A nitrogen-containing heterocyclic indole xanthine oxidase inhibitor and its preparation method and application

Abstract

The present invention belongs to the field of pharmaceutical technology. The present invention provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor and its preparation method and application. The nitrogen-containing heterocyclic indole xanthine oxidase inhibitor of the present invention is a compound as shown in general formula I or a pharmaceutically acceptable salt, stereoisomer, isotope-labeled substance, solvate, polymorph or prodrug thereof. The nitrogen-containing heterocyclic indole xanthine oxidase inhibitor of the present invention has good xanthine oxidase inhibitory activity, and the IC values of most specific compounds are as follows: 50 The value can reach the micromolar level, which is superior to the inhibitory activity of the classic anti-gout drug allopurinol. It can effectively inhibit uric acid production and has potential application value in anti-hyperuricemia and gout drugs.

Description

Technical Field

[0001] The present invention relates to the field of medical technology, and in particular to a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, a preparation method and an application thereof. Background Art

[0002] Hyperuricemia (HUA) refers to a pathological condition in which the concentration of uric acid in the plasma exceeds the normal range, with the plasma uric acid concentration exceeding 420 μmol / L (7.0 mg / dL) in men and exceeding 360 μmol / L (6.0 mg / dL) in women. This pathological condition is due to the accumulation of uric acid in the body due to increased uric acid production or decreased excretion. Gout is one of the clinical manifestations of hyperuricemia, characterized by recurrent acute arthritis, which can lead to chronic damage to tissues such as joints and kidneys through long-term accumulation. Globally, the prevalence of hyperuricemia and gout is on the rise, which is closely related to factors such as changes in lifestyle, increased obesity rates, and dietary habits. With economic development and an aging population, this trend has become more pronounced. Hyperuricemia not only increases the risk of gout, but is also associated with a variety of metabolic diseases such as hypertension, heart disease, and diabetes, highlighting the severity of its public health issues.

[0003] Xanthine oxidase (XO), a macromolecular enzyme containing flavin adenine dinucleotide (FAD) and multiple iron-sulfur (Fe-S) clusters, is a key enzyme at the end of the purine metabolic pathway. It is responsible for oxidizing the metabolic intermediates of purine nucleosides, hypoxanthine and xanthine, to uric acid. The regulation of XO activity and the process of uric acid production are mediated by a complex electron transport chain that involves not only the redox reactions of FAD and Fe-S clusters but also the participation of oxygen, ultimately generating uric acid and superoxide radicals. Therefore, XO is not only a catalyst for uric acid production but also a source of reactive oxygen species, which play a role in the pathogenesis of gout and other inflammatory diseases. Increased activity of this enzyme plays a central role in the pathogenesis of hyperuricemia and gout. By exacerbating uric acid production, it leads to its accumulation in the blood and tissues, further inducing gout and its associated complications. Therefore, rationally designing and developing xanthine oxidase inhibitors to inhibit this physiological process can reduce the production of uric acid, thereby controlling hyperuricemia and preventing gout attacks.

[0004] Allopurine is a classic purine skeleton XO inhibitor that has been used clinically for more than 50 years and can effectively lower blood uric acid levels. However, its purine skeleton also brings possible liver side effects and even life-threatening adverse reactions. These limitations have prompted the development of non-purine skeleton XO inhibitors, such as febuxostat. Compared with allopurine, febuxostat has better tolerability and safety and has now become a first-line drug for clinical treatment. However, it was also issued a black box warning by the FDA in 2019 because it may increase the risk of cardiac death. Therefore, there is an urgent need to develop new therapeutic drugs in clinical practice to control uric acid levels more safely and effectively to meet the treatment needs of the majority of gout patients. Therefore, the development of new non-purine skeleton XO inhibitors is particularly important. Summary of the Invention

[0005] In response to the problems of limited types of XO inhibitors in the prior art, the present invention provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor and a preparation method thereof, and provides the use of a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor in the preparation of xanthine oxidase inhibitor drugs or in the preparation of drugs for preventing and / or treating hyperuricemia and / or gout.

[0006] To achieve the above objectives, the present invention is specifically implemented through the following technical solutions:

[0007] In a first aspect, the present invention provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, which is a compound represented by general formula I or a pharmaceutically acceptable salt, stereoisomer, isotope-labeled substance, solvate, polymorph or prodrug thereof;

[0008]

[0009] Wherein, the Ar is selected from Any of;

[0010] The R 1 Selected from hydrogen, deuterium, halogen or C 1-3 One or more of alkyl groups;

[0011] The R 2 Any one selected from hydrogen, C1-C8 alkyl, substituted C1-C8 alkyl, C3-C8 cycloalkyl, substituted C3-C8 cycloalkyl, C3-C8 alkene group, substituted C3-C8 alkene group, C3-C8 alkynyl, substituted C3-C8 alkynyl, 3-8 membered heterocycloalkyl, substituted 3-8 membered heterocycloalkyl, aryl or substituted aryl;

[0012] R 3 Any one selected from hydrogen, C1-C8 alkyl.

[0013] In a second aspect, the present invention further provides a method for preparing the nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, comprising the following steps:

[0014] a) 6-chloro-pyridazine-3-carboxylic acid methyl ester, 2-chloropyrimidine-5-carboxylic acid ethyl ester, and 5-chloropyrazine-2-carboxylic acid methyl ester are mixed with 5-indoleboric acid, a base, a catalyst, and solvent A, respectively, and subjected to a Suzuki coupling reaction to obtain a compound of formula I-1;

[0015] b) dispersing the compound of formula I-1 and chlorosulfonyl isocyanate in solvent B, and adding N,N-dimethylformamide to obtain a compound of formula I-2;

[0016] c) dispersing the compound of formula I-2 and the bromide in solvent C, adding a base to carry out an alkylation reaction to obtain a compound of formula I-3;

[0017] d) subjecting the compound of formula I-3 to alkaline hydrolysis to obtain a compound of formula I-4, which is the nitrogen-containing heterocyclic indole xanthine oxidase inhibitor of the present invention;

[0018] Wherein, the structural formula of the compound of formula I-1 is:

[0019]

[0020] The structural formula of the compound of formula I-2 is:

[0021]

[0022] The structural formula of the compound of formula I-3 is:

[0023]

[0024] The structural formula of the compound of formula I-4 is:

[0025]

[0026] The R 2 Any one selected from hydrogen, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, allyl, isobutenyl, propynyl, cyclobutyl, cyclopentyl, benzyl, p-fluorobenzyl, p-chlorobenzyl, p-bromobenzyl, o-chlorobenzyl, m-chlorobenzyl, o-fluorobenzyl, m-fluorobenzyl, o-methylbenzyl, carboxyl, propionyl, butyryl and ethoxybenzene.

[0027] In a third aspect, the present invention further provides a use of the nitrogen-containing heterocyclic indole xanthine oxidase inhibitor in the preparation of a xanthine oxidase inhibitor drug or in the preparation of a drug for preventing and / or treating hyperuricemia and / or gout.

