Sulfuryl fluorocoumarin compound as well as preparation method and application thereof

Abstract

The invention discloses a sulfuryl fluorocoumarin compound as well as a preparation method and application thereof. The sulfuryl fluorocoumarin compound has broad-spectrum and efficient bactericidal activity, particularly has better antibacterial activity on plant pathogenic bacteria, and has better control effect on diseases caused by the plant pathogenic bacteria.

Description

Technical Field

[0001] The present invention belongs to the technical field of agricultural bactericides, and more specifically, relates to sulfuryl fluoride coumarin compounds and preparation methods and applications thereof. Background Art

[0002] Plant bacterial diseases are diseases caused by plant infection by pathogens. The global rice yield loss caused by plant bacterial diseases that are difficult to cure has seriously restricted the development of agricultural products and has seriously endangered food security. At present, although a variety of molecular structures can be obtained by chemical means, the development of new pesticides based on natural products is still one of the important methods. Many natural products have complex structures and excellent biological activities, showing good application prospects in the development of drugs / agricultural chemicals. In addition, natural products have antibacterial mechanisms different from existing antibacterial drugs. Therefore, the development of pesticides with novel structures and new mechanisms of action by transforming or modifying the structures of natural products is still one of the most effective ways to develop new pesticides.

[0003] For a long time, the activity of sulfuryl fluoride derivatives has not been studied. Recently, Ravindar et al. took advantage of the relative chemical stability of sulfuryl fluoride derivatives and made some unique modifications to retain the sulfuryl fluoride functional group to study their antibacterial activity. They synthesized a series of sulfuryl fluoride derivatives and conducted in vitro antibacterial activity tests, and found that they showed strong antibacterial activity against Staphylococcus aureus. Subsequently, Zhang Jiong et al. successfully synthesized a series of sulfuryl fluoride derivatives using the SuFEx reaction, most of which showed rapid bactericidal efficacy and selective killing of Gram-positive strains. Exploring more compounds with bactericidal activity against plant pathogenic bacteria based on sulfuryl fluoride derivatives has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] Based on the above existing technical problems, the primary purpose of the present invention is to provide a class of sulfuryl fluoride coumarin compounds. The sulfuryl fluoride coumarin compounds have broad-spectrum and high-efficiency fungicidal activity, especially good antibacterial activity against plant pathogenic bacteria, and have good prevention and control effects on diseases caused by them.

[0005] The second object of the present invention is to provide a method for preparing sulfuryl fluoride coumarin compounds.

[0006] The third object of the present invention is to provide an agricultural composition.

[0007] The fourth object of the present invention is to provide the use of the above-mentioned sulfuryl fluoride coumarin compound or the agricultural composition in the preparation of a medicine or bactericide for controlling plant pathogenic bacteria.

[0008] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0009] The present invention seeks to protect a sulfuryl fluoride coumarin compound, the structure of which is shown in formula (I):

[0010]

[0011] In the formula, R1 is monosubstituted or polysubstituted, and R1 is independently selected from hydrogen, C 1-8 Alkyl, halogen or C 1-8 Alkoxy;

[0012] R2 is selected from hydrogen, halogen, C 1-8 alkyl.

[0013] In some embodiments, R1 is monosubstituted or polysubstituted, and R1 is independently selected from hydrogen, C 1-6 Alkyl, fluorine, chlorine, bromine, iodine or C 1-6 Alkoxy; R2 is selected from hydrogen, fluorine, chlorine, bromine, C 1-6 alkyl.

[0014] In some embodiments, the structure of the sulfuryl fluoride coumarin compound is as shown in formula (II):

[0015]

[0016] In the formula,

[0017] R2 is selected from hydrogen, C 1-4 alkyl;

[0018] R3 is selected from hydrogen, C 1-4 alkyl;

[0019] R4 is selected from chloro, methyl, butyl, tert-butyl;

[0020] R5 is selected from hydrogen, fluorine, chlorine, bromine, C 1-4 Alkyl, C 1-4 Alkoxy;

[0021] R6 is selected from hydrogen, fluorine, chlorine, and bromine.

