A 4-amino-3,5-dichloro-6-aryl-2-heterocyclic pyridine compound, a synthetic method and application thereof

Abstract

The application discloses a compound of formula I, stereoisomers, nitroxides or salts thereof, wherein X, A, Y and m are defined in the description. The compound provided by the application is safe to plants, has high control effect on weeds, shows good control effect on resistant barnyard grasses, and has good application and promotion prospects.

Description

Technical Field

[0001] This invention belongs to the field of pesticide chemistry, specifically relating to a 4-amino-3,5-dichloro-6-aryl-2-heterocyclic pyridine compound, its synthesis method, and its application. Background Technology

[0002] Pyridine compounds possess a wide range of biological activities in agrochemicals, finding applications in fungicides, insecticides, herbicides, and plant growth regulators. They have long been a research hotspot, with commercially available examples including pyridine-containing fluorochloropyridine esters, chlorofluoropyridine esters, and chlorofluoropyroxyacetic acid isooctyl ester. These are already widely used in the herbicide field.

[0003] However, as the application time increases, weeds will develop resistance to herbicides. For example, the common weed barnyard grass is becoming increasingly resistant to cyhalofop-butyl, penoxsulam, etc. The most effective way to solve the problem of resistant weeds is to develop new herbicides. Summary of the Invention

[0004] This invention provides a 4-amino-3,5-dichloro-6-aryl-2-heterocyclic pyridine compound that has excellent herbicidal activity, is safe for crops, and has a good control effect on resistant weeds.

[0005] Specifically, the present invention provides a compound of formula I.

[0006]

[0007] Wherein, X is selected from O, S or NH;

[0008] A is an optional substitution of C2-C 10 Alkylene;

[0009] Y is selected from halogens, optionally substituted C1-C6 alkyl groups, optionally substituted C1-C6 alkoxy groups, nitro groups, cyano groups, halo-C1-C6 alkyl groups, optionally substituted C1-C6 alkylthio groups, and m is selected from integers from 0 to 5.

[0010] This invention also provides a method for synthesizing a compound of formula I, the synthetic route of which is as follows:

[0011] .

[0012] The present invention also provides a herbicidal composition comprising a compound of formula I of the present invention and at least one pesticide-acceptable adjuvant.

[0013] On the other hand, the present invention provides the use of the compounds of the present invention or compositions containing the compounds of the present invention in agriculture.

[0014] The present invention also provides a method for controlling unwanted weeds in useful plants.

[0015] Beneficial effects

[0016] The compounds of this invention have high herbicidal activity and are safe for crops, while also exhibiting excellent control of resistant weeds, and have broad application prospects. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprising of," etc., will be understood to include the stated components or steps, without excluding other substances or steps.

[0018] Furthermore, to better illustrate the present invention, numerous specific details are provided in the following detailed embodiments.

[0019] Those skilled in the art will understand that the present invention can be practiced even without certain specific details. In some embodiments, materials, methods, and means well known to those skilled in the art are not described in detail in order to highlight the spirit of the invention.

[0020] The terms “prevention” and “elimination” used in this invention are synonyms.

[0021] The terms “undesirable plant growth,” “harmful plant,” and “weed” used in this invention are synonyms and refer to any unwanted plant, including not only important farmland weeds but also native crop plants.

[0022] In this invention, "weed control" or "herbicide" means a compound that controls or alters plant growth. The term "effective amount" means the amount of such a compound or a combination of such compounds that produces an effect of controlling or altering plant growth. Controlled or altered effects include all deviations from natural development, such as killing, delaying, leaf burn, albinism, dwarfing, etc. The term "plant" refers to all tangible parts of a plant, including seeds, seedlings, young plants, roots, tubers, stems, stalks, leaves, and fruits. "Useful plants" in this invention include, but are not limited to, perennial crops such as citrus fruits, grapevines, nuts, oil palms, olives, pome fruits, stone fruits, and rubber, as well as annual arable crops such as barley, wheat, cotton, rapeseed, corn, rice, soybeans, sugar beets, sugarcane, sunflowers, ornamental plants, switchgrass, turf, and vegetables, especially rice, corn, and soybeans.

[0023] If the compound of Formula I described in this invention can form geometric isomers, such as E / Z isomers, then both the pure isomers and mixtures thereof can be used in the compositions of this invention.

[0024] If the compound of Formula I described in this invention has one or more chiral centers and is therefore present as an enantiomer or diastereomer, then the pure enantiomer, the racemic version, or the diastereomer may be used in the compositions of this invention.

[0025] It should be noted that, unless otherwise explicitly stated, the descriptive terms “each…independently is”, “each…independently is”, and “independently is” used in this invention are interchangeable and should be interpreted broadly. They can mean that the specific options expressed by the same symbols in different groups do not affect each other, or that the specific options expressed by the same symbols in the same group do not affect each other.

[0026] In this invention, all hydrocarbon chains, i.e., all alkyl groups, can be straight-chain or branched, C n -C mThe subscript indicates the number of carbon atoms in the group in all cases. The term "alkyl" as used herein (and in the alkyl structural part containing other groups such as alkoxy groups) is used. Examples of C1-C6 alkyl groups include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, 1-methylpropyl (sec-butyl), 2-methylpropyl (isobutyl), 1,1-dimethylethyl (tert-butyl), n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, hexyl, 1-methylpentyl, ... 2-Methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl, or 1-ethyl-2-methylpropyl.

