WO2009116558A1

WO2009116558A1 - 1-phenyl-5-difluoromethylpyrazole-4-carboxamide derivative and herbicide containing the same as active ingredient

Info

Publication number: WO2009116558A1
Application number: PCT/JP2009/055251
Authority: WO
Inventors: 至岡田; 麻紀子牛江; 貴史中山; 英世藤井; 誠司柿沼
Original assignee: アグロカネショウ株式会社
Priority date: 2008-03-19
Filing date: 2009-03-18
Publication date: 2009-09-24
Also published as: WO2009116151A1

Abstract

Disclosed is a 1-phenyl-5-difluoromethylpyrazole-4-carboxamide derivative having excellent herbicidal activity. The carboxamide derivative is represented by formula (I). (In the formula, R¹ and R² independently represent a hydrogen atom, a halogen atom, a C₁-C₄ alkyl group, a trifluoromethyl group, a nitro group, a cyano group, a C₁-C₄ alkoxy group, a difluoromethoxy group, a trifluoromethoxy group, a difluoromethylthio group, trifluoromethylthio group, a difluoromethylsulfinyl group, a difluoromethylsulfonyl group, a trifluoromethylsulfinyl group or a trifluoromethylsulfonyl group; and R³ represents a hydroxyl group, a C₁-C₄ alkoxy group, an amino group, a C₁-C₄ alkylamino group, a C₂-C₄ N,N-dialkylamino group or a C₂-C₄ N-alkyl-N-alkoxyamino group.)

Description

1-Phenyl-5-difluoromethylpyrazole-4-carboxamide derivative and herbicide containing the same as an active ingredient

The present invention relates to novel pyrazole carboxamide derivatives and herbicides containing them as active ingredients.

Conventionally, weed control by herbicides is essential for labor saving, improvement of crop productivity, and landscape protection in cultivation of agricultural and horticultural crops and in management of green areas such as parks, recreation facilities and roads. For this reason, research and development of herbicides has been actively carried out for many years, and various herbicides have been put to practical use at present.
However, the emergence of weeds that have acquired resistance to conventionally used herbicides has also become a problem. For example, in the vineyard, hardione resistant to bipyridinium herbicides has been confirmed, and in recent years, as a sulfonylurea herbicide-resistant weed in paddy field cultivation, weeds such as mizuaoi, azenas, izohakobe, chikasigusa, anifish, and konagi are all over the place Control of these weeds is becoming more difficult every year. In addition, environmental pollution such as pollution damage to the surrounding cultivation land due to rainfall infiltration migration or runoff, gasification, etc., groundwater contamination, pollution damage to subsequent crops due to soil residue is also a problem.

On the other hand, with the change of climate and the use of imported feed, the emergence of alien species of weeds, which were not found in conventional cultivation areas, has also become a problem. For example, in corn cultivation, Ibi, Harunasbi, Arechiuri, and Stag beetle have appeared, and weeds that can not be sufficiently satisfactorily controlled by general-purpose herbicides are increasing.
Thus, even today, herbicides that selectively kill only target weeds without causing phytotoxicity to crops even more rapidly, or various types of weeds that occur anywhere else than the crop cultivation site are rapidly killed. There is a need for herbicides and compounds that have high herbicidal effects at lower doses and that can be quickly degraded after the purpose is achieved to reduce environmental pollution.

As compounds most similar to the present invention, the following herbicidally active compounds are known (eg, Patent Document 1 and Non-patent Documents 1 and 2).

However, this compound remains undegraded in the soil for a long period of time and there is a risk of soil contamination and adverse effects on subsequent crops, and the effect of reducing the amount of sprayed water is inferior. It has not been put into practical use because it has problems such as the difficulty in securing areas and the effect of large-scale spraying situations or uneven spraying.

On the other hand, pyrazole carboxamide derivatives are known to have insecticidal, acaricidal, bactericidal, herbicidal or medicinal activity, depending on the type of three substituents on the pyrazole ring and the amino group of carboxamide moiety. For example, the following microbicides have been developed as 1-alkylpyrazole-4-carboxamide derivatives (for example, Patent Documents 2 to 8).

Common Name: Flametopill

Common Name: Penthiopyrade

Common Name: bixafen

Common Name: sedaxane

Common name: isopyrazam

In addition, the following herbicides have been developed (for example, Patent Documents 9 to 11).

