JPH1045754A - 1,2,4-triazole derivative and herbicide containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a herbicide having a high herbicidal activity at a low dose and safe to farm products, containing the subject compound having herbicidal effect and selectivity on crops as active ingredient. SOLUTION: This compound is an 1,2,4-triazole derivative of formula I (R<1> and R<4> are each methyl or ethyl; R<2> and R<3> are each a halogen or lower alkyl; R<5> is monofluoromethyl or difluoromethyl; Y is S or O), e.g. 4-(4,7-dichloro-2- methylbenzofuran-5-yl)-3-difluoromethyl-1-methyl-1,2,4-triazole-5(1H)- thione. The compound of formula I is obtained by reaction of a (thio)semicarbazine compound of formula II with an ethyl (thio)fluoroacetate of the formula R<5> COOR<6> (R<6> is a lower alkyl) in the presence of a base at about 0.1-3 molar times the compound of formula II under heating in order to shortening normal reaction time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a 1,2,4-triazole derivative and a herbicide containing the derivative as an active ingredient.

[0002]

BACKGROUND OF THE INVENTION To date, many herbicidally active compounds have been found, some of which are widely used for weed control in agricultural crops. U.S. Pat. No. 5,108,486 discloses that certain 4-phenyl-1,2,4-triazole derivatives have herbicidal activity.

[0003] Japanese Patent Application Laid-Open No. Hei 8-20583 discloses that
General formula

[0004]

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[Wherein R ^A and R ^B are the same or different and each represent a hydrogen atom or a lower alkyl group. R ^C represents a lower alkyl group. X represents an oxygen atom or a sulfur atom. ) Wherein the 3-position of the triazole ring is a trifluoromethyl group.

[0006]

Based on the above background, the present inventors have continued to study in detail the herbicidal effect and selectivity of various 4-aryl-1,2,4-triazole derivatives on crops. Have been. As a result, the following general formula (1)
The novel 1,2,4-triazole derivative represented by formula (1) has excellent herbicidal activity at a low dose and is extremely safe not only for rice but also for crops such as soybean, wheat, radish, buckwheat and lawns. High selectivity. The present invention has been completed based on such findings.

[0007]

That is, the present invention provides a compound represented by the following general formula:

[0008]

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[In the formula, R ¹ represents a methyl group or an ethyl group. R ² and R ³ are the same or different and represent a halogen atom or a lower alkyl group. R ⁴ represents a methyl group or an ethyl group. R ⁵ represents a monofluoromethyl group or a difluoromethyl group. Y represents a sulfur atom or an oxygen atom. And a herbicide containing the derivative as an active ingredient.

In the present invention, 1, 1 represented by the above general formula (1)
Since the 2,4-triazole derivative has a lower molecular weight monofluoromethyl group or difluoromethyl group at the 3-position of the triazole ring, its safety, selectivity to a specific plant, simplification of the industrial production process, ease of preparation, etc. It is a compound that is expected to have advantages.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The compounds of the present invention represented by the above general formula (1) include the following compounds.

A compound of the general formula (1) wherein R ¹ is a methyl group, R ² and R ³ are both a halogen atom, and R ⁵ is a fluoromethyl group or a difluoromethyl group; R ¹ is a methyl group, R ² and R ³ Are both lower alkyl groups, and R ⁵ is a fluoromethyl group or a difluoromethyl group; a compound of the general formula (1);
A compound of the general formula (1) wherein R ¹ is a methyl group, R ² is a lower alkyl group, R ³ is a halogen atom, and R ⁵ is a monofluoromethyl group or a difluoromethyl group; R ¹ is a methyl group, R ²
Is a halogen atom, R ³ is a lower alkyl group, and R ⁵ is a monofluoromethyl group or a difluoromethyl group.

In the present specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. In addition, examples of the lower alkyl group include a linear or branched alkyl group having 1 to 6 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, and hexyl. .

The compound represented by the general formula (1) of the present invention is produced, for example, by the method shown in the following reaction formula-1.

