Aromatic hydrazide compound and its preparation method and sterilization application

Abstract

The present invention relates to an aromatic hydrazide compound or an agronomically acceptable salt thereof as shown in formula I-1 and a preparation method thereof, as well as use thereof as a plant antibacterial agent, wherein some compounds show excellent fungicidal activity.

Description

Technical Field

[0001] The invention belongs to an aromatic hydrazide compound and the technical field of plant fungicides, and specifically relates to an aromatic hydrazide compound and a preparation method and application thereof. Background Art

[0002] Plant fungal diseases have always been one of the main reasons hindering agricultural development. In recent decades, crop yield reductions due to the rampant plant fungal diseases have occurred frequently, causing huge economic losses. At present, chemical fungicides are still an effective prevention and control method. Although there are many types of fungicides, the abuse of pesticides, excessive pesticide residues and many other reasons have led to the increasing resistance of pathogenic fungi. Therefore, developing novel fungicidal lead compounds and exploring new targets are effective ways to solve drug resistance.

[0003] Succinate dehydrogenase inhibitors (SDHIs) are a new generation of highly effective broad-spectrum fungicides that have been widely used in the production of various crops. From the chemical structure of representative SDHI fungicides, it can be seen that the amide bond plays a very important role in antifungal activity.

[0004] In order to develop novel and efficient fungicides, a series of novel amide-containing hydrazide compounds were designed and synthesized for the first time, using the amide structure with fungicidal activity reported in the literature and the hydrazide group with excellent fungicidal activity found in previous work (Chang et al. J. Agric. Food Chem., 2023, 71, 8297; Fang et al. J. Agric. Food Chem., 2022, 71, 920; Chen et al. J. Agric. Food Chem., 2023, 71, 12333) as the parent skeleton. The biological activity test found that some target compounds showed fungicidal activity comparable to or even better than the control drugs carbendazim, fluopyram, and tebuconazole. This result has important guiding significance for the development of new amide-containing hydrazide candidate fungicide molecules, and provides a new prevention and control strategy to solve the increasingly serious drug resistance of agricultural pathogens. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides an aromatic hydrazide compound and a preparation method and application thereof.

[0006] In a first aspect, the present invention provides a compound represented by formula I-1, or a stereoisomer thereof, or an agrochemically acceptable salt thereof:

[0007]

[0008] Among them, R 1 , R 2independently selected from the following groups: hydrogen, halogen, C1-C6 straight or branched alkyl, C1-C6 alkoxy, C6-C 12 Aryl, C6-C 12 Any of the heteroaryl groups;

[0009] R 3 Selected from the following groups: hydrogen, C1-C6 straight chain or branched alkyl, substituted C6-C 12 Aryl, substituted C6-C 12 Any one of the heteroaryl groups, the substituted C6-C 12 Aryl, substituted C6-C 12 The heteroaryl group is optionally substituted by one, two, three, or four independent C1-C6 straight or branched chain alkyl groups, or halogenated C1-C6 straight or branched chain alkyl groups;

[0010] R 4 , R 5 , R 6 , R 7 , R 8 are independently selected from the following groups: any one of hydrogen, halogen, C1-C6 straight chain or branched alkyl, C1-C6 alkoxy, halogenated C1-C6 straight chain or branched alkyl, and R 4 , R 5 , R 6 , R 7 , R 8 wherein at least one substituent is selected from halogen.

[0011] Furthermore, R 1 , R 2 independently selected from the following groups: hydrogen, halogen, C1-C6 straight or branched alkyl, C6-C 12 Any of the aromatic groups;

[0012] R 3 Selected from the following groups: C1-C6 straight chain alkyl, substituted C6-C 12 Aryl, substituted C6-C 12 Any one of the heteroaryl groups, the substituted C6-C 12 Aryl, substituted C6-C 12 The heteroaryl group is optionally substituted with one, two, three, or four independent -CH3, -CH2CH3, -CFH2, -CF2H, -CF3, -CH3CFH, -CH3CF2H, or -CH3CF3,

[0013] R 4 , R 5 , R 6 , R 7 , R 8are independently selected from the following groups: any one of hydrogen, halogen, C1-C6 straight or branched alkyl, C1-C6 alkoxy, and R 4 , R 5 , R 6 , R 7 , R 8 wherein at least one substituent is selected from halogen.