[0028] In a fourth aspect, the present invention further provides a pharmaceutical composition comprising the nitrogen-containing heterocyclic indole xanthine oxidase inhibitor and pharmaceutically acceptable excipients.

[0029] The nitrogen-containing heterocyclic indole xanthine oxidase inhibitors of the present invention have the following beneficial effects compared to the prior art:

[0030] The nitrogen-containing heterocyclic indole xanthine oxidase inhibitors of the present invention have good xanthine oxidase inhibitory activity. The IC values of most specific compounds are 50 The value can reach the micromolar level, which is superior to the inhibitory activity of the classic anti-gout drug allopurinol, can effectively inhibit uric acid production, and has potential application value in anti-hyperuricemia and gout drugs. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the embodiments. The embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0032] Given the information contained herein, it will be readily apparent to those skilled in the art that various modifications may be made to the precise description of the present invention without departing from the spirit and scope of the appended claims. It should be understood that the scope of the present invention is not limited to the processes, properties, or components defined herein, as these embodiments and other descriptions are intended only to illustrate specific aspects of the present invention. Indeed, various modifications to the embodiments of the present invention that are apparent to those skilled in the art or related fields are intended to be within the scope of the appended claims.

[0033] In order to better understand the present invention rather than limit the scope of the present invention, all numerals and other numerical values representing dosage, percentage used in the present invention should be understood as modified by the word "about" in all cases. Therefore, unless otherwise specified, the numerical parameters listed in the specification and the appended claims are approximate values, which may be changed according to the different ideal properties attempted to be obtained. Each numerical parameter should at least be regarded as obtained based on the reported significant figures and by conventional rounding methods. In addition, it should be noted that "and / or" used in the present invention should be regarded as the specific disclosure of each of the two specified features or components with or without the other. For example, "A and / or B" will be regarded as (i) A, (ii) B and (iii) A and B.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is described in detail below.

[0035] Unless otherwise specified, the groups indicated in the present invention have the following meanings:

[0036] "Alkyl" refers to a saturated, straight-chain or branched hydrocarbon group containing, for example, 1 to 8 carbon atoms (C1-C8), consisting solely of carbon and hydrogen atoms. Examples include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-methylbutyl, 2,2-dimethylpropyl, n-hexyl, heptyl, and octyl.

[0037] "Alkenyl" refers to an unsaturated straight or branched hydrocarbon group containing, for example, 3 to 8 carbon atoms (C3-C8) and at least one carbon-carbon double bond, including a single double bond or multiple discontinuous double bonds. Examples include, but are not limited to, 1-propenyl, 2-propenyl (or allyl), 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-2-propenyl, 2-pentenyl, 3-pentenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 2-methyl-2-butenyl, and 2-methyl-2-pentenyl.

[0038] "Alkynyl" refers to an unsaturated straight or branched hydrocarbon group containing, for example, 3 to 8 carbon atoms (C3-C8) and at least one carbon-carbon triple bond, including a single triple bond or multiple discontinuous triple bonds. Examples include, but are not limited to, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 2-pentynyl, 3-pentynyl, 2-hexynyl, 3-hexynyl, and the like.

[0039] "Cycloalkyl" refers to a cyclic saturated hydrocarbon group containing 3 carbon atoms, 4 carbon atoms, 5 carbon atoms or even more carbon atoms as ring atoms. In the present invention, C3-C8 cycloalkyl refers to a group containing 3-8 carbon atoms as ring atoms. Cycloalkyl includes monocyclic, polycyclic (such as bicyclic) and fused ring systems. For example, it includes but is not limited to: cyclopropyl, cyclobutyl, 1-methyl-cyclopropyl, 2-methyl-cyclopropyl, cyclopentyl, 1-methyl-cyclobutyl, 2-methyl-cyclobutyl, 3-methyl-cyclobutyl, 1,2-dimethyl-cyclopropyl, 2,3-dimethyl-cyclopropyl, 1-ethyl-cyclopropyl, 2-ethyl-cyclopropyl, cyclohexyl, 1-methyl-cyclopentyl, 2-methyl-cyclopentyl, 3-methyl-cyclopentyl, 1-ethyl-cyclobutyl, 2-ethyl-cyclobutyl, 3-ethyl-cyclobutyl, 1,2-dimethyl-cyclobutyl, 1,3-dimethyl -cyclobutyl, 2,2-dimethyl-cyclobutyl, 2,3-dimethyl-cyclobutyl, 2,4-dimethyl-cyclobutyl, 3,3-dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl, 2-n-propyl-cyclopropyl, 1-isopropyl-cyclopropyl, 2-isopropyl-cyclopropyl, 1,2,2-trimethyl-cyclopropyl, 1,2,3-trimethyl-cyclopropyl, 2,2,3-trimethyl-cyclopropyl, 1-ethyl-2-methyl-cyclopropyl, 2-ethyl-1-methyl-cyclopropyl, 2-ethyl-2-methyl-cyclopropyl, cycloheptyl, cyclooctyl, etc.

[0040] "Heterocycloalkyl" refers to a group in which one or more of the ring atoms are replaced by heteroatoms (e.g., N, O, S), and the remaining ring atoms are C, which may optionally include a double bond. Examples include, but are not limited to, furan, thiophene, pyrrole, pyridine, pyrimidine, triazole, piperazine, thiazole, morpholine, thiomorpholine, and the like.

[0041] "Aryl" refers to a group having a covalent π-electron system and at least one benzene ring, including monocyclic, polycyclic (e.g., bicyclic) and fused ring (rings sharing adjacent carbon pairs) systems, and also includes a cycloalkyl or heterocycloalkyl group as defined above fused to a benzene ring. Examples include, but are not limited to, phenyl, benzyl (or benzyl), xylyl, cumyl, naphthyl, anthracenyl, phenanthrenyl, fluorenyl, pyrrole, and the like.

[0042] The aforementioned groups, such as alkyl, alkene, and aryl groups, may be substituted or unsubstituted. When "substituted," the hydrogen atoms on the group may be independently replaced by one or more substituents. When there are two or more substituents, the substituents may be the same or different. For example, "fluoromethyl" refers to a methyl group having one, two, or three fluorine substituents, and "fluoroethyl" refers to an ethyl group having one to five fluorine substituents.

[0043] The present application provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, which is a compound represented by the general formula I or a pharmaceutically acceptable salt, stereoisomer, isotope-labeled substance, solvate, polymorph or prodrug thereof;

[0044]

[0045] Wherein, Ar is selected from Any of;

[0046] R 1 Selected from hydrogen, deuterium, halogen or C 1-3 One or more of alkyl groups;

[0047] R 2 Any one selected from hydrogen, C1-C8 alkyl, substituted C1-C8 alkyl, C3-C8 cycloalkyl, substituted C3-C8 cycloalkyl, C3-C8 alkene group, substituted C3-C8 alkene group, C3-C8 alkynyl, substituted C3-C8 alkynyl, 3-8 membered heterocycloalkyl, substituted 3-8 membered heterocycloalkyl, aryl or substituted aryl;

[0048] R 3 Any one selected from hydrogen, C1-C8 alkyl.

