KR0174374B1 - Herbicidal pyrimidine compound having benzophenoneoxime ester and process for preparation thereof - Google Patents

Abstract

The present invention provides a novel benzophenone oxime ester derivative of 2,6-di (4,6-dimethoxypyrimidin-2-yl) oxy benzoic acid represented by the following formula (1), a preparation method thereof and a compound thereof as an active ingredient Regarding herbicide compositions: Wherein R ₁ and R ₂ are each independently halogen, cyano, nitro, C ₁ -C ₄ alkyl, C ₁ -C ₂ haloalkyl, C ₁ -C ₄ alkoxy, C ₁ -C ₄ alkylthio or 1 Or amino substituted or unsubstituted by two C ₁ -C ₄ alkyl, m and n each independently represent an integer of 0 to 5, and m + n is an integer of 1 to 10.

Description

[Name of invention]

Herbicidal pyrimidine compounds having a benzophenone oxime ester structure and preparation method thereof

The present invention relates to a novel herbicidal pyrimidine derivative of formula (I) having a benzophenone oxime ester structure. More specifically, the present invention provides a novel benzophenone oxime ester derivative of 2,6-di (4,6-dimethoxypyrimidin-2-yl) oxybenzoic acid represented by the following formula (1), a preparation method thereof, and a compound thereof It relates to a herbicide composition for the fight against plants harmful to crops containing as an ingredient:

Wherein R ₁ and R ₂ are each independently halogen, cyano, nitro, C ₁ -C ₄ alkyl, C ₁ -C ₂ haloalkyl, C ₁ -C ₄ alkoxy, C ₁ -C ₄ alkylthio or 1 Or amino substituted or unsubstituted by two C ₁ -C ₄ alkyl, m and n each independently represent an integer of 0 to 5 and m + n is an integer of 1 to 10.

In the above definition, the term alkyl, when used alone or as a compound word such as alkylthio, means a straight or branched chain saturated hydrocarbon radical such as methyl, ethyl, n-propyl, isopropyl or various butyl isomers and the like; The term alkoxy means methoxy, ethoxy, n-propoxy, isopropoxy or various butoxy isomers; The term halogen means fluorine, chlorine, bromine or iodine; The term haloalkyl refers to chloromethyl, dichloromethyl, trichloromethyl, trifluoromethyl, 1-fluoroethyl, 2,2,2-trichloroethyl, 2,2,2-trifluoroethyl or pentachloroethyl, and the like. Means.

It is known that 2-phenoxypyrimidine or (pyrimidin-2-yl) oxybenzene derivatives have been useful as herbicides in the past (Agr. Biol. Chem. Vol 30, p896 (1966), Japanese Patent Publication No. 79 -55729, U.S. Patent Nos. 4,248,619 and 4,427,437), and recently, 2- (pyrimidin-2-yl) oxybenzoic acid derivatives among compounds developed based on 2-phenoxypyrimidine have excellent herbicidal effect. Has been discovered and attracted attention (see European Patent Application Nos. 223,406, 249,708, 287,072, 287,079, 315,889, 321,846, 330,990, 335,409, 346,789, 363,040, 402,751, 435,170, 435,186, 457,505, 459,243 and 468,690.

The herbicidal activity and crop selectivity of these derivatives depend on which substituents are substituted in the benzene ring of 2- (pyrimidin-2-yl) oxybenzoic acid or depending on the form of the benzoic acid ester derivative. The inventors have already found and patented an oxime ester derivative of benzoic acid, which shows a wide range of excellent herbicidal effects over weeds, broadleaf weeds or annual weeds or perennial weeds (Korean Patent Publication No. 95-17991).

On the other hand, the present inventors studied the relationship between the chemical structure, herbicidal activity and crop selectivity of herbicidal compounds so far identified, and based on this, by modifying the structure of pyrimidyloxy benzoic acid derivatives, As a result of a long effort to develop a compound, the compound of Formula 1 is found to meet this purpose due to excellent crop selectivity, etc. and has completed the present invention. Hereinafter, the configuration of the present invention will be described in detail.

It is an object of the present invention to provide substituted benzophenone oxime ester derivatives of the novel 2,6-di (4,6-dimethoxypyrimidin-2-yl) oxybenzoic acid of the general formula (1).

Wherein R ₁ , R ₂ , m and n are as defined above.

The compound provided in the present invention exhibits herbicidal power against blood and broadleaf weeds, and no damage to wheat, rice and corn was found.

Representative examples of the compound of formula 1 according to the present invention are shown in Table 1 below.

The novel compounds of formula (1) provided by the present invention can be prepared by reacting a compound of formula (2) with a compound of formula (3) in the presence of a metal salt in a solvent. It is therefore an object of the present invention to provide a method for preparing the compound of formula (1).

