Pyridazinone compounds, their preparation methods and their application as herbicides

Abstract

This disclosure provides pyridazinone compounds or their agronomically acceptable salts, methods for their preparation, and their application as herbicides. The pyridazinone compounds have the structural formula shown in Formula 1 or Formula 2, wherein the definitions of R1, R2, and X are detailed in the specification. The pyridazinone compounds or their agronomically acceptable salts provided in this disclosure have enhanced herbicidal effects.

Description

Technical Field

[0001] This disclosure relates to agricultural chemical technology, particularly pyridazinone compounds, their preparation methods, and their application as herbicides. Background Technology

[0002] Due to the long-term use of herbicides, problems such as weed resistance, reduced efficacy, and significant environmental pollution have emerged, becoming major factors restricting the effectiveness of herbicides.

[0003] Therefore, there is a need for a herbicide that is both effective and environmentally friendly. Summary of the Invention

[0004] The following is an overview of the subject matter described in detail in this disclosure. This overview is not intended to limit the scope of the claims.

[0005] In a first aspect, this disclosure provides pyridazinone compounds or agronomically acceptable salts thereof, said pyridazinone compounds having the structural formula shown in Formula 1 or Formula 2:

[0006]

[0007] Where R1 is H, fluorine, chlorine, bromine, or iodine; X is oxygen or sulfur; and R2 is C. 1-4 Alkyl or C 1-4 Halogenated alkyl groups.

[0008] Optionally, when R1 is H, R2 is 2,2-difluoroethyl or 2,2,2-trifluoroethyl.

[0009] In a second aspect, this disclosure provides a pesticide composition comprising a pesticide-effective amount of at least one of the above-mentioned pyridazinone compounds or an agronomically acceptable salt thereof.

[0010] In a third aspect, this disclosure provides a herbicide composition comprising at least one of the above-described pyridazinone compounds or an agronomically acceptable salt thereof.

[0011] In a fourth aspect, this disclosure provides the use of the above-mentioned pyridazinone compounds or their agronomically acceptable salts, or the above-mentioned pesticide compositions, as herbicides.

[0012] In a fifth aspect, this disclosure provides a method for preparing pyridazinone compounds.

[0013] Other aspects will become clear after reading and understanding the detailed description of this disclosure.

[0014] Detailed Explanation

[0015] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of the present invention will be described in detail below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined with each other.

[0016] In a first aspect, this disclosure provides pyridazinone compounds or agronomically acceptable salts thereof, said pyridazinone compounds having the structural formula shown in Formula 1 or Formula 2:

[0017]

[0018] Where R1 is H, fluorine, chlorine, bromine, or iodine; X is oxygen or sulfur; and R2 is C. 1-4 Alkyl or C 1-4 Halogenated alkyl groups.

[0019] For the compound of formula 1, when R1 is Br, X is O, and R2 is CH3, i.e., compound 1-1,2-[2-(3-bromo-4-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione, it has the following structural formula:

[0020]

[0021] When R1 is Cl, X is O, and R2 is CH3, the compound 1-2,2-[2-(3-chloro-4-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione has the following structural formula:

[0022]

[0023] When R1 is F, X is O, and R2 is CH3, the compound 1-3,2-[2-(3-fluoro-4-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione has the following structural formula:

[0024]

[0025] When R1 is F, X is O, and R2 is CH2CH3, the compound 1-4,2-[2-(4-ethoxy-3-fluorophenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione has the following structural formula:

[0026]

[0027] When R1 is F, X is S, and R2 is CH3, the compound 1-5,2-[2-(3-fluoro-4-(methylthio)phenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione has the following structural formula:

[0028]

[0029] When R1 is F, X is O, and R2 is CH2CH2F, the compound 1-6,2-[2-(3-fluoro-4-(2-fluoroethoxy)phenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione has the following structural formula:

[0030]

[0031] When R1 is F, X is O, and R2 is CH2CHF2, the compound 1-7,2-[2-(4-(2,2-difluoroethoxy)-3-fluorophenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione has the following structural formula:

[0032]

[0033] When R1 is F, X is O, and R2 is CH2CF3, the compound 1-8,2-[2-(3-fluoro-4-(2,2,2-trifluoroethoxy)phenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione has the following structural formula:

[0034]

[0035] When R1 is F, X is S, and R2 is CH2CHF2, compound 1-9,2-[2-(4-((2,2-difluoroethyl)thioalkyl)3-fluorophenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione has the following structural formula:

[0036]

[0037] When R1 is H, X is O, and R2 is CH2CHF2, the compound 1-10,2-[2-(4-(2,2-difluoroethoxy)phenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione has the following structural formula:

[0038]

[0039] When R1 is H, X is O, and R2 is CH2CF3, the compound 1-11,2-[2-(4-(2,2,2-trifluoroethoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione has the following structural formula:

[0040]

[0041] For the compound of formula 2, when R1 is Br, X is O, and R2 is CH3, i.e., compound 2-1,2-[2-(4-bromo-3-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione, it has the following structural formula:

[0042]

[0043] When R1 is Cl, X is O, and R2 is CH3, the compound 2-2,2-[2-(4-chloro-3-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione has the following structural formula:

[0044]

[0045] When R1 is F, X is O, and R2 is CH3, the compound 2-3,2-[2-(4-fluoro-3-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione has the following structural formula:

[0046]

[0047] In one embodiment, the pyridazinone compound may be in the form of an agronomically acceptable salt. Agronomically acceptable salts include, but are not limited to, aluminum, calcium, cobalt, copper, iron, magnesium, potassium, sodium, and zinc salts of pyridazinone compounds.

