A class of 2-(1h-indol-2-yl)-1,3,4-oxadiazole derivatives, processes for their preparation and uses thereof

Abstract

This invention provides a class of 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivatives, their preparation methods, and uses. Specifically, it relates to a class of derivatives whose general chemical structural formula is shown in Formula I: I: This invention discloses the general structural formula of the above-mentioned compounds, their synthesis methods, and their uses as insecticides, acaricides, fungicides, antiviral agents for plants, and plant activators. It also discloses their uses and preparation methods in combination with agriculturally acceptable adjuvants or synergists, as well as in combination with commercial insecticides, acaricides, fungicides, antiviral agents for plants, and plant immune activators for the prevention and control of pests, mites, diseases, and viral diseases in agricultural, forestry, and horticultural plants.

Description

Technical Field

[0001] The technical solution of this invention belongs to the field of pesticides, specifically involving a class of 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivatives, their preparation methods and uses. Background Technology

[0002] Naturally derived compounds, due to their high bioavailability and relatively low environmental impact, have become an important treasure trove for the discovery of new pesticide lead structures (Srivastava, A. et al. Asian J. Pharm. Clin. Res. 2021, 4, 5–8; Nieto, MJ et al. Curr. Med. Chem. 2021, 28, 4828–4844). The indole skeleton is widely found in natural products and synthetic organic compounds, playing a crucial role in pesticide and drug development. In the field of agrochemicals, the indole skeleton has wide applications in plant growth regulation, antiviral agents, insecticides, herbicides, and fungicides (Huo, J. et al. J. Agric. Food Chem. 2022, 70, 6982–6992; Huang, D. et al. J. Agric. Food Chem. 2023, 71, 6226-6235). Although the indole skeleton shows great promise in the development of agrochemicals, there are currently no commercially available fungicides containing indole groups. Therefore, the development of indole skeleton fungicides with novel modes of action is of great significance (Zeng, D. et al. PestManag. Sci. 2020, 76, 2681-2692; Yang, Z. et al. J. Agric. Food Chem. 2021, 69, 13373-13385; Wang, Y. et al. J. Agric. Food Chem. 2022, 70, 2510–2519).

[0003] The N,S-heterocyclic skeleton plays an important role in the design of bactericides (Zhang, Y. et al. Org. Lett. 2022, 24, 6599–6603). Compound YZK-C22 is a compound containing the [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole skeleton with broad-spectrum bactericidal activity. Its mechanism of action is unique, and its potential bactericidal target is pyruvate kinase (Zhao, B. et al. J. Agric. Food Chem. 2018, 66, 12439–12452). In order to develop novel and highly active bactericidal lead compounds, this invention uses the highly active bactericidal compound YZK-C22 as the lead structure and adopts a bioisosteric strategy to introduce an indole skeleton structure to design and synthesize 2-(1H-indole-2-yl)-1,3,4-oxadiazole compounds. However, since this skeleton has been rarely reported in pesticide research, exploring its fungicidal activity and discussing its structure-activity relationship is of great significance for enriching the application of this type of skeleton in fungicides. This invention develops a class of 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivatives and their preparation method, and found that they exhibit good fungicidal activity at low concentrations, making them potential candidate compounds for fungicides. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a new method for synthesizing a class of 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivatives, to provide methods for measuring the bioactivity of these compounds in regulating agricultural, horticultural, health, and forestry plant pests and pathogens, and to provide applications of these compounds in the fields of agriculture, horticulture, forestry, and health.

[0005] The technical solution adopted by this invention to solve this technical problem is: a chemical structure containing a 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative with insecticidal, acaricidal, fungicidal, antiviral, and plant disease-inducing activities in agriculture, horticulture, and forestry is shown in Figure I.

[0006]

[0007] Among them, R 1Selected from: 4-fluoro, 4-chloro, 6-chloro, 6-bromo, 4,6-dichloro, 7-fluoro, 7-chloro, 7-bromo, 7-methyl, 5-methylsulfonyl, 7-(3,4-dichlorophenyl), 7-(3,4-difluorophenyl), 7-(4-methylthiophen-2-yl)phenyl, 7-(furan-3-yl), 7-(2-chloropyridin-4-yl), 7-nitro, 7-amino, 7-cyclopropanecarbamate, 7-propamido, 7-(2-trifluoromethyl)benzamido, 7-(2-chloroacetamido), 7-ethylaminoamido, 7-ethanesulfonamido, 7-dimethylaminosulfonamido, 7-(4-methoxy)benzenesulfonamido; R 2 Selected from: hydrogen, methyl, ethyl, n-propyl, isopropyl, cyclopropylmethyl, 2,2-difluoroethyl, 3-fluoropropyl, 1-methoxy, 2-methoxyethyl, 2-ethyl acetate methyl, 2-(3-(but-3-yn-1-yl)-3H-diazacyclopropane-3-yl), 4-fluorobenzyl, amino; R 3 Selected from: hydrogen, aldehyde, difluoromethyl, formaldehyde oxime, formaldehyde O-methyl oxime, formaldehyde O-ethyl oxime, formaldehyde O-isopropyl oxime, formaldehyde O-3-fluoropropyl oxime, formaldehyde O-(4-fluorobenzyl) oxime, formaldehyde O-(3,4-difluorobenzyl) oxime, hydroxymethyl.

[0008] The synthetic route of the present invention containing 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I and its intermediates is as follows:

[0009]

[0010] The first route: Compound Ia is prepared by heating substituted 1H-indole-2-carbonylhydrazide and triethyl orthoformate in a solvent under the action of an organic acid such as p-toluenesulfonic acid.

[0011] The second route: Compound 3 is prepared by heating 7-bromo-1H-indol-2-carbamate and triethyl orthoformate in a solvent under the action of an organic acid such as p-toluenesulfonic acid; Compound Ib is prepared by heating 2-(7-bromo-1H-indol-2-yl)-1,3,4-oxadiazole and substituted arylboronic ester in a solvent under the action of bis(triphenylphosphine)palladium chloride and an inorganic base such as potassium carbonate.

[0012] The third route: Compound 4 is prepared by heating 7-nitro-1H-indole-2-carbonylhydrazine and triethyl orthoformate in a solvent under the action of an organic acid such as p-toluenesulfonic acid; Compound 5 is prepared by heating 2-(7-nitro-1H-indole-2-yl)-1,3,4-oxadiazole in the action of reduced iron powder and a solvent; Compound Ic is prepared by reacting 2-(7-amino-1H-indole-2-yl)-1,3,4-oxadiazole and substituted formyl chloride in the action of an acid-binding agent such as N,N-diisopropylethylamine at room temperature; Compound Id is prepared by reacting 2-(7-amino-1H-indole-2-yl)-1,3,4-oxadiazole and substituted sulfonyl chloride in the action of an acid-binding agent such as N,N-diisopropylethylamine at room temperature.

[0013] The fourth route: Compound 6 is prepared by heating 6-chloro-1H-indole-2-carbonylhydrazine and triethyl orthoformate in a solvent under the action of an organic acid such as p-toluenesulfonic acid. Compound 6 is 2-(6-chloro-1H-indole-2-yl)-1,3,4-oxadiazole.

[0014] Compound Ie is prepared by heating 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole and haloalkane in a solvent under the action of an inorganic base such as potassium carbonate.

[0015] Compound Ig was prepared by heating substituted 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole and Wiesmeer's reagent; compound Ih was prepared by heating substituted 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole-3-carboxaldehyde and hydroxylamine hydrochloride in a solvent under the action of a base such as potassium carbonate; compound Ii was prepared by heating substituted (E)-6-chloro-2-(1,3,4-oxadiazole-2-yl)-1-propyl-1H-indol- 3-Carbaldehyde oxime and haloalkanes were prepared by reacting in a solvent with an inorganic base such as sodium hydride at room temperature under stirring. Compound Ij was prepared by reacting substituted 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole-3-carboxaldehyde and diethylaminosulfur trifluoride in a solvent at room temperature. Compound Ik was prepared by reacting substituted 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole-3-carboxaldehyde and a reducing agent such as sodium borohydride in a solvent at room temperature.

[0016] The fifth route: Compound If is prepared at room temperature in a solvent by 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole and O-(4-nitrobenzoyl)hydroxylamine in the presence of potassium tert-butoxide.

[0017] The synthetic method of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I described in this invention comprises the following steps:

[0018] A. Preparation of compound 2:

[0019] Take a 100 mL round-bottom flask and add an anhydrous ethanol (25 mL) solution of 1H-indole-2-carboxylic acid ethyl ester (10.0 mmol, 1.0 equivalent). At room temperature, add 80% hydrazine hydrate (20.0 mmol, 2.0 equivalent) dropwise to the reaction system. Stir the mixture at 80 °C for 4 hours (TLC monitoring). After the reaction is complete, a solid precipitates out. Filter the solid and dry it to obtain substituted 1H-indole-2-carbazide (2).

[0020] B. Preparation of compound Ia:

[0021] Take a 100 mL round-bottom flask and add substituted 1H-indole-2-carbazide (2.0 mmol, 1.0 equivalence), triethyl orthoformate (6.0 mmol, 3.0 equivalence), p-toluenesulfonic acid (0.2 mmol, 0.2 equivalence), and N,N-dimethylformamide (10.0 mL) sequentially. Heat under reflux at 100 °C for 12 hours (TLC monitoring). Cool the mixture to room temperature. Wash the reaction solution with ethyl acetate (20 mL) and brine (20 mL), dry to anhydrous sodium sulfate, and concentrate under vacuum. Remove the solvent under reduced pressure. Purify the residue by silica gel column chromatography (200–300 mesh) using ethyl acetate / petroleum ether as the eluent to obtain 2-(1H-indole-2-carbazide). (-indole-2-yl)-1,3,4-oxadiazole derivative Ia; wherein the substituted 1H-indole-2-carbazide is selected from: 4-fluoro-1H-indole-2-carbazide, 4-chloro-1H-indole-2-carbazide, 6-chloro-1H-indole-2-carbazide, 6-bromo-1H-indole-2-carbazide, 4,6-dichloro-1H-indole-2-carbazide, 7-fluoro-1H-indole-2-carbazide, 7-chloro-1H-indole-2-carbazide, 7-bromo-1H-indole-2-carbazide, 7-methyl-1H-indole-2-carbazide, 5-methylsulfonyl-1H-indole-2-carbazide, 7-nitro-1H-indole-2-carbazide.

[0022] C. Preparation of compound 3:

[0023] Take a 100 mL round-bottom flask and add 7-bromo-1H-indol-2-carbazide (2.0 mmol, 1.0 equivalence), triethyl orthoformate (6.0 mmol, 3.0 equivalence), p-toluenesulfonic acid (0.2 mmol, 0.2 equivalence), and N,N-dimethylformamide (10.0 mL) sequentially. Heat the mixture under reflux at 100 °C for 12 hours (TLC monitoring). Then cool the mixture to room temperature. Wash the reaction solution with ethyl acetate (20 mL) and brine (20 mL), dry with anhydrous sodium sulfate, and concentrate under vacuum. Remove the solvent under reduced pressure. Purify the residue by silica gel column chromatography (200–300 mesh) with ethyl acetate / petroleum ether as the eluent to obtain 2-(7-bromo-1H-indol-2-yl)-1,3,4-oxadiazole 3.

