JPH01301668A - Mandelic acid derivative and herbicide - Google Patents

Abstract

NEW MATERIAL:A mandelic acid shown by formula I (X is halogen or alkyl; R is H or alkyl; Y is O or S; A is halogen, alkoxy or alkoxy replaced with halogen atom; n is 0, 1 or 2). EXAMPLE:2-(4, 6-dimethoxypyrimidin-2-yloxy)-2-phenyl acetic acid. USE:Useful as herbicide showing excellently herbicidal effects on annual weeds and perennial weeds and high safety to crops, especially to rise plant and wheat and applicable to paddy fields, plowed fields and nonagricultural land, etc. PREPARATION:For example, as shown the reaction formula, a compound shown by formula II is reacted with a compound shown by formula III in the presence of a base such as sodium metal or pyridine in a solvent such as benzene at room temperature-the boiling temperature of the solvent for 30 minutes-24 hours to give a compound shown by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a novel mandelic acid derivative and a herbicide containing the same as an active ingredient that can be applied to paddy fields, fields, non-agricultural land, etc.

(Prior Art) In recent years, a large number of herbicides have been developed and put into practical use, contributing to labor savings and improved productivity in agricultural work.

(Problems to be Solved by the Invention) However, these herbicides also have various problems in terms of herbicidal efficacy and safety in actual use.

The present inventors conducted extensive research on mandelic acid derivatives with the aim of developing a compound that has excellent herbicidal effects and is highly safe for crops.As a result, the present invention found that the compound of the present invention has an excellent herbicidal effect on not only annual weeds but also perennial weeds. The present invention was completed by discovering that the present invention is highly safe for crops, especially rice and wheat.

(Means for Solving the Problems) The mandelic acid derivative of the present invention has the general formula (wherein, X represents a halogen atom or an alkyl group, R represents a hydrogen atom or an alkyl group, and Y represents an oxygen atom or a sulfur atom. , A represents a halogen atom, an alkoxy group, or an alkoxy group substituted with a halogen atom, and n represents an integer of 0 or 1.2).

Next, the compounds of the present invention represented by the above general formula are illustrated in Table 1. In addition, the compound number will be referred to in the following description.

Table 1-3 ~ Compound 4 and Compound 10 are R-forms, and Compound 5 and Compound 1] are 8-forms.

The compound of the present invention can be produced by the following method.

(Method A) CII) Cm) (Bf5) X, n [■] [■] [■] (wherein, R1 is a halogen atom, an alkylsulfonyl group,
represents a benzylsulfonyl group or a substituted benzylsulfonyl group, Z represents a halogen atom, R, A, , X, Y and n
has the same meaning as above. ) The compound of the present invention represented by the general formula (1) has the general formula [IT]
The compound represented by the formula [) and the compound represented by the general formula [)] or the compound represented by the general formula (IV) and the compound represented by the general formula (V,) are mixed in a suitable solvent at room temperature or in the presence of a base. It can be produced by reacting within the boiling temperature range for 30 minutes to 24 hours.

Bases include alkali metals such as sodium metal and potassium metal, alkali metal hydrides such as sodium hydride, potassium hydride, and calcium hydride, alkaline earth metal hydrides, and alkali metals such as sodium carbonate and potassium carbonate. Carbonates, alkali metal hydroxides such as sulfurium hydroxide and potassium hydroxide, and organic amines such as triethylamine and pyridine can be used. When R represents a hydrogen atom, a base of 2 or more equivalents is used, and after the reaction, the compound of the present invention can be made acidic to obtain the compound of the present invention represented by the general formula [1]. Examples of solvents include hydrocarbon solvents such as benzene, toluene, and xylene, halogenated hydrocarbon solvents such as methylene chloride, and chloroform, methanol, ethanol,
Alcohol solvents such as 2-propanol, ether solvents such as ethyl ether 1, tetrahydrofuran, and dioxane, ketone solvents such as acetone and methyl ethyl ketone, ester solvents such as methyl acetate and ethyl acetate, dimethylformamide, dimethylacetamide, and dimethyl Aprotic polar solvents such as sulfoxide, acetonitrile, water, etc. can be used.