[0048] In a second aspect, this disclosure provides a pesticide composition comprising an agronomically effective amount of at least one pyridazinone compound or an agronomically acceptable salt thereof as described in the first aspect of this disclosure.

[0049] In a third aspect, this disclosure provides a herbicide composition comprising at least one pyridazinone compound as described in the first aspect of this disclosure or an agronomically acceptable salt thereof.

[0050] In a fourth aspect, this disclosure provides the use of the above-mentioned pyridazinone compounds or their agronomically acceptable salts, or the above-mentioned pesticide compositions, as herbicides.

[0051] For example, at least one of the above-mentioned pyridazinone compounds or its agronomically acceptable salt, or the above-mentioned pesticide composition, can be applied (e.g., sprayed) to locations where weeds are not desired to grow, such as places where crops are grown or in non-cultivated land.

[0052] The pesticide or herbicide compositions disclosed herein may typically contain 0.05 wt% to 95 wt%, preferably 0.5 wt% to 50 wt%, of at least one pyridazinone compound of Formula 1 or Formula 2, or an agronomically acceptable salt thereof.

[0053] The pyridazinone compounds of Formula 1 or Formula 2 disclosed herein can be used as herbicides to remove grass weeds and some broadleaf weeds. They are partially selective and therefore can be used on non-arable land, as well as on monocotyledonous fields such as wheat, rice, corn, sorghum, and millet, and on broadleaf plants such as soybeans, peanuts, and sugarcane.

[0054] The pyridazinone compounds of this disclosure, or pesticide compositions containing them, can be applied by spraying, misting, dusting, broadcasting, or irrigating in the form of directly sprayable aqueous solutions, powders, suspensions, highly concentrated aqueous formulations, oils or other suspensions or dispersions, emulsions, oil dispersions, pastes, dusting compositions, broadcasting compositions, or granules. The method of application depends on the intended use, and in each case, the pyridazinone compounds of this disclosure should be dispersed as uniformly as possible.

[0055] The pyridazinone compounds shown in Formula 1 or 2 are generally suitable for preparing solutions, emulsions, ointments, or oil dispersions that can be sprayed directly. Suitable inert additives include: medium to high boiling point mineral oils (such as kerosene or diesel oil and coal tar), vegetable or animal oils, aliphatic hydrocarbons, cyclic hydrocarbons and aromatic hydrocarbons (such as paraffin, tetrahydronaphthalene, tetrahydronaphthalene or its derivatives, alkylbenzene or its derivatives), methanol, ethanol, propanol, butanol, cyclohexanol, cyclohexanone or strongly polar solvents such as N-methylpyrrolidone or water.

[0056] Aqueous formulations can be prepared by adding water to concentrated emulsions, suspensions, ointments, wettable powders, or water-dispersible particles. To prepare emulsions, ointments, or oil dispersions, the raw materials themselves, or those dissolved in oil or solvent, can be homogenized in water using a wetting agent, binder, dispersant, or emulsifier. However, concentrates consisting of compounds of formula 1 or 2 of this disclosure, wetting agents, binders, dispersants, or emulsifiers can also be prepared, as well as concentrates containing solvents or oils, which are suitable for dilution with water.

[0057] Powders, spreading and dusting compositions can be prepared by mixing or grinding the pyridazinone compounds of Formula 1 or Formula 2 of this disclosure with a solid carrier.

[0058] By incorporating the pyridazinone compounds of Formula 1 or Formula 2 of this disclosure onto a solid carrier, particles such as coated, impregnated, and homogeneous particles can be prepared. The solid carrier may be selected from, for example, mineral soils such as silica, silica gel, silicates, talc, kaolin, limestone, lime, red basalt, loess, clay, dolomite, diatomaceous earth, calcium sulfate and magnesium sulfate, magnesium oxide; ground synthetic materials; fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate, urea; and plant products such as cereal flour, bark powder, wood material and nut shell powder, cellulose powder; or other solid carriers.

[0059] Preferably, the pyridazinone compounds of Formula 1 or Formula 2 of this disclosure are formulated as emulsifiable concentrates, and the content of the pyridazinone compounds of Formula 1 or Formula 2 is 0.05-95 wt% based on the total weight of the emulsifiable concentrate; preferably 0.5-50 wt%.

[0060] Based on the total weight of the emulsifiable concentrate, the preferred formulation of the emulsifiable concentrate is: 1-20 wt% of the compound shown in Formula 1 or Formula 2, 20 wt% of DMF (N,N-dimethylformamide), 5 wt% of calcium dodecylbenzenesulfonate, 10 wt% of triphenylphenol polyoxyethylene ether (600-2), and made up to 100 wt% with solvent oil.

