JPH0331705B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides: (1) N-(4-bromo-2-fluoro-5-isopropoxyphenyl)-3,4,5,6-tetrahydrophthalimide, (2) 4-bromo-2-fluoro-5- N-(4-bromo-2-fluoro-5-isopropoxyphenyl)-3,4,5 characterized by reacting isopropoxyaniline and 3,4,5,6-tetrahydrophthalic anhydride , a method for producing 6-tetrahydrophthalimide, and (3) containing N-(4-bromo-2-fluoro-5-isopropoxyphenyl)-3,4,5,6-tetrahydrophthalimide as an active ingredient. It is a herbicide that The compound of the present invention is a new compound and has strong herbicidal activity against annual, perennial grass, and broad-leaved weeds in fields, and against annual, perennial grass, Cyperaceae, and broad-leaved weeds in paddy fields at low concentrations. It is characterized by In particular, in soil treatment and foliage treatment in upland fields, it has a strong herbicidal effect on problem weeds such as morning glory, sorghum, Japanese sorghum, sunflower, and sorghum that are difficult to control with general herbicides, and is less harmful to important crops, especially corn. can be used as an excellent herbicide with a high degree of selectivity. JP-A-51-51521 describes that substituted phenyltetrahydrophthalimide derivatives, such as 2-fluoro-4-chlorophenyltetrahydrophthalimide (control compound 1), have herbicidal activity. As is clear from the Examples below, the compound of the present invention exhibits selectivity for corn in both soil and foliage treatments, and is more selective than the control compound 1 for weeds such as morning glory and Ebisugusa.
It has more than four times the herbicidal efficacy compared to In addition, in Japanese Patent Application Laid-open No. 139305/1983, 2,4-
dichloro-5-isopropoxyphenyl-3,
It has been shown that 4,5,6-tetrahydrophthalimide (comparative compound 2) and the like have herbicidal activity and are selective to corn. However, as is clear from the Examples below, the compound of the present invention has a much higher efficacy than Control Compound 2 against weeds such as morning glory, Ebisugusa, and Japanese crocodile, which are considered to be problem weeds in both soil treatment and foliage treatment. It shows very little phytotoxicity to corn and has excellent selectivity. Furthermore, in rice fields, whereas the above-mentioned compounds have no activity at all on weeds, which have become a problem in recent years, the compounds of the present invention can sufficiently kill weeds without causing any harm to rice. In addition, although control compounds 1 and 2 do not have sufficient herbicidal activity against the common grass, which has become particularly difficult to control in recent years, the compound of the present invention has sufficient herbicidal activity at 10 g/a. ing. As described above, the compound of the present invention, which is characterized by simultaneously having a fluorine atom at the 2-position of the phenyl group, a bromine atom at the 4-position, and an isopropoxy group at the 5-position, is more effective than the control compound 1 or 2, which does not have these at the same time. The excellence of the present invention lies in the fact that it is extremely superior. The compound of the present invention comprises 5-isopropoxy-4-bromo-2-fluoroaniline and 3,4,5,6-
It can be easily produced by heating tetrahydrophthalic anhydride in an inert organic solvent such as benzene, toluene, xylene, or acetic acid. The raw material 4-bromo-2-fluoro-5-isopropoxyaniline is, for example, 2-bromo-2-fluoro-5-isopropoxyaniline.
After converting 4-fluorophenol into a carbonate ester with methyl formate, nitration and hydrolysis reaction yielded 2-bromo-4-fluoro-5-nitrophenol, which was further converted into 2-bromo-4-fluoro-5-nitrophenol with isopropyl halide. It is obtained by reducing phenyl isopropyl ether. By selecting the solvent aid in each reaction step, the desired product can be obtained in good yield. 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, fine granules, or powders can be used. In preparing these pharmaceutical products, examples of solid carriers include mineral powders (kaolin, bentonite, clay, montmorillonite, talc, diatom, mica, vermiculite, gypsum,
calcium carbonate, apatite, etc.), vegetable powders (soybean flour, wheat flour, wood flour, tobacco flour, starch,
crystalline cellulose, etc.), polymer compounds (petroleum resin,