[0024] D. Preparation of compound Ib:

[0025] Take a 100 mL round-bottom flask and add 2-(7-bromo-1H-indol-2-yl)-1,3,4-oxadiazole (2.0 mmol, 1.0 equivalence), substituted arylboronic acid (2.0 mmol, 2.0 equivalence), bis(triphenylphosphine)palladium chloride (0.1 mmol, 0.05 equivalence), potassium carbonate (4.0 mmol, 2.0 equivalence), and 1,4-dioxane (10.0 mL) sequentially. Heat under reflux at 80°C for 12 hours (monitored by TLC), then cool the mixture to room temperature; the reaction... The solution was washed with ethyl acetate (20 mL) and brine (20 mL), dried over anhydrous sodium sulfate and concentrated under vacuum. The solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (200–300 mesh) using ethyl acetate / petroleum ether as the eluent to give the substituted 2-(7-aryl-1H-indol-2-yl)-1,3,4-oxadiazole derivative Ib. The arylboronic acid was selected from: 3,4-dichlorophenylboronic acid, 3,4-difluorophenylboronic acid, 4-methyl-2-thiopheneboronic acid, 2-furanboronic acid, and 2-chloro-4-pyridineboronic acid.

[0026] E. Preparation of Compound 4:

[0027] Take a 100 mL round-bottom flask and add 7-nitro-1H-indole-2-carbonylhydrazide (2.0 mmol, 1.0 equivalence), triethyl orthoformate (6.0 mmol, 3.0 equivalence), p-toluenesulfonic acid (0.2 mmol, 0.2 equivalence), and N,N-dimethylformamide (10.0 mL) sequentially. Heat the mixture under reflux at 100 °C for 12 hours (TLC monitoring). Then cool the mixture to room temperature. Wash the reaction solution with ethyl acetate (20 mL) and brine (20 mL), dry with anhydrous sodium sulfate, and concentrate under vacuum. Remove the solvent under reduced pressure. Purify the residue by silica gel column chromatography (200–300 mesh) with ethyl acetate / petroleum ether as the eluent to obtain 2-(7-nitro-1H-indole-2-yl)-1,3,4-oxadiazole 4.

[0028] F. Preparation of compound 5:

[0029] Take a 100 mL round-bottom flask and add 2-(7-nitro-1H-indol-2-yl)-1,3,4-oxadiazole (1.0 mmol, 1.0 equivalent), iron powder (3.0 mmol, 3.0 equivalent), ammonium chloride (3.0 mmol, 3.0 equivalent), and a mixture of ethanol and water (v / v) in sequence.

[0030] The mixture (2:1, 9.0 mL) was heated to reflux at 80°C for 4 hours (TLC monitoring). The mixture was then filtered while hot. The filtrate was washed with ethyl acetate (20 mL) and brine (20 mL), dried over anhydrous sodium sulfate, and concentrated under vacuum. The solvent was removed under reduced pressure. The residue was purified by silica gel column chromatography (200–300 mesh) using ethyl acetate / petroleum ether as the eluent to give 2-(7-amino-1H-indole).

[0031] -2-yl)-1,3,4-oxadiazole 5;

[0032] Preparation of compound Ic:

[0033] N,N-diisopropylethylamine (2.0 mmol, 2.0 equivalence) was added to an anhydrous dichloromethane solution containing 2-(7-amino-1H-indol-2-yl)-1,3,4-oxadiazole (1.0 mmol, 1.0 equivalence); the reaction mixture was stirred at room temperature for 0.5 hours, and then substituted formyl chloride was slowly added dropwise to the reaction system at 0°C. A dichloromethane solution (1.1 mmol, 1.1 equivalents) was added dropwise; after the reaction was complete, the reaction mixture was stirred at room temperature for 12 hours (TLC monitoring); after the reaction was complete, the mixture was extracted with dichloromethane (3 × 10 mL) and brine (10 mL), the organic layers were combined and collected, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and the residue was purified by silica gel column chromatography, eluted with ethyl acetate / petroleum ether to give derivative Ic, the substituted formyl chloride being selected from: cyclopropylformyl chloride, ethyl chloroformate, acetyl chloride, 2-trifluoromethylbenzoyl chloride, and chloroacetyl chloride;

[0034] Preparation of compound Id:

[0035] N,N-diisopropylethylamine (2.0 mmol, 2.0 equivalence) was added to an anhydrous dichloromethane solution containing 2-(7-amino-1H-indol-2-yl)-1,3,4-oxadiazole (1.0 mmol, 1.0 equivalence); the reaction mixture was stirred at room temperature for 0.5 hours, and then substituted sulfonyl chloride was slowly added dropwise to the reaction system at 0°C. A dichloromethane solution (1.1 mmol, 1.1 equivalents) was added dropwise; after the reaction was complete, the reaction mixture was stirred at room temperature for 12 hours (TLC monitoring); after the reaction was complete, the mixture was extracted with dichloromethane (3 × 10 mL) and brine (10 mL), the organic layers were combined and collected, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and the residue was purified by silica gel column chromatography, eluted with ethyl acetate / petroleum ether to give derivative Id, the substituted sulfonyl chloride being selected from: ethyl sulfonyl chloride, p-methoxybenzenesulfonyl chloride, and dimethylaminosulfonyl chloride;

[0036] I. Preparation of Compound 6:

[0037] Take a 100 mL round-bottom flask and add 6-chloro-1H-indol-2-carbazide (2.0 mmol, 1.0 equivalence), triethyl orthoformate (6.0 mmol, 3.0 equivalence), p-toluenesulfonic acid (0.2 mmol, 0.2 equivalence), and N,N-dimethylformamide (10.0 mL) sequentially. Heat the mixture under reflux at 100 °C for 12 hours (TLC monitoring). Then cool the mixture to room temperature. Wash the reaction solution with ethyl acetate (20 mL) and brine (20 mL), dry with anhydrous sodium sulfate, and concentrate under vacuum. Remove the solvent under reduced pressure. Purify the residue by silica gel column chromatography (200–300 mesh) with ethyl acetate / petroleum ether as the eluent to obtain 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole 6.

[0038] Preparation of compound Ie:

[0039] Add compound 6 (1.0 mmol, 1.0 equivalent), potassium carbonate (1.5 mmol, 1.5 equivalent), and N,N-dimethylformamide (5.0 mL) to a 100 mL round-bottom flask; stir the mixture at room temperature, then add the halogenated compound (1.1 mmol, ...

[0040] 1.1 equivalents), stirred at 100°C for 3–5 hours (TLC monitoring); then, the mixture was cooled to room temperature, washed with brine (10 mL) and extracted with ethyl acetate (3 × 10 mL), and the organic phases were combined and collected; the organic phases were dried over anhydrous sodium sulfate and concentrated under vacuum, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (200–300 mesh) using ethyl acetate / petroleum ether as the eluent to give the substituted 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole derivative Ie; the halogenated derivative is selected from: iodomethane, iodoethane, 1-iodopropane, 2-iodopropane, bromomethylcyclopropane, 1,1-difluoro-2-iodoethane, 1-fluoro-3-iodopropane,

[0041] 2-Iodoethyl methyl ether, iodomethyl methyl ether, ethyl bromoacetate, 3-(but-3-ynyl)-3-(2-iodoethyl)-3H-diazine, 4-fluorobenzyl bromide;

[0042] Preparation of compound If (K):

[0043] Add compound 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole 6 (1.0 mmol) sequentially to a 100 mL round-bottom flask.

[0044] 1.0 equivalent of N-methylpyrrolidone (15.0 mL) was added and stirred at room temperature; then O-(4-nitrobenzoyl)hydroxylamine (1.2 mmol, 1.2 equivalent) and potassium tert-butoxide (2.0 mmol, 2.0 equivalent) were added and stirred overnight at room temperature (TLC monitoring); then, the mixture was washed with brine (10 mL) and extracted with ethyl acetate (3 × 10 mL), and the organic phases were combined and collected; the organic phases were dried over anhydrous sodium sulfate and concentrated under vacuum, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (200–300 mesh) using [eluent not specified].

[0045] Ethyl acetate / petroleum ether yields compound 6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-1-amine If;

[0046] Preparation of compound Ig:

[0047] Under ice bath conditions, phosphorus oxychloride (0.5 mL) and N,N-dimethylformamide (2.0 mL) were added sequentially to a 100 mL round-bottom flask. After stirring for 0.5 hours, the mixture was transferred to room temperature. A solution of substituted 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole (Ie, 1.0 mmol, 1.0 equivalent) in N,N-dimethylformamide (5.0 mL) was added, and the mixture was reacted at 80 °C for 4 hours (monitored by TLC). Subsequently, the reaction solution was poured into ice water, and the pH of the reaction solution was adjusted to neutral with saturated sodium bicarbonate. The mixture was washed with brine (10 mL) and extracted with ethyl acetate (3 × 10 mL). The organic phases were combined and collected. The organic phase was dried over anhydrous sodium sulfate and concentrated under vacuum. The solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (200-300 mesh) using ethyl acetate / petroleum ether as the eluent to give a substituted 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole-3-carboxaldehyde derivative Ig. The 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole compound Ig is selected from: 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole, 2-(6-chloro-1-methyl-1H-indol-2-yl)-1,3,4-oxadiazole, 2-(6-chloro-1-ethyl-1H-indol-2-yl)- 1,3,4-Oxadiazole, 2-(6-chloro-1-propyl-1H-indol-2-yl)-1,3,4-Oxadiazole, 2-(6-chloro-1-isopropyl-1H-indol-2-yl)-1,3,4-Oxadiazole, 2-(6-chloro-1-(2,2-difluoroethyl)-1H-indol-2-yl)-1,3,4-Oxadiazole, 2-(6-chloro-1-(3-fluoropropyl)-1H-indol-2-yl)-1,3,4-Oxadiazole, 2-(6-chloro-1-methoxy-1H-indol-2-yl)-1,3,4-Oxadiazole, 2-(6-chloro-1-(2-methoxyethyl)-1H-indol-2-yl)-1, 3,4-Oxadiazole, 2-(6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indol-1-yl)ethyl acetate, 2-(6-chloro-1-(cyclopropylmethyl)-1H-indol-2-yl)-1,3,4-oxadiazole, 2-(1-(2-(3-(but-3-yn-1-yl)-3H-diazacyclopropane-3-yl)ethyl)-6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole, 2-(6-chloro-1-(4-fluorobenzyl)-1H-indol-2-yl)-1,3,4-oxadiazole, 6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indol-1-amine;

[0048] Preparation of compound Ih (M):

[0049] Add 1g (1.0 mmol, 1.0 equivalence) of substituted 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole-3-carboxaldehyde compound, hydroxylamine hydrochloride (1.5 mmol, 1.5 equivalence), potassium carbonate (0.8 mmol, 0.8 equivalence), and ethanol and water (v / v = 2:1) to a 100 mL round-bottom flask. The mixture was stirred at 100°C for 3–5 hours (TLC monitoring); then, the mixture was cooled to room temperature, washed with brine (10 mL), and extracted with ethyl acetate (3 × 10 mL). The organic phases were combined and collected; the organic phases were dried over anhydrous sodium sulfate and concentrated under vacuum, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (200–300 mesh) using ethyl acetate / petroleum ether as the eluent to give the substituted (E)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime derivative Ih; the 2-(6-chloro-1H-indole-2-yl)-1,3 ,4-Oxadiazol-3-carboxaldehyde compound Ig is selected from: 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazol-3-carboxaldehyde, 6-chloro-2-(1,3,4-oxadiazol-2-yl)-1-methyl-1H-indol-3-carboxaldehyde, 6-chloro-2-(1,3,4-oxadiazol-2-yl)-1-ethyl-1H-indol-3-carboxaldehyde, 6-chloro-2-(1,3,4-oxadiazol-2-yl)-1-propyl-1H-indol-3-carboxaldehyde, 6-chloro-2-(1,3,4-oxadiazol-2-yl)-1-isopropyl-1H-indol-3-carboxaldehyde, 6 -Chloro-1-(2,2-difluoroethyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 6-chloro-1-(3-fluoropropyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 6-chloro-1-methoxy-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 6-chloro-1-(2-methoxyethyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 2-(6-chloro-3-formyl-2-(1,3,4-oxadiazol-2-yl)-1H- Ethyl indole-1-yl), 6-chloro-1-(cyclopropylmethyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 1-(2-(3-(but-3-yn-1-yl)-3H-diazacyclopropane-3-yl)ethyl)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 6-chloro-1-(4-fluorobenzyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 1-amino-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde;

