 1. A process for preparing the potassium salt of a compound of formula 13CC, comprising: 【Chemistry 29】 A process comprising treating a compound of formula 13CC or a salt thereof with potassium carbonate in a suitable solvent to provide the potassium salt of the compound of formula 13CC.

23. A process for preparing a compound of formula 11B, comprising: 【Transformation 30】 Compound of Formula 11A: 【Chemistry 31】 or a salt thereof, to a compound of formula 11B:

24. 24. The method of claim 23, wherein the compound of formula 11A or a salt thereof is converted to the compound of formula 11B by treating the compound of formula 11A or a salt thereof with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide in a suitable solvent.

25. A process for preparing a compound of formula 12, comprising: 【Chemistry 32】 Compound of Formula 11B: 【Transformation 33】 to a compound of formula 12.

26. In the presence of a suitable base and a suitable solvent, a compound of formula 11B is converted into a compound of formula 11: 【Transformation 34】 26. The method of claim 25, wherein the compound of formula 11B is converted to the compound of formula 12 by treatment with HCl, or a salt thereof.

27. 1. A process for preparing a compound of formula 13 or a salt thereof, comprising: 【Chemistry 35】 Compound of Formula 12: 【Transformation 36】 to provide a compound of formula 13 or a salt thereof.

28. The compound of formula 13 or a salt thereof is a trifluoroacetate salt of the formula: 【Chemistry 37】 28. The method of claim 27, wherein:

29. A process for preparing a compound of formula 14, comprising: 【Transformation 38】 Compound of Formula 13: 【Chemistry 39】 or a salt thereof, to a compound of formula 14.

30. Under suitable coupling conditions, a compound of formula 13 can be converted to a compound of the formula: 【Chemistry 40】 30. The method of claim 29, wherein the compound of formula 13 is converted to the compound of formula 14 by treatment with Benzyloxymethyl methylpropional, ... or a salt thereof.

31. A process for preparing a compound of formula 16, comprising: 【Chemistry 41】 (In the formula, R １６ is an amine protecting group) Compound of Formula 13: 【Chemistry 42】 or a salt thereof, to a compound of formula 16.

32. Under suitable coupling conditions, a compound of formula 13 can be converted to a compound of formula 15DD: 【Chemistry 43】 (In the formula, R １６ is an amine protecting group) 32. The method of claim 31 , wherein the compound of formula 13, or a salt thereof, is converted to the compound of formula 16 by treatment with 1,3-dimethyl-2,4-trimethyl ...

33. Under suitable coupling conditions, the trifluoroacetate salt of the compound of formula 13: 【Chemistry 44】 with a compound of formula 15D: 【Chemistry 45】 to give a compound of formula 16: 【Chemistry 46】 (In the formula, R １６ is benzyloxycarbonyl) 32. The method of claim 31 , wherein

34. 34. The method of any one of claims 31 to 33, wherein a compound of formula 13 is treated with a compound of formula 15D or 15DD in the presence of propanephosphonic anhydride and a solvent comprising dichloromethane to provide a compound of formula 16.

35. A process for preparing a compound of formula 18, comprising: 【Chemistry 47】 (In the formula, R １８ is a suitable protecting group) Compound of Formula 13: 【Chemistry 48】 or a salt thereof, to a compound of formula 18.

36. Under suitable coupling conditions, a compound of formula 13 can be converted to a compound of formula 13C: 【Chemistry 49】 36. The method of claim 35, wherein the compound of formula 13 or a salt thereof is converted to the compound of formula 18 by treating with

37. Under suitable coupling conditions, the trifluoroacetate salt of the compound of formula 13: [Transformation 50] is treated with a compound of formula 13C to give a compound of formula 18: 【Chemistry 51】 (In the formula, R １８ is 4,4-dimethoxytriphenylmethyl) 37. The method of claim 36, wherein

38. 38. The method of any one of claims 36 to 37, wherein a compound of formula 13 is treated with a compound of formula 13C in the presence of propanephosphonic anhydride and a solvent comprising dichloromethane to provide a compound of formula 18.

39. A process for preparing a compound of formula 16-2, comprising: 【Chemistry 52】 Compound of formula 16-1: 【Chemistry 53】 or a salt thereof to a compound of formula 16-2.

40. A process for preparing a compound of formula 16-3, comprising: 【Chemistry 54】 Compound of formula 16-2: 【Transformation 55】 to a compound of formula 16-3.

41. A process for preparing a compound of formula 16-4, comprising: 【Transformation 56】 Compound of formula 16-3: 【Chemistry 57】 to a compound of formula 16-4.

42. A process for preparing a compound of formula 16-5 or a salt thereof, comprising: 【Transformation 58】 Compound of formula 16-4: 【Chemistry 59】 to a compound of formula 16-5.

43. 1. A process for preparing a compound of formula 16D or a salt thereof, comprising: 【Transformation 60】 Compound of formula 16-5: 【Chemistry 61】 to a compound of formula 16D.

44. 1. A process for preparing a compound of formula 16E or a salt thereof, comprising: 【Transformation 62】 Compound of formula 16D: 【Transformation 63】 or a salt thereof to a compound of formula 16E.

45. 1. A process for preparing a compound of formula 16 or a salt thereof, comprising: 【Chemistry 64】 Compound of formula 16E: 【Chemistry 65】 or a salt thereof, to a compound of formula 16.

46. Under suitable coupling conditions, a compound of formula 16E or a salt thereof can be coupled to a compound of formula 11: 【Chemical Formula 66】 46. ​​The method of claim 45, wherein the compound of formula 16E, or a salt thereof, is converted to a compound of formula 16, or a salt thereof, by reacting the compound of formula 16E, or a salt thereof, with 【Request Item 47】 【Transformation 67】 【Transformation 68】 or a salt thereof (wherein each R １５ (C １ -C ６ ) alkyl, and each T is an optionally substituted triphenylmethyl group). [Request Item 48] [Transformation 69] 【Transformation 70】 or a salt thereof (wherein each R １５ (C １ -C ６ ) alkyl).

49. The following salts: 【Chemistry 71】

50. The compound of formula 18 is reacted with a compound of formula 19: 【Chemistry 72】 The method of any one of claims 35 to 38, further comprising converting

51. The compound of formula 18 is reacted with a compound of formula 20: 【Transformation 73】 wherein the siRNA is suitable for treating HBV and / or HDV. The method of any one of claims 35 to 38, further comprising converting

52. A method for treating HBV and / or HDV infection in a human subject, comprising administering to the human subject a therapeutically effective amount of a compound of formula 19 or formula 20 prepared as described in claim 50 or claim 51, and a second therapeutic agent useful for treating HBV and / or HDV.

53. 53. The method of claim 52, wherein the second therapeutic agent is an HBV encapsidation inhibitor or an HBV RNA destabilizing agent.

54. 54. The method of claim 53, wherein the HBV RNA destabilizing agent is an HBV surface antigen inhibitor.

55. 55. The method of any one of claims 52-54, wherein the compound of Formula 19 or Formula 20 and the second therapeutic agent are administered separately.

Images