Benzo alpha-pyrone imine derivative, preparation method thereof and application of benzo alpha-pyrone imine derivative as antifungal agent

Abstract

The invention discloses a benzo alpha-pyrone imine derivative, a preparation method thereof and application of the benzo alpha-pyrone imine derivative as an antifungal agent. Amino coumarin is used as a basic raw material, and under the action of a catalyst, various benzo alpha-pyrone imine derivatives are synthesized in one step through an aldehyde amine condensation reaction. Tests show that the benzo alpha-pyrone imine derivative disclosed by the invention has antibacterial activity, and particularly, part of compounds have excellent antifungal activity. Therefore, the compound has the potential of serving as a novel plant source pesticide antifungal agent, and lays a foundation for developing novel plant source pesticides.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical drug synthesis of coumarin derivatives, and more particularly to benzo alpha-pyrone imine derivatives and a preparation method thereof and application thereof as antifungal agents. Background Art

[0002] Plant fungal diseases can seriously harm crops, causing symptoms such as fruit rot, trunk rot, and branch wilting. According to statistics, serious crop economic losses caused by plant pathogenic fungi amount to 40 million US dollars each year, accounting for about 20% to 40% of the total production losses of major crops in the world. At present, the most economical and effective way to prevent and control plant diseases caused by various pathogens is still the large-scale use of chemical fungicides. However, with the extensive use of chemical pesticides, the drug resistance of plant pathogens has gradually increased. Therefore, it is urgent to find fungicides with new chemical structure fragments, broad spectrum and high efficiency.

[0003] Natural products not only have good biocompatibility and biodegradability, but also have structural diversity and a wide range of biological activities. Using natural products or their derivatives as lead compounds is a reliable way to discover new fungicides. Coumarin, as one of the important natural products, occupies an important position in medicinal chemistry and has been shown to have a variety of significant pharmacological properties and biological activities. Coumarin derivatives can be used as drugs for the treatment of diseases such as cancer, inflammation, neurodegenerative diseases and thromboembolic diseases, and can also be used to prepare antifungal and bacterial drugs. In addition, some coumarin-based drugs have been launched on the market, including neomycin, warfarin, osthole, etc. Therefore, coumarins with structural diversity can be considered as important candidates for the development of highly effective fungicides. Schiff bases are called imine compounds because of the -CH=N- functional group in their structure. They have been shown to have a wide range of pharmacological and biological activities.

[0004] Therefore, coumarin was used as the parent compound and derivatized using the imine structure in order to obtain lead compounds that can be used as potential antifungal agents, providing a certain research basis for the preparation of highly efficient agricultural fungicides. Summary of the invention

[0005] In order to solve the problems in the prior art, the present invention proposes a benzo α-pyrone imine derivative, a preparation method thereof and an application thereof as an antifungal agent. The present invention uses aminocoumarin as a basic raw material, synthesizes a variety of benzo α-pyrone imine derivatives in one step through an aldehyde-amine condensation reaction, and on this basis, uses 4 common plant pathogenic fungi as receptor fungi for activity screening, and uses a mycelium growth rate method to measure the activity of the obtained compounds, and finds that the benzo α-pyrone imine derivatives of the present invention have antibacterial activity, especially some compounds have excellent antifungal activity, and can be used as antifungal drugs.

[0006] One of the purposes of the present invention is to provide a benzo α-pyrone imine derivative, wherein the benzo α-pyrone imine derivative is selected from the compounds shown in the following structural formula:

[0007]

[0008] Wherein, R1 in Formula A, Formula A-1, Formula B-1 and Formula B is independently selected from -H, -OH, halogen, substituted or unsubstituted C1-C 20 The alkyl group;

[0009] R2 in Formula A, Formula A-1, Formula B-1, and Formula B is independently selected from -H, halogen;

[0010] R3 in Formula A, Formula A-1, Formula B-1, and Formula B is independently selected from -H, halogen, aryl, C1-C 20 The alkyl group;

[0011] R4 in formula A and formula B is independently selected from -H, halogen, C1-C 20 The alkyl group;

[0012] R5 in formula A and formula B is independently selected from -H, halogen;

[0013] R6 in Formula B-1 and Formula B are each independently selected from C1-C 10 of alkyl.

[0014] Among the benzo α-pyrone imine derivatives described in the present invention, preferably,

[0015] The substituted or unsubstituted C1-C 20 The alkyl groups are each independently selected from halogen-substituted or unsubstituted C1-C 10 alkyl; preferably a halogen-substituted or unsubstituted C1-C5 alkyl; further preferably a halogen-substituted or unsubstituted C1-C3 alkyl; wherein the halogen is -F; and / or,

[0016] C1-C in R3 in Formula A, Formula A-1, Formula B-1, Formula B 20 The alkyl groups are each independently selected from C1-C 10 preferably an unsubstituted C1-C5 alkyl group; further preferably an unsubstituted C1-C3 alkyl group; and / or,

[0017] C1-C in R4 in Formula A and Formula B 20 The alkyl groups are each independently selected from C1-C 10 preferably an unsubstituted C1-C5 alkyl group; further preferably an unsubstituted C1-C3 alkyl group; and / or,

[0018] R6 in Formula B-1 and Formula B is independently selected from a C1-C5 alkyl group; preferably a C1-C3 alkyl group; and more preferably a methyl group.

[0019] Among the benzo α-pyrone imine derivatives described in the present invention, preferably,

[0020] The halogen in R1, R2, R3, R4, and R5 is independently selected from -F, -Cl, and -Br; and / or,

[0021] Preferably,

[0022] R1 in Formula A, Formula A-1, Formula B-1 and Formula B is independently selected from -H, -OH, -Br, -Cl or a halogen-substituted or unsubstituted C1-C3 alkyl group; preferably -CF3; and / or,

[0023] R2 in Formula A, Formula A-1, Formula B-1, and Formula B is independently selected from -H, -Br; and / or,

[0024] R3 in Formula A, Formula A-1, Formula B-1, and Formula B is independently selected from -H, -Cl, -F, phenyl, C1-C3 alkyl; preferably -CH3; and / or,

[0025] R4 in formula A and formula B is independently selected from -H, -Br, -Cl, -F, C1-C3 alkyl; preferably -CH3; and / or,

[0026] R5 in Formula A and Formula B is independently selected from -H and -Cl.

[0027] Among the benzo α-pyrone imine derivatives described in the present invention, preferably,

[0028] Two or three of the R1, R2, R3, R4, and R5 in Formula A and Formula B are hydrogen;

[0029] Two or three of the R1, R2, and R3 in Formula A-1 and Formula B-1 are hydrogen;

[0030] Preferably, at least one of R1, R2, R3, R4, and R5 in Formula A or Formula B is -OH, and / or at least one of R1, R2, R3, R4, and R5 in Formula A or Formula B is halogen; and / or

[0031] In formula A-1 and formula B-1, two of R1, R2 and R3 are hydrogen, and the remaining substituent is a C1-C3 alkyl, phenyl or halogen.

