3-phenylisoxazoline-5-formamide oxime ester compound and application thereof

Abstract

The invention belongs to the field of herbicides. In particular to a 3-phenylisoxazoline-5-formamide oxime ester compound and application thereof. The 3-phenylisoxazoline-5-formamide oxime ester compound disclosed by the invention is shown as a general formula I: # imgabs0. The compound disclosed by the invention generally has a relatively high control effect on various weeds. Part of the compounds of the general formula I have a good control effect on barnyard grass, digitaria sanguinalis, edible amaranth or piemarker when the application dosage is 150 ga.i. / hm < 2 >.

Description

Technical Field

[0001] The present invention belongs to the field of herbicides, and specifically relates to a 3-phenylisoxazoline-5-carboxamide oxime ester compound and its application. Background Art

[0002] With the changes of the times, people's environmental requirements and ecological protection awareness have been strengthened. The awareness of chemical pesticide pollution, the impact of pesticides on non-target organisms, and the fate of pesticides in the ecological environment has been increasing. This has forced people to vigorously develop agricultural production technology, improve and perfect farming systems, and continuously improve and modify new herbicidal compounds and combinations. However, weed control is an indispensable part of achieving efficient agriculture, so new and improved herbicidal compounds have received more attention.

[0003] WO1995 / 014681A1, WO1995 / 014680A1, WO2008 / 035315A1, WO1995 / 014681A1 report compounds substituted at the 3- and 4-positions of the benzene ring, which are disclosed as pharmacologically active compounds, and DE4026018A1 and EP0520371A2 disclose 3-phenylisoxazoline-5-carboxamide having a hydrogen atom at the 5th position of the isoxazoline ring, which are described as agricultural chemical active safeners, and CN111868042A specifically discloses the preparation of the following compounds KC-1, KC-2, and KC-3 (compounds No. I-01, I-07, and II-01 in the patent specification):

[0004]

[0005] The prior art does not involve the preparation and application of the novel carboxylic acid oxime ester compounds as shown in the present invention. Summary of the invention

[0006] It is an object of the present invention to provide novel structurally active herbicidal compounds (herbicides) which are highly effective against economically important harmful plants even at relatively low application doses.

[0007] To achieve the above object, the technical solution of the present invention is as follows:

[0008] A 3-phenylisoxazoline-5-carboxamide oxime ester compound, the compound is shown in general formula I:

[0009]

[0010] Where:

[0011] X1 and X2 are independently selected from hydrogen, cyano, nitro, halogen, C1-C6 alkyl, C3-C6 cycloalkyl, C3-C6 alkenyl, C3-C6 alkynyl, C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkyloxy, C1-C6 alkyl, and C1-C6 alkylsulfonyl;

[0012] R1 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 haloalkyl;

[0013] R2 and R3 are independently the same or different and are selected from hydrogen, halogen, cyano, nitro, amino, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 alkenyl, C3-C6 cycloalkyl, C1-C6 alkylcarbonyl, C3-C6 alkoxy, acyloxy, C1-C6 alkoxycarbonyl, C1-C6 alkylthio, aryl, benzyl, heteroaryl, aryloxy, arylthio, heteroaryloxy and heteroarylthio which are unsubstituted or substituted with at least one of the following substituents which are the same or different; or R2 and R3 are linked to form a 5- or 6-membered saturated or unsaturated ring;

[0014] The following substituents are selected from halogen, cyano, nitro, amino, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C2-C6 alkenyloxy, C1-C6 alkylthio, C1-C6 alkylsulfonyl, aryl;

[0015] A is selected from the following two substituent groups:

[0016]

[0017] Or the stereoisomers of the above compounds or the corresponding salts of the compounds of formula I and their isomers.

