Group of theanine derivatives as well as preparation method and application thereof

Abstract

The invention relates to a preparation method and anti-hepatic fibrosis application of a theanine derivative, the application further comprises treatment of chronic liver diseases such as alcoholic steatohepatitis and non-alcoholic steatohepatitis, and the structural formula of the theanine derivative is a compound shown as a formula I, the invention also relates to application of pharmaceutically acceptable salts or esters, prodrugs, stereoisomers, hydrates, solvates, crystal forms, metabolic forms of the pharmaceutically acceptable salts or esters, the prodrugs, the stereoisomers, the hydrates, the solvates and the crystal forms of the pharmaceutically acceptable salts or the pharmaceutically acceptable esters, the hydrates, the solvates and the crystal forms in preparation of medicines or reagents.

Description

Technical Field

[0001] This invention relates to theanine derivatives and their preparation methods, as well as the uses of said compounds. This invention belongs to the field of pharmaceutical technology. Background Technology

[0002] Liver fibrosis is a chronic, characteristic pathological response and a common feature of most liver diseases. Fibrosis manifests as excessive deposition of extracellular matrix proteins or fibrous connective tissue within the liver, leading to structural disorder of the liver parenchyma and potentially resulting in cirrhosis and liver cancer. The mechanisms leading to liver fibrosis are complex, involving multiple cell types, cytokines, and signaling pathways, including chronic liver injury (viral hepatitis, chronic alcoholism, alcoholic steatohepatitis, autoimmune diseases, etc.), hepatic stellate cell activation, inflammatory responses, oxidative stress, extracellular matrix (ECM) remodeling, and cell death and regeneration. It is a complex, multifactorial, and multi-stage process.

[0003] Treatment of liver fibrosis requires a comprehensive consideration of its etiology and pathological process. Current medications mainly focus on antiviral, anti-inflammatory, anti-fibrotic, antioxidant, and metabolic regulation. Although many new drugs are under research and trials, further exploration and optimization are needed to achieve better clinical outcomes in the treatment of liver fibrosis.

[0004] Natural products are a crucial method in drug development, accounting for 30% of clinically used drugs for disease treatment. Many natural products, such as flavonoids, quinones, and phenols like silymarin, emodin, salvianolic acid B, and resveratrol, have shown potent functions in liver protection and liver disease treatment. Natural products are also an important resource for finding drugs to combat liver fibrosis.

[0005] Theanine, an amino acid naturally found in green tea, has been found to have potential roles in various health problems in recent years. In the prevention and treatment of liver disease, theanine possesses antioxidant, anti-inflammatory, and immunomodulatory effects, directly protecting hepatocytes. Simultaneously, theanine can improve the metabolic state of the liver, reduce fat accumulation and insulin resistance, and can be used to prevent and treat liver fibrosis associated with non-alcoholic fatty liver disease (NAFLD). The activation and transformation of hepatic stellate cells (HSCs) is a core process in liver fibrosis. Studies have shown that theanine may inhibit the activation and proliferation of HSCs through mechanisms such as inhibiting the TGF-β signaling pathway and regulating cell cycle and apoptosis. Therefore, theanine may have certain potential in the fight against liver fibrosis.

[0006] This invention uses theanine as an active lead compound, performs structural modification to obtain theanine derivatives, and evaluates their anti-liver fibrosis activity. Bioactivity tests show that theanine and its derivatives can inhibit the activity of the type I collagen α1 (COL1A1) promoter, and simultaneously inhibit the expression of fibrosis-related proteins such as type I collagen α1 (COL1A1), transforming growth factor-β (TGF-β), smooth muscle actin (α-SMA), connective tissue growth factor (CTGF), and tissue inhibitor of metalloproteinases (TIMP1) at the cellular level. This, to a certain extent, inhibits hepatic stellate cell activation and alleviates the progression of liver fibrosis, demonstrating promising potential for future development and application. Summary of the Invention

[0007] One objective of this invention is to provide a theanine derivative of Formula I, which is a pharmaceutical salt or ester, solvate, isomer, polymorph, isotope-labeled compound, metabolite, or prodrug compound.

[0008] Another object of the present invention is to provide the use of the compounds of Formula I, their pharmaceutical salts or esters, solvates, isomers, polymorphs, isotopically labeled compounds, metabolites or prodrugs, or any combination or mixture thereof, in the preparation of anti-hepatic fibrosis agents.

[0009] Another object of the present invention is to provide a method for synthesizing the compound of Formula I.

[0010] To achieve the above objectives, the present invention employs the following technical means:

[0011] A compound having the structure described in Formula I according to the present invention, wherein the pharmaceutical salt or ester, solvate, isomer, polymorph, isotopically labeled compound, metabolite or prodrug:

[0012]

[0013] in

[0014] R1 represents -OR a1 ,-NR a2 R a3 ,-(C1-C4 alkyl)nR a4

[0015] R a1 R a2 R a3 and R a4Each group is independently selected from the following groups: hydrogen, deuterium, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 ynyl, C3-C7 cycloalkyl, C6-C10 aryl, and 3-15 membered heterocyclic groups. The alkyl, alkenyl, ynyl, cycloalkyl, aryl, and heterocyclic groups may optionally be substituted by one or more groups independently selected from hydroxyl, amino, trifluoromethyl, nitro, halogen, C1-C6 alkyl, halo-C1-C6 alkyl, C1-C6 alkoxy, aryl, and heterocyclic groups.

[0016] R2 represents hydrogen, deuterium, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkynyl, C3-C7 cycloalkyl, C6-C10 aryl, -(C1-C4 alkyl)nOR a5 -(C1-C4 alkyl)nSR a6 -(C1-C4 alkyl)nNR a7 R a8 .

[0017] R a5 R a6 R a7、 R a8 The groups are individually selected from the following groups: hydrogen, deuterium, C3-C7 cycloalkyl, C6-C10 aryl, and 3-7 membered heterocyclic groups. The alkyl, alkenyl, alkynyl, cycloalkyl, aryl, and heterocyclic groups may optionally be substituted by one or more groups individually selected from hydroxyl, amino, trifluoromethyl, halogen, nitro, C1-C6 alkyl, halo-C1-C6 alkyl, C1-C6 alkoxy, aryl, and heterocyclic groups.

[0018] R3 and R4 may be the same or different, and are independently selected from hydrogen, deuterium, and -CH2-R. a9 -CO-R a10 -CO-SO2-R a11 ,

[0019] R a9 R a10 R a11 Each group is independently selected from the following groups: C1-C6 alkyl, C1-C6 alkenyl, C1-C6 ynyl, C3-C7 cycloalkyl, C6-C10 aryl, 3-15 membered heterocyclic groups. The alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocyclic groups, It may optionally be substituted with one or more groups independently selected from hydroxyl, amino, trifluoromethyl, nitro, halogen, C1-C6 alkyl, halo-C1-C6 alkyl, C1-C6 alkoxy, C1-C6 acyl, substituted aryl, and heterocyclic groups. The substituted aryl groups include halogen, hydroxyl, methoxy, nitro, and trifluoromethyl substituted groups.

[0020] The configurations described in Formula I include the S configuration and the R configuration.

[0021] Preferably, the compound of formula I, its pharmaceutical salt or ester, solvate, isomer, polymorph, isotope-labeled compound, metabolite, or prodrug of the present invention is characterized in that: when R1 represents -OR a1 ,-NR a2 R a3 ,-(C1-C4 alkyl)nR a4 In this case, R2 represents hydrogen, deuterium, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 ynyl, C3-C7 cycloalkyl, C6-C10 aryl, or -(C1-C4 alkyl)nOR. a5 -(C1-C4 alkyl)nSR a6 -(C1-C4 alkyl)nNR a7 R a8 R3 equals R4, which equals hydrogen or deuterium.

[0022] R a1 R a2 R a3 R a4 R a5 R a6 R a7 R a8 Each group is independently selected from the following groups: hydrogen, deuterium, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 ynyl, C3-C7 cycloalkyl, C6-C10 aryl, and 3-15 membered heterocyclic groups. The alkyl, alkenyl, ynyl, cycloalkyl, aryl, and heterocyclic groups may optionally be substituted by one or more groups independently selected from hydroxyl, amino, trifluoromethyl, nitro, halogen, C1-C6 alkyl, halo-C1-C6 alkyl, C1-C6 alkoxy, aryl, and heterocyclic groups.

[0023] Preferably, the compound of formula I, its pharmaceutical salt or ester, solvate, isomer, polymorph, isotope-labeled compound, metabolite, or prodrug of the present invention is characterized in that: when R2 represents hydrogen, deuterium, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkynyl, C3-C7 cycloalkyl, C6-C10 aryl, -(C1-C4 alkyl)nOR a5 -(C1-C4 alkyl)nSR a6 -(C1-C4 alkyl)nNR a7 In this case, R1 represents hydroxyl, methoxy, benzyloxy, benzylamino-(C1-C4 alkyl)nR a4 R3 and R4 may be the same or different, and are independently selected from hydrogen, deuterium, benzyl, benzoyl, and benzenesulfonyl. a4 R a5 R a6 R a7 Ra8 Each group is independently selected from the following groups: hydrogen, deuterium, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 ynyl, C3-C7 cycloalkyl, C6-C10 aryl, and 3-15 membered heterocyclic groups. The alkyl, alkenyl, ynyl, cycloalkyl, aryl, and heterocyclic groups may optionally be substituted by one or more groups independently selected from hydroxyl, amino, trifluoromethyl, nitro, halogen, C1-C6 alkyl, halo-C1-C6 alkyl, C1-C6 alkoxy, aryl, and heterocyclic groups.

[0024] Preferably, the compound of formula I, its pharmaceutical salt or ester, solvate, isomer, polymorph, isotope-labeled compound, metabolite, or prodrug of the present invention is characterized in that: when R3 and R4 are the same or different, they are independently selected from hydrogen, deuterium, and -CH2-R. a9 -CO-R a10 -CO-SO2-R a11 In this case, R1 represents hydroxyl, methoxy, benzyloxy, or benzylamino; R2 represents C1-C6 alkyl. a9 R a10 R a11 Each group is independently selected from the following groups: C1-C6 alkyl, C1-C6 alkenyl, C1-C6 ynyl, C3-C7 cycloalkyl, C6-C10 aryl, 3-15 membered heterocyclic groups. The alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocyclic groups, It may optionally be substituted with one or more groups independently selected from hydroxyl, amino, trifluoromethyl, nitro, halogen, C1-C6 alkyl, halo-C1-C6 alkyl, C1-C6 alkoxy, C1-C6 acyl, substituted aryl, and heterocyclic groups. The substituted aryl groups include halogen, hydroxyl, methoxy, nitro, and trifluoromethyl substituted groups.

[0025] Particularly preferred are the compounds of formula I, pharmaceutical salts or esters thereof, solvates, isomers, polymorphs, isotopically labeled compounds, metabolites, or prodrugs of the present invention, characterized in that the compound represented by formula I is:

[0026] 2-Amino-N 5 Methyl 5-oxovalerate

[0027] 2-Amino-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0028] 2-Amino-N 1 -Benzyl-N 5 -Ethylglutaramide

[0029] 2-Amino-N 5Hexyl 5-oxopentanoate

[0030] 2-Amino-N 5 2-Hydroxyethyl 5-ethyl-5-oxovalerate

[0031] 2-Amino-N 5 2-(1-pyrrolidinyl)ethyl 5-oxopentanoic acid-2-(1-pyrrolidinyl)ethyl ester

[0032] 2-Amino-N 5 -Ethyl-N 1 -[4-(trifluoromethyl)benzyl]glutaramide

[0033] 2-Amino-N 5 -Ethyl-N 1 -[4-(methoxy)benzyl]glutaramide

[0034] 2-Amino-N 5 -[2-(1H-imidazol-2-ylmethylthio)ethyl]-N 1 -Benzylglutaramide

[0035] 2-Amino-N 1 -Benzyl-N 5 -[2-(benzyloxy)ethyl]glutaramide

[0036] 2-Amino-N 5 -Ethyl-N 1 -(3-pyridinemethyl)glutaramide

[0037] 2-Amino-N 5 methyl butyl-5-oxovalerate

[0038] 2-Amino-N 5 Methyl benzyl-5-oxovalerate

[0039] 2-Amino-N 5 Methyl 2-[2-(benzyloxy)ethyl]-5-oxovalerate

[0040] 2-Amino-N 5 Methyl isopropyl-5-oxovalerate

[0041] 2-Amino-N 5 Methyl 2-(2-hydroxyethyl)-5-oxovalerate

[0042] 2-Amino-N 5 Methyl 2-(pyridin-2-yl)-5-oxovalerate

[0043] 2-Amino-N 5 Methyl -(thiazo-2-yl)-5-oxovalerate

[0044] 2-Amino-N 5 Methyl 5-phenyl-oxovalerate

[0045] 2-Amino-N 5 Methyl 2-((4-chlorobenzyloxy)ethyl)-5-oxovalerate

[0046] 2-Amino-N 5 Methyl 2-((3-chlorobenzyloxy)ethyl)-5-oxovalerate

[0047] 2-Amino-N 5 Methyl 2-((2-chlorobenzyloxy)ethyl)-5-oxovalerate

[0048] 2-Amino-N 5 Methyl 2-(2-(benzylamino)ethyl)-5-oxovalerate

[0049] 2-Amino-N 5 Methyl 2-(2-(benzylthio)ethyl)-5-oxovalerate

[0050] 2-Amino-N 5 Methyl 2-[2-(dibenzylamino)ethyl]-5-oxovalerate

[0051] 2-Amino-N 5 -(2-hydroxyethyl)-5-oxovaleric acid

[0052] 2-Amino-N 5 -Butyl-5-oxovaleric acid

[0053] 2-Amino-N 5 -Isopropyl-5-oxo-valeric acid

[0054] 2-Amino-N 5 methyl cyclopropylmethyl-5-oxovalerate

[0055] N 2 -Benzyl-N 5 Methyl 2-(2-(piperidin-1-yl)ethyl)-5-oxo-1-pentanoate

[0056] N 2 -Benzyl-N 5 Methyl 2-[2-(benzyloxy)ethyl]-5-oxo-1-pentanoate

[0057] N 2 -Benzyl-N 5 Methyl butyl-5-oxo-1-pentanoate

[0058] N 2 -benzoyl-N 5 Methyl 5-oxo-1-pentanoate

[0059] N 2 -Benzyl-N 5 Methyl 5-oxo-1-pentanoate

[0060] N 2 -(4-Trifluoromethylphenyl)-N 5 Methyl 5-oxo-1-pentanoate

[0061] N 2 -(2-Hydroxybenzyl)-N 5 Methyl 5-oxo-1-pentanoate

[0062] N 2 -(3-hydroxybenzyl)-N 5 Methyl 5-oxo-1-pentanoate

[0063] N 2 -(4-hydroxybenzyl)-N 5 Methyl 5-oxo-1-pentanoate

[0064] N 2 -(4-chlorobenzyl)-N 5 Methyl 5-oxo-1-pentanoate

[0065] N 2 -benzenesulfonyl-N 5 Methyl 5-oxo-1-pentanoate

[0066] N 1 -Benzyl-N 5 2-Ethyl-2-(benzenesulfonylamino)glutaramide

[0067] N 2 -(6-bromo-4-chloroquinoline-2-formyl)-N 5 Methyl 5-oxo-1-pentanoate

[0068] N 2 -(6-bromo-4-methylquinoline-2-formyl)-N 5 Methyl 5-oxo-1-pentanoate

[0069] N 2 -(benzodihydropyran-3-formyl)-N 5 Methyl 5-oxo-1-pentanoate

[0070] N 2 -(6-Chlorobenzodihydropyran-3-formyl)-N 5 Methyl 5-oxo-1-pentanoate

[0071] N2 -(6-Chloro-4-methylquinoline-2-formyl)-N 5 Methyl 5-oxo-1-pentanoate

[0072] N 2 N 2 -Dibenzyl-N 5 Methyl 5-oxo-1-pentanoate

[0073] N 2 N 2 -dibenzyl-N 5 Methyl butyl-5-oxo-1-pentanoate

[0074] N 2 N 2 -Dibenzyl-N 5 Ethyl 5-oxo-1-pentanoate

[0075] N 2 N 2 -dibenzyl-N 5 propyl 5-ethyl-5-oxo-1-pentanoate

[0076] N 2 N 2 -Dibenzyl-N 5 Butyl ethyl-5-oxo-1-pentanoate

[0077] N 2 N 2 -dibenzyl-N 5 ethyl-5-oxo-1-pentanoic acid benzyl ester

[0078] N 1 -Benzyl-2-(Dibenzylamino)-N 5 -Ethylglutaramide

[0079] N 2 N 2 -di(4-hydroxybenzyl)-N 5 Methyl 5-oxo-1-pentanoate

[0080] N 2 N 2 -di(4-methoxybenzyl)-N 5 Methyl 5-oxo-1-pentanoate

[0081] N 2 N 2 -Di(4-chlorobenzyl)-N 5 Methyl 5-oxo-1-pentanoate

[0082] N 2 N2 -di(3,4-dihydroxybenzyl)-N 5 Methyl 5-oxo-1-pentanoate

[0083] N 2 N 2 -dibenzyl-N 5 Ethyl butyl-5-oxo-1-pentanoate

[0084] N 2 -benzenesulfonyl-N 5 ethyl-5-oxo-1-pentanoic acid benzyl ester

[0085] N 2 -(4-Methylbenzenesulfonyl)-N 5 ethyl-5-oxo-1-pentanoic acid benzyl ester

