JPH0434538B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to thiocarbamate derivatives and methods for producing the same. It has been well known that certain O-aryl N-arylthiocarbamate compounds have antibacterial and nematocidal effects as pharmaceuticals. It is also known that certain carbamate, thiol carbamate and dithiocarbamate compounds have herbicidal activity. Furthermore, JP-A-48-49925 discloses that certain aryl N-aryl carbamate compounds can be used as herbicides. Previously, the inventors have discovered that certain O-aryl N-arylthiocarbamate compounds can be used as effective herbicides. The present inventors further conducted intensive research to develop a compound having sufficient herbicidal effect and a high degree of selectivity among 0-aryl N-arylthiocarbamate derivatives, and as a result, the compound of the present invention was developed. The present invention was completed based on the discovery that this compound exhibits excellent herbicidal activity against various weeds. That is, the present invention provides general formula (): (In the formula, R ₁ and R ₂ each represent a halogen atom, a lower alkyl group, a lower alkoxy group, a lower alkenyloxy group, a lower alkynyloxy group, a lower alkylthio group, or a nitro group, and R ₃ represents a lower alkyl group, R ₄ and R ₅ each represent a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, or a trifluoromethyl group. _{R 1} and R ₂ and R ₄ and R ₅ are the same or different from each other. However, R ₁ and R ₂ are both lower alkyl groups, at least one of them is a lower alkyl group having 2 or more carbon atoms. It is. The compound of the present invention is a novel compound that has not been described in any literature, and its useful physiological activity is unknown. The herbicide containing the compound of the present invention as an active ingredient exhibits extremely excellent herbicidal activity against many weeds including field weed, especially in flooded rice fields, and is virtually harmless to transplanted paddy rice. , suitable as a herbicide for paddy fields. In addition, when treated with upland soil, it showed an excellent selective weeding effect between grass weeds and broad-leaved weeds, and was recognized to have applicability as a herbicide for upland. The compound of the present invention represented by the above general formula () can be produced according to the following reaction. (In the formula, R ₁ and R ₂ each represent a halogen atom, a lower alkyl group, a lower alkoxy group, a lower alkenyloxy group, a lower alkynyloxy group, a lower alkylthio group, or a nitro group, and R ₃ represents a lower alkyl group, R ₄ and R ₅ each represent a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, or a trifluoromethyl group. _{R 1} and R ₂ and R ₄ and R ₅ are the same or different from each other. However, R ₁ and R ₂ are both lower alkyl groups, at least one of them is a lower alkyl group having 2 or more carbon atoms.Hal represents a halogen atom.) The above reaction is carried out in the presence of a dehydrohalogenating agent,
Further, the reaction usually proceeds in the presence or absence of a reaction solvent at a reaction temperature of 0°C to 150°C, and the reaction time is about several minutes to 48 hours. Examples of dehydrohalogenation agents include alkali hydroxides such as sodium hydroxide and potassium hydroxide, alkaline earth hydroxides such as calcium hydroxide, and alkali carbonate salts such as sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate. , metal hydrides such as sodium hydride, and tertiary amines such as triethylamine, dimethylaniline, and pyridine. In reaction formula (2), the aniline derivative as a raw material can be used as a dehydrohalogenating agent. Reaction solvents include water, alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone and methyl ethyl ketone, aromatic hydrocarbons such as benzene, triene, and xylene, ethers such as ethyl ether, tetrahydrofuran, and dioxane, and chlorobenzene. , halogenated hydrocarbons such as chloroform, carbon tetrachloride, and dichloroethane, and polar solvents such as dimethylformamide and dimethyl sulfoxide. The chlorothioformate derivative as a raw material in reaction formula (2) can be obtained, for example, by reacting the corresponding phenol derivative with thiophosgene. Next, the method for producing the compound of the present invention will be specifically explained. Example 1 Method for producing O-4-ethyl-3-methylphenyl N-methyl-N-(3-methylphenyl)thiocarbamate (invention compound No. 1) N-methyl-N-(3-methylphenyl)thiocarbamoyl chloride 2.00g, 4-ethyl-3
- 1.36g of methylphere and anhydrous potassium carbonate
Add 1.38g to 50m of methyl ethyl ketone,
The mixture was heated to reflux for an hour. After the reaction mixture was cooled to room temperature, it was poured into cold water and the product was extracted with benzene. Wash the benzene solution with a 10% aqueous sodium hydroxide solution, water, and a saturated aqueous sodium chloride solution in that order.