[0027] In this invention, alkylene refers to a group that has lost one more hydrogen atom from an alkyl group. Exemplary alkylenes include: -C2H4-, -C3H6-, -C4H8-, -C5H4 ... 10 -、-C6H 12 -、-C7H 14 -、-C8H 16 -、-C9H 18 -、-C 10 H 20 -, preferably -CH2 CH2-, -CH2 CH2CH2-, -CH2 CH2 CH2 CH2-, -CH2 CH2CH2 CH2 CH2-, -CH(CH3)CH2-, -CH(CH(CH3)2)CH2-, -CH(CH3)CH(CH3)-.

[0028] Alkyl thio group, without particular limitation, generally refers to "alkyl-S-", for example, C1-C. 10 Alkyl thiols, preferably C1-C6 alkyl thiols, more preferably CH3S-, C2H5S-, C3H7S-, C4H9S-, C5H 11 S-, C6H 13 S-etc., but not limited to this.

[0029] Alkoxy groups, without specific definition, generally refer to "alkyl-O-", for example, C1-C. 10 Alkoxy groups, preferably C1-C6 alkoxy groups, more preferably methoxy, ethoxy, propoxy, etc., but not limited thereto.

[0030] The term "optional substitution" means that the relevant group may or may not be substituted by a substituent.

[0031] When a relevant group (such as an alkyl group) is substituted with a substituent, the substituent may include hydroxyl, cyano, nitro, halogen, alkyl, alkoxy, or alkylthio. When an alkyl group is substituted with a halogen, a haloalkyl group is formed. A haloalkyl group may have some or all of its hydrogen atoms replaced by a halogen, such as monofluoromethyl, difluoromethyl, or trifluoromethyl, but is not limited thereto. The alkyl group may be substituted with an alkoxy group, such as C1-C6 alkoxy-C1-C6 alkyl, but is not limited thereto. The alkyl group may also be substituted with an alkylthio group, such as C1-C6 alkylthio-C1-C6 alkyl, but is not limited thereto.

[0032] This invention first provides a compound of formula I, its stereoisomer, its nitride, or a salt thereof.

[0033] ,

[0034] Wherein, X is selected from O, S or NH;

[0035] A is an optional substitution of C2-C 10 Alkylene;

[0036] Y is selected from halogens, optionally substituted C1-C6 alkyl groups, optionally substituted C1-C6 alkoxy groups, nitro groups, cyano groups, halo-C1-C6 alkyl groups, optionally substituted C1-C6 alkylthio groups, and m is selected from integers from 0 to 5.

[0037] Preferably, A is selected from -C2H4-, -C3H6-, -C4H8-, and -C5H. 10 -、-C6H 12 -、-C7H 14 -、-C8H 16 -、-C9H 18 -or-C 10 H 20 -, preferably -CH2 CH2-, -CH2 CH2 CH2-, -CH2 CH2 CH2 CH2-, -CH2 CH2CH2 CH2 CH2-, -CH(CH3)CH2-, -CH(CH(CH3)2)CH2-, -CH(CH3)CH(CH3)-.

[0038] Preferably, Y is -F, -Cl, -Br, -I, -CH3, -C2H5, -C3H7, -C4H9, or -C5H. 11 -C6H 13 , -OCH3, -OC2H5, -OC3H7, -OC4H9, -OC5H 11 -OC6H 13-NO2, -CN, -CF3, or -CHF2, preferably -F, -Cl, -Br, -I, -CH3, -C2H5, -OCH3, -OC2H5, -NO2, -CN, or -CF3. m is 0, 1, 2, 3, 4, or 5.

[0039] Preferably, the present invention is selected from the following compounds:

[0040] , , , , , , , , .

[0041] Particularly preferred, the present invention is selected from the following compounds,

[0042] , , .

[0043] This invention also provides a method for preparing a compound of formula I, the synthetic route of which is as follows: ,

[0044] The above preparation method includes the following two steps:

[0045] Step 1: Compound of Formula IV is prepared by reacting it with compound of Formula III. Preferably, compounds of Formula IV and Formula III are added to a solvent and reacted at 0-120℃ (preferably 40-120℃) for 1-5 hours. After the reaction is completed, water is added, the mixture is filtered, and dried to obtain compound of Formula II. The solvent is selected from one or more of methanol, ethanol, DMSO, dichloroethane, chloroform, acetonitrile, dioxane, tetrahydrofuran, benzene, toluene, and xylene. The molar ratio of compounds of Formula IV and Formula III is 1:1~5, preferably 1:1.2~3.

[0046] Step 2: Preparation of Formula I compound from Formula II compound

[0047] Preferably, the method for preparing compound I from formula II includes the following steps:

[0048] Compound of formula II is added to a solvent selected from toluene, benzene, xylene, dichloroethane, chloroform, acetonitrile, petroleum ether, tetrahydrofuran, dioxane, DMSO, ethyl acetate, isopropyl acetate, and dimethyl carbonate. Then, thionyl chloride, polyphosphoric acid, paraformaldehyde, or concentrated sulfuric acid is added. The reaction is carried out at 0-120°C for 1-5 hours. After the reaction is completed, the solvent is removed by vacuum distillation, and the product is washed with water and dried to obtain the intermediate product. The molar ratio of the compound of formula II to thionyl chloride, polyphosphoric acid, paraformaldehyde, or concentrated sulfuric acid is 1:1-6, preferably 1:2-4.

