JPS61257974A - Pyrazole derivative, production thereof, and selective herbicide - Google Patents

Abstract

NEW MATERIAL:A compound shown by the formula I [X is halogen, NO2, lower alkyl, CF3, or SO2CH3; n is 1, 2, or 3; Z is (lower alkyl, lower alkenyl, or lower alkynyl) which may be replaced with halogen, CH2CN, group shown by the formula II, or organic acid residue; R is H or lower alkyl; m is 0 or 1; R' is phenyl or lower alkyl which may contain <=5 substituent groups (lower alkyl, halogen, NO2, or CF3)]. EXAMPLE:4-(2,4-Dichlorobenzoyl)-1-ethyl-5-benzyloxypyrazole. USE:A selective herbicide effective against weeds in a wide range, especially perennial weeds such as water nutgrass, etc., which are not controlled with ease with a well-known herbicide, having no phytotoxicity to paddy-rice plant at all, usable safety. PREPARATION:A compound shown by the formula III is reacted with a compound shown by the formula Hal-Z (Hal is halogen) to give a compound shown by the formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the general formula 11): [wherein, Indicates an integer of 5. When G is 2 or more, X may be the same or different. zt/-1 A lower alkyl group which may be substituted with a halogen atom, a lower alkenyl group which may be substituted with a halogen atom, a lower alkynyl group which may be substituted with a roger/atom, a cyanomethyl group.

(In the formula, R represents a hydrogen atom or a lower alkyl group,
@ indicates an integer from 0 to 1. R'' is a lower alkyl group,
selected from halogen/atom, nitro group, trifluoromethyl group, and represents a phenyl group or lower alkyl group which may be substituted with up to five different substituents. ) represents all organic acid residues. ] A compound represented by the formula (1), a method for producing the same, a selective herbicide containing one or more of the derivatives as an active ingredient, and an important intermediate in the production of the compound represented by the above general formula (1). This invention relates to a pyrazole derivative represented by the following formula (IVI) and a method for producing the same.

The novel pyrazole derivative C represented by the above general formula, which has not been published in any literature, is hereinafter referred to as a two-wing compound +1). ) is useful as a herbicide active ingredient, and has the characteristic of whitening weeds and causing them to wither, and has strong herbicidal power even against weeds that are difficult to control in conventional rice fields, even when applied in extremely small amounts. ing. Conventionally, many metal compounds have been known as pyrazole derivatives, and among these, one that has already been put to practical use as a herbicide for rice fields and is commercially available is virazolate (common name) represented by the structural formula below. and so on.

On the other hand, many herbicides other than pyrazole derivatives have been put into practical use as herbicides for paddy fields.

Single agent Maku is generally widely used as a mixture. However, perennial weeds that occur in paddy fields generally grow vigorously and have a long outbreak period, making them extremely difficult to control.There are many herbicides that are effective against annual weeds; The current situation is that there are very few.

In addition, recent rice cultivation has become more suitable for weeds due to the introduction of mechanization and earlier transplantation, and one-time herbicide treatment alone is not sufficient to eliminate annual weeds and perennial weeds. It is difficult to expect complete control of weeds.

In recent years, attempts have been made to completely control all weeds in wet rice cultivation by spraying them once before and after planting, using various single agents or mixtures, but the herbicidal effects are extremely insufficient, so it is impossible to forcefully control all weeds. In order to obtain the effect with only one treatment, a large amount of drug is required per unit area.

In order to solve the above-mentioned problems, there is currently a long-awaited development of a one-time herbicide that requires extremely low dosage and is effective against a wide range of weeds.

The inventors of the present invention have conducted various studies and found that they are effective against a wide range of weeds, and among these weeds, it has been particularly difficult to control, and there are almost no effective herbicides available for controlling these weeds, such as Japanese cypress and black cypress. Compounds of the present invention are extremely effective against perennial weeds such as (11') We have completed the present invention.