[0049] Specifically, in the above embodiments, Ar is selected from any one of pyridazinyl, pyrazinyl, and pyrimidinyl.

[0050] In some embodiments, R 2 Any one selected from hydrogen, C1-C6 alkyl, substituted C1-C6 alkyl, C3-C6 cycloalkyl, substituted C3-C6 cycloalkyl, C3-C6 alkene group, substituted C3-C6 alkene group, C3-C6 alkynyl, substituted C3-C6 alkynyl, 3-6 membered heterocycloalkyl, substituted 3-6 membered heterocycloalkyl, benzyl or substituted benzyl;

[0051] R 3 Any one selected from hydrogen, C2-C6 alkyl.

[0052] In some embodiments, R 2 Any one selected from hydrogen, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, allyl, isobutenyl, propynyl, cyclobutyl, cyclopentyl, benzyl, p-fluorobenzyl, p-chlorobenzyl, p-bromobenzyl, o-chlorobenzyl, m-chlorobenzyl, o-fluorobenzyl, m-fluorobenzyl, o-methylbenzyl, carboxyl, propionyl, butyryl and ethoxybenzene;

[0053] R 3 Any one selected from hydrogen, methyl, and ethyl.

[0054] In some embodiments, the nitrogen-containing heterocyclic indole xanthine oxidase inhibitor is selected from any one of the following formulas a01-50, b01-06, and c01-06; preferably any one of the following formulas a26-50, b04-06, and c04-06;

[0055]

[0056]

[0057] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, comprising the following steps:

[0058] a) 6-chloro-pyridazine-3-carboxylic acid methyl ester, 2-chloropyrimidine-5-carboxylic acid ethyl ester, and 5-chloropyrazine-2-carboxylic acid methyl ester are mixed with 5-indoleboric acid, a base, a catalyst, and solvent A, respectively, and subjected to a Suzuki coupling reaction to obtain a compound of formula I-1;

[0059] b) dispersing the compound of formula I-1 and chlorosulfonyl isocyanate in solvent B, and adding N,N-dimethylformamide to obtain a compound of formula I-2;

[0060] c) dispersing the compound of formula I-2 and the bromide in solvent C, adding a base to carry out an alkylation reaction to obtain a compound of formula I-3;

[0061] d) alkaline hydrolysis of the compound of formula I-3 to obtain a compound of formula I-4, which is the nitrogen-containing heterocyclic indole xanthine oxidase inhibitor of the present invention;

[0062] Wherein, the structural formula of the compound of formula I-1 is (any one of I-1a, I-1b, and I-1c):

[0063]

[0064] The structural formula of the compound of formula I-2 is (any one of I-2a, I-2b, and I-2c):

[0065]

[0066] The structural formula of the compound of formula I-3 is (any one of I-3a, I-3b, and I-3c):

[0067]

[0068] The structural formula of the compound of formula I-4 is (any one of I-4a, I-4b, and I-4c):

[0069]

[0070] R 2 Any one selected from hydrogen, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, allyl, isobutenyl, propynyl, cyclobutyl, cyclopentyl, benzyl, p-fluorobenzyl, p-chlorobenzyl, p-bromobenzyl, o-chlorobenzyl, m-chlorobenzyl, o-fluorobenzyl, m-fluorobenzyl, o-methylbenzyl, carboxyl, propionyl, butyryl and ethoxybenzene.

[0071] Specifically, the preparation process of the nitrogen-containing heterocyclic indole xanthine oxidase inhibitor of the present invention is:

[0072]

[0073] The preparation method of the nitrogen-containing heterocyclic indole xanthine oxidase inhibitor of the present invention comprises the following steps: using 2-chloropyrimidine-5-carboxylic acid ethyl ester, 5-chloropyrazine-2-carboxylic acid methyl ester, and 6-chloropyridazine-3-carboxylic acid methyl ester as starting materials, and subjecting them to Suzuki coupling reaction with 5-indoleboric acid to obtain 2-(1H-indol-5-yl)pyrimidine-5-carboxylic acid ethyl ester, 5-(1H-indol-5-yl)pyrazine-2-carboxylic acid methyl ester, and 6-(1H-indol-5-yl)pyridazine-3-carboxylic acid methyl ester; and then introducing a cyano group at the 3-position of the indole ring by using chlorosulfonyl isocyanate to generate 2-(3-cyano-1H-indol-5-yl)pyrimidine-5-carboxylic acid ethyl ester and 5-(3-cyano-1H-indol-5-yl)pyrazine-2-carboxylic acid methyl ester. The invention discloses a novel novel pyrimidine-5-carboxylic acid inhibitor comprising a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor and a pyrimidine-5-carboxylic acid ester, a pyrimidine-5-carboxylic acid ester, a pyrimidine-2-carboxylic acid methyl ester, and a pyrimidine-3-carboxylic acid methyl ester. The pyrimidine-5-carboxylic acid ester comprises a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor and a pyrimidine-5-carboxylic acid ester. The pyrimidine-5-carboxylic acid ester comprises a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor and a pyrimidine-2-carboxylic acid methyl ester. The pyrimidine-5-carboxylic acid ester comprises a pyrimidine-5-carboxylic acid ester, a pyrimidine-2-carboxylic acid methyl ester, and a pyrimidine-3-carboxylic acid methyl ester. The pyrimidine-5-carboxylic acid ester comprises a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor and a pyrimidine-5-carboxylic acid ester.

[0074] In some embodiments, in step a, the molar ratio of 2-chloropyrimidine-5-carboxylic acid ethyl ester or 5-chloropyrazine-2-carboxylic acid methyl ester or 6-chloropyridazine-3-carboxylic acid methyl ester, 5-indoleboric acid, base and catalyst is 1:(1.2-1.6):(1.5-2.0):(0.02-0.04);

[0075] The base includes at least one of sodium carbonate, potassium carbonate, potassium phosphate, and cesium carbonate;

[0076] The catalyst comprises at least one of palladium acetate, tetrakis(triphenylphosphine)palladium or bis(triphenylphosphine)palladium dichloride;

[0077] The solvent A includes at least one of N,N-dimethylformamide (DMF) and dimethyl sulfoxide.

[0078] In some embodiments, in step b, the molar ratio of the compound of formula I-1, chlorosulfonyl isocyanate and N,N-dimethylformamide is 1:(1.1-1.5):(5.0-7.0);

[0079] In step b, the reaction temperature is 0-2°C and the reaction time is 4-6h;

[0080] Solvent B includes at least one of N,N-dimethylformamide and acetonitrile (CH3CN).

[0081] In some embodiments, in step c, the molar ratio of the compound of formula I-2, the bromide and the base is 1:(1.8-2.5):(1.5-3.0);

[0082] In step c, the reaction temperature is 80-110°C, the reaction time is 4-8h, and the base is potassium carbonate or cesium carbonate;

[0083] The solvent C includes at least one of N,N-dimethylformamide and dimethyl sulfoxide.