[0014] Furthermore, R 1 , R 2 Independently selected from the following groups: any one of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, hexyl, and phenyl;

[0015] R 3 Selected from the following groups: C1-C6 straight chain alkyl, substituted C6-C 12 Aryl, substituted C6-C 12 Any one of the heteroaryl groups, the substituted C6-C 12 Aryl, substituted C6-C 12 The heteroaryl group is optionally substituted by one, two, three, or four independent -CH3, -CH2CH3, -CFH2, -CF2H, -CF3, -CH3CFH, -CH3CF2H, or -CH3CF3. 12 Aryl is phenyl, the C6-C 12 Heteroaryl is pyrazolyl;

[0016] Preferably, R 3 Selected from the following groups: methyl,

[0017] R 4 , R 5 , R 6 , R 7 , R 8 are independently selected from the following groups: any one of hydrogen and halogen, and R 4 , R 5 , R 6 , R 7 , R 8 wherein at least one substituent is selected from halogen;

[0018] Further preferably, wherein R 1 , R 2 Independently selected from the following groups: any one of hydrogen, methyl, ethyl, and phenyl;

[0019] R 3 Selected from the following groups: methyl, Any of the following:

[0020] R 4 , R 5 , R 6 , R 7 , R 8 are independently selected from the following groups: any one of hydrogen, fluorine, and chlorine, and R 4 , R 5 , R 6 , R 7 , R 8 wherein at least one substituent is selected from halogen.

[0021] Furthermore, the compound described in Formula I is specifically:

[0022]

[0023]

[0024]

[0025] The second aspect of the present invention provides a method for preparing the compound of formula I, or its stereoisomers, or its agrochemically acceptable salts, which comprises the following steps:

[0026] Step 1: dissolving the compounds represented by Formula 1 and Formula 2 in an organic solvent to react and prepare the compound represented by Formula 3;

[0027] Step 2: dissolving the compound of formula 3 in a mixed solvent and hydrolyzing it with an alkali to prepare the compound of formula 4;

[0028] Step 3: dissolving the compound of formula 4 in an organic solvent and reacting with the compound of formula 5 under the condition of a condensing agent to prepare the compound of formula I-1;

[0029]

[0030] Wherein, compound 1, compound 2, compound 3, compound 4, compound 5 and the substituent R of formula I-1 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 The definition is the same as that in any one of claims 1 to 4, and X represents a halogen.

[0031] Wherein, the organic solvent in step (1) or step (2) is selected from one or more of N,N-dimethylformamide, ethyl acetate, dichloromethane, toluene, DMSO, acetone, acetonitrile, methyl tert-butyl ether, and diethyl ether, preferably N,N-dimethylformamide; the mixed solvent in step (2) is two or more of N,N-dimethylformamide, ethanol, ethyl acetate, methanol, toluene, DMSO, acetone, and water, preferably methanol and water;

[0032] And / or, the base in step (2) is selected from an organic base or an inorganic base, the inorganic base is selected from sodium bicarbonate, sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, lithium hydroxide or barium hydroxide, one or two or more; the organic base is selected from N,N-diisopropylethylamine, triethylamine, lithium diisopropylamide, n-(C 1-6 One or two or more of hexamethyldisilazane (alkyl) lithium, lithium hexamethyldisilazane, potassium hexamethyldisilazane, sodium hexamethyldisilazane, lithium tetramethylpiperidinium, potassium butoxide, potassium pentoxide, and potassium pentoxide;

[0033] And / or, the condensing agent in step (3) is selected from one of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 4-dimethylaminopyridine or 2-(1H-benzotriazol L-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate and N,N-diisopropylethylamine.