[0018] Preferred compounds are:

[0019] X1 and X2 are independently selected from hydrogen, cyano, nitro, halogen, C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkyloxy, C1-C6 alkyl, and C1-C6 alkylsulfonyl;

[0020] R1 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C2-C6 alkenyl, C1-C6 haloalkyl;

[0021] R2 and R3 are independently the same or different and are selected from hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 alkenyl, C3-C6 cycloalkyl, C1-C6 alkylcarbonyl, C3-C6 alkoxy, acyloxy, C1-C6 alkoxycarbonyl, C1-C6 alkylthio, aryl, benzyl, heteroaryl, aryloxy, arylthio, heteroaryloxy and heteroarylthio which are unsubstituted or substituted with at least one of the following substituents which are the same or different; or R2 and R3 are linked to form a 5- or 6-membered saturated or unsaturated ring;

[0022] The following substituents are selected from halogen, cyano, nitro, amino, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C2-C6 alkenyloxy, C1-C6 alkylthio, C1-C6 alkylsulfonyl, aryl;

[0023] A is selected from the following two substituent groups:

[0024]

[0025] Or the stereoisomers of the above compounds or the corresponding salts of the compounds of formula I and their isomers.

[0026] Further preferred compounds are wherein

[0027] X1 and X2 are independently the same or different and are selected from hydrogen, cyano, nitro, halogen, C1-C6 haloalkyl, C1-C6 alkylsulfonyl;

[0028] R1 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C2-C6 alkenyl, C1-C6 haloalkyl;

[0029] R2 and R3 are independently the same or different and are selected from hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 cycloalkyl, C1-C6 alkylcarbonyl, C3-C6 alkoxy, acyloxy, C1-C6 alkoxycarbonyl, aryl which is unsubstituted or substituted by at least one of the same or different substituents listed below, or R2 and R3 are linked to form a 5- or 6-membered saturated or unsaturated ring;

[0030] The following substituents are selected from halogen, cyano, nitro, amino, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C2-C6 alkenyloxy, C1-C6 alkylthio, C1-C6 alkylsulfonyl, aryl;

[0031] A is selected from the following two substituent groups:

[0032]

[0033] Or the stereoisomers of the above compounds or the corresponding salts of the compounds of formula I and their isomers.

[0034] More preferably, the compound is

[0035] X1 and X2 are independently selected from hydrogen, cyano, and halogen;

[0036] R1 is selected from methyl and vinyl;

[0037] R2 and R3 are independently the same or different and are selected from hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 cycloalkyl, C1-C6 alkylcarbonyl, C3-C6 alkoxy, aryl which is unsubstituted or substituted by at least one of the same or different substituents listed below, or R2 and R3 are linked to form a cyclopentyl or cyclohexyl group;

[0038] The following substituents are selected from halogen, cyano, nitro, amino, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkylsulfonyl, aryl;

[0039] A is selected from the following two substituent groups:

[0040]

[0041] Or the stereoisomers of the above compounds or the corresponding salts of the compounds of formula I and their isomers.

[0042] An application of the compound of general formula I, the compound of general formula I, its stereoisomers or the compound of general formula I and its isomers' agriculturally acceptable salts for controlling weeds.

[0043] A herbicidal composition, comprising an active substance and an agriculturally acceptable carrier, wherein the active component comprises a compound of the general formula I as claimed in claim 1 and its stereoisomer, or an agriculturally acceptable salt of the compound of the general formula I and its isomer; and the weight percentage of the active component in the composition is 1-99%.

[0044] A method for controlling harmful plants comprises applying a herbicidally effective amount of at least one of the 3-phenylisoxazoline-5-carboxamide oxime ester compounds or the herbicide composition on plants or in an area containing harmful plants.

[0045] Unless otherwise specified, all technical terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. All patents and publications related to the present invention are incorporated herein by reference in their entirety.

[0046] Unless otherwise indicated, the following definitions used herein shall apply. For purposes of the present invention, chemical elements are consistent with the Periodic Table of the Elements, CAS version, and Handbook of Chemistry and Physics, 75th edition, 1994. In addition, general principles of organic chemistry can be found in "Organic Chemistry", Thomas Sorrell, University Science Books, Sausalito: 1999, and "March's Advanced Organic Chemistry" by Michael B. Smith and Jerry March, John Wiley & Sons, New York: 2007, the entire contents of which are incorporated herein by reference.

