Pyridine-type coumarin derivatives, process for their preparation and use thereof

Abstract

The application discloses pyridine coumarin derivatives, a preparation method and application thereof. The pyridine coumarin derivative is selected from the following structural general formula: the pyridine coumarin derivative is independently designed and synthesized, and the experimental results show that the pyridine coumarin derivative has good antifungal activity on botrytis cinerea, alternaria solani, fusarium oxysporum and alternaria alternata, which expands a new field for prevention and treatment of various plant fungal diseases, has wide development space and good development and application prospect, and has good application value.

Description

Technical Field

[0001] This invention relates to the technical field of coumarin derivative synthesis, and more specifically, to pyridine-type coumarin derivatives, their preparation methods, and applications. Background Technology

[0002] Plant pathogenic fungi are destructive parasites that secrete large amounts of toxins and harmful metabolites, directly or indirectly leading to a significant decline in plant yield and quality. Therefore, the management of plant fungal diseases is crucial in agricultural production. In the past few decades, traditional chemical fungicides have been widely used to reduce the harm caused by plant pathogenic fungi. Unfortunately, many chemical fungicides are not only toxic to humans but also to insects and microorganisms that benefit plant growth. Therefore, the long-term use of traditional fungicides in agriculture has led to many problems, such as slow degradation and negative environmental impacts, harmful effects on non-target species, and fungicide resistance.

[0003] Therefore, the discovery and development of novel, eco-friendly, and highly effective agricultural fungicides with novel mechanisms of action is an urgent research focus in this field. Natural products, due to their structural diversity and eco-friendly properties, have always been a rich source for pesticide development. Many natural products have been isolated from plants or microorganisms and have inspired the discovery of novel fungicides. Natural products are secondary metabolites produced by plants, possessing good biocompatibility and biodegradability. Furthermore, they exhibit structural diversity, good biological activity, and environmental compatibility. For these reasons, natural products have always been a powerful source of raw materials in the discovery of pharmaceutical and agrochemicals. In fact, using natural plant-derived products is an effective way to develop green and highly effective fungicides.

[0004] Coumarins are natural products that, due to their diverse pharmacological effects including anticoagulation, anticancer, antioxidant, antiviral, anti-inflammatory, and antifungal activities, have been recognized as a "privileged scaffold" for phytomedicine and agrochemical applications. The bioactivities of warfarin and Cnidium monnieri, as typical coumarin derivatives, have been reported in detail. Coumarins, with their structural diversity, are considered important candidates for developing highly effective fungicides. Pyridine heterocycles, as active groups, are widely used in the structural optimization of agrochemical compounds. Pyridine is a commonly used fungicide; its mechanism of action is to disrupt the cell membrane and cell wall of bacteria, thereby causing cell death. Pyridine can kill a variety of common pathogens and fungi, such as *Fusarium solani*, *Fusarium oxysporum*, *Botrytis cinerea*, and *Helicobacter pylori*, demonstrating significant health benefits for plants.

[0005] Further modification of existing coumarin-pyridine compounds to improve their aforementioned properties. Summary of the Invention

[0006] To address the problems in existing technologies, this invention proposes pyridine-type coumarin derivatives, their preparation methods, and applications. This invention designs and synthesizes novel substituent-containing coumarin derivatives and preliminarily studies their inhibitory effects on four plant pathogens: *Botrytis cinerea*, *Alternaria alternata*, *Fusarium oxysporum*, and *Alternaria alternata*. Experimental results show that the pyridine-type coumarin derivatives of this invention have significant inhibitory effects on fungi and exhibit significant plant health benefits.

[0007] One object of the present invention is to provide a pyridine-type coumarin derivative, wherein the pyridine-type coumarin derivative is selected from compounds represented by the following general structural formula:

[0008] Formula A;

[0009] Among them, R1, R2, and R3 may be the same or different, and each is independently selected. Among them, R a The group is selected from alkenyl, substituted, or unsubstituted aryl groups; and only one of the substituents appears simultaneously in OR1, OR2, and OR3. This invention... The term "bond" indicates whether the substituents connected to the bond may or may not be present.

[0010] In the pyridine-type coumarin derivatives of the present invention, preferably, the pyridine-type coumarin derivatives are selected from compounds represented by the following general structural formulas:

[0011] Formula 1;

[0012] Wherein, R1 in Equation 1 is selected from ;R 1a Selected from alkenyl, substituted or unsubstituted thiophene, substituted or unsubstituted phenyl;

[0013] Preferably, R 1a Selected from C2-C8 alkenyl groups; halogen-substituted thienyl or thienyl groups; phenyl groups substituted with at least one of halogen, C1-C4 alkyl, or fluoroalkyl groups;

[0014] More preferably, R 1a Selected from a C3-C8 alkenyl group, a halogenated and C1-C2 alkyl-substituted phenyl group, a fluoroalkyl-substituted phenyl group, a fluoroalkyl-substituted and halogen-substituted phenyl group, a halogen-substituted thiophene group, and a thiophene group;

[0015] More preferably, Formula 1 is selected from the following compounds:

[0016] ;

[0017] .

[0018] In the pyridine-type coumarin derivatives described in this invention, preferably, the pyridine-type coumarin derivatives are selected from the following general structural formulas:

[0019] Formula 2;

[0020] In Equation 2, R2 is selected from... Among them, R 2a Selected from substituted or unsubstituted thiophene groups

[0021] Preferably, R 2a Selected from halogen-substituted thiophene groups and thiophene groups;

[0022] More preferably, R 2a Selected from a halogen-substituted thiophene group, or a thiophene group;

[0023] More preferably, Formula 2 is selected from the following compounds:

[0024] ;

[0025] .

