JPS6134417B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel compound, a method for producing the same, and a use thereof, and in particular, the present invention relates to a novel compound, a method for producing the same, and a use thereof. (In the formula, X represents a 3,5-dichloro-2-pyridyl group, R ₁ represents a lower alkylene group with a straight chain or a side chain, R ₂ represents a lower alkyl group, and n represents O.) The present invention relates to a herbicide containing a compound as an active ingredient. The object of the present invention is to obtain these compounds industrially advantageously and to provide a simple and highly effective herbicide. The present inventors synthesized a large number of phenoxypropionic acid derivatives and examined those that met the above objectives, and found that the compounds represented by the above general formula () were found to be effective in both soil treatment and foliage spraying treatment. They discovered that it has a selectivity that shows excellent herbicidal action against weeds and is almost harmless against broad-leaved crops, and after further biological and physicochemical research, they completed the present invention. In the production of the compound of the present invention, the general formula () (wherein, X has the same meaning as defined above) and the general formula () HOR ₁ S(O) _o R ₂ () (wherein, R ₁ , R ₂ and n have the same meanings as defined above) are reacted in the presence of an acid binder. As the acid binder, pyridine, triethylamine, trimethylamine, sodium carbonate, etc. are used. Generally, the reaction is carried out in an inert solvent, but when pyridine is used as the acid binding agent, pyridine is used as the solvent. The reaction is carried out at 0°C to 50°C, preferably at room temperature, for 1 to 50°C.
Do it for several hours. After completion of the reaction, the reaction mixture is poured into cold water, extracted with a suitable organic solvent, washed with water, dried, and the solvent is distilled off to obtain the compound of the present invention in a good yield. Moreover, the compound of the present invention can also be produced according to the following reaction formula. (1) (2) Next, the method for producing the compound of the present invention will be explained in more detail with reference to Examples. Example 1 2-(ethylthio)ethyl-2-{4-(3・5
-dichloropyridyl-2-oxy)phenoxy}-propionic acid ester (compound number 11) 2-{4(3,5-dichloropyridyl-2-oxy)phenoxy}propionyl chloride 1.5 g
was dissolved in 15 ml of pyridine, 0.5 g of 2-(ethylthio)ethanol was added dropwise at 0°C, and the mixture was stirred at room temperature for 1 hour. Next, the reaction product was poured into water, extracted with ether, washed with water, dried over magnesium sulfate, and the solvent was distilled off to obtain 1.3 g of the target product. n
³² _D 1.5703 Table 1 shows the structural formulas of the compounds of the present invention and their physical constants.