Development code No .: EL-177

Development code No .: KPP-297

Development code No .: KPP-856

The following compounds have been developed as acaricides (eg, Patent Documents 12 to 13).

The following herbicidally active compounds are known as 1-phenylpyrazole-4-carboxamide (for example, Patent Documents 14 to 15).

The following acaricides are disclosed as pyrazole-5-carboxamide derivatives (for example, Patent Document 16).

Common name: tebufen pilade

For example, the following compounds are known as insecticides and acaricides (for example, Patent Document 17).

Common Name: Tolfenpilado

In addition, the following compounds are known as insecticides (eg, Patent Documents 18 to 19).

Common Name: Chlorantylpyrrole

For 1-phenylpyrazole-3-carboxamide derivatives, for example, Patent Document 20 reports N-aralkyl-1-phenylpyrazole-3-carboxamide derivatives having insecticidal and acaricidal activity. Moreover, as a substance having a safening effect of a herbicide, for example, Patent Document 21 describes N-hydroxy-4-halo-5-unsubstituted-1-phenylpyrazole-3-carboxamide derivatives, for example, Patent Document 22. In addition, N-alkyl-4-unsubstituted-5-alkyl-1-phenylpyrazole-3-carboxamide derivatives are also disclosed in, for example, Patent Document 23, N-alkyl-4-unsubstituted-1,5- Diphenylpyrazole-3-carboxamide derivatives have been described. Also, for example, Patent Document 24 describes the herbicidal activity of N-alkyl-4-halo-1,5-diphenylpyrazole-3-carboxamide.

Furthermore, N-alkyl-4-unsubstituted-5-alkoxy-1-phenylpyrazole-3-carboxamide derivatives having pharmaceutical activity are described in Non-Patent Document 3 and Non-Patent Document 4, but the description related to pesticidal activity There is no. In addition, N-methyl-4-bromo-5-methoxy-1-phenylpyrazole-3-carboxamide is described, for example, in Non-Patent Document 5, but it has no pharmaceutically activity but also completely describes pesticide activity. Not.
Furthermore, as 1-phenylpyrazole-3-carboxamide derivatives, for example, compounds having the following bactericidal activity are disclosed (for example, Patent Documents 25 to 31).

Japanese Patent Application Laid-Open No. 60-172967 Patent No. 2638966 gazette JP 2001-151770 A Japanese Patent Application Publication No. 2005-530694 Japanese Patent Application Publication No. 2005-532271 Japanese Patent Application Publication No. 2006-511485 Japanese Patent Application Publication No. 2008-515834 WO 2008-113447 Japanese Patent Application Laid-Open No. 60-172968 WO 2001-23358 JP 2002-348280 A JP 2006-56788 A Unexamined-Japanese-Patent No. 2006-199637 Japanese Patent Application Laid-Open No. 60-172968 Japanese Patent Application Laid-Open No. 61-72757 Patent No. 1838897 gazette Patent No. 2861104 Japanese Patent Publication No. 2004-538328 Japanese Patent Application Publication No. 2005-502716 Japanese Patent Application Laid-Open No. 64-25763 Japanese Patent Application Laid-Open No. 63-91373 Unexamined-Japanese-Patent No. 1-283274 Japanese Patent Application Laid-Open No. 63-115867 Japanese Patent Application Laid-Open No. 8-21654 Unexamined-Japanese-Patent No. 11-171867 gazette Japanese Patent Application Laid-Open No. 11-199566 JP 2000-103784 A JP 2000-169453 A JP, 2001-240592, A Japanese Patent Laid-Open No. 2002-205985 JP 2002-265452 A

The present invention provides a highly safe and useful chemical substance as an active ingredient of a herbicide, which exhibits high control effect on various weeds and has reduced problems such as soil contamination and effects on subsequent crops. It is.

As a result of earnest efforts by the present inventors to solve the above problems, 1-phenyl-5-difluoromethylpyrazole-4-carboxamide derivative represented by the following formula (hereinafter referred to as "the compound of the present invention as a generic term") Is found to be a useful compound having the above characteristics, and the present invention has been completed. That is, the present invention relates to the following formula (I):

(I)

The present invention relates to a 1-phenyl-5-difluoromethylpyrazole-4-carboxamide derivative represented by and a herbicide containing the derivative as an active ingredient.