[0026] In the pyridine-type coumarin derivatives described in this invention, preferably, the pyridine-type coumarin derivatives are selected from the following general structural formulas:

[0027] Formula 3;

[0028] R3 in Equation 3 is selected from Among them, R 3a Selected from alkenyl, substituted or unsubstituted thiophene, substituted or unsubstituted phenyl;

[0029] Preferably, R 3a Selected from C2-C8 alkenyl groups; halogen-substituted thienyl or thienyl groups; phenyl groups substituted with at least one of halogen, C1-C4 alkyl, or fluoroalkyl groups;

[0030] More preferably, R 3a Selected from C3-C8 alkenyl, phenyl substituted with one halogen and one C1-C2 alkyl, phenyl substituted with one fluoroalkyl, phenyl substituted with one fluoroalkyl and one halogen, thiophenyl substituted with one halogen, and thiophenyl.

[0031] More preferably, Formula 3 is selected from the following compounds:

[0032] ;

[0033] .

[0034] A second objective of this invention is to provide a method for preparing pyridine-type coumarin derivatives, comprising the following steps:

[0035] Substrate 1 was reacted with substrate 2, a condensing agent, and a basic catalyst in a solvent to obtain the pyridine-type pyridine-type coumarin derivatives.

[0036] Substrate 1 is selected from the following general structural formula:

[0037] Formula B;

[0038] In formula B, only one of the three hydroxyl groups exists at any given time.

[0039] Substrate 2 is selected from At least one of them; R a R as described in any one of the objectives of this invention a The correspondence is the same.

[0040] In the preparation method of pyridine-type coumarin derivatives described in this invention, preferably,

[0041] The substrate 1 is selected from one of the following compounds:

[0042] , , ; and / or,

[0043] Substrate 2 is selected from , or At least one of them; R 1a R 2a R 3a R as described in any one of the objectives of this invention 1a R 2a R 3a The correspondence is the same.

[0044] In the preparation method of pyridine-type coumarin derivatives described in this invention, preferably,

[0045] The condensing agent is selected from at least one of EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) or DCC (N,N-dicyclohexylcarbonyldiimide); and / or,

[0046] The alkaline catalyst is selected from at least one of 4-dimethylaminopyridine (DMAP) or 1-hydroxybenzotriazole (HOBT); and / or,

[0047] The solvent is selected from at least one of dichloromethane or a mixture of petroleum ether and ethyl acetate; preferably, in the mixture of petroleum ether and ethyl acetate, the volume ratio of petroleum ether to ethyl acetate is 15-10:1.

[0048] In the preparation method of pyridine-type coumarin derivatives described in this invention, preferably,

[0049] The molar ratio of substrate 2 to substrate 1 is (2~4):1; for example, 2:1, 3:1, 4:1; and / or,

[0050] The molar ratio of condensing agent to substrate 1 is (3~6):1; for example, 3:1, 4:1, 5:1, 6:1; and / or,

[0051] The molar ratio of condensing agent to basic catalyst is (5~8):1; for example, 5:1, 6:1, 7:1, 8:1; and / or,

[0052] The mass-to-volume ratio of condensing agent to solvent is (2~20) mg:1 mL; for example, 2 mg:1 mL, 5 mg:1 mL, 10 mg:1 mL, 15 mg:1 mL, 20 mg:1 mL; and / or,

[0053] The reaction time is 6-10 hours; for example, 6, 7, 8, 9, or 10 hours.

[0054] A third objective of this invention is to provide an application of at least one of the pyridine-type coumarin derivatives described in one objective of this invention in antifungal, antiviral, anti-inflammatory, or antitumor activities.

[0055] In the applications described herein, preferably, the pyridine coumarin derivatives are used to inhibit at least one of the fungi selected from Botrytis cinerea, Alternaria solanacea, Fusarium oxysporum, or Alternaria.

[0056] The substances and parameters not limited in this invention can be selected according to existing technology, which is a conventional technical means in this field.

[0057] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In the following, various technical solutions can, in principle, be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0058] Compared with the prior art, the present invention has at least the following advantages:

[0059] The pyridine-type coumarin derivatives of this invention have excellent application value in combating plant-derived fungi. They are particularly effective against *Botrytis cinerea*, the fungus that causes gray mold in strawberries and tomatoes. Botrytis cinerea Alternaria alternata, which causes early blight in tomatoes ( Nightshade Fusarium oxysporum, which causes crop wilt ( Fusarium oxysporum Alternaria, which causes diseases such as black mold in tomatoes ( Alternaria alternata The pyridine-type coumarin derivatives of this invention exhibit good inhibitory activity against four common basic plant fungi, including [specific fungi mentioned earlier]. They can serve as lead compounds for the development of novel agricultural fungicides, used to treat or prevent fungal infections in plants. Therefore, the pyridine-type coumarin derivatives of this invention have significant applications in the preparation of antifungal drugs, particularly in the preparation of antifungal plant drugs. Detailed Implementation

[0060] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0061] It should also be noted that the various specific technical features described in the following embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the various possible combinations will not be described separately in this invention.

[0062] Furthermore, various embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention. The resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0063] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, such as those that can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0064] Example 1

[0065] Synthesis of compound 1a

[0066]

[0067] 3-Chloro-4-methylbenzoic acid (102.4 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 1 (the same substance as compound 1 in this specification) (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 1a.

[0068] Example 2

[0069] Synthesis of compound 1b

[0070]

[0071] 2-Trifluoromethylbenzoic acid (114.0 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 1 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 1b.

[0072] Example 3

[0073] Synthesis of compound 1c

[0074]

[0075] 4-Trifluoromethylbenzoic acid (114.0 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 1 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 1c.

[0076] Example 4

[0077] Synthesis of compound 1d

[0078]

[0079] 3-Bromo-4-trifluoromethylbenzoic acid (161.5 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 1 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 1d.

