JPH0336823B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Field The present invention is directed to a novel 5-(2'-chloro-4'-trifluoromethylphenol compound) which has selective herbicidal properties and can be suitably used as a weed control pesticide for various agricultural crops. c)-2-nitro-α-methoxyacetophenone and 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime derivatives and their active ingredients The invention relates to selective herbicides. Prior Art Until now, alkyl [2-nitro-5-(2'-
It is known that chloro-4'-trifluoromethylphenoxy)phenyl]ketone and its oxime derivatives can be used as herbicides (Japanese Patent Application Laid-open No. 1986-1999).
Publication No. 32432). However, with conventional diphenyl ether herbicides, those that exhibit strong herbicidal activity tend to have low selectivity, and those that exhibit high selectivity tend to have weak herbicidal activity. Only weeds could not be removed efficiently and quickly. By the way, in addition to strong herbicidal power and high selectivity, conventional herbicides have low toxicity to warm-blooded animals, can be commonly used throughout the entire growing season of crops, and It is considered ideal that the herbicide should be decomposed as quickly as possible and not contaminate the soil, but no diphenyl ether herbicide that meets these requirements is known yet. Problems to be Solved by the Invention Under these circumstances, the purpose of the present invention is to overcome the drawbacks of conventional diphenyl ether herbicides, and to provide a herbicide that is harmless to cultivated crops and It has a selective and strong herbicidal power that can rapidly eliminate other unwanted plants that coexist, and can be used consistently throughout the growing period of the crop, and is not toxic to warm-blooded animals. An object of the present invention is to provide a novel diphenyl ether herbicide with low energy consumption. Means for Solving the Problems As a result of extensive research, the inventors found that 5-
(2'-Chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone and its oxime derivatives are suitable for the above-mentioned purposes and can be applied to soybean, cotton, and corn at low application rates. It has been found that this method is useful for a wide range of broad-leaved and legume crops such as wheat and rice, and based on this knowledge, the present invention has been completed. That is, the present invention includes, for example, the general formula ( ^In the formula ^, linear or branched lower alkyl group substituted with a group; lower alkenyl group; lower alkynyl group or

A group represented by [Formula], R ² is a hydrogen atom or a methyl group, R ³ is a hydrogen atom, an unsubstituted lower alkyl group, an alkali metal, an alkaline earth metal equivalent to one valence, an ammonium group, or an alkyl substituted A novel 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-
Methoxyacetophenone and 5-(2'-chloro-
By using a 4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime derivative as an active ingredient of a herbicide,
That purpose can be achieved. The compounds of the present invention act more effectively as pre- and post-emergence herbicides on various agricultural crops than conventionally known compounds with similar structures at low spray doses, and also act on mammals, fish and shellfish. The fact that it did not cause any harm to other species was completely unexpected. Furthermore, the compound of the present invention is characterized in that, whereas the compounds known so far are alkyl phenyl ketones and their oxime derivatives such as acetophenone and propiophenone, they are α-methoxyacetophenone and its oxime derivatives. There is something about it. It is a surprising fact that the compound of the present invention exhibits excellent selectivity for various agricultural crops by introducing a methoxy group into the α-position of the carbonyl group. Specific examples of the compounds of the present invention represented by the general formula [] include 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone, 5- (2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenoxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2- Nitro-α-methoxyacetophenone-O-methyloxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-ethyloxime, 5 -(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-n-propyloxime, 5-(2'-chloro-4'-trifluoromethyl phenoxy)-2-nitro-α-methoxyacetophenone-O-iso-propyloxime, 5-(2′-chloro-4′-trifluoromethylphenoxy)-2-nitro-α-methoxyaceto Phenone-O-n-butyloxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-iso-butyloxime, 5-( 