Furthermore, the two compounds of the present invention (11) have the effect that they have no phytotoxicity to paddy rice and can be used safely.

The compound of the present invention (11 has the general formula as described above...
It is a pyrazole derivative represented by 1.3.

Hitherto, several compounds have been known as pyrazole derivatives having herbicidal activity.
No. 6648, Japanese Patent Publication No. 56-281385, and Japanese Patent Publication No. 58-185568 describe that 4-benzoyl derivatives are useful as herbicides. Practical and commercially available pyrazole derivatives include the above-mentioned virazolate (-several names) and viradixifene (-several names).

The pyrazole derivatives described in the above-mentioned Japanese Patent Publication No. 56-28885 are all 3-positions of the pyrazole ring of the metal compound represented by the above formula (11). In the pyrazole derivative described in the above publication, the 3-position of the pyrazole ring of the metal compound represented by the above formula +1) is almost always a lower alkyl group.

The substituent at the 5-position is OH, 13H, a salt thereof, or an ester with a specific organic acid. Among these, when the 3-position is a hydrogen atom, only the - example is specifically described as an example, as shown below.

OR.

However, this compound A is
As is clear from the description of the biological test data in Publication No. 8, the herbicidal activity is inferior to that of commercially available virazolate.

The present inventors conducted a comparative test with the metallic material of the present invention, these virazolates, and Compound A, and confirmed that the compound of the present invention had far superior herbicidal activity.

Although a large number of pyrazole derivatives and conductors have been synthesized and tested for herbicidal activity, the above-mentioned compound A is the only compound in which the 5-position of the pyrazole ring is a hydrogen atom.

The reason for this is that compounds with substituents such as alkyl at the 6-position (5-position alkyl derivatives) are relatively easy to synthesize, but when the 5-position is a hydrogen atom, it is extremely difficult to synthesize them. This was thought to be due to the fact that the herbicidal activity was lower than that of the 5-alkyl derivative, and that it was less practical. The present inventors have conducted various studies on compounds in which the 6-position of the pyrazole ring is a hydrogen atom, and as a result, have found a method for easily forming a metal. As for the substituted moiety of 5-vinegar, as a result of various experiments, it was found that the compound tl+ of the present invention represented by the above general formula (summer) has strong herbicidal power, and is also very safe for paddy rice. It was discovered that it has extremely excellent properties as a herbicide for paddy rice.

In addition, as a compound in which the 3rd position of pyrazole is a hydrogen atom, RI JP-A No. 58-167588. Japanese Patent Application Publication No. 1978-16789. @Opening 58-185568゜%Opening 59-46272. ! 1987-104562, Japanese Patent Publication No. 59-122472. Japanese Patent Publication No. 60-16974. There is Japanese Patent Application Laid-Open No. 60-51175. However, while these 5-H-containing metal products of the earlier application are highly effective against general paddy field weeds, they are particularly low in safety for directly sown paddy rice, and their application is limited to transplanted paddy rice.

In recent years, rice cultivation has been shifting from so-called transplant cultivation to direct sowing cultivation, in which rice seeds are sown directly into paddy fields, with the aim of saving labor.Also, this direct sowing analogy has been developed in such a way that the rice seeds germinate and grow at the same time. It relies on the advent of highly selective herbicides that control competition with weeds.

In general, when transplanting paddy rice, rice is transplanted at the 2-5 leaf stage or above, whereas in direct-seeding cultivation, rice plants at the germination stage are used, so the damage to the rice plants caused by herbicides tends to be severe. It is extremely difficult to apply herbicides to directly sown rice, which is why the emergence of herbicides with higher selectivity is awaited.

The compound of the present invention is a herbicide for paddy rice with high selectivity between rice and weeds that meets the above requirements, and can be used not only for transplanted paddy rice but also for directly sown paddy rice.

This compound has extremely low harmful effects and has characteristics that are significantly different from the 5-H pyrazole compound of the previous application.