In the compound of the present invention represented by the formula (I), R ¹ and R ^{2 each} represent a hydrogen atom, a halogen atom, a C ₁ to C ₄ alkyl group, a trifluoromethyl group, a nitro group, a cyano group, C ₁ to an alkoxy group having C _4, difluoromethoxy group, trifluoromethoxy group, a difluoromethylthio group, a trifluoromethylthio group, difluoromethyl sulfinyl group, a difluoromethyl sulfonyl group, trifluoromethyl sulfinyl group, or a trifluoromethylsulfonyl group.
As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned suitably, for example.
As the C ₁ to C ₄ alkyl group, for example, methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, etc. And C ₁ -C ₄ straight-chain, branched or cyclic alkyl groups, and the like.
The alkoxy group of C ₁ ~ C _4, for example, a methoxy group, an ethoxy group, n- propoxy group, isopropoxy group, n- butoxy group, isobutoxy group, sec- butoxy group, C ₁ such as t- butoxy such as linear or branched alkoxy group having ~ C ₄ are preferably exemplified.
In particular, R ¹ is a hydrogen atom, a chlorine atom, a bromine atom, a fluorine atom, a difluoromethoxy group, a trifluoromethoxy group or the like, and R ² is preferably a hydrogen atom.

R ³ represents a hydroxyl group, a C ₁ to C ₄ alkoxy group, an amino group, a C ₁ to C ₄ alkylamino group, a C ₂ to C ₄ N, N-dialkylamino group or a C ₂ to C ₄ N -Represents an alkyl N-alkoxyamino group.
The range of the C ₁ to C ₄ alkoxy group is as described above, and examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxyl group, an n-butoxy group, an isobutoxy group, and a sec-butoxy group. And a C ₁ to C ₄ linear or branched alkoxy group such as t-butoxy group.
The C ₁ to C ₄ alkylamino group is a C ₁ to C ₄ alkyl group wherein the alkyl group of the amino group is a C ₁ to C ₄ alkyl group. Examples of such a C ₁ to C ₄ alkylamino group include a methylamino group and the like , C ₁ -C ₄ straight such as ethylamino group, n-propylamino group, isopropylamino group, cyclopropylamino group, n-butylamino group, isobutylamino group, sec-butylamino group, t-butylamino group, etc. Preferred are amino groups of chain, branched or cyclic alkyl groups.
The C ₂ -C ₄ N, N-dialkylamino group is one in which the nitrogen atom of the amino group is substituted with two alkyl groups, and the range of the alkyl group is the total number of carbon atoms in the alkyl group Is 2 to 4, and specifically, for example, C ₂ to C ₄ N, N-dialkylamino groups such as dimethylamino, diethylamino, methylethylamino, methylpropylamino and the like are preferably mentioned. Be
As the C ₂ to C ₄ N-alkyl N-alkoxyamino group, for example, methylmethoxyamino group, methylethoxyamino group, methyl-n-propoxyamino group, ethylmethoxy group, n-propylmethoxy group and the like are preferable. It can be mentioned.
As R ³ , for example, a methylamino group or a cyclopropylamino group is preferable.

The compounds of the present invention represented by the above formula (I) are novel compounds.
The compound of the present invention can be produced, for example, according to the following reaction formula 1, in accordance with, for example, JP-A-60-172,967 (Patent Document 1).
Reaction formula 1

In the above formulae, R ¹ , R ² and R ³ are as defined in the above formula (I), and X represents a chlorine atom, a bromine atom, a hydroxyl group, a methoxy group, an ethoxy group or a propoxy group.
In the above formula (II), when X represents a chlorine atom or a bromine atom, as a solvent, for example, benzene, or an aromatic hydrocarbon such as toluene or xylene; acetone, methyl ethyl ketone, methyl isobutyl ketone or the like Ketones; halogenated hydrocarbons such as chloroform and methylene chloride; water; esters such as methyl acetate and ethyl acetate; or tetrahydrofuran, acetonitrile, dioxane, N, N-dimethylformamide, N-methylpyrrolidone or dimethyl sulfoxide, etc. The reaction can be performed in the presence of a base at, for example, 0 ° C. to 30 ° C., preferably 0 ° C. to 5 ° C., using a polar solvent of As a base, for example, sodium hydroxide, potassium hydroxide, pyridine or triethylamine can be used.
Further, in the formula (II), when X is a hydroxyl group, a methoxy group, an ethoxy group or a propoxy group, in the absence of a solvent or in an alcohol such as methyl alcohol, ethyl alcohol or propyl alcohol. For example, the reaction can be carried out at 5 to 100.degree. C., preferably 20 to 80.degree.

