JPH0660178B2 - Pyrazolsulfonylurea derivative, its production method and selective herbicide - Google Patents

Description

The present invention relates to a novel pyrazole sulfonylurea derivative, a method for producing the compound, and a selective herbicide containing the compound as an active ingredient.

It is indispensable to use herbicides to protect important crops such as rice, wheat and cotton from weed damage and increase their yield. Particularly in recent years, in arable land where these useful crops and weeds are mixed, a selective herbicide capable of selectively killing only the weeds without showing phytotoxicity to the crops even when the foliage of the crops and the weeds are simultaneously treated is desired. It is rare. Also, environmental pollution prevention, transportation,
From the viewpoint of economic cost reduction at the time of application, exploratory research on compounds that show high herbicidal effect with the lowest possible dose has been continued for many years. Although some of the compounds with such properties are currently used as selective herbicides, there is still a need for new compounds with these properties.

The present inventors have continued to study for many years to develop a herbicide having selectivity for important crops, and to produce a compound having higher herbicidal activity and selectivity, many compounds have herbicidal properties. Have been considering. As a result, the above general formula (I) [In the formula, R ¹ and R ² represent a lower alkyl group.

X and Y each independently represent a lower alkyl group or a lower alkoxy group, and Z represents a nitrogen atom or a -CH = group. ] The pyrazole sulfonylurea derivative represented by the following is referred to as the compound of the present invention) has a strong herbicidal activity against many weeds in both soil treatment and foliage treatment, and is an important crop such as rice, wheat and cotton. The present invention has been completed by finding that it has a high level of safety. On the other hand, the compound of the present invention exhibits a high herbicidal activity at a very low dose as compared with conventional herbicides, and is therefore also useful as a herbicide for orchards and non-arable land.

As a prior art having a structure similar to that of the compound of the present invention, for example, European Patent Application Publication No. 87,780 discloses a compound having an alkoxy group at the 3-position as a characteristic of the compound of the present invention and an alkyl group at the 3-position. ing. However, the compound of the present invention is not specifically disclosed, and is a novel compound. The present inventors have found that by substituting the alkyl group at the 3-position with an alkoxy group, the selectivity for useful crops, particularly the safety for cotton, is significantly increased, and the present invention has been completed.

The compound of the present invention represented by the general formula (I) is a novel compound and can be easily produced by selecting one of the following reaction formulas 1 and 2.

Reaction formula 1 [In the formula, R ¹ , R ² , X, Y and Z have the same meanings as described above. ] That is, the pyrazole sulfonyl isocyanate derivative (II) is dissolved in a sufficiently dried dioxane, an inert solvent such as acetonitrile, by adding the pyrimidine or triazine derivative represented by the formula (III) and stirring, Generally, the compound (I) of the present invention is obtained by a rapid reaction. When the reaction is difficult to proceed, the reaction easily proceeds by adding an appropriate base, for example, triethylamine, triethylenediamine, pyridine, sodium alkoxide, sodium hydride and the like in minute amounts.

Reaction formula 2 [In the formula, R ¹ , R ² , X, Y and Z have the same meanings as described above. R ³ represents an alkyl group or a phenyl group. ] That is, the pyrazole sulfonamide derivative (IV)
Compound (VI) is obtained by reacting with chloroformic acid ester or carbonic acid ester in the presence of a base such as potassium carbonate in a solvent such as acetone or methyl ethyl ketone, and after the reaction, treating with an acidic substance such as hydrochloric acid. Then, the compound (I) of the present invention can be obtained by heating the compound (III) in a solvent such as toluene.

The pyrazole sulfonyl isocyanate (II) or the pyrazole sulfonyl carbamate derivative (III) used as the raw materials in the reaction formulas 1 and 2 was synthesized as a pyrazole sulfonamide by the method described below.
It can be synthesized with reference to the methods described in JP-A-58-70407 and JP-A-55-13266.

