JPH0240673B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is (1) General formula () (In the formula, R represents a lower alkyl group having 1 to 3 carbon atoms.) An urazole derivative represented by the following formula. (2) General formula () (In the formula, R represents a lower alkyl group having 1 _{to 3} carbon atoms, and M represents an alkali metal atom.) , X represents a bromine atom or a chlorine atom.) A method for producing a urazole derivative represented by the general formula () by reacting with a dihalobutane represented by () and (3) containing the urazole derivative represented by the general formula () as an active ingredient. This relates to herbicides. The present inventors have developed rice, corn, wheat,
In order to protect important crops such as cotton and soybeans from weed damage and maintain high yields, we have continued our research with the aim of developing highly selective and highly active herbicides, and we have developed a herbicide with the general formula (4). - The present invention was completed based on the discovery that phenylurazole derivatives have excellent herbicidal efficacy and are virtually harmless to important crops such as soybeans, cotton, corn, and wheat. It is shown in JP-A-50-160429 and JP-A-53-44587 that 4-substituted phenylurazole derivatives have herbicidal activity. However, compared to the similar compounds described in these publications, the compound of the present invention has a much superior herbicidal effect, as is clear from the examples below, and has a much superior herbicidal effect on annual and perennial weeds in fields and paddy fields. In pre-emergence or post-emergence treatment, extremely high herbicidal effects can be shown at low doses. Next, a method for synthesizing the compound of the present invention will be described. The method for synthesizing urazole derivatives is described in detail in Heterocyclic Bound Vol. 37, 1981 (Jon-Wheeley and Sun). The compound of the present invention can be synthesized by heating the urazole derivative of the general formula () and the dihalobutane of the general formula () in an aprotic polar solvent such as dimethylformamide or dimethyl sulfoxide, if necessary. The compound of general formula () used as a raw material is synthesized from substituted phenyl isocyanate by the method described in Organic Synthesis 51 121 (1971). This isocyanate is a 2-
Chloro-4-fluorophenol is made into an alkali metal salt, then reacted with an alkyl halide, alkoxylated, nitrated with nitric acid-sulfuric acid, and reduced with hydrogen. The resulting aniline derivative is treated with phosgene in an inert solvent such as toluene. It is synthesized by reacting with EXAMPLES Next, the present invention will be explained in more detail with reference to Examples. Example 1 4-(4-chloro-2-fluoro-5-methoxyphenyl)-1,2-tetramethyleneurazole (compound (1)) Dissolve 0.7 g of sodium in 40 ml of methanol,
Add 4-(4-chloro-2-fluoro-5) to this solution.
After adding and dissolving 3.87 g of -methoxy)-urazole, the mixture was concentrated under reduced pressure. Add DMF40 to the concentrated residue
ml of 1,4-dibromobutane was added thereto, and the mixture was stirred at 100°C to 110°C for 4 hours. After cooling to room temperature, water was added and extracted with ether, and the ether layer was washed with water, dried, and concentrated to obtain crystals. This crystal was washed with ethanol and 4-
(4-chloro-2-fluoro-5-methoxyphenyl)-1,2-tetramethyleneurazole was obtained. mp 131-132.2℃ Elemental analysis value C(%) H(%) N(%) Cl(%) Calculated value 49.77 4.18 13.39 11.30 Actual value 49.60 4.24 13.17 11.29 Compound of the present invention obtained by the same method as Example 1 are shown in Table 1.