After the reaction, in order to isolate the desired compound of the present invention represented by the formula (I), when a solvent dissolved in water was used, the solvent was distilled off under reduced pressure and water was added. After that, extract with water-insoluble benzene, aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as chloroform and methylene chloride; esters such as ethyl acetate, and wash with saturated saline, and then anhydrous sodium sulfate After drying with a desiccant such as, the solvent may be distilled off under reduced pressure. When a solvent insoluble in water is used, water is added and then separated, and the organic phase is washed with saturated saline and then dried with a desiccant such as anhydrous sodium sulfate and the solvent is distilled off under reduced pressure. good. After evaporation of the solvent, the obtained residue may be sufficiently pure as it is, but if it is impure, it may be washed with a hydrocarbon such as hexane, heptane or the like which does not dissolve the object significantly, or recrystallization or column chromatography Purification by chromatography yields a pure product.
The following formula (III) which is a part of the compound of the formula (II) as the starting material,

(III)

(Wherein, R ¹ and R ² are as defined in the formula (II), and R ⁴ represents a C ₁ to C ₄ alkoxy group as described for R ³ ). The 1-phenyl-5-difluoromethyl-4-carboxylic acid ester derivative to be represented is a novel compound not described in the literature, and can be synthesized according to the following reaction formula.
Reaction formula 2

(In the above formula, R ¹ , R ² and R ⁴ are as defined in the above formula (III).)
The above reaction can be carried out in the presence or absence of a solvent and a base. The solvent is not particularly limited as long as it does not directly participate in the reaction, and examples thereof include benzene, aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as chloroform and dichloromethane; water; methyl acetate And esters such as ethyl acetate; polar solvents such as acetonitrile, N, N-dimethylformamide, N-methyl pyrrolidone and dimethyl sulfoxide; ethers such as tetrahydrofuran, dioxane and diisopropyl ether; methanol, ethanol, propanol, ethylene glycol and the like Or mixed solvents of the above solvents. Examples of the base include alkali metal hydrates such as sodium hydroxide and potassium hydroxide; alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate Sodium hydrogen carbonate; alkali metal hydrogen carbonates such as potassium hydrogen carbonate; alkaline earth metal carbonates such as calcium carbonate and magnesium carbonate; metal alkoxides such as sodium methoxide and sodium ethoxide. The reaction temperature is, for example, 5 to 100 ° C., preferably 0 to 50 ° C.

After the reaction, in order to isolate the compound of the present invention represented by the target compound (III), mineral acids such as hydrochloric acid and sulfuric acid; acidification with organic acids such as acetic acid and propionic acid; When a solvent that dissolves is used, the solvent is distilled off under reduced pressure, water is added, and then benzene insoluble in water, aromatic hydrocarbons such as toluene and xylene; halogen based hydrocarbons such as chloroform and dichloromethane Extraction with an ester such as ethyl acetate and the like, washing with saturated brine, drying with a desiccant such as anhydrous sodium sulfate, and evaporation of the solvent under reduced pressure may be carried out. When a solvent insoluble in water is used, water is added to the reaction mixture and then separated, and the organic layer is washed with saturated brine, dried with a desiccant such as anhydrous sodium sulfate and the solvent is distilled off under reduced pressure. do it. The residue obtained after evaporation may be sufficiently pure as it is, but if it is impure, it may be washed with a hydrocarbon such as hexane or heptane which does not dissolve the object very much, or by recrystallization or column chromatography. If refined, a pure product is obtained.
Among the compounds of the formula (II) as starting materials, the following formula (VI) in which X is represented by a hydroxyl group can be synthesized by hydrolysis of the following formula (III).
Reaction formula 3