(Method C) [VI) [■] (In the formula, R2 represents an alkyl group, and A, X, Y and n have the same meanings as above.) The compound of the present invention represented by the general formula [■] After hydrolyzing the compound represented by the general formula [■] in water in the presence of an equivalent amount or more of a base at a temperature ranging from room temperature to the boiling point of the solvent for 1 to 48 hours, the reaction solution is made neutral or acidic with an acid. It can be manufactured by

As the base, alkali metal hydroxides such as sulfur hydroxide, potassium hydroxide, etc. can be used. Furthermore, for the purpose of accelerating the reaction, alcohols such as methanol and ethanol, and water-soluble organic solvents such as dioxane or acetonitrile can be added.

(Method D) [■] [■] (In the formula, R2 represents an alkyl group, and A, X, Y and n have the same meanings as above.) The compound represented by the general formula (Vf) is a compound represented by the general formula [ (2)] can be produced by reacting the compound represented by [2] with an alcohol in a suitable solvent in the presence of a base at a temperature ranging from room temperature to the boiling point of the solvent for 1 to 24 hours.

Examples of bases include alkali metal carbonates such as sodium carbonate, potassium carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate, alkali metal hydrides such as sodium hydride and potassium hydride, and organic amines such as triethylamine, pyridine, and DBU. Can be used. Examples of solvents include hydrocarbon solvents such as benzene, toluene, and xylene, ether solvents such as ethyl ether, ethylene glycol dimethyl ether, tetrahydrofuran, and dioxane, aprotic polar solvents such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and others. Acetonitrile etc. can be used. Crown ether as a catalyst,
It is also possible to use tetramethylethylenediamine and the like.

(Method E) [■] [VI) [■] [■] [■] [■] In the formula c, R2 represents an alkyl group, L is a halogen atom,
The group -○C(○)○R3 (here, R'' represents a lower alkyl group or a phenyl group) or an imidazolyl group, and A
, X, Y and n have the same meanings as above. ] The compound of the present invention represented by general formula VI) is represented by general formula [■]
Using the compound represented by the formula and an appropriate reaction reagent, the general formula [
It can be produced by producing the compound shown in (2) and reacting it with an alcohol without isolation or isolation.

Examples of the reaction reagent for obtaining the compound represented by the formula [■] include thionyl chloride, oxalic acid dichloride, chlorocarbonate, and carbonyldiimidazole. Examples of solvents include hydrocarbon solvents such as benzene, toluene, and xylene, halogenated hydrocarbon solvents such as methylene chloride and chloroform, ketone solvents such as acetone and methyl ethyl ketone, ester solvents such as methyl acetate and ethyl acetate, and ethyl ether. , ether solvents such as ethylene glycol dimethyl ether and tetrahydrofuran,
Aprotic polar solvents such as dimethylformamide, acetonitrile, etc. can be used. The reaction is carried out at a temperature ranging from 0°C to the boiling point of the solvent for 30 minutes to 24 hours.

In the following, the method for producing the compound of the present invention will be specifically explained with reference to Examples.

Example 1 Synthesis of ethyl 2-(4,6-cymethoxypyrimidin-2-yloxy)-2-phenylacetate (Compound 1) 60%
Sodium hydride (0.4g) was dissolved in toluene (100mQ
), and ethyl mandelate (1.8 g) was added little by little to this suspension at room temperature, followed by stirring at room temperature for 15 minutes. 4,6-Simethoxy 2-
Methylsulfonylpyrimidine (2.2 g) was added, and the mixture was heated under reflux for 10 hours. After the reaction was completed, the reaction solution was poured into water and extracted with ethyl acetate. The extract was further washed with water and then dried. The solvent was distilled off under reduced pressure, and the resulting residue was purified by silica gel column chromatography to obtain 2.7 g of the title compound as white crystals.

Melting point = 90-93°C Example 2 Synthesis of 2-(3-chlorophenyl)-2-(4,6-simethoxypyrimidin-2-yloxy)acetic acid (Compound 1
8) 2-(3-chlorophenyl)-2-(4,6-simethoxypyrimidin-2-yloxy)acetic acid (1.1 g)
After dissolving in ethanol (20 mQ), a 1.5-fold molar amount of sodium hydroxide aqueous solution (20 rr+Q) was added, and the mixture was reacted with stirring at room temperature for 1 hour. After completion of the reaction, one reaction solution was poured into water, extracted with ether to remove unreacted raw materials, and the aqueous phase was made acidic with a 10% aqueous hydrochloric acid solution. This was extracted with ether, washed with water, dried, and then the solvent was distilled off under reduced pressure to obtain 0.90 g of the title compound as white crystals.

