7-amino coumarin derivatives, methods for their synthesis and use

Abstract

The application discloses a 7-amino coumarin derivative and a synthesis method and application thereof, and the synthesis method comprises the following steps: placing substituted 3-cyano-4-methyl coumarin and 20% Dabco of the volume of the substituted 3-cyano-4-methyl coumarin in a thick-wall pressure-resistant pipe containing a stirrer, adding tetrahydrofuran solvent, then slowly adding dimethyl butyne diacid in a stoichiometric ratio under stirring, and monitoring the reaction by TLC at normal temperature, removing the solvent under reduced pressure after the reaction is completed, and performing column chromatography separation to obtain the 7-amino coumarin derivative; the application has the advantages of flexible reaction time, cheap and easily-obtained solvent, simple operation, wide application range and the like, and is suitable for industrialized production; the synthesized 7-amino coumarin derivative has certain inhibiting effects on potato dry rot fungus, brassica nigra, tomato botrytis cinerea and apple rot fungus, and can be used as an antibacterial agent.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, and relates to coumarin compounds and their synthesis methods, specifically to a 7-aminocoumarin 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 synthesis of aminobenzopyranone derivatives is as follows:

[0005] (1) In 1970, Petropoulos et al. reported the tandem reaction of benzopyran derivatives with ammonia to synthesize 7-aminocoumarin derivatives (J Heterocyclic Chem, 7(5), 1061-1069; 1970.).

[0006]

[0007] (2) In 1990, Truscott et al. synthesized 7-aminocoumarin derivatives using 3-hydroxy-2-aminobenzoic acid as a raw material via intramolecular free radical coupling reaction (J. Org. Chem., 55; 4581-4585, 1990.);

[0008]

[0009] (3) In 2006, Henkel et al. synthesized 7-aminocoumarin derivatives by reacting 4-hydrothiopheno[3,4-c]benzopyran with acetylacetic acid esters through a series of reactions (Tetrahedron, 62, 7121-7131, 2006.).

[0010]

[0011] (4) In 2019, Baidya et al. synthesized 7-amino coumarin derivatives using benzopyran derivatives as raw materials and a series of reactions with cyclopentene 1,3 dione derivatives (Adv. Synth. Catal, 361(23), 5472-5477, 2019.).

[0012]

[0013] These methods also have complex synthesis steps, and the activity and application method of the product are not clear. SUMMARY

[0014] In view of the deficiencies of the prior art, the purpose of the present application is to provide a 7-amino coumarin derivative and a synthesis method and application thereof. The synthesis method is easy to obtain raw materials, simple to operate and friendly to the environment. The synthesized 7-amino coumarin derivative can be used as an antibacterial agent.

[0015] In order to achieve the above purpose, the following technical solutions are adopted:

[0016] A 7-amino coumarin derivative, the structural general formula is shown as formula (I):

[0017]

[0018] In formula (I), R includes any one of hydrogen, methoxy or halogen.

[0019] Preferably, the structural general formula includes formula (I-1), (I-2) or (I-3) as shown below:

[0020]

[0021] In the formula, R1 is hydrogen or methoxy; R2 is methyl, chlorine or bromine; and R3 is methyl, methoxy, fluorine or chlorine.

[0022] Further, the structural formula includes any one of the following formulas:

[0023]

[0024] The present application also protects a synthesis method of the 7-amino coumarin derivative as described above, comprising the following steps:

[0025] The substituted 3-cyano-4-methyl coumarin and 20% Dabco by volume are placed in a thick-walled pressure tube containing a stirrer, tetrahydrofuran solvent is added, then dimethyl acetylene dicarboxylate is slowly added in stoichiometric ratio under stirring at room temperature, after the reaction is completed, the solvent is removed under reduced pressure, and column chromatography separation is carried out to obtain 7-amino coumarin derivative;

[0026] The structural formula of the substituted 3-cyano-4-methyl coumarin includes:

[0027] or or

[0028] wherein R1 is hydrogen or methoxy; R2 is methyl, chlorine or bromine; and R3 is methyl, methoxy, fluorine or chlorine.

[0029] Preferably, the reaction time is 3 hours.