[0086] N 2 -(4-bromobenzenesulfonyl)-N 5 ethyl-5-oxo-1-pentanoic acid benzyl ester

[0087] N 1 -benzyl-2-(benzylamino)-N 5 -Ethylglutaramide

[0088] N 2 -benzoyl-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0089] N 2 -Benzyl-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0090] N 2 -(2-pyridinylmethyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0091] N 2 -(1H-pyrrolo-2-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0092] N 2 -cyclohexanoyl-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0093] N 2 -Cyclohexylmethyl-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0094] N 2 -Cyclopropylmethyl-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0095] N2 N 5 Benzyl diethyl-5-oxovalerate

[0096] N 2 -acetyl-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0097] N 2 N 2 N 5 Benzyl triethyl-5-oxovalerate

[0098] N 2 -Hexagen-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0099] N 2 -(piperidin-4-ylmethyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0100] N 2 -(piperidin-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0101] N 2 -(1-benzoylpiperidin-4-formyl)-N 5 ethyl-5-oxovalerate benzyl ester N 2 -(1-Benzylpiperidin-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0102] N 2 -(1-(4-hydroxybenzyl)piperidine-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0103] N 2 -(1-(4-chlorobenzyl)piperidin-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0104] N 2 -(1-(4-nitrobenzyl)piperidine-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0105] N 2 -(1-Propionylpiperidin-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester

[0106] N 2 -(cyclohexanoyl)-N 5 -Ethyl-5-oxovaleric acid

[0107] N 2 -Benzyl-N 5 -Ethyl-5-oxovaleric acid

[0108] N 2 -(pyridine-2-methyl)-N 5 -Ethyl-5-oxovaleric acid

[0109] N 2 -(1H-pyrrolo-2-yl)-N 5 -Ethyl-5-oxovaleric acid

[0110] N 2 -(6-bromo-4-chloroquinoline-2-formyl)-N 5 ethyl-5-oxo-1-pentanoic acid

[0111] N 2 -(6-bromo-4-methylquinoline-2-formyl)-N 5 ethyl-5-oxo-1-pentanoic acid

[0112] N 2 N 2 -dibenzyl-N 5 -Butyl-5-oxo-1-pentanoic acid

[0113] N 2 N 2 -dibenzyl-N 5 ethyl-5-oxo-1-pentanoic acid

[0114] N 2 -benzoyl-N 5 ethyl-5-oxo-1-pentanoic acid

[0115] N 2 -(4-Methoxybenzoyl)-N 5 ethyl-5-oxo-1-pentanoic acid

[0116] N 2 -(2-Methoxybenzoyl)-N 5 ethyl-5-oxo-1-pentanoic acid

[0117] N 2 -(3-Methoxybenzoyl)-N 5 ethyl-5-oxo-1-pentanoic acid

[0118] N 2 -benzenesulfonyl-N 5 1-Ethyl-5-oxo-1-pentanoic acid.

[0119] Furthermore, the present invention also proposes a method for preparing the compound of formula I, which is carried out according to the following method:

[0120] When R3 = R4 is hydrogen, and R1 and R2 are as defined in claim 1, the method shown in synthetic route 1 is adopted;

[0121] Synthesis Route 1:

[0122]

[0123] (S)-N-tert-Butoxycarbonylglutamate-1-benzyl ester or (R)-N-tert-Butoxycarbonylglutamate-1-benzyl ester undergoes a condensation reaction with various substituted primary amine compounds to generate compound 2. Then, it is debenzylated (Bn) with hydrogen on palladium on carbon to obtain compound 3. Compound 3 is condensed with various substituted alcohols or substituted amine compounds to obtain compound 4. Finally, the benzyl group of the compound is removed by trifluoroacetic acid (TFA) to obtain compound 5. R1 (not a hydroxyl group) and R2 are the same as defined in claim 1.

[0124] When R1 is a hydroxyl group, R3 = R4 are hydrogen, and R2 is as defined in claim 1, the method shown in synthetic route 2 shall be used;

[0125] Synthesis Route 2:

[0126]

[0127] Compound 4 was obtained from the synthetic route 1. Compound 4 was then directly subjected to deBoc removal with trifluoroacetic acid to obtain compound 7 (N). 5 -R2-5-oxovaleric acid compounds).

[0128] R1 represents hydroxyl, methoxy, benzyloxy, and benzylamino; R2 represents C1-C6 alkyl; when R3 and R4 are defined as described above, the method shown in synthetic route 3 shall be used.

[0129] Synthesis Route 3:

[0130]

[0131] Compound 6 undergoes substitution reactions with various chlorinated derivatives under alkaline conditions to give compound 8, and condenses with various carboxylic acids to give compound 9. Compound 8 or 9, when R1 is methoxy, is hydrolyzed by reflux with cesium carbonate to give compound 10.

[0132] The present invention further provides the use of compounds of Formula I, their pharmaceutical salts or esters, solvates, isomers, polymorphs, isotope-labeled compounds, metabolites or prodrugs in the preparation of drugs for treating liver fibrosis.

[0133] The applications also include the treatment of chronic liver diseases such as alcoholic steatohepatitis and non-alcoholic steatohepatitis.

[0134] The present invention also provides pharmaceutical compositions comprising compounds containing the structure of Formula I, pharmaceutical salts or esters thereof, solvates, isomers, polymorphs, isotopically labeled compounds, metabolites or prodrugs.

[0135] The pharmaceutically active substance of the present invention may constitute 0.1-99.9% by weight in the formulation, with the remainder being a pharmaceutically acceptable carrier. The pharmaceutical formulation of the present invention exists in unit dose form, where unit dose form refers to a unit of the formulation, such as each tablet, each capsule, each bottle of oral liquid, or each sachet of granules.

[0136] The pharmaceutical formulation of the present invention can be any pharmaceutically acceptable dosage form, including oral, topical, and injectable dosage forms.

[0137] These dosage forms include: tablets, sugar-coated tablets, film-coated tablets, enteric-coated tablets, capsules, hard capsules, soft capsules, oral liquids, lozenges, granules, powders, pills, powders, ointments, elixirs, suspensions, powders, solutions, injections, suppositories, ointments, plasters, creams, sprays, drops, and patches. The formulations of this invention are preferably oral dosage forms, such as: capsules, tablets, oral liquids, granules, pills, powders, elixirs, ointments, etc.

[0138] The pharmaceutical formulations of the present invention, when administered orally, may contain commonly used excipients such as binders, fillers, diluents, tableting agents, lubricants, disintegrants, colorants, flavoring agents, and humectants, and the tablets may be coated if necessary.

[0139] Suitable fillers include cellulose, mannitol, lactose, and other similar fillers. Suitable disintegrants include starch, polyvinylpyrrolidone, and starch derivatives, such as sodium glycolate starch. Suitable lubricants include, for example, magnesium stearate. Suitable pharmaceutically acceptable wetting agents include sodium lauryl sulfate.

[0140] Solid oral compositions can be prepared using common methods such as mixing, filling, and tableting. Repeated mixing allows the active ingredient to be distributed throughout compositions that use a large amount of filler.

[0141] Oral liquid formulations may take the form of aqueous or oily suspensions, solutions, emulsions, syrups, or elixirs, or may be a dry product that can be reconstituted with water or other suitable carriers before use. Such liquid formulations may contain conventional additives, such as suspending agents like sorbitol, syrups, methylcellulose, gelatin, hydroxyethylcellulose, carboxymethylcellulose, aluminum stearate gel, or hydrogenated edible fats; emulsifiers like lecithin, dehydrated sorbitan monooleate, or gum arabic; non-aqueous carriers (which may include edible oils such as almond oil, fractionated coconut oil, oily esters such as glycerol, propylene glycol, or ethanol); preservatives such as methylparaben or propylparaben or sorbic acid; and, if desired, conventional flavorings or colorings.

[0142] For injectable formulations, the prepared liquid unit contains the active ingredient of this invention and a sterile carrier. Depending on the carrier and concentration, this compound can be suspended or dissolved. Solution preparation typically involves dissolving the active ingredient in a carrier, filtering and sterilizing it before filling it into a suitable vial or ampoule, and then sealing it. Excipients such as a local anesthetic, preservative, and buffer can also be dissolved in this carrier. To improve its stability, the composition can be frozen after filling into the vial, and water can be removed under vacuum.

[0143] The pharmaceutical formulation of the present invention may selectively incorporate a suitable pharmaceutically acceptable carrier during preparation. The pharmaceutically acceptable carrier is selected from: mannitol, sorbitol, sodium metabisulfite, sodium bisulfite, sodium thiosulfate, cysteine ​​hydrochloride, thioglycolic acid, methionine, vitamin C, disodium EDTA, sodium calcium EDTA, carbonates, acetates, phosphates or aqueous solutions of monovalent alkali metals, hydrochloric acid, acetic acid, sulfuric acid, phosphoric acid, amino acids, sodium chloride, potassium chloride, sodium lactate, xylitol, maltose, glucose, fructose, dextran, glycine, starch, sucrose, lactose, mannitol, silicon derivatives, cellulose and its derivatives, alginate, gelatin, polyvinylpyrrolidone, glycerol, Twenty-80, agar, calcium carbonate, calcium bicarbonate, surfactants, polyethylene glycol, cyclodextrin, β-cyclodextrin, phospholipids, kaolin, talc, calcium stearate, magnesium stearate, etc.

[0144] Furthermore, the present invention also provides a method for treating liver fibrosis, comprising administering to a subject in need a therapeutically effective amount of one or more of the compounds of the present invention, either alone or in combination with other compounds. The compounds herein include compounds of Formula I, as well as pharmaceutical salts, solvates, isomers, polymorphs, isotope labels, metabolites, or prodrugs of said Formula I compounds.

[0145] Terminology Definition

[0146] The terminology used in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The nomenclature used herein and the laboratory procedures described herein in organic chemistry, medicinal chemistry, and biology are well-known and commonly used in the art. Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0147] As used in the description of embodiments of the invention and the appended claims, the singular forms of “a,” “an,” “the,” and “its” are used to refer to the singular and plural of the article, unless the context clearly indicates otherwise. For example, a compound comprises one or more compounds.

[0148] As used in this article, “and / or” means any and all possible combinations of one or more of the related listed items.

[0149] As used herein, the term “disease” or “patient” refers to any change in physical condition or organ that interrupts or interferes with the functioning of the organ and / or causes symptoms.

[0150] As used herein, the term "treatment" aims to alleviate or eliminate a targeted disease state or symptom. A subject is successfully "treated" if, in accordance with the methods described herein, a therapeutic amount of a compound or its pharmaceutically acceptable salt, isomer, polymorph, solvate, isotopically labeled compound, metabolite, or prodrug, or a pharmaceutical composition thereof, is received and one or more indications and symptoms show an observable and / or detectable reduction or improvement. It should also be understood that treatment of the disease state or symptom includes not only complete treatment but also the achievement of some biological or medically relevant outcome without achieving complete treatment.

[0151] As used herein, the term "subject" may refer to a patient or other animal that receives the compositions of the present invention to treat, prevent, reduce and / or alleviate the disease or condition described herein, and in particular to humans and mammals.

[0152] As used herein, "hydrocarbon group" can be, but is not limited to, a straight-chain, cyclic, or branched hydrocarbon group, and can be saturated or unsaturated, such as methyl, ethyl, isopropyl, n-propyl, n-butoxy, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, cyclopropylmethyl, allyl, etc.

[0153] As used herein, "hydroxyl group" can be, but is not limited to, straight-chain, cyclic, or branched hydroxyl groups, and can be saturated or unsaturated, such as methoxy, ethoxy, isopropoxy, n-propoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, isopentoxy, cyclopropylmethoxy, allyloxy, etc.

[0154] As used herein, “substituted benzyloxy” can be, but is not limited to, a monosubstituted, disubstituted, or trisubstituted benzyloxy at various substitution positions, such as halogen, alkyloxy, hydroxyl, hydrocarbon, amino, and substituted amino.

[0155] As used in this article, "acyloxy" can be a hydrocarbon-substituted acyloxy, such as formyloxy, acetoxy, isopropyloxy, n-propyloxy, allyloxy, cyclopropyloxy, n-butyloxy, isobutyloxy, sec-butyloxy, tert-butyloxy, n-pentyloxy, isopentyloxy, n-hexyloxy, isohexyloxy, etc.

[0156] As used in this article, "halogenated" or "halogen" can refer to fluorine, chlorine, bromine, or iodine.

[0157] As used herein, "alkyl" can be straight-chain, cyclic, or branched, and can be saturated or unsaturated, for example, methyl, ethyl, isopropyl, n-propyl, n-butoxy, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, cyclohexylmethyl, cyclopropylmethyl, allyl, etc.

[0158] As used herein, "pharmaceutical salt" refers to a salt that retains the desired biological activity of the target compound and exhibits minimal undesirable toxicological effects. When the compounds of the present invention contain relatively acidic functional groups, base addition salts can be obtained by contacting the neutral form of the compounds of the present invention with a sufficient amount of base in a pure solution or a suitable inert solvent. Pharmaceutically acceptable bases include salts prepared from inorganic bases and organic bases, wherein the inorganic base salts include aluminum salts, ammonium salts, calcium salts, copper salts, iron salts, ferrous salts, lithium salts, magnesium salts, manganese salts, manganese salts, potassium salts, sodium salts, zinc salts, etc. The organic non-toxic base salts include salts of primary amines, secondary amines, and tertiary amines, including substituted amines and cyclic amines. Examples include: N,N'-dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol, aminoethanol, ethanolamine, ethylenediamine, N-ethylmorpholine, N-ethylpiperidine, glucosamine, glucosamine, histidine, hydroxycobalamin, isopropylamine, lysine, methylglucosamine, morpholine, piperazine, piperidine, guanidine, polyamine resins, procaine, purine, theobromine, triethylamine, trimethylamine, tripropylamine, etc. When the compounds of the present invention contain relatively basic functional groups, acid addition salts can be obtained by contacting the neutral form of such compounds with a sufficient amount of acid in a pure solution or a suitable inert solvent. Examples of pharmaceutically acceptable acid addition salts include inorganic acid salts, such as hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, phosphoric acid, or nitric acid; and organic acids such as formic acid, acetic acid, acetoacetic acid, pyruvic acid, trifluoroacetic acid, propionic acid, butyric acid, hexanoic acid, heptanoic acid, undecanoic acid, lauric acid, benzoic acid, salicylic acid, 2-(4-hydroxybenzoyl)-benzoic acid, camphoric acid, cinnamic acid, cyclopentanepropionic acid, digluconic acid, 3-hydroxy-2-naphthoic acid, nicotinic acid, bamoic acid, pectinic acid, 3-phenylpropionic acid, picric acid, terpentinic acid, 2-hydroxyethanesulfonic acid, itaconic acid, and aminosulfonic acid. Trifluoromethanesulfonic acid, dodecyl sulfate, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, 2-naphthalenesulfonic acid, naphthalenedisulfonic acid, camphorsulfonic acid, citric acid, tartaric acid, stearic acid, lactic acid, oxalic acid, malonic acid, succinic acid, malic acid, adipic acid, alginic acid, maleic acid, fumaric acid, D-gluconic acid, mandelic acid, ascorbic acid, glucoheponic acid, glycerophosphate, aspartic acid, sulfosalicylic acid, and salts formed from sodium, potassium, magnesium, lithium, aluminum, calcium, zinc, N,N'-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine, N-methylglucosamine, and procaine.