[0015]

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[Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ and Y
Is the same as above. R ⁶ represents a lower alkyl group. According to the above reaction formula-1, the compound of the present invention represented by the general formula (1) is obtained by converting the (thio) semicarbazide represented by the general formula (2) and the fluoroacetic acid ester represented by the general formula (3) ,
It is produced by reacting in the absence of a solvent or in a solvent in the presence of a base. Examples of the solvent used in this reaction include alcohols such as methanol and ethanol, ethers such as dioxane and tetrahydrofuran, amides such as dimethylformamide and N-methylpyrrolidone, sulfoxides such as dimethyl sulfoxide, and mixed solvents thereof. And the like. Examples of the base used in this reaction include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide and magnesium hydroxide, sodium methoxide, potassium Examples thereof include metal alkoxides such as ethoxide, and organic amines such as triethylamine and pyridine. The use ratio of the (thio) semicarbazide of the general formula (2) and the fluoroacetate of the general formula (3) is not particularly limited, but the latter is usually 0.5 to 5 moles per mole of the former. The amount is preferably about 1 to 3 times mol. The use ratio of the (thio) semicarbazide of the general formula (2) and the base is not particularly limited, but is usually about 0.1 to 3 times, preferably 0.5 to 3 times, the amount of the latter with respect to the former. It is preferable to use about twice the molar amount. The above reaction proceeds in a temperature range from room temperature to the boiling point of the solvent used, but it is usually preferable to heat the reaction to shorten the reaction time.

The (thio) semicarbazide represented by the general formula (2) used in the above reaction formula-1 can be produced from the corresponding aniline according to a known method. The details are described in, for example, U.S. Pat. No. 4,514,419. Further, the fluoroacetic acid ester of the general formula (3) is a compound that can be industrially easily obtained.

According to the present invention, rice, rice, lawn and upland are treated by soil treatment with the compound of the present invention.
Lawn (rice brassicae, turmeric grass, bentgrass, bluegrass, ryegrass, tefton) and soybeans,
Since it is safe for crops such as wheat, radish, and buckwheat, and can selectively control various weeds that hinder the growth of crops, it is extremely useful for improving crop production and reducing labor for agricultural work.

When the compound of the present invention is used as a herbicide, emulsions, wettable powders, dry flowables, flowables, aqueous solvents, granules, fine granules, granules, powders, coatings, spray preparations, aerosol preparations , Microcapsule preparations, fumigation preparations, fumigation preparations and the like. As the auxiliary, those commonly used in this field can be widely used, for example, fillers such as diatomaceous earth, kaolin, clay, bentonite, white carbon, and talc, and polyoxyethylene alkyl ethers as nonionic surfactants, Polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ester,
Examples of the anionic surfactant include alkylbenzene sulfonate, alkyl sulfosuccinate, alkyl sulfate, polyoxyethylene alkyl sulfate, allyl sulfonate, and lignin sulfite.

As the solubilizer and diluent, water, various organic solvents, various aerosol propellants, various natural minerals and various synthetic compounds can be used. For example, organic solvents such as benzene, toluene, xylene, ethylbenzene, chlorobenzene, alkylnaphthalene, chloroethylene, cyclohexanone, methylethylketone, methylisobutylketone, alcohols, cellosolves, dimethylformamide, dimethylsulfoxide, acetonitrile, and mineral oil fraction are preferred. Used in Examples of the aerosol propellant include, for example, propane, butane, halogenated hydrocarbon, nitrogen, carbon dioxide and the like. These preparations can be colored using an organic or inorganic dye.

In preparing the above-mentioned various preparations in the present invention, the compound of the present invention is used in an amount of about 0.1 to 95% by weight,
It can be preferably formulated to contain about 0.5-90% by weight. The prepared preparation is used as it is or after being diluted with a carrier or water, but can be freely diluted in the range of about 0.0001 to 100% by weight, preferably 0.001 to 10% by weight depending on the purpose. It is preferable to use it after dilution so as to contain the active ingredient.

In using the herbicide of the present invention,
Although not particularly limited, it is preferable to use the herbicide of the present invention in a soil treatment method. For example, the composition of the present invention is used in an amount of from 1 to 1000 g / 10a, preferably from 5 to 2 in terms of the active ingredient before the occurrence of weeds and in the early stage of weed growth.
It is preferable to control the weeds by spraying to give 00g / 10a. Further, in the use of the present invention, it is possible to use a mixture with other herbicides, fungicides or insecticides.

[0023]

EXAMPLES The present invention will be further clarified with reference to Formulation Examples, Production Examples and Test Examples of the compounds of the present invention, but the present invention is not limited thereto. In the following, simply “parts” means “parts by weight”.

Formulation Example 1 (10% wettable powder) Compound of the general formula (1) 10.0 parts Di-crite (kaolin-based clay: manufactured by Di-Crite Industry Co., Ltd.) 87.3 parts Sorpol 800A 1.35 parts Lunox P-65-L (manufactured by Toho Chemical Industry Co., Ltd.) 1.35 parts.

Formulation Example 2 (10% flowable agent) Compound of general formula (1) 10.0 parts KP-1436 (25) (manufactured by Kao Corporation) 10.0 parts Lunox 100C (manufactured by Toho Chemical Industry Co., Ltd.) 0.5 part 1% Rhodopol water (Rhone Poulin) 40.0 parts Water 39.5 parts.

Production Example 1 4- (4,7-dichloro-2-methylbenzofuran 5
-Yl) -3-difluoromethyl-1-methyl-1,
Production of 2,4-triazole-5 (1H) -thione (compound 1) 0.50 g of ethyl difluoroacetate and 0.28 g of thiosemicarbazide were suspended in 5 ml of methanol.
0.58 g of a% sodium methoxide / methanol solution was added, and the mixture was refluxed overnight. Ethyl acetate 50ml
And washed with water and saturated saline. After drying over anhydrous magnesium sulfate, the solvent was distilled off, and the residue was purified by silica gel column chromatography (developing solvent; hexane: ethyl acetate = 3: 1) to obtain 0.8 g of white crystals (yield 7).
3%).

Melting point: 179-181 ° C. ¹ H-NMR (CDCl ₃ ) δ ppm; 2.51 (3
H) 3.83 (3H), 6.43 (1H), 6.53
(1H), 7.18 (1H).

Production Example 2 4- (4,7-dichloro-2-methylbenzofuran 5
-Yl) -3-fluoromethyl-1-methyl-1,2,2,
Preparation of 4-triazole-5 (1H) -thione (compound 2) 0.86 g of ethyl fluoroacetate and 28% of thiosemicarbazide were suspended in 10 ml of methanol.
1.12 g of a% sodium methoxide / methanol solution was added, and the mixture was refluxed overnight. The reaction solution was ethyl acetate 100m
and extracted with water and saturated saline. After drying over anhydrous magnesium sulfate, the solvent was distilled off, and the residue was purified by silica gel column chromatography (developing solvent; hexane: ethyl acetate = 2: 1) to obtain 1.2 g of white crystals (yield 5).
8%).

Melting point: 88 (softening) to 120 ° C. ¹ H-NMR (CDCl ₃ ) δ ppm; 2.56 (3
H), 3.90 (3H), 5.06 (1H), 5.21
(1H), 6.62 (1H), 7.27 (1H).

The compounds prepared according to the above Preparation Examples and their spectroscopic data are shown in Tables 1 and 2.

[0031]

[Table 1]

[0032]

[Table 2]

Test Example 1 (Flooded soil treatment test) A porcelain pot having an outer shape of 9.2 cm, an inner diameter of 8.5 cm, and a height of 9.0 cm was adjusted to an appropriate viscosity by adding water in a mixer in advance. And an appropriate amount of mixed fertilizer, put on the soil surface nobies, fireflies, broadleaf weeds (Kikasigusa, Azena),
The seeds of the oyster fir and the onion were sown. After lightly crushing to flatten the soil surface, rice (cultivar: Akinishiki) at the 2 leaf stage was transplanted and flooded to a depth of about 3 cm. Three days later,
The test compound was uniformly sprayed on the flooded surface so that the amount of the active ingredient became 20 g / 10a. The chemical solution at the time of spraying was prepared by diluting the wettable powder of the formulation shown in Formulation Example 1 with water and dropping it uniformly on the flooded surface with a pipette. Three weeks after the application of the chemical solution, the control effect on rice and various weeds was examined according to the following criteria, and the results are shown in Table 3. The test compound numbers (Compound Nos.) In Table 3 correspond to the compound numbers in the above Production Examples. For comparison, 2-benzothiazol-2-yloxy-N-methylacetanilide (mefenacet, this compound is referred to as “compound B”)
Was used to determine the herbicidal effect in the same manner as described above, and the results are shown in Table 3.