[0061] Preferably, the solvent oil is selected from aromatic solvent oil, and the amount used is preferably 10-60 wt%, and most preferably 25-50 wt%.

[0062] The pyridazinone compounds of Formula 1 or Formula 2 disclosed herein can also be formulated into an aqueous emulsion, wherein the content of the compound of Formula 1 or Formula 2 is 1-50 wt% based on the total weight of the aqueous emulsion; preferably 2-35 wt%.

[0063] Based on the total weight of the water emulsion, the formulation of the water emulsion is 2 wt% of the compound shown in Formula 1 or Formula 2, 10 wt% of solvent oil, 3 wt% of calcium dodecylbenzenesulfonate, 4 wt% of nonylphenol polyoxyethylene (10) ether, 5 wt% of ethylene glycol, and water to make up to 100 wt%.

[0064] The pyridazinone compounds of Formula 1 or Formula 2 disclosed herein can also be formulated into oil suspensions, wherein the content of the compound of Formula 1 or Formula 2 is 0.5-80 wt% based on the total weight of the oil suspension; preferably 2-35 wt%.

[0065] Based on the total weight of the oil suspension, the formulation of the oil suspension is 10 wt% of the compound shown in Formula 1 or Formula 2, 5 wt% of solvent oil, 7.5 wt% of calcium dodecylbenzenesulfonate, 7.5 wt% of castor oil polyoxyethylene (10) ether, 1.5 wt% of organobentonite, 1 wt% of silica, and methyl oleate to make up to 100 wt%.

[0066] The pyridazinone compounds represented by Formula 1 or Formula 2 of this disclosure can also be formulated into suspensions, wherein the content of the compound represented by Formula 1 or Formula 2 is 0.5-80 wt% based on the total weight of the suspension; preferably 2-35 wt%.

[0067] Based on the total weight of the suspending agent, the formulation of the suspending agent is 10 wt% of the compound shown in Formula 1 or Formula 2, 3 wt% of the dispersant, 2 wt% of the wetting agent, 5 wt% of propylene glycol, 1.2 wt% of magnesium aluminum silicate, 0.5 wt% of silica, and water to make up to 100 wt%.

[0068] This disclosure does not impose any particular restrictions on the methods for forming emulsifiable concentrates, water-in-oil emulsions, oil suspensions, water suspensions, etc. Those skilled in the art can refer to "Modern Pesticide Formulation Processing Technology" for formulation.

[0069] In a fifth aspect, this disclosure provides a method for preparing pyridazinone compounds, comprising reacting compounds of formula 3 and formula 4 with 1,3-cyclohexanedione in the presence of an inert organic solvent, a base, and a catalyst to generate compounds of formula 1 and formula 2, respectively, wherein R1, R2, and X are as defined above; and LG is a suitable leaving group (e.g., a halogen atom, such as chlorine).

[0070]

[0071] The catalyst can be a cyanide-containing compound, including but not limited to sodium cyanide, potassium cyanide, acetone cyanohydrin, and trimethylcyanosilane.

[0072] Inert organic solvents can be dichloromethane, dichloroethane, or acetonitrile.

[0073] The alkali can be triethylamine, etc.

[0074] The compounds represented by formulas 3 and 4 can be prepared from the carboxylic acid compounds represented by formulas 5 and 6, respectively:

[0075]

[0076] For example, when the leaving group of LG is chlorine, conventional methods in the art can be used, such as in a nonpolar solvent (e.g., dichloromethane, dichloroethane, acetonitrile, toluene), with 1-5 equivalents of oxalyl chloride or thionyl chloride to carry out the reaction.

[0077] The carboxylic acid compounds represented by Formulas 5 and 6 can be obtained by cyclizing hydrazone compounds represented by Formulas 7 and 8 with malonic acid esters (such as Miescherichia coli) (optionally in the presence of a catalyst (such as piperidine)) and then hydrolyzing them in the presence of an inorganic base (such as sodium hydroxide, potassium hydroxide, or lithium hydroxide).

[0078]

[0079] The hydrazones represented by Formulas 7 and 8 can be obtained by reacting phenylhydrazines represented by Formulas 9 and 10 with aldehydes and ketones in a suitable polar solvent (such as methanol, ethanol, isopropanol, etc.).

[0080]

[0081] The phenylhydrazine compounds represented by Formulas 9 and 10 can be prepared from aniline compounds represented by Formulas 11 and 12, respectively, including salt formation under acidic conditions (such as hydrochloric acid, sulfuric acid, fluoroboric acid, etc.); reaction with sodium nitrite solution (sodium nitrite equivalent of 1-2) to form diazonium salts; and reduction reaction with tin powder or stannous chloride in the reaction solution to obtain the phenylhydrazine compounds represented by Formulas 9 and 10, respectively. These compounds can be isolated or directly proceeded to the next reaction in solution without isolation.

[0082]

[0083] The aniline compounds represented by Formulas 11 and 12 can be obtained commercially or synthesized using conventional methods.

[0084] For example, the aniline compounds represented by Formula 11 may include, but are not limited to, p-methoxyaniline, 3-chloro-4-methoxyaniline, 3-fluoro-4-methoxyaniline, 3-fluoro-4-ethoxyaniline, 3-fluoro-4-methylthioaniline, 2-fluoro-4-nitrophenol, etc.

[0085] For example, the aniline compounds represented by Formula 12 may include, but are not limited to, 4-bromo-3-methoxyaniline, 3-methoxy-4-chloroaniline, 4-fluoro-3-methoxyaniline, etc.

[0086] The preparation methods of the specific compounds provided in this disclosure are described below.

[0087] Unless otherwise specified, NMR measurements in this disclosure were performed on an AVANCE III 600 NMR spectrometer (Bruker, Germany). LC-MS measurements were performed using an Agilent 1260-6120.

[0088] Example 1-1: Preparation of 2-[2-(3-bromo-4-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compound 1-1)

[0089]

[0090] Step 1:

[0091]

[0092] Take a 500ml three-necked flask, add p-methoxyaniline (20.1g, 0.1mol) and 80ml of 20wt% hydrochloric acid, stir until fully dissolved, and cool to 0℃; then dissolve sodium nitrite (8.28g, 0.12mol) in 80ml of water to prepare a sodium nitrite solution; slowly add the prepared sodium nitrite solution dropwise to the above solution, and stir the reaction at 0℃ for 1h; slowly add stannous chloride (45g, 0.2mol) solution dissolved in 80ml of 35wt% hydrochloric acid dropwise to the above reaction solution; after the addition is complete, maintain the reaction at 0℃ for 1h, and then slowly raise it to room temperature for 2h; after the reaction is complete, cool the reaction solution to 0℃, and then add 500ml of ethyl acetate and 500ml of water to the reaction solution; slowly add 40wt% sodium hydroxide solution to the reaction solution to adjust the pH to 9; separate the liquids, the organic phase is the intermediate: ethyl acetate solution of 3-bromo-4-methoxyphenylhydrazine, and use this solution directly for the next reaction.

[0093] Step 2:

[0094]

[0095] Take a 1000 ml three-necked flask and add an ethyl acetate solution of 3-bromo-4-methoxyphenylhydrazine obtained in step 1; add 40 wt% acetone aldehyde aqueous solution (20.52 g, 0.1 mol) at room temperature and react for 2 hours; after the reaction is complete, separate the liquid and add anhydrous sodium sulfate to the organic phase to dry it, filter, and evaporate to dryness to obtain 7.6 g of crude product; purify by column chromatography (petroleum ether: ethyl acetate 10:1-2:1 (v:v)) to obtain 4.3 g of brownish-red solid 2-(2-(3-bromo-4-methoxyphenyl)hydrazine)propionaldehyde, with a purity of 93% and a yield of 16%.

[0096] Step 3:

[0097]

[0098] Take a 250ml three-necked flask and add 25ml of toluene, 0.04g of acetic acid (0.0007mol), piperidine (0.06g, 0.0007mol), Michaelis acid (2.56g, 0.02mol), and 2-(2-(3-bromo-4-methoxyphenyl)hydrazine)propionaldehyde (4.3g, 0.04mol, 93% purity) obtained in step 2 at room temperature; heat to 95℃ and react for 2.5 hours; after the reaction is complete, cool the reaction solution to a temperature below 95℃. At room temperature, 10 g of an aqueous solution of sodium hydroxide (2.37 g, 0.06 mol) was added; the temperature was raised to 80 °C and the reaction was carried out for 2 hours; after the reaction was completed, the reaction solution was cooled to room temperature and separated; the aqueous phase was extracted once with toluene; concentrated hydrochloric acid was added to the aqueous phase to adjust the pH to 3, a solid was precipitated, filtered, and the filter cake was dried at 60 °C to obtain 4.72 g of 2-(4-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-carboxylic acid with a purity of 95% and a yield of 80%.

[0099] 1 H NMR (400MHz, CDCl3) δ13.84(s,1H),8.17(s,1H),7.81(d,J=2.6Hz,1H),7.58(dd,J=8.9,2.6Hz,1H),7.01(d,J=8.9Hz,1H),3.97(s,3H),2.54(s,3H).

[0100] LC-MS: m / s = 339 [M+H] + .

[0101] Step 4:

[0102]

[0103] Take a 250ml three-necked flask and add 80ml of dichloromethane and 4.72g (0.03mol, purity 95%) of 2-(4-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-carboxylic acid obtained in step 3; cool to 0℃ and add 7.53g (0.06mol) of oxaloyl chloride dropwise; after the addition is complete, heat the reaction solution to reflux for 4 hours; after the reaction is completed, cool to 30℃ and desolvate under reduced pressure to obtain 4.22g of 2-(4-methoxyphenyl)-3-oxo-2,3-dihydropyridazine-4-carboxylic chloride with a purity of 95% and a yield of 95%, and proceed directly to the next reaction without purification.