Another point that is markedly different from the 6-8 pyrazole compound of the previous application is that the two invented metals have very strong activity against the important annual harmful grasses, which have been on the rise again in recent years, such as wild grass and grasshopper. The high level of activity against these annual weeds also makes it possible to completely control weeds using so-called initial agents in paddy fields. Namely, Nobie.

1. The compound of the present invention is effective against perennial weeds, and 2. the compound of the present invention is a true 1. It will be explained that it is effective as a double treatment agent (or one time treatment agent 1).

Furthermore, the compound of the present invention (11) represented by the general formula (1)
shows a high herbicidal effect of 11L<11L> even against Cyperaceae, a perennial weed of the Cyperaceae family that is extremely difficult to control as a weed in corn fields, soybean fields, etc.
Moreover, no chemical damage to corn or soybeans was observed.
It is also extremely useful as a field herbicide.

Compound 11+ of the present invention can be easily prepared according to the following reaction formula (I
V)
(In the formula, Q represents a halogen atom or a hydroxyl group, Hat represents a halogeno atom, and X, n, and Z have the same meanings as above.1 Reaction formula (1) is one important point in the present invention. Formula of intermediate ml
By benzoylating the metal compound represented by
The compound of the present invention (in It, 2 is a hydrogen atom (referred to as compound II'l).

) is shown. To give an example of a reaction, the compound σ)
a dehydrohalogenating agent (preferably sodium hydroxide,
potassium hydroxide, sodium carbonate, triethylamine,
pyridine).

Reaction with various penzoylnolides in a reaction-inert solvent gives esters, which are then rearranged to form compounds tI.
It can be obtained at the ceIc rate.

As a solvent for the esterification reaction, for example, dioxane, acetonitrile, benzene, toluene, chloroform, etc. can be used alone, but two-phase systems such as water-toluene, water-liform, etc. can also be used. The rearrangement reaction is carried out without a solvent or in a reaction-inert solvent (preferably dioxane, acetonitrile, etc.) using a Lewis acid such as aluminum chloride, tin chloride, or zinc chloride, or a base such as calcium hydroxide, potassium carbonate, or sodium carbonate. It can be easily progressed by presence.

Reaction formula (2) shows a reaction in which the compound (1) of the present invention is obtained by condensing Fi, the compound (1'), and a suitable no1lide.

The reaction is carried out using solvents that are inert to the reaction (e.g. ethers such as diethyl ether, tetrahydrofuran, dioxane, aromatic hydrocarbons such as benzene, toluene, xylene, ketones such as acetone, methyl ethyl ketone, dichloromethane, Dehydrohalogenation in eI roform, halogenated hydrocarbons such as carbon tetrachloride, ethyl acetate, N,N-dimethylformamide, a7tonitrile, etc. can be used singly or as a mixture of Fi). agents (e.g.
Inorganic bases such as sodium carbonate and potassium carbonate, pyridine, triethylamine/.

Examples include organic bases such as N,N-dimethylaniline. ) is desirable.

Although the reaction temperature can range from room temperature to the boiling point of the solvent used, it is operationally advantageous to set the reaction temperature to the boiling point of the solvent. If the gold reduction reaction shown in reaction formula (2) is carried out under appropriate conditions taking into consideration the above conditions, two compounds of the present invention (I
1 can be obtained in very good yield.

In addition, the formula LMI (hereinafter referred to as 0invented metal compound (IVI)), which is an important intermediate of the present invention used in the reaction formula (1), is used.

The pyrazole derivative represented by ) is a new compound that has not been described in any literature, and is a metal compound that is expected to be particularly useful in the synthesis of good drugs and medicines, including the compound of the present invention [1].

Compound ① of the present invention is a pyrazole derivative having a substituent such as an alkyl group at the 5-position as described above, which is relatively easy to synthesize, but when the 3-position of the pyrazole is a hydrogen atom, one synthesis is possible. It is thought that because it was extremely difficult, no examples of acid-containing cases have been