[0034] The third aspect of the present invention provides a pesticide composition, which comprises at least one compound of the above formula I-1, or a stereoisomer thereof, or an agrochemically acceptable salt thereof and a carrier; the carrier is in liquid or solid form.

[0035] Furthermore, the use of the compound of formula I-1, or its stereoisomer, or its agrochemically acceptable salt or the above-mentioned pesticide composition in preventing and controlling plant fungal diseases, preferably, the plant fungal disease is at least one of wheat fusarium sphaeroides, corn sheath blight, rice blast, pepper gray mold, rapeseed sclerotinia, apple anthracnose, apple ring rot, and Alternaria pathogens.

[0036] The fourth aspect of the present invention provides a fungicide, wherein the fungicide contains a fungicidal effective amount of the compound of formula I-1, or at least one of its stereoisomers, or its agrochemically acceptable salts, and optionally contains auxiliary materials.

[0037] The dosage form of the fungicide is selected from at least one of emulsifiable concentrate, suspension, wettable powder, powder, granule, aqueous solution, mother liquor and mother powder.

[0038] The following is an explanation and description of the terms of the present invention:

[0039] The compounds and derivatives provided in the present invention can be named according to the IUPAC (International Union of Pure and Applied Chemistry) or CAS (Chemical Abstracts Service, Columbus, OH) nomenclature system.

[0040] Definitions of terms used in the present invention: Unless otherwise stated, the initial definitions provided for groups or terms in this document apply to the groups or terms throughout the specification; for terms that are not specifically defined in this document, the meaning that a person skilled in the art can give them should be given based on the disclosure and context.

[0041] "Substitution" refers to the replacement of a hydrogen atom in a molecule by another different atom or molecule.

[0042] The minimum and maximum carbon atom content of a hydrocarbon group is indicated by a prefix, for example, the prefix C1-b alkyl indicates any alkyl group containing from "a" to "b" carbon atoms. Thus, for example, "C1-4 alkyl" refers to an alkyl group containing 1 to 4 carbon atoms.

[0043] The term "alkyl" refers to a saturated hydrocarbon chain with a specified number of member atoms. For example, C1-6 alkyl refers to an alkyl group with 1 to 6 member atoms, such as 1 to 4 member atoms. The alkyl group can be straight or branched. Representative branched alkyl groups have one, two or three branches. The alkyl group may be optionally substituted with one or more substituents as defined herein. Alkyl includes methyl, ethyl, propyl (n-propyl and isopropyl), butyl (n-butyl, isobutyl and tert-butyl), pentyl (n-pentyl, isopentyl and neopentyl) and hexyl, 2,2-dimethylbutyl and 2,3-dimethylbutyl, etc. The term "C1-C3 alkyl" refers to a straight or branched saturated hydrocarbon group with 1-3 carbon atoms. The alkyl group may also be part of other groups, such as C1-C6 alkoxy.

[0044] The term "alkoxy" refers to an O-alkyl group. The term "C1-C8 alkoxy" refers to an O-C1-C8 alkyl group.

[0045] The term "C6-C 10 "Aryl" refers to an all-carbon monocyclic or fused polycyclic group of 6 to 10 carbon atoms, with a completely conjugated π electron system. Typical examples include, but are not limited to, phenyl and naphthyl rings.

[0046] The term "heteroaryl" refers to a monocyclic or fused ring group containing one, two, three or four ring heteroatoms selected from N, O or S, the remaining ring atoms being C, and having a completely conjugated π electron system. 12 "Heteroaryl" refers to a heteroaryl group containing 3 to 10 carbon atoms in its ring. 10Heteroaryl groups include, but are not limited to, pyrrolyl, furanyl, thienyl, imidazolyl, oxazolyl, thiazolyl, pyrazolyl, pyrimidinyl, pyridinyl.