[0032] Among the benzo α-pyrone imine derivatives described in the present invention, preferably,

[0033] In Formula A, Formula A-1, Formula B, and Formula B-1, R1 is -OH, and one or two of R2, R3, R4, and R5 are halogens; the halogens are each independently selected from -F, -Cl, and -Br; and / or,

[0034] In Formula A, Formula A-1, Formula B, and Formula B-1, R1 is -Br or -Cl, and at least one of R2, R3, R4, and R5 is H or F; and / or,

[0035] In Formula A, Formula A-1, Formula B, and Formula B-1, R1 is -CF3, and only one of R2, R3, R4, and R5 is -Cl or H;

[0036] In formula A and formula B, R1 is H, and at least two of R2, R3, R4, and R5 are halogens; and the halogens are each independently selected from -F, -Cl or -Br.

[0037] Among the benzo α-pyrone imine derivatives described in the present invention, preferably,

[0038] The halogen in R1, R2, R3, R4, and R5 in Formula A, Formula A-1, Formula B-1, and Formula B is independently selected from -Cl, -Br, and -F;

[0039] More preferably, R1 in Formula A, Formula A-1, Formula B, and Formula B-1 is -OH, -H, -Cl, -Br, substituted or unsubstituted C1-C 20 Alkyl; preferably -CH3, -CF3; and / or,

[0040] R2 in Formula A, Formula A-1, Formula B, and Formula B-1 is -H or -Br; and / or,

[0041] In formula A, formula A-1, formula B, and formula B-1, R3 is -H, -PH, -Cl, -F, unsubstituted C1-C 20 preferably -CH3; and / or,

[0042] R4 in Formula A, Formula A-1, Formula B, and Formula B-1 is -H, or -Cl, -Br, or -F; and / or,

[0043] R5 in Formula A, Formula A-1, Formula B, and Formula B-1 is -H or -Cl; and / or,

[0044] In the benzo α-pyrone imine derivatives described in the present invention, preferably, at least one of R1, R2, R3, R4, and R5 in Formula A and Formula B is -OH, and / or, at least one of R1, R2, R3, R4, and R5 is halogen; further preferably, the halogens are independently selected from -F, -Cl, and -Br.

[0045] In the benzo α-pyrone imine derivatives described in the present invention, preferably, in the formula A, formula A-1, formula B, and formula B-1, R1 is -OH, and at least one of the R2, R3, R4, and R5 is -OH, -CH3, or halogen; further preferably, the halogens are each independently selected from -F, -Cl, and -Br.

[0046] Preferably, in Formula A, Formula A-1, Formula B, and Formula B-1, R1 is -OH, and one or two of R2, R3, R4, and R5 are halogen; and / or,

[0047] The R1 is -Br or -Cl, and at least one of the R2, R3, R4, and R5 is H or F; preferably, the R1 is -CF3, and only one of the R2, R3, R4, and R5 is -Cl or H; preferably, the R1 is -CH3, and only one of the R2, R3, R4, and R5 is H; and / or,

[0048] Preferably, in Formula A and Formula B, R1 is H, and at least two of R2, R3, R4, and R5 are halogens; the halogens are -F, -Cl, or -Br; and / or,

[0049] The benzo α-pyrone imine derivative is selected from the compounds shown in the following structural formula:

[0050]

[0051] The second object of the present invention is to provide a method for preparing the benzo α-pyrone imine derivative described in one of the objects of the present invention, comprising the following steps:

[0052] Under the action of a catalyst, reacting a substrate with a compound represented by formula [3] or formula [4] in a solvent to obtain the benzo α-pyrone imine derivative;

[0053] The substrate is 3-aminocoumarin or 7-amino-4-methylcoumarin;

[0054] The compound represented by formula [3] is Wherein, R1, R2, R3, R4, and R5 in the formula [3] correspond to R1, R2, R3, R4, and R5 in the benzo α-pyrone imine derivative described in one of the objectives of the present invention;

[0055] The compound represented by formula [4] is Wherein, R1, R2, and R3 in the formula [4] correspond to R1, R2, and R3 in the benzo α-pyrone imine derivative described in one of the objectives of the present invention.

[0056] In the method for preparing the coumarin benzo α-pyrone imine derivative of the present invention, preferably,

[0057] The catalyst is selected from at least one of acetic acid, acetic anhydride and triethylamine; and / or,

[0058] The solvent is selected from alcohol solvents, preferably at least one of methanol or ethanol; and / or,

[0059] The compound represented by formula [3] is selected from the following compounds:

[0060]

[0061] and / or,

[0062] The compound represented by formula [4] is selected from the following compounds:

[0063]

[0064] Preferably,

[0065] The molar ratio of the substrate to the compound represented by formula [3] or formula [4] is 1:1-2; for example, preferably 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2 and any parameter range between the above two values; and / or,

[0066] The molar volume ratio of the substrate to the solvent is 1 mmol:(5-50) mL; and / or, for example, preferably 1 mmol:5 mL, 1 mmol:10 mL, 1 mmol:20 mL, 1 mmol:30 mL, 1 mmol:40 mL, 1 mmol:50 mL and any parameter range between the above two values; and / or,

[0067] The molar volume ratio of the substrate to the catalyst is 1 mmol: (0.01-0.5) mL; for example, preferably 1 mmol: 0.01 mL, 1 mmol: 0.02 mL, 1 mmol: 0.03 mL, 1 mmol: 0.04 mL, 1 mmol: 0.05 mL, 1 mmol: 0.2 mL, 1 mmol: 0.3 mL, 1 mmol: 0.4 mL, 1 mmol: 0.5 mL and any parameter range between the above two values; and / or,

[0068] The reaction temperature is 70-85°C; for example, preferably 70, 72, 74, 76, 78, 80, 82, 84, 85°C and any parameter range between the above two values; and / or,

[0069] The reaction time is 6 to 12 hours; for example, preferably 6, 7, 8, 9, 10, 11, 12 hours and any parameter range between the above two values.

[0070] In the method for preparing the coumarin benzo α-pyrone imine derivative of the present invention, preferably,

[0071] First, the substrate is dissolved in an alcohol solvent at room temperature, and then the compound shown in formula C is added, and then a catalyst is added, and the temperature is increased to start the reaction to obtain the iminocoumarin compound.

