An N-(2-oxopropyl)acetamide derivative and its preparation method and application

Abstract

The present invention relates to an N-(2-oxopropyl)acetamide derivative, its preparation method, and its use. The N-(2-oxopropyl)acetamide derivative has a structure as described in Formula (I), its stereoisomers, or pharmaceutically acceptable salts thereof. The N-(2-oxopropyl)acetamide derivative provided by the present invention has a quinazolinone and its analogue skeleton and exhibits good water solubility, low cytotoxicity, and high in vitro and in vivo anticoccidial and anti-Toxoplasma activity. This addresses the problems of strong drug resistance in existing anticoccidial drugs and the lack of anti-Toxoplasma drugs. #imgabs0#

Description

Technical Field

[0001] The present invention relates to the technical field of medicinal chemistry, and in particular to an N-(2-oxopropyl)acetamide derivative and a preparation method and application thereof. Background Art

[0002] Coccidiosis is a serious disease that threatens the poultry industry. It is caused by a single-celled parasitic protozoan of the genus Eimeria. Infected chickens damage the intestinal epithelial cells, leading to clinical symptoms such as weight loss, loss of appetite, lethargy, decreased egg production, bloody stools, and even death.

[0003] Clinically, coccidiosis prevention and treatment primarily relies on chemically synthesized drugs such as diclazuril, sulfonamides, and decoquinate. These drugs are highly effective in preventing and treating coccidiosis in chickens, but they also present numerous challenges, including: 1. Strong drug resistance. Currently, coccidia have developed resistance to over 20 anticoccidial drugs, including sulfonamides, triazines, polyethers, and quinoline carboxylates, with resistance rates reaching as high as 90% for some. 2. Strong side effects. Long-term use of anticoccidial drugs can lead to vitamin deficiencies, soft-shelled eggs, and growth delays in chickens. Furthermore, genetically engineered vaccines are immature and less effective than chemical drugs. There is no mature, stable, and highly effective vaccine on the market for preventing coccidiosis in the field. Therefore, the development of new, highly effective, low-toxic, and less susceptible to drug resistance anticoccidial drugs is urgent.

[0004] Toxoplasma gondii is an obligate zoonotic parasite with a wide geographical distribution, multiple hosts, a complex life cycle, and significant harm. It poses a significant threat to pregnant humans and animals, as well as those with compromised immune systems. Currently, clinical treatments primarily use drugs such as pyrimethamine and sulfonamides for acute infection, but they are ineffective against latent infection and have significant side effects, such as allergic reactions, bone marrow suppression, and poor tolerance. Although vaccines offer a more direct approach to preventing and controlling Toxoplasma infection, there is currently only one commercially available vaccine for the prevention of abortion in sheep (Toxovax1, MSDA Animal Health). This vaccine has a short protection period and cannot completely eliminate tachyzoites. Furthermore, the molecular mechanisms underlying its design remain unclear, and it is susceptible to mutations that could transform attenuated strains into pathogenic strains. Therefore, the development of new anti-Toxoplasma drugs that can treat latent infection with minimal toxicity and side effects is of great significance to both human public health and the healthy development of the animal husbandry industry.

[0005] Halofuginone is a halogenated derivative of the natural product febrifugine, which exhibits antimalarial and anticoccidial activity. While exhibiting promising anticoccidial effects, its practical application in poultry farming for the prevention and treatment of coccidiosis in chickens is limited. This is primarily due to the complex synthesis of halofugone's N-3 side chain, which results in high production costs. Therefore, structural modification and optimization of febrifugine are being conducted to develop novel anticoccidial and toxoplasmic drugs with readily available raw materials and low costs. This is of great significance for addressing the serious problem of coccidial resistance and the lack of clinically available drugs for the treatment of toxoplasmosis. Summary of the Invention

[0006] The purpose of the present invention is to provide an N-(2-oxopropyl)acetamide derivative and its preparation method and application, so as to solve the problems of strong drug resistance of existing anticoccidial drugs and the shortage of anti-Toxoplasma drugs.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] An N-(2-oxopropyl)acetamide derivative, the structure of which is a compound as described in formula (I) and its stereoisomers or pharmaceutically acceptable salts thereof:

[0009]

[0010] In formula (I), X is selected from CH or N;

[0011] Ring A is selected from aryl or heteroaryl, and there are 0 to 5 substituents R1 on the aryl or heteroaryl, and the substituents R1 are selected from hydrogen, halogen, cyano, hydroxyl, amino, nitro, trifluoromethyl, trifluoromethoxy, C 1-4 Alkyl or C 1-4 alkoxy;

[0012] R is selected from a heterocyclic group, and there is at least one substituent R2 on the heterocyclic group, and the substituent R2 is selected from an aryl group, a halogenated aryl group, a cycloalkylaryl group, a halogenated alkylaryl group, a halogenated alkoxyaryl group, a heterocyclic group, a halogenated heterocyclic group, a heteroaryl group, a halogenated heteroaryl group, a halogenated alkylheteroaryl group, a halogenated alkoxyheteroaryl group, an alkylformyl group, an arylformyl group, a halogenated arylformyl group, a heteroarylformyl group, a halogenated heteroarylformyl group, a halogenated arylsulfonyl group, a hydroxyalkyl group, a hydroxyalkynyl group, an aminoalkyl group, a hydrogen group, a halogen group, a carboxyl group, an ester group, a cyano group, a C 1-4 Alkyl or C 1-4 alkoxy;

