JPH0745457B2 - Novel urea or thiourea derivative, process for producing the same and herbicide containing the same - Google Patents

Description

The present invention relates to a novel urea (or thiourea) derivative, a method for producing the same, and a herbicide containing the same as an active ingredient.

Many α, α-dimethylbenzylurea derivatives are already known. For example, Japanese Patent Publication No. 48-35454 discloses a general formula (Wherein, X and Y represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group, a halogen atom or a trifluoromethyl group), and the 3- (2-phenylisopropyl) -urea derivative is represented by Mizuta. It is described that the herbicide is effective as a weed herbicide. Japanese Patent Publication No. 57-29443 discloses N- (α, α-dimethylbenzyl) -N'-.
Methyl-N'-phenylurea is described as being used as a lawn growth regulator. But so far 1
N-alkyl-N in which the N atom at position is substituted with an alkyl group
There is no report on the herbicidal activity of the-(α, α-dimethylbenzyl) -N'-phenylurea (or thiourea) derivative.

The inventors of the present invention attempted to create a new herbicide while trying various modifications on the compounds of this system, and as a result, N-alkyl-N- (αα-dimethylbenzyl) -N′-phenylurea (or thiourea) was obtained. Derivatives exhibit strong herbicidal action and growth inhibitory action against weeds competing with useful plants in paddy field and upland field, excellent residual effect, and low toxicity to human livestock and fish. It was found that it brings various improvement effects.

The present invention has the general formula (In the formula, X and Y are hydrogen atom, methyl group or halogen atom, Z is oxygen atom or sulfur atom, R is a target alkyl group, n
Represents 1 or 2) N-alkyl-N-
It is an (α, α-dimethylbenzyl) -N′-phenylurea (or thiourea) derivative.

The present invention is a herbicide which further contains a compound of formula I as an active ingredient.

The compound of formula I has excellent intergeneric selectivity for Gramineae plants by the treatment of flooded soil before germination of paddy field weeds and the treatment of flooded soil during the growing season, and shows little harm to rice, It exhibits excellent herbicidal action and growth inhibitory action against weeds such as Nobie, Tamagawai and Firefly. In addition, the present compound is an excellent weeding agent for field germination, post-emergence soil and post-emergence foliar treatments against grass weeds such as the field weeds such as cedargrass, purslane, Amaranthus chinensis, Shiroza, chickweed and annual broadleaf weeds. Shows activity. Furthermore, the present compound exhibits extremely strong herbicidal activity against weeds in paddy fields and upland fields at low doses as compared with known compounds, as shown in the following herbicidal effect test examples.

The compound of formula I has the general formula (Wherein X and R have the above-mentioned meanings), and the N-alkyl-N-α, α-dimethylbenzylamine derivative represented by the general formula It can be produced by reacting with a phenyliso (thio) cyanate derivative represented by the formula (wherein Y, Z and n have the above-mentioned meanings).

This reaction is preferably carried out in a solvent, if necessary, with the addition of a catalytic amount of a reaction aid. Examples of the solvent include aliphatic hydrocarbons such as n-heptane, n-hexane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, ethers such as diethyl ether and tetrahydrofuran, esters such as ethyl acetate, and acetone. Inert solvents such as ketones such as methyl ethyl ketone, halogenated hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride are used. As a reaction aid, trimethylamine,
Tertiary amines such as pyridine, 4-dimethylaminopyridine and N, N-dimethylaniline are preferred.

In the reaction, it is preferable to use the compounds of the formulas II and III in an equimolar ratio. The reaction temperature is 0 ° C to the reflux temperature of the solvent, preferably 20 to 40 ° C, and the reaction is generally completed in 1 to 10 hours.

The product can be isolated and purified by filtration, recrystallization, column chromatography and the like. As a solvent for recrystallization and column chromatography, for example, benzene, toluene, methyl alcohol, ethyl alcohol, chloroform, n-hexane, ethyl acetate, or a mixed solvent thereof is used.