[0072] In the method for preparing the benzo α-pyrone imine derivative of the present invention, most preferably, the method comprises:

[0073] The substrate, i.e., 3-aminocoumarin or 7-amino-4-methylcoumarin, is fully dissolved in a solvent under the assistance of ultrasound at room temperature, a compound represented by formula [3] or formula [4] is added, and a catalyst is added dropwise thereto for catalysis; the temperature is then raised for reaction for 6-12 hours, during which the degree of reaction is monitored by thin layer chromatography. After the reaction is completed, the precipitate produced in the reaction is separated, rinsed with methanol or ethanol solution for multiple times, and dried to obtain a benzo α-pyrone imine derivative (imine coumarin compound).

[0074] The third object of the present invention is to provide a benzo α-pyrone imine derivative as described in the first object of the present invention or a benzo α-pyrone imine derivative prepared by the method described in the second object of the present invention in antibacterial use;

[0075] Preferably, when used as an antifungal agent, the agent is preferably a plant pathogenic fungus, and more preferably used in the development of antifungal drugs for at least one of Botrytis cinerea, Altemaria solani, Fusarium oxysporum or Alternaria alternata.

[0076] The third object of the present invention is to provide a plant antibacterial agent, characterized in that it includes the benzo α-pyrone imine derivative prepared by the method described in the object of the present invention or the benzo α-pyrone imine derivative prepared by the method described in the second object of the present invention.

[0077] The endpoints and any values ​​of the scope disclosed in the present invention are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, the endpoint values ​​of each scope, the endpoint values ​​of each scope and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this article. Hereinafter, in principle, each technical solution can be combined with each other to obtain a new technical solution, which should also be regarded as specifically disclosed in this article.

[0078] Compared with the prior art, the present invention has the following advantages:

[0079] The benzo α-pyrone imine derivatives of the present invention are simple to synthesize, have a small molecular weight, and have good in vitro antifungal activity. They have different degrees of inhibitory effects on all tested fungi. In particular, some compounds have excellent antifungal activity against Botrytis cinerea, Alternaria alternata, and Fusarium oxysporum, and are even superior to commercial fungicides chlorothalonil and osthole, which proves that the compounds have the potential to be used as new botanical pesticide antibacterial agents, and can also be used as lead structures for developing antifungal drugs, laying a foundation for the development of new botanical pesticides. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 This is a graph showing the in vivo antifungal activity test of benzo α-pyrone imine derivatives. DETAILED DESCRIPTION

[0080] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0081] It should also be noted that the various specific technical features described in the following specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0082] In addition, the various embodiments of the present invention may be arbitrarily combined as long as they do not violate the concept of the present invention. The technical solutions thus formed belong to part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0083] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0084] (I) The method for synthesizing benzo α-pyrone imine derivatives is as follows:

[0085] Example 1

[0086] Compound 1a: 3-((2-hydroxy-4-fluorophenyl)imino)coumarin

[0087]

[0088] 3-Aminocoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-hydroxy-4-fluorobenzaldehyde (104 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85 ° C for reflux reaction. TLC spot plate was used for monitoring during the reaction. The reaction was stopped after 8 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a yellow solid with a yield of 83% and a melting range of 210-213 ° C.

[0089] Example 2

[0090] Compound 1b: 3-((3-bromo-4-fluorophenyl)imino)coumarin

[0091]

[0092] 3-Aminocoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 3-bromo-4-fluorobenzaldehyde (151 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 10 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a light green solid with a yield of 53% and a melting range of 209-212°C.

[0093] Example 3

[0094] Compound 1c: 3-((2-bromo-4-fluorophenyl)imino)coumarin

[0095]

[0096] 3-Aminocoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-bromo-4-fluorobenzaldehyde (151 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85 ° C for reflux reaction. TLC spot plate was used for monitoring during the reaction. The reaction was stopped after 7 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a light green solid with a yield of 58% and a melting range of 171-174 ° C.

[0097] Example 4

[0098] Compound 1d: 3-((2-Hydroxy-5-bromophenyl)imino)coumarin

[0099]

[0100] 3-Aminocoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-hydroxy-5-bromobenzaldehyde (150 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. TLC spot plate was used for monitoring during the reaction. The reaction was stopped after 7 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a yellow solid with a yield of 63% and a melting range of 210-214°C.

[0101] Example 5

[0102] Compound 1e: 3-((2-hydroxy-5-chlorophenyl)imino)coumarin

[0103]

[0104] 3-Aminocoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-hydroxy-5-chlorobenzaldehyde (117 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 6 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a yellow solid with a yield of 69% and a melting range of 164-168°C.

[0105] Example 6

[0106] Compound 1f: 3-((2-Hydroxy-5-fluorophenyl)imino)coumarin

[0107]

[0108] 3-Aminocoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-hydroxy-5-fluorobenzaldehyde (104 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85 ° C for reflux reaction. TLC spot plate was used for monitoring during the reaction. The reaction was stopped after 8 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a yellow solid with a yield of 67% and a melting range of 234-237 ° C.

[0109] Example 7

[0110] Compound 1g: 3-((2-hydroxy-4,6-dichlorophenyl)imino)coumarin

[0111]

[0112] 3-Aminocoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-hydroxy-4,6-dichlorobenzaldehyde (142 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 6 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a yellow solid with a yield of 55% and a melting range of 214-219°C.

[0113] Example 8

[0114] Compound 1h: 3-((2-thiophene)imino)coumarin

[0115]

[0116] 3-Aminocoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-thiophenecarboxaldehyde (83 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. TLC spot plate was used for monitoring during the reaction. The reaction was stopped after 10 h of reaction. A precipitate was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a light green solid with a yield of 85% and a melting range of 143-146°C.

[0117] Example 9

[0118] Compound 1i: 3-((5-phenyl-2-thiophene)imino)coumarin

[0119]

[0120] 3-Aminocoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 5-phenyl-2-thiophenecarboxaldehyde (140 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85 ° C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 10 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a light green solid with a yield of 75% and a melting range of 178-181 ° C.

[0121] Example 10

[0122] Compound 1j: 3-((2-hydroxy-4-methylphenyl)imino)coumarin

[0123]

[0124] 3-Aminocoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-hydroxy-4-methylbenzaldehyde (101 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85 ° C for reflux reaction. TLC spot plate was used for monitoring during the reaction. The reaction was stopped after 9 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a light yellow solid with a yield of 88% and a melting range of 188-192 ° C.

[0125] Embodiment 11

[0126] Compound 1k: 3-((2-Hydroxy-5-methylphenyl)imino)coumarin

[0127]

[0128] 3-Aminocoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-hydroxy-5-methylbenzaldehyde (101 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 10 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a light yellow solid with a yield of 86% and a melting range of 210-213°C.

[0129] Example 12

[0130] Compound 2a: 7-((5-chloro-2-trifluoromethylphenyl)imino)-4-methylcoumarin

[0131]

[0132] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2,4-dihydroxy-5-chlorobenzaldehyde (143 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 8 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a white solid with a yield of 78% and a melting range of 148-152°C.