[0030] The application also protects the use of the 7-aminocoumarin derivative as an antibacterial agent.

[0031] Preferably, the antibacterial agent is used for preventing and treating potato dry rot, brassica black stem, tomato gray mold and apple rot.

[0032] Compared with the prior art, the application has the following technical effects:

[0033] The synthesis method of the 7-aminocoumarin derivative has the following technical key points: 3-cyano-4-methyl coumarin and chain acetylene ester are used, a cheap reaction solvent is selected, Dabco is selected as a catalyst, and the 7-aminocoumarin derivative is directly synthesized by one-pot method; the method has the advantages of flexible reaction time, cheap and easily available solvent, simple operation and wide application range, and is suitable for industrial production.

[0034] The 7-aminocoumarin derivative has certain inhibitory effect on potato dry rot fungus, brassica black stem fungus, tomato gray mold fungus and apple rot fungus, and can be used as an antibacterial agent. DETAILED DESCRIPTION

[0035] The specific content of the application is further explained and described in detail below in combination with examples.

[0036] Example 1

[0037] 3-cyano-4-methyl coumarin (0.1 mmol, 1.0 eq) and Dabco (0.02 mmol, 0.2 eq) are placed in a thick-walled pressure tube with a stirrer, 1 mL of tetrahydrofuran is added, then dimethyl butyne diacid (0.3 mmol, 3.0 eq) is slowly added under stirring, TLC is used to monitor the reaction, after the reaction is completed, the solvent is removed under reduced pressure, and column chromatography is carried out with a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate is 3:1) as the eluent to obtain 7-aminocoumarin derivative a (18 mg, yield 55%). The reaction equation is as follows:

[0038]

[0039] The structure of the obtained 7-aminocoumarin derivative a was identified by nuclear magnetic resonance and high resolution mass spectrometry, 1 H NMR (600 MHz, CDC13) δ 7.74 (dd, J = 12.6, 5.3 Hz, 1H), 7.67 (d, J = 8.0 Hz, 1H), 7.46 - 7.38 (m, 1H), 3.91 (s, 3H), 3.61 (s, 3H). 13 C NMR (151 MHz, CDC13) δ 169.39, 165.08, 158.43, 156.02, 153.73, 135.99, 135.15, 131.21, 127.69, 125.78, 117.78, 116.55, 112.59, 101.58, 53.14, 52.37, 34.19. ESI-HRMS: calcd. for C 17 H 13 NO6+Na, 350.0641, found 350.0642. The obtained 7-aminocoumarin derivative has the structure shown in formula a.

[0040] Example 2

[0041] 3-cyano-4-methyl-7-fluorocoumarin (0.1 mmol, 1.0 eq) and Dabco (0.02 mmol, 0.2 eq) were placed in a thick-walled pressure tube with a stir bar, 1 mL of tetrahydrofuran was added, then dimethyl acetylene dicarboxylate (0.3 mmol, 3.0 eq) was slowly added under stirring, TLC was used to monitor the reaction, after the reaction was completed, the solvent was removed under reduced pressure, and column chromatography was carried out with a mixture of petroleum ether and ethyl acetate (volume ratio of petroleum ether to ethyl acetate was 3:1) as the eluent to obtain 7-aminocoumarin derivative b (22 mg, yield 65%). The reaction equation is as follows:

[0042]

[0043] The structure of the obtained 7-aminocoumarin derivative b was identified by nuclear magnetic resonance and high resolution mass spectrometry, 1 H NMR (600 MHz, CDC13) δ 7.74 (dd, J = 12.6, 5.3 Hz, 1H), 7.67 (d, J = 8.0 Hz, 1H), 7.46 - 7.38 (m, 1H), 3.91 (s, 3H), 3.61 (s, 3H). 13C NMR (151 MHz, CDC13) δ 169.36, 164.93, 157.90, 155.37, 153.71, 135.52, 130.81, 129.34, 128.57, 121.07, 115.51, 112.41, 101.55, 53.21, 52.45, 34.15, 18.27. ESI-HRMS: calcd for C17H 13 FNO6+Na, 368.0546, found 368.0543. The 7-aminocoumarin derivative obtained was shown to have the structure shown in formula b.