[0159] As used herein, "pharmaceutical ester" refers to an ester formed by the -OH group present in the compounds provided by this invention and a suitable acid (e.g., a carboxylic acid or an oxy-containing inorganic acid). Suitable ester groups include, but are not limited to, formate, acetate, propionate, butyrate, acrylate, ethyl succinate, stearic acid ester, or palmitate.

[0160] As used herein, "isomer" refers to the presence of compounds of Formula I containing one or more asymmetric centers and / or double bonds, and that the compounds of the present invention can exist as racemic derivatives, racemic mixtures, single enantiomers, diastereomer mixtures, single diastereomers, geometric isomers, etc. These compounds may be represented by the symbols "R" or "S," depending on the configuration of the substituents surrounding the stereocarbon atom, and may also be represented by the symbols "Z" or "E," depending on the arrangement of the substituents surrounding the carbon-carbon double bond, or the substituents surrounding the carbon-carbon double bond may be referred to as "cis" or "trans." The compounds disclosed herein can exist as tautomers, and both tautomer forms are intended to be included within the scope of the invention, even if only one tautomer structure is described, such as keto-enol tautomers, phenol-keto tautomers, nitroso-oxime tautomers, imine-enamine tautomers, etc.

[0161] As used herein, “polymorph” means that compounds of Formula I can also exist in various crystalline forms, and different single crystalline forms and mixtures of polymorphs are obtained by recrystallizing the compound or its pharmaceutically acceptable salt in a solvent.

[0162] As used herein, "solvent" means that a compound of Formula I can exist in the form of a solvate (such as a hydrate), wherein the compounds of the present invention contain a polar solvent, particularly, for example, water, methanol, or ethanol, as a structural element of the lattice of the compound. The amount of the polar solvent, particularly water, can be stoichiometric or non-stoichiometric.

[0163] As used herein, "isotope" refers to a compound of formula I and is also intended to include compounds distinguished only by the presence of one or more isotopically enriched atoms. For example, compounds having the structure of the present invention, but with deuterium (2H) or tritium (3H) instead of hydrogen, or with 13C- or 14C-carbon atoms instead of carbon, are within the scope of the present invention. Such compounds can be used, for example, as probes or therapeutic agents in analytical tools, bioassays.

[0164] As used herein, "prodrug" refers to a compound of formula I that may also be in the form of a prodrug or in a form that releases the active ingredient after metabolic changes in vivo. The selection and preparation of appropriate prodrug derivatives are techniques well known to those skilled in the art.

[0165] As used herein, a "pharmaceutical composition" comprises a therapeutically effective amount of a pharmaceutically acceptable salt or ester, solvate, isomer, polymorph, isotopically labeled compound, metabolite, or prodrug of Formula I, and one or more pharmaceutically acceptable carriers, prepared in the form of tablets, capsules, granules, powders, suspensions, emulsions, powders, solutions, gels, syrups, pills, tinctures, tinctures, decoctions, lozenges, mixtures, suppositories, injections, inhalants, or sprays. Preferably, the pharmaceutical composition contains 0.1% to 99.5% by weight of the compound of Formula I of the present invention or its pharmaceutically acceptable salt as the active ingredient, more preferably 0.5% to 99.5% by weight of the active ingredient.

[0166] As used herein, “pharmaceutically acceptable carriers or excipients” include: diluents, fillers, binders, disintegrants, lubricants, flow aids, granulators, coating agents, wetting agents, solvents, co-solvents, suspending agents, emulsifiers, sweeteners, flavoring agents, taste masking agents, colorants, anti-caking agents, humectants, chelating agents, plasticizers, thickeners, antioxidants, preservatives, stabilizers, surfactants, and buffers. Those skilled in the art will understand that some pharmaceutically acceptable excipients may be used for more than one function and for alternative functions, depending on the amount of said excipient present in the formulation and what other ingredients are present in the formulation. For example, when intended for oral administration, it can be formulated into oral preparations such as tablets (including regular tablets, enteric-coated tablets, lozenges, dispersible tablets, chewable tablets, effervescent tablets, and orally disintegrating tablets), capsules (including hard capsules, soft capsules, and enteric-coated capsules), granules, and pills, containing fillers (e.g., sugar derivatives such as lactose, sucrose, glucose, mannitol, and sorbitol; starch derivatives such as corn starch, potato starch, dextrin, and carboxymethyl starch; cellulose derivatives such as crystalline cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, calcium carboxymethyl cellulose, and sodium carboxymethyl cellulose); Arabica... Gum; dextran; silicate derivatives such as magnesium aluminum metasilicate; phosphate derivatives such as calcium phosphate; carbonate derivatives such as calcium carbonate; sulfate derivatives such as calcium sulfate, etc.), binders (e.g., gelatin, polyvinylpyrrolidone, and polyethylene glycol), disintegrants (e.g., cellulose derivatives such as sodium carboxymethyl cellulose and polyvinylpyrrolidone), lubricants (e.g., talc, calcium stearate, magnesium stearate, cetyl, boric acid, sodium benzoate, leucine), stabilizers (e.g., methylparaben, propylparaben, etc.), flavoring agents (e.g., commonly used sweeteners, acidulants, and flavorings, etc.). When used parenterally, it can be formulated as an injectable preparation, including sterile powder for injection and solvent for injection. The carrier or excipients used include sterile water, Ringer's solution, and isotonic sodium chloride solution. Appropriate excipients such as antioxidants, buffers, antibacterial agents, solubilizers, cosolvents, pH adjusters, and osmotic pressure regulators may also be added according to the properties of the drug. Solubilizers or co-solvents can be poloxamer, lecithin, hydroxypropyl-β-cyclodextrin, etc.; pH adjusters can be phosphates, acetates, hydrochloric acid, sodium hydroxide, etc.; osmotic pressure adjusters can be sodium chloride, mannitol, glucose, phosphates, acetates, etc. When preparing lyophilized powder injections, mannitol, glucose, etc., can also be added as support agents. When used for rectal administration, the drug can be formulated as suppositories, etc. When used for pulmonary administration, the drug can be formulated as inhalers or sprays, etc. Many resources available to those skilled in the art describe pharmaceutically acceptable excipients and can be used to select suitable pharmaceutically acceptable excipients, such as the Remington Pharmacy Encyclopedia, the Chinese Pharmaceutical Yearbook, and Pharmaceutics.

[0167] The compounds of this invention and their pharmaceutically acceptable salts can be formulated into conventional formulations, as well as sustained-release formulations, controlled-release formulations, targeted formulations, and various microparticle delivery systems.

[0168] This invention can be administered by any suitable method known in the art, such as oral, intravenous, intraperitoneal, intramuscular, local, transdermal, ocular, nasal, inhalation, subcutaneous, intramuscular, oral, sublingual, or rectal administration. The appropriate daily dose range is 0.001-150 mg / kg body weight, preferably 0.1-100 mg / kg body weight, more preferably 1-60 mg / kg body weight, and most preferably 2-30 mg / kg body weight. The above doses can be administered as a single unit or divided into several units, depending on the physician's clinical experience and the administration regimen, including the use of other treatment methods.

[0169] The compounds of the present invention can be used alone or in combination with one or more other active ingredients for the treatment, prevention, inhibition, or improvement of diseases or symptoms, wherein the combined use of the drugs is safer or more effective than the use of any one drug alone. Such other drugs can be administered simultaneously or sequentially with the compounds of the present invention in the manner and amount normally used therein. When the compounds of the present invention are used simultaneously with one or more other drugs, pharmaceutical compositions containing the other drug and the compounds of the present invention in a unit dosage form are preferred, particularly in combination with a pharmaceutically acceptable carrier. However, combination therapy may also include treatment with the compounds of the present invention and one or more other drugs administered on different overlapping schedules. It is also contemplated that when used in combination with one or more other active ingredients, the compounds of the present invention and the other active ingredients can be used at lower doses than when used individually. Therefore, in addition to the compounds of the present invention, the pharmaceutical compositions of the present invention also include those compositions containing one or more other active ingredients.

[0170] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0171] This invention has revealed that the compound shown in Formula I can inhibit the activity of the COL1A1 promoter at the gene level, and simultaneously inhibit the expression of fibrosis-related proteins COL1A1, TGF-β, α-SMA, CTGF, and TIMP1 at the cellular level and in vivo, thereby inhibiting hepatic stellate cell activation to some extent and alleviating the progression of liver fibrosis. Therefore, this invention provides a novel technical approach for the treatment of liver fibrosis. Attached Figure Description

[0172] Figure 1 Results of inhibiting fibrosis-related protein expression. Note: In the figure, "LT" and "DT" represent L-theanine and D-theanine, respectively.

[0173] Figure 2 Results of inhibiting fibrosis-related protein expression. Note: In the figure, "LT" and "DT" represent L-theanine and D-theanine, respectively.

[0174] Figure 3 Inhibitory effect of I-61 on fibrosis-related mRNAs. Detailed Implementation

[0175] The present invention is illustrated below with reference to specific embodiments. These embodiments are not intended to limit the scope of the invention, but rather to provide guidance to those skilled in the art for the preparation and use of the compounds and compositions of the present invention. The chemical names of the compounds described in this application are generally derived from ChemDraw Ultra (Chambridge Soft) and generated / or generally follow the principles of IUPAC nomenclature. Unless otherwise specified, the methods described in this invention are conventional methods. Unless otherwise specified, the raw materials are all available from publicly available commercial sources.

[0176] The compounds in this embodiment were prepared via the following route:

[0177] When R3 = R4 is hydrogen, and R1 and R2 are as defined in claim 1, the method shown in synthetic route 1 is adopted;

[0178] Synthesis Route 1:

[0179]

[0180] (S)-N-tert-Butoxycarbonylglutamate-1-benzyl ester or (R)-N-tert-Butoxycarbonylglutamate-1-benzyl ester undergoes a condensation reaction with various substituted primary amine compounds to generate compound 2. Then, it is debenzylated (Bn) with hydrogen on palladium on carbon to give compound 3. Compound 3 is condensed with various substituted alcohols or substituted amine compounds to give compound 4. Finally, the benzyl group of the compound is removed by trifluoroacetic acid (TFA) to give compound 5. R1 (not a hydroxyl group) and R2 are defined as described above.

[0181] When R1 is a hydroxyl group, R3 = R4 are hydrogen, and R2 is as defined above, the method shown in synthetic route 2 shall be used.

[0182] Synthesis Route 2:

[0183]

[0184] Compound 4 was obtained from the synthetic route 1. Compound 4 was then directly subjected to deBoc removal with trifluoroacetic acid to obtain compound 7 (N). 5 -R2-5-oxovaleric acid compounds).

[0185] R1 represents hydroxyl, methoxy, benzyloxy, or benzylamino; R2 represents C1-C6 alkyl. When other parameters are the same as those defined above, the method shown in synthetic route 3 shall be used.

[0186] Synthesis Route 3:

[0187]

[0188] Compound 6 undergoes substitution reactions with various chlorinated derivatives under alkaline conditions to give compound 8, and condenses with various carboxylic acids to give compound 9. Compound 8 or 9, when R1 is methoxylated, is hydrolyzed by reflux with cesium carbonate to give compound 10. R1, R2, R3, and R4 are defined as in the aforementioned general formulas.

[0189] Example 1

[0190] 2-Amino-N 5 methyl 5-ethyl-oxovalerate (I-1)

[0191]

[0192] 1 H NMR(500MHz,Chloroform-d)δ6.67(t,J=4.1Hz,1H),3.70(s,2H),3.63–3.55(m,1H),3.25–3. 16(m,2H),2.95(d,J=6.4Hz,2H),2.28–2.17(m,2H),2.15–1.97(m,2H),1.12(t,J=6.5Hz,3H).

[0193] Example 2

[0194] 2-Amino-N 5 1-Ethyl-5-oxovalerate (I-2)

[0195]

[0196] 1 H NMR(600MHz, Methanol-d4)δ4.17(t,J=6.7Hz,2H),3.49(dd,J=7.4,5.6Hz,1H),3.22(q,J=7.2Hz,2H),2.34–2.25(m,2H),2.09–2 .00(m,1H),1.94–1.84(m,1H),1.73–1.65(m,2H),1.46–1.39(m,2H),1.38–1.30(m,4H),1.15(t,J=7.3Hz,3H),0.99–0.90(m,3H).

[0197] Example 3

[0198] 2-Amino-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-3)

[0199]

[0200] 1 H NMR(600MHz,Methanol-d4)δ7.47–7.34(m,5H),5.34–5.28(m,2H),4.19–4.13(m,1H) ,3.24–3.16(m,2H),2.43(t,J=7.2Hz,2H),2.26–2.11(m,2H),1.12(t,J=7.3Hz,3H).

[0201] Example 4

[0202] 2-Amino-N 1 -Benzyl-N 5 -Ethylglutaramide (I-4)

[0203]

[0204]

[0205] 1 H NMR(600MHz,Deuterium Oxide)δ7.46–7.32(m,5H),4.48–4.37(m,2H),3.45(t,J=6.8Hz,1H),3.19(q ,J=7.3Hz,2H),2.25(t,J=7.8Hz,2H),1.98–1.83(m,2H),1.13–1.06(m,3H).

[0206] Example 5

[0207] 2-Amino-N 5 2-Hydroxyethyl ethyl-5-oxovalerate (I-5)

[0208]

[0209] 1H NMR(500MHz,Chloroform-d)δ6.67(t,J=4.1Hz,1H),4.25–4.13(m,2H),3.83–3.73(m,2H),3.64–3.55(m,1H),3.22(dd,J =6.5,4.1Hz,1H),3.22–3.16(m,3H),3.00(t,J=6.4Hz,1H),2.28–2.17(m,2H),2.13–1.92(m,2H),1.12(t,J=6.5Hz,3H).

[0210] Example 6

[0211] 2-Amino-N 5 2-(1-pyrrolidinyl)ethyl 5-oxovalerate (I-6)

[0212]

[0213] 1 H NMR(500MHz,Chloroform-d)δ6.67(t,J=4.1Hz,1H),4.21–4.09(m,2H),3.64–3.55(m,1H),3.22(dd,J=6.5,4.1Hz,1H),3.22–3.16 (m,3H),2.97–2.90(m,4H),2.82(t,J=6.3Hz,2H),2.31–2.17(m,2H),2.13–1.92(m,2H),1.89–1.79(m,4H),1.12(t,J=6.5Hz,3H).

[0214] Example 7

[0215] 2-Amino-N 5 -Ethyl-N 1 -[4-(trifluoromethyl)benzyl]glutaramide (I-7)

[0216]

[0217] 1H NMR(500MHz,Chloroform-d)δ7.62–7.56(m,2H),7.44–7.38(m,2H),7.31(t,J=5.9Hz,1H),6.67(t,J=4.0Hz,1H),4.41–4.32(m,2H),3.72–3.63( m,1H),3.30(dd,J=8.1,6.0Hz,1H),3.25–3.16(m,2H),2.89(dd,J=8.0,6.1Hz,1H),2.27–2.13(m,2H),1.99–1.92(m,2H),1.12(t,J=6.5Hz,3H).

[0218] Example 8

[0219] 2-Amino-N 5 -Ethyl-N 1 -[4-(methoxy)benzyl]glutaramide (I-8)

[0220]

[0221] 1 H NMR(500MHz,Chloroform-d)δ7.35–7.29(m,1H),7.20–7.14(m,2H),6.88–6.82(m,2H),6.67(t,J=4.0Hz,1H),4.41–4.33(m,2H) ,3.78(s,2H),3.72–3.63(m,1H),3.30(dd,J=8.1,6.0Hz,1H),3.25–3.16(m,2H),2.89(dd,J=8.0,6.1Hz,1H),2.27–2.13(m,2H),

[0222] 1.99–1.92(m,2H),1.12(t,J=6.5Hz,3H).

[0223] Example 9

[0224] 2-Amino-N 5 -[2-(1H-imidazol-2-ylmethylthio)ethyl]-N 1 -Benzylglutaramide (I-9)

[0225]

[0226] 1H NMR(500MHz,Chloroform-d)δ9.89(d,J=4.6Hz,1H),7.36–7.22(m,6H),7.04(dd,J =4.5,2.8Hz,1H),6.96(d,J=2.9Hz,1H),6.92(t,J=4.1Hz,1H),4.39–4.31(m,2H), 3.68(s,2H),3.72–3.63(m,1H),3.30(dd,J=8.1,6.0Hz,1H),3.30–3.20(m,2H),2. 89(dd,J=8.0,6.1Hz,1H),2.84–2.71(m,2H),2.24–2.15(m,2H),1.99–1.91(m,2H).

