JPH02149566A - 4-substituted-2,6-diphenylpyrimidine derivative, production thereof and herbicide containing the same as active ingredient - Google Patents

Abstract

NEW MATERIAL:A 4-substituted-2,6-diphenylpyrimidine derivative expressed by formula I (R<1> is lower alkyl, halogen or low haloalkyl at the o- or m-position; R<2> is H, halogen or lower haloalkyl; R<3> is lower alkoxy, lower alkylthio or lower alkylamino). EXAMPLE:2-(4-Trifluoromethylphenyl)-4-methylthio-6-(2-chlorophenyl)pyr imidine. USE:Useful as a herbicide having herbicidal effects on broad-leaved weeds, such as chickweed or cleavars, in farmland and gramineous weeds, such as barnyard millet, without phytotoxicity to main crops, such as wheat and barley. PREPARATION:A ketene dithioacetal derivative expressed by formula II (R<4> is lower alkyl) is reacted with a benzamidine derivative expressed by formula III at 20-150 deg.C temperature to afford the compound expressed by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel 4-substituted-2,6-diphenylpyrimidine derivative, a method for producing the same, and a herbicide containing the same as an active ingredient.

Hitherto, the herbicidal activity of certain 2-phenylpyrimidine derivatives, however, has not been described at all. Furthermore, there is no mention of the chemical structure or physiological activity of the 4-substituted-2,6-diphenylpyrimidine derivative of the present invention.

As a result of various studies aimed at developing an excellent herbicide, the present inventors found that the compound represented by the following general formula has excellent herbicidal activity and exhibits excellent selectivity between crops and weeds. This discovery led to the present invention.

That is, the present invention is based on the general formula CI) R' [wherein R represents a lower alkyl group, a halogen atom, or a lower haloalkyl group at the 〇-position or m-position, and R2 represents a hydrogen atom, a halogen atom, or a lower haloalkyl group] Representation R1 represents a lower alkoxy group, a lower alkylthio group or a lower alkylamino group. ] The present invention provides a 4-substituted-2,6-diphenylpyrimidine derivative (hereinafter referred to as the compound of the present invention) represented by the following, a method for producing the same, and a herbicide containing the same as an active ingredient.

Next, a method for producing the compound of the present invention will be explained.

Among the compounds of the present invention, those in which R3 is a lower alkylthio group have the formula [■] [wherein R1 represents the same meaning as above and R4 represents a lower alkyl group]. ] A ketene dithioacetal derivative represented by the general formula (1
[1] [In the formula, R2 represents the same meaning as above. It can be produced by reacting with a benzamidine derivative shown in

The reaction is usually carried out in a solvent, and the reaction temperature range is 20°C.
The standard reaction time range is 2 to 20 hours at ~150°C, and the amount of reagent used in the reaction is -1 equivalent of the ketene dithioacetal derivative represented by the formula [■],
- The benzamidine derivative represented by formula (III') is usually 1 to 8 equivalents.

The solvents used include aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as chlorobenzene and dichlorobenzene, diethyl ether,
Ethers such as diisopropyl ether, dioxane, tetrahydrofuran, and diethylene glycol dimethyl ether, alcohols such as isopropanol, t-butanol, and cyclohexanol, nitro compounds such as nitroethane and nitrobenzene, nitriles such as acetonitrile and isobutyronitrile, pyridine, Triethylamine, N, N-diethylaniline, tributylamine, N-
Examples include tertiary amines such as methylmorpholine, acid salts such as N,N-dimethylformamide, sulfur compounds such as dimethyl sulfoxide and sulfolane, and mixtures thereof.

After completion of the reaction, the reaction solution is subjected to conventional post-treatments such as organic solvent extraction and condensation to obtain the desired compound of the present invention. Further, operations such as chromatography and recrystallization can be performed if necessary.

Among the compounds of the present invention, those in which R is a lower alkoxy group are obtained by combining the ketene dithioacetal derivative represented by the formula [II] and the benzamidine derivative represented by the general formula [■] with the general formula [■] R50M CIV) [In the formula, R6 represents a lower alkyl group, and M represents an alkali metal. ] It can be produced by reacting in the presence of the metal alkoxide shown below.

The reaction is usually carried out in a solvent, and the reaction temperature range is 20°C.
The standard reaction time range is 2 to 20 hours at ~150°C, and the amount of reagents used for the reaction is -1 equivalent of ketene dithioacetal derivative represented by formula [■], 1ζ, -formula ( The benzamidine derivative represented by II[) is usually 1 to 8 equivalents, and the metal alkoxide represented by formula [IV] is usually 0.1 to 8 equivalents.

The solvents used include aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as chlorobenzene and dichlorobenzene, diethyl ether,
Ethers such as diisopropyl ether, dioxane, tetrahydrofuran, and diethylene glycol dimethyl ether, alcohols such as isopropanol, t-butanol, and cyclohexanol, nitro compounds such as nitroethane and nitrobenzene, nitriles such as acetonitrile and isobutyronitrile, pyridine, Triethylamine, N, N-diethylaniline, tributylamine, N-
Examples include tertiary amines such as methylmorpholine, acid amides such as N,N-dimethylformamide, sulfur compounds such as dimethyl sulfoxide and sulfolane, and mixtures thereof.

After completion of the reaction, the reaction solution is subjected to conventional post-treatments such as organic solvent extraction and concentration to obtain the desired compound of the present invention. Further, operations such as chromatography and recrystallization can be performed if necessary.

Among the compounds of the present invention, those in which R8 is a lower alkylamino group have the formula [v] 1?2 λ [wherein R1 and R8 represent the same meanings as above, and
represents a halogen atom. ] A pyrimidine derivative represented by the formula [■] [wherein,
R and R are the same or different and represent a hydrogen atom or a lower alkyl group. It can be produced by reacting with an amine derivative shown in ].

The compound of the present invention can be used to treat various weeds that are problematic in the treatment of foliage and soil in upland areas, such as chickweed, tikon, ferret, Japanese croaker, red deer, field pansy, morning glory, mulva gamma sagao, Physalis spp. The compound of the present invention has a herbicidal effect on grass weeds such as broad-leaved weeds, barnyard grass, barnyard grass, foxtail grass, grass grass, oats, and oats. Does not show any drug damage.

In addition, the compound of the present invention has a herbicidal effect on various weeds that are problematic in the flooding treatment of rice fields, such as grass weeds such as Japanese millet, and moreover, Does not show drug damage.

When using the compound of the present invention as an active ingredient of a herbicide,
It is usually mixed with solid carriers, liquid carriers, surfactants, and other formulation auxiliaries to formulate emulsions, wettable powders, suspensions, granules, and the like.

These preparations contain the compound of the present invention as an active ingredient in a weight ratio of 1 to 90%, preferably 2 to 80%.

Examples of solid carriers include powders or granules such as kaolin clay, attapulgite clay, bentonite, acid clay, pyrophyllite, talc, diatomaceous earth, calcite, walnut shell powder, urea, ammonium sulfate, and synthetic hydrous silicon oxide. Liquid carriers include aromatic hydrocarbons such as xylene and methylnaphthalene, alcohols such as isopropanol, ethylene glycol, and cellosolve, ketones such as acetone, cyclohexanone, and isophorone, vegetable oils such as soybean oil and cottonseed oil, and dimethyl sulfoxide. ,N,
Examples include N-dimethylformamide, acetonitrile, water and the like.

Surfactants used for emulsification, dispersion, wetting layers, etc. include alkyl sulfate salts, alkyl sulfonate salts, alkylaryl sulfonate salts, dialkyl sulfosuccinate salts, polyoxyethylene alkylaryl ether phosphate salts, etc. Examples include anionic surfactants such as polyoxyethylene alkylaryl ether, polyoxyethylene polyoxypropylene block copolymer, sorbitan fatty acid ester, and nonionic surfactants such as polyoxyethylene sorbitan fatty acid ester.

Other formulation adjuvants include lignin sulfonate, alginate, polyvinyl alcohol, gum arabic, CMC (carboxymethyl cellulose), PAP (isopropyl acid phosphate), and the like.

The compound of the present invention is usually formulated and used for soil treatment, foliage treatment, or flooding treatment of weeds before or after emergence. Soil treatment includes soil surface treatment, soil mixing treatment, etc., and foliage treatment includes treatment from above the plant body, as well as local treatment that treats only weeds so that they do not attach to crops.

