A coumarin derivative, its synthesis method and application

Abstract

This invention discloses a coumarin derivative, its synthesis method, and its applications. The synthesis method includes: placing equimolar amounts of substituted 3-cyano-4-methylcoumarin and substituted nitrodihydrochromene in a test tube containing a stir bar, adding acetone, and then adding 20% ​​(by weight) of triethylamine of the substituted 3-cyano-4-methylcoumarin under stirring. The reaction is carried out at room temperature for three hours, and the reaction is monitored by TLC. After the reaction is completed, the solid product is filtered and washed to obtain the coumarin derivative. This method has many advantages, such as inexpensive and readily available solvents, simple operation, and wide applicability, making it suitable for industrial production. The prepared coumarin derivative has certain inhibitory effects on potato wilt pathogens, rapeseed black shank pathogens, tomato gray mold pathogens, and apple rot pathogens, and can be used as an antibacterial agent.

Description

Technical Field

[0001] This invention belongs to the field of coumarin derivatives and their synthesis technology, specifically relating to a coumarin derivative, its synthesis method, and its application. Background Technology

[0002] Coumarins and their derivatives are an important class of heterocyclic compounds, widely found in natural products and possessing significant biological activities. Many coumarin derivatives exhibit antifungal and insecticidal effects; for example, psolalen has photosensitizing activity and is used to treat vitiligo. Osthole, a coumarin active ingredient derived from Cnidium monnieri and Angelica sinensis, has pharmacological activity that inhibits hepatitis B surface antigen (HBsAg). Calophylloide has strong anticoagulant activity. Scoparon is the main active ingredient in the herb Artemisia capillaris, known for its liver-soothing, choleretic, and smooth muscle-relaxing properties. Therefore, the synthesis of coumarin derivatives has broad application prospects.

[0003] Therefore, we believe that constructing a series of aminocoumarin derivatives will have unique biological activities, and there are relatively few reports on the synthesis of such compounds in the literature.

[0004] Currently, the main literature on the construction of coumarin heterocyclic compounds using 3-cyano-4-methylcoumarin derivatives as raw materials is as follows:

[0005] (1) In 2015, Xiong-Li Liu et al. reported the synthesis of coumarin derivatives containing hydroxyindole structures by Dabco-catalyzed CH bond activation reaction. (Tetrahedron Lett., 56, 5637-5645; 2015.).

[0006]

[0007] (2) In 2020, Wangze Song et al. used 3-cyano-4-methylcoumarin derivatives as raw materials and carried out a coupling reaction with Boc-protected dihydropyranone derivatives to synthesize a coumarin derivative containing dihydropyranone (Adv.Synth.Catal.,363;846-850,2020.).

[0008]

[0009] (3) In 2023, Singh et al. synthesized a coumarin derivative containing an N-heterocyclic ring by reacting a 3-cyano-4-methylcoumarin derivative with a substituted maleimide (J.Org.Chem.,88,7712-7723,2023.).

[0010]

[0011] These methods involve complex catalytic reaction processes and produce products with unclear activity, which hinders their application and promotion. Summary of the Invention

[0012] To address the shortcomings of existing technologies, the present invention aims to provide a coumarin derivative, its synthesis method, and its applications. The raw materials are readily available, the operation is simple, and it is environmentally friendly. The product has a wide range of applications as an antibacterial agent.

[0013] To achieve the above objectives, the present invention employs the following technical solution:

[0014] A coumarin derivative, with the general structural formula shown in formula (I):

[0015]

[0016] In formula (I), R1 includes any one of hydrogen, methyl, halogen or methoxy, R2 includes hydrogen or halogen, and R3 includes any one of hydrogen, methyl, halogen, trifluoromethyl or nitro.

[0017] Preferably, the general structural formula is (I-1), (I-2), (I-3), (I-4), (I-5), or (I-6):

[0018]

[0019]

[0020] Among them, R 1-1 It is hydrogen, methyl, chloro, or methoxy; R 1-2 Methyl; R 2-1 It is hydrogen or bromine; R 2-2 It is bromine; R 3-1 It is hydrogen, bromine, or nitro; R 3-2 It can be methyl, trifluoromethyl, or bromine.