[0084] In some embodiments, in step d, the base is an aqueous solution of sodium hydroxide;

[0085] The mass volume ratio of the compound of formula I-3 to the aqueous solution of sodium hydroxide is 1 g: (3-5) mL;

[0086] The mass concentration of the sodium hydroxide aqueous solution is 3-5%.

[0087] Based on the same inventive concept, the present invention also provides a use of the above-mentioned nitrogen-containing heterocyclic indole xanthine oxidase inhibitor in the preparation of xanthine oxidase inhibitor drugs or in the preparation of drugs for preventing and / or treating hyperuricemia and / or gout.

[0088] Based on the same inventive concept, the present invention also provides a pharmaceutical composition comprising the above-mentioned nitrogen-containing heterocyclic indole xanthine oxidase inhibitor and a pharmaceutically acceptable excipient; specifically, the pharmaceutical composition of the present invention comprises a therapeutically effective amount of a compound as represented by general formula I or a pharmaceutically acceptable salt, stereoisomer, isotope-labeled substance, solvate, polymorph or prodrug thereof, and a pharmaceutically acceptable excipient.

[0089] The nitrogen-containing heterocyclic indole xanthine oxidase inhibitors of the present invention have good xanthine oxidase inhibitory activity. The IC values of most specific compounds are 50 The value can reach the micromolar level, which is superior to the inhibitory activity of the classic anti-gout drug allopurinol, can effectively inhibit uric acid production, and has potential application value in anti-hyperuricemia and gout drugs.

[0090] The following further illustrates the nitrogen-containing heterocyclic indole xanthine oxidase inhibitors of the present invention, their preparation methods, and uses, using specific examples. This section further illustrates the present invention in conjunction with specific examples, but should not be construed as limiting the present invention. Unless otherwise specified, the techniques employed in the examples are conventional techniques well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment employed in the present invention are conventional in the art.

[0091] Example 1

[0092] This example provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, specifically 2-(3-cyano-1-cyclopentyl-indol-5-yl)pyrimidine-5-carboxylic acid (Compound C06), whose structural formula is:

[0093]

[0094] The preparation method of 2-(3-cyano-1-cyclopentyl-indol-5-yl)pyrimidine-5-carboxylic acid (Compound C06) comprises the following steps:

[0095] a) Preparation of ethyl 2-(1H-indol-5-yl)pyrimidine-5-carboxylate

[0096] In a 100 mL two-necked flask, ethyl 2-chloropyrimidine-5-carboxylate (1.00 g, 5.35 mmol), 1.31 g (7.00 mmol) of 5-indoleboric acid, anhydrous potassium carbonate (4.67 g, 26.53 mmol), 18 mL of DMF and catalyst [1,1'-bis(diphenylphosphino)ferrocene] palladium dichloride (PdCl2(dppf)) (0.20 g, 0.55 mmol) were added in sequence, and the mixture was reacted at 90°C under condensation reflux under the protection of inert gas argon (Ar) for 8 hours. After completion of the reaction, the reaction solution was extracted three times with 45 mL of ethyl acetate (EA), washed three times with 30 mL of saturated brine, and then dried over a small amount of anhydrous sodium sulfate for half an hour. The product was filtered, and the filtrate was concentrated under reduced pressure to obtain a crude product, which was then separated and purified by column chromatography (200-300 mesh) (eluent: petroleum ether:ethyl acetate (PE:EA) = 8:1 (volume ratio)) to obtain a yellow powder with a yield of 55.56%. 1 HNMR (400MHz, DMSO-d6) δ11.38(s,1H),9.23(s,2H),8.78(d,J=1.7Hz,1H),8.27(dd,J=8.7,1.7Hz,1H),7.53(d,J=8.7H z,1H),7.44(t,J=2.7Hz,1H),6.61(d,J=3.1Hz,1H),4.39(q,J=7.1Hz,2H),1.36(t,J=7.1Hz,3H); MS(ESI+):m / z([M+H] + )calcdforC 15 H 14 N3O2268.09,found267.95.

[0097] b) Preparation of ethyl 2-(3-cyano-1H-indol-5-yl)pyrimidine-5-carboxylate

[0098] In a 100 mL single-necked flask, the intermediate ethyl 2-(1H-indol-5-yl)pyrimidine-5-carboxylate (1 g, 3.74 mmol) and 10 mL of CH3CN (acetonitrile) were added sequentially. After stirring at 0°C for 10 minutes, CSI (chlorosulfonyl isocyanate 1.30 mL, 14.93 mmol) was slowly added dropwise to the flask. After two hours of reaction, DMF (4 mL, 51.71 mmol) was added dropwise and the reaction was continued in an ice bath for two hours. The reaction solution was poured into an ice-water mixture and stirred for 20 minutes. The mixture was then filtered and the filter cake was vacuum dried for 12 hours to obtain a yellow solid with a yield of 82.31%. 1 HNMR (400MHz, DMSO-d6) δ9.28(d,J=2.6Hz,2H),8.78(d,J=1.6Hz,1H),8.43(dd,J=8.7,1.7Hz,1H),8.36( d,J=3.1Hz,1H),7.70(d,J=8.7Hz,1H),4.40(q,J=7.1Hz,2H),1.37(t,J=7.1Hz,3H); MS(ESI+):m / z([M+H] + )calcdforC 16 H 13 N4O2293.09,found293.15.

[0099] c) Preparation of ethyl 2-(3-cyano-1-cyclopentyl-indol-5-yl)pyrimidine-5-carboxylate

[0100] In a 100 mL two-necked flask, the intermediate ethyl 2-(3-cyano-1H-indol-5-yl)pyrimidine-5-carboxylate (0.20 g, 0.68 mmol), anhydrous potassium carbonate (0.19 g, 1.36 mmol), and 8 mL of DMF were added in sequence. The temperature was raised to 100° C., cyclopentane bromide (0.11 mL, 1.02 mmol) was added, and the mixture was refluxed under condensation for 6 hours. After completion of the reaction, the reaction solution was extracted three times with 45 mL of EA, washed three times with 30 mL of saturated brine, and dried over a small amount of anhydrous sodium sulfate for half an hour. The mixture was filtered and the filtrate was concentrated under reduced pressure to obtain the crude product, which was then separated and purified by column chromatography (200-300 mesh) (eluent: PE:EA = 10:1 (volume ratio)) to obtain a yellow powder with a yield of 79.81%. 1HNMR(400MHz,DMSO-d6)δ9.32(s,1H),8.79(d,J=1.6Hz,1H),8.55(s,1H),8.47(dd,J=9.0,1.7Hz,1H),7.92(d, J=8.9Hz,1H),7.44-7.35(m,1H),4.40(d,J=14.3Hz,1H),2.76(s,3H),1.42-1.27(m,8H); MS(ESI+):m / z([M+H] + )calcdforC 21 H 21 N4O2for361.16,found361.10.

