JPS6213949B2 - - 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 is a trifluoromethyl group,

[Formula] group, -COOR' group (R' is lower alkyl group),

4-(4-cyanophenoxy)-α- represented by [Formula] group (R'' represents a lower alkyl group), or a chlorine atom or a bromine atom, and n represents an integer from 0 to 4.]
The present invention relates to a herbicide characterized by containing a phenoxypropionic acid derivative (hereinafter referred to as the compound of the present invention) and the compound of the present invention as active ingredients. 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 on the highly harmful weed, Novie, especially when applied to the surface of water in rice cultivation, while having almost no effect on rice at any stage from direct sowing to transplanting. It shows intergeneric selective herbicidal effect, such as no Conventionally, 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 time of Noviae and rice, and controls only the Noviae at the time of germination, without harming the paddy rice that has advanced in growth. Or, a physical selection method that utilizes the adsorption of treatment chemicals to the topsoil of the soil to inhibit the germination of Novie seeds located between the chemical adsorption layers, while leaving the paddy rice roots distributed outside the chemical adsorption layers unharmed. I have been weeding by weeding. Therefore, it has been extremely difficult to apply these herbicides to seedlings of flooded, direct-seeded rice immediately after transplanting. 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 excellent intergeneric selectivity, has almost no effect on paddy rice, and has a strong herbicidal effect on wild grass, and its efficacy is extremely persistent, with little change in efficacy depending on soil type. Therefore, the present invention was completed based on the discovery that the present invention can be applied to a wide range of fields, from direct sowing of flooded rice to transplanted paddy rice. The compounds of the present invention can be applied to foliar sprays on, for example, Digitaria spp., Setaria spp., Echinochioa spp., Rottboellia spp., and Avena huatua spp.
Even at a dose that completely kills weeds such as Japanese radish, peas, spinach, soybeans, adzuki beans, beets, and cotton, there is no effect on broad-leaved crops such as Japanese radish, adzuki beans, beets, and cotton. , broad-leaved crops, even at dosages that completely inhibit the germination of hackberry.
It has a very wide range of applications, with almost no effect on cereal crops such as rice, barley, and wheat. The compound of the present invention can be produced using the following reaction formula. However, in the following formula, Hal represents a halogen atom, and R and n have the same meanings as above. In the above reaction formula, the 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 carbons such as benzene, toluene and xylene, ethers such as ethyl ether, tetrahydrofuran and dioxane, methanol, ethanol, isopropanol and butanol. Alcohols, halogenated hydrocarbons such as chlorobenzene, chloroform, carbon tetrachloride, and dichloroethane, dimethylformamide, dimethylsulfoxide, and the like are used. Examples of the base include alkali hydroxides such as sodium hydroxide and potassium hydroxide; alkali carbonates such as sodium carbonate, potassium carbonate, and sodium hydrogen carbonate;
Examples include alcoholates such as sodium ethoxide, tertiary amines such as triethylamine, dimethylaniline, and pyridine. The reaction temperature was between 0 and 20℃, and the reaction time was 1
It can be carried out over hours or days, depending on the solvent chosen and the reaction temperature. The compound of the present invention can also be produced by the following reaction formula. However, in the following formula, Hal represents a halogen atom, and R and n 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 proceed under normal acidic catalysis. 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 to reduce spraying effort or to broaden the range of grass species that can be effectively controlled. Examples of herbicides that can be added are as follows. 