[0021] Furthermore, the structural formula can be any of the following:

[0022]

[0023] This invention also protects a method for synthesizing the coumarin derivative as described above, comprising the steps of:

[0024] Equal amounts of substituted 3-cyano-4-methylcoumarin and substituted nitrodihydrochromene were placed in a test tube containing a stir bar. Acetone was added, and 20% of the amount of substituted 3-cyano-4-methylcoumarin triethylamine was added while stirring. The mixture was stirred at room temperature for three hours. After the reaction was completed, the solid product was filtered and washed to obtain the coumarin derivative.

[0025] The structural formula of the substituted 3-cyano-4-methylcoumarin is as follows:

[0026]

[0027] Among them, R 1-1 It is hydrogen, methyl, chloro, or methoxy; R 1-2 It is methyl;

[0028] The structural formula of the substituted nitrodihydrochromene is:

[0029]

[0030] Among them, R 2-1 It is hydrogen or bromine; R 2-2 It is bromine; R 3-1 It is hydrogen, bromine, or nitro; R 3-2 It can be methyl, trifluoromethyl, or bromine.

[0031] Preferably, the washing process involves repeatedly washing with DCM and MeOH 3 to 5 times.

[0032] The present invention also protects the use of a coumarin derivative as described above as an antibacterial agent.

[0033] Preferably, the antibacterial agent is used to prevent potato wilting, rapeseed blackleg, tomato gray mold, and apple rot.

[0034] Compared with the prior art, the present invention has the following technical effects:

[0035] The key technology of the method for synthesizing coumarin derivatives of the present invention is the reaction of 3-cyano-4-methylcoumarin with substituted nitrodihydrochromene, using an inexpensive reaction solvent and triethylamine as a catalyst, to directly synthesize coumarin derivatives containing heterocyclic rings in a one-pot process; it has many advantages such as inexpensive and readily available solvents, simple operation, and wide applicability, and is suitable for industrial production.

[0036] The coumarin derivatives of the present invention have certain inhibitory effects on potato wilt pathogen, rapeseed black shank pathogen, tomato gray mold pathogen and apple rot pathogen, and can be used as antibacterial agents. Detailed Implementation

[0037] The specific content of the present invention will be further explained in detail below with reference to the embodiments.

[0038] Example 1

[0039] 3-Methyl-4-cyanocoumarin (0.1 mmol, 1.0 eq) and nitrodihydrochrome MBH substrate (0.1 mmol, 1.0 eq) were placed in a test tube containing a stir bar. 1 mL of acetone was added, followed by (0.02 mmol, 3 μL) of triethylamine with stirring. The mixture was stirred at room temperature for three hours, and the reaction was monitored by TLC. After the reaction was complete, the solid product was filtered and washed repeatedly with a small amount of DCM and MeOH to obtain coumarin derivative a (39 mg, 90% yield). The reaction equation is as follows:

[0040]

[0041] The structure of the coumarin derivative a obtained above was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 HNMR (400MHz, DMSO-d6) δ8.34(d,J=7.6Hz,1H),7.90(s,1H),7.62(d,J=8.2Hz,2H),7.55-7.38(m,4H),7.41-7.43(m,2H) ,7.28(d,J=7.4Hz,2H),7.17-6.93(m,2H),6.14(s,1H),5.28(d,J=1.4Hz,1H),4.07-3.91(m,2H),3.61(t,J=9.0Hz,1H). 13 C NMR(101MHz,DMSO-d6)δ162.39,157.35,153.79,153.61,136.65,136.14,129.83,128.99,128.90,128.85,127.56, 126.08,122.15,121.60,118.65,118.04,117.31,114.94,104.72,85.40,72.46,38.74,31.20.ESI-HRMS:calcd.for C 25 H 18 N2O5+Na,461.1108,found 461.1114. This indicates that the obtained coumarin derivative has the structure shown in structural formula a.