[0013] The heterocyclic group refers to a C 2-11-heterocyclyl, which is a saturated or partially saturated monocyclic or bicyclic heterocycle, at least one of the ring atoms being selected from the group consisting of N, O and S, and the remaining ring atoms being selected from carbon; a bicyclic heterocyclyl refers to a heterocycle consisting of two rings having two common ring atoms, the bridge separating the two rings being a single bond, a chain of at least one ring atom, or a spirocycle where the two rings are connected via one common ring atom;

[0014] The aryl group refers to a monocyclic, bicyclic or tricyclic carbon ring system, wherein at least one ring is aromatic and the whole is a C 6-14 -aryl;

[0015] The heteroaryl group refers to a monocyclic, bicyclic or tricyclic ring system of at least one valence, wherein at least one ring is aromatic, contains 1 to 4 heteroatoms, and the whole is a C 5-11 -heteroaryl, wherein the heteroatom is selected from O, S or N;

[0016] The C 1-4 Alkyl refers to a saturated straight-chain or branched hydrocarbon group having 1 to 4 carbon atoms;

[0017] The C 1-4 Alkoxy refers to an alkoxy group having a total of 1 to 4 carbon atoms and connected to the rest of the molecule through O.

[0018] According to the above technical means, the N-(2-oxopropyl)acetamide derivatives of the present invention have a quinazolinone and its analogue skeleton, and have been experimentally determined to have good water solubility, low cytotoxicity, and high in vitro and in vivo anticoccidial and anti-Toxoplasma activity, thereby solving the problems of strong drug resistance of existing anticoccidial drugs and the lack of anti-Toxoplasma drugs.

[0019] Preferably, the heterocyclic group refers to a C 2-11 -heterocyclyl, and is a saturated or partially saturated monocyclic or bicyclic heterocycle, 1, 2 or 3 of the ring atoms are heteroatoms selected from the group consisting of N, O and S, and the remaining ring atoms are selected from carbon; a bicyclic heterocyclyl refers to a heterocycle consisting of two rings having two common ring atoms, the bridge separating the two rings being a single bond, a chain of one or two ring atoms, or a spirocycle where the two rings are connected via one common ring atom.

[0020] Preferably, the aryl group is selected from C 6-12 -aryl.

[0021] Preferably, the aryl group is selected from C 6-12 -aryl.

[0022] Preferably, the heteroaryl group is selected from C 5-9 -heteroaryl.

[0023] Preferably, the heterocyclic group refers to a C 3-8 -heterocyclic group.

[0024] Preferably, the heterocyclic group is selected from azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, 1,6-diazaspiro[3.4]octane, 1,7-diazaspiro[3.5]nonane, 2-azaspiro[3.3]heptane, 2-oxa-7-azaspiro[3.5]nonane, 2-oxa-6-azaspiro[3.3]heptane, 2,6-diazaspiro[3.3]heptane, 2,7-diazaspiro[3.5]nonane, 2,6-diazaspiro[3.5]nonane, 7-oxa-2-azaspiro[3.5]nonane, morpholinyl or thiomorpholinyl.

[0025] Preferably, the aryl group is selected from phenyl, naphthyl, indanyl or anthracenyl.

[0026] Preferably, the heteroaryl group is selected from pyridyl, pyrrolyl, thienyl, furyl, indolyl or quinolinyl.

[0027] Preferably, the C 1-4 The alkyl group is selected from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl.

[0028] Preferably, the C 1-4 The alkoxy group is selected from methoxy, ethoxy, propoxy or tert-butoxy.

[0029] Preferably, the pharmaceutically acceptable salt is a salt formed by an acid and a nitrogen containing a lone pair of electrons in compound (I), and the acid is selected from hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, methanesulfonic acid, trifluoroacetic acid, tartaric acid, lactic acid, maleic acid, fumaric acid, malic acid or citric acid.

[0030] Preferably, the compound of formula (I) is selected from any one of the following compounds ((Ia), (Ib), (Ic), (Id), (Ie), (If), (Ig)):

[0031]

[0032] Preferably, the compound of formula (I) is selected from any one of the following compounds 1-28:

[0033] The present invention also provides a method for preparing the N-(2-oxopropyl)acetamide derivative according to the present invention, comprising the following steps:

[0034]

[0035] The compound of formula (II) undergoes an acylation reaction to obtain a compound of formula (III); the compound of formula (III) undergoes a nucleophilic substitution reaction with compound RH to obtain a compound of formula (I);

[0036] Wherein, A, X, Y and R have the same definitions as described above.

[0037] The present invention also provides a method for preparing the N-(2-oxopropyl)acetamide derivative according to the present invention, comprising the following steps:

[0038] The compound of formula (II) and an organic base are dissolved in an organic solvent, chloroacetyl chloride is slowly added dropwise at low temperature, stirred at room temperature, and the reaction is monitored by thin-layer plate. After the reaction is completed, water is added and extracted with an organic solvent. The organic phases are combined, dried, and concentrated. The crude product is subjected to column chromatography on a silica gel column to obtain a compound of formula (III);

[0039] The compound of formula (III) and a base are dissolved in an organic solvent, and compound RH is added at room temperature. The mixture is stirred at room temperature for reaction. After the reaction is completed, the mixture is diluted with water and extracted with an organic solvent. The mixture is combined, dried, and concentrated. The crude product is subjected to column chromatography on a silica gel column to obtain the compound of formula (I);

[0040] The organic solvent is pyridine, chloroform, dichloromethane, ethyl acetate, tetrahydrofuran, 1,4-dioxane, chlorobenzene, toluene, acetonitrile, N,N-dimethylformamide or dimethyl sulfoxide;

[0041] The organic base is triethylamine, N,N-diisopropylethylamine, pyridine, 4-dimethylaminopyridine or 2,6-lutidine;

[0042] The base is potassium carbonate, sodium bicarbonate, sodium carbonate, triethylamine, N,N-diisopropylethylamine, pyridine, 4-dimethylaminopyridine or 2,6-lutidine.

