JPS6237035B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a carbamate derivative, a method for producing the same, and a herbicide containing the compound as an active ingredient. It has been well known that certain O-aryl N-arylthiocarbamate compounds have antibacterial and nematocidal effects as medicines. It is also known that certain aryl N-aryl carbamate compounds can be used as herbicides. The present inventors previously discovered that a new compound, an N-pyridyl carbamate derivative, has herbicidal activity. The present inventors further completed the present invention as a result of intensive research to develop a compound having a sufficient herbicidal effect and a high degree of selectivity using N-pyridyl carbamate derivatives. That is, the present invention is based on the general formula () (In the formula, m represents 1 or 2, and n represents 0, 1 or 2.
, X represents an oxygen atom or a sulfur atom, R represents a hydrogen atom, a halogen atom or a lower alkyl group, and l represents 1 or 2. However, if n is 0,
-(CH ₂ ) _o - is bonded to two carbons -
(CH ₂ ) In place of _o −, a hydrogen atom is bonded to each. ) (hereinafter referred to as the compound of the present invention), a method for producing the same, and a herbicide containing the compound of the present invention as an active ingredient. 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 harmless to transplanted paddy rice. Suitable as a herbicide. In addition, it showed excellent selective weeding effect among grasses and broad-leaved crops when treated with upland soil, and was recognized to have applicability as a herbicide for upland fields. The carbamate derivative represented by the general formula () of the present invention can be produced according to the following reaction formula. (In the formula, m represents 1 or 2, and n represents 0, 1 or 2.
, X represents an oxygen atom or a sulfur atom, R represents a hydrogen atom, a halogen atom or a lower alkyl group, l represents 1 or 2, and Hal represents a halogen atom. However, when n is 0, a hydrogen atom is bonded to each of the two carbons to which -(CH ₂ ) _{o -} is bonded, instead of -(CH ₂ ) o -. ) 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 2-methylaminopyridine derivative as a raw material can be used as a dehydrohalogenating agent. As a reaction solvent, water and 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, toterahydrofuran, and dioxane, halogenated hydrocarbons such as chlorobenzene, chloroform, carbon tetrachloride, and dichloroethane, and polar media such as dimethylformamide and dimethyl sulfoxide are used. Next, the present invention will be explained in more detail with reference to Examples. The carbamoyl halide derivative used in the reaction formula (1) can be easily obtained, for example, by reacting the corresponding 2-methylaminopyridine derivative with phosgene, thiophosgene or trichloromethyl chloroformate. The above-mentioned 2-methylaminopyridine derivative is also used in the reaction formula (2). These 2-
Methylaminopyridine derivatives are produced by various reactions, but are advantageously obtained by heating and stirring 2-halopyridine derivatives such as 2-chloropyridine derivatives and 2-bromopyridine derivatives and methylamine in an autoclave. . Reference example 2.6 in a 200ml electromagnetic stirring autoclave
25 g of -dichloropyridine and 60 ml of a 40% aqueous methylamine solution were taken and reacted at 120°C for 5 hours. After the reaction was completed, the autoclave was cooled, the contents were taken out, and the solids were collected by filtration. Next, this solid was recrystallized from n-hexane to give a melting point of 63.5 to 64.5.
2-chloro-6-methylaminopyridine 22.7 °C
I got g. Elemental analysis value (%) Actual value C: 50.41 H: 4.99 N: 19.73 Calculated value C: 50.54 H: 4.95 N: 19.64 15 g of trichloromethyl chloroformate
Dissolve in 200ml of benzene and add 2-chloro-
A solution of 14.25 g of 6-methylaminopyridine dissolved in 100 ml of benzene was added dropwise at 10°C with stirring. After the reaction mixture was heated under reflux for one day and night, benzene was distilled off under reduced pressure. The resulting residue was purified by column chromatography (silica gel, developed with benzene) and further recrystallized from hexane to give N-(6-chloro-2-pyridyl)-N-methyl with a melting point of 41-42°C. Carbamoyl chloride 19.5
I got g. Elemental analysis value (%) Actual value C: 40.79 H: 3.11 N: 13.29 Calculated value C: 41.00 H: 2.94 N: 13.66 Example 1 5, 6, 7, 8-tetrahydro-2-naphthyl N-(6-chlor -2-pyridyl)-N-methylcarbamate manufacturing method (Compound No. 4) N-(6-chloro-2pyridyl)-N-methylcarbamoyl chloride 2.05g, 5.6.7.8-
1.4 g of tetrahydro-2-naphthol and 1.38 g of anhydrous potassium carbonate were added to 50 ml of methyl ethyl ketone, and the mixture was 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 subjected to column chromatography (silica gel,
benzene development) to give 5,6,7,8-tetrahydro-2-naphthyl N-(6-chloro-2
-pyridyl)-N-methylcarbamate 2.55g
(yield 81%). A part of this product was recrystallized from benzene-n-hexane to obtain colorless crystals with a melting point of 70-71°C. Example 2 0-5-indanyl N-methyl-N-(6-
Method for producing methyl-2-pyridyl)thiocarbamate (Compound No. 9) 2-methyl-6-methylaminopyridine 1.22g
and 1.38 g of anhydrous potassium carbonate were added to 20 ml of acetone, and while stirring at room temperature, 2.13 g of 0-5-indanyl chlorothioformate was added to 20 ml of acetone.
It was dissolved in and added. After stirring for 30 minutes,
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. 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 ethyl acetate/benzene = 1/9 (V/V)) to obtain 0-5-indanyl N-methyl-N-(6-
Methyl-2-pyridyl)thiocarbamate 2.68g
(yield 90%). A part of this product was recrystallized from ethanol to obtain colorless crystals with a melting point of 140-141°C. Next, representative examples of the compounds represented by the general formula () and their physical properties are shown in Table 1 below.