[0042] Example 2

[0043] 3-Cyano-4,7-dimethylcoumarin (0.1 mmol, 1.0 eq) and nitrodihydrochromene MBH substrate (0.1 mmol, 1.0 eq) were placed in a test tube containing a stir bar. 1 mL of acetone was added, followed by (0.02 mmol, 3 μL) of triethylamine with stirring. The mixture was stirred at room temperature for three hours, and the reaction was monitored by TLC. After the reaction was complete, the solid product was filtered and washed three times repeatedly with a small amount of DCM and MeOH to obtain coumarin derivative b (38 mg, yield 85%). The reaction equation is as follows:

[0044]

[0045] The structure of the coumarin derivative b obtained above was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 HNMR(400MHz,DMSO-d6)δ8.22(d,J=8.7Hz,1H),7.63-7.36(m,7H),7.27(dd,J=15.4,7.3Hz,2H),7.15-6.9 5(m,2H),6.12(d,J=1.1Hz,1H),5.26(d,J=1.5Hz,1H),4.06-3.85(m,2H),3.68-3.46(m,1H),2.53(s,3H). 13 C NMR(101MHz,DMSO-d6)δ162.43,157.60,153.89,153.61,147.95,136.64,129.79,128.98,128.87,127.29,127.18,126 .10,122.13,121.59,118.01,117.30,116.37,115.09,103.32,85.42,72.45,38.75,37.45,21.86.ESI-HRMS:calcd.for C 27 H 20 N2O5+Na, 475.1264, found 475.1280. This indicates that the obtained coumarin derivative has the structure shown in structural formula b.

[0046] Example 3

[0047] 3-Cyano-4-methyl-7-bromocoumarin (0.1 mmol, 1.0 eq) and nitrodihydrochromene MBH substrate (0.1 mmol, 1.0 eq) were placed in a test tube containing a stir bar. 1 mL of acetone was added, followed by (0.02 mmol, 3 μL) of triethylamine with stirring. The mixture was stirred at room temperature for three hours, and the reaction was monitored by TLC. After the reaction was complete, the solid product was filtered and washed four times repeatedly with a small amount of DCM and MeOH to obtain coumarin derivative c (42 mg, yield 82%). The reaction equation is as follows:

[0048]

[0049] The structure of the coumarin derivative C obtained above was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 HNMR(600MHz,DMSO-d6)δ8.28(d,J=8.7Hz,1H),7.83(d,J=2.0Hz,1H),7.64(dd,J =8.6,2.0Hz,1H),7.50(d,J=7.5Hz,2H),7.46(t,J=7.6Hz,2H),7.39(t,J=7.3Hz,1 H),7.29-7.23(m,1H),7.20(d,J=7.5Hz,1H),7.05(t,J=8.1Hz,1H),6.95(t,J=7.4 Hz,1H),6.07(s,1H),5.36(d,J=1.2Hz,1H),3.99-3.82(m,2H),3.68-3.51(m,1H). 13 C NMR(151MHz,DMSO-d6)δ161.17,156.33,153.64,152.99,139.77,136.03,129.40,128.47,128.31,128.26,125.62, 125.55,121.39,120.61,117.52,117.12,116.69,114.05,104.14,84.79,71.83,38.13,37.03.ESI-HRMS:calcd.for C 26 H 17 N2O5+Na,539.0213,found 539.0222. This indicates that the obtained coumarin derivative has the structure shown in structural formula c.

[0050] Example 4

[0051] 3-Cyano-4-methyl-7-methoxycoumarin (0.1 mmol, 1.0 eq) and nitrodihydrochromene MBH substrate (0.1 mmol, 1.0 eq) were placed in a test tube containing a stir bar. 1 mL of acetone was added, followed by (0.02 mmol, 3 μL) of triethylamine with stirring. The mixture was stirred at room temperature for three hours, and the reaction was monitored by TLC. After the reaction was complete, the solid product was filtered and washed repeatedly with a small amount of DCM and MeOH to obtain coumarin derivative d (39 mg, yield 83%). The reaction equation is as follows:

[0052]

[0053] The structure of the coumarin derivative d obtained above was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 HNMR (400MHz, DMSO-d6) δ8.33(d,J=7.5Hz,1H),7.90(t,J=7.4Hz,1H),7.60(dd,J=16.6,8.0Hz,2H),7.46-7.19(m,3H),7.12-7.04(m ,3H),7.02-6.94(m,2H),6.08(s,1H),5.29(d,J=1.4Hz,1H),3.92(dd,J=18.6,6.7Hz,2H),3.79(s,3H),3.59(dd,J=11.6,4.3Hz,1H). 13 CNMR(101MHz,DMSO-d6)δ162.37,159.64,157.35,153.80,153.52,138.21,136.12,131.15,130.04,129.83,128.99,127.54,126.02,122 .13,121.54,118.63,118.18,118.04,117.33,114.94,114.08,111.95,104.70,85.35,72.29,55.66,38.71,37.43.ESI-HRMS:calcd.forC 27 H 20 N2O6+Na,491.1214,found 491.1226. This indicates that the obtained coumarin derivative has the structure shown in structural formula d.

