JPS61165374A - Pyrazole derivative and herbicide containing said derivative as active component - Google Patents

Abstract

NEW MATERIAL:The pyrazole derivative of formula I (X is H, halogen or 1-2C alkyl; Y is 1-2C alkyl; X and Y may together form a ring with a 3-4C methylene group; W is halogen; R is H or SO2CF3; Z is H, halogen or lower alkyl; n is 1 or 2). EXAMPLE:1-(2,4-Dimethyl-5-amino-phenyl)-3,4-tetramethylene-5-chloropyr azole. USE:A herbicide having extremely strong herbicidal activity and nevertheless, low phytotoxicity to crops. PREPARATION:The pyrazole derivative of formula I can be prepared e.g. by reducing the N-substituted pyrazole of formula II, and reacting the resultant compound of formula III with sulfonic acid halide of formula IV or sulfonic acid anhydride of formula V.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to novel pyrazole derivatives.

Derivatives of the invention are useful as herbicides.

[Conventional technology]

It is known that some pyrazole derivatives have herbicidal activity. For example, JP-A-52-91861
Examples include compounds of No.

[Problem that the invention seeks to solve]

None of the pyrazole derivatives to date have been found to be effective at low doses against harmful weeds that grow in rice paddies and fields, and there has been a desire for a compound that does not have these drawbacks.

[Means for solving problems]

As a result of various studies on pyrazole derivatives, the present inventors determined that the formula (wherein, may form a ring with a methylene group having 3 or 4 carbon atoms. W represents a halogen atom,
R represents a hydrogen atom or a 5O2CF3 group, Z represents a hydrogen atom, a halogen atom or a lower alkyl group, and n is 1
Or represents 2. The present inventors have discovered that the compound represented by () exhibits extremely strong herbicidal activity, has little phytotoxicity to crops, and can be used as a practical herbicide, leading to the completion of the present invention.

The novel pyrazole derivative represented by formula (1) of the present invention can be produced, for example, by the following method.

First, an N-substituted pyrazole represented by the following formula (2) (in the formula, x, y, w and 7.n are the same as in formula (1)) is usually used to reduce the nitro group on the aromatic ring to an amine group. General formula (3) (where X, Y, W, Z
n is the same as above. ) can be obtained.

For example, it can be synthesized by reacting with iron powder and a hydrochloric acid catalyst in a hydrous alcohol, preferably at 50 to 90°C for 1 to 3 hours.

Furthermore, N-substituted pyrazole (
In the formula, X, Y, W, and Zn are the same as above. ) and equation (4
A sulfonic acid anhydride represented by J or a sulfonic acid halide represented by the formula (4) (wherein Hal represents a halogen) and optionally in an inert solvent, The pyrazole derivative represented by the general formula (1) can be synthesized by carrying out the reaction preferably at 0°C to 50°C in the presence of a suitable basic catalyst if necessary.

The raw material compound represented by formula (2) (wherein X, Y, W, and Zn are the same as above) is first converted into an N-substituted pyrazolone represented by the following formula (8) (wherein X, Y, and Zn are the same as above). Z
n is the same as above. ), and the formula ( 2) (wherein X, Y, W, and Zn are the same as above) can be obtained. In this case, dimethylformamide, pyridine, N,N-dialkylaniline, etc. can be added to promote the reaction. As the genifying agent mentioned herein, general halogen ratios can be used, and phosphorus oxychloride or oxy-odor halogens are preferably used.

Alternatively, the formula (10) (in the formula , Y, W
and h are the same as above. ) can be obtained.

In addition, the compound represented by the formula (13) which is a raw material is the formula (
11) (In the formula, X and Y are the same as K in formula (1). %R11 represents lower alkyl.) and formula (12) (In the formula, & represents a hydrogen atom or a nitro group, and Zn is the same as above.) The substituted phenylhydrazine represented by the formula is dissolved in a suitable inert solvent (for example, methylene chloride, aliphatic or aromatic hydrocarbons such as toluene, alcohol or ethers, etc.), preferably at 60 to 150°C for 30 minutes to 30 minutes. Obtained by dehydration under reflux for a period of time. In this case, the reaction can be completed under milder conditions (for example, between 5° C. and reflux temperature) by adding an appropriate base (eg, triethylamine, sodium hydroxide, alcolade, etc.) as necessary.

Substituted phenylhydrazines of formula 1 (12) are obtained by diazotizing aniline represented by the formula (in the formula, Zn and R2 are the same as above) with sodium nitrite. (In the formula, a2.zn is the same as above.) It can be produced by reduction with sodium bisulfite or the like.