[0104] Step 5:

[0105]

[0106] Take a 500ml three-necked flask, add 4.22g (0.03mol, 95% purity) of 2-(4-methoxyphenyl)-3-oxo-2,3-dihydropyridazine-4-carboxyl chloride obtained in step 4, and 60ml of dichloromethane, and cool to 0℃; add 1,3-cyclohexanedione (1.78g, 0.02mol), triethylamine (2.19g, 0.02mol), and acetone cyanohydrin (0.06g, 0.0015mol); after all the ingredients are added, heat to reflux and react for 8 hours; monitor the reaction for completion using LC; add the reaction solution to 200ml of water, extract and separate the layers; add 15wt% hydrochloric acid to the organic phase sequentially. Wash once with 1 ml of water and once with 200 ml of water. After washing, add anhydrous sodium sulfate to the organic phase and dry, filter, and evaporate to dryness to obtain 7.32 g of crude product. Column chromatography (petroleum ether: ethyl acetate 10:1-2:1 (v:v)) of the crude product yielded 4.81 g of a yellow solid of 2-[2-(3-bromo-4-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione, with a purity of 92% and a yield of 71%.

[0107] 1 H NMR (400MHz, CDCl3) δ16.13(s,1H),7.80(d,J=2.5Hz,1H),7.55(dd,J=8.8,2.5Hz,1H),7.07(s,1H),6.94( d,J=8.9Hz,1H),3.92(s,3H),2.73(t,J=6.3Hz,2H),2.47(t,J=6.5Hz,2H),2.40(s,3H),2.11-1.98(m,2H).

[0108] LC-MS: m / s = 433 [M+H] + .

[0109] Examples 1-2: Preparation of 2-[2-(3-chloro-4-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compounds 1-2)

[0110] The starting material was 3-chloro-4-methoxyaniline, and the operation steps were the same as in Example 1-1, yielding 5.87 g of yellow solid compound 1-2 with a purity of 95% and a reaction yield of 82%.

[0111]

[0112] 1H NMR (400MHz, CDCl3) δ16.09(s,1H),7.73(d,J=2.3Hz,1H),7.24(dd,J=8.8,2.2Hz,1H),7.02(s,1H),6.83( d,J=8.7Hz,1H),3.91(s,3H),2.70(t,J=6.1Hz,2H),2.35(t,J=6.1Hz,2H),2.38(s,3H),2.05-1.84(m,2H).

[0113] LC-MS: m / s = 389 [M+H] + .

[0114] Examples 1-3: Preparation of 2-[2-(3-fluoro-4-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compounds 1-3)

[0115] The starting material was 3-fluoro-4-methoxyaniline. The operation steps were the same as in Example 1-1, and 3.84 g of yellow solid compound 1-3 was obtained with a purity of 93% and a reaction yield of 69%.

[0116]

[0117] 1 H NMR (400MHz, CDCl3) δ16.16(s,1H),7.67(d,J=2.7Hz,1H),7.12(dd,J=8.6,2.5Hz,1H),7.05(s,1H),6.77( d,J=8.5Hz,1H),3.85(s,3H),2.68(t,J=6.1Hz,2H),2.31(t,J=6.1Hz,2H),2.34(s,3H),2.07-1.85(m,2H).

[0118] LC-MS: m / s = 373 [M+H] + .

[0119] Examples 1-4: Preparation of 2-[2-(4-ethoxy-3-fluorophenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compounds 1-4)

[0120] The starting material was 3-fluoro-4-ethoxyaniline. The operation steps were the same as in Example 1-1, yielding 4.42 g of yellow solid compound 1-4 with a purity of 93.5% and a reaction yield of 71%.

[0121]

[0122] 1 H NMR (400MHz, CDCl3) δ16.15(s,1H),7.45-7.29(m,2H),7.06(d,J=16.1Hz,1H),6.89(dd,J=20.3,11.5Hz 1H),4.25-4.00(m,2H),2.81-2.66(m,2H),2.47(s,2H),2.39(d,J=12.3Hz,3H),2.04(td,J=12.5,6.1Hz,2H),1.50-1.41(m,3H).

[0123] LC-MS: m / s = 387 [M+H] + .

[0124] Examples 1-5: Preparation of 2-[2-(3-fluoro-4-(methylthio)phenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compounds 1-5)

[0125] The starting material was 3-fluoro-4-methylthioaniline. The operation steps were the same as in Example 1-1, yielding 7.15 g of yellow solid compound 1-5 with a purity of 92% and a reaction yield of 65.4%.

[0126]

[0127] 1 H NMR(400MHz, CDCl3)δ16.15(s,1H),7.49-7.36(m,2H),7.30(s,1H),7.07(s ,1H),2.83-2.66(m,2H),2.55-2.43(m,5H),2.41(s,3H),2.14-1.98(m,2H).

[0128] LC-MS: m / s = 389 [M+H] + .

[0129] Examples 1-6: Preparation of 2-[2-(3-fluoro-4-(2-fluoroethoxy)phenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compounds 1-6)

[0130] The starting material was 3-fluoro-4-(fluoroethoxy)aniline. The operation steps were the same as in Example 1-1, yielding 5.35 g of yellow solid compound 1-6 with a purity of 92.6% and a reaction yield of 77.3%.

[0131]

[0132] 1H NMR (400MHz, CDCl3) δ16.11(s,1H),7.43(dd,J=12.5,2.5Hz,1H),7.29(dt,J=8.8,2.0Hz,1H),7.02(s,1H),7.11(t,J=8.5Hz,1H), 4.33(td,J=12.9,4.7Hz,2H),5.31-4.73(m,2H),2.65(t,J=6.1Hz,2H),2.75(t,J=6.9Hz,2H),2.36(s,3H),2.15(p,J=6.2Hz,2H).