An example of the synthesis of the intermediate pyrazole sulfonamide used in the present invention will be described below as a reference example.

Reference Example-1 Synthesis of 3-methoxy-4-ethoxycarbonyl-1-methylpyrazole-5-sulfonamide (1) Synthesis of 3-methoxy-4-ethoxycarbonyl-1-methylpyrazole 4-ethoxycarbonyl-3-hydroxy 10 g of -1-methylpyrazole, 41.7 g of methyl iodide, and 17.9 g of anhydrous potassium carbonate were heated under reflux in 200 ml of dry methyl ethyl ketone for 15 hours.

After the reaction was completed, the inorganic substances were separated by filtration while heating, and the solvent was distilled off under reduced pressure. The crude product obtained is diluted with chloroform and diluted with 5
% Caustic soda aqueous solution and water, and then solvent drying,
It was dried under reduced pressure. The obtained crude crystals were recrystallized with a mixed solvent of n-hexane-benzene to obtain 8.2 g of the desired product. Melting point 8
7-88.5 ° C (2) Synthesis of 3-methoxy-4-ethoxycarbonyl-1-methylpyrazole-5-sulfonamide 7.33 g of ethyl 3-methoxy-1-methylpyrazole-4-carboxylate was suspended in 225 ml of dry ether. , -60 ° C or lower. Then, a lithium diisopropylamide (1.2 times mol) ether solution was added dropwise. The mixture was stirred for 1 hour as it was, and then sulfurous acid gas was bubbled therein for 30 minutes. −60
After stirring at C for 1 hour, the precipitated crystals were filtered and dried to obtain 8.1 g of solid lithium 3-methoxy-4-ethoxycarbonyl-1-methylpyrazole-5-sulfonate.

Next, this was added to a solution of 150 ml of ice water and 150 ml of dichloromethane, and 4.3 g of N-chlorosuccinimide was added at a temperature of 0 to 5 ° C. After stirring at room temperature for 30 minutes, the dichloromethane layer was separated, and the aqueous layer was extracted with 100 ml of dichloromethane and combined. A solution of the obtained 3-methoxy-4-ethoxycarbonyl-1-methylpyrazole-5-sulfonyl chloride (boiling point 142-144 ° C / 0.5 mmHg) in dichloromethane was added 10 times.
The solution was added dropwise to 110 ml of ammonia water (28%) cooled to below ℃. After stirring at room temperature, the solvent was distilled off to obtain 2.7 g of the desired product. Melting point 131-133 ° C. Reference Example 2 Synthesis of N- (3-methoxy-4-ethoxycarbonyl-1-methylpyrazole-5-sulfonyl) ethylcarbamate 3-Methoxy-4-ethoxycarbonyl-1-methylpyrazole-5-sulfone 2.51 g of amide, 1.25 g of ethyl chloroformate and 1.59 g of anhydrous potassium carbonate were heated to reflux in 20 ml of dehydrated acetonitrile for 5 hours. After the reaction was completed, the solvent was distilled off under reduced pressure, the mixture was diluted with ice water, the insoluble material was filtered off, and the filtrate was washed with dilute hydrochloric acid. The precipitated crystals were separated by filtration, washed with water and dried to obtain 2.51 g of the desired product. Melting point 99 to 101 ° C. Reference Example 3 Synthesis of N- (3-ethoxy-4-ethoxycarbonyl-1-methylpyrazole-5-sulfonyl) ethylcarbamate 3-Ethoxy-4-ethoxycarbonyl-1-in accordance with Reference Example 1. Methylpyrazole-5-sulfonamide was synthesized and then synthesized according to Reference Example 2. Melting point 95 to 96 ° C. A specific synthesis example of the compound of the present invention will be described below using the intermediate obtained in the above Reference Example, but the present invention is not limited thereto.