[0227] Example 10

[0228] 2-Amino-N 1 -Benzyl-N 5 -[2-(benzyloxy)ethyl]glutaramide (I-10)

[0229]

[0230] 1 H NMR(500MHz,Chloroform-d)δ7.39–7.22(m,12H),6.57(t,J=5.1Hz,1H),4.44(t,J=1.0Hz,2H),4.39–4.31(m,2H),3.72–3.63(m,1H),3.6 3(t,J=4.2Hz,2H),3.39–3.30(m,2H),3.30(dd,J=8.1,6.0Hz,1H),2.89(dd,J=8.0,6.1Hz,1H),2.19(t,J=8.3Hz,2H),1.99–1.91(m,2H).

[0231] Example 11

[0232] 2-Amino-N 5 -Ethyl-N 1 3-Pyridinemethyl)glutaramide (I-11)

[0233]

[0234] 1H NMR(500MHz,Chloroform-d)δ8.55(dd,J=2.2,1.6Hz,1H),8.49–8.43(m,1H),7.72–7. 66(m,1H),7.49(t,J=6.9Hz,1H),7.28(dd,J=7.8,4.2Hz,1H),6.67(t,J=4.0Hz,1H),4. 48–4.35(m,2H),3.72–3.63(m,1H),3.30(dd,J=8.1,6.0Hz,1H),3.25–3.16(m,2H),2. 89(dd,J=8.0,6.1Hz,1H),2.27–2.13(m,2H),1.99–1.91(m,2H),1.12(t,J=6.5Hz,3H).

[0235] Example 12

[0236] 2-Amino-N 5 methyl butyl-5-oxovalerate (I-12)

[0237]

[0238] 1 H NMR (400MHz, Methanol-d4) δ4.09(t,J=6.4Hz,1H),3.84(d,J=1.7Hz,3H),3.18(t,J=7.0Hz,2H),2.44 (t,J=7.1Hz,2H),2.27–2.04(m,2H),1.53–1.44(m,2H),1.41–1.30(m,2H),0.94(t,J=7.3,1.6Hz,3H).

[0239] Example 13

[0240] 2-Amino-N 5 methyl benzyl-5-oxovalerate (I-13)

[0241]

[0242] 1 H NMR (400MHz, Methanol-d4) δ7.31–7.18(m,5H),4.33(t,J=2.4Hz,2H),4.10–4.04(m,1H),3.79(d,J=1.7Hz,3H),2.52–2.43(m,2H),2.25–2.07(m,2H).

[0243] Example 14

[0244] 2-Amino-N5 Methyl 2-[2-(benzyloxy)ethyl]-5-oxovalerate (I-14)

[0245]

[0246] 1 H NMR (400MHz, Methanol-d4) δ7.35–7.29(m,5H),4.52(s,2H),4.08(t,J=6.4Hz,1H),3.83(d,J=1. 1Hz,3H),3.55(t,J=5.5Hz,2H),3.40(t,J=5.5Hz,2H),2.45(t,J=7.0Hz,2H),2.22–2.09(m,2H).

[0247] Example 15

[0248] 2-Amino-N 5 Methyl isopropyl-5-oxovalerate (I-15)

[0249]

[0250] 1 H NMR (400MHz, Methanol-d4) δ4.06(t,J=6.4Hz,1H),3.97–3.87(m,1H),3.82(s,3H),2.45–2.32(m,2H),2.21–2.04(m,2H),1.11(d,J=6.6Hz,6H).

[0251] Example 16

[0252] 2-Amino-N 5 Methyl 2-(2-hydroxyethyl)-5-oxovalerate (I-16)

[0253]

[0254] 1 H NMR (400MHz, Methanol-d4) δ4.05(t,J=6.3Hz,1H),3.79(d,J=1.2Hz,3H),3.55(t,J=5.7Hz,2H),2.42(t,J=6.9Hz,2H),2.24–2.02(m,2H).

[0255] Example 17

[0256] 2-Amino-N 5 Methyl 2-(pyridin-2-yl)-5-oxovalerate (I-17)

[0257]

[0258] 1 H NMR(400MHz, Methanol-d4)δ8.33(d,J=5.7Hz,1H),8.21–8.11(m,1H),7.77(d,J=8.6Hz,1H),7 .39(t,J=6.6Hz,1H),4.16(t,J=6.8Hz,1H),3.83(s,3H),2.88–2.71(m,2H),2.40–2.18(m,2H).

[0259] Example 18

[0260] 2-Amino-N 5 Methyl 2-(thiazolyl)-5-oxovalerate (I-18)

[0261]

[0262] 1 H NMR(400MHz,Methanol-d4)δ7.43(d,J=3.7Hz,1H),7.12(d,J=3.7Hz,1H),4.16 (t,J=6.8Hz,1H),3.83(d,J=1.1Hz,3H),2.81–2.70(m,2H),2.38–2.18(m,2H).

[0263] Example 19

[0264] 2-Amino-N 5 methyl 5-phenyl-oxovalerate (I-19)

[0265]

[0266] 1 H NMR (600MHz, Methanol-d4) δ7.54–7.52(m,2H),7.30–7.27(m,2H),7.09–7.06(m,1H),3.72( s,3H),3.52(dd,J=7.1,6.0Hz,1H),2.50–2.45(m,3H),2.13–2.07(m,1H),1.98–1.93(m,1H).

[0267] Example 20

[0268] 2-Amino-N 5 Methyl 2-((4-chlorobenzyloxy)ethyl)]-5-oxovalerate (I-20)

[0269]

[0270] 1 H NMR(500MHz,Chloroform-d)δ7.34–7.28(m,2H),7.28–7.21(m,2H),6.57(t,J=5.1Hz,1H),4.48(t,J=1.0Hz,2H),3.70(s,2H ),3.63(t,J=4.2Hz,2H),3.62–3.55(m,1H),3.40–3.29(m,2H),2.95(d,J=6.4Hz,2H),2.27–2.17(m,2H),2.15–1.97(m,2H).

[0271] Example 21

[0272] 2-Amino-N 5 Methyl 2-((3-chlorobenzyloxy)ethyl)]-5-oxovalerate (I-21)

[0273]

[0274] 1 H NMR(500MHz,Chloroform-d)δ7.41–7.34(m,2H),7.32–7.27(m,1H),7.27–7.21(m,1H),6.57(t,J=5.1Hz,1H),4.53(t,J=1.0Hz,2H),3 .70(s,2H),3.63(t,J=4.2Hz,2H),3.63–3.55(m,1H),3.41–3.28(m,2H),2.95(d,J=6.4Hz,2H),2.27–2.17(m,2H),2.15–1.97(m,2H).

[0275] Example 22

[0276] 2-Amino-N 5 Methyl 2-((2-chlorobenzyloxy)ethyl)]-5-oxovalerate (I-22)

[0277]

[0278] 1H NMR(500MHz,Chloroform-d)δ7.43–7.36(m,1H),7.30–7.25(m,2H),7.28–7.22(m,1H),6.57(t,J=5.1Hz,1H),4.64–4.54(m,2H),3 .70(s,2H),3.66–3.59(m,2H),3.62–3.55(m,1H),3.41–3.28(m,2H),2.95(d,J=6.4Hz,2H),2.27–2.17(m,2H),2.15–1.97(m,2H).

[0279] Example 23

[0280] 2-Amino-N 5 Methyl 2-(2-(benzylamino)ethyl)-5-oxovalerate (I-23)

[0281]

[0282] 1 H NMR(500MHz,Chloroform-d)δ7.32(d,J=1.7Hz,2H),7.29–7.22(m,1H),6.99(t,J=5.0Hz,1H),3.89–3.84(m,2H),3.70(s,2H),3.63 –3.55(m,1H),3.34–3.22(m,2H),3.02–2.95(m,1H),2.95(d,J=6.4Hz,2H),2.87–2.80(m,2H),2.28–2.17(m,2H),2.15–1.97(m,2H).

[0283] Example 24

[0284] 2-Amino-N 5 Methyl 2-(2-(benzylthio)ethyl)-5-oxovalerate (I-24)

[0285]

[0286] 1H NMR(500MHz,Chloroform-d)δ7.36–7.28(m,2H),7.28–7.21(m,1H),6.92(t,J=4.1Hz,1H),3.70(s,2H),3.64(s,1H),3. 66–3.55(m,2H),3.31–3.19(m,2H),2.95(d,J=6.4Hz,2H),2.64(t,J=4.0Hz,2H),2.30–2.21(m,2H),2.15–1.97(m,2H).

[0287] Example 25

[0288] 2-Amino-N 5 Methyl 2-[2-(dibenzylamino)ethyl]-5-oxovalerate (I-25)

[0289]

[0290] 1 H NMR(500MHz,Chloroform-d)δ7.35–7.26(m,4H),7.29–7.22(m,1H),6.89(t,J=4.5Hz,0H),3.71–3.55(m ,4H),3.39–3.26(m,1H),2.95(d,J=6.4Hz,1H),2.84–2.69(m,1H),2.28–2.17(m,1H),2.15–1.97(m,1H).

[0291] Example 26

[0292] 2-Amino-N 5 2-Hydroxyethyl)-5-oxovaleric acid (I-26)

[0293]

[0294] 1 H NMR (400MHz, Deuterium Oxide) δ3.77(t,J=6.1Hz,1H),3.66(t,J=5.5Hz,2H),3.34(t,J=5.5Hz,2H),2.47–2.40(m,2H),2.14(q,J=7.3Hz,2H).

[0295] Example 27

[0296] 2-Amino-N 5 -Butyl-5-oxovalerate (I-27)

[0297]

[0298] 1 H NMR(400MHz, Deuterium Oxide)δ3.75(t,J=6.1Hz,1H),3.18(t,J=6.9Hz,2H),2.45–2.30(m,2H),2.1 6–2.08(m,2H),1.56–1.41(m,2H),1.36–1.26(m,2H),0.89(t,J=7.3Hz,3H).

[0299] Example 28

[0300] 2-Amino-N 5 -Isopropyl-5-oxo-valeric acid (I-28)

[0301]

[0302] 1 H NMR (400MHz, Deuterium Oxide) δ3.97–3.84(m,1H),3.75(t,J=6.1Hz,1H),2.42–2.28(m,2H),2.17–2.06(m,2H),1.13(d,J=6.6Hz,6H).

[0303] Example 29

[0304] N 2 -Benzyl-N 5 Methyl 2-(2-(piperidin-1-yl)ethyl)-5-oxo-1-pentanoate (I-29)

[0305]

[0306] 1 H NMR(500MHz,Chloroform-d)δ7.35–7.29(m,2H),7.32–7.22(m,1H),7.22–7.16(m,2H),6.96(t,J=4.5Hz,1H),3.88–3.83(m,2H),3.68(s,2H),3.61 –3.54(m,1H),3.33–3.27(m,2H),3.17–3.09(m,1H),2.59–2.49(m,6H),2. 32–2.17(m,2H),1.99–1.87(m,2H),1.60–1.50(m,3H),1.49–1.41(m,2H).

[0307] Example 30

[0308] N 2 -Benzyl-N 5Methyl 2-[2-(benzyloxy)ethyl]-5-oxo-1-pentanoate (I-30)

[0309]

[0310] 1 H NMR(500MHz,Chloroform-d)δ7.39–7.22(m,8H),7.22–7.16(m,2H),6.57(t,J=5.1Hz,1H),4.44(t,J=0.9Hz,2H),3.88–3.83(m,2H) ,3.68(s,2H),3.63(t,J=4.2Hz,2H),3.61–3.54(m,1H),3.40–3.30(m,2H),3.17–3.09(m,1H),2.32–2.17(m,2H),1.99–1.87(m,2H).

[0311] Example 31

[0312] N 2 -Benzyl-N 5 methyl butyl-5-oxo-1-pentanoate (I-31)

[0313]

[0314] 1 H NMR(500MHz,Chloroform-d)δ7.36–7.29(m,2H),7.32–7.22(m,1H),7.22–7.16(m,2H),6.51(t,J=4.9Hz,1H),3.88–3.83(m,2H),3.68(s,2H) ),3.61–3.54(m,1H),3.17–3.09(m,3H),2.32–2.17(m,2H),1.99–1.87(m,2H),1.53–1.41(m,2H),1.38–1.28(m,2H),0.93(t,J=6.6Hz,3H).

[0315] Example 32

[0316] 2-Amino-N 5 methyl cyclopropylmethyl-5-oxovalerate (I-32)

[0317]

[0318] 1H NMR (400MHz, Methanol-d4) δ4.09–4.02(m,1H),3.81(d,J=1.6Hz,3H),3.01(d,J=7.1Hz,2H),2. 46–2.37(m,2H),2.23–2.05(m,2H),0.97–0.88(m,1H),0.50–0.43(m,2H),0.17(d,J=5.0Hz,2H).

[0319] Example 33

[0320] N 2 -benzoyl-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-33)

[0321]

[0322]

[0323] 1 H NMR (400MHz, Methanol-d4) δ7.92–7.85(m,2H),7.60–7.53(m,1H),7.49(t,J=7.5Hz,2H),4.61(dd,J=9.3,4.7Hz,1H) ,3.76(s,3H),3.24–3.13(m,2H),2.36(t,J=6.8Hz,2H),2.32–2.22(m,1H),2.18–2.06(m,1H),1.09(t,J=7.3Hz,3H).

[0324] Example 34

[0325] N 2 -benzenesulfonyl-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-34)

[0326]

[0327] 1 H NMR(500MHz,Chloroform-d)δ7.80–7.72(m,3H),7.52(d,J=10.6Hz,1H),7.49–7.42(m,2H),6.65(t,J=4.1Hz,1H) ,4.03–3.94(m,1H),3.69(s,2H),3.25–3.16(m,2H),2.34–2.19(m,2H),2.01–1.93(m,2H),1.12(t,J=6.5Hz,3H).

[0328] Example 35

[0329] N 2 -(benzodihydropyran-3-formyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-35)

[0330]

[0331] 1 H NMR (400MHz, Methanol-d4) δ7.13–7.03(m,2H),6.84(t,J=7.4Hz,1H),6.77(dd,J=8.2,1.7Hz,1H),4.47–4.31(m,2H),4.08–3.89(m ,1H),3.74(s,3H),3.20(s,2H),3.09–2.86(m,4H),2.28(t,J=7.4Hz,2H),2.25–2.11(m,1H),2.02–1.89(m,1H),1.19–1.00(m,3H).

[0332] Example 36

[0333] N 2 -(6-bromo-4-chloroquinoline-2-formyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-36)

[0334]

[0335] 1 H NMR(600MHz,Chloroform-d)δ8.75(d,J=8.4Hz,1H),8.44(d,J=2.1Hz,1H),8.35(s,1H),8.06(d,J=8.9Hz,1H),7.91(dd,J=9.0,2.2Hz,1H),6. 04(s,1H),4.85–4.80(m,1H),3.80(s,3H),3.33–3.21(m,2H),2.45–2. 37(m,1H),2.32(t,J=7.0Hz,2H),2.21–2.14(m,1H),1.15–1.09(m,3H).

[0336] Example 37

[0337] N 2 -(6-bromo-4-methylquinoline-2-formyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-37)

[0338]

[0339] 1 H NMR(500MHz,Chloroform-d)δ8.18(d,J=9.7Hz,1H),8.07(d,J=1.8Hz,1H),7.86(d,J=8.1Hz,1H),7.82(dd,J=8.3,1.9Hz,1H),7.62–7.59(m,1H),6 .66(t,J=4.1Hz,1H),4.51–4.43(m,1H),3.69(s,2H),3.25–3.16(m,2H), 2.68(s,2H),2.35–2.20(m,2H),2.09–1.88(m,2H),1.12(t,J=6.5Hz,3H).

[0340] Example 38

[0341] N 2 -(6-Chloro-4-methylquinoline-2-formyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-38)

[0342]

[0343] 1 H NMR(500MHz,Chloroform-d)δ8.24(d,J=1.7Hz,1H),8.18(d,J=9.7Hz,1H),7.87(d,J=8.1Hz,1H),7.74(dd,J=8.2,2.0Hz,1H),7.61–7.57(m,1H),6 .66(t,J=4.1Hz,1H),4.51–4.43(m,1H),3.69(s,2H),3.25–3.16(m,2H), 2.68(s,2H),2.35–2.20(m,2H),2.09–1.88(m,2H),1.12(t,J=6.5Hz,3H).

