CN118598859A - A nitrogen-containing heterocyclic indole xanthine oxidase inhibitor and its preparation method and application - Google Patents

Abstract

The present invention belongs to the field of medical technology. The present invention provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor and a preparation method and application thereof. 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 label, 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 ₅₀ value of most specific compounds can reach the micromolar level, which is better than 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.

Description

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

Technical Field

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

Background Art

Hyperuricemia (HUA) refers to a pathological state in which the concentration of uric acid in 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 state is caused by the accumulation of uric acid in the body due to increased production or decreased excretion of uric acid. Gout is one of the clinical manifestations of hyperuricemia, characterized by recurrent acute arthritis, and long-term accumulation can lead to chronic damage to tissues such as joints and kidneys. 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 eating habits. With the development of the economy and the aging of the population, this trend is more obvious. 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 problems.

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 completed through a complex electron transport chain, which not only involves the redox reaction of FAD and Fe-S clusters, but also includes the participation of oxygen, ultimately generating uric acid and superoxide radicals. Therefore, XO is not only a catalyst for uric acid production, but also one of the sources of reactive oxygen species, which also play a role in the pathology of gout and other inflammatory diseases. Increased activity of this enzyme occupies a central position in the pathogenesis of hyperuricemia and gout, by exacerbating the production of uric acid, leading to its accumulation in the blood and tissues, thereby inducing gout and its related 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.

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, but it has also been explicitly 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, so the development of new non-purine skeleton XO inhibitors is particularly important.

Summary of the invention

In view of the problem that there are few 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 an application of the 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.

To achieve the above object, the present invention is specifically implemented through the following technical solutions:

In a first aspect, the present invention 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;

Wherein, Ar is selected from Any of;

The R ¹ is selected from one or more of hydrogen, deuterium, halogen or C _1-3 alkyl;

The ^R2 is selected from any one of hydrogen, _C1 - _C8 alkyl, substituted _C1 - _C8 alkyl, _C3 - _C8 cycloalkyl, substituted C3- _C8 cycloalkyl _{, C3-C8 alkene, substituted C3-C8 alkene, C3-C8 alkynyl, substituted C3-C8 alkynyl , 3-8 membered heterocycloalkyl , substituted 3-8} membered heterocycloalkyl, aryl or substituted aryl;

R ³ is selected from any one of hydrogen and C ₁ -C ₈ alkyl.

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:

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

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

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;

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

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

The structural formula of the compound of formula I-2 is:

The structural formula of the compound of formula I-3 is:

The structural formula of the compound of formula I-4 is:

The ^R2 is selected from any one of 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.

In a third aspect, the present invention also 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.

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

Compared with the prior art, the nitrogen-containing heterocyclic indole xanthine oxidase inhibitor of the present invention has the following beneficial effects:

The nitrogen-containing heterocyclic indole xanthine oxidase inhibitor of the present invention has good xanthine oxidase inhibitory activity, and the _IC50 value of most specific compounds 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

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

Based on the information contained in the present invention, it is easy for those skilled in the art to make various changes 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 defined processes, properties or components, because these embodiments and other descriptions are only for the purpose of illustrating specific aspects of the present invention. In fact, various changes that a person skilled in the art or related fields can obviously make to the embodiments of the present invention are all within the scope of the appended claims.

In order to better understand the present invention rather than limit the scope of the present invention, all numerals and other numerical values used in the present invention indicating dosage, percentage, etc., 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 according to the reported significant figures and by conventional rounding methods. In addition, it should be noted that the "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.

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.

Unless otherwise clearly defined, the groups indicated in the present invention have the following meanings:

"Alkyl" refers to a saturated straight or branched hydrocarbon group containing, for example, 1 to 8 carbon atoms (C ₁ -C ₈ ), consisting only of carbon atoms and hydrogen atoms, including, but 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, octyl, etc.

"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, 2-methyl-2-pentenyl.

"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, including, but not limited to, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 2-pentynyl, 3-pentynyl, 2-hexynyl, 3-hexynyl, etc.

"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.

"Heterocycloalkyl" refers to a ring containing one or more atoms replaced by heteroatoms (such as N, O, S), and the remaining ring atoms are C, which may optionally include double bonds. Examples include but are not limited to: furan, thiophene, pyrrole, pyridine, pyrimidine, triazole, piperazine, thiazole, morpholine, thiomorpholine, etc.