[0101] d) Preparation of 2-(3-cyano-1-cyclopentyl-indol-5-yl)pyrimidine-5-carboxylic acid ethyl ester (Compound C06)

[0102] In a 100 mL single-necked flask, 0.20 g of ethyl 2-(3-cyano-1-cyclopentyl-indol-5-yl)pyrimidine-5-carboxylate was stirred and dissolved in 3 mL of THF. The pH was adjusted to 8 by adding 3 mL of 5% aqueous NaOH solution, and the mixture was heated to 50°C and refluxed for 1 hour. The mixture was concentrated under reduced pressure to obtain a solid. After dissolving in distilled water, 12% dilute HCl was added dropwise to bring the solution pH to 1, resulting in the precipitation of a solid. The solution was then filtered, and the filter cake was vacuum dried for 12 hours to obtain the target compound, ethyl 2-(3-cyano-1-cyclopentyl-indol-5-yl)pyrimidine-5-carboxylate (Formula C06), as a yellow powder with an 86.71% yield; mp 277-282°C. 1 HNMR(400MHz,DMSO-d6)δ9.28(s,2H,ArH),8.77(d,J=1.7Hz,1H,ArH),8.53(s,1H,ArH),8.46(dd,J=8.9,1.7Hz,1H,ArH),7.90(d,J=8.9H z,1H,ArH),5.04(p,J=7.1Hz,1H,CH),2.28-2.15(m,2H,CH2),1.98-1.80(m,2H,CH2),1.79-1.66(m,2H,CH2),1.26(t,J=15.6Hz,2H,CH2); 13 CNMR(101MHz,DMSO-d6)δ166.30,165.48,158.89,137.85,136.15,130.81,128.05,124 .03,122.87,120.00,116.12,112.74,85.66,58.09,32.54,23.91; HRMScalculatedforC19 H 16 N4O2([M+H] + )333.1352,found333.1350.

[0103] Example 2

[0104] This embodiment provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, specifically 2-(3-cyano-1-isopropyl-indol-5-yl)pyrimidine-5-carboxylic acid (Compound C04), whose structural formula is:

[0105]

[0106] The preparation method of 2-(3-cyano-1-isopropyl-indol-5-yl)pyrimidine-5-carboxylic acid (Compound C04) comprises the following steps:

[0107] Steps a) and b) are the same as steps a) and b) in Example 1;

[0108] c) Preparation of 2-(3-cyano-1-isopropyl-indol-5-yl)pyrimidine-5-carboxylic acid ethyl ester

[0109] In a 100 mL two-necked flask, the intermediate ethyl 2-(3-cyano-1H-indol-5-yl)pyrimidine-5-carboxylate (0.20 g, 0.68 mmol), anhydrous potassium carbonate (0.19 g, 1.36 mmol), and 8 mL of DMF were added in sequence. After heating to 100° C., isopropyl bromide (0.10 mL, 1.02 mmol) was added and the mixture was allowed to reflux under condensation for 6 hours. After completion of the reaction, the reaction solution was extracted three times with 45 mL of EA, washed three times with 30 mL of saturated brine, and dried over a small amount of anhydrous sodium sulfate for half an hour. The mixture was filtered and the filtrate was concentrated under reduced pressure to obtain the crude product, which was then separated and purified by column chromatography (200-300 mesh) (eluent: PE:EA = 10:1 (volume ratio)) to obtain a yellow powder with a yield of 83.24%. 1 HNMR(400MHz,DMSO-d6)δ9.32(s,2H),8.80(d,J=1.6Hz,1H),8.60(s,1H),8.51–8.44(m,1H),7.93(d,J =8.9Hz,1H),4.94(p,J=6.8Hz,1H),4.41(q,J=7.1Hz,3H),1.53(d,J=6.6Hz,6H); MS(ESI+):m / z([M+H] + )calcdforC 19 H 18 N4O2335.15,found335.05.

[0110] d) Preparation of 2-(3-cyano-1-isopropyl-indol-5-yl)pyrimidine-5-carboxylic acid (Compound C04)

[0111] In a 100mL single-necked flask, 3mL of THF was added to dissolve 0.20g of ethyl 2-(3-cyano-1-isopropyl-indol-5-yl)pyrimidine-5-carboxylate with stirring. 3mL of 5% aqueous NaOH solution was added to adjust the pH to 8, and the mixture was heated to 50°C and refluxed for 1 hour. The mixture was concentrated under reduced pressure to obtain a solid. After dissolving in distilled water, 12% dilute HCl was added dropwise to adjust the solution pH to 1, resulting in the precipitation of a solid. The solution was then filtered, and the filter cake was vacuum dried for 12 hours to obtain the target compound, 2-(3-cyano-1-cyclopentyl-indol-5-yl)pyrimidine-5-carboxylic acid (Formula C04), as a yellow powder with a yield of 85.90%; mp 272-275°C. 1 HNMR(400MHz,DMSO-d6)δ9.28(s,2H,ArH),8.78(d,J=1.7Hz,1H,ArH),8.57(s,1H,ArH),8.46(dd,J=8 .9,1.7Hz,1H,ArH),7.90(d,J=8.9Hz,1H,ArH),4.93(p,J=6.7Hz,1H,CH),1.52(d,J=6.5Hz,6H,CH3); 13 CNMR(101MHz,DMSO-d6)δ166.40,165.46,158.90,137.22,135.74,130.72,127.95, 124.02,122.53,120.10,116.11,112.46,85.72,48.89,22.66; HRMScalculatedforC 17 H 14 N4O2([M+H] + )307.1195,found307.1190.

[0112] Example 3

[0113] This example provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, specifically 5-(3-cyano-1-isopropyl-indol-5-yl)pyrazine-2-carboxylic acid (Compound b04), whose structural formula is:

[0114]

[0115] The preparation method of 5-(3-cyano-1-isopropyl-indol-5-yl)pyrazine-2-carboxylic acid (Compound B04) comprises the following steps:

[0116] a) Preparation of 5-(1H-indol-5-yl)pyrazine-2-carboxylic acid methyl ester

[0117] In a 100 mL two-necked flask, methyl 2-chloropyrazine-5-carboxylate (1.00 g, 5.80 mmol), 5-indoleboric acid (1.33 g, 8.26 mmol), anhydrous potassium carbonate (4.67 g, 26.53 mmol), 18 mL of DMF, and catalyst [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (PdCl2(dppf)) (0.20 g, 0.55 mmol) were added in sequence. The temperature was raised to 100° C. under the protection of inert gas Ar, and the reaction was refluxed under condensation for 8 hours. After the reaction was completed, the reaction solution was extracted three times with 45 mL of EA, washed three times with 30 mL of saturated brine, and dried for half an hour with a small amount of anhydrous sodium sulfate. The product was filtered and the filtrate was concentrated under reduced pressure to obtain a crude product, which was then separated and purified by column chromatography (200-300 mesh) to obtain a brown powder with a yield of 53.42%. 1 H NMR (400MHz, DMSO-d6) δ11.69(s,1H),9.68(d,J=1.5Hz,1H),9.47(d,J=1.4Hz,1H),8.81(d,J=1.7Hz,1H),8.30(dd,J= 8.6,1.8Hz,1H),7.85(d,J=8.6Hz,1H),7.75(t,J=2.8Hz,1H),6.88(t,J=2.5Hz,1H),4.22(s,3H); MS(ESI+):m / z([M+H] + )calcd for C 14 H 12 N3O2254.08,found 253.95.