[0133] LC-MS: m / s = 405 [M+H] + .

[0134] Examples 1-7: Preparation of 2-[2-(4-(2,2-difluoroethoxy)-3-fluorophenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compounds 1-7)

[0135] The starting material was 4-(difluoroethoxy)-3-fluoroaniline. The operation steps were the same as in Example 1-1, yielding 8.51 g of yellow solid compound 1-7 with a purity of 95.7% and a reaction yield of 75.8%.

[0136]

[0137] 1 H NMR (400MHz, CDCl3) δ16.15(s,1H),7.45(dd,J=11.8,2.5Hz,1H),7.39(dt,J=8.8,2.0Hz,1H),7.07(s,1H),7.04(t,J=8.8Hz,1H), 4.27(td,J=12.9,4.2Hz,2H),6.31-5.93(m,1H),2.74(t,J=6.4Hz,2H),2.47(t,J=6.5Hz,2H),2.41(s,3H),2.05(p,J=6.5Hz,2H).

[0138] LC-MS: m / s = 423 [M+H] + .

[0139] Examples 1-8: Preparation of 2-[2-(3-fluoro-4-(2,2,2-trifluoroethoxy)phenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compounds 1-8)

[0140] The starting material was 3-fluoro-4-(trifluoroethoxy)aniline. The operation steps were the same as in Example 1-1, yielding 6.95 g of yellow solid compound 1-8 with a purity of 93.3% and a reaction yield of 73.5%.

[0141]

[0142] 1 H NMR (400MHz, CDCl3) δ16.15(s,1H),7.54-7.34(m,2H),7.15-7.01(m,2H),4.44(q,J=8. 1Hz, 2H), 2.74 (t, J = 6.4Hz, 2H), 2.47 (t, J = 6.5Hz, 2H), 2.41 (s, 3H), 2.14-2.00 (m, 2H).

[0143] LC-MS: m / s = 441 [M+H] + .

[0144] Examples 1-9: Preparation of 2-[2-(4-((2,2-difluoroethyl)thioalkyl)3-fluorophenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compounds 1-9)

[0145] The starting material was 4-((2,2-difluoroethyl)thio)-3-fluoroaniline. The operation steps were the same as in Example 1-1, yielding 5.21 g of yellow solid compounds 1-9 with a purity of 92.2% and a reaction yield of 77.2%.

[0146]

[0147] 1 H NMR (400MHz, CDCl3) δ16.15(s,1H),7.59-7.44(m,3H),7.07(s,1H),5.88(tt,J=56.3,4.5Hz1H),3.36-3.13(m 2H), 2.75 (t, J = 6.4Hz, 2H), 2.56-2.44 (m, 2H), 2.41 (s, 3H), 2.09-2.04 (m, 2H).

[0148] LC-MS: m / s = 439 [M+H] + .

[0149] Examples 1-10: Preparation of 2-[2-(4-(2,2-difluoroethoxy)phenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compounds 1-10)

[0150] The starting material was 4-(2,2-difluoroethoxy)aniline. The operation steps were the same as in Example 1-1, yielding 6.28 g of yellow solid compound 1-10 with a purity of 97.3% and a reaction yield of 88%.

[0151]

[0152] 1 H NMR(400MHz, CDCl3)δ16.15(s,1H),7.74-7.34(m,2H),7.18-7.04(m,1H),7.01-6.89(m,2H) ,6.32-5.82(t,1H),4.22(d,2H),2.69(t,2H),2.46(t,2H),2.42(s,3H),2.12-1.95(m,2H).

[0153] LC-MS: m / s = 405 [M+H] + .

[0154] Examples 1-11: Preparation of 2-[2-(4-(2,2,2-trifluoroethoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compounds 1-11)

[0155] The starting material was 4-(2,2,2-trifluoroethoxy)aniline. The operation steps were the same as in Example 1-1, yielding 7.28 g of yellow solid compound 1-11 with a purity of 95% and a reaction yield of 82%.

[0156]

[0157] 1 H NMR (400MHz, CDCl3) δ16.15(s,1H),7.67-7.43(m,2H),7.08(s,1H),7.04-6.92(m,2H),2.73(t,2H),2.47(t,2H),2.40(s,3H),2.13-1.96(m,2H).

[0158] LC-MS: m / s = 423 [M+H] + .

[0159] Example 2-1: Preparation of 2-[2-(4-bromo-3-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compound 2-1)

[0160] The starting material was 4-bromo-3-methoxyaniline. The operation steps were the same as in Example 1-1, yielding 5.48 g of yellow solid compound 2-1 with a purity of 97.8% and a reaction yield of 89.5%.

[0161]

[0162] 1 H NMR(400MHz, CDCl3)δ16.15(s,1H),7.49-7.36(m,2H),7.30(s,1H),7.07(s,1H),3.80 2-3.74(s,3H),2.83-2.66(m,2H),2.55-2.49(m,2H),2.41(s,3H),2.14-1.98(m,2H).

[0163] LC-MS: m / s = 433 [M+H] + .