[0044] Example 3

[0045] A thick-walled pressure tube containing a stir bar was charged with 3-cyano-4-methyl-7-methoxycoumarin (0.1 mmol, 1.0 eq) and Dabco (0.02 mmol, 0.2 eq), 1 mL of tetrahydrofuran was added, then dimethyl butyne dicarboxylate (0.3 mmol, 3.0 eq) was slowly added under stirring, TLC was used to monitor the reaction, after the reaction was completed, the solvent was removed under reduced pressure, and column chromatography was performed with a mixture of petroleum ether and ethyl acetate (3:1 by volume) as the eluent to obtain 7-aminocoumarin derivative c (18 mg, yield 50%). The reaction equation is as follows:

[0046]

[0047] The structure of the 7-aminocoumarin derivative c obtained above was identified by nuclear magnetic resonance and high resolution mass spectrometry, 1 H NMR (600 MHz, CDC13) δ 7.72 (s, 1H), 7.55 (d, J = 8.9 Hz, 1H), 6.93 (dd, J = 8.9, 2.4 Hz, 1H), 6.87 (d, J = 2.4 Hz, 1H), 3.94 (d, J = 1.8 Hz, 3H), 3.90 (s, 3H), 3.63 (s, 3H). 13 C NMR (151 MHz, CDC13) δ 169.56, 168.23, 166.23, 165.16, 158.11, 156.24, 134.72, 131.64, 128.99, 114.38, 110.15, 101.38, 97.28, 56.30, 53.08, 52.35, 34.13, 28.79. ESI-HRMS: calcd for C 18 H 15 NO7+Na, 380.0746, found 380.0739. The 7-aminocoumarin derivative obtained was shown to have the structure shown in formula c.

[0048] Example 4

[0049] The 3-cyano-4,7-dimethylcoumarin (0.1 mmol, 1.0 eq) and Dabco (0.02 mmol, 0.2 eq) were placed in a thick-walled pressure tube with a stir bar, 1 mL of tetrahydrofuran was added, then dimethyl butyne dicarboxylate (0.3 mmol, 3.0 eq) was slowly added under stirring, the reaction was monitored by TLC, after the reaction was completed, the solvent was removed under reduced pressure, and column chromatography was carried out with a mixture of petroleum ether and ethyl acetate (3:1 by volume) as the eluent to obtain 7-aminocoumarin derivative d (16 mg, yield 48%). The reaction equation is as follows:

[0050]

[0051] The structure of the obtained 7-aminocoumarin derivative d was identified by nuclear magnetic resonance and high-resolution mass spectrometry, 1 H NMR (600 MHz, CDC13) δ 7.93 (s, 1H), 7.64 (t, J = 8.4 Hz, 1H), 7.00 (d, J = 8.3 Hz, 1H), 6.81 (d, J = 8.4 Hz, 1H), 3.92 (s, 3H), 3.88 (s, 3H), 3.58 (s, 3H). 13 C NMR (151 MHz, CDC13) δ 169.10, 164.90, 157.35, 155.38, 152.06, 135.80, 131.50, 130.40, 126.84, 119.22, 117.56, 112.23, 102.71, 53.26, 52.53, 34.32. ESI-HRMS: calcd. for C 18 H 15 NO6+Na, 364.0797, found 364.0801. It was shown that the obtained 7-aminocoumarin derivative had the structure shown in formula d.

[0052] Example 5

[0053] The 3-cyano-4-methyl-7-chloro-coumarin (0.1 mmol, 1.0 eq) and Dabco (0.02 mmol, 0.2 eq) were placed in a thick-walled pressure tube with a stir bar, 1 mL of tetrahydrofuran was added, then dimethyl butyne dicarboxylate (0.3 mmol, 3.0 eq) was slowly added under stirring, the reaction was monitored by TLC, after the reaction was completed, the solvent was removed under reduced pressure, and column chromatography was carried out with a mixture of petroleum ether and ethyl acetate (3:1 by volume) as the eluent to obtain 7-amino-coumarin derivative e (25 mg, yield 68%). The reaction equation is as follows:

[0054]