(Wherein, R ¹ , R ² and R ⁴ are as defined in the above formula (III))
The above reaction can be carried out in the presence or absence of a solvent and in the presence of a base. Examples of the solvent include water; alcohols such as methanol, ethanol, propanol and ethylene glycol, and mixed solvents of the above solvents. Examples of the base include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate; hydrogen carbonate Examples thereof include alkali metal carbonates such as sodium and potassium hydrogen carbonate; and alkaline earth metal carbonates such as calcium carbonate and magnesium carbonate. The reaction temperature is, for example, 5 to 150 ° C., preferably 10 to 110 ° C. After the reaction, in order to isolate the compound represented by the formula (VI) which is the target product, the precipitate is acidified after being acidified with a mineral acid such as hydrochloric acid or sulfuric acid; acetic acid or an organic acid such as propionic acid It may be filtered and washed with water and then dried.

Reaction formula 4

(In the above formulae, R ¹ and R ² are as defined in the formula (I), and Z represents a chlorine atom or a bromine atom.)
The compound of formula (VI) is reacted with a halogenating agent to give a compound of formula (VII). The above reaction can be carried out in the presence or absence of a solvent. The solvent is not particularly limited as long as it does not directly participate in the reaction, and examples thereof include benzene, aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as chloroform and dichloromethane. Examples of the halogenating agent include thionyl chloride, thionyl bromide, oxalyl chloride, oxalyl bromide, phosphorus pentachloride, phosphorus pentabromide, phosphorus trichloride and the like. The reaction temperature is, for example, 5 to 100 ° C., preferably 20 to 90 ° C. After the reaction, in order to isolate the desired compound represented by the formula (VII), the reaction solution is concentrated under reduced pressure, and the obtained residue is dissolved with a hydrocarbon such as hexane or heptane which does not dissolve the desired product very much. It may be dried after washing.

The herbicide of the present invention containing the compound of the present invention represented by the formula (I) as an active ingredient has an excellent herbicidal effect on various weeds of agricultural land and non-agricultural land. Above all, it is useful as an active ingredient of a foliage treating herbicide for upland field annual weeds.
As such weeds, for example, crabgrass, enokologsa, pokeweed, bluefish, shiroza, ichibi, chickweed, morning glory and the like can be mentioned. However, weeds to be controlled by the compounds of the present invention are not limited to those exemplified above. In addition, the herbicide of the present invention containing the compound of the present invention represented by the formula (I) as an active ingredient has high safety to crops such as wheat, barley, sorghum, corn, cotton and beets. When the compound of the present invention represented by the formula (I) is used as a herbicide, it may be used alone, but it is preferably used as a composition to which a pesticide adjuvant widely used in the art is added.
Although the dosage form of the herbicide is not particularly limited, for example, the form of an emulsion, a wettable powder, a powder, a flowable, a fine granule, a granule, a tablet, an oil and the like is preferable. One or two or more of the compounds of the present invention can be blended as an active ingredient.

Pesticide adjuvants used to produce herbicides are, for example, substances having effects such as enhancement of the effect of herbicide, stabilization, improvement of dispersibility, and enhancement of crop safety, for example, carriers (Diluents), spreaders, emulsifiers, wetting agents, dispersants, disintegrants, wetting agents and the like can be used. Liquid carriers include, for example, water; aromatic hydrocarbons such as toluene and xylene; alcohols such as methanol, butanol and glycol; ketones such as acetone; amides such as dimethylformamide; sulfoxides such as dimethyl sulfoxide; Naphthalene; cyclohexane; animal and vegetable oils; or fatty acids and the like can be mentioned.

Further, examples of the solid carrier include clay, kaolin, talc, diatomaceous earth, silica, calcium carbonate, montmorillonite, bentonite, feldspar, quartz, alumina, saw dust, nitrocellulose, starch, gum arabic and the like. As the emulsifying agent and the dispersing agent, usual surfactants can be used. For example, anionic surfactants such as higher alcohol sodium sulfate, stearyltrimethyl ammonium chloride, polyoxyethylene alkylphenyl ether, lauryl betaine and the like; An ionic surfactant; a nonionic surfactant; or a zwitterionic surfactant etc. can be used. In addition, spreading agents such as polyoxyethylene fatty acid ester and polyoxyethylene alkyl ester, wetting agents such as dialkyl sulfosuccinate; fixing agents such as carboxyl methyl cellulose and polyvinyl alcohol; collapse such as sodium lignin sulfonate and sodium lauryl sulfate Agents can be used.