Melting point = 158-159°C Example 3 Synthesis of ethyl 2-(4,,6-simethoxypyrimidin-2-yloxy)-2-phenylacetate (compound 1) 60
% sodium hydride (0,9 g) was suspended in tetrahydrofuran (50 mQ) and added to this suspension at room temperature 4,6
-Simethoxy 2-mercaptopyrimidine (3.6g)
was added little by little and stirred at room temperature for 15 minutes. To this suspension was added ethyl 2-bromo-2-phenylacetate (5.1 g).
was added dropwise, and the mixture was allowed to react for 1 hour. After the reaction was completed, one reaction solution was poured into water and extracted with ethyl acetate. The extract was further washed with water and then dried. The solvent was distilled off under reduced pressure, and the resulting residue was purified by silica gel column chromatography.
5.2 g of the title compound was obtained as white crystals.

Melting point = 78-80°C Example 4 2-(4,6-cymethoxypyrimidin-2-ylthio)
-2=Synthesis of phenylacetic acid (compound 22) 2-(4,6-simethoxypyrimidin-2-ylthio)
= Ethyl 2-phenylacetate (2.0 g) was dissolved in ethanol (
After dissolving in 20 mQ), a 122-fold molar amount of an aqueous sodium hydroxide solution (20 mQ) was added, and the mixture was reacted with stirring at room temperature for 8 hours.

After the reaction was completed, the reaction solution was poured into water, extracted with ether to remove unreacted raw materials, and then acidified with a 10% aqueous hydrochloric acid solution.

After extracting this with ether, washing with water, and drying, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography to obtain the title compound as white crystals.
I got 4g.

Melting point = 166-168°C Next, the herbicide of the present invention comprises the mandelic acid derivative of the present invention. When using the compound of the present invention as a herbicide,
The compound can be formulated into various forms such as wettable powders, granules, emulsions, or powders by combining the compound alone or with carriers, surfactants, dispersants, adjuvants, etc. commonly used in the formulation of agricultural chemicals. can be used.

As carriers used in formulation, ziecrite,
Solid carriers such as talc, bentonite, clay, kaolin, diatomaceous earth, white carbon, vermiculite, slaked lime, silica sand, ammonium sulfate, urea, 2-propertool, xylene,
Examples include liquid carriers such as cyclohexanone and methylnaphthalene. As surfactants and dispersants, alcohol sulfate ester salt, alkylaryl sulfonate, lignin sulfonate, polyoxyethylene glycol ether, polyoxyethylene alkylaryl ether,
Examples include polyoxyethylene sorbitan monoalkylene-1. Examples of the adjuvant include carboxymethyl cellulose, polyethylene glycol, gum arabic, and the like. When using it, either dilute it to an appropriate concentration and spray it, or apply it directly.

Moreover, the herbicide of the present invention can also be used in combination with other herbicides.

The herbicide of the present invention can control many weeds that occur in fields by applying it to soil or foliage before or after weed germination. In addition, many weeds that occur in rice fields can be controlled by treating the flooded soil or foliage of the weeds before or after they germinate. The herbicide of the present invention has an active ingredient of 0.1 g to 10 are/kg, preferably 1
Apply ~400g. In addition, when spraying on plant stems and leaves, ippm to 10. Apply diluted to OOppm.

Next, examples of the herbicide of the present invention will be given, but the present invention is not limited to this scope. In addition, % described in an example shows a weight percentage.

Example 5 Wettable powder compound (4) 10%, Emulgen 810 (registered trademark of Kao Corporation) 0.5%, Demol N (registered trademark of Kao Corporation) 025%, Kunilite 20 F, (registered by Kunimine Industries, Ltd.) 4m) 20% and Sickleite CA
(Zikrite Co., Ltd. registered trademark) 69% was mixed and pulverized uniformly to prepare a wettable powder.

Example 6 Emulsion An emulsion was prepared by uniformly dissolving 30% of compound (4), 20% of cyclohexanone, 11% of polyoxyethylene alkylaryl ether, 4% of calcium alkylbenzenesulfonate, and 35% of methylnaphthalene.

Example 7 Granule Compound (4) 5%, sodium salt of lauryl alcohol sulfate 2%, sodium lignin sulfonate 5%
, 2% carboxymethylcellulose and 86% clay are uniformly mixed and ground. This mixture contains 100 parts of water and 20 parts of water.
Add parts by weight, knead, and use an extrusion granulator to make 14 to 3 parts by weight.
After processing into 2 mesh granules, they were dried to form granules.