[0050] Preparation of compound Ii:

[0051] Sodium hydride (80.0 mg, 2.0 mmol, 2.0 equivalence, 60 wt%, in mineral oil) was slowly added to a 3.0 mL solution of the substituted (E)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1-propyl-1H-indole-3-carboxaldehyde oxime compound Ih (1.0 mmol, 1.0 equivalence) in tetrahydrofuran; after stirring the reaction mixture at room temperature for 0.5 hours, the halogenated compound R was added dropwise. 3 -X (1.1 mmol, 1.1 equivalence) of tetrahydrofuran solution (1.0 mL) was added, and the mixture was stirred at room temperature for 3–5 hours (TLC monitoring). After the reaction was complete, 10 mL of 1 mol / L ammonium chloride aqueous solution and 30 mL of ethyl acetate were added, and the organic layer was extracted with brine (3 × 10 mL). The organic layers were collected, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (200–300 mesh) using ethyl acetate / petroleum ether as the eluent to give (E)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime derivative Ii; the halogenated product R 3-X is selected from: iodomethane, iodoethane, 1-iodopropane, 1-fluoro-3-iodopropane, 4-fluorobenzyl bromide, 3,4-difluorobenzyl bromide; the (E)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime compound Ih is selected from: (E)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime, (E)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime, (E)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-methyl-1H-indole-3-carboxaldehyde oxime, (E)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-methyl-1H-indole-3-carboxaldehyde oxime, (E)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime, (E)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1-propyl-1H-indole-3-carboxaldehyde oxime, (E)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1-isopropyl-1H-indole-3-carboxaldehyde oxime, (E)-6-chloro-1-(2,2-difluoroethyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime, (E)-6-chloro-1-(3-fluoropropyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime, (E)-6-chloro-1-(3-fluoropropyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime, (E)-6-chloro-1-(3-fluoropropyl)-2-(1,3,4-oxadiazol- (E)-6-chloro-1-methoxy-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime, (E)-6-chloro-1-(2-methoxyethyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime, (E)-2-(6-chloro-3-((hydroxyimino)methyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-1-yl)ethyl acetate, (E)-6-chloro-1-(cyclopropylmethyl)-2-(1, 3,4-Oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime, (E)-1-(2-(3-(but-3-yn-1-yl)-3H-diazacyclopropane-3-yl)ethyl)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime, (E)-6-chloro-1-(4-fluorobenzyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime, (E)-1-amino-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde oxime;

[0052] Preparation of compound Ij:

[0053] Add 1 g (1.0 mmol, 1.0 equivalence) of substituted 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazol-3-carboxaldehyde and 10.0 mL of dichloromethane to a 100 mL round-bottom flask; stir the mixture in an ice bath, add diethylaminosulfuric acid (6.0 mmol, 6.0 equivalence) in portions, and stir at this temperature for 3–5 hours (TLC monitoring); then wash with brine (10 mL) and extract with ethyl acetate (3 × 10 mL), and collect the organic phases; dry the organic phases to anhydrous sodium sulfate and concentrate under vacuum, remove the solvent under reduced pressure, and purify the residue by silica gel column chromatography (200–300 mesh) using [eluent name missing]. Ethyl acetate / petroleum ether yields a substituted 2-(6-chloro-3-(difluoromethyl)-1H-indol-2-yl)-1,3,4-oxadiazole Ij; wherein the 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole-3-carboxaldehyde compound Ig is selected from: 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazole-3-carboxaldehyde, 6-chloro-2-(1,3,4-oxadiazole-2-yl)-1-methyl-1H-indol-3-carboxaldehyde, 6-chloro-2-(1,3,4-oxadiazole-2-yl)-1-ethyl-1H-indol-3-carboxaldehyde, 6-chloro-2-(1,3,4-oxadiazole-2-yl)-1-propyl-1 H-Indole-3-carboxaldehyde, 6-chloro-2-(1,3,4-oxadiazol-2-yl)-1-isopropyl-1H-indole-3-carboxaldehyde, 6-chloro-1-(2,2-difluoroethyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 6-chloro-1-(3-fluoropropyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 6-chloro-1-methoxy-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 6-chloro-1-(2-methoxyethyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 2-(6-chloro-3- Ethyl formyl-2-(1,3,4-oxadiazol-2-yl)-1H-indole-1-yl)ethyl acetate, 6-chloro-1-(cyclopropylmethyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 1-(2-(3-(but-3-yn-1-yl)-3H-diazacyclopropane-3-yl)ethyl)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 6-chloro-1-(4-fluorobenzyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 1-amino-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde;

[0054] Preparation of compound Ik:

[0055] Add 1 g (1.0 mmol, 1.0 equivalence) of substituted 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazol-3-carboxaldehyde and 10.0 mL of dichloromethane to a 100 mL round-bottom flask; stir the mixture in an ice bath, add sodium borohydride (4.0 mmol, 4.0 equivalence) in portions, and stir at this temperature for 3–5 hours (TLC monitoring); then wash with brine (10 mL) and extract with ethyl acetate (3 × 10 mL), and collect the organic phases; dry the organic phase with anhydrous sodium sulfate and concentrate under vacuum, remove the solvent under reduced pressure, and purify the residue by silica gel column chromatography (200–300 mesh) using ethyl acetate as the eluent. Ester / petroleum ether yields a substituted (6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indol-3-yl)methanol derivative Ik; wherein the 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazol-3-carboxaldehyde compound Ig is selected from: 2-(6-chloro-1H-indol-2-yl)-1,3,4-oxadiazol-3-carboxaldehyde, 6-chloro-2-(1,3,4-oxadiazol-2-yl)-1-methyl-1H-indol-3-carboxaldehyde, 6-chloro-2-(1,3,4-oxadiazol-2-yl)-1-ethyl-1H-indol-3-carboxaldehyde, 6-chloro-2-(1,3,4-oxadiazol-2-yl)-1-propyl-1 H-Indole-3-carboxaldehyde, 6-chloro-2-(1,3,4-oxadiazol-2-yl)-1-isopropyl-1H-indole-3-carboxaldehyde, 6-chloro-1-(2,2-difluoroethyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 6-chloro-1-(3-fluoropropyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 6-chloro-1-methoxy-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 6-chloro-1-(2-methoxyethyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 2-(6-chloro-3- Ethyl formyl-2-(1,3,4-oxadiazol-2-yl)-1H-indole-1-yl)acetate, 6-chloro-1-(cyclopropylmethyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 1-(2-(3-(but-3-yn-1-yl)-3H-diazacyclopropane-3-yl)ethyl)-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 6-chloro-1-(4-fluorobenzyl)-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde, 1-amino-6-chloro-2-(1,3,4-oxadiazol-2-yl)-1H-indole-3-carboxaldehyde.

[0056] Q. Uses of 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I:

[0057] This invention provides the use of 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the preparation of insecticides.

[0058] This invention provides the use of 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the preparation of fungicides.

[0059] This invention provides the use of 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the preparation of an anti-tobacco mosaic virus agent.

[0060] This invention provides the use of 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the preparation of plant immune activators for inducing tobacco resistance to tobacco mosaic virus and for inducing Arabidopsis resistance to Arabidopsis downy mildew.

[0061] It should be noted that plant immune activators were formerly called plant activators. They have the activity of inducing disease resistance, and their disease resistance induction activity is broad-spectrum and long-lasting.

[0062] This invention provides a pesticide composition containing 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I suitable for controlling pests and pathogens in agricultural, forestry, and horticultural plants, and for inducing plants to develop defense capabilities against plant pests and pathogens. The pesticide composition includes agricultural fungicides, agricultural insecticides, agricultural antiviral compositions, and agricultural plant immune activators. The composition contains the aforementioned 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative as the active ingredient. The composition contains 0.1% to 99.9% by weight of the active ingredient, 99.9% to 0.1% by weight of a solid or liquid adjuvant, and a surfactant selected from 0 to 25% by weight.

[0063] R. Compositions containing 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I and their uses:

[0064] An agricultural composition is formed by combining 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I with a commercial pesticide for application; the commercial pesticide is selected from one or more of insecticides, fungicides, antiviral agents for plants, acaricides, and plant immune activators. The composition contains 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I and other commercial insecticides, fungicides, antiviral agents for plants, acaricides, and plant immune activators as active ingredients; the content of the active ingredient in the composition is 1%:99% to 99%:1% by weight. This compound composition contains 1% to 99% by weight of the active ingredient, 99% to 1% by weight of a solid or liquid adjuvant, and a surfactant selected from 0 to 25% by weight. Specific combinations are as follows:

[0065] The 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I, combined with any one or two of the insecticides, forms an insecticidal composition for the prevention and control of agricultural, forestry, and horticultural plant pests.

[0066] The insecticides mentioned are selected from: imidacloprid, difenoconazole, acetamiprid, emamectin benzoate, abamectin, spinosad, heptamethrin, cyhalothrin, lambda-cyhalothrin, deltamethrin, deltamethrin, cypermethrin, β-cyhalothrin, λ-cyhalothrin, dichlorvos, permethrin, allethrin, bifenthrin, permethrin, fenpropathrin, flufenoxuron, cyhalothrin, imidacloprid, acetamiprid, chlorpyrifos, thiamethoxam, thiamethoxam, dinotefuran, fenpropathrin, fenpropathrin, difenoconazole, fenpropathrin, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole, difenoconazole , bis(phenylfluorouron), flufenoxuron, fenflurfen, bis(triflufenoxuron), furazolidone, chlorfenapyr, methoxyfenozide, cyclone dichlorvos, dichlorvos, quinalphos, pyridazin, leafhopper powder, carbaryl, pirimicarb, methamidophos, isoprocarb, pyridaben, methyl parathion, methyl parathion, bromopropylate, thiamethoxam, azoxystrobin, pyridaben, tetradifon, propargite, bufenozide, pymetrozine, spirodiclofen, spirotetramat, triazophos, thiamethoxam, chlorfenapyr, tetrachlorfenapyr, flufenoxuron, flufenoxuron, cyanfenoxuron, butenylflufenoxuron, azoxystrobin, bromopropylate, pyrazinazole, etoxazole, pyridaben, pyridaben, pyriproxyfen, emamectin, pendimethalin;

[0067] The mass percentage of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the insecticidal composition is 1%-90%; preferably, the ratio of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I to the insecticide is 1%:99% to 99%:1% by mass.