[0164] Example 2-2: Preparation of 2-[2-(4-chloro-3-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compound 2-2)

[0165] The starting material was 3-methoxy-4-chloroaniline. The operation steps were the same as in Example 1-1, yielding 7.97 g of yellow solid compound 2-2 with a purity of 97.3% and a reaction yield of 87.6%.

[0166]

[0167] 1 H NMR(400MHz, CDCl3)δ16.15(s,1H),7.49-7.36(m,2H),7.30(s,1H),7.07(s,1H),3.9 0-3.74(m,3H),2.83-2.66(m,2H),2.55-2.43(m,2H),2.42(s,3H),2.14-1.95(m,2H).

[0168] LC-MS: m / s = 389 [M+H] + .

[0169] Examples 2-3: Preparation of 2-[2-(4-fluoro-3-methoxyphenyl)-6-methyl-3-oxo-2,3-dihydropyridazine-4-formyl]cyclohexane-1,3-dione (compound 2-3)

[0170] The starting material was 4-fluoro-3-methoxyaniline. The operation steps were the same as in Example 1-1, yielding 5.87 g of yellow solid compound 2-3 with a purity of 98.5% and a reaction yield of 73.2%.

[0171]

[0172] 1 H NMR(400MHz, CDCl3)δ16.15(s,1H),7.39-7.26(m,2H),7.29(s,1H),7.012(s,1H),3.9 0-3.74(s,3H),2.73-2.56(m,2H),2.47-2.39(m,2H),2.45(s,3H),2.24-1.99(m,2H).

[0173] LC-MS: m / s = 373 [M+H] + .

[0174] Test Implementation Example:

[0175] The applicant used compounds 1-1 to 1-11 and compounds 2-1 to 2-3 as test compounds, and compound 2-[2-(3,4-dimethoxyphenyl)-6-methyl-3-oxo-pyridazine-4-carbonyl]cyclohexane-1,3-dione (see compound 1.3 in CN108884074A) as a comparative compound. The test compounds and comparative compounds were used as treatment groups for weed control.

[0176] The weeds selected for testing in this disclosure are barnyard grass (Echinochloa crusgalli (L.)), foxtail grass (Setariaviridis (L.) P. Beauv.), Japanese wild oats (Alopecurus japonicus Steud.), and multiflora ryegrass (Lolium multiflorum Lamk.).

[0177] The amount of compound added when treating weeds can be 75, 150, and 250 g.ai / ha. In this disclosure, the unit "gai / ha" represents the grams of active ingredient per hectare.

[0178] The crops selected for testing in this disclosure are maize (Zea mays L.) and wheat (Triticum aestivum L.).

[0179] The amount of compound added when treating crops can be 250 g.ai / ha.

[0180] The test compound and the comparison compound were prepared into a 1 wt% DMF solution.

[0181] Treatment concentration: A 1 wt% DMF solution of the compound was diluted 60, 30, and 18 times with a 0.1 wt% Tween-80 (sorbitan monooleate polyoxyethylene ether) solution; spraying was carried out at a rate of 450 kg / ha, a spraying pressure of 0.3 MPa, and an actual spraying area of ​​0.5 m². 2 The diluent volume is 22.5 mL.

[0182] Herbicidal activity test method: The foliar spray method (NY / T 1155.4-2006) was used. A measured amount of soil was filled to 3 / 4 of the height of a plastic cup with a mouth diameter of 9 cm. 15-20 seeds of the test weed (or 4 seeds of test corn, or 10-15 seeds of test wheat) were evenly sown on the soil surface of the pot, covered with about 1 cm of fine soil, and then placed in a greenhouse (temperature of 18-30℃) for cultivation. When the weeds grew to the 2-5 leaf stage, the foliar spray treatment was carried out. Each treatment was repeated 3 times, and the treatment without the test compound and the comparative compound was used as the control group.

[0183] Fifteen days after treatment, weigh the fresh weight of the above-ground parts of the treated weeds or crops, and calculate the fresh weight control efficacy (or fresh weight inhibition rate %) using the following formula:

[0184] Fresh weight control efficacy (or fresh weight inhibition rate %) = (fresh weight of aboveground parts of control group - fresh weight of aboveground parts of treatment group) / fresh weight of aboveground parts of control group × 100

[0185] The test results are shown in Table 1 below.

[0186] Table 1

[0187]

[0188]

[0189] As shown in Table 1, for barnyard grass, at an addition level of 75 g.ai / ha, the fresh weight control efficacy from best to worst was 2-3, 1-9, 1-7, and 1-6, with fresh weight control efficacies of 100%, 96.4%, 94.2%, and 71.1%, respectively, which was significantly higher than the 33.4% of the comparative compound. At an addition level of 150 g.ai / ha, the fresh weight control efficacy from best to worst was 2-3, 1-9, 1-10, 1-7, 1-8, 1-6, 1-5, 1-11, 1-3, and 1-4, with fresh weight control efficacies of 100%, 100%, 100%, 100%, 94.2%, 93.2%, 91.6%, 85.9%, 72.5%, and 65.5%, respectively, which was higher than the 63.8% of the comparative compound.