[0133] Example 13

[0134] Compound 2b: 7-((4-fluoro-2-hydroxyphenyl)imino)-4-methylcoumarin

[0135]

[0136] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 4-fluoro-2-hydroxybenzaldehyde (96 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 7 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain an orange-yellow solid with a yield of 86% and a melting range of 201-204°C.

[0137] Embodiment 14

[0138] Compound 2c: 7-((2-bromo-4-fluorophenyl)imino)-4-methylcoumarin

[0139]

[0140] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-bromo-4-fluorobenzaldehyde (139 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85 ° C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 9 hours of reaction. It was observed that a precipitate was precipitated in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a light green solid with a yield of 54% and a melting range of 176-179 ° C.

[0141] Embodiment 15

[0142] Compound 2d: 7-((2-chloro-4-fluorophenyl)imino)-4-methylcoumarin

[0143]

[0144] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-chloro-4-fluorobenzaldehyde (109 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 10 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a light green solid with a yield of 60% and a melting range of 168-173°C.

[0145] Example 16

[0146] Compound 2e: 7-((3-bromo-4-fluorophenyl)imino)-4-methylcoumarin

[0147]

[0148] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 3-bromo-4-fluorobenzaldehyde (139 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. TLC spot plate was used for monitoring during the reaction. The reaction was stopped after 9 hours of reaction. A precipitate was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a light green solid with a yield of 55% and a melting range of 162-167°C.

[0149] Embodiment 17

[0150] Compound 2f: 7-((2-Hydroxy-5-bromophenyl)imino)-4-methylcoumarin

[0151]

[0152] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-hydroxy-5-bromobenzaldehyde (138 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 7 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a light yellow solid with a yield of 55% and a melting range of 245-249°C.

[0153] Embodiment 18

[0154] Compound 2g: 7-((2-hydroxy-5-chlorophenyl)imino)-4-methylcoumarin

[0155]

[0156] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-hydroxy-5-chlorophenylbenzaldehyde (107 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 6 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a light yellow solid with a yield of 70% and a melting range of 243-247°C.

[0157] Embodiment 19

[0158] Compound 2h: 7-((2-Hydroxy-5-fluorophenyl)imino)-4-methylcoumarin

[0159]

[0160] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-hydroxy-5-fluorobenzaldehyde (96 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. TLC spot plate was used for monitoring during the reaction. The reaction was stopped after 6 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a light yellow solid with a yield of 75% and a melting range of 214-218°C.

[0161] Embodiment 20

[0162] Compound 2i: 7-((4-bromo-2-thienyl)imino)-4-methylcoumarin

[0163]

[0164] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 4-bromo-2-thiophenecarboxaldehyde (131 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 10 h of reaction. A precipitate was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a brown solid with a yield of 55% and a melting range of 174-177°C.

[0165] Embodiment 21

[0166] Compound 2j: 7-((5-phenyl-2-thienyl)imino)-4-methylcoumarin

[0167]

[0168] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 5-phenyl-2-thiophenecarboxaldehyde (129 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 9 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a yellow solid with a yield of 58% and a melting range of 152-154°C.

[0169] Embodiment 22

[0170] Compound 2k: 7-((5-methyl-2-thienyl)imino)-4-methylcoumarin

[0171]

[0172] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 5-methyl-2-thiophenecarboxaldehyde (86 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 10 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a yellow solid with a yield of 54% and a melting range of 135-140°C.

[0173] Embodiment 23

[0174] Compound 21: 7-((2-hydroxy-4-methylphenyl)imino)-4-methylcoumarin

[0175]

[0176] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 5,2-hydroxy-4-methylbenzaldehyde (93 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 10 h of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a yellow solid with a yield of 68% and a melting range of 225-227°C.

[0177] Embodiment 24

[0178] Compound 2m: 7-((2-hydroxy-5-methylphenyl)imino)-5-methylcoumarin

[0179]

[0180] 7-Amino-4-methylcoumarin (100 mg, 1 mmol) was dissolved in 10 mL of anhydrous methanol, and then 2-hydroxy-5-methylbenzaldehyde (93 mg, 1.2 mmol) was added. After sufficient dissolution with the assistance of ultrasound, 0.02 mL of glacial acetic acid was added dropwise. After stirring at room temperature, the mixture was heated to 85°C for reflux reaction. The reaction was monitored by TLC spot plate. The reaction was stopped after 10 hours of reaction. Precipitation was observed in the reaction bottle. The precipitate was filtered, rinsed with methanol several times and dried to obtain a yellow solid with a yield of 72% and a melting range of 233-234°C.

[0181] (II) Spectral data of synthesized benzo-α-pyrone imine derivatives

[0182] Using modern spectroscopy technology, nuclear magnetic resonance hydrogen spectrum (1 H NMR) and carbon nuclear magnetic resonance spectroscopy ( 13 C NMR) was used to characterize the structures of the synthesized compounds.

[0183] 1. Compound 1a

[0184] 1 H NMR (600MHz, CDCl3) δ9.46(s,1H),7.70(s,1H),7.60–7.52(m,2H),7.44–7.31(m,3H),6.72–6.64(m,2H).

[0185] 13 C NMR (150MHz, CDCl3) δ166.55,164.03,158.26,152.50,135.56,134.78,131.9 2,131.71,128.43,125.34,119.89,116.83,107.89,107.73,104.91,104.76.

[0186] 2. Compound 1b

[0187] 1 H NMR (600MHz, CDCl3) δ9.21 (s, 1H), 8.11 (d, J = 8.6Hz, 1H), 7.87–7.81 (m, 2H), 7.70(s,1H),7.58–7.50(m,2H),7.37(d,J=8.2Hz,1H),7.22(d,J=8.2Hz,1H).

[0188] 13 C NMR (150MHz, CDCl3) δ163.59,161.18,152.12,148.98,135.13,134.21,133.8 1,131.90,131.17,130.17,127.93,125.01,121.09,117.33,116.10,110.80.

[0189] 3. Compound 1c

[0190] 1 H NMR (600MHz, CDCl3) δ9.48(s,1H),7.98(d,J=8.5Hz,1H),7.60(s,1H),7.32–7.29(m,2H),7.27(d,J=2.5Hz,1H),7.21–7.18(m,2H),7.10(s,1H).

[0191] 13C NMR (150MHz, CDCl3) δ167.07,165.35,159.85,152.63,149.38,132.70,131. 97,131.2,128.27,126.96,125.41,124.96,121.51,120.99,116.50,115.60.