[0118] b) Preparation of 5-(3-cyano-1H-indol-5-yl)pyrazine-2-carboxylic acid methyl ester

[0119] In a 100 mL single-necked flask, the intermediate methyl 5-(1H-indol-5-yl)pyrazine-2-carboxylate (1 g, 3.94 mmol) and 10 mL of CHCN were added sequentially. After stirring at 0°C for 10 minutes, CSI (2 mL, 22.98 mmol) was slowly added dropwise to the flask. After two hours of reaction, DMF (4 mL, 51.71 mmol) was added dropwise and the reaction was continued in an ice bath for two hours. After completion of the reaction, the reaction solution was poured into an ice-water mixture and stirred for 20 minutes. The mixture was then filtered and the filter cake was vacuum dried for 12 hours to obtain a yellow powder with a yield of 77.41%. 1H NMR (400MHz, DMSO-d6) δ11.41(s,1H),9.39(d,J=1.5Hz,1H),9.18(d,J=1.4Hz,1H),8.52(d,J=1.7Hz,1H) ,8.01(dd,J=8.6,1.8Hz,1H),7.58-7.27(m,2H),6.59(t,J=2.7Hz,1H),3.93(s,3H); MS(ESI+):m / z([M+H] + )calcd for C 15 H 11 N4O2279.08,found279.05.

[0120] c) Preparation of 5-(3-cyano-1-isopropyl-indol-5-yl)pyrazine-2-carboxylic acid methyl ester

[0121] In a 100 mL two-necked flask, the intermediate methyl 5-(3-cyano-1H-indol-5-yl)pyrazine-2-carboxylate (0.20 g, 0.71 mmol), anhydrous potassium carbonate (0.25 g, 1.79 mmol), and 8 mL of DMF were added in sequence. The temperature was raised to 100° C., and isopropyl bromide (0.10 mL, 1.07 mmol) was added. The mixture was refluxed under condensation for 6 hours. After completion of the reaction, the reaction solution was extracted three times with 45 mL of EA, washed three times with 30 mL of saturated brine, and dried over a small amount of anhydrous sodium sulfate for half an hour. The mixture was filtered and the filtrate was concentrated under reduced pressure to obtain the crude product, which was then separated and purified by column chromatography (200-300 mesh) (eluent: PE:EA = 8:1 (volume ratio)) to obtain a yellow powder with a yield of 72.80%. 1 H NMR (400MHz, DMSO-d6) δ9.52(d,J=1.5Hz,1H),9.23(d,J=1.4Hz,1H),8.61-8.53(m,2H),8.23(dd,J=8.8,1.7Hz ,1H),7.93(d,J=8.8Hz,1H),4.95(hept,J=6.7Hz,1H),3.96(s,3H),1.53(d,J=6.6Hz,6H); MS(ESI+):m / z([M+H] + )calcd forC 18 H 17 N4O2321.13,found 321.10.

[0122] d) Preparation of 5-(3-cyano-1-isopropyl-indol-5-yl)pyrazine-2-carboxylic acid (Compound b04)

[0123] In a 100mL single-necked flask, 0.20g of methyl 5-(3-cyano-1-isopropyl-indol-5-yl)pyrazine-2-carboxylate was dissolved with 3mL of THF and stirred. The pH was adjusted to 8 by adding 3mL of 5% aqueous NaOH solution, and the mixture was heated to 50°C and refluxed for 1 hour. The mixture was concentrated under reduced pressure to obtain a solid. After dissolving the solid in distilled water, 12% dilute HCl was added dropwise to a pH of 1, causing solid precipitation. The solution was then filtered and the filter cake was vacuum dried for 12 hours to obtain the target compound as a yellow powder with a yield of 86.91%; mp 250-253°C. 1 HNMR(400MHz,DMSO-d6)δ9.50(s,1H,ArH),9.23(s,1H,ArH),8.6-8.54(m,2H,ArH),8.27-8.20 (m,1H,ArH),7.93(d,J=8.8Hz,1H,ArH),4.95(p,J=6.7Hz,1H,CH),1.53(d,J=6.4Hz,6H,CH3); 13 CNMR(101MHz,DMSO-d6)δ165.66,154.24,145.44,141.91,136.53,135.80,129.51, 128.10,123.02,118.83,116.19,112.84,85.58,48.84,22.66; HRMScalculatedforC 17 H 14 N4O2([M+H] + )307.1195,found307.1194.

[0124] Example 4

[0125] This example provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, specifically 5-(3-cyano-1-cyclopentyl-indol-5-yl)pyrazine-2-carboxylic acid (Compound b06), whose structural formula is:

[0126]

[0127] The preparation method of 5-(3-cyano-1-cyclopentyl-indol-5-yl)pyrazine-2-carboxylic acid (Compound B06) comprises the following steps:

[0128] Steps a) and b) are the same as steps a) and b) in Example 3;

[0129] c) Preparation of 5-(3-cyano-1-cyclopentyl-indol-5-yl)pyrazine-2-carboxylic acid methyl ester

[0130] In a 100 mL two-necked flask, the intermediate methyl 5-(3-cyano-1H-indol-5-yl)pyrazine-2-carboxylate (0.20 g, 0.71 mmol), anhydrous potassium carbonate (0.25 g, 1.79 mmol), and 8 mL of DMF were added in sequence. The temperature was raised to 100° C., cyclopentane bromide (0.12 mL, 1.07 mmol) was added, and the mixture was refluxed under condensation for 6 hours. After completion of the reaction, the reaction solution was extracted three times with 45 mL of EA, washed three times with 30 mL of saturated brine, and dried over a small amount of anhydrous sodium sulfate for half an hour. The mixture was filtered and the filtrate was concentrated under reduced pressure to obtain the crude product, which was then separated and purified by column chromatography (200-300 mesh) (eluent: PE:EA = 8:1 (volume ratio)) to obtain a yellow powder with a yield of 69.70%. 1 HNMR (400MHz, DMSO-d6) δ9.53(d,J=1.5Hz,1H),9.23(dd,J=6.8,3.4Hz,1H),8.58-8.53(m,2H),8.28-8.19(m,1H),7.93(d,J=8. 8Hz,1H),5.06(p,J=7.0Hz,1H),3.96(s,3H),2.27-2.20(m,3H),1.96-1.86(m,3H),1.74(d,J=6.8Hz,2H); MS(ESI+):m / z([M+H] + )calcdforC 20 H 19 N4O2347.14,found347.05.