Example 1 Synthesis of N-[(4-methoxy-6-methylpyrimidin-2-yl) aminocarbonyl] -3-methoxy-4-ethoxycarbonyl-1-methylpyrazole-5-sulfonamide (Compound No. 7) N- (3-methoxy-4-ethoxycarbonyl-1-methylpyrazole-5-sulfonyl) ethyl carbamate
1.04 g (3.1 mmol) and 2-amino-4-methoxy-6-
0.42 g (3.1 mmol) of methylpyrimidine in 30 ml of toluene, 2
Heated to reflux for hours. After completion of the reaction, toluene was distilled off under reduced pressure, and the residue was left standing overnight for crystallization. The crude crystals were mixed with a small amount of acetonitrile, thoroughly disintegrated, filtered, and dried under reduced pressure to give a white target crystal.
61 g were obtained. Melting point 158-160 ° C.

Example 2 Synthesis of N-[(4,6-dimethoxypyrimidin-2-yl) aminocarbonyl] -3-methoxy-4-ethoxycarbonyl-1-methylpyrazole-5-sulfonamide (Compound No. 8) 3- To a mixture of 6.1 g of methoxy-4-ethoxycarbonyl-1-methylpyrazole-5-sulfonamide and 4.6 g of anhydrous potassium carbonate, 50 g of acetone was added 2.5 g of n-butyl isocyanate at room temperature, and the mixture was heated under reflux for 3 hours. After completion of the reaction, acetone was distilled off under reduced pressure, the residue was poured into ice water, the insoluble matter was filtered off, and the filtrate was acid precipitated with hydrochloric acid. The precipitated crystals were separated by filtration, washed with water and dried to give N- (n-butylcarbamoyl) -3-methoxy-4-ethoxycarbonyl-1.
4.5 g of methylpyrazole-5-sulfonamide were obtained. Melting point 125-128 [deg.] C. Then, this was added to 100 ml of dry toluene, 4.0 g of phosgene was blown thereinto under heating under reflux, and the mixture was further heated under reflux for 1.5 hours. After completion of the reaction, the solvent was distilled off under reduced pressure to obtain 0.85 g of crude sulfonyl isocyanate. 0.85 g of this crude sulfonyl isocyanate was added to a solution of 0.35 g of 2-amino-4,6-dimethoxypyrimidine in 20 ml of dry acetonitrile, and the mixture was stirred at room temperature. The produced crystals were separated by filtration, washed, and dried to obtain 0.7 g of the desired product. Melting point 142 to 143 ° C. Next, examples of compounds included in the present invention are shown in Table 1 below and the compounds synthesized in the above Examples, but the compounds of the present invention are not limited thereto.

Me: methyl group Et: represents an ethyl group.

In applying the invention compounds as herbicides, generally suitable carriers such as clay, talc, bentonite,
Solid carriers such as diatomaceous earth or water, alcohols (methanol, ethanol, etc.), aromatic hydrocarbons (benzene, toluene, xylene, etc.), chlorinated hydrocarbons, ethers, ketones, esters (ethyl acetate, etc.), It can be applied by mixing with a liquid carrier such as acid amides (dimethylformamide, etc.), and if desired, an emulsifier, a dispersant, a suspending agent, a penetrating agent, a spreading agent, a stabilizer, etc. are added, and a liquid agent, an emulsion. It can be put into practical use in any dosage form such as a wettable powder, a powder, and a granule.

Next, formulation examples of a herbicide containing the compound of the present invention as an active ingredient will be shown, but the invention is not limited thereto. In the following formulation examples, "part" means part by weight.

Formulation Example 1 Wettable powder Compound of the present invention No. 7 ...... 50 parts Dikrite A ...... 46 parts (Kaolin clay: product name of Sikhlite Industrial Co., Ltd.) Solpol 5039 ...... 2 parts (Nonionic surfactant And anionic surfactant: Toho Chemical Co., Ltd. trade name Carplex (anti-caking agent) 2 parts (white carbon: Shionogi Seiyaku Co., Ltd. trade name) To make wettable powder.