[0192] 4. Compound 1d

[0193] 1 H NMR (600MHz, CDCl3) δ12.97(s,1H),9.46(s,1H),7.75(s,1H),7.59(d,J=9.8Hz,1H),7.58–7.55( m,2H),7.47(d,J=8.9Hz,1H),7.39(d,J=7.9Hz,1H),7.34(t,J=8.2Hz,1H),6.92(d,J=8.9Hz,1H).

[0194] 13 C NMR (150MHz, DMSO-d6) δ163.56,159.69,152.33,138.85,136.57,133.53,131.78,130.95,128.97,125.30,125.18,119.65,116.40,110.64.

[0195] 5. Compound 1e

[0196] 1 H NMR (600MHz, DMSO-d6) δ10.97(s,1H),9.22(s,1H),7.59(s,1H),7.55(d,J=8.8Hz,1H),7.41( t,J=7.3Hz,1H),7.27(d,J=7.8Hz,1H),7.24–7.19(m,2H),7.03(d,J=8.7Hz,1H),6.71(s,1H). 13 C NMR(150MHz,DMSO-d6)δ159.77,157.94,148.17,136.03,133.60,127.66, 125.62,125.09,124.78,123.75,123.61,122.08,119.80,115.71,107.91.

[0197] 6. Compound 1f

[0198] 1H NMR (600MHz, CDCl3) δ12.73(s,1H),9.47(s,1H),7.75(s,1H),7.57(t,J=9.4Hz,2H),7.41–7.31(m,2H),7.19–7.09(m,2H),6.97(d,J=4.5Hz,1H).

[0199] 13 C NMR(150MHz,DMSO-d6)δ163.10,157.20,156.10,155.41,153.85,151.48,13 3.39,130.91,130.17,128.12,124.45,121,120.47,119.03,117.80,115.55.

[0200] 7. Compound 1g

[0201] 1 H NMR (600MHz, CDCl3) δ9.88(s,1H),7.73(s,1H),7.57(t,J=8.3Hz,2H),7.39(d,J=8.1Hz,1H),7.34(t,J=7.5Hz,1H),7.26(s,1H),6.97(s,1H).

[0202] 13 C NMR (150MHz, CDCl3) δ164.01,163.85,157.96,152.74,140.14,137.90,134.7 6,132.30,131.72,128.62,125.41,121.05,119.65,117.35,116.95,115.37.

[0203] 8. Compound 1h

[0204] 1 H NMR (600MHz, DMSO-d6) δ9.18(s,1H),8.04(s,1H),7.41(d,J=6.8Hz,1H),7.33(d,J=4.5Hz,1H),7.28–7.25(m,2H),7.23–7.19(m,3H).

[0205] 13 C NMR (150MHz, DMSO-d6) δ158.64,147.89,143.54,138.01,136.15,133.32,128.99,125.34,124.82,124.50,121.80,115.43,107.64.

[0206] 9. Compound 1i

[0207] 1 H NMR (600MHz, CDCl3) δ9.46 (s, 1H), 7.80–7.68 (m, 2H), 7.68–7.65 (m, 3H), 7.51 (t, J = 7.9Hz, 1H), 7.43–7.38 (m, 5H), 7.19 (d, J = 5.5Hz, 1H).

[0208] 13 C NMR (150 MHz, CDCl3) δ 159.34, 156.94, 154.23, 148.95, 142.38, 137.34, 132.97, 131.90, 129.37, 129.13, 129.02, 128.63, 127.79, 126.53, 126.36, 124.99, 124.54, 124.02, 121.10, 116.07.10. Compound 1j

[0209] 1 H NMR (600MHz, DMSO-d6) δ12.70(s,1H),9.16(s,1H),8.06(s,1H),7.74(d,J=9.4Hz,1H),7.60(t,J=7.0Hz,1 H),7.55(d,J=7.5Hz,1H),7.45(d,J=8.3Hz,1H),7.40(d,J=6.3Hz,1H),6.83(d,J=9.5Hz,2H),2.34(s,3H).

[0210] 13 C NMR(151MHz,DMSO-d6)δ164.99,160.43,157.69,151.64,147.35,144.80,132.16, 130.91,129.18,128.24,125.14,120.55,120.39,119.38,116.89,115.79,21.30.

[0211] 11. Compound 1k

[0212] 1H NMR(600MHz,DMSO-d6)δ12.31(s,1H),9.16(s,1H),8.05(s,1H),7.74(d,J=9.4Hz,1H),7.63–7.57 (m,1H),7.47–7.44(m,2H),7.39(d,J=8.5Hz,1H),7.26(s,1H),6.89(d,J=8.4Hz,1H),2.28(s,3H).

[0213] 13 C NMR(150MHz,DMSO-d6)δ165.45,158.55,158.04,152.09,148.14,132.13,131.38, 129.90,129.14,128.70,128.23,125.10,122.02,119.26,116.93,116.21,20.12.

[0214] 12. Compound 2a

[0215] 1 H NMR (600MHz, DMSO-d6) δ7.94–7.77(m,2H),7.72(d,J=8.6Hz,1H),7.54(d,J=8.6Hz,1H ),7.48(d,J=8.0Hz,1H),6.78(d,J=8.4Hz,1H),6.67(s,1H),6.05(s,1H),2.34(s,3H).

[0216] 13 C NMR(150MHz,DMSO-d6)δ160.64,155.20,153.78,150.13,139.88,138.21,129.40,127.9 1,126.44,125.77,125.56,124.80,122.98,110.95,109.34,98.71,81.80,54.34,18.17.

[0217] 13. Compound 2b

[0218] 1 H NMR (600MHz, CDCl3) δ9.84 (s, 1H), δ8.62 (s, 1H), 7.65 (d, J = 8.3Hz, 1H), 7.42 (t, J = 7.5Hz, 1H) ,7.24–7.16(m,2H),6.74(d,J=10.5Hz,1H),6.70(t,J=8.4Hz,1H),6.29(s,1H),2.46(s,3H).

[0219] 13 C NMR (150MHz, CDCl3) δ165.86,163.78,161.00,154.86,152.30,151.65,135. 02,126.02,118.98,118.64,114.98,109.04,107.97,107.82,104.85,19.08.

[0220] 14. Compound 2c

[0221] 1 H NMR (600MHz, CDCl3) δ8.79(s,1H),8.27(d,J=7.6Hz,1H),7.62(d,J=8.2Hz,1H),7.39(d,J=7.9Hz,1H),7.18–7.13(m,3H),6.26(s,1H),2.45(s,3H).

[0222] 13 C NMR (150MHz, CDCl3) δ165.41,160.98,159.92,154.52,152.25,127.03,126.97,125.55,120.58,118.28,117.97,115.80,114.38,108.98,18.85.

[0223] 15. Compound 2d

[0224] 1 H NMR (600MHz, CDCl3) δ8.85 (s, 1H), 8.29 (d, J = 6.5Hz, 1H), 7.62 (d, J = 8.2Hz, 1H), 7.20(d,J=8.3Hz,1H),7.16–7.13(m,2H),7.12(s,1H),6.26(s,1H),2.45(s,3H).