[0068] The formulation of the insecticidal composition is selected from: seed treatment emulsions, water-in-oil emulsions, microemulsions, suspensions, capsule suspensions, water-soluble granules, fine granules, soluble concentrates, poison grains, block poison baits, granular poison baits, flake poison baits, concentrated poison baits, slow-release blocks, electrostatic sprays, oil-in-water emulsions, smoke cans, smoke candles, smoke tubes, smoke sticks, smoke sheets, smoke pellets, gas generators, ointments, hot fogging agents, cold fogging agents, aerosols, solid / liquid mixtures, liquid / liquid mixtures, solid / solid mixtures, medicated paints, microparticles, tracking powders, oil suspensions, oil-dispersible powders, concentrated gels, pouring agents, seed coating agents, coating agents, film-forming oils, ultra-low volume liquids, and vapor release agents;

[0069] The plant pests controlled by the insecticidal composition are selected from: fall armyworm, spider mite, Oriental migratory locust, spotted locust, Chinese rice locust, Japanese yellow-spined locust, single-spined mole cricket, oriental mole cricket, rice thrips, tobacco thrips, greenhouse thrips, rice tube thrips, wheat tube thrips, greenhouse whitefly, tobacco whitefly, black-tailed leafhopper, large green leafhopper, cotton leafhopper, spotted lanternfly, brown planthopper, white-backed planthopper, gray planthopper, sugarcane flat-horned planthopper, cotton aphid, wheat two-forked aphid, wheat long-tubed aphid, peach aphid, sorghum aphid, radish aphid, cottony cushion scale, mulberry shield scale, arrowhead shield scale, pear round scale, white wax insect, red wax scale, Korean ball scale. Pear lace bug, banana lace bug, slender horned flower bug, miniature flower bug, needle-edged bug, rice spider-web bug, rice brown bug, rice black bug, rice green bug, green mirid bug, alfalfa mirid bug, medium black mirid bug, large lacewing, beautiful lacewing, Chinese lacewing, grain moth, clothes moth, yellow tussock moth, brown tussock moth, flat tussock moth, wheat moth, cotton bollworm, sweet potato wheat moth, diamondback moth, peach fruit moth, soybean fruit moth, peach fruit moth, apple top leafroller, brown-banded long leafroller, false yellow leafroller, rice stem borer, bean pod borer, corn borer, three-spined rice stem borer, cabbage stem borer, rice leaf roller, striped stem borer, cotton leafroller, peach borer, armyworm, sedge beetle. Noctuid moth, rice stem borer, cotton budworm, beet armyworm, large stem borer, cotton bollworm, *Diamond borer*, small cutworm, large cutworm, yellow cutworm, tussock moth, gypsy moth, sweet potato hawk moth, bean hawk moth, straight-striped rice skipper, hidden-striped rice skipper, citrus swallowtail butterfly, white-banded swallowtail butterfly, cabbage white butterfly, ramie red nymph, ramie yellow nymph, bean blister beetle, golden ground beetle, wrinkled sheath beetle, wheat ear beetle, wireworm, fine-breasted wireworm, grain bark beetle, black bark beetle, citrus small jewel beetle, golden-edged jewel beetle, yellow mealworm, black mealworm, red flour beetle, mixed flour beetle, green-green scarab beetle, dark scarab beetle, North China large Black-breasted beetle, mulberry longhorn beetle, star longhorn beetle, orange brown longhorn beetle, peach red-necked longhorn beetle, large ape leaf beetle, small ape leaf beetle, yellow cucumber beetle, yellow striped flea beetle, green bean weevil, pea weevil, broad bean weevil, corn weevil, rice weevil, wheat leaf beetle, pear fruit wasp, yellow-banded ichthys wasp, armyworm white-spotted ichthys wasp, moth larvae hanging cocoon ichthys wasp, cotton bollworm toothed ichthys wasp, moth black-spotted wart ichthys wasp, mosquito, fly, horsefly, wheat red midge, wheat yellow midge, rice gall midge, citrus fruit fly, melon fruit fly, wheat leaf gray leafminer, American serpentine leafminer, bean stalk black leafminer, wheat straw fly, seed fly, onion fly, turnip fly, umbrella-skirted parasitic fly, corn borer parasitic fly, armyworm;

[0070] The insecticidal composition controls plants selected from: rice, wheat, barley, oats, corn, sorghum, sweet potato, potato, cassava, soybean, snow pea, broad bean, pea, mung bean, adzuki bean, cotton, silkworm, peanut, rapeseed, sesame, sunflower, beet, sugarcane, coffee, cocoa, ginseng, fritillaria, rubber, coconut, oil palm, sisal, tobacco, tomato, chili pepper, radish, cucumber, cabbage, celery, pickled mustard greens, beet, rapeseed, onion, garlic, watermelon, cantaloupe, honeydew melon, papaya, apple, citrus and peach trees, tea, wild vegetables, bamboo shoots, hops, pepper, banana, papaya, orchid, and bonsai.

[0071] The 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I, combined with any one or two of the fungicides, forms a fungicidal composition for the prevention and control of diseases in agricultural, forestry, and horticultural plants.

[0072] The fungicides are selected from: benzothiadiazole, thiamethoxam, methyl thiamethoxam, DL-β-aminobutyric acid, isothiazamide, ribavirin, antofenfen, ningnanmycin or salicylic acid, cymoxanil, thiram, zinc thiram, mancozeb, aluminum fosetyl-aluminum, thiophanate-methyl, chlorothalonil, dichlorvos, iprodione, benzyl benzoate, thiophanate-methyl, thiophanate-methyl, metalaxyl, flumorph, dimethomorph, high-efficiency metalaxyl, high-efficiency benzyl benzoate, diclofenac, sulfadiazine, mesotrione, thiabendazole, chlorothalonil, propiconazole, cyclopropiconazole, cyclofluoroacetate, cyclopropiconazole, cyproconazole, silthiamethoxam, carbendazim, oxidized carbendazim, carbendazim, mefenoxam, chlorpyrifos, fluopyram, furazolidone, thiabendazole, cyproconazole, pyraclostrobin, pyraclostrobin, bifenazate, fluopyram, fluorinated parabens. Azoxystrobin, fluopyram, fluopyram aniline, benzyl-fluoroquinolones, isothiazamide, fluopyram hydroxylamine, flufenoxuron, fluopyram, diyrylamide, benzylamide, ethoxysulfuron, iprodione, pyraclostrobin, azoxystrobin, fluopyram, azoxystrobin, fenoxystrobin, oxadiazon, azoxystrobin, oxadiazon, oxadiazon, oxadiazon, oxadiazon, oxadiazon, oxadiazon, oxadiazon, oxadiazon, oxadiazon, oxadiazon, fenoxystrobin Azoxystrobin, propiconazole, difenoconazole, tebuconazole, high-efficiency tebuconazole, flutriafol, cyproconazole, fluquinazole, flusilazole, fenbendazole, hexaconazole, imidacloprid, tebuconazole, propiconazole, thiophanate-methyl, siloxyfenozide, tebuconazole, tetrafluoroether, triazole, tebuconazole, bifenthrin, thiamethoxam, cyproconazole, imazalil, high-efficiency imazalil, prochloraz. Fluopyram, Cyazofamid, Imidacloprid, Oxalide, Isoprothiolane, Oxalide, Pyrimethanil, Oxafloxacin, Oxafloxacin, Thiazolamide, Tebuconazole, Benzylthiocyanate, Dodecylmorpholine, Butylmorpholine, Tridemorpholine, Seed dressing, Fludioxonil, Fluazinam, Pyridabenoxac, Cyclopyridamole, Fluazinam, Pyrimethanil, Azoxystrobin, Fluazinam, Thifluzamide, Azoxystrobin, Pyrimethanil, Chlorpyrimethanil, Fluazinam, Acaricide, Dicyandioxonone, Ethoxyquinoline, Hydroxyquinoline, Propoxyquinoline, Phenoxyquinoline, Ethiocarb, Isopropamidone, Benzylthiamethoxam, Cymoxanil, Sulfocarb, Difenoconazole, Isoprothiolane, Pyridaben, Methyl thiophanate, Pyrimethanil, Kasugamycin, Polyoxin, Polyoxin, Activiamycin, Jinggangmycin, Streptomycin, Metalaxyl, Furazolidone Benzoyl, furazolidone, carbendazim, benomyl, thiophanate-methyl, triadimefon, ethirimol sulfonate, dimethomorph, ethirimol, captan, captan, thiophanate-methyl, chlorothalonil, fluchlorothalonil, chlorothalonil, isoprothiolane, isoprothiolane, tebuconazole, pentachloronitrobenzene, propineb, aluminum tris(ethylphosphonate), sulfur, Bordeaux mixture, copper sulfate, copper oxychloride, cuprous oxide, copper hydroxide, benomyl, pendimethalin, pyridaben, tetrachlorophthalide, quinclorac, spirocycline, tricyclazole, pyrazosulfuron, doxycycline, biguanide octyl salt, biguanide octylamine, chlorothalonil, benzylsulfonamide, toluenesulfonamide, indole ester, sodium dichloroisocyanurate, quinclorac, allylbenzylthiazide, bromonitol, iodomethyl, methyl methoxide, dimethoate, dazomet, dichloroisopropyl ether, thiamethoxam, fensodium, fenoxam, fenpyroxim, fenpyroximKiller carbendazim, thiocyanate, dichloropropene, dichloroisocyanuric acid, allylisothiazol;

[0073] The total mass percentage of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the bactericidal composition is 1%-90%; the ratio of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I to the bactericide is 1%:99% to 99%:1% by mass percentage.

[0074] The formulation of the bactericidal composition is selected from: seed treatment emulsions, water-in-oil emulsions, microemulsions, suspensions, capsule suspensions, water-soluble granules, fine granules, soluble concentrates, poison grains, block poison baits, granular poison baits, flake poison baits, concentrated poison baits, slow-release blocks, electrostatic sprays, oil-in-water emulsions, smoke cans, smoke candles, smoke tubes, smoke sticks, smoke sheets, smoke pellets, gas generators, ointments, hot fogging agents, cold fogging agents, aerosols, solid / liquid mixtures, liquid / liquid mixtures, solid / solid mixtures, medicated paints, microparticles, tracking powders, oil suspensions, oil-dispersible powders, concentrated gels, pouring agents, seed coating agents, coating agents, film-forming oils, ultra-low volume liquids, and vapor release agents;

[0075] The plant diseases controlled by the bactericidal composition are selected from: rice seedling cottony rot, tomato root rot, potato late blight, tobacco black shank, millet powdery mildew, grape downy mildew, lettuce downy mildew, cucumber downy mildew, and cucumber anthracnose.

[0076] The plants suitable for use in the bactericidal composition are selected from: rice, wheat, barley, oats, corn, sorghum, sweet potato, potato, cassava, soybean, snow pea, broad bean, pea, mung bean, adzuki bean, cotton, silkworm, peanut, rapeseed, sesame, sunflower, beet, sugarcane, coffee, cocoa, ginseng, fritillaria, rubber, coconut, oil palm, sisal, tobacco, tomato, chili pepper, radish, cucumber, cabbage, celery, pickled mustard greens, beet, rapeseed, onion, garlic, watermelon, cantaloupe, honeydew melon, papaya, apple, citrus and peach trees, tea, wild vegetables, bamboo shoots, hops, pepper, banana, papaya, orchid, and bonsai.

[0077] The 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I, combined with any one or two of the antiviral agents, forms an antiviral composition for the prevention and control of viral diseases in agricultural, forestry, and horticultural plants.

[0078] The antiviral agents are selected from: benzothiadiazole, thiamethoxam, isothiazine DL-β-aminobutyric acid, 2,6-dichloroisonicotinic acid, N-cyanomethyl-2-chloroisonicotinamide, allylisothiazide, ribavirin, antofen, ningnanmycin, methiazolinone or salicylic acid, pyrimethanil, dichloroisonicotinic acid, allylisothiazide, jinggangmycin, and morpholine guanidine hydrochloride;

[0079] The total mass percentage of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the antiviral composition is 1%-90%; preferably, the ratio of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I to the anti-plant virus agent is 1%:99% to 99%:1% by mass percentage.

[0080] The dosage forms of the antiviral composition are selected from: seed treatment emulsions, water-in-oil emulsions, microemulsions, suspensions, capsule suspensions, water-soluble granules, fine granules, soluble concentrates, poison grains, block poison baits, granular poison baits, flake poison baits, concentrated poison baits, slow-release blocks, electrostatic sprays, oil-in-water emulsions, smoke cans, smoke candles, smoke tubes, smoke sticks, smoke sheets, smoke pellets, gas generators, ointments, hot fogging agents, cold fogging agents, aerosols, solid / liquid mixtures, liquid / liquid mixtures, solid / solid mixtures, medicated paints, microparticles, tracking powders, oil suspensions, oil-dispersible powders, concentrated gels, pouring agents, seed coating agents, coating agents, film-forming oils, ultra-low volume liquids, and vapor release agents.

[0081] The antiviral composition controls viral diseases selected from: rice dwarf virus, yellow dwarf virus, stripe leaf blight, tomato fern leaf virus, pepper mosaic virus, tobacco vein necrosis virus, maize dwarf mosaic virus, cauliflower mosaic virus, citrus virus, Cymbidium faberi leaf virus, and Cymbidium faberi ringspot virus.