[0080] Example 5

[0081] Synthesis of compound 1e

[0082]

[0083] (E)-2-methyl-2-butenoic acid (60.0 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 1 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 1e.

[0084] Example 6

[0085] Synthesis of compound 1f

[0086]

[0087] 3-Bromothiophene-2-carboxylic acid (124.2 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 1 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 1f.

[0088] Example 7

[0089] Synthesis of 1g of compound

[0090]

[0091] 3-Chlorothiophene-2-carboxylic acid (97.6 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 1 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain 1 g of the target compound.

[0092] Example 8

[0093] Synthesis of compound 1h

[0094]

[0095] 5-Bromothiophene-3-carboxylic acid (124.2 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 1 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 1 h.

[0096] Example 9

[0097] Synthesis of compound 1i

[0098]

[0099] 3-Thiophenecarboxylic acid (77.0 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 1 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 1i.

[0100] Example 10

[0101] Synthesis of compound 2a

[0102]

[0103] 3-Bromothiophene-2-carboxylic acid (124.2 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 2 (58.7 mg, 1 mmol) (compound 2 here has the same structure as compound 2 of the present invention) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 2a.

[0104] Example 11

[0105] Synthesis of compound 2b

[0106]

[0107] 3-Chlorothiophene-2-carboxylic acid (97.6 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 2 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 2b.

[0108] Example 12

[0109] Synthesis of compound 2c

[0110]

[0111] 5-Bromothiophene-3-carboxylic acid (124.2 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 2 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 2c.

[0112] Example 13

[0113] Synthesis of compound 2d

[0114]

[0115] 3-Thiophenecarboxylic acid (77.0 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 2 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 2d.

[0116] Example 14

[0117] Synthesis of compound 3a

[0118]

[0119] 3-Chloro-4-methylbenzoic acid (102.4 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 3 (58.7 mg, 1 mmol) (compound 3 here has the same structure as compound 3 of this invention) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 3a.

[0120] Example 15

[0121] Synthesis of compound 3b

[0122]

[0123] 2-Trifluoromethylbenzoic acid (114.0 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 3 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 3b.

[0124] Example 16

[0125] Synthesis of compound 3c

[0126]

[0127] p-Bromo-o-methylbenzoic acid (129.0 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 3 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 3c.

[0128] Example 17

[0129] Synthesis of compound 3d

[0130]

[0131] 3-Bromo-4-trifluoromethylbenzoic acid (161.5 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 3 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 3d.

[0132] Example 18

[0133] Synthesis of compound 3e

[0134]

[0135] (E)-2-methyl-2-butenoic acid (60.0 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 3 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 3e.

[0136] Example 19

[0137] Synthesis of compound 3f

[0138]

[0139] (E)-2-methyl-2-pentenoic acid (68.5 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 3 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 3f.

[0140] Example 20

[0141] Synthesis of compound 3g

[0142]

[0143] 3-Bromothiophene-2-carboxylic acid (124.2 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 3 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain 3 g of the target compound.

[0144] Example 21

[0145] Synthesis of compound 3h

[0146]

[0147] 3-Chlorothiophene-2-carboxylic acid (97.6 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 3 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 3h.

[0148] Example 22

[0149] Synthesis of compound 3i

[0150]

[0151] 5-Bromothiophene-3-carboxylic acid (124.2 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 3 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 3i.

[0152] Example 23

[0153] Synthesis of compound 3j

[0154]

[0155] 3-Thiophenecarboxylic acid (77.0 mg, 3.00 mmol), EDC (93.0 mg, 3.00 mmol), and DMAP (9.8 mg, 0.4 mmol) were weighed and added to a 50 mL round-bottom flask. Dichloromethane (20 mL) was added, and the mixture was stirred at room temperature for 20 min. Then, compound 3 (58.7 mg, 1 mmol) was weighed and added to the reaction flask. The mixture was stirred at 25 °C for 6 h, and the reaction was detected by TLC. After the reaction was completed, the reaction solution was evaporated under reduced pressure, and the crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate = 15-10 / 1, V / V) to obtain the target compound 3j.

[0156] The structural characterization results of the target compounds prepared in Examples 1-23 above are as follows:

[0157] 1. Compound 1a

[0158]

[0159] White solid, yield 50.6%. 1 H NMR (600 MHz, CDCl3) δ 8.55 (dd, J = 7.9, 1.7 Hz, 1H), 8.24 (d, J = 1.8 Hz, 1H), 8.05 (dd, J = 7.9, 1.8 Hz, 1H), 7.45 (dd, J =7.9, 1.6 Hz, 1H), 7.40 (t, J = 7.9 Hz, 2H), 4.48 (q, J = 7.1 Hz, 2H), 2.77 (s,3H), 2.70 (s, 3H), 1.44 (t, J = 7.1 Hz, 4H).

[0160] 13 C NMR (150 MHz, CDCl3) δ 168.07, 163.55, 160.93, 158.99, 152.14,150.18, 144.85, 142.89, 137.94, 135.00, 132.17, 131.31, 131.16, 128.81,128.03, 125.85, 124.37, 123.35, 120.81, 114.03, 62.25, 23.94, 20.69, 19.55,14.32.

[0161] 2. Compound 1b

[0162]

[0163] White solid, yield 56.8%. 1 H NMR (600 MHz, CDCl3) δ 8.56 (dd, J = 8.0, 1.5 Hz, 1H), 8.22 (d, J = 8.8 Hz, 1H), 7.86 (d, J = 7.6 Hz, 1H), 7.78 – 7.70 (m, 2H), 4.49 (q, J= 7.1 Hz, 2H), 2.79 (s, 3H), 2.70 (s, 3H), 1.44 (t, J = 7.2 Hz, 3H).