In addition, in formula (2), a compound in which X is norogen is a compound represented by formula (15) (wherein Y, W, and Zn are the same as above) in an inert solvent such as acetic acid or chloroform. , preferably by halogenating with a halogenating agent such as chlorine or bromine at 0 to 30°C, to obtain the formula (2) (
In the formula, X is )・Rogen, Y, W.

Zn is the same as above. ) can be obtained.

WWThe basic catalyst as used in the present invention includes triethylamine, tributylamine, pyridine, N-methylmorpholine, N,N-
Diethylaniline, N,N-dimethylaniline, potassium carbonate, sodium carbonate, etc. are used.

The inert solvent used in the present invention is benzene.

Aromatic hydrocarbons such as toluene, xylene, and chlorobenzenato; aliphatic hydrocarbons such as n-hexane, n-heptane, and petroleum ether; alicyclic hydrocarbons such as dichlorohexane; chloroform, carbon tetrachloride: perchloren Halogenated hydrocarbons such as: ethers such as ethyl ether, tetrahydrofuran, and dioxane; esters such as ethyl acetate; amides such as dimethylformamide; or water.

In the present invention, examples of the halogen atom include a chlorine atom, a bromine atom, and a fluorine atom. Examples of the lower alkyl group include methyl group, ethyl group, n-propyl group, and isopropyl group.

When the compound of the present invention is used as a herbicide, depending on the purpose of use, it can be used as it is, or in combination with a pesticide adjuvant to enhance or stabilize the effect, by a method commonly used in the field of pesticide manufacturing. It can be used in the form of powders, fine granules, granules, wettable powders, flowable preparations, emulsions, and the like.

In actual use, these various formulations can be used directly or diluted with water to a desired concentration.

The agrochemical auxiliary agents mentioned herein include carriers (diluents) and other auxiliary agents such as spreading agents, emulsifiers, wetting agents, dispersants, fixing agents, and disintegrants.

Examples of liquid carriers include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as ligroin and kerosene, alcohols such as methanol, butanol and glycol, ketones such as acetone, amides such as dimethylformamide, dimethyl sulfoxide, etc. sulfoxides, methylnaphthalene, cyclohexane, animal and vegetable oils, and fatty acids.

Examples include fatty acid esters.

Solid carriers include clay, kaolin, and talc.

Diatomaceous earth, silica, calcium carbonate, montmorillonite,
Examples include bentonite, feldspar 1 quartz, alumina, and sawdust.

In addition, surfactants are usually used as emulsifiers or dispersants, such as anionic surfactants such as higher alcohol sodium sulfate, stearyltrimethylammonium chloride, polyoxyethylene alkylphenyl ether, lauryl betaine, and cationic surfactants. , nonionic surfactant 1 and amphoteric ionic surfactant.

Spreading agents include polyoxyethylene nonylphenyl ether and polyoxyethylene lauryl ether; wetting agents include dialkyl sulfosuccinate,
Examples of the fixing agent include carboxymethyl cellulose or polyvinyl alcohol, and examples of the disintegrant include sodium chloride sulfonate or calcium salt of carboxymethyl cellulose.

Not only can any laceration be used alone, but it can also be mixed with fungicides, insecticides, plant growth regulators, acaricides, agricultural and horticultural fungicides, soil fungicides, soil conditioners, or nematicides. It can also often be used in combination with fertilizers and other herbicides.

The active ingredient compound content in the herbicide of the present invention is determined by the formulation form,
It varies depending on the application method and other conditions, and in some cases only the active ingredient compound may be used, but it is usually 0.1
It ranges from 95% (by weight), preferably from 0.5 to 50% (by weight).

In addition, when weeding with the herbicide of the present invention, the amount used varies depending on the compound used and the location of application, but usually the amount of active ingredient compound per are is 0.1? Preferably 20? used within the range.

〔Effect of the invention〕

The compound of the present invention is applied to firefly in rice fields.

It exhibits a high herbicidal effect at low concentrations on plants such as Prunus japonicum and Cyperus japonica, and shows almost no phytotoxicity on rice. It also shows a high herbicidal effect at low concentrations on grasshopper, foxtail grass, goldenrod, white grass, etc. in upland fields, and has little phytotoxicity on crops such as corn, soybeans, and cotton.

〔Example〕

The present invention will be explained below with reference to Examples.