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

The above-mentioned groups such as alkyl, olefin, and aryl may be substituted or unsubstituted. In the case of "substituted", the hydrogen atoms on the group may be independently substituted by one or more substituents, and when the number of substituents is 2 or more, each substituent 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 1-5 fluorine substituents.

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;

Among them, Ar is selected from Any of;

^R1 is selected from one or more of hydrogen, deuterium, halogen or _C1-3 alkyl;

^R2 is selected from any one of hydrogen, _C1 - _C8 alkyl, substituted _C1 - _C8 alkyl, _C3 - _C8 cycloalkyl _, substituted C3- _{C8 cycloalkyl, C3-C8 alkenyl ,} substituted _C3 - _C8 alkenyl, _C3 - _C8 alkynyl, substituted _C3 - _C8 alkynyl, 3-8 membered heterocycloalkyl, substituted 3-8 membered heterocycloalkyl, aryl or substituted aryl;

R ³ is selected from any one of hydrogen and C ₁ -C ₈ alkyl.

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

In some embodiments, ^R2 is selected from any one of hydrogen, _C1 - _C6 alkyl, substituted _C1 - _C6 alkyl, C3- _C6 cycloalkyl, substituted _C3 - _{C6 cycloalkyl} , _C3 - _C6 alkenyl, substituted _C3 - _C6 alkenyl, _C3 - _C6 alkynyl, substituted _C3 - _C6 alkynyl, 3-6 membered heterocycloalkyl, substituted 3-6 membered heterocycloalkyl, benzyl, or substituted benzyl;

R ³ is selected from any one of hydrogen and C ₂ -C ₆ alkyl.

In some embodiments, R ² is selected from any one of 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;

^R3 is selected from any one of hydrogen, methyl and ethyl.

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

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:

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

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

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;

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

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

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

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

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

^R2 is selected from any one of 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.

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

The invention discloses a method for preparing a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor. The method 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 performing Suzuki coupling reaction on all of them 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. Ester, 6-(3-cyano-1H-indol-5-yl)pyridazine-3-carboxylic acid methyl ester; then react with the corresponding bromine to obtain 2-(3-cyano-N-substituted indol-5-yl)pyrimidine-5-carboxylic acid ethyl ester, 5-(3-cyano-N-substituted indol-5-yl)pyrazine-2-carboxylic acid methyl ester, 6-(3-cyano-N-substituted indol-5-yl)pyridazine-3-carboxylic acid methyl ester, and the ester group is hydrolyzed to obtain 2-(3-cyano-N-substituted indol-5-yl)pyrimidine-5-carboxylic acid, 5-(3-cyano-N-substituted indol-5-yl)pyrazine-2-carboxylic acid, 6-(3-cyano-N-substituted indol-5-yl)pyridazine-3-carboxylic acid, that is, to obtain nitrogen-containing heterocyclic indole xanthine oxidase inhibitors.

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);

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

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

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

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);

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

The solvent B includes at least one of N,N-dimethylformamide and acetonitrile (CH ₃ CN).

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);

In step c, the reaction temperature is 80-110° C., the reaction time is 4-8 hours, and the base is one of potassium carbonate or cesium carbonate;

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

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

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

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

Based on the same inventive concept, the present invention also provides an application 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.

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 shown in general formula I or a pharmaceutically acceptable salt, stereoisomer, isotope-labeled substance, solvate, polymorph or prodrug thereof, and a pharmaceutically acceptable excipient.

The nitrogen-containing heterocyclic indole xanthine oxidase inhibitors of the present invention have good xanthine oxidase inhibitory activity, and the _IC50 values of most specific compounds can reach the micromolar level. They are superior to the inhibitory activity of the classic anti-gout drug allopurinol, can effectively inhibit uric acid production, and have potential application value in anti-hyperuricemia and gout drugs.

