Peptidomimetic protease inhibitor, and pharmaceutical composition and use thereof

Abstract

The present disclosure provides a compound represented by formula (I) or formula (II), which has good protease inhibitory activity and can be used as a peptidomimetic protease inhibitor.

Description

Peptidase inhibitors, pharmaceutical compositions thereof, and uses

[0001] This disclosure claims priority to an earlier application filed by the applicant with the China National Intellectual Property Administration on December 20, 2024, with patent application number 202411892405.0, entitled "Peptidomorphic protease inhibitors and pharmaceutical compositions thereof and uses thereof". The entire contents of the earlier application are incorporated herein by reference. Technical Field

[0002] This disclosure pertains to the pharmaceutical field, specifically relating to a peptide-like protease inhibitor, its pharmaceutical composition, and its uses. Background Technology

[0003] Many biological functions depend on proteases, including food digestion, lysosomal degradation, and signaling cascades. Because proteases trigger an irreversible event—protein hydrolysis—their activity must be tightly controlled. A broad regulatory network of protease inhibitors has been established to ensure targeted spatial and temporal control of their activity. Naturally occurring protease inhibitors (antiproteases) are typically proteins or peptides that control protein hydrolysis in organisms and competitively or predatoryly inactivate proteases. Based on their mechanism of action at the protease's active site, protease inhibitors can be further classified into five classes (serine, threonine, cysteine, aspartic acid, and metalloproteinase inhibitors). Some protease inhibitors interfere with more than one protease.

[0004] Feline infectious peritonitis (FIP) is a disease caused by a mutation of feline coronavirus. Cats carry the coronavirus for life, but the disease can develop when their immune system is weakened. FIP is a highly contagious, complex, and serious disease affecting approximately 10% of felines and often leads to death. It is characterized by fibrinous and granulomatous serositis, protein-rich serous effusions in body cavities, and / or granulomatous lesions (pyogenic granulomas). The causative agent of this fatal disease is feline enteric coronavirus (FECV) and feline infectious peritonitis virus (FIPV). Both viruses belong to the feline coronavirus (FCoV) family. FCoVs are part of the Alpha Coronavirus coronavirus species and are primarily composed of nucleocapsid (N) protein, transmembrane (M) protein, and (S) protein. FECV is asymptomatic in cats, but FIPV infection can induce FIP. FIP is a progressive, immune-associated disease in cats. FIP can present as either "wet" or "dry" forms. Wet FIP ​​is associated with inflammation of the visceral serosals and omentum, leading to fluid leakage into the abdomen and / or pleural cavity. Dry FIP is characterized by granulomatous involvement of paracnchymatous organs such as the liver, central nervous system, or eyes. The development of either wet or dry FIP is always fatal. FIP is an immune-mediated and difficult-to-treat viral infection with a mortality rate reaching 100%. Feline infectious peritonitis (FIP) has a high mortality rate, yet effective treatments remain lacking. Currently, the main treatments for FIP are immunosuppressive and anti-inflammatory drugs, such as corticosteroids and interferon-like drugs with immunomodulatory effects. While these drugs can prolong the life of infected cats to some extent, they cannot cure the disease. Therefore, FIP is considered one of the most challenging feline infectious diseases known in veterinary medicine. Thus, developing safe and effective treatments for FIP has significant social and economic value. Summary of the Invention

[0005] To address the aforementioned technical problems, this disclosure provides a compound of formula (I) or formula (II) or a pharmaceutically acceptable salt thereof:

[0006] in,

[0007] X is selected from CH2 or S;

[0008] R1 is selected from unsubstituted or arbitrarily selected by one, two or more R1s. 11 The following groups are substituted: C 1-10 Alkyl, 3-10 membered heterocyclic, 5-10 membered heteroaryl; each R 11 They are either the same or different, and are independently selected from oxygen (=O), halogen, and carbon. 1-10 Alkyl, C1- 10 Alkoxy group, -C(O)NHC 1-10 Alkyl group, -NHC(O)C 1-10 Alkyl, Halogenated C 1-10 Alkyl, Halogenated C 1-10 Alkoxy;

[0009] R2 is selected from H;

[0010] or, Selected from unsubstituted or arbitrarily assigned to one, two or more R 21 The following groups are substituted: 3-10 membered heterocyclic groups, 5-10 membered heteroaryl groups; each R 21 Whether the two are the same or different, they are independently selected from oxygen (=O) and C. 1-10 Alkyl, C 1-10 Alkoxy;

[0011] R3 is selected from unsubstituted or optionally by one, two or more R3s. 31 The following groups are substituted: C 1-10 Alkyl, C 3-10 Cycloalkyl, 3-10 membered heterocyclic, 5-10 membered heteroaryl, C 6-10 Aryl; each R 31 They are the same or different, and are independently selected from halogens and C. 3-10 cycloalkyl, halogenated C 3-10 cycloalkyl;

[0012] R4 is selected from H;

[0013] Alternatively, R3 and R4, together with their respective atoms, form unsubstituted or optionally substituted atoms with one, two, or more R atoms. 41 The following groups are substituted: 3-10 membered heterocyclic groups, 5-10 membered heteroaryl groups; each R 41 They are the same or different, and are independently selected from halogens and C. 1-10 Alkyl, Halogenated C 1-10 alkyl;

[0014] R5 is selected from No substitution or optional use by one, two or more R 51 Replacement C 1-10 Alkyl, 5-10 heteroaryl; each R 51 They are identical or different, selected independently of each other without substitution or arbitrarily selected by one, two or more Rs. 511 The following groups are substituted: C 1-10 Alkyl, Halogenated C 1-10 Alkyl, C 6-10 Aryl, 5-10 membered heteroaryl, 3-10 membered heterocyclic, -B(OH)2, -Si(OH)2C 1-10Alkyl; each R 511 They are either the same or different, and are independently selected from oxidized, halogenated, and C-type substances. 1-10 Alkyl, Halogenated C 1-10 alkyl;

[0015] R 5a Selected from unsubstituted or arbitrarily assigned to one, two or more R 5a1 The following groups are substituted: C 1-10 Alkyl, C 6-10 Aryl, 5-10 membered heteroaryl, 3-10 membered heterocyclic; each R 5a1 They may be the same or different, and are independently selected from oxo- or 5-10-membered heteroaryl groups;

[0016] R 5b Selected from H;

[0017] R 5c Selected from unsubstituted or arbitrarily assigned to one, two or more R 5c1 The following groups are substituted: C 1-10 Alkyl, C 3-10 Cycloalkyl, 3-10 membered heterocyclic, 5-10 membered heteroaryl, NH2, -B(OH)2, -Si(OH)2C 1-10 Alkyl; each R 5c1 They are either the same or different, and are independently selected from oxidized, halogenated, and C-type substances. 1-10 Alkyl, C 3-10 Cycloalkyl, hydroxy C 1-10 Alkyl, Halogenated C 1-10 alkyl;

[0018] Alternatively, R4 and R5, together with their respective atoms, form unsubstituted or optionally substituted atoms with one, two, or more R atoms. 52 The following groups are substituted: 3-10 membered heterocyclic groups, 3-10 membered heteroaryl groups; each R 52 Whether the same or different, they are independently selected from oxygen, C 6-10 aryloxy group, C 6-10 Aryl-C 1-10 Alkyl, Halogenated C 1-10 alkyl.

[0019] According to embodiments of this disclosure, R1 is selected from those without substitution or optionally by one, two or more R1s. 11 The following groups are substituted: C 1-6 Alkyl, 5-6 membered heterocyclic, 5-6 membered heteroaryl, 9-10 membered heteroaryl;

[0020] According to embodiments of this disclosure, R1 is selected from those without substitution or optionally by one, two or more R1s. 11 The following groups are substituted: propyl,

[0021] According to the implementation scheme of this disclosure, each R 11 They are either the same or different, and are independently selected from oxygen (=O), halogen, and carbon. 1-6 Alkyl group, -C(O)NHC 1-6 Alkyl group, -NHC(O)C 1-6 Alkyl, Halogenated C 1-6 Alkyl, Halogenated C 1-6 Alkoxy;

[0022] According to the implementation scheme of this disclosure, each R 11 They are either the same or different, and are independently selected from oxo (=O), F, Cl, methyl, -C(O)NHCH3, -NHC(O)CH3, CF3, CHF2, -OCHF2, -CH2CHF2;

[0023] According to the implementation scheme of this disclosure, R1 is selected from... (like ), (like ), (like ), (like ), (like ), (like ), (like ).

[0024] According to the implementation scheme of this disclosure, Selected from unsubstituted or arbitrarily assigned to one, two or more R 21 The following groups are substituted: 8-10 membered heterocyclic groups, 8-10 membered heteroaryl groups; each R 21 Whether the two are the same or different, they are independently selected from oxygen (=O) and C. 1- 6-alkyl;

[0025] According to the implementation scheme of this disclosure, Selected from

[0026] According to embodiments of this disclosure, R3 is selected from unsubstituted or optionally replaced by one, two or more R3s. 31 The following groups are substituted: C 1-6 Alkyl, C 8-10Alkyl, 5-6 membered heterocyclic, 5-6 membered heteroaryl, C6 aryl;

[0027] According to embodiments of this disclosure, R3 is selected from unsubstituted or optionally replaced by one, two or more R3s. 31 The following groups can be substituted: methyl, ethyl, butyl (e.g., isobutyl), pentyl (e.g., neopentyl), thienyl, thiazolyl, phenyl, adamantyl, According to the implementation scheme of this disclosure, each R 31 They are the same or different, and are independently selected from halogens and C. 3-6 cycloalkyl, halogenated C 3- 6-cycloalkyl;

[0028] According to the implementation scheme of this disclosure, each R 31 They may be the same or different, and are independently selected from F, cyclobutyl, fluorocyclobutyl, and others.

[0029] According to the implementation scheme of this disclosure, R3 is selected from...

[0030] According to embodiments of this disclosure, R3 and R4 form unsubstituted or optionally substituted atoms with one, two or more R atoms. 41 The following groups are substituted: 5-9 membered heterocyclic groups, 8-9 membered heteroaryl groups;

[0031] According to embodiments of this disclosure, R3 and R4 form unsubstituted or optionally substituted atoms with one, two or more R atoms. 41 The following groups are substituted:

[0032] According to the implementation scheme of this disclosure, each R 41 They are the same or different, and are independently selected from halogens and C. 1-6 Alkyl, Halogenated C 1-6 alkyl;

[0033] According to the implementation scheme of this disclosure, each R 41 They may be the same or different, and are independently selected from F, methyl, and trifluoromethyl.

[0034] According to embodiments of this disclosure, R3 and R4 form with their respective connected atoms

[0035] According to the implementation scheme of this disclosure, R5 is selected from... No substitution or optional use by one, two or more R 51 The following groups are substituted: C 1-6Alkyl, 5-6 membered heteroaryl;

[0036] According to the implementation scheme of this disclosure, R5 is selected from... No substitution or optional use by one, two or more R 51 The following groups are substituted: methoxy, imidazole (e.g.) ), triazole group (such as );

[0037] According to the implementation scheme of this disclosure, each R 51 They are identical or different, selected independently of each other without substitution or arbitrarily selected by one, two or more Rs. 511 The following groups are substituted: C 1-6 Alkyl, Halogenated C 1-6 Alkyl, C6 aryl, 5-6 membered heteroaryl, 5-6 membered heterocyclic, -B(OH)2, -Si(OH)2C 1-6 alkyl;

[0038] According to the implementation scheme of this disclosure, each R 51 They are identical or different, selected independently of each other without substitution or arbitrarily selected by one, two or more Rs. 511 The following groups can be substituted: ethyl, phenyl, imidazolyl, thiazolyl, triazolyl, tetrahydropyrrolyl, isoxazolyl, -B(OH)2, -Si(OH)2CH3.

[0039] According to the implementation scheme of this disclosure, each R 51 They may be the same or different, and are independently selected from ethyl, phenyl,

[0040] According to the implementation scheme of this disclosure, each R 511 They are either the same or different, and are independently selected from oxidized, halogenated, and C-type substances. 1-6 Alkyl, Halogenated C 1-6 alkyl.

[0041] According to the implementation scheme of this disclosure, each R 511 They may be the same or different, and are independently selected from oxo, F, methyl, and trifluoromethyl.

[0042] According to the implementation scheme of this disclosure, R 5a Selected from unsubstituted or arbitrarily assigned to one, two or more R 5a1 The following groups are substituted: C 1-6 Alkyl, C6 aryl, 5-6 membered heteroaryl (e.g., pyrazolyl), 5-6 membered heterocyclic; each R 5a1 They may be the same or different, and are independently selected from oxo, 5-6 membered heteroaryl groups (e.g., imidazole groups);

[0043] According to the implementation scheme of this disclosure, R 5a Selected from tert-butyl, phenyl,

[0044] According to the implementation scheme of this disclosure, R 5c Selected from unsubstituted or arbitrarily assigned to one, two or more R 5c1 The following groups are substituted: C 1-6 Alkyl, C 3-6 cycloalkyl, 5-6 membered heterocyclic, 5-6 membered heteroaryl, NH2, -B(OH)2, -Si(OH)2C 1-6 Alkyl; each R 5c1 They are either the same or different, and are independently selected from oxidized, halogenated, and C-type substances. 1-6 Alkyl, C 3-6 Cycloalkyl, hydroxy C 1-6 Alkyl, Halogenated C 1-6 alkyl;

[0045] According to the implementation scheme of this disclosure, R 5c Selected from trifluoromethyl, (like or ), (like ),

[0046] According to the implementation scheme of this disclosure, R5 is selected from...

[0047] According to the implementation scheme of this disclosure, Selected from

[0048] According to embodiments of this disclosure, R4 and R5, together with their respective connected atoms, form unsubstituted or optionally substituted atoms with one, two, or more R atoms. 52 The following groups are substituted: 5-6 membered heterocyclic group, 9 membered heterocyclic group, 5-6 membered heteroaryl group, 9 membered heteroaryl group;

[0049] According to embodiments of this disclosure, R4 and R5, together with their respective connected atoms, form unsubstituted or optionally substituted atoms with one, two, or more R atoms. 52 The following groups are substituted:

[0050] According to the implementation scheme of this disclosure, each R 52 They may be the same or different, and are independently selected from oxo, C6 aryloxy, and C6 aryl-C. 1-6 Alkyl, Halogenated C1-6 alkyl;

[0051] According to the implementation scheme of this disclosure, each R 52 They may be the same or different, and are independently selected from oxo, phenoxy, benzyl, and

[0052] According to embodiments of this disclosure, R4 and R5 form with their respective connected atoms

[0053] According to embodiments of this disclosure, the compound represented by formula (I) or formula (II) has the following structure:

[0054] Among them, R1, R2, R3, R4, R5, R 51 X and X are independently defined as described in this invention.

[0055] According to embodiments of this disclosure, the compound represented by formula (I) or formula (II) has the following structure:

[0056] Among them, R1, R2, R3, R4, R5, R 5a R 5b R 5c X and X are independently defined as described in this invention.

[0057] According to embodiments of this disclosure, the compound represented by formula (I) or formula (II) has the following structure:

[0058] Among them, R1, R2, R3, R4, R5, R 5a R 5b R 5c X and X are independently defined as described in this invention.

[0059] According to embodiments of this disclosure, the compound represented by formula (I) or formula (II) has the following structure:

[0060] Among them, R1, R3, R4, R5, R 51 R 5a R 5b R 5c R 5c1 Each has its own definition as described in this invention.

[0061] According to embodiments of this disclosure, the compound represented by formula (I) or formula (II) is selected from the following compounds:

[0062] This disclosure also provides a pharmaceutical composition comprising a therapeutically effective amount of at least one of the compounds of formula (I) or formula (II) or a pharmaceutically acceptable salt thereof.

[0063] According to embodiments of this disclosure, the pharmaceutical composition further includes one or more pharmaceutically acceptable excipients.

[0064] This disclosure also provides the use of a compound of formula (I) or formula (II) or a pharmaceutically acceptable salt thereof in the preparation of a medicament for treating and / or preventing at least one of the following diseases or conditions:

[0065] (1) Diseases or symptoms in animals caused by or related to pathogen infection;

[0066] (2) Animal tumors.

[0067] According to the embodiments of this disclosure, the pathogen is a virus.

[0068] According to the embodiments of this disclosure, the virus may be selected from: Herpesviridae, Iridoviridae, Baculoviridae, Rhabdoviridae, Reoviridae, BiRNAviridae, Poxviridae, African Swine Fever Viridae, Adenoviridae, Parvoviridae, Circoviridae, Retroviridae, Orthomyxoviridae, Paramyxoviridae, Coronaviridae, Arteritis Viridae, MicroRNA Viridae, Calicoviridae, Flaviviridae, Prions, Filoviridae, Polyomaviridae, Papillomaviridae, Threadviridae, Retroviridae, Hepatoviridae, Papillomaviridae, Bonaviridae, Bunniviridae, Acanthaviridae, Baculoviridae, Hepatitis E Viridae, Astroviridae, Capoviridae, Bicistronic Viridae, and Nodamuraviridae; preferably, the virus is a coronavirus.

[0069] According to the embodiments of this disclosure, the virus may be selected from: chicken infectious bronchitis virus, porcine transmissible gastroenteritis virus, porcine epidemic diarrhea virus, porcine hemagglutinating encephalomyelitis virus, mouse hepatitis virus, turkey blue crown virus, bovine coronavirus, canine coronavirus, feline infectious peritonitis virus, rat coronavirus, rat lacrimation coronavirus, and mink epidemic diarrhea coronavirus.

[0070] According to embodiments of this disclosure, the disease is selected from diseases caused by coronaviruses, such as feline infectious peritonitis (FIP).

[0071] According to an embodiment of this disclosure, the coronavirus is selected from feline infectious peritonitis virus (FIPV).

[0072] According to the embodiments of this disclosure, the tumor is a malignant tumor; preferably, the malignant tumor is selected from malignant epithelial tumors, sarcomas, leukemia, and mixed tumors.

[0073] According to the embodiments of this disclosure, the malignant epithelial tumor is selected from: lung cancer, breast cancer, liver cancer, pancreatic cancer, colorectal cancer, gastric cancer, gastroesophageal adenocarcinoma, esophageal cancer, small bowel cancer, large bowel cancer, cardia cancer, endometrial cancer, ovarian cancer, fallopian tube cancer, vulvar cancer, testicular cancer, prostate cancer, penile cancer, kidney cancer, bladder cancer, anal cancer, gallbladder cancer, bile duct cancer, skin cancer, nasopharyngeal cancer, laryngeal cancer, thyroid cancer, tongue cancer, intracranial tumors, cardiac tumors, and spinal tumors.

[0074] This disclosure also provides a method of treating and / or preventing disease, comprising administering to a patient a therapeutically effective amount of at least one of a compound of formula (I) or formula (II) or a pharmaceutically acceptable salt or a pharmaceutical composition containing a compound of formula (I) or formula (II) or a pharmaceutically acceptable salt.

[0075] According to the embodiments of this disclosure, the patient can be an animal, and the animal is a domesticated animal; preferably, the animal is an economic animal, a pet, or a laboratory animal; preferably, the economic animal is selected from: pigs, cattle, sheep, horses, donkeys, foxes, raccoon dogs, minks, and camels; preferably, the pet is selected from: dogs, cats, rabbits, and mice; preferably, the laboratory animal is selected from: monkeys, dogs, rabbits, and mice.

[0076] According to embodiments of this disclosure, the pharmaceutical composition or the drug may be used as a functional food composition or additive. Beneficial effects

[0077] This disclosure provides a compound of formula (I) or formula (II) that has good protease inhibitory activity and can be used as a peptide-like protease inhibitor.

[0078] Terminology Definitions and Explanations

[0079] Unless otherwise stated, the definitions of groups and terms recorded in this application specification and claims, including their definitions as examples, exemplary definitions, preferred definitions, definitions recorded in tables, and definitions of specific compounds in the examples, can be arbitrarily combined and combined with each other. Such combinations and combinations of group definitions and compound structures should be understood as being within the scope of this application specification and / or claims.

[0080] Unless otherwise stated, the numerical ranges described in this specification and claims are equivalent to describing at least each specific integer value therein. For example, the numerical range "1-10" is equivalent to describing each integer value in the numerical range "1-10", namely 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0081] It should be understood that in this article, when describing one, two or more, "more" should refer to integers greater than 2, such as 3 or greater than or equal to 3, such as 3, 4, 5, 6, 7, 8, 9 or 10.

[0082] The context of this disclosure is used Represents a chemical bond.

[0083] Term "C" 1-10 "alkyl" refers to a straight-chain or branched saturated hydrocarbon group, preferably a straight-chain or branched saturated hydrocarbon group having 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. The alkyl group includes C... 1-3 Alkyl, C 1-6 Alkyl, C 3-6 Alkyl, C 1-10 Alkyl groups, etc. "C" 1-10 "Alkyl" refers to straight-chain and branched alkyl groups having 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. 1-8 "Alkyl" refers to straight-chain and branched alkyl groups having 1, 2, 3, 4, 5, 6, 7, or 8 carbon atoms. 1-6 "Alkyl" means a straight-chain or branched alkyl group having 1, 2, 3, 4, 5, or 6 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl, or 1,2-dimethylbutyl, or their isomers.

[0084] Term "C" 3-10"Cycloalkyl" refers to a saturated monovalent monocyclic, bicyclic (e.g., fused, bridged, spirocyclic) hydrocarbon ring or tricyclic alkane, preferably having 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. The cycloalkyl group includes C... 3-8 cycloalkyl, C 3-5 cycloalkyl, C 6-8 cycloalkyl, C 3-4 cycloalkyl, C 5-6 Cycloalkyl, C6 cycloalkyl, C 3-10 Cycloalkyl groups, etc. The C... 3-10 Cycloalkyl groups can be monocyclic hydrocarbon groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, or cyclodecyl; or bicyclic hydrocarbon groups, such as borneolyl, indolyl, hexahydroindolyl, tetrahydronaphthyl, decahydronaphthyl, bicyclo[2.1.1]hexyl, bicyclo[2.2.1]heptyl, bicyclo[2.2.1]heptenyl, 6,6-dimethylbicyclo[3.1.1]heptyl, 2,6,6-trimethylbicyclo[3.1.1]heptyl, bicyclo[2.2.2]octyl, 2,7-diazaspiro[3,5]nonyl, 2,6-diazaspiro[3,4]octyl; or tricyclic hydrocarbon groups, such as adamantyl.

[0085] The term "3-10 membered heterocyclic group" refers to a monocyclic, bicyclic, or tricyclic saturated or unsaturated non-aromatic ring or ring system (preferably 3-8 membered heterocyclic group) containing 1-5 heteroatoms independently selected from N, O, and S, with monovalent or polyvalent rings of 3, 4, 5, 6, 7, 8, 9, or 10 ring atoms. For example, a 3-8 membered heterocyclic group can be a monocyclic, bicyclic, or tricyclic saturated or unsaturated non-aromatic ring or ring system containing 3, 4, 5, 6, 7, or 8 ring atoms, wherein the 3-8 membered heterocyclic group contains 1-5 heteroatoms independently selected from N, O, and S. The bicyclic and tricyclic aromatic ring systems can be fused rings, spirocyclic rings, or bridged rings. The 3-10 membered heterocyclic group includes 3-8 membered heterocyclic groups and 5-6 membered heterocyclic groups. The 3-10 membered heterocyclic group can be connected to the rest of the molecule via any one of the carbon atoms or a nitrogen atom (if present). The 3-10 membered heterocyclic groups may include fused or bridged rings and spirocyclic rings. Specifically, the heterocyclic groups may include, but are not limited to: 3-membered rings, such as azirropropyl or oxacyclopropyl; 4-membered rings, such as azirrobutyl or oxacyclobutyl; 5-membered rings, such as tetrahydrofuranyl, dioxacyclopentenyl, pyrrolyl, imidazoalkyl, pyrazolyl, or pyrrololinyl; or 6-membered rings, such as tetrahydropyranyl, piperidinyl, morpholinyl, dithiaalkyl, thiomorpholinyl, piperazinyl, or trithiaalkyl; or 7-membered rings, such as diazacycloheptyl. Optionally, the heterocyclic group may be benzofused. The heterocyclic group may be bicyclic, for example, but not limited to, 5,5-membered rings, such as hexahydrocyclopenta[c]pyrrolo-2(1H)-yl rings, or 5,6-membered bicyclic rings, such as hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl rings. The heterocyclic group can be partially unsaturated, meaning it can contain one or more double bonds, such as, but not limited to, dihydrofuranyl, dihydropyranyl, 2,5-dihydro-1H-pyrroleyl, 4H-[1,3,4]thiadiazinyl, 1,2,3,5-tetrahydrooxazolyl, or 4H-[1,4]thiazinyl. Alternatively, it can be benzofused, such as, but not limited to, dihydroisoquinolinyl. When the 3-10 membered heterocyclic group is linked to other groups to form the compounds of this disclosure, the carbon atom on the 3-10 membered heterocyclic group can be linked to other groups, or a heterocyclic atom (such as a nitrogen atom) on the ring of the 3-10 membered heterocyclic group can be linked to other groups. For example, when the 3-10 membered heterocyclic group is selected from piperazineyl or tetrahydropyrroleyl, the nitrogen atom or carbon atom on the piperazineyl group can be linked to other groups. Alternatively, when the 3-10 membered heterocyclic group is selected from piperidinyl, it can be the nitrogen atom on the piperidinyl ring or the carbon atom at the ortho, meta or para position connected to other groups.

[0086] Term "C" 6-10"Aryl" should preferably be understood to refer to a monocyclic, bicyclic (such as fused ring, bridged ring, spiro ring), or tricyclic hydrocarbon ring having 6 to 10 carbon atoms and possessing monovalent aromaticity or partial aromaticity. It can be a monoaromatic ring or a polyaromatic ring fused together. The term "C" 6- 10 "Aryl" should be understood to preferably represent a monocyclic, bicyclic, or tricyclic hydrocarbon ring having 6, 7, 8, 9, or 10 carbon atoms and possessing monovalent aromatic or partially aromatic properties ("C"). 6-10 Aryl), particularly a ring with 6 carbon atoms (“C6 aryl”), such as phenyl; or biphenyl, or a ring with 9 carbon atoms (“C9 aryl”), such as indenyl or indenyl, or a ring with 10 carbon atoms (“C9 aryl”). 10 Aryl), such as tetrahydronaphthyl, dihydronaphthyl, or naphthyl. When the C... 6-10 When the aryl group is substituted, it can be monosubstituted or polysubstituted. Furthermore, there are no restrictions on the substitution site; for example, it can be ortho, para, or meta substituted.

[0087] The term "5-10-membered heteroaryl" refers to a monocyclic, bicyclic, or tricyclic aromatic ring system having 5, 6, 7, 8, 9, or 10 ring atoms, wherein the ring atoms comprise 1-5 heteroatoms independently selected from N, O, and S, and the bicyclic and tricyclic aromatic ring systems can be fused rings, spirocyclic, or bridged rings (preferably 5-9-membered heteroaryl). The 5-9-membered heteroaryl contains 1-5 heteroatoms, preferably 1-3. Additionally, in each case, the 5-10-membered heteroaryl can be benzofused. The 5-10-membered heteroaryl includes 5-8-membered heteroaryl, 5-9-membered heteroaryl, 5-10-membered heteroaryl, 5-6-membered heteroaryl, 8-10-membered heteroaryl, 6-membered heteroaryl, etc. Examples of heteroaryl groups include, but are not limited to: 5-membered rings, such as oxazolyl, pyrazolyl, thiophene, thiazolyl, triazole, imidazolyl, etc.; 6-membered rings, such as pyridinyl, pyrimidinyl, pyrazinyl, pyridazinyl, etc. The heterocyclic group may be bicyclic, including but not limited to: 5,5-membered rings, such as tetrahydrocyclopentanopyrazole; 5,6-membered rings, such as tetrahydroindole, tetrahydropyrazolopyridine, tetrahydroimidazopyridine, tetrahydrobenzisoxazole, tetrahydrobenzoxazole, tetrahydrobenzothiazole, tetrahydrobenzisoxazole, dihydrofuranopyrazole, tetrahydrobenzofuran, dihydrobenzofuran, tetrahydrobenzothiophene; 6,6-membered rings, such as tetrahydroquinoline; 5,7-membered rings, such as tetrahydrocycloheptazothiazole, tetrahydrocycloheptazofuran. The heterocyclic group can be tricyclic, including but not limited to: 6,7-dihydrospiro[cyclopropane-1,5-pyrrolo[1,2-c]imidazole]. When the 5-10 membered heteroaryl group is substituted, it can be monosubstituted or polysubstituted. Furthermore, there are no restrictions on the substitution site; for example, the hydrogen atom bonded to the carbon atom on the heteroaryl ring can be substituted, or the hydrogen atom bonded to the heteroatom on the heteroaryl ring can be substituted.

[0088] The term "spirocycle" refers to a ring system in which two rings share a single ring atom.

[0089] The term "fused ring" refers to a ring system in which two rings share two cyclic atoms.

[0090] The term "bridged ring" refers to a ring system in which two rings share three or more cyclic atoms.

[0091] The term "halogen" refers to fluorine, chlorine, bromine, or iodine.

[0092] "Halogenation" refers to the substitution of a substance by one or more halogens.

[0093] Unless otherwise stated, the definitions of terms in this document also apply to groups that contain the term; for example, the definition of alkyl also applies to the definition of alkyl-containing groups such as alkoxy (i.e., alkyloxy).

[0094] Unless otherwise stated, the term “compound” in the context of this disclosure shall be understood to include the compound itself and its tautomers, stereoisomers, solvates or isotopic labels.

[0095] Crystallization often produces solvates of the compounds disclosed herein. As used herein, a solvate is a combination of one or more molecules of the compounds disclosed and one or more solvent molecules.

[0096] The solvent can be water, in which case the solvate is a hydrate; alternatively, it can be an organic solvate.

[0097] As used herein, the term “acceptable” in relation to formulations, compositions or ingredients means that it does not have a lasting harmful effect on the overall health of the subject of treatment.

[0098] As used herein, the term "pharmaceutically acceptable" means a substance (such as a carrier or diluent) that does not affect the biological activity or properties of the compounds disclosed herein and is relatively non-toxic, i.e., that the substance can be administered to an individual without causing an adverse biological response or interacting adversely with any component contained in the composition.

[0099] Those skilled in the art will understand that the compounds of this disclosure can exist in the form of various pharmaceutically acceptable salts. If these compounds have a basic center, they can form acid addition salts; if these compounds have an acidic center, they can form base addition salts; if these compounds contain both an acidic center (e.g., a carboxyl group) and a basic center (e.g., an amino group), they can also form inner salts.

[0100] The term "tautomer" refers to a functional group isomer resulting from the rapid movement of an atom between two positions within a molecule. The compounds disclosed herein can exhibit tautomerism. Tautomers can exist in two or more interconvertible forms. Proton-transfer tautomers arise from the migration of covalently bonded hydrogen atoms between two atoms. Tautomers generally exist in equilibrium form, and attempts to isolate a single tautomer typically yield a mixture whose physicochemical properties are consistent with those of the mixture of compounds. The equilibrium position depends on the intramolecular chemical characteristics. For example, in many aliphatic aldehydes and ketones such as acetaldehyde, the keto form is dominant; while in phenols, the enol form is dominant. This disclosure encompasses all tautomeric forms of the compounds.

[0101] Based on their molecular structure, the compounds disclosed herein can be chiral, and therefore may exist in various enantiomeric forms. Consequently, these compounds can exist in racemic or optically active forms. The compounds disclosed herein cover isomers of each chiral carbon with an R or S configuration, or mixtures thereof, or racemates. The compounds disclosed herein, or intermediates thereof, can be isolated as enantiomers by chemical or physical methods known to those skilled in the art, or used in this form for synthesis. In the case of racemic amines, diastereomers are obtained from the mixture by reaction with an optically active resolving agent. Examples of suitable resolving agents are optically active acids, such as tartaric acid in R and S forms, diacetyltartaric acid, dibenzoyltartaric acid, mandelic acid, malic acid, lactic acid, suitable N-protected amino acids (e.g., N-benzoylproline or N-benzenesulfonylproline), or various optically active camphorsulfonic acids. Chromatographic enantiomeric separation can also be advantageously performed using optically active resolving agents (e.g., dinitrobenzoylphenylglycine immobilized on silica gel, cellulose triacetate or other carbohydrate derivatives, or chiral derivatized isobutylene ester polymers). Suitable eluents for this purpose are aqueous or alcoholic solvent mixtures, such as hexane / isopropanol / acetonitrile.