[0043] The present invention also provides a use of the N-(2-oxopropyl)acetamide derivative of the present invention in the preparation of anticoccidial and anti-Toxoplasma drugs.

[0044] The present invention also provides a use of the N-(2-oxopropyl)acetamide derivative of the present invention in the preparation of drugs against Eimeria tenella and Toxoplasma gondii.

[0045] Beneficial effects of the present invention:

[0046] The present invention provides an N-(2-oxopropyl)acetamide derivative having a quinazolinone and its analogue skeleton, and having the advantages of good water solubility, low cytotoxicity, and high in vitro and in vivo anticoccidial and anti-Toxoplasma activity;

[0047] The present invention provides a method for preparing an N-(2-oxopropyl)acetamide derivative, which is synthesized through bromination, reduction, acylation, and nucleophilic substitution reactions. The synthetic process has the advantages of simple and mild conditions and low production cost. The derivative is suitable for development into anticoccidial and anti-toxoplasmic drugs and has potential value in the development of new drugs in the field of medicinal chemistry technology.

[0048] In vitro anticoccidial and anti-Toxoplasma gondii activity tests of the N-(2-oxopropyl)acetamide derivatives provided by the present invention show that most of them exhibit high inhibitory activity and have the advantage of low host cell toxicity, thereby demonstrating that the N-(2-oxopropyl)acetamide derivatives have potential application prospects in anticoccidial and anti-Toxoplasma gondii active drugs. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is the mass spectrum of compound 1;

[0050] Figure 2 is the mass spectrum of compound 3;

[0051] Figure 3 is the mass spectrum of compound 8;

[0052] Figure 4 is the mass spectrum of compound 9. DETAILED DESCRIPTION

[0053] The following describes the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will readily appreciate the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the various details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0054] Example 1

[0055] A method for preparing an N-(2-oxopropyl)acetamide derivative as shown in compound 1,

[0056] The synthesis process of compound 1 is as follows:

[0057]

[0058] The preparation method comprises the following steps:

[0059] Step 1: Add quinazolin-4(3H)-one (14.6 g, 100 mmol) to a flask containing anhydrous N,N-dimethylformamide (250 mL) and replace the nitrogen with vacuum; add sodium hydride (4.8 g, 120 mmol, 60%) to the above solution in portions at 0°C; after stirring the reaction solution for 1 hour, add 2-(3-bromo-2-oxopropyl)isoindoline-1,3-dione (Compound 1-1) (28.1 g, 100 mmol) to the flask under ice bath; after the addition is complete, the reaction solution is reacted at room temperature overnight; thin When the starting material was no longer reduced, water (50 mL) was slowly added to the reaction solution to terminate the reaction. 500 mL of water was added to the reaction solution, which was then extracted with ethyl acetate (200 mL x 3). The organic phases were combined and washed with saturated brine (100 mL x 3). The organic phases were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain a crude product. The crude product was recrystallized from ethanol to obtain Compound 1-2 (2-(2-oxo-3-(4-oxoquinazolin-3(4H)-yl)propyl)isoindoline-1,3-dione) as a pale yellow solid (yield: 21.5 g, yield: 62%). LC-MS (m / z): 348.1 [M+H] + .

[0060] Step 2: Compound 1-2 (3.47 g, 10 mmol) was added to a round-bottom flask containing isopropanol / water (50 mL, v / v = 6 / 1). Sodium borohydride (0.45 g, 10 mmol) was slowly added with stirring. The reaction mixture was stirred at room temperature for 24 hours. After the complete disappearance of the starting material, as monitored by thin-layer chromatography, glacial acetic acid (5 mL) was added to the reaction mixture, which was then heated to 80°C and stirred for 2 hours. The solvent was evaporated to dryness, and the crude product was dissolved in water. The pH was adjusted to 7 with saturated aqueous sodium bicarbonate. The precipitated solid was filtered and washed twice with water, ethanol, and ethyl acetate. The solid was collected and dried under reduced pressure to obtain Compound 1-3 (3-(3-amino-2-oxopropyl)quinazolin-4(3H)-one (Compound 1-3)) as an off-white solid (yield 1.84 g, 85%). LC-MS (m / z): 218.1 [M+H] + .

[0061] Step 3: Compound 1-3 (1.5 g, 6.9 mmol) was added to a round-bottom flask containing dichloromethane / N,N-dimethylformamide (30 mL, v / v = 9 / 1) and placed in an ice bath. Under nitrogen, chloroacetyl chloride (1.2 g, 10.4 mmol) was slowly added dropwise. After the addition was complete, the reaction solution was reacted at room temperature for 6 hours. After the complete disappearance of the starting material as monitored by thin-layer chromatography, the reaction was quenched with water and extracted. The combined organic phases were washed with saturated brine (30 mL x 3), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The crude product was recrystallized from methanol / dichloromethane to obtain compound 1-4 (2-chloro-N-(2-oxo-3-(4-oxoquinazolin-3(4H)-yl)propyl)acetamide) as an off-white solid (yield 1.58 g, 78%). LC-MS (m / z): 294.1 [M+H] + .