After drying over anhydrous magnesium sulfate, benzene was distilled off under reduced pressure. The residue was subjected to column chromatography (silica gel, benzene/hexane = 1/
1 (V/V) development) to obtain O-4-ethyl-3-methylphenyl N-methyl-N-(3-
methylphenyl) thiocarbamate 2.25g (yield
75%). (Oil) Example 2 Method for producing O-4-chloro-3-methylphenyl N-methyl-N-(3-methylphenyl)thiocarbamate (invention compound No. 4) 29.5 g of 4-chloro-3-methylphenol and 25 g of thiophosgene was dissolved in 300 ml of chloroform, and 100 ml of 10% aqueous sodium hydroxide solution was added dropwise while stirring under ice cooling. After dropping, at room temperature
Stirring was continued for 12 hours. The chloroform layer was separated from the reaction solution, dried over anhydrous calcium chloride, and then chloroform was distilled off under reduced pressure. By distilling the residue under reduced pressure, O-4- with a boiling point of 104-106℃/5mmHg
36 g of chloro-3-methylphenyl chlorothioformate was obtained. Elemental analysis value (%) C H Analysis value 43.23 2.65 Calculated value 43.45 2.73 1.21 g of N-methyl-3-toluidine and 1.38 g of anhydrous potassium carbonate were added to 20 ml of acetone, and while stirring at room temperature, O-4-chloro- 2.21 g of 3-methylphenyl chlorothioformate was dissolved in 20 ml of acetone and added. After stirring as it was for 30 minutes, the mixture was heated under reflux for 2 hours. After the reaction mixture was cooled to room temperature, it was poured into cold water and the product was extracted with benzene. The benzene solution was washed with water and a saturated aqueous sodium chloride solution in that order, dried over anhydrous magnesium sulfate, and then benzene was distilled off under reduced pressure. The residue was purified by column chromatography (silica gel, developed with benzene/hexane = 1/1 (V/V)) to obtain O-4-chloro-3-methylphenyl N
-Methyl-N-(3-methylphenyl)thiocarbamate 2.11 g (yield 69%) was obtained. A part of this substance was recrystallized from hexane, with a melting point of 100.5 to 102℃.
Colorless crystals were obtained. Next, representative examples of the compounds of the present invention represented by the general formula () and their physical properties are shown in Table 1 below. The compounds of the present invention are not limited to the compounds of this specific example.

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[Table] The compound of the present invention exhibits excellent herbicidal activity against various weeds and does not cause any phytotoxicity to crops such as paddy rice, soybeans, and cotton, so it is suitable as an active ingredient of a herbicide. In other words, the action of the compound of the present invention is that it kills weeds, stops their growth, or significantly inhibits and retards their growth without causing chemical damage to crops, thereby eliminating growth competition with crops. There are many things that can be done. The compound of the present invention is particularly effective against many weeds such as wild grass, Japanese grasshopper, Japanese grasshopper, Japanese fireweed, and firefly, especially in flooded rice fields.