In Formulas 2 and 3, R ₁ , R ₂ , m and n are as defined above.

Preferred solvents for use in the process according to the method for preparing the compound of Formula 1 include halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride and 1,2-dichloroethane, nitriles such as acetonitrile and propionitrile. As a metal salt, cupric salts, such as cupric softened and cupric brominated, are used preferably. Under these conditions, the compound of Formula 3 is preferably reacted at a temperature of from room temperature to 60 ° C. by applying 1 to 2 equivalents of the compound of Formula 2.

The pyridine thioester compound of the formula (2) used as a starting material in the preparation method of the compound of the formula (1) can be easily synthesized from a known benzoic acid compound (see European Patent Application No. 321,846) as shown in Scheme 1 below. .

In Scheme 1, a 2,2'-dipyridyldisulfide compound having the same equivalent weight as the benzoic acid compound is reacted with triphenylphosphine in a suitable solvent to obtain a compound of Chemical Formula 2, in which case the solvent is benzene, Hydrocarbon solvents such as toluene, xylene, acetonitrile, dichloromethane and the like are preferably used.

On the other hand, it is another object of the present invention to provide a herbicide composition for combating plants harmful to crops, characterized by containing the compound of formula 1 according to the present invention together with a carrier commonly used in the preparation of pesticides.

In the present invention, pot cultivation and pharmaceutical treatment of the potted plant in the greenhouse to test whether the compound of Formula 1 exhibits herbicidal efficacy as intended, the effect is determined by the evaluation of the efficacy and weakness evaluation criteria in Table 2 below It was carried out by carrying out.

Field weeds were Digitaria sanguinalis, Echinochlor crus-galli var.caudata, Aeschynomene indica, Abutilon theophrasti, Xanthium strumarium, Wheatgrass (Agropyron tsukushiense) Eleusine indica and morning glory (Ipomoea spp) were selected, and the weeds were Echinochlor crus-galli var.oryzicola, Eleocharis kuroguwai, Sagittaria trifolia, and Sagittaria pygmaea. And the like.

The compound of the present invention is mixed with solid materials such as clay, talc, diatomaceous earth and liquid materials such as water, alcohol, benzene, toluene, ether, ketones, esters, acids, amides, etc. It can be used in the formulation of the formulation, and at this time, emulsifiers, dispersants, penetrants, electrodeposition agents, stabilizers and the like can be added.

Depending on the object to be controlled, year-round time, the plant to be grown and the growth stage thereof, the use rate of the active compound according to the present invention may vary, and the active compound is usually used at a rate of 0.001 to 5.0 kg / ha.

Hereinafter, the present invention will be described in more detail through the following Preparation Examples and Examples. However, these examples are only for the understanding of the present invention, and the scope of the present invention is not limited to these examples in any sense.

[Production Example 1]

[Synthesis of 4,4′-dichlorobenzophenone oxime (III-17)]

13.8 g of 4,4'-dichlorobenzophenone, 15.3 g of hydroxylamine hydrochloride and 11.4 g of potassium carbonate were added to 300 ml of methanol and stirred at room temperature for 5 hours. After filtering the reaction mixture, methanol was distilled under reduced pressure to give 14.1 g (yield: 97%) of the title compound as a white solid.

In the same manner, the benzophenone oxime compounds of the formula (3) having various substituents can be easily synthesized from the corresponding benzophenone compounds.

[Production Example 2]

[Synthesis of 2-pyridinethioester (II) of 2,6-di (4,6-dimethoxypyrimidin-2-yl) oxybenzoic acid]

48.0 g of 2,6-di (4,6-dimethoxypyrimidin-2-yl) oxybenzoic acid, 22.0 g of 2,2'-dipyridyldisulfide and 26.2 g of triphenylphosphine were added to 250 ml of toluene, and The mixture was stirred vigorously at room temperature for hours. The reaction mixture was filtered and distilled under reduced pressure to remove toluene. The residue was separated by silica gel column chromatography (hexane: ethyl acetate = 2: 1, v / v) to give 42.0 g (yield: 90%) of the title compound as a white solid.

H NMR (CDCl, δ) 3.77 (s, 6H), 6.03 (s, 2H), 7.32-7.87 (m, 6H), 8.54-8.55 (d, 1H)

Example 1

[Synthesis of Compound No. 17 of Table 1]

1 g of 4,4'-dichlorobenzophenone oxime compound synthesized in Preparation Example 1 and pyridine thioester of 2,6-di (4,6-dimethoxypyrimidin-2-yl) oxybenzoic acid synthesized in Preparation Example 2 1.8 g of the compound was dissolved in 50 ml of dichloromethane and stirred at room temperature. After 5 minutes, 1.2 g of cupric bromide was added, followed by further stirring for 1 hour. The reaction mixture was filtered, concentrated and separated by silica gel column chromatography (hexane: ethyl acetate = 3: 1, v / v) to give 2 g (yield: 85%) of the title compound.

