JPH0149685B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is based on the formula (In the formula, Y is a hydrogen atom, a phenacyl group, or a 4-
Indicates a methylphenacyl group. ) as one of the active ingredients. In JP-A-50-126830 and JP-A-55-33454, (wherein, X represents a halogen atom or a lower alkyl group, n represents 1 to 4, and Y is the same as above) is disclosed as a herbicide. Compounds having formula () are included in the above patent, but are not specifically described. The present inventors have discovered that a novel pyrazole derivative having the formula () has herbicidal activity. The following compounds are exemplified as the active ingredients of the herbicide of the present invention. (1) 1,3-dimethyl-4-(2,4-dichloro-3
-Methylbenzoyl)-5-hydroxypyrazole and the phenacyl ether and 4-methylphenacyl ether of these compounds are converted into free 5-hydroxy forms in soil or plants when used, so they can be used in the same way. Can be used. The above compound (1) and its derivatives are preferred, and among them, compound (1) and its phenacyl ether, particularly the phenacyl ether of compound (1), is preferred. A compound having the formula () can be obtained by reacting a reactive derivative of a substituted benzoic acid corresponding to 1,3-dimethyl-5-hydroxypyrazole and then esterifying or etherifying the 5-position by the method described in the above-mentioned patent publication. It is obtained by Next, a production example of the compound of formula () will be shown. Production example 1 1,3-dimethyl-4-(2,4-dichloro-3-
Methylbenzoyl)-5-hydroxypyrazole 1,3-dimethylpyrazole in 80ml of benzene
Dissolve 5.94g and add 2.8g of sodium carbonate to this solution.
20ml of water solution was added dropwise, and then 2,4-
A solution of 12 g of dichloro-3-methylbenzoyl chloride in 20 ml of benzene was added dropwise at room temperature. About 2 more
After stirring for an hour, it was left overnight. The reaction solution was transferred to a separating funnel, and the benzene layer was washed once with 40 ml of water, dried over anhydrous sodium sulfate, and the benzene was distilled off under reduced pressure to give 1.3-dimethyl-5-(2,4-dichloro-3 -methylbenzoyloxy)pyrazole
14.8g (yield 93%) was obtained. mp89-91゜[Hexane:ethyl acetate (4:1)] 1,3-dimethyl-5 obtained by the above method
-(2,4-dichloro-3-methylbenzoyloxy)pyrazole 8.9g and anhydrous potassium carbonate
9.1g were mixed well and solidified by heating at 150° for 1 hour. After cooling the reaction mixture to about 70°, 50 ml of t-butanol was added, and the mixture was heated under reflux at 100° for 1 hour. After the reaction mixture was cooled to room temperature, about 10 ml of water was added thereto, the pH was adjusted to 3 with 6N hydrochloric acid, and the mixture was extracted once with 100 ml of benzene. After drying the benzene over anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure to obtain 7.6 g of the desired product as a white solid. Yield 85
%. mp150° (ethanol, colorless prismatic crystals), IRν ^Nujol _nax 2550 (board, OH), 1620cm ^-1 (CO). Production example 2 1,3-dimethyl-4-(2,4-dichloro-3-
Methylbenzoyl)-5-pyrazolyl p-toluenesulfonate 1,3-dimethyl- produced according to Production Example 1 above
4-(2,4-dichloro-3-methylbenzoyl)
6.9 g of -5-hydroxypyrazole was dissolved in 100 ml of acetonitrile, and 2.6 g of triethylamine was added dropwise while stirring at 5°. While cooling, a solution of 4.8 g of para-toluenesulfonyl chloride in 10 ml of acetonitrile was added dropwise. The reaction solution was returned to room temperature, stirred for an additional 4 hours, and then left overnight. Acetonitrile was distilled off under reduced pressure, and the residue was extracted with 50 ml of hot benzene to obtain 9 g of the target product as a white solid. Yield 86%. mp148−150゜ [hexane-ethyl acetate (5:
1), white prismatic crystal], IRν ^Nujol _nax : 1640 (CO), 1380, 1190 cm ^-1 (−OSO ₂
-) Production Example 3 1,3-dimethyl-4-(2,4-dichloro-3-
methylbenzoyl)-5-phenacyloxypyrazole 1,3-dimethyl- obtained in Production Example 1 above
4-(2,4-dichloro-3-methylbenzoyl)
1.5 g of -5-hydroxypyrazole, 1 g of phenacyl bromide and 0.7 g of anhydrous potassium carbonate were added to 20 ml of acetonitrile, stirred at room temperature for 9 hours, and then left overnight. Add 20 ml of water to the reaction solution, adjust the pH to 3 with 6N hydrochloric acid, and then dilute with 50 ml of dichloromethane.
Extracted twice. Dichloromethane was combined and the solvent was distilled off under reduced pressure. The residual oil was dissolved in a small amount of ethyl acetate and subjected to silica gel column chromatography. Elution with benzene-ethyl acetate (4:1) yielded 1.8 g of the target product as a white solid. obtained as.
Yield 90%. mp150-151° [hexane-ethyl acetate (4:1), white prismatic crystals]. IRν ^Nujol _nax 1700, 1635 cm ^-1 (CO). The compound having the formula () is effective against annual weeds such as field weed, broad-leaved weeds, and perennial weeds such as Japanese grasshopper, firefly, urikawa, omodaka, helaomodaka, water cyperus, and hirumushiro in paddy fields.
In particular, it has a herbicidal effect in pre-emergence soil treatment at the early stage of growth of these weeds, but 2-bromo-N-(α,α-dimethylbenzyl)-3,3-
When used in combination with dimethylbutyramide (M), a remarkable herbicidal effect can be obtained even on weeds with advanced growth. (M), one of the ingredients of this herbicide, is very effective against firefly etc. and is also highly safe against rice plants, but it is also effective against grasshoppers, annual broad-leaved weeds, and perennial weeds such as weeds. The effect is small. In addition, it is active against perennial weeds such as black mullet and cypress when treated in the early stages of growth, but the effect becomes weaker as growth progresses. The combined herbicide of the present invention can improve the drawbacks of the herbicide (M) above, and when used in combination, its efficacy can be maintained for a long time and even many types of weeds with advanced growth can be killed. Therefore, it brings about a synergistic effect that cannot be expected from single agent application. Test examples of the combined herbicide of the present invention are given below. Test Example 1 A polyethylene pot with an inner diameter of 8 cm was filled with paddy soil, firefly was grown in the paddy field, and at the first leaf stage of firefly, the flooded soil was treated with a predetermined amount of each drug formulated into a wettable powder. The pots were placed in a greenhouse at 25 to 30°C to grow under control, and 30 days after treatment, the fresh weight of the above-ground parts of the remaining firefly was measured, and the ratio to the untreated area was calculated. The results are shown in Table 1.

[Table] Test Example 2 Using a paddy field with clay loam and reduced water depth of 1 to 2 cm/day, rice seedlings at the 2nd to 3rd leaf stage were transplanted, and 7 days after transplantation.
On the following day, a predetermined amount of the granulated drug was applied to flooded soil. On the 40th day after the chemical treatment, weeds that remained unwithered were collected, their dry weight was measured, and the ratio to the untreated plot was calculated.
Each test area was ^6m2 , and the test was conducted in two consecutive sessions. The results are shown in Table 2.

[Table] The herbicide of the present invention may be sprayed as a raw material, or mixed with a carrier and other auxiliary agents as necessary, and prepared in the form of a formulation commonly used as a herbicide, such as a powder, a coarse powder, or a powder. It is prepared and used as fine granules, granules, wettable powders, emulsions, aqueous solutions, aqueous solutions, oil suspensions, etc. Suitable solid carriers for use in preparing the herbicide of the present invention include clays represented by the kaolinite group, montmorillonite group, or attapulgite group, talc, mica, pyrophyllite, pumice, vermiyukilite, and gypsum. , calcium carbonate, dolomite, diatomaceous earth, magnesium lime, phosphorous lime, zeolite, anhydrous silicic acid, synthetic calcium silicate, and other inorganic substances, soybean flour, tobacco flour, walnut flour, wheat flour, wood flour, starch, crystalline cellulose, etc. synthetic or natural polymer compounds such as coumaron resin, petroleum resin, alkyd resin, polyvinyl chloride, polyalkylene glycol, ketone resin, ester gum, copal gum, dammar gum, waxes such as carnauba wax and beeswax. ,
Alternatively, urea etc. can be mentioned. Suitable liquid carriers include paraffinic or naphthenic hydrocarbons such as kerosene, mineral oil, spindle oil, white oil, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene, methylnaphthalene, carbon tetrachloride, chloroform, etc. , chlorinated hydrocarbons such as trichloroethylene, monochlorobenzene, O-chlorotoluene, ethers such as dioxane and tetrahydrofuran, ketones such as acetone, methyl ethyl ketone, diisobutyl ketone, cyclohexanone, acetophenone, isophorone, ethyl acetate, amyl acetate, Esters such as ethylene glycol acetate, diethylene glycol acetate, dibutyl maleate, diethyl succinate, alcohols such as methanol, n-hexanol, ethylene glycol, diethylene glycol, cyclohexanol, benzyl alcohol, ethylene glycol ethyl ether, ethylene glycol phenyl ether , ether alcohols such as diethylene glycol ethyl ether and diethylene glycol butyl ether, dimethylformamide,
Examples include polar solvents such as dimethyl sulfoxide, water, and the like. Emulsification, dispersion, wetting, spreading, binding, disintegration control,
Surfactants used for the purpose of stabilizing active ingredients, improving fluidity, and preventing rust can be nonionic, anionic, cationic, or amphoteric, but usually used are nonionic and/or anionic. Suitable nonionic surfactants include, for example, those obtained by polymerizing and adding ethylene oxide to higher alcohols such as lauryl alcohol, stearyl alcohol, and oleyl alcohol, and those obtained by polymerizing and adding ethylene oxide to alkyl phenols such as isooctylphenol and nonylphenol. products obtained by polymerizing and adding ethylene oxide to alkylnaphthols such as butylnaphthol and octylnaphthol; products obtained by polymerizing and adding ethylene oxide to higher fatty acids such as palmitic acid, stearic acid, and oleic acid; products containing stearyl phosphoric acid and dilauryl phosphoric acid; Polymerized addition of ethylene oxide to mono- or dialkyl phosphoric acid, dotesylamine,
Examples include those obtained by polymerizing and adding ethylene oxide to an amine such as thearic acid amide, those obtained by polymerizing and adding ethylene oxide to a higher fatty acid ester of a polyhydric alcohol such as sorbitan, and those obtained by polymerizing and adding ethylene oxide and propylene oxide. Suitable anionic surfactants include, for example, sodium lauryl sulfate, alkyl sulfate salts such as oleyl alcohol sulfate amine salts, alkyl sulfonates such as sodium sulfosuccinate dioctyl ester, and sodium 2-ethylhexene sulfonate. , aryl sulfonates such as sodium isopropylnaphthalene sulfonate, sodium methylene bisnaphthalene sulfonate, sodium lignin sulfonate, and sodium dodecylbenzenesulfonate. Furthermore, the herbicide of the present invention includes casein, gelatin, albumin, glue, sodium alginate, carboxymethyl cellulose, methyl cellulose,
High molecular compounds such as hydroxyethyl cellulose and polyvinyl alcohol and other auxiliary agents can also be used in combination. The above-mentioned carriers and various auxiliary agents are used in the dosage form of the preparation,
They are used individually or in combination as appropriate depending on the purpose, taking into consideration the application situation. Powders, for example, usually contain 1 to 25 parts by weight of the active ingredient compound, with the remainder being a solid carrier. Wettable powders usually contain, for example, 25 to 90 parts by weight of the active ingredient compound, with the remainder being a solid carrier, a dispersing wetting agent, and optionally a protective colloid agent, a thixotropic agent, an antifoaming agent, and the like. Granules, for example, usually contain 1 to 35 parts by weight of the active ingredient compound, with the remainder being mostly solid carrier. The active ingredient compound is uniformly mixed with the solid carrier, or is uniformly fixed or adsorbed on the surface of the solid carrier, and the particle size is about 0.2 to
It is about 1.5mm. Emulsions, for example, usually contain 5 to 30 parts by weight of the active ingredient compound, this includes about 5 to 20 parts by weight of emulsifier, and the remainder is a liquid carrier;
Rust inhibitors are added if necessary. Examples of formulations of the herbicide of the present invention are given below. In the text,
All parts simply refer to parts by weight. Formulation Example 1 2 parts by weight of phenacyl ether of compound (1), 2 parts by weight of compound (M), 1 part by weight of isopropyl phosphate, 65 parts by weight of clay and 30 parts by weight of talc are thoroughly ground and mixed to obtain a powder.

Claims (1)

[Claims] 1 formula (In the formula, Y is a hydrogen atom, a phenacyl group, or a 4-
Indicates a methylphenacyl group. ), and
2-bromo-N-(α,α-dimethylbenzyl)-
A herbicidal composition containing 3,3-dimethylbutyramide as an active ingredient. 2. Claim 1, wherein the active ingredient compound of formula () is 1,3-dimethyl-4-(2,4-dichloro-3-methylbenzoyl)-5-(4-methylphenacyloxy)pyrazole The herbicidal composition described in .