[0102] In this application, "pharmaceutical composition" refers to a formulation of the disclosed compound and a medium conventionally accepted in the art for delivering a bioactive compound to a mammal (e.g., a human). This medium includes pharmaceutically acceptable carriers. The purpose of the pharmaceutical composition is to facilitate administration to the organism, thereby promoting the absorption of the active ingredient and the exertion of its bioactivity.

[0103] In this application, "pharmaceuticalally acceptable excipients" include, but are not limited to, any adjuvants, carriers, excipients, flow aids, sweeteners, diluents, preservatives, dyes / colorants, flavoring agents, surfactants, wetting agents, dispersants, suspending agents, stabilizers, isotonic agents, solvents, or emulsifiers that are permitted by the relevant government regulatory authorities to be acceptable for human or livestock use.

[0104] In this application, the term "prodrug" refers to a compound of this disclosure that can be converted into a biologically active form under physiological conditions or by solvation. The prodrugs of this disclosure are prepared by modifying functional groups in the compound; such modification can be performed conventionally or removed in vivo to obtain the parent compound. Prodrugs comprise compounds formed by attaching a hydroxyl or amino group to any group in the compound of this disclosure. When a prodrug of the compound of this disclosure is administered to a mammalian individual, the prodrug is cleaved to form a free hydroxyl group and a free amino group.

[0105] "Isotope" refers to all isotopes of atoms appearing in the compounds disclosed herein. Isotopes include those atoms having the same atomic number but different mass numbers. Examples of isotopes suitable for inclusion in the compounds disclosed herein are hydrogen, carbon, nitrogen, oxygen, phosphorus, fluorine, and chlorine, respectively, for example, but not limited to, [examples of isotopes]. 2 H, 3 H, 13 C 14 C 15 N、 18 O、 31 P, 32 P, 35 S, 18 F and 36 C1. The isotopically labeled compounds of this disclosure can generally be prepared by conventional techniques known to those skilled in the art or by methods similar to those described in the appended examples, using appropriate isotopically labeled reagents instead of non-isotopically labeled preparations. Such compounds have a variety of potential uses, for example, as standards and reagents in the determination of biological activity. In the case of stable isotopes, such compounds have the potential to advantageously alter biological, pharmacological, or pharmacokinetic properties.

[0106] The term "treatment" and other similar synonyms used in this article include the following meanings:

[0107] (i) To prevent the occurrence of disease or condition in mammals, especially when such mammals are susceptible to the disease or condition but have not yet been diagnosed with it;

[0108] (ii) To suppress a disease or symptom, that is, to curb its development;

[0109] (iii) To alleviate a disease or symptom, that is, to cause the condition of the disease or symptom to subside; or

[0110] (iv) To alleviate the symptoms caused by the disease or condition.

[0111] The term "patient" refers to any animal, including mammals, preferably mice, rats, other rodents, rabbits, dogs, cats, pigs, cattle, sheep, horses, or primates, with humans being the most preferred.

[0112] The term “therapeutic effective amount” refers to the amount of an active compound or drug that researchers, veterinarians, physicians, or other clinicians are searching for in tissues, systems, animals, individuals, or humans to elicit a biological or medical response. It includes one or more of the following: (1) prevention of disease: e.g., prevention of disease, disorder, or condition in individuals susceptible to disease, disorder, or symptom but not yet experiencing or exhibiting the pathology or symptoms of the disease; (2) suppression of disease: e.g., suppression of disease, disorder, or symptom in individuals experiencing or exhibiting the pathology or symptoms of the disease, disorder, or symptom (i.e., prevention of further development of the pathology and / or symptoms); (3) relief of disease: e.g., relief of disease, disorder, or symptom in individuals experiencing or exhibiting the pathology or symptoms of the disease, disorder, or symptom (i.e., reversal of the pathology and / or symptoms). Detailed Implementation

[0113] The technical solutions of this disclosure will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of this disclosure and should not be construed as limiting the scope of protection of this disclosure. All technologies implemented based on the above content of this disclosure are covered within the scope of protection intended by this disclosure.

[0114] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0115] Example 1: Synthesis of compound C1-2A

[0116] 1. Synthesize compound 2

[0117] Under nitrogen atmosphere, methyl (S)-2-((tert-Butoxycarbonyl)amino)-3-((S)-2-oxopiridine-3-yl)propionate (490 mg, 1.6 mmol, 1.0 eq.) was added dropwise to a mixture of (S)-2-((tert-Butoxycarbonyl)amino)-3-((S)-2-oxopiridine-3-yl)propionate (5 mL) under stirring at 25 °C. The resulting mixture was stirred at 25 °C for 2 hours. The mixture was then concentrated under reduced pressure to give methyl (2S)-2-amino-3-[(3S)-2-oxopiridine-3-yl]propionate (330 mg, crude product) as a yellow solid.

[0118] LCMS:(ESI,m / z):[M+H] + =201.0

[0119] 2. Synthesize compound 3

[0120] To a mixture of carboxyphenoxy-L-leucine (300 mg, 1.1 mmol, 1.0 eq.) and (2S)-2-amino-3-[(3S)-2-oxopiperidin-3-yl]propionate (226 mg, 1.1 mmol, 1.0 eq.) in dichloromethane (5 mL), N,N-diisopropylethylamine (438 mg, 3.4 mmol, 3.0 eq.) and HATU (645 mg, 1.7 mmol) were added. l, 1.5 eq.). The resulting mixture was stirred at 25 °C for 2 hours. The resulting residue was purified by reversed-phase column chromatography under the following conditions: column specifications, mobile phase, water and acetonitrile, 10% to 50% gradient for 10 minutes, UV 200 nm detector. A white solid (S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-4-methylpentanamino)-3-((S)-2-oxopiperidin-3-yl)propionate (280 mg) was obtained.

[0121] LCMS:(ESI,m / z):[M+H] + =448.0

[0122] 3. Synthesize compound 4

[0123] Under nitrogen atmosphere, lithium borohydride (4.0 M in THF) (0.5 mL) was added dropwise to a mixture of methyl (2S)-2-[(2S)-2-{[(benzyloxy)carbonyl]amino}-4-methylpentanamino]-3-[(3S)-2-oxopiridine-3-yl]propionate (280 mg, 0.6 mmol, 1.0 eq.) in tetrahydrofuran (3 mL) at 0 °C. The resulting mixture was stirred at 25 °C for 2 hours. The reaction was quenched with water at 0 °C. The aqueous layer was extracted with ethyl acetate (3 x 30 mL). The combined organic layers were dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to obtain N-[(1S)-1-{[(2S)-1-hydroxy-3-[(3S)-2-oxopiperidin-3-yl]propyl-2-yl]carbamoyl}-3-methylbutyl]carbamate (200 mg), which is a yellow solid.

[0124] LCMS:(ESI,m / z):[M+H] + =420.2

[0125] 4. Synthesize compound 5

[0126] At 0 °C, Dysmartin oxidant (DMP, 288 mg, 0.6 mmol, 1.5 eq.) was added fractionally to dichloromethane (2 mL) containing N-[(1S)-1-{[(2S)-1-hydroxy-3-[(3S)-2-oxopiperidin-3-yl]propyl-2-yl]carbamoyl}-3-methylbutyl]carbamate (190 mg, 0.4 mmol, 1.0 eq.). The resulting mixture was stirred at 25 °C for 2 h. The resulting residue was purified by reversed-phase column chromatography under the following conditions: column specifications, mobile phase, water and acetonitrile, 10% to 50% gradient for 10 min, UV 254 nm detector. 100 mg of benzyl((S)-4-methyl-1-oxo-1-(((S)-1-oxo-3-((S)-2-oxopiridin-3-yl)propyl-2-yl)amino)pent-2-yl)carbamate was obtained as a white solid.

[0127] LCMS:(ESI,m / z):[M+H] + =418.0

[0128] 5. Synthesize compound C1-2A

[0129] Under nitrogen protection and at 25°C, sodium bisulfite (75 mg, 0.6 mmol, 3 eq.) was added in portions to a stirred mixture of N-[(1S)-3-methyl-1-{[(2S)-1-oxo-3-[(3S)-2-oxopiridin-3-yl]propyl-2-yl]carbamoyl}butyl]carbamate (100 mg, 0.2 mmol, 1.0 eq.) and N,N-dimethylformamide (1 mL). The resulting mixture was stirred at 25°C for 1 hour. The crude product was purified by high performance liquid chromatography under the following conditions (column: Xselect CSH C185): Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 mL / min; gradient: 45% B to 65% B, 10 min; wavelength: 254 nm / 220 nm; RT1 (min): 5.65, yielding a white solid -(2S)-2-[(2S)-2-{[(benzyloxy)carbonyl]amino}-4-methylpentanamino]-1-hydroxy-3-[(3S)-2-oxopiridine-3-yl]propane-1-sulfonate sodium (12.0 mg).

[0130] LCMS:(ESI,m / z):[M-Na] - =498.0

[0131] H NMR(400MHz,D2O)δ7.99–7.91(m,1H),7.61–7.56(m,1H),7.42(t,J=7.6Hz,1H),7.39–7.25(m,5H),7.17(t,J=7.7Hz,1 H),5.19–4.88(m,2H),4.57–3.60(m,3H),3.31–2.88(m,2H),2.30-1.92(m,3H),1.78–1.35(m,8H),0.85–0.70(m,6H).

[0132] Example 2 Synthesis of compound C1-22A

[0133] 1. Synthesis of Compound 2

[0134] At room temperature, in air, cesium carbonate (5.2 g, 15.9 mmol, 2.0 eq.) was added to a stirred solution of (2R)-2-[(tert-butyloxycarbonyl)amino]-3-iodopropionate methyl ester (5.3 g, 15.9 mmol, 2.0 eq.) and N-methyl-1H-pyrazole-4-carboxamide (1.0 g, 8.0 mmol, 1.0 eq.) in N,N-dimethylformamide (10 mL). The reactants were quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L ammonium bicarbonate), 30%–45% gradient, 10 min; detector, UV 254 nm. A light yellow, oily methyl (2S)-2-[(tert-butoxycarbonyl)amino]-3-[4-(methylcarbamoyl)pyrazol-1-yl]propionate (1.3 g) was obtained.

[0135] LCMS(ESI,m / z): [M+H] + =327.25

[0136] 2. Synthesis of Compound 3

[0137] At room temperature and in air, HCl (8 mL) in 1,4-dioxane (4.0 M) was added to a stirred solution of methyl (2S)-2-[(tert-butoxycarbonyl)amino]-3-[4-(methylcarbamoyl)pyrazol-1-yl]propionate (1.2 g, 3.7 mmol, 1.0 eq.). The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The mixture was then concentrated under reduced pressure to give methyl (2S)-2-amino-3-[4-(methylcarbamoyl)pyrazol-1-yl]propionate (1.1 g) as a white solid.

[0138] LCMS(ESI,m / z): [M+H] + =227.20

[0139] 3. Synthesis of Compound 4

[0140] At room temperature, in air, N,N-diisopropylethylamine (3.1 mL, 17.7 mmol, 4 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (3.4 g, 8.8 mmol, 2.0 eq.) were added to a stirred solution of (2S)-2-amino-3-[4-(methylcarbamoyl)pyrazol-1-yl]propionate (10 mg, 0.044 mmol, 1 eq.) and benzyloxycarbonyl-L-leucine (1.2 g, 4.4 mmol, 1.0 eq.) in dichloromethane (15 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 1 hour. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L ammonium bicarbonate), 35%–45% gradient, 10 min; detector: UV 254 nm. The product was a pale yellow solid (2S)-2-[(2S)-2-{[(benzyloxy)carbonyl]amino}-4-methylpentanamino]-3-[4-(methylcarbamoyl)pyrazol-1-yl]propionate methyl ester (800 mg).

[0141] LCMS(ESI,m / z): [M+H] + =474.24

[0142] 4. Synthesis of Compound 5

[0143] Under nitrogen atmosphere at 0 °C, methyl (2S)-2-[(2S)-2-{[(benzyloxy)carbonyl]amino}-4-methylpentanamino]-3-[4-(methylcarbamoyl)pyrazol-1-yl]propionate (800 mg, 1.0 mmol, 1.0 eq.) was stirred and then added to lithium borohydride (4.0 M, tetrahydrofuran) (0.6 mL, 2.5 mmol, 1.5 eq.). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 1.5 h. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 80 mL). The combined organic layers were washed with brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L ammonium bicarbonate), gradient 34%-45% over 10 minutes; detector: UV 254 nm. A white solid, N-[(1S)-1-{[(2S)-1-hydroxy-3-[4-(methylcarbamoyl)pyrazol-1-yl]propyl-2-yl]carbamoyl}-3-methylbutyl]carbamate (160 mg), was obtained.

[0144] LCMS(ESI,m / z): [M+H] + =446.24

[0145] 5. Synthesis of Compound 6

[0146] Sodium bicarbonate (91 mg, 1.1 mmol, 3.0 eq.) and Desmartin oxidant (305 mg, 0.7 mmol, 2.0 eq.) were added to a stirred solution of N-[(1S)-1-{[(2S)-1-hydroxy-3-[4-(methylcarbamoyl)pyrazol-1-yl]propyl-2-yl]carbamoyl}-3-methylbutyl]carbamate (160 mg, 0.4 mmol, 1.0 eq.) in dichloromethane (2 mL). The mixture was stirred at room temperature under nitrogen atmosphere for 1.5 h. The reaction was quenched with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. N-[(1S)-3-methyl-1-{[(2S)-1-[4-(methylcarbamoyl)pyrazol-1-yl]-3-oxopropane-2-yl]carbamoyl}butyl]carbamate (130 mg) was obtained as a yellow oil.

[0147] LCMS(ESI,m / z): [M+H] + =444.24

[0148] 6. Synthesis of compound C1-22A

[0149] Sodium bisulfite (1 mL) was added to a stirred solution of N-[(1S)-3-methyl-1-{[(2S)-1-[4-(methylcarbamoyl)pyrazol-1-yl]-3-oxopropane-2-yl]carbamoyl}butyl]carbamate (120 mg, 0.3 mmol, 1.0 eq.) in N,N-dimethylformamide (1.2 mL). The resulting mixture was stirred in air at room temperature for 3 minutes. The resulting mixture was diluted with water (3 mL) and then extracted with ethyl acetate (1 x 4 mL). The aqueous layer was concentrated under reduced pressure. The crude product (150 mg) was purified by pre-liquid chromatography under the following conditions (column: Xselect CSH C185): Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 mL / min; gradient: 35% B to 50% B, 10 min; wavelength: 254 nm / 220 nm; RT1 (min): 7.32), yielding sodium (2S)-2-[(2S)-2-{[(benzyloxy)carbonyl]amino}-4-methylpentanamino]-1-hydroxy-3-[4-(methylcarbamoyl)pyrazol-1-yl]propane-1-sulfonate (25.0 mg), a pale yellow solid.

[0150] LCMS(ESI,m / z):[M-Na] - =524.40

[0151] 1H NMR(400MHz,D2O)δ7.96–7.59(m,2H),7.40–7.15(m,5H),5.10–4.95(m,2H),4.62(d,J=3.7Hz,1H ),4.54–4.10(m,3H),4.01–3.79(m,1H),2.75–2.70(m,3H),1.47–0.95(m,3H),0.84–0.62(m,6H).

[0152] Example 3 Synthesis of compound C2-1

[0153] 1. Synthesize compound 2

[0154] Under nitrogen atmosphere at 0°C, benzyl chloroformate (717 mg, 4.2 mmol, 1.5 eq.) was added dropwise to a stirred mixture of ethyl (2S,4S)-4-methylpiperidine-2-carboxylate (480 mg, 2.8 mmol, 1.0 eq.) and sodium carbonate (891 mg, 8.4 mmol, 3.0 eq.) in 1,4-dioxane (5 mL). The resulting mixture was stirred at 25°C for 16 hours. The residue was purified by reversed-phase column chromatography under the following conditions: column specifications, mobile phase: water and acetonitrile, 10% to 50% gradient for 10 min, UV 200 nm detector. A colorless oily 1-benzyl 2-ethyl(2S,4S)-4-methylpiperidine-1,2-dicarboxylate (600 mg, 70% yield) was obtained.

[0155] LCMS:(ESI,m / z):[M+H] + =306.1

[0156] 2. Synthesize compound 3

[0157] Under nitrogen atmosphere at 25°C, water (2 mL) and sodium hydroxide (298 mg, 7.4 mmol, 3.0 eq.) were added to a solution of 1-benzyl 2-ethyl(2S,4S)-4-methylpiperidin-1,2-dicarboxylic acid (1-benzyl ester) (600 mg, 1.9 mmol, 1.0 eq.) in methanol (2 mL) and tetrahydrofuran (2 mL). The resulting mixture was stirred at 25°C for 2 hours. The mixture was then concentrated under reduced pressure to give a white solid (2S,4S)-1-[(benzyloxy)carbonyl]-4-methylpiperidin-2-carboxylic acid (500 mg).

[0158] LCMS:(ESI,m / z):[M+H] + =278.1

[0159] 3. Synthesize compound 4

[0160] Under nitrogen atmosphere and at 25°C, N,N-diisopropylethylamine (671 mg, 5.1 mmol, 3.0 eq.) and HATU (2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate, 987 mg, 2.6 mmol, 1.50 eq.) were added to N,N-dimethylformamide (5 mL) containing (2S,4S)-1-[(benzyloxy)carbonyl]-4-methylpiperidin-2-carboxylic acid (480 mg, 1.7 mmol, 1.0 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (322 mg, 1.7 mmol, 1.0 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (322 mg, 1.7 mmol, 1.0 eq.) at 25°C. The resulting mixture was stirred for 2 hours at 25°C. The resulting residue was purified by reversed-phase column chromatography under the following conditions: column specifications, mobile phase, water and acetonitrile, 10% to 50% gradient for 10 min, UV 200 nm detector. A white solid (2S,4S)-2-{[(2S)-1-methoxy-1-oxo-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]carbamoyl}-4-methylpiperidin-1-carboxylic acid benzyl ester (320 mg) was obtained.

[0161] LCMS:(ESI,m / z):[M+H] + =446.0

[0162] 4. Synthesize compound 5

[0163] Under nitrogen atmosphere and at 0°C, lithium borohydride (4.0 M in THF) (0.4 mL) was added dropwise to tetrahydrofuran containing (2S,4S)-2-{[(2S)-1-methoxy-1-oxo-3-[(3S)-2-oxopyrrolidone-3-yl]propyl-2-yl]carbamoyl}-4-methylpiperidin-1-carboxylic acid benzyl ester (300 mg, 0.7 mmol, 1.0 eq.). The resulting mixture was stirred at 25°C for 2 hours. The reaction was quenched with water at 0°C. The resulting mixture was extracted with ethyl acetate (3 x 30 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to obtain (2S,4S)-2-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)carbamoyl)-4-methylpiperidine-1-carboxylic acid benzyl ester (270 mg), which is a yellow oil.

[0164] LCMS:(ESI,m / z):[M+H] + =418.0

[0165] 5. Synthesize compound 6

[0166] At 0 °C, Dysmartin oxidant (508 mg, 1.2 mmol, 2.0 eq.) was added to 3 mL of dichloromethane containing (2S,4S)-2-{[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidone-3-yl]propyl-2-yl]carbamoyl}-4-methylpiperidin-1-carboxylic acid benzyl ester (250 mg, 0.6 mmol, 1.0 eq.). The resulting mixture was stirred at 25 °C for 2 hours. The resulting mixture was extracted with dichloromethane (3 x 30 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to obtain (2S,4S)-4-methyl-2-{[(2S)-1-oxo-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]carbamoyl}piperidine-1-carboxylic acid benzyl ester (110 mg, crude product), which is a yellow oil.

[0167] LCMS:(ESI,m / z):[M+H] + =416.0

[0168] 6. Synthesis of compound C2-1

[0169] Sodium bisulfite (45 mg, 0.4 mmol, 2.0 eq.) was added to a mixture of (2S,4S)-4-methyl-2-{[(2S)-1-oxo-3-[(3S)-2-oxopyrrolidone-3-yl]propyl-2-yl]carbamoyl}piperidin-1-carboxylic acid benzyl ester (90 mg, 0.2 mmol, 1.0 eq.) and N,N-dimethylformamide (1.0 mL) at 25 °C. The resulting mixture was stirred at 25°C for 1 hour, and the crude product was purified by high performance liquid chromatography under the following conditions (column: Xselect CSH C185): Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 mL / min; gradient: 35% B to 50% B, 10 min; wavelength: 254 nm / 220 nm; RT1 (min): 7.73), yielding a white solid (2S)-2-((2S,4S)-1-((benzyloxy)carbonyl)-4-methylpiperidin-2-carboxamido)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propane-1-sulfonate sodium salt (25.0 mg).

[0170] LCMS:(ESI,m / z):[M-Na] - =486.0

[0171] 1H NMR (400MHz, MeODl-d4) δ8.10–8.00(m,1H),7.85–7.76(m,1H),7.47(t,J=7.6Hz,1H),7.38(s,2H),7.35(s,2H),7.21(t,J=7.6Hz,1H),5.32– 5.09(m,3H),4.83(s,1H),4.20–3.80(m,2H),3.21–2.87(m,2H),2.75– 2.09(m,3H),2.03–1.88(m,1H),1.81–1.03(m,7H),1.06–0.76(m,3H).

[0172] Example 4 Synthesis of compound C2-3A

[0173] 1. Synthesis of Compound 2

[0174] At room temperature and in air, 1-hydroxybenzotriazole (342 mg, 2.9 mmol, 1.5 eq.) and ({[3-(dimethylamino)propyl]imino}methylene)(ethyl)amine (179 mg, 0.1 mmol, 1.5 eq.) were added to a solution of (S)-1-(tert-butyloxycarbonyl)-4,4-difluoropiperidine-2-carboxylic acid (300 mg, 1.9 mmol, 1 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (304 mg, 2.5 mmol, 1.3 eq.) and N,N-diisopropylethylamine (0.7 mL, 5.9 mmol, 3 eq.) in N,N-dimethylformamide (5 mL). The resulting mixture was stirred at room temperature under nitrogen for 3 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH₄HCO₃), 37%–45% gradient, 10 min; detector: UV 200 nm. The final product was (S)-4,4-difluoro-2-(((S)-1-methoxy-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)carbamoyl)piperidine-1-carboxylic acid tert-butyl ester (290 mg), a white solid.

[0175] LCMS(ESI,m / z): [M+H] + =434.25

[0176] 2. Synthesis of Compound 3

[0177] At room temperature and in an air atmosphere, a solution of 1,4-dioxane hydrochloride (4.0 M, 3 mL) was added to a stirred solution of (S)-4,4-difluoro-2-(((S)-1-methoxy-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)prop-2-yl)carbamoyl)piperidin-1-carboxylic acid tert-butyl ester (280 mg, 1.2 mmol, 1 eq.) in 1,4-dioxane (3 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The resulting mixture was concentrated under reduced pressure to give methyl (S)-2-((S)-4,4-difluoropiperidin-2-carboxamido)-3-((S)-2-oxopyrrolidone-3-yl)propionate (220 mg), a white solid.

[0178] LCMS(ESI,m / z): [M+H] + =334.20

[0179] 3. Synthesis of Compound 4

[0180] In a stirred solution of methyl (S)-2-((S)-4,4-difluoropiperidin-2-carboxamido)-3-((S)-2-oxopyrrolidone-3-yl)propionate (220 mg, 1.2 mmol, 1 eq.) and sodium carbonate (182 mg, 2.5 mmol, 2 eq.) in 1,4-dioxane (5 mL), benzyl chloroformate (CbzCl, 213 mg, 1.5 mmol, 1.2 eq.) was added to the mixture under nitrogen atmosphere at room temperature for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH4HCO3), 35%-43% gradient, 10 min; detector: UV 200 nm. (S)-4,4-difluoro-2-(((S)-1-methoxy-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)carbamoyl)piperidin-1-carboxylic acid benzyl ester (140 mg) was obtained as a white solid.

[0181] LCMS(ESI,m / z): [M+H] + =468.24

[0182] 4. Synthesis of Compound 5

[0183] Under nitrogen atmosphere at 0°C, lithium borohydride (4.0 M, in tetrahydrofuran) (0.4 mL, 2.7 mmol, 3 eq.) was added to a stirred solution of (S)-4,4-difluoro-2-((S)-1-methoxy-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)carbamoyl)piperidin-1-carboxylic acid benzyl ester (140 mg, 0.9 mmol, 1 eq.) in tetrahydrofuran (4 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were saturated with brine (2 x 20 mL). Wash with 40 mL of water and dry with anhydrous sodium sulfate. Filter and concentrate the filtrate under reduced pressure to give (S)-4,4-difluoro-2-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)carbamoyl)piperidine-1-carboxylic acid benzyl ester (100 mg) as a white solid.

[0184] LCMS(ESI,m / z): [M+H] + =440.24

[0185] 5. Synthesis of compound C2-3A

[0186] Under an air atmosphere at 0°C, a solution of (S)-4,4-difluoro-2-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)carbamoyl)piperidin-1-carboxylate (100 mg, 0.4 mmol, 1 eq.) and sodium bicarbonate (124.2 mg, 1.7 mmol, 4 eq.) in dichloromethane (2 mL) was added with Dysmartin oxidant (176 mg, 1.3 mmol, 3 eq.). The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The reaction was quenched with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with saturated brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. Finally, (S)-4,4-difluoro-2-(((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)carbamoyl)piperidin-1-carboxylic acid benzyl ester (80 mg, 60% purity) was obtained as a pale yellow oil. At room temperature, sodium bisulfite (1 mL) was added to a stirred solution of (S)-4,4-difluoro-2-(((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)carbamoyl)piperidin-1-carboxylic acid benzyl ester (80 mg, 0.2 mmol, 1 eq.) in N,N-dimethylformamide (1 mL). The resulting mixture was stirred in air at room temperature for 2 minutes. The resulting mixture was concentrated under reduced pressure. The crude product (70 mg) was purified by high performance liquid chromatography under the following conditions (column: Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: acetonitrile; flow rate: 25 mL / min; gradient: 35% B to 55% B, 10 min; wavelength: 254 nm / 220 nm; RT1 (min): 8.37), yielding a pale yellow solid -(2S)-2-((S)-1-((benzyloxy)carbonyl)-4,4-difluoropiperidine-2-carboxamido)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propane-1-sulfonate sodium (7.2 mg).

[0187] LCMS(ESI, m / z): [M-Na] - =518.30

[0188] 1H NMR(400MHz,D2O)δ7.43–7.20(m,5H),5.21–4.94(m,3H),4.47–3.77(m,3H),3.57–3.07(m,3H),2.90–1.90(m,5H),1.97–1.42(m,4H).

[0189] Example 5 Synthesis of compound C2-4A

[0190] 1. Synthesis of Compound 2

[0191] At room temperature and in air, 1-hydroxybenzotriazole (242 mg, 2.9 mmol, 1.5 eq.) and ({[3-(dimethylamino)propyl]imino}methylene)(ethyl)amine (179 mg, 0.1 mmol, 1.5 eq.) were added to a solution of (S)-6-(tert-butoxycarbonyl)-6-azaspiro[2.5]octane-5-carboxylic acid (200 mg, 1.9 mmol, 1 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (204 mg, 2.5 mmol, 1.3 eq.) and N,N-diisopropylethylamine (0.6 mL, 5.9 mmol, 3 eq.) in N,N-dimethylformamide (5 mL). The resulting mixture was stirred at room temperature under nitrogen for 3 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L NH4HCO3), 37%–45% gradient, 10 min; detector, UV 200 nm. The final product was (S)-5-(((S)-1-methoxy-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)carbamoyl)-6-azaspiro[2.5]octane-6-carboxylic acid tert-butyl ester (220 mg), white solid.

[0192] LCMS(ESI,m / z): [M+H] + =424.25

[0193] 2. Synthesis of Compound 3

[0194] At room temperature and in an air atmosphere, a solution of 1,4-dioxane (4.0 M) in 2 mL of hydrochloric acid (2 mL, 0.04 mmol, 2 eq.) was added to a stirred solution of (S)-5-((S)-1-methoxy-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)prop-2-yl)carbamoyl)-6-azaspiro[2.5]octane-6-carboxylic acid. The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The resulting mixture was concentrated under reduced pressure. Methyl (S)-3-((S)-2-oxopyrrolidone-3-yl)-2-((S)-6-azaspiro[2.5]octane-5-carbamate)propionate (180 mg) was obtained as a white solid.

[0195] LCMS(ESI,m / z): [M+H] + =324.20

[0196] 3. Synthesis of Compound 4

[0197] Benzyl chloroformate (213 mg, 1.5 mmol, 1.2 eq.) was added to a stirred solution of methyl (S)-3-((S)-2-oxopyrrolidone-3-yl)-2-((S)-6-azaspiro[2.5]octane-5-carbamate)propionate (180 mg, 1.2 mmol, 1 eq.) and sodium carbonate (182 mg, 2.5 mmol, 2 eq.) in 1,4-dioxane (5 mL). The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH4HCO3), 35%-43% gradient, 10 min; detector: UV 200 nm. (S)-5-(((S)-1-methoxy-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)prop-2-yl)carbamoyl)-6-azaspiro[2.5]octane-6-carboxylate (130 mg) was obtained as a white solid.

[0198] LCMS(ESI,m / z): [M+H] + =458.24

[0199] 4. Synthesis of Compound 5

[0200] Under nitrogen atmosphere at 0°C, lithium borohydride (4.0 M, in tetrahydrofuran) (0.4 mL, 2.7 mmol, 3 eq.) was added to a stirred solution of (S)-5-((S)-1-methoxy-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)carbamoyl)-6-azaspiro[2.5]octane-6-carboxylate (130 mg, 0.9 mmol, 1 eq.) in tetrahydrofuran (4 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were saturated with brine (2 x 20 mL). Wash with 40 mL of water and dry with anhydrous sodium sulfate. Filter and concentrate the filtrate under reduced pressure. A white solid (110 mg) of (S)-5-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)carbamoyl)-6-azaspiro[2.5]octane-6-carboxylate was obtained.

[0201] LCMS(ESI,m / z): [M+H] + =430.24

[0202] 5. Synthesis of compound C2-4A

[0203] Under an air atmosphere at 0°C, a solution of (S)-5-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)carbamoyl)-6-azaspiro[2.5]octane-6-carboxylate (110 mg, 0.4 mmol, 1 eq.) and sodium bicarbonate (124.2 mg, 1.7 mmol, 4 eq.) in dichloromethane (2 mL) was added with Dysmartin oxidant (176 mg, 1.3 mmol, 3 eq.). The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The reaction was quenched with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with saturated brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. Finally, (S)-5-(((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)carbamoyl)-6-azaspiro[2.5]octane-6-carboxylate (80 mg, 60% purity) was obtained as a pale yellow oil. At room temperature, sodium bisulfite (1 mL) was added to a stirred solution of (S)-5-(((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)carbamoyl)-6-azaspiro[2.5]octane-6-carboxylate (80 mg, 0.2 mmol, 1 eq.) in N,N-dimethylformamide (1 mL). The resulting mixture was stirred in air at room temperature for 2 minutes. The resulting mixture was concentrated under reduced pressure. The crude product (70 mg) was purified by pre-high performance liquid chromatography under the following conditions (column: Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: acetonitrile; flow rate: 25 mL / min; gradient: 35% B to 55% B, 10 min; wavelength: 254 nm / 220 nm; RT1 (min): 8.37), yielding a pale yellow solid -(2S)-2-((S)-6-((benzyloxy)carbonyl)-6-azaspiro[2.5]octane-5-carboxamido)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propane-1-sulfonate sodium (12.3 mg).

[0204] LCMS(ESI,m / z):[M-Na] - =508.35

[0205] 1H NMR(400MHz,D2O)δ7.43–7.20(m,5H),5.12–5.06(m,2H),4.88–4.76(m,1H),4.45–3.91(m,3H),3 .50–2.80(m,3H),2.70–1.91(m,3H),1.88–1.44(m,6H),1.02–0.77(m,1H),0.27(d,J=9.6Hz,4H).