The nitrogen-containing heterocyclic indole xanthine oxidase inhibitor of the present invention and its preparation method and application are further described below with specific examples. This section further illustrates the content of the present invention in conjunction with specific examples, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means adopted in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

Example 1

This embodiment provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, specifically 2-(3-cyano-1-cyclopentyl-indol-5-yl)pyrimidine-5-carboxylic acid (compound C06), and its structural formula is:

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

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

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 for 8 hours under condensation reflux under the protection of inert gas argon (Ar). After the reaction was completed, 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 for half an hour by adding a small amount of anhydrous sodium sulfate. The product was filtered and concentrated under reduced pressure to obtain a crude product, which was then separated and purified by column chromatography (200-300 mesh) (eluent was 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-d ₆ ) 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＝8.7Hz,1H),7.44(t,J＝2.7Hz,1H),6.6 1(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 N ₃ O ₂ 268.09, found 267.95.

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

In a 100 mL single-necked flask, add the intermediate ethyl 2-(1H-indol-5-yl)pyrimidine-5-carboxylate (1 g, 3.74 mmol) and 10 mL CH ₃ CN (acetonitrile) in sequence, stir at 0°C for 10 minutes, then slowly drop CSI (chlorosulfonyl isocyanate 1.30 mL, 14.93 mmol) into the flask, react for two hours, then drop DMF (4 mL, 51.71 mmol), continue to react in an ice bath for two hours. Pour the reaction solution into an ice-water mixture, stir for 20 minutes, filter, and vacuum dry the filter cake for 12 hours to obtain a yellow solid with a yield of 82.31%. ¹ HNMR (400MHz, DMSO-d ₆ ) 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 N ₄ O ₂ 293.09, found 293.15.

c) Preparation of 2-(3-cyano-1-cyclopentyl-indol-5-yl)pyrimidine-5-carboxylic acid ethyl ester

In a 100mL two-necked flask, add the intermediate 2-(3-cyano-1H-indol-5-yl)pyrimidine-5-carboxylic acid ethyl ester (0.20g, 0.68mmol), anhydrous potassium carbonate (0.19g, 1.36mmol), and 8mL DMF in sequence, heat to 100°C, add bromocyclopentane (0.11mL, 1.02mmol), and condense and reflux for 6 hours. After the reaction is completed, extract the reaction solution three times with 45mL EA, wash it three times with 30mL saturated brine, add a small amount of anhydrous sodium sulfate, dry it for half an hour, filter it, and concentrate the filtrate under reduced pressure to obtain a crude product, which is then separated and purified by column chromatography (200-300 mesh) (eluent is PE:EA=10:1 (volume ratio)) to obtain a yellow powder with a yield of 79.81%; ¹ HNMR (400MHz, DMSO-d ₆ )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 N ₄ O ₂ for361.16,found361.10.

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

In a 100mL single-necked flask, 3mL of THF was added to stir and dissolve 0.20g of 2-(3-cyano-1-cyclopentyl-indol-5-yl)pyrimidine-5-carboxylic acid ethyl ester, and 3mL of 5% NaOH aqueous solution was added to adjust the pH to 8, and then the temperature was raised to 50°C for condensation and reflux reaction for 1 hour. The solid was concentrated under reduced pressure, and after dissolving in distilled water, 12% dilute HCl was added dropwise to make the pH value of the solution 1, and the solid precipitated. 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 ethyl ester (Formula c06) as a yellow powder with a yield of 86.71%; mp277-282°C; ¹ HNMR (400MHz, DMSO-d ₆ )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＝8.9Hz,1H,ArH),5.04(p,J＝7.1Hz,1H,CH),2.28- 2.15(m,2H,CH ₂ ),1.98-1.80(m,2H,CH ₂ ),1.79-1.66(m,2H,CH ₂ ),1.26(t,J＝15.6Hz,2H,CH ₂ ); ¹³ CNMR(101MHz,DMSO-d ₆ )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; HRMScalculatedforC ₁₉ H ₁₆ N ₄ O ₂ ([M+H] ⁺ )333.1352,found333.1350.

Example 2

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), and its structural formula is:

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

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

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

In a 100mL two-necked flask, add the intermediate 2-(3-cyano-1H-indol-5-yl)pyrimidine-5-carboxylic acid ethyl ester (0.20g, 0.68mmol), anhydrous potassium carbonate (0.19g, 1.36mmol), and 8mL DMF in sequence, heat to 100°C, add isopropyl bromide (0.10mL, 1.02mmol), and condense and reflux for 6 hours. After the reaction is completed, extract the reaction solution three times with 45mL EA, wash it three times with 30mL saturated brine, add a small amount of anhydrous sodium sulfate, dry it for half an hour, filter it, and concentrate the filtrate under reduced pressure to obtain a crude product, which is then separated and purified by column chromatography (200-300 mesh) (eluent is PE:EA=10:1 (volume ratio)) to obtain a yellow powder with a yield of 83.24%; ¹ HNMR (400MHz, DMSO-d ₆ )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 N ₄ O ₂ 335.15, found 335.05.