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[Table] To use the compound of the present invention as a herbicide, an appropriate amount of one or more compounds represented by the above general formula () is mixed with an inert carrier, and the compound is hydrated, which is the usual form of agricultural chemical use. Used in the form of tablets, 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. Furthermore, the herbicide of the present invention can be applied in combination with other agricultural chemicals used in the same field, such as insecticides, fungicides, herbicides, 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; covermate herbicides such as asylum, bentiocarb, and molinate; urea herbicides such as Linuron and Daimeron; MCP,
Phenoxy herbicides such as MCPB and naproanilide, diphenyl ether herbicides such as nitrophene, chlornitrophenone, and chromethoxyl, heterocyclic herbicides such as oxadiazone, pyrazolate, and bentazone, and amides such as alachlor, butachlor, and propanil. Examples include herbicides. By skillfully combining one or more of these herbicides, it is possible to provide a mixture that is effective against many grass species. Next, examples of formulations using the compounds of the present invention will be described. In the formulation examples, "part" indicates an important part. Example 3 (Wettable powder) Compound No. 1 of the present invention, 10 parts as a carrier material, 87.3 parts of Zeekrite [trade name, manufactured by Kunimine Kogyo Co., Ltd.], and as a surfactant, Neopex [trade name, Kao Atlas Co., Ltd.] )] 1.35 parts and Solpol 800A [product name,
Mixed and crushed with 1.35 parts of Toho Chemical Industry Co., Ltd.
% hydration agent was obtained. Example 4 (Emulsion) 25 parts of Compound No. 5 of the present invention were mixed and dissolved with 65 parts of benzene and 10 parts of Solpol 800A as a surfactant to obtain a 25% emulsion. Example 5 (Granules) Compound No. 10 of the present invention, 10 parts, bentonite 50 parts,
After mixing and pulverizing 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 added and stirred uniformly.
After extrusion through a 0.7 mm sieve hole and drying, the mixture was cut into 1 to 2 mm lengths to obtain 10% granules. 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, and is therefore suitable as an active ingredient in herbicides. 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 preventing crops from losing competitive growth. One example is to make it possible. The amount of the compound 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 compound of the present invention can be used particularly in flooded paddy fields.
Including wild wildflowers, Japanese cypresses, Japanese cypresses,
50 against many weeds such as Kikashigusa and Firefly
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 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 even against grasshoppers during the growing season (1-2 leaf stage), 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 paddy rice cultivation, and as a soil treatment agent immediately after flooding in dry field direct-seeded rice cultivation. 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 Examples. Example 6 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 after plowing, 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.
The value of 2 shares was set as 2 shares. The next day, the pot was filled with water to a depth of 2 cm, and 10 ml of the prescribed dose of the hydrating agent of each compound of the present invention was added to each pot.
It was diluted with water 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 Table 2. Display Paddy rice chemical damage Weeding effect 5 Death: 100% control (residual amount: 0%) 4: Severe damage: 80% control (residual amount: 0%) 3: Medium damage: 60% control (remaining amount: 40%) 2: Minor damage: 40% control ( 60% amount of remaining grass) 1 Slight damage 20% control (80% amount of remaining grass) 0 Harmless 0% control (100% amount of remaining grass)