[0206] Example 6 Synthesis of compound C2-7A

[0207] 1. Synthesis of Compound 2

[0208] (2S)-1-(tert-butylcarbonyl)-4,4-dimethylpyrrolidine-2-carboxylic acid (1.0 g, 0.1 mmol, 1.0 eq.) and methyl(2S)-2-amino-3-[(3S)-2-oxopyrrolidine-3-yl]propionic acid (10 mL) were stirred in dichloromethane (10 mL), and EDCI (19 mg, 0.1 mmol, 1.5 eq.) and DIEA (32 mg, 0.2 mmol, 3.0 eq.) were added aliquots at room temperature under a nitrogen atmosphere. HOBt (17 mg, 0.1 mmol, 1.5 eq.) was added to the mixture in aliquots over 2 minutes at room temperature. The resulting mixture was stirred at room temperature for another 2 hours. The resulting mixture was extracted with dichloromethane (3 × 5 mL). The combined organic layers were washed with dichloromethane (10 mL) (3 × 7 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure. Purification was performed by reversed-phase flash chromatography under the following conditions: C18 silica gel column; mobile phase: acetonitrile in water (0.1% FA), gradient 10%–50%, for 10 min; UV detector: 200 nm. The result was (2S)-2-([(2S)-1-methoxy-1-oxo-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]carbamoyl-4,4-dimethylpyrrolidine-1-carboxylic acid ester (822 mg) as a white solid.

[0209] LCMS(ESI,m / z):[M+H] + =411.24.

[0210] 2. Synthesis of Compound 3

[0211] HCl from 1,4-dioxane (4.0 M) (10 mL) was added dropwise to 1,4-dioxane (10 mL) at room temperature, and the mixture was stirred for 2 hours to obtain a mixture of (2S)-2-([2S)-1-methoxy-1-oxy-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]carbamoyl-4,4-dimethylpyrrolidine-1-carboxylic acid ester (800 mg, 1.9 mmol, 1.0 eq.). The resulting mixture was concentrated under reduced pressure. The crude product was used directly in the next step without further purification.

[0212] LCMS(ESI,m / z):[M+H] + =:311.18.

[0213] 3. Synthesis of Compound 4

[0214] Sodium carbonate (545 mg, 5.1 mmol, 2.0 eq.) was added to 1,4-dioxane (10 mL), and a mixture of methyl (2S)-2-([(2S)-4,4-dimethylpyrrolidine-2-acyl]formamidin-3-[(3S)-2-oxopyrrolidine-3-acyl]propionate (800 mg, 2.6 mmol, 1.0 eq.) and Cb2Cl (438 mg, 2.6 mmol, 1.0 eq.) was added at room temperature. The resulting mixture was stirred at room temperature for 2 hours. The resulting mixture was extracted with ethyl acetate (3 × 7 mL). The bound organic layer was washed with saturated salt solution (3 × 10 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure. Purification was performed by reversed-phase flash chromatography under the following conditions: C18 silica gel column; mobile phase: acetonitrile in water (0.1%). FA), 10%–50% gradient, 10 min; UV detector, 200 nm. The result was (2S)-2-([(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propane-2-yl]carbamoyl-4,4-dimethylpyrrolidine-1-carboxylic acid benzyl ester (400 mg) as a white solid.

[0215] LCMS(ESI,m / z):[M+H] + =445.22.

[0216] 4. Synthesis of Compound 5

[0217] Under a nitrogen atmosphere at 0 °C, benzene(2S)-2-([(2S)-1-methoxy-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propyl-2-yl]carbamoyl-4,4-dimethylpyridine-1-carboxylate (350 mg, 0.8 mmol, 1.0 eq.) was added to a stirred solution (5 mL), along with lithium borohydride (4.0 M, tetrahydrofuran) (0.5 mL, 0.02 mmol, 3.0 eq.). The resulting mixture was then allowed to stand at room temperature. Stir for another 2 hours. Quench the reaction with water at 0°C. Extract the resulting mixture with ethyl acetate (3 × 5 mL). Wash the bound organic layer with saturated salt solution (3 × 5 mL) and dry on anhydrous sodium sulfate. Concentrate the filtrate under reduced pressure. The result is (2S)-2-([(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propane-2-yl]carbamoyl-4,4-dimethylpyrrolidine-1-carboxylic acid benzyl ester (150 mg) as a white solid.

[0218] LCMS(ESI,m / z):[M+H] + =417.23.

[0219] 5. Synthesis of Compound 6

[0220] Using benzene(2S)-2-([(2S)-1-hydroxy-3-[(3S)-2-oxopyridin-3-yl]propane-2-yl]carbamoyl-4,4-dimethylpyridine-1-carboxylic acid ester (130 mg, 0.3 mmol, 1.0 eq.) and Desmartin oxidant as a stirring solution, sodium bicarbonate (104 mg, 1.2 mmol, 4.0 eq.) was added to dichloromethane (2 mL), and 2-benzopyridine-1-acetate (396 mg, 0.9 mmol, 3.0 eq.) was added to air at room temperature. The resulting mixture was stirred for another 2 hours at room temperature. The reaction was quenched with sodium thiosulfate at room temperature. The resulting mixture was extracted with ethyl acetate (3 × 5 mL). The bound organic layer was washed with sodium carbonate (3 × 5 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure. The result was (2S)-4,4-dimethyl-2-([(2S)-1-oxo-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]aminopyrrolidine-1-carboxylic acid benzyl ester (130 mg) as a white solid.

[0221] LCMS(ESI,m / z):[M+H] + =415.21.

[0222] 6. Synthesis of compound C2-7A

[0223] (2S)-4,4-dimethyl-2-([(2S)-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propyl-2-yl]aminopyridine-1-carboxylic acid benzyl ester (1.0 eq.) was stirred in DMF (2 mL) until homogeneous. Sodium bisulfite (97 mg, 0.9 mmol, 3.0 eq.) was added at room temperature, and the mixture was stirred for 2 min. The resulting mixture was extracted with ethyl acetate (2 × 20 mL). The aqueous layer was concentrated under reduced pressure. The residue was washed with DMF (2 × 5 mL). The crude product was purified by high performance liquid chromatography (HPLC). Column: Xselect CSH C185 μm, 19 mm × 250 mm; Mobile phase A: water (0.1% FA), Mobile phase B: ACN; Flow rate: 25 mL / min; Gradient: 30% B to 50% B, 10 min; Wavelength: 200 nm / 220 nm nm; RT1(min): 7.19. Benzyl(2S)-2-([(2S)-1-hydroxy-3-[(3S)-2-oxopyrone-3-yl]-1-(sodium sulfonyl)propyl-2-yl)carbamoyl-4,4-dimethylpyrone-1-carboxylate (13.3 mg) was obtained as a light yellow solid.

[0224] LCMS(ESI,m / z):[M-Na] - =496.35.

[0225] 1 H NMR(400MHz,D2O)δ7.82–7.01(m,5H),5.21–5.03(m,2H),4.63–4.01(m,3H),3.51–2.6 5(m,4H),2.42–2.01(m,2H),2.00–1.91(m,3H),1.85–1.22(m,2H),1.18–0.85(m,6H).

[0226] Example 7 Synthesis of compound C2-8A

[0227] 1. Synthesis of Compound 2

[0228] At room temperature and in air, 1-hydroxybenzotriazole (442 mg, 2.9 mmol, 1.5 eq.) and ({[3-(dimethylamino)propyl]imino}methylene)(ethyl)amine (474 ​​mg, 2.5 mmol, 1.3 eq.) were added to a solution of N,N-dimethylformamide (5 mL) containing (S)-1-(tert-butoxycarbonyl)-4,4-difluoropyrrolidine-2-carboxylic acid (500 mg, 1.9 mmol, 1 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (474 ​​mg, 2.5 mmol, 1.3 eq.) and N,N-diisopropylethylamine (1.2 mL, 5.9 mmol, 3 eq.) at room temperature and in air atmosphere. The resulting mixture was stirred at room temperature under nitrogen atmosphere for 3 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH₄HCO₃), 37%–45% gradient, 10 min; detector: UV 200 nm. The final product was (S)-4,4-difluoro-2-(((S)-1-methoxy-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)carbamoyl)pyrrolidine-1-carboxylic acid tert-butyl ester (490 mg), a white solid.

[0229] LCMS(ESI,m / z): [M+H] + =420.25

[0230] 2. Synthesis of Compound 3

[0231] At room temperature and in an air atmosphere, a solution of 1,4-dioxane (2 mL) of 1,4-dioxane (2 mL, 0.04 mmol, 2 eq.) of hydrochloric acid (4.0 M) was added to a stirred solution of (S)-4,4-difluoro-2-((S)-1-methoxy-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)prop-2-yl)carbamoyl)pyrrolidine-1-carboxylate (480 mg, 1.2 mmol, 1 eq.). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The mixture was then concentrated under reduced pressure to give methyl (S)-2-((S)-4,4-difluoropyrrolidine-2-carbamoyl)-3-((S)-2-oxopyrrolidine-3-yl)propionate (410 mg), a white solid.

[0232] LCMS(ESI,m / z): [M+H] + =320.20

[0233] 3. Synthesis of Compound 4

[0234] Benzyl chloroformate (413 mg, 1.5 mmol, 1 eq.) was added to a stirred solution of methyl (S)-2-((S)-4,4-difluoropyrrolidine-2-carboxamido)-3-((S)-2-oxopyrrolidine-3-yl)propionate (400 mg, 1.2 mmol, 1 eq.) and sodium carbonate (382 mg, 2.5 mmol, 2 eq.) in 1,4-dioxane (5 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH4HCO3), 35%-43% gradient, 10 min; detector: UV 200 nm. The product was (S)-4,4-difluoro-2-(((S)-1-methoxy-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)carbamoyl)pyrrolidine-1-carboxylic acid benzyl ester (240 mg), a white solid.

[0235] LCMS(ESI,m / z): [M+H] + =454.24

[0236] 4. Synthesis of Compound 5

[0237] Under nitrogen atmosphere at 0°C, lithium borohydride (4.0 M, in tetrahydrofuran) (0.4 mL, 2.7 mmol, 3 eq.) was added to a stirred solution of (S)-4,4-difluoro-2-(((S)-1-methoxy-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)carbamoyl)pyrrolidine-1-carboxylate (240 mg, 0.9 mmol, 1 eq.) in tetrahydrofuran (4 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with saturated brine (2 x 40 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. (S)-4,4-difluoro-2-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)carbamoyl)pyrrolidine-1-carboxylic acid benzyl ester (180 mg) was obtained as a white solid.

[0238] LCMS(ESI,m / z): [M+H] + =426.24

[0239] 5. Synthesis of compound C2-8A

[0240] Under an air atmosphere at 0°C, a solution of (S)-4,4-difluoro-2-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)carbamoyl)pyrrolidine-1-carboxylate (180 mg, 0.4 mmol, 1 eq.) and sodium bicarbonate (204.2 mg, 1.7 mmol, 4 eq.) in dichloromethane (2 mL) was added with Dysmartin oxidant (356 mg, 1.3 mmol, 3 eq.). The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The reaction was quenched with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with saturated brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. Finally, (S)-4,4-difluoro-2-(((S)-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)carbamoyl)pyrrolidine-1-carboxylate (150 mg, 60% purity) was obtained as a pale yellow oil. At room temperature, sodium bisulfite (1 mL) was added to a stirred solution of (S)-4,4-difluoro-2-(((S)-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)carbamoyl)pyrrolidine-1-carboxylate (150 mg, 0.2 mmol, 1 eq.) in N,N-dimethylformamide (1 mL). The resulting mixture was stirred in air at room temperature for 2 minutes. The resulting mixture was concentrated under reduced pressure. The crude product (70 mg) was purified by high performance liquid chromatography under the following conditions (column: Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: acetonitrile; flow rate: 25 mL / min; gradient: 35% B to 55% B, 10 min; wavelength: 254 nm / 220 nm; RT1 (min): 8.37), yielding a pale yellow solid (2S)-2-((S)-1-((benzyloxy)carbonyl)-4,4-difluoropyrrolidine-2-carboxamido)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propane-1-sulfonate sodium (28.8 mg).

[0241] LCMS(ESI,m / z):[M-Na] - =504.35

[0242] 1H NMR(400MHz,D2O)δ7.44–7.22(m,5H),5.19–5.03(m,2H),4.38–4.20(m,1H), 4.04–3.70(m,3H),3.50–2.75(m,3H),2.70–2.00(m,2H),1.92–1.45(m,4H).

[0243] Example 8 Synthesis of compound C2-9A

[0244] 1. Synthesis of Compound 2

[0245] (6S)-5-[(benzyloxy)carbonyl]-5-azaspiro[2,4]heptane-6-carboxylic acid (500 mg, 1.8 mmol, 1.0 eq.) and methyl(2S)-2-amino-3-[(3S)-2-oxopyridin-3-yl]propionic acid (338 mg, 1.8 mmol, 1.0 eq.) were dissolved in dichloromethane (5 mL), and DIEA (352 mg, 2.7 mmol, 1.5 eq.) was added under a nitrogen atmosphere at room temperature. After stirring for 2 minutes, HATU (1035 mg, 2.7 mmol, 1.5 eq.) was added to the mixture. The resulting mixture was stirred at room temperature for another 2 hours. The mixture was extracted with ethyl acetate (3 × 20 mL). The organic layer was washed with a saturated salt solution (3 × 20 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure. Purification was performed using reversed-phase flash chromatography under the following conditions: C18 silica gel column; mobile phase: acetonitrile in water (0.1% FA), gradient 10%–50%, for 10 min; UV detector: 200 nm. This resulted in benzene(6S)-6-{[(2S)-1-methoxy-1-oxo-3-[(3S)-2-oxopyrrolidone-3-yl]propane-2-yl]carbamoyl}-5-azaspiro[2,4]heptane-5-carboxylic acid ester (300 mg) as a white solid.

[0246] LCMS(ESI,m / z):[M+H] + =444.20

[0247] 2. Synthesis of Compound 3

[0248] Under a nitrogen atmosphere at 0 °C, benzene(6S)-6-([(2S)-1-methoxy-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propan-2-yl]carbamoyl-5-azaspiro[2,4]heptane-5-carboxylic acid ester (300 mg, 0.7 mmol, 1.0 eq.) was dissolved in tetrahydrofuran (5 mL), and the solution was stirred. Lithium borohydride (4.0 M, tetrahydrofuran) 44 mg, 2.0 mmol, 3.0 eq.) was added. The resulting mixture was stirred at room temperature for another 2 hours. The resulting mixture was extracted with ethyl acetate (3 × 20 mL). The organic layer was washed with a saturated salt solution (3 × 20 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure. This makes benzene(6S)-6-([(2S)-1-hydroxy-3-[(3S)-2-oxopyridin-3-yl]propane-2-yl]carbamoyl-5-azaspiro[2.4]heptane-5-carboxylic acid ester (200 mg) a white solid.

[0249] LCMS(ESI,m / z):[M+H] + =416.15

[0250] 3. Synthesis of Compound 4

[0251] A mixture of benzene(6S)-6-([(2S)-1-hydroxy-3-[(3S)-2-oxopyridin-3-yl]propane-2-yl]carbamoyl-5-azaspiro[2,4]heptane-5-carboxylic acid ester (180 mg, 0.4 mmol, 1.0 eq.) and Desmartin oxidant (551 mg, 1.3 mmol, 3.0 eq.) was added to sodium bicarbonate (145 mg, 1.7 mmol, 4 eq.) in DCM (5 mL) at room temperature. The mixture was stirred under an atmosphere of gas. The resulting mixture was stirred for another 2 hours at room temperature. The resulting mixture was extracted with ethyl acetate (3 × 20 mL). The organic layer was washed with sodium carbonate (3 × 20 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure. This resulted in benzene(6S)-6-([(2S)-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propane-2-yl]carbamoyl-5-azaspiro[2,4]heptane-5-carboxylic acid ester (150 mg) as a white solid.

[0252] LCMS(ESI,m / z):[M+H] + =414.20

[0253] 4. Synthesis of compound C2-9A

[0254] A well-stirred mixture of benzene(6S)-6-([(2S)-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propan-2-yl]carbamoyl-5-azaspiro[2,4]heptane-5-carboxylic acid ester (120 mg, 0.3 mmol, 1.0 eq.) was added to N,N-dimethylformamide (2 mL) with sodium bisulfite (90 mg, 0.9 mmol, 3.0 eq.) at room temperature. The resulting mixture was stirred at room temperature for another 2 hours. The resulting mixture was extracted with ethyl acetate (3 × 20 mL). The aqueous layer was concentrated under reduced pressure. The residue was washed with N,N-dimethylformamide (3 × 3 mL). Preparation - Purification of the crude product by high performance liquid chromatography: column: Xselect CSH C185 μm, 19 mm × 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 mL / min; gradient: 25% B to 45%. B, 10 minutes; wavelength: 254 nm / 220 nm; RT1(min): 8.83. Benzyl(6S)-6-([(2S)-1-hydroxy-3-[(3S)-2-oxopyridin-3-yl)-1-(sodium sulfonyl)propyl-2-yl)carbamoyl-5-azaspiro[2.4]heptane-5-carboxylic acid ester (40.5 mg) was obtained as a brown solid.

[0255] LCMS(ESI,m / z):[M-Na] - =494.35

[0256] 1 H NMR(400MHz,D2O)δ7.51–7.16(m,5H),5.20–5.02(m,2H),4.60–4.41(m,2H),4.40–4.11(m,1H),3.55–3.35(m,1H),3.50–2.8 0(m,3H),2.60–2.00(m,2H),2.00–1.70(m,1H),1.71–1.60(m,4H),1.64–1.31(m,1H),1.30–1.11(m,2H),0-90–0.36(m,4H).

[0257] Example 9 Synthesis of compound C2-10A

[0258] 1. Synthesis of Compound 2

[0259] At room temperature and in air, 1-hydroxybenzotriazole (0.8 g, 6.2 mmol, 1.5 eq.) and ({[3-(dimethylamino)propyl]imino}methylene)(ethyl)amine (1.0 g, 6.2 mmol, 1.5 eq.) were added to a solution of (2S)-2-[(tert-butyloxycarbonyl)amino]-3-cyclobutylpropionic acid (1.0 g, 4.1 mmol, 1 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (1.2 g, 6.2 mmol, 1.5 eq.) and N,N-diisopropylethylamine (2.2 mL, 12.3 mmol, 3 eq.) in N,N-dimethylformamide (12 mL). The resulting mixture was stirred at room temperature under nitrogen for 3 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 200 mL). The combined organic layers were washed with saturated brine (2 x 160 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH4HCO3), 37%–45% gradient, 10 min; detector: UV 254 nm. The final product was methyl (2S)-2-[(2S)-2-[(tert-Butoxycarbonyl)amino]-3-cyclobutylpropylamino]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (980 mg), a white solid.

[0260] LCMS(ESI,m / z): [M+H] + =411.25

[0261] 2. Synthesis of Compound 3

[0262] At room temperature and in an air atmosphere, a solution of 1,4-dioxane (5 mL) of methyl (2S)-2-[(2S)-2-[(tert-butyloxycarbonyl)amino]-3-cyclobutylpropylamino]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (970 mg, 1.2 mmol, 1 eq.) was added to a stirred solution of 1,4-dioxane (4.0 M) of hydrochloric acid (5 mL, 0.04 mmol, 2 eq.). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The mixture was then concentrated under reduced pressure. Methyl (S)-2-((S)-2-amino-3-cyclobutylpropylamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (880 mg) was obtained as a white solid.

[0263] LCMS(ESI,m / z): [M+H] + =311.20

[0264] 3. Synthesis of Compound 4

[0265] Benzyl chloroformate (548 mg, 3.2 mmol, 4.0 eq.) was added to a stirred solution of (2S)-2-[(2S)-2-amino-3-cyclobutylpropylamino]-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (500 mg, 1.6 mmol, 1.0 eq.) and Et3N (0.9 mL, 6.4 mmol, 4.0 eq.) in DCM (5 mL). Benzyl chloroformate (548 mg, 3.2 mmol, 2.0 eq.) and triethylamine (0.9 mL, 6.4 mmol, 4.0 eq.) in dichloromethane (5 mL) at room temperature under air. The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN in water (10 mmol / L NH4HCO3), 38%–48% gradient, 10 min; detector: UV 190 nm. The result was methyl (2S)-2-[(2S)-2-{[(benzyloxy)carbonyl]amino}-3-cyclobutylpropylamino]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (250 mg), a white solid.

[0266] LCMS(ESI,m / z): [M+H] + =446.24

[0267] 4. Synthesis of Compound 5

[0268] Under nitrogen atmosphere at 0°C, lithium borohydride (4.0 M, in tetrahydrofuran) (0.4 mL, 2.7 mmol, 3 eq.) was added to a stirred solution of methyl (2S)-2-[(2S)-2-{[(benzyloxy)carbonyl]amino}-3-cyclobutylpropylamino]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (200 mg, 0.9 mmol, 1 eq.) in tetrahydrofuran (2 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with saturated brine (2 x 40 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. ((S)-3-cyclobutyl-1-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)amino)-1-oxopropyl-2-yl)carbamate (200 mg) was obtained as a white solid.

[0269] LCMS(ESI,m / z): [M+H] + =418.24

[0270] 5. Synthesis of compound C2-10A

[0271] Under an air atmosphere at 0°C, a solution of ((S)-3-cyclobutyl-1-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)amino)-1-oxopropyl-2-yl)carbamate (200 mg, 0.4 mmol, 1 eq.) and sodium bicarbonate (204.2 mg, 1.7 mmol, 4 eq.) in dichloromethane (2 mL) was added with Dysmartin oxidant (356 mg, 1.3 mmol, 3 eq.). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The reaction was quenched with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with saturated brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. Finally, (S)-5-(((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)carbamoyl)-6-azaspiro[2.5]octane-6-carboxylate (140 mg, 60% purity) was obtained as a pale yellow oil. At room temperature, sodium bisulfite (1 ml) was added to a stirred solution of (S)-5-(((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)carbamoyl)-6-azaspiro[2.5]octane-6-carboxylate (140 mg, 0.2 mmol, 1 eq.) in N,N-dimethylformamide (1 ml). The resulting mixture was stirred in air at room temperature for 2 minutes. The resulting mixture was concentrated under reduced pressure. The crude product (70 mg) was purified by high performance liquid chromatography under the following conditions (column: Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: acetonitrile; flow rate: 25 mL / min; gradient: 35% B to 55% B, 10 min; wavelength: 254 nm / 220 nm; RT1 (min): 8.37), yielding a pale yellow solid (2S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-3-cyclobutylpropylamino)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propane-1-sulfonate sodium salt (23.3 mg).

[0272] LCMS(ESI,m / z):[M-Na] - =496.35

[0273] 1H NMR(400MHz,D2O)δ7.46–7.20(m,5H),5.11–5.00(m,2H),4.43–3.84(m,3H), 3.30–2.98(m,2H),2.40–2.22(m,2H),2.18–1.97(m,2H),1.91–1.46(m,10H)

[0274] Example 10 Synthesis of compound C2-13A

[0275] 1. Synthesis of Compound 2

[0276] At room temperature and in air, 1-hydroxybenzotriazole (413 mg, 3.0 mmol, 1.5 eq.) and ({[3-(dimethylamino)propyl]imino}methylene)(ethyl)amine (474 ​​mg, 3.1 mmol, 1.5 eq.) were added to a solution of (2S)-2-[(tert-butoxycarbonyl)amino]-4,4-dimethylpentanoic acid (500 mg, 1.9 mmol, 1 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (455 mg, 2.4 mmol, 1.2 eq.) and N,N-diisopropylethylamine (1.1 mL, 6.1 mmol, 3 eq.) in N,N-dimethylformamide (5 mL). The resulting mixture was stirred at room temperature under nitrogen for 3 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH₄HCO₃), 37%–45% gradient, 10 min; detector: UV 200 nm. The final product was methyl (2S)-2-[(2S)-2-[(tert-Butoxycarbonyl)amino]-4,4-dimethylpentanamino]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (480 mg), a white solid.

[0277] LCMS(ESI,m / z): [M+H] + =414.25

[0278] 2. Synthesis of Compound 3

[0279] At room temperature and in air, a solution of 1,4-dioxane (3 mL) of methyl (2S)-2-[(2S)-2-[(tert-butyloxycarbonyl)amino]-4,4-dimethylpentanamino]-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (480 mg, 1.2 mmol, 1 eq.) was added to a stirred solution of 1,4-dioxane (4.0 M) in hydrochloric acid (3 mL, 0.04 mmol, 2 eq.). The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The mixture was then concentrated under reduced pressure. Methyl (2S)-2-[(2S)-2-amino-4,4-dimethylpentanamino]-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (350 mg) was given as a white solid.

[0280] LCMS(ESI,m / z): [M+H] + =314.20

[0281] 3. Synthesis of Compound 4

[0282] Benzyl chloroformate (354 mg, 1.2 mmol, 1 eq.) was added to a stirred solution of methyl (2S)-2-[(2S)-2-amino-4,4-dimethylpentanamino]-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (500 mg, 1.6 mmol, 1 eq.) and sodium carbonate (338 mg, 3.2 mmol, 2 eq.) in 1,4-dioxane (5 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH4HCO3), 35%-43% gradient, 10 min; detector: UV 200 nm. Methyl (2S)-2-[(2S)-2-{[(benzyloxy)carbonyl]amino}-4,4-dimethylpentanamino]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (400 mg) was obtained as a white solid.

[0283] LCMS(ESI,m / z): [M+H] + =448.24

[0284] 4. Synthesis of Compound 5

[0285] Under nitrogen atmosphere at 0°C, lithium borohydride (4.0 M, in tetrahydrofuran) (0.7 mL, 2.7 mmol, 3 eq.) was added to a stirred solution of methyl (2S)-2-[(2S)-2-{[(benzyloxy)carbonyl]amino}-4,4-dimethylpentanamino]-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (400 mg, 0.9 mmol, 1 eq.) in tetrahydrofuran (4 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were then rinsed with brine (2 x 20 mL). Wash with 40 mL of water and dry with anhydrous Na₂SO₄. Filter and concentrate the filtrate under reduced pressure. Purify the residue by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, MeCN in water (10 mmol / L NH₄HCO₃), 35%–43% gradient, 10 min; detector, UV 254 nm. The result was N-[(1S)-1-{[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidone-3-yl]propyl-2-yl]carbamoyl}-3,3-dimethylbutyl]carbamate (200 mg), a white solid.

[0286] LCMS(ESI,m / z): [M+H] + =420.24

[0287] 5. Synthesis of compound C2-13A

[0288] Under an air atmosphere at 0°C, a solution of N-[(1S)-1-{[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidone-3-yl]propyl-2-yl]carbamoyl}-3,3-dimethylbutyl]carbamate (180 mg, 0.4 mmol, 1 eq.) and sodium bicarbonate (144.2 mg, 1.7 mmol, 4 eq.) in dichloromethane (2 mL) was added with Dysmartin oxidant (546 mg, 1.3 mmol, 3 eq.). The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The reaction was quenched with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with saturated brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. Finally, benzyl N-[(1S)-3,3-dimethyl-1-{[(2S)-1-oxo-3-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]carbamoyl}butyl]carbamate (100 mg, purity 60%) was obtained as a pale yellow oil. Sodium bisulfite (1 ml) was added to a stirred solution of N-[(1S)-3,3-dimethyl-1-{[(2S)-1-oxo-3-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]carbamoyl}butyl]carbamate (100 mg) in N,N-dimethylformamide (1 ml) at room temperature. The resulting mixture was stirred in air at room temperature for 2 minutes. The resulting mixture was concentrated under reduced pressure. The crude product (60 mg) was purified by pre-high performance liquid chromatography under the following conditions (column: Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: acetonitrile; flow rate: 25 mL / min; gradient: 35% B to 60% B, 10 min; wavelength: 254 nm / 220 nm; RT1 (min): 8.37), yielding a white solid -(2S)-2-[(2S)-2-{[(benzyloxy)carbonyl]amino}-4,4-dimethylpentanamino]-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propane-1-sulfonate sodium salt (8.1 mg).

[0289] LCMS(ESI,m / z):[M-Na] - =498.19

[0290] 1H NMR(400MHz,D2O)δ7.48–7.20(m,5H),5.13–4.97(m,2H),4.41–4.02(m,3H), 3.35–3.02(m,2H),2.20–2.00(m,1H),1.93–1.40(m,6H),1.20–0.60(m,9H).

[0291] Example 11 Synthesis of compound C2-14A

[0292] 1. Synthesis of Compound 2

[0293] At room temperature and in an air atmosphere, 1-hydroxybenzotriazole (442 mg, 3.0 mmol, 1.5 eq.) and ({[3-(dimethylamino)propyl]imino}methylene)(ethyl)amine (459 mg, 3.1 mmol, 1.5 eq.) were added to a solution of ((S)-2-((tert-butyloxycarbonyl)amino)-4,4,4-trifluorobutyric acid (500 mg, 1.9 mmol, 1 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (474 ​​mg, 2.4 mmol, 1.2 eq.) and N,N-diisopropylethylamine (1.1 mL, 6.1 mmol, 3 eq.) in N,N-dimethylformamide (5 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 3 hours. The reaction was quenched with water at room temperature. The resulting mixture was then dilute with ethyl acetate (2x... Extracted by 50 mL extraction. The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L NH4HCO3), 37%–45% gradient, 10 min; detector, UV 200 nm. The final product was methyl (S)-2-((S)-2-amino-4,4,4-trifluorobutylamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (490 mg), white solid.

[0294] LCMS(ESI,m / z): [M+H] + =426.25

[0295] 2. Synthesis of Compound 3

[0296] At room temperature and in an air atmosphere, a solution of 1,4-dioxane (3 mL) of hydrochloric acid (3 mL, 0.04 mmol, 2 eq.) in methyl (480 mg, 1.2 mmol, 1 eq.) propionate was added to a stirred solution of 1,4-dioxane (4.0 M). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The mixture was then concentrated under reduced pressure to give methyl (350 mg) propionate as a white solid.

[0297] LCMS(ESI,m / z): [M+H] + =326.20

[0298] 3. Synthesis of Compound 4

[0299] Benzyl chloroformate (354 mg, 1.2 mmol, 1 eq.) was added to a stirred solution of methyl (S)-2-((S)-2-amino-4,4,4-trifluorobutylamino)-3-((S)-2-oxopyrrolidone-3-yl)propionate (350 mg, 1.6 mmol, 1 eq.) and sodium carbonate (338 mg, 3.2 mmol, 2 eq.) in 1,4-dioxane (5 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH4HCO3), 35%-43% gradient, 10 min; detector: UV 200 nm. Methyl (S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-4,4,4-trifluorobutylamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (150 mg) was obtained as a white solid.

[0300] LCMS(ESI,m / z): [M+H] + =460.24

[0301] 4. Synthesis of Compound 5

[0302] Under nitrogen atmosphere at 0°C, lithium borohydride (4.0 M, in tetrahydrofuran) (0.4 mL, 2.7 mmol, 3 eq.) was added to a stirred solution of methyl (S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-4,4,4-trifluorobutylamino)-3-((S)-2-oxopyrrolidone-3-yl)propionate (130 mg, 0.9 mmol, 1 eq.) in tetrahydrofuran (2 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 mL) and dried over anhydrous Na₂SO₄. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, MeCN in water (10 mmol / L). NH4HCO3), 35%-43% gradient, 10 min; detector, UV 200 nm. The result was ((S)-4,4,4-trifluoro-1-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)amino)-1-oxobut-2-yl)carbamate (100 mg), white solid.

[0303] LCMS(ESI,m / z): [M+H] + =432.24

[0304] 5. Synthesis of compound C2-14A

[0305] Under an air atmosphere at 0°C, a solution of ((S)-4,4,4-trifluoro-1-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)amino)-1-oxobut-2-yl)carbamate (100 mg, 0.4 mmol, 1 eq.) and sodium bicarbonate (104.2 mg, 1.7 mmol, 4 eq.) in dichloromethane (2 mL) was added with Dysmartin oxidant (346 mg, 1.3 mmol, 3 eq.). The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The reaction was quenched with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with saturated brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. Finally, benzyl ((S)-4,4,4-trifluoro-1-oxo-1-(((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)amino)but-2-yl)carbamate (80 mg) was obtained as a pale yellow oil. At room temperature, sodium bisulfite (1 mL) was added to a stirred solution of ((S)-4,4,4-trifluoro-1-oxo-1-(((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)amino)but-2-yl)carbamate (80 mg) in N,N-dimethylformamide (1 mL). The resulting mixture was stirred in air at room temperature for 2 minutes. The resulting mixture was concentrated under reduced pressure. The crude product (60 mg) was purified by pre-high performance liquid chromatography under the following conditions (column: Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: acetonitrile; flow rate: 25 mL / min; gradient: 35% B to 55% B, 10 min; wavelength: 254 nm / 220 nm; RT1 (min): 8.37), yielding a white solid -(2S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-4,4,4-trifluorobutylamino)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propane-1-sulfonate sodium salt (11.0 mg).

[0306] LCMS(ESI,m / z):[M-Na] - =510.30

[0307] 1H NMR(400MHz,D2O)δ7.48–7.22(m,5H),5.15–4.99(m,2H),4.55–3.88(m,3H), 3.28–3.04(m,2H),2.91–2.36(m,2H),2.30–2.00(m,1H),1.90–1.22(m,4H).