[0049] The intermediate product from the previous step is added to a solvent, and then a base is added. The reaction is carried out at 0-100℃ (preferably 40-100℃) for 1-5 hours. After the reaction is completed, the solvent is removed, and the product is washed with water and dried to obtain compound I. The solvent is selected from methanol, ethanol, DMF, acetone, petroleum ether, toluene, benzene, xylene, dichloroethane, chloroform, acetonitrile, tetrahydrofuran, dioxane, DMSO, ethyl acetate, and isopropyl acetate. The base is selected from sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate. The molar ratio of intermediate 1 to base is 1:1-5.

[0050] Preferably, the present invention also provides another method for preparing compound of formula I from formula II, comprising the following steps:

[0051] Compound II is added to a solvent, which is selected from toluene, benzene, xylene, dichloroethane, chloroform, tetrahydrofuran, and dioxane. Then, phosphorus oxychloride is added, and the reaction is carried out at 0-120℃ (preferably 60-120℃) for 1-5 hours. After the reaction is completed, the solvent is removed by vacuum distillation, the mixture is quenched with water, filtered, and recrystallized from methanol to obtain compound I. The molar ratio of compound II to phosphorus oxychloride is 1:1-5. In this method, phosphorus oxychloride can also be used directly as a solvent.

[0052] Compounds of Formula I have herbicidal activity and can be formulated into agriculturally acceptable formulations for use, including wettable powders, powders, suspensions, soluble powders / granules, emulsifiable concentrates, aqueous solutions, granules, water-dispersible granules, dispersible oil suspensions, and water-emulsions.

[0053] The weight content of the compound of formula I in the formulation is 0.01~99%, and in addition to the active ingredient, it also contains one or more of the following: emulsifier, wetting agent / penetrating agent, dispersant, stabilizer, thickener, disintegrant, antifreeze, preservative, defoamer, binder, filler / carrier, solvent / cosolvent.

[0054] The preferred emulsifiers include fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, fatty amine polyoxyethylene ether, alkyl glycosides, and agricultural emulsion series: Agricultural Emulsion 601#, Agricultural Emulsion 602#, Agricultural Emulsion 603#, Agricultural Emulsion 604#, Agricultural Emulsion 401#, Agricultural Emulsion 402#, Agricultural Emulsion 700#, Agricultural Emulsion 33#, Agricultural Emulsion 34#, Agricultural Emulsion 1601#, Agricultural Emulsion 1602#, etc., and Span series: Span-20, Span-40, Span-60, Span- 65, Span-80, Span-85, etc., Tween series: Tween-20, Tween-40, Tween-60, Tween-65, Tween-80, Tween-85, etc., castor oil polyoxyethylene ether, polyoxyethylene oleate, ethylene oxide / propylene oxide co-ether, polyglycerol fatty acid ester, calcium dodecylbenzene sulfonate, polyoxyethylene ether sulfate salt, polyoxyethylene ether phosphate salt, etc.

[0055] Preferred wetting agents / penetrating agents include fatty alcohol ethers (such as isomeric alcohol ethers 1300 series, MOA series, penetrant JFC, emulsifier AEO, etc.), alkylphenol polyoxyethylene ethers (such as TX, OP, NP series, etc.), fatty amine polyoxyethylene ethers (such as AC-1800 series, AC-1200 series, AN-1800 series, etc.), alkyl glycosides (C8-C10 alkyl glycosides, C12-C14 alkyl glycosides, C8-C14 alkyl glycosides, etc.), and polyarylphenols. Polyoxyethylene ether (such as agricultural emulsion 600#, agricultural emulsion 400#, agricultural emulsion 33#, agricultural emulsion 34#), castor oil polyoxyethylene ether (such as BY-110, BY-125, BY-140, etc.), calcium dodecylbenzene sulfonate, sodium α-alkenyl sulfonate, sodium salt of fatty alcohol ether sulfate AES, sodium alkyl succinate sulfonate (such as fast T, etc.), polycyclic aromatic hydrocarbon formaldehyde condensate sulfonate or alkyl aromatic hydrocarbon sulfonate (such as dispersant NNO, pull-opening powder BX, etc.) and one or more of the following.

[0056] The preferred dispersants are naphthalene or alkylnaphthalene formaldehyde condensate sulfonates (such as dispersant N), lignin sulfonates, phosphate salts (such as 601PT), polyoxyethylene ether sulfates, sodium succinate diester sulfonate, polycarboxylate, fatty alcohol polyoxypropylene polyoxyethylene ether, and polyoxyethylene polypropylene ether block copolymers.

[0057] The stabilizer is preferably one or more of the following: phosphite, epichlorohydrin, epoxidized soybean oil, epoxidized linseed oil, BHA, BHT, etc.

[0058] The preferred thickeners are one or more of the following: sodium chloride, ammonium chloride, ammonium sulfate, magnesium aluminum silicate, starch, xanthan gum, agar, hydroxymethyl cellulose, hydroxypropyl methyl cellulose, organobentonite, diatomaceous earth, and polyvinyl alcohol.