In the herbicides of the present invention, the compound of the formula I can be used as it is, but it is usually mixed with an inert solid carrier or a liquid carrier, and optionally with an auxiliary agent by a conventional method, for example, a wettable powder, an emulsion, It is used after being formulated into granules and powders. Other appropriate additives, fertilizers, pesticides such as herbicides, insecticides,
A germicide or the like may be added. Examples of the solid carrier include clay, talc, kaolin, bentonite, diatomaceous earth,
Examples of the calcium carbonate and the like or a mixture thereof and the liquid carrier include benzene, xylene, kerosene, alcohol, dimethylformamide and the like or a mixture thereof. In addition, as an auxiliary agent for improving properties such as dispersion, suspension, wetting, emulsification, and adhesion of a drug, a surfactant,
For example, polymer compounds such as sodium lauryl sulfate, alkyldimethylbenzylammonium chloride, polyoxyethylene alkylaryl ether, polyoxyethylene fatty acid ester, and alkyldimethyl betaine.
For example, polyvinyl alcohol, sodium alginate, etc. can be used.

The herbicidal formulation of the present invention generally contains the active ingredient in a weight ratio of 0.5-9.
5%, preferably 1 to 90%. The content of the active ingredient varies depending on the dosage form. For example, 1 to 15% in the case of granules and powders, 10 to 80% in the case of wettable powders, and 1 to 50% in the case of emulsions. Is preferred.

The amount of the herbicide of the present invention is the dosage form, weather conditions, time of use,
It depends on the soil conditions, the type of target weeds, etc., but normally 0.5 to 50 g, preferably 1 as the active ingredient amount per are
~ 30g.

Synthesis Example 1 (Compound No. 2) N-methyl-α, α-dimethylbenzylamine 1.00 g
(6.71 mmol) was added to 10 ml of hexane in a 50 ml eggplant-shaped flask and stirred at room temperature (about 23 ° C.) using a magnetic stir bar. 0.89 g (6.69 mmol) of m-methylphenyl isocyanate was added dropwise to this solution using a dropping funnel. After completion of the dropwise addition, the mixture was stirred at room temperature for 2 hours, and the precipitated crystals were recrystallized from a mixed solvent of n-hexane and ethyl acetate to give N-methyl-N- (α, α-dimethylbenzyl)-
Colorless plate crystals of N '-(m-methylphenyl) urea 1.56
g was obtained. Yield: 82.5%, melting point: 91.5-93.0 ° C.

Synthesis Example 2 (Compound No. 11) 1.00 g (5.45 mmol) of N-methyl-p-chloro-α, α-dimethylbenzylamine was placed in a 50 ml eggplant-shaped flask, 10 ml of hexane was added, and the mixture was magnetized at room temperature (about 23 ° C.). It stirred using the stirrer. 0.83 g (5.41 mmol) of p-chlorophenyl isocyanate was added dropwise to this solution using a dropping funnel. After completion of the dropwise addition, the mixture was stirred at room temperature for 2 hours, and the precipitated crystals were recrystallized from a mixed solvent of n-hexane and chloroform to give N-methyl-N- (p-chloro-α, α.
-Dimethylbenzyl) -N '-(p-chlorophenyl)
1.54 g of colorless fluffy crystals of urea were obtained. Yield: 82.1%, melting point: 168.5-169.5 ° C.

Synthesis Example 3 (Compound No. 32) N-ethyl-α, α-dimethylbenzylamine 0.82 g
(5.03 mmol) was placed in a 50 ml eggplant-shaped flask, 7 ml of hexane and a catalytic amount of triethylamine were added, and the mixture was stirred at room temperature (about 23 ° C.) using a magnetic stir bar. 0.83 g (5.41 mmol) of p-chlorophenyl isocyanate was added dropwise to this solution using a dropping funnel. After completion of the dropwise addition, the mixture was stirred at room temperature for 2 hours, and the precipitated crystals were recrystallized from a mixed solvent of n-hexane and ethyl acetate to give N-ethyl-N-
1.25 g of colorless needle crystals of (α, α-dimethylbenzyl) -N'-phenylurea were obtained. Yield: 89.4%, melting point: 66.
0 to 69.0 ° C.