Example 8 Powder 2% of compound (4), 5% of diatomaceous earth, and 93% of clay were uniformly mixed and ground to obtain a powder.

(Effects of the invention) The compounds and herbicides of the present invention can be used for
It is also possible to effectively control annual weeds such as cyperus japonica, cyperus japonica, firefly, and cyperus japonica, as well as perennial weeds such as cyperus japonica, cypress japonica, and cypress japonica. In addition, annual grasses such as barnyard grass, crabgrass, ohigrass, foxtail grass, johnson grass, sycamore grass, sycamore grass, inch grass, azegaya, sycamore, sycamore, oat, Italian ryegrass, horsetail grass, shutter cane, and honeycomb grass occur in fields. Weeds, annual broad-leaved weeds such as Japanese knotweed, Japanese knotweed, whiteweed, pigweed, Japanese fir, Japanese fir, Noasagao, chickweed, American goldenrod, Ebisugusa, American heliflower, Japanese sagebrush, freckle, Japanese violet, Common grass, shepherd's purse, purslane, annual cypress such as cyperus japonica and cyperus japonica It is also possible to effectively control perennial weeds such as the family weeds and perennial weeds such as sedge grass, johnson grass, staghorn grass, staghorn grass, staghorn grass, mugwort, dandelion, staghorn grass, and plantain. On the other hand, it is highly safe for one crop, especially rice and wheat.

Next, the effects of the herbicide of the present invention will be explained using test examples. The test plants in the table of each test example are indicated by the following abbreviations.

Ec ; Hie Cd ; Kamagayari Mo
; Konagi Sc; Firefly D]; Mehishiba PO; Giant knotweed Am; Aobiyu
Ch; Shiroza C]; So; Johnson grass A]; Black grass Ab; Ichibi Ze; Corn test example 4 Paddy field weed control test A 100 d pot was filled with paddy soil, and after puddling, barnyard grass,
Seeds of cypress, konagi, and firefly are sown,
Submerged in 5G. Two days after sowing, a wettable powder prepared according to Example 5 was diluted with water, and the active ingredient was added at 40% per 0 are.
It was dropped onto the water surface so that the amount was 0 g. Investigation after drug treatment 2
The test was carried out on the first day according to the standards in Table 2, and the results are shown in Table 3 as an index.

Test Example 2 Stalk and Leaf Treatment Test 100cr+? filled with soil Seeds of Japanese barnyard grass, Japanese knotweed, Japanese violet, Japanese whitewort, and Japanese cypress were sown in pots, and the pots were covered with soil to a thickness of 0.5 to 1 inch. The pot is
After growing in a glass room at 20 to 25°C for two weeks, dilute a predetermined amount of the wettable powder prepared according to Example 5 with water, and add 100Q per 10 ares so that the active ingredient is 100 g per 10 ares. Sprayed on the surface of the leaves at the same rate. The investigation was conducted on the 14th day after the chemical spraying according to the criteria in Table 2. The results are shown in Table 4 as an index.

Test Example 3 Soil Treatment Test 5 seeds of Japanese barnyard grass, Japanese knotweed, Japanese blueberry, white staghorn and Japanese cypress were sown in 1001 pounds filled with soil, and covered with soil to a thickness of 0.5 to 1 inch. On the day after sowing, a predetermined amount of the hydrating agent prepared according to Example 5 was diluted with water and sprayed on the soil surface at a rate of 100 fl/10 are so that the active ingredient was 100 g/10 are. The investigation was conducted on the 20th day after spraying the chemicals according to the criteria in Table 2. The results are shown in Table 5 as an index.

Claims (2)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, X represents a halogen atom or an alkyl group, R represents a hydrogen atom or an alkyl group, Y represents an oxygen atom or a sulfur atom, A is a halogen atom, an alkoxy group, or an alkoxy group substituted with a halogen atom, and n is an integer of 0, 1, or 2. (2) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, X represents a halogen atom or an alkyl group, R represents a hydrogen atom or an alkyl group, Y represents an oxygen atom or a sulfur atom, A herbicide containing a mandelic acid derivative represented by the formula (A represents a halogen atom, an alkoxy group, or an alkoxy group substituted with a halogen atom, and n represents an integer of 0, 1, or 2) as an active ingredient.