[0047] The term "heterocyclyl" is a heterocycloalkyl group, which means a monocyclic or fused ring containing one or more heteroatoms of N, O or S. The term "C4-C8 heterocyclyl" refers to a heterocyclyl group containing 4 to 8 carbon atoms in its ring. C4-C8 heterocyclyl includes, but is not limited to, piperazino, morpholino, piperidino, pyrrolidinyl, etc.

[0048] The term "halogen" refers to fluorine, chlorine, bromine or iodine.

[0049] The term "halogen alkyl" refers to an alkyl group in which the hydrogen atoms may be substituted by one or more halogen atoms. For example, C1-4 halogen alkyl refers to an alkyl group containing 1 to 4 carbon atoms in which the hydrogen atoms are substituted by one or more halogen atoms.

[0050] The compounds of the present invention may contain asymmetric centers or chiral centers and therefore exist as different stereoisomers. All stereoisomeric forms of the compounds of the present invention, including but not limited to, diastereomers, enantiomers, atropisomers, and mixtures thereof, such as racemic mixtures, form part of the present invention. Many organic compounds exist in optically active forms, i.e., they have the ability to rotate the plane of plane polarized light. When describing optically active compounds, the prefix D, L or R, S is used to indicate the absolute configuration of the chiral center of the molecule. The chemical structure of these stereoisomers is the same, but their stereostructure is different. Specific stereoisomers can be enantiomers, and mixtures of isomers are usually called enantiomeric mixtures. A 50:50 mixture of enantiomers is called a racemic mixture or racemate, which may result in no stereoselectivity or stereospecificity during chemical reactions. The terms "racemic mixture" and "racemate" refer to an equimolar mixture of two enantiomers that lacks optical activity.

[0051] The term "agronomically acceptable salt" refers to the above-mentioned compound or its stereoisomer, acidic and / or basic salts formed with inorganic and / or organic acids and bases, also including zwitterionic salts (inner salts), and also including quaternary ammonium salts, such as alkylammonium salts. These salts can be directly obtained in the final separation and purification of the compound. It can also be obtained by mixing the above-mentioned compound, or its stereoisomer, with a certain amount of acid or base appropriately (such as equivalent). These salts may form precipitation in the solution and be collected by filtering, or be recovered after solvent evaporation, or be obtained by freeze drying after reaction in an aqueous medium. The salt described in the present invention can be the hydrochloride, sulfate, citrate, benzenesulfonate, hydrobromide, hydrofluoride, phosphate, acetate, propionate, succinate, oxalate, malate, succinate, fumarate, maleate, tartrate or trifluoroacetate of the compound.

[0052] Obviously, according to the above contents of the present invention, in accordance with common technical knowledge and customary means in the art, without departing from the above basic technical ideas of the present invention, other various forms of modification, replacement or change may be made.

[0053] The beneficial technical effects of the present invention are as follows: 1. The present invention provides an aromatic hydrazide compound containing an amide structure, which uses an amide structure with fungicidal activity reported in the literature and a hydrazide group with excellent fungicidal activity found in previous work as a parent skeleton, and designs and synthesizes a series of novel hydrazide compounds containing an amide structure for the first time. The compounds of the present invention have good fungicidal activity, and some compounds show better antibacterial rates against specific plant pathogens than commercial agents such as tebuconazole, carbendazim, and fluopyram. The results have important guiding significance for exploring new and highly effective fungicides.

[0054] 2. The results of in vitro fungicidal activity of the compounds of the present invention show that the compounds of the present invention exhibit excellent fungicidal activity. Compound I-5 exhibits excellent antibacterial activity against wheat fusarium, corn sheath blight, rice blast and apple anthracnose pathogens, with an inhibition rate of 100%, and the antibacterial activity against apple anthracnose pathogens is significantly better than that of commercial agents carbendazim and fluopyram. In addition, the compounds of the present invention have weak inhibitory effects on rapeseed sclerotinia pathogens and apple ring rot pathogens. From the structure-activity relationship analysis, the introduction of 3,4-difluoro groups on the benzene ring on the right side of the hydrazide bridge is beneficial to improve the fungicidal activity of the target molecule. For example, compounds I-5 and I-29 both exhibit broad-spectrum antibacterial activity superior to other compounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 : The inhibitory effect of the compounds of the present invention on rice blast fungus at 50 μg / mL, wherein A1 is a blank control; A2 is treated with the commercial drug tebuconazole; A3 is treated with the commercial drug carbendazim; A4 is treated with compound I-4; A5 is treated with compound I-5; A6 is treated with compound I-20;