[0054] Example 5

[0055] 3-Cyano-4,6-dimethylcoumarin (0.1 mmol, 1.0 eq) and nitrodihydrochrome MBH substrate (0.1 mmol, 1.0 eq) were placed in a test tube containing a stir bar. 1 mL of acetone was added, followed by (0.02 mmol, 3 μL) of triethylamine with stirring. The mixture was stirred at room temperature for three hours, and the reaction was monitored by TLC. After the reaction was complete, the solid product was filtered and washed five times repeatedly with a small amount of DCM and MeOH to obtain coumarin derivative e (27 mg, 60% yield). The reaction equation is as follows:

[0056]

[0057] The structure of the coumarin derivative e obtained above was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 HNMR (400MHz, DMSO-d6) δ8.14(s,1H),7.73(dd,J=8.5,1.2Hz,1H),7.53(d,J=3.9Hz,1H),7.46(d,J=3.7Hz,4H),7.31(dd,J=7.6,3.0Hz,2H ),7.06(dd,J=13.6,7.5Hz,2H),6.20(d,J=1.3Hz,1H),5.15(d,J=1.4Hz,1H),4.06-3.89(m,2H),3.53(dd,J=11.3,3.4Hz,1H),2.50(s,3H). 13 C NMR (101MHz, DMSO-d6) δ162.10,157.32,153.77,152.55,138.30,136.16,133.22,129.45,129.37,128.89,127.64,125. 98,125.52,123.48,119.10,118.58,117.96,114.97,104.81,84.91,72.57,38.57,37.03,21.38.ESI-HRMS:calcd.forC 27 H 20 N2O5+Na,475.1264,found 475.1273. This indicates that the obtained coumarin derivative has the structure shown in structural formula e.

[0058] Example 6

[0059] 3-Cyano-4-methylcoumarin (0.1 mmol, 1.0 eq) and substituted nitrodihydrochrome MBH substrate (0.1 mmol, 1.0 eq) were placed in a test tube containing a stir bar. 1 mL of acetone was added, followed by (0.02 mmol, 3 μL) of triethylamine with stirring. The mixture was stirred at room temperature for three hours, and the reaction was monitored by TLC. After the reaction was complete, the solid product was filtered and washed repeatedly with a small amount of DCM and MeOH to obtain the coumarin derivative f (45 mg, yield 88%). The reaction equation is as follows:

[0060]

[0061] The structure of the coumarin derivative f obtained above was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 HNMR(400MHz, DMSO-d6)δ8.25(d,J=7.4Hz,1H),7.99-7.80(m,1H),7.64-7.55(m,2H),7.51-7.40(m,7H),7.05( d,J=8.6Hz,1H),6.15(d,J=1.5Hz,1H),5.37(d,J=1.5Hz,1H),4.09-3.84(m,2H),3.64(dd,J=12.1,5.2Hz,1H). 13 C NMR(101MHz,DMSO-d6)δ162.09,157.32,153.76,152.91,136.20,132.30,131.75,129.03,128.90,127.64,126.07, 125.97,123.94,119.52,118.57,117.96,114.97,113.25,104.82,84.85,72.55,38.44,37.04.ESI-HRMS:calcd.for C 26 H 17 BrN2O5+Na, 539.0213, found 539.0224. This indicates that the obtained coumarin derivative has the structure shown in structural formula f.

[0062] Example 7

[0063] 3-Cyano-4-methylcoumarin (0.1 mmol, 1.0 eq) and substituted nitrodihydrochrome MBH substrate (0.1 mmol, 1.0 eq) were placed in a test tube containing a stir bar. 1 mL of acetone was added, followed by (0.02 mmol, 3 μL) of triethylamine with stirring. The mixture was stirred at room temperature for three hours, and the reaction was monitored by TLC. After the reaction was complete, the solid product was filtered and washed repeatedly with a small amount of DCM and MeOH to obtain g (39 mg, yield 76%) of the coumarin derivative. The reaction equation is as follows:

[0064]