Synthesis example 1゜1-(2,4-dimethyl-5-amino-phenyl)-3
, 4-tetramethylene-5-chlorpyrazole (compound N[Ll): 49 ethanol, 14 mj water, and 11 iron powder? , hydrochloric acid 0.
3 ml of 1-(2,4-dimethyl-5-nitrophenyl)-3,4-f tramethylene-5-chlorpyrazole (8ψ) (0,026 M) is added while maintaining reflux. After the addition, reflux was maintained for 2 hours, and 1.4y- of sodium hydrogen carbonate was added thereto.

Then, it was filtered, the filtrate was concentrated, extracted with ethyl acetate, concentrated, and separated and purified using silica gel column chromatography to give yellow crystals of 6.5 mm. The desired product was obtained (yield 91%). Melting point is 7~
It showed a temperature of 7 to 80°C.

Elemental analysis value CIS Hlg CIt N3 calculated value C:
65.33 H: 6.58 N: 15.24 Actual value C:
65.30 H:6.62 N:15.31 Polymerizable 2゜1-(3-trifluoromethylsulfonylamine/-4-
chlorophenyl) -3,4-tetramethylene-5-chloropyrazole (compound car 7): 1-(3-amino-4
-chlorophenyl)-3゜4-tetramethylene-5-chloropyrazole (Synthesis Example 6) 1.5! ? (0,0
053 mol) dissolved in methylene chloride 2r)at, -5 to 0°C, 1.7 mol of trifluoromethanesulfonic anhydride was added. (0,0060 mol) and then triethylamine 0.6 P (0,0059
mol) was added. After stirring with Tlc-C for 2 hours, the mixture was poured into water, and the dichloromethane layer was extracted with 5% aqueous sodium hydroxide. After making the extracted alkaline water acidic with hydrochloric acid, it was extracted with ethyl acetate, and the ethyl acetate layer was washed with water.
By drying and concentrating yellow crystals 1.1PC yield 50
%] was obtained. Melting point 180-4°C Elemental analysis value C14H12C12F3NS028 (
414,25) Calculated value C: 40.59 H: 2.93
N: 10.15 Actual value C: 40.15 H: 2.90
N: 10.18 Synthesis Example 3゜1-(2-fluoro-4-chloro-5-trifluoromethanesulfonylaminophenyl)-3,4-tetramethylene-5-chloropyrazole (compound #N [Ll 3 ) 1- (2-Fluoro-4-chloro-5-aminophenyl)-3,4-tetramethylene-5-chlorpyrazole 3.5SF-(0,012M) in methylene chloride 20mg
Triethylamine 1.
Add 7ml (0,12M) of trifluoromethanesulfonic anhydride (2.1111C0,12M),
After stirring for 1 hour, the mixture was poured into water, extracted with ethyl acetate, washed with water, concentrated, and separated and purified using a silica gel column to obtain the desired product as pale yellow crystals, 3.9P (yield: 75%). The melting point was 199-202°C.

Elemental analysis value CI4 Hll C12F2 N, O□S
l Calculated value C: 38.90 H: 2.57 N: 9.72
Actual value C: 38.95 H: 2.65 N: 9.76 Synthesis example 4゜1-(2-fluoro-4-chloro-5-aminophenyl)-3-mer? 4-promo5-10 rhopyrazole (Compound 11): 1-(2-fluoro-4-chloro-5-nitrophenyl)-3-methyl-4-promo5-chloropyrazole (
Reference example 2) 12.5i? (0,034 mol) to iron powder 13.6! i', ethanol-A/44 ml, water 20
ml and 0.2 at of hydrochloric acid under stirring,
Added at 75°C. After stirring at 75°C for 2 hours, the mixture was filtered, cold water was added to the filtrate, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with water, concentrated, and purified by column chromatography to obtain brown crystals 11.0P (yield 96%). Melting point 113-6℃ Elemental analysis value CloH7BrCI□FNa C339,
01] Calculated value C: 35.43 H: 2.09 N: 12
゜40 Actual value C: 35.26 H: 2.05 N: 12
．． 48 Synthesis Example 5゜1-(3-amino-4-chloror:Iphenyl) -3゜4-tetramethylene-5-chloropyrazole (compound 1
'll&117): 1-(3-nitro-4-chlorophenyl)-3゜4-tetramethylene-5-chloropyrazole (Reference Example 5)
4.5! i' (0,014 mof), 5.8 g of iron powder, 20 ml of ethanol, 9 rul of water, and 0.0 ml of hydrochloric acid.
1- under stirring at 70 to 75°C. 75℃
After stirring for 2 hours, the mixture was filtered, cold water was added to the P solution, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with water, concentrated, and purified by column chromatography to give brown crystals 3.2P.
(yield 79%).