The content of the active ingredient in the herbicide of the present invention is, for example, selected from the range of 0.01 to 99.5%, and may be suitably determined according to various conditions such as the formulation form, application method and the like. For example, in the emulsion, for example, about 1 to 90% by mass, preferably 10 to 40% by mass, in the wettable powder, for example, about 1 to 90% by mass, preferably 10 to 80% by mass, For example, about 0.5 to 20% by mass, preferably 1 to 10% by mass, and in the case of a flowable, for example, about 1 to 90% by mass, preferably 10 to 50% by mass. It is preferred to manufacture.

For example, in the case of an emulsion, an emulsion of a stock solution can be prepared by mixing a solvent, a surfactant and the like with the compound of the present invention which is an active ingredient, and this stock solution is Can be diluted and applied.
In the case of the flowable agent, the compound of the present invention, which is the active ingredient, can be mixed with water, surfactant, etc. to produce a stock solution, and this stock solution is further diluted with water to a predetermined concentration when used. Can be applied.
In the case of a wettable powder, the compound of the present invention as an active ingredient, a solid carrier, a surfactant and the like can be mixed and manufactured, and when used, it can be applied diluted with water to a predetermined concentration.
In the case of powders, the compound of the present invention as an active ingredient, a solid carrier and the like can be mixed and applied as they are. However, the manufacturing method of each above-mentioned formulation form is not limited to the above-mentioned thing, those skilled in the art can select suitably according to the kind of an active ingredient, the purpose of application, etc.

In the herbicide of the present invention, other herbicides, insecticides, acaricides, fungicides, growth regulators, fertilizers, as long as the activity of the compound of the present invention of the formula (I) which is the active ingredient is not impaired. You may mix | blend arbitrary active ingredients, such as a soil conditioner.
The compounds of the present invention can be used in the same manner as conventional herbicides, and for example, soil treatment or foliage treatment is carried out using the compounds of the present invention before germination, early germination and growth stage of upland weeds. be able to. The application amount of the herbicide of the present invention can be appropriately selected depending on the application method, purpose, time, weeding condition and the like, but the amount of active ingredient is usually 0.001 kg to 10 kg per hectare, for example. Is preferably 0.003 kg to 3 kg.

Next, the present invention will be more specifically described by Synthesis Examples, Formulation Examples and Test Examples, but the scope of the present invention is not limited at all by these Synthesis Examples, Formulation Examples and Test Examples.

<Example 1> Synthesis of ethyl 1- (4-chlorophenyl) -5-difluoromethylpyrazole-4-carboxylate According to the above reaction formula 2, 11.1 g of 2- (ethoxymethylene) -4,4-difluoroacetoacetic acid ethyl ester And 4.95 g of 4-chlorophenylhydrazine hydrochloride were heated to reflux for 1 hour in 50 ml of water and 50 ml of toluene. The reaction mixture was separated, and the aqueous phase was washed with saturated brine and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography to obtain 10.2 g of the compound of the present invention (No. 3) described in Table 1. The melting point was 42-44 ° C.
¹ H-NMR (CDCl ₃ ) δ ppm: 1.40 (3H, t), 4.38 (2H, q), 7.48 (4H, m), 7.48 (1H, t), 8.10 (1H, s)

<Example 2> Synthesis of 1- (4-chlorophenyl) -5-difluoromethylpyrazole-4-carboxylic acid Ethyl 1- (4-chlorophenyl) -5-difluoromethylpyrazole-4-carboxylate obtained in Example 1 A mixture of 9.02 g, 2.40 g of sodium hydroxide, 40 ml of ethyl alcohol and 40 ml of water was heated to reflux for 1 hour. After cooling to room temperature, hydrochloric acid is added to acidify and crystals are collected by filtration, washed with water and dried to obtain 8.10 g of the compound of the present invention (No. 4) described in Table 1. The melting point was 140-142 ° C.