2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(2-chloroethyl)oxime, 5-(2'-chloro-4'-trifluoromethyl phenoxy)-2-nitro-α-methoxyacetophenone-O-(2-bromoethyl)oxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α- Methoxyacetophenone-O-(3-chloropropyl)oxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(2- chloropropyl)oxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(3-bromopropyl)oxime, 5-(2'-Chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(2-fluoroethyl)oxime,5-(2'-chloro-4'-trifluoromethylphenoxy) enoxy)-2-nitro-α-methoxyacetophenone-O-(3-fluoropropyl)oxime, 5-(2′-chloro-4′-trifluoromethylphenoxy)-2-nitro-α- Methoxyacetophenone-O-(2-methylethoxy)oxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(2- ethoxyethyl)oxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(3-methoxypropyl)oxime, 5-(2'-Chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(1-methyl-2-methoxyethyl)
Oxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(1-methyl-2-ethoxyethyl)
Oxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(2-methoxypropyl)oxime, 5-(2'-chloro- 4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(2-ethoxypropyl)oxime, 5-(2'-chloro-4'-trifluoromethylphenoxy) -2-nitro-α-methoxyacetophenone-O-(1-methyl-3-methoxypropyl)oxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α -Methoxyacetophenone-O-(1-methyl-2-methoxypropyl)oxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone- O-cyanomethyloxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(2-cyanoethyl)oxime, 5-(2'-Chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(3-cyanopropyl)oxime,5-(2'-chloro-4'-trifluoromethylphenoxy) enoxy)-2-nitro-α-methoxyacetophenone-O-allyloxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone- O-2-butenyloxime, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-(2-methyl-2-propenyl)oxime, 5 -(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-propargyloxime, 5-(2'-chloro-4'-trifluoromethylphenoxy) -2-nitro-α-methoxyacetophenone-O-(2-butynyl)oxime, 5-(2′-chloro-4′-trifluoromethylphenoxy)-2-nitro-α-methoxyaceto Phenone oxime-O-acetic acid, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-acetate, 5-(2'- Chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-potassium acetate, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2 -Nitro-α-methoxyacetophenone oxime-O-calcium acetate, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-acetic acid Magnesium, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-ammonium acetate, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-ammonium acetate; fluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-methylammonium acetate, 5-(2′-chloro-4′-trifluoromethylphenoxy)-2-nitro-α- Methoxyacetophenone oxime-O-dimethylammonium acetate, 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-(acetic acid methyl ester) , 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-(acetic acid ethyl ester), 5-(2'-chloro-4' -trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-(acetic acid n-propyl ester), 5-(2'-chloro-4'-trifluoromethylphenoxy)- 2-Nitro-α-methoxyacetophenone oxime-O-(acetic acid isopropyl ester), 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime -O- (n-butyl acetic acid ester), 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime -O- (2-propionic acid) , 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-(sodium 2-propionate), 5-(2'-chloro- 4'-Trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-(2-potassium propionate), 5-(2'-chloro-4'-trifluoromethylphenoxy) )-2-Nitro-α-methoxyacetophenone oxime-O-(2-calcium propionate), 5-(2′-chloro-4′-trifluoromethylphenoxy)-2-nitro-α-methoxy Acetophenone oxime-O-(2-propionate ammonium), 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-(2 -propionic acid methyl ester), 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-(2-propionic acid ethyl ester), 5 -(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-(2-propionic acid n-propyl ester), 5-(2'-chloro -4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-(2-propionic acid n-butyl ester), 5-(2'-chloro-4'-trifluoro Examples include methylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-(2-propionic acid isopropyl ester). All of these compounds are new compounds that have not been described in any literature, and can be produced, for example, according to Methods A to E shown below. That is, 3-(2'-chloro-4'-trifluoromethylphenoxy)-α shown by the formula []
The compound [a] of the present invention can be obtained by nitrating -methoxyacetophenone with potassium nitrate, mixed sulfuric acid/nitric acid, or similar nitrating agents in concentrated sulfuric acid. The reaction temperature in the nitration reaction is generally about -20°C.