[0062] Step 4: Compound 1-4 (0.5 g, 1.7 mmol) was added to a round-bottom flask containing pyridine (10 mL), stirred evenly, and then phenylpiperazine (0.28 g, 1.7 mmol) (i.e., compound RH in the subsequent examples) was added; the reaction solution was stirred at room temperature overnight, and water (30 mL) was added after the starting material was no longer reduced as monitored by thin layer plate, and extracted with dichloromethane (15 mL×3); the organic phases were combined and washed with saturated brine (20 mL×3); after drying over anhydrous sodium sulfate, the mixture was filtered and the filtrate was concentrated under reduced pressure; the crude product was purified by silica gel column chromatography using dichloromethane / methanol (v / v=30 / 1) as eluent, and the eluate was concentrated to obtain a light yellow solid compound 1 (N-(2-oxo-3-(4-oxoquinazolin-3(4H)-yl)propyl)-2-(4-phenylpiperazin-1-yl)acetamide) (yield 0.4 g, yield 56%). LC-MS (m / z): 420.1 [M+H] + .

[0063] Examples 2 to 24 are methods for preparing N-(2-oxopropyl)acetamide derivatives represented by Compounds 2 to 24.

[0064] The preparation steps and conditions for Compounds 2 to 24 are the same as those for Compound 1, except for the difference in compound RH in Step 4 shown in Table 1. The names and structural formulas of the synthesized Compounds 2 to 24 are shown in Table 1.

[0065] Table 1 Names and structural formulas of compounds 2 to 24

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072] Example 25

[0073] A method for preparing an N-(2-oxopropyl)acetamide derivative as shown in compound 25,

[0074] The synthesis process of compound 25 is as follows:

[0075]

[0076] The preparation method comprises the following steps:

[0077] Step 1: Pyrido[2,3-d]pyrimidin-4(3H)-one (14.7 g, 100 mmol) and cesium carbonate (39.0 g, 120 mmol) were added to a round-bottom flask containing N,N-dimethylformamide (150 mL); the temperature of the reaction mixture was lowered to -20°C, and 1,3-dibromoacetone (23.5 g, 110 mmol) was slowly added dropwise; the reaction solution was stirred at -20°C for 4 hours and monitored by thin-layer plate. When the starting material was no longer reduced, water was added to quench the reaction; extraction was performed with ethyl acetate (150 mL × 3), and the combined organic phases were washed with saturated brine (100 mL × 3), dried over anhydrous sodium sulfate, filtered, and the filtrate concentrated under reduced pressure. The crude product was recrystallized from methanol / dichloromethane to obtain a light yellow solid compound 1-6 (3-(3-bromo-2-oxopropyl)pyrido[2,3-d]pyrimidin-4(3H)-one) (yield 13.5 g, 48%). LC-MS (m / z): 282.1 [M+H] + .

[0078] Step 2: Compound 1-6 (10.0 g, 40.8 mmol) was added to a round-bottom flask containing N,N-dimethylformamide (100 mL). Sodium azide (2.7 g, 40.8 mmol) was slowly added with stirring at room temperature. After the addition was complete, the reaction solution was heated to 50°C and stirred. When the starting material stopped decreasing as monitored by TLC, the reaction was quenched by adding water. The mixture was extracted with dichloromethane (60 mL × 3). The combined organic phases were washed with saturated brine (50 mL × 3), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The crude product was compound 1-7 (3-(3-azido-2-oxopropyl)pyrido[2,3-d]pyrimidin-4(3H)-one), which was used directly in the next reaction. LC-MS (m / z): 245.1 [M+H] + .

[0079] Step 3: Compound 1-7 (4.9 g, 20 mmol) was added to a round-bottom flask containing methanol (50 mL). Palladium / carbon (10.6 g, 2 mmol, 5%) was added with stirring. The hydrogen atmosphere was replaced by vacuum. The reaction solution was stirred at room temperature for 3 hours. When the starting material was no longer reduced as monitored by thin-layer plate, it was filtered under reduced pressure and the filtrate was concentrated under reduced pressure. The crude product was compound 1-8 (3-(3-amino-2-oxopropyl)pyrido[2,3-d]pyrimidin-4(3H)-one), which was used directly in the next reaction. LC-MS (m / z): 219.1 [M+H] + .

[0080] Step 4: Compound 1-8 (1.5 g, 6.9 mmol) was added to a round-bottom flask containing dichloromethane / N,N-dimethylformamide (30 mL, v / v = 9 / 1), and then placed on an ice bath; chloroacetyl chloride (1.2 g, 10.4 mmol) was slowly added dropwise under nitrogen protection. After the addition was completed, the reaction solution was reacted at room temperature for 6 hours; after the complete disappearance of the raw material monitored by thin layer plate, water was added to quench the reaction and extraction was performed. The combined organic phase was washed with saturated brine (30 mL × 3), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure; the crude product was recrystallized from methanol / dichloromethane to obtain an off-white solid compound 1-9 (2-chloro-N-(2-oxo-3-(4-oxopyrido[2,3-d]pyrimidin-3(4H)-yl)propyl)acetamide) (yield 1.09 g, yield 54%). LC-MS (m / z): 295.2 [M+H] + .