(polyvinyl chloride, dammargum, ketone resin, etc.), alumina, waxes, etc. Examples of liquid carriers include alcohols (methyl alcohol, ethyl alcohol, ethylene glycol, benzyl alcohol, etc.), aromatic hydrocarbons (toluene, benzene, xylene, methylnaphthalene, etc.), chlorinated hydrocarbons (chloroform, carbon tetrachloride, monochlorobenzene, etc.), ethers (dioxane, tetrahydrofuran, etc.), ketones (acetone, methyl ethyl ketone, cyclohexanone, etc.), esters (ethyl acetate, butyl acetate, ethylene glycol acetate, etc.), acid amides (dimethylformamide, etc.) ), nitriles (such as acetonitrile), ether alcohols (such as ethylene glycol ethyl ether), and water. The surfactant used for the purpose of emulsification, dispersion, spreading, etc. may be nonionic, anionic, cationic, or amphoteric. Examples of surfactants used include polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, oxyethylene oxypropylene polymer, polyoxy Ethylene alkyl phosphate ester, fatty acid salt,
Alkyl sulfate salts, alkyl sulfonates, alkylaryl sulfonates, alkyl phosphate salts, polyoxyethylene alkyl sulfate esters, quaternary ammonium salts, etc.
Of course, it is not limited to these.
In addition, 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. Furthermore, the compound of the present invention can be used in combination with insecticides, nematicides, fungicides, plant growth regulators, fertilizers, etc., if necessary. When using the compound of the present invention, it can be used as an active ingredient at a rate of about 0.1 to 50 g per are, depending on the treatment method, formulation form, applicable crops, applicable weeds, soil conditions, etc. Preferably it is 0.5-30g. When the compound of the present invention is formulated as a herbicide, it is possible to contain the compound of the present invention in an amount of 1 to 95% as an active ingredient, but preferably 3 to 80%. Examples of blending the compounds of the present invention are shown below. Formulation Example 1 80 parts by weight of the compound of the present invention, 3 parts by weight of alkyl sulfate, 2 parts by weight of lignin sulfonate and 15 parts by weight of white carbon are thoroughly ground and mixed to obtain a wettable powder. Formulation Example 2 80 parts by weight of the compound of the present invention, 6 parts by weight of 50% polyoxyethylene alkylaryl ether powder, 2 parts by weight of lignin sulfonate and 12 parts by weight of white carbon are thoroughly ground and mixed to obtain a wettable powder. Formulation example 3 10 parts by weight of the compound of the present invention, emulsifier Solpol 2680
(Toho Chemical registered trademark), 60 parts by weight of cyclohexanone, and 20 parts by weight of xylene are thoroughly mixed to obtain an emulsion. Formulation Example 4 5 parts by weight of the compound of the present invention, 1 part by weight of white carbon, 35 parts by weight of bentonite and 59 parts by weight of clay are thoroughly ground and mixed, water is added and the mixture is thoroughly kneaded, followed by granulation and drying to obtain granules. Formulation Example 5 3 parts by weight of the compound of the present invention, isopropyl phosphate
0.3 parts by weight, 66.7 parts by weight of clay, and 30 parts by weight of talc are thoroughly ground and mixed to obtain a powder. Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples unless it exceeds the gist thereof. Example 1 2.0 g of 4-bromo-2-fluoro-5-isopropoxyaniline and 1.23 g of 3,4,5,6-tetrahydrophthalic anhydride were dissolved in 10 ml of acetic acid.
The mixture was heated under reflux for 3 hours. After cooling to room temperature, the reaction solution was poured into water and extracted with ether. The extract was washed with water, dried over anhydrous sodium sulfate, the desiccant was removed, and the extract was concentrated under reduced pressure. The residue was purified by silica gel column chromatography to obtain 1.6 g of the above N-(4-bromo-2-fluoro-5-isopropoxyphenyl)-3,4,5,6-tetrahydrophthalimide. mp116.5-117.5°C In each of the following examples as a herbicide, the evaluation of phytotoxicity to cultivated plants and efficacy against weeds was all expressed as an evaluation value using an integer from 0 to 5 in accordance with the criteria described below. Measure the fresh weight of the above-ground parts of the plants that remained withered at the time of the survey, and compare it to the fresh weight of the plants in the untreated area (%)
Calculate. Cultivated plants and weeds were evaluated for chemical damage and herbicidal efficacy using numbers from 0 to 5 based on the criteria shown in the table below. Evaluation value for cultivated plants: 0
or 1 or weed rating 5 or 4
is generally considered to be a valid cultivated plant protection effect or weed control effect. In addition, only in the case of the paddy rice test, the evaluation value is calculated based on the dry weight of the plant.