[0059] The preferred disintegrants are one or more of sodium carboxymethyl starch, croscarmellose sodium, croscarmellose cellulose, modified starch, croscarmellose polyvinylpyrrolidone, magnesium aluminum silicate, sodium alginate, etc.

[0060] The preferred antifreeze is one or more of the following: ethylene glycol, propylene glycol, glycerol, polyethylene glycol, and urea.

[0061] Preservatives are preferably one or more of benzoic acid, sorbic acid, p-hydroxybenzoic acid, hydroquinone, etc.

[0062] The preferred defoamer is one or more of the following: propanol, butanol, tributyl phosphate, polyether surfactants, polyethylene glycol fatty acid esters, mineral oil, and siloxane oil.

[0063] The binder is selected from one or more of starch, gelatin and gum arabic, povidone, sucrose, glucose, and dextrin.

[0064] The carrier / filler is preferably one or more of the following: diatomaceous earth, attapulgite, bentonite, zeolite, sepiolite, kaolin, clay, silica, light calcium carbonate, starch, magnesium stearate, talc.

[0065] The solvent / co-solvent is preferably one or more of the following: water, soybean oil, rapeseed oil, corn oil, sunflower oil, cottonseed oil, palm oil, peanut oil, castor oil or methylated vegetable oil, solvent naphtha, liquid paraffin oil, benzene, toluene, xylene, naphthalene, methanol, ethanol, ethylene glycol, isopropanol, cyclohexanol, cyclohexanone, acetonitrile, acetone, dimethyl sulfoxide, N-methylpyrrolidone, propionic acid alcohol, acetate, dichloromethane, trichloromethane, cresol, etc.

[0066] The pesticide reagent of the present invention for controlling unwanted plants can be used in farmland for the following crops. The crops mentioned include: corn, rice, wheat, barley, rye, oats, sorghum, cotton, soybeans, peanuts, buckwheat, sugar beets, rapeseed, sunflowers, sugarcane, tobacco, eggplant, tomatoes, bell peppers, chili peppers, potatoes, cucumbers, pumpkins, zucchini, watermelons, cantaloupes, Japanese radishes, white radishes, horseradishes, kohlrabi, Chinese cabbage, cabbage, mustard greens, broccoli, cauliflower, garland chrysanthemum, artichokes, lettuce, scallions, onions, garlic or asparagus, carrots, parsley, celery, parsnip, spinach, Swiss chard, apples, pears, papayas, peaches, plums, nectarines, prunes, cherries, apricots, prunes, Satsuma mandarins, oranges, lemons, limes, grapefruits, chestnuts, walnuts, hazelnuts, almonds, pistachios, cashews or macadamia nuts, grapes, persimmons, olives, loquats, bananas, coffee, dates, coconut palms, oil palms, etc.

[0067] The compound of formula I of this invention has excellent herbicidal activity and crop safety. The compound of formula I of this invention is suitable for plant protection and control of unwanted plants in agriculture, forestry and horticulture.

[0068] The compound of Formula I of the present invention can control weeds by using an effective amount of the compound of Formula I of the present invention.

[0069] The present invention provides a composition comprising the compound described herein or a stereoisomer of the compound described herein, a nitrogen oxide or a salt thereof.

[0070] The herbicidal compositions or formulations of the present invention typically contain 0.01 to 99 wt%, preferably 0.5 to 90 wt%, of compounds of formula (I). When reagents containing compounds of the present invention are used to control unwanted plants and weeds, the application rate based on compounds of formula I is typically selected as 0.01 to 1000 g per hectare, preferably an effective amount of 0.01 to 500 g per hectare. The effective amount of the present invention refers to the application rate of compounds of formula I. Preferred compounds of formula I, for example, compounds 1-9, as active ingredients, can have good weed-killing effects at a dose of 0.1 g / acre (i.e., an active ingredient dosage of 0.1 g per acre), and particularly preferred compounds have good weed-killing effects at a dose of 0.05 g / acre (i.e., an active ingredient dosage of 0.05 g per acre). When pesticide compositions containing Formula I are used for weed control in formulations such as emulsifiable concentrates, wettable powders, or microemulsions, they are typically applied by diluting the formulation containing Formula I of the present invention with water to a concentration of the active ingredient ranging from 0.01 to 5000 ppm. Granules or powders can be applied undiluted. Research results indicate that the compounds of Formula (I) of the present invention exhibit at least 90% killing efficacy against certain weeds and resistant weeds in the concentration range of 0.1 to 100 ppm (0.1 mg / L to 100 mg / L). Preferred compounds exhibit at least 90% killing efficacy against certain weeds and resistant weeds in the concentration range of 0.01 ppm to 100 ppm.

[0071] The compounds of this invention can control broadleaf weeds including, for example, shepherd's purse, duckweed, jointed greens, cleavers, eupatorium, speedwell, wild ginger, cocklebur, burdock, lambsquarters, thistle, large thistle, knotweed, chickweed, cowherb, cowherb seed, knotweed, styrax, geranium, wild lettuce, water spinach, vetch, alligator weed, amaranth, black nightshade, and bulrush. Purslane, amaranth, sedge, hop, arrowhead, etc.; also includes grass weeds, such as barnyard grass, crabgrass, wild oats, annual bluegrass, barnyard grass, reed, purslane, foxtail grass, trevally, clover, hard grass, brome, goosegrass, barnyard grass, etc.; also includes sedge weeds, such as nutgrass, sedge, water sedge, rice sedge, water centipede, etc., but not limited to these.