[0081] Step 5: Compound 1-9 (0.5 g, 1.7 mmol) was added to a round-bottom flask containing pyridine (10 mL), stirred evenly, and then phenylpiperazine (0.28 g, 1.7 mmol) was added; the reaction solution was stirred at room temperature overnight, and water (30 mL) was added after the raw material was no longer reduced by thin layer plate monitoring. The mixture was extracted with dichloromethane (15 mL × 3); the organic phases were combined and washed with saturated brine (20 mL × 3); and dried over anhydrous sodium sulfate. The reaction mixture was then filtered and the filtrate was concentrated under reduced pressure. The crude product was purified by silica gel column chromatography using dichloromethane / methanol (v / v = 30 / 1) as the eluent. The eluate was concentrated to obtain Compound 25 (N-(2-oxo-3-(4-oxopyrido[2,3-d]pyrimidin-3(4H)-yl)propyl)-2-(4-(4-phenoxybenzoyl)piperazin-1-yl)acetamide) as a pale yellow solid (0.41 g, 45% yield). LC-MS (m / z): 541.1 [M+H] + .

[0082] Example 26

[0083] A method for preparing an N-(2-oxopropyl)acetamide derivative as shown in compound 26 comprises the following steps:

[0084] Step 1: 3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one (14.7 g, 100 mmol) and cesium carbonate (39.0 g, 120 mmol) were added to a round-bottom flask containing N,N-dimethylformamide (150 mL); the temperature of the reaction mixture was lowered to -20°C, and 1,3-dibromoacetone (23.5 g, 110 mmol) was slowly added dropwise; the reaction solution was stirred at -20°C for 4 hours, and the original When the product stopped decreasing, water was added to quench the reaction; extraction was performed with ethyl acetate (150 mL × 3), and the combined organic phases were washed with saturated brine (100 mL × 3), dried over anhydrous sodium sulfate, filtered, and the filtrate concentrated under reduced pressure. The crude product was recrystallized from methanol / dichloromethane to obtain the light yellow solid compound 3-(3-bromo-2-oxopropyl)-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one (1-10) (yield 11.34 g, yield 42%). LC-MS (m / z): 270.1 [M+H] + .

[0085] Step 2: Compound 1-10 (9.6 g, 35.5 mmol) was added to a round-bottom flask containing N,N-dimethylformamide (100 mL). Sodium azide (2.7 g, 40.8 mmol) was slowly added with stirring at room temperature. After the addition was complete, the reaction solution was heated to 50°C and stirred. When the starting material stopped decreasing as monitored by TLC, the reaction was quenched by adding water. The mixture was extracted with dichloromethane (60 mL × 3). The combined organic phases were washed with saturated brine (50 mL × 3), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The crude product was compound 3-(3-azido-2-oxopropyl)-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one (1-11), which was used directly in the next reaction. LC-MS (m / z): 233.1 [M+H] + .

[0086] Step 3: Compound 1-11 (4.64 g, 20 mmol) was added to a round-bottom flask containing methanol (50 mL). Palladium / carbon (10.6 g, 2 mmol, 5%) was added with stirring. The hydrogen atmosphere was replaced by vacuum. The reaction solution was stirred at room temperature for 3 hours. When the starting material was no longer reduced as monitored by thin-layer plate, it was filtered under reduced pressure and the filtrate was concentrated under reduced pressure. The crude product was compound 3-(3-amino-2-oxopropyl)-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one (1-12), which was used directly in the next reaction. LC-MS (m / z): 207.2 [M+H] + .

[0087] Step 4: Compound 1-12 (1.42 g, 6.9 mmol) was added to a round-bottom flask containing dichloromethane / N,N-dimethylformamide (30 mL, v / v = 9 / 1), and then placed on an ice bath; chloroacetyl chloride (1.2 g, 10.4 mmol) was slowly added dropwise under nitrogen protection. After the addition was completed, the reaction solution was reacted at room temperature for 6 hours; after the complete disappearance of the starting material monitored by thin layer plate, water was added to quench the reaction and extraction was performed. The combined organic phase was washed with saturated brine (30 mL × 3), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure; the crude product was recrystallized from methanol / dichloromethane to obtain an off-white solid compound 2-chloro-N-(2-oxo-3-(4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-3-yl)propyl)acetamide (1-13) (yield 1.21 g, yield 62%). LC-MS (m / z): 283.1 [M+H] + .

[0088] Step 5: Compound 1-13 (0.48 g, 1.7 mmol) was added to a round-bottom flask containing pyridine (10 mL), stirred evenly, and then phenylpiperazine (0.28 g, 1.7 mmol) was added; the reaction solution was stirred at room temperature overnight, and water (30 mL) was added after the raw material was no longer reduced by thin layer plate monitoring, and extracted with dichloromethane (15 mL × 3); the organic phases were combined and washed with saturated brine (20 mL × 3); dried over anhydrous sodium sulfate The reaction mixture was filtered and the filtrate was concentrated under reduced pressure. The crude product was purified by silica gel column chromatography using dichloromethane / methanol (v / v = 30 / 1) as the eluent. The eluate was concentrated to give a light yellow solid compound 2-(3-ethynylazetidin-1-yl)-N-(2-oxo-3-(4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-3-yl)propyl)acetamide (26) (0.19 g, yield 34%). LC-MS (m / z): 328.2 [M+H] + .