[0047] In the definition of the compounds of the general formula given above, the terms used are collectively defined as follows:

[0048] Alkyl refers to a straight chain or branched chain form, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, n-hexyl and other groups. Cycloalkyl refers to a cyclic chain form, such as cyclopropyl, methylcyclopropyl, cyclopropylcyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and other groups. Alkenyl refers to a straight chain or branched chain alkenyl, such as vinyl, 1-propenyl, 2-propenyl, butenyl, pentenyl and hexenyl and other groups. Alkyl refers to a straight chain or branched chain alkynyl, such as 1-propynyl, 2-propynyl, butynyl, pentynyl and hexynyl and other groups. Alkoxy refers to a group with an oxygen atom attached to the end of the alkyl group, such as methoxy, ethoxy, n-propoxy, isopropoxy, tert-butoxy and the like. The 5-7 membered heterocyclic ring containing 1-4 heteroatoms refers to a 5-7 membered heterocyclic compound containing 1-4 heteroatoms without aromatic characteristics, such as tetrahydrofuran, imidazolidinone, caprolactam and the like.

[0049] The compounds of the general formula I of the present invention can be prepared by the following method. Unless otherwise specified, the definitions of the other groups in the reaction formula are the same as above:

[0050]

[0051] The compound of formula III of the present invention can be prepared by the following method:

[0052]

[0053] The compound of formula II is reacted with hydroxylamine hydrochloride in a suitable solvent at a temperature of 0°C to the boiling point of the suitable solvent for 0.5-18 hours to obtain a compound of formula III, preferably 10°C-30°C. The suitable solvent is selected from dichloromethane, 1,2-dichloroethane, chloroform, carbon tetrachloride, ethanol, methanol, benzene, toluene, ethyl acetate, acetonitrile, acetic acid, tetrahydrofuran, dioxane, N,N-dimethylformamide or dimethyl sulfoxide.

[0054] The preparation method of the compound of formula V is as follows:

[0055]

[0056] In the above formula, the compound of formula III and NCS are reacted in a suitable solvent at a temperature ranging from room temperature to the boiling point of the suitable solvent for 0.5-24 hours, preferably 20°C-50°C. Then, a mixed solution of the compound of formula IV and a suitable organic base is added and the reaction is continued for 0.5-24 hours to obtain the compound of formula V. The suitable solvent is selected from dichloromethane, 1,2-dichloroethane, chloroform, carbon tetrachloride, benzene, toluene, tetrahydrofuran, dioxane, N,N-dimethylformamide or dimethyl sulfoxide, etc. The suitable organic base is selected from triethylamine, DIEA, trimethylamine, DBU, etc.

[0057] The preparation method of the compound of formula VI is as follows:

[0058]

[0059] The compound of formula VI is prepared by adding the compound of formula V and a base to a suitable solvent and reacting at a temperature ranging from room temperature to the boiling point of the suitable solvent for 0.5-24 hours, preferably 10° C.-40° C. The suitable solvent is selected from methanol, ethanol, tetrahydrofuran, dioxane, etc. The base is selected from NaOH, KOH, LiOH, etc.

[0060] The preparation method of the compound of formula VIII is as follows:

[0061]

[0062] In the above formula, the general formula VI is dissolved in a suitable solvent, an acylating agent is added, and the reaction is carried out at a temperature ranging from room temperature to the boiling point of the suitable solvent for 0.5-24 hours, preferably 10°C-50°C, and then the general formula VII and an organic base are added and reacted for 0.5-24 hours to obtain the general formula VIII compound. The acylating agent is at least one of oxalyl chloride, thionyl chloride, phosphorus oxychloride, phosphorus trichloride or phosphorus pentachloride, etc. The solvent is preferably selected from dichloromethane, 1,2-dichloroethane, chloroform, carbon tetrachloride, benzene, toluene, tetrahydrofuran, dioxane, N,N-dimethylformamide or dimethyl sulfoxide, etc. The preferred base is triethylamine, DIPEA, trimethylamine, DBU, etc.