[Table] The compounds of the present invention were used in both soil treatment and foliage treatment for foxtail grass, sparrow gnome, blackberry, barnyard grass,
It exhibits an extremely excellent selective herbicidal effect against regular weeds such as oats, and is particularly effective against legumes such as azuki beans and soybeans, which are susceptible to chemical damage caused by many other herbicides, as well as broad-leaved crops such as beets. , which has the property of being almost harmless. The compounds of the present invention exhibit excellent herbicidal activity against weeds when treated at any growth period, whether before or after germination. Even when the compound of the present invention is sprayed on foliage at a dose that completely kills the weed, for example, radish, radish, etc.
Almost no effect was observed on broad-leaved crops such as adzuki beans, soybeans, peas, spinach, and beets, and in pre-emergence soil treatment for weeds, even at doses that completely inhibited the germination of crabgrass, broad-leaved crop seeds were not affected. There is no fear of herbicide damage to broad-leaved crops, as there is almost no effect on herbicides, and the herbicide can be applied in a very wide range of application times, locations, and concentrations. Furthermore, since the compound of the present invention is used at a low concentration, there is no concern about residual toxicity in plants or acute toxicity to farmed fish, and it can be used safely. The herbicide of the present invention can be prepared by mixing an appropriate amount of the compounds represented by the general formula () with a carrier in the form of a commonly used agricultural chemical, such as a wettable powder, an emulsion, or
It is used in the form of granules, etc. Examples of solid carriers include talc, bentonite, clay, diatomaceous earth, etc., and examples of liquid carriers include water, alcohol, benzene, xylene, kerosene, mineral oil, cyclohexane, cyclohexanone, dimethylformamide, and the like. If necessary, a surfactant may be added in order to obtain a uniform and stable form in these preparations. The preparation method is similar to that of ordinary pesticides, but for example, for wettable powders, appropriate amounts of the active ingredient and solid carrier are uniformly mixed by adding a surfactant if necessary. , obtained by finely grinding. The active ingredient content in the hydrating powder is approximately 5 to 80
%, preferably 10-60%. The emulsion is obtained by sufficiently dissolving a suitable amount of the active ingredient in the above-mentioned liquid carrier with or without the addition of a surfactant, and the active ingredient content is about 5-70%, especially
20-60% is preferred. For granules, an appropriate amount of the active ingredient and a solid carrier are uniformly mixed with a surfactant if necessary, finely ground, and then granulated using a granulator with a diameter of 0.1 to 1.5 mm, preferably 0.5 to 1.0 mm. A method of making it into granules is carried out. The amount of active ingredient in the granules is approximately 0.5 to 30%, preferably 1 to 10%. The wettable powders and emulsions thus obtained are diluted with water to a predetermined concentration to form a suspension or emulsion.
The granules are subjected to soil surface treatment or soil mixing treatment before weed germination, or to foliar spray treatment after weed germination. When actually applying the herbicide of the present invention, 10 g or more of the active ingredient per 10 ares,
Preferably, an appropriate amount of 25 g or more is applied. The herbicide of the present invention can also be used in combination with known bactericides, insecticides, acaricides, herbicides, plant growth regulators, and the like. In particular, when used in combination with a herbicide, not only the amount of chemicals used can be reduced and labor savings can be achieved, but even higher effects can be expected due to the synergistic action of both chemicals. Known herbicides suitable for use in combination with the herbicide of the present invention include triazine herbicides such as simazine, propazine, and promethrin, carbamate herbicides such as betanal, and urea herbicides such as linyuron and tribunyl. Examples include heterocyclic herbicides such as pentazone agents, pyrazone agents, renacil agents, and the like. Next, some examples regarding the herbicide of the present invention will be shown, but the active ingredient compounds, additives, and addition ratios are not limited to these examples and can be varied within a wide range. Example 2 Emulsion Compound 1 25 parts Dimethylformamide 47 parts Xylene 20 parts Polyoxyethylene phenyl ether 8 parts The above ingredients were mixed and dissolved to obtain an emulsion containing 25% of the active ingredient. Example 3 Wettable powder compound 2 30 parts silicon oxide 30 parts alkylbenzenesulfonic acid sodium salt 8 parts diatomaceous earth 32 parts The above are mixed uniformly and finely ground to form the active ingredient.
A 30% hydrate was obtained. Example 4 Granule Compound 7 3 parts bentonite 10 parts talc 40 parts clay 45 parts polyoxyethylene alkylaryl sulfate 1 part alkylbenzene sulfonic acid sodium salt 1 part The above was mixed and pulverized uniformly, and the diameter was 0.5 to 0.5 in a granulator.
It was granulated to a size of 1.0 mm to obtain granules containing 3% of the active ingredient. Next, test examples will be shown to demonstrate the effectiveness of the herbicide of the present invention. Next, test examples will be given to demonstrate the herbicidal activity of the compounds of the present invention. Test Example 1 Soil Treatment Test ^Two 250cm pots were filled with soil, and seeds of crabgrass, oat, pigweed, goldenrod, and soybean were sown, and the soil was covered to the extent that each seed was not visible. A drug solution of a prescribed concentration prepared by dispersing an emulsion of each test compound with water was added to 100%
/10a on the soil surface. Three weeks later, the growth status of each plant was investigated. 0 to 10, where 0 indicates the same level of growth as without treatment, and 10 indicates withering or non-germination.
The growth status was expressed in 11 stages, and the results shown in Table 2 were obtained.

【table】

[Table] Test Example 2 Stem and Leaf Treatment Test ^Two 200cm pots were filled with soil, and seeds of crabgrass, oat, pigweed, and goldenrod were sown, lightly covered with soil, and grown in a greenhouse. When the weeds grew to the 2-4 leaf stage, an emulsion of each test compound was diluted with water and a chemical solution of a predetermined concentration was sprayed on the leaves at a ratio of 100/10a. After 3 weeks, the growth status of each weed was investigated, and the growth status was expressed according to the same criteria as Test Example 1, and the results shown in Table 3 were obtained.

【table】

Claims (1)

[Claims] 1. General formula (wherein, X is a 3,5-dichloro-2-pyridyl group, _R1 is a lower alkylene group, _R2 is a lower alkyl group, and n is O). 2 General formula (In the formula, X is a 3,5-dichloro-2-pyridyl group, R ₁ is a lower alkylene group, R ₂ is a lower alkyl group, and n is O.)
A selective herbicide characterized by containing one species or two or more species as active ingredients.