[0225] 13 C NMR (150MHz, CDCl3) δ165.33,160.79,157.43,154.30,152.74,152.05,137.47,1 31.55,130.50,129.11,118.05,117.69,117.21,115.12,114.16,108.79,18.64.

[0226] 16. Compound 2e

[0227] 1H NMR (600MHz, CDCl3) δ8.38(s,1H),8.19(d,J=6.7Hz,1H),7.84(s,1H),7.62(d,J =8.8Hz,1H),7.35(d,J=8.3Hz,1H),7.16–7.05(m,2H),6.26(s,1H),2.45(s,3H).

[0228] 13 C NMR (150MHz, CDCl3) δ163.56,160.81,160.34,152.09,150.20,135.11,130. 08,130.03,125.71,125.36,118.00,117.73,116.84,114.12,111.57,18.65.

[0229] 17. Compound 2f

[0230] 1 H NMR (600MHz, CDCl3) δ10.94(s,1H),8.59(s,1H),7.66(d,J=8.2Hz,1H),7.56(s,1H),7. 50(d,J=6.3Hz,1H),7.24–7.19(m,2H),6.96(d,J=8.8Hz,1H),6.30(s,1H),2.47(s,3H). 13 C NMR (150MHz, CDCl3) δ163.49,160.92,161,154.81,151.38,137.01,135.07 ,126.10,120.18,119.83,119.27,118.51,115.17,111.22,109.28,19.10.

[0231] 18. Compound 2g

[0232] 1 H NMR (600MHz, CDCl3) δ12.78 (s, 1H), 8.59 (s, 1H), 7.66 (d, J = 7.5Hz, 1H), 7.44–7 .35(m,2H),7.24–7.18(m,2H),7.01(d,J=8.3Hz,1H),6.30(s,1H),2.47(s,3H).

[0233] 13C NMR (150MHz, DMSO-d6) δ163.17,158.67,153.69,133.20,131,126.32,122.63,120.58,118.62,118.12,113.62,108.57,17.95.

[0234] 19. Compound 2h

[0235] 1 H NMR (600MHz, CDCl3) δ12.57(s,1H),8.60(s,1H),7.66(d,J=8.2Hz,1H),7.25–7.15( m,3H),7.14(d,J=3.0Hz,1H),7.01(dd,J=8.9,4.4Hz,1H),6.30(s,1H),2.47(s,3H).

[0236] 13 C NMR (150MHz, CDCl3) δ163.75,160.95,157.80,156.76,152.28,151.51,126. 06,121.76,121.61,119.19,119.04,118.98,118.53,115.11,109.24,19.10.

[0237] 20. Compound 2i

[0238] 1 H NMR (600MHz, CDCl3) δ8.50 (s, 1H), 7.60 (d, J = 8.4Hz, 1H), 7.46 (d, J = 2.0Hz, 2H), 7.16–7.10 (m, 2H), 6.26 (s, 1H), 2.44 (s, 3H). 13 C NMR (150MHz, CDCl3) δ161.21,154.73,153.47,152.46,150.61,135.45,132.53,128.91,125.75,118.56,118.37,114.61,112.00,108.97,19.05.

[0239] 21. Compound 2j

[0240] 1H NMR (600MHz, CDCl3) δ8.55 (s, 1H), 7.70–7.66 (m, 3H), 7.60 (d, J = 8.4Hz, 1H), 7. 45–7.39(m,4H),7.17(d,J=8.3Hz,1H),7.14(s,1H),6.24(s,1H),2.44(s,3H).

[0241] 13 C NMR (150MHz, CDCl3) δ160.95,154.54,154.43,152.14,150.41,150.19,137.34,134.63,129.13,1 29.06,128.76,126.36,126.08,125.71,125.23,123.80,118.18,113.88,111.57,108.45,18.63.

[0242] 22. Compound 2k

[0243] 1 H NMR (600MHz, CDCl3) δ9.34 (s, 1H), 7.59 (d, J = 3.7Hz, 1H), 7.51–7.47 (m, 2H), 7.2 0(d,J=5.8Hz,1H),6.81(d,J=3.6Hz,1H),6.70(s,1H),2.57(s,3H),2.55(s,3H).

[0244] 13 C NMR (150MHz, CDCl3) δ161.42,153.20,152.61,151.99,150.64,142.33,137. 63,127.39,127.01,126.14,118.58,118.00,114.18,112.00,19.05,16.45.

[0245] 23. Compound 21

[0246] 1 H NMR (600MHz, DMSO-d6) δ12.66(s,1H),9.00(s,1H),7.84(d,J=8.4Hz,1H),7.58(d,J=7. 7Hz,1H),7.46–7.39(m,2H),6.85–6.79(m,2H),6.38(s,1H),2.46(s,3H),2.34(s,3H).

[0247] 13C NMR(150MHz,DMSO-d6)δ165.00,160.53,159.93,154.03,153.80,153.11,144.96,1 29.79,126.50,120.83,121,118.48,118.09,117.33,117.05,113.66,21.57,18.21.

[0248] 24. Compound 2m

[0249] 1 H NMR (400MHz, DMSO-d6) δ12.31(s,1H),8.95(s,1H),7.81(d,J=8.4Hz,1H),7.44–7.36(m, 2H),7.26(d,J=8.6Hz,1H),6.89(d,J=8.3Hz,1H),6.36(s,1H),2.44(s,3H),2.28(s,3H). 13 C NMR(101MHz,DMSO-d6)δ164.88,159.83,158.17,153.87,152.98,151.65,134.76,132 .27,127.91,126.38,118.98,118.35,118.03,116.57,113.59,108.53,19.91,18.12.

[0250] A series of benzo α-pyrone imine derivatives synthesized in the above examples were subjected to antifungal tests, as follows:

[0251] (III) In vitro antifungal activity of benzo-α-pyrone imine derivatives

[0252] 1. Test bacteria used in the experiment

[0253] Table 1

[0254]

[0255] The above four standard strains were used in this part of the experiment. The 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 through Gary Chemical Network, Shanghai Bo Ke Biotechnology Co., Ltd., etc.

[0256] 2. Preparation of PDA medium

[0257] Weigh about 200g of fresh potatoes, peel and cut into long strips of equal thickness, put into 1000mL distilled water heated to boiling state, and stir with a glass rod. After the potatoes are completely soft, filter the filtrate into a 1000mL beaker with medical gauze and make up the volume with distilled water. Then heat the filtrate, add glucose (20g / 1000mL distilled water) and agar powder (18g / 1000mL distilled water) in turn, and stir with a glass rod. After the agar is completely dissolved, add distilled water to the required amount. Finally, the prepared culture medium is respectively placed in 500mL conical flasks, completely sealed with newspapers, and sterilized in an autoclave for 20min before use.