When the compound of the present invention is used as an active ingredient of a herbicide, the amount to be treated will vary depending on weather conditions, formulation form, treatment time, method, location, target weeds, target crops, etc., but usually 1.
0.1y to 200g per are, preferably 0.5
Emulsions, wettable powders, suspension agents, etc. are usually mixed with 1 liter to 10 liters of water per 1 area (adding auxiliary agents such as spreading agents if necessary). Granules and the like are usually processed as they are without any dilution.

In addition to the above-mentioned surfactants, the spreading agents include polyoxyethylene resin acid (ester), lignin sulfonate,
Examples include abietate, dinaphthylmethane disulfonate, and paraffin.

Hereinafter, the present invention will be explained in more detail with reference to production examples, formulation examples, and test examples, but the present invention is not limited to these examples.

First, a production example of the compound of the present invention will be shown.

Production Example 1 [Production of compound (1) of the present invention] 8.3-bis(
Methylthio)-1-(2-chlorophenyl)-2-propen-1-one 1.Of, 4-)lifluoromethylbenzamine hydrochloride 1. Of, 0.7 g of potassium carbonate, and 20 g of isopropanol were mixed and refluxed for 20 hours. After the solvent was distilled off under reduced pressure, the mixture was extracted twice with 50 m of ethyl acetate, and the ethyl acetate layers were combined, washed with water, and then dried over anhydrous magnesium sulfate. The residue obtained by distilling off the solvent under reduced pressure was recrystallized from isopropanol to obtain 0.95 g of 2-(4-trifluoromethylphenyl)-14-methylthio-6-(2-chlorophenyl)pyrimidine. Ta.

Melting point: 106.8°C Production Example 2 [Production of compound (4) of the present invention] 3.3-bis(
1.0 g of methylthio)-1-(8-trifluoromethylphenyl)-2-propen-1-one, 0.9 f of 4-chlorobenzamidine hydrochloride, 2 of sodium methoxide
8% methanol solution 1.01 and methanol 201I
Ij was mixed and refluxed for 20 hours. The solvent was distilled off under reduced pressure, 100 rd of water was added to the residue obtained, the obtained crystals were separated, and further recrystallized from isopropanol to give 2-(
4-methoxy-6-(8-trifluoromethylphenyl)pyrimidine o,8ry was obtained.

Melting point: 90.5°C Production Example 8 [Production of compound (18) of the present invention] 1 g of 2-(4-fluorophenyl)-4-chloro-6-(2-methylphenyl)pyrimidine and methylamine dissolved in methanol!
(40%) 10- was mixed and refluxed for 2 hours. The solvent was distilled off, 50 ml of water was added to the residue, and the resulting crystals were collected with P and recrystallized from isopropanol to give 2-(4-fluorophenyl)-4-methylamino-6-(2-methyl 0.9f of phenyl)pyrimidine was obtained.

Melting point: 108.1°C Table 1 shows some of the compounds of the present invention produced according to the above production method.

Table 1 shows examples of formulations. The compounds of the present invention are indicated by compound numbers in Table 1. Parts are parts by weight.

Formulation Example 1 80 parts of the compound of the present invention (12), 8 parts of calcium lignin sulfonate, 2 parts of sodium lauryl sulfate, and 15 parts of synthetic hydrous silicon oxide are thoroughly ground and mixed to obtain a wettable powder.

Formulation Example 2 10 parts each of the compounds (1) to (16) of the present invention, 14 parts of polyoxyethylene styrylphenyl ether, 6 parts of calcium dodecylbenzenesulfonate, and 70 parts of xylene are thoroughly mixed to obtain an emulsion.

Formulation Example 8 2 parts of the compound of the present invention (11), 1 part of synthetic hydrous silicon oxide,
2 parts calcium lignin sulfonate, 80 parts bentonite
1 part and 65 parts of kaolin clay are thoroughly ground and mixed, water is added and the mixture is thoroughly kneaded, and then granulated and dried to obtain granules.

Formulation Example 4 25 parts of the compound of the present invention (12), 8 parts of polyoxyethylene sorbitan monooleate, 8 parts of CMC, and 69 parts of water are mixed and wet-pulverized until the particle size becomes 5 microns or less to obtain a suspension.

Next, test examples demonstrate that the compounds of the present invention are useful as active ingredients of herbicides. The compounds of the present invention are indicated by the compound numbers in Table 1, and the compounds used for comparison are indicated by the compound symbols in Table 2.