[0055] The structure of the obtained 7-amino-coumarin derivative e was identified by nuclear magnetic resonance and high resolution mass spectrometry, 1 H NMR (600 MHz, CDC13) δ 7.69 (d, J = 35.9 Hz, 1H), 7.62 (d, J = 8.5 Hz, 1H), 7.55-7.41 (m, 1H), 7.39 (t, J = 16.7 Hz, 1H), 3.89 (s, J = 28.1 Hz, 3H), 3.77-3.31 (s, 3H). 13 C NMR (151 MHz, CDC13) δ 169.38, 164.94, 157.78, 155.44, 153.94, 142.47, 135.50, 130.83, 128.62, 126.49, 118.08, 115.17, 112.37, 101.33, 53.21, 52.45, 34.15. ESI-HRMS: calcd. for C 17 H 12 ClNO6+Na, 384.0251, found 384.0251. It was shown that the obtained 7-amino-coumarin derivative had the structure shown in formula e.

[0056] Example 6

[0057] The 3-cyano-4-methyl-5-chloro-coumarin (0.1 mmol, 1.0 eq) and Dabco (0.02 mmol, 0.2 eq) were placed in a thick-walled pressure tube with a stir bar, 1 mL of tetrahydrofuran was added, then dimethyl butyne dicarboxylate (0.3 mmol, 3.0 eq) was slowly added under stirring, the reaction was monitored by TLC, after the reaction was completed, the solvent was removed under reduced pressure, and column chromatography was carried out with a mixture of petroleum ether and ethyl acetate (3:1 by volume) as the eluent to obtain 7-amino-coumarin derivative f (19 mg, yield 52%). The reaction equation is as follows:

[0058]

[0059] The structure of the obtained 7-aminocoumarin derivative f was identified by nuclear magnetic resonance and high resolution mass spectrometry, 1 H NMR (600 MHz, CDC13) δ 7.74 (dd, J = 12.6, 5.3 Hz, 1H), 7.67 (d, J = 8.0 Hz, 1H), 7.46 - 7.38 (m, 1H), 3.94 (d, J = 1.8 Hz, 3H), 3.91 (s, 3H), 3.61 (s, 3H). 13 C NMR (151 MHz, CDC13) δ 169.36, 164.93, 157.90, 155.37, 153.71, 135.52, 130.81, 129.34, 128.57, 121.07, 115.51, 112.41, 101.55, 53.21, 52.45, 34.15, 29.64, 18.27. ESI-HRMS: calcd. for C 18 H 15 NO7+Na, 380.0746, found 380.0749. It was shown that the obtained 7-aminocoumarin derivative had the structure shown in formula f.

[0060] Example 7

[0061] 3-cyano-4-methyl-6-bromocoumarin (0.1 mmol, 1.0 eq) and Dabco (0.02 mmol, 0.2 eq) were placed in a thick-walled pressure tube with a stir bar, 1 mL of tetrahydrofuran was added, then dimethyl butyne dicarboxylate (0.3 mmol, 3.0 eq) was slowly added under stirring, TLC was used to monitor the reaction, after the reaction was completed, the solvent was removed under reduced pressure, and column chromatography was carried out with a mixture of petroleum ether and ethyl acetate (volume ratio of petroleum ether to ethyl acetate was 3:1) as the eluent to obtain 7-aminocoumarin derivative g (19 mg, yield 52%). The reaction equation is as follows:

[0062]

[0063] The structure of the obtained 7-aminocoumarin derivative g was identified by nuclear magnetic resonance and high resolution mass spectrometry, 1 H NMR (600 MHz, CDC13) δ 7.72 (s, 1H), 7.62 (s, 1H), 7.53 (s, 2H), 3.91 (s, 3H), 3.63 (s, 3H). 13C NMR (151 MHz, CDC13) δ 169.36, 164.93, 157.90, 155.37, 153.71, 135.52, 130.81, 130.79, 129.34, 128.57, 121.07, 115.51, 112.41, 101.55, 53.21, 52.45, 34.15. ESI-HRMS: calcd. for C 17 H 12 BrNO6+Na, 427.9746, found 427.9760. The 7-aminocoumarin derivative obtained was shown to have the structure shown in formula g.