[0082] The antiviral composition is used to prevent and control diseases from plants selected from: rice, wheat, barley, oats, corn, sorghum, sweet potato, potato, cassava, soybean, snow pea, broad bean, pea, mung bean, adzuki bean, cotton, silkworm, peanut, rapeseed, sesame, sunflower, beet, sugarcane, coffee, cocoa, ginseng, fritillaria, rubber, coconut, oil palm, sisal, tobacco, tomato, chili pepper, radish, cucumber, cabbage, celery, pickled mustard greens, beet, rapeseed, onion, garlic, watermelon, cantaloupe, honeydew melon, papaya, apple, citrus and peach trees, tea, wild vegetables, bamboo shoots, hops, pepper, banana, papaya, orchid, and bonsai.

[0083] The 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I, combined with any one or two of the acaricides, forms an acaricide composition for the prevention and control of mite pests in agricultural, forestry, and horticultural plants.

[0084] The acaricides are selected from: dichlorvos, heptamethrin, methamidophos, dibromophos, pyrimiphos, chlorpyrifos, ethion, chlorfenapyr, fenpropathrin, methyl pyrimiphos, quinalphos, abamectin, acephate, chlorpyrifos, fenpropathrin, bifenthrin, cyhalothrin, lambda-cyhalothrin, cypermethrin, flufenoxuron, deltamethrin, bifenazate, benzalkonium chloride, methyl ethyl methyl methoxide, chlorpyrifos, chlorfenapyr, chlorpyrifos, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr, chlorfenapyr. Carbendazim, thiamethoxam, tebufenozide, benzyl benzoate, bromopropylate, diflubenzuron, fenpyroximate, flufenoxuron, liuyangmycin, chlorfenapyr, thiophanate-methyl, acaricide, liuyangmycin, avermectin, doramectin, epoxim, ivermectin, selamectin, moxibustion, pyrethroid, nicotine, matrine, azadirachtin, rotenone, pyridaben, pyridaben, azoxystrobin, tetradifon, propargite, thiamethoxam, spirodiclofen, pyrimethanil, dicofol, dicofol, pyridaben;

[0085] The total mass percentage of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the acaricide composition is 1%-90%; the ratio of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I to the acaricide is 1%:99% to 99%:1% by mass.

[0086] The formulation of the acaricide composition is selected from: seed treatment emulsions, water-in-oil emulsions, microemulsions, suspensions, capsule suspensions, water-soluble granules, fine granules, soluble concentrates, poison grains, block poison baits, granular poison baits, flake poison baits, concentrated poison baits, slow-release blocks, electrostatic sprays, oil-in-water emulsions, smoke cans, smoke candles, smoke tubes, smoke sticks, smoke sheets, smoke pellets, gas generators, ointments, hot fogging agents, cold fogging agents, aerosols, solid / liquid mixtures, liquid / liquid mixtures, solid / solid mixtures, medicated paints, microparticles, tracking powders, oil suspensions, oil-dispersible powders, concentrated gels, pouring agents, seed coating agents, coating agents, film-forming oils, ultra-low volume liquids, and vapor release agents;

[0087] The mites controlled by the acaricidal composition are selected from: mites from the Tetranychidae, Tetranychidae, Fusarium, Eriophyridae, Chlorella, and Eriophyridae families, and the mites are global agricultural mites, forestry mites, horticultural mites, and sanitary mites.

[0088] The acaricide composition is used to control plants selected from: rice, wheat, barley, oats, corn, sorghum, sweet potato, potato, cassava, soybean, snow pea, broad bean, pea, mung bean, adzuki bean, cotton, silkworm, peanut, rapeseed, sesame, sunflower, beet, sugarcane, coffee, cocoa, ginseng, fritillaria, rubber, coconut, oil palm, sisal, tobacco, tomato, chili pepper, radish, cucumber, cabbage, celery, pickled mustard greens, beet, rapeseed, onion, garlic, watermelon, cantaloupe, honeydew melon, papaya, apple, citrus and peach trees, tea, wild vegetables, bamboo shoots, hops, pepper, banana, papaya, orchid, and bonsai.

[0089] The bioactivity of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I described in this invention was determined as follows:

[0090] Determination of the bactericidal activity of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I of the present invention:

[0091] The bactericidal or bacteriostatic activity of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I of the present invention was determined by the cell growth rate assay. The specific steps were as follows: 1.8 mg of sample was dissolved in 2 drops of dimethyl sulfoxide, and then diluted to 500 μg / mL with an aqueous solution containing a certain amount of Tween 20 emulsifier. Under aseptic conditions, 1 mL of the test reagent was placed in each petri dish, and 9 mL of PDA medium was added to each dish. After shaking well, a 50 μg / mL drug-containing plate was prepared. A plate containing 1 mL of sterile water was used as a blank control. Using a 4 mm diameter punch, mycelial discs were cut along the outer edge of the hyphae and transferred to drug-containing plates, arranged in an equilateral triangle. Each treatment was repeated three times. The petri dishes were incubated in a constant temperature incubator at 24 ± 1 degrees Celsius. After the control colony diameter expanded to 2-3 cm, the expansion diameter of the mycelial discs in each treatment was investigated, and the average value was calculated. The relative inhibition rate was calculated by comparing the average value with the blank control. The tested fungal species are most of the typical plant pathogens that actually occur in the field in my country's agricultural production. Their codes and names are as follows: As: Tomato early blight pathogen, its Latin name is Alternaria. solani, Bc: Botrytis cinerea, the causal agent of gray mold in cucumber; Ca: Cercospora aracidola, the causal agent of brown spot in peanut; Fg: Fusarium graminearum, the causal agent of Fusarium graminearum in cereals; Pp: Physalosporapiricola, the causal agent of ring rot in apples; Rs: Rhizoctonia solani, the causal agent of sheath blight in rice; Ss: Sclerotinia sclerotiorum, the causal agent of sclerotinia in rapeseed.

[0092] Assay of the plant immunomodulatory activity of the present invention containing 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I:

[0093] The plant immunomodulatory activity of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I of this invention was determined by spore counting. The specific steps were as follows: Arabidopsis leaves, 24 hours after spraying with 50 μmol of the agent, were inoculated with *Arabidopsis thaliana* downy mildew. Leaves containing downy mildew spores, stored at -80°C, were thawed on ice and then placed at room temperature. The leaves were then immersed in sterile water to wash away the spores attached to the leaves, and spore viability was detected under a microscope. After confirming spore viability, sterile water containing spores was sprayed onto Arabidopsis leaves approximately 10 days later. Finally, the leaves were cultured under moist conditions: 18°C, 16 hours light / 8 hours dark. One week later, diseased Arabidopsis leaves were collected, and downy mildew spores were washed away with sterile water, adjusting the spore concentration to 5 × 10⁻⁶. 4 The colony count was determined per milliliter, and the solution was then evenly sprayed onto Arabidopsis leaves that had grown for approximately 10 days. The leaves were kept well-moistened and incubated in a light incubator at 18°C ​​with 16 hours of light / 8 hours of darkness. Disease incidence was observed in Arabidopsis after approximately 7 days, and spore counts were performed. The tested fungal species was *Hyaloperonospora arabidopsidis*, whose code and name are as follows: Ha: *Hyaloperonospora arabidopsidis*.

[0094] The beneficial effects of this invention are: the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I was synthesized, and the antibacterial activity and plant immune activity of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I were screened.

[0095] This invention further illustrates the synthesis, bioactivity, and applications of 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I through specific preparation and bioactivity assay examples. Detailed Implementation

[0096] The embodiments described are for illustrative purposes only and are not intended to limit the invention. In particular, the biological activity is only illustrative and not intended to limit the patent. The specific implementation methods are as follows:

[0097] Example 1: Preparation of compound I-1:

[0098] (1) Take a 100 mL round-bottom flask and add an anhydrous ethanol (25 mL) solution of ethyl 6-chloro-1H-indole-2-carboxylate (10.0 mmol, 1.0 equivalence). At room temperature, add 80% hydrazine hydrate (20.0 mmol, 2.0 equivalence) dropwise to the reaction system. Stir the mixture at 80 °C for 4 hours (TLC monitoring). After the reaction is complete, a solid precipitates out. Filter the solid and dry it to obtain 6-chloro-1H-indole-2-carbazide (white solid, 1.88 g, 90% yield).

[0099] (2) Take a 100 mL round-bottom flask and add 6-chloro-1H-indole-2-carbonylhydrazide (2.0 mmol, 1.0 equivalence), triethyl orthoformate (6.0 mmol, 3.0 equivalence), p-toluenesulfonic acid (0.2 mmol, 0.2 equivalence), and N,N-dimethylformamide (10.0 mL) in sequence. Heat the mixture under reflux at 100 °C for 12 hours (TLC monitoring). Then cool the mixture to room temperature. Wash the reaction solution with ethyl acetate (20 mL) and brine (20 mL), dry with anhydrous sodium sulfate, and concentrate under vacuum. Remove the solvent under reduced pressure. Purify the residue by silica gel column chromatography with ethyl acetate / petroleum ether as the eluent. The purified product is a yellow solid compound I-1, 195.1 mg, with a yield of 90%.

[0100] Example 2: Preparation of compound I-10:

[0101] (1) Take a 100 mL round-bottom flask and add 7-bromo-1H-indole-2-carbonylhydrazine (2.0 mmol, 1.0 equivalence), triethyl orthoformate (6.0 mmol, 3.0 equivalence), p-toluenesulfonic acid (0.2 mmol, 0.2 equivalence), and N,N-dimethylformamide (10.0 mL) in sequence. Heat the mixture under reflux at 100 °C for 12 hours (TLC monitoring). Then cool the mixture to room temperature. Wash the reaction solution with ethyl acetate (20 mL) and brine (20 mL), dry with anhydrous sodium sulfate, and concentrate under vacuum. Remove the solvent under reduced pressure. Purify the residue by silica gel column chromatography with ethyl acetate / petroleum ether as the eluent. The purified product is a yellow solid compound I-9, 224.5 mg, with a yield of 85%.

[0102] (2) Take a 100 mL round-bottom flask and add 2-(7-bromo-1H-indol-2-yl)-1,3,4-oxadiazole (2.0 mmol, 1.0 equivalent), 3,4-dichlorophenylboronic acid (2.0 mmol, 2.0 equivalent), bis(triphenylphosphine)palladium chloride (0.1 mmol, 0.05 equivalent), potassium carbonate (4.0 mmol, 2.0 equivalent), and 1,4-dioxane (10.0 mL) in sequence. Heat under reflux at 80°C for 12 hours (TLC follow). After the tracer detection, the mixture was cooled to room temperature; the reaction solution was washed with ethyl acetate (20 mL) and brine (20 mL), dried over anhydrous sodium sulfate and concentrated under vacuum, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography with ethyl acetate / petroleum ether as the eluent to give 2-(7-(3,4-dichlorophenyl)-1H-indol-2-yl)-1,3,4-oxadiazole compound I-10 (yellow solid, 264.0 mg, yield 80%).

[0103] Example 3: Preparation of compound I-17:

[0104] (1) Take a 100 mL round-bottom flask and add 7-nitro-1H-indole-2-carbonylhydrazine (2.0 mmol, 1.0 equivalence), triethyl orthoformate (6.0 mmol, 3.0 equivalence), p-toluenesulfonic acid (0.2 mmol, 0.2 equivalence), and N,N-dimethylformamide (10.0 mL) in sequence. Heat the mixture under reflux at 100 °C for 12 hours (TLC monitoring). Then cool the mixture to room temperature. Wash the reaction solution with ethyl acetate (20 mL) and brine (20 mL), dry with anhydrous sodium sulfate, and concentrate under vacuum. Remove the solvent under reduced pressure. Purify the residue by silica gel column chromatography with ethyl acetate / petroleum ether as the eluent to obtain compound I-15 (yellow solid, 284.1 mg, yield 83%).