Formulation Example 2 Wettable powder Compound of the present invention No.8 …… 45 parts Diklite A …… 51 parts (Kaolin-based clay: product name of Sikhlite Industry Co., Ltd.) Solpol 5039 …… 2 parts (Nonionic surfactant And anionic surfactant: Toho Chemical Co., Ltd. trade name Carplex (anti-caking agent) …… 4 parts (white carbon: Shionogi Seiyaku Co., Ltd. trade name) To make wettable powder.

Formulation Example 3 Emulsion Compound No. 7 of the present invention 2 parts xylene 78 parts dimethylformamide 15 parts Sorpol 2680 5 parts (mixture of nonionic surfactant and anionic surfactant: Toho Kagaku) Brand name) The above is uniformly mixed to form an emulsion. At the time of use, the above emulsion is diluted 10 to 10,000 times and sprayed so that the amount of the active ingredient is 0.005 kg to 10 kg per hectare.

Formulation Example 4 Flowable compound of the present invention No. 7 ...... 25 parts Agrisol S-710 ...... 10 parts (Nonionic surfactant: Kao Atlas Co., Ltd. trade name) Lunox 1000C ...... 0.5 parts (Anionic surfactant : Toho Chemical Co., Ltd. product name) 1% Rhodopol water ...... 20 parts (Thickener: Lone Poulean Company product name) Water ...... 44.5 parts

Formulation Example 5 Granules Compound of the present invention No.8 …… 0.1 part Bentonite …… 55.0 parts Talc …… 44.9 parts After uniformly mixing and pulverizing the above, add a small amount of water and knead with stirring, kneading, extrusion molding Granulate with a granulator and dry to give granules.

Formulation Example 6 Granules Compound of the present invention No. 7 ...... 0.5 parts Bentonite ...... 55.0 parts Talc ...... 44.5 parts After uniformly mixing and crushing the above, add a small amount of water, knead with stirring, knead, extrusion molding Granulate with a granulator and dry to give granules.

Further, the compound of the present invention may be mixed and applied with other kinds of herbicides, various insecticides, fungicides, synergists and the like at the time of preparation or spraying, if necessary.

Examples of the above-mentioned other types of herbicides include, for example, Farm Chemicals. Handbook (Farm Chemicals Handbook) 7
Compounds described in Edition 0 (1984).

The compound of the present invention can be applied to the control of various weeds in non-agricultural fields such as fields, paddy fields, orchards in fields other than agricultural and horticultural fields such as orchards, and its application dosage is Although there are differences depending on the time of application, method of application, target grass species, cultivated crops, etc., it is generally appropriate that the amount of active ingredient is about 0.005 to 10 kg per hectare.

Next, the usefulness of the compound of the present invention as a herbicide will be specifically described in the following test examples.

Test Example-1 Herbicidal Effect Test by Soil Treatment Put sterilized diluvial soil in a plastic box having a length of 15 cm, a width of 22 cm, and a depth of 6 cm, and sowing rice, novier, crabgrass, cyperaceae, dogpea, dogwood, dogtail, and cotton together. After covering the soil with about 1.5 cm, it was uniformly sprayed on the soil surface so that the amount of the active ingredient was a predetermined ratio.

The chemical solution for spraying was prepared by diluting the wettable powder of the above formulation example with water and spraying it over the entire surface with a small spray. Four weeks after spraying the chemical solution, the herbicidal effect on rice and various weeds was investigated according to the following criteria.

The results are shown in Table 2.

Some of the compounds of this invention are selective for certain crops.

Judgment criteria 5: Herbicide rate 90% or more (almost complete death) 4 ... Herbicide rate 70-90% 3 ... Herbicide rate 40-70% 2 ... Herbicide rate 20-40% 1 ... Herbicide rate 5-20 % 0 …… grass-killing rate 5% or less (almost no effect) However, the above-mentioned herbicidal rate is calculated by the following formula by measuring the above-ground weed weight of the chemical treatment area and the above-ground weed weight of the untreated area It is a thing.