[0022] In some embodiments, the structure of the sulfuryl fluoride coumarin compound is selected from any one of the following structures:

[0023]

[0024] In some embodiments, the structure of the sulfuryl fluoride coumarin compound is selected from any one of the following structures:

[0025]

[0026] Furthermore, the present invention claims a method for preparing a sulfuryl fluoride coumarin compound, comprising the following steps:

[0027] The hydroxy coumarin compound represented by formula (I-1) and the fluorosulfonyl imidazole salt represented by formula (I-2) are reacted by SuFEx to prepare the sulfuryl fluoride coumarin compound represented by formula (I);

[0028] The reaction formula of the preparation method is as follows:

[0029]

[0030] Preferably, a base is added to form alkaline conditions in the SuFEx reaction, and the base is selected from one or more of triethylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene and pyridine.

[0031] Preferably, the solvent is selected from one or more of acetonitrile, dichloromethane, tetrahydrofuran, 1,4-dioxane and N,N-dimethylformamide.

[0032] In some embodiments, the reaction temperature is greater than or equal to room temperature and less than or equal to the boiling point of the reaction solvent. More specifically, the reaction temperature is 20-110° C. For example, 35° C., 40° C., 45° C., 50° C., 60° C., 70° C., 75° C., 80° C., 85° C., 90° C., etc., or the reaction is carried out at the boiling point of the solvent, i.e., under reflux.

[0033] In some embodiments, the reaction time is 0.1-48 h, for example 0.5 h, 1 h, 3 h, 5 h, 8 h, 10 h, 12 h, 15 h, 18 h, 20 h, 23 h, 25 h, 28 h, 30 h, 33 h, 35 h, 38 h, 40 h, 44 h or 48 h.

[0034] Furthermore, the present invention claims an agricultural composition comprising:

[0035] (a) 0.001-99.99 wt % of the sulfuryl fluoride coumarin compound, its optical isomers, cis-trans isomers or its pesticide-acceptable salt, or a combination thereof; and

[0036] (b) pesticide-acceptable carriers and / or excipients.

[0037] Furthermore, the present invention seeks to protect the use of the sulfuryl fluoride coumarin compound or the agricultural composition in the preparation of a drug or bactericide for controlling plant pathogenic bacteria.

[0038] Preferably, the drug or bactericide is applied directly to the plant pathogenic bacteria or the locus where it comes into contact.

[0039] Preferably, the plant pathogenic bacteria are selected from:

[0040] Gram-negative bacteria: Erwinia (causing fire blight of apricot, etc.); Pectobacterium (causing soft rot of cruciferous vegetables, potato black leg, etc.); Dickie's genus (causing sweet potato stem rot, corn bacterial stem rot, rice bacterial basal rot, potato black leg, pear rust, etc.); Pantoea (causing corn bacterial wilt, corn Pantoea leaf spot, red bean bacterial leaf blight, stone fruit tree canker, etc.); Pseudomonas (causing peach canker, pea bacterial blight) Bacteria, bacterial black spot of crucifer, bacterial leaf spot of tomato, bacterial spot of tomato, bacterial black spot of rape, bacterial angular spot of sesame, bacterial angular spot of cucumber, wildfire of tobacco, bacterial brown spot of corn, bacterial brown spot of corn, bacterial stem blight of broad bean, bacterial spot of soybean, bacterial leaf spot of beet, bacterial pith necrosis of tomato, soft rot of Pseudomonas aeruginosa of ginseng, etc.); Ralstonia (causing various bacterial wilt diseases, such as tobacco bacterial wilt); Burke's The genus Acidovorax (cause bacterial wilt of carnation, onion rot, bacterial ear blight of rice, etc.); the genus Acidovorax (cause fruit spot of melon, brown spot of orchid, brown streak of oat, bacterial leaf spot of konjac, etc.); the genus Xanthomonas (cause bacterial leaf blight of rice, bacterial streak of rice, spot disease of pepper and tomato, scab of pepper and tomato, bacterial black spot of mango, bacterial leaf spot of pepper, bacterial blight of poinsettia, angular spot of cotton, bacterial spot of soybean, black rot of cruciferae, etc.) disease, cassava bacterial wilt, sugarcane gummosis, anthurium bacterial blight, citrus canker, hyacinth yellow rot, peach bacterial punchhole, strawberry angular leaf spot, poplar bacterial canker, etc.); Agrobacterium (causing root cancer of Rosaceae, etc.); Xylem bacteria (causing Pierce's disease of grapes and citrus variegated chlorosis, etc.); Phloemobacter (causing citrus Huanglongbing, etc.); Enterobacter (causing poplar wilt, etc.); Xylophilus (causing bacterial blight of grapes, etc.).