[0308] Example 12 Synthesis of compound C2-15A

[0309] 1. Synthesis of Compound 2

[0310] At room temperature and in an air atmosphere, 1-hydroxybenzotriazole (442 mg, 3.0 mmol, 1.5 eq.) and ({[3-(dimethylamino)propyl]imino}methylene)(ethyl)amine (459 mg, 3.1 mmol, 1.5 eq.) were added to a solution of (2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(tert-butoxycarbonyl)amino]propionic acid (500 mg, 1.9 mmol, 1 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (474 ​​mg, 2.4 mmol, 1.2 eq.) and N,N-dimethylformamide (1.1 mL, 6.1 mmol, 3 eq.) (5 mL) under N,N-dimethylformamide (5 mL) with stirring. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L NH4HCO3), 37%–45% gradient, 10 min; detector, UV 200 nm. The final product was (2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(tert-butyloxycarbonyl)amino]propionic acid (490 mg), a white solid.

[0311] LCMS(ESI,m / z): [M+H] + =424.25

[0312] 2. Synthesis of Compound 3

[0313] At room temperature and in air atmosphere, a solution of 1,4-dioxane (3 mL) of hydrochloric acid (3 mL, 0.04 mmol, 2 eq.) in 1,4-dioxane (4.0 M) was added. The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The resulting mixture was concentrated under reduced pressure. Methyl (S)-2-((S)-2-amino-3-(bicyclo[1.1.1]pentan-1-yl)propylamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (350 mg) was obtained as a white solid.

[0314] LCMS(ESI,m / z): [M+H] + =324.20

[0315] 3. Synthesis of Compound 4

[0316] Benzyl chloroformate (354 mg, 1.2 mmol, 1 eq.) was added to a stirred solution of methyl (S)-2-((S)-2-amino-3-(bicyclo[1.1.1]pentan-1-yl)propylamino)-3-((S)-2-oxopyrrolidone-3-yl)propionate (350 mg, 1.6 mmol, 1 eq.) and sodium carbonate (338 mg, 3.2 mmol, 2 eq.) in 1,4-dioxane (5 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH4HCO3), 35%-43% gradient, 10 min; detector: UV 200 nm. Methyl (S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-3-(bicyclo[1.1.1]pentan-1-yl)propylamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (290 mg) was obtained as a white solid.

[0317] LCMS(ESI,m / z): [M+H] + =458.24

[0318] 4. Synthesis of Compound 5

[0319] Under nitrogen atmosphere at 0°C, lithium borohydride (4.0 M, in tetrahydrofuran) (0.4 mL, 2.7 mmol, 3 eq.) was added to a stirred solution of methyl (S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-3-(bicyclo[1.1.1]pentan-1-yl)propylamino)-3-((S)-2-oxopyrrolidone-3-yl)propionate (290 mg, 0.9 mmol, 1 eq.) in tetrahydrofuran (2 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were extracted with brine (2 x 20 mL). Wash with 40 mL of water and dry with anhydrous Na2SO4. Filter and concentrate the filtrate under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, MeCN in water (10 mmol / L NH4HCO3), 35%-43% gradient, 10 min; detector, UV 200 nm. The result was methyl (S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-3-(bicyclo[1.1.1]pentan-1-yl)propylamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (180 mg), white solid.

[0320] LCMS(ESI,m / z): [M+H] + =430.24

[0321] 5. Synthesis of compound C2-15A

[0322] Under an air atmosphere at 0°C, a solution of methyl (S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-3-(bicyclo[1.1.1]pentan-1-yl)propylamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (100 mg, 0.4 mmol, 1 eq.) and sodium bicarbonate (104.2 mg, 1.7 mmol, 4 eq.) in dichloromethane (2 mL) was added with Dysmartin oxidant (346 mg, 1.3 mmol, 3 eq.). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The reaction was quenched with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with saturated brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. Finally, ((S)-3-(bicyclo[1.1.1]pentan-1-yl)-1-oxo-1-(((S)-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)amino)propyl-2-yl)carbamate (100 mg) was obtained as a pale yellow oil. At room temperature, sodium bisulfite (1 ml) was added to a stirred solution of ((S)-3-(bicyclo[1.1.1]pentan-1-yl)-1-oxo-1-(((S)-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)amino)propyl-2-yl)carbamate (100 mg) in air in N,N-dimethylformamide (1 ml). The resulting mixture was stirred in air at room temperature for 2 minutes. The resulting mixture was concentrated under reduced pressure. The crude product (60 mg) was purified by high performance liquid chromatography under the following conditions (column: Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: acetonitrile; flow rate: 25 mL / min; gradient: 35% B to 55% B, 10 min; wavelength: 254 nm / 220 nm; RT1 (min): 8.37), yielding a white solid (2S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-3-(bicyclo[1.1.1]pentan-1-yl)propylamino)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propane-1-sulfonate sodium salt (4.3 mg).

[0323] LCMS(ESI,m / z):[M-Na] - =508.19

[0324] 1H NMR(400MHz,D2O)δ7.48–7.20(m,5H),5.13–4.97(m,2H),4.41–4.02(m,3H), 3.35–3.02(m,2H),2.54–2.12(m,2H),1.95–1.80(m,3H),1.80–1.30(m,9H).

[0325] Example 13 Synthesis of compound C2-16A

[0326] 1. Synthesis of Compound 2

[0327] At room temperature and in an air atmosphere, 1-hydroxybenzotriazole (242 mg, 3.0 mmol, 1.5 eq.) and ({[3-(dimethylamino)propyl]imino}methylene)(ethyl)amine (259 mg, 3.1 mmol, 1.5 eq.) were added to a solution of (S)-2-((tert-butyloxycarbonyl)amino)-3-(3,3-difluorocyclobutyl)propionic acid (300 mg, 1.9 mmol, 1 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (274 mg, 2.4 mmol, 1.2 eq.) and N,N-diisopropylethylamine (0.7 mL, 6.1 mmol, 3 eq.) in N,N-dimethylformamide (5 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 3 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L NH4HCO3), 37%–45% gradient, 10 min; detector, UV 200 nm. The final product was methyl (S)-2-((S)-2-((tert-Butoxycarbonyl)amino)-3-(3,3-difluorocyclobutyl)propylamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (290 mg), a white solid.

[0328] LCMS(ESI,m / z): [M+H] + =448.25

[0329] 2. Synthesis of Compound 3

[0330] At room temperature and in an air atmosphere, a solution of 1,4-dioxane (3 mL) of methyl (S)-2-((S)-2-((tert-butyloxycarbonyl)amino)-3-(3,3-difluorocyclobutyl)propylamino)-3-((S)-2-oxopyrrolidone-3-yl)propionate (280 mg, 1.2 mmol, 1 eq.) was added to a stirred solution of 1,4-dioxane (4.0 M) of hydrochloric acid (3 mL, 0.04 mmol, 2 eq.). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The resulting mixture was concentrated under reduced pressure. Methyl (S)-2-((S)-2-amino-3-(3,3-difluorocyclobutyl)propylamino)-3-((S)-2-oxopyrrolidone-3-yl)propionate (250 mg) was given as a white solid.

[0331] LCMS(ESI,m / z): [M+H] + =348.20

[0332] 3. Synthesis of Compound 4

[0333] Benzyl chloroformate (254 mg, 1.2 mmol, 1 eq.) was added to a stirred solution of methyl (S)-2-((S)-2-amino-3-(3,3-difluorocyclobutyl)propylamino)-3-((S)-2-oxopyrrolidone-3-yl)propionate (250 mg, 1.6 mmol, 1 eq.) and sodium carbonate (238 mg, 3.2 mmol, 2 eq.) in 1,4-dioxane (5 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with saturated brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH4HCO3), 35%-43% gradient, 10 min; detector: UV 200 nm. Methyl (S)-2-((S)-2-amino-3-(3,3-difluorocyclobutyl)propylamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (130 mg) was obtained as a white solid.

[0334] LCMS(ESI,m / z): [M+H] + =482.24

[0335] 4. Synthesis of Compound 5

[0336] Under nitrogen atmosphere at 0°C, lithium borohydride (4.0 M, in tetrahydrofuran) (0.4 mL, 2.7 mmol, 3 eq.) was added to a stirred solution of methyl (S)-2-((S)-2-amino-3-(3,3-difluorocyclobutyl)propylamino)-3-((S)-2-oxopyrrolidone-3-yl)propionate (130 mg, 0.9 mmol, 1 eq.) in tetrahydrofuran (2 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 2 hours. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 mL) and dried over anhydrous Na₂SO₄. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN in water (10 mmol / L NH4HCO3), 35%–43% gradient, 10 min; detector: UV 200 nm. The result was (S)-3-(3,3-difluorocyclobutyl)-1-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)amino)-1-oxopropyl-2-yl)carbamate (100 mg), a white solid.

[0337] LCMS(ESI,m / z): [M+H] + =454.24

[0338] 5. Synthesis of compound C2-16A

[0339] Under an air atmosphere at 0°C, a solution of (S)-3-(3,3-difluorocyclobutyl)-1-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)amino)-1-oxopropyl-2-yl)carbamate (100 mg, 0.4 mmol, 1 eq.) and sodium bicarbonate (104.2 mg, 1.7 mmol, 4 eq.) in dichloromethane (2 mL) was added with Dysmartin oxidant (346 mg, 1.3 mmol, 3 eq.). The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The reaction was quenched with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with saturated brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. Finally, (S)-3-(bicyclo[1.1.1]pentan-1-yl)-1-oxo-1-(((S)-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)amino)propyl-2-yl)carbamate (100 mg) was obtained as a pale yellow oil. At room temperature, sodium bisulfite (1 ml) was added to a stirred solution of ((S)-3-(bicyclo[1.1.1]pentan-1-yl)-1-oxo-1-(((S)-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)amino)propyl-2-yl)carbamate (100 mg) in air in N,N-dimethylformamide (1 ml). The resulting mixture was stirred in air at room temperature for 2 minutes. The resulting mixture was concentrated under reduced pressure. The crude product (60 mg) was purified by pre-high performance liquid chromatography under the following conditions (column: Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: acetonitrile; flow rate: 25 mL / min; gradient: 35% B to 55% B, 10 min; wavelength: 254 nm / 220 nm; RT1 (min): 8.37), yielding a white solid (2S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-3-(3,3-difluorocyclobutyl)propylamino)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propane-1-sulfonate sodium salt (8.1 mg).

[0340] LCMS(ESI,m / z):[M-Na] - =532.25

[0341] 1H NMR(400MHz,D2O)δ7.34(d,J=9.8Hz,5H),5.30–5.00(m,2H),4.43–3.92(m,3H) ),3.28–3.02(m,2H),2.90–2.50(m,2H),2.42–2.05(m,5H),1.87–1.36(m,5H).

[0342] Example 14 Synthesis of compound C2-36A

[0343] 1. Synthesize compound 2

[0344] Under nitrogen atmosphere at 25°C, N,N-dimethylformamide (10 mL) was added in portions to (S)-2-(((benzyloxy)carbonyl)amino)-2-phenylacetic acid (0.9 g, 3.4 mmol, 1.0 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (0.6 g, 3.4 mmol, 1.0 eq.) and N,N-diisopropylethylamine (1.3 g, 10.3 mmol, 3.0 eq.) and HATU (1.9 g, 5.2 mmol, 1.5 eq.). The resulting mixture was stirred at 25°C for 2 hours. The residue was purified by reversed-phase column chromatography under the following conditions: column specifications, mobile phase: water and acetonitrile, gradient from 10% to 50% for 10 minutes, UV 200 nm detector. A yellow oily methyl (S)-2-((S)-2-(((benzyloxy)carbonyl)amino)-2-phenylacetamido)-3-((S)-2-oxopyrrolidine-3-yl)propionate (800 mg) was obtained.

[0345] LCMS:(ESI,m / z):[M+H] + =454.1

[0346] 2. Synthesize compound 3

[0347] In a nitrogen atmosphere at 0°C, lithium borohydride (4.0 M in THF) (1.3 mL, 3.0 eq.) was added dropwise to methyl (780 mg, 1.7 mmol, 1.0 eq.) of (S)-2-((S)-2-(((benzyloxycarbonyl)amino)-2-phenylacetamyl)-3-((S)-2-oxopyrrolidine-3-yl)prop-2-yl)amino)-2-oxo-1-phenylethyl)carbamate (780 mg, 1.7 mmol, 1.0 eq.). The resulting mixture was stirred at 25°C for 2 hours. The reaction was quenched with water at 0°C. The resulting mixture was extracted with ethyl acetate (3 x 30 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to give a yellow oily substance ((S)-2-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)prop-2-yl)amino)-2-oxo-1-phenylethyl)carbamate (500 mg, crude).

[0348] LCMS:(ESI,m / z):[M+H] + =426.2

[0349] 3. Synthesize compound 4

[0350] At 25 °C, Dysmartin oxidant (717 mg, 1.7 mmol, 1.5 eq.) was added in portions to dichloromethane containing benzyl ((S)-2-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)amino)-2-oxo-1-phenylethyl)carbamate (480 mg, 1.1 mmol, 1.0 eq.). The resulting mixture was stirred at 25 °C for 2 hours. The reaction was quenched with saturated sodium bicarbonate solution, and the resulting mixture was extracted with dichloromethane (3 x 30 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to obtain a yellow oily substance ((S)-2-oxo-2-(((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)amino)-1-phenylethyl)carbamate (200 mg, crude product).

[0351] LCMS:(ESI,m / z):[M+H] + =424.0

[0352] 4. Synthesis of compound C2-36A

[0353] Under nitrogen atmosphere and at 25°C, saturated sodium bisulfite (1 mL) was added in portions to ((S)-2-oxo-2-(((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)amino)-1-phenylethyl)carbamate (200 mg, 0.5 mmol, 1.0 eq.) N,N-dimethylformamide (2 mL). The resulting mixture was stirred at 25°C for 1 hour. The crude product was purified by pre-high performance liquid chromatography under the following conditions (column: Xselect CSH C185): Xselect CSH C185 μm, 19 mm x 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 mL / min; gradient: from 35% B to 50% B over 10 minutes; wavelength: 195 nm / 200 nm; RT1 (min): 6.4), yielding a pale yellow solid (1S,2S)-2-((S)-2-(((benzyloxycarbonyl)amino)-2-phenylacetamido)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propane-1-sulfonate sodium (14.9 mg).

[0354] LCMS(ESI,m / z):[M-Na] - =504.2

[0355] 1 H NMR (400MHz, D2O) δ7.70–6.90(m,10H),5.36–4.96(m,4H),4.53–3.93(m,1H),3.93–3.57(m,1H),3.54–2.68(m,2H),2.60–1.13(m,5H).

[0356] Example 15 Synthesis of compound C2-37A

[0357] 1. Synthesis of Compound 2

[0358] At room temperature, N,N-diisopropylethylamine (1.7 mL, 9.7 mmol, 3.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (1.8 g, 4.8 mmol, 1.5 eq.) were added to a stirred DCM solution of (S)-adamantane-1-yl[(tert-butoxycarbonyl)amino]acetic acid (1.0 g, 3.2 mmol, 1.0 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (722 mg, 3.9 mmol, 1.2 eq.) in air (10 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 1 hour. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L ammonium bicarbonate), 35%–50% gradient, 10 min; detector: UV 200 nm. The final product was a white solid methyl (2S)-2-[(2S)-2-(adamantane-1-yl)-2-[(tert-butoxycarbonyl)amino]acetamido]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (1.1 g).

[0359] LCMS(ESI,m / z): [M+H] + =478.25

[0360] 2. Synthesis of Compound 3

[0361] Methyl (2S)-2-[(2S)-2-(adamantane-1-yl)-2-[(tert-butoxycarbonyl)amino]acetamido]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (1.0 g, 0.4 mmol, 1.0 eq.) was added to a stirred mixture of 1,4-dioxane hydrochloride (4.0 M, 5 mL) at room temperature and in air. The mixture was stirred at room temperature under nitrogen for 2 hours. The mixture was concentrated under reduced pressure to give methyl (2S)-2-[(2S)-2-(adamantane-1-yl)-2-aminoacetamido]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (900 mg) as a white solid.

[0362] LCMS(ESI,m / z): [M+H] + =378.20

[0363] 3. Synthesis of Compound 4

[0364] Benzyl chloroformate (610 mg, 3.6 mmol, 1.0 eq.) was added to a stirred solution of methyl (2S)-2-[(2S)-2-(adamantane-1-yl)-2-aminoacetamido]-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (900 mg, 0.6 mmol, 1.0 eq.) and Et3N (724 mg, 7.2 mmol, 3.0 eq.) in DCM (10 mL). Benzyl chloroformate (610 mg, 3.6 mmol, 1.5 eq.) and Et3N (724 mg, 7.2 mmol, 3.0 eq.) were added to DCM (10 mL) in air at room temperature. The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The resulting mixture was concentrated under reduced pressure. Methyl (2S)-2-[(2S)-2-(adamantane-1-yl)-2-{[(benzyloxy)carbonyl]amino}acetamido]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (700 mg) was obtained as a pale yellow oil.

[0365] LCMS(ESI,m / z): [M+H] + =512.24

[0366] 4. Synthesis of Compound 5

[0367] Lithium borohydride (4.0 M in THF) (0.6 mL, 2.3 mmol, 2.0 eq.) was added to a stirred solution of methyl (2S)-2-[(2S)-2-(adamantane-1-yl)-2-{[(benzyloxy)carbonyl]amino}acetamido]-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (700 mg, 0.2 mmol, 1.0 eq.) in 7 mL of THF at room temperature. The resulting mixture was stirred at room temperature under nitrogen for 1.5 h. The reaction was quenched with water at room temperature. The resulting mixture was extracted with EtOAc (2 x 20 mL). The combined organic layers were washed with brine (2 x 50 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L ammonium bicarbonate), 35%-50% gradient, 10 min; detector: UV 200 nm. The final product was N-[(S)-adamantane-1-yl({[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]carbamoyl})methyl]benzyl carbamate (200 mg), a white solid.

[0368] LCMS(ESI,m / z): [M+H] + =484.24

[0369] 5. Synthesis of Compound 6

[0370] To a stirred mixture of N-[(S)-adamantane-1-yl({[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]carbamoyl})methyl]carbamate benzyl ester (130 mg, 0.3 mmol, 1.0 eq.) and sodium bicarbonate (67.7 mg, 0.8 mmol, 3.0 eq.) in dichloromethane (3 mL), Dysmartin oxidant (228 mg, 0.5 mmol, 2.0 eq.) was added. The resulting mixture was stirred at room temperature under nitrogen atmosphere for 1.5 h. The reaction was quenched at room temperature with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with EtOAc (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. A yellow oily substance, N-[(S)-adamantane-1-yl({[(2S)-1-oxo-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]carbamoyl})methyl]carbamate (100 mg), was obtained.

[0371] LCMS(ESI,m / z): [M+H] + =482.24

[0372] 6. Synthesis of compound C2-37A

[0373] Sodium bisulfite (1 ml) was added to a stirred solution of N-[(S)-adamantane-1-yl({[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidone-3-yl]propyl-2-yl]carbamoyl})methyl]carbamate (120 mg, 0.2 mmol, 1.0 eq.) in N,N-dimethylformamide (1 ml). The resulting mixture was stirred in air at room temperature for 3 minutes. The resulting mixture was diluted with water (3 ml) and then extracted with ethyl acetate (2 x 5 ml). The aqueous layer was concentrated under reduced pressure. The crude product (150 mg) was purified by pre-liquid chromatography under the following conditions (column: Xselect CSH C185): Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 mL / min; gradient: from 47% B to 65% B over 10 minutes; wavelength: 254 nm / 220 nm; RT1 (min): 7.82) to obtain N-[(S)-adamantane-1-yl({[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]-1-(sodium dioxysulfonyl)propyl-2-yl]carbamoyl})methyl] benzyl carbamate (26.7 mg), which was an off-white solid.

[0374] LCMS(ESI,m / z):[M-Na] - =562.40

[0375] 1H NMR(400MHz,D2O)δ7.32(d,J=8.6Hz,5H),5.11–4.98(m,2H),4.44–4.33(m,1H),3.90–3.60(m,1H),3.25–3.15(m,1H) ),3.10–2.97(m,1H),2.28–2.20(m,1H),2.07–1.96(m,1H),1.92–1.82(m,2H)1.81–1.69(m,2H),1.68–1.16(m,14H).

[0376] Example 16 Synthesis of compound C4-1

[0377] Under nitrogen atmosphere and at -78°C, diisobutylaluminum hydride (1M dioxane solution) (0.2 mL, 5.0 eq.) was added dropwise to a stirred solution of (1R,2S,5S)-N-((S)-1-cyano-2-((S)-2-oxopyrrolidone-3-yl)ethyl)-3-((S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butyryl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamide (200 mg, 0.4 mmol, 1.0 eq.) in tetrahydrofuran (2 mL). The resulting mixture was stirred at -78°C for 1 hour. The crude product was purified by high-performance liquid chromatography (HPLC) under the following conditions (column: XSelect CSH phenyl column): Column type: XSelect CSH Phenyl-Hexyl OBD Prep Column, 5 μm, 19 mm x 250 mm; Mobile phase A: water (0.1% FA), Mobile phase B: ACN; Flow rate: 25 mL / min; Gradient: 27% B to 45% B in 10 min; Monitoring wavelength: 200 nm / 220 nm nm; RT1(min): 7.68), yielded (1R,2S,5S)-3-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butyryl]-6,6-dimethyl-N-[(2S)-1-oxo-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]-3-azabicyclo[3.1.0]hexane-2-carboxamide (13.5 mg), a white solid.

[0378] LCMS(ESI,m / z):[M+H] + =503.0

[0379] 1 H NMR (400MHz, CDCl3-d) δ9.63–9.43(m,1H),8.11(d,J=6.3Hz,1H),6.98(d,J=10.7Hz ,1H),5.75(s,1H),4.59(d,J=9.4Hz,1H),4.52–4.17(m,2H),4.03(d,J=10.2Hz,1H), 3.94–3.70(m,1H),3.42(t,J=9.6Hz,2H),2.71–2.23(m,2H),2.02(t,J=6.9Hz,2H), 1.96–1.85(m,1H),1.68–1.49(m,2H),1.17–1.02(m,11H),0.97(s,2H),0.92(s,2H).

[0380] Example 17 Synthesis of compound C4-1A

[0381] 1. Synthesize compound 2

[0382] Under nitrogen atmosphere at -78°C, diisobutylaluminum hydride (1M dioxane solution) (0.2 mL, 5.0 eq.) was added dropwise to (1R,2S,5S)-N-((S)-1-cyano-2-((S)-2-oxopyrrolidone-3-yl)ethyl)-3-((S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butyryl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamide (200 mg, 0.4 mmol, 1.0 eq.) in tetrahydrofuran (2 mL). The resulting mixture was stirred at 25°C for 1 hour. The crude product was purified by high performance liquid chromatography under the following conditions (column: Xselect CSH C185): Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 mL / min; gradient: 45% B to 65% B, 10 min; wavelength: 200 nm / 220 nm; RT1 (min): 5.65), yielding a white solid (1R,2S,5S)-3-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butyryl]-6,6-dimethyl-N-[(2S)-1-oxo-3-[(3S)-2-oxopyrrolidone-3-yl]propyl-2-yl]-3-azabicyclo[3.1.0]hexane-2-carboxamide (150 mg).

[0383] LCMS(ESI,m / z):[M+H] + =503.0

[0384] 2. Synthesis of compound C4-1A

[0385] Under nitrogen atmosphere, at 25°C, sodium bisulfite (31 mg, 0.3 mmol, 1.0 eq.) was added to 2 mL of DMF containing (1R,2S,5S)-3-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butyryl]-6,6-dimethyl-N-[(2S)-1-oxo-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]-3-azabicyclo[3.1.0]hexane-2-carboxamide (150 mg, 0.3 mmol, 1.0 eq.). The resulting mixture was stirred at 25°C for 1 hour. The crude product was purified by pre-high performance liquid chromatography under the following conditions (column: Xselect CSH C185): Xselect CSH C185 μm, 19 mm X 250 mm; Mobile phase A: water (0.1% FA), Mobile phase B: acetonitrile (ACN); Flow rate: 25 mL / min; Gradient (B%): 38% B to 55% B; Wavelength: 200 nm / 220 nm; RT1 (min): 9.75) yielded (2S)-2-((1R,2S,5S)-3-((S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butyryl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamido)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propane-1-sulfonate sodium salt (17.8 mg), a pale yellow solid.

[0386] LCMS(ESI,m / z):[M-Na] - =583.0

[0387] 1 H NMR(400MHz,D2O)δ4.93(d,J=4.2Hz,1H),4.52–4.39(m,2H),4.26–4.17(m,1H),3.95(d,J=5.4Hz,1H),3.89–3.75(m,1H),3.34–3. 18(m,2H),2.58–2.42(m,1H),2.26–2.00(m,1H),1.95–1.68(m,2H),1.67–1.33(m,3H),1.07–0.87(m,10H),0.84(d,J=2.4Hz,5H).

[0388] Example 18 Synthesis of compound C4-2

[0389] 1. Synthesis of Compound 2

[0390] Leucine methyl ester hydrochloride (2.0 g, 11.0 mmol, 1.0 aliquot) and (2S)-2-[(tert-butoxycarbonyl)amino]-3,3-dimethylbutyric acid (2.6 g, 11.0 mmol, 1.0 eq.) were mixed with N,N-diisopropylethylamine (4.3 g, 33.0 mmol, 3.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (6.3 g, 16.5 mmol, 1.5 eq.) in dichloromethane (20 mL). The resulting mixture was stirred at room temperature under nitrogen for 1 hour. The mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L NH4HCO3), 33%–45% gradient, 10 min; detector, UV 200 nm. Finally, a white solid (2S)-2-[(2S)-2-[(tert-butoxycarbonyl)amino]-3,3-dimethylbutanoamino]-4-methylvalerate methyl ester (2.2 g) was obtained.

[0391] LCMS(ESI,m / z): [M+H] + =359.25

[0392] 2. Synthesis of Compound 3

[0393] Under nitrogen atmosphere, at room temperature, water (6 mL) and lithium hydroxide monohydrate (281 mg, 6.7 mmol, 2.0 eq.) were added to a stirred solution of (2S)-2-[(2S)-2-[(tert-butyloxycarbonyl)amino]-3,3-dimethylbutylamino]-4-methylpentanoate methyl ester (1.2 g, 3.347 mmol, 1 eq.) in tetrahydrofuran (6 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 1.5 h. The reactants were quenched with water at room temperature, the mixture was acidified to pH 3 with concentrated hydrochloric acid, extracted with ethyl acetate (2 x 40 mL), and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to give (2S)-2-[(2S)-2-[(tert-butyloxycarbonyl)amino]-3,3-dimethylbutylamino]-4-methylpentanoic acid (1.1 g), a white solid.

[0394] LCMS(ESI,m / z): [M+H] + =345.20

[0395] 3. Synthesis of Compound 4

[0396] To a solution of (2S)-2-[(2S)-2-[(tert-butyloxycarbonyl)amino]-3,3-dimethylbutylamino]-4-methylpentanoic acid (1.1 g, 3.2 mmol, 1 eq.) in 1,4-dioxane (5 mL), 1,4-dioxane hydrochloride (4.0 M) (6 mL) was added. The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The mixture was concentrated under reduced pressure to give a white solid (2S)-2-[(2S)-2-{[(benzyloxy)carbonyl]amino}-4-methylpentanamino]-3-[4-(methylcarbamoyl)pyrazol-1-yl]propionate methyl ester (800 mg).

[0397] LCMS(ESI,m / z): [M+H] + =245.24

[0398] 4. Synthesis of Compound 5

[0399] At room temperature, ethyl trifluoroacetate (526 mg, 3.7 mmol, 1.3 eq.) was added to a stirred methanol (10 mL) solution of (2S)-2-[(2S)-2-{[(benzyloxy)carbonyl]amino}-4-methylpentanamino]-3-[4-(methylcarbamoyl)pyrazol-1-yl]propionate (800 mg, 2.8 mmol, 1.0 eq.) and N,N-diisopropylethylamine (1.0 mL, 5.7 mmol, 2.0 eq.) in air. The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L ammonium bicarbonate), gradient 23%–29%, 10 min; detector, UV 200 nm. Finally, a white solid (2S)-2-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butamido]-4-methylvaleric acid (450 mg) was obtained.

[0400] LCMS(ESI,m / z): [M+H] + =341.24

[0401] 5. Synthesis of Compound 6

[0402] At room temperature and in an air atmosphere, N,N-diisopropylethylamine (0.7 mL, 3.9 mmol, 3.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (1.0 g, 2.6 mmol, 2.0 eq.) were added in portions to a stirred solution of (2S)-2-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamyl)butamido]-4-methylpentanoic acid (450 mg, 1.3 mmol, 1.0 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidone-3-yl]propionate methyl hydrochloride (382 mg, 1.7 mmol, 1.3 eq.) in dichloromethane (6 mL). The resulting mixture was stirred at room temperature for 1 hour under nitrogen atmosphere. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L ammonium bicarbonate), 30%-39% gradient, 10 min; detector: UV 200 nm. The result was methyl (2S)-2-[(2S)-2-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butanyl]-4-methylpentanyl]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (390 mg), a white solid.

[0403] LCMS(ESI,m / z): [M+H] + =509.24

[0404] 6. Synthesis of Compound 7

[0405] Under nitrogen atmosphere and at room temperature, lithium borohydride (4.0 M in tetrahydrofuran) (0.4 mL, 1.5 mmol, 2.0 eq.) was added to a stirred solution of methyl (390 mg, 0.5 mmol, 1.0 eq.) in tetrahydrofuran (5 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 1 hour. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 40 mL). The combined organic layers were washed with brine (2 x 80 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. (2S)-2-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butanylamino]-N-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]-4-methylpentanamide (300 mg) was obtained as a white solid.

[0406] LCMS(ESI,m / z): [M+H] + =481.24

[0407] 7. Synthesis of compound C4-2

[0408] At room temperature, Dysmartin oxidant (176.5 mg, 0.4 mmol, 2.0 eq.) and sodium bicarbonate (52.4 mg, 0.6 mmol, 3.0 eq.) were added to a solution of dichloromethane (5 mL). The resulting mixture was stirred at room temperature for 2 hours under nitrogen atmosphere. The reaction was quenched at room temperature with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The crude product (80 mg) was purified by pre-high performance liquid chromatography under the following conditions (column: Xselect CSH C185, 5.5 mm × 4.5 mm, 5.5 mm × 4.5 mm; Xselect CSH C185 μm, 19 mm × 250 mm; mobile phase A: water (0.1% FA); mobile phase B: ACN; flow rate: 25 mL / min; gradient: from 30% B to 45% B over 10 minutes; wavelength: 254 nm / 220 nm; RT1 (min): 5.9), yielding (2S)-2-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butanylamino]-4-methyl-N-[(2S)-1-oxo-3-[(3S)-2-oxopyrrolidone-3-yl]propyl-2-yl]pentanamide (12.9 mg), a white solid.

[0409] LCMS(ESI,m / z):[M+H] + =479.30

[0410] 1H NMR(400MHz, CDCl3-d)δ9.56–9.50(m,1H),8.45(d,J=5.6Hz,1H),7.15(d,J=9.3Hz,1H),6.59(d,J=8.0Hz,1H),6.18–6.06(m,1H),4.65–4.55 (m,1H),4.44–4.30(m,2H),3.50–3.34(m,2H),2.57–2.41(m,2H),2.01 –1.88(m,3H),1.75–1.66(m,3H),1.06–1.02(m,9H),1.01–0.96(m,6H).

[0411] Example 19 Synthesis of compound C4-3

[0412] 1. Synthesis of Compound 2

[0413] To a stirred solution of leucine methyl ester hydrochloride (2.0 g, 11.0 mmol, 1.0 eq.) and (2S)-2-[(tert-butoxycarbonyl)amino]-3,3-dimethylbutyric acid (2.6 g, 11.0 mmol, 1.0 eq.) in dichloromethane (20 mL), N,N-diisopropylethylamine (4.3 g, 33.0 mmol, 3.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (6.3 g, 16.5 mmol, 1.5 eq.) were added. The resulting mixture was stirred at room temperature under nitrogen for 1 hour. The mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L NH4HCO3), 33%–45% gradient, 10 min; detector, UV 200 nm. Finally, a white solid (S)-2-((S)-2-((tert-butoxycarbonyl)amino)-3,3-dimethylbutamino)-4,4-dimethylvalerate methyl ester (2.2 g) was obtained.