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

In a 100mL single-necked flask, 3mL of THF was added to stir and dissolve 0.20g of ethyl 2-(3-cyano-1-isopropyl-indol-5-yl)pyrimidine-5-carboxylate, and 3mL of 5% NaOH aqueous solution was added to adjust the pH to 8, and then the temperature was raised to 50°C for condensation and reflux reaction for 1 hour. The solid was concentrated under reduced pressure, and after dissolving in distilled water, 12% dilute HCl was added dropwise to make the pH value of the solution 1, and the solid precipitated. 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-d ₆ )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, CH ₃ ); ¹³ CNMR (101MHz, DMSO-d ₆ )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 N ₄ O ₂ ([M+H] ⁺ )307.1195,found307.1190.

Example 3

This embodiment provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, specifically 5-(3-cyano-1-isopropyl-indol-5-yl)pyrazine-2-carboxylic acid (compound b04), and its structural formula is:

The preparation method of 5-(3-cyano-1-isopropyl-indol-5-yl)pyrazine-2-carboxylic acid (compound b04) comprises the following steps:

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

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 DMF and catalyst [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (PdCl ₂ (dppf)) (0.20 g, 0.55 mmol) were added in sequence, and the temperature was raised to 100° C. under the protection of inert gas Ar, and the reaction was condensed and refluxed for 8 hours. After the reaction was completed, the reaction solution was extracted three times with 45 mL EA, washed three times with 30 mL saturated brine, and then dried for half an hour with a small amount of anhydrous sodium sulfate, 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-d ₆ ) δ 11.69 (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 N ₃ O ₂ 254.08, found 253.95.

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

In a 100 mL single-necked flask, the intermediate 5-(1H-indol-5-yl)pyrazine-2-carboxylic acid methyl ester (1 g, 3.94 mmol) and 10 mL CH ₃ CN were added in sequence. After stirring at 0°C for 10 minutes, CSI (2 mL, 22.98 mmol) was slowly dripped into the flask. After reacting for two hours, DMF (4 mL, 51.71 mmol) was added dropwise, and the reaction was continued in an ice bath for two hours. After the reaction was completed, the reaction solution was poured into an ice-water mixture and stirred for 20 minutes, filtered, and the filter cake was vacuum dried for 12 hours to obtain a yellow powder with a yield of 77.41%. ¹ H NMR (400MHz, DMSO-d ₆ ) 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 N ₄ O ₂ 279.08, found279.05.

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

In a 100mL two-necked flask, add the intermediate 5-(3-cyano-1H-indol-5-yl)pyrazine-2-carboxylic acid methyl ester (0.20g, 0.71mmol), anhydrous potassium carbonate (0.25g, 1.79mmol), and 8mL DMF in sequence, heat to 100°C, add isopropyl bromide (0.10mL, 1.07mmol), and condense and reflux for 6 hours. After the reaction is completed, extract the reaction solution three times with 45mL EA, wash it three times with 30mL saturated brine, add a small amount of anhydrous sodium sulfate, dry it for half an hour, filter it, and concentrate the filtrate under reduced pressure to obtain a crude product, which is then separated and purified by column chromatography (200-300 mesh) (eluent is PE:EA=8:1 (volume ratio)) to obtain a yellow powder with a yield of 72.80%; ¹ H NMR (400MHz, DMSO-d ₆ )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 N ₄ O ₂ 321.13, found 321.10.

d) Preparation of 5-(3-cyano-1-isopropyl-indol-5-yl)pyrazine-2-carboxylic acid (compound b04)

In a 100-mL single-necked flask, 3 mL of THF was added to dissolve 0.20 g of 5-(3-cyano-1-isopropyl-indol-5-yl)pyrazine-2-carboxylic acid methyl ester by stirring, and 3 mL of 5% NaOH aqueous solution was added to adjust the pH to 8, and then the temperature was raised to 50°C and refluxed for reaction for 1 hour. The solid was concentrated under reduced pressure, dissolved in distilled water, and diluted HCl with a mass concentration of 12% was added dropwise to make the pH value of the solution 1, and the solid precipitated. 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-d ₆ ) δ 9.50 (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 = 8.8 Hz, 1H, ArH), 4.95 (p, J = 6.7 Hz, 1H, CH 3 ), 1.53 (d, J = 6.4 Hz, 6H, CH ₃ ); ¹³ CNMR (101MHz, DMSO-d ₆ )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 N ₄ O ₂ ([M+H] ⁺ )307.1195,found307.1194.

