JPS6145981B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel compound and its use, and in particular, the present invention relates to a novel compound and its use, and in particular, the general formula () (In the formula, X is a halogen atom or a trifluoromethyl group, R ₁ is a hydrogen atom or a lower alkyl group,
R ₂ represents a hydrogen atom, a lower alkyl group, a lower alkenyl group or a benzyl group. However, when R ₂ is a hydrogen atom, X represents an iodine atom or a fluorine atom, and when X is a trifluoromethyl group,
R ₁ represents a hydrogen atom. ) and selective herbicides containing the compounds as active ingredients. The object of the present invention is to provide a herbicide that can be industrially advantageously obtained, is easy to use, and is highly effective. The present inventors synthesized various diphenylamine derivatives and examined those suitable for the above purpose, and found that the anilinophenoxycarboxylic acid derivative represented by the general formula [] exhibits excellent selective herbicidal action. After making this discovery and conducting further biological and physicochemical research, the present invention was completed. The compound of the present invention exhibits extremely excellent selective herbicidal activity against weeds of the grass family such as barnyard grass, crabgrass, oat, and sparrow gnome, and is almost harmless to rice or broad-leaved crops such as adzuki beans, soybeans, and beets. It has the following characteristics. The compound of the present invention exhibits excellent herbicidal efficacy against weeds when treated at any growth period, whether before or after germination, but in general, when the same dosage is used, the efficacy is higher when treated after germination. You can expect it to be active. The compound of the present invention has almost no effect on broad-leaved crops such as radish, adzuki beans, soybeans, peas, spinach, beets, etc., even at doses that completely kill the grasshopper, a common weed, when applied to leaves. In addition, in pre-emergence soil treatment for weeds, even at doses that completely inhibit the germination of crabgrass, there is almost no effect on the seeds of broad-leaved crops, indicating that herbicides are extremely safe against chemical damage to broad-leaved crops. The range of application, such as application period, application location, and application concentration, is also extremely wide. In addition, since the compound of the present invention can be used at low concentrations, there is little concern about acute toxicity to livestock and fish, and it can be used safely. In addition, the compound of the present invention is selective for rice both under paddy field conditions and upland conditions, and has the property that even a dose that completely kills noviidae has little effect on rice. have. The compound of the present invention also has a controlling effect on plant diseases such as downy mildew of Japanese cucumber, and also has acaricidal and insecticidal effects. The compounds of the present invention also have analgesic, hypotensive, anti-inflammatory, and antibacterial activities, and are useful as medicines. The compound of the present invention is produced by the following reaction formula.
However, in the following formula, Hal represents a halogen atom, R ₁ ' represents a lower alkyl group, and R ₂ ' represents a lower alkyl group, a lower alkenyl group, or a benzyl group. The above reaction is usually carried out under heating under reflux for 3 to 6 hours in an inert solvent in the presence of an acid binder. As the inert solvent, common inert solvents such as acetone, methyl ethyl ketone, acetonitrile, and cyclomethane are used, and as the acid binder, potassium carbonate, sodium carbonate, sodium methylate, etc. are used. In the above formula, chlorine or bromine is usually used as the halogen represented by Hal. The reaction solution is poured into cold water, extracted with a suitable organic solvent, the organic solvent layer is washed with water, dried, and the solvent is distilled off to obtain an ester, that is, a compound of the present invention in which R ₁ is lower alkyl. The compound of the present invention in which R ₁ is a hydrogen atom can be obtained by subjecting the obtained ester to alkaline hydrolysis using a conventional method. Among the compounds of the present invention, compounds in which R ₂ is a hydrogen atom are usually produced by the above reaction formula (1), and compounds in which R ₂ is a lower alkyl group, a lower alkenyl group, or a benzyl group are usually produced by The above reaction formula
Manufactured by (2). The raw material compound represented by the general formula [] is
It can also be obtained by reacting p-aminophenol with the corresponding substituted benzene in the presence of an acid binder in a polar solvent, or by reacting p-anisidine with the corresponding substituted benzene followed by reduction. . Acid binders used in the reaction between p-aminophenol and benzene include soda carbonate,
Inorganic bases such as caustic soda or organic bases such as pyridine, trimethylamine, tributylamine, p-aminophenol are used, but it is preferable to use organic bases. Next, the method for producing the compound of the present invention will be explained in more detail with reference to Examples. Example 1 2-{4-(4-iodo-2-nitroanilino)
Phenoxy}propionate ethyl ester (compound number 1) 4-(4-iodo-2-nitroanilino)phenol 4.3g and ethyl 2-bromopropionate 2.4g
g was dissolved in 50 ml of methyl ethyl ketone, 2 g of anhydrous potassium carbonate was added, and the mixture was heated under reflux for 5 hours with stirring. Thereafter, the reaction solution was poured into water, extracted with ethyl acetate, washed with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off to obtain 5 g of the target product. mp70-71℃ Example 2 -{4-(N-Ethyl-4-chloro-2-nitroanilino)phenoxy}propionic acid ethyl ester (Compound No. 3) 50% sodium hydride 0.5 in 50 ml of N·N-dimethylformamide g was suspended, and under cooling, 2-{4
-(4-Chloro-2-nitroanilino)phenoxy}propionic acid ethyl ester (3 g) was added little by little, and after stirring for 30 minutes, ethyl iodide was added.
1.9 g was added and the mixture was gradually heated to react at 50° C. for 5 hours. Thereafter, the reaction solution was poured into water, extracted with ethyl acetate, washed with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off to obtain 3 g of a red-black oily crude product. The crude product was purified by silica gel column chromatography (developing solvent: hexane:ethyl acetate = 4:1) to obtain 2.5 g of crystals of the desired product. mp62-65°C Table 1 shows representative compounds of the present invention.