[0105] (2) Take a 100 mL round-bottom flask and add 2-(7-nitro-1H-indol-2-yl)-1,3,4-oxadiazole (1.0 mmol, 1.0 equivalent), iron powder (3.0 mmol, 3.0 equivalent), ammonium chloride (3.0 mmol, 3.0 equivalent) and a mixture of ethanol and water (v / v = 2:1, 9.0 mL) in sequence. Heat the mixture under reflux at 80 °C for 4 hours (TLC monitoring). Filter the mixture while it is hot. Wash the filtrate with ethyl acetate (20 mL) and brine (20 mL), dry it with anhydrous sodium sulfate and concentrate it under vacuum. Remove the solvent under reduced pressure. Purify the residue by silica gel column chromatography with ethyl acetate / petroleum ether as the eluent to obtain I-16 (yellow solid, 150.2 mg, yield 75%).

[0106] (3) N,N-diisopropylethylamine (2.0 mmol, 2.0 equivalence) was added to an anhydrous dichloromethane solution containing 2-(7-amino-1H-indol-2-yl)-1,3,4-oxadiazole (I-16, 1.0 mmol, 1.0 equivalence); the reaction mixture was stirred at room temperature for 0.5 hours, and then a dichloromethane solution of cyclopropionyl chloride (1.1 mmol, 1.1 equivalence) was slowly added dropwise to the reaction system at 0°C; after the addition was complete, the reaction mixture was stirred at room temperature for 12 hours (TLC monitoring); after the reaction was completed, the mixture was extracted with dichloromethane (3 × 10 mL) and brine (10 mL), the organic layers were combined and collected, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and the residue was purified by silica gel column chromatography, eluted with ethyl acetate / petroleum ether, to give compound I-17 (yellow solid, 193.2 mg, yield 72%).

[0107] Example 4: Preparation of compound I-22:

[0108] N,N-diisopropylethylamine (2.0 mmol, 2.0 equivalence) was added to an anhydrous dichloromethane solution containing 2-(7-amino-1H-indol-2-yl)-1,3,4-oxadiazole (I-16, 1.0 mmol, 1.0 equivalence). The reaction mixture was stirred at room temperature for 0.5 hours, and then a dichloromethane solution of ethylsulfonyl chloride (1.1 mmol, 1.1 equivalence) was slowly added dropwise to the reaction system at 0°C. After the addition was complete, the reaction mixture was stirred at room temperature for 12 hours (TLC monitoring). After the reaction was completed, the mixture was extracted with dichloromethane (3 × 10 mL) and brine (10 mL), the organic layers were combined and collected, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and the residue was purified by silica gel column chromatography, eluted with ethyl acetate / petroleum ether, to give compound I-22 (yellow solid, 184.2 mg, yield 63%).

[0109] Example 5: Preparation of compound I-27:

[0110] Compound I-1 (1.0 mmol, 1.0 equivalence), potassium carbonate (1.5 mmol, 1.5 equivalence), and N,N-dimethylformamide solution (5.0 mL) were added to a 100 mL round-bottom flask. The mixture was stirred at room temperature, and then 1-iodopropane (1.1 mmol, 1.1 equivalence) was added. The mixture was stirred at 100 °C for 3–5 hours (TLC monitoring). The mixture was then cooled to room temperature, washed with brine (10 mL), and extracted with ethyl acetate (3 × 10 mL). The organic phases were combined and collected. The organic phases were dried over anhydrous sodium sulfate and concentrated under vacuum. The solvent was removed under reduced pressure. The residue was purified by silica gel column chromatography (200–300 mesh) using ethyl acetate / petroleum ether as the eluent to give compound I-27 (yellow solid, 235.5 mg, 90% yield).

[0111] Example 6: Preparation of compound I-40:

[0112] (1) Under ice bath conditions, phosphorus oxychloride (0.5 mL) and N,N-dimethylformamide (2.0 mL) were added sequentially to a 100 mL round-bottom flask. After stirring for 0.5 hours, the mixture was transferred to room temperature. A solution of 2-(6-chloro-1-propyl-1H-indol-2-yl)-1,3,4-oxadiazole (I-27, 1.0 mmol, 1.0 equivalence) in N,N-dimethylformamide (5.0 mL) was added, and the mixture was reacted at 80 °C for 4 hours (TLC). (Follow-up detection); then, the reaction solution was poured into ice water, the pH of the reaction solution was adjusted to neutral with saturated sodium bicarbonate, washed with brine (10 mL) and extracted with ethyl acetate (3 × 10 mL), and the organic phases were combined and collected; the organic phase was dried over anhydrous sodium sulfate and concentrated under vacuum, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography with ethyl acetate / petroleum ether as the eluent to give compound I-38 (yellow solid, 197.0 mg, yield 68%).

[0113] (2) Compound I-38 (1.0 mmol, 1.0 equivalence), hydroxylamine hydrochloride (1.5 mmol, 1.5 equivalence), potassium carbonate (0.8 mmol, 0.8 equivalence), and ethanol and water (v / v = 2:1) were added to a 100 mL round-bottom flask. The mixture was stirred at 100 °C for 3–5 hours (TLC monitoring). The mixture was then cooled to room temperature, washed with brine (10 mL), and extracted with ethyl acetate (3 × 10 mL). The organic phases were combined and collected. The organic phases were dried over anhydrous sodium sulfate and concentrated under vacuum. The solvent was removed under reduced pressure. The residue was purified by silica gel column chromatography (200–300 mesh) using ethyl acetate / petroleum ether as the eluent to give compound I-39 (yellow solid, 201.1 mg, yield 66%).

[0114] (3) Sodium hydride (80.0 mg, 2.0 mmol, 2.0 equivalence, 60 wt%, in mineral oil) was slowly added to a tetrahydrofuran solution (3.0 mL) of compound I-39 (1.0 mmol, 1.0 equivalence); the reaction mixture was stirred at room temperature for 0.5 hours, and then a tetrahydrofuran solution (1.0 mL) of iodomethane (1.1 mmol, 1.1 equivalence) was added dropwise, and the mixture was stirred at room temperature for 3–5 hours (TLC monitoring); after the reaction was complete, 10 mL of 1 mol / L ammonium chloride aqueous solution and 30 mL of ethyl acetate were added, and the organic layer was extracted with brine (3 × 10 mL); the organic layers were combined and collected, dried over anhydrous sodium sulfate and concentrated under reduced pressure; the residue was purified by silica gel column chromatography (200–300 mesh) with ethyl acetate / petroleum ether as the eluent to give compound I-40 (yellow solid, 286.9 mg, yield 90%).

[0115] Example 7: Results of antibacterial activity assay of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I of the present invention:

[0116] The common plant pathogenic fungi tested in this invention are coded and named as follows: As: *Alternaria solani*, the Latin name for early blight of tomato; Bc: *Botrytis cinerea*, the Latin name for gray mold of cucumber; Ca: *Cercospora arachidicola*, the Latin name for brown spot of peanut; Fg: *Fusarium graminearum*, the Latin name for Fusarium graminearum; Pp: *Physalospora piricola*, the Latin name for ring rot of apple; Rs: *Rhizoctonia solani*, the Latin name for sheath blight of rice; Ss: *Sclerotinia sclerotiorum*, the Latin name for sclerotinia sclerotiorum, the Latin name for sclerotinia sclerotiorum. These species are highly representative and can represent most of the pathogenic fungi occurring in the field during agricultural production.

[0117] The results of the cell growth rate assay are shown in Table 2. Table 2 shows that all compounds synthesized in this invention exhibited varying degrees of fungicidal activity at 50 μg / mL. The bioactivity of the new compounds was determined using different types of commercially available fungicides such as thifluzamide, fluopyram, pyrimethanil, pyraclostrobin, and the lead structure YZK-C22 as positive controls. The results showed that for *Phytophthora blight* of tomato, compounds I-6 and I-7 exhibited fungicidal activity above 75%, comparable to the controls thifluzamide (70.8%), pyraclostrobin (80.5%), and YZK-C22 (78.9%). For *Gyromitra esculenta* of cucumber, most compounds showed good fungicidal activity. The activity of compounds I-7, I-9, I-10, I-13, I-29, I-34, I-35, I-37, and I-47 was greater than 90%, with compounds I-27 and I-28 achieving 100% inhibition. This was comparable to the control drugs pyrimethanil and YZK-C22, and superior to pyraclostrobin (86.5%), thifluzamide (30.4%), and fluopyram (63.2%). Against peanut brown spot pathogens, compounds I-7 and I-9 showed fungicidal activity of over 70%. The inhibition rates of compounds I-7, I-9, I-24, I-37, and I-39 against Fusarium graminearum were slightly lower than those of the control drugs thifluzamide (100%), pyraclostrobin (81.2%), and YZK-C22 (100%), which were greater than 60%, and higher than the positive control drugs pyrimethanil (36.6%), fluopyram (46.6%), and thifluzamide (26.8%). Against rice sheath blight, the inhibition rates of compounds I-9, I-27, I-28, and I-37 were all above 70%. Among them, compound I-7 achieved an inhibition rate of 100%, which was basically comparable to that of pyraclostrobin (100%), pyrimethanil (94.7%), fluopyram (94.0%), thifluzamide (100%), and YZK-C22 (90.1%). In summary, compounds I-7, I-9, I-27, and I-28 exhibited high fungicidal activity. Further results of the precise toxicity assay for the antifungal activity of these fungicides are shown in Table 3. Table 3 indicates that for Rhizoctonia solani, compound I-28 showed the highest EC50 concentration. 50 Comparable to lead compound YZK-C22 (3.14 μg / mL); EC50 values ​​for compounds I-6, I-7, I-9, I-10, I-13, I-18, I-25, I-27, I-28, I-29, I-30, I-34, I-37, and I-47 against cucumber gray mold. 50 Superior to the lead compound YZK-C22 (8.78 μg / mL), among which compounds I-9, I-18, I-25, I-27, I-28, I-30, I-34, and I-37 showed better EC50 performance. 50The activity was superior to or comparable to commercial fungicides pyraclostrobin (1.30 μg / mL) and pyrimethanil (0.99 μg / mL) in the range of 0.12 μg / mL to 1.84 μg / mL; for Fusarium graminearum, compound I-9 had an EC50 value of 0.12 μg / mL. 50 The EC of YZK-C22 is 7.15 μg / mL. 50 The concentration was 6.13 μg / mL; for early blight pathogens of tomato, the EC50 of compounds I-6, I-7, and I-9 was... 50 The EC values ​​for YZK-C22 were 11.71 μg / mL, 5.33 μg / mL, and 10.35 μg / mL, respectively. 50 It was 11.09 micrograms per milliliter.

[0118] Example 8: Results of the assay of the plant immunomodulatory activity of the present invention containing 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I:

[0119] The test strain used in this invention was *Hyaloperonospora arabidopsidis*, whose code and name are as follows: Ha: *Hyaloperonospora arabidopsidis*. The results of the plant immune activity assay are shown in Table 4. Table 4 shows that compounds I-7 and I-47 had inhibition rates greater than 50% against *Hyaloperonospora arabidopsidis*. Compound I-7 had an inhibition rate of 67.5%, making it a candidate compound for plant immune activator, slightly lower than the inhibition rate of the positive control benzothiadiazole (79.7%). No literature reports have been found regarding the plant immune activating activity of indole and oxadiazole derivatives.