Similarly, the compounds shown in Table 1 are obtained.

Formulation Example 1 Granules 5 parts of the compound of the present invention (No. 2), 3 parts of sodium dodecylbenzene sulfonate, 2 parts of sodium lauryl sulfate, 70 parts of bentonite and 20 parts of talc are well pulverized and mixed, and an appropriate amount of water is added. Knead well, granulate through a granulator, dry and size to obtain granules.

Formulation Example 2 Emulsion 20 parts of the compound (No. 13) of the present invention, 10 parts of polyoxyethylene alkylaryl ether and 70 parts of xylene are mixed well to obtain an emulsion.

Formulation Example 3 Wettable powder 50 parts of the compound (No. 27) of the present invention, 2 parts of sodium dodecylbenzenesulfonate, 2 parts of sodium ligninsulfonate and 46 parts of diatomaceous earth are pulverized and mixed to obtain a wettable powder.

Test Example 1 A pot of 1/5000 are was filled with paddy field soil, paddy rice at the two-leaf stage was transplanted, and seeds of Novier, Magnolia vulgaris and Firefly were sowed, and the water was flooded to a depth of 3 cm. On the third day after germination of the weeds, the flooded soil was treated with a predetermined amount of the wettable powder produced according to Formulation Example 3. Three weeks after the chemical treatment, the degree of phytotoxicity and herbicidal effect on the paddy rice and each weed was observed. The results are shown in Table 2.

For comparison, N- (α, α-dimethylbenzyl) -N ′-(p-tolyl) urea (Compound A) and N- (α, α-dimethylbenzyl) -N′-methyl represented by the following formula -N'-phenylurea (Compound B) was used.

Test Example 2 1/1000 ares pot was filled with upland soil, seeds of various weeds were sown, and after covering with soil, the wettable powder produced according to Formulation Example 3 was diluted with water and a predetermined amount was hand sprayed. It was sprayed on the soil surface and grown in a glass room with an average temperature of 25 ° C. On the 20th day after the treatment, the degree of herbicidal effect was observed for the remaining weeds. The results are shown in Table 3. Compounds A and B were used for comparison.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuya Yano 173-2 Hiroshi Otomitake, Nagano City, Nagano Prefecture Yasu Chemical Industry Co., Ltd.

Claims (3)

[Claims] 1. A general formula (In the formula, X and Y are a hydrogen atom, a methyl group or a halogen atom, Z is an oxygen atom or a sulfur atom, R is a lower alkyl group,
n represents 1 or 2) represented by N-alkyl-N-
(Α, α-Dimethylbenzyl) -N′-phenylurea (or thiourea) derivative. 2. General formula (Wherein X and R have the meanings given below), the N-alkyl-N-α, α-dimethylbenzylamine derivative represented by the general formula (Wherein Y, Z and n have the meanings given below), and the reaction is carried out with a phenyl isocyanate derivative. (In the formula, X and Y are a hydrogen atom, a methyl group or a halogen atom, Z is an oxygen atom or a sulfur atom, R is a lower alkyl group,
n represents 1 or 2) represented by N-alkyl-N-
Process for producing (α, α-dimethylbenzyl) -N′-phenylurea (or thiourea) derivative. 3. General formula (In the formula, X and Y are a hydrogen atom, a methyl group or a halogen atom, Z is an oxygen atom or a sulfur atom, R is a lower alkyl group,
n represents 1 or 2) represented by N-alkyl-N-
A herbicide containing a (α, α-dimethylbenzyl) -N′-phenylurea (or thiourea) derivative as an active ingredient.