Example 4

This embodiment provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, specifically 5-(3-cyano-1-cyclopentyl-indol-5-yl)pyrazine-2-carboxylic acid (compound b06), and its structural formula is:

The preparation method of 5-(3-cyano-1-cyclopentyl-indol-5-yl)pyrazine-2-carboxylic acid (compound b06) comprises the following steps:

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

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

In a 100mL two-necked flask, add the intermediate 5-(3-cyano-1H-indol-5-yl)pyrazine-2-carboxylic acid methyl ester (0.20g, 0.71mmol), anhydrous potassium carbonate (0.25g, 1.79mmol), and 8mL DMF in sequence, heat to 100°C, add bromocyclopentane (0.12mL, 1.07mmol), and condense and reflux for 6 hours. After the reaction is completed, extract the reaction solution three times with 45mL EA, wash it three times with 30mL saturated salt water, add a small amount of anhydrous sodium sulfate, dry it for half an hour, filter it, and concentrate the filtrate under reduced pressure to obtain a crude product, which is then separated and purified by column chromatography (200-300 mesh) (eluent is PE:EA=8:1 (volume ratio)) to obtain a yellow powder with a yield of 69.70%; ¹ HNMR (400MHz, DMSO-d ₆ )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 N ₄ O ₂ 347.14, found 347.05.

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

In a 100-mL single-necked flask, 3 mL of THF was added to dissolve 0.20 g of 5-(3-cyano-1-cyclopentyl-indol-5-yl)pyrazine-2-carboxylic acid methyl ester by stirring, and 3 mL of 5% NaOH aqueous solution was added to adjust the pH to 8, then the temperature was raised to 50°C and refluxed for reaction for 1 hour. The solid was concentrated under reduced pressure, dissolved in distilled water, and diluted HCl with a mass concentration of 12% was added dropwise to make the pH value of the solution 1, and the solid precipitated. The solution was then filtered and the filter cake was dried in vacuum for 12 hours to obtain the target compound as a yellow powder with a yield of 81.34%; mp 261-265°C; ¹ HNMR (400 MHz, DMSO-d ₆ ) δ 9.39 (s, 1H, ArH), 9.23 (s, 1H, ArH), 8.52 (s, 1H, ArH), 8.45 (s, 1H, ArH), 8.14 (d, J = 8.8 Hz, 1H, ArH), 7.90 (d, J = 8.8 Hz, 1H, ArH), 5.03 (p, J = 7.2 Hz, 1H, CH 2 ), 2.25-2.19 (m, 2H, CH ₂ ), 1.80 (dt, J = 58.4, 6.9 Hz, 6H, CH ₂ ); ¹³ CNMR (101MHz, DMSO-d ₆ ) 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 N ₄ O ₂ ([M+H] ⁺ )333.1352, found333.1350.

Example 5

This embodiment provides a nitrogen-containing heterocyclic indole xanthine oxidase inhibitor, specifically 6-(3-cyano-1-ethyl-indol-5-yl)pyridazine-3-carboxylic acid (compound a26), and its structural formula is:

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

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

In 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 catalyst [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride _PdCl2 (dppf) (0.20 g, 0.55 mmol) were added in sequence, and the temperature was raised to 100°C under the protection of inert gas Ar, and the reaction was carried out under condensation reflux for 8 hours. After the reaction was completed, the reaction solution was extracted three times with 45 mL EA, washed three times with 30 mL saturated brine, and then dried for half an hour with a small amount of anhydrous sodium sulfate, 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 PE:EA = 5:1 (volume ratio)) to obtain a yellow powder with a yield of 55.22%; ¹ HNMR (400 MHz, DMSO-d ₆ )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,1 H), 6.61 (td, J=2.0, 0.9Hz, 1H), 3.99 (s, 3H); MS (ESI+): m/z ([M+H] ⁺ )calcdforC ₁₄ H ₁₂ N ₃ O ₂ 254.08, found 254.15.