[0056] Figure 2 : The inhibitory effect of the compounds of the present invention on apple ring rot pathogen at 50 μg / mL, wherein B1 is a blank control; B2 is treated with the commercial drug carbendazim; B3 is treated with the commercial drug tebuconazole; B4 is treated with compound I-18; B5 is treated with compound I-5; B6 is treated with compound I-24;

[0057] Figure 3: The inhibitory effect of the compounds of the present invention on corn sheath blight at 50 μg / mL, wherein C1 is a blank control; C2 is treated with the commercial drug carbendazim; C3 is treated with compound I-1; C4 is treated with compound I-3; C5 is treated with compound I-5; C6 is treated with compound I-20;

[0058] Figure 4 : The in vivo control effect of the compounds of the present invention on sheath blight at 100 μg / mL, wherein D1 is a blank control; D2 is treated with compound I-29; and D3 is treated with compound I-45. DETAILED DESCRIPTION

[0059] The present invention is further described below in conjunction with embodiments, the purpose of which is to provide a better understanding of the content of the present invention and to embody the essential features of the present invention. Therefore, the examples given should not be regarded as limiting the scope of protection of the present invention.

[0060] Intermediate Example 1: Synthesis of N-acetyl-L-isoleucine methyl ester

[0061]

[0062] L-isoleucine methyl ester hydrochloride (3.00 g, 16.5 mmol), acetyl chloride (2.33 g, 29.7 mmol), triethylamine (3.19 g, 38.0 mmol) were added to dichloromethane (30 mL), the system was cooled to 0 ° C in an ice bath for 2 hours, and the reaction was monitored by TLC. After the reaction was completed, the system was poured into a mixed solution of dichloromethane (200 mL) and water (200 mL), the dichloromethane layer was taken, dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under vacuum to remove the solvent dichloromethane, and the residue was purified by column chromatography to obtain a white solid product, the eluent was dichloromethane: methanol, the volume ratio was 20:1, and the yield was 65%.

[0063] Intermediate Example 2: Synthesis of N-acetyl-L-isoleucine

[0064]

[0065] Dissolve N-acetyl-L-isoleucine methyl ester (2.00 g, 10.7 mmol) in a mixed solution of methanol (50 mL) and water (5 mL), add sodium hydroxide (1.28 g, 32.0 mmol), stir at room temperature for 2 hours, and monitor the reaction progress by TLC. After the reaction is completed, vacuum concentrate to remove the solvent, dissolve the residue in water (5 mL), adjust the pH to weak acidity with dilute hydrochloric acid, vacuum concentrate to remove part of the solvent, add methanol (5 mL) to precipitate solid, filter, and concentrate the filtrate to dryness to obtain a white solid product with a yield of 88%.

[0066] Example 1: Synthesis of N-((2S,3S)-1-(2-(4-fluorophenyl)hydrazino)-3-methyl-1-oxopentan-2-yl)acetamide

[0067]

[0068] N-acetyl-L-isoleucine (0.50 g, 2.9 mmol), 4-fluorophenylhydrazine hydrochloride (0.52 g, 3.2 mmol), 2-(1H-benzotriazolyl L-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (1.11 g, 3.5 mmol) were dissolved in N,N-dimethylformamide (15 mL), and then N,N-diisopropylethylamine (0.93 g, 7.2 mmol) was added. The mixture was stirred at room temperature for 6 hours, and the reaction progress was monitored by TLC. After the reaction was completed, water was added to produce a solid, which was filtered. The filter cake was purified by column chromatography to obtain a white solid product, and the eluent was dichloromethane:methanol, with a volume ratio of 20:1, and the yield was 65%.