Table 2 In addition, the herbicidal efficacy was determined by visually observing the degree of budding and growth inhibition of the test plants during the survey, and ``0'' indicates that there was no or almost no difference from the case where the compound was not tested. The plant is rated on an 11-point scale from 0 to 10, with a score of 10 indicating that the plant has died or its growth has been completely inhibited.
．． 2.8.4.5.6.7.8.9.10.

Test Example 1 Upland Stem and Leaves Treatment Test A cylindrical plastic pot with a diameter of 10 mm and a depth of 10 e1 N was filled with upland soil, and radish and Japanese radish were sown and grown in a greenhouse for 10 days. Thereafter, the test compound was made into an emulsion according to Formulation Example 2, a predetermined amount of the emulsion was diluted with water containing a spreading agent equivalent to 10 liters per are, and the foliage was treated from above the plant using a small sprayer. After treatment, the plants were grown in a greenhouse for 20 days and their herbicidal efficacy was investigated. The results are shown in Table 8.

Table 8 Test Example 2 Paddy field flooding treatment test A cylindrical plastic pot measuring 8 in diameter and 12 in deep was filled with paddy soil, and a dish of Japanese millet was mixed in at a depth of 1 to 2 crs. After flooding the rice field to create a paddy field, two-leaf stage rice was transplanted and grown in a greenhouse. Six days later (at the beginning of each weed's emergence), the test compound was made into granules according to Formulation Example 8, a predetermined amount of which was diluted with 5 milliliters of water, and applied to the water surface. After treatment, the plants were grown in a greenhouse for 20 days, and their herbicidal efficacy and phytotoxicity were investigated. The results are shown in Table 4.

Table 4 Test Example 8 Upland Soil Treatment Test A vat with an area of 88 x 28i% and a depth of 11α is filled with upland soil, and wheat, chickweed, violets, violets, wildflowers, oats, sycamores, and sycamores are sown in a 1-2 m thick vat. It was covered with pureness.

A predetermined amount of the test compound made into an emulsion according to Formulation Example 2 was diluted with water equivalent to 10 liters per are, and applied to the soil surface using a small sprayer. After treatment, the plants were grown in a greenhouse for 20 days and their herbicidal efficacy was examined. The results are shown in Table 5.

Table 6

Claims (4)

[Claims] (1) General formula▲ Numerical formula, chemical formula, table, etc.▼ [In the formula, R^1 represents a lower alkyl group, a halogen atom, or a lower haloalkyl group at the o- or m-position, and R^2 is a hydrogen atom. , represents a halogen atom or a lower haloalkyl group, and R^3 represents a lower alkoxy group, a lower alkylthio group, or a lower alkylamino group. ] A 4-substituted-2,6-diphenylpyrimidine derivative. (2) General formula▲ Numerical formula, chemical formula, table, etc.▼ [In the formula, R^1 represents a lower alkyl group, a halogen atom, or a lower haloalkyl group at the o- or m-position, and R^4 represents a lower alkyl group. represents a group. ] There are ketene dithioacetal derivatives and the general formula ▲ mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R^2 represents a hydrogen atom, a halogen atom, or a lower haloalkyl group. [In the formula, R^1, R^2 and R^4 have the same meanings as above. ] A method for producing a 4-substituted-2,6-diphenylpyrimidine derivative. (3) General formula▲ Numerical formula, chemical formula, table, etc.▼ [In the formula, R^1 represents a lower alkyl group, a halogen atom, or a lower haloalkyl group at the o- or m-position, and R^4 represents a lower alkyl group. represents a group. ] There are ketene dithioacetal derivatives and the general formula ▲ mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R^2 represents a hydrogen atom, a halogen atom, or a lower haloalkyl group. ] A benzamidine derivative represented by the general formula R^5OM [wherein R^5 represents a lower alkyl group and M represents an alkali metal. ] A general formula characterized by the reaction in the presence of a metal alkoxide represented by ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R^1, R^2 and R^5 have the same meanings as above. represent ] A method for producing a 4-substituted-2,6-diphenylpyrimidine derivative. (4) A herbicide containing the 4-substituted-2,6-diphenylpyrimidine derivative according to claim 1 as an active ingredient.