Melting point 87-9℃ Elemental analysis value Cl5HI3CI2N3 C282,19
] Calculated value C255.33 H:4.65 N+14.8
9 Actual measurement value C: 55.20 H: 4.71 N: 14.9
6 Reference Example 1゜Synthesis of 1-(2-fluoro-4-chloro-5-nitrophenyl)-3,4-dimethyl-5-chloropyrazole: 1-(2-fluoro-4-chlorophenyl)-3,4 −
Dimethyl-5-chloropyrazole, 2-fluoro-4-
Obtained from ethyl chlorophenylhytracinto 2-methyl-3-oxobutanoate.

Melting point 95-8℃, 13.854 (0,053 mo+
) was added with concentrated sulfuric acid (50WLlK) and concentrated nitric acid (9°4%) was added with stirring.
) A mixed solution of lQml and concentrated sulfuric acid lO- was added dropwise at 0-5°C. After stirring at the same temperature for 6 hours, the mixture was poured into ice water.

After neutralizing with NaHCOs, the mixture was extracted with ethyl acetate.

The solid obtained by concentration was purified by column chromatography to obtain yellow crystals of 1-(2-fluoro-4-chloro-5-nitrophenyl)-3,4-dimethyl-5-chloropyrazole 8. .21 (yield 51%) was obtained. Melting point 138-140°C.

Elemental analysis value C11H1lCI2FN302 C304
, 12] Calculated value C2 43.44 H: 2.66 N: 1
3.82 actual value C: 43.82 H: 2.63 N: 1
3.80 Reference Example 2 Synthesis of 1-(2-fluoro-4-chloro-5-nitrophenyl)-3-methyl-4-promo-5-chloropyrazole: 1-(2-fluoro-4-chloro-5 -nitrophenyl)-3-MeF-ru 5-10 Rohilasole 12.5
After adding 3.9 P of sodium acetate (0,047 mol) to a solution of S' (0,043 mol) dissolved in a mixed solvent of 100 mL of OO form and 100 ml of acetic acid, 7.2'? of bromine was added at 10°C. (0,045mol
) was added. After stirring at the same temperature for 2 hours, the mixture was poured into ice water and the chloroform layer was separated. After washing the chloroform layer with sodium bicarbonate water and water, the chloroform layer was concentrated to obtain a fresh solution of 1-(2-fluoro-4-chloro-5-nitrophenyl)-3-methyl-4-7'' lomo-5-10 lopyrazole. Yellow crystals 13.0P (yield 82%) were obtained. Melting point 1
35-7℃ Elemental analysis value CtoHsCIJrFN30z C368
,99] Calculated value C: 32.55) I: 1.37 N:
11.39 Actual value C: 32.94 H: 1.30 N:
11.30 Reference Example 3 Synthesis of 1-(2-fluoro-4-chloro-5-nitrophenyl)-3,4-tetramethylene-5-chloropyrazole: 1-(2-fluoro-4-10-ruphenyl) )-3,4-
Tetramethylene-5-chlorpyrazole 8.71 (0,
0305M) was added to 201d of concentrated sulfuric acid, and while cooling, 1.64ml of fuming glass rR (d=1.5.p, 86%)
, 335M) was added dropwise. After stirring for a while, it was poured into a large amount of water, extracted with ethyl acetate, and separated and purified using silica gel column chromatography to give light brown crystals of 8.2P (yield: 82
%) of the target product was obtained. The melting point was 108-11°C.

Elemental analysis value C13Hl. C1□RNz O2 calculation value C
:47.30 H:3.05 N:12.73 Actual value C
:47.35 H:3.17 N:12.81 Reference example 4
゜1-(2,4-dimethyl-5-nitrophenyl)-3,
Synthesis of 4-tetramethylene-5-chlorpyrazole: 2,4-') l f Roux 5-nitrophenylhydrazine 12.1! P (0,07M) and ethoxycarboethoxymicrohexanone 11.4SF-(0,07M
) Toxylene 50- was mixed and heated under reflux for 3 hours, then concentrated and the resulting crystals were filtered to obtain 16.79-1.
-C2゜4-dimethyl-5-nitrophenyl)-2H
-3°4-tetramethylene-5-pyrazolone was obtained.

(The melting point was 175-80°C) The crystals obtained were 16.7! Phosphorus oxychloride to iF-6.
Add 4d and 10WLt of N,N-dimethylaniline to 1
The mixture was heated and stirred at 30 to 140°C for 5 hours, then the cooled mixture was poured into water, extracted with chloroform, and the concentrated oily substance was separated using silica gel column chromatography to give yellow crystals 16? The desired product was obtained (yield 75%). Melting point is 82
It showed ~5°C.

Elemental analysis value Cps Hls C11N30□Calculated value C
:58.92 H:5.28 N:13.74 Actual value C
:58.87 H:5.33 N:13.80 Reference example 5
Synthesis of ゜1-(3-nitro-4-chlorophenyl)-3゜4-tetramethylene-5-chloropyrazole: Ethyl 2-oxocyclohexanoate 9.5?(0.05
6m0f) 4-chlorophenylhydrazine 7,9f
1-(4-chlorophenyl)-
'; IH-3,4-tetramethylene-5-pyrazolone 1
Obtained 2.8P.

Next, in the crystal 12.8P obtained, 8.71 phosphorus oxychloride and 6.9 ? After stirring at 130°C for 5 hours, the mixture was poured into ice water and extracted with chloroform. The chloroform layer was washed with dilute hydrochloric acid and water and then concentrated to obtain a solid solid. Purified by column chromatography to obtain pale yellow crystals of 1-(4-10 lophenyl)-3.
,4-f) 571 + ren-5-chloropyrazole lO? (yield 73%).

1-(4-chlorophenyl)-3,4-tetramethylene-5-chloropyrazole 6,O? (0,022mo
1) was dissolved in 201 M of concentrated sulfuric acid, and 2.3 P of concentrated nitric acid (94%) was added at -de~0°C. After stirring at the same temperature for 2 hours, it was poured into ice water and neutralized with NaHC03.
Extracted with ethyl acetate. After concentration, the residue was purified by column chromatography to obtain yellow crystals 5.3P (yield 76%). Melting point 94-7℃ Elemental analysis value C+5H
uC1□NsO□[312,17] Calculated value C: 50.0
1 H: 3.56 N: 13.46 Actual value C: 50.5
1 H: 3.50 N: 13.36 Next, formulation examples of the present invention will be explained in more detail, but the types and mixing ratios of additives are not limited to these and can be used in a wide range. Note that 1 part refers to parts by weight.

Formulation example 1. By adding and dissolving 35 parts of xylene to Emulsion Compound No. 31,050, and further mixing with 15 parts of polyoxyethylenealkylphenylnitertoalkylbenzenesulfonate calcium tetracompound C872, emulsion 9 is obtained. To use it, dilute it with water to a concentration of 0.01 to 1%.

Formulation example 2. Powder A powder is obtained by adding 95 parts of clay to 903 parts of compound number and mixing and pulverizing. This is used for direct spraying.

Formulation example 3. Permanent agent compound number 18050 parts, diatom ±10 parts, kaolin 32 parts
2. % of the carrier and further mixed with sodium lauryl sulfate.
8 parts of a mixture of sodium 2-cyna-7-methyl methanesulfonate was mixed evenly and ground to a fine powder to obtain a wettable powder. The crystal is diluted to a concentration of 0.06 to 1% and used as a suspension.

Formulation Example 41 Granules Using an appropriate mixer, 5 parts of fine powder of Compound No. 6 was added to 94.5 parts of silica grains (16-32 mesh) using a methanol solution of 0.5 part of polyvinyl acetate as a binder. Granules are obtained by spreading and coating. It is sprinkled directly into the soil and rice fields.

Experimental example 1. Pre-emergence of paddy field weeds Submergence treatment A certain amount of paddy soil was packed in a 115,000 are Wagner set to make it into a planting state, and a certain amount of seeds of Japanese millet, Japanese cabbage, Japanese grass, azalea, Japanese chickweed, and firefly were sown. Furthermore, three tubers of Urikawa per pot were buried at a depth of 1 crn from the soil surface layer, and after flooding to a depth of 3 crn, the active ingredient compound of the present invention was added to the soil at a depth of 0.8 cm per pot. A diluted solution adjusted to have a concentration of ~507 was added dropwise to the submerged water. Three days later, three paddy rice seedlings (Nihonbare) at the 2.5 leaf stage were transplanted. Thirty days after chemical treatment, the herbicidal effect of the treatment and the presence or absence of chemical damage to paddy rice were investigated. The investigation was conducted using the following criteria and the results shown in Table 2 were obtained.

*Herbicidal effectiveness index 5: Complete weeding 4: Weeding around 80% 3: 60% 2: 40% l: 20% 0: No effect ※※Phytotoxicity index 12 No Harm +: Slight harm +: Slight damage : Medium Damage: Serious Damage: X: Death Table 2 Experimental Example 1. Underwater treatment before the emergence of paddy field weeds Note) Broad leaves (1): Paddy field weeds, Kikashigusa, Azena, Mizono and Kobe As seen in the results of Experimental Example 1, the compound of the present invention is
It showed excellent herbicidal efficacy against major annual and perennial weeds. Moreover, it was found to be highly safe for paddy rice.

Next, we will show an example of an experiment conducted in a field.

Experimental Example 2 A certain amount of field soil was packed in a circular plastic case with a diameter of 8 crn and a depth of 8 crn, and a certain amount of seeds of crabgrass, foxtail grass, staghorn grass, and white grass were sown to give a concentration of 0.5 to ICr.
I covered it with soil to the extent of n. Immediately add a hydrating agent containing the active ingredient compound of the present invention to an amount of 12.5 to 50% of the active ingredient per area.
? A diluted solution adjusted to give the following was applied to the entire soil surface. After the treatment, growth was controlled in a greenhouse, and the herbicidal effect of the treatment was investigated on the 20th day. The experiment was conducted in duplicate, and the average value of each was determined. The investigation criteria were the same as in Experimental Example 1, and the results shown in Tables 3 and 4 were obtained.

Table 3 Experimental Example-2 Weed Pre-emergence Soil Treatment Table 4 Experimental Example-2 Weed Pre-emergent Soil Treatment Control Agent N i t rof
en l Experimental Example 3 A certain amount of field soil was packed into a plastic vat measuring 23 cm long, 45 wide, and 12.5 cr deep, and certain amounts of soybean, cotton, corn, wheat, sunflower, and rice seeds were sown. I covered it with a small amount of soil.

Immediately, a diluted solution containing the active ingredient compound of the present invention was prepared so that the amount of active ingredient per area was 12.5 to 509, and 20 doses per vat were applied to the soil surface using a small sprayer. After treatment, the greenhouse average value was determined.

The investigation criteria are the same as in Experimental Example 1, and Tables 5 and 6
Obtained the results in the table.

Table 5 Experimental Example-3 Table 6 Experimental Example-3 Experimental Example 4 Fill a circular plastic case with a diameter of 8 crn and a depth of 8 crn with a certain amount of field soil, and sow a certain amount of wild foxtail and golden grass seeds, respectively. When the plants were grown to the 3rd to 4th leaf stage, a solution prepared by diluting a hydrating powder containing the active ingredient compound of the present invention to 12.5 to 50 parts of the active ingredient per area was sprayed onto the plants.

The experiment was conducted in duplicate. On the 20th day after the drug treatment, an investigation was conducted using the same investigation criteria as in Experimental Example 1, and the results shown in Table 7 were obtained.

Table 7 Experimental Example 4 Weed Growth Period Treatment As is clear from the results of Experimental Examples 2 and 4, the compound of the present invention was used as a pre-germination treatment for major weeds in fields.

It can be seen that the growth treatment exhibits an extremely excellent herbicidal effect. Furthermore, as is clear from the results of Experimental Example 3, there is no phytotoxicity to crops and it is also suitable as a herbicide for upland fields.

Claims (2)

[Claims] (1) Formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (1) (In the formula, X represents a hydrogen atom, a halogen atom, or an alkyl group of C_1 to C_2, and Y represents a C_1 to
C_2 represents an alkyl group, and X and Y may form a ring with a methylene group having 3 or 4 carbon atoms. W represents a halogen atom, R represents a hydrogen atom or a SO_2CF_3 group, Z represents a hydrogen atom, a halogen atom or a lower alkyl group, and n represents 1 or 2. ) A pyrazole derivative represented by (2) Formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (1) (In the formula, X represents a hydrogen atom, a halogen atom, or an alkyl group of C_1 to C_2, and Y represents a C_1 to C_2
_2 alkyl group, X and Y have 3 or 4 carbon atoms
The methylene group may form a ring. W represents a halogen atom, R is a hydrogen atom or SO_2
It represents a CF_3 group, Z represents a hydrogen atom, a halogen atom or a lower alkyl group, and n represents 1 or 2. ) A herbicide characterized by containing a pyrazole derivative represented by the following as an active ingredient.