[0041] Gram-positive bacteria: Corynebacterium (causing potato ring rot, tomato canker, alfalfa bacterial wilt, corn internal wilt, wheat bacterial mosaic, etc.); Streptomyces (causing potato scab, etc.); Brevibacterium (causing bean bacterial wilt, tulip yellow blister disease, bean wilt, etc.); Arthrobacter (causing American holly leaf blight, etc.); Rhodococcus (causing sweet pea banding, etc.); Bacillus (causing corn Bacillus leaf spot, wheat white leaf streak, etc.); Russell's bacillus (causing duckgrass honey ear disease, etc.).

[0042] Further preferably, the plant pathogenic bacteria are selected from one or more of Xanthomonas, Corynebacterium, and Pseudomonas. Further preferably, the plant pathogenic bacteria are selected from one or more of Xanthomonas carpeti, Corynebacterium michiganensis, and Pseudomonas syringae. Furthermore, the sulfuryl fluoride coumarin compounds of the present invention have a good control effect on diseases such as citrus canker, tomato canker, and cucumber bacterial angular leaf spot caused by the above-mentioned plant pathogenic bacteria.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The present invention provides a class of sulfuryl fluoride coumarin compounds, which have broad-spectrum and highly effective fungicidal activity, especially excellent fungicidal activity against plant pathogenic bacteria, and good control effect on various plant diseases caused by plant pathogenic bacteria, and have great application potential and value in the field of plant disease control. DETAILED DESCRIPTION

[0045] The present invention is further described below in conjunction with specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art. Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0046] In the present invention, unless otherwise specified in the context, the words, phrases and symbols used below have the following meanings. The following abbreviations and terms have the following meanings throughout the text:

[0047] Example 1

[0048] The preparation of sulfuryl fluoride coumarin compounds, the specific synthesis steps are as follows:

[0049]

[0050] In a 100 mL round-bottom flask, 4-hydroxycoumarin compounds (compound of formula (I-1), 0.5 mmol), triethylamine (0.75 mmol) and acetonitrile (3.0 mL) were added in sequence and stirred for 5 min. Fluorosulfonyl imidazole salt (compound of formula (I-2), 0.6 mmol) was dissolved in acetonitrile solvent at 0°C and slowly added dropwise to the above solution. The mixture was reacted at room temperature for 0.5 h and monitored by TLC. After the reaction was completed, it was cooled to room temperature and then extracted with ethyl acetate (30 mL × 3). The organic phase was washed with saturated brine (30 mL × 3), dried over anhydrous sodium sulfate, filtered through a Buchner funnel to remove anhydrous sodium sulfate, and concentrated in vacuo. The crude product was purified by column chromatography (petroleum ether / ethyl acetate = 4 / 1; v / v) to obtain sulfuryl fluoride coumarin compounds (compound of formula (I)).

[0051] Compounds D1 to D38 were prepared by referring to the above method. The compound structures, yields and characterization data of compounds D1 to D38 are shown in Table 1 below.