[0063] The preparation method of the compound of formula IX is as follows:

[0064]

[0065] The compound of formula IX is prepared by adding the compound of formula VIII and a base to a suitable solvent and reacting at a temperature ranging from room temperature to the boiling point of the suitable solvent for 0.5-24 hours, preferably at 10°C-40°C. The solvent is preferably selected from methanol, ethanol, tetrahydrofuran, dioxane, etc. The preferred base is NaOH, KOH, LiOH, etc.

[0066] The preparation method of the compound of general formula I is as follows:

[0067]

[0068] In the above formula, the compound of general formula IX is dissolved in a suitable solvent, an acylating agent is added, and the reaction is carried out at a temperature ranging from room temperature to the boiling point of the suitable solvent for 0.5-24 hours, preferably 10°C-50°C, and then the compound of general formula X and a base are added and reacted for 0.5-24 hours to obtain the compound of general formula 7. The acylating agent is at least one of oxalyl chloride, thionyl chloride, phosphorus oxychloride, phosphorus trichloride or phosphorus pentachloride, etc. The solvent is preferably selected from dichloromethane, 1,2-dichloroethane, chloroform, carbon tetrachloride, benzene, toluene, tetrahydrofuran, dioxane, N,N-dimethylformamide or dimethyl sulfoxide, etc. The preferred base is triethylamine, DIEA, trimethylamine, DBU, K2CO3, Cs2CO3, etc.

[0069] The present disclosure also provides a method for removing unwanted plants, comprising applying a compound, a stereoisomer thereof or a pesticidally acceptable salt thereof, or the herbicidal composition, in a herbicidally active amount to unwanted plants, plant seeds and / or their growth environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 The compound 174 prepared in Example 1 of the present invention 1 H NMR spectra.

[0071] Figure 2 The compound 206 prepared in the present invention is 1 H NMR spectra. DETAILED DESCRIPTION

[0072] The following examples and biological test results can be used to further illustrate the present invention, but are not intended to limit the present invention.

[0073] Synthesis Example

[0074] Example 1 Synthesis of key intermediates:

[0075] (1) Synthesis of 3,5-dichlorobenzaldehyde oxime

[0076]

[0077] Add 3,5-dichlorobenzaldehyde (25 g, 142.85 mmol) and ethanol (200 ml) to the reaction flask. Dissolve hydroxylamine hydrochloride (10.92 g, 157.14 mmol) in 50 ml of water and slowly add it to the above reaction at 0°C. Warm the mixture to room temperature and react for 2 hours. After the reaction is completed, evaporate the ethanol under reduced pressure, pour the mother liquor into water, and a large amount of white solid is produced. Filter to obtain 19.8 g of white solid, which is directly used in the next step.

[0078] (2) Synthesis of methyl 3-(3,5-dichlorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxylate

[0079]

[0080] Add 3,5-dichlorobenzaldehyde oxime (10.00 g, 52.63 mmol) and DMF (50 ml) to the reaction bottle and heat to 30°C. At this temperature, add NCS (8.43 g, 63.15 mmol) in batches to form a light yellow liquid. Keep 35°C for 1 hour and monitor by TLC. After the reaction is complete, cool to room temperature, add 50 ml of DCM, and add a mixture of triethylamine (7.99 g, 78.94 mmol) and methyl methacrylate (7.90 g, 78.94 mmol) dropwise at 5°C. React at this temperature for 1 hour and monitor by TLC. After the reaction is complete, add water, separate the organic phase, and evaporate to dryness to obtain 8.52 g of 3-(3,5-dichlorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxylic acid methyl ester as a white solid, which is directly used in the next step.