<Example 3> Synthesis of N-methyl-1- (4-chlorophenyl) -5-difluoromethylpyrazole-3-carboxamide 1- (4-chlorophenyl) -5-difluoromethylpyrazole-4-obtained in Example 2 The solution was heated under reflux for 1 hour in 5 ml of thionyl chloride and concentrated under reduced pressure. The resulting residue was added to 1.16 g of 40% aqueous methylamine solution and stirred at room temperature for 1 hour. The mixture was extracted with ethyl acetate, and the organic layer was washed with saturated brine and then dried over anhydrous sodium sulfate. After concentration under reduced pressure, the resulting residue was washed with hexane to obtain 0.35 g of the compound of the present invention (No. 31) described in Table 2. The melting point was 167-169 ° C.

<Example 4> Synthesis of Nn-propyl-1- (4-chlorophenyl) -5-difluoromethylpyrazole-4-carboxamide 1- (4-chlorophenyl) -5-difluoromethylpyrazole-4-obtained in Example 1 3.01 g of ethyl carboxylate and 0.18 g of n-propylamine were stirred in 10 ml of methanol at room temperature for 18 hours. The mixture was concentrated under reduced pressure, and the obtained residue was purified by silica gel column chromatography to obtain 2.50 g of a compound (No. 33) described in Table 2 below. The melting point was 128-130 ° C.
Other than that, the compound of the present invention was prepared similarly. Tables 1 and 2 below describe the compounds of the invention prepared according to the examples.

1) ¹ H-NMR (CDCl ₃ ) δ ppm: 1.40 (3 H, t), 4.40 (2 H, q), 7.4-7.7 (6 H, m), 8. 10 (1 H, s).
2) ¹ H-NMR (CDCl ₃ ) δ ppm: 1.40 (3 H, t), 4.40 (2 H, q), 7.2-7.6 (5 H, m), 8.13 (1 H, s).
3) ¹ H-NMR (CDCl ₃ ) δ ppm: 1.40 (3H, t), 2.43 (3H, s), 4.40 (2H, q), 7.3-7.5 (5H, m), 8.10 (1H, s).
4) ¹ H-NMR (CDCl ₃ ) δ ppm: 1.40 (3H, t), 4.38 (2H, q), 4.88 (3H, s), 7.0-7.5 (5H, m), 8.04 (1H, s).

5) ¹ H-NMR (CDCl ₃ ) δ ppm: 1.40 (3H, t), 4.40 (2H, q), 7.35-7.69 (5H, m), 8.09 (1H, s).
6) ¹ H-NMR (CDCl ₃ ) δ ppm: 1.40 (3H, t), 4.38 (2H, q), 6.51 (1H, t), 7.21-7.67 (5H, m), 8.08 (1H, s).

Hereinafter, formulation examples of a herbicide containing the compound of the present invention as an active ingredient are shown. The scope of the present invention is not limited at all by the following formulation examples. Moreover, all being "part" in an Example represents a mass part.

Formulation Example 1 Emulsion A compound of the present invention (10 parts), xylene (60 parts), N-methyl-2-pyrrolidone (20 parts) and Sorpol 3005X (10 parts) as an emulsifier are uniformly mixed and dissolved. An emulsion was obtained.

Formulation Example 2 Hydrating agent Compound of the present invention (20 parts), Carplex # 80 (20 parts), ST kaolin clay (50 parts), sodium lignin sulfonate (5 parts) and Lunox P-as a wetting agent 65 L (5 parts) was uniformly mixed and ground in a jet air mill to obtain a wettable powder.

Formulation Example 3 Granule The compound of the present invention (5 parts), bentonite (30 parts), clay (60 parts) and sodium lignin sulfonate (5 parts) were uniformly ground and mixed, water was added and thoroughly mixed. Thereafter, the mixture was extruded and granulated, and dried and sized to obtain granules.

<Test Example 1> Herbicidal Efficacy Test Field soil is filled in an aluminum pot having a surface area of 160 cm ² and sown seeds of crabgrass, bluegrass and shiroza are covered with about 0.5 cm of soil, and then grown in a greenhouse, crabgrass at three leaf stages At that time, 3 kg / ha of the compound of the present invention prepared according to Preparation Example 1 such that the amount of the active ingredient was a predetermined ratio was uniformly dispersed to the stem and leaf and the soil. The herbicidal effect on each weed was investigated according to the following criteria 14 days after chemical solution spraying, and the results shown in Table 3 were obtained. The compound No. corresponds to the compound No. in Table 1 and Table 2. As apparent from Table 3, the compounds of the present invention show excellent herbicidal effects on weeds.