[0052] Table 1 Structure and data characterization of sulfuryl fluoride coumarin compounds

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061] Test Example 1 Antibacterial activity and EC of sulfuryl fluoride coumarin compounds against three plant pathogenic bacteria 50 value

[0062] The test was based on the turbidity method and was improved by changing the NA liquid culture medium to the NA solid culture medium. The bacterial solution was quantitatively and evenly spread on the NA solid plate culture medium with or without the drug, and cultured at an appropriate temperature of 26-28°C for 24-48 hours. The bacteria on the plate were washed off to form a bacterial suspension, and the turbidity of the bacterial suspension was tested by absorbance (OD 600 ) to characterize and calculate the inhibition rate. The plant diseases and their corresponding test bacteria are citrus canker (Xanthomonas carpetii), tomato canker (Corynebacterium michiganensis) and cucumber bacterial angular leaf spot (Pseudomonas syringae).

[0063] Preparation of the above NA solid medium: 5.0g of peptone, 3.0g of beef extract powder, 1.0g of yeast extract powder, 10.0g of sucrose, 20g of agar powder, add water to 1L, mix well and adjust the pH to about 7.0, dispense into Erlenmeyer bottles, seal and sterilize with high pressure steam. Preparation of NA liquid medium: remove agar powder from NA solid medium.

[0064] The agent was prepared into a mother solution, and 20 mg of the target compound, 20 mg of chlorothiazide and thiophanate-methyl were weighed respectively, and then the samples were dissolved in dimethyl sulfoxide, and the volume was fixed to a concentration of 10000 μg / mL for use. A single colony of the pathogen was picked and placed in 50 mL of NA liquid culture medium, and the pathogen seed solution was obtained by shaking and culturing at 28°C and 180 r / min for 24 h. The seed solution was diluted to 1×10 8 / mL bacterial suspension for later use.

[0065] Take 0.25mL and 0.125mL of 10000μg / mL drug solution and mix with 49.5mL and 49.775mL of melted NA medium to prepare 50mL of toxic medium with a concentration of 50μg / mL and 25μg / mL. Divide the toxic medium into 4 equal parts and pour them into 4 culture dishes with a diameter of 9cm to make toxic NA plates. Wait for the toxic medium in the dish to condense. Take 0.1mL of bacterial suspension and spread it evenly on the drug-containing plate, and place it in a 25℃ incubator for culture. Use the same concentration of chlorothiazide and thiophanate-methyl as the control agent, dimethyl sulfoxide as the solvent control, and sterile water as the blank control. Repeat 4 times for each sample, and all the above operations are aseptic. 0.1 mL of bacterial suspension was evenly spread on the drug-containing plate and placed in a constant temperature incubator at 28°C for 24 h. 10 mL of sterile water was taken to wash the colonies on the lesions and mixed them evenly. The absorbance value (OD 600 ). According to the experimental design, gradient drug-containing plates were prepared, and blank controls were set up without drugs but with an equal amount of sterile water. Each treatment was repeated 3 times, and pathogens were inoculated, cultured, washed, and the absorbance values ​​were measured.

[0066] The inhibition rate of each agent at different concentrations on the growth of pathogenic bacteria was calculated according to the following formula. The data were statistically analyzed using Excel data processing software to calculate the toxicity regression equation (Y = b + aX), correlation coefficient (R), and the inhibitory concentration (EC 50 ).

[0067]

[0068] The in vitro antibacterial activity results of sulfuryl fluoride coumarin compounds D1 to D38 are shown in Table 1.

[0069] Table 1

[0070]

[0071]

[0072]

[0073] As can be seen from Table 1, most compounds showed good initial screening activity against Xac, CBALS and TBC. Among these compounds, the antibacterial activity of halogen substituents was better. Among them, the antibacterial activity of halogen substituents at position 6 of the compound was generally greater than that of compounds at positions 5, 7 and 8. Compounds with inhibition rates greater than 70% at a concentration of 50 mg / L were rescreened and their EC values ​​were calculated. 50 value.

[0074] Table 2 EC values ​​of sulfuryl fluoride coumarins against three plant pathogenic bacteria 50 value

[0075]

[0076]

[0077]

[0078] As shown in Table 2, the antibacterial activity of sulfuryl fluoride coumarin compounds with Cl at position 6 is the best. The EC values ​​of sulfuryl fluoride coumarin compounds against citrus canker, cucumber bacterial angular leaf spot and tomato canker are 50 The values ​​were between 1.15-32.5 mg / L, 3.25-40.5 mg / L and 2.10-25.5 mg / L, respectively, showing excellent bactericidal activity.

