JPS6234002B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a herbicide containing a carbamate derivative as an active ingredient. Conventionally, it is well known that aryl carbamate compounds have antibacterial properties as medicines, but it is not known that they can be used as effective herbicides. The present inventors have previously discovered that certain naphthyl carbamate derivatives have herbicidal activity, and have disclosed them in the specifications of Japanese Patent Application No. 56-30512, Japanese Patent Application No. 181043-1983, and Japanese Patent Application No. 40759-1987. was disclosed. The present inventors further conducted intensive research to develop a carbamate derivative with sufficient herbicidal effect and a high degree of selectivity.
The invention has been completed. That is, the present invention is based on the general formula (): (In the formula, m is 1 or 2, n is 0, 1 or 2
shows. However, when n is 0, a hydrogen atom is bonded to each of the two carbons to which -(CH ₂ ) _{o -} is bonded in place of -(CH ₂ ) o -. X represents a hydrogen atom or a sulfur atom, and R ₁ and R ₂ each represent a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, or a trifluoromethyl group, and may be the same or different. ) The present invention provides a herbicide containing a carbamate derivative represented by the following as an active ingredient. The herbicide containing the carbamate derivative 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 harmless to multi-planted 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 crops, and was recognized to have applicability as a herbicide for upland fields. The carbamate derivative represented by the general formula () used in the herbicide of the present invention can be produced according to the following reaction formula. (In the formula, m is 1 or 2, n is 0, 1 or 2
shows. However, when n is 0, hydrogen is bonded to each of the two carbons to which -(CH ₂ ) _o - is bonded, instead of -(CH ₂ ) _o -. X represents an oxygen atom or a sulfur atom, and R ₁ and R ₂ each represent a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, or a trifluoromethyl group, and are the same or different. Hal indicates 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 carbonates such as sodium carbonate, potassium carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate. , 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, toluene, and xylene, ethers such as ethyl ether, tetrahydrofuran, and dioxane, and chlorine. Halogenated hydrocarbons such as benzene, chloroform, carbon tetrachloride and dichloroethane, polar solvents such as dimethylformamide and dimethyl sulfoxide, and the like are used. Next, a method for producing the active ingredient compound used in the herbicide of the present invention will be specifically explained. Synthesis Example 1 Method for producing 5-indanyl N-methyl-N-(3-methylphenyl)carbamate (compound No.
3) 1.84 g of N-methyl-N-(3-methylphenyl)carbamoyl chloride, 5-indanol
1.34 g and 1.38 g of anhydrous potassium carbonate were added to 50 ml of methyl ethyl ketone and heated under reflux for 15 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) to obtain 5-indanyl N-methyl-
N-(3-methylphenyl)carbamate 1.97g
(yield 70%). A part of this product was recrystallized from n-hexane to obtain colorless crystals with a melting point of 73.5 to 75°C. Synthesis Example 2 Method for producing O-5.6.7.8-tetrahydro-2-naphthyl N-methyl-N-phenylthiocarbamate (Compound No. 16) 1.07 g of N-methylaniline and 1.38 g of anhydrous potassium carbonate were added. O-5,6,7,8-tetrahydro-2 was added to 20 ml of acetone and stirred at room temperature.
- 2.27 g of naphthyl 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 subjected to column chromatography (silica gel,
Hexane/benzene = 3/7 (V/V) development) to purify O-5.6.7.8-tetrahydro-2
-Naphthyl N-methyl-N-phenylthiocarbamate 2.53 g (yield 85%) was obtained. A part of this product was recrystallized from ethanol to obtain colorless crystals with a melting point of 79-80°C. Table 1 shows typical examples of active ingredient compounds used in the herbicide of the present invention.