[0064] Example 8

[0065] The 3-cyano-4-methyl-6-chlorocoumarin (0.1 mmol, 1.0 eq) and Dabco (0.02 mmol, 0.2 eq) were placed in a thick-walled pressure tube with a stir bar, 1 mL of tetrahydrofuran was added, then dimethyl acetylene dicarboxylate (0.3 mmol, 3.0 eq) was slowly added under stirring, TLC monitoring of the reaction, after the reaction was completed, the solvent was removed under reduced pressure, and column chromatography was carried out with a mixture of petroleum ether and ethyl acetate (petroleum ether and ethyl acetate volume ratio was 3:1) as the eluent to obtain 7-aminocoumarin derivative h (16 mg, yield 45%). The reaction equation is as follows:

[0066]

[0067] The structure of the 7-aminocoumarin derivative h obtained above was identified by nuclear magnetic resonance and high resolution mass spectrometry, 1 H NMR (600 MHz, CDC13) δ 7.70 (s, 1H), 7.44 (d, J = 4.5 Hz, 2H), 7.36 (d, J = 7.9, 2.6 Hz, 1H), 3.92 (s, 3H), 3.64 (s, 3H). 13 C NMR (151 MHz, CDC13) δ 169.10, 164.90, 157.35, 155.38, 152.06, 135.80, 131.50, 130.40, 126.84, 119.22, 117.56, 112.23, 102.71, 53.26, 52.53, 34.32. ESI-HRMS: calcd. for C 17 H 12 ClNO6+Na, 384.0251, found 384.0260. The 7-aminocoumarin derivative obtained was shown to have the structure shown in formula h.

[0068] Example 9

[0069] The 3-cyano-4,6-dimethylcoumarin (0.1 mmol, 1.0 eq) and Dabco (0.02 mmol, 0.2 eq) were placed in a thick-walled pressure tube with a stir bar, 1 mL of tetrahydrofuran was added, then dimethyl acetylene dicarboxylate (0.3 mmol, 3.0 eq) was slowly added under stirring, TLC monitoring reaction, after the reaction was completed, the solvent was removed under reduced pressure, and column chromatography was carried out with a mixture of petroleum ether and ethyl acetate (volume ratio of petroleum ether to ethyl acetate was 3:1) as the eluent to obtain 7-aminocoumarin derivative i (15 mg, yield 43%). The reaction equation is as follows:

[0070]

[0071] The structure of the obtained 7-aminocoumarin derivative i was identified by nuclear magnetic resonance and high resolution mass spectrometry, 1 H NMR (600 MHz, CDC13) δ 7.75 (s, 1H), 7.53 (d, J = 8.2 Hz, 1H), 7.42 (s, 1H), 7.32 (d, J = 8.5 Hz, 1H), 3.92 (s, 3H), 3.63 (s, 3H), 2.42 (s, 3H). 13 C NMR (151 MHz, CDC13) δ 169.45, 165.16, 158.29, 156.26, 151.93, 137.12, 135.94, 135.03, 131.34, 127.20, 117.49, 116.23, 112.73, 101.38, 53.12, 52.33, 34.26, 20.77. ESI-HRMS: calcd. for C 18 H 15 NO6+Na, 364.0797, found 364.0806. The obtained 7-aminocoumarin derivative has the structure shown in formula i.

[0072] The antibacterial properties of some products were tested as follows:

[0073] 1. Antifungal activity determination process:

[0074] Preparation of PDA medium: PDA medium (potato 20 g, glucose 20 g, agar 20 g, water 100 mL) was weighed with a hundredth scale, 37.0 mg, dissolved in 1000 mL of boiling water, stirred until completely melted without flocculent solid, then according to the experimental requirements, hotly divided into conical flask, ready for use.

[0075] Activation of plant pathogenic fungi: The plant pathogenic fungi strains stored in 4°C refrigerator were taken out and placed in a clean bench. The pathogenic fungi were inoculated in the center of PDA medium which had been sterilized by high pressure. After inoculation, the medium was placed in a mold incubator (25°C) for 3-5 days. When the colony growth area covered 2 / 3 of the plate, the fungi were ready for use.