[0065] The structure of the coumarin derivative g obtained above was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 HNMR(400MHz, DMSO-d6)δ8.23(d,J=7.6Hz,1H),7.85(d,J=7.3Hz,1H),7.68-7.51(m,2H),7.51-7.33(m,7H),7.03 (d,J=8.6Hz,1H),6.12(s,1H),5.34(d,J=1.3Hz,1H),3.89(dd,J=19.7,7.1Hz,1H),3.61(dd,J=12.2,5.2Hz,1H). 13 C NMR(101MHz,DMSO-d6)δ162.09,157.32,153.76,152.91,136.20,132.30,131.76,129.03,128.90,127.65,126 .07,125.98,123.94,119.52,118.57,117.96,114.97,113.25,104.82,84.86,72.55,38.44,37.04.calcd.for C 26 H 17 BrN2O5+Na, 539.0213, found 539.0224. This indicates that the obtained coumarin derivative has the structure shown in structural formula g.

[0066] Example 8

[0067] 3-Cyano-4-methylcoumarin (0.1 mmol, 1.0 eq) and substituted nitrodihydrochrome MBH substrate (0.1 mmol, 1.0 eq) were placed in a test tube containing a stir bar. 1 mL of acetone was added, followed by (0.02 mmol, 3 μL) of triethylamine with stirring. The mixture was stirred at room temperature for three hours, and the reaction was monitored by TLC. After the reaction was complete, the solid product was filtered and washed repeatedly with a small amount of DCM and MeOH to obtain coumarin derivative h (33 mg, yield 68%). The reaction equation is as follows:

[0068]

[0069] The structure of the coumarin derivative h obtained above was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1HNMR(400MHz,DMSO-d6)δ8.39(d,J=8.7Hz,2H),8.31(d,J=7.6Hz,1H),7.90 (t,J=7.7Hz,1H),7.82(d,J=8.7Hz,2H),7.66-7.59(m,2H),7.29(t,J=7.6H z,1H),7.22(d,J=7.4Hz,1H),7.10(d,J=8.1Hz,1H),7.00(t,J=7.4Hz,1H), 6.34(s,1H),5.51(s,1H),4.09-3.85(m,2H),3.62(dd,J=13.0,6.4Hz,1H). 13 C NMR (101MHz, DMSO-d6) δ163.68,162.36,157.33,153.78,153.49,136.13,132.89,129.87,129.01,128.24,127.52,126. 05,122.19,121.46,118.59,118.04,117.29,115.70,114.92,104.72,85.36,71.98,38.65,37.46.ESI-HRMS:calcd.for C 26 H 17 N3O7+Na, 506.0959, found 506.0968. This indicates that the obtained coumarin derivative has the structure shown in structural formula h.

[0070] Example 9

[0071] 3-Cyano-4-methylcoumarin (0.1 mmol, 1.0 eq) and substituted nitrodihydrochrome MBH substrate (0.1 mmol, 1.0 eq) were placed in a test tube containing a stir bar. 1 mL of acetone was added, followed by (0.02 mmol, 3 μL) of triethylamine with stirring. The mixture was stirred at room temperature for three hours, and the reaction was monitored by TLC. After the reaction was complete, the solid product was filtered and washed repeatedly with a small amount of DCM and MeOH to obtain coumarin derivative i (30 mg, yield 68%). The reaction equation is as follows:

[0072]

[0073] The structure of the coumarin derivative i obtained above was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1HNMR (400MHz, DMSO-d6) δ8.32(d,J=7.9Hz,1H),7.89(s,1H),7.61(d,J=8.2Hz,2H),7.38(d,J=8.1Hz,2H),7.29-7.20(m ,4H),7.08-6.93(m,2H),6.08(s,1H),5.22(d,J=1.4Hz,1H),3.94(d,J=5.1Hz,2H),3.56(d,J=7.1Hz,1H),2.35(s,3H). 13 C NMR(101MHz,DMSO-d6)δ162.10,157.32,153.77,152.55,138.30,136.16,133.22,129.45,129.37,128.89,127.64,125 .98,125.52,123.48,119.10,118.58,117.96,114.97,104.81,84.91,72.57,38.57,37.03,21.26.ESI-HRMS:calcd.for C 27 H 20 N2O5+Na,475.1264,found 475.1276. This indicates that the obtained coumarin derivative has the structure shown in structural formula i.

