JPS6152140B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to novel compounds and selective herbicides containing the compounds. More specifically, the present invention relates to the general formula (In the formula, R ₁ represents a hydrogen atom, a halogen atom, a lower alkyl group, or a lower alkoxy group, and R ₂ represents a hydrogen atom or a halogen atom.) 4-(4-cyanophenoxy)-α-
The present invention relates to a herbicide characterized by containing a phenoxypropionanilide derivative (hereinafter referred to as the compound of the present invention) and the compound of the present invention as an active ingredient. The object of the present invention is to provide such a compound industrially and to provide an effective selective herbicide containing the compound. In other words, the compound of the present invention exhibits a strong herbicidal effect in paddy rice cultivation, especially against the harmful weed, Noviidae, when applied to the surface of the water, while it has almost no effect on rice at any stage from direct sowing to transplanting. It shows intergeneric selective herbicidal effect, such as not giving any Traditionally, weeding of Noviae, which is an important weed in rice fields, takes advantage of the difference in drug resistance due to the difference in the growing period of Noviae and paddy rice, and controls only the Noviae at the time of germination, without harming paddy rice that has advanced in growth. Alternatively, it is a physical option that utilizes the adsorption of treatment chemicals to the soil topsoil to inhibit the germination of wild grass seeds located within the chemical adsorption layer, while leaving the paddy rice root groups distributed outside the chemical adsorption layer unharmed. Weeding has been carried out according to the law. Therefore, it has been extremely difficult to apply these herbicides to flooded, directly sown paddy rice or young seedlings immediately after transplantation. In order to provide a herbicide that is safe for weak rice such as direct-seeded rice, the present inventors conducted a search for a compound that has a physiological selective activity specific to the drug between paddy rice and wild grass, and as a result, the compound of the present invention was found to be remarkable. It has a strong intergeneric selectivity, has almost no effect on paddy rice, has a strong herbicidal effect on wild grasses, has extremely long-lasting effects, and has little change in effectiveness depending on the type of soil. The present invention was completed based on the discovery that it can be applied to a wide range of fields, from direct sowing to transplanted paddy rice. The compound of the present invention can be applied to foliar spray treatments, such as Digitaria spp., Setaria spp.
Even doses that completely kill Echinochloa, Rottboellia, and Avenafatua have no effect on broadleaf crops such as radish, pea, spinach, soybean, adzuki beet, beet, and cotton. Not seen,
In addition, in pre-emergence soil treatment for weeds, even at doses that completely inhibit the germination of barnyard grass, blackberry grass, and foxtail grass, there is little effect on broad-leaved crops and cereal crops such as rice, barley, and wheat. Extremely large. The compound of the present invention can be produced by the following reaction formula. However, in the reaction formula below, Hal represents a halogen atom, and R ₁ and R ₂ have the same meanings as above. The above reaction is carried out in the presence of a reaction solvent and a base. The solvent for the reaction is water, ketones such as acetone and methyl ethyl ketone, aromatic hydrocarbons such as benzene, toluene, and xylene, ethers such as ethyl ether, tetrahydrofuran, and dioxane, and alcohols such as methanol, ethanol, isopropanol, and butanol. halogenated hydrocarbons such as chlorobenzene, chloroform, carbon tetrachloride, dichloroethane, dimethylformamide, dimethyl sulfoxide, etc. are used. Examples of the base include alkali hydroxides such as sodium hydroxide and potassium hydroxide, sodium carbonate,
Alkali carbonates such as potassium carbonate and sodium hydrogen carbonate, alcoholates such as sodium ethoxide,
Tertiary amines include triethylamine, dimethylaniline, and pyridine. The reaction temperature is between 0 DEG and 200 DEG C. and the reaction time can range from 1 hour to several days, depending on the chosen solvent and reaction temperature. The compound of the present invention can also be produced by the following reaction formula. However, in the reaction formula below, Hal represents a halogen atom, and R ₁ and R ₂ have the same meanings as above. The reaction of formula (3) is carried out in the presence or absence of a reaction solvent and a base. As the solvent for the reaction, the aforementioned ketones, ethers, hydrocarbons, dimethylformamide, dimethyl sulfoxide, etc. are used. As the base, those mentioned above are used. The reaction usually proceeds at a temperature of 0 to 150°C, and the reaction time is about several minutes to 48 hours. The reaction of formula (4) can be carried out by heating a mixture of carboxylic acid and aniline to a high temperature, or by removing the produced water by azeotropic distillation. Further, by adding a condensing agent such as carbodiimides, the process can be carried out quickly under mild conditions. Table 1 shows representative examples of the compounds of the present invention.

[Table] To use the compound of the present invention as a herbicide, it is mixed with various adjuvants, such as diluents, solvents, surfactants, etc., and formulated into emulsions, wettable powders, powders, granules, etc. do. It may be appropriate to add other herbicides, such as those listed below, for the purpose of reducing spraying effort or expanding the range of grass species that can be effectively controlled. 2,4-dichlorophenoxyacetic acid, its salts, esters and alkylamine salts, 2-methyl-4-chlorophenoxyacetic acid, its salts and esters, 2-methyl-4-chlorophenoxybutyric acid, its salts and esters , d.l-2-(4-chloro-o-tolyloxy)propionic acid, its salts and esters, 4-cyano-2.6-diiodophenyl octanoate, 2.4-dichlorophenyl-4'-nitroph. enyl ether, 2,4,6-trichlorophenyl-4'-nitrophenyl ether, 2,4-dichlorophenyl-3'-methoxy-
4'-Nitrophenyl ether, methyl 3,4-dichlorocarbanilide, isopropyl 3-chlorocarbanilate, S-4-chlorobenzyl diethylthiocarbamate, 4-nitrophenyl-3',5'- Xylyl ether, hexahydro-1H-azepine-1-carbothioate-S-ethyl 3,4-dichloropropionanilide, 2-chloro-2',6'-diethyl-N-(butoxymethyl)acetanilide, 2-chloro-2 ',6'-diethyl-N-(m-propoxyethyl)acetanilide 1-(α,α-dimethylbenzyl)-3-p-tolylurea, 2,4-bis(ethylamino)-6-methylthio-1. 3,5-triazine, 2-ethylamino-4-isopropylamino-
6-methylthio-1,3,5-triazine, 2,4-bis(ethylamino)-6-methylthio-1,3,5-triazine, 2-ethylamino-4-isopropylamino-
6-methylthio-1,3,5-triazine, 2,4-bis(isopropylamino)-6-methylthio-1,3,5-triazine, 5-tert-butyl-3-(2,4-dichloro-
5-isopropoxyphenyl)-1,3,4-oxadiazolin-2-one, 2,6-dichlorobenzonitrile, 2,6-dichlorothiobenzamide, 2-amino-3-chloro-1,4- Naphthoquinone, 2,4-dichlorophenyl-3'-carbomethoxy-4'-nitrophenyl ether, N-p-chlorobenzyloxyphenyl-3.
4,5,6-tetrahydrophthalimide, 2,4-dichlorophenyl-3'-ethoxyethoxyethoxy-4'-nitrophenyl ether, N-(1-ethylpropyl)-2,6-dinitro-3,4 -xylidine, 4-(2,4-dichlorobenzoyl)-1,3-
Dimethyl-pyrazol-5-yl-p-toluenesulfonate, 4-(2,4-dichlorobenzoyl)-1,3-
Dimethyl-5-(benzoylmethoxy)pyrazole, 4-(2,4-dichloro-3-methylbenzoyl)-1,3-dimethyl-5-(benzoylmethoxy)-pyrazole, o・o-diisopropyl-2-(benzene) sulfonamide)-ethylene dithiophosphate, 3,3'-dimethyl-4-methoxybenzophenone, α-(2-naphthoxy)-propionanilide, o-ethyl-o-(3-methyl-6-nitrophenyl) -N-sec-butylphosphorothioamidate, 3-isopropyl-2,1,3-benzothiadiazone-(4)-2,2-dioxide and its salts, S-(2-methyl-1-piperidyl -o.o-di-n-propyl dithiophosphate, S-benzyl-N.N-dimethylthiocarbamate. It is possible to provide an effective admixture for grass species. Next, the present invention will be explained using examples, but the present invention is not limited to these examples. Synthesis Example 1 4-(4-cyanophenoxy)-α-phenoxy-propionanilide (Compound No. 1) 4-(4-cyanophenoxy)phenol 1.06
g, 0.99 g of α-bromopropionanilide and 0.83 g of anhydrous potassium carbonate were added to 30 ml of acetone,
The mixture was refluxed for 16 hours with stirring. After the reaction mixture was cooled, the inorganic substances were separated and the acetone was distilled off. The residue was subjected to column chromatography [silica gel, ethyl acetate/n-hexane = 1/1
(v/v)] and purified by 1.07 g (yield 60
%) of the target product was obtained. Recrystallization was performed from a mixed solvent of benzene-n-hexane to obtain crystals with a melting point of 133-134°C. Synthesis Example 2 4-(4-cyanophenoxy)-α-phenoxy-m-anisidide (Compound No. 9) 0.81 g of m-anisidine was added to 10 ml of diethyl ether.
4-(4-cyanophenoxy)-
1.0 g of α-phenoxy-propionic acid chloride was dissolved in diethyl ether and added dropwise at room temperature.
After stirring the reaction mixture at room temperature for 6 hours, water was added and the ether layer was separated. The ether layer was washed with dilute hydrochloric acid and water in that order, and then dried using anhydrous magnesium sulfate. After removing the drying agent, the ether was distilled off. The obtained residue was purified by column chromatography (silica gel, developed with benzene) to obtain 0.98 g (yield: 77%) of the target product. The melting point is
The temperature is 118-119.5°C. Formulation example 1 Wettable powder 20 parts of the present invention compound No. 1 (parts mean parts by weight, the same applies hereinafter), 15 parts of diatomaceous earth, 60 parts of clay
1 part, 3 parts of sodium ligninsulfonate, and 2 parts of sodium dodecylbenzenesulfonate are mixed and ground to obtain a wettable powder. Formulation Example 2 Emulsion 20 parts of the present compound No. 8, 72 parts of xylene, 3 parts of polyoxyethylene alkyl ether, 2 parts of polyoxyethylene alkyl allyl ether, and 3 parts of calcium alkylbenzenesulfonate are uniformly dissolved to prepare an emulsion. . Formulation Example 3 Granules 5 parts of the compound No. 13 of the present invention, bentonite 22
1 part, 42.5 parts of talc, 28 parts of clay, 2 parts of sodium lignin sulfonate, and 0.5 part of sodium dodecylbenzenesulfonate are mixed uniformly, water is added, the mixture is made into granules using an extrusion granulator, and the mixture is dried and sieved to form granules. . Next, the herbicidal effect of the agent of the present invention will be explained using test examples. Test Example 1 Effectiveness test against Japanese wildflowers Paddy soil was filled in a 1/5000 Ahr Wagner pot, and after plowing, 50 Japanese wildflower seeds were sown. The water was kept at a depth of 3 cm, and when the wildflower seeds germinated and reached the two-leaf stage, the compound of the present invention was made into an emulsion according to Formulation Example 2, diluted with water in a predetermined amount, and applied uniformly to the water surface. . On the 15th day after the chemical treatment, the herbicidal effect and chemical damage were investigated, and the results shown in Table 2 were obtained. The herbicidal effect was evaluated according to the following criteria. Evaluation index Herbicidal effect 5 Death 4 80-99% suppression 3 60-79 〃 2 40-59 〃 1 20-39 〃 0 No suppression

【table】

[Table] Test example 2 Novie pest control test in direct sowing by flooding Fill a 1/5000 Ahl Wagner pot with paddy soil, plow through it, and then add paddy rice seeds (variety: Nipponbare)
20 seeds and 50 Novie seeds were sown. When paddy rice seeds and wild field seeds germinated, the water was kept at a depth of 3 cm, and the compound of the present invention was made into an emulsion according to Formulation Example 2, diluted with water in a predetermined amount, and applied uniformly to the water surface. On the 14th day after the chemical treatment, the herbicidal effect and chemical damage were investigated, and the results shown in Table 3 were obtained.

【table】

【table】

Claims (1)

[Claims] 1. General formula (In the formula, R ₁ represents a hydrogen atom, a halogen atom, a lower alkyl group, or a lower alkoxy group, and R ₂ represents a hydrogen atom or a halogen atom.) 4-(4-cyanophenoxy)-α-
Phenoxypropionanilide derivative. 2 General formula (In the formula, R ₁ represents a hydrogen atom, a halogen atom, a lower alkyl group, or a lower alkoxy group, and R ₂ represents a hydrogen atom or a halogen atom.) 4-(4-cyanophenoxy)-α-
A selective herbicide characterized by containing a phenoxypropionanilide derivative as an active ingredient.