[0414] LCMS(ESI,m / z): [M+H] + =373.25

[0415] 2. Synthesis of Compound 3

[0416] Under nitrogen atmosphere, at room temperature, water (6 mL) and lithium hydroxide monohydrate (281 mg, 6.7 mmol, 2.0 eq.) monohydrate were added to a stirred solution of (2S)-2-[(2S)-2-[(tert-butyloxycarbonyl)amino)-3,3-dimethylbutylamino)-4-methylvalerate (1.2 g, 3.3 mmol, 1.0 eq.) tetrahydrofuran (6 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 1.5 h. The reactants were quenched with water at room temperature, and the mixture was acidified to pH 3 with concentrated hydrochloric acid. The mixture was extracted with ethyl acetate (2 x 20 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to give (S)-2-((S)-2-((tert-butyloxycarbonyl)amino)-3,3-dimethylbutylamino)-4,4-dimethylvalerate (1.1 g) as a white solid.

[0417] LCMS(ESI,m / z): [M+H] + =359.20

[0418] 3. Synthesis of Compound 4

[0419] Under nitrogen atmosphere, a solution of 1,4-dioxane (4.0 M, 6 mL) of HCl was added to a solution of (2S)-2-[(2S)-2-[(tert-butoxycarbonyl)amino]-3,3-dimethylbutanamino]-4-methylpentanoic acid (1.1 g, 3.2 mmol, 1.0 eq.) in 1,4-dioxane (5 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 2 hours. The mixture was then concentrated under reduced pressure to give a white solid (S)-2-((S)-2-amino-3,3-dimethylbutanamino)-4,4-dimethylpentanoic acid (800 mg).

[0420] LCMS(ESI,m / z): [M+H] + =259.24

[0421] 4. Synthesis of Compound 5

[0422] At room temperature, ethyl trifluoroacetate (526 mg, 3.7 mmol, 1.3 eq.) was added to a stirred methanol (10 mL) solution of (S)-2-((S)-2-amino-3,3-dimethylbutano)-4,4-dimethylvaleric acid (800 mg, 2.8 mmol, 1.0 eq.) and N,N-diisopropylethylamine (1.0 mL, 5.7 mmol, 2.0 eq.) in air. The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L ammonium bicarbonate), gradient 23%–29%, 10 min; detector, UV 254 nm. The final product was a white solid (S)-2-((S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butano)-4,4-dimethylvaleric acid (450 mg).

[0423] LCMS(ESI,m / z): [M+H] + =355.24

[0424] 5. Synthesis of Compound 6

[0425] At room temperature and in an air atmosphere, N,N-diisopropylethylamine (0.7 mL, 3.9 mmol, 3.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (1.0 g, 2.6 mmol, 2.0 eq.) were added in portions to a stirred solution of (2S)-2-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamyl)butamido]-4-methylpentanoic acid (450 mg, 1.3 mmol, 1.0 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidone-3-yl]propionate methyl hydrochloride (382 mg, 1.7 mmol, 1.3 eq.) in dichloromethane (6 mL). The resulting mixture was stirred at room temperature for 1 hour under nitrogen atmosphere. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L ammonium bicarbonate), 30%-39% gradient, 10 min; detector: UV 200 nm. The result was methyl (S)-2-((S)-2-((S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butanyl)-4,4-dimethylpentanyl)-3-((S)-2-oxopyrrolidone-3-yl)propionate (390 mg) as a white solid.

[0426] LCMS(ESI,m / z): [M+H] + =523.24

[0427] 6. Synthesis of Compound 7

[0428] Under nitrogen atmosphere and at room temperature, lithium borohydride (4.0 M in tetrahydrofuran) (0.4 mL, 1.5 mmol, 2.0 eq.) was added to a stirred solution of methyl (390 mg, 0.5 mmol, 1.0 eq.) in tetrahydrofuran (5 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 1 hour. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 40 mL). The combined organic layers were washed with brine (2 x 80 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. (S)-2-((S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butamido)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)-4,4-dimethylpentanamide (300 mg) was obtained as a white solid.

[0429] LCMS(ESI,m / z): [M+H] + =495.24

[0430] 7. Synthesis of compound C4-3

[0431] At room temperature, in air, a solution of (S)-2-((S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butamido)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)-4,4-dimethylpentanamide (150 mg, 0.2 mmol, 1.0 eq.) and sodium bicarbonate (52.4 mg, 0.6 mmol, 3.0 eq.) in dichloromethane (2 mL) was added with Dys-Martin oxidant (176 mg, 0.4 mmol, 2.0 eq.). The resulting mixture was stirred at room temperature for 2 hours under nitrogen atmosphere. The reaction was quenched at room temperature with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with brine (2 x 50 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The crude product (80 mg) was purified by high performance liquid chromatography under the following conditions (column: Xselect CSH C185, 5.5 mm × 4.5 mm, 5.5 mm × 4.5 mm; Xselect CSH C185 μm, 19 mm × 250 mm; mobile phase A: water (0.1% FA); mobile phase B: ACN; flow rate: 25 mL / min; gradient: from 30% B to 45% B over 10 minutes; wavelength: 254 nm / 220 nm; RT1 (min): 5.9), yielding (S)-2-((S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butanyl)-4,4-dimethyl-N-((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)pentanamide (11.5 mg) as a white solid.

[0432] LCMS(ESI,m / z):[M+H] + =493.3

[0433] 1H NMR (400MHz, CDCl3-d) δ9.54–9.49(m,1H),8.41(d,J=5.8Hz,1H),7.07(d,J =9.2Hz,1H),6.43(d,J=8.2Hz,1H),6.03–5.94(m,1H),4.66–4.57(m,1H),4. 37–4.28(m,2H),3.47–3.37(m,2H),2.57–2.41(m,2H),1.98(d,J=6.6Hz,1H) ,1.93–1.86(m,2H),1.58–1.50(m,2H),1.09–1.02(m,9H),1.01–0.96(m,9H)

[0434] Example 20 Synthesis of compound C4-4

[0435] 1. Synthesis of Compound 2

[0436] (2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(tert-butylcarbonyl)amino]propionic acid (1.0 g, 3.9 mmol, 1.0 eq.) was stirred in methanol (10 mL), and thionyl chloride (931.9 mg, 7.8 mmol, 2.0 eq.) was added dropwise under a nitrogen atmosphere at -78 °C. The resulting mixture was stirred at room temperature for another 2 hours. The resulting mixture was concentrated under reduced pressure to give methyl (2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(tert-butylcarbonyl)amino]propionic acid ester (900 mg, crude product), a brown oil.

[0437] LCMS(ESI,m / z):[M+H] + =270.3

[0438] 2. Synthesis of Compound 3

[0439] Under a nitrogen atmosphere, a solution of 1,4-dioxane hydrochloride (4.0 M) (6 mL) was added to a 5 mL solution of methyl(2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(tert-butylcarbonyl)amino]propionic acid (900 mg, 3.3 mmol, 1.0 eq.) in 1,4-dioxane. The resulting mixture was stirred at room temperature for another 2 hours. The mixture was then concentrated under reduced pressure to give a brown oil of methyl(2S)-2-amino-3-{bicyclo[1.1.1]pentan-1-yl}propionate (600 mg, crude product).

[0440] LCMS(ESI,m / z):[M+H] + =170.1

[0441] 3. Synthesis of Compound 4

[0442] Methyl(2S)-2-amino-3-{bicyclo[1.1.1]pentan-1-yl}propionic acid (2.0 g, 11.8 mmol, 1.0 eq.) and (2S)-2-[(tert-butyloxycarbonyl)amino]-3,3-dimethylsuccinic acid (2.7 g, 11.8 mmol, 1.0 eq.) were dissolved in dichloromethane (20 mL) and treated with DIEA (4.6 g, 35.5 mmol, 3.0 eq.) for 5 min at room temperature under a nitrogen atmosphere. Then, HATU (6.7 g, 17.7 mmol, 1.5 eq.) was added in portions at room temperature. The resulting mixture was stirred at room temperature under a nitrogen atmosphere for 1 h. The residue was washed with water (2 × 10 mL). The organic layer was dried over anhydrous sodium sulfide. After filtration, the filtrate was concentrated under reduced pressure. The resulting residue was purified by reversed-phase column chromatography under the following conditions: column specifications, mobile phase: water and acetonitrile, gradient from 10% to 50% for 10 minutes, UV 200 nm detector. The result was a white solid methyl(2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(2S)-2-[(tert-butyloxycarbonyl)amino]-3,3-dimethylbutamido]propionic acid (3.0 g).

[0443] LCMS(ESI,m / z):[M+H] + =383.5

[0444] 4. Synthesis of Compound 5

[0445] At 0 °C, a solution of LiOH (281.8 mg, 11.8 mmol, 1.5 eq.) in water (10 mL) was added dropwise to a solution of methyl(2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(2S)-2-[(tert-butylcarbonyl)amino]-3,3-dimethylbutylamino]propionic acid (3.0 g, 7.8 mmol, 1.0 eq.) in tetrahydrofuran (30 mL). The resulting mixture was stirred at room temperature under a nitrogen atmosphere for 3 hours. The mixture was acidified to pH 5 with hydrochloric acid. The resulting mixture was extracted with dichloromethane (3 × 20 mL). The bound organic layer was washed with brine (20 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure. The resulting residue was purified by reversed-phase column chromatography under the following conditions: column specifications, mobile phase: water and acetonitrile, gradient from 10% to 50% for 10 minutes, UV 200 nm detector. A white solid (2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(2S)-2-[(tert-butylcarbonyl)amino]-3,3-dimethylbutylamine]propionic acid (2.5 g) was obtained.

[0446] LCMS(ESI,m / z):[M+H] + =369.2

[0447] 5. Synthesis of Compound 6

[0448] A solution of (2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(2S)-2-[(tert-butylcarbonyl)amino]-3,3-dimethylbutyl]propionic acid (2.4 g, 6.5 mmol, 1.0 eq.) and HCl in 1,4-dioxane (10 mL) was stirred in dioxane (10 mL) for 1 h. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase column chromatography under the following conditions: column specifications, mobile phase, water and acetonitrile, 10% to 50% gradient for 10 min, UV 200 nm detector. (2S)-2-[(2S)-2-amino-3,3-dimethylbutylamine]-3-{bicyclo[1.1.1]pentan-1-yl}propionic acid (1.7 g) was given as a white solid.

[0449] LCMS(ESI,m / z):[M+H] + =269.2

[0450] 6. Synthesis of Compound 7

[0451] Under a nitrogen atmosphere, at 0 °C, TEA (1.3 g, 13.0 mmol, 3.0 eq.) and TFAA (4.6 g, 21.7 mmol, 5.0 eq.) were added dropwise to a stirred solution of (2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(2S)-2-[(tert-butoxycarbonyl)amino]-3,3-dimethylbutamido]propionic acid (1.6 g, 4.3 mmol, 1.0 eq.) in DCM (20 mL). The resulting mixture was stirred at 25 °C for 2 hours. The resulting residue was purified by reversed-phase column chromatography under the following conditions: column specifications, mobile phase, water and acetonitrile, 10% to 50% gradient for 10 min, UV 200 nm detector. The white solid (2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butamido]propionic acid (1.2 g) was obtained.

[0452] LCMS(ESI,m / z):[M+H] + =365.1

[0453] 7. Synthesis of Compound 8

[0454] Under nitrogen atmosphere and at 25°C, HATU (1.8 g, 4.9 mmol, 1.5 eq.) and DIEA (1.2 g, 9.8 mmol, 3.0 eq.) were added in portions to a DMF (10 mL) of (2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butamido]propionic acid (1.2 g, 3.2 mmol, 1.0 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidone-3-yl]propionic acid methyl ester (0.61 g, 3.2 mmol, 1.0 eq.) incorporating nitrogen. The resulting mixture was stirred at 25°C for another 2 hours. The resulting residue was purified by reversed-phase column chromatography under the following conditions: column specifications, mobile phase: water and acetonitrile, gradient from 10% to 50% for 10 minutes, UV 200 nm detector. Methyl (2S)-2-[(2S)-3-{bicyclo[1.1.1]pentan-1-yl}-2-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butanyl]propylamino]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (1.0 g) was obtained as a white solid.

[0455] LCMS(ESI,m / z):[M+H] + =533.2

[0456] 8. Synthesis of Compound 9

[0457] Under nitrogen atmosphere and at room temperature, lithium borohydride (4.0 M in THF) (0.4 mL, 1.5 mmol, 2.0 eq.) was added to a stirred solution of methyl (390 mg, 0.5 mmol, 1.0 eq.) in tetrahydrofuran (5 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 1 hour. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 40 mL). The combined organic layers were washed with brine (2 x 80 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. (S)-2-((S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butamido)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)-4,4-dimethylpentanamide (300 mg, crude product) was obtained as a white solid.

[0458] LCMS(ESI,m / z): [M+H] + =481.24

[0459] 9. Synthesis of compound C4-4

[0460] At room temperature, in air, a solution of (S)-2-((S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butamido)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)-4,4-dimethylpentanamide (150 mg, 0.2 mmol, 1.0 eq.) and sodium bicarbonate (52.4 mg, 0.6 mmol, 3.0 eq.) in dichloromethane (2 mL) was added with Dys-Martin oxidant (176 mg, 0.4 mmol, 2.0 eq.). The resulting mixture was stirred at room temperature for 2 hours under nitrogen atmosphere. The reaction was quenched at room temperature with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The crude product was purified by high performance liquid chromatography (HPLC) under the following conditions (column: Xselect CSH C185, 5.5 mm × 4.5 mm, 5.5 mm × 4.5 mm; Xselect CSH C185 μm, 19 mm × 250 mm; mobile phase A: water (0.1% FA); mobile phase B: ACN; flow rate: 25 ml / min; gradient: from 30% B to 45% B over 10 minutes; wavelength: 200 nm / 220 nm; RT1 (min): 5.9), yielding (S)-2-((S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butanyl)-4,4-dimethyl-N-((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)pentanamide (11.5 mg) as a white solid.

[0461] LCMS(ESI,m / z):[M+H] + =503.5

[0462] 1H NMR (400MHz, D2O) δ8.37 (s, 1H), 7.77 (d, J = 7.2Hz, 1H), 7.35-7.31 (m, 1H), 7. 26–7.16(m,1H),7.03(d,J=7.6Hz,1H),4.32–4.27(m,2H),3.95–3.80(m,1H) ,3.26(d,J=9.8Hz,2H),2.35(d,J=11.4Hz,2H),2.20–2.12(m,1H),1.91–1.7 5(m,4H),1.44(d,J=7.1Hz,3H),1.35(s,3H),1.20(s,1H),0.97-0.93(m,9H).

[0463] Example 21 Synthesis of compound C4-5

[0464] 1. Synthesis of Compound 2

[0465] To a stirred solution of (S)-[(tert-butoxycarbonyl)amino](phenyl)acetic acid (2.0 g, 7.9 mmol, 1.0 eq.) and (1R,2S,5S)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylate hydrochloride (1.6 g, 7.9 mmol, 1.0 eq.) in dichloromethane (20 mL), N,N-diisopropylethylamine (4.3 mL, 23.9 mmol, 3.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (4.5 g, 11.9 mmol, 1.5 eq.) were added. The resulting mixture was stirred at room temperature under nitrogen atmosphere for 1 hour. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH4HCO3), 33%–45% gradient, 10 min; detector: UV 200 nm. The final product was a white solid (1R,2S,5S)-3-[(2S)-2-[(tert-butoxycarbonyl)amino]-2-phenylacetyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylate (2.4 g).

[0466] LCMS(ESI,m / z): [M+H] + =403.25

[0467] 2. Synthesis of Compound 3

[0468] Under nitrogen atmosphere, at room temperature, water (10 mL) and lithium hydroxide monohydrate (500 mg, 11.0 mmol, 2.0 eq.) were added to a stirred tetrahydrofuran (10 mL) solution of methyl (1R,2S,5S)-3-[(2S)-2-[(tert-butoxycarbonyl)amino]-2-phenylacetyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylate (2.4 g, 5.9 mmol, 1 eq.) at tetrahydrofuran (10 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 1.5 h. The reactants were quenched with water at room temperature, the mixture was acidified to pH 3 with concentrated hydrochloric acid, the mixture was extracted with ethyl acetate (2 x 50 mL), and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to obtain (1R,2S,5S)-3-[(2S)-2-[(tert-butoxycarbonyl)amino]-2-phenylacetyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (2.2 g), which is a white solid.

[0469] LCMS(ESI,m / z): [M+H] + =389.20

[0470] 3. Synthesis of Compound 4

[0471] Under nitrogen atmosphere, a solution of 1,4-dioxane-2-carboxylic acid (1R,2S,5S)-3-[(2S)-2-[(tert-butoxycarbonyl)amino]-2-phenylacetyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (2.4 g, 6.2 mmol, 1.0 eq.) in 1,4-dioxane (10 mL) was added to HCl in 1,4-dioxane (4.0 M) (15 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 2 hours. The mixture was concentrated under reduced pressure to give a white solid (1R,2S,5S)-3-((S)-2-amino-2-phenylacetyl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (2.2 g).

[0472] LCMS(ESI,m / z): [M+H] + =289.24

[0473] 4. Synthesis of Compound 5

[0474] At room temperature, ethyl trifluoroacetate (1.5 g, 10.4 mmol, 1.5 eq.) was added to a stirred methanol (10 mL) solution of (1R,2S,5S)-3-((S)-2-amino-2-phenylacetyl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (2.0 g, 6.9 mmol, 1.0 eq.) and N,N-diisopropylethylamine (3.6 mL, 20.8 mmol, 3.0 eq.) in air. The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L ammonium bicarbonate), gradient 23%–29%, 10 min; detector, UV 200 nm. Finally, a white solid (1R,2S,5S)-6,6-dimethyl-3-[(2S)-2-phenyl-2-(2,2,2-trifluoroacetamido)acetyl]-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (2.1 g) was obtained.

[0475] LCMS(ESI,m / z): [M+H] + =385.24

[0476] 5. Synthesis of Compound 6

[0477] At room temperature and in an air atmosphere, N,N-diisopropylethylamine (3.1 mL, 4.4 mmol, 1.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (3.4 g) were added in portions to a stirred solution of ((1R,2S,5S)-6,6-dimethyl-3-[(2S)-2-phenyl-2-(2,2,2-trifluoroacetamido)acetyl]-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (1.7 g, 4.4 mmol, 1.0 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidone-3-yl]propionate methyl hydrochloride (1.5 g, 6.6 mmol, 1.3 eq.) in dichloromethane (15 mL). 8.8 mmol, 2.0 eq.). The resulting mixture was stirred at room temperature for 1 hour under nitrogen atmosphere. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L ammonium bicarbonate), 30%-39% gradient, 10 min; detector, UV 200 nm. The result was methyl (S)-2-((1R,2S,5S)-6,6-dimethyl-3-((S)-2-phenyl-2-(2,2,2-trifluoroacetamido)acetyl)-3-azabicyclo[3.1.0]hexane-2-carboxamido)-3-((S)-2-oxopyrrolidine-3-yl)propionate (2.1 g), as a white solid.

[0478] LCMS(ESI,m / z): [M+H] + =553.24

[0479] 6. Synthesis of Compound 7

[0480] Under nitrogen atmosphere and at room temperature, lithium borohydride (4.0 M in tetrahydrofuran) (0.9 mL, 1.5 mmol, 2.0 eq.) was added to a stirred solution of methyl (S)-2-((1R,2S,5S)-6,6-dimethyl-3-((S)-2-phenyl-2-(2,2,2-trifluoroacetamido)acetyl)-3-azabicyclo[3.1.0]hexane-2-carboxamido)-3-((S)-2-oxopyrrolidine-3-yl)propionate (1.0 g, 1.8 mmol, 1.0 eq.) in 10 mL of tetrahydrofuran (10 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 1 hour. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 40 mL). The combined organic layers were washed with brine (2 x 80 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. (1R,2S,5S)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)-6,6-dimethyl-3-((S)-2-phenyl-2-(2,2,2-trifluoroacetamido)acetyl)-3-azabicyclo[3.1.0]hexane-2-carboxamide (190 mg) was obtained as a white solid.

[0481] LCMS(ESI,m / z): [M+H] + =525.25

[0482] 7. Synthesis of compound C4-5

[0483] At room temperature, a solution of (1R,2S,5S)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)-6,6-dimethyl-3-((S)-2-phenyl-2-(2,2,2-trifluoroacetamido)acetyl)-3-azabicyclo[3.1.0]hexane-2-carboxamide (90 mg, 0.2 mmol, 2.0 eq.) and sodium bicarbonate (52.4 mg, 0.6 mmol, 3.0 eq.) in dichloromethane (5 mL) was added with Dys-Martin oxidant (112 mg, 0.4 mmol, 2.0 eq.). The resulting mixture was stirred at room temperature for 2 hours under nitrogen atmosphere. The reaction was quenched at room temperature with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The crude product (80 mg) was purified by high-performance liquid chromatography (HPLC) under the following conditions: column: Xselect CSH C185, 5.5 mm × 4.5 mm, 5.5 mm × 4.5 mm; Xselect CSH C185 μm, 19 mm. 250 mm; Mobile phase A: water (0.1% FA), Mobile phase B: ACN; Flow rate: 25 mL / min; Gradient: from 30% B to 45% B over 10 minutes; Wavelength: 200 nm; RT1 (min): 5.9), yielded (1R,2S,5S)-6,6-dimethyl-N-((S)-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)-3-((S)-2-phenyl-2-(2,2,2-trifluoroacetamido)acetyl)-3-azabicyclo[3.1.0]hexane-2-carboxamide (9.6 mg), a white solid.

[0484] LCMS(ESI,m / z):[M+H] + =523.30

[0485] 1 H NMR(400MHz,D2O)δ7.46–7.25(m,5H),5.66–5.58(m,1H),4.97–4.88(m,1H),4.34–4.26(m,1H),3.94–3.70(m,2H), 3.45–3.23(m,3H),2.53–2.41(m,1H),2.22–2.10(m,1H),1.92–1.69(m,2H),1.61–1.33(m,3H),0.99–0.27(m,6H).

[0486] Example 22 Synthesis of compound C4-6

[0487] 1. Synthesis of Compound 2

[0488] Under nitrogen atmosphere and at 25°C, potassium cyanide (2.8 g, 43.7 mmol, 1.2 eq.) was added in portions to a stirred mixture of 6-methoxypyridin-3-carboxaldehyde (5.0 g, 36.5 mmol, 1.0 eq.) and ammonium carbonate (12.3 g, 127.6 mmol, 3.5 eq.) in anhydrous ethanol (50 mL) and water. The resulting mixture was stirred at 80°C for 6 hours. The mixture was then concentrated under reduced pressure. The residue was washed with anhydrous ethanol (3 x 50 mL) to give 2-amino-4-(6-methoxypyridin-3-yl)-1,3-oxazol-5-ol (3.0 g) as a white solid.

[0489] LCMS(ESI,m / z):[M+H] + =208.1

[0490] 2. Synthesis of Compound 3

[0491] Under nitrogen atmosphere and at 25°C, sodium hydroxide (0.6 g, 14.5 mmol, 1.0 eq.) was added in portions to a stirred mixture of 2-amino-4-(6-methoxypyridin-3-yl)-1,3-oxazol-5-ol (3.0 g, 14.5 mmol, 1.0 eq.) and water (30 mL). The resulting mixture was stirred at 120°C for 24 hours. The mixture was concentrated under reduced pressure to give 1.6 g of white solid amino(6-methoxypyridin-3-yl)acetic acid.

[0492] LCMS(ESI,m / z):[M+H] + =183.1

[0493] 3. Synthesis of Compound 4

[0494] Under nitrogen atmosphere and at 0°C, di-tert-butyl dicarbonate (2.9 g, 13.2 mmol, 1.5 eq.) was added dropwise to a mixture of amino(6-methoxypyridin-3-yl)acetic acid (1.6 g, 8.8 mmol, 1.0 eq.) and triethylamine (2.7 g, 26.3 mmol, 3.0 eq.) in methanol (20 mL). The resulting mixture was stirred at 25°C for 2 hours. The mixture was then concentrated under reduced pressure to give a yellow oily substance, [(tert-butyloxycarbonyl)amino](6-methoxypyridin-3-yl)acetic acid (2.2 g).

[0495] LCMS(ESI,m / z):[M+H] + =283.1

[0496] 4. Synthesis of Compound 5

[0497] Under nitrogen atmosphere at 25°C, HATU (4.2 g, 11.2 mmol, 1.5 eq.) and N,N-diisopropylethylamine (2.9 g, 22.3 mmol, 3.0 eq.) were added to N,N-dimethylformamide (20 mL) of [(tert-butoxycarbonyl)amino](6-methoxypyridin-3-yl)acetic acid (2.1 g, 7.4 mmol, 1.0 eq.) and (1R,2S,5S)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylate (1.3 g, 7.4 mmol, 1.0 eq.) under stirring. The resulting mixture was stirred at 25°C for 2 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN aqueous solution (0.1% FA), gradient from 10% to 50% over 10 minutes; detector: UV 200 nm. The result was (1R,2S,5S)-3-{2-[(tert-butoxycarbonyl)amino]-2-(6-methoxypyridin-3-yl)acetyl}-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylate (2.2 g), a yellow solid.

[0498] LCMS(ESI,m / z):[M+H] + =434.2

[0499] 5. Synthesis of Compound 6

[0500] Under nitrogen atmosphere and at 25°C, lithium hydroxide (0.4 g, 14.5 mmol, 3.0 eq.) was added in portions to a mixture of (1R,2S,5S)-3-{2-[(tert-butoxycarbonyl)amino]-2-(6-methoxypyridin-3-yl)acetyl}-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylate (2.1 g, 4.8 mmol, 1.0 eq.) in tetrahydrofuran (10 mL) and water (10 mL). The resulting mixture was stirred at 25°C for 2 hours. The resulting mixture was concentrated under reduced pressure to give a yellow solid (1R,2S,5S)-3-{2-[(tert-butoxycarbonyl)amino]-2-(6-methoxypyridin-3-yl)acetyl}-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (1.8 g).

[0501] LCMS(ESI,m / z):[M+H] + =420.2

[0502] 6. Synthesis of Compound 7

[0503] Under nitrogen atmosphere and at 25°C, sodium iodide (6.4 g, 42.9 mmol, 10.0 eq.) and trimethylchlorosilane (2.3 g, 21.5 mmol, 5.0 eq.) were added to acetonitrile (20 mL) of (1R,2S,5S)-3-{2-[(tert-butoxycarbonyl)amino]-2-(6-methoxypyridin-3-yl)acetyl}-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (1.8 g, 4.3 mmol, 1.0 eq.) and acetonitrile (20 mL). The resulting mixture was stirred at 80°C for 16 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, MeCN water (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector, UV 200 nm, yielding a yellow oily substance of (1R,2S,5S)-3-{2-[(tert-butoxycarbonyl)amino]-2-(6-oxo-1H-pyridin-3-yl)acetyl}-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (1.4 g).

[0504] LCMS(ESI,m / z):[M+H] + =306.1

[0505] 7. Synthesis of Compound 8

[0506] Under nitrogen atmosphere and at 25°C, ethyl trifluoroacetate (1.9 g, 13.7 mmol, 3.0 eq.) was added to a stirred mixture of (1R,2S,5S)-3-[2-amino-2-(6-oxo-1H-pyridin-3-yl)acetyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (1.4 g, 4.6 mmol, 1.0 eq.) and N,N-diisopropylethylamine (1.8 g, 13.8 mmol, 3.0 eq.) in methanol (10 mL). The resulting mixture was stirred at 60°C for 16 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, MeCN water (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector, UV 200 nm, yielding a white solid of (1R,2S,5S)-6,6-dimethyl-3-[2-(6-oxo-1H-pyridin-3-yl)-2-(2,2,2-trifluoroacetamido)acetyl]-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (1.3 g).

[0507] LCMS(ESI,m / z):[M+H] + =402.1

[0508] 8. Synthesis of Compound 9

[0509] Under a nitrogen atmosphere at 25°C, EDCI (0.7 g, 4.5 mmol, 1.5 eq.) and HOBt (0.6 g, 4.5 mmol, 1.5 eq.) were added in portions to N,N-dimethylformamide (10 mL) containing (2S)-2-amino-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (0.7 g, 2.9 mmol, 1.0 eq.). The resulting mixture was stirred at 25°C for 2 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, MeCN water (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector, UV 200 nm, yielding methyl(2S)-2-{[(1R,2S,5S)-6,6dimethyl-3-[2-(6-oxo-1H-pyridin-3-yl)-2-(2,2,2-trifluoroacetamido)acetyl]-3-azabicyclo[3.1.0]hexane-2-yl]formamido}-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (800 mg), as a yellow solid.

[0510] LCMS(ESI,m / z):[M+H] + =570.2

[0511] 9. Synthesis of Compound 10

[0512] Under nitrogen atmosphere and at 0°C, lithium borohydride (4.0 M in THF) (38 mg, 1.7 mmol, 2.0 eq.) was added dropwise to a mixture of (2S)-2-{[(1R,2S,5S)-6,6-dimethyl-3-[2-(6-oxo-1H-pyridin-3-yl)-2-(2,2,2-trifluoroacetamido)acetyl]-3-azabicyclo[3.1.0]hexan-2-yl]carbamate}-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (500 mg, 0.8 mmol, 1.0 eq.) in tetrahydrofuran (5 mL). The resulting mixture was stirred at 25°C for 2 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, MeCN water (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector, UV 200 nm, yielding a yellow solid of R,2S,5S)-n-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propane-2-yl]-6,6-dimethyl-3-[2-(6-oxo-1h-pyridin-3-yl)-2-(2,2,2-trifluoroacetamido)acetyl]-3-azacyclic[3.1.0]hexane-2-carboxamide (160 mg).

[0513] LCMS(ESI,m / z):[M+H] + =542.2

[0514] 10. Synthesis of compound C4-6

[0515] Under nitrogen atmosphere and at 0°C, sodium bicarbonate (65 mg, 0.8 mmol, 3.0 eq.) and Desmartin oxidant (219 mg, 0.5 mmol, 2.0 eq.) were added to dichloromethane (2 mL) containing (1R,2S,5S)-N-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidone-3-yl]propyl-2-yl]-6,6-dimethyl-3-[2-(6-oxo-1H-pyridin-3-yl)-2-(2,2,2-trifluoroacetamido)acetyl]-3-azabicyclo[3.1.0]hexane-2-carboxamide (140 mg, 0.3 mmol, 1.0 eq.) and acemartin oxidant (219 mg, 0.5 mmol, 2.0 eq.) in 140 mg, 0.3 mmol, 1.0 eq.) for 2 mL. The resulting mixture was stirred at 25°C for 2 hours. The crude product was purified by pre-high performance liquid chromatography (HPLC) under the following conditions (column: YMC Triart C18ExR): YMC Triart C18ExRs 5μm, 30mm*150mm; mobile phase A: water (10mmol / L NH4HCO3 + 0.1% NH4OH), mobile phase B: ACN; flow rate: 60mL / min; gradient: 0.1% NH4HCO3 + 0.1% NH4OH, 0.1% NH4HCO3 + 0.1% NH4OH. NH4OH: 60 mL / min; gradient (B%): wavelength: 200 / 220 nm; RT1 (min): 6.43; 7.24) yielded a white solid of (1R,2S,5S)-6,6-dimethyl-3-(2-(6-oxo-1,6-dihydropyridin-3-yl)-2-(2,2,2-trifluoroacetamido)acetyl)-n-((S)-1-oxo-3-(S)-2-oxopyridin-3-yl)propane-2-yl)-3-aza-heterocyclic [3.1.0]-2-carboxamide (2.1 mg).

[0516] LCMS(ESI,m / z):[M+H] + =540.2

[0517] 1 H NMR(400MHz,D2O)δ7.67–7.41(m,2H),6.60(d,J=8.9Hz,1H),5.49(d,J=7.2Hz,1H),4.57– 4.10(m,2H),4.03–3.11(m,5H),2.88–1.98(m,2H),1.96–1.12(m,4H),1.15–0.71(m,6H).

[0518] Example 23 Synthesis of compound C4-8

[0519] 1. Synthesize compound 2

[0520] Under nitrogen atmosphere and at 0°C, lithium borohydride (4.0 M in THF) (38 mg, 1.8 mmol, 2.0 eq.) was added to a stirred mixture of (2S)-2-{[(1R,2S,5S)-6,6-dimethyl-3-[2-(6-oxo-1H-pyridin-3-yl)-2-(2,2,2-trifluoroacetamido)acetyl]-3-azabicyclo[3.1.0]hexan-2-yl]carbamate}-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (500 mg, 0.9 mmol, 1.0 eq.) in tetrahydrofuran (5 mL). The resulting mixture was stirred at 25°C for 2 hours. The reaction mixture was then poured into water at 0°C. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN water (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector: UV 200 nm, yielding a white solid of (1R,2S,5S)-3-[2-amino-2-(6-oxo-1H-pyridin-3-yl)acetyl]-N-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamide (100 mg).