[0089] Example 27

[0090] A method for preparing an N-(2-oxopropyl)acetamide derivative as shown in compound 27 comprises the following steps:

[0091] Step 1: Add thieno[2,3-d]pyrimidin-4(3H)-one (15.2 g, 100 mmol) and cesium carbonate (39.0 g, 120 mmol) into a round-bottom flask containing N,N-dimethylformamide (150 mL); lower the temperature of the reaction mixture to -20°C, and slowly add 1,3-dibromoacetone (23.5 g, 110 mmol) dropwise; stir the reaction mixture at -20°C for 4 hours and monitor the reaction on a thin layer plate. When the starting material was no longer reduced, water was added to quench the reaction; extraction was performed with ethyl acetate (150 mL x 3), and the combined organic phases were washed with saturated brine (100 mL x 3), dried over anhydrous sodium sulfate, filtered, and the filtrate concentrated under reduced pressure. The crude product was recrystallized from methanol / dichloromethane to obtain the light yellow solid compound 3-(3-bromo-2-oxopropyl)thieno[2,3-d]pyrimidin-4(3H)-one (1-14) (yield 15.2 g, 53%). LC-MS (m / z): 287.1 [M+H] + .

[0092] Step 2: Compound 1-14 (10.2 g, 35.5 mmol) was added to a round-bottom flask containing N,N-dimethylformamide (100 mL). Sodium azide (2.7 g, 40.8 mmol) was slowly added with stirring at room temperature. After the addition was complete, the reaction solution was heated to 50°C and stirred. When the starting material stopped decreasing as monitored by thin-layer plate, the reaction was quenched by adding water. The mixture was extracted with dichloromethane (60 mL × 3). The combined organic phases were washed with saturated brine (50 mL × 3), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The crude product was compound 3-(3-azido-2-oxypropyl)thieno[2,3-d]pyrimidin-4(3H)-one (1-15), which was used directly in the next reaction. LC-MS (m / z): 250.1 [M+H] + .

[0093] Step 3: Compound 1-15 (4.98 g, 20 mmol) was added to a round-bottom flask containing methanol (50 mL). Palladium / carbon (10.6 g, 2 mmol, 5%) was added with stirring. The hydrogen atmosphere was replaced by vacuum. The reaction solution was stirred at room temperature for 3 hours. When the starting material was no longer reduced as monitored by thin-layer plate, it was filtered under reduced pressure and the filtrate was concentrated under reduced pressure. The crude product was compound 3-(3-amino-2-oxopropyl)thieno[2,3-d]pyrimidin-4(3H)-one (1-16), which was used directly in the next reaction. LC-MS (m / z): 224.3 [M+H] + .

[0094] Step 4: Compound 1-16 (1.54 g, 6.9 mmol) was added to a round-bottom flask containing dichloromethane / N,N-dimethylformamide (30 mL, v / v = 9 / 1), and then placed on an ice bath; chloroacetyl chloride (1.2 g, 10.4 mmol) was slowly added dropwise under nitrogen protection. After the addition was completed, the reaction solution was reacted at room temperature for 6 hours; after the complete disappearance of the starting material monitored by thin layer plate, water was added to quench the reaction and extraction was performed. The combined organic phase was washed with saturated brine (30 mL × 3), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure; the crude product was recrystallized from methanol / dichloromethane to obtain an off-white solid compound 2-chloro-N-(2-oxo-3-(4-oxothieno[2,3-d]pyrimidin-3(4H)-yl)propyl)acetamide (1-17) (yield 1.36 g, yield 66%). LC-MS (m / z): 300.1 [M+H] + .

[0095] Step 5: Compound 1-17 (0.5 g, 1.7 mmol) was added to a round-bottom flask containing pyridine (10 mL), stirred evenly, and then phenylpiperazine (0.28 g, 1.7 mmol) was added; the reaction solution was stirred at room temperature overnight, and water (30 mL) was added after the raw material was no longer reduced as monitored by thin layer plate, and extracted with dichloromethane (15 mL×3); the organic phases were combined and washed with saturated brine (20 mL×3); after drying over anhydrous sodium sulfate, the mixture was filtered and the filtrate was concentrated under reduced pressure; the crude product was purified by silica gel column chromatography using dichloromethane / methanol (v / v=30 / 1) as eluent, and the eluate was concentrated to obtain a light yellow solid compound N-(2-oxo-3-(4-oxothieno[2,3-d]pyrimidin-3(4H)-yl)propyl)-2-(4-(4-phenoxyphenyl)piperazin-1-yl)acetamide (27) (0.4 g, yield 45%). LC-MS (m / z): 518.2 [M+H] + .

[0096] The names and structural formulas of the synthesized compounds 26 and 27 are shown in Table 2.