[0072] The preferred plants for this invention are barnyard grass, crabgrass, Echinochloa crus-galli, duckweed, jointed grass, alligator weed, and sedge.

[0073] The compound of Formula I of this invention exhibits high safety for important crops, including but not limited to barley, cotton, wheat, rapeseed, sugar beet, corn, sorghum, soybean, rice, oats, peanuts, vegetables, tomatoes, and potatoes.

[0074] Preparation Examples

[0075] In this specification, if there are any differences between chemical names and chemical structures, the structure is preferred. Generally, the compounds of this invention can be prepared by the methods described herein, unless further specified. The raw materials, reagents, etc., used to prepare the compounds of this invention are commercially available or can be prepared by methods conventional in the art.

[0076] Example 1: Synthesis of Compound 1

[0077]

[0078] 5.94 g of methyl 4-amino-3,5-dichloro-6-phenylpyridine-2-carboxylate and 3.09 g of 2-aminoethanethiol were added to 100 ml of methanol and reacted at 60 °C for 4 h. After the reaction was completed, water was added, the mixture was filtered, and dried to obtain 6.72 g of 4-amino-3,5-dichloro-6-phenylpyridine-2-carboxylic acid (2-mercaptoethyl)amide.

[0079] Take 150 ml of ethyl acetate, add 6.72 g of 4-amino-3,5-dichloro-6-phenylpyridine-2-carboxylic acid (2-mercaptoethyl)amide and 4.76 g of thionyl chloride, react at 70 °C for 3 h, remove the solvent by vacuum distillation after the reaction is completed, wash with water and dry to obtain 6.59 g of intermediate product 1.

[0080] Take 150 ml of methanol, add 6.59 g of intermediate product 1 and 1.6 g of sodium hydroxide, react at 60 °C for 3 h, remove the solvent after the reaction is complete, wash with water and dry to obtain 6.15 g of compound 1, with an overall yield of 95%.

[0081] Example 2 Synthesis of Compound 2

[0082]

[0083] 6.63 g of methyl 4-amino-3,5-dichloro-6-(4-chlorophenyl)pyridine-2-carboxylate and 3.66 g of 2-aminoethanol were added to 100 ml of ethanol and reacted at 70 °C for 3 h. After the reaction was completed, water was added, the mixture was filtered, and dried to obtain 7.10 g of 4-amino-3,5-dichloro-6-(4-chlorophenyl)pyridine-2-carboxylic acid (2-hydroxyethyl)amide.

[0084] Take 120 ml of isopropyl acetate, add 7.10 g of 4-amino-3,5-dichloro-6-(4-chlorophenyl)pyridine-2-carboxylic acid (2-hydroxyethyl)amide and 5.95 g of thionyl chloride, react at 80 °C for 2 h, remove the solvent by vacuum distillation after the reaction is completed, wash with water and dry to obtain 6.93 g of intermediate product 2.

[0085] Take 150 ml of dichloroethane, add 6.93 g of intermediate product 2 and 2.4 g of sodium hydroxide, react at 80 °C for 3 h, remove the solvent after the reaction is complete, wash with water and dry to obtain 6.39 g of compound 2, with an overall yield of 93.5%.

[0086] ¹H NMR (300 MHz, deuterated DMSO): δ7.51–7.61 (m, 4H), δ6.99 (s, 2H), δ4.36–4.42 (t, 2H), δ3.95–4.02 (t, 2H)

[0087] Example 3 Synthesis of Compound 3

[0088]

[0089] 7.88 g of methyl 4-amino-6-(3-bromo-5-fluorophenyl)-3,5-dichloropyridine-2-carboxylate and 2.25 g of 2-aminoprop-1-ol were added to 100 ml of dichloroethane and reacted at 80 °C for 2 h. After the reaction was completed, water was added, the mixture was filtered, and dried to obtain 8.52 g of 4-amino-6-(3-bromo-5-fluorophenyl)-3,5-dichloropyridine-2-carboxylic acid (2-hydroxy-1-methylethyl)-amide.

[0090] 8.52 g of 4-amino-6-(3-bromo-5-fluorophenyl)-3,5-dichloropyridine-2-carboxylic acid (2-hydroxy-1-methylethyl)-amide was added to 150 ml of tetrahydrofuran, followed by 6.13 g of phosphorus oxychloride. The reaction was carried out at 60 °C for 3 h. After the reaction was completed, the solvent was removed by vacuum distillation, the solvent was quenched with water, filtered, and recrystallized from methanol to give 7.78 g of compound 3, with an overall yield of 93%.

[0091] Example 4 Synthesis of Compound 4

[0092]

[0093] 6.63 g of methyl 4-amino-3,5-dichloro-6-(4-chlorophenyl)pyridine-2-carboxylate and 3.61 g of ethylenediamine were added to 120 ml of toluene and reacted at 100 °C for 1 h. After the reaction was completed, water was added, the mixture was filtered, and dried to obtain 7.06 g of 4-amino-3,5-dichloro-6-(4-chlorophenyl)pyridine-2-carboxylic acid (2-aminoethyl)amide.

