JPH0248550B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to pyrazole derivatives. More specifically, the present invention relates to the general formula () (In the formula, X and Y are a hydrogen atom, a halogen atom, or a methylsulfonyl group, provided that at least one of them is a methylsulfonyl group, Z is a lower alkyl group, and R is a 2,4-dinitrophenyl group, a benzyl group, or a phenacyl group. or pivaloylmethyl group). In the definition of the general formula (), examples of the halogen atom include fluorine, chlorine, bromine, and iodine, and examples of the lower alkyl group include methyl, ethyl, and isopropyl. The pyrazole derivative of the present invention can be produced, for example, by the method described below. In the above reaction formula, X, Y, Z and R are as described above. Further, Hal. is a halogen atom. Examples of the solvent used in the above reaction include acetone, ketones such as methyl ethyl ketone, and dimethylformamide, and examples of the alkaline substance include potassium carbonate, sodium carbonate, and sodium hydroxide. Furthermore, when a cuprous halide catalyst such as copper iodide or copper fluoride is present, the reactivity can be improved. The pyrazole derivative of the present invention can be produced by, for example, producing a compound of general formula (') according to the above-mentioned production method,
It can also be produced by oxidizing it using a conventional method. In the above reaction formula, at least one of X' and Y' is a methylthio group, the other is a hydrogen atom, a halogen atom or a methylsulfonyl group, and Hal, Z and R are as described above. Next, specific synthesis examples according to the present invention will be described. Synthesis Example 1 Synthesis of 1,3-dimethyl-4-(2-chloro-4-methylsulfonylbenzoyl)-5-(pivaloylmethoxy)pyrazole 1,3-dimethyl-4-(2-chloro-4-methyl Dissolve 0.6 g of sulfonylbenzoyl)-5-hydroxypyrazole in 30 ml of methyl ethyl ketone, add 0.3 g of anhydrous potassium carbonate,
The mixture was stirred for a minute, then 0.34 g of tert-butyl bromomethyl ketone was added, and the mixture was reacted under reflux for 1 hour. After the reaction was completed, the inorganic salt was separated and the solvent was distilled off to obtain a crude product. After separating this with a silica gel column (eluent: methylene chloride), methylene chloride was distilled off to obtain 0.5 g of the target product with a mp of 55 to 57°C. Synthesis Example 2 Synthesis of 1,3-dimethyl-4-(2-methyl-sulfonylbenzoyl)-5-(phenacyloxy)pyrazole 0.8 g of 1,3-dimethyl-4-(2-methylthiobenzoyl)-5-hydroxypyrazole It was dissolved in 20 ml of methyl ethyl ketone, 0.4 g of anhydrous potassium carbonate was added thereto, and the mixture was stirred for 30 minutes. Thereafter, 0.6 g of phenacyl bromide was added, and the mixture was reacted under stirring for 1 hour under reflux. After the reaction, the inorganic salt was separated and the solvent was distilled off to give 1,3-dimethyl-4
0.7 g of -(2-methylthiobenzoyl)-5-(phenacyloxy)pyrazole was obtained. Next, the pyrazole was dissolved in 20 ml of glacial acetic acid, 0.2 g of 26% hydrogen peroxide solution was added dropwise, and the mixture was stirred at 80°C for 55 minutes.
Allowed time to react. After the reaction was completed, the product was poured into water, extracted with methylene chloride, the extracted layer was dried, and the solvent was distilled off to obtain a crude product. After separating this with a silica gel column (eluent: methylene chloride), methylene chloride was distilled off to obtain 0.45 g of the target product with a mp of 165 to 167°C. Specific compounds of the present invention obtained in the above synthesis examples or in a similar manner to those synthesis examples will be described below. Compound No. 1 1,3-dimethyl-4-(2-methylsulfonylbenzoyl)-5-(phenacyloxy)pyrazole mp165-167℃ Compound No. 2 1,3-dimethyl-4-(2-chloro-4-methyl sulfonylbenzoyl)-5-
(Phenacyloxy)pyrazole mp147-149℃ Compound No. 3 1,3-dimethyl-4-(2-chloro-4-methylsulfonylbenzoyl)-5-
(pivaloylmethoxy)pyrazole mp55-57℃ Compound No. 4 1-isopropyl-3-methyl-4
-(2-chloro-4-methylsulfonylbenzoyl)-5-(benzyloxy)pyrazole White crystals mp111-113℃ Compound No. 5 1,3-dimethyl-4-(2-chloro-4-methylsulfonylbenzoyl)- 5-
(2,4-dinitrophenoxy)pyrazole White crystals mp224-226°C As shown in the test examples below, the pyrazole derivative of the present invention exhibits suitable effects when used as an active ingredient of a herbicide. In particular, it effectively controls harmful weeds such as barnyard grass, cyperus japonica, cyperus japonica, bulrush, scallops, and other plants without causing any substantial harm to crops such as rice. The herbicide of the present invention has an excellent herbicidal effect on various weeds, so its application range is wide-ranging, including paddy fields, fields, orchards, mulberry orchards, mountain forests, farm roads, grounds, and factory grounds. Application methods include soil treatment. , foliage treatment can be selected as appropriate. The herbicide of the present invention can be prepared by directly dissolving or dispersing the above-mentioned active ingredient, i.e., a pyrazole derivative, in water to form an aqueous solution or aqueous dispersion. , Sickleite, and other carriers; solvents such as benzene, toluene, xylene, solvent naphtha, ethanol, dioxane, acetone, isophorone, methyl isobutyl ketone, dimethyl formamide, dimethyl sulfoxide, and water; and, if necessary, alkyl sodium sulfate and alkyl benzene sulfone. Sodium acid, sodium lignin sulfonate, polyoxyethylene lauryl ether, polyoxyethylene alkyl aryether, polyoxyethylene fatty acid ester,
Anionic or nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters may be appropriately blended and used in the form of emulsions, wettable powders, solutions, powders, and granules. The blending ratio at the time of formulation is, for example, 1 to 90% by weight of the active ingredient, preferably 1 to 70% by weight.
Suitably, the amount of the carrier or solvent is 5 to 99% by weight, preferably 25 to 99% by weight, and the surfactant is 0 to 30% by weight, preferably 1 to 20% by weight. Furthermore, the herbicide of the present invention can be mixed or used in combination with other herbicides, pesticides such as insecticides, fungicides, fertilizers, soils, etc., and in this case may exhibit even better effects. The appropriate amount of the herbicide of the present invention to be applied cannot be determined unconditionally due to differences in weather conditions, soil conditions, drug formulation, application timing, application method, type of target weed, etc., but in general, the amount of active ingredient applied per are is 1. ~500g, preferably 10-100g. Next, examples of plant tests and formulations of herbicides according to the present invention will be described, but of course the present invention is not limited only to these descriptions. Test Example 1 A pot of paddy soil was placed in a 1/5000-sized pot and the pot was saturated with water. Then, the seeds of millet for food were sown, and the pot was lightly covered with soil.
After germination in the field, the seeds were grown under water at a depth of approximately 3 cm, and when coleoptiles appeared, a predetermined amount of an aqueous dispersion of the compound of the present invention was added dropwise. Three weeks after the chemical solution treatment, the growth state was observed with the naked eye, and the degree of growth inhibition was expressed based on the following criteria (5-point scale from 1 to 5), and the results are listed in Table 1. Growth suppression degree 5: Complete withering state ~ ~ 1: Growth similar to untreated area