[0521] LCMS(ESI,m / z):[M+H] + =446.2

[0522] 2. Synthesize compound 3

[0523] Under a nitrogen atmosphere at 25°C, DIEA (69 mg, 0.5 mmol, 3.0 eq.) and HATU (102 mg, 0.3 mmol, 1.5 eq.) were added to a stirred mixture of (1R,2S,5S)-3-[2-amino-2-(6-oxo-1H-pyridin-3-yl)acetyl]-N-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamide (80 mg, 0.2 mmol, 1.0 eq.) and bicyclo[1.1.1]pentane-1-carboxylic acid (20 mg, 0.2 mmol, 1.0 eq.) in DMF (1 mL). The resulting mixture was stirred at 25°C for 2 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN water (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector: UV 200 nm. The result was (1R,2S,5S)-3-(2-(bicyclo[1.1.1]pentane-1-carboxamido)-2-(6-oxo-1,6-dihydropyridin-3-yl)acetyl)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamide (100 mg), a yellow solid.

[0524] LCMS(ESI,m / z):[M+H] + =540.2

[0525] 3. Synthesis of compound C4-8

[0526] Under a nitrogen atmosphere at 0°C, Dysmart oxidant (126 mg, 0.3 mmol, 3.0 eq.) was added in portions to a mixture of (1R,2S,5S)-3-(2-(bicyclo[1.1.1]pentane-1-carboxamido)-2-(6-oxo-1,6-dihydropyridin-3-yl)acetyl)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamide (80 mg, 0.1 mmol, 1.0 eq.) and sodium bicarbonate (37 mg, 0.3 mmol, 3.0 eq.) in dichloromethane (1 mL). The resulting mixture was stirred at 25°C for 2 hours. The crude product was purified by pre-high performance liquid chromatography (HPLC) under the following conditions (column: XSelect CSH Fluoro-HPLC): XSelect CSH Fluoro Phenyl 5 μm, 19*250 mm; mobile phase A: water (0.1% FA), mobile phase B: acetonitrile; flow rate: 25 mL / min; gradient (B%): 10% B to 25% B, 9 min; wavelength: 200 nm / 220 nm; RT1 (min): 8.42) yielded (1R,2S,5S)-3-(2-(bicyclo[1.1.1]pentane-1-carboxyl)-2-(6-oxy-1,6-dihydropyridin-3-yl)acetyl)-6,6-dimethyl-n-((S)-1-oxy-3-((S)-2-oxopyridin-3-yl)propane-2-azacyclo[3.1.0]hexane-2-carboxamide (16.5 mg) as a white solid.

[0527] LCMS(ESI,m / z):[M+H] + =438.2

[0528] 1 H NMR(400MHz,D2O)δ7.75–7.38(m,2H),6.80–6.46(m,1H),5.49–5.20(m,1H),4. 19(d,J=13.5Hz,1H),3.97–3.72(m,1H),3.67–3.44(m,1H),3.22(s,2H),2.82–2 .67(m,1H),2.35–2.18(m,1H),1.96–1.91(m,2H),1.90(s,3H),1.79–1.67(m,3 H),1.59–1.51(m,1H),1.52–1.40(m,2H),1.19–1.08(m,2H),0.96–0.79(m,6H).

[0529] Example 24 Synthesis of compound C4-11

[0530] 1. Synthesis of Compound 2

[0531] To a stirred solution of (2S)-2-[(tert-butoxycarbonyl)amino]-3-(1H-imidazol-4-yl)propionic acid (5.0 g, 19.6 mmol, 1.0 eq.) and (1R,2S,5S)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylate (4.0 g, 23.5 mmol, 1.2 eq.) in dichloromethane (50 mL), N,N-diisopropylethylamine (10.2 mL, 58.7 mmol, 3.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (11.2 g, 29.4 mmol, 1.5 eq.) were added. The resulting mixture was stirred at room temperature under nitrogen atmosphere for 1 hour. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L NH4HCO3), 33%–45% gradient, 10 min; detector: UV 200 nm. The final product was a white solid (1R,2S,5S)-3-[(2S)-2-[(tert-butoxycarbonyl)amino]-3-(1H-imidazol-4-yl)propionyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylate (5.3 g).

[0532] LCMS(ESI,m / z): [M+H] + =407.25

[0533] 2. Synthesis of Compound 3

[0534] Under air and at room temperature, benzyl bromide (1.0 g, 5.9 mmol, 1.1 eq.) and potassium carbonate (1.5 g, 10.8 mmol, 2.0 eq.) were added to a stirred solution of (1R,2S,5S)-3-[(2S)-2-[(tert-butyloxycarbonyl)amino]-3-(1H-imidazol-4-yl)propionyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylate (2.2 g, 5.4 mmol, 1.0 eq.) in N,N-dimethylformamide (20 mL). The resulting mixture was stirred under nitrogen at room temperature for 1.5 h. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. Methyl (1.0 g) of (1R,2S,5S)-3-[(2S)-3-(1-benzylimidazol-4-yl)-2-[(tert-butoxycarbonyl)amino]propionyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylate was obtained as a yellow oil.

[0535] LCMS(ESI,m / z): [M+H] + =497.20

[0536] 3. Synthesis of Compound 4

[0537] Under air, lithium hydroxide monohydrate (169 mg, 4.0 mmol, 2.0 eq.) was added to a stirred solution of (1R,2S,5S)-3-[(2S)-3-(1-benzylimidazol-4-yl)-2-[(tert-butoxycarbonyl)amino]propionyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylate (1.0 g, 2.0 mmol, 1.0 eq.) and water (5 mL) in tetrahydrofuran (5 mL). The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The mixture was acidified to pH 3 with concentrated hydrochloric acid. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were concentrated under reduced pressure. (1R,2S,5S)-3-[(2S)-3-(1-benzylimidazol-4-yl)-2-[(tert-butoxycarbonyl)amino]propionyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (900 mg) was obtained as a white solid.

[0538] LCMS(ESI,m / z): [M+H] + =483.24

[0539] 4. Synthesis of Compound 5

[0540] At room temperature and in an air atmosphere, N,N-diisopropylethylamine (0.7 mL, 3.9 mmol, 3.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (1.0 g, 2.6 mmol, 2.0 eq.) were added in portions to a stirred solution of (1R,2S,5S)-3-[(2S)-3-(1-benzylimidazol-4-yl)-2-[(tert-butoxycarbonyl)amino]propionyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxylic acid (450 mg, 1.3 mmol, 1.0 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidine-3-yl]propionate methyl hydrochloride (382 mg, 1.7 mmol, 1.3 eq.) in dichloromethane (6 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 1 hour. The mixture was then concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L ammonium bicarbonate), 30%–39% gradient, 10 min; detector: UV 200 nm. The result yielded (S)⁻²⁻((1R,2S,5S)⁻³⁻(N t -Benzyl-N a -(tert-butoxycarbonyl)-L-histyl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carbamoyl)-3-((S)-2-oxopyrrolidine-3-yl)methyl propionate (390 mg) is a white solid.

[0541] LCMS(ESI,m / z): [M+H] + =651.24

[0542] 5. Synthesis of Compound 6

[0543] Under room temperature and nitrogen atmosphere, the (S)-2-((1R,2S,5S)-3-(N) t -Benzyl-N a Methyl (-(tert-butoxycarbonyl)-L-histyl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamido)-3-((S)-2-oxopyrrolidone-3-yl)propionate (700 mg, 3.2 mmol, 1.0 eq.) was added to a 1,4-dioxane (5 mL) solution, followed by the addition of a 1,4-dioxane (4.0 M, 6 mL) solution of HCl. The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The mixture was then concentrated under reduced pressure to give a white solid (S)-2-((1R,2S,5S)-3-(N tBenzyl-L-histyl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carbamoyl)-3-((S)-2-oxopyrrolidine-3-yl)methyl propionate (600mg).

[0544] LCMS(ESI,m / z): [M+H] + =551.24

[0545] 6. Synthesis of Compound 7

[0546] At room temperature and in an air atmosphere, the (S)-2-((1R,2S,5S)-3-(N)- is stirred. t A solution of methyl benzyl-L-histyl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamido)-3-((S)-2-oxopyrrolidine-3-yl)propionate (450 mg, 1.3 mmol, 1.0 eq.) and bicyclo[1.1.1]pentane-1-carboxylic acid (382 mg, 1.7 mmol, 1.3 eq.) in dichloromethane (6 mL) was added in portions with N,N-diisopropylethylamine (0.7 mL, 3.9 mmol, 3.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (1.0 g, 2.6 mmol, 2.0 eq.). The resulting mixture was stirred at room temperature under nitrogen for 1 hour. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L ammonium bicarbonate), 30%-39% gradient, 10 min; detector: UV 200 nm. The result yielded (S)-2-((1R,2S,5S)-3-(N t Benzyl-Na-(bicyclo[1.1.1]pentane-1-formyl)-L-histyl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carbamate)-3-((S)-2-oxopyrrolidine-3-yl)methyl propionate (390 mg) is a white solid.

[0547] LCMS(ESI,m / z): [M+H] + =645.24

[0548] 7. Synthesis of Compound 8

[0549] Under nitrogen atmosphere and at room temperature, the (S)-2-((1R,2S,5S)-3-(N)- is stirred. t -Benzyl-N aSodium borohydride (117 mg, 3.1 mmol, 5.0 eq.) was added to a tetrahydrofuran (5 mL) solution of methyl methyl (390 mg, 0.5 mmol, 1.0 eq.) of hexane-2-carboxamido)-3-((S)-2-oxopyrrolidine-3-yl)propionate. The resulting mixture was stirred at room temperature under nitrogen atmosphere for 1 hour. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 40 mL). The combined organic layers were washed with brine (2 x 80 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration to give (1R,2S,5S)-3-(N t -Benzyl-N a -(bicyclo[1.1.1]pentane-1-formyl)-L-histyl)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)prop-2-yl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamide (300 mg) is a white solid.

[0550] LCMS(ESI,m / z): [M+H] + =617.24

[0551] 8. Synthesis of Compound 9

[0552] At room temperature, under a hydrogen atmosphere, (1R,2S,5S)-3-(N)- is stirred. t -Benzyl-N a -(bicyclo[1.1.1]pentane-1-formyl)-L-histyl)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamide (350 mg, 0.6 mmol, 1.0 eq.) was added to a solution of palladium hydroxide on carbon (797 mg, 20%) in acetic acid (3 mL). The resulting mixture was filtered, and the filter cake was washed with ethyl acetate (2 x 30 mL). The filtrate was concentrated under reduced pressure. Finally, a white solid (1R,2S,5S)-3-((bicyclo[1.1.1]pentane-1-formyl)-L-histyl)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamide (230 mg) was obtained.

[0553] LCMS(ESI,m / z): [M+H] + =527.24

[0554] 9. Synthesis of compound C4-11

[0555] At room temperature, in air, (1R,2S,5S)-3-((bicyclo[1.1.1]pentane-1-formyl)-L-histyl)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamide (150 mg, 0.2 mmol, 1.0 eq.) and sodium bicarbonate (52.4 mg, 0.6 mmol, 3.0 eq.) in dichloromethane (2 mL) were added with Dys-Martin oxidant (176 mg, 0.4 mmol, 2.0 eq.). The resulting mixture was stirred at room temperature for 2 hours under nitrogen atmosphere. The reaction was quenched at room temperature with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The crude product (80 mg) was purified by pre-high performance liquid chromatography under the following conditions: column: Xselect CSH C185, 5.5 mm × 4.5 mm, 5.5 mm × 4.5 mm; Xselect CSH C185 μm, 19 mm × 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 mL / min; gradient: from 30% B to 45% B over 10 minutes; wavelength: 254 nm / 220 nm. nm; RT1(min): 5.9), yielded (1R,2S,5S)-3-[(2S)-2-{bicyclo[1.1.1]pentan-1-ylcarbamoyl}{bicyclo[1.1.1]pentan-1-ylcarbamoyl}.-3-(1H-imidazol-4-yl)propionyl]-6,6-dimethyl-N-[(2S)-1-oxo-3-(3S)-2-oxopyrrolidine-3-yl]propane-3-azabicyclo[3.1.0]hexane-2-carbamoyl (5.4 mg) as a white solid.

[0556] LCMS(ESI,m / z):[M+H] + =525.30

[0557] 1H NMR(400MHz,D2O)δ8.45–8.34(m,1H),8.28–8.18(m,1H),7.13–7.00(m,1H),4.93(d,J=4.6Hz,1H) ,4.28–4.18(m,1H),3.91–3.81(m,1H),3.77–3.67(m,1H),3.55(d,J=10.8Hz,1H),3.36–3.20(m,2H ),3.07–2.88(m,2H),2.56–2.46(m,1H),2.40–2.31(m,1H),2.19–2.10(m,1H),2.02–1.81(m,7H), 1.81–1.72(m,1H),1.66–1.54(m,2H),1.42(d,J=7.6Hz,1H),1.02–0.92(m,3H),0.87–0.77(m,3H).

[0558] Example 25 Synthesis of compound C4-15

[0559] 1. Synthesis of Compound 2

[0560] At room temperature, lithium hydroxide monohydrate (349 mg, 8.4 mmol, 2.0 eq.) was added to a solution of ethyl 4-ethyl-3H-imidazolium-2-carboxylate (700 mg, 4.2 mmol, 1.0 eq.) and H₂O (4 mL) in air to a solution of 4 mL of tetrahydrofuran. The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The mixture was then concentrated under reduced pressure. The final product was 1.0 g of 4-ethyl-3H-imidazolium-2-carboxylic acid as a yellow solid.

[0561] LCMS(ESI,m / z): [M+H] + =141.25

[0562] 2. Synthesis of Compound 3

[0563] To a mixture of 4-ethyl-3H-imidazolium-2-carboxylic acid (700 mg, 5.0 mmol, 1.0 eq.) and (2S)-2-amino-4,4-dimethylvalerate methyl hydrochloride (1.2 g, 6.0 mmol, 1.2 eq.) in N,N-dimethylformamide (1 mL), N,N-diisopropylethylamine (2.6 mL, 15 mmol, 3.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (3.8 g, 10.0 mmol, 2.0 eq.) was added. The resulting mixture was stirred at room temperature under nitrogen for 1 hour. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L NH4HCO3), 50%–60% gradient, 10 min; detector, UV 200 nm. The final product was a yellow oily methyl (S)-2-(5-ethyl-1H-imidazol-2-carboxamido)-4,4-dimethylvalerate (500 mg).

[0564] LCMS(ESI,m / z): [M+H] + =282.20

[0565] 3. Synthesis of Compound 4

[0566] Under nitrogen atmosphere at 0°C, lithium hydroxide monohydrate (232 mg, 5.5 mmol, 3.0 eq.) was added to a stirred solution of (S)-2-(5-ethyl-1H-imidazol-2-carboxamido)-4,4-dimethylpentanoate (500 mg, 1.8 mmol, 1.0 eq.) and water (4 mL) in tetrahydrofuran (4 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 1.5 hours. The mixture was acidified to pH 2 with concentrated hydrochloric acid. The resulting mixture was concentrated under reduced pressure. Finally, (2S)-2-[(4-ethyl-3H-imidazol-2-yl)carboxamido]-4,4-dimethylpentanoic acid (750 mg) was obtained as a pale yellow solid.

[0567] LCMS(ESI,m / z): [M+H] + =268.24

[0568] 4. Synthesis of Compound 5

[0569] At room temperature and in an air atmosphere, N,N-diisopropylethylamine (1.1 mL, 5.6 mmol, 3.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (1.4 g, 3.7 mmol, 2.0 eq.) were added in portions to a stirred solution of (S)-2-(5-ethyl-1H-imidazol-2-carboxamido)-4,4-dimethylvaleric acid (500 mg, 1.9 mmol, 1.0 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidone-3-yl]propionate methyl hydrochloride (452 ​​mg, 1.4 mmol, 1.3 eq.) in dichloromethane (5 mL). The resulting mixture was stirred at room temperature under nitrogen atmosphere for 1 hour. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: acetonitrile in water (10 mmol / L ammonium bicarbonate), 30%-39% gradient, 10 min; detector: UV 200 nm. The result was methyl (S)-2-((S)-2-(5-ethyl-1H-imidazol-2-carboxamido)-4,4-dimethylpentamido)-3-((S)-2-oxopyrrolidine-3-yl)propionate (430 mg), a white solid.

[0570] LCMS(ESI,m / z): [M+H] + =436.24

[0571] 5. Synthesis of Compound 6

[0572] Sodium borohydride (34.7 mg, 0.9 mmol, 2.0 eq.) was added to a stirred methanol (3 mL) solution of methyl (S)-2-((S)-2-(5-ethyl-1H-imidazol-2-carboxamido)-4,4-dimethylpentamido)-3-((S)-2-oxopyrrolidine-3-yl)propionate (200 mg, 0.5 mmol, 1.0 eq.) in air at 0 °C. The resulting mixture was stirred at room temperature for 2 hours under nitrogen atmosphere. The reaction mixture was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with brine (2 x 100 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. 5-Ethyl-N-((S)-1-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)amino)-4,4-dimethyl-1-oxopyran-2-yl)-1H-imidazol-2-carboxamide (120 mg) was obtained as a white solid.

[0573] LCMS(ESI,m / z): [M+H] + =408.25

[0574] 6. Synthesis of compound C4-15

[0575] At room temperature, 5-ethyl-N-((S)-1-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)amino)-4,4-dimethyl-1-oxopyran-2-yl)-1H-imidazol-2-carboxamide (90 mg, 0.2 mmol, 2.0 eq.) and sodium bicarbonate (52.4 mg, 0.6 mmol, 3.0 eq.) were added to a solution of dichloromethane (5 mL). The resulting mixture was stirred at room temperature for 2 hours under nitrogen atmosphere. The reaction was quenched at room temperature with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The crude product (80 mg) was purified by high performance liquid chromatography under the following conditions (column: Xselect CSH C185, 5.5 mm × 4.5 mm, 5.5 mm × 4.5 mm; Xselect CSH C185 μm, 19 mm × 250 mm; mobile phase A: water (0.1% FA); mobile phase B: ACN; flow rate: 25 mL / min; gradient: from 30% B to 45% B over 10 minutes; wavelength: 200 nm / 220 nm; RT1 (min): 5.9), yielding N-((S)-4,4-dimethyl-1-oxo-1-(((S)-1-oxo-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)amino)pent-2-yl)-5-ethyl-1H-imidazol-2-carboxamide (12.7 mg), a white solid.

[0576] LCMS(ESI,m / z):[M+H] + =406.25

[0577] 1 H NMR(400MHz, CDCl3-d)δ9.56–9.48(m,1H),8.50–8.01(m,1H),6.95–6.89(m,1H ),6.51–6.42(m,1H),4.83–4.61(m,1H),4.50–4.39(m,1H),3.51–3.33(m,1H),2 .76–2.65(m,2H),2.51(d,J=7.9Hz,1H),2.40–2.28(m,1H),2.09–2.03(m,1H), 2.00–1.93(m,2H),1.90–1.73(m,2H),1.34–1.25(m,3H),1.00(d,J=5.0Hz,9H).

[0578] Example 26 Synthesis of compound C4-15A

[0579] Sodium bisulfite (0.5 mL) was added to a stirred solution of (2S)-2-[(4-ethyl-3H-imidazol-2-yl)carbamate]-4,4-dimethyl-N-[(2S)-1-oxo-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]pentanamide (100 mg, 0.2 mmol, 1.0 eq.) in N,N-dimethylformamide (0.5 mL). The resulting mixture was stirred in air at room temperature for 3 minutes. The resulting mixture was diluted with H2O (3 mL). The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The aqueous layer was concentrated under reduced pressure. The crude product (100 mg) was purified by pre-high performance liquid chromatography under the following conditions (column: XSelect CSH Fluoro-Phenyl-Phenyl-Phenyl-HPLC): XSelect CSH Fluoro Phenyl 5 μm, 19*250 mm; mobile phase A: water (0.1% FA), mobile phase B: acetonitrile; flow rate: 25 mL / min; gradient (B%): from 25% B to 35% B over 10 minutes; wavelength: 200 nm / 220 nm; RT1 (min): 6.73), yielding sodium (1R,2R)-2-[(2S)-2-[(4-ethyl-3H-imidazol-2-yl)carbamate]-4,4-dimethylpentamido]-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propane-1-sulfonate (4.0 mg), a light white solid.

[0580] LCMS(ESI,m / z):[M-Na] - =486.40

[0581] 1 H NMR(400MHz,D2O)δ7.38–7.22(m,1H),4.71–4.20(m,2H),4.10–3.40(m,1H),3.36–3.14(m,2H),2.90–2.7 1(m,2H),2.46–2.32(m,1H),2.30–1.90(m,2H),1.88–1.54(m,4H),1.45–1.10(m,3H),1.10–0.55(m,9H).

[0582] Example 27 Synthesis of compound C4-20

[0583] 1. Synthesis of Compound 2

[0584] Under nitrogen atmosphere and at 0°C, tert-butyl(chloro)diphenylsilane (914 mg, 3.3 mmol, 1.2 eq.) was added in portions to dichloromethane (5 mL) containing (480 mg, 2.7 mmol, 1.0 eq.) and imidazole (566 mg, 8.1 mmol, 3.0 eq.) under stirring. The resulting mixture was stirred at 25°C for 2 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, MeCN water (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector, UV 200 nm, yielding a yellow oily substance (S)-2-(((tert-butyldiphenylsiloxy)methyl)-5-oxopyrrolidine-2-carboxylate (960 mg).

[0585] LCMS(ESI,m / z):[M+H] + =412.1

[0586] 2. Synthesis of Compound 3

[0587] Under nitrogen atmosphere and at 25°C, lithium hydroxide (109 mg, 4.6 mmol, 2.0 eq.) was added to a stirred mixture of (S)-2-(((tert-butyldiphenylsilyl)oxy)methyl)-5-oxopyrrolidine-2-carboxylic acid (940 mg, 2.3 mmol, 1.0 eq.) in methanol (5 mL) and water (5 mL). The resulting mixture was stirred at 25°C for 2 hours. The mixture was concentrated under reduced pressure to give a white solid (2S)-2-{[(tert-butyldiphenylsilyl)oxy]methyl}-5-oxopyrrolidine-2-carboxylic acid (800 mg).

[0588] LCMS(ESI,m / z):[M+H] + =398.1

[0589] 3. Synthesis of Compound 4

[0590] Under nitrogen atmosphere and at 25°C, HATU (1.1 g, 2.9 mmol, 1.5 eq.) and DIEA (760 mg, 5.9 mmol, 3.0 eq.) were added to (2S)-2-{(tert-butyldiphenylsilyl)oxy]methyl}-5-oxopyridine-2-carboxylic acid (780 mg, 1.9 mmol, 1.0 eq.) and N,N-dimethylformamide (836 mg, 1.9 mmol, 1.0 eq.) at N,N-dimethylformamide (10 mL). The resulting mixture was stirred at 25°C for another 2 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN water (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector: UV 200 nm. Methyl (2S)-2-[(2S)-2-[(2S)-2-{[(2S)-2-{[(tert-butyldiphenylsilyl)oxy]methyl}-5-oxopyrrolidine-2-yl]carbamate}-3,3-dimethylbutamido]-4,4-dimethylpentamido]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (600 mg) was obtained as a white solid.

[0591] LCMS(ESI,m / z):[M+H] + =806.4

[0592] 4. Synthesize compound 5

[0593] Under nitrogen atmosphere and at 0°C, lithium borohydride (4.0 min THF) (27 mg, 1.2 mmol, 2.0 eq.) was added dropwise to a stirred mixture of (2S)-2-[(2S)-2-[(2S)-2-{[(2S)-2-{[(tert-butyldiphenylsilyl)oxy]methyl}-5-oxopyrrolidine-2-yl]formamido}-3,3-dimethylbutamido]-4,4-dimethylpentamido]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (500 mg, 0.6 mmol, 1.0 eq.) tetrahydrofuran (6 mL) with 0°C. The resulting mixture was stirred at 25°C for 2 hours. The reaction was quenched by adding water (10 mL) at 0°C. The resulting mixture was extracted with ethyl acetate (3 x 30 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to obtain (2S)-2-[(2S)-2-{[(2S)-2-{[(tert-butyldiphenylsilyl)oxy]methyl}-5-oxopyrrolidone-2-yl]formamido}-3,3-dimethylbutamido]-N-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidone-3-yl]propyl-2-yl]-4,4-dimethylpentanamide (300 mg), which is a white oily substance.

[0594] LCMS(ESI,m / z):[M+H] + =778.4

[0595] 5. Synthesize compound 6

[0596] Under nitrogen atmosphere and at 0°C, Dys-Martin oxidant (327 mg, 0.8 mmol, 2.0 eq.) was added in portions to a mixture of (2S)-2-[(2S)-2-{[(2S)-2-{[(tert-butyldiphenylsilyl)oxy]methyl}-5-oxopyrrolidine-2-yl]carbamate}-3,3-dimethylbutamido]-N-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]-4,4-dimethylpentanamide (300 mg, 0.4 mmol, 1.0 eq.) and ammonium bicarbonate (97 mg, 1.2 mmol, 3.0 eq.) in dichloromethane (5 mL). The resulting mixture was stirred at 25°C for 2 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN aqueous solution (0.1% FA), gradient of 10%-50% over 10 minutes; detector: UV 200 nm. The result was (2S)-2-[(2S)-2-{[(2S)-2-{[(tert-butyldiphenylsilyl)oxy]methyl}-5-oxopyrrolidone-2-yl]carbamate}-3,3-dimethylbutamido]-4,4-dimethyl-N-[(2S)-1-oxo-3-[(3S)-2-oxopyrrolidone-3-yl]propyl-2-yl]pentanamide (150 mg), a white solid.

[0597] LCMS(ESI,m / z):[M+H] + =776.4

[0598] 6. Synthesis of compound C4-20

[0599] Under nitrogen atmosphere and at 0°C, tetrabutylammonium fluoride (0.3 mL) was added dropwise to a mixture of (2S)-2-[(2S)-2-{[(2S)-2-{[(tert-butyldiphenylsilyl)oxy]methyl}-5-oxopyrrolidone-2-yl]carbamate}-3,3-dimethylbutamido]-4,4-dimethyl-N-[(2S)-1-oxo-3-[(3S)-2-oxopyrrolidone-3-yl]propyl-2-yl]pentanamide (110 mg, 0.1 mmol, 1.0 eq.) in tetrahydrofuran (1 mL). The resulting mixture was stirred at 0°C for 2 hours. The crude product was purified by pre-high performance liquid chromatography (HPLC) under the following conditions (column: XBridge BEH C18O18): XBridge BEH C18OBD pretreated column, 5 μm, 30 mm * 150 mm; mobile phase A: water (10 mmol / L NH4HCO3 + 0.1% NH4OH), mobile phase B: acetonitrile; flow rate: 60 mL / min; gradient HPLC column (10 mmol / L NH4HCO3 + 0.1% NH4OH). NH4OH), flow rate: 60 mL / min; gradient (B%): wavelength: 200 / 220 nm; RT1 (min): 5.88), yielded (2S)-2-[(2S)-2-{[(2S)-2-(hydroxymethyl)-5-oxopyrrolidine-2-yl]carbamate}-3,3-dimethylbutyramido]-4,4-dimethyl-N-[(2S)-1-oxo-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]pentanamide (3.9 mg), a white solid.

[0600] LCMS(ESI,m / z):[M+H] + =538.3

[0601] 1 H NMR(400MHz,D2O)δ4.37(d,J=8.2Hz,1H),4.28–4.15(m,1H),3.83(d,J=11.7Hz,1H),3.62(d,J=11.7Hz,2H),3.3 7–3.17(m,2H),2.37-2.15(m,3H),2.15-2.08(m,3H),1.92–1.70(m,2H),1.69–1.52(m,3H),0.99–0.72(m,18H).

[0602] Example 28 Synthesis of compound C4-21

[0603] 1. Synthesis of Compound 2

[0604] To a stirred solution of (S)-2-((S)-2-((S)-2-amino-3,3-dimethylbutanoamino)-4,4-dimethylpentanoamino)-3-((S)-2-oxopyrrolidone-3-yl)propionate (500 mg, 1.4 mmol, 1.0 eq.) and bicyclo[1.1.1]pentane-1-carboxylic acid (157 mg, 1.4 mmol, 1.0 eq.) in N,N-dimethylformamide (6 mL), N,N-diisopropylethylamine (0.5 mL, 2.8 mmol, 2.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (802 mg, 2.1 mmol, 1.5 eq.) was added. The resulting mixture was stirred at room temperature under nitrogen for 1 hour. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN in water (10 mmol / L NH4HCO3), 35%-44% gradient, 10 min; detector: UV 200 nm. The result was methyl propionate (200 mg) of (S)-2-((S)-2-((S)-2-(bicyclo[1.1.1]pentane-1-carboxamido)-3,3-dimethylbutyramido)-4,4-dimethylpentamido)-3-((S)-2-oxopyrrolidine-3-yl)propionate as a white solid.

[0605] LCMS(ESI,m / z): [M+H] + =606.34

[0606] 2. Synthesis of Compound 3

[0607] Under nitrogen atmosphere and at room temperature, lithium borohydride (4.0 M in tetrahydrofuran) (0.4 mL, 1.5 mmol, 2.0 eq.) was added to a stirred solution of methyl (200 mg, 0.2 mmol, 1.0 eq.) of (S)-2-((S)-2-((S)-2-(3-(bicyclo[1.1.1]pentan-1-yl)ureo)-3,3-dimethylbutylamino)-4,4-dimethylpentanamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (3 mL) in tetrahydrofuran (4 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 1 hour. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 40 mL). The combined organic layers were washed with brine (2 x 80 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. (S)-2-((S)-2-(3-(bicyclo[1.1.1]pentan-1-yl)ureo)-3,3-dimethylbutanamino)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)-4,4-dimethylpentanamide (100 mg) was obtained as a white solid.

[0608] LCMS(ESI,m / z): [M+H] + =578.24

[0609] 3. Synthesis of compound C4-21

[0610] At room temperature and in air, a solution of (S)-2-((S)-2-(3-(bicyclo[1.1.1]pentan-1-yl)ureo)-3,3-dimethylbutanoyl)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)-4,4-dimethylpentanamide (100 mg, 0.2 mmol, 1.0 eq.) and sodium bicarbonate (52.4 mg, 0.6 mmol, 3.0 eq.) in dichloromethane (2 mL) was added, and the resulting mixture was stirred at room temperature for 2 hours under nitrogen atmosphere. The reaction was quenched at room temperature with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The crude product (80 mg) was purified by pre-high performance liquid chromatography under the following conditions: column: Xselect CSH C185, 5.5 mm × 4.5 mm, 5.5 mm × 4.5 mm; Xselect CSH C185 μm, 19 mm × 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 mL / min; gradient: from 30% B to 45% B over 10 minutes; wavelength: 200 nm / 220 nm. nm; RT1(min): 5.9), yielded (S)-2-((S)-2-(3-(bicyclo[1.1.1]pentan-1-yl)ureo)-3,3-dimethylbutano)-4,4-dimethyl-N-((S)-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)prop-2-yl)pentanamide (19.7 mg) as a white solid.

[0611] LCMS(ESI,m / z):[M+H] + =576.35

[0612] 1H NMR(400MHz,D2O)δ4.93–4.88(m,1H),4.41–4.35(m,1H),4.31(d,J=2.0Hz,1H),3.84–3.77(m,1H),3.35–3.28(m,1H),3.33–3. 12(m,1H),2.71–2.62(m,1H),2.59–2.29(m,4H),2.22–2.13(m,1H),1.90–1.72(m,2H),1.68–1.53(m,3H),0.98–0.79(m,18H).