[0094] 7.06 g of 4-amino-3,5-dichloro-6-(4-chlorophenyl)pyridine-2-carboxylic acid (2-aminoethyl)amide was added to 150 ml of toluene, followed by 9.19 g of phosphorus oxychloride. The reaction was carried out at 110 °C for 1 h. After the reaction was completed, the solvent was removed by vacuum distillation, the mixture was quenched with water, filtered, and recrystallized from methanol to obtain 6.60 g of compound 4, with an overall yield of 96.5%.

[0095] ¹H NMR (300MHz, deuterated DMSO): δ7.52–7.68 (m, 4H), δ6.86 (s, 2H), δ3.60 (s, 4H)

[0096] Example 5 Synthesis of Compound 5

[0097]

[0098] 7.27 g of methyl 4-amino-3,5-dichloro-6-(2-fluoro-3-chloro-4-methylphenyl)-pyridine-2-carboxylate and 3.09 g of 2-amino-3-methylbut-1-ol were added to 100 ml of dioxane and reacted at 50 °C for 3 h. After the reaction was completed, water was added, the mixture was filtered, and dried to obtain 8.38 g of 4-amino-3,5-dichloro-6-(2-fluoro-3-chloro-4-methylphenyl)-pyridine-2-carboxylic acid (1-hydroxymethyl-2-methylpropyl)amide.

[0099] 8.38 g of 4-amino-3,5-dichloro-6-(2-fluoro-3-chloro-4-methylphenyl)-pyridine-2-carboxylic acid (1-hydroxymethyl-2-methylpropyl)amide was added to 100 ml of phosphorus oxychloride and reacted at 80 °C for 1 h. After the reaction was completed, a large amount of water was added to quench the reaction, and the mixture was filtered and recrystallized from methanol to give 7.57 g of compound 5, with an overall yield of 91%.

[0100] Example 6: Synthesis of Compound 6

[0101]

[0102] 6.50 g of methyl 4-amino-3,5-dichloro-6-(2,4-dimethylphenyl)pyridine-2-carboxylate and 2.29 g of 1,2-dimethylethylenediamine were added to 120 ml of acetonitrile and reacted at 50 °C for 2 h. After the reaction was completed, water was added, the mixture was filtered, and dried to obtain 7.07 g of 4-amino-3,5-dichloro-6-(2,4-dimethylphenyl)pyridine-2-carboxylic acid (2-amino-1-methylpropyl)amide.

[0103] Take 100 ml of dichloroethane, add 7.07 g of 4-amino-3,5-dichloro-6-(2,4-dimethylphenyl)pyridine-2-carboxylic acid (2-amino-1-methylpropyl)amide and 1.96 g of concentrated sulfuric acid, react at 40 °C for 4 h, remove the solvent by vacuum distillation after the reaction is completed, wash with water and dry to obtain 6.59 g of intermediate product 3.

[0104] Take 100 ml of tetrahydrofuran, add 6.59 g of intermediate product 3 and 1.85 g of sodium bicarbonate, react at 50 °C for 3 h, remove the solvent after the reaction is complete, wash with water and dry to obtain 5.93 g of compound 6, with an overall yield of 81.5%.

[0105] Example 7 Synthesis of Compound 7

[0106]

[0107] 6.63 g of methyl 4-amino-3,5-dichloro-6-(4-chlorophenyl)pyridine-2-carboxylate and 4.51 g of 3-aminoprop-1-ol were added to 100 ml of toluene and reacted at 80 °C for 2 h. After the reaction was completed, water was added, the mixture was filtered, and dried to obtain 7.37 g of 4-amino-3,5-dichloro-6-(4-chlorophenyl)pyridine-2-carboxylic acid (3-hydroxypropyl)amide.

[0108] Take 100 ml of isopropyl acetate, add 7.37 g of 4-amino-3,5-dichloro-6-(4-chlorophenyl)pyridine-2-carboxylic acid (3-hydroxypropyl)amide and 7.14 g of thionyl chloride, react at 70 °C for 3 h, remove the solvent by vacuum distillation after the reaction is completed, wash with water and dry to obtain 7.25 g of intermediate product 4.

[0109] Take 120 ml of toluene, add 7.25 g of intermediate product 4 and 2.24 g of potassium hydroxide, react at 90 °C for 2 h, remove the solvent after the reaction is complete, wash with water and dry to obtain 6.74 g of compound 7, with an overall yield of 94.5%.

[0110] 1H NMR (300MHz, deuterated DMSO): δ7.50-7.59 (m,4H), δ6.84 (s,2H), δ4.26-4.30(t,2H), δ3.41-3.45 (t,2H), δ1.87-1.94 (m,2H)

[0111] Example 8 Synthesis of Compound 8

[0112]

[0113] 6.84 g of methyl 4-amino-3,5-dichloro-6-(4-nitrophenyl)pyridine-2-carboxylate and 3.0 g of 3-aminoprop-1-ol were added to 150 ml of tetrahydrofuran and reacted at 60 °C for 3 h. After the reaction was completed, water was added, the mixture was filtered, and dried to obtain 7.54 g of 4-amino-3,5-dichloro-6-(4-nitrophenyl)pyridine-2-carboxylic acid (3-hydroxypropyl)amide.

[0114] 7.54 g of 4-amino-3,5-dichloro-6-(4-nitrophenyl)pyridine-2-carboxylic acid (3-hydroxypropyl)amide was added to 150 ml of dioxane, followed by 3.07 g of phosphorus oxychloride. The reaction was carried out at 70 °C for 3 h. After the reaction was completed, the solvent was removed by vacuum distillation, the solvent was quenched with water, filtered, and recrystallized from methanol to obtain 6.92 g of compound 8, with an overall yield of 94%.