[0076] Preparation of the drug solution: 5.0 mg of the test drug was accurately weighed on a 1 / 10,000 balance in a brown reagent bottle. Then 0.5 mL of DMSO and 9.5 mL of sterile water were added in sequence. The solution was completely dissolved. 0.5 mL of DMSO and 9.5 mL of sterile water were used as a negative control.

[0077] Inoculation: The sterilized culture dishes and other standby items were promptly transferred to a clean bench. 10 mL of the drug solution was poured into the culture medium and mixed well. Then it was quickly poured into the culture dish to ensure that about 15 mL of the drug solution medium mixture was poured into each dish, so that the final concentration of the medium was about 50 μg / mL. The dish was placed flat and allowed to solidify. At the same time, the colony punch was performed. The colonies were selected as much as possible to be in a similar growth state. The puncher was used to punch (diameter 0.5 cm). After the medium solidified, the colonies were picked with an inoculation needle. Three places of the same strain were inoculated in an equilateral triangle form in each culture dish to ensure the accuracy of the test results. After the inoculation was completed, the culture dishes were placed in a mold incubator for culture. The culture conditions were set as follows: 25°C, culture for 48-72 h.

[0078] Measurement and calculation: The diameter of the colony was measured by the cross method.

[0079] Calculation of mycelial growth inhibition rate: Mycelial growth inhibition rate (%) = (dc-ds) / (dc-5) x 100%

[0080] 2. Antifungal performance

[0081] As shown in Table 1, 7-amino coumarin derivatives a, c, d, and h have inhibitory activity against four fungi, i.e., potato dry rot (Fusarium oxysporum Schlecht), rape black foot (Leptosphaeria biglobosa), tomato gray mold (Botrytis cinerea), and apple rot (Valsa ceratosperma). In particular, a has good inhibitory activity against tomato gray mold, c has good inhibitory activity against apple rot, d has good inhibitory activity against rape black foot, and h has good inhibitory activity against potato dry rot.

[0082] Table 1 Inhibitory effect of different 7-amino coumarin derivatives on four plant pathogenic fungi

[0083]

[0084] Finally, it should be pointed out that the amount of reaction raw materials in the present application is not strictly limited, and generally, the reaction is carried out according to the stoichiometric ratio of chemical reaction, or one of the compounds can be in excess.

[0085] The amount of reaction solvent and catalyst in the present application is not strictly limited, and can be adjusted according to the amount of reaction raw materials: if the amount of reaction raw materials is more, the amount of reaction solvent and catalyst is increased, and if the amount of reaction raw materials is less, the amount of reaction solvent and catalyst is reduced.

[0086] The above examples are only used to illustrate the technical solutions of the present application but not to limit it, and although the present application has been described in detail with reference to the above examples, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered in the scope of the present claims.

Claims

1. A 7-aminocoumarin derivative, characterized in that, The general structural formula is shown in equation (I): In formula (I), R includes either methoxy or halogen.

2. The 7-aminocoumarin derivative according to claim 1, characterized in that, The general structural formulas include the following formulas (I-1), (I-2), or (I-3); Wherein, R1 is methoxy; R2 is chlorine or bromine; R3 is methoxy, fluorine or chlorine; Its structural formula includes:

3. A method for synthesizing the 7-aminocoumarin derivative according to claim 1 or 2, characterized in that, Includes the following steps: The substituted 3-cyano-4-methylcoumarin and 0.2 eq of Dabco were placed in a thick-walled pressure-resistant tube containing a stir bar, tetrahydrofuran solvent was added, and then dimethyl butynedioate was slowly added under stirring according to the stoichiometric ratio for a room temperature reaction. After the reaction was completed, the solvent was removed under reduced pressure, and the 7-aminocoumarin derivative was obtained by column chromatography. The substituted 3-cyano-4-methylcoumarin has the following structural formula: Wherein, R1 is methoxy; R2 is chlorine or bromine; and R3 is methoxy, fluorine, or chlorine.

4. The method for synthesizing the 7-aminocoumarin derivative according to claim 3, characterized in that, The reaction time is 3 hours.

5. The application of a 7-aminocoumarin derivative according to claim 1 or 2 as an antibacterial agent for preventing potato rot, rapeseed blackleg, tomato gray mold, and apple rot.

Images