[0069] The derivatives prepared by using different raw materials according to the preparation methods of intermediate Examples 1-2 and Example 1 are listed in Table 1. 1 HNMR, 13 C NMR (Bruker AV-500 spectrometer using tetramethylsilane as the internal standard) and melting point data are shown in Table 2.

[0070]

[0071] Table 1 Structure of target compound I-1

[0072]

[0073]

[0074]

[0075] Table 2 NMR and melting point data of some target compounds

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084] Efficacy Example 1 In vitro bactericidal activity test of the derivatives provided by the present invention

[0085] The derivatives provided by the present invention are used to carry out in vitro fungicidal activity tests, the test objects are corn sheath blight (Rhizoctonia solani), wheat fusarium rust (Gibberellazeae), rice blast (Pyricularia grisea), pepper gray mold (Botrytis cinerea), apple anthracnose (Colletotrichum gloeosporioides), apple ring rot (Physalosporapiricola), rapeseed sclerotinia (Sclerotinia sclerotiorum) and Alternaria sp., and the test method is a colony growth diameter inhibition method.

[0086] The test method is as follows: Accurately weigh 5.0 mg of the target compound and place it in a 1.5 mL centrifuge tube, add 2 drops of dimethyl sulfoxide to dissolve it, and then dilute it to 10 mL with 0.1% Tween 80 aqueous solution to obtain 500 μg / mL of the mother solution to be tested. Take 1 mL of the mother solution to be tested and mix it evenly with 9 mL of PDA culture medium to obtain a drug-containing culture medium with a test concentration of 50 μg / mL. Use a 7 mm diameter puncher to take the corresponding bacterial cake and place it in the drug-containing culture medium. Culture it at 25°C for 72 hours. Calculate the antibacterial rate of the compound based on the colony diameter. Distilled water is used as a negative control, and fluopyram and carbendazim are used as positive controls. Repeat each treatment three times, and calculate the average and standard deviation. The test results of the above in vitro bactericidal activity are shown in Table 3, see the attached figure of the specification Figure 1-Figure 3 .

[0087] Table 3 Inhibition rate of in vitro bactericidal activity of some target compounds I (%)

[0088]

[0089]

[0090] Experimental conclusion: The results of in vitro fungicidal activity showed that some target compounds showed excellent fungicidal activity. For example, compound I-5 showed excellent antibacterial activity against wheat fusarium, corn sheath blight, rice blast, apple anthracnose and Alternaria, and its antibacterial activity against apple anthracnose was significantly better than that of commercial agents carbendazim and fluopyram. Compounds I-28 and I-29 showed excellent fungicidal activity against corn sheath blight, rice blast and apple anthracnose, and the inhibition rate reached 100%. Compared with commercial agents tebuconazole and carbendazim, most target compounds showed weak antibacterial activity against pepper gray mold, rapeseed sclerotinia and apple ring rot, with the exception of compounds I-27 and I-32. The inhibition rates of I-27 against pepper gray mold and rapeseed sclerotinia were 92.0% and 99.4%, respectively. In addition, the hydrazide compounds of the present invention mainly exhibit excellent antibacterial activity against corn sheath blight, rice blast and apple anthracnose. For example, the inhibition rates of compounds I-1–I-5, I-20, I-21, I-28 and I-29 against corn sheath blight all reached 100%, the inhibition rates of compounds I-4, I-5, I-20, I-25, I-28, I-29 and I-30 against rice blast all reached 100%, and the inhibition rates of compounds I-3, I-5, I-18, I-19, I-26, I-29, I-32, I-42 and I-43 against apple anthracnose all reached 100%. From the structure-activity relationship analysis, the introduction of 3,4-difluoro group on the benzene ring on the right side of the hydrazide bridge is beneficial to improve the antibacterial activity of the target molecule. For example, compounds I-5 and I-29 both exhibit excellent antibacterial activity.