[0079] Among them, the EC of compound D21 against Xanthomonas citri citri 50 The value reached 1.15 mg / L, which was much higher than chlorothalonil (30.1 mg / L) and thiophanate-methyl (48.00 mg / L); the EC value of compound D21 against cucumber bacterial angular leaf spot pathogen 50 The value reached 3.40 mg / L, which was much higher than chlorothalonil (59.40 mg / L) and thiophanate-methyl (27.60 mg / L); the EC of compound D21 against tomato canker pathogen 50 The value reached 2.10 mg / L, which is much higher than chlorothalonil (28.20 mg / L) and thiophanate-methyl (24.50 mg / L). In summary, sulfuryl fluoride coumarin compounds have great development value and significance in the prevention and control of pathogenic fungi in plant agriculture.

[0080] Test Example 2 Antibacterial activity test of compound D21 against citrus canker pathogen in potted plants

[0081] Compound D21 was used to determine the protective and therapeutic effects against citrus canker.

[0082] In this experiment, thiophanate-methyl and chlorothalonil were used as control drugs, DMSO was used as blank control and water was used as a control, and a pot experiment was conducted on the highly active compound D21 against citrus canker bacteria. Citrus plants that were about two years old were selected for the treatment and protection activity tests.

[0083] For the treatment effect: Use a disposable sterile syringe to make two 3×3 rectangular wounds on both sides of the new citrus leaves, and inject the Xac bacteria solution (OD 595 =0.01) was soaked in filter paper and placed tightly on the wound. After 24 hours, the bacteria-containing filter paper was discarded, and the filter paper containing 200ug / mL of the drug solution was re-pasted on the leaf blade for 24 hours, and the leaf blade was placed in an incubator for cultivation. The culture conditions were: light for 16 hours, temperature for 28°C, darkness for 8 hours at 25°C, and humidity for 95%.

[0084] For the protective effect: Use a disposable sterile syringe to make two 3×3 rectangular wounds on both sides of the new citrus leaves, and stick the filter paper soaked with 200ug / mL of the drug solution on the wounds. After 24 hours, throw away the drug-containing filter paper and stick the leaves with the Xac solution (OD 595 =0.01) filter paper for 24 hours, and then placed in an incubator for cultivation under the following conditions: light for 16 hours, temperature for 28°C, darkness for 8 hours at 25°C, and humidity for 95%. The disease was observed after 14 days.

[0085] Calculation of control effect: The chlorophyll content in the leaves is used to reflect the control effect of citrus canker. According to the method reported in the literature, accurately weigh about 0.1g of the diseased leaves, cut them into pieces, add 10.0mL of extract (the extract is prepared by 85% acetone: 85% ethanol = 1:1), grind into powder at 4℃, transfer to a 15mL test tube, cover it, and treat it in the dark at 35℃ for 2h. Take 200L of the supernatant and put it in a 96-well plate, and measure its absorbance at 663nm and 645nm respectively.

[0086] The chlorophyll content was calculated according to the following formula:

[0087] Ca (mg L -1 )=9.784OD 663 -0.990OD 645

[0088] Cb(mg L -1 )=21.426OD 645 -4.650OD 663

[0089] Ct(mg L -1 )=Ca+Cb=5.135OD 663 +20.643OD 645

[0090] Chlorophyll content (mg g -1 ) = [concentration (mg L -1 )×total amount of extract (mL) / total amount of leaves (g). Where Ca, Cb and Ct represent the concentration of chlorophyll a, chlorophyll b and total chlorophyll concentration respectively.

[0091] EC activity of compound D21 against Xanthomonas citri citri 50 The value is 1.15ug / mL. Therefore, we conducted an in vivo pot experiment on compound D21 at a concentration of 200g / mL, with thiophanate-methyl (TC) and chlorothalonil (BT) as control drugs. The activity test results are shown in Table 3.