Test Example 2 Herbicidal effect test by foliar treatment 15 cm long, 22 cm wide, 6 cm deep in a plastic box containing sterilized diluvial soil, rice, cotton, novier, and cereal,
Approximately 1.
5 cm of soil was covered. When various plants reached the 2-3 leaf stage, the active ingredients were sprayed evenly on the foliage so that the amount of the active ingredient became a predetermined ratio.

The chemical solution for spraying was prepared by diluting the wettable powder of the above formulation example with water and spraying it over the entire surface of the foliage of various weeds with a small spray. Four weeks after spraying the chemical solution, the herbicidal effect on rice and various weeds was investigated according to the criteria of Test Example-1.

The results are shown in Table 3.

The control compound is the same as in Test Example-1.

Test Example 3 Herbicidal effect test under flooded condition After alluvial soil was placed in a 1/5000 ares Wagner pot, water was added to mix it to obtain a fresh water condition with a water depth of 2 cm. The seeds of the sea urchin, the Japanese eel, the azalea, the yellow cypress, and the firefly were mixed-sown in the above-mentioned pot, and further tubers of Urikawa, Mizugaya-tsuri, and Kurogui were placed. Furthermore, rice seedlings at the 2.5 leaf stage were transplanted. The next day, the drug diluted solution was dropped on the water surface with a measuring pipette so that a predetermined amount of the drug was obtained.

The herbicidal effect against various weeds was investigated 3 weeks after the drug was dropped according to the criteria of Test Example 1. The results are shown in Table 4.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Takashi Inoi, 1470 Shiraoka, Shirooka-cho, Minami-Saitama-gun, Saitama Nissan Biochemical Research Institute, Inc. Misao Takanashi, Examiner, Biochemistry Research Institute, Chemical Industry Co., Ltd. (56) Reference JP-A-59-1480 (JP, A) JP-A-58-219179 (JP, A)

Claims (4)

[Claims] 1. General formula (I): [In the formula, R ¹ and R ² represent a lower alkyl group. X and Y each independently represent a lower alkyl group or a lower alkoxy group, and Z represents a -CH = group. ] The pyrazole sulfonyl urea derivative represented by these. 2. General formula (II): [In the formula, R ¹ and R ² represent a lower alkyl group. ] The pyrazole sulfonyl isocyanate derivative represented by the following formula (III): [In the formula, X and Y each independently represent a lower alkyl group or a lower alkoxy group, and Z represents a -CH = group. ] The general formula (I) characterized by reacting with an aminopyrimidine derivative represented by: in an inert solvent: [In the formula, R ¹ and R ² represent a lower alkyl group. X and Y each independently represent a lower alkyl group or a lower alkoxy group, and Z represents a -CH = group. ] The manufacturing method of the pyrazole sulfonyl urea derivative represented by these. 3. General formula (IV): [In the formula, R ¹ and R ² represent a lower alkyl group. R ³ represents a lower alkyl group or a phenyl group. ] The pyrazole sulfonyl carbamate derivative represented by the following formula (III): [In the formula, X and Y each independently represent a lower alkyl group or a lower alkoxy group, and Z represents a -CH = group. ] The general formula (I) characterized by reacting with an aminopyrimidine derivative represented by: in an inert solvent: [In the formula, R ¹ and R ² represent a lower alkyl group. X and Y each independently represent a lower alkyl group or a lower alkoxy group, and Z represents a -CH = group. ] The manufacturing method of the pyrazole sulfonyl urea derivative represented by these. 4. General formula (I): [In the formula, R ¹ and R ² represent a lower alkyl group. X and Y each independently represent a lower alkyl group or a lower alkoxy group, and Z represents a -CH = group. ] The selective herbicide characterized by containing 1 type (s) or 2 or more types of the pyrazole sulfonyl urea derivative represented by these as an active ingredient.