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'- Nitrophenyl 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, S-ethyl hexahydro-1H-azepine-1-carbothioate, 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(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, o・o-diisopropyl-2-(benzenesulfonamide)-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-benzothiadiazinone-(4)-2,2- Dioxide and its salts, S-(2-methyl-1-piperidyl-carbonylmethyl)-o.o-di-n-propyldithiophosphate, S-benzyl-N.N-dimethylthiocarbamate, these herbicides By judicious combinations of one or more of the following, it is possible to provide mixtures that are effective against many grass species. Next, the present invention will be explained using examples, but the present invention is not limited to these examples. Synthesis Example 1 2,2,2-trifluoroethyl 4-(4-cyanophenoxy)-α-phenoxy-propionic acid (Compound No. 1) 4-(4-cyanophenoxy)phenol 1.06
g, 1.41 g of 2,2,2-trifluoroethyl α-bromopropionate and 0.83 g of anhydrous potassium carbonate.
g was added to 30 ml of acetone and refluxed for 4.5 hours while stirring. After the reaction mixture was cooled, the inorganic substances were filtered out, and then the acetone was distilled off. The residue was purified by column chromatography (silica gel, developed with benzene) to obtain 1.5 g (yield: 82%) of the desired product. ^n25D ₌ 1.5221. Synthesis Example 2 Ethoxycarbonylmethyl 4-(4-cyanophenoxy)-α-phenoxy-propionate (Compound No. 4) 0.3 g of ethyl hydroxyacetate and 2.29 g of triethylamine were dissolved in 20 ml of ether, and 4-4% was added to this while stirring at room temperature. -(4-cyanophenoxy)-α-phenoxy-propionic acid chloride
After 1.1 g was added dropwise and the mixture was stirred for 16 hours, water was added to the reaction mixture to separate the ether. The obtained ether solution was washed with water, dried over anhydrous magnesium sulfate, and then the ether was distilled off. The residue was subjected to column chromatography [silica gel, ethyl acetate/n-hexane = 1/1 (V/
V)] to obtain 0.72 g (yield 67%) of the target product. n ²⁵ _D = 1.5454 Formulation example 1 Wettable powder 20 parts of the present invention compound No. 3 (parts mean parts by weight, the same applies hereinafter), 35 parts of diatomaceous earth, 40 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 Compound No. 2 of the present invention, 72 parts of xylene, 4 parts of polyoxyethylene alkyl ether, and 4 parts of alkylbenzene sulfonate are uniformly dissolved to prepare an emulsion. Formulation Example 3 Granules 5 parts of Compound No. 1 of the present invention, White Carbon 3
part, bentonite 22 parts, talc 42.5 parts, clay 25 parts
1 part, 2 parts of sodium ligninsulfonate, and 0.5 parts of sodium dodecylbenzenesulfonate are uniformly mixed, water is added, the mixture is made into granules using an extrusion granulator, and the mixture is dried and sieved to obtain granules. Next, the herbicidal effect of the present invention will be explained using test examples. Test example 1 Novex control test in direct sowing by flooding Paddy soil was filled in a 1/5000 Ahl Wagner pot, and after plowing, rice seeds (variety: Nipponbare) were planted.
20 seeds and 50 Novie seeds were sown. When paddy rice seeds and wild field seeds germinate and reach the two-leaf stage, the water is maintained at a depth of 3 cm, the compound of the present invention is made into an emulsion according to Formulation Example 2, and a predetermined amount is diluted with water and spread uniformly on the water surface. Each was processed. On the 15th day after the chemical treatment, the herbicidal effect and chemical damage were investigated, and the results shown in Tables 2 and 3 were obtained.

【table】

【table】

[Table] 〓The numbers are the ratio of live weight to the untreated area.
(%) 〓

Claims (1)

[Claims] 1. General formula [In the formula, R is a trifluoromethyl group,
[Formula] group, -COOR' group (R' is a lower alkyl group), [Formula] group (R'' is a lower alkyl group), or a chlorine atom or a bromine atom, and n represents an integer from 0 to 4. ] 4-(4-cyanophenoxy)-α- represented by
Phenoxypropionic acid derivative. 2 General formula [In the formula, R is a trifluoromethyl group,
[Formula] group, -COOR' group (R' is a lower alkyl group), [Formula] group (R'' is a lower alkyl group), or a chlorine atom or a bromine atom, and n represents an integer from 0 to 4. ] 4-(4-cyanophenoxy)-α- represented by
A selective herbicide characterized by containing a phenoxypropionic acid derivative as an active ingredient.