b) Preparation of 6-(3-cyano-1H-indol-5-yl)pyridazine-3-carboxylic acid methyl ester

In a 100 mL single-necked flask, 1 g of methyl 6-(1H-indol-5-yl)pyridazine-3-carboxylate and 10 mL of CH ₃ CN were added in sequence. After stirring at 0°C for 10 minutes, CSI (2 mL, 22.98 mmol) was slowly dripped into the flask. 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 the reaction was completed, the reaction solution was poured into an ice-water mixture and stirred for 20 minutes, filtered, and the filter cake was vacuum dried for 12 hours to obtain a black solid with a yield of 53.87%. ¹ H NMR (400MHz, DMSO-d ₆ ) 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),4.0 0(s,3H); MS(ESI+):m/z([M+H] ⁺ )calcd for C ₁₅ H ₁₁ N ₄ O ₂ 279.08, found 279.15.

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

In a 100mL two-necked flask, add the intermediate 6-(3-cyano-1H-indol-5-yl)pyridazine-3-carboxylic acid methyl ester (0.20g, 0.71mmol), anhydrous potassium carbonate (0.25g, 1.79mmol) and 8mL DMF in sequence, heat to 100°C, add ethyl bromide (0.09mL, 1.07mmol), and react under condensation reflux for 6 hours. After the reaction was completed, the reaction solution was extracted three times with 45 mL EA, washed three times with 30 mL saturated brine, and then dried for half an hour by adding a small amount of anhydrous sodium sulfate. The mixture 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: PE:EA=5:1) to obtain a yellow powder with a yield of 61.32%; ¹ H NMR (400 MHz, DMSO-d ₆ ) δ8.64-8.47 (m, 2H), 8.43 (d, J=1.5 Hz, 1H), 8.28-8.20 (m, 2H), 7.89 (d, J=8.8 Hz, 1H), 4.36 (q, J=7.3 Hz, 2H), 4.00 (s, 3H), 1.45 (t, J=7.2 Hz, 3H); MS (ESI+): m/z ([M+H] ⁺ ) calcd for C ₁₇ H ₁₅ N ₄ O ₂ 307.11, found 307.05.

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

In a 100-mL single-necked flask, 3 mL of THF was added to dissolve 0.20 g of methyl 6-(3-cyano-1-ethyl-indol-5-yl)pyridazine-3-carboxylate by stirring, and 3 mL of 5% NaOH aqueous solution was added to adjust the pH to 8. The temperature was then raised to 50° C. and the mixture was condensed and refluxed for reaction for 1 hour. The solid was concentrated under reduced pressure, dissolved in distilled water, and diluted HCl with a mass concentration of 12% was added dropwise to make the pH value of the solution 1, and the solid precipitated. 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 79.89%; mp 158-160°C; ¹ H NMR (400 MHz, DMSO-d ₆ ) ¹ H NMR (400 MHz, DMSO-d ₆ ) δ8.60-8.53 (m, 1H, ArH), 8.39 (d, J＝9.0 Hz, 1H, ArH), 8.30-8.16 (m, 2H, ArH), 8.12 (dd, J＝8.8, 1.8 Hz, 1H, ArH), 7.75 (d, J＝8.8 Hz, 1H, ArH), 4.34 (dq, J＝26.7, 7.2 Hz, 2H, CH ₂ ), 1.45 (td, J=7.2, 1.6Hz, 3H, CH ₃ ); ¹³ C NMR (101MHz, DMSO-d ₆ ) δ 166.37, 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 N ₄ O ₂ ([M+H] ⁺ )293.1039.Found 293.1028.