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[Table] The herbicide of the present invention can be prepared by mixing an appropriate amount of one or more compounds represented by the above general formula () with an inert carrier, and preparing a wettable powder, which is a conventional concentrated drug form.
It is used in the form of emulsions, granules, etc. Examples of solid carriers include talc, clay, diatomaceous earth, bentonite, etc., and examples of liquid carriers include water, alcohol, benzene, kerosene, cyclohexane, cyclohexanone, dimethylformamide, mineral oil, and the like. Furthermore, surfactants and stabilizers may be added if necessary for formulation. In addition, the herbicide of the present invention may be used in combination with other agricultural chemicals used in the same field, such as insecticides, fungicides, herbicides,
Can be applied in combination with growth regulators or fertilizers. In particular, it may be appropriate to add and mix other herbicides in order to reduce the spraying effort or to widen the range of grass species that can be effectively controlled. Examples of herbicides that can be added include triazine herbicides such as atrazine, simazine, cymetrin, and promethrin, carbamate herbicides such as asylum, bentiocarb, and molinate, urea herbicides such as Linuron and Daimeron, 2,4-D, and MCP. ,
Phenoxy herbicides such as MCPB and nabroanilide, diphenyl ether herbicides such as nitrophene, chlornitrophene, and chromethoxynil, heterocyclic herbicides such as oxadiazone, pyrazolate, and bentazone, and amide herbicides such as alachlor, butachlor, and propanil. Agents, etc. can be given. By judiciously combining one or more of these herbicides, it is possible to provide mixtures that are effective against many grass species. Next, formulation examples of the herbicide of the present invention will be described. In the formulation examples, "parts" are parts by weight. Formulation Example 1 (Water Powder) Compound No. 1, 10 parts as a carrier material, 87.3 parts of Siegrite [trade name, manufactured by Kuniho Kogyo Co., Ltd.], and as a surfactant, Neopellex [trade name, manufactured by Kao Atlas Co., Ltd.]
[manufactured by Toho Chemical Industry Co., Ltd.] 1.35 parts and Solbol 800A [trade name, manufactured by Toho Chemical Industry Co., Ltd.] 1.35 parts mixed and crushed to 10%
A hydrating agent was obtained. Formulation example 2 (emulsion) Compound No. 16, 25 parts mixed and dissolved with 65 parts of benzene and 10 parts of Sorbol 800A as a surfactant to give a 25%
An emulsion was obtained. Formulation Example 3 (Granules) After mixing and pulverizing 10 parts of Compound No. 66 with 50 parts of bentonite, 35 parts of Kunilite [trade name, manufactured by Kuniho Kogyo Co., Ltd.] and 5 parts of Solpol 800A as a surfactant, 10 parts of water was mixed and ground. 0.7 mm in diameter and stir evenly.
After extrusion through the sieve holes and drying, the mixture was cut into 1-2 mm lengths to obtain 10% granules. The herbicide of the present invention exhibits excellent herbicidal activity against various weeds and does not cause chemical damage to crops such as paddy rice, soybeans, and cotton, and is thus suitable as an active ingredient of a herbicide. In other words, the herbicide of the present invention eliminates growth competition with crops by killing weeds, stopping their growth, or significantly inhibiting and delaying their growth without causing chemical damage to crops. There are things that can be done. The amount of the herbicide of the present invention to be applied varies depending on the application situation, application time, application method, target grass species, etc., but generally the amount of active ingredient is 10 to 1000 g/10a, preferably
A range of 50 to 500 g/10a is suitable. The herbicide of the present invention exhibits extremely excellent herbicidal activity against many weeds such as field weed, Japanese grasshopper, Japanese cypress, Japanese grass weed, and firefly, especially in flooded paddy fields, with an active ingredient amount of 50 to 500 g/10a. was recognized. 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. In particular, it exhibits excellent herbicidal activity against grasshoppers (2- to 3-leaf stage) during the growing season, and is characterized by an extremely wide range of application times. In other words, it was shown to be highly applicable as a soil treatment agent in the early to mid-stage of transplanted rice cultivation, and as a soil treatment agent immediately after flooding in dry field direct-seeded rice cultivation. Furthermore, when the herbicide 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 the crops and will reduce the
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 effect of the herbicide of the present invention will be explained using test examples. Test example 1 Weeding effect test under flooded conditions (1) Paddy soil was placed in a porcelain pot with a diameter of 9 cm, water was added, and weed seeds were sown on the soil surface.
Paddy rice seedlings (variety, Nipponbare) in the leaf stage are planted at a depth of 1 cm.
Two plants were planted. The next day, the pot was flooded with water to a depth of 2 cm, and the prescribed dose of the hydrating powder of each herbicide of the present invention was added to the pot at 10 ml per pot.
It was diluted in 1 ml of water and dropped onto the water surface. after that,
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 Table 2. Display Paddy rice chemical damage Weeding effect 5 Death: 100% control (residual weed amount 0%) 4 Severe damage: 80% control (residual weed amount 20%) 3 Moderate damage: 60% control (remaining weed amount: 40%) 2 Minor damage: 40% control ( 1 Slight damage 20% control (80% residual grass amount) 0 Harmless 0% control (100% residual grass amount)

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[Table] Test Example 2 Weeding effect test under flooded conditions (2) Paddy soil was placed in a porcelain pot with a diameter of 9 cm, water was added, and after plowing, wild grass seeds were sown on the surface layer of the soil.
Two paddy rice seedlings (variety: Nipponbare) at the two-leaf stage were planted at a depth of 1 cm. The next day, the pots were flooded with water to a depth of 2 cm, and before the germination of wild plants and at the 2-leaf stage (10 days after sowing), a predetermined amount of a wettable powder of the herbicide of the present invention was diluted in 10 ml of water per pot and dropped onto the water surface. An investigation was conducted 3 weeks after the chemical solution treatment, and evaluation was made according to Test Example 1. The results are shown in Table 3.

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[Table] Test Example 3 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 was diluted in 10 ml of water per pot, which was sprayed onto the soil surface, and then left to stand 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 Test Example 1. The results are shown in Table 4.

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Claims (1)

[Claims] 1 General formula (): (In the formula, m is 1 or 2, n is 0, 1 or 2
shows. However, when n is 0, a hydrogen atom is bonded to each of the two carbons to which -( _CH2 )n- is bonded in place of -( _CH2 )n-. X represents an oxygen atom or a sulfur atom, R ₁ and R ₂ each represent a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group or a trifluoromethyl group,
Same or different from each other. ) A herbicide characterized by containing a carbamate derivative represented by the following as an active ingredient.