[0190] For foxtail grass, at an addition amount of 75 g.ai / ha, the fresh weight control efficacy from best to worst was 1-6, 1-7, 1-9, 1-5, 1-10, 2-3, 2-2, 1-4, 1-2, and 1-11, with fresh weight control efficacy results of 86.4%, 73.9%, 67.8%, 63.4%, 51.4%, 41.6%, 37.3%, 33.6%, 26.9%, and 23.8%, respectively, which was higher than the 21.4% of the comparative compound.

[0191] For *Lycium oryzae*, at an addition rate of 150 g.ai / ha, the fresh weight control efficacy from best to worst was 1-9, 1-7, 1-10, 1-8, 2-1, 2-3, 1-11, 1-4, 1-5, 1-6, and 1-1, respectively, with fresh weight control efficacy results of 100%, 100%, 100%, 100%, 100%, 91.8%, 83.2%, 82.8%, 76.8%, and 68.1%, respectively, which were higher than those of the comparison compound. The fresh weight efficacy was 64%; at an addition of 250 g.ai / ha, the fresh weight efficacy from best to worst was 1-7, 1-10, 1-9, 1-6, 1-8, 1-11, 1-5, 2-3, 2-1, 1-4, and 1-1, respectively, with fresh weight efficacy results of 100%, 100%, 100%, 100%, 100%, 100%, 100%, 97.6%, 82.9%, and 79.9%, respectively, which was higher than the 77% of the comparative compound.

[0192] For *Alopecurus aequalis*, at an addition amount of 150 g.ai / ha, the fresh weight control efficacy from best to worst was 1-9, 1-10, 1-7, 1-6, 1-8, 1-11, 1-5, and 2-3, respectively, with fresh weight control efficacy results of 100%, 100%, 100%, 99.2%, 87.2%, 83.3%, 83.0%, and 60.0%, which was higher than the 37.3% of the comparative compound.

[0193] For maize crops, at a dose of 250 g.ai / ha, except for compounds 1-5, the fresh weight inhibition rates of the other compounds were relatively small, mostly below 10%, indicating that the compounds disclosed herein have high safety for maize; in addition, compounds 1-9 and 2-3 had small fresh weight inhibition rates and were safer than the comparative compounds.

[0194] For wheat crops, at a dose of 250 g.ai / ha, the fresh weight inhibition rates of compounds 1-1, 1-2, 1-3, 2-1, 2-2, and 2-3 were all relatively small, indicating that the compounds disclosed herein have high safety for wheat.

[0195] Therefore, it can be seen that the compounds prepared in the embodiments of this disclosure have obvious activity advantages against these four weeds and can be widely used in weeding in both non-cultivated and cultivated land.

[0196] Furthermore, the results in Table 1 also show that the present disclosure can achieve the desired herbicidal effect with a relatively low amount of compound added (e.g., 75 g.ai / ha).

[0197] While the embodiments disclosed herein are as described above, the content is merely for the purpose of facilitating understanding of this disclosure and is not intended to limit this disclosure. Any person skilled in the art to which this disclosure pertains may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection of this disclosure shall still be determined by the scope defined in the appended claims.

Claims

1. A pyridazinone compound or an agronomically acceptable salt thereof, said pyridazinone compound having the structural formula shown in Formula 1 or Formula 2: Where R1 is H, fluorine, chlorine, bromine, or iodine; X is oxygen or sulfur; and R2 is C. 1-4 Alkyl or C 1-4 Halogenated alkyl groups.

2. The pyridazinone compound according to claim 1, wherein the compound of formula 1 is selected from one of the following compounds:

3. The pyridazinone compound according to claim 1, wherein the compound of formula 2 is selected from one of the following compounds:

4. The pyridazinone compound according to any one of claims 1-3, wherein the pyridazinone compound is in the form of an agronomically acceptable salt, the agronomically acceptable salt being selected from the group consisting of aluminum, calcium, cobalt, copper, iron, magnesium, potassium, sodium and zinc.

5. A pesticide composition comprising a pesticide-effective amount of at least one pyridazinone compound or an agronomically acceptable salt thereof according to any one of claims 1-4.

6. The pesticide composition according to claim 5, wherein the formulation is a technical grade pesticide, emulsifiable concentrate, powder, granule, suspension concentrate, water emulsion, or aqueous solution; wherein the powder is optionally a wettable powder; wherein the granule is optionally a water-dispersible granule; and wherein the suspension concentrate is optionally a dispersible oil suspension.

7. A herbicide composition comprising at least one pyridazinone compound or an agronomically acceptable salt thereof according to any one of claims 1-4.

8. The use of the pyridazinone compound or its agronomically acceptable salt according to any one of claims 1-4, or the pesticide composition according to claim 5 or 6, as a herbicide.

9. A method for preparing pyridazinone compounds according to any one of claims 1-4, wherein the method comprises reacting compounds of formula 3 and formula 4 with 1,3-cyclohexanedione, respectively, in the presence of an inert organic solvent, a base, and a catalyst to generate compounds of formula 1 and formula 2. in, R1, R2, and X are as defined above, and LG is a leaving group selected from halogen atoms.

10. The method according to claim 9, wherein the catalyst is a cyano-containing compound; the inert organic solvent is selected from dichloromethane, dichloroethane, or acetonitrile; and the base is selected from triethylamine.

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