Example 6

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), and its structural formula is:

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

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

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

In a 100mL two-necked flask, add the intermediate 6-(3-cyano-1H-indol-5-yl)pyridazine-3-carboxylic acid methyl ester (0.20g, 0.71mmol), anhydrous potassium carbonate (0.25g, 1.79mmol), and 8mL DMF in sequence, heat to 100°C, add bromocyclopentane (0.10mL, 1.07mmol), and condense and reflux for 6 hours. After the reaction is completed, extract the reaction solution three times with 45mL EA, wash it three times with 30mL saturated brine, add a small amount of anhydrous sodium sulfate, dry it for half an hour, filter it, and concentrate the filtrate under reduced pressure to obtain a crude product, which is then separated and purified by column chromatography (200-300 mesh) (eluent is PE:EA=5:1 (volume ratio)) to obtain a yellow powder with a yield of 53.30%; ¹ HNMR (400MHz, DMSO-d ₆ )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 N ₄ O ₂ 347.14,found347.15.

d) Preparation of 6-(3-cyano-1-cyclopentyl-indol-5-yl)pyridazine-3-carboxylic acid (compound a34)

In a 100-mL single-necked flask, 3 mL of THF was added to dissolve 0.20 g of 6-(3-cyano-1-cyclopentyl-indol-5-yl)pyridazine-3-carboxylic acid methyl ester by stirring, and 3 mL of 5% NaOH aqueous solution was added to adjust the pH to 8, then the temperature was raised to 50°C and refluxed for reaction for 1 hour. The solid was concentrated under reduced pressure, dissolved in distilled water, and diluted HCl with a mass concentration of 12% was added dropwise to make the pH value of the solution 1, and the solid precipitated. 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 78.87%; mp 178-282°C; ¹ HNMR (400MHz, DMSO-d ₆ ) δ 8.55 (d, J = 9.9 Hz, 3H, ArH), 8.24 (dd, J = 10.1, 3.6 Hz, 2H, ArH), 7.95 (d, J = 8.8 Hz, 1H, ArH), 5.05 (q, J = 7.2 Hz, 1H, CH), 2.24 (t, J = 6.9 Hz, 2H, CH ₂ ), 1.96-1.71 (m, 6H, CH ₂ ). ¹³ CNMR (101MHz, DMSO-d ₆ )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 N ₄ O ₂ ([M+H] ⁺ )333.1352,found333.1349.

Example 7

Application effect test

Inhibitory activity test of target compounds on xanthine oxidase (XO)

1. Experimental reagents and instruments

(1) Reagents: xanthine oxidase (Sigma-Aldrich), xanthine (≥99%, Sigma-Aldrich), allopurinol (≥98%, Anergy Chemical), sodium pyrophosphate (≥99%, Anergy Chemical), disodium ethylenediaminetetraacetate (≥98%, Shanghai Bid Pharmaceutical Technology Co., Ltd.).

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

2. Experimental methods

(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.

(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 make up the volume. The present invention prepares a 20 mmol/L xanthine mother solution.

(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 with a buffer solution to the required concentration for testing.

(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-inhibitory concentration IC ₅₀ value (half-inhibitory concentration). Inhibition rate = (1-reaction rate of inhibitor action/reaction rate of blank control) × 100%.

3. Experimental results

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.

Table 1 - IC ₅₀ values of the test substances

As can be seen from the data in Table 1, most of the compounds provided by the present invention exhibit significant xanthine oxidase inhibitory activity, and the IC ₅₀ value can reach the micromolar level. The nitrogen-containing heterocyclic indole xanthine oxidase inhibitor of the present invention has a good in-depth research value as a xanthine oxidase inhibitor in the treatment of hyperuricemia and gout.

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 protection scope of the present invention.

Claims (10)

1. A nitrogenous heterocyclic indole xanthine oxidase inhibitor, which is characterized in that the nitrogenous heterocyclic indole xanthine oxidase inhibitor is a compound shown in a general formula I or pharmaceutically acceptable salt, stereoisomer, isotope label, solvate, polymorph or prodrug thereof;

Wherein Ar is selected from Any one of them;

The R ¹ is selected from one or more of hydrogen, deuterium, halogen or C _1-3 alkyl;

the R ² is selected from any one of hydrogen, C ₁-C₈ alkyl, substituted C ₁-C₈ alkyl, C ₃-C₈ cycloalkyl, substituted C ₃-C₈ cycloalkyl, C ₃-C₈ alkylene, substituted C ₃-C₈ alkylene, C ₃-C₈ alkynyl, substituted C ₃-C₈ alkynyl, 3-8 membered heterocycloalkyl, substituted 3-8 membered heterocycloalkyl, aryl or substituted aryl;

R ³ is selected from any one of hydrogen and C ₁-C₈ alkyl.