[0164] 13 C NMR (150 MHz, CDCl3) δ 168.06, 164.37, 161.00, 158.93, 152.12,150.21, 144.76, 137.59, 132.21, 131.26, 129.60 (d, J = 18.5 Hz), 127.08,125.58, 124.47, 123.63, 122.55, 120.84, 114.08, 62.27, 23.95, 19.56, 14.32.

[0165] 3. Compound 1c

[0166]

[0167] Pale yellow solid, yield 33.4%. 1 H NMR (600 MHz, CDCl3) δ 8.57 (dd, J = 8.0, 1.6Hz, 1H), 8.40 (d, J = 8.0 Hz, 2H), 7.82 (d, J = 8.1 Hz, 2H), 7.47 (dd, J = 7.9, 1.6 Hz, 1H), 7.42 (t, J = 7.9 Hz, 1H), 4.49 (q, J = 7.1 Hz, 2H), 2.77 (s, 3H), 2.70 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0168] 13 C NMR (150 MHz, CDCl3) δ 168.04, 163.43, 161.02, 158.93, 152.08,150.22, 144.73, 137.77, 135.57, 135.36, 132.19 (d, J = 19.1 Hz), 131.09,125.78 (d, J= 21.8 Hz), 124.41, 123.57, 120.90, 114.04, 62.28, 23.94, 19.55,14.32.

[0169] 4. Compound 1d

[0170]

[0171] White solid, yield 32.3%. 1 H NMR (600 MHz, CDCl3) δ 8.70 (d, J = 8.5 Hz, 1H), 8.55 (d, J = 1.8 Hz, 1H), 8.24 (s, 1H), 7.87 (d, J = 8.3 Hz, 1H), 7.29 – 7.23(m, 2H), 4.49 (q, J = 7.2 Hz, 2H), 2.81 (s, 3H), 2.70 (s, 3H), 1.45 (t, J = 7.2Hz, 3H).

[0172] 13 C NMR (150 MHz, CDCl3) δ 168.07, 162.34, 161.05, 159.95, 153.30 (d, J = 6.0 Hz), 151.86, 150.23, 136.56, 135.05, 133.50, 132.07, 129.09, 128.38,127.13, 121.62, 120.76, 118.34, 117.58, 113.68, 110.15, 62.29, 23.95, 19.55,14.33.

[0173] 5. Compound 1e

[0174]

[0175] White solid, yield 47.3%. 1 H NMR (600 MHz, CDCl3) δ 8.64 – 8.59 (m, 1H), 7.19– 7.12 (m, 3H), 4.48 (q, J= 7.1 Hz, 2H), 2.79 (s, 3H), 2.68 (s, 3H), 1.99 –1.96 (m, 3H), 1.91 (dd, J = 7.1, 1.3 Hz, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0176] 13 C NMR (150 MHz, CDCl3) δ 168.17, 165.96, 160.89, 160.18, 154.39,153.25, 152.14, 150.13, 140.69, 131.78, 127.91, 126.70, 118.81, 116.75,113.47, 110.25, 62.21, 23.93, 19.54, 14.91, 14.32, 12.32.

[0177] 6. Compound 1f

[0178]

[0179] Yellow solid, yield 26.5%. 1 H NMR (600 MHz, CDCl3) δ 8.55 (dd, J = 8.0, 1.7 Hz, 1H), 7.63 (d, J = 5.7 Hz, 1H), 7.47 (dd, J = 7.9, 1.7 Hz, 1H), 7.39 (t, J = 8.0Hz, 1H), 7.21 (d, J = 5.3 Hz, 1H), 4.48 (q, J = 7.1 Hz, 2H), 2.77 (s, 3H), 2.70(s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0180] 13C NMR (150 MHz, CDCl3) δ 168.05, 160.93, 158.94, 152.08, 150.24,137.35, 133.54, 133.07, 132.21, 126.00, 124.31, 123.55, 120.78, 119.80,114.09, 62.25, 23.91, 19.55, 14.32.

[0181] 7. 1g of compound

[0182]

[0183] White solid, yield 33.4%. 1 H NMR (600 MHz, CDCl3) δ 8.55 (dd, J = 8.0, 1.6 Hz, 1H), 7.64 (d, J = 5.3 Hz, 1H), 7.47 (dd, J = 7.9, 1.6 Hz, 1H), 7.39 (t, J = 7.9Hz, 1H), 4.49 (q, J = 7.1 Hz, 2H), 2.77 (s, 3H), 2.69 (s, 3H), 1.44 (t, J = 7.2Hz, 3H).

[0184] 13 C NMR (150 MHz, CDCl3) δ 168.08, 160.94, 158.96, 158.21, 152.09, 150.19, 144.89, 137.32, 134.21, 132.18, 130.71, 125.97, 124.31, 124.02,123.52, 120.79, 114.06, 62.25, 23.94, 19.55, 14.32.

[0185] 8. Compound 1h

[0186]

[0187] White solid, yield 75.1%. 1 H NMR (600 MHz, CDCl3) δ 8.54 (dd, J = 7.8, 1.9 Hz, 1H), 8.29 (d,J = 1.6 Hz, 1H), 7.67 (d, J = 1.5 Hz, 1H), 7.46 – 7.36 (m, 2H), 4.48 (q, J = 7.1 Hz, 2H), 2.77 (s, 3H), 2.69 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0188] 13 C NMR (150 MHz, CDCl3) δ 168.04, 160.96, 159.06 (d, J = 14.5 Hz),152.12, 150.20, 144.81, 137.61 (d, J = 1.9 Hz), 136.18, 132.27 (d, J = 11.8Hz), 130.79, 125.79, 124.35, 123.41, 120.83, 114.04, 113.66, 62.25, 23.95,19.55, 14.32.