[0120] Example 9: Application of the present invention in combination with an insecticide containing 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the control of agricultural, forestry, and horticultural plant pests:

[0121] The present invention relates to an insecticidal composition comprising a 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I and any one or two commercial insecticides for the control of agricultural, forestry, and horticultural plant pests. The commercial insecticides are selected from: imidacloprid, difenoconazole, acetamiprid, emamectin, mibamectin, abamectin, spinosad, fenflurfen, cypermethrin, lambda-cyhalothrin, deltamethrin, deltamethrin, cypermethrin, β-cypermethrin, λ-cypermethrin, dichlorvos, permethrin, allethrin, bifenthrin, permethrin, fenflurfen, flufenoxuron, and flufenoxuron. Cypermethrin, imidacloprid, acetamiprid, chlorpyrifos, thiamethoxam, thiamethoxam, dinotefuran, conidine, datnam, diflubenzuron, diflubenzuron, flufenoxuron, flufenoxuron, acetamiprid, lufenuron, fenflurfen, flufenoxuron, polyfluorourea, flufenoxuron, difenoconazole, flufenoxuron, fenflurfen, chlorfenapyr, methoxyfenozide, cyclophosphamide, dichlorvos, quinalphos, pyridaben, leafhopper spray, carbaryl, imidacloprid, fenpropathrin, isoprocarb, fenitrothion, sec-butylcarbide, leaf spray, carbaryl, fenitrothion, bromopropylate, thiamethoxam, azoxystrobin, pyridaben, tetradifon, propargite, difenoconazole, pymetrozine Spirodiclofen, spirotetramat, spirotetramat, triazophos, thiamethoxam, cartap, chlorantraniliprole, tetrachlorantraniliprole, flufenoxuron, flufenoxuron, cyantraniliprole, butenpyram, acetamiprid, bromfenoxuron, pyrazinone, etoxazole, pyridoxamine, pyridaben, pyriproxyfen, emamectin, pendimethalin; the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I of the present invention has a mass percentage content of 1%-90% in the insecticidal composition, and the ratio of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I of the present invention to the aforementioned commercial insecticides is 1%:99% to 99%:1% by mass percentage. The formulation of the insecticidal composition is selected from: seed treatment emulsions, water-in-oil emulsions, microemulsions, suspensions, capsule suspensions, water-soluble granules, fine granules, soluble concentrates, poison grains, block poison baits, granular poison baits, flake poison baits, concentrated poison baits, slow-release blocks, electrostatic sprays, oil-in-water emulsions, smoke cans, smoke candles, smoke tubes, smoke sticks, smoke sheets, smoke pellets, gas generators, ointments, hot fogging agents, cold fogging agents, aerosols, solid / liquid mixtures, liquid / liquid mixtures, solid / solid mixtures, medicated paints, microparticles, tracking powders, oil suspensions, oil-dispersible powders, concentrated gels, pouring agents, seed coating agents, coating agents, film-forming oils, ultra-low volume liquids, and vapor release agents.The insecticidal composition is suitable for the following plant pests: fall armyworm, spider mite, Oriental migratory locust, spotted locust, Chinese rice locust, Japanese yellow-spined locust, single-spined mole cricket, oriental mole cricket, rice thrips, tobacco thrips, greenhouse thrips, rice tube thrips, wheat tube thrips, greenhouse whitefly, tobacco whitefly, black-tailed leafhopper, large green leafhopper, cotton leafhopper, spotted lanternfly, brown planthopper, white-backed leafhopper. Planthoppers, gray planthoppers, sugarcane flat-horned planthoppers, cotton aphids, wheat two-pronged aphids, wheat long-tubed aphids, peach aphids, sorghum aphids, radish aphids, cottony cushion scale, mulberry shield scale, arrowhead shield scale, pear round scale, white wax insect, red wax scale, Korean ball scale, pear lace bug, banana lace bug, slender flower bug, tiny flower bug, needle-edged bug, rice spider-edged bug, rice brown bug, rice black bug, rice green bug, green mirid bug, alfalfa mirid bug, Black mirid bug, large lacewing, beautiful lacewing, Chinese lacewing, grain moth, clothes moth, yellow tussock moth, brown tussock moth, flat tussock moth, wheat moth, cotton bollworm, sweet potato wheat moth, diamondback moth, peach fruit moth, soybean fruit moth, peach fruit moth, apple top leafroller, brown-banded long leafroller, false yellow leafroller, rice stem borer, bean pod borer, corn borer, three-spined rice stem borer, cabbage stem borer, rice leaf roller, rice leaf roller The following are listed: Rice leaf roller, cotton leaf roller, peach borer, armyworm, beet armyworm, rice stem borer, cotton bollworm, beet armyworm, large stem borer, cotton bollworm, *Gnaphalium affine*, cutworm, large cutworm, yellow cutworm, tussock moth, gypsy moth, sweet potato hawk moth, bean hawk moth, straight-striped rice skipper, hidden-striped rice skipper, citrus swallowtail butterfly, white-banded swallowtail butterfly, cabbage white butterfly, ramie red ramie butterfly, ramie yellow ramie butterfly. Butterfly, Bean Fern, Golden Ground Beetle, Wrinkled-Sheath Ground Beetle, Wheat Ear Ground Beetle, Threadworm, Fine-breasted Threadworm, Grain-spotted Ground Beetle, Black Ground Beetle, Citrus Small Jewel Beetle, Golden-edged Jewel Beetle, Yellow Mealworm, Black Mealworm, Red Flour Beetle, Mixed Flour Beetle, Green-green Scarab Beetle, Dark Scarab Beetle, North China Large Black-gilled Scarab Beetle, Mulberry Longhorn Beetle, Star Longhorn Beetle, Orange Brown Longhorn Beetle, Peach Red-necked Longhorn Beetle, Large Ape Leaf Beetle, Small Leaf beetle, cucumber beetle, yellow-striped flea beetle, bean weevil, pea weevil, broad bean weevil, corn weevil, rice weevil, wheat leaf beetle, pear fruit wasp, yellow-banded ichneumon wasp, armyworm white-spotted ichneumon wasp, larval ichneumon wasp, cotton bollworm toothed ichneumon wasp, larval black-spotted wart ichneumon wasp, mosquito, fly, horsefly, wheat red midge, wheat yellow midge, rice gall midge, citrus fruit fly, melon fruit fly, wheat leaf miner, American serpentine leafminer Flies, including black leafminer flies, wheat stem flies, seed flies, onion flies, turnip flies, umbrella-shaped leafminer flies, corn borers, and armyworms; the insecticidal composition is suitable for plants selected from: rice, wheat, barley, oats, corn, sorghum, sweet potato, potato, cassava, soybean, snow pea, broad bean, pea, mung bean, adzuki bean, cotton, silkworm, peanut, rapeseed, sesame, sunflower, beet, sugarcane, coffee, cocoa, ginseng, fritillaria, rubber, coconut, oil palm, sisal, tobacco, tomato, chili pepper, radish, cucumber, cabbage, celery, pickled mustard greens, beet, rapeseed, onion, garlic, watermelon, cantaloupe, honeydew melon, papaya, apple, citrus and peach trees, tea, wild vegetables, bamboo shoots, hops, pepper, banana, papaya, orchid, and bonsai.

[0122] Example 10: Application of the present invention, in combination with fungicides, of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the prevention and control of diseases in agricultural, forestry, and horticultural plants:

[0123] The present invention relates to a fungicidal composition comprising a 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I and any one or two commercial fungicides for the control of diseases in agricultural, forestry, and horticultural plants. The commercial fungicides are selected from: benzothiadiazole, thiamethoxam, methyl thiamethoxam, isothiazine, ribavirin, anthraquinone, ningnanmycin, or salicylic acid, cymoxanil, thiram, thiram, mancozeb, fosetyl-aluminum, thiophanate-methyl, chlorothalonil, dichlorvos, iprodione, benzyl benzoate, thiophanate-methyl, thiophanate-methyl, metalaxyl, flumorph, dimethomorph, high-efficiency metalaxyl, high-efficiency benzyl benzoate, cyhalofop-p-ethyl, sulfadiazine, mesotrione, thiabendazole, chlorothalonil, propiconazole, cyclopropiconazole, cycloflufenoxam, cyclopyridamole, cyproconazole, silthiamethoxam. , ... Azoxystrobin, ethoxysulfuron, iprodione, pyraclostrobin, fenpyroxime azoxystrobin, fluopyram, fenpyroxime azoxystrobin, fenpyroxime azoxystrobin, fenpyroxime azoxystrobin, fenpyroxime azoxystrobin, oxadiazon, furazolidone, cyproconazole, difenoconazole, tebuconazole, high-efficiency tebuconazole, flutriafol, cyproconazole, fluquinazole, flusilazole, fenpyroxime azoxystrobin, hexaconazole, imidacloprid, tebuconazole, leaf fungicide Azoxystrobin, cyazofamid, tebuconazole, propiconazole, prothioconazole, silflubaconazole, tebuconazole, tetraflufenazole, triazole, tebuconazole, bifenthrin, thiamethoxam, imazalil, pyraclostrobin, prochloraz, imazalil, prochloraz, fluopyram, cyazofamid, imazalil, oxadiazon, isoprothiolane, oxadiazon, pyraclostrobin, oxadiazon, oxadiazon, thiamethoxam, terbuconazole, octothiamethoxam, benzylthiamethoxam Dodecyl morpholine, butyl morpholine, tridemorpholine, seed dressing agent, fludioxonil, fluazinam, pyridaben, cyclopyridamole, fluazinam, pyrimethanil, pyrimethanil, thifluzamide, pyrimethanil, chlorophenazine alcohol, fluphenazine alcohol, acaricide, dicyananthraquinone, ethoxyquinoline, hydroxyquinoline, propoxyquinoline, phenoxyquinoline, ethoxycarb, isopropylamine, benomyl. Fiprozil, Sulfuric acid carbendazim, Difenoconazole, Isoprothiolane, Pyraclostrobin, Methyl thiophanate, Miconazole, Kasugamycin, Polyoxin, Polyoxin, Activiamycin, Jinggangmycin, Streptomycin, Metalaxyl, Furazolidone, Benzopyr, Furazolidone, Carbendazim, Benomyl, Thiophanate-methyl, Triadimefon, Ethirimol sulfonate, Dimethomorph, Ethirimol, Captan, Captan, Captan, Ethylbenzene, Fluorochlorothalonil, Isopropylbenzene, Chlorothalonil, Isoprothiolane, Isoprothiolane, Effluox, Pentachloronitrobenzene, Propineb, Aluminum triethylphosphonate, Sulfur, Bordeaux mixture, Copper sulfate, Copper oxychloride, Cuprous oxide, Copper hydroxide, Benzophenone, Pendimethalin, Pyridaben, Tetrachlorophthalide, Pyrimethanil, Spirocyclohexane, Tricyclazole, Azoxystrobin, Polyoxin, Biguanidine, Biguanidine octylamine, ChlornithineToluenesulfonamide, indole ester, sodium dichloroisocyanurate, quinacrine, allylbenzylthiazide, bromonitol, iodomethane, methyl thiophanate, dimethoate, dazomet, dichloroisopropyl ether, thiamethoxam, fenpropathrin, fenpropathrin, fenpropathrin, thiamethoxam, thiocarbamate, thiocarbamate, thiocarbamate, thiocarbamate, dichloropropene, dichloroisonicotinic acid, allylisothiazide; the total mass percentage of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the bactericidal composition of the present invention is 1%-90%, the 2-(1H-indol-2-yl)- The percentage of 1,3,4-oxadiazole derivative I to the aforementioned commercial fungicide is 1%:99% to 99%:1%; the formulation of the fungicide composition is selected from: seed treatment emulsions, water-in-oil emulsions, microemulsions, suspensions, capsule suspensions, water-soluble granules, fine granules, soluble concentrates, poisoned grains, block poisoned bait, granular poisoned bait, flake poisoned bait, concentrated poisoned bait, slow-release blocks, electrostatic sprays, oil-in-water emulsions, smoke cans, smoke candles, smoke tubes, smoke sticks, smoke sheets, smoke pellets, vaporizers, ointments, hot fogging agents, cold fogging agents, and aerosols. The fungicidal composition includes: solid / liquid mixtures, liquid / liquid mixtures, solid / solid mixtures, medicated paints, microparticles, tracking powders, oil suspensions, oil-dispersible powders, concentrated colloids, pouring agents, seed coating agents, coating agents, film-forming oils, ultra-low volume liquids, and vapor-releasing agents. The plant diseases for which the fungicidal composition is applicable are selected from: rice seedling rot, tomato root rot, potato late blight, tobacco black shank, millet powdery mildew, grape downy mildew, lettuce downy mildew, cucumber downy mildew, and cucumber anthracnose. The plants for which the fungicidal composition is applicable are selected from: rice, wheat, and... Barley, oats, corn, sorghum, sweet potatoes, potatoes, cassava, soybeans, snow peas, broad beans, peas, mung beans, adzuki beans, cotton, silkworms, peanuts, rapeseed, sesame, sunflowers, beets, sugarcane, coffee, cocoa, ginseng, fritillaria, rubber, coconut, oil palm, sisal, tobacco, tomatoes, chili peppers, radishes, cucumbers, cabbage, celery, pickled mustard greens, beets, rapeseed, scallions, garlic, watermelon, cantaloupe, honeydew melon, papaya, apples, citrus fruits and peaches, tea, wild vegetables, bamboo shoots, hops, pepper, bananas, papaya, orchids, bonsai.