Survey criteria
10 100% suppression weeding effect
9 90-99% suppression of weeding effect
8 Weeding effect of 80 to 89% suppression
7 Weeding effect of 70 to 79% suppression
Weeding effect of 6 60-69% suppression
5 50-59% suppression of weeding effect
Weeding effect of 4 40-49% suppression
Weeding effect of 3 30-39% suppression
Weeding effect of 2 20-29% suppression
Weeding effect of 1 1-19% suppression

(Continuation of Table 3)
Compound No. Throughput kg / ha crabgrass Aobilu Shiroza
76 3 10 10 10
77 3 10 10 10
78 3 10 10 10
79 3 10 10 10
80 3 10 10 10
81 3 10 10 10
82 3 10 10 10
83 3 10 10 10
84 3 10 10 10
85 3 10 10 10

<Test Example 2> Herbicidal effect test according to the number of days after treatment A field soil is filled in an aluminum pot having a surface area of 160 cm ² , and the compound of the present invention prepared according to Formulation Example 1 such that the amount of the active ingredient becomes a predetermined ratio. A known compound A similar to the compound of the present invention was uniformly sprayed on the soil surface in an amount of 1.5 kg / ha each. Seeds of crabgrass and morning glory were sowed 1, 30, and 60 days after chemical solution spraying, and investigations were conducted based on the same criteria as in Test Example 1, and the results shown in Table 4 below were obtained. The compound No. corresponds to the compound No. in Table 2, and the structural formula of the compound A is as shown below.
As apparent from Table 4, the compounds of the present invention are rapidly degraded after the treatment, and are excellent ones with less load on the environment and subsequent crops.

* Number of days from spraying to sowing

Compound A

<Test Example 3> Herbicidal effect test according to the amount of sprayed water Field soil is filled in an aluminum pot having a surface area of 160 cm ² and sown with Aobiru seeds and covered with soil for about 0.5 cm, and then grown in a greenhouse. The compound of the present invention prepared according to Formulation Example 1 such that the amount of the active ingredient becomes a predetermined ratio at the same time, and the compound A in an amount of 0.025, 0.0125 kg / ha The solution was diluted to (L) and 250 L and uniformly sprayed to stems and leaves and soil. The herbicidal effect on each weed was examined 14 days after chemical solution spraying based on the same criteria as in Test Example 1, and the results shown in Table 5 below were obtained. The compound No. corresponds to the compound No. in Table 2, and the compound A is as defined in Test Example 2.
As apparent from Table 5, the compounds of the present invention show excellent herbicidal effects even when the amount of water sprayed is small, and are stable even in areas where water is difficult to secure, in large-scale spraying situations, and also in uneven spraying. Exhibit excellent weeding effects.

* Sprayed water volume per ha

The 1-phenyl-5-difluoromethylpyrazole-4-carboxamide derivative compound of the present invention has an excellent control effect on various weeds and is effective as a herbicide.

Claims

The following formula (I),

(I)

(Wherein, R 1 and R 2 are each independently a hydrogen atom, a halogen atom, a C 1 to C 4 alkyl group, a trifluoromethyl group, a nitro group, a cyano group, a C 1 to C 4 alkoxy group, And a difluoromethoxy group, a trifluoromethoxy group, a difluoromethylthio group, a trifluoromethylthio group, a difluoromethylsulfinyl group, a difluoromethylsulfonyl group, a trifluorothromethyl methylfinyl group, or a trifluoromethylsulfonyl group.
R 3 represents a hydroxyl group, a C 1 to C 4 alkoxy group, an amino group, a C 1 to C 4 alkylamino group, a C 2 to C 4 N, N-dialkylamino group or a C 2 to C 4 N -Represents an alkyl N-alkoxyamino group. )
1-phenyl-5-difluoromethylpyrazole-4-carboxamide derivative represented by
The carboxamide derivative according to claim 1, wherein R 3 in the formula (I) is a methylamino group or a cyclopropylamino group.
In formula (I), R 1 and R 2 are a hydrogen atom, or R 1 is a chlorine atom, a bromine atom, a fluorine atom, a difluoromethoxy group or a trifluoromethoxy group at the 4-position of the phenyl group And R 2 is a hydrogen atom.
A herbicide comprising the carboxamide derivative according to any one of claims 1 to 3 as an active ingredient.