[0189] 9. Compound 1i

[0190]

[0191] White solid, yield 66.4%. 1 H NMR (600 MHz, CDCl3) δ 8.54 (dd, J = 7.9, 1.8 Hz, 1H), 8.41 (d, J = 3.1 Hz, 1H), 7.72 (d, J = 5.1 Hz, 1H), 7.49 – 7.31 (m, 3H), 4.48 (q, J = 7.1 Hz, 2H), 2.77 (s, 3H), 2.70 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0192] 13C NMR (150 MHz, CDCl3) δ 168.08, 160.91, 160.30, 159.08, 152.19,150.18, 144.95, 137.86, 135.01, 132.15, 132.03, 128.57, 126.61, 125.97,124.34, 123.24, 120.78, 114.04, 62.24, 23.94, 19.54, 14.31.

[0193] 10. Compound 2a

[0194]

[0195] White solid, yield 45.7%. 1 H NMR (600 MHz, CDCl3) δ 8.68 – 8.64 (m, 1H), 7.63(d, J = 5.3 Hz, 1H), 7.31 – 7.27 (m, 2H), 7.21 (d, J = 5.3 Hz, 1H), 4.49 (q, J =7.1 Hz, 2H), 2.80 (s, 3H), 2.69 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0196] 13 C NMR (150 MHz, CDCl3) δ 168.12, 160.97, 160.04, 158.52, 153.22,151.98, 150.19, 133.67, 133.05, 131.95, 126.87, 126.06, 119.64, 118.58,117.28, 113.62, 110.22, 62.24, 23.94, 19.55, 14.33.

[0197] 11. Compound 2b

[0198]

[0199] Pale yellow solid, yield 46.5%. 1 H NMR (600 MHz, CDCl3) δ 8.68 – 8.64 (m, 1H),7.63 (d, J= 5.3 Hz, 1H), 7.30 – 7.25 (m, 2H), 7.13 (d, J = 5.3 Hz, 1H), 4.49(q, J = 7.2 Hz, 2H), 2.80 (s, 3H), 2.69 (s, 3H), 1.44 (t, J = 7.2 Hz, 3H).

[0200] 13 C NMR (150 MHz, CDCl3) δ 168.12, 160.96, 160.04, 158.33, 153.22,151.98, 150.18, 134.06, 132.18, 131.94, 130.83, 126.86, 124.32, 118.58,117.27, 113.61, 110.22, 62.24, 23.93, 19.55, 14.32.

[0201] 12. Compound 2c

[0202]

[0203] White solid, yield 55.7%. 1 H NMR (600 MHz, CDCl3) δ 8.68 – 8.64 (m, 1H), 8.24(d, J = 1.5 Hz, 1H), 7.64 (d, J = 1.5 Hz, 1H), 7.24 – 7.20 (m, 2H), 4.49 (q, J =7.2 Hz, 2H), 2.80 (s, 3H), 2.69 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0204] 13 C NMR (150 MHz, CDCl3) δ 168.11, 160.98, 160.04, 159.27, 153.49,153.25, 151.98, 150.18, 135.96, 132.62, 131.94, 130.56, 126.94, 118.53,117.22, 113.81, 113.58, 110.18, 62.25, 23.94, 19.54, 14.33.

[0205] 13. Compound 2d

[0206]

[0207] White solid, yield 35.7%. 1 H NMR (600 MHz, CDCl3) δ 8.68 – 8.64 (m, 1H), 8.36(dd, J = 3.1, 1.3 Hz, 1H), 7.68 (dd, J = 5.1, 1.2 Hz, 1H), 7.42 (dd, J = 5.1,3.0 Hz, 1H), 7.27 – 7.22 (m, 2H), 4.49 (q, J = 7.1 Hz, 2H), 2.80 (s, 3H), 2.69(s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0208] 13 C NMR (150 MHz, CDCl3) δ 168.15, 160.94, 160.46, 160.12, 153.75,153.24, 152.04, 150.16, 134.82, 132.28, 131.86, 128.34, 126.83 (d, J = 6.5Hz), 118.72, 117.05, 113.52, 110.29, 62.25, 23.95, 19.58, 14.33.

[0209] 14. Compound 3a

[0210]

[0211] White solid, yield 25.7%. 1 H NMR (600 MHz, CDCl3) δ 8.55 (dd, J = 7.9, 1.8 Hz, 1H), 8.24 (d, J = 1.9 Hz, 1H), 8.05 (dd, J = 7.9, 1.9 Hz, 1H), 7.48 – 7.35 (m,3H), 4.48 (q, J= 7.1 Hz, 2H), 2.77 (s, 3H), 2.70 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0212] 13 C NMR (150 MHz, CDCl3) δ 168.04, 163.54, 160.92, 158.97, 152.12,150.24, 144.86, 142.88, 137.96, 135.00, 132.20, 131.23 (d, J = 13.0 Hz),128.82, 128.05, 125.87, 124.38, 123.37, 120.78, 114.05, 62.25, 23.91, 19.54,18.57, 14.31.

[0213] 15. Compound 3b

[0214]

[0215] White solid, yield 25.6%. 1 H NMR (600 MHz, CDCl3) δ 8.48 (d, J = 2.7 Hz, 1H),8.07 – 8.03 (m, 1H), 7.89 – 7.84 (m, 1H), 7.76 – 7.69 (m, 2H), 7.48 – 7.39(m, 2H), 4.49 (q, J = 7.2 Hz, 2H), 2.82 (s, 3H), 2.69 (s, 3H), 1.44 (t, J = 7.2Hz, 3H).

[0216] 13 C NMR (150 MHz, CDCl3) δ 168.06, 165.29, 160.96, 160.00, 151.75,150.55, 150.18, 147.13, 132.35, 132.20, 130.99, 130.08, 127.18 (d, J = 5.4Hz), 125.85, 120.24, 118.15, 113.98, 62.29, 23.88, 19.57, 14.32.