[0115] Example 9 Synthesis of Compound 9

[0116]

[0117] 7.04 g of methyl 4-amino-3,5-dichloro-6-(3-cyano-4-methoxyphenyl)pyridine-2-carboxylate and 1.78 g of 1,3-propanediamine were added to 100 ml of dichloroethane and reacted at 65 °C for 3 h. After the reaction was completed, water was added, the mixture was filtered, and dried to obtain 7.65 g of 4-amino-3,5-dichloro-6-(3-cyano-4-methoxyphenyl)pyridine-2-carboxylic acid (3-aminopropyl)amide.

[0118] 7.65 g of 4-amino-3,5-dichloro-6-(3-cyano-4-methoxyphenyl)pyridine-2-carboxylic acid (3-aminopropyl)amide was added to 150 ml of dichloroethane, followed by 4.59 g of phosphorus oxychloride. The reaction was carried out at 65 °C for 3 h. After the reaction was completed, the solvent was removed by vacuum distillation, the solvent was quenched with water, filtered, and recrystallized from methanol to obtain 7.04 g of compound 9, with an overall yield of 93.5%.

[0119] II. Life Test

[0120] I) Herbicidal Activity Experiment

[0121] 1. Test target

[0122] Barnyard grass, Echinochloa crus-galli, Crataegus pinnatifida, Common duckweed, Jointed greens, Alternanthera philoxeroides, Cyperus difformis, Resistant barnyard grass

[0123] 2. Testing Methods

[0124] The experimental method was in accordance with the standard “NY / T 1155.4-2006 Guidelines for Indoor Bioassay of Pesticides. Herbicides. Part 4 Activity Assay. Foliar Spray Method”. A certain amount of compounds 1-9, cyhalofop-butyl, and penflusulfonamide were weighed and dissolved in acetone. The solutions were then diluted with 0.1% Tween 80 aqueous solution for later use. The specific amounts used are shown in Table 1-3. Compounds 1-9 were synthesized in our laboratory, while cyhalofop-butyl and penflusulfonamide were purchased from the market.

[0125] Take well-drained, sieved, and air-dried soil with a permeable organic matter content of 2.5% and a pH of approximately 7. Fill pots 4 / 5 full with the soil and water from the top until the soil is completely moist. Sow 35 weed seeds evenly on the soil surface, cover with about 1.0 cm of soil, and move to a greenhouse for cultivation at 20±2℃. For dryland weeds, water is added to the pots by drip irrigation from the bottom, and for paddy field weeds, water is added to the pots by irrigation from the top until saturation. After emergence, thin and transplant, leaving 15 weeds of similar growth in each pot, evenly distributed. Spray the herbicide when the weeds are at the 3-4 leaf stage, at a spray volume of 350 L / ha. Each treatment has 4 replicates, and a treatment without active ingredients is set up as a blank control. After 14 days, observe the growth inhibition of the weeds, weigh the fresh weight of the above-ground portion of the weeds, and calculate and record the fresh weight inhibition rate (%).

[0126] 3. Calculation method and results

[0127] Fresh weight inhibition rate (%) = (control fresh weight - treatment fresh weight) / control fresh weight × 100.

[0128] Table 1. Inhibition rates of fresh weight of Formula I compounds on barnyard grass, Echinochloa crus-galli, and Digitaria sanguinalis.

[0129]

[0130] As shown in Table 1, the compound of Formula I of this invention has a good control effect on grass weeds such as barnyard grass, Echinochloa crus-galli, and Digitaria sanguinalis.

[0131] Table 2. Inhibition rates of Formula I compounds on the fresh weight of *Monochoria vaginalis*, *Spatholobus suberectus*, *Alternanthera philoxeroides*, and *Cyperus difformis*.

[0132]

[0133] Table 2 shows that compound I has a good control effect on broadleaf weeds such as duckweed, jointed grass, alligator weed and sedge.

[0134] Table 3. Fresh weight inhibition rate of Formula I compound against barnyardgrass

[0135]

[0136] As shown in Table 3, compound I also has a good control effect on barnyardgrass resistant to cyhalofop-butyl and penoxsulam.

[0137] II) Safety Experiment

[0138] 1. Test crops

[0139] Corn, wheat, rice

[0140] 2. Testing Methods

[0141] The method refers to the standard "NY / T 1155.8-2007 Guidelines for Indoor Bioassay of Pesticides - Herbicides - Part 8: Safety Tests of Crops - Foliar Spray Method". A certain amount of compound 1, compound 2, compound 4, compound 7, and compound 8 were weighed, dissolved in acetone, and diluted with 0.1% Tween 80 aqueous solution for later use. The specific usage is shown in Table 4.