【table】

[Table] The herbicide of the present invention can be prepared by mixing an appropriate amount of one or more of the compounds represented by the above general formula () with a carrier, and using the usual forms of concentrated medicine, such as wettable powders, emulsions, granules, etc. used in the form of 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 formulation method is similar to the usual formulation method for agricultural chemicals.For example, for wettable powders, the active ingredient and solid carrier are added in appropriate amounts and a surfactant if necessary, mixed uniformly, and finely dispersed. Obtained by grinding. The active ingredient content in the hydrating agent is approximately 5-80%,
Preferably, 10 to 60% is appropriate. Emulsions are made by adding appropriate amounts of active ingredients and surfactants.
Alternatively, it can be obtained by sufficiently dissolving it in the liquid carrier mentioned above without adding it, and the active ingredient content is about 5 to 70%.
%, especially 20-60% is preferred. For granules, appropriate amounts of the active ingredient and solid carrier are uniformly mixed together with a surfactant, if necessary, and finely ground.
Furthermore, in a granulator, the diameter is 0.5 to 1.5 mm, preferably 0.5 mm.
A method of making granules of ~1.0 mm is performed. 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 can be treated as they are by soil surface treatment or soil mixing treatment before weed germination, or by spraying on foliage 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 phenoxyalkane carboxylic acid herbicides such as 2,4-PA agents, and heterocyclic herbicides such as pyrazone agents and renacil agents. 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 3 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 4 Wettable powder compound 3 30 parts diatomaceous earth 56 parts Higher alcohol sulfate ester 8 parts White carbon 6 parts The above are mixed uniformly and finely ground to form the active ingredients.
A 30% hydrating powder was obtained. Example 5 Granule Compound 6 3 parts bentonite 8 parts talc 85 parts polyoxyethylene alkylaryl sulfate 4 parts The above was mixed and ground 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. Test Example 1 Soil treatment test ^Two 250cm pots were filled with soil, and seeds of crabgrass, oat, pigweed, goldenrod, chrysanthemum, and soybean were sown, and the soil was covered to the extent that each seed was not visible. A chemical solution with a predetermined concentration prepared by diluting an emulsion of each test compound with water was sprayed onto the soil surface at a ratio of 100/10a. Three weeks later, the growth status of each weed was investigated. 0 indicates the same level of growth as no treatment, 10 indicates withering or non-germination.
The growth status was expressed in 11 stages from 0 to 10, and the results shown in Table 2 were obtained.

【table】

[Table] Test Example 2 Stem and Leaf Treatment Test ^Two 200 cm 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, a chemical solution of a predetermined concentration prepared by diluting an emulsion of each test compound with water was sprayed on the leaves at a ratio of 100/10a. After three weeks, the growth status of each weed was adjusted and expressed according to the same criteria as Test Example 1, and the results shown in Table 3 were obtained.

【table】

【table】

Claims (1)

[Claims] 1. General formula (In the formula, X is a halogen atom or a trifluoromethyl group, R ₁ is a hydrogen atom or a lower alkyl group,
R ₂ represents a hydrogen atom, a lower alkyl group, a lower alkenyl group or a benzyl group. However, when R ₂ is a hydrogen atom, X represents an iodine atom or a fluorine atom, and when X is a trifluoromethyl group,
R ₁ represents a hydrogen atom. ) A compound represented by 2 General formula (In the formula, X is a halogen atom or a trifluoromethyl group, R ₁ is a hydrogen atom or a lower alkyl group,
R ₂ represents a hydrogen atom, a lower alkyl group, a lower alkenyl group or a benzyl group. However, when R ₂ is a hydrogen atom, X represents an iodine atom or a fluorine atom, and when X is a trifluoromethyl group,
R ₁ represents a hydrogen atom. ) A herbicide containing the compound represented by as an active ingredient.