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[Table] Example 7 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 of the soil.
2nd stage paddy rice seedlings (variety, Nipponbare) are planted at a depth of 1cm.
Two plants were planted. The next day, the pots were flooded with 2 cm of water, and before the germination of the wild grass and at the 1.2 leaf stage (7 days after sowing), a predetermined amount of the wettable powder of the compound 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 Example 6. The results are shown in Table 3.

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[Table] Example 8 Weeding effect test by surface treatment of field soil Field soil was placed in 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 dose of a hydrating powder of the compound of the present invention was diluted in 10 ml of water per pot and sprayed onto the surface of the pot, and then allowed to stand at room temperature 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 Example 6. The result is the fourth
Shown in the table.

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Claims (1)

[Claims] 1 General formula (): (In the formula, m represents 1 or 2, and n represents 0, 1 or 2.
, X represents an oxygen atom or a sulfur atom, R represents a hydrogen atom, a halogen atom or a lower alkyl group, and l represents 1 or 2. However, if n is 0,
-(CH ₂ ) _o - is bonded to two carbons -
(CH ₂ ) In place of _o −, a hydrogen atom is bonded to each. ) Carbamate derivatives represented by 2 General formula () (In the formula, Y is a hydrogen atom, a halocarbonyl group, or a halothiocarbonyl group, m is 1 or 2, and n is 0, 1, or 2. However, when n is 0, -
(CH ₂ ) _o The two carbons to which - is bonded are -
(CH ₂ ) In place of _o −, a hydrogen atom is bonded to each. ) The phenol derivative represented by the general formula () (In the formula, Z is a halocarbonyl group or a halothiocarbonyl group when Y in the formula () is a hydrogen atom, and is a hydrogen atom when Y in the formula () is a halocarbonyl group or a halothiocarbonyl group.R is a hydrogen atom) atom, halogen atom or lower alkyl group, l
indicates 1 or 2. General formula () characterized by reacting with an aminopyridine derivative represented by (In the formula, m represents 1 or 2, n represents 0, 1 or 2, X represents an oxygen atom or a sulfur atom, R represents a hydrogen atom, a halogen atom or a lower alkyl group,
l represents 1 or 2. However, if n is 0, -
(CH ₂ ) _o - is bonded to two carbons -
(CH ₂ ) In place of _o −, a hydrogen atom is bonded to each. ) A method for producing a carbamate derivative represented by 3 General formula () (In the formula, m represents 1 or 2, and n represents 0, 1 or 2.
, X represents an oxygen atom or a sulfur atom, R represents a hydrogen atom, a halogen atom or a lower alkyl group, and l represents 1 or 2. However, if n is 0,
-(CH ₂ ) _o - is bonded to two carbons -
(CH ₂ ) In place of _o −, a hydrogen atom is bonded to each. A herbicide characterized by containing a carbamate derivative represented by ) as an active ingredient.