[Table] Test Example 2 A 1/5000-sized earth pot was filled with soil and flooded with water, and seeds of Hotarui were sown, and tubers of Urikawa were planted and grown in a greenhouse. When the firefly and urikawa reached the one-leaf stage, the water depth was set to about 3 cm, and a predetermined amount of an aqueous dispersion of the compound of the present invention was dropped into the water. The growth state was observed 3 weeks after the chemical solution treatment, and the degree of growth inhibition was evaluated using the same criteria as in Test Example 1, and the results shown in Table 2 were obtained.

[Table] Formulation example 1 (1) Bentonite 58 parts by weight (2) Siegrite 30 parts by weight (3) Sodium ligninsulfonate 5 parts by weight The above ingredients were mixed and granulated, and diluted with an appropriate amount of acetone. 1,3-dimethyl-4-(2-
Chloro-4-methylsulfonylbenzoyl)-5
-7 parts by weight of (phenacyloxy)pyrazole was sprayed to obtain granules. Formulation example 2 (1) Siegrite 78 parts by weight (2) Lavelin S (product name: Daiichi Kogyo Seiyaku)
2 parts by weight (3) Solpol 5039 (Product name: Toho Chemical Industries)
5 parts by weight (4) Carplex (product name: manufactured by Shionogi & Co., Ltd.)
15 parts by weight mixture of each of the above components and 1,3-dimethyl-4
-(2-chloro-4-methylsulfonylbenzoyl)-5-(pivaloylmethoxy)pyrazole in a weight ratio of 4:1 to obtain a wettable powder.

Claims (1)

[Claims] 1. General formula (In the formula, X and Y are a hydrogen atom, a halogen atom, or a methylsulfonyl group, provided that at least one is a methylsulfonyl group, Z is a lower alkyl group, and R is a 2,4-dinitrophenyl group, a benzyl group, or a phenacyl group. or a pivaloylmethyl group).