It was observed that an extremely excellent herbicidal activity was exhibited at an active ingredient amount of 500g/10a. On the other hand, it is extremely safe for young paddy rice seedlings, with no effects observed even at an active ingredient amount of 1000g/10a, and has extremely excellent properties as a herbicide for paddy fields. Furthermore, when the compound of the present invention is used as a soil treatment agent after sowing general broad-leaved crops such as soybeans, which are upland crops, it will not cause chemical damage to crops,
It was found that it can effectively control grass weeds such as grasshopper and foxtail grass, and has applicability as a herbicide for upland fields. Next, the herbicidal effects of the compounds of the present invention will be explained using usage examples. In use, "parts" are parts by weight. Usage example 1 Herbicidal effect test under flooded conditions 10 parts of each of the compounds of the present invention were used as a carrier material, 87.3 parts of Siegrite [trade name, manufactured by Kuniho Kogyo Co., Ltd.], and as a surfactant, Neopellex [trade name, Kao Atlas]
Co., Ltd.] 1.35 parts and Solpol 800A [trade name, Toho Chemical Industry Co., Ltd.] 1.35 parts mixed and crushed to 10%
A hydrating agent was obtained. Next, put paddy soil in a porcelain pot with a diameter of 9 cm, add water, and after puddling, weed seeds are sown on the soil surface layer, and two paddy rice seedlings (variety, Nipponbare) at the two-leaf stage are planted at a depth of 1 cm. I planted it. The next day, the pots were flooded with water to a depth of 2 cm, and a predetermined amount of the wettable powder of each compound of the present invention obtained as described above was diluted in 10 ml of water per pot and dropped onto the water surface. Thereafter, the plants were left in a greenhouse, and three weeks after the chemical solution treatment, the herbicidal effect and the effect on paddy rice were investigated. The evaluation was displayed on a 6-level scale, and the specific details are as follows. The results are shown in Tables 2 and 3. Indication Paddy rice chemical damage Weeding effect 5 Death 100% control (residual amount of weeds 0%) 4 Severe damage 80% control (residual amount of weeds 20%) 3 Medium damage 60% control (residual amount of weeds 40%) 2 Minor damage 40% control (60% amount of remaining grass) 1 Slight damage 20% control (80% amount of remaining grass) 0 No harm 0% control (100% amount of remaining grass)

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[Table] Usage Example 2 Weeding effect test by field soil surface treatment Field soil was put into a porcelain pot with a diameter of 12 cm, seeds of several types of plants were sown, and the pot was covered with 1 cm of soil. A predetermined amount of the hydrating powder of the herbicide of the present invention obtained as in Use Example 1 was diluted with 10 ml of water per pot and sprayed onto the soil surface, and then left standing in a greenhouse and watered at appropriate times. .
Three weeks after the chemical solution treatment, the herbicidal effect and the effect on soybeans and cotton were investigated and evaluated according to Use Example 1. The results are shown in Table 4.

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Claims (1)

[Claims] 1 General formula (): (In the formula, R ₁ and R ₂ each represent a halogen atom, a lower alkyl group, a lower alkoxy group, a lower alkenyloxy group, a lower alkynyloxy group, a lower alkylthio group, or a nitro group, and R ₃ represents a lower alkyl group, R ₄ and R ₅ each represent a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, or a trifluoromethyl group. _{R 1} and R ₂ and R ₄ and R ₅ are the same or different from each other. However, R ₁ and R ₂ are both lower alkyl groups, at least one of them shall be a lower alkyl group having 2 or more carbon atoms. 2 General formula (): (In the _{formula ,} R ₁ and R ₂ are the same or different from each other. However, if R ₁ and R ₂ are both lower alkyl groups, at least one of them shall be a lower alkyl group having 2 or more carbon atoms. General formula (): (In the formula, Y is a halotiocarbonyl group when X in the formula () is a hydrogen atom, and is a hydrogen atom when X in the formula () is a halothiocarbonyl group, R ₃ represents a lower alkyl group, and R ₄ and R ₅ each represent a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, or a trifluoromethyl group. _{R 4}
and R ₅ are the same or different from each other. ) General formula () characterized by reacting with an aniline derivative represented by: (In the formula, R ₁ and R ₂ each represent a halogen atom, a lower alkyl group, a lower alkoxy group, a lower alkenyloxy group, a lower alkynyloxy group, a lower alkylthio group, or a nitro group, and R ₃ represents a lower alkyl group, R ₄ and R ₅ each represent a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, or a trifluoromethyl group. _{R 1} and R ₂ and R ₅ and R ₁ are the same or different from each other. However, R ₁ and (If R ₂ is both a lower alkyl group, at least one of them is a lower alkyl group having 2 or more carbon atoms.) A method for producing a thiocarbamate derivative represented by: