WO2009116151A1 - 1-phenyl-5-difluoromethylpyrazole-4-carboxamide derivatives and herbicides containing the derivatives as the active ingredient - Google Patents

Abstract

The invention provides 1-phenyl-5-difluoromethylpyrazole-4- carboxamide derivatives having excellent herbicidal activity. The derivatives are represented by the general formula: (I) wherein R¹ and R² are each independently hydrogen, halogeno, C_1-4 alkyl, trifluoromethyl, nitro, cyano, or C_1-4 alkoxy; and R³ is hydroxyl, C_1-4 alkoxy, amino, C_1-4 alkylamino, C_2-4 dialkylamino, or C_2-4 alkylalkoxyamino.

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 these as active ingredients.

Conventionally, weed control with herbicides is indispensable for labor saving, crop productivity improvement, and landscape protection when cultivating agricultural and horticultural crops and managing green spaces in parks, recreational facilities, and roads. For this reason, research and development of herbicides have been actively conducted for many years, and a wide variety of herbicides are now in practical use.
However, the emergence of weeds that have acquired resistance to conventional general herbicides is also a problem. For example, mulberry plant has been confirmed to be resistant to bipyridylium herbicides, and recently, sulfonylurea herbicide-resistant weeds in paddy field cultivation have been found in various places such as squirrel mushrooms, azenas, mizojakusa, kakashigusa, inu firefly, and kogagi. However, it is difficult to control these weeds year by year. In addition, environmental pollution, such as soil infiltration due to rainfall, runoff, gasification, damage to surrounding cultivated land, groundwater contamination, and subsequent crop damage 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 non-native weeds that did not exist in conventional cultivation areas is also a problem. For example, there are litter, walnut bee, alliuri, shrimp, and so on in corn cultivation, and weeds that cannot be satisfactorily controlled with general-purpose herbicides are increasing.
In this way, even today, a herbicide that selectively kills only the target weeds without causing any phytotoxicity to the crop, or quickly kills a wide variety of weeds that occur in places other than the crop cultivation area. In order to reduce environmental pollution, there is a need for a compound that has a high herbicidal effect at a lower dose and that can be rapidly degraded after the purpose is achieved.

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

However, this compound remains undegraded in the soil for a long period of time, has the risk of adversely affecting soil contamination and subsequent crops, and is less effective when the amount of sprayed water is reduced. It has not been put into practical use due to problems such as areas that are difficult to secure and problems such as large-scale spraying situations or uneven spraying.

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

Generic name: Frametopil

Generic name: Penthiopyrad

Generic name: bixafen

In addition, the following herbicides have been developed (for example, Patent Documents 5 to 7).

Development code No .: EL-177

Development code: KPP-297

Development code: KPP-856

The following compounds have been developed as acaricides (for example, Patent Documents 8 to 9).

The following herbicidal active compounds are known as 1-phenylpyrazole-4-carboxamide (for example, Patent Documents 10 to 11).

The following acaricides are disclosed as pyrazole-5-carboxamide derivatives (for example, Patent Document 12).

Generic name: Tebufenpyrad

As insecticides and acaricides, for example, the following compounds are known (for example, Patent Document 13).

Generic name: Torfenpyrad

Further, the following compounds are known as insecticides (for example, Patent Documents 14 to 15).

Generic name: chlorantil pyrrole

Regarding 1-phenylpyrazole-3-carboxamide derivatives, for example, Patent Document 16 reports N-aralkyl-1-phenylpyrazole-3-carboxamide derivatives having insecticidal and acaricidal activity. In addition, as a substance having a herbicide reducing action, for example, Patent Document 17 discloses an N-hydroxy-4-halo-5-unsubstituted-1-phenylpyrazole-3-carboxamide derivative, for example, Patent Document 18 Include N-alkyl-4-unsubstituted-5-alkyl-1-phenylpyrazole-3-carboxamide derivatives. For example, Patent Document 19 discloses N-alkyl-4-unsubstituted-1,5- Diphenylpyrazole-3-carboxamide derivatives are described. For example, Patent Document 20 describes the herbicidal activity of N-alkyl-4-halo-1,5-diphenylpyrazole-3-carboxamide.

Further, 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 a description of agrochemical activity There is no. N-methyl-4-bromo-5-methoxy-1-phenylpyrazole-3-carboxamide is described in, for example, Non-Patent Document 5, but not only has no pharmaceutical activity but also has no description of pesticide activity. Not.
Further, as 1-phenylpyrazole-3-carboxamide derivatives, for example, compounds having the following bactericidal activity are disclosed (for example, Patent Documents 21 to 27).

Japanese Unexamined Patent Publication No. 60-172967 Japanese Patent No. 2638966 Japanese Patent Laid-Open No. 2001-151770 WO2007-68370 Publication Japanese Unexamined Patent Publication No. 60-172968 WO2001-23358 Japanese Patent Laid-Open No. 2002-348280 Japanese Unexamined Patent Publication No. 2006-56788 JP 2006-199637 Japanese Unexamined Patent Publication No. 60-172968 JP 61-72757 A Japanese Patent No. 1838897 Japanese Patent No. 2861104 Special Publication 2004-538328 JP 2005-502716 Publication JP-A 64-25763 Japanese Unexamined Patent Publication No. 63-91373 Japanese Unexamined Patent Publication No. 1-283274 JP 63-115867 A Japanese Patent Laid-Open No. 8-12654 Japanese Patent Laid-Open No. 11-171867 Japanese Patent Laid-Open No. 11-199566 Japanese Unexamined Patent Publication No. 2000-103784 JP 2000-169453 A JP 2001-240592 A JP 2002-205985 A Japanese Patent Laid-Open No. 2002-265452

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

As a result of diligent efforts to solve the above-mentioned problems, the present inventors have obtained a 1-phenyl-5-difluoromethylpyrazole-4-carboxamide derivative represented by the following formula (hereinafter referred to as “the compound of the present invention”). However, the inventors have found that the compound is a useful compound having the characteristics described above, and have completed the present invention. That is, the present invention includes the following formula (I),

(I)

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

In the compound of the present invention represented by the formula (I), R ¹ and R ² are each independently hydrogen atom; halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom; methyl group, ethyl group, n -C ₁ -C ₄ linear, branched or cyclic alkyl groups such as -propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group; trifluoromethyl group a nitro group; a cyano group; methoxy group, ethoxy group, n- propoxy group, isopropoxy group, n- butoxy group, isobutoxy group, sec- butoxy group, t-linear C ₁ ~ C ₄ or butoxy group or Examples include branched chain alkoxy groups. In particular, R ¹ is a hydrogen atom, chlorine atom, bromine atom, fluorine atom, or the like, and R ² is preferably a hydrogen atom.

R ³ is a hydroxyl group; a C ₁ -C ₄ straight chain such as a methoxy group, an ethoxy group, an n-propoxyl group, an isopropoxyl group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, or a t-butoxy group. Chain or branched alkoxy group; amino group; methylamino group, ethylamino group, n-propylamino group, isopropylamino group, cyclopropylamino group, n-butylamino group, isobutylamino group, sec-butylamino group, t -C ₁ -C ₄ linear, branched or cyclic alkylamino groups such as butylamino group; C ₂ -C ₄ dialkylamino groups such as dimethylamino group, diethylamino group, methylethylamino group, methylpropylamino group ; methyl methoxy group, a methyl ethoxy group, alkylamine of C ₂ ~ C ₄ such as methyl -n- propoxy group, an ethyl methoxy, n- propyl methoxy Kokishiamino group, and the like.
R ³ is preferably, for example, a methylamino group or a cyclopropylamino group.
The compound of the present invention represented by the formula (I) is a novel compound.
The compound of the present invention can be produced, for example, according to the following reaction formula 1, according to JP-A-60-172967 (Patent Document 1).

Reaction formula 1

In the above formula, R ¹ , R ² and R ³ are as defined in the formula (I), and X represents a chlorine atom, bromine atom, hydroxyl group, methoxy group, ethoxy group or propoxy group.
In the above formula (II), when X represents a chlorine atom or a bromine atom, aromatic solvents such as benzene, toluene and xylene; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; chloroform Or halogenated hydrocarbons such as methylene chloride; water; esters such as methyl acetate and ethyl acetate; or polar solvents such as tetrahydrofuran, acetonitrile, dioxane, N, N-dimethylformamide, N-methylpyrrolidone or dimethyl sulfoxide, etc. Can be used in the presence of a base at 0 ° C. to 30 ° C., preferably 0 ° C. to 5 ° C., for example. As the base, for example, sodium hydroxide, potassium hydroxide, pyridine, triethylamine, or the like can be used.
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 ° C., preferably 20 to 80 ° C.

After the reaction, in order to isolate the compound of the present invention represented by the formula (I) as a target product, when using a solvent that dissolves in water, the solvent was distilled off under reduced pressure, and water was added. Extracted with water-insoluble benzene, toluene, xylene and other aromatic hydrocarbons; chloroform, methylene chloride and other halogenated hydrocarbons; ethyl acetate and other esters, washed with saturated brine, and anhydrous sodium sulfate After drying with a desiccant such as, the solvent may be distilled off under reduced pressure. In the case of using a solvent insoluble in water, it is separated after adding water, and after washing the organic phase with saturated saline and drying with a desiccant such as anhydrous sodium sulfate, the solvent is distilled off under reduced pressure. good. After evaporation of the solvent, the resulting residue may be sufficiently pure as it is, but if it is impure, it can be washed with a hydrocarbon such as hexane or heptane that does not dissolve the target product, or recrystallized or column chromatographed. Pure product can be obtained by refining by chromatography.
The following formula (III), which is part of the compound of formula (II) as a starting material,

(III)

(Wherein R ¹ and R ² are as defined in the formula (II), and R ⁴ represents a C ₁ -C ₄ alkoxy group as described for R ³ ). The represented 1-phenyl-5-difluoromethyl-4-carboxylic acid ester derivative is a novel compound not described in any 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 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 this reaction. For example, aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as chloroform and dichloromethane; water; Esters such as ethyl acetate; Polar solvents such as acetonitrile, N, N-dimethylformamide, N-methylpyrrolidone or dimethyl sulfoxide; Ethers such as tetrahydrofuran, dioxane, diisopropyl ether; Methanol, ethanol, propanol, ethylene glycol, etc. Or a mixed solvent 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 Alkali metal hydrogen carbonates such as sodium hydrogen carbonate and 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, the compound of the present invention represented by the formula (III), which is the target product, is isolated by acidifying with a mineral acid such as hydrochloric acid or sulfuric acid; an organic acid such as acetic acid or propionic acid, and then into water. When a solvent that dissolves is used, the solvent is distilled off under reduced pressure, water is added, and then water-insoluble benzene, toluene, xylene, and other aromatic hydrocarbons; chloroform, dichloromethane, and other halogenated hydrocarbons Extraction with an ester such as ethyl acetate, washing with a saturated saline solution, drying with a desiccant such as anhydrous sodium sulfate, and evaporation of the solvent under reduced pressure. When a solvent insoluble in water is used, water is added to the reaction mixture and the layers are separated. The organic layer is washed with saturated brine, dried over a drying agent such as anhydrous sodium sulfate, and the solvent is distilled off under reduced pressure. do it. The residue obtained after distillation may be sufficiently pure as it is, but if it is impure, it may be washed with a hydrocarbon such as hexane or heptane that does not dissolve the target product, or recrystallization or column chromatography. If purified, a pure product is obtained.
Among the compounds of the formula (II) as a starting material, the following formula (VI) in which X is a hydroxyl group can be synthesized by hydrolyzing 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 of a base in the presence or absence of a solvent. Examples of the solvent include water; alcohols such as methanol, ethanol, propanol, and ethylene glycol, or a mixed solvent of the above solvents. Bases 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; 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, the target compound of formula (VI) can be isolated by acidifying with a mineral acid such as hydrochloric acid or sulfuric acid; an organic acid such as acetic acid or propionic acid, and then depositing the precipitate. Filter, wash with water and dry.

Reaction formula 4

(In the above formula, R ¹ and R ² are as defined in the formula (I), and Z represents a chlorine atom or a bromine atom.)
When the compound of formula (VI) is reacted with a halogenating agent, a compound of formula (VII) is obtained. 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 this reaction, and examples thereof include aromatic hydrocarbons such as benzene, toluene and xylene; and 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 target compound represented by formula (VII), the reaction solution is concentrated under reduced pressure, and the resulting residue is dissolved in a hydrocarbon such as hexane or heptane that does not dissolve the target product much. What is necessary is just to dry after washing | cleaning.

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 on agricultural land and non-agricultural land. Among them, it is particularly useful as an active ingredient of a foliar treatment herbicide for upland annual weeds.
Such weeds include, for example, barbet, Enocorogusa, Nobier, Aobiu, Shiroza, Ichibi, Jacobe, and morning glory. However, the weeds to be controlled by the compound 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 against crops such as wheat, barley, sorghum, corn, cotton and beet. 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 an agricultural chemical auxiliary widely used in the industry is added.
The dosage form of the herbicide is not particularly limited, but for example, it is preferably in the form of an emulsion, a wettable powder, a powder, a flowable, a fine granule, a granule, a tablet, an oil or the like. One or more of the above compounds can be blended as an active ingredient.

Examples of the agrochemical adjuvant used for producing the herbicide include substances having actions such as improvement of the effect of the herbicide, stabilization, improvement of dispersibility, improvement of safety for crops, and the like. (Diluents), spreading agents, emulsifiers, wetting agents, dispersing agents, disintegrating agents, wetting agents and the like can be used. Examples of the liquid carrier include 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.

Also, examples of the solid carrier include clay, kaolin, talc, diatomaceous earth, silica, calcium carbonate, montmorillonite, bentonite, feldspar, quartz, alumina, sawdust, nitrocellulose, starch, and gum arabic. As the emulsifier and dispersant, a normal surfactant can be used. For example, anionic surfactants such as higher alcohol sodium sulfate, stearyltrimethylammonium chloride, polyoxyethylene alkylphenyl ether, lauryl betaine; An ionic surfactant; a nonionic surfactant; or a zwitterionic surfactant can be used. Also, spreading agents such as polyoxyethylene fatty acid esters and polyoxyethylene alkyl esters, wetting agents such as dialkyl sulfosuccinates; fixing agents such as carboxymethyl cellulose and polyvinyl alcohol; disintegration of sodium lignin sulfonate, sodium lauryl sulfate, etc. An agent 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 appropriately determined according to various conditions such as the formulation form and application method. For example, in the case of an emulsion, for example, about 1 to 90% by mass, preferably about 10 to 40% by mass, and in the case of a wettable powder, for example, about 1 to 90% by mass, preferably about 10 to 80% by mass. For example, about 0.5 to 20% by mass, preferably 1 to 10% by mass. In the flowable agent, for example, about 1 to 90% by mass, preferably 10 to 50% by mass of the active ingredient is contained. It is preferred to manufacture.

For example, in the case of an emulsion, the compound of the present invention, which is an active ingredient, can be mixed with a solvent and a surfactant to produce a stock emulsion. It can be diluted and applied.
In the case of a flowable agent, it is possible to prepare a stock solution by mixing water and a surfactant with the compound of the present invention which is an active ingredient, and further diluting this stock solution 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 are mixed and manufactured, and when used, it can be diluted with water to a predetermined concentration and applied.
In the case of a powder, the compound of the present invention as an active ingredient, a solid carrier and the like can be mixed and applied as it is. However, the manufacturing method of each of the above-mentioned preparation forms is not limited to the above-mentioned ones, and can be appropriately selected by those skilled in the art according to the type of active ingredient, application purpose, and the like.

As long as the herbicide of the present invention does not impair the activity of the compound of the present invention of the formula (I) as an active ingredient, other herbicides, insecticides, acaricides, fungicides, growth regulators, fertilizers, You may mix | blend arbitrary active ingredients, such as a soil improvement agent.
The compound of the present invention can be used in the same manner as a normal herbicide, and for example, soil treatment or foliage treatment is performed using the compound of the present invention before germination, early germination, or growing season of upland weeds. be able to. The application rate of the herbicide of the present invention can be appropriately selected depending on the application method, purpose, timing, weed generation status, etc., but is usually an active ingredient amount per hectare, for example, 0.001 kg to 10 kg, preferably Is preferably 0.003 kg to 3 kg.

Next, the present invention will be described more specifically with reference to synthesis examples, formulation examples, and test examples, but the scope of the present invention is not limited 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, 2- (ethoxymethylene) -4,4-difluoroacetoacetic acid ethyl ester 11.1 g And 8.95 g of 4-chlorophenylhydrazine hydrochloride were heated to reflux in 50 ml of water and 50 ml of toluene for 1 hour. 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 (No. 3) of the present invention 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, sodium hydroxide 2.40 g, ethyl alcohol 40 ml and water 40 ml was heated to reflux for 1 hour. After cooling to room temperature, the mixture was acidified with hydrochloric acid, and the crystals were collected by filtration, washed with water and dried to give 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 -0.41 g of carboxylic acid was heated to reflux in 5 ml of thionyl chloride for 1 hour and then concentrated under reduced pressure. The obtained 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 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 (No. 31) of the present invention 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. After concentration under reduced pressure, the resulting residue was purified by silica gel column chromatography to obtain 2.50 g of the compound (No. 33) described in Table 2 below. The melting point was 128-130 ° C.
In the same manner, the compound of the present invention was prepared in the same manner. Tables 1 and 2 below list the compounds of the invention prepared according to the examples.

1) ¹ H-NMR (CDCl ₃ ) δ ppm: 1.40 (3H, t), 4.40 (2H, q), 7.4-7.7 (6H, m), 8.10 (1H, s).
2) ¹ H-NMR (CDCl ₃ ) δ ppm: 1.40 (3H, t), 4.40 (2H, q), 7.2-7.6 (5H, m), 8.13 (1H, 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).

Hereinafter, formulation examples of herbicides containing the compound of the present invention as an active ingredient will be shown. The scope of the present invention is not limited by the following formulation examples. In the examples, “parts” means all parts by mass.

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

<Formulation example 2> Wetting 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 wetting agent 65 L (5 parts) was uniformly mixed and ground with 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, and water was added and kneaded well. Thereafter, extrusion granulation was performed, and dry granulation was performed to obtain granules.

<Test Example 1> Herbicidal effect test Filled with field soil in an aluminum pot with a surface area of 160 cm ² , seeded with barnyard grass, abalone, and white rosa seeds, covered with about 0.5 cm, and then grown in a greenhouse. At that time, 3 kg / ha of the compound of the present invention prepared according to Formulation Example 1 so that the amount of the active ingredient was a predetermined ratio was uniformly sprayed on the foliage and soil. The herbicidal effect on each weed was investigated 14 days after spraying with the chemical solution, and the results shown in Table 3 were obtained. The compound numbers correspond to the compound numbers in Tables 1 and 2. As is apparent from Table 3, the compound of the present invention exhibits an excellent herbicidal effect on weeds.

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

<Test Example 2> Herbicidal effect test according to the number of days after treatment The compound of the present invention prepared according to Formulation Example 1 so as to fill field soil in an aluminum pot having a surface area of 160 cm ^{2 and} the amount of active ingredient to be a predetermined ratio; A known compound A approximating to the compound of the present invention was uniformly sprayed on the soil surface in an amount of 1.5 kg / ha. After 1, 30 and 60 days after chemical spraying, seeds of Japanese barnyard grass and morning glory were sown and examined according to the same criteria as in Test Example 1, and the results shown in Table 4 below were obtained. Compound No. corresponds to Compound No. in Table 2, and the structural formula of Compound A is as shown below.
As is clear from Table 4, the compound of the present invention is rapidly decomposed after the treatment, and is excellent in that it has less burden on the environment and after crops.

* Number of days from spraying to sowing

Compound A

<Test Example 3> Herbicidal effect test according to the amount of sprayed water Filled with aluminum soil with a surface area of 160cm ² and planted with field soil, seeded with abalone seeds, covered with about 0.5cm, and then grown in a greenhouse. At the same time, the compound of the present invention prepared according to Formulation Example 1 so that the amount of the active ingredient is in a predetermined ratio, and Compound A are dispersed in an amount of 0.025, 0.0125 kg / ha and the amount of sprayed water is 500 liters per ha. It diluted so that it might become (L) and 250L, and it sprayed uniformly on the foliage part and the soil part. The herbicidal effect on each weed was examined 14 days after spraying with the chemical solution according to the same criteria as in Test Example 1, and the results shown in Table 5 below were obtained. Compound No. corresponds to Compound No. in Table 2, and Compound A is as defined in Test Example 2.
As is apparent from Table 5, the compound of the present invention exhibits an excellent herbicidal effect even when the amount of sprayed water is small, and is stable even in areas where it is difficult to secure water, large-scale spraying situations, and uneven spraying. Excellent herbicidal effect.

* Sprayed water volume per ha

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

Claims (4)

1. The following formula (I),
   

   

   (I)
   (Wherein R ¹ and R ² each independently represents a hydrogen atom, a halogen atom, a C ₁ -C ₄ alkyl group, a trifluoromethyl group, a nitro group, a cyano group, or a C ₁ -C ₄ alkoxy group. Show.
   R ³ represents a hydroxyl group, a C ₁ -C ₄ alkoxy group, an amino group, a C ₁ -C ₄ alkylamino group, a C ₂ -C ₄ dialkylamino group, or a C ₂ -C ₄ alkylalkoxyamino group. Show. )
   A 1-phenyl-5-difluoromethylpyrazole-4-carboxamide derivative represented by the formula:
2. The carboxamide derivative according to claim 1, wherein R ³ in formula (I) is a methylamino group or a cyclopropylamino group.
3. In the formula (I), R ¹ and R ² are a hydrogen atom, or R ¹ is a chlorine atom, a bromine atom or a fluorine atom at the 4-position of the phenyl group, and R ² is a hydrogen atom. The carboxamide derivative according to claim 1.
4. A herbicide containing the carboxamide derivative according to any one of claims 1 to 3 as an active ingredient.