[0344] Example 39

[0345] N 2 -(6-Chlorobenzodihydropyran-3-formyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-39)

[0346]

[0347] 1H NMR(500MHz,Chloroform-d)δ7.39(d,J=9.0Hz,1H),7.16(dd,J=9.0,2.6Hz,1H),7.07–7.03(m,1H),6.79(d,J=9.1Hz,1H),6.66(t,J=4.1Hz,1H),4. 35–4.27(m,1H),4.29–4.21(m,2H),3.69(s,2H),3.25–3.10(m,4H),2.97– 2.88(m,1H),2.33–2.18(m,2H),2.04–1.88(m,2H),1.12(t,J=6.5Hz,3H).

[0348] Example 40

[0349] N 1 -Benzyl-N 5 2-Ethyl-2-(benzenesulfonamide)glutaramide (I-40)

[0350]

[0351] 1 H NMR (500MHz, Chloroform-d) δ7.80–7.72(m,3H),7.50–7.42(m,3H),7.36–7.29(m,4H),7.32–7.25(m,2H),7.29–7.22(m,1H),6.67(t,J=4. 1Hz,1H),4.41–4.31(m,2H),3.92–3.83(m,1H),3.25–3.16(m,2H),2.23(dd,J=17.3,0.8Hz,1H),2.12–1.94(m,2H),1.12(t,J=6.5Hz,3H).

[0352] Example 41

[0353] N 2 -benzenesulfonyl-N 5 1-Ethyl-5-oxo-1-pentanoic acid benzyl ester (I-41)

[0354]

[0355] 1H NMR(400MHz,Chloroform-d)δ7.78(d,J=8.0Hz,2H),7.55–7.47(m,1H),7.42(t,J=7.7Hz,2H),7.37–7.29(m,3H),7.21–7.11(m,2H),5.69(s ,1H),5.55(d,J=9.1Hz,1H),4.92–4.82(m,2H),3.96–3.86(m,1H),3.3 4–3.22(m,2H),2.42–2.12(m,3H),1.86(s,1H),1.15(t,J=7.2Hz,3H).

[0356] Example 42

[0357] N 2 -(4-Methylbenzenesulfonyl)-N 5 1-Ethyl-5-oxo-1-pentanoic acid benzyl ester (I-42)

[0358]

[0359] 1 H NMR(500MHz,Chloroform-d)δ7.72–7.65(m,3H),7.38–7.25(m,5H),6.65(t,J=4.1Hz,1H),5.15(d,J=0.9Hz,2H) ,4.09–4.00(m,1H),3.25–3.16(m,2H),2.41(s,2H),2.34–2.19(m,2H),2.02–1.93(m,2H),1.12(t,J=6.5Hz,3H).

[0360] Example 43

[0361] N 2 -(4-bromobenzenesulfonyl)-N 5 1-Ethyl-5-oxo-1-pentanoic acid benzyl ester (I-43)

[0362]

[0363]

[0364] 1H NMR(500MHz,Chloroform-d)δ7.82–7.76(m,2H),7.71–7.65(m,3H),7.38–7.29(m,2H),7.32–7.25(m,1H),6.65(t,J=4.1Hz,1 H),5.15(d,J=0.9Hz,2H),4.09–4.00(m,1H),3.25–3.16(m,2H),2.34–2.19(m,2H),2.02–1.93(m,2H),1.12(t,J=6.5Hz,3H).

[0365] Example 44

[0366] N 2 -benzoyl-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-44)

[0367]

[0368] 1 H NMR(600MHz, Methanol-d4)δ7.46–7.21(m,10H),5.25–5.16(m,2H),3.79(d,J=12.9Hz,1H),3.63 (d,J=12.9Hz,1H),3.22–3.13(m,2H),2.29(t,J=7.9Hz,2H),1.97(s,2H),1.10(t,J=7.3Hz,3H).

[0369] Example 45

[0370] N 2 -(1H-pyrrolo-2-formyl)-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-45)

[0371]

[0372] 1 H NMR(400MHz, Methanol-d4)δ7.40–7.27(m,5H),6.96–6.86(m,2H),6.19(dd,J=3.8,2.6Hz,1H),5.19(s,2H), 4.60(dd,J=9.6,4.3Hz,1H),3.21–3.09(m,2H),2.35–2.21(m,3H),2.14–1.98(m,1H),1.07(t,J=7.3Hz,3H).

[0373] Example 46

[0374] N2 -acetyl-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-46)

[0375]

[0376]

[0377] 1 H NMR(400MHz, Methanol-d4)δ7.42–7.28(m,5H),5.17(s,2H),4.43(dd,J=9.2,4.9Hz,1H),3.22–3.12(m ,2H),2.25(t,J=7.4Hz,2H),2.21–2.11(m,1H),1.99(s,3H),1.97–1.88(m,1H),1.10(t,J=7.2Hz,3H).

[0378] Example 47

[0379] N 2 -(piperidin-4-formyl)-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-47)

[0380]

[0381] 1 H NMR (400MHz, Methanol-d4) δ7.40–7.29(m,5H),5.16(d,J=2.9Hz,2H),4.41(dd,J=9.0,5.1Hz,1H),3.47–3.35(m,2H),3.18(q,J=7. 3Hz,2H),3.08–2.96(m,2H),2.65–2.56(m,1H),2.27(t,J=7.3Hz,2H),2.23–2.11(m,1H),2.05–1.75(m,5H),1.10(t,J=6.8Hz,3H).

[0382] Example 48

[0383] N 2 -(1-benzoylpiperidin-4-formyl)-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-48)

[0384]

[0385] 1H NMR(500MHz,Chloroform-d)δ7.69(d,J=9.3Hz,1H),7.56–7.48(m,1H),7.51–7.45(m,4 H),7.38–7.32(m,2H),7.32–7.25(m,1H),6.66(t,J=4.1Hz,1H),5.16(d,J=0.9Hz,2H), 4.32–4.24(m,1H),3.87–3.78(m,2H),3.40–3.31(m,2H),3.25–3.16(m,2H),2.47–2.39 (m,1H),2.35–2.18(m,2H),2.04–1.89(m,2H),1.91–1.75(m,4H),1.12(t,J=6.5Hz,3H).

[0386] Example 49

[0387] N 2 -(1-Benzylpiperidin-4-formyl)-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-49)

[0388]

[0389] 1 H NMR(500MHz,Chloroform-d)δ7.68(d,J=9.3Hz,1H),7.38–7.29(m,4H),7.32–7.26(m, 2H),7.29–7.22(m,1H),6.66(t,J=4.1Hz,1H),5.16(d,J=0.9Hz,2H),4.32–4.24(m,1H ),3.49(s,2H),3.25–3.16(m,2H),2.82–2.73(m,2H),2.52–2.43(m,2H),2.41–2.34(m ,1H),2.34–2.18(m,2H),2.03–1.89(m,2H),1.89–1.75(m,4H),1.12(t,J=6.5Hz,3H).

[0390] Example 50

[0391] N 2 -(1-(4-hydroxybenzyl)piperidine-4-formyl)-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-50)

[0392]

[0393] 1H NMR(500MHz,Chloroform-d)δ7.68(d,J=9.3Hz,1H),7.38–7.32(m,2H),7.34(s,2H),7.32–7.25(m, 1H),7.13–7.07(m,2H),6.98(s,1H),6.78–6.72(m,2H),6.66(t,J=4.1Hz,1H),5.16(d,J=0.9Hz,2H) ,4.32–4.24(m,1H),3.52(t,J=1.0Hz,2H),3.25–3.16(m,2H),2.82–2.73(m,2H),2.52–2.43(m,2H) ,2.41–2.34(m,1H),2.34–2.18(m,2H),2.04–1.90(m,2H),1.90–1.75(m,4H),1.12(t,J=6.5Hz,3H).

[0394] Example 51

[0395] N 2 -(1-(4-chlorobenzyl)piperidin-4-formyl)-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-51)

[0396]

[0397] 1 H NMR(500MHz,Chloroform-d)δ7.68(d,J=9.3Hz,1H),7.38–7.24(m,7H),6.66(t ,J=4.1Hz,1H),5.16(d,J=0.9Hz,2H),4.32–4.24(m,1H),3.51(t,J=1.0Hz,2H) ,3.25–3.16(m,2H),2.82–2.73(m,2H),2.52–2.43(m,2H),2.41–2.34(m,1H),2 .34–2.18(m,2H),2.03–1.89(m,2H),1.89–1.75(m,4H),1.12(t,J=6.5Hz,3H).

[0398] Example 52

[0399] N 2 -(1-(4-nitrobenzyl)piperidine-4-formyl)-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-52)

[0400]

[0401] 1 H NMR(500MHz,Chloroform-d)δ8.18–8.12(m,2H),7.68(d,J=9.3Hz,1H),7.55–7.49(m,2H ),7.38–7.25(m,3H),6.66(t,J=4.1Hz,1H),5.16(d,J=0.9Hz,2H),4.32–4.24(m,1H),3. 52(t,J=1.0Hz,2H),3.25–3.16(m,2H),2.82–2.73(m,2H),2.52–2.43(m,2H),2.41–2.34 (m,1H),2.34–2.18(m,2H),2.04–1.90(m,2H),1.90–1.75(m,4H),1.12(t,J=6.5Hz,3H).

[0402] Example 53

[0403] N 2 -(1-Propionylpiperidin-4-formyl)-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-53)

[0404]

[0405] 1 H NMR(500MHz,Chloroform-d)δ7.69(d,J=9.3Hz,1H),7.38–7.25(m,3H),6.66(t,J=4.1Hz ,1H),5.16(d,J=0.9Hz,2H),4.32–4.24(m,1H),3.81–3.72(m,2H),3.42–3.33(m,2H),3. 25–3.16(m,2H),2.40(q,J=5.3Hz,1H),2.34(d,J=7.9Hz,1H),2.34–2.25(m,2H),2.28–2 .18(m,1H),2.04–1.89(m,2H),1.89–1.80(m,2H),1.80–1.71(m,2H),1.15–1.06(m,6H).

[0406] Example 54

[0407] N 2 -cyclohexanoyl-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-54)

[0408]

[0409] 1H NMR (400MHz, Methanol-d4) δ7.41–7.29(m,5H),5.20–5.10(m,2H),4.40(dd,J=9.2,5.0Hz,1H),3.22–3.12(m,2H),2.26(d,J=7. 5Hz,2H),2.21–2.11(m,1H),2.01–1.89(m,1H),1.83–1.72(m,4H),1.72–1.64(m,1H),1.52–1.18(m,6H),1.10(t,J=7.2Hz,3H).

[0410] Example 55

[0411] N 2 -Benzyl-N 5 Methyl 5-oxo-1-pentanoate (I-55)

[0412]

[0413] 1 H NMR (400MHz, Methanol-d4) δ7.55–7.43(m,5H),4.26(s,2H),4.12(t,J=6.3Hz,1H),3.87( s,3H),3.22(q,J=7.3Hz,2H),2.54–2.42(m,2H),2.29–2.11(m,2H),1.12(t,J=7.2Hz,3H).

[0414] Example 56

[0415] N 2 -(4-Trifluoromethylphenyl)-N 5 Methyl 5-oxo-1-pentanoate (I-56)

[0416]

[0417] 1 H NMR(500MHz,Chloroform-d)δ7.62–7.57(m,2H),7.43–7.37(m,2H),6.65(t,J=4.1Hz,1H),3.95–3.83(m,2H),3.68(s,2H ),3.61–3.54(m,1H),3.25–3.16(m,2H),3.16–3.09(m,1H),2.33–2.18(m,2H),1.99–1.87(m,2H),1.12(t,J=6.5Hz,3H).

[0418] Example 57

[0419] N 2 -(2-Hydroxybenzyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-57)

[0420]

[0421] 1 H NMR(500MHz,Chloroform-d)δ9.49(s,1H),7.20–7.14(m,1H),7.08–7.01(m,1H),6.88–6.81(m,1H),6.81(dd,J=8.3,1.3Hz,1H),6.65(t,J=4 .1Hz,1H),3.99–3.85(m,2H),3.68(s,2H),3.67–3.56(m,2H),3.25–3. 16(m,2H),2.33–2.18(m,2H),1.99–1.87(m,2H),1.12(t,J=6.5Hz,3H).

[0422] Example 58

[0423] N 2 -(3-hydroxybenzyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-58)

[0424]

[0425] 1 H NMR(500MHz,Chloroform-d)δ7.13(dd,J=8.5,7.8Hz,1H),6.96(s,1H),6.93–6.86(m,1H),6.81–6.76(m,1H),6.73–6.67(m,1H),6.67–6.62(m,1H),3 .87–3.82(m,2H),3.68(s,2H),3.61–3.53(m,1H),3.30–3.24(m,1H),3.24 –3.16(m,2H),2.33–2.18(m,2H),1.99–1.87(m,2H),1.12(t,J=6.5Hz,3H).

[0426] Example 59

[0427] N 2 -(4-hydroxybenzyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-59)

[0428]

[0429] 1 H NMR(500MHz,Chloroform-d)δ7.14–7.08(m,2H),6.98(s,1H),6.77–6.71(m,2H),6.65(t,J=4.1Hz,1H),3.95–3.83(m,2H),3.6 8(s,2H),3.61–3.54(m,1H),3.25–3.16(m,2H),3.16–3.09(m,1H),2.33–2.18(m,2H),1.99–1.87(m,2H),1.12(t,J=6.5Hz,3H).

[0430] Example 60

[0431] N 2 -(4-chlorobenzyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-60)

[0432]

[0433] 1 H NMR(500MHz,Chloroform-d)δ7.35–7.29(m,2H),7.29–7.22(m,2H),6.65(t,J=4.1Hz,1H),3.95–3.83(m,2H),3.68(s,2H ),3.61–3.54(m,1H),3.25–3.16(m,2H),3.16–3.09(m,1H),2.33–2.18(m,2H),1.99–1.87(m,2H),1.12(t,J=6.5Hz,3H).

[0434] Example 61

[0435] N 2 N 2 -dibenzyl-N 5 Methyl 5-oxo-1-pentanoate (I-61)

[0436]

[0437] 1H NMR(400MHz, Methanol-d4)δ7.45–7.27(m,10H),4.14(d,J=13.4Hz,2H),3.93–3.84(m,1H),3.82(s,3 H),3.61(d,J=23.8Hz,1H),3.19–2.99(m,J=7.2,6.8Hz,2H),2.37–2.06(m,4H),1.08(t,J=7.3Hz,3H).

[0438] Example 62

[0439] N 2 N 2 -dibenzyl-N 5 Methyl butyl-5-oxo-1-pentanoate (I-62)

[0440]

[0441] 1 H NMR(500MHz,Chloroform-d)δ7.32–7.22(m,3H),6.51(t,J=4.9Hz,0H),3.85–3.71(m,2H),3.68(s,1H),3.17–3 .10(m,1H),2.39–2.25(m,1H),2.00–1.91(m,1H),1.51–1.42(m,1H),1.38–1.28(m,1H),0.93(t,J=6.6Hz,1H).

[0442] Example 63

[0443] N 2 N 2 -dibenzyl-N 5 1-Ethyl-5-oxo-1-pentanoic acid propyl ester (I-63)

[0444]

[0445] 1 H NMR(500MHz,Chloroform-d)δ7.29(s,5H),7.33–7.22(m,3H),6.65(t,J=4.1Hz,1H),4.12–4.04(m,2H),3.85–3.76(m,4H),3.73(t,J=7 .4Hz,1H),3.25–3.16(m,2H),2.38–2.24(m,2H),1.95(q,J=7.6Hz,2H),1.76–1.64(m,2H),1.12(t,J=6.5Hz,3H),0.97(t,J=8.0Hz,3H).

[0446] Example 64

[0447] N 2 N 2 -dibenzyl-N 5 1-Ethyl-5-oxo-1-pentanoic acid butyl ester (I-64)

[0448]

[0449] 1 H NMR(500MHz,Chloroform-d)δ7.33–7.22(m,5H),6.65(t,J=4.1Hz,1H),

[0450] 4.13–4.05(m,2H),3.85–3.76(m,4H),3.73(t,J=7.4Hz,1H),3.25–3.16(m,2H),2.38–2.24(m,2H),1 .99–1.91(m,2H),1.69–1.60(m,2H),1.45–1.34(m,2H),1.12(t,J=6.5Hz,3H),0.97(t,J=7.0Hz,3H).