[0081] (3) Synthesis of 3-(3,5-dichlorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxylic acid

[0082]

[0083] 3-(3,5-dichlorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxylic acid methyl ester (10 g, 34.71 mmol), MeOH (40 ml), H2O (10 ml), and NaOH (2.78 g, 69.41 mmol) were added to the reaction bottle, and the mixture was reacted at room temperature for 3 hours. Methanol was removed under reduced pressure, and EA was added for stripping. The pH of the aqueous phase was adjusted to 3 with dilute hydrochloric acid, and a solid precipitated. The liquid was filtered and the filter cake was dried to obtain 8.00 g of 3-(3,5-dichlorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxylic acid as a white solid.

[0084] (4) Synthesis of 4-(3-(3,5-dichlorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxamide)cyclopent-2-ene-1-carboxylic acid methyl ester

[0085]

[0086] Add 3-(3,5-dichlorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxylic acid (5 g, 18.24 mmol), DCM (50 ml), oxalyl chloride (6.95 g, 54.73 mmol) and DMF (1 drop) to the reaction bottle, react at room temperature for 1 hour, spin dry for use. Then add 4-aminocyclopent-2-ene-1-carboxylic acid methyl ester (2.58 g, 18.24 mmol) and DCM (20 ml) to another reaction bottle, and then add triethylamine (5.54 g, 54.73 mmol). Then slowly add the reserved DCM solution of acid chloride (20 ml). React at room temperature for 1 hour, evaporate the solvent, add 50 ml of water and 30 ml of ethyl acetate, separate the liquid, evaporate the organic phase, use PE:EA=1:1 column chromatography to obtain 5.33g (yield 73.6) of product as off-white solid.

[0087] (5) Synthesis of 4-(3-(3,5-dichlorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxamide)cyclopent-2-ene-1-carboxylic acid

[0088]

[0089] To the reaction flask were added 4-(3-(3,5-dichlorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxamide)cyclopent-2-ene-1-carboxylic acid methyl ester (10 g, 25.17 mmol), MeOH (40 ml), H2O (10 ml), and NaOH (2.01 g, 50.35 mmol). The mixture was reacted at room temperature for 3 hours. The methanol was removed under reduced pressure, and EA was added for stripping. The pH of the aqueous phase was adjusted to 3 with dilute hydrochloric acid. Solids precipitated, the liquid was filtered, and the filter cake was dried to obtain 7.44 g of 4-(3-(3,5-dichlorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxamide)cyclopent-2-ene-1-carboxylic acid as a white solid.

[0090] Synthesis of compound 206

[0091]

[0092] To the reaction flask, 4-(3-(3,5-dichlorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxamide)cyclopent-2-ene-1-carboxylic acid (500 mg, 1.30 mmol), DCM (3 ml), oxalyl chloride (185.15 mg, 1.44 mmol) and DMF (1 drop) were added. The mixture was reacted at room temperature for 1 hour and then dried by rotation for later use. Then, acetone oxime (143.05 mg, 1.96 mmol) was added to the reaction bottle, DCM (2 ml), and triethylamine (264.06 mg, 2.61 mmol) was added. The reserved acid chloride was dissolved in DCM (2 ml) and added slowly. The reaction was carried out at room temperature for 1 hour, and the solvent was evaporated. 5 ml of water and 3 ml of ethyl acetate were added, and the liquid was separated. The organic phase was evaporated and chromatographed by PE:EA=1:1 column to obtain 350 mg of a light yellow solid (purity 98.6%, yield 61.2%). LC-MS [M+H] + =438.0, [M+Na] + =460.0.

[0093] Synthesis of compound 207

[0094]

[0095] To the reaction flask, 4-(3-(3,5-dichlorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxamide)cyclopent-2-ene-1-carboxylic acid (500 mg, 1.30 mmol), DCM (3 ml), oxalyl chloride (185.15 mg, 1.44 mmol) and DMF (1 drop) were added. The mixture was reacted at room temperature for 1 hour and then dried by rotation for later use. Then, butanone oxime (170.5 mg, 1.96 mmol) was added to the reaction bottle, DCM (2 ml), and triethylamine (264.06 mg, 2.61 mmol) was added, the reserved acid chloride was dissolved in DCM (2 ml), and slowly added, reacted at room temperature for 1 hour, the solvent was evaporated, 5 ml of water and 3 ml of ethyl acetate were added, the liquid was separated, the organic phase was evaporated, and PE: EA = 1: 1 column chromatography was used to obtain 403 mg of a light yellow solid (purity 98.2%, yield 67.1%), LC-MS [M + H] + =452.1, [M+Na] + =474.1.