Criteria: 5 ... 100% herbicidal rate (complete mortality), 4.5 ... 90-100%, 4 ... 70-90%, 3
... 40-70%, 2 ... 20-40%, 1 ... 0-20%,
0 ... 0% (harmless)

[0035]

[Table 3]

Test Example 2 (Test for Herbicidal Activity against Lawn Weeds) Pots were filled with clay loam and an appropriate amount of mixed fertilizer, and seedlings of Mehisiba, Poa annua, Chlorophyta, and Dutch clover were gently covered with soil. An aqueous solution obtained by diluting the 10% flowable agent prepared in Formulation Example 2 1000 times was uniformly applied to the soil surface so that the treatment amount per area was 30 g / 10a, and then the test plant was grown by water absorption at the lower part. . Three weeks later, they were visually observed, and the results are shown in Table 4. The judgment of the herbicidal effect was performed in accordance with the same criterion as the criterion in Test Example 1 described above. The test compound numbers in Table 4 correspond to the compound numbers in the above Production Examples.

For comparison, the expression

[0038]

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(US Pat. No. 5,184,841)
No. 86, this compound is referred to as “compound C”), and the herbicidal effect was determined in the same manner as described above. The results are shown in Table 4.

[0040]

[Table 4]

Test Example 3 (Grass Safety Test) (1) Himekouraishiba A pot of 15 cm in diameter was filled with a mixture of equivalent amounts of masama and clay loam, and cut into pieces according to the diameter of the pot. Mats were planted. One month after the planting, it was confirmed that the grass in the pot had sufficiently taken down the roots, and the foliage was cut to about 1 cm above the ground, and then prepared in Formulation Example 2
An aqueous solution obtained by diluting the 0% flowable agent 500 times was evenly sprayed on the lawn so that the treatment amount per area was 100 g / 10a. After treatment with the chemical, the turf was grown for one month, and the effect of each chemical on the growth of the turf was observed. The degree of phytotoxicity to the turf was evaluated according to the criteria of Test Example 1.

(2) Bentgrass A pot having a diameter of 15 cm was filled with a mixture obtained by mixing an equivalent amount of sasa and clay loam, and the bentgrass was sown and grown for 2 months. In the meantime, cutting was performed twice, and the foliage that had grown on the day before the chemical treatment was cut to 1 cm above the ground.
The chemical treatment and the judgment of phytotoxicity to turf were performed in the same manner as in the above-mentioned test using the Japanese turtle.

Table 5 shows the results of these tests. Table 5
The test compound numbers in the table correspond to the compound numbers in the above Production Examples.

[0044]

[Table 5]

Test Example 4 (Herbicidal activity test on upland weeds and phytotoxicity test on crops) A pot was filled with clay loam and an appropriate amount of mixed fertilizer, and as test plants, Aoubiyu, Nobie, Ichibi, Cyperaceae, Soybean,
After sowing wheat, radish and buckwheat, the soil was lightly covered.
An aqueous solution obtained by diluting the 10% flowable agent prepared in Formulation Example 1000 by 1000 times was treated with a treatment amount of 50 g / 10 per area.
After uniformly treating the soil surface so as to obtain a, the test plant was grown by water absorption at the bottom. Table 6 shows the results of the macroscopic observation at the third week. The judgment of the herbicidal effect was performed in accordance with the same criterion as the criterion in Test Example 1 described above. The test compound numbers in Table 6 correspond to the compound numbers in the above Production Examples.

For comparison, equations (D) and (E)

[0047]

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A compound represented by the formula (JP-A-8-20583)
The herbicidal effect and the phytotoxicity were determined in the same manner as described above using the compounds described in the specification of Japanese Patent Application Publication No. 2000-214, and these compounds are referred to as “Compound D” and “Compound E”. The results are shown in Table 6.

[0049]

[Table 6]

Continued on the front page. Otsuka Chemical Co., Ltd.

Claims (2)

[Claims] 1. A compound of the general formula [Wherein, R ¹ represents a methyl group or an ethyl group. R ² and R
³ is the same or different and represents a halogen atom or a lower alkyl group. R ⁴ represents a methyl group or an ethyl group. R ⁵ represents a monofluoromethyl group or a difluoromethyl group. Y
Represents a sulfur atom or an oxygen atom. 1, 2,
4-triazole derivatives. 2. The 1,2,4-triazo- according to claim 1.
A herbicide containing a benzoyl derivative as an active ingredient.