[0091] Efficacy Example 2 Test of the in vivo antibacterial effect on sheath blight pathogen

[0092] The compounds provided by the present invention were used to test the in vivo antibacterial effect. The test object was Rhizoctonia solani. The test method was as follows: 1.00 mg of the target compound was accurately weighed and placed in a 1.5 mL centrifuge tube, 2 drops of dimethyl sulfoxide were added to dissolve it, and then diluted to 10 mL with a 0.1% Tween 80 aqueous solution to obtain a 100 μg / mL mother solution to be tested. The drug-containing solution was evenly sprayed onto the rice leaves. After the solvent evaporated completely, the leaves were cut and placed in a culture dish with a diameter of 10 cm containing 2 wet filter papers. Then, a 7 mm cake of Rhizoctonia solani was inoculated on the rice leaves, cultured at 25°C for 72 hours, and the disease conditions of the leaves were recorded. Distilled water was used as the negative control, tebuconazole and carbendazim were used as the positive controls, and each treatment was repeated three times. The results are shown in the attached Figure 4 .

[0093] As shown in the attached picture Figure 4As shown, the in vivo control effect of the compounds of the present invention on sheath blight at 100 μg / mL, wherein D1 is a blank control; D2 is a treatment with compound I-29; and D3 is a treatment with compound I-45. In the blank treatment group, the rice leaves were seriously diseased, with lesions all over the leaves, while in the agent treatment group, the rice leaves were not diseased, indicating that the target compounds I-29 and I-45 both showed excellent in vivo control effects on sheath blight.

[0094] The research results of the present invention provide important theoretical and technical support for the development of new hydrazide fungicides.

[0095] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A compound represented by formula I-1 or an agrochemically acceptable salt thereof: in, R 1 , R 2 independently selected from hydrogen, C1-C6 straight or branched alkyl or C6-C 12 Any of the aromatic groups; R 3 Selected from C1-C6 straight or branched alkyl, substituted C6-C 12 Aryl or substituted C6-C 12 Any one of the heteroaryl groups, the substituted C6-C 12 Aryl, substituted C6-C 12 The heteroaryl group is optionally substituted by one, two, three, or four independent C1-C6 straight or branched chain alkyl groups, or halogenated C1-C6 straight or branched chain alkyl groups; R 4 , R 5 , R 6 , R 7 , R 8 are independently selected from hydrogen or halogen, and R 4 , R 5 , R 6 , R 7 , R 8 wherein at least one substituent is selected from halogen; The structure shown in formula I-1 does not contain the compound 2. The compound according to claim 1 or its agrochemically acceptable salt, characterized in that: in, R 1 , R 2 independently selected from hydrogen, C1-C6 straight or branched alkyl or C6-C 12 Any of the aromatic groups; R 3 Selected from C1-C6 straight chain alkyl, substituted C6-C 12 Aryl or substituted C6-C 12 Any one of the heteroaryl groups, the substituted C6-C 12 Aryl, substituted C6-C 12 The heteroaryl group is optionally substituted by one, two, three, or four independent -CH3, -CH2CH3, -CFH2, -CF2H, or -CF3, R 4 , R 5 , R 6 , R 7 , R 8 are independently selected from hydrogen or halogen, and R 4 , R 5 , R 6 , R 7 , R 8 wherein at least one substituent is selected from halogen.

3. The compound according to any one of claims 1 to 2 or an agrochemically acceptable salt thereof, characterized in that: in, R 1 , R 2 Any one independently selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, hexyl or phenyl; R 3 Selected from C1-C6 straight chain alkyl, substituted C6-C 12 Aryl or substituted C6-C 12 Any one of the heteroaryl groups, the substituted C6-C 12 Aryl, substituted C6-C 12 Heteroaryl is optionally substituted with one, two, three, or four independent -CH3, -CH2CH3, -CFH2, -CF2H, or -CF3; R 4 , R 5 , R 6 , R 7 , R 8 are independently selected from hydrogen or halogen, and R 4 , R 5 , R 6 , R 7 , R 8 wherein at least one substituent is selected from halogen.