The compound shown in Table 1 can be easily synthesized by the same method as in Example 1.

The following shows a part of the formulation of the herbicide containing the compound according to the present invention as an active ingredient. However, these compounding examples are only an illustration and do not limit the technical scope of this invention.

Formulation Example 1

[Field conditions (500g / ha)]

After dissolving 160 mg of the compound according to the present invention in 640 ml of acetone, a mixture was prepared by diluting in 640 ml of distilled water containing 0.2% of the nonionic surfactant Tween20.

Formulation Example 2

[Field conditions (250g / ha)]

80 mg of the compound according to the present invention was dissolved in 640 ml of acetone, and then diluted in 640 ml of distilled water containing 0.2% of the nonionic surfactant Tween 20 to prepare a blend.

[Example 1]

[Field conditions]

300cm after filling sterilized soil (sand soil, pH 5.5-6.0) in a square plastic container (20 × 15 × 10cm) In the phosphorus state, the seeds of the test plants were sown separately and sown by 0.5 cm. In order to test the herbicidal power before germination by soil treatment, the mixture of active ingredients corresponding to the prescribed treatment amount was evenly sprayed on the soil surface after 1 day of watering. After growing to the size of, the compound of the active ingredient corresponding to the prescribed amount of treatment was uniformly sprayed on the plant foliage.

Experiments were carried out over two to four weeks, maintaining at a temperature of 10-25 ° C. or 20-30 ° C., depending on the plant species. During this time, the plants were cared for and the response of the plants with each treatment was evaluated.

[Example 2]

[Discussion conditions]

Fill the sterilized paddy soil (plow soil, pH 5.5-6.0) to the square pot (30 × 15cm), and then the surface area 450cm Rice and paddy weeds were sown in soil and mixed in soil. In order to test the herbicidal power before germination by soil treatment, the mixture of active ingredients corresponding to the prescribed dosage was treated after 1 day of irrigation, and for treatment after germination, the plants were grown for 12 to 14 days in a greenhouse at 20-25 ° C. When two to three leaves were reached, the compound solution of the active ingredient corresponding to the prescribed dose was sprayed uniformly on the plant foliage. Cultivation and observation for 4-5 weeks after treatment were followed to assess the response of the plants with each treatment.

Among the compounds according to the present invention, compounds of Nos. 8, 11, 17 and 23 of Table 1 were selected to evaluate their herbicidal efficacy and crop damage, and the results are shown in Table 3.

[Effects of the Invention]

As can be seen from the results of Table 3, the compound of formula 1 according to the present invention is hardly harmful to crops such as corn, rice, wheat, etc., while showing excellent herbicidal power against blood and broadleaf weeds, it is preferable as a herbicide. It is expected to be able to use.

Claims (9)

Benzophenone oxime ester derivatives of 2,6-di (4,6-dimethoxypyrimidin-2-yl) oxybenzoic acid of formula Wherein R ₁ and R ₂ are each independently halogen, cyano, nitro, C ₁ -C ₄ alkyl, C ₁ -C ₂ haloalkyl, C ₁ -C ₄ alkoxy, C ₁ -C ₄ alkylthio or 1 Or amino substituted or unsubstituted by two C ₁ -C ₄ alkyl, m and n each independently represent an integer of 0 to 5, and m + n is an integer of 1 to 10. A process for preparing the compound of formula 1, characterized in that the compound of formula 2 is reacted with a compound of formula 3 in the presence of a metal salt in a solvent. Wherein R ₁ , R ₂ , m and n are as defined in claim 1. The method of claim 2, wherein the compound of Formula 3 is used in an amount of 1 to 2 equivalents based on the compound of Formula 2. The process of claim 2 wherein the solvent is at least one selected from dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, acetonitrile and propionitrile. The method of claim 2, wherein the metal salt is cupric chloride or cupric bromide. The process of claim 2 wherein the reaction is carried out at room temperature to 60 ° C. As an active ingredient, a herbicide composition for eradicating plants harmful to crops containing the compound of formula 1 according to claim 1 together with a carrier which is commonly used in the preparation of agrochemicals. A method of removing weeds in arable land using the herbicide composition according to claim 7. The method of claim 8, wherein the amount of herbicide composition used is 0.001 to 5.0 kg / ha.