[0074] Example 10

[0075] 3-Cyano-4-methylcoumarin (0.1 mmol, 1.0 eq) and substituted nitrodihydrochrome MBH substrate (0.1 mmol, 1.0 eq) were placed in a test tube containing a stir bar. 1 mL of acetone was added, followed by (0.02 mmol, 3 μL) of triethylamine with stirring. The mixture was stirred at room temperature for three hours, and the reaction was monitored by TLC. After the reaction was complete, the solid product was filtered and washed repeatedly with a small amount of DCM and MeOH to obtain coumarin derivative j (43 mg, yield 85%). The reaction equation is as follows:

[0076]

[0077] The structure of the coumarin derivative j obtained above was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1HNMR (400MHz, DMSO-d6) δ8.32(d,J=7.4Hz,1H),7.89(d,J=8.1Hz,3H),7.75(d,J=8.3Hz,2H),7.66-7.59(m,2H),7.36- 7.18(m,2H),7.09(d,J=7.5Hz,1H),7.05-6.95(m,1H),6.28(s,1H),5.41(s,1H),4.14-3.83(m,2H),3.71-3.49(m,1H). 13 C NMR(101MHz,DMSO-d6)δ162.38,157.35,153.79,153.23,141.50,136.18,129.92,129.12,127.49,126.99,126.10, 125.88,122.36,121.43,118.62,118.06,117.33,114.89,104.70,85.11,72.03,38.66,37.30.ESI-HRMS:calcd.for C 27 H 17 F3N2O5+Na,529.0982found 529.0993. indicates that the obtained coumarin derivative has the structure shown in structural formula j.

[0078] Example 11

[0079] 3-Cyano-4-methylcoumarin (0.1 mmol, 1.0 eq) and substituted nitrodihydrochrome MBH substrate (0.1 mmol, 1.0 eq) were placed in a test tube containing a stir bar. 1 mL of acetone was added, followed by (0.02 mmol, 3 μL) of triethylamine with stirring. The mixture was stirred at room temperature for three hours, and the reaction was monitored by TLC. After the reaction was complete, the solid product was filtered and washed repeatedly with a small amount of DCM and MeOH to obtain coumarin derivative k (46 mg, yield 89%). The reaction equation is as follows:

[0080]

[0081] The structure of the coumarin derivative k obtained above was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1HNMR(400MHz,DMSO-d6)δ8.25(d,J=7.4Hz,1H),7.86-7.81(m,1H),7.65(d,J=8.5Hz,2H),7.55(t,J=9.0Hz,2H),7.41(d,J=8.5Hz,2H), 7.25-7.13(m,2H),7.01(d,J=7.4Hz,1H),6.97-6.89(m,1H),6.09(s,1H),5.27(d,J=1.5Hz,1H),3.97-3.75(m,2H),3.61-3.44(m,1H). 13 C NMR(101MHz,DMSO-d6)δ162.38,157.34,153.77,153.36,136.19,131.85,129.88,129.05,128.31,127.51,126 .07,122.24,122.12,121.43,118.61,118.04,117.29,114.88,104.69,85.18,71.99,38.65,37.37.calcd.for C 26 H 17 BrN2O5+Na,539.0213,found539.0224. This indicates that the obtained coumarin derivative has the structure shown in structural formula k.

[0082] The antibacterial properties of some products were tested, as follows:

[0083] 1. Antifungal activity assay procedure:

[0084] Preparation of PDA medium: Weigh 37.0 mg of PDA medium (20 g potato, 20 g glucose, 20 g agar, 100 mL water) using a 0.01% balance, dissolve it in 1000 mL of boiling water, stir until completely dissolved and free of flocculent solids, and then dispense it into Erlenmeyer flasks while hot according to experimental requirements for later use.

[0085] Activation of plant pathogens: Take out the plant pathogen strains stored in a 4℃ refrigerator and place them in a clean bench. Use the spot inoculation method to inoculate the pathogens into the center of the autoclaved PDA medium. After inoculation, place it in a mold incubator (25℃) for 3-5 days. When the colony growth area covers 2 / 3 of the plate, it is ready for use.

[0086] Preparation of reagent solution: Accurately weigh 5.0 mg of the test drug into a brown reagent bottle using a 0.01 g / mL balance, add 0.5 mL of DMSO and 9.5 mL of sterile water in sequence, and dissolve completely. Use 0.5 mL of DMSO and 9.5 mL of sterile water as negative controls.