4. The compound according to claim 3 or its agrochemically acceptable salt, characterized in that: Wherein the C6-C 12 Aryl is phenyl, the C6-C 12 Heteroaryl is pyrazolyl.

5. The compound according to claim 3 or its agrochemically acceptable salt, characterized in that: R 3 Selected from the following groups: methyl, 6. The compound according to claim 3 or its agrochemically acceptable salt, characterized in that: in, R 1 , R 2 Any one independently selected from hydrogen, methyl, ethyl or phenyl; R 3 Selected from methyl, Any of the following: R 4 , R 5 , R 6 , R 7 , R 8 are independently selected from any one of hydrogen, fluorine or chlorine, and R 4 , R 5 , R 6 , R 7 , R 8 wherein at least one substituent is selected from fluorine or chlorine.

7. The compound according to claim 1 or an agrochemically acceptable salt thereof, characterized in that: The compound described in formula I-1 is specifically: 。 8. A method for preparing the compound of formula I-1 or an agrochemically acceptable salt thereof according to any one of claims 1 to 7, characterized in that: It includes the following steps: Step 1: dissolving the compounds represented by Formula 1 and Formula 2 in an organic solvent to react and prepare the compound represented by Formula 3; Step 2: dissolving the compound of formula 3 in a mixed solvent and hydrolyzing it with an alkali to prepare the compound of formula 4; Step 3: dissolving the compound of formula 4 in an organic solvent and reacting with the compound of formula 5 under the condition of a condensing agent to prepare the compound of formula I-1; Wherein, compound 1, compound 2, compound 3, compound 4, compound 5 and the substituent R of formula I-1 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 The definition is the same as that in any one of claims 1 to 7, and X represents a halogen.

9. The preparation method according to claim 8, characterized in that: The organic solvent in step 1 or step 3 is selected from one or more of N,N-dimethylformamide, ethyl acetate, dichloromethane, toluene, DMSO, acetone, acetonitrile, methyl tert-butyl ether, and diethyl ether; the mixed solvent in step 2 is two or more of N,N-dimethylformamide, ethanol, ethyl acetate, methanol, toluene, DMSO, acetone, and water; And / or, the base in step 2 is selected from an organic base or an inorganic base, the inorganic base is selected from sodium bicarbonate, sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, lithium hydroxide or barium hydroxide, one or two or more; the organic base is selected from N,N-diisopropylethylamine, triethylamine, n-(C 1-6 One or two or more of lithium (alkyl), potassium butoxide, and potassium pentanolate; And / or, the condensing agent in step 3 is selected from 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 4-dimethylaminopyridine.

10. The preparation method according to claim 9, characterized in that: The organic solvent in step 1 or step 3 is selected from N,N-dimethylformamide; the mixed solvent in step 2 is methanol and water.

11. A pesticide composition comprising at least one compound of formula I-1 according to any one of claims 1 to 7 or an agrochemically acceptable salt thereof and a carrier; the carrier is in liquid or solid form.

12. Use of the compound of formula I-1 or an agrochemically acceptable salt thereof according to any one of claims 1 to 7 or the pesticide composition according to claim 11 in preventing and controlling plant fungal diseases.

13. The use according to claim 12, characterized in that: The plant fungal disease is at least one of wheat fusarium rust pathogen, corn sheath blight pathogen, rice blast pathogen, pepper gray mold pathogen, rapeseed sclerotinia pathogen, apple anthracnose pathogen, apple ring rot pathogen, and alternaria pathogen.

14. A fungicide, characterized in that: The bactericide contains a bactericidal effective amount of at least one of the compounds of formula I-1 according to any one of claims 1 to 7 or their agrochemically acceptable salts, and optionally contains auxiliary materials.

15. The fungicide according to claim 14, characterized in that The dosage form of the fungicide is selected from at least one of emulsifiable concentrate, suspension, wettable powder, dust, granule, aqueous solution, mother solution and mother powder.

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