[0124] Example 11: Application of the combination of the present invention containing 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I and a plant immune activator in the prevention and control of viral diseases in agricultural, forestry, and horticultural plants:

[0125] The present invention relates to an antiviral composition comprising a 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I and any one or two of commercial plant activators for the prevention and control of viral diseases in agricultural, forestry, and horticultural plants. The commercial plant activators are selected from: benzothiadiazole, thiamethoxam, isothiazamide, ribavirin, antofenfen, ningnanmycin, methamidophos, or salicylic acid, pyrimethanil, dichloroisonicotinic acid, allylisothiazide, jinggangmycin, and morpholine guanidine hydrochloride. The 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I of the present invention is used in the antiviral composition. The total mass percentage of the active ingredient is 1%-90%. The ratio of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I of this invention to the aforementioned commercial plant activator is 1%:99% to 99%:1% by mass percentage. The dosage form of the antiviral composition is selected from: seed treatment emulsions, water-in-oil emulsions, microemulsions, suspensions, capsule suspensions, water-soluble granules, fine granules, soluble concentrates, poisoned grains, block poisoned bait, granular poisoned bait, flake poisoned bait, concentrated poisoned bait, slow-release blocks, electrostatic sprays, oil-in-water emulsions, smoke cans, smoke candles, smoke tubes, smoke sticks, smoke sheets, and smoke generators. Fog pellets, aerosol generators, ointments, hot fogging agents, cold fogging agents, aerosols, solid / liquid mixtures, liquid / liquid mixtures, solid / solid mixtures, medicated paints, microparticles, tracking powders, oil suspensions, oil-dispersible powders, concentrated colloids, pouring agents, seed coating agents, coating agents, film-forming oils, ultra-low volume liquids, vapor release agents; the viral diseases controlled by the antiviral composition are selected from: rice dwarf virus, yellow dwarf virus, rice stripe leaf blight, tomato fern leaf virus, pepper mosaic virus, tobacco vein necrosis virus, maize dwarf mosaic virus, cauliflower mosaic virus, citrus virus, Cymbidium faberi leaf virus, and Cymbidium ringspot virus; The plants used in the antiviral composition for prevention and control are selected from: rice, wheat, barley, oats, corn, sorghum, sweet potato, potato, cassava, soybean, snow pea, broad bean, pea, mung bean, adzuki bean, cotton, silkworm, peanut, rapeseed, sesame, sunflower, beet, sugarcane, coffee, cocoa, ginseng, fritillaria, rubber, coconut, oil palm, sisal, tobacco, tomato, chili pepper, radish, cucumber, cabbage, celery, pickled mustard greens, beet, rapeseed, onion, garlic, watermelon, cantaloupe, honeydew melon, papaya, apple, citrus and peach trees, tea, wild vegetables, bamboo shoots, hops, pepper, banana, papaya, orchid, and bonsai.

[0126] Example 12: Application of the present invention, in combination with an acaricide, of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the control of mites in agricultural, forestry, and horticultural plants:

[0127] The present invention relates to a combination of a 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I with any one or two commercial acaricides to form an acaricide composition for controlling mite pests in agricultural, forestry, and horticultural plants. The commercial acaricides are selected from: dichlorvos, heptamethrin, methamidophos, dibromophos, pyrimiphos, chlorpyrifos, ethion, chlorfenapyr, fenpropathrin, methyl pyrimiphos, quinalphos, abamectin, acephate, chlorpyrifos, chlorpyrifos, chlorpyrifos, chlorfenapyr, bifenthrin, cyhalothrin, lambda-cyhalothrin, cypermethrin, flufenoxuron, and deltamethrin. Bifenazate, benzyl thiocarb, methyl ethyl ketone, chlorpyrifos, carbaryl, chlorfenapyr, benomyl, chlorfenapyr, thiodicarb, tebufenozide, benzyl benzoate, bromopropylate, diflubenzuron, fenpyroximate, flufenoxuron, liuyangmycin, chlorfenapyr, thiophanate-methyl, fenpyroximate, avermectin, doramectin, epoximectin, ivermectin, selamectin, moxibustion, pyrethroid, nicotine, matrine, azadirachtin, rotenone, pyridaben, pyridaben, tetradifon, propargite, thiamethoxam, spirodiclofen, pyrimethanil, dicofol, clodinafop-methyl, pyridaben; the present invention contains 2-(1H The total mass percentage of 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the acaricide composition is 1%-90%. The ratio of 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I to the commercial acaricide is 1%:99% to 99%:1% by mass. The formulation of the acaricide composition is selected from: seed treatment emulsions, water-in-oil emulsions, microemulsions, suspensions, capsule suspensions, water-soluble granules, fine granules, soluble concentrates, poisoned grains, block poisoned baits, granular poisoned baits, flake poisoned baits, concentrated poisoned baits, slow-release blocks, electrostatic sprays, and oil-in-water emulsions. The acaricide composition includes: smoke cans, smoke candles, smoke tubes, smoke sticks, smoke sheets, smoke pellets, vaporizing agents, ointments, hot fogging agents, cold fogging agents, aerosols, solid / liquid mixtures, liquid / liquid mixtures, solid / solid mixtures, medicated paints, microparticles, tracking powders, oil suspensions, oil-dispersible powders, concentrated adhesives, pouring agents, seed coating agents, smearing agents, film-forming oils, ultra-low volume liquids, and vapor-releasing agents. The acaricide composition controls mites selected from: mites belonging to the Tetranychidae, Amanita phalloides, Fusarium moniliformes, Eriophyta, Chlorella, and Eriophyta genus, which are globally prevalent agricultural, forestry, horticultural, and sanitary mites.The acaricide composition is used to control plants selected from: rice, wheat, barley, oats, corn, sorghum, sweet potato, potato, cassava, soybean, snow pea, broad bean, pea, mung bean, adzuki bean, cotton, silkworm, peanut, rapeseed, sesame, sunflower, beet, sugarcane, coffee, cocoa, ginseng, fritillaria, rubber, coconut, oil palm, sisal, tobacco, tomato, chili pepper, radish, cucumber, cabbage, celery, pickled mustard greens, beet, rapeseed, onion, garlic, watermelon, cantaloupe, honeydew melon, papaya, apple, citrus and peach trees, tea, wild vegetables, bamboo shoots, hops, pepper, banana, papaya, orchid, and bonsai.

[0128] Example 13: Application of the present invention containing 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the preparation of pesticide compositions:

[0129] The present invention relates to a pesticide composition containing 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I as the active ingredient, wherein the active ingredient comprises 0.1% to 99.9% by mass, the solid or liquid adjuvant comprises 99.9% to 0.1% by mass, and further comprises optionally 0 to 25% by mass of a surfactant.

[0130] Example 14: Application of the present invention containing 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I in the preparation of pesticide compound compositions:

[0131] The 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I of the present invention can be compounded with other commercial pesticides, namely insecticides, acaricides, fungicides, antiviral agents, or plant immune activators, to prepare pesticide compound compositions. These compound compositions contain the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I of the present invention and commercial pesticides, namely insecticides, acaricides, fungicides, antiviral agents, or plant immune activators, as active ingredients. The invention contains 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I and other commercial pesticides, namely insecticides, acaricides, fungicides, antivirals or plant immune activators, in a mass percentage ratio of 1%:99% to 99%:1%, with an active ingredient mass percentage of 0.1% to 99.9%, a solid or liquid adjuvant mass percentage of 99.9% to 0.1%, and optionally a surfactant mass percentage of 0 to 25%.

[0132] Industrial applicability

[0133] This invention provides a class of derivatives containing 2-(1H-indol-2-yl)-1,3,4-oxadiazole; the derivatives of this invention can regulate the biological activity of agricultural, horticultural, sanitary, and forestry plant pests and plant pathogens, and can be used in the fields of agriculture, horticulture, and forestry for insecticidal, acaricidal, bactericidal, antiviral, and inducing plant disease resistance, and have good economic value and application prospects.

[0134] Table 1. Chemical structure and physicochemical parameters of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivatives of the present invention.

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142] Table 2. Antibacterial activity of the present invention containing 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I (inhibition rate / %) at 50 μg / mL

[0143]

[0144]

[0145] As: Alternaria solani, the causal agent of early blight in tomatoes; Bc: Botrytis cinerea, the causal agent of gray mold in cucumbers; Ca: Cercospora arachidicola, the causal agent of brown spot in peanuts; Fg: Fusarium graminearum, the causal agent of Fusarium graminearum in cereals; Pp: Physalospora piricola, the causal agent of ring rot in apples; Rs: Rhizoctonia solani, the causal agent of sheath blight in rice; Ss: Sclerotinia sclerotiorum, the causal agent of sclerotinia in rapeseed.

[0146] Table 3. Results of Precise Toxicity Determination of Antibacterial Activity of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole Derivative I of the Present Invention

[0147]

[0148] Table 4. Results of the assay for the plant immunogenicity of the 2-(1H-indol-2-yl)-1,3,4-oxadiazole derivative I of the present invention.

[0149]

Claims

1. A class containing 2-(1 H -Indol-2-yl)-1,3,4-oxadiazole derivative, characterized in that... Specifically: I: ， I-7: R 1 is: 7-chloro; R 2 is: hydrogen; R 3 is: hydrogen; I-26: R 1 For: 6-chloro; R 2 For: Ethyl; R 3 For: hydrogen; I-27:R 1 For: 6-chloro; R 2 For: n-propyl; R 3 For: hydrogen; I-28: R 1 For: 6-chloro; R 2 For: isopropyl; R 3 For: hydrogen; I-34:R 1 For: 6-chloro; R 2 For: cyclopropylmethyl; R 3 For: hydrogen; I-37:R 1 For: 6-chloro; R 2 For: amino group; R 3 For: hydrogen; I-47:R 1 For: 6-chloro; R 2 For: n-propyl; R 3 It is: hydroxymethyl.

2. The 2-(1)-containing compound as described in claim 1 H The use of (-indol-2-yl)-1,3,4-oxadiazole derivatives in the preparation of agricultural fungicides, wherein the fungicides control the fungi that cause early blight of tomato, gray mold of cucumber, and sheath blight of rice; specifically, compound I-7 controls early blight of tomato; compounds I-7 and I-37 control sheath blight of rice; and compounds I-7, I-26, I-27, I-28, I-34, I-37, and I-47 control gray mold of cucumber.

3. An agricultural bactericidal composition comprising the 2-(1-)-(1-)-(2 ... H (-indol-2-yl)-1,3,4-oxadiazole derivative as the active ingredient; the composition contains 0.1% to 99.9% by weight of the active ingredient and 99.9% to 0.1% by weight of solid or liquid adjuvants.

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