[0131] d) Preparation of 5-(3-cyano-1-cyclopentyl-indol-5-yl)pyrazine-2-carboxylic acid (Compound b06)

[0132] In a 100mL single-necked flask, 0.20g of methyl 5-(3-cyano-1-cyclopentyl-indol-5-yl)pyrazine-2-carboxylate was dissolved with 3mL of THF and stirred. The pH was adjusted to 8 by adding 3mL of 5% aqueous NaOH solution, and the mixture was heated to 50°C and refluxed for 1 hour. The reaction was concentrated under reduced pressure to obtain a solid. After dissolving the solid in distilled water, 12% dilute HCl was added dropwise to raise the pH to 1, causing solid precipitation. The solution was then filtered, and the filter cake was vacuum-dried for 12 hours to obtain the target compound as a yellow powder in an 81.34% yield; mp: 261-265°C. 1HNMR(400MHz,DMSO-d6)δ9.39(s,1H,ArH),9.23(s,1H,ArH),8.52(s,1H,ArH),8.45(s,1H,ArH),8.14(d,J=8.8Hz,1H, ArH),7.90(d,J=8.8Hz,1H,ArH),5.03(p,J=7.2Hz,1H,CH),2.25-2.19(m,2H,CH2),1.80(dt,J=58.4,6.9Hz,6H,CH2); 13 CNMR(101MHz,DMSO-d6)δ165.71,154.20,145.45,141.91,137.21,136.23,129.61,128 .22,123.04,118.76,116.19,113.16,85.53,58.05,32.55,23.93; HRMScalculatedforC 19 H 16 N4O2([M+H] + )333.1352,found333.1350.

[0133] Example 5

[0134] This example provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, specifically 6-(3-cyano-1-ethyl-indol-5-yl)pyridazine-3-carboxylic acid (Compound a26), whose structural formula is:

[0135]

[0136] The preparation method of 6-(3-cyano-1-ethyl-indol-5-yl)pyridazine-3-carboxylic acid (Compound a26) comprises the following steps:

[0137] a) Preparation of methyl 6-(1H-indol-5-yl)pyridazine-3-carboxylate

[0138] To a 100 mL two-necked flask, methyl 2-chloropyridazine-5-carboxylate (1.00 g, 5.80 mmol), 5-indoleboric acid (1.33 g, 8.26 mmol), anhydrous potassium carbonate (4.67 g, 26.53 mmol), 18 mL of DMF, and the catalyst [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (PdCl2(dppf)) (0.20 g, 0.55 mmol) were added in sequence. The mixture was heated to 100°C under the protection of inert gas (Ar) and refluxed for 8 hours. After completion of the reaction, the reaction solution was extracted three times with 45 mL of EA, washed three times with 30 mL of saturated brine, and dried over a small amount of anhydrous sodium sulfate for half an hour. The mixture was filtered and the filtrate was concentrated under reduced pressure to obtain the crude product, which was then separated and purified by column chromatography (200-300 mesh) using an eluent of PE:EA = 5:1 (volume ratio) to obtain a yellow powder with a yield of 55.22%. 1 HNMR (400MHz, DMSO-d6) δ11.39(s,1H),8.49(d,J=1.8Hz,1H),8.39(d,J=9.0Hz,1H),8.20(d,J=8.9Hz,1H),8.05(dd,J=8. 6,1.8Hz,1H),7.59(d,J=8.6Hz,1H),7.46(t,J=2.8Hz,1H),6.61(td,J=2.0,0.9Hz,1H),3.99(s,3H); MS(ESI+):m / z([M+H] + )calcdforC 14 H 12 N3O2254.08,found254.15.

[0139] b) Preparation of methyl 6-(3-cyano-1H-indol-5-yl)pyridazine-3-carboxylate

[0140] To a 100 mL single-necked flask, 1 g of methyl 6-(1H-indol-5-yl)pyridazine-3-carboxylate and 10 mL of CHCN were added sequentially. After stirring at 0°C for 10 minutes, CSI (2 mL, 22.98 mmol) was slowly added dropwise. After reacting for 2 hours, DMF (4 mL, 51.71 mmol) was added dropwise and the reaction was continued in an ice bath for 2 hours. After completion of the reaction, the reaction solution was poured into an ice-water mixture and stirred for 20 minutes. The mixture was then filtered and the filter cake was vacuum dried for 12 hours to obtain a black solid with a yield of 53.87%. 1H NMR (400MHz, DMSO-d6) δ8.59-8.51(m,1H),8.38(d,J=3.1Hz,1H),8.27-8.22(m,1H),8.15 -8.05(m,1H),7.76(d,J=8.7Hz,1H),7.36-7.25(m,1H),4.00(s,3H); MS(ESI+):m / z([M+H] + )calcd for C 15 H 11 N4O2279.08,found 279.15.

[0141] c) Preparation of 6-(3-cyano-1-ethyl-indol-5-yl)pyridazine-3-carboxylic acid methyl ester

[0142] In a 100 mL two-necked flask, the intermediate methyl 6-(3-cyano-1H-indol-5-yl)pyridazine-3-carboxylate (0.20 g, 0.71 mmol), anhydrous potassium carbonate (0.25 g, 1.79 mmol), and 8 mL of DMF were added in sequence. The temperature was raised to 100° C., bromoethane (0.09 mL, 1.07 mmol) was added, and the mixture was refluxed under condensation for 6 hours. After completion of the reaction, the reaction solution was extracted three times with 45 mL of EA, washed three times with 30 mL of saturated brine, and dried over a small amount of anhydrous sodium sulfate for half an hour. The mixture was filtered and the filtrate was concentrated under reduced pressure to obtain the crude product, which was then separated and purified by column chromatography (200-300 mesh) (eluent: PE:EA = 5:1) to obtain a yellow powder with a yield of 61.32%. 1 H NMR (400MHz, DMSO-d6) δ8.64-8.47(m,2H),8.43(d,J=1.5Hz,1H),8.28-8.20(m,2H),7.89(d, J=8.8Hz,1H),4.36(q,J=7.3Hz,2H),4.00(s,3H),1.45(t,J=7.2Hz,3H); MS(ESI+):m / z([M+H] + )calcd for C 17 H 15 N4O2307.11,found 307.05.

[0143] d) Preparation of 6-(3-cyano-1-ethyl-indol-5-yl)pyridazine-3-carboxylic acid (Compound a26)

[0144] In a 100mL single-necked flask, 0.20g of methyl 6-(3-cyano-1-ethyl-indol-5-yl)pyridazine-3-carboxylate was dissolved with 3mL of THF and stirred. The pH was adjusted to 8 by adding 3mL of 5% aqueous NaOH solution, and the mixture was heated to 50°C and refluxed for 1 hour. The mixture was concentrated under reduced pressure to obtain a solid. After dissolving in distilled water, 12% dilute HCl was added dropwise to raise the pH to 1, causing solid precipitation. The solution was then filtered, and the filter cake was vacuum-dried for 12 hours to obtain the target compound as a yellow powder in a 79.89% yield; mp: 158-160°C. 1 H NMR (400 MHz, DMSO-d6) 1 H NMR (400MHz, DMSO-d6) δ8.60-8.53(m,1H,ArH),8.39(d,J=9.0Hz,1H,ArH),8.30-8.16(m,2H,ArH),8.12(dd,J=8. 8,1.8Hz,1H,ArH),7.75(d,J=8.8Hz,1H,ArH),4.34(dq,J=26.7,7.2Hz,2H,CH2),1.45(td,J=7.2,1.6Hz,3H,CH3); 13 C NMR (101MHz, DMSO-d6) δ166.37,161.27,150.48,137.77,128.70,127.61,125. 21,124.79,123.13,121.73,118.79,112.77,111.52,85.16,41.44,15.62; HRMS calculated for C 16 H 12 N4O2([M+H] + )293.1039.Found 293.1028.