[0087] Inoculation: Transfer sterilized petri dishes and other prepared materials to a clean bench promptly. Pour 10 mL of the drug solution into the culture medium, mix thoroughly, and quickly pour into the petri dishes, ensuring each dish contains approximately 15 mL of the drug-medium mixture. This will result in a final drug concentration of approximately 50 μg / mL. Let the dishes stand flat to solidify. Simultaneously, punch holes for colonies. Select colonies with similar growth stages. Use a hole punch (0.5 cm in diameter). After the culture medium has solidified, use an inoculation needle to pick up colonies and inoculate the same strain in three equilateral triangular locations in each petri dish to ensure accurate results. After inoculation, place the petri dishes in a mold incubator at 25°C for 48-72 hours.

[0088] Measurement and calculation: Colony diameter was determined using the cross-cross method.

[0089] Calculate the mycelial growth inhibition rate: Mycelial growth inhibition rate (%) = (dc - ds) / (dc - 5) × 100%

[0090] 2. Antibacterial properties

[0091] As shown in Table 1, compounds f, g, i, and k exhibit inhibitory activity against four fungi: *Fusarium oxysporum* Schlecht (potato wilt), *Leptosphaeria biglobosa* (rapeseed black shank), *Botrytis cinerea* (tomato gray mold), and *Valsaceratosperma* (apple rot). In particular, f showed better inhibition rates against *Fusarium oxysporum* Schlecht, g against *Botrytis cinerea* Schlecht, i against *Valsaceratosperma* Schlecht, and k against *Leptosphaeria biglobosa* Schlecht.

[0092] Table 1. Inhibitory effects of different compounds on four plant pathogenic fungi.

[0093]

[0094] Finally, it should be noted that the amount of reactants used in this invention is not strictly limited. Generally, the reaction is carried out according to the stoichiometric ratio of the chemical reaction, or one of the compounds may be used in excess.

[0095] In this invention, the amount of reaction solvent and catalyst is not strictly limited and can be adjusted according to the amount of reaction raw materials: if there are more reaction raw materials, the amount of reaction solvent and catalyst should be increased, and if there are fewer reaction raw materials, the amount of reaction solvent and catalyst should be decreased.

[0096] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims.

Claims

1. A coumarin derivative, characterized in that, The general structural formula is shown in equation (I): In formula (I), R1 is any one of hydrogen, methyl, halogen or methoxy, R2 is hydrogen or halogen, and R3 is any one of hydrogen, methyl, halogen, trifluoromethyl or nitro.

2. The coumarin derivative according to claim 1, characterized in that, The general structural formula is (I-1), (I-2), (I-3), (I-4), (I-5) or (I-6): Among them, R 1-1 It is hydrogen, methyl, chloro, or methoxy; R 1-2 Methyl; R 2-1 It is hydrogen or bromine; R 2-2 It is bromine; R 3-1 It is hydrogen, bromine, or nitro; R 3-2 It can be methyl, trifluoromethyl, or bromine.

3. The coumarin derivative according to claim 1 or 2, characterized in that, The structural formula is any one of the following:

4. A method for synthesizing a coumarin derivative as described in any one of claims 2-3, characterized in that, Including the following steps: Equal amounts of substituted 3-cyano-4-methylcoumarin and substituted nitrodihydrochromene were placed in a test tube containing a stir bar. Acetone was added, and 20% of the amount of substituted 3-cyano-4-methylcoumarin triethylamine was added while stirring. The mixture was stirred at room temperature for three hours. After the reaction was completed, the solid product was filtered and washed to obtain the coumarin derivative. The structural formula of the substituted 3-cyano-4-methylcoumarin is as follows: Among them, R 1-1 It is hydrogen, methyl, chloro, or methoxy; R 1-2 It is methyl; The structural formula of the substituted nitrodihydrochromene is: Among them, R 2-1 It is hydrogen or bromine; R 2-2 It is bromine; R 3-1 It is hydrogen, bromine, or nitro; R 3-2 It can be methyl, trifluoromethyl, or bromine.

5. The method for synthesizing coumarin derivatives according to claim 4, characterized in that, The washing process involves repeatedly washing with DCM and MeOH 3 to 5 times.

6. The application of a coumarin derivative according to any one of claims 1 to 3 as an antibacterial agent, wherein the antibacterial agent is used to prevent potato wilting, rapeseed blackleg, tomato gray mold, and apple rot.

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