[0096] Other compounds of general formula I can be obtained by replacing different substances in the raw materials according to the above-mentioned method. Some compounds of general formula I are shown in Table 1

[0097]

[0098] Table 1 Structures and physicochemical properties of some compounds of general formula I

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113] Biotest Examples

[0114] After the original drug is dissolved in acetone or DMF, the test solution of the required concentration is prepared by standing tap water with 1‰ Tween 80 according to the test requirements. The following test is carried out. All the results are observed after 20 days of treatment.

[0115] The efficacy observation was carried out by visual inspection, and the standards were as follows

[0116] 0-same as control, drug-resistant, protection efficiency is less than 10%;

[0117] 1- Growth is slightly affected, slightly inhibited, poor activity, and the control effect is 10% to less than 30%;

[0118] 2- Growth is affected, slight bleaching, poor activity, and the control effect is 30% to less than 50%;

[0119] 3- Growth is affected, whitening is obvious, activity is moderate, and the control effect is 50% to less than 70%;

[0120] 4-More sensitive, significant bleaching, better activity, control efficiency is 70% to less than 90%;

[0121] 5-Extremely sensitive, completely bleached, basically dead, protection efficiency is 90% to 100%;

[0122] Post-emergence test experiment:

[0123] Seeds of broadleaf weeds (grayweed, ramie) and grass weeds (barnyard grass, crabgrass) were sown in paper cups with a diameter of 7 cm filled with nutrient soil, covered with 1 cm of soil after sowing, suppressed and watered, and cultured in a greenhouse according to conventional methods. When the weeds reached the 2-3 leaf stage, they were sprayed with stems and leaves after seedlings. The results of the treated plants and controls were observed after 20 days in the greenhouse.

[0124] The test results show that the compounds of general formula I generally have high control effects on a variety of weeds. Among some of the tested compounds, for example, some compounds of general formula I have a high control effect at an application dose of 150 g ai / hm 2 It has good preventive effect on barnyard grass, crabgrass, amaranth or ramie.

[0125] Table 2 Post-emergence compound activity test results

[0126]

[0127] According to the above test method, some compounds of general formula I and control compounds were selected to conduct parallel tests on weed control activity at reduced dosages. The results are shown in Table 3.

[0128] Table 3 Post-emergence compound activity test results

[0129]

[0130] It can be seen from Table 3 that after reducing the dosage, the compound of the present invention is superior to the control compound.

Claims

1. A 3-phenylisoxazoline-5-carboxamide oxime ester compound, characterized in that: The compound is shown in general formula I: Where: X1 and X2 are independently selected from hydrogen, cyano, nitro, halogen, C1-C6 alkyl, C3-C6 cycloalkyl, C3-C6 alkenyl, C3-C6 alkynyl, C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkyloxy, C1-C6 alkyl, and C1-C6 alkylsulfonyl; R1 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 haloalkyl; R2 and R3 are independently the same or different and are selected from hydrogen, halogen, cyano, nitro, amino, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 alkenyl, C3-C6 cycloalkyl, C1-C6 alkylcarbonyl, C3-C6 alkoxy, acyloxy, C1-C6 alkoxycarbonyl, C1-C6 alkylthio, aryl, benzyl, heteroaryl, aryloxy, arylthio, heteroaryloxy and heteroarylthio which are unsubstituted or substituted with at least one of the following substituents which are the same or different; or R2 and R3 are linked to form a 5- or 6-membered saturated or unsaturated ring; The following substituents are selected from halogen, cyano, nitro, amino, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C2-C6 alkenyloxy, C1-C6 alkylthio, C1-C6 alkylsulfonyl, aryl; A is selected from the following two substituent groups: Or the stereoisomers of the above compounds or the corresponding salts of the compounds described in general formula I and their isomers.