[0097] Table 2 Names and structural formulas of compounds 26 and 27

[0098]

[0099]

[0100] Example 28

[0101] A method for preparing an N-(2-oxopropyl)acetamide derivative as shown in compound 28,

[0102] The synthesis process of compound 28 is as follows:

[0103]

[0104] The preparation method comprises the following steps:

[0105] Step 1: 3H-pyrimido[4,5-b]indole-4(9H)-one (3.7 g, 20 mmol) and potassium carbonate (4.1 g, 30 mmol) were added to a round-bottom flask containing N,N-dimethylformamide (50 mL); 1-bromopropan-2-one (3.0 g, 22 mmol) (Compound 1-10) was slowly added under stirring at room temperature; the reaction solution was stirred at room temperature overnight, and the raw material was no longer reduced as monitored by thin layer plate, and water was added to quench the reaction; the mixture was extracted with dichloromethane (50 mL × 3), and the combined organic phase was washed with saturated brine (50 mL × 3), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure; the crude product was chromatographed on a silica gel column with dichloromethane / methanol (v / v = 50 / 1 to 30 / 1) as the eluent; the combined eluents were concentrated to obtain a pale yellow solid compound 1-18 (3-(2-oxopropyl)-3H-pyrimido[4,5-b]indol-4(9H)-one) (yield: 2.5 g, yield: 52%). LC-MS (m / z): 242.1 [M+H] + .

[0106] Step 2: Compound 1-18 (2.0 g, 8.3 mmol) was added to a round-bottom flask containing methanol (30 mL); bromine water (44.0 g, 8.3 mmol, 3% content) was slowly added dropwise at 0°C; the reaction solution was heated to 65°C and stirred after 1 hour at room temperature; the disappearance of the raw material was monitored by thin layer plate, the solvent was evaporated, water (80 mL) was added to the residue, and it was extracted with dichloromethane (30 mL×3), and the combined organic phase was washed with saturated brine (30 mL×3), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure; the crude product was chromatographed on a silica gel column, petroleum ether / ethyl acetate (v / v=20 / 1 to 10 / 1) as the eluent; the combined eluents were concentrated to obtain a pale yellow solid compound 1-19 (3-(3-bromo-2-oxopropyl)-3H-pyrimido[4,5-b]indol-4(9H)-one) (yield: 2.6 g, yield: 91%). LC-MS (m / z): 320.1 [M+H] + .

[0107] Step 3: Compound 1-19 (2.5 g, 7.8 mmol) was added to a round-bottom flask containing N,N-dimethylformamide (30 mL). Sodium azide (0.5 g, 7.8 mmol) was slowly added with stirring at room temperature. After the addition was complete, the reaction solution was heated to 50°C and stirred. When the starting material stopped decreasing as monitored by TLC, the reaction was quenched by adding water. The mixture was extracted with dichloromethane (30 mL × 3). The combined organic phases were washed with saturated brine (20 mL × 3), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The crude product was compound 1-20 (3-(3-azido-2-oxopropyl)-3H-pyrimido[4,5-b]indol-4(9H)-one), which was used directly in the next reaction. LC-MS (m / z): 283.2 [M+H] + .

[0108] Step 4: Compound 1-20 (2.0 g, 7.1 mmol) was added to a round-bottom flask containing methanol (20 mL). Palladium / carbon (1.5 g, 0.7 mmol, 5%) was added with stirring. The hydrogen atmosphere was replaced by vacuum. The reaction solution was stirred at room temperature for 3 hours. When the starting material was no longer reduced as monitored by thin-layer plate, it was filtered under reduced pressure and the filtrate was concentrated under reduced pressure. The crude product was compound 1-21 (3-(3-amino-2-oxopropyl)-3H-pyrimido[4,5-b]indol-4(9H)-one), which was used directly in the next reaction. LC-MS (m / z): 257.2 [M+H] + .

[0109] Step 5: Compound 1-21 (1.5 g, 5.8 mmol) was added to a round-bottom flask containing dichloromethane / N,N-dimethylformamide (30 mL, v / v = 9 / 1), and then placed on an ice bath; chloroacetyl chloride (1.0 g, 8.8 mmol) was slowly added dropwise under nitrogen protection. After the addition was completed, the reaction solution was reacted at room temperature for 6 hours; after the complete disappearance of the raw material monitored by thin layer plate, water was added to quench the reaction and extraction was performed. The combined organic phase was washed with saturated brine (30 mL × 3), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure; the crude product was recrystallized from methanol / dichloromethane to obtain an off-white solid compound 1-22 (2-chloro-N-(2-oxo-3-(4-oxo-4,9-dihydro-3H-pyrimido[4,5-b]indol-3-yl)propyl)acetamide) (0.9 g, 47% yield). LC-MS (m / z): 333.1 [M+H] + .

[0110] Step 6: Compound 1-22 (0.5 g, 1.5 mmol) was added to a round-bottom flask containing pyridine (10 mL), stirred evenly, and then phenylpiperazine (0.24 g, 1.5 mmol) was added; the reaction solution was stirred at room temperature overnight, and water (30 mL) was added after the raw material was no longer reduced by thin layer plate monitoring. The mixture was extracted with dichloromethane (15 mL × 3); the organic phases were combined and washed with saturated brine (20 mL × 3); dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under reduced pressure; the crude product was purified by silica gel column chromatography using dichloromethane / methanol (v / v = 20 / 1) as the eluent. The eluate was concentrated to obtain Compound 28 (N-(2-oxo-3-(4-oxo-4,9-dihydro-3H-pyrimido[4,5-b]indol-3-yl)propyl)-2-(2-oxa-6-azaspiro[3.3]heptane-6-yl)acetamide) as a pale yellow solid (0.25 g, 43% yield). LC-MS (m / z): 396.2 [M+H] + .

[0111] Detection and Analysis

[0112] 1. Mass spectrometry detection

[0113] The compounds obtained in Example 1, Example 3, Example 8 and Example 9 were subjected to mass spectrometry analysis. The results were as follows: Figures 1 to 4 shown.