[0613] Example 29 Synthesis of compound C4-21A

[0614] Sodium bisulfite (0.5 mL) was added to a stirred solution of N-((S)-1-(((S)-4,4-dimethyl-1-oxo-1-(((S)-1-oxo-3-((S)-2-(2-amino-3-oxopyrrolidinepropan-2-yl)amino)pentan-2-yl)amino)-3,3-dimethyl-1-oxobutan-2-yl)-5-oxo-2-(trifluoromethyl)pyrrolidine-2-carboxamide (100 mg, 0.2 mmol, 1.0 eq.) in N,N-dimethylformamide (0.5 mL). The resulting mixture was stirred in air at room temperature for 3 minutes. The resulting mixture was diluted with H2O (3 mL). The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The aqueous layer was concentrated under reduced pressure. The crude product (100 mg) was purified by pre-high performance liquid chromatography under the following conditions (column: XSelect CSH). Fluoro-Phenyl-Phenyl-Phenyl-HPLC: XSelect CSH Fluoro Phenyl 5μm, 19*250mm; Mobile phase A: water (0.1% FA), Mobile phase B: acetonitrile; Flow rate: 25mL / min; Gradient (B%): from 25% B to 35% B over 10 minutes; Wavelength: 200nm / 220nm; RT1 (min): 6.73, yielding (1R,2R)-2-((2S)-2-((2S)-3,3-dimethyl-2-(5-oxo-2-trifluoromethyl)pyrrolidine-2-carboxamido)butamido)-4,4-dimethylpentanamino)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propane-1-sulfonate sodium salt (19.6mg), a light white solid.

[0615] LCMS(ESI,m / z):[M-Na] - =656.35

[0616] 1H NMR(400MHz,D2O)δ4.41–4.28(m,3H),3.36–3.19(m,2H),2.71–2.61(m,1H),2.59–2.39(m,3H),2.37–2.30(m,1H), 2.23–2.11(m,1H),1.92(s,1H),1.89–1.71(m,2H),1.67–1.52(m,3H),0.89(d,J=2.8Hz,9H),0.83(d,J=3.0Hz,9H).

[0617] Example 30 Synthesis of compound C4-23

[0618] 1. Synthesis of Compound 2

[0619] In a tetrahydrofuran (6 mL) solution of (2S)-2-[(2S)-2-[(2S)-2-amino-3,3-dimethylbutanoamino]-4,4-dimethylpentanoamino]-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (500 mg, 1.2 mmol, 1.0 eq.) and bicyclo[1.1.1]pentane-1-amine (77.9 mg, 0.9 mmol, 0.8 eq.), N,N'-carbonyldiimidazole (190 mg, 1.2 mmol, 1.0 eq.) was added. The resulting mixture was stirred at room temperature under nitrogen atmosphere for 2 hours. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN in water (10 mmol / L NH4HCO3), 30%-40% gradient, 10 min; detector: UV 200 nm. Methyl (S)-2-((S)-2-((S)-2-(3-(bicyclo[1.1.1]pentan-1-yl)ureo)-3,3-dimethylbutanamino)-4,4-dimethylpentanamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (130 mg), white solid.

[0620] LCMS(ESI,m / z): [M+H] + =536.24

[0621] 2. Synthesis of Compound 3

[0622] Under nitrogen atmosphere and at room temperature, lithium borohydride (4.0 M in tetrahydrofuran) (0.2 mL, 1.5 mmol, 2.0 eq.) was added to a stirred solution of methyl (S)-2-((S)-2-((S)-2-(3-(bicyclo[1.1.1]pentan-1-yl)ureo)-3,3-dimethylbutano)-4,4-dimethylpentano)-3-((S)-2-oxopyrrolidine-3-yl)propionate (120 mg, 0.2 mmol, 1.0 eq.) in 5 mL of tetrahydrofuran (2 mL). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 1 hour. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 40 mL). The combined organic layers were washed with brine (2 x 80 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. (S)-2-((S)-2-(3-(bicyclo[1.1.1]pentan-1-yl)ureo)-3,3-dimethylbutanamino)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)-4,4-dimethylpentanamide (100 mg) was obtained as a white solid.

[0623] LCMS(ESI,m / z): [M+H] + =508.24

[0624] 3. Synthesis of compound C4-23

[0625] At room temperature and in air, a solution of (S)-2-((S)-2-(3-(bicyclo[1.1.1]pentan-1-yl)ureo)-3,3-dimethylbutanoyl)-N-((S)-1-hydroxy-3-((S)-2-oxopyrrolidone-3-yl)propyl-2-yl)-4,4-dimethylpentanamide (100 mg, 0.2 mmol, 1.0 eq.) and sodium bicarbonate (52.4 mg, 0.6 mmol, 3.0 eq.) in dichloromethane (2 mL) was added, and the resulting mixture was stirred at room temperature for 2 hours under nitrogen atmosphere. The reaction was quenched at room temperature with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate is concentrated under reduced pressure. The crude product (80 mg) was purified by high performance liquid chromatography under the following conditions (column: Xselect CSH C185, 5.5 mm × 4.5 mm, 5.5 mm × 4.5 mm; Xselect CSH C185 μm, 19 mm × 250 mm; mobile phase A: water (0.1% FA); mobile phase B: ACN; flow rate: 25 mL / min; gradient: from 30% B to 45% B over 10 minutes; wavelength: 200 nm / 220 nm; RT1 (min): 5.9), yielding (S)-2-((S)-2-(3-(bicyclo[1.1.1]pentan-1-yl)ureo)-3,3-dimethylbutanamino)-4,4-dimethyl-N-((S)-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)prop-2-yl)pentanamide (6.6 mg), a white solid.

[0626] LCMS(ESI,m / z):[M+H] + =506.40

[0627] 1H NMR (400MHz, CDCl3-d) δ9.60–9.47(m,1H),8.03(d,J=12.4Hz,1H),7.18–7.00(m,1H),6.40–6.19(m,1H),5.65–5.41(m,1H),4.50–4.52(m 2H),4.19–4.00(m,1H),3.46–3.32(m,2H),2.47(d,J=3.0Hz,3H),2.06(d,J=5.2Hz,6H),1.97–1.82(m,3H),1.59–1.50(m,2H),1.25–1.18(m 1H),1.08(d,J=4.0Hz,2H),1.06–1.00(m,7H),0.97(d,J=2.6Hz,9H)

[0628] Example 31 Synthesis of compound C4-24

[0629] 1. Synthesis of Compound 2

[0630] Leucine methyl ester hydrochloride (2.0 g, 11.0 mmol, 1.0 eq.) and (2S)-2-[(tert-butoxycarbonyl)amino]-3,3-dimethylbutyric acid (2.6 g, 11.0 mmol, 1.0 eq.) were stirred in dichloromethane (20 mL) with N,N-diisopropylethylamine (4.3 g, 33.0 mmol, 3.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (6.3 g, 16.5 mmol, 1.5 eq.). The resulting mixture was stirred at room temperature under nitrogen for 1 hour. The mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, acetonitrile in water (10 mmol / L NH4HCO3), 33%–45% gradient, 10 min; detector, UV 200 nm. Finally, a white solid (S)-2-((S)-2-((tert-butoxycarbonyl)amino)-3,3-dimethylbutamino)-4,4-dimethylvalerate methyl ester (2.2 g) was obtained.

[0631] LCMS(ESI,m / z): [M+H] + =373.25

[0632] 2. Synthesis of Compound 3

[0633] Under nitrogen atmosphere, at room temperature, water (6 ml) and lithium hydroxide monohydrate (281 mg, 6.7 mmol, 2.0 eq.) were added to a stirred solution of (2S)-2-[(2S)-2-[(tert-butyloxycarbonyl)amino)-3,3-dimethylbutylamino)-4-methylvalerate methyl ester (1.2 g, 3.3 mmol, 1 eq.) in tetrahydrofuran (6 ml). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 1.5 h. The reactants were quenched with water at room temperature, the mixture was acidified to pH 3 with concentrated hydrochloric acid, and the mixture was extracted with ethyl acetate (2 x 20 ml) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to give (S)-2-((S)-2-((tert-butyloxycarbonyl)amino)-3,3-dimethylbutylamino)-4,4-dimethylvalerate (1.1 g) as a white solid.

[0634] LCMS(ESI,m / z): [M+H] + =359.20

[0635] 3. Synthesis of Compound 4

[0636] At room temperature and in an air atmosphere, N,N-diisopropylethylamine (5.4 ml, 30.7 mmol, 1.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (5.8 g, 15.4 mmol, 1.5 eq.) were added in portions to a stirred solution of (2S)-2-[(2S)-2-[(3S)-2-oxopyrrolidone-3-yl]propionate (12.5 mg, 0.1 mmol, 1.2 eq.) in dichloromethane (30 ml). The resulting mixture was stirred in a nitrogen atmosphere at room temperature for 1 hour. The resulting mixture was then concentrated under reduced pressure. The residue was purified by reversed-phase chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN in water (10 mmol / L NH4HCO3), gradient 45%-53% over 10 minutes; detector: UV 200 nm. The final product was a white solid (6S,9S,12S)-6-(tert-butyl)-2,2-dimethyl-9-neopentyl-4,7,10-trioxo-12-(((S)-2-oxopyrrolidine-3-yl)methyl)-3-oxa-5,8,11-triazatridecane-13-olate (3.3 g).

[0637] LCMS(ESI,m / z): [M+H] + =527.24

[0638] 4. Synthesis of Compound 5

[0639] At room temperature, 1,4-dioxane (4.0 M, 20 mL) of HCl was added to a stirred solution of methyl (6S,9S,12S)-6-(tert-butyl)-2,2-dimethyl-9-neopentyl-4,7,10-trioxo-12-(((S)-2-oxopyrrolidine-3-yl)methyl)-3-oxa-5,8,11-triazatridecane-13-oate in air. The resulting mixture was stirred at room temperature under nitrogen for 2 hours. The mixture was then concentrated under reduced pressure to give methyl (S)-2-((S)-2-((S)-2-amino-3,3-dimethylbutanamino)-4,4-dimethylpentanamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (450 mg) as a white solid.

[0640] LCMS(ESI,m / z): [M+H] + =427.24

[0641] 5. Synthesis of Compound 6

[0642] To a stirred solution of methyl (S)-2-((S)-2-((S)-2-amino-3,3-dimethylbutanoamino)-4,4-dimethylpentanoamino)-3-((S)-2-oxopyrrolidine-3-yl)propionate (600 mg, 1.4 mmol, 1.0 eq.) and bicyclo[1.1.1]pentane-1-carboxylic acid (157.7 mg, 1.4 mmol, 1.0 eq.) in dichloromethane (6 mL), N,N-diisopropylethylamine (0.5 mL, 2.8 mmol, 2.0 eq.) and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (802 mg, 2.1 mmol, 1.5 eq.) were added. The resulting mixture was stirred at room temperature under nitrogen for 1 hour. The resulting mixture was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN in water (10 mmol / L NH4HCO3), 35%-44% gradient, 10 min; detector: UV 200 nm. The result was methyl (S)-2-((S)-2-((S)-2-(bicyclo[1.1.1]pentane-1-carbamate)-3,3-dimethylbutyramido)-4,4-dimethylpentamido)-3-((S)-2-oxopyrrolidine-3-yl)propionate (380 mg), a white solid.

[0643] LCMS(ESI,m / z): [M+H] + =521.24

[0644] 6. Synthesis of Compound 7

[0645] Under nitrogen atmosphere and at room temperature, lithium borohydride (4.0 M in tetrahydrofuran) (0.4 mL, 1.5 mmol, 2.0 eq.) was added to a stirred solution of methyl (390 mg, 0.5 mmol, 1.0 eq.) of (S)-2-((S)-2-((S)-2-(bicyclo[1.1.1]pentane-1-carbamoyl)-3,3-dimethylbutamido)-4,4-dimethylpentamido)-3-((S)-2-oxopyrrolidine-3-yl)propionate (390 mg, 0.5 mmol, 1.0 eq.) in 5 mL of tetrahydrofuran (4.0 M in tetrahydrofuran). The resulting mixture was stirred under nitrogen atmosphere at room temperature for 1 hour. The reaction was quenched with water at room temperature. The resulting mixture was extracted with ethyl acetate (2 x 40 mL). The combined organic layers were washed with brine (2 x 80 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure after filtration. N-((S)-1-(((S)-1-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)amino)-4,4-dimethyl-1-oxopent-2-yl)amino)-3,3-dimethyl-1-oxobut-2-yl)bicyclo[1.1.1]pentane-1-carboxamide (300 mg) was obtained as a white solid.

[0646] LCMS(ESI,m / z): [M+H] + =493.24

[0647] 7. Synthesis of compound C4-24

[0648] At room temperature, in a solution of N-((S)-1-(((S)-1-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)amino)-4,4-dimethyl-1-oxopent-2-yl)amino)-3,3-dimethyl-1-oxobut-2-yl)bicyclo[1.1.1]pentane-1-carboxamide (300 mg, 0.2 mmol, 1.0 eq.) and sodium bicarbonate (92.4 mg, 0.6 mmol, 3.0 eq.) in dichloromethane (5 mL), Dysmart oxidant (276.5 mg, 0.4 mmol, 2.0 eq.) was added. The resulting mixture was stirred at room temperature for 2 hours under nitrogen atmosphere. The reaction was quenched at room temperature with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The crude product (80 mg) was purified by pre-HPLC under the following conditions: column: Xselect CSH C185, 5.5 mm × 4.5 mm, 5.5 mm × 4.5 mm; Xselect CSH C185 μm, 19 mm × 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 mL / min; gradient: from 30% B to 45% B over 10 minutes; wavelength: 200 nm / 220 nm. nm; RT1(min): 5.9), yielded N-((S)-1-(((S)-4,4-dimethyl-1-oxo-1-(((S)-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)amino)pent-2-yl)amino)-3,3-dimethyl-1-oxobut-2-yl)bicyclo[1.1.1]pentane-1-carboxamide (28.0 mg), a white solid.

[0649] LCMS(ESI,m / z):[M+H] + =491.35

[0650] 1H NMR (400MHz, CDCl3-d) δ9.55–9.49(m,1H),7.92(d,J=7.2Hz,1H),7.49(d,J=9. 0Hz,1H),7.04–6.95(m,1H),6.14(d,J=9.8Hz,1H),4.72–4.63(m,1H),4.60–4.4 9(m,1H),4.27(d,J=9.8Hz,1H),3.48–3.37(m,2H),2.48(m,3H),2.07–2.05(m,6 H),1.97–1.86(m,4H),1.53–1.46(m,1H),1.03–0.99(m,9H),0.96–0.93(m,9H).

[0651] Example 32 Compound C4-24-1

[0652] At room temperature, in a solution of N-((R)-1-(((S)-1-(((S)-1-hydroxy-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)amino)-4,4-dimethyl-1-oxopent-2-yl)amino)-3,3-dimethyl-1-oxobut-2-yl)bicyclo[1.1.1]pentane-1-carboxamide (300 mg, 0.4 mmol, 2.0 eq.) and sodium bicarbonate (92.4 mg, 0.6 mmol, 3.0 eq.) in dichloromethane (5 mL), Dysmart oxidant (276.5 mg, 0.4 mmol, 2.0 eq.) was added. The resulting mixture was stirred at room temperature for 2 hours under nitrogen atmosphere. The reaction was quenched at room temperature with saturated sodium thiosulfate and saturated sodium carbonate solutions. The resulting mixture was extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine (2 x 40 ml) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The crude product (80 mg) was purified by pre-HPLC under the following conditions: column: Xselect CSH C185, 5.5 mm × 4.5 mm, 5.5 mm × 4.5 mm; Xselect CSH C185 μm, 19 mm × 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 ml / min; gradient: from 30% B to 45% B over 10 minutes; wavelength: 254 nm / 220 nm. nm; RT1(min): 5.9), yielded N-((R)-1-(((S)-4,4-dimethyl-1-oxo-1-(((S)-1-oxo-3-((S)-2-oxopyrrolidine-3-yl)propyl-2-yl)amino)pent-2-yl)amino)-3,3-dimethyl-1-oxobut-2-yl)bicyclo[1.1.1]pentane-1-carboxamide (9.6 mg), a white solid.

[0653] LCMS(ESI,m / z):[M+H] + =491.30

[0654] 1H NMR(400MHz, CDCl3-d)δ9.55–9.49(m,1H),8.04(d,J=5.0Hz,1H),7.11–7.00(m,1 H),6.61–6.53(m,1H),6.13(d,J=9.6Hz,1H),4.62(d,J=9.0Hz,1H),4.46(s,1H), 4.26(d,J=9.7Hz,1H),3.42(d,J=8.8Hz,2H),2.49(d,J=9.4Hz,3H),2.12–2.05(m ,6H),1.98–1.84(m,4H),1.53–1.45(m,1H),1.07–0.99(m,9H),0.98–0.91(m,9H).

[0655] Example 33 Synthesis of compound C4-25

[0656] 1. Synthesize compound 2

[0657] Under nitrogen atmosphere and at 25°C, methyl (2S)-2-[(2S)-2-[(2S)-2-amino-3,3-dimethylbutanoamino]-4,4-dimethylpentanoamino]-3-[(3S)-2-oxopyrrolidone-3-yl]propionate (500 mg, 1.2 mmol, 1.0 eq.) and 2-oxabicyclo[2.1.1]hexane-4-carboxylic acid (180.2 mg, 1.4 mmol, 1.2 eq.) were added in portions to DIEA (455 mg, 3.5 mmol, 3.0 eq.) and HATU (669 mg, 1.8 mmol, 1.5 eq.) in DMF at 25°C. The resulting mixture was stirred at 25°C for 2 hours. The crude product was purified by high performance liquid chromatography under the following conditions (column: Xselect CSH C185): Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 mL / min; gradient: 45% B to 65% B, 10 min; wavelength: 200 nm / 220 nm; RT1 (min): 5.65), yielding methyl (2R)-2-[(2R)-2-[(2R)-3,3-dimethyl-2-[(4r)-2-oxabicyclo[2.1.1]hex-4-ylformamido]butamido]-4,4-dimethylpentamido]-3-[(3R)-2-oxopyrrolidone-3-yl]propionate (390 mg), which was a yellow oil.

[0658] LCMS(ESI,m / z):[M+H] + =537.6

[0659] 2. Synthesize compound 3

[0660] Under nitrogen atmosphere and at 0°C, lithium borohydride (4.0 M in THF) (30 mg, 1.4 mmol, 2.0 eq.) was added dropwise to a mixture of (2R)-2-[(2R)-2-[(2R)-3,3-dimethyl-2-[(4r)-2-oxabicyclo[2.1.1]hexane-4-ylformamido]butamido]-4,4-dimethylpentamido]-3-[(3R)-2-oxopyrrolidone-3-yl]propionate (370 mg, 0.7 mmol, 1.0 eq.) in 5 mL of THF. The resulting mixture was stirred at 25°C for 2 hours. The reaction was quenched with water (20 mL). The resulting mixture was extracted with ethyl acetate (3 x 30 mL). The combined organic layers were dried over anhydrous ammonium sulfate. After filtration, the filtrate was concentrated under reduced pressure to obtain (2S)-2-[(2S)-3,3-dimethyl-2-[(4r)-2-oxabicyclo[2.1.1]hexane-4-ylformamido]butyrylamino]-N-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]-4,4-dimethylpentanamide (260 mg, crude), which is a white solid.

[0661] LCMS(ESI,m / z):[M+H] + =509.6

[0662] 3. Synthesis of compound C4-25

[0663] Under nitrogen atmosphere and at 0°C, Dysmart oxidant (400 mg, 0.9 mmol, 2.0 eq.) was added in portions to a mixture of (2S)-2-[(2S)-3,3-dimethyl-2-[(4r)-2-oxabicyclo[2.1.1]hexane-4-ylformamido]butamido]-N-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]-4,4-dimethylpentanamide (240 mg, 0.5 mmol, 1.0 eq.) and sodium bicarbonate (159 mg, 1.9 mmol, 4.0 eq.) in dichloromethane (5 mL). The resulting mixture was stirred at 25°C for 2 hours. The crude product was purified by high performance liquid chromatography under the following conditions (column: Xselect CSH C185): Xselect CSH C185 μm, 19 mm X 250 mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25 mL / min; gradient: 20% B to 30% B, 10 min; wavelength: 200 nm / 220 nm; RT1 (min): 6.5), yielding (2S)-2-[(2S)-3,3-dimethyl-2-[(1r,4r)-2-oxabicyclo[2.1.1]hexane-4-ylformamido]butamido]-4,4-dimethyl-N-[(2S)-1-oxo-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]pentanamide (16.2 mg), a white solid.

[0664] LCMS(ESI,m / z):[M+H] + =507.6

[0665] 1 H NMR (400MHz, CDCl3-d) δ9.53(s,1H),8.01(d,J=7.2Hz,1H),7.53(d,J=9.0Hz,1H),6.93(s,1 H),6.34(d,J=9.7Hz,1H),4.67(d,J=9.1Hz,1H),4.56–4.50(m,2H),4.38(d,J=9.8Hz,1H),3. 85(s,2H),3.41(d,J=9.2Hz,2H),2.51–2.36(m,2H),2.04-2.01(m,2H),1.93(d,J=7.8Hz,1H ),1.92–1.85(m,4H),1.84(d,J=3.2Hz,1H),1.51(d,J=9.2Hz,1H),1.01(s,9H),0.95(s,9H).

[0666] Example 34 Synthesis of compound C4-25A

[0667] 1. Synthesis of Compound 2

[0668] Under a nitrogen atmosphere at 25°C, (2S)-2-[(2S)-3,3-dimethyl-2-[(2S)-2,3-dimethyl-2-[(2S)-1-hydroxy-3-[(3S)-2-oxopyridin-3-acyl]butane]-n-[(2S)-1-hydroxy-3-[(3S)-2-oxopyridin-3-acyl]propane-2-acyl]-4,4-dimethylpentanamide (100 mg, 0.2 mmol, 1.0 eq.) and sodium bicarbonate (66 mg, 0.8 mmol, 4.0 eq.) were dissolved in dichloromethane (5 mL), and Dysmartin oxidant (417 mg, 1.0 mmol, 5.0 eq.) was added fractionally with stirring. The resulting mixture was stirred at 25°C for another 2 hours. The resulting mixture was extracted with ethyl acetate (20 mL). The combined organic layer was washed with deionized water (3 × 20 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure to give (2S)-2-[(2S)-3,3-dimethyl-2-[(4r)-2-sapiocyclo[2.1.1]hexen-4-acylmethylamine]butanamine]-4,4-dimethyl-n-[(2S)-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propen-2-yl]pentaamide (50 mg).

[0669] LCMS(ESI,m / z):[M+H] + =507.23

[0670] 2. Synthesis of compound C4-25A

[0671] Sodium bisulfite (41 mg, 0.4 mmol, 5.0 eq.) was added to a stirred solution of (2S)-2-[(2S)-3,3-dimethyl-2-[(2S)-2,3-dimethyl-2-[(4r)-2-sapiocyclo[2.1.1]hexane-4-acylmethylamine]butane]-4,4-dimethyl-n-[(2S)-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propyl-2-yl]pentaamide (40 mg, 0.08 mmol, 1.0 eq.) in DMF (1 mL) at 25 °C. The resulting mixture was stirred at 25 °C for another 2 minutes. The resulting mixture was extracted with ethyl acetate (3 × 20 mL). The bound organic layer was washed with deionized water (3 × 20 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure. Preparation - Purification of crude product by high performance liquid chromatography (HPLC): Column: Xselect CSH C185μm, 19mm X 250mm; Mobile phase A: water (0.1% formic acid), Mobile phase B: acetonitrile; Flow rate: 25mL / min; Gradient (B%): 25% B ~ 40% B, 8min; Wavelength: 200nm / 220nm; RT1 (min): 6.86) yielded sodium (11.2mg) of (1S,2S)-2-[(2S)-2-[(2S)-3,3-dimethyl-2-[(4r)-2-sapiocyclo[2.1.1]hexane-4-methylamino]butamine]-4,4-dimethylpentamine]-1-hydroxy-3-[(3S)-2-oxopyridin-3-yl]propane-1-sulfonate.

[0672] LCMS(ESI,m / z):[M-Na] - =587.23

[0673] 1 H NMR(400MHz,D2O)δ5.11–4.78(m,2H),4.57(s,3H),4.53–4.11(m,2H),3.80(s,2H),3.62–3.07(m,2H) ,2.51–2.28(m,1H),2.13(d,J=5.3Hz,2H),1.99–1.70(m,3H),1.65–1.42(m,3H),0.99–0.76(m,18H).

[0674] Example 35 Synthesis of compound C4-26

[0675] 1. Synthesis of Compound 2

[0676] Methyl (2S)-2-[(2S)-2-[(2S)-2-[(2S)-2-amino-3,3-dimethylbutylamine]-4,4-dimethylpentylamine]-3-[(3S)-2-oxopyridin-3-yl]propionate (500 mg, 1.2 mmol, 1.0 eq.) and 3,3,3-trifluoropropionic acid (225 mg, 1.8 mmol, 1.5 eq.) were stirred in N,N-dimethylformamide (5 mL) until homogeneous. N,N-diisopropylethylamine (454 mg, 3.5 mmol, 3.0 eq.) was added dropwise at room temperature. After 2 min, the mixture was aliquoted with HATU (668 mg, 1.7 mmol, 1.5 eq.). The resulting mixture was stirred at room temperature for another 2 hours. The mixture was filtered, and the filter cake was washed with acetonitrile (3 x 5 mL). The filtrate was concentrated under reduced pressure. Purification was performed by reversed-phase flash chromatography under the following conditions: C18 silica gel column; mobile phase: acetonitrile in water (0.1% formic acid solution), gradient 10%–50%, for 10 min; UV detector: 200 nm. Methyl(2S)-2-[(2S)-2-[(2S)-3,3-dimethyl-2-(3,3,3-trifluoropropylamine)butylamine]-4,4-dimethylpentylamine]-3-[(3S)-2-oxopyridin-3-yl]propionate (430 mg) was obtained as a light brown solid.

[0677] LCMS(ESI,m / z): [M+H] + =536.28

[0678] 2. Synthesis of Compound 3

[0679] Sodium borohydride (176 mg, 4.7 mmol, 5.0 eq.) was added to a stirred solution of methyl (2S)-2-[(2S)-2-[(2S)-2-[(2S)-3,3-dimethyl-2-(3,3,3-trifluoropropylamine)butylamine]-4,4-dimethylpentylamine]-3-[(3S)-2-oxopyridin-3-yl]propionate (500 mg, 0.9 mmol, 1.0 eq.) in 7 mL of methanol under nitrogen atmosphere at 0 °C. The resulting mixture was stirred for another 2 hours at room temperature. The reaction was quenched with water at 0 °C. The resulting mixture was concentrated under reduced pressure. It was purified by reversed-phase flash chromatography under the following conditions: C18 silica gel column; mobile phase: acetonitrile in water (10 mmol / L ammonium bicarbonate) with a gradient of 10%–50% over 10 min; UV detector: 200 nm. The result was that (2S)-2-[(2S)-3,3-dimethyl-2-(3,3,3-trifluoropropylamine)butanamine]-n-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propane-2-yl]-4,4-dimethylpentanamide (120 mg) was a white solid.

[0680] LCMS(ESI,m / z): [M+H] + =508.29

[0681] 3. Synthesis of compound C4-26

[0682] Sodium bicarbonate (99 mg, 1.2 mmol, 3.0 eq.) and Desmartin oxidant (1667 mg, 3.9 mmol, 10.0 eq.) were added aliquots into a solution of (2S)-2-[(2S)-3,3-dimethyl-2-(3,3,3-trifluoropropylamine)butane]-n-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrone-3-yl]-4,4-dimethylpentanamide (200 mg, 0.4 mmol, 1.0 eq.) in 3 mL of dichloromethane with stirring. The resulting mixture was stirred at room temperature for another 2 hours. The mixture was filtered, and the filter cake was washed with dichloromethane (3 x 5 mL). The filtrate was concentrated under reduced pressure. Preparation - Purification of crude product (mg) by high performance liquid chromatography: Column type: XSelect CSH Phenyl-Hexyl OBD Prep column, 5μm, 19mm X 250mm; Mobile phase A: water (0.1% FA), Mobile phase B: acetonitrile; Flow rate: 25ml / min; Gradient (B%): 25% B ~ 37% B, 10min; Wavelength: 200nm / 220nm; RT1 (min): 7.99. (2S)-2-[(2S)-3,3-dimethyl-2-(3,3,3-trifluoropropylamine)butylamine]-4,4-dimethyl-n-[(2S)-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propen-2-yl]pentaamide (15.6mg) was obtained.

[0683] LCMS(ESI,m / z):[M+H] + =507.30

[0684] 1 H NMR(400MHz, CDCl3-d)δ9.52(s,1H),8.34–7.91(s,1H),6.82(s,1H),6.74(s,1H),6.24(s,1H),4.59(s,1H),4.52–4.15(m,2H),3.98–3.63(m,1 H),3.40(d,J=11.3Hz,2H),3.20–3.11(m,1H),2.78–2.28(m,2H),1.99– 1.90(m,1H),1.88–1.78(m,2H),1.53–1.43(m,2H),1.18–0.93(m,18H).

[0685] Example 36 Synthesis of compound C4-26A

[0686] 1. Synthesis of Compound 2

[0687] At 25 °C, Dysmartin oxidant (208 mg, 0.5 mmol, 5.0 eq.) was added in portions to dichloromethane containing (2S)-2-[(2S)-3,3-dimethyl-2-(3,3,3-trifluoropropylamine)butane]-n-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrone-3-yl]propane-2-yl]-4,4-dimethylpentanamide (50 mg, 0.1 mmol, 1.0 eq.) and sodium bicarbonate (33 mg, 0.4 mmol, 4.0 eq.) in 2 mL. The resulting mixture was stirred at 25 °C for 2 hours. The resulting mixture was extracted with ethyl acetate (20 mL). The bound organic layer was washed with deionized water (3 × 20 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure. (2S)-2-tert-butyl-n-[(1S)-3,3-dimethyl-1-{(2S)-1-oxo-3-[(3S)-2-oxopyrone-3-yl]propane-2-yl]carbamoylbutyl]-6,6,6-trifluoro-4-oxocyclopentanamine (30 mg) was obtained as a white solid.

[0688] LCMS(ESI,m / z):[M+H] + =506.22

[0689] 2. Synthesis of compound C4-26A

[0690] At 25 °C, (2S)-2-tert-butyl-n-[(1S)-3,3-dimethyl-1-{(2S)-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propane-2-yl]carbamoyl}butyl]-6,6,6-trifluoro-4-oxocyclopentanamine (20 mg, 0.04 mmol, 1.0 eq.) was dissolved in N,N-dimethylethylamine (2 mL), and sodium bisulfite (20 mg, 0.2 mmol, 5.0 eq.) was added with stirring. The resulting mixture was stirred at 25 °C for another 2 minutes. The mixture was extracted with ethyl acetate (3 × 20 mL). The bound organic layer was washed with deionized water (3 × 20 mL) and dried over anhydrous sodium sulfite. The filtrate was concentrated under reduced pressure. Preparation - The crude product was purified by high performance liquid chromatography. The chromatographic column was Xselect CSH C185μm, 19mm x 250mm; mobile phase A: water (0.1% formic acid), mobile phase B: acetonitrile; flow rate: 25mL / min; gradient (B%): 40% B to 52% B, 8min; wavelength: 200nm / 220nm; RT1 (min): 8.04. Sodium (1S,2S)-2-[(2S)-2-[(2S)-3,3-dimethyl-2-(3,3,3-trifluoropropylamine)butanamine]-4,4-dimethylpentanamine]-1-hydroxy-3-[(3S)-2-oxopyridin-3-yl]propane-1-sulfonate (2.5mg) was a white solid.

[0691] LCMS(ESI,m / z):[M-Na] - =587.10

[0692] 1 H NMR(400MHz,D2O)δ4.89(d,J=4.5Hz,2H),4.49–4.28(m,2H),4.25–4.06(s,1H),3.33–3.21(m,4H) ,2.69–2.35(s,1H),2.26–2.08(s,1H),2.06–1.69(m,2H),1.67–1.49(m,2H),0.99–0.74(m,18H).

[0693] Example 37 Synthesis of compound C4-28

[0694] 1. Synthesis of Compound 2

[0695] Under nitrogen atmosphere and at 0°C, benzyl bromide (5.8 g, 34.2 mmol, 1.5 eq.) was added dropwise to a stirred mixture of ethyl 4-bromo-3H-imidazolium-2-carboxylate (5.0 g, 22.8 mmol, 1.0 eq.) and potassium carbonate (9.5 g, 68.5 mmol, 3.0 eq.) in N,N-dimethylformamide (50 mL). The resulting mixture was stirred at 25°C for 2 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column, C18 silica gel; mobile phase, MeCN water (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector, UV 200 nm, to give a white solid ethyl 1-benzyl-5-bromoimidazolium-2-carboxylate (3.0 g).