[0145] Example 6

[0146] This embodiment provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, specifically 6-(3-cyano-1-cyclopentyl-indol-5-yl)pyridazine-3-carboxylic acid (Compound a34), whose structural formula is:

[0147]

[0148] The preparation method of 6-(3-cyano-1-cyclopentyl-indol-5-yl)pyridazine-3-carboxylic acid (Formula a34) comprises the following steps:

[0149] Steps a) and b) are the same as steps a) and b) in Example 5;

[0150] c) Preparation of 6-(3-cyano-1-cyclopentyl-indol-5-yl)pyridazine-3-carboxylic acid methyl ester

[0151] In a 100 mL two-necked flask, the intermediate methyl 6-(3-cyano-1H-indol-5-yl)pyridazine-3-carboxylate (0.20 g, 0.71 mmol), anhydrous potassium carbonate (0.25 g, 1.79 mmol), and 8 mL of DMF were added in sequence. The temperature was raised to 100° C., cyclopentane bromide (0.10 mL, 1.07 mmol) was added, and the mixture was refluxed under condensation for 6 hours. After completion of the reaction, the reaction solution was extracted three times with 45 mL of EA, washed three times with 30 mL of saturated brine, and dried over a small amount of anhydrous sodium sulfate for half an hour. The mixture was filtered and the filtrate was concentrated under reduced pressure to obtain the crude product, which was then separated and purified by column chromatography (200-300 mesh) (eluent: PE:EA = 5:1 (volume ratio)) to obtain a yellow powder with a yield of 53.30%. 1 HNMR (400MHz, DMSO-d6) δ8.63-8.49(m,3H),8.33-8.18(m,2H),7.95(d,J=8.8Hz,1H),5.14-4.96(m,1H),4. 00(s,3H),2.28-2.21(m,2H),1.97-1.85(m,4H),1.78-1.70(m,1H),1.37-1.18(m,1H); MS(ESI+):m / z([M+H] + )calcdforC 20 H 19 N4O2347.14,found347.15.

[0152] d) Preparation of 6-(3-cyano-1-cyclopentyl-indol-5-yl)pyridazine-3-carboxylic acid (Compound a34)

[0153] In a 100mL single-necked flask, 0.20g of methyl 6-(3-cyano-1-cyclopentyl-indol-5-yl)pyridazine-3-carboxylate was dissolved with 3mL of THF and stirred. The pH was adjusted to 8 by adding 3mL of 5% aqueous NaOH solution, and the mixture was heated to 50°C and refluxed for 1 hour. The reaction was concentrated under reduced pressure to obtain a solid. After dissolving the solid in distilled water, 12% dilute HCl was added dropwise to raise the pH to 1, causing solid precipitation. The solution was then filtered, and the filter cake was vacuum-dried for 12 hours to obtain the target compound as a yellow powder in a 78.87% yield; mp: 178-282°C. 1HNMR(400MHz,DMSO-d6)δ8.55(d,J=9.9Hz,3H,ArH),8.24(dd,J=10.1,3.6Hz,2H,ArH),7.95(d, J=8.8Hz,1H,ArH),5.05(q,J=7.2Hz,1H,CH),2.24(t,J=6.9Hz,2H,CH2),1.96-1.71(m,6H,CH2). 13 CNMR(101MHz,DMSO-d6)δ165.71,160.41,150.81,137.19,129.71,128.72,128.19,125.21 ,123.06,118.73,116.20,113.16,85.48,76.13,58.06,32.53,23.93; HRMScalculatedforC 19 H 16 N4O2([M+H] + )333.1352,found333.1349.

[0154] Example 7

[0155] Application effect test

[0156] Inhibitory activity test of target compounds against xanthine oxidase (XO)

[0157] 1. Experimental reagents and instruments

[0158] (1) Experimental reagents: xanthine oxidase (Sigma-Aldrich), xanthine (≥99%, Sigma-Aldrich), allopurinol (≥98%, Anaiji Chemical), sodium pyrophosphate (≥99%, Anaiji Chemical), disodium edetate (≥98%, Shanghai Bid Pharmaceutical Technology Co., Ltd.).

[0159] (2) Experimental instruments: electronic analytical balance (FA2204C), pH meter (Ray-PhS-3C), and microplate reader (SpectraMax M2 Microplate reader).

[0160] 2. Experimental methods

[0161] (1) Preparation of buffer solution: Use 0.1 mol / L sodium pyrophosphate and 0.3 mmol / L disodium EDTA to prepare a buffer solution with a pH of 8.3.

[0162] (2) Preparation of substrate xanthine: 0.1 mmol xanthine requires 1 mL of 1 mol / L sodium hydroxide solution to adjust the pH, and then a buffer solution is added to the volume. The present invention prepares a 20 mmol / L xanthine stock solution.

[0163] (3) Preparation of the test substance: The test substance (i.e., the compound represented by the general formula I of the present invention) is dissolved in DMSO to prepare a stock solution, which is then prepared using a buffer solution to the desired concentration for testing.

[0164] (4)IC 50 Value test method: Add bovine xanthine oxidase (XO), different concentrations of inhibitors to be tested and buffer to a 96-well plate, incubate for 15 minutes, and then add substrate xanthine to initiate the reaction. Apply ultraviolet spectrophotometry to measure the absorbance change of the reaction between XO and substrate xanthine at 295nm, calculate the reaction rate and inhibition rate, and fit them in Origin software to obtain the half-maximal inhibitory concentration IC 50 Inhibition rate = (1-reaction rate of inhibitor / reaction rate of blank control) × 100%.

[0165] 3. Experimental results

[0166] The test substances of the present invention (ie, the compounds represented by the general formula I of the present invention) all showed strong inhibitory activity against xanthine oxidase, and the experimental data are shown in Table 1.

[0167] Table 1 - IC under test 50 value

[0168]

[0169]

[0170] As shown in Table 1, most of the compounds provided by the present invention exhibited significant xanthine oxidase inhibitory activity, IC 50 The nitrogen-containing heterocyclic indole xanthine oxidase inhibitor of the present invention has a great value for in-depth research in the field of anti-hyperuricemia and gout as a xanthine oxidase inhibitor.

[0171] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Use of a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor in the preparation of a xanthine oxidase inhibitor drug or in the preparation of a drug for preventing and / or treating hyperuricemia and / or gout; The nitrogen-containing heterocyclic indole xanthine oxidase inhibitor is the compound shown in a34; The chemical structure of a34 is:

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