[0114] 2. In vitro anticoccidial activity assay

[0115] MDBK cells were infected with sporulated oocysts of E. tenella to establish an in vitro infection model. The in vitro anti-coccidial activities of the N-(2-oxopropyl)acetamide derivatives (Compounds 1 to 28) prepared in Examples 1 to 28 were then investigated. The inhibition of the growth and development of the coccidia by the compounds was detected by RT-qPCR. The toxicity of the compounds to MDBK cells was tested by the MTT assay, and the IC values ​​were calculated using SPSS software. 50 The specific results are shown in Table 3.

[0116] Table 3 Inhibitory activity of compounds against coccidia

[0117]

[0118] 3. Activity test on inhibition of Toxoplasma gondii (T.gondii) and human foreskin fibroblasts (HFF)

[0119] The N-(2-oxopropyl)acetamide derivatives (Compounds 1-28) prepared in Examples 1-28 were tested for their inhibitory activity against Toxoplasma gondii (T. gondii) and human foreskin fibroblasts (HFF) using the MTT assay. The absorbance at 490 nm was rapidly measured using a microplate reader, and the IC values ​​were calculated using SPSS software. 50 The specific results are shown in Table 4.

[0120] Table 4 Inhibitory activity of compounds against Toxoplasma gondii (T.gondii) and human foreskin fibroblasts (HFF)

[0121]

[0122]

[0123] As can be seen from Tables 3 and 4, the N-(2-oxopropyl)acetamide derivatives of the present invention have good inhibitory activity against Eimeria tenella and Toxoplasma gondii, have low toxicity to host cells, and have potential development value.

[0124] In summary, the N-(2-oxopropyl)acetamide derivatives provided by the present invention have a quinazolinone and its analogue skeleton, and have the advantages of good water solubility, low cytotoxicity, and high in vitro and in vivo anticoccidial and anti-Toxoplasma activity. The preparation method of the N-(2-oxopropyl)acetamide derivatives provided by the present invention is synthesized through the steps of bromination, reduction, acylation and nucleophilic substitution reaction, and its synthesis process has the advantages of simple and mild conditions and low production cost. It is suitable for development into anticoccidial and anti-Toxoplasma drugs, and has potential new drug development value in the field of pharmaceutical chemistry technology. The N-(2-oxopropyl)acetamide derivatives provided by the present invention were tested for in vitro anticoccidial activity and anti-Toxoplasma gondii activity, and the results showed that most of them showed high inhibitory activity and had the advantage of less toxicity to host cells, thereby proving that the N-(2-oxopropyl)acetamide derivatives have potential application prospects in anticoccidial and anti-Toxoplasma gondii active drugs.

[0125] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A N -(2-oxopropyl)acetamide derivative, characterized in that Its structure is selected from any one of the following compounds: 、 、 、 、 、 、 、 、 、 。 2. A method as claimed in claim 1 N -A method for preparing a (2-oxopropyl)acetamide derivative, characterized in that: The following steps are involved: The compound of formula (II) undergoes an acylation reaction to obtain a compound of formula (III); the compound of formula (III) undergoes a nucleophilic substitution reaction with compound RH to obtain a compound of formula (I); Wherein, in formula (I), (II) and formula (III), X is selected from N; Ring A is selected from 、 、 、 or ; R is selected from 、 、 、 、 or .

3. A method as claimed in claim 2 N -A method for preparing a (2-oxopropyl) acetamide derivative, characterized in that: The following steps are involved: The compound of formula (II) and an organic base are dissolved in an organic solvent, chloroacetyl chloride is added dropwise, and the mixture is stirred at room temperature. The reaction is monitored by thin-layer plate. After the reaction is completed, water is added and the mixture is extracted with an organic solvent. The organic phases are combined, concentrated, and chromatographed to obtain the compound of formula (III); The compound of formula (III) and a base are dissolved in an organic solvent, compound RH is added, stirred and reacted, diluted with water after the reaction is completed, extracted with an organic solvent, and the organic phases are combined, concentrated, and chromatographed to obtain the compound of formula (I); The organic solvent is pyridine, chloroform, dichloromethane, ethyl acetate, tetrahydrofuran, 1,4-dioxane, chlorobenzene, toluene, acetonitrile, N,N-dimethylformamide or dimethyl sulfoxide; The organic base is triethylamine, N,N-diisopropylethylamine, pyridine, 4-dimethylaminopyridine or 2,6-lutidine; The base is potassium carbonate, sodium bicarbonate, sodium carbonate, triethylamine, N,N-diisopropylethylamine, pyridine, 4-dimethylaminopyridine or 2,6-lutidine.

4. A N -(2-oxopropyl)acetamide derivatives in the preparation of anticoccidial drugs, characterized in that: described N -(2-Oxopropyl)acetamide derivatives are selected from any one of the following compounds: 、 、 、 、 、 、 。 5. The use according to claim 4, characterized in that The coccidia is Eimeria tenella.

6. A N The use of a -(2-oxopropyl)acetamide derivative in the preparation of an anti-Toxoplasma drug is characterized in that: described N -(2-Oxopropyl)acetamide derivatives are selected from any one of the following compounds: 、 、 、 、 、 。 7. The use according to claim 6, characterized in that The Toxoplasma gondii is Toxoplasma gondii.

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