[0092] Table 3

[0093]

[0094] Note: TC-P is the control effect of thiophanate-methyl; TC-C is the therapeutic effect of thiophanate-methyl; other samples are the same.

[0095] As can be seen from Table 3, compound D21 has a good protective and therapeutic effect on citrus canker, and is better than the commercial drugs thiophanate-methyl and chlorothalonil. Compound D21 showed good in vivo activity against citrus canker. 14 days after inoculation, at 200 mg / L, compound D21 showed good protective and therapeutic effects, which were 91.20% and 61.59%, respectively, and the activity was better than the commercial drugs thiophanate-methyl (82.86% and 26.60%) and chlorothalonil (79.70% and 41.54%).

[0096] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A sulfuryl fluoride coumarin compound, characterized in that: The structure of the sulfuryl fluoride coumarin compound is shown in formula (I): In the formula, R1 is monosubstituted or polysubstituted, and R1 is independently selected from hydrogen, C 1-8 Alkyl, halogen or C 1-8 Alkoxy; R2 is selected from hydrogen, halogen, C 1-8 alkyl.

2. The sulfuryl fluoride coumarin compound according to claim 1, characterized in that: R1 is monosubstituted or polysubstituted, and R1 is independently selected from hydrogen, C 1-6 Alkyl, fluorine, chlorine, bromine, iodine or C 1-6 Alkoxy; R2 is selected from hydrogen, fluorine, chlorine, bromine, C 1-6 alkyl.

3. The sulfuryl fluoride coumarin compound according to claim 2, characterized in that: The structure of the sulfuryl fluoride coumarin compound is shown in formula (II): In the formula, R2 is selected from hydrogen, C 1-4 alkyl; R3 is selected from hydrogen, C 1-4 alkyl; R4 is selected from chloro, methyl, butyl, tert-butyl; R5 is selected from hydrogen, fluorine, chlorine, bromine, C 1-4 Alkyl, C 1-4 Alkoxy; R6 is selected from hydrogen, fluorine, chlorine, and bromine.

4. The sulfuryl fluoride coumarin compound according to claim 3, characterized in that: The structure of the sulfuryl fluoride coumarin compound is selected from any one of the following structures:

5. The method for preparing the sulfuryl fluoride coumarin compound according to any one of claims 1 to 4, characterized in that: The following steps are involved: The hydroxy coumarin compound represented by formula (I-1) and the fluorosulfonyl imidazole salt represented by formula (I-2) are reacted by SuFEx to prepare the sulfuryl fluoride coumarin compound represented by formula (I); The reaction formula of the preparation method is as follows:

6. The preparation method according to claim 5, characterized in that: A base is added to the SuFEx reaction to form alkaline conditions, and the base is selected from one or more of triethylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene and pyridine.

7. The preparation method according to claim 5, characterized in that: The solvent is selected from one or more of acetonitrile, dichloromethane, tetrahydrofuran, 1,4-dioxane and N,N-dimethylformamide.

8. An agricultural composition, characterized in that Include: (a) 0.001-99.99 wt % of the sulfuryl fluoride coumarin compound according to any one of claims 1 to 4, its optical isomers, cis-trans isomers or its pesticide-acceptable salt, or a combination thereof; and (b) pesticide-acceptable carriers and / or excipients.

9. Use of the sulfuryl fluoride coumarin compound according to any one of claims 1 to 4 or the agricultural composition according to claim 8 in the preparation of a medicine or bactericide for controlling plant pathogenic bacteria.

10. The use according to claim 9, characterized in that: The plant pathogenic bacteria are selected from one or more of the genera Erwinia, Pectobacterium, Dickie's, Pantoea, Pseudomonas, Ralstonia, Burkholderia, Acidovorax, Xanthomonas, Agrobacterium, Xylella, Bacillus, Enterobacter, Xylophilus, Corynebacterium, Streptomyces, Brevibacterium, Arthrobacter, Rhodococcus, Bacillus, and Russell's.

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