[0217] 16. Compound 3c

[0218]

[0219] White solid, yield 65.7%. 1 H NMR (600 MHz, CDCl3) δ 8.44 – 8.41 (m, 1H), 8.08(d, J = 8.4 Hz, 1H), 7.53 – 7.47 (m, 2H), 7.40 (d, J = 1.3 Hz, 2H), 4.49 (q, J =7.1 Hz, 2H), 2.81 (s, 3H), 2.67 (s, 6H), 1.44 (t, J = 7.2 Hz, 3H).

[0220] 13 C NMR (150 MHz, CDCl3) δ 168.05, 165.17, 160.89, 160.00, 151.80,150.37, 150.20, 147.29, 143.84, 135.11, 132.87, 132.31, 129.43, 128.10,127.01, 126.32, 120.20, 118.42, 117.99, 113.98, 62.28, 23.86, 22.02, 19.56,14.32.

[0221] 17. Compound 3d

[0222]

[0223] White solid, yield 23.7%. 1 H NMR (600 MHz, CDCl3) δ 8.56 (d, J = 1.8 Hz, 1H), 8.46 (dd, J = 2.0, 1.4 Hz, 1H), 8.25 (s, 1H), 7.87 (d, J = 8.3 Hz, 1H), 7.44 –7.41 (m, 2H), 4.49 (q, J = 7.1 Hz, 2H), 2.82 (s, 3H), 2.67 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0224] 13 C NMR (150 MHz, CDCl3) δ 168.00, 162.97, 160.98, 159.90, 151.66,150.61, 150.26, 146.99, 136.51, 133.73, 132.44, 129.02, 128.35, 125.85,123.46, 120.71, 120.35, 118.24, 114.06, 62.31, 23.87, 19.55, 14.32.

[0225] 18. Compound 3e

[0226]

[0227] Pale yellow solid, yield 35.7%. 1 H NMR (600 MHz, CDCl3) δ 8.33 (d, J = 2.8 Hz, 1H), 7.35 (d, J = 8.8 Hz, 1H), 7.31 (dd, J = 8.9, 2.8 Hz, 1H), 7.17 (d, J = 8.4,7.1, 5.7, 1.5 Hz, 1H), 4.48 (q, J = 7.1 Hz, 2H), 2.80 (s, 3H), 2.66 (s, 3H), 2.00 – 1.97 (m, 3H), 1.91 (dd, J = 7.1, 1.2 Hz, 3H), 1.44 (t, J = 7.2 Hz, 3H).

[0228] 13 C NMR (150 MHz, CDCl3) δ 168.10, 166.67, 160.81, 160.11, 151.93,150.13, 147.77, 140.21, 132.18, 128.04, 126.37, 120.03, 118.37, 117.79,113.91, 62.24, 23.84, 19.55, 14.87, 14.31, 12.33.

[0229] 19. Compound 3f

[0230]

[0231] White solid, yield 33.5%. 1 H NMR (600 MHz, CDCl3) δ 8.34 (d, J = 2.6 Hz, 1H),7.38 – 7.29 (m, 2H), 7.06 (td, J = 7.4, 1.5 Hz, 1H), 4.48 (q, J = 7.1 Hz, 2H), 2.80 (s, 3H), 2.66 (s, 3H), 2.34 – 2.18 (m, 4H), 1.97 (d, J = 1.4 Hz, 3H), 1.88 (d, J = 1.5 Hz, 2H), 1.44 (t, J = 7.2 Hz, 3H), 1.15 – 1.03 (m, 6H).

[0232] 13 C NMR (150 MHz, CDCl3) δ 168.13, 166.87, 160.81, 160.14, 151.95,150.15, 148.58, 147.79, 146.96, 132.19, 127.21, 126.40, 120.04, 118.39,117.81, 113.93, 62.26, 23.86, 22.48, 19.58, 14.32, 13.12, 12.51.

[0233] 20. Compound 3g

[0234]

[0235] White solid, yield 23.5%. 1 H NMR (600 MHz, CDCl3) δ 8.47 (d, J = 2.7 Hz, 1H), 7.62 (d, J = 5.3 Hz, 1H), 7.46 – 7.37 (m, 2H), 4.49 (q, J = 7.1 Hz, 2H), 2.81(s, 3H), 2.67 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0236] 13C NMR (150 MHz, CDCl3) δ 168.06, 160.92, 160.00, 159.23, 151.78,150.48, 150.18, 146.80, 133.59, 132.84, 132.33, 126.20 (d, J = 10.4 Hz),120.17, 119.37, 118.47, 117.95, 114.00, 62.28, 23.86, 19.56, 14.32.

[0237] 21. Compound 3h

[0238]

[0239] White solid, yield 24.8%. 1 H NMR (600 MHz, CDCl3) δ 8.47 (d, J = 2.5 Hz, 1H), 7.63 (d, J = 5.4 Hz, 1H), 7.46 – 7.37 (m, 2H), 4.49 (q, J = 7.2 Hz, 2H), 2.81(s, 3H), 2.67 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0240] 13 C NMR (150 MHz, CDCl3) δ 168.06, 160.92, 160.00, 159.05, 151.78,150.47, 150.18, 146.79, 133.80, 132.32, 131.96, 130.76, 126.16, 124.51,120.16, 118.47, 117.95, 113.99, 62.27, 23.85, 19.55, 14.32.

[0241] 22. Compound 3i

[0242]

[0243] White solid, yield 73.5%. 1 H NMR (600 MHz, CDCl3) δ 8.42 (t, J = 1.7 Hz, 1H), 8.24 (d, J= 1.5 Hz, 1H), 7.65 (d, J = 1.5 Hz, 1H), 7.39 (d, J = 1.6 Hz, 2H), 4.49 (q, J = 7.2 Hz, 2H), 2.81 (s, 3H), 2.67 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0244] 13 C NMR (150 MHz, CDCl3) δ 168.06, 160.92, 160.01, 151.78, 150.42,150.20, 147.06, 135.69, 132.86, 132.33, 130.59, 126.09, 120.21, 118.34,118.01, 113.99, 113.71, 62.29, 23.86, 19.55, 14.32.