【table】

Example 2 Corn weed control test (stem and foliage treatment) A plastic tray measuring 35 cm in height, 25 cm in width, and 10 cm in height was filled with field soil, and corn, Japanese radish, sunflower, Ebisu grass, Malva morning glory, Wildflower, chickweed, and foxglove were sown and placed in a greenhouse. After growing the plants for two weeks, two of these trays were arranged in a frame measuring 50 cm in length, 100 cm in width, and 40 cm in height, and the prescribed amount of each chemical was applied to the entire frame within the frame using a small sprayer from above the plants. . After being grown in a greenhouse for an additional three weeks after spraying the chemicals, each plant was examined for chemical damage or herbicidal efficacy. The result is the first
Shown in the table. The processing agent used was an emulsion prepared according to the recipe in Formulation Example 3, and the emulsion was emulsified in 25 ml of water to which a spreading agent was added. The size of plants when treated with chemicals varies depending on the species, but approximately 1 to 3 true leaves.
The plant height was 2 to 20 cm at the leaf stage.

【table】

[Table] Example 3 Pre-germination soil treatment test A plastic tray measuring 35 cm in length, 25 cm in width, and 15 cm in height was filled with field soil, and sown with morning glory, Japanese croaker, Ebisugusa, Seiban sorghum, and corn. A predetermined amount of the hydrating agent was dispersed in water, and the entire surface of the soil was sprayed from above the tray using a small sprayer at a rate of 5 liters per are. After treatment, the plants were placed in a greenhouse for 20 days and their phytotoxicity and herbicidal efficacy were investigated. The results are shown in Table 2.

[Table] Example 4 Weed control test (growth season foliage treatment) Fill a plastic pot with an inner diameter of 10 cm with 500 ml of field soil, embed 5 tubers of Chimney persimmon at a depth of 2 cm from the ground surface, and heat the pot at 20 to 30°C. Seedlings were grown in a greenhouse for 4 weeks to obtain individuals of the 7th leaf stage. Two of these pots were arranged in a frame with a base area of 1/4 m ² , and a predetermined amount of each chemical was applied to the entire surface of the frame using a small sprayer from above the plants. After the pesticide was applied, the plants were grown in a greenhouse for another four weeks, and the soil in the pot was removed by washing with water.The fresh weight of the aboveground and underground parts of the grasshoppers was calculated, and the ratio was calculated using the untreated area as 100%. The results are shown in Table 3. As the processing agent, an emulsion prepared according to the formulation of Formulation Example 3 was used, and for glyphosate, a commercially available water solvent was used.

[Table] *Glyph oxate
OOOH
‖ ‖／
HO−C−CH ₂ −N−CH ₂ −P
H \
OH
Example 5 Hot water treatment Fill a 1/5000a Wagner pot with paddy soil containing various weed seeds, add water to a depth of 4 cm, then transplant rice seedlings at the 3.5 leaf stage and Urikawa tubers for 2 days. Grow in a greenhouse. A predetermined amount of the drug formulated into an emulsion was dispersed in water and irrigated into the pot at a rate of 10 liters per are. After growing in the greenhouse for an additional three weeks, the herbicidal efficacy of each plant was investigated. The soil was mixed with seeds of Japanese millet, firefly, and broad-leaved weeds (Japanese aspen, Japanese azalea, Kikashigusa, etc.). Table 4 shows the results of the above three types of investigations.

【table】

Claims (1)

[Claims] 1 N-(4-bromo-2-fluoro-5-isopropoxyphenyl)-3,4,5,6-tetrahydrophthalimide. 2 N characterized by reacting 4-bromo-2-fluoro-5-isopropoxyaniline and 3,4,5,6-tetrahydrophthalic anhydride
A method for producing -(4-bromo-2-fluoro-5-isopropoxyphenyl)-3,4,5,6-tetrahydrophthalimide. A herbicide characterized by containing 3N-(4-bromo-2-fluoro-5-isopropoxyphenyl)-3,4,5,6-tetrahydrophthalimide as an active ingredient. 4. The herbicide according to claim 3, wherein the herbicide is a selective herbicide for corn.