[0696] LCMS(ESI,m / z):[M+H] + =309.2

[0697] 2. Synthesis of Compound 3

[0698] Under nitrogen atmosphere and at 25°C, Pd(dppf)Cl2 (1.2 g, 1.6 mmol, 0.1 eq.) and cesium carbonate (15.8 g, 48.5 mmol, 3.0 eq.) were added in portions to ethyl 1-benzyl-5-bromoimidazole-2-carboxylate (5.0 g, 16.2 mmol, 1.0 eq.) and water (5 mL) in portions. The resulting mixture was stirred at 100°C for 16 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN water (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector: UV 200 nm, yielding a purple solid ethyl 1-benzyl-5-(3,5-dimethyl-1,2-oxazol-4-yl)imidazolium-2-carboxylate (3.5 g).

[0699] LCMS(ESI,m / z):[M+H] + =326.1

[0700] 3. Synthesis of Compound 4

[0701] Under nitrogen atmosphere and at 0°C, lithium hydroxide (662 mg, 27.6 mmol, 3.0 eq.) was added in portions to a stirred mixture of ethyl 1-benzyl-5-(3,5-dimethyl-1,2-oxazol-4-yl)imidazolium-2-carboxylate (3.0 g, 9.2 mmol, 1.0 eq.) in tetrahydrofuran (10 mL) and water (10 mL). The resulting mixture was stirred at 25°C for 1 hour. The mixture was then concentrated under vacuum to give 2.5 g of 1-benzyl-5-(3,5-dimethyl-1,2-oxazol-4-yl)imidazolium-2-carboxylic acid as a purple solid.

[0702] LCMS(ESI,m / z):[M+H] + =298.1

[0703] 4. Synthesis of Compound 5

[0704] Under nitrogen atmosphere and at 0°C, N,N-dimethylformamide (20 mL) containing 1-benzyl-5-(3,5-dimethyl-1,2-oxazol-4-yl)imidazol-2-carboxylic acid (2.5 g, 8.4 mmol, 1.0 eq.) and (2S)-2-amino-4,4-dimethylvalerate (1.3 g, 8.4 mmol, 1.0 eq.) was added in portions to N,N-diisopropylethylamine (3.3 g, 25.2 mmol, 3.0 eq.) and HATU (4.8 g, 12.6 mmol, 1.5 eq.). The resulting mixture was stirred at 25°C for 2 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN water (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector: UV 200 nm, yielding a yellow solid (2S)-2-{[1-benzyl-5-(3,5-dimethyl-1,2-oxazol-4-yl)imidazol-2-yl]formamido}-4,4-dimethylvalerate (1.8 g).

[0705] LCMS(ESI,m / z):[M+H] + =439.2

[0706] 5. Synthesis of Compound 6

[0707] Under a nitrogen atmosphere at 0°C, lithium hydroxide (294 mg, 12.3 mmol, 3.0 eq.) was added in portions to a stirred mixture of tetrahydrofuran (10 mL) of (2S)-2-{[1-benzyl-5-(3,5-dimethyl-1,2-oxazol-4-yl)imidazol-2-yl]formamido}-4,4-dimethylpentanoate (1.8 g, 4.1 mmol, 1.0 eq.) and water (3 mL). The resulting mixture was stirred at 25°C for 2 hours. The mixture was concentrated under reduced pressure to give a white solid (2S)-2-{[1-benzyl-5-(3,5-dimethyl-1,2-oxazol-4-yl)imidazol-2-yl]formamido}-4,4-dimethylpentanoic acid (1.2 g).

[0708] LCMS(ESI,m / z):[M+H] + =425.2

[0709] 6. Synthesis of Compound 7

[0710] Under nitrogen atmosphere and at 25°C, HATU (1.6 g, 4.2 mmol, 1.0 eq.) and N,N-diisopropylethylamine (1.1 g, 8.5 mmol, 3.0 eq.) were added in portions to (2S)-2-{[1-benzyl-5-(3,5-dimethyl-1,2-oxazol-4-yl)imidazol-2-yl]formamido}-4,4-dimethylvaleric acid (1.2 g, 2.8 mmol, 1.0 eq.) and (2S)-2-amino-3-[(3S)-2-oxopyrrolidine-3-yl]propionate methyl ester (0.5 g, 2.8 mmol, 1.0 eq.) in N,N-dimethylformamide (10 mL) in portions. The resulting mixture was stirred at 25°C for 2 hours. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN water (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector: UV 200 nm. The result was methyl (S)-2-((S)-2-(1-benzyl-5-(3,5-dimethylisoxazol-4-yl)-1H-imidazol-2-carboxamido)-4,4-dimethylpentamido)-3-((S)-2-oxopyrrolidine-3-yl)propionate (800 mg), a yellow solid.

[0711] LCMS(ESI,m / z):[M+H] + =593.3

[0712] 7. Synthesize compound 8

[0713] Under nitrogen atmosphere and at 0°C, lithium borohydride (4.0 M in THF) (57 mg, 2.6 mmol, 2.0 eq.) was added dropwise to a stirred mixture of (2S)-2-[(2S)-2-{[1-benzyl-5-(3,5-dimethyl-1,2-oxazol-4-yl)imidazol-2-yl]formamido}-4,4-dimethylpentamido]-3-[(3S)-2-oxopyrrolidine-3-yl]propionate (780 mg, 1.3 mmol, 1.0 eq.) tetrahydrofuran (10 mL) (4.0 M in THF). The resulting mixture was stirred at 25°C for 2 hours. The reaction was quenched with water at 0°C. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN aqueous solution (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector: UV 200 nm. The result was (2S)-2-{[1-benzyl-5-(3,5-dimethyl-1,2-oxazol-4-yl)imidazol-2-yl]formamido}-N-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]-4,4-dimethylpentanamide (480 mg), a white solid.

[0714] LCMS(ESI,m / z):[M+H] + =565.3

[0715] 8. Synthesizing compound 9

[0716] Palladium hydroxide (Pd 5%, carbon powder, anhydrous) (228 mg, 1.6 mmol, 2.0 eq.) was added to (2S)-2-{[1-benzyl-5-(3,5-dimethyl-1,2-oxazol-4-yl)imidazol-2-yl]formamido}-N-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]-4,4-dimethylpentanamide (460 mg, 0.8 mmol, 1.0 eq.) in acetic acid (5 mL). The resulting mixture was stirred at 60 °C for 2 hours. The mixture was filtered, and the filter cake was washed with MeCN (3 x 20 mL). The filtrate was concentrated under reduced pressure. The residue was purified by reversed-phase flash chromatography under the following conditions: column: C18 silica gel; mobile phase: MeCN aqueous solution (10 mmol / L NH4HCO3), gradient from 10% to 50% over 10 minutes; detector: UV 200 nm. The result was (2S)-2-{[4-(3,5-dimethyl-1,2-oxazol-4-yl)-3H-imidazol-2-yl]formamido}-N-[(2S)-1-hydroxy-3-[(3S)-2-oxopyrrolidine-3-yl]propyl-2-yl]-4,4-dimethylpentanamide (100 mg), a white solid.

[0717] LCMS(ESI,m / z):[M+H] + =475.2

[0718] 9. Synthesize compound C4-28

[0719] Under a nitrogen atmosphere at 25°C, Dysmartin (721 mg, 1.7 mmol, 2.0 eq.) was added to a solution of dichloromethane containing Dysmartin oxidant (480 mg, 0.8 mmol, 1 eq.) and sodium bicarbonate (214 mg, 2.5 mmol, 3.0 eq.) in 5 mL of nitrogen. The resulting mixture was stirred at 25°C for 2 hours. The crude product was purified by preparative high performance liquid chromatography (HPLC). Column type: Xselect CSH C185μm, 19mm x 250mm; mobile phase A: water (0.1% FA), mobile phase B: ACN; flow rate: 25ml / min; gradient (B%): 25% B ~ 40% B, 10min; wavelength: 200nm / 220nm; RT1 (min): 8.03. (2S)-2-{[4-(3,5-dimethyl-1,2-oxazol-4-yl)-3h-imidazol-2-yl]formamide}-4,4-dimethyl-n-[(2S)-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propen-2-yl]pentaamide (15.2mg) was a white solid.

[0720] LCMS(ESI,m / z):[M+H] + =473.2

[0721] 1 H NMR(400MHz,D2O)δ7.36(s,1H),4.90(d,J=4.7Hz,1H),4.49(d,J=8.2Hz,1H),3.92–3.53(m,1H),3.38–3.04(m,2H),2.41( s,4H),2.24(s,3H),2.14(d,J=8.1Hz,1H),1.99–1.81(m,1H),1.79–1.65(m,3H),1.62–1.41(m,1H),0.90(d,J=3.7Hz,9H).

[0722] Example 38 Synthesis of compound C4-30

[0723] 1. Synthesis of Compound 2

[0724] Under a nitrogen atmosphere at 25°C, methyl(2S)-2-[(2S)-2-[(2S)-2-[(2S)-2-amino-3,3-dimethylbutylamine]-4,4-dimethylpentylamine]-3-[(3S)-2-oxopyridin-3-acyl]propionic acid (500 mg, 1.2 mmol, 1.0 eq.) and dimethyl-1,2-oxazol-4-carboxylic acid (165 mg, 1.2 mmol, 1.0 eq.) were dissolved in N,N-dimethylethylamine (5 mL), stirred until homogeneous, and N,N-diisopropylethylamine (454 mg, 3.5 mmol, 3.0 eq.) was added dropwise. After 2 minutes, the mixture was added aliquots of benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (668 mg, 1.7 mmol, 1.5 eq.). The resulting mixture was stirred at 25°C for another 2 hours. The resulting mixture was concentrated under reduced pressure. Purification was performed by reversed-phase flash chromatography under the following conditions: C18 silica gel column; mobile phase: acetonitrile dissolved in water (10 mmol / L ammonium bicarbonate), with a gradient of 10%–50% over 10 min; UV detector: 200 nm. Methyl(2S)-2-[(2S)-2-[(2S)-2-[(2S)-2-[(3,5-dimethyl-1,2-oxazol-4-yl)methylamine]-3,3-dimethylbutylamine]-4,4-dimethylpentylamine]-3-[(3S)-2-oxopyridin-3-yl]propionate (420 mg) was obtained as a white solid.

[0725] LCMS(ESI,m / z):[M+H] + =550.31

[0726] 2. Synthesis of Compound 3

[0727] Methyl(2S)-2-[(2S)-2-[(2S)-2-[(2S)-2-[(3,5-dimethyl-1,2-oxazol-4-acyl)methylamine]-3,3-dimethylbutane]-4,4-dimethylpentanamine]-3-[(3S)-2-oxopyridin-3-acyl]propionate (380 mg, 0.7 mmol, 1.0 eq.) was dissolved in tetrahydrofuran (5 mL) under a nitrogen atmosphere at 0 °C, and lithium borohydride (4.0 M tetrahydrofuran) (1.4 mL, 0.06 mmol, 0.1 eq.) was added dropwise over 3 minutes. The resulting mixture was stirred at 25 °C for 2 hours. The reaction was quenched with water at 0 °C. The resulting mixture was concentrated under reduced pressure. Purification was performed by reversed-phase flash chromatography under the following conditions: C18 silica gel column; mobile phase: acetonitrile dissolved in water (10 mmol / L ammonium bicarbonate), with a gradient of 10%–50% over 10 min; UV detector: 200 nm. The resulting product was (2S)-2-[(2S)-2-[(2S)-2-[(3,5-dimethyl-1,2-oxazol-4-yl)formamide]-3,3-dimethylbutyramide]-n-[(2S)-1-hydroxy-3-[(3S)-2-oxopyridin-3-yl]propen-2-yl]-4,4-dimethylpentanamide (130 mg).

[0728] LCMS(ESI,m / z):[M+H] + =522.18

[0729] 3. Synthesis of compound C4-30

[0730] Under a nitrogen atmosphere at 25°C, (2S)-2-[(2S)-2-[(3,5-dimethyl-1,2-oxazol-4-yl)carboxamide]-3,3-dimethylbutyramide]-n-[2S)-1-hydroxy-3-[(3S)-2-oxopyridin-3-yl]propyl-2-yl]-4,4-dimethylpentanamide (70 mg, 0.1 mmol, 1.0 eq.) and sodium bicarbonate (45 mg, 0.5 mmol, 4.0 eq.) were dissolved in dichloromethane (5 mL) and stirred until homogeneous. Desmartin oxidant (284 mg, 0.7 mmol, 5.0 eq.) was added aliquots. The resulting mixture was stirred at 25°C for another 2 hours. The reaction was quenched at 25°C by adding saturated sodium metabisulfite (5 mL). The resulting mixture was extracted with ethyl acetate (3 × 20 mL). The combined organic layer was washed with deionized water (3 × 20 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure. The crude product was purified by reversed-phase flash evaporation under the following conditions: column: YMC Triart C18ExRs 5μm, 30mm*150mm; mobile phase A: water (10mmol / L ammonium bicarbonate + 0.1% ammonia), mobile phase B: acetonitrile; flow rate: 60mL / min; gradient (B%): 18% B to 41% B, 8min; wavelength: 200 / 220nm; RT1 (min): 6.62. (2S)-2-[(2S)-2-[(3,5-dimethyl-1,2-oxazol-4-yl)carboxamide]-3,3-dimethylbutanamide]-4,4-dimethyl-n-[(2S)-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propen-2-yl]pentaamide (10.8mg).

[0731] LCMS(ESI,m / z):[M+H] + =520.17

[0732] 1 H NMR(400MHz, CDCl3-d)δ9.73–9.38(m,1H),8.97–8.53(m,1H),6.58–6.18(m,2H),6.02–5.52(m,1H),4.52–4.(m,1H),4.51–4.29(m, 2H),3.51–3.24(m,2H),2.83–2.63(s,3H),2.56–2.31(d,J=3.1Hz,5H),2.19–1.76(m,5H),1.11–1.02(d,J=3.5Hz,9H),0.97(s,9H).

[0733] Example 39 Synthesis of compound C4-30A

[0734] 1. Synthesis of Compound 2

[0735] At 25 °C, (2S)-2-[(2S)-2-[(3,5-dimethyl-1,2-oxazol-4-yl)carboxamide]-3,3-dimethylbutane]-n-[(2S)-1-hydroxy-3-[(3S)-2-oxopyronyl-3-yl]propane-2-yl]-4,4-dimethylpentanamide (60 mg, 0.1 mmol, 1.0 eq.) and sodium bicarbonate (38 mg, 0.4 mmol, 4.0 eq.) were dissolved in dichloromethane (2 mL), and Dysmartin oxidant (244 mg, 0.6 mmol, 5.0 eq.) was added in portions. The resulting mixture was stirred at 25 °C for another 2 hours. The resulting mixture was extracted with ethyl acetate (20 mL). The bound organic layer was washed with deionized water (3 × 20 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure. (2S)-2-[(2S)-2-[(3,5-dimethyl-1,2-oxazol-4-yl)carboxamide]-3,3-dimethylbutanamide]-4,4-dimethyl-n-[(2S)-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propen-2-yl]pentaamide (50 mg) was obtained as a white solid.

[0736] LCMS(ESI,m / z):[M+H] + =520.13

[0737] 2. Synthesis of compound C4-30A

[0738] Under a nitrogen atmosphere at 25°C, (2S)-2-[(2S)-2-[(3,5-dimethyl-1,2-oxazol-4-yl)methylamine]-3,3-dimethylbutane]-4,4-dimethyl-n-[(2S)-1-oxo-3-[(3S)-2-oxopyridin-3-yl]propyl-2-yl]pentaamide (30 mg, 0.06 mmol, 1.0 eq.) was dissolved in DMF (2 mL) and stirred. Sodium bisulfite (30 mg, 0.3 mmol, 5.0 eq.) was then added in portions. The resulting mixture was stirred at 25°C for another 2 minutes. The mixture was extracted with ethyl acetate (3 × 20 mL). The bound organic layer was washed with deionized water (3 × 20 mL) and dried over anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure. Preparation - The crude product was purified by high performance liquid chromatography. The chromatographic column was Xselect CSH C185μm, 19mm x 250mm; mobile phase A: water (0.1% formic acid), mobile phase B: acetonitrile; flow rate: 25mL / min; gradient (B%): 30% B to 45% B, 10min; wavelength: 200nm / 220nm; RT1 (min): 9.42. Sodium 2-[(2S)-2-[(2S)-2-[(2S)-2-[(3,5-dimethyl-1,2-oxazol-4-yl)methylamine]-3,3-dimethylbutylamine]-4,4-dimethylpentylamine]-1-hydroxy-3-[(3S)-2-oxopyridin-3-yl]propane-1-sulfonate (6.6mg) was a white solid.

[0739] LCMS(ESI,m / z):[M-Na] - =600.15

[0740] 1 H NMR(400MHz,D2O)δ4.99–4.82(m,1H),4.63–4.48(m,1H),4.49–4.33(m,2H),4.33–3.73(m,1H), 3.45–3.24(m,2H),2.53–2.08(m,7H),1.96–1.41(m,5H),1.02–0.87(m,9H),0.88–0.77(m,9H).

[0741] Test case

[0742] 1. Experimental Equipment

[0743] 2 Experimental Methods

[0744] 2.1 Preparation and treatment of compounds

[0745] 2.1.1 Compound DMSO Stock Formulation

[0746] All compounds were reconstituted into stock solutions using DMSO.

[0747] 2.1.2 Compound Storage

[0748] All compounds in DMSO are stored in a desiccator at room temperature for short-term storage (up to 3 months).

[0749] 2.2 Compound Screening:

[0750] 1) Add 160 nL of 100X series diluted compound to the 384 test plate.

[0751] 2) Prepare 2X FIPV enzyme solution.

[0752] 3) Add 8 μL of 2X FIPV enzyme to a single well of the assay plate.

[0753] 4) Prepare a 2X FIPV substrate.

[0754] 5) Add 8 μL of 2X FIPV substrate.

[0755] 6) Read the board at wavelengths of 320nm and 405nm on the BMG.

[0756] 3. Data Analysis

[0757] The 3.1% inhibition rate was calculated as follows:

[0758] Inhibition rate (%) = 100 - (Signal) cmpd -Signal Ave_PC ) / (Signal Ave_VC -Signal Ave_PC )×100.

[0759] Signal ave_pc : The average percentage of positive controls on the plate.

[0760] Signal ave_vc : The average percentage of negative controls on the entire plate.

[0761] 3.2 Calculate IC 50 And plot the effect-dose curve of cmpds:

[0762] IC was calculated by fitting the inhibition rate and the logarithm of compound concentration to a nonlinear regression (dose-response-variable slope) using Graphpad 8.0. 50 The test results are shown in Table 1 below.

[0763] Y=Bottom+(Top-Bottom) / (1+10^((LogIC 50-X)*HillSlope))

[0764] X: Logarithm of inhibitor concentration; Y: Inhibition rate (%).

[0765] Table 1

[0766] The above description provides an exemplary account of the implementation methods of the technical solution disclosed herein. It should be understood that the scope of protection of this disclosure is not limited to the above-described embodiments. Any modifications, equivalent substitutions, or improvements made by those skilled in the art within the spirit and principles of this disclosure should be included within the scope of protection of the claims of this application.

Claims

1. A compound of formula (I) or formula (II) or a pharmaceutically acceptable salt thereof: in, X is selected from CH2 or S; R1is selected from the following groups, which are unsubstituted or optionally substituted by one, two or more R 11 substituted C 1-10 alkyl, 3-10 membered heterocyclyl, 5-10 membered heteroaryl; each R 11 the same or different, independently of one another, are selected from the group consisting of oxo (=0), halogen, C 1-10 alkyl, C 1-10 alkoxy, -C(O)NHC 1-10 alkyl, -NHC(O)C 1-10 alkyl, halogenated C 1-10 alkyl, halogenated C 1-10 alkoxy; R2 is selected from H; or, Selected from unsubstituted or arbitrarily assigned to one, two or more R 21 The following groups are substituted: 3-10 membered heterocyclic groups, 5-10 membered heteroaryl groups; each R 21 Whether the two are the same or different, they are independently selected from oxygen (=O) and C. 1-10 Alkyl, C 1- 10 Alkoxy; R3 is selected from unsubstituted or optionally by one, two or more R3s. 31 The following groups are substituted: C 1-10 Alkyl, C 3-10 Cycloalkyl, 3-10 membered heterocyclic, 5-10 membered heteroaryl, C 6-10 Aryl; each R 31 They are the same or different, and are independently selected from halogens and C. 3-10 cycloalkyl, halogenated C 3-10 cycloalkyl; R4 is selected from H; Alternatively, R3 and R4, together with their respective atoms, form unsubstituted or optionally substituted atoms with one, two, or more R atoms. 41 The following groups are substituted: 3-10 membered heterocyclic groups, 5-10 membered heteroaryl groups; each R 41 They are the same or different, and are independently selected from halogens and C. 1- 10 Alkyl, Halogenated C 1-10 alkyl; R5 is selected from No substitution or optional use by one, two or more R 51 Replacement C 1-10 Alkyl, 5-10 heteroaryl; each R 51 They are identical or different, selected independently of each other without substitution or arbitrarily selected by one, two or more Rs. 511 The following groups are substituted: C 1-10 Alkyl, Halogenated C 1-10 Alkyl, C 6-10 Aryl, 5-10 membered heteroaryl, 3-10 membered heterocyclic, -B(OH)2, -Si(OH)2C 1-10 Alkyl; each R 511 They are either the same or different, and are independently selected from oxidized, halogenated, and C-type substances. 1-10 Alkyl, Halogenated C 1-10 alkyl; R 5a Selected from unsubstituted or arbitrarily assigned to one, two or more R 5a1 The following groups are substituted: C 1-10 Alkyl, C 6-10 Aryl, 5-10 membered heteroaryl, 3-10 membered heterocyclic; each R 5a1 They may be the same or different, and are independently selected from oxo- or 5-10-membered heteroaryl groups; R 5b Selected from H; R 5c Selected from unsubstituted or arbitrarily assigned to one, two or more R 5c1 The following groups are substituted: C 1-10 Alkyl, C 3-10 Cycloalkyl, 3-10 membered heterocyclic, 5-10 membered heteroaryl, NH2, -B(OH)2, -Si(OH)2C 1-10 Alkyl; each R 5c1 They are either the same or different, and are independently selected from oxidized, halogenated, and C-type substances. 1-10 Alkyl, C 3-10 Cycloalkyl, hydroxy C 1-10 Alkyl, Halogenated C 1-10 alkyl; Alternatively, R4 and R5, together with their respective atoms, form unsubstituted or optionally substituted atoms with one, two, or more R atoms. 52 The following groups are substituted: 3-10 membered heterocyclic groups, 3-10 membered heteroaryl groups; each R 52 Whether the same or different, they are independently selected from oxygen, C 6-10 aryloxy group, C 6-10 Aryl-C 1-10 Alkyl, Halogenated C 1-10 alkyl.

2. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, characterized in that, R1 is selected from unsubstituted or arbitrarily selected by one, two or more R1s. 11 The following groups are substituted: C 1-6 Alkyl, 5-6 membered heterocyclic, 5-6 membered heteroaryl, 9-10 membered heteroaryl; Preferably, R1 is selected from unsubstituted or optionally substituted by one, two or more R1s. 11 The following groups are substituted: propyl, Preferably, each R 11 They are either the same or different, and are independently selected from oxygen (=O), halogen, and carbon. 1-6 Alkyl group, -C(O)NHC 1- 6-alkyl, -NHC(O)C 1-6 Alkyl, Halogenated C 1-6 Alkyl, Halogenated C 1-6 Alkoxy; Preferably, each R 11 They are either the same or different, and are independently selected from oxo (=O), F, Cl, methyl, -C(O)NHCH3, -NHC(O)CH3, CF3, CHF2, -OCHF2, -CH2CHF2; Preferably, R1 is selected from (like )、 (like )、 (like )、 (like )、 (like )、 (like )、 (like )； Preferably, Selected from unsubstituted or arbitrarily assigned to one, two or more R 21 The following groups are substituted: 8-10 membered heterocyclic groups, 8-10 membered heteroaryl groups; each R 21 Whether the two are the same or different, they are independently selected from oxygen (=O) and C. 1-6 alkyl; Preferably, Selected from 3. The compound according to claim 1 or 2, or a pharmaceutically acceptable salt thereof, characterized in that, R3 is selected from unsubstituted or optionally by one, two or more R3s. 31 The following groups are substituted: C 1-6 Alkyl, C 8-10 Alkyl, 5-6 membered heterocyclic, 5-6 membered heteroaryl, C6 aryl; Preferably, R3 is selected from unsubstituted or optionally substituted by one, two or more R3 groups. 31 The following groups can be substituted: methyl, ethyl, butyl (e.g., isobutyl), pentyl (e.g., neopentyl), thienyl, thiazolyl, phenyl, adamantyl, Preferably, each R 31 They are the same or different, and are independently selected from halogens and C. 3-6 cycloalkyl, halogenated C 3-6 cycloalkyl; Preferably, each R 31 They may be the same or different, and are independently selected from F, cyclobutyl, fluorocyclobutyl, and others. According to the implementation scheme of this disclosure, R3 is selected from...

4. The compound or a pharmaceutically acceptable salt thereof according to any one of claims 1-3, characterized in that, R3 and R4, together with their respective attached atoms, form unsubstituted or optionally substituted atoms with one, two or more R atoms. 41 The following groups are substituted: 5-9 membered heterocyclic groups, 8-9 membered heteroaryl groups; Preferably, R3 and R4 form unsubstituted or optionally substituted atoms with one, two or more R atoms. 41 The following groups are substituted: Preferably, each R 41 They are the same or different, and are independently selected from halogens and C. 1-6 Alkyl, Halogenated C 1-6 alkyl; Preferably, each R 41 They may be the same or different, and are independently selected from F, methyl, and trifluoromethyl. Preferably, R3 and R4 form with the atoms they are respectively connected to.

5. The compound or a pharmaceutically acceptable salt thereof according to any one of claims 1-4, characterized in that, R5 is selected from No substitution or optional use by one, two or more R 51 The following groups are substituted: C 1-6 Alkyl, 5-6 membered heteroaryl; Preferably, R5 is selected from No substitution or optional use by one, two or more R 51 The following groups are substituted: methoxy, imidazole (e.g.) ), triazole group (such as )； Preferably, each R 51 They are identical or different, selected independently of each other without substitution or arbitrarily selected by one, two or more Rs. 511 The following groups are substituted: C 1-6 Alkyl, Halogenated C 1-6 Alkyl, C6 aryl, 5-6 membered heteroaryl, 5-6 membered heterocyclic, -B(OH)2, -Si(OH)2C 1-6 alkyl; Preferably, each R 51 They are identical or different, selected independently of each other without substitution or arbitrarily selected by one, two or more Rs. 511 The following groups can be substituted: ethyl, phenyl, imidazolyl, thiazolyl, triazolyl, tetrahydropyrrolyl, isoxazolyl, -B(OH)2, -Si(OH)2CH3. Preferably, each R 51 They may be the same or different, and are independently selected from ethyl, phenyl, Preferably, each R 511 They are either the same or different, and are independently selected from oxidized, halogenated, and C-type substances. 1-6 Alkyl, Halogenated C 1-6 alkyl; Preferably, each R 511 They may be the same or different, and are independently selected from oxo, F, methyl, and trifluoromethyl.

6. The compound according to any one of claims 1-5, or a pharmaceutically acceptable salt thereof, characterized in that, R 5a Selected from unsubstituted or arbitrarily assigned to one, two or more R 5a1 The following groups are substituted: C 1-6 Alkyl, C6 aryl, 5-6 membered heteroaryl (e.g., pyrazolyl), 5-6 membered heterocyclic; each R 5a1 They may be the same or different, and are independently selected from oxo, 5-6 membered heteroaryl groups (e.g., imidazole groups); Preferably, R 5a Selected from tert-butyl, phenyl, Preferably, R 5c Selected from unsubstituted or arbitrarily assigned to one, two or more R 5c1 The following groups are substituted: C 1-6 Alkyl, C 3- 6-cycloalkyl, 5-6-membered heterocyclic, 5-6-membered heteroaryl, NH2, -B(OH)2, -Si(OH)2C 1-6 Alkyl; each R 5c1 They are either the same or different, and are independently selected from oxidized, halogenated, and C-type substances. 1-6 Alkyl, C 3-6 Cycloalkyl, hydroxy C 1-6 Alkyl, Halogenated C 1-6 alkyl; Preferably, R 5c Selected from trifluoromethyl, (like )、 (like )、 Preferably, R5 is selected from Preferably, Selected from Preferably, R4 and R5 are unsubstituted with their respective attached atoms or optionally substituted with one, two or more R atoms. 52 The following groups are substituted: 5-6 membered heterocyclic group, 9 membered heterocyclic group, 5-6 membered heteroaryl group, 9 membered heteroaryl group; Preferably, R4 and R5 are unsubstituted with their respective attached atoms or optionally substituted with one, two or more R atoms. 52 The following groups are substituted: Preferably, each R 52 They may be the same or different, and are independently selected from oxo, C6 aryloxy, and C6 aryl-C. 1-6 Alkyl, Halogenated C 1-6 alkyl; Preferably, each R 52 They may be the same or different, and are independently selected from oxo, phenoxy, benzyl, and Preferably, R4 and R5 form with the atoms they are respectively connected to.

7. The compound or a pharmaceutically acceptable salt thereof according to any one of claims 1-6, characterized in that, The compound has the following structure: Among them, R1, R2, R3, R4, R5, R 51 X and X independently have the definition as described in any one of claims 1-6; Preferably, the compound has the following structure: Among them, R1, R2, R3, R4, R5, R 5a R 5b R 5c X and X independently have the definition as described in any one of claims 1-6; Preferably, the compound represented by formula (I) has the following structure: Among them, R1, R2, R3, R4, R5, R 5a R 5b R 5c X and X independently have the definition as described in any one of claims 1-6; Preferably, the compound represented by formula (I) has the following structure: Among them, R1, R3, R4, R5, R 51 R 5a R 5b R 5c R 5c1 Each of them independently has the definition as described in any one of claims 1-6.

8. The compound according to any one of claims 1-7 or a pharmaceutically acceptable salt thereof, characterized in that, The compound is selected from the following compounds:

9. A pharmaceutical composition comprising a therapeutically effective amount of at least one of the compounds of any one of claims 1-8 or a pharmaceutically acceptable salt thereof.

10. The use of the compound of any one of claims 1-8 or a pharmaceutically acceptable salt thereof in the preparation of a medicament for treating and / or preventing at least one of the following diseases or conditions: (1) Diseases or symptoms in animals caused by or related to pathogen infection; (2) Animal tumors; Preferably, the pathogen is a virus; Preferably, the virus may be selected from: Herpesviridae, Iridoviridae, Baculoviridae, Rhabdoviridae, Reoviridae, BiRNAviridae, Poxviridae, African Swine Fever Viridae, Adenoviridae, Parvoviridae, Circoviridae, Retroviridae, Orthomyxoviridae, Paramyxoviridae, Coronaviridae, Arteritis Viridae, MicroRNA Viridae, Calicoviridae, Flaviviridae, Prions, Filoviridae, Polyomaviridae, Papillomaviridae, Threadviridae, Retroviridae, Hepatoviridae, Papillomaviridae, Bonaviridae, Bunniviridae, Acanthaviridae, Baculoviridae, Hepatitis E Viridae, Astroviridae, Capoviridae, Bicistronic Viridae, and Nodamuraviridae; preferably, the virus is a coronavirus; Preferably, the virus may be selected from: chicken infectious bronchitis virus, porcine transmissible gastroenteritis virus, porcine epidemic diarrhea virus, porcine hemagglutinating encephalomyelitis virus, mouse hepatitis virus, turkey blue crown virus, bovine coronavirus, canine coronavirus, feline infectious peritonitis virus, rat coronavirus, rat lacrimation coronavirus, and mink epidemic diarrhea coronavirus. Preferably, the disease is selected from diseases caused by coronaviruses, such as feline infectious peritonitis (FIP); Preferably, the coronavirus is selected from feline infectious peritonitis virus (FIPV); Preferably, the tumor is a malignant tumor; preferably, the malignant tumor is selected from malignant epithelial tumors, sarcomas, leukemia, and mixed tumors; Preferably, the malignant epithelial tumor is selected from: lung cancer, breast cancer, liver cancer, pancreatic cancer, colorectal cancer, gastric cancer, gastroesophageal adenocarcinoma, esophageal cancer, small bowel cancer, large bowel cancer, cardia cancer, endometrial cancer, ovarian cancer, fallopian tube cancer, vulvar cancer, testicular cancer, prostate cancer, penile cancer, kidney cancer, bladder cancer, anal cancer, gallbladder cancer, bile duct cancer, skin cancer, nasopharyngeal cancer, laryngeal cancer, thyroid cancer, tongue cancer, intracranial tumors, cardiac tumors, and spinal tumors.

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