A range of from about 100°C to about 100°C is used, preferably from about -10°C to about 50°C, optionally in the presence of an inert organic solvent such as 1,2-dichloroethane or other chlorinated hydrocarbon. . (Z in the formula is a halogen atom) This method is preferably carried out under anhydrous conditions. That is, 5-(2'-chloro-4'-
trifluoromethylphenoxy)-2-nitro-
α-methoxyacetophenone and hydroxylamine hydrohalide represented by the formula [],
Alcohols such as anhydrous ethanol, alcohols such as anhydrous ethanol and dry benzene, and aromatic solvents in the presence of an acid binder such as an anhydrous organic acid salt such as anhydrous sodium acetate or an organic tertiary amine such as triethylamine. The compound of the present invention, 5-(2'-chloro-4'-tri- Fluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime is obtained. The reaction temperature in the oxime formation reaction is generally in the range of about 0° C. to the boiling point of the single solvent or mixed solvent, preferably in the range of room temperature to the boiling point of the single solvent or mixed solvent. (R ¹ and Z in the formula have the same meanings as above) That is, the α-methoxyacetophenone oxime derivative represented by the formula [b] and the halogeno compound represented by the formula [] are mixed together, such as sodium methylate. The compound of the present invention represented by formula [c] can be obtained by reacting in the presence of an acid binder such as an alkali metal alcoholate or sodium hydride. Examples of solvents used here include alkanol solvents such as methanol and ethanol, ether solvents such as diethyl ether and tetrahydrofuran, and aprotic polar solvents such as N,N-dimethylformamide and N,N-dimethylacetamide. The solvent is an aromatic solvent such as benzene, and each of them can be used alone or in a mixture of two or more kinds. The reaction temperature generally ranges from about -10°C to about 150°C, preferably from about 0°C to about 100°C. (R ¹ and Z in the formula have the same meanings as above) This method is preferably carried out under anhydrous conditions. That is, an α-methoxyacetophenone derivative represented by formula [a] and a hydrohalide salt of a hydroxylamine derivative represented by formula [] are combined with an anhydrous organic acid salt such as anhydrous sodium acetate or an organic acid salt such as triethylamine. alcohols, such as absolute ethanol, in the presence of acid binders such as triamines;
The compound of the present invention represented by formula [c] can be obtained by dehydrating anhydrous ethanol, an alcohol such as dry benzene, and an aromatic solvent in a single or mixed organic solvent such as a mixed solvent according to a conventional method. is obtained. The reaction temperature in the oxime formation reaction is as described in Method B. (R ¹ and Z in the formula have the same meanings as above.) The first stage reaction of this method is preferably carried out under anhydrous conditions. That is, by reacting the α-methoxyacetophenone derivative represented by the formula [] with the hydrohalide salt of the hydroxylamine derivative represented by the formula [] in the same manner as in Method D, α- represented by the formula [] A methoxyacetophenone oxime-O-substituted product is obtained. Next, the compound represented by the formula [] is nitrated to obtain the compound [c] of the present invention. The nitration reaction can be carried out using potassium nitrate in concentrated sulfuric acid, mixed sulfuric acid/nitric acid, and similar nitration agents. The reaction temperature in the nitration reaction is generally about -20°C to about 80°C, preferably about -10°C to
A temperature range of about 50° C. is used, optionally in the presence of an inert organic solvent such as 1,2-dichloroethane or other chlorinated hydrocarbon. The methods for producing the compounds of the present invention include these methods A to E.
There is no need to limit the method, and it can be produced by various methods by modifying conventionally known methods for producing similar compounds. Next, the herbicidal action of the compounds of the present invention will be explained using weed control in fields as an example. The compound of the present invention can be used to treat weeds of the grass family, such as grasshopper, foxtail grass, and grasshopper, which are harmful weeds in fields.
In particular, pigweed, Japanese knotweed, Japanese knotweed, Japanese knotweed, American hornwort, Japanese knotweed, Maruba morning glory,
It exhibits extremely strong herbicidal activity against broad-leaved weeds such as chickweed and purslane, as well as various other weeds, in both pre-emergence soil treatment and post-emergence foliage treatment at surprisingly low doses. The characteristics of the compound of the present invention include the above-mentioned strong herbicidal activity and its ability to be used in pre- and post-emergence treatments against broad-leaved crops such as soybeans and cotton, as well as legume crops such as corn, wheat, and rice. It also has extremely excellent selectivity. The general usage amount of the compound of the present invention is 0.5 to 100 g per 10 ares.