[0142] Sifted and air-dried soil with good permeability, an organic matter content of 2.5%, and a pH of approximately 7 was collected. The soil was filled to 4 / 5 of the pot's capacity, and watered from the top until completely moist. Thirty crop seeds were evenly sown on the soil surface, covered with approximately 1.0 cm of soil, and then transferred to a greenhouse for cultivation at 20±2℃. For dryland crops, water was applied via bottom irrigation; for paddy field crops, water was applied via top irrigation until saturation. After emergence, thinning and transplanting were carried out. When the crops reached the 3-4 leaf stage, foliar spraying was applied to treat the crops at a rate of 350 L / ha. Each treatment was replicated four times, with a control group containing no active ingredient. After treatment, the solution was allowed to air dry naturally, and the plants were then transferred to a greenhouse for conventional cultivation. Dryland crops were watered via bottom irrigation, and paddy field crops were watered via top irrigation until saturation. Results were recorded visually after 14 days, and the results are shown in Table 4.

[0143] Phytotoxicity effect is indicated as follows: 0 indicates safety and no phytotoxicity; 1-10 indicates no obvious phytotoxicity; 11-30 indicates slight phytotoxicity; 31-50 indicates moderate phytotoxicity; and >50 indicates severe phytotoxicity.

[0144] Table 4. Safety data of Formula I compounds for crops such as corn, wheat, and rice.

[0145]

[0146] As shown in Table 4, the compound of Formula I of this invention has high safety for crops such as corn, wheat, and rice.

[0147] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A compound of formula I, its stereoisomer, its nitride, or a salt thereof, in, X is selected from O, S, or NH; A is an optional substitution of C2-C 10 Alkylene; Y is selected from halogens, optionally substituted C1-C6 alkyl groups, optionally substituted C1-C6 alkoxy groups, nitro groups, cyano groups, halo-C1-C6 alkyl groups, optionally substituted C1-C6 alkylthio groups, and m is selected from integers from 0 to 5.

2. The compound of formula I, its stereoisomers, its nitrides, or salts thereof according to claim 1, characterized in that, The A is selected from -C2H4-, -C3H6-, -C4H8-, and -C5H. 10 -、-C6H 12 -、-C7H 14 -、-C8H 16 -、-C9H 18 -or-C 10 H 20 -, preferably -CH2 CH2-, -CH2 CH2 CH2-, -CH2 CH2 CH2 CH2-, -CH2 CH2CH2 CH2 CH2-, -CH(CH3)CH2-, -CH(CH(CH3)2)CH2-, -CH(CH3)CH(CH3)-.

3. The compound of formula I, its stereoisomers, its nitrides, or salts thereof according to claim 1, characterized in that, The Y is -F, -Cl, -Br, -I, -CH3, -C2H5, -C3H7, -C4H9, -C5H 11 -C6H 13 , -OCH3, -OC2H5, -OC3H7, -OC4H9, -OC5H 11 -OC6H 13 -NO2, -CN, -CF3, or -CHF2, preferably -F, -Cl, -Br, -I, -CH3, -C2H5, -OCH3, -OC2H5, -NO2, -CN, or -CF3.

4. The compound of formula I according to claim 1, its stereoisomer, its nitride or its salt m is 0, 1, 2, 3, 4 or 5.

5. The compound of formula I, its stereoisomers, its nitrides, or salts thereof according to claim 1, characterized in that, Selected from the following compounds: ， ， ， ， ， ， ， ， 。 6. A method for preparing the compound of formula I according to any one of claims 1-5, its stereoisomers, its nitrides, or salts thereof, characterized in that, Includes the following steps: Step 1: Add compounds of formula IV and formula III to a solvent and react them at 0-120°C, preferably 40-120°C, to prepare compound II; wherein the solvent is selected from one or more of methanol, ethanol, DMSO, dichloroethane, chloroform, acetonitrile, dioxane, tetrahydrofuran, benzene, toluene, and xylene. Step 2: Compound of Formula II is reacted in a solvent to prepare compound of Formula I; Its synthetic route is as follows: 。 7. The preparation method according to claim 6, characterized in that, Step two includes the following steps: 1) Add the compound of formula II to a solvent selected from toluene, benzene, xylene, dichloroethane, chloroform, acetonitrile, petroleum ether, tetrahydrofuran, dioxane, DMSO, ethyl acetate, isopropyl acetate, and dimethyl carbonate. Then add thionyl chloride, polyphosphoric acid, paraformaldehyde, or concentrated sulfuric acid. React at 0-120°C for 1-5 hours to obtain the intermediate product. ; 2) Add the intermediate product obtained in step 1) to a solvent, then add an alkali, and react at 0-100°C, preferably 40-100°C, for 1-5 hours; wherein the solvent is selected from one or more of methanol, ethanol, DMF, acetone, petroleum ether, toluene, benzene, xylene, dichloroethane, chloroform, acetonitrile, tetrahydrofuran, dioxane, DMSO, ethyl acetate, and isopropyl acetate, and the alkali is selected from sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, or potassium bicarbonate.

8. The preparation method according to claim 6, characterized in that, Step two includes the following steps: The compound of formula II is added to a solvent selected from one or more of toluene, benzene, xylene, dichloroethane, chloroform, phosphorus oxychloride, tetrahydrofuran, and dioxane, and then phosphorus oxychloride is added. The reaction is carried out at 0-120°C, preferably 60-120°C, for 1-5 hours.

9. The compound of formula I according to any one of claims 1-5, its stereoisomers, its nitrogen oxides or salts thereof, shall be used as an active ingredient in herbicides.

10. A composition, characterized in that, It contains a compound of formula I as described in any one of claims 1-5, its stereoisomers, its nitrogen oxides or salts thereof, and pesticide-acceptable adjuvants.

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