[0451] Example 65

[0452] N 2 N 2 -dibenzyl-N 5 1-Ethyl-5-oxo-1-pentanoic acid benzyl ester (I-65)

[0453]

[0454] 1 H NMR(500MHz,Chloroform-d)δ7.38–7.32(m,2H),7.30(s,2H),7.29–7.23(m,1H),6.65(t,J=4.1Hz,0H),5.15(d,J=1.1Hz,1H ),3.85–3.75(m,2H),3.74(t,J=7.4Hz,0H),3.25–3.16(m,1H),2.35–2.24(m,1H),1.99–1.91(m,1H),1.12(t,J=6.5Hz,1H).

[0455] Example 66

[0456] N 1 -Benzyl-2-(Dibenzylamino)-N 5 -Ethylglutaramide (I-66)

[0457]

[0458] 1 H NMR(500MHz,Chloroform-d)δ7.36–7.26(m,7H),7.29–7.22(m,3H),7.09(t,J=5.9Hz,1H),6.67(t,J=4.0Hz,1H),4.42–4.31(m ,2H),3.84–3.74(m,4H),3.46(t,J=6.7Hz,1H),3.25–3.16(m,2H),2.35–2.25(m,2H),1.94–1.79(m,2H),1.12(t,J=6.5Hz,3H).

[0459] Example 67

[0460] N 2 N 2 -dibenzyl-N 5 ethyl 5-oxo-1-pentanoate (I-67)

[0461]

[0462] 1 H NMR(500MHz,Chloroform-d)δ7.30(s,2H),7.33–7.26(m,1H),7.29–7.22(m,2H),6.65(t,J=4.1Hz,1H),4.19–4.10(m,2H),3.85–3. 75(m,4H),3.74(t,J=7.4Hz,1H),3.25–3.16(m,2H),2.38–2.24(m,2H),1.99–1.91(m,2H),1.28–1.22(m,3H),1.12(t,J=6.5Hz,3H).

[0463] Example 68

[0464] N 2 N 2 -di(4-hydroxybenzyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-68)

[0465]

[0466] 1H NMR(500MHz,Chloroform-d)δ7.10–7.04(m,2H),6.98(s,1H),6.78–6.72(m,2H),6.65(t,J=4.1Hz,1H),3.83(d,J=1.2Hz ,2H),3.75(t,J=7.0Hz,1H),3.68(s,1H),3.25–3.16(m,1H),2.38–2.24(m,1H),2.00–1.91(m,1H),1.12(t,J=6.5Hz,2H).

[0467] Example 69

[0468] N 2 N 2 -di(4-methoxybenzyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-69)

[0469]

[0470] 1 H NMR(500MHz,Chloroform-d)δ7.22–7.16(m,4H),6.83–6.77(m,4H),6.65(t,J=4.1Hz,1H),3.85–3.81(m,4H),3.78(s,5 H),3.75(t,J=7.1Hz,1H),3.68(s,2H),3.25–3.16(m,2H),2.35–2.24(m,2H),2.00–1.91(m,2H),1.12(t,J=6.5Hz,3H).

[0471] Example 70

[0472] N 2 N 2 -Di(4-chlorobenzyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-70)

[0473]

[0474] 1H NMR(500MHz,Chloroform-d)δ7.36–7.30(m,4H),7.28–7.22(m,4H),6.65(t,J=4.1Hz,1H),3.87–3.77(m,4H),3. 75(t,J=7.1Hz,1H),3.68(s,2H),3.25–3.16(m,2H),2.35–2.26(m,2H),2.00–1.91(m,2H),1.12(t,J=6.5Hz,3H).

[0475] Example 71

[0476] N 2 N 2 -di(3,4-dihydroxybenzyl)-N 5 methyl 5-ethyl-5-oxo-1-pentanoate (I-71)

[0477]

[0478] 1 H NMR(500MHz,Chloroform-d)δ6.77(s,1H),6.75–6.65(m,2H),6.68–6.62(m,2H),6.29(s,1H),3.88–3.82(m,1H),3.85–3.78 (m,1H),3.75(t,J=7.1Hz,0H),3.68(s,1H),3.25–3.16(m,1H),2.35–2.24(m,1H),2.00–1.91(m,1H),1.12(t,J=6.5Hz,1H).

[0479] Example 72

[0480] N 2 N 2 -dibenzyl-N 5 ethyl butyl-5-oxo-1-pentanoate (I-72)

[0481]

[0482] 1H NMR(500MHz,Chloroform-d)δ7.33–7.25(m,4H),7.28–7.22(m,1H),6.51(t,J=4 .9Hz,1H),4.19–4.10(m,2H),3.82(d,J=12.6Hz,2H),3.78(d,J=12.8Hz,2H),3. 74(t,J=7.4Hz,1H),3.17–3.10(m,2H),2.39–2.25(m,2H),1.99–1.91(m,2H),1. 51–1.41(m,2H),1.38–1.29(m,2H),1.25(t,J=6.3Hz,3H),0.93(t,J=6.6Hz,3H).

[0483] Example 73

[0484] N 1 -benzyl-2-(benzylamino)-N 5 -Ethylglutaramide (I-73)

[0485]

[0486] 1 H NMR(500MHz,Chloroform-d)δ7.36–7.30(m,4H),7.32–7.27(m,2H),7.30–7.22(m,2H),7.20(t,J=1.2Hz,1H),7.20–7.14(m,2H),6.67(t,J=4.0H z,1H),4.43–4.33(m,2H),3.92–3.81(m,2H),3.50–3.40(m,2H),3.25–3 .16(m,2H),2.28–2.19(m,2H),2.10–1.92(m,2H),1.12(t,J=6.5Hz,3H).

[0487] Example 74

[0488] N 2 -Benzyl-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-74)

[0489]

[0490] 1H NMR(600MHz, Methanol-d4)δ7.46–7.21(m,10H),5.25–5.16(m,2H),3.79(d,J=12.9Hz,1H),3.63 (d,J=12.9Hz,1H),3.22–3.13(m,2H),2.29(t,J=7.9Hz,2H),1.97(s,2H),1.10(t,J=7.3Hz,3H).

[0491] Example 75

[0492] N 2 -(2-pyridinylmethyl)-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-75)

[0493]

[0494] 1 H NMR(500MHz,Chloroform-d)δ8.50(dd,J=4.1,1.8Hz,1H),7.73–7.66(m,1H) ,7.55–7.48(m,1H),7.34(s,2H),7.38–7.25(m,3H),6.65(t,J=4.1Hz,1H),5. 19–5.10(m,2H),4.05–3.93(m,2H),3.70–3.57(m,2H),3.25–3.16(m,2H),2. 33–2.25(m,1H),2.27–2.18(m,1H),2.00–1.86(m,2H),1.12(t,J=6.5Hz,3H).

[0495] Example 76

[0496] N 2 -Cyclohexylmethyl-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-76)

[0497]

[0498] 1H NMR(400MHz,Chloroform-d)δ7.43–7.28(m,4H),5.87(s,1H),5.23–5.09(m,2H),3.26–3.19(m,2H),2.42(dd,J=11.2,6.8Hz,1H),2.27–2.20 (m,2H),2.07–1.95(m,1H),1.91–1.79(m,1H),1.77–1.58(m,6H),1.43 –1.31(m,1H),1.30–1.14(m,3H),1.13–1.06(m,3H),0.93–0.81(m,2H).

[0499] Example 77

[0500] N 2 -Cyclopropylmethyl-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-77)

[0501]

[0502] 1 H NMR(500MHz,Chloroform-d)δ7.35(dd,J=1.6,0.8Hz,2H),7.32–7.25(m,1H),6.65(t,J=4.1Hz,1H),5.19–5.10(m,2H),3.58–3.50(m,1H),3.43–3.35(m ,1H),3.25–3.16(m,2H),2.63(dd,J=5.3,4.0Hz,2H),2.32–2.17(m,2H),1.9 5–1.86(m,2H),1.12(t,J=6.5Hz,3H),1.10–1.02(m,1H),0.37–0.21(m,4H).

[0503] Example 78

[0504] N 2 N 2 N 5 - Triethyl-5-oxovalerate benzyl ester (I-78)

[0505]

[0506] 1H NMR(500MHz,Chloroform-d)δ7.37–7.26(m,1H),6.65(t,J=4.1Hz,0H),5.20–5.11(m,1H),3. 25–3.16(m,1H),2.81–2.67(m,2H),2.38–2.24(m,1H),2.00–1.87(m,1H),1.15–1.08(m,4H).

[0507] Example 79

[0508] N 2 N 5 1-Diethyl-5-oxovalerate benzyl ester (I-79)

[0509]

[0510] 1 H NMR(500MHz,Chloroform-d)δ7.38–7.29(m,2H),7.32–7.25(m,1H),6.65(t,J=4.1Hz,1H),5.19–5.10(m,2H),3.59–3.52(m,1H),3.25–3.16 (m,2H),2.80–2.72(m,2H),2.56(dt,J=8.2,4.1Hz,1H),2.32–2.17(m,2H),1.95–1.87(m,2H),1.20(t,J=6.3Hz,3H),1.12(t,J=6.5Hz,3H).

[0511] Example 80

[0512] N 2 -Hexagen-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-80)

[0513]

[0514] 1 H NMR(400MHz,Chloroform-d)δ7.43–7.29(m,6H),6.73(s,1H),5.35–5.10(m,2H),4.01(s,1H),3.35–3.13(m,2H),3.1 6–2.88(m,2H),2.48–2.19(m,4H),1.79–1.60(m,2H),1.39–1.19(m,6H),1.10(t,J=7.0Hz,3H),0.87(t,J=6.6Hz,3H).

[0515] Example 81

[0516] N 2 -(piperidin-4-ylmethyl)-N 5 1-Ethyl-5-oxovalerate benzyl ester (I-81)

[0517]

[0518] 1 H NMR(500MHz,Chloroform-d)δ7.38–7.32(m,2H),7.32–7.25(m,1H),6.65(t,J=4.1Hz,1 H),5.19–5.10(m,2H),3.58–3.50(m,1H),3.25–3.16(m,2H),3.09–3.01(m,1H),2.97–2. 88(m,2H),2.80–2.71(m,2H),2.60(dd,J=6.1,4.4Hz,2H),2.37–2.31(m,1H),2.31–2.17 (m,2H),1.95–1.86(m,2H),1.75–1.60(m,3H),1.53–1.44(m,2H),1.12(t,J=6.5Hz,3H).

[0519] Example 82

[0520] N 2 -(cyclohexanoyl)-N 5 5-Ethyl-Oxovaleric acid (I-82)

[0521]

[0522] 1 H NMR(400MHz, Methanol-d4)δ4.35(dd,J=9.1,4.8Hz,1H),3.19(q,J=7.2Hz,2H),2.32–2.22(m,3H),2.22–2.0 9(m,1H),1.99–1.87(m,1H),1.87–1.76(m,4H),1.73–1.64(m,1H),1.50–1.21(m,5H),1.11(t,J=7.3Hz,3H).

[0523] Example 83

[0524] N 2 -Benzyl-N 5 5-Ethyl-Oxovaleric acid (I-83)

[0525]

[0526] 1 H NMR(600MHz,Deuterium Oxide)δ7.46–7.38(m,5H),4.28–4.15(m,2H),3.94(dd,J=7.3,5.6Hz,1H),3. 14–3.03(m,2H),2.46–2.30(m,2H),2.23–2.09(m,2H),1.01(t,J=7.3Hz,3H).

[0527] Example 84

[0528] N 2 -(pyridine-2-methyl)-N 5 -Ethyl-5-oxovaleric acid

[0529]

[0530] 1 H NMR(500MHz,Chloroform-d)δ8.50(dd,J=4.1,1.8Hz,1H),7.73–7.66(m,1H),7.55–7.48(m,1H),7.28(dd,J=7.6,1.5Hz,1H),6.65(t,J=4.1Hz,1H) ,4.44–4.37(m,1H),4.00(dd,J=5.3,0.7Hz,2H),3.57–3.49(m,1H),3.25– 3.16(m,2H),2.32–2.21(m,2H),1.96–1.80(m,2H),1.12(t,J=6.5Hz,3H).

[0531] Example 85

[0532] N 2 -(1H-pyrrolo-2-yl)-N 5 5-Ethyl-Oxovaleric acid (I-85)

[0533]

[0534] 1H NMR(500MHz,Chloroform-d)δ8.99(d,J=6.8Hz,1H),6.92–6.86(m,1H),6.65(t,J=4.1Hz,1H),6.31(dd,J=6.6,1.6Hz,1H),6.12(dd,J=6.6,3.5Hz ,1H),5.36–5.28(m,1H),3.85(d,J=5.8Hz,2H),3.59–3.51(m,1H),3.25– 3.16(m,2H),2.32–2.21(m,2H),1.96–1.80(m,2H),1.12(t,J=6.5Hz,3H).

[0535] Example 86

[0536] N 2 -(6-bromo-4-chloroquinoline-2-formyl)-N 5 1-Ethyl-5-oxo-1-pentanoic acid (I-86)

[0537]

[0538] 1 H NMR(500MHz,Chloroform-d)δ8.55(d,J=9.7Hz,1H),8.33(d,J=2.2Hz,1H),7.95(d,J=8.2Hz,1H),7.82(dd,J=8.2,2.0Hz,1H),7.5 3(s,1H),6.66(t,J=4.1Hz,1H),4.45–4.36(m,1H),3.25–3.16(m,2H),2.35–2.20(m,2H),2.01–1.83(m,2H),1.12(t,J=6.5Hz,3H).

[0539] Example 87

[0540] N 2 -(6-bromo-4-methylquinoline-2-formyl)-N 5 1-Ethyl-5-oxo-1-pentanoic acid (I-87)

[0541]

[0542] 1H NMR(500MHz,Chloroform-d)δ8.49(d,J=9.5Hz,1H),8.07(d,J=1.8Hz,1H),7.89–7.79(m,3H),7.60(d,J=1.1Hz,1H),6.66(t, J=4.1Hz,1H),4.45–4.36(m,1H),3.25–3.16(m,3H),2.68(s,3H),2.34–2.20(m,2H),2.01–1.83(m,3H),1.12(t,J=6.5Hz,4H).

[0543] Example 88

[0544] N 2 N 2 -dibenzyl-N 5 1-Butyl-5-oxo-1-pentanoic acid (I-88)

[0545]

[0546] 1 H NMR(500MHz,Chloroform-d)δ7.33–7.22(m,5H),6.51(t,J=4.9Hz,1H),3.89–3.78(m,4H),3.59(t,J=7.0Hz,1H),3. 17–3.10(m,2H),2.35–2.20(m,2H),1.96–1.87(m,2H),1.53–1.41(m,2H),1.38–1.28(m,2H),0.93(t,J=6.6Hz,3H).

[0547] Example 89

[0548] N 2 N 2 -dibenzyl-N 5 1-Ethyl-5-oxo-1-pentanoic acid (I-89)

[0549]

[0550] 1 H NMR (400MHz, Methanol-d4) δ7.34–7.14(m,10H),3.92(d,J=13.5Hz,2H),3.73(d,J=13.5Hz,2H),3. 26–3.22(m,1H),3.10–2.96(m,2H),2.29–2.11(m,2H),2.00(q,J=7.3Hz,2H),0.99(t,J=7.2Hz,3H).

[0551] Example 90

[0552] N 2 -benzoyl-N 5 1-Ethyl-5-oxo-1-pentanoic acid (I-90)

[0553]

[0554] 1 H NMR (400MHz, Methanol-d4) δ7.88(d,J=7.5Hz,2H),7.55(t,J=7.2Hz,1H),7.47(t,J=7.5Hz,2H ),4.57(s,1H),3.22–3.12(m,2H),2.40–2.24(m,3H),2.22–1.96(m,2H),1.08(t,J=7.3Hz,3H).

[0555] Example 91

[0556] N 2 -(4-Methoxybenzoyl)-N 5 1-Ethyl-5-oxo-1-pentanoic acid (I-91)

[0557]

[0558] 1 H NMR(500MHz,Chloroform-d)δ8.32(d,J=8.8Hz,1H),7.78–7.72(m,2H),6.98–6.92(m,2H),6.66(t,J=4.1Hz,1H) ,4.41–4.33(m,1H),3.83(s,2H),3.25–3.16(m,2H),2.35–2.20(m,2H),2.03–1.86(m,2H),1.12(t,J=6.5Hz,3H).