[Table] When actually applying the compound of the present invention obtained as described above, the raw material of the compound of the present invention () may be sprayed as it is, but in general, powders, granules,
Spread in formulations such as wettable powders and emulsions. The content of the compound of the present invention as an active ingredient in a formulation is usually in the range of 0.1 to 80%, but depending on the purpose, the content can be less than 0.1% or more than 80%. In preparing these pharmaceutical products, solid carriers such as mineral powders (kaolin, bentonite, clay, montmorillonite, talc, diatomaceous earth, mica, vermiculite, gypsum,
calcium carbonate, apatite, etc.), vegetable powders (soybean flour, wheat flour, charcoal, tobacco flour, starch,
crystalline cellulose, etc.), polymer compounds (petroleum resin,
Polyvinyl chloride, dammar gum, ketone resin, etc.), alumina, waxes, etc. Also. 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, tetrachloride, etc.). carbon, 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. Examples of formulations of the herbicide of the present invention are shown below. In addition, the compound name is indicated by the above-mentioned compound number. Formulation Example 1 80 parts by weight of compound (3), 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 Compound (4) 20 parts by weight, emulsifier Solpol 2680 (registered trademark of Toho Chemical) 10 parts by weight, cyclohexanone
50 parts by weight and 20 parts by weight of xylene are thoroughly mixed to obtain an emulsion. Formulation Example 3 0.1 part by weight of compound (3), 1 part by weight of white carbon, 35 parts by weight of bentonite and 63.9 parts by weight of clay are thoroughly ground and mixed, water is added and the mixture is thoroughly kneaded, then granulated and dried to obtain granules. . Formulation Example 4 3 parts by weight of compound (1), 0.3 parts by weight of isopropyl phosphate, 66.7 parts by weight of clay and 30 parts by weight of talc are thoroughly ground and mixed to obtain a powder. 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. Examples of this include, for example, 2,4-dichlorophenoxyacetic acid; 2-methyl-4-chlorophenoxybutyric acid; 2-methyl-4-chlorophenoxybutyric acid;
- Phenoxy herbicides such as chlorphenoxyacetic acid (including esters and salts), 2,4-dichlorophenyl-4'-nitrophenyl ether; 2,
4,6-Trichlorophenyl-4'-nitrophenyl ether; 2-chloro-4-trifluoromethylphenyl-3'-ethoxy-4'-nitrophenyl ether; 2,4-dichlorophenyl-4'- Nitro-3'-methoxyphenyl ether; 2,4-dichlorophenyl-3'-methoxycarbonyl-4'-
Diphenyl ether herbicides such as nitrophenyl ether, 2-chloro-4,6-bisethylamino-1,3,5-triazine; 2-chloro-4-
ethylamino-6-isopropylamino-1,
3,5-triazine; 2-methylthio-4,6-
Bisethylamino-1,3,5-triazine; 2
-Methylthio-4,6-bisisopropylamino-1,3,5-triazine; 4-amino-6-tert-butyl-3-methylthio-1,2,4
-Triazine herbicides such as triazin-5-one, 3-(3,4-dichlorophenyl)-1,1
-Dimethylurea; 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea; 1-
(2,2-dimethylbenzyl)-3-p-tolylurea; urea-based herbicides such as 1,1-dimethyl-3-(3-trifluoromethylphenyl)urea;
Carbamate herbicides such as isopropyl N-(3-chlorophenyl) carbamate; methyl N-(3,4-dichlorophenyl) carbamate, S
-(4-Chlorbenzyl)-N,N-diethylthiol carbamate; S-ethyl-N,N-hexamethylenethiol carbamate; S-ethyl-
N,N-diisobutylthiol carbamate; S
-Ethyl-N,N-dinormalpropylthiol carbamate; S-normalpropyl-N,N-
Thiol carbamate herbicides such as di-n-propylthiol carbamate, 3,4-dichloropropionanilide; N-methoxymethyl-2,
6-diethyl-α-chloroacetanilide; 2-
Chlor-2',6'-diethyl-N-(butoxymethyl)-acetanilide;2-chloro-2',6'-diethyl-N-(n-propoxyethyl)-acetanilide; N-chloroacetyl-N-( 2,6-
diethyl phenyl)-glycine ethyl ester;
Acid anilide herbicides such as 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methyl)acetamide, 5-bromo-
3-Secondary butyl-6-methyluracil;
Uracil herbicides such as 3-cyclohexyl-5,6-trimethyleneuracil, 1,1'-dimethyl-
Pyridinium chlorine herbicides such as 4,4-bispyridinium chloride, N,N-bis(phosphonomethyl)-glycine, O-ethyl-O-(2-nitro-5-methylphenyl)-N-secondary-butylphosphoramide Thioate, S-(2-methyl-1-piperidylcarbonylmethyl)O,O-
Di-n-propyldithiophosphate; S-(2
-Methyl-1-piperidylcarbonylmethyl)
Phosphorus herbicides such as O,O-diphenyldithiophosphate, α,α,α-trifluoro-2,6-
Toluidine herbicides such as dinitro-N,N-dipropyl-p-toluidine, 5-tert-butyl-3-(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazoline ―
2-one; 3-isopropyl-1H-2,1,3
-Benzothiadiazine-(4)-3H-one-2,2
-dioxide, α-(β-naphthoxy)-propionanilide, 4-(2,4-dichlorobenzoyl)-1,3-dimethylpyrazol-5-yl p-toluenesulfonate; 4'-phenylsulfonyl-1, 1,1-trifluorosulfono-O-
Toluidide; 4-chloro-5-methylamino-
2-(3-trifluoromethylphenyl)pyridazin-3(2H)-one, 1-methyl-3-phenyl-5-(3-trifluoromethylphenyl)pyridin-4(1H)-one, 2- Methyl-4-phenylsulfonyl trifluoromethylsulfanilide, 2-(3,4-dichlorophenyl)-4-methyltetrahydro-1,2,4-oxadiazole-3,5-dione; 4-chloro- 5-methylamino-2-(3-trifluoromethylphenyl)
Examples include, but are not limited to, pyridazine-3(2H)-one. 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 compounds of the invention by pre-emergence and post-emergence application methods, the application rates can be varied over a fairly wide range. Generally, the application amount of the compound of the invention as an active ingredient is 1 g to 500 g per 10 ares, preferably 2 g to 300 g. 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 on a scale from 0 to 5 based on the criteria shown in the table below. An evaluation value of 0 or 1 for cultivated plants or an evaluation value of 5 or 4 for weeds is generally considered to be an appropriate cultivated plant protection effect or weed control effect.