[0258] 3. Preparation of benzo α-pyrone imine derivative solution

[0259] First, 10 mg of the compound to be tested was dissolved in 1000 μL of dimethyl sulfoxide (DMSO) solution, and then ultrasonic vibration was applied to completely dissolve the compound solution, and the solution was sterilized under ultraviolet sterilization lamp for 30 minutes.

[0260] 4. Experimental Procedure

[0261] In a double-person single-sided clean bench, take 10mL of PDA culture medium and place it in a culture dish, add 100μL of the prepared benzo α-pyrone imine derivative solution, shake well and place it horizontally to cool, then use a 0.7cm diameter puncher to take the edge cakes of the four test colonies and inoculate them into the center of the new culture medium, with three groups repeated in each group. At the same time, use 100μL of dimethyl sulfoxide (DMSO) as a blank control, and thiophanate-methyl and osthole as positive controls. After the inoculation is completed, seal it with a sealing film and invert it in a 25℃ constant temperature incubator.

[0262] Finally, after 72 hours, the colony diameter was measured by the cross method, and the average value was calculated to calculate the antibacterial rate of the compound. The formula for mycelium growth inhibition rate is as follows:

[0263]

[0264] I: Inhibition rate of compound on fungi, d o : Diameter of mushroom cake, d c : colony diameter in blank medium, ds: colony diameter in compound-treated medium.

[0265] 5. Measurement results

[0266] The above-mentioned mycelium growth rate method was used to determine the inhibitory activity of the synthetic benzo α-pyrone imine derivatives against four common plant pathogens: Botrytis cinerea, Alternaria solani, Fusarium oxysporum and Alternaria alternata. The experimental results are shown in Table 2.

[0267] Table 2

[0268]

[0269]

[0270] Table 2

[0271]

[0272] Note: In Table 2, higher values ​​represent higher antibacterial activity, and negative values ​​represent that the compounds have a growth-promoting effect on fungi.

[0273] The results in Table 2 show that most compounds have good inhibitory activity against Staphylococcus cinerea at a concentration of 100ug / mL. In particular, compounds 1a (93.24%), 1e (63.75%), 1f (88.13%), 2b (100%), 2h (93.16%), 2i (62.58%) and 2k (60.11%) have an inhibitory effect on Botrytis cinerea of ​​more than 60%. Among them, the antibacterial activity of compounds 1a, 2b and 2h all reached the agricultural fungicide level of the positive control thiophanate-methyl (88.20%), which is significantly better than osthole (29.60%). Compounds 1a (100%) and 2b (93.26%) have significant anti-Fusarium oxysporum activity, and the antibacterial activity is much higher than that of agricultural fungicides thiophanate-methyl (80.25%) and osthole (39.60%). Compounds 2j (82.7%), 1g (63.13%) and 2a (56.43%) have good inhibitory activity against Alternaria alternata, with an inhibition rate of more than 50%. In addition, compound 2j has high inhibitory activity against Alternaria alternata and Alternaria solani, with inhibition rates of 82.70% and 64.05%, respectively, which are higher than osthole (60.20% and 43.70%).

[0274] Subsequently, we determined the antibacterial rates of compounds 1a, 1f, 2b, 2h, and 2j at concentrations of 100, 50, 25, 12.5, and 6.25 μg / mL, and repeated the experiment three times in parallel. The EC values ​​of the compounds were calculated using SPSS 27.0 software based on the concentration-dependent curves. 50 The test data are shown in Table 3.

[0275] Table 3

[0276]

[0277] The results in Table 3 show that all tested compounds exhibited excellent antifungal activity. Compounds 1a, 1f, 2b and 2h exhibited good antifungal activity against Botrytis cinerea, with EC 50The values ​​were 0.92, 5.60, 0.52 and 4.79 μg / mL, respectively. Compounds 1a and 2b also had strong antibacterial activity against Fusarium oxysporum, with EC 50 The values ​​were 7.85 and 8.47 μg / mL, respectively. Compound 2j showed strong antifungal activity against Alternaria alternata, with EC 50 The value was 5.60 μg / mL. Among all the compounds, compound 2b showed the best antifungal activity and can be considered as a lead structure of a potential fungicide. In addition, these compounds EC 50 Value of R 2 All of them were greater than 0.99, indicating that there was a strong correlation between the compound concentration and the antibacterial effect.

[0278] (IV) In vivo antifungal activity of benzo-α-pyrone imine derivatives

[0279] Compound 2b with different concentrations (400, 200, 100 μg / mL) was selected to evaluate its in vivo inhibitory activity against Botrytis cinerea on Korla pear. First, suitable pears were selected and randomly divided into 4 groups, with 3 pears in each group. After rinsing with water, the surface of the pear was wiped with 80% alcohol. Then, a hole with a diameter of 5 mm and a depth of 2 mm was drilled at the equator of each pear, and dimethyl sulfoxide (DMSO) solutions of compound 2b with different concentrations (400, 200 and 100 μg / mL) were added to the hole. Then, after natural drying under sterile conditions, pear mycelium with a diameter of 5 mm was placed in the hole. Finally, the pears were cultured at 25°C for 9 days, and the size of the lesions was observed. DMSO solution was used as a negative control. The results are shown in Figure 1 As shown in Table 4

[0280] Table 4

[0281]

[0282] The results in Table 4 show that compound 2b can effectively inhibit the effect of Botrytis cinerea on Korla pear, and the inhibitory activity increases with the increase of concentration. When the concentration of compound 2b is 200 μg / mL, the growth of Botrytis cinerea on Korla pear can be completely inhibited within 9 days after treatment, and the inhibition rate can reach 92.25%.

[0283] In general, some of the benzo α-pyrone imine derivatives synthesized by the present invention have excellent performance in inhibiting plant pathogenic fungi. The in vitro antifungal activity shows that the compounds have a strong broad spectrum and a significant antifungal effect, which is even stronger than the agricultural fungicides chlorothalonil and osthole. The in vivo antifungal activity shows that compound 2b can well inhibit the growth of fungi in Korla pear at a concentration of 200 μg / mL, and the inhibition rate can reach 92.25%. All these prove that this type of compound has the potential to be a new type of botanical pesticide antifungal agent, laying a foundation for the development of new botanical pesticides.

[0284] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0285] 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 conventionally understood by those skilled in the art. In the event of a conflict, the definition in this specification shall prevail.

[0286] When this specification uses the prefix "well-known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, etc., the objects introduced by the prefix cover those commonly used in the art when this application is filed, but also include those that are not commonly used at present but will become recognized in the art as being suitable for similar purposes.