[0245] 23. Compound 3j

[0246]

[0247] White solid, yield 73.5%. 1 H NMR (600 MHz, CDCl3) δ 8.44 (dd, J = 2.6, 0.7 Hz, 1H), 8.36 (dd, J = 3.1, 1.2 Hz, 1H), 7.69 (dd, J = 5.1, 1.2 Hz, 1H), 7.44 –7.37 (m, 3H), 4.49 (q, J = 7.2 Hz, 2H), 2.81 (s, 3H), 2.66 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0248] 13C NMR (150 MHz, CDCl3) δ 168.08, 161.18, 160.88, 160.06, 151.86,150.34, 150.17, 147.28, 134.53, 132.57, 132.27, 128.35, 126.71, 126.27,120.16, 118.44, 117.93, 113.97, 62.26, 23.86, 19.55, 14.32.

[0249] Comparative Example 1

[0250] Its preparation method is basically the same as that of Example 2, the only difference being that the substrate 2 used is The structure of the compound prepared by the above method is as follows: .

[0251] Example 24

[0252] Performance testing:

[0253] First, preliminary in vitro antibacterial activity tests were conducted on the 23 synthesized compounds. The test bacteria and experimental procedures are as follows:

[0254] 1. Test bacteria used in the experiment

[0255] Table 1

[0256]

[0257] The above four standard bacterial strains were used in this part of the experiments. All strains were provided by the Chemical Ecology Laboratory of the Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, and can also be purchased directly from Gary Chemical Network, Shanghai Boco Biotechnology Co., Ltd., etc.

[0258] 2. Preparation of PDA culture medium

[0259] (1) Weighing and cooking: Calculate the total amount of culture medium required based on the requirement of 10 mL of PDA culture medium per petri dish. Weigh a certain amount of peeled potatoes according to the calculation of adding 200 g of potatoes to every 1000 mL of distilled water. Cut the potatoes into small pieces and put them in a pot. Add 1000 mL of water and heat to boiling in the pot. Cook the potatoes until soft but not mushy. Filter while hot through 6-8 layers of gauze and discard the residue. Add water to the filtrate to 1000 mL.

[0260] (2) Heating and dissolving: Put the filtrate into a pot, add glucose (20 g / 1000 mL distilled water) and agar powder (18 g / 1000 mL distilled water), heat over low heat and stir constantly with a glass rod to prevent the agar powder from sticking to the bottom or overflowing. After the agar is completely dissolved, add water to the required amount.

[0261] (3) Dispensing and autoclaving: Dispense the prepared culture medium into 500 ml Erlenmeyer flasks. It is advisable to dispense into the Erlenmeyer flasks no more than half of their volume, seal them with sealing film, and autoclave them for later use.

[0262] 3. Solution preparation of synthesized coumarin-pyridine derivatives

[0263] The compound solution was prepared to a concentration of 100 μg / mL by accurately weighing 10 mg of the compound into a centrifuge tube, adding 1000 μL of dimethyl sulfoxide (DMSO) using a pipette, and sonicating until completely dissolved. The compound solution was then sterilized under a UV lamp for 30 min.

[0264] 4. Experimental Procedure

[0265] Place 10 mL of PDA medium in a petri dish, add 100 μL of the compound solution, gently shake to mix, label, and cool horizontally (drug concentration: 100 μg / mL). Use 100 μL of dimethyl sulfoxide (DMSO) as a blank control. Perform three parallel experiments. Use commercially available drugs Cnidium monnieri and azoxystrobin as positive controls. Use a 0.7 cm diameter punch to collect vigorous mycelial cakes and punch concentric circles. Inoculate the center of fresh medium and invert the dish in a 25°C incubator. Measure the colony diameter at 96 h using the cross-cross method, calculate the average diameter, and calculate the compound's inhibition rate.

[0266] Formula for calculating antibacterial rate: I=[(D0-D t [(D0-0.7)]×100%

[0267] (I: Mycelial growth inhibition rate, D0: Diameter of blank colony, D) t (Diameter of bacterial colonies after chemical treatment)

[0268] 5. Measurement Results

[0269] The inhibitory activity of the synthesized pyridine coumarin derivatives against four common plant pathogens—Botrytis cinerea, Alternaria solanacea, Fusarium oxysporum, and Alternaria alternata—was determined using the mycelial growth rate method described above. The experimental results are shown in Table 2.

[0270] Table 2

[0271]

[0272] Note: Higher values ​​in Table 2 indicate higher antibacterial activity, while negative values ​​indicate that the compound promotes fungal growth.

[0273] Based on the above results, we selected 1a, 1b, 1c, 1d, 1i, 2d, 3b, 3c, and 3j, which showed better antibacterial activity, for EC testing. 50 Testing. The test method was the colony diameter method using PDA medium. The compound test concentrations were: 100 μg / mL, 50 μg / mL, 25 μg / mL, 12.5 μg / mL, and 6.25 μg / mL. The comparative test concentrations of the commercial drugs *Cnidium monnieri* and azoxystrobin were: 100 μg / mL, 50 μg / mL, 25 μg / mL, 12.5 μg / mL, and 6.25 μg / mL. The test data are shown in Table 3.

[0274] Table 3

[0275]

[0276] A smaller EC50 value indicates that the drug can achieve 50% of its maximum effect at a lower concentration, which means that the drug is more effective.