2. The nitrogen-containing heterocyclic indole xanthine oxidase inhibitor according to claim 1, wherein R ² is selected from any of hydrogen, C ₁-C₆ alkyl, substituted C ₁-C₆ alkyl, C ₃-C₆ cycloalkyl, substituted C ₃-C₆ cycloalkyl, C ₃-C₆ alkylene, substituted C ₃-C₆ alkylene, C ₃-C₆ alkynyl, substituted C ₃-C₆ alkynyl, 3-6 membered heterocycloalkyl, substituted 3-6 membered heterocycloalkyl, benzyl or substituted benzyl;

R ³ is selected from any one of hydrogen and C ₂-C₆ alkyl.

3. The nitrogen-containing heterocyclic indole xanthine oxidase inhibitor according to claim 2, wherein R ² is selected from any of 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;

and R ³ is selected from any one of hydrogen, methyl and ethyl.

4. A nitrogenous heterocyclic indole xanthine oxidase inhibitor according to any of claims 1 to 3, characterised in that it is selected from any of the following formulae a01-50, b01-06, c 01-06;

5. A process for the preparation of a nitrogenous heterocyclic indole xanthine oxidase inhibitor according to any one of claims 1 to 4, characterised in that it comprises the steps of:

a) Mixing 6-chloro-pyridazine-3-methyl formate, 2-chloropyrimidine-5-ethyl carboxylate and 5-chloropyrazine-2-methyl carboxylate with 5-indoleboronic acid, alkali, a catalyst and a solvent A respectively, and carrying out Suzuki coupling reaction to obtain a compound of a formula I-1;

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

c) Dispersing the compound of the formula I-2 and the bromo-compound in a solvent C, and adding alkali for alkylation reaction to obtain a compound of the formula I-3;

d) Performing alkaline hydrolysis on the compound shown in the formula I-3 to obtain a compound shown in the formula I-4, wherein the compound shown in the formula I-4 is the nitrogenous heterocyclic indole xanthine oxidase inhibitor;

wherein the structural formula of the compound of the formula I-1 is as follows:

The structural formula of the compound of the formula I-2 is as follows:

the structural formula of the compound of the formula I-3 is as follows:

The structural formula of the compound of the formula I-4 is as follows:

6. The process for the preparation of a nitrogenous heterocyclic indole xanthine oxidase inhibitor according to claim 5, wherein in step a, the molar ratio of the 2-chloropyrimidine-5-carboxylic acid ethyl ester or 5-chloropyrazine-2-carboxylic acid methyl ester or 6-chloropyridazine-3-carboxylic acid methyl ester, the 5-indoleboronic acid, the base and the catalyst is 1 (1.2-1.6): 1.5-2.0): 0.02-0.04;

The alkali comprises at least one of sodium carbonate, potassium phosphate and cesium carbonate;

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

The solvent A comprises at least one of N, N-dimethylformamide and dimethyl sulfoxide.

7. The process for the preparation of a nitrogenous heterocyclic indole xanthine oxidase inhibitor according to claim 5, wherein in step b the molar ratio of the compound of formula I-1, the chlorosulfonyl isocyanate and the N, N-dimethylformamide is 1 (1.1-1.5): 5.0-7.0;

In the step b, the reaction temperature is 0-2 ℃ and the reaction time is 4-6h;

the solvent B comprises at least one of acetonitrile and N, N-dimethylformamide.

8. The method of preparing a nitrogenous heterocyclic indole xanthine oxidase inhibitor according to claim 5, wherein in step c, the molar ratio of the compound of formula I-2, the bromo and the base is 1 (1.8-2.5): 1.5-3.0;

in the step c, the reaction temperature is 80-110 ℃, the reaction time is 4-8h, and the alkali is one of potassium carbonate or cesium carbonate;

The solvent C comprises at least one of N, N-dimethylformamide and dimethyl sulfoxide.

In the step d, the alkali is aqueous solution of sodium hydroxide;

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

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

9. The use of a nitrogenous heterocyclic indole xanthine oxidase inhibitor according to any of claims 1-4 in the manufacture of a medicament for xanthine oxidase inhibitor or in the manufacture of a medicament for the prevention and/or treatment of hyperuricemia and/or gout.

10. A pharmaceutical composition comprising a nitrogenous heterocyclic indole xanthine oxidase inhibitor according to any one of claims 1-4 and a pharmaceutically acceptable adjuvant.