[Table] In order to further clarify the properties of the compounds of the present invention, the following compounds shown in Table 3 were used as comparative compounds in the following examples.

[Table] Example 2 Pre-emergence Soil Treatment Efficacy Comparison Test for Upland Field Field soil was packed into a cylindrical plastic beaker with a diameter of 10 cm and a height of 10 cm, and weed seeds of millet, oat, mulva morning glory, and Japanese yam and crop seeds of soybean, cotton, and corn were added. was sown. After sanding, a predetermined amount of the raw material was made into an emulsion, diluted with water, and treated with a hand sprayer. After that, it was grown in a greenhouse and the herbicidal efficacy was observed on the 20th day after treatment.
The results are shown in Table 4.

[Table] Example 3 Comparative test on post-germination foliage treatment efficacy A cylindrical plastic beaker with a diameter of 10 cm and a height of 10 cm was filled with field soil, weed seeds of Japanese barnyard grass, oat, wild mustard, and Japanese crocodile were sown, and tubers of Japanese commonweed were transplanted. After soiling and growing in a greenhouse for two weeks, a predetermined amount of the chemical was applied to the entire stem and leaf area from above the plant using a hand sprayer. After the chemical treatment, each plant was grown in a greenhouse for another three weeks, and then the herbicidal efficacy of each plant was investigated. The results are shown in Table 5. The processing agent was formulated into an emulsion, a predetermined amount of which was dispersed in water (including a spreading agent), and the test was conducted at a rate of 5 liters per are.

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[Table] Example 4 Pre-germination treatment test A plastic tray with a height of 35 cm, a width of 25 cm and a height of 15 cm was filled with field soil, and the soil was used to plant field soil, which was then used to plant soil in the field. of weeds, cotton and soybean crops were sown. A predetermined amount of the hydrating agent was dispersed in water and sprayed over the entire surface of the soil using a small sprayer from above the tray 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 6.

[Table] Example 5 Weeding test on corn and wheat (post-emergence treatment) Field soil was packed into plastic trays measuring 35 cm in height, 25 cm in width, and 10 cm in height, and corn, wheat, Japanese croaker, Japanese staghorn, Japanese mulberry morning glory, white radish, Japanese brilliance, After sowing chickweed and foxtail grass and growing them in a greenhouse for 2 to 3 weeks,
Arrange two of these trays in a frame measuring 50 cm, width 100 cm, and height 40 cm, and use a small sprayer from above the plants.
A predetermined amount of each drug was applied to the entire area within the frame. 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 results are shown in Table 7. The processing agent used was an emulsion prepared according to the recipe in Formulation Example 2, and the emulsion was emulsified in 25 ml of water to which a spreading agent was added. The size of the plants at the time of chemical treatment varied depending on the species, but they were approximately 1.5-20 cm tall at the 1-4 true leaf stage.

[Table] Example 6 Paddy-like soil treatment test A 1/5000a Wagner pot was filled with Takarazuka paddy soil, seeds of annual weeds were mixed in at a depth of 2 to 3 cm from the soil surface layer, and the pot was flooded with water. After flooding, tubers and overwintering buds of perennial weeds were planted. Five days later, when each weed started to germinate, a predetermined amount of the chemical was dropped onto the water surface using an emulsion. The herbicidal efficacy was investigated 4 weeks after the treatment, and the results are shown in Table 8.

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Claims (1)

[Claims] 1. General formula (In the formula, R represents a lower alkyl group having 1 to 3 carbon atoms.) An urazole derivative represented by the following formula. 2 General formula (In the formula, R is a lower alkyl group having 1 to 3 carbon atoms,
M represents an alkali metal atom. ) is reacted with a dihalobutane represented by the general formula X(-CH ₂ )- ₄ general formula to (In the formula, R represents a lower alkyl group having 1 to 3 carbon atoms.) A method for producing a urazole derivative represented by the following formula. 3 General formula (In the formula, R represents a lower alkyl group having 1 to 3 carbon atoms.) A herbicide characterized by containing a urazole derivative represented by the following as an active ingredient.