It exhibits excellent herbicidal effects preferably in doses of 1 to 50 g. The most outstanding feature of the compounds of the present invention is their selectivity to soybeans. For example, 5-(2'-chloro-
4'-trifluoromethylphenoxy)-2-nitro-acetophenone oxime derivative (JP-A-1986-1999-
32432), the dosage required to obtain a satisfactory herbicidal effect is 1 to 10 ares.
30g, which is almost the same for both, but the compound of the present invention is more than 10 times safer for soybeans. In addition, 2-nitro-5, which is said to have selectivity for soybeans,
Considering that the amount of sodium -(2'-chloro-4'-trifluoromethylphenoxy)benzoate used is 20 to 50 g per 10 ares, the compound of the present invention is far more effective than conventional known compounds. It can be seen that it has strong herbicidal activity and excellent selectivity. Furthermore, the compounds of the present invention have extremely strong herbicidal activity against paddy field weeds other than upland weeds. That is, the compound of the present invention can be applied to, for example, broad-leaved weeds that grow in paddy fields, such as the harmful grass weeds such as grasshoppers, grass weeds, staghorn weeds, water chickweed, and azalea;
It also exhibits strong herbicidal activity against perennial weeds such as weeds and cypress at low doses. On the other hand, in the effective dosage of the compound of the present invention against weeds,
The chemical damage to paddy rice is extremely slight and almost unnoticeable. Therefore, the compounds of the present invention can be used for the purpose of selectively killing weeds in agricultural crops such as soybeans, cotton, corn, wheat, barley, and rice; It can be applied to both of the following. Further, the compound of the present invention can be used as a herbicide for pastures, orchards, lawns, and non-agricultural lands by taking advantage of its wide herbicidal range and strong herbicidal power. When actually using the compound of the present invention, the active substance itself can be sprayed, or hydrating powders, emulsions,
Any formulation form such as granules or powders can be used. In preparing these formulations, solid carriers include, for example, mineral powders (kaolin, bentonite, clay, montmorillonite, talc, diatomaceous earth, mica, vermiculite, cetacean,
calcium carbonate, phosphorous lime, etc.), vegetable powders (soybean flour, wheat flour, wood flour, tobacco flour, starch,
crystalline cellulose, etc.), polymer compounds (petroleum resin,
Polyvinyl chloride, ketone resin, etc.), alumina, waxes, etc. can be used.
Examples of liquid carriers include alcohols (methanol, ethanol, butanol, ethylene glycol, benzyl alcohol, etc.), aromatic hydrocarbons (toluene, benzene, xylene, etc.),
Chlorinated hydrocarbons (chloroform, carbon tetrachloride,
monochlorobenzene, etc.), ethers (dioxane, tetrahydrofuran, etc.), ketones (acetone, methyl ethyl ketone, cyclohexanone, etc.), esters (ethyl acetate, butyl acetate, etc.), acid amides (N,N-dimethylacetamide, etc.), nitriles (such as acetonitrile), ether alcohols (such as ethylene glycol ethyl ether), or water. As the surfactant used for the purpose of emulsification, dispersion, diffusion, etc., any of nonionic, anionic, cationic, and amphoteric surfactants can be used. Examples of surfactants that can be used in the present invention include polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and oxyethylene polymer. , oxypropylene polymer, polyoxyethylene alkyl phosphate, fatty acid salt, alkyl sulfate salt, alkyl sulfonate, alkylaryl sulfonate, alkyl phosphate salt, polyoxyethylene alkyl sulfate, quaternary ammonium salt , oxyalkylamines, etc. Also, if necessary,