[0287] In the context of the present specification, any matters or items not mentioned are directly applicable to those known in the art without any changes except those explicitly stated.

Claims

1. A benzo α-pyrone imine derivative, wherein the benzo α-pyrone imine derivative is selected from the compounds represented by the following structural formula: in, R1 in Formula A, Formula A-1, Formula B-1, and Formula B is independently selected from -H, -OH, halogen, substituted or unsubstituted C1-C 20 The alkyl group; R2 in Formula A, Formula A-1, Formula B-1, and Formula B is independently selected from -H, halogen; R3 in Formula A, Formula A-1, Formula B-1, and Formula B is independently selected from -H, halogen, aryl, C1-C 20 The alkyl group; R4 in formula A and formula B is independently selected from -H, halogen, C1-C 20 The alkyl group; R5 in formula A and formula B is independently selected from -H, halogen; R6 in Formula B-1 and Formula B are each independently selected from C1-C 10 of alkyl.

2. The benzo-α-pyrone imine derivative according to claim 1, characterized in that: The substituted or unsubstituted C1-C 20 The alkyl groups are each independently selected from halogen-substituted or unsubstituted C1-C 10 alkyl; preferably a halogen-substituted or unsubstituted C1-C5 alkyl; further preferably a halogen-substituted or unsubstituted C1-C3 alkyl; wherein the halogen is -F; and / or, C1-C in R3 in Formula A, Formula A-1, Formula B-1, Formula B 20 The alkyl groups are each independently selected from C1-C 10 preferably an unsubstituted C1-C5 alkyl group; further preferably an unsubstituted C1-C3 alkyl group; and / or, C1-C in R4 in Formula A and Formula B 20 The alkyl groups are each independently selected from C1-C 10 preferably an unsubstituted C1-C5 alkyl group; further preferably an unsubstituted C1-C3 alkyl group; and / or, R6 in Formula B-1 and Formula B is independently selected from a C1-C5 alkyl group; preferably a C1-C3 alkyl group; and more preferably a methyl group.

3. The benzo α-pyrone imine derivative according to claim 1, characterized in that: The halogen in R1, R2, R3, R4, and R5 is independently selected from -F, -Cl, and -Br; and / or, Preferably, R1 in Formula A, Formula A-1, Formula B-1 and Formula B is independently selected from -H, -OH, -Br, -Cl or halogen substituted or unsubstituted C 1- C3 alkyl; preferably -CF3; and / or, R2 in Formula A, Formula A-1, Formula B-1, and Formula B is independently selected from -H, -Br; and / or, R3 in Formula A, Formula A-1, Formula B-1, and Formula B is independently selected from -H, -Cl, -F, phenyl, C1-C3 alkyl; preferably -CH3; and / or, R4 in formula A and formula B is independently selected from -H, -Br, -Cl, -F, C1-C3 alkyl; preferably -CH3; and / or, R5 in Formula A and Formula B is independently selected from -H and -Cl.

4. The benzo α-pyrone imine derivative according to claim 1, characterized in that: Two or three of the R1, R2, R3, R4, and R5 in Formula A and Formula B are hydrogen; Two or three of the R1, R2, and R3 in Formula A-1 and Formula B-1 are hydrogen; Preferably, at least one of R1, R2, R3, R4, and R5 in Formula A or Formula B is -OH, and / or at least one of R1, R2, R3, R4, and R5 in Formula A or Formula B is halogen; and / or In formula A-1 and formula B-1, two of R1, R2 and R3 are hydrogen, and the remaining substituent is a C1-C3 alkyl, phenyl or halogen.

5. The benzo α-pyrone imine derivative according to claim 1, characterized in that: In Formula A, Formula A-1, Formula B, and Formula B-1, R1 is -OH, and one or two of R2, R3, R4, and R5 are halogens; the halogens are each independently selected from -F, -Cl, and -Br; and / or, In Formula A, Formula A-1, Formula B, and Formula B-1, R1 is -Br or -Cl, and at least one of R2, R3, R4, and R5 is H or F; and / or, In Formula A, Formula A-1, Formula B, and Formula B-1, R1 is -CF3, and only one of R2, R3, R4, and R5 is -Cl or H; In formula A and formula B, R1 is H, and at least two of R2, R3, R4, and R5 are halogens; and the halogens are each independently selected from -F, -Cl or -Br.

6. The benzo α-pyrone imine derivative according to claim 1, characterized in that The benzo α-pyrone imine derivative is selected from the compounds shown in the following structural formula:

7. A method for preparing a benzo α-pyrone imine derivative according to any one of claims 1 to 6, characterized in that: The following steps are involved: Under the action of a catalyst, reacting a substrate with a compound represented by formula [3] or formula [4] in a solvent to obtain the benzo α-pyrone imine derivative; The substrate is 3-aminocoumarin or 7-amino-4-methylcoumarin; The compound represented by formula [3] is Wherein, R1, R2, R3, R4, and R5 in the formula [3] correspond to R1, R2, R3, R4, and R5 in the benzo α-pyrone imine derivative according to any one of claims 1 to 6; The compound represented by formula [4] is Wherein, R1, R2, and R3 in the formula [4] are the same as R in the benzo α-pyrone imine derivative according to any one of claims 1 to 6. 1 , R 2 , R 3 The corresponding same.

8. The method for preparing a benzo-α-pyrone imine derivative according to claim 7, characterized in that: The catalyst is selected from at least one of acetic acid, acetic anhydride or triethylamine; and / or, The solvent is selected from alcohol solvents, preferably at least one of methanol or ethanol; and / or, The compound represented by formula [3] is selected from the following compounds: and / or, The compound represented by formula [4] is selected from the following compounds: Preferably, The molar ratio of the substrate to the compound represented by formula [3] or formula [4] is 1:1-2; and / or, The molar volume ratio of the substrate to the solvent is 1 mmol: (5-50) mL; and / or, The molar volume ratio of the substrate to the catalyst is 1 mmol: (0.01-0.5) mL; and / or, The reaction temperature is 70-85°C; and / or, The reaction time is 6 to 12 hours.

9. Use of the benzo α-pyrone imine derivative according to any one of claims 1 to 6 or the benzo α-pyrone imine derivative prepared by the method according to any one of claims 7 to 8 in antibacterial treatment; Preferably, when used as an antibacterial agent, the antibacterial agent is preferably plant pathogenic fungi, and more preferably, the antibacterial agent is used in an antibacterial drug for at least one of Botrytis cinerea, Alternaria solani, Fusarium oxysporum or Alternaria alternata.

10. A plant antibacterial agent, characterized in that: The invention comprises the benzo α-pyrone imine derivative according to any one of claims 1 to 6 or the benzo α-pyrone imine derivative prepared by the method according to any one of claims 7 to 8.

Images