2. A 3-phenylisoxazoline-5-carboxamide oxime ester compound according to claim 1, characterized in that: X1 and X2 are independently selected from hydrogen, cyano, nitro, halogen, C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkyloxy, C1-C6 alkyl, and C1-C6 alkylsulfonyl; R1 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C2-C6 alkenyl, C1-C6 haloalkyl; R2 and R3 are independently the same or different and are selected from hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 alkenyl, C3-C6 cycloalkyl, C1-C6 alkylcarbonyl, C3-C6 alkoxy, acyloxy, C1-C6 alkoxycarbonyl, C1-C6 alkylthio, aryl, benzyl, heteroaryl, aryloxy, arylthio, heteroaryloxy and heteroarylthio which are unsubstituted or substituted with at least one of the following substituents which are the same or different; or R2 and R3 are linked to form a 5- or 6-membered saturated or unsaturated ring; The following substituents are selected from halogen, cyano, nitro, amino, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C2-C6 alkenyloxy, C1-C6 alkylthio, C1-C6 alkylsulfonyl, aryl; A is selected from the following two substituent groups: Or the stereoisomers of the above compounds or the corresponding salts of the compounds described in general formula I and their isomers.

3. A 3-phenylisoxazoline-5-carboxamide oxime ester compound according to claim 1, characterized in that: X1 and X2 are independently the same or different and are selected from hydrogen, cyano, nitro, halogen, C1-C6 haloalkyl, C1-C6 alkylsulfonyl; R1 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C2-C6 alkenyl, C1-C6 haloalkyl; R2 and R3 are independently the same or different and are selected from hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 cycloalkyl, C1-C6 alkylcarbonyl, C3-C6 alkoxy, acyloxy, C1-C6 alkoxycarbonyl, aryl which is unsubstituted or substituted by at least one of the same or different substituents listed below, or R2 and R3 are linked to form a 5- or 6-membered saturated or unsaturated ring; The following substituents are selected from halogen, cyano, nitro, amino, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C2-C6 alkenyloxy, C1-C6 alkylthio, C1-C6 alkylsulfonyl, aryl; A is selected from the following two substituent groups: Or the stereoisomers of the above compounds or the corresponding salts of the compounds of formula I and their isomers.

4. A 3-phenylisoxazoline-5-carboxamide oxime ester compound and its use according to claim 1, characterized in that: X1 and X2 are independently selected from hydrogen, cyano, and halogen; R1 is selected from methyl and vinyl; R2 and R3 are independently the same or different and are selected from hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6 cycloalkyl, C1-C6 alkylcarbonyl, C3-C6 alkoxy, aryl which is unsubstituted or substituted by at least one of the same or different substituents listed below, or R2 and R3 are linked to form a cyclopentyl or cyclohexyl group; The following substituents are selected from halogen, cyano, nitro, amino, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkylsulfonyl, aryl; A is selected from the following two substituent groups: Or the stereoisomers of the above compounds or the corresponding salts of the compounds of formula I and their isomers.

5. Use of the compound of general formula I according to claim 1, characterized in that: Use of the compound of general formula I, its stereoisomers or the compound of general formula I and its isomers' agriculturally acceptable salts for controlling weeds.

6. A herbicidal composition, characterized in that: The herbicidal composition comprises an active substance and an agriculturally acceptable carrier, wherein the active component comprises the compound of the general formula I as claimed in claim 1 and its stereoisomer, or the compound of the general formula I and its agriculturally acceptable salt of its isomer; the weight percentage of the active component in the composition is 1-99%.

7. A method for controlling harmful plants, characterized in that: The method comprises applying a herbicidally effective amount of at least one of the 3-phenylisoxazoline-5-carboxamide oxime ester compounds according to any one of claims 1 to 4 or the herbicide composition according to any one of claims 5 to 6 on plants or areas with harmful plants.

Images