[0277] From EC 50 The test results show that, among these compounds, compounds 1d, 1i, and 3b have the best EC50 values ​​for Alternaria. 50 The values ​​of 30.957 µg / mL, 28.523 µg / mL, and 37.537 µg / mL, respectively, all showed inhibitory activity comparable to the positive controls of Cnidium monnieri and azoxystrobin. For Alternaria alternata, compounds 1a, 1b, and 1c showed good antibacterial activity, with EC50 values ​​of [missing value]. 50 The values ​​of 16.119 µg / mL, 15.722 µg / mL, and 17.738 µg / mL were significantly better than the inhibitory activities of the two positive controls, Cnidium monnieri and azoxystrobin. For Fusarium oxysporum, compound 1b showed relatively good inhibitory activity, with an EC50 value of 16.119 µg / mL, 15.722 µg / mL, and 17.738 µg / mL, respectively. 50 The value was 21.784 µg / mL, far exceeding the efficacy of Cnidium monnieri and azoxystrobin. Furthermore, the EC50 values ​​of these 10 compounds were... 50 The value of R 2 All values ​​were greater than 0.9, indicating a good correlation between concentration and antibacterial effect. Overall, this series of compounds has a broad fungicidal spectrum and generally superior activity. The compounds are particularly effective in inhibiting early blight in tomatoes and wilt in crops, and may become lead compounds for the development of green pesticides.

[0278] Using the same test method, the compound of Comparative Example 1 was tested under the same test conditions to determine its half-maximal inhibitory concentration (EC50) antibacterial activity. 50 The results are as follows.

[0279] Table 4

[0280]

[0281] As shown in Table 4, the compounds in Comparative Example 1 and Compound 1b of this invention have similar structures, with the main difference being the substituents at C-7. The substituents used in Comparative Example 1 are straight-chain acids, while the substituent in Compound 1b of this invention is 2-trifluoromethylbenzoic acid. A comparison of the results shows that the EC50 of Compound 1b of this invention... 50 The value (15.722 µg / mL) was significantly better than that of EC in Comparative Example 1. 50 The value (62.68 µg / mL) further demonstrates that when the substituents contain trifluoromethyl (-CF3) or halogens (-F, Cl, Br), the inhibitory activity of the compound against plant-derived fungi is significantly enhanced on top of its previous antifungal activity.

[0282] The above results demonstrate that the pyridine-type coumarin derivatives of this invention have significant application value in combating plant-derived fungi. They are particularly effective against *Botrytis cinerea*, the fungus that causes gray mold in strawberries and tomatoes. Botrytis gray Alternaria alternata, which causes early blight in tomatoes ( Nightshade Fusarium oxysporum, which causes crop wilt ( Fusarium oxysporum Alternaria, which causes diseases such as black mold in tomatoes ( Alternaria alternata The pyridine-type coumarin derivatives of this invention exhibit good inhibitory activity against four common basic plant fungi, including [specific fungal species name missing]. They can serve as lead compounds for the development of novel agricultural fungicides, used to treat or prevent fungal infections in plants. Therefore, the pyridine-type coumarin derivatives of this invention have significant applications in the preparation of antifungal drugs, particularly in this area.

[0283] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0284] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0285] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0286] In the context of this specification, except where expressly stated otherwise, any matters or issues not mentioned shall apply directly to those known in the art without any modification.

Claims

1. A pyridine-type coumarin derivative, characterized in that... The pyridine-type coumarin derivatives are selected from compounds represented by the following general formula 1: Formula 1; In Equation 1, R1 is selected from... ;R 1a Selected from substituted phenyl groups; wherein, the compound represented by Formula 1 is specifically: ； ； or, The pyridine-type coumarin derivatives are selected from compounds represented by the following general formula 3: Formula 3; R3 in Equation 3 is selected from Among them, R 3a Selected from a fluoroalkyl-substituted phenyl group; wherein, the compound shown in Formula 3 is specifically: 。 2. A method for preparing a pyridine-type coumarin derivative as described in claim 1, characterized in that, Includes the following steps: Substrate 1 was reacted with substrate 2, a condensing agent, and a basic catalyst in a solvent to obtain the pyridine-type pyridine-type coumarin derivatives. Substrate 1 is selected from the following general structural formula: ； Formula B In formula B, only one of the three hydroxyl groups exists at any given time. Substrate 2 is selected from At least one of them; R a With respect to R as described in claim 1 1a and R 3a The correspondence is the same.

3. The method for preparing pyridine-type coumarin derivatives according to claim 2, characterized in that: The substrate 1 is selected from one of the following compounds: , ; and / or, Substrate 2 is selected from or At least one of them; R 1a R 3a With respect to R as described in claim 1 1a R 3a The correspondence is the same.

4. The method for preparing pyridine-type coumarin derivatives according to claim 2, characterized in that: The condensing agent is selected from at least one of EDC or DCC; and / or, The alkaline catalyst is selected from at least one of 4-dimethylaminopyridine or 1-hydroxybenzotriazole; and / or, The solvent is selected from at least one of dichloromethane or a mixture of petroleum ether and ethyl acetate.

5. The method for preparing pyridine-type coumarin derivatives according to claim 4, characterized in that: The molar ratio of substrate 2 to substrate 1 is (2~4):1; and / or, The molar ratio of condensing agent to substrate 1 is (3~6):1; and / or, The molar ratio of condensing agent to basic catalyst is (5~8):1; and / or, The mass-to-volume ratio of condensing agent to solvent is (2~20) mg: 1 mL; and / or, The reaction time is 6-10 hours.

6. The use of a pyridine coumarin derivative as described in claim 1 in the preparation of at least one of an antifungal drug, an antiviral drug, an anti-inflammatory drug, or an antitumor drug.

7. The application according to claim 6, wherein the fungus is at least one of Botrytis cinerea, Alternaria solanacea, Fusarium oxysporum, or Alternaria.

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