[0559] Example 92

[0560] N 2 -(2-Methoxybenzoyl)-N 5 1-Ethyl-5-oxo-1-pentanoic acid (I-92)

[0561]

[0562] 1H NMR(500MHz,Chloroform-d)δ8.27(d,J=8.6Hz,1H),7.92(dd,J=8.0,1.8Hz,1H),7.49–7.42(m,1H),7.37–7.30(m,1H),7.00(dd,J=8.3,1.3H z,1H),6.66(t,J=4.1Hz,1H),4.42–4.34(m,1H),3.90(s,2H),3.25–3. 16(m,2H),2.35–2.20(m,2H),2.02–1.85(m,2H),1.12(t,J=6.5Hz,3H).

[0563] Example 93

[0564] N 2 -(3-Methoxybenzoyl)-N 5 1-Ethyl-5-oxo-1-pentanoic acid (I-93)

[0565]

[0566] 1 H NMR(500MHz,Chloroform-d)δ8.40(d,J=8.8Hz,1H),7.49–7.43(m,1H),7.40–7.33(m,2H),7.08–7.02(m,1H),6.66(t,J=4 .1Hz,1H),4.41–4.33(m,1H),3.81(s,2H),3.25–3.16(m,2H),2.35–2.20(m,2H),2.03–1.86(m,2H),1.12(t,J=6.5Hz,3H).

[0567] Example 94

[0568] N 2 -benzenesulfonyl-N 5 ethyl-5-oxo-1-pentanoic acid

[0569]

[0570] 1H NMR(500MHz,Chloroform-d)δ7.86(d,J=10.6Hz,1H),7.80–7.72(m,3H),7.50–7.42(m,2H),6.65(t,J=4.1 Hz,1H),3.80–3.71(m,1H),3.25–3.16(m,2H),2.33–2.17(m,2H),1.99–1.90(m,2H),1.12(t,J=6.5Hz,3H).

[0571] Experimental Example 1

[0572] Single-luciferase reporter gene assay system for screening candidate compounds

[0573] LX-2 cells that had reached approximately 90% confluence were digested and seeded into 6-well plates, and cultured for 24 h. Before transfection, 600 μL of Opti-MEM medium was added to a 1.5 mL centrifuge tube to dilute the plasmid and transfection reagent. 6 μg of plasmid and 15 μL of transfection reagent were added to the centrifuge tube, gently mixed, and incubated for 5 min. Then, the medium containing the transfection reagent was aspirated into the centrifuge tube containing the plasmid, gently mixed, and incubated for 5 min. The medium in the 6-well plate was discarded, and 2 mL of FBS-free DMEM medium was added to each well. 400 μL of the Opti-MEM medium containing the plasmid and transfection reagent was added to each well, until 2 μg of plasmid was transfected into each well. The medium was gently shaken to mix, and the plate was incubated for 6 h. After 6 h of culture, the liquid in the plate was discarded, and 2 mL of complete medium was added to each well. The plate was then cultured for another 18 h. Finally, the cells in the 6-well plates were digested and counted, and then seeded into 96-well plates at a ratio of 1.5 × 10⁴ cells / well. Cell culture and seeding were completed after 24 hours. (In this invention, LifeTechnology's Lipofectamine™ 2000 reagent was used to transfect the plasmid into the cells, with a plasmid (μg):Lipo2000 (μL) ratio of 1:2.5.)

[0574] Dilute the test compound to 40 μM·L using complete culture medium. -1 After incubating the 96-well plate for 24 hours, aspirate the liquid from each well and add 200 μL of culture medium containing the test compound to each well. Gently shake and continue incubation for another 24 hours to allow the compound to react. Then, add FBS-free DMEM medium and Bright-Glo... TMThe Assay System reagent kit reaction solution was mixed at a 1:1 ratio to prepare the working solution. After 24 hours of incubation, the liquid in the 96-well plate was discarded. Each well was carefully rinsed once with PBS along the wall, followed by 100 μL of working solution. The plate was then shaken for 2 minutes to ensure complete cell lysis and mixing. 50 μL of the solution was transferred from each well to a Costa 96-flat White plate, and the fluorescence value at all wavelengths was measured using a microplate reader. The inhibition rate of the compound against the COL1A1 promoter was calculated using the following formula:

[0575] Inhibition rate = (Fluorescence value of control group - Fluorescence value of treatment group) / Fluorescence value of control group × 100%

[0576] The results are shown in Table 1.

[0577] Table 1. Inhibition rate (%) of the compounds of this invention on the COL1A1 promoter

[0578]

[0579]

[0580] Note: All compounds used in the activity test of this invention in the table are in the S configuration.

[0581] Example 2

[0582] The compounds of this invention inhibit the expression of fibrosis-related proteins.

[0583] 1. Preparation of protein samples

[0584] Protein Extraction: A: Cell Samples: Discard the liquid in the well plate, wash the cells twice along the wall with pre-cooled PBS, add cell lysis buffer (containing protease inhibitors), and lyse in an ice bath for 30 min; then scrape off the cells with a cell scraper, transfer the liquid to a centrifuge tube, centrifuge at 12000 rpm for 15 min at 4°C, and collect the supernatant. B: Animal Tissue Samples: Weigh 50-100 mg of animal tissue frozen at -80°C or in liquid nitrogen, add 1 mL of cell lysis buffer (containing protease inhibitors) to a glass homogenizer, and homogenize thoroughly with a handheld high-speed homogenizer for 1-2 min until no obvious tissue blocks are visible; lyse the homogenizer in an ice bath for 30 min, then centrifuge at 1200 rpm for 15 min at 4°C, and transfer the supernatant to a centrifuge tube.

[0585] Protein concentration determination: In this paper, the total protein concentration was determined using the BCA Protein Concentration Assay Kit (Enhanced Version) (Beyotime Biotechnology Co., Ltd.) to ensure the uniformity of the protein load. The specific steps are as follows:

[0586] Preparation of standard solution: Add 1.2 mL of protein standard solution to 30 mg of standard protein BSA, dissolve thoroughly to obtain 25 mg / mL. -1 Protein standard stock solution. Take an appropriate amount of 25 mg / mL. -1 Protein standard solution, diluted to a final concentration of 0.5 mg / mL. -1 It is then frozen at -20℃ for long-term storage.

[0587] Prepare an appropriate volume of BCA working solution according to the number of samples to be tested, with a reagent A: reagent B ratio of 50:1 (V / V), mix thoroughly, and use a 96-well plate as the measurement plate, adding 200 μL of working solution to each well.

[0588] 0.5 mg·mL -1 Standard proteins were added to 96-well plates containing working solution in volumes of 0, 1, 2, 4, 8, 12, 16, and 20, respectively, with the corresponding volumes of sterile water added to bring the total sample volume to 20 μL, thus obtaining standard control wells with concentration gradients. 2 μL of the test sample and 18 μL of sterile water were added to each sample well to obtain a 10-fold dilution.

[0589] The plate was shaken on a shaker for 1 min to mix thoroughly, and then incubated at 37°C for 30 min. After incubation, the absorbance of each well was measured at 570 nm. A protein concentration standard curve was plotted with the standard protein concentration on the x-axis and the OD value on the y-axis. The protein concentration of the sample to be tested was calculated based on the standard curve.

[0590] Protein sample preparation: Dilute the sample to 0.5 μg / μL using cell lysis buffer (containing protease inhibitors). -1 Based on the total volume of the diluted sample, add 5× Loading Buffer to the sample until the final concentration is 1×.

[0591] Heat the denatured protein sample in a metal bath (95℃) for 10 minutes. Immediately after heating, place it on ice to cool, allowing water vapor to condense and preventing changes in protein concentration. After cooling, centrifuge briefly and mix well before loading the sample, or freeze it at -20℃ for later loading.

[0592] 2. Sodium dodecyl sulfate-polyacrylamide (SDS-PAGE) gel electrophoresis

[0593] Preparation of acrylamide gel: Wash the thick and thin glass plates, rinse with double-distilled water, and air dry. Prepare the required concentration of separating gel (unit: mL) according to the following formula:

[0594]

[0595]

[0596] Pour the separating adhesive into the two assembled glass plates, seal with double-distilled water, and let stand. When a clear boundary line can be seen between the water and the adhesive (i.e., after the separating adhesive has solidified), discard the upper layer of water and absorb the remaining moisture with a paper towel.

[0597] Prepare the concentrated gel according to the following formula:

[0598]

[0599] Pour the stacking gel onto the top layer of the separating gel and insert the comb; once the gel has completely solidified, it can be used for sample loading.

[0600] Polyacrylamide gel electrophoresis: Remove the prepared gel along with the gel plate, clamp it on the electrophoresis rack, and place it in the electrophoresis tank. Fill the inner tank with 1× protein electrophoresis buffer. Carefully remove the comb and inject 20 μL of protein sample into each well. Add 5 μL of pre-stained protein marker to the marker well. Perform electrophoresis at 80V. After the bromophenol blue front has completely entered the separating gel, adjust the voltage to 120V and continue electrophoresis until the bromophenol blue front reaches the lower edge of the gel. Stop electrophoresis at this point.

[0601] 3. Western blot (protein immunoblotting)

[0602] After electrophoresis, cut off the stacking gel and the bromophenol blue leading edge of the gel. Carefully remove the gel from the plate and place it along with the transfer filter paper in 1× electrotransfer buffer for 10 min to equilibrate. Activate the cut PVDF membrane in anhydrous methanol for 1 min, then place it in 1× electrotransfer buffer for 10 min to equilibrate. Assemble the transfer apparatus in the following order: black gel → white membrane: sponge → three layers of filter paper → gel → PVDF membrane → three layers of filter paper → sponge. During assembly, ensure complete adhesion between the gel and membrane to prevent air bubbles from affecting subsequent experimental results.

[0603] The transfer conditions were: 200 mA, constant current transfer for 90 min. After transfer, the PVDF membrane was carefully removed, and the gel was discarded. The membrane was placed in 5% skim milk and blocked at room temperature for 1 h. The membrane was cut into strips according to the pre-staining marker and the desired protein molecular weight. Primary antibody was prepared using primary antibody dilution buffer (Beyotime Biotechnology Co., Ltd.). The membrane was placed in a hybridization bag, the corresponding primary antibody solution was added, and incubated overnight in a chromatography cabinet at 4°C. The membrane was removed from the hybridization bag and washed three times with PBST (1×), 10 min each time. Secondary antibody was prepared using 1% BSA. The membrane was placed in an incubation box, the corresponding secondary antibody solution was added, ensuring the solution completely covered the membrane strips, and incubated at room temperature for 2 h. The membrane was removed and washed three times with PBST (1×), 10 min each time.

[0604] Preparation of the chromogenic solution: The ECL chromogenic substrate and buffer were mixed at a 1:1 (V / V) ratio to prepare the chromogenic solution, which was then uniformly dropped onto the surface of the membrane strip and exposed in a developer. The results of the exposure were scanned and analyzed to analyze the changes in protein expression levels. Some compounds of the present invention that have inhibitory activity against the COL1A1 promoter were selected for testing.

[0605] 4. Results of inhibiting the expression of fibrosis-related proteins

[0606] Figure 1 Results of inhibiting the expression of fibrosis-related proteins

[0607] Figure 2 Results of inhibiting fibrosis-related protein expression. Note: In the figure, "LT" and "DT" represent L-theanine and D-theanine, respectively.

[0608] 5. Conclusion on inhibiting the expression of fibrosis-related proteins

[0609] Example 2 demonstrates that compounds I-1, I-16, and I-61 of this invention, like theanine, can inhibit the expression of fibrosis-related proteins COL1A1, α-SMA, and CTGF. In particular, compound I-61 exhibits a significant dose-dependent inhibition of the expression of fibrosis-related proteins COL1A1, fibronectin, TGF-β, and α-SMA, initially demonstrating potential for the treatment of liver fibrosis.

[0610] Example 3

[0611] Compound I-61 of this invention inhibits liver fibrosis at the animal level.

[0612] 1. Animal modeling:

[0613] Male Sprague-Dawley rats (weighing 160-180g) were randomly divided into four groups: sham operation group, BDL model group, positive control drug 5mg / kg ATRA group, BDL+100mg / kg I-61 group, and BDL+200mg / kg I-61 group; six animals were in each group.

[0614] Before surgery, the animal was acclimatized in the animal laboratory for two days. The night before surgery, the animal was fasted but given normal water access. The operating table was sterilized with ultraviolet light for 30 minutes, all surgical instruments were autoclaved, and disposable sutures and other supplies were prepared. Surgical instruments and suture needles were soaked in 75% alcohol. The rat was placed in a small animal anesthetic and anesthetized by inhaling isoflurane. After the animal was fully anesthetized, the abdominal hair was shaved, and the surgical site and surrounding skin were thoroughly disinfected with povidone-iodine. An incision was made in the midline of the upper abdomen, and the skin on both sides was grasped with hemostatic forceps to open the abdomen. The liver edge was raised with sterile cotton swabs to expose the duodenum, and the common bile duct connecting the liver and intestine was located.

[0615] Using pointed curved forceps, the common bile duct was separated from the surrounding fat. Two sutures were made near the porta hepatis and two near the duodenum. The common bile duct was then cut in the middle of the ligation points, restoring the internal organs to their original state. After applying 1% vitamin K to the abdomen to stop bleeding and penicillin to prevent infection, the endothelium and epithelium were sutured sequentially. The surgical area and surrounding skin were disinfected again with povidone-iodine. In the sham surgery group, only the abdomen was opened, and the bile duct was not ligated. After the animals regained consciousness, they were given normal food and water.

[0616] 2. Administration:

[0617] Starting the day after surgery, the medication was administered continuously for 14 days. Oral administration was used; the sham surgery group received normal saline as a control, and the BDL group received solvent as a control; the compound I-61 group received an oral suspension prepared with 10% HS-15 solution, administered orally by gavage at doses of 100 mg / kg and 200 mg / kg, respectively.

[0618] 3. Animal sample collection:

[0619] The night before sample collection, rats were moved to metabolic cages, fasted, and given free access to water. Urine and feces were collected during this period. After collection, urine was allowed to stand for 30 minutes to settle, and 1 mL of the supernatant was taken and centrifuged at 3000 rpm for 5 minutes. The supernatant was then diluted 10 times and used to measure urinary biochemical indicators. Feces were directly placed in centrifuge tubes and stored at -80°C.

[0620] After anesthetizing the animal with 10% chloral hydrate via intraperitoneal injection, the abdomen was opened. Blood was collected from the abdominal aorta, and after standing at room temperature for 30 minutes, the blood sample was centrifuged at 3000 rpm for 5 minutes. The supernatant was collected for measuring biochemical indicators in the serum.

[0621] After ligation, due to bile duct obstruction, bile vesicles will be generated below the porta hepatis in rats. The bile in the vesicles will be aspirated, the volume will be measured, and 1 mL will be centrifuged at 3000 rpm for 5 min. The supernatant will be collected after centrifugation, diluted 10 times, and used to measure biochemical indicators in the bile.

[0622] The liver, kidneys, and ileum were dissected sequentially, and the liver and kidneys were weighed. Two pieces from the middle of the largest lobe of the liver were placed in an embedding cassette; one piece was immersed in 10% formalin solution for paraffin sectioning, and the other piece was placed in liquid nitrogen for frozen sectioning. The remaining liver lobes, kidneys, and ileum were cut into small pieces, flash-frozen in liquid nitrogen, and then placed in centrifuge tubes for long-term storage at -80°C for detecting the expression of relevant mRNAs and proteins in animal tissue samples.

[0623] 4. Animal experiment results

[0624] As shown in Table 2 and Figure 3 As shown.

[0625] Table 2. Results of biochemical index determination in serum, urine and bile of BDL model animals

[0626]

[0627]

[0628] * P<0.05 vs control group, ** P<0.01 vs control group, # P<0.05 vs modelgroup, ## P<0.01 vs model group Figure 3 Inhibitory effect of I-61 on fibrosis-related mRNAs.

[0629] 5. Conclusions from animal experiments

[0630] Compound I-61 of this invention can alleviate liver injury and liver fibrosis in bile duct ligation (BDL) rats. In Example 3 of this invention, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total cholesterol (TC), total bilirubin (TBIL), and bile acid (TBA) in the model group were significantly higher than those in the control group. At a dose of 200 mg / kg, compound I-61 of this invention reduced most liver injury indicators compared to the model group, especially blood triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and total bilirubin (TBIL). Under the influence of 200 mg / kg of compound I-61 of this invention, the expression of fibrosis-related genes, type I α collagen, and transforming growth factor β was also significantly reduced. Example 3 illustrates that compound I-61 of this invention has a certain alleviating effect on liver injury and liver fibrosis in BDL rats and has great potential for the treatment of liver fibrosis.

[0631] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compound having the structure described in Formula I, or a pharmaceutical salt, ester, solvate, isomer, polymorph, isotopically labeled compound, metabolite, or prodrug thereof: in R1 represents -OR a1 ,-NR a2 R a3 ,-(C1-C4 alkyl)nR a4 R a1 R a2 R a3 and R a4 The groups are independently selected from the following: hydrogen, deuterium, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 ynyl, C3-C7 cycloalkyl, C6-C10 aryl, 3-15 membered heterocyclic groups. These alkyl, alkenyl, ynyl, cycloalkyl, aryl, and heterocyclic groups may optionally be substituted by one or more groups independently selected from hydroxyl, amino, trifluoromethyl, nitro, halogen, C1-C6 alkyl, halo-C1-C6 alkyl, C1-C6 alkoxy, aryl, and heterocyclic groups. R2 represents hydrogen, deuterium, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkynyl, C3-C7 cycloalkyl, C6-C10 aryl, -(C1-C4 alkyl)nOR a5 -(C1-C4 alkyl)nSR a6 -(C1-C4 alkyl)nNR a7 R a8 , R a5 R a6 R a7 R a8 The groups are each independently selected from the following groups: hydrogen, deuterium, C3-C7 cycloalkyl, C6-C10 aryl, 3-7 membered heterocyclic groups. The alkyl, alkenyl, alkynyl, cycloalkyl, aryl, and heterocyclic groups may optionally be substituted by one or more groups independently selected from hydroxyl, amino, trifluoromethyl, halogen, nitro, C1-C6 alkyl, halo-C1-C6 alkyl, C1-C6 alkoxy, aryl, and heterocyclic groups. R3 and R4 may be the same or different, and are independently selected from hydrogen, deuterium, and -CH2-R. a9 -CO-R a10 -CO-SO2-R a11 , R a9 R a10 R a11 Each group is independently selected from the following groups: C1-C6 alkyl, C1-C6 alkenyl, C1-C6 ynyl, C3-C7 cycloalkyl, C6-C10 aryl, 3-15 membered heterocyclic groups. The alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocyclic groups, It may optionally be substituted with one or more groups independently selected from hydroxyl, amino, trifluoromethyl, nitro, halogen, C1-C6 alkyl, halo-C1-C6 alkyl, C1-C6 alkoxy, C1-C6 acyl, substituted aryl, heterocyclic, wherein the substituted aryl includes halogen, hydroxyl, methoxy, nitro and trifluoromethyl substituted.

2. The compound having the structure of Formula I as described in claim 1, its pharmaceutical salt or ester, solvate, isomer, polymorph, isotopically labeled compound, metabolite, or prodrug, characterized in that: R1 represents -OR a1 ,-NR a2 R a3 ,-(C1-C4 alkyl)nR a4 R2 represents hydrogen, deuterium, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkynyl, C3-C7 cycloalkyl, C6-C10 aryl, -(C1-C4 alkyl)nOR a5 -(C1-C4 alkyl)nSR a6 -(C1-C4 alkyl)nNR a7 R a8 R3 equals R4, which equals hydrogen or deuterium. R a1 R a2 R a3 R a4 R a5 R a6 R a7 R a8 Each group is independently selected from the following groups: hydrogen, deuterium, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkynyl, C3-C7 cycloalkyl, C6-C10 aryl, 3-15 membered heterocyclic groups, wherein the alkyl, alkenyl, alkynyl, cycloalkyl, aryl, and heterocyclic groups may optionally be substituted by one or more groups independently selected from hydroxyl, amino, trifluoromethyl, nitro, halogen, C1-C6 alkyl, halo-C1-C6 alkyl, C1-C6 alkoxy, aryl, and heterocyclic groups.

3. The compound having the structure of Formula I as described in claim 2, its pharmaceutical salt or ester, solvate, isomer, polymorph, isotopically labeled compound, metabolite, or prodrug, characterized in that: When R2 represents hydrogen, deuterium, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 ynyl, C3-C7 cycloalkyl, C6-C10 aryl, or -(C1-C4 alkyl)nOR a5 -(C1-C4 alkyl)nSR a6 -(C1-C4 alkyl)nNR a7 In this case, R1 represents hydroxyl, methoxy, benzyloxy, benzylamino-(C1-C4 alkyl)nR a4 R3 and R4 may be the same or different, and are independently selected from hydrogen, deuterium, benzyl, benzoyl, and benzenesulfonyl, respectively. a4 R a5 R a6 R a7 R a8 Each group is independently selected from the following groups: hydrogen, deuterium, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkynyl, C3-C7 cycloalkyl, C6-C10 aryl, 3-15 membered heterocyclic groups, wherein the alkyl, alkenyl, alkynyl, cycloalkyl, aryl, and heterocyclic groups may optionally be substituted by one or more groups independently selected from hydroxyl, amino, trifluoromethyl, nitro, halogen, C1-C6 alkyl, halo-C1-C6 alkyl, C1-C6 alkoxy, aryl, and heterocyclic groups.

4. The compound having the structure of Formula I as described in claim 3, its pharmaceutical salt or ester, solvate, isomer, polymorph, isotope-labeled compound, metabolite or prodrug, characterized in that; When R3 and R4 are the same or different, they are independently selected from hydrogen, deuterium, and -CH2-R. a9 -CO-R a10 -CO-SO2-R a11 In this case, R1 represents hydroxyl, methoxy, benzyloxy, or benzylamino; R2 represents C1-C6 alkyl; R a9 R a10 R a11 Each group is independently selected from the following groups: C1-C6 alkyl, C1-C6 alkenyl, C1-C6 ynyl, C3-C7 cycloalkyl, C6-C10 aryl, 3-15 membered heterocyclic groups. The alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocyclic groups, It may optionally be substituted with one or more groups independently selected from hydroxyl, amino, trifluoromethyl, nitro, halogen, C1-C6 alkyl, halo-C1-C6 alkyl, C1-C6 alkoxy, C1-C6 acyl, substituted aryl, heterocyclic, wherein the substituted aryl includes halogen, hydroxyl, methoxy, nitro and trifluoromethyl substituted.

5. The compound having the structure of Formula I as claimed in claim 1, its pharmaceutical salt or ester, solvate, isomer, polymorph, isotopically labeled compound, metabolite, or prodrug, characterized in that, The compound represented by Formula I is: 2-Amino-N 5 Methyl 5-oxovalerate 2-Amino-N 5 ethyl-5-oxopentanoic acid benzyl ester 2-Amino-N 1 -Benzyl-N 5 -Ethylglutaramide 2-Amino-N 5 Hexyl 5-oxopentanoate 2-Amino-N 5 2-Hydroxyethyl 5-ethyl-5-oxovalerate 2-Amino-N 5 2-(1-pyrrolidinyl)ethyl 5-oxopentanoic acid-2-(1-pyrrolidinyl)ethyl ester 2-Amino-N 5 -Ethyl-N 1 -[4-(trifluoromethyl)benzyl]glutaramide 2-Amino-N 5 -Ethyl-N 1 -[4-(methoxy)benzyl]glutaramide 2-Amino-N 5 -[2-(1H-imidazol-2-ylmethylthio)ethyl]-N 1 -Benzylglutaramide 2-Amino-N 1 -Benzyl-N 5 -[2-(benzyloxy)ethyl]glutaramide 2-Amino-N 5 -Ethyl-N 1 -(3-pyridinemethyl)glutaramide 2-Amino-N 5 methyl butyl-5-oxovalerate 2-Amino-N 5 Methyl benzyl-5-oxovalerate 2-Amino-N 5 Methyl 2-[2-(benzyloxy)ethyl]-5-oxovalerate 2-Amino-N 5 Methyl isopropyl-5-oxovalerate 2-Amino-N 5 Methyl 2-(2-hydroxyethyl)-5-oxovalerate 2-Amino-N 5 Methyl 2-(pyridin-2-yl)-5-oxovalerate 2-Amino-N 5 Methyl -(thiazo-2-yl)-5-oxovalerate 2-Amino-N 5 methyl 5-phenyl-5-oxovalerate 2-Amino-N 5 Methyl 2-((4-chlorobenzyloxy)ethyl)-5-oxovalerate 2-Amino-N 5 Methyl 2-((3-chlorobenzyloxy)ethyl)-5-oxovalerate 2-Amino-N 5 Methyl 2-((2-chlorobenzyloxy)ethyl)-5-oxovalerate 2-Amino-N 5 Methyl 2-(2-(benzylamino)ethyl)-5-oxovalerate 2-Amino-N 5 Methyl 2-(2-(benzylthio)ethyl)-5-oxovalerate 2-Amino-N 5 Methyl 2-[2-(dibenzylamino)ethyl]-5-oxovalerate 2-Amino-N 5 -(2-hydroxyethyl)-5-oxovaleric acid 2-Amino-N 5 -Butyl-5-oxovaleric acid 2-Amino-N 5 -Isopropyl-5-oxo-valeric acid 2-Amino-N 5 methyl cyclopropylmethyl-5-oxovalerate N 2 -Benzyl-N 5 Methyl 2-(2-(piperidin-1-yl)ethyl)-5-oxo-1-pentanoate N 2 -Benzyl-N 5 Methyl 2-[2-(benzyloxy)ethyl]-5-oxo-1-pentanoate N 2 -Benzyl-N 5 Methyl butyl-5-oxo-1-pentanoate N 2 -benzoyl-N 5 Methyl 5-oxo-1-pentanoate N 2 -Benzyl-N 5 Methyl 5-oxo-1-pentanoate N 2 -(4-Trifluoromethylphenyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 -(2-Hydroxybenzyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 -(3-hydroxybenzyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 -(4-hydroxybenzyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 -(4-chlorobenzyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 -benzenesulfonyl-N 5 Methyl 5-oxo-1-pentanoate N 1 -Benzyl-N 5 2-Ethyl-2-(benzenesulfonylamino)glutaramide N 2 -(6-bromo-4-chloroquinoline-2-formyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 -(6-bromo-4-methylquinoline-2-formyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 -(benzodihydropyran-3-formyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 -(6-Chlorobenzodihydropyran-3-formyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 -(6-Chloro-4-methylquinoline-2-formyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 N 2 -Dibenzyl-N 5 Methyl 5-oxo-1-pentanoate N 2 N 2 -Dibenzyl-N 5 Methyl butyl-5-oxo-1-pentanoate N 2 N 2 -Dibenzyl-N 5 Ethyl 5-oxo-1-pentanoate N 2 N 2 -Dibenzyl-N 5 propyl 5-ethyl-5-oxo-1-pentanoate N 2 N 2 -Dibenzyl-N 5 Butyl ethyl-5-oxo-1-pentanoate N 2 N 2 -Dibenzyl-N 5 ethyl-5-oxo-1-pentanoic acid benzyl ester N 1 -Benzyl-2-(Dibenzylamino)-N 5 -Ethylglutaramide N 2 N 2 -di(4-hydroxybenzyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 N 2 -di(4-methoxybenzyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 N 2 -Di(4-chlorobenzyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 N 2 -di(3,4-dihydroxybenzyl)-N 5 Methyl 5-oxo-1-pentanoate N 2 N 2 -Dibenzyl-N 5 Ethyl butyl-5-oxo-1-pentanoate N 2 -benzenesulfonyl-N 5 ethyl-5-oxo-1-pentanoic acid benzyl ester N 2 -(4-Methylbenzenesulfonyl)-N 5 ethyl-5-oxo-1-pentanoic acid benzyl ester N 2 -(4-bromobenzenesulfonyl)-N 5 ethyl-5-oxo-1-pentanoic acid benzyl ester N 1 -benzyl-2-(benzylamino)-N 5 -Ethylglutaramide N 2 -benzoyl-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -Benzyl-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -(2-pyridinylmethyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -(1H-pyrrolo-2-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -cyclohexanoyl-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -Cyclohexylmethyl-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -Cyclopropylmethyl-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 N 5 Benzyl diethyl-5-oxovalerate N 2 -Acetyl-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 N 2 N 5 Benzyl triethyl-5-oxovalerate N 2 -Hexagen-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -(piperidin-4-ylmethyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -(piperidin-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -(1-benzoylpiperidin-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -(1-Benzylpiperidin-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -(1-(4-hydroxybenzyl)piperidine-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -(1-(4-chlorobenzyl)piperidin-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -(1-(4-nitrobenzyl)piperidine-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -(1-Propionylpiperidin-4-formyl)-N 5 ethyl-5-oxopentanoic acid benzyl ester N 2 -(cyclohexanoyl)-N 5 -Ethyl-5-oxovaleric acid N 2 -Benzyl-N 5 -Ethyl-5-oxovaleric acid N 2 -(pyridine-2-methyl)-N 5 -Ethyl-5-oxovaleric acid N 2 -(1H-pyrrolo-2-yl)-N 5 -Ethyl-5-oxovaleric acid N 2 -(6-bromo-4-chloroquinoline-2-formyl)-N 5 ethyl-5-oxo-1-pentanoic acid N 2 -(6-bromo-4-methylquinoline-2-formyl)-N 5 ethyl-5-oxo-1-pentanoic acid N 2 N 2 -Dibenzyl-N 5 -Butyl-5-oxo-1-pentanoic acid N 2 N 2 -Dibenzyl-N 5 ethyl-5-oxo-1-pentanoic acid N 2 -benzoyl-N 5 ethyl-5-oxo-1-pentanoic acid N 2 -(4-Methoxybenzoyl)-N 5 ethyl-5-oxo-1-pentanoic acid N 2 -(2-Methoxybenzoyl)-N 5 ethyl-5-oxo-1-pentanoic acid N 2 -(3-Methoxybenzoyl)-N 5 ethyl-5-oxo-1-pentanoic acid N 2 -benzenesulfonyl-N 5 1-Ethyl-5-oxo-1-pentanoic acid.

6. A method for preparing the compound of formula I according to claim 1, characterized in that, Follow these steps: When R3 = R4 is hydrogen, and R1 and R2 are as defined in claim 1, the method shown in synthetic route 1 is adopted; Synthesis Route 1: (S)-N-tert-Butoxycarbonylglutamate-1-benzyl ester or (R)-N-tert-Butoxycarbonylglutamate-1-benzyl ester undergoes a condensation reaction with various substituted primary amine compounds to generate compound 2. Then, it is debenzylated (Bn) with hydrogen on palladium on carbon to obtain compound 3. Compound 3 is condensed with various substituted alcohols or substituted amine compounds to obtain compound 4. Finally, the benzyl group of the compound is removed by trifluoroacetic acid (TFA) to obtain compound 5. R1 (not a hydroxyl group) and R2 are the same as defined in claim 1. When R1 is a hydroxyl group, R3 = R4 are hydrogen, and R2 is as defined in claim 1, the method shown in synthetic route 2 shall be used; Synthesis Route 2: Rights Compound 4 was obtained from the synthetic route 1. Compound 4 was then directly subjected to deBoc removal with trifluoroacetic acid to obtain compound 7 (N). 5 -R2-5-oxopentanoic acid compounds), R1 represents hydroxyl, methoxy, benzyloxy, or benzylamino; R2 represents a C1-C6 alkyl group; when R3 and R4 are the same as defined in claim 1, the method shown in synthetic route 3 shall be used; Synthetic route 3: Compound 6 undergoes substitution reactions with various chlorinated derivatives under alkaline conditions to give compound 8, and condenses with various carboxylic acids to give compound 9. Among them, when R1 is methoxy, compound 8 or 9 is hydrolyzed by reflux with cesium carbonate to give compound 10.

7. Use of any compound having the structure of Formula I, pharmaceutical salt or ester, solvate, isomer, polymorph, isotope-labeled compound, metabolite or prodrug of any one of claims 1-5 in the preparation of a drug for treating liver fibrosis.

8. The use as described in claim 7, characterized in that, The applications also include the treatment of chronic liver diseases such as alcoholic steatohepatitis and non-alcoholic steatohepatitis.

9. A pharmaceutical composition comprising a compound containing the structure of Formula I, a pharmaceutical salt or ester thereof, a solvate, an isomer, a polymorph thereof, an isotopically labeled compound, a metabolite, or a prodrug.

10. The pharmaceutical composition according to claim 9, characterized in that, It can be prepared into any pharmaceutically usable dosage form, selected from oral, topical, and injectable dosage forms.

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