Gelatin, casein, sodium alginate, starch, agar, polyvinyl alcohol, etc. can be used as adjuvants. Furthermore, the compound of the present invention can be used in combination with other herbicides in order to improve its effectiveness as a herbicide, and in some cases, a synergistic effect can be expected. For example, the following components may be used. (A) Phenoxy herbicide 2,4-dichlorophenoxyacetic acid; 2-methyl-4-chlorophenoxyacetic acid; Butyl-2-[4
-(5-trifluoromethyl-2-pyridyloxy)phenoxy]propionate (including respective esters and salts); ethyl-2-[4-(6-
Chloro-2-quinoxalinyloxy)phenoxy]propionate, etc. (B) Diphenyl ether herbicide 2,4-dichlorophenyl-4'-nitrophenyl ether; 2,4,6-trichlorophenyl-
4'-Nitrophenyl ether; 2,4-dichlorophenyl-4'-nitro-3'-methoxyphenyl ether; 2,4-dichlorophenyl-3'-methoxycarbonyl-4'-nitrophenyl ether; 2
-Chloro-4-trifluoromethylphenyl-
3'-ethoxy-4'-nitrophenyl ether; 5
-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid sodium salt and the like. (C) Triazine herbicide 2-chloro-4,6-bisethylamino-1,
3,5-triazine; 2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine; 2-methylthio-4,6-bisethylamino-1,3,5-triazine, and the like. (D) Urea herbicide 3-(3,4-dichlorophenyl)-1,1-dimethylurea; 3-(3,4-dichlorophenyl)
-1-methoxy-1-methylurea; 3-(α,
α,α-trifluoro-m-tolyl)-1,1-
Dimethylurea; 3-[4-(4-methylphenethyloxy)phenyl]-1-methoxy-1-methylurea; 3.(5-t-butyl-3,4-thiadiazol-2-yl)-4- Hydroxy-1-
Methyl-2-imidazolidone, etc. (E) Carbamate herbicides Isopropyl-N-(3-chlorophenyl)carbamate; Methyl-N-(3,4-dichlorophenyl)carbamate; 4-chloro-2-butynyl-N-(3-chlorophenyl)carbamate, etc. (F) Thiol carbamate herbicide S-ethyl-N,N-hexamethylenethiol carbamate; S-(4-chlorobenzyl)-N,
N-diethylthiol carbamate; S-ethyldipropylthiol carbamate, etc. (G) Anilide herbicide 3,4-dichloropropionanilide; N-methoxymethyl-2',6'-diethyl-2-chloroacetanilide;2-chloro-2',6'-diethyl-
N-(butoxymethyl)-acetanilide;2-chloro-2',6'-diethyl-N-(propoxyethyl)-acetanilide; α-(2-naphthoxy)propionanilide, and the like. (H) Uracil herbicides 5-bromo-3-sec-butyl-6-methyluracil; 3-cyclohexyl-5,6-trimethyleneuracil, etc. (I) Dipyridinium salt herbicides 1,1'-dimethyl-4,4'-dipyridinium dichloride; 1,1'-ethylene-2,2'-dipyridinium dibromide, etc. (J) Phosphorus herbicide N-(phosphonomethyl)glycine; O-ethyl-O-(2-nitro-5-methylphenyl)-N-
sec-Butylphosphoramidothioate; O-methyl-O-(2-nitro-4-methylphenyl)-
N-isopropyl phosphoroamide thioate; S
-(2-methyl-1,1-piperidylcarbonylmethyl)-O,O-di-n-propyldithiophosphate; (2-amino-4-methylphosphinobutyryl)-alanylalanine monosodium salt, and the like. (K) Toluidine herbicide α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine; N-
(cyclopropylmethyl)-α,α,α-trifluoro-2,6-dinitro-N-propyl-p-toluidine, etc. (L) Other herbicides 5-t-butyl-3-(2,4-dichloro-5
-isopropoxyphenyl)-1,3,4-oxadiazolin-2-one; 3-isopropyl-
2,1,3-Benzothiadiazinone-4,2,2
-dioxide; 2-(α-naphthoxy)-N,N
-diethylpropylonamide; 3-amino-
2,5-dichlorobenzoic acid; 4-(2,4-dichlorobenzoyl)-1,3-dimethylpyrazol-5-yl-p-toluenesulfonate; 2-chloro-N-[(4-methoxy-6-methyl -1,
3,5-triazin-2-yl)aminocarbonyl]benzenesulfonamide; 2-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonylaminosulfonylmethyl]benzoic acid methyl ester; N-(1-methyl- 1-phenylethyl)-
2-bromo-3,3-dimethylbutanamide; 2
-[1-(N-allyloxyamino)butylidene]
-4-methoxycarbonyl-5,5-dimethylcyclohexane-1,3-dione sodium salt; 2
-[1-(ethoxyimino)butyl]-5-(2-ethylthiopropyl)-3-hydroxy-2-cyclohexan-1-one, etc. The above herbicides are merely examples, and other herbicides that can be used in combination with the compound of the present invention are not limited to these. The herbicide of the present invention can also be used in combination with pyrethroid insecticides, other insecticides, fungicides, plant regulators, microbial pesticides, and fertilizers. Effects of the Invention As described above, the compound of the present invention not only exhibits a strong herbicidal effect at a lower usage amount than conventional diphenyl ether herbicides, but also has selectivity for soybeans and Since it can be used in the same manner throughout the world and has low toxicity, it is suitably used as a herbicide for broad-leaved and legume crops such as soybean, cotton, corn, wheat, barley, and rice. The amount of the herbicide of the present invention to be used varies depending on the method of use, place of use, and type of target weed, but usually
It is sufficient to use an amount of 1 to 50 g (active ingredient) per 10 ares. Examples Next, the present invention will be explained in more detail with reference to Examples. Example 1 Production of 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone (compound 1) 3-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone (compound 1) Fluoromethylphenoxy)-α-methoxyacetophenone 3.4g
was added to a mixed solution of 20 ml of dichloromethane and 10 ml of concentrated sulfuric acid cooled to below 5°C, and then 1 g of potassium nitrate was added little by little over 10 minutes. After the addition was completed, the reaction was carried out at 5° C. or lower for 30 minutes. After the reaction was completed, the reaction solution was poured into ice water, 50 ml of dichloromethane was added, and an extraction operation was performed to separate the dichloromethane layer, which was washed with saturated brine and water.
It was dried with anhydrous sodium sulfate. After drying, dichloromethane was distilled off under reduced pressure, and the resulting crude product was purified by silica gel column chromatography. As a result, 5-(2'-chloro-4'-
trifluoromethylphenoxy)-2-nitro-
Pale and colored crystals of α-methoxyacetophenone 2.3
I got g. Example 2 Preparation of syn and anti isomers (compound 2 and compound 3) of 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime 5- Anhydrous sodium acetate was added to a solution of 3.9 g of (2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone dissolved in 20 ml of absolute ethanol and 20 ml of dry benzene.
1.4 g and 1.2 g of hydroxylamine hydrochloride were added. The reaction mixture was heated under reflux for 8 hours, then cooled,
Water and ether were added to extract the reaction product. The organic layer was washed with water, dried over anhydrous sodium sulfate, ether and benzene were distilled off under reduced pressure, and 5-
A crude product consisting of syn and anti isomers of (2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime was obtained. As a result of separation and purification by silica gel column chromatography, the syn isomerism of 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime with a melting point of 123-125°C was found. 1.8 g of light and colored crystals of the isomer (compound 2) and 1.4 g of a pale yellow sticky oil of the anti isomer (compound 3) with a refractive index n ³⁰ _D 1.5278 were obtained. Example 3 Syn and anti isomers (compound Production of 17) Add anhydrous sodium acetate
0.6 g and 1.2 g of O-ethoxycarbonylmethylhydroxylamine hydrochloride were added. The reaction mixture was heated under reflux for 8 hours, cooled, and water and ether were added to extract the reaction product. Wash the organic layer with water,
After drying over anhydrous sodium sulfate, ether and benzene were distilled off under reduced pressure to give 5-(2'-chloro-4'-
trifluoromethylphenoxy)-2-nitro-
A crude product consisting of syn and anti isomers of α-methoxyacetophenone oxime-O-(acetic acid, ethyl ester) was obtained. As a result of purification by silica gel column chromatography, the refractive index n ³⁰ _D
Consisting of syn and anti isomers of 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone oxime-O-(acetic acid, ethyl ester) with 1.5276 2.1 g of pale orange sticky oil (Compound 17) was obtained. Example 4 Syn and anti of 5-(2'-chloro-4'-trifluoromethylphenoxy)-2-nitro-α-methoxyacetophenone-O-methyloxime
Preparation of isomer (compound 4) a 3-(2'-chloro-4'-trifluoromethylphenoxy)-α-methoxyacetophenone 3.4
g to 20 ml of absolute ethanol and 20 ml of dry benzene.
To the solution, 1 g of anhydrous sodium acetate and 1 g of O-methylhydroxylamine hydrochloride were added. The reaction mixture was reacted at 45-50°C for 3 hours. After the reaction was completed, water and ether were added to extract the reaction product, washed with water and dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure to obtain 3-
3.6 g of a pale yellow oily substance of (2'-chloro-4'-trifluoromethylphenoxy)-α-methoxyacetophenone-O-methyloxime was obtained. b 3.6 g of 3-(2'-chloro-4'-trifluoromethylphenoxy)-α-methoxyacetophenone-O-methyloxime obtained in a) was heated at 5°C.
Add 30 ml of cooled dichloromethane to 10 ml of concentrated sulfuric acid.
ml of the mixed solution, and then 1 g of potassium nitrate was added little by little over 10 minutes. After the addition was completed, the reaction was carried out at 5° C. or lower for 30 minutes. After the reaction was completed, the reaction solution was poured into ice water, and 50 ml of dichloromethane was added, followed by extraction, and the dichloromethane layer was separated, washed with saturated brine and water, and dried over anhydrous sodium sulfate. After drying, dichloromethane was distilled off under reduced pressure, and the resulting crude product was purified by silica gel column chromatography. As a result, 5-( ^2' - _chloro -4'-trifluoro methylphenoxy)-2-nitro-α-methoxyacetophenone-O-methyloxime syn and
2.8 g of a pale yellow sticky oil (compound 4) consisting of the anti isomer was obtained. When this pale yellow oil was dissolved in methanol, pale yellow crystals with a melting point of 81-82°C were obtained. Example 5 Structure, physical property values, elemental analysis values, and ¹ H-
Although NMR analysis data are illustrated in Table 1, it goes without saying that the present invention is not limited to only these compounds. Note that the compound numbers in the table are commonly used in the examples of this specification.

【table】

【table】

【table】

[Table] Application Examples Next, typical formulation examples of the compounds of the present invention are shown. Prescription 1 (Wettable powder) 25 parts by weight of the compound of the present invention, 5 parts by weight of Solbol 5039 (manufactured by Toho Chemical Industry Co., Ltd., trade name), and 10 parts by weight of talc are thoroughly ground and mixed to form a wettable powder. . Formulation 2 (Emulsion) 5 parts by weight of the compound of the present invention, 10 parts by weight of Solpol 3005X (manufactured by Toho Chemical Industry Co., Ltd.), 45 parts by weight of n-butanol, and 40 parts by weight of xylene are thoroughly mixed to prepare an emulsion. Formulation 3 (Granules) 1 part by weight of the compound of the present invention, 45 parts by weight of bentonite, 44 parts by weight of clay, 5 parts by weight of sodium ligninsulfonate and 5 parts by weight of sodium dodecylbenzenesulfonate are thoroughly ground and mixed, and water may be added. After kneading, the mixture is granulated and dried to form granules. Formulation 4 (Powder) 1 part by weight of the compound of the present invention and 99 parts by weight of clay are thoroughly mixed to prepare a powder. Usage example 1 A pot filled with field soil of 1/2500 are was prepared in a greenhouse. Seeds of soybeans, corn, crabgrass, Japanese knotweed, and Japanese knotweed were sown in each pot. Pre-germination treatment is applied per 10 ares 24 hours after sowing.
25g was applied. On the other hand, post-emergence treatment was carried out by applying 10g per 10 ares for soybeans at the 2nd to 3rd true leaf stage, for corn at the 3rd to 4th leaf stage, and for weeds at the 2nd to 2.5th leaf stage. The spraying method was to dilute an emulsion (Formulation 2) with a predetermined concentration in 10 parts of water per area and use a glass sprayer. The degree of weed control ability was observed on the 14th day after chemical treatment, and the degree of chemical damage to the crops was observed on the 30th day. The results are shown in Table 2 below.
The values in the table are based on the following criteria. 5: Complete suppression 4: 80% suppression 3: 60% suppression 2: 40% suppression 1: 20% suppression 0: No effect

【table】

[Table] Usage Example 2 A test was conducted to find the difference in activity between syn and anti isomers of oxime derivatives. In a greenhouse, pots with a size of 1/2500 are filled with field soil were prepared. Soybeans, corn, crabgrass, goldenrod, pigweed, and Japanese knotweed were grown in each pot. Soybeans are in the 2nd to 3rd leaf stage, corn is in the 3rd to 4th leaf stage, and weeds are in the 2nd to 3rd leaf stage.
Stem and leaf treatments were performed at the 2.5 leaf stage. The spraying method was to dilute the emulsion (Formulation 2) at a given temperature to 10 parts water per area and use a glass sprayer. After drug treatment,
The degree of weed control ability was observed on the 15th day, and the degree of chemical damage to crops was observed on the 30th day. The results are shown in Table 3. Note that the criteria in the table are the same as in Use Example 1.

[Table] Example 3 A ^1m2 plot was set up in a field, and soybeans and soybeans were grown as crops.
Corn seeds are used as weeds,
Golden millet, pigweed, giant knotweed, Japanese croaker, American hornwort, mulva morning glory, golden knotweed,
Chickweed seeds were sown and grown. Soybeans are true leaves 2~
At the 3-leaf stage, in corn at the 3-4 true leaf stage,
Weeds were treated with foliage at the 3rd to 5th leaf stage. The spraying method is 10 emulsions (formulation 2) of a specified concentration per area.
It was diluted with water and applied with a sprayer. After chemical treatment, the degree of weed control ability was observed on the 14th day, and the degree of chemical damage to the crops was observed on the 30th day. The results are shown in Table 4. Note that the criteria in the table are the same as in Use Example 1.

【table】

[Table] Usage Example 4 A pot filled with paddy soil of 1/5000 are was prepared in a greenhouse. Seeds of Japanese barnyard grass and Japanese grasshopper, annual broad-leaved weeds Kikashigusa, azalea, and perennial weed bulrush were mixed with dry paddy soil and used in a method of mixing into the surface layer. In addition, tubers of perennial weeds such as Prunus spp.
For rice, three-leaf stage seedlings were transplanted into the soil surface layer 2 to 3 cm.
For the chemical treatment, a solution prepared by diluting an emulsion (prescription 2) of a predetermined concentration with water was dropped with a pipette at the 0.5 to 1 leaf stage of barnyard grass. On the 21st day after spraying, the damage to rice and the degree of weed control ability were observed. The results are shown in Table 5.
Note that the criteria in the table are the same as in Use Example 1.

【table】

【table】

Claims (1)

[Claims] 1. General formula ( ^In the formula ^, A linear or branched lower alkyl group substituted with a group; a lower alkenyl group; a lower alkynyl group or a group represented by [Formula], where R ² is a hydrogen atom or a methyl group, R ³ is a hydrogen atom, 5-(2'-chloro-4'-trifluoromethylphenoxy )-2-nitro-α-methoxyacetophenone and 5-(2′-chloro-4′-trifluoromethylphenoxy)-2-nitro-α
-Methoxyacetophenone oxime derivative. 2 General formula ( ^In the formula ^, A linear or branched lower alkyl group substituted with a group; a lower alkenyl group; a lower alkynyl group or a group represented by [Formula], where R ² is a hydrogen atom or a methyl group, R ³ is a hydrogen atom, 5-(2'-chloro-4'-trifluoromethylphenoxy )-2-nitro-α-methoxyacetophenone and 5-(2′-chloro-4′-trifluoromethylphenoxy)-2-nitro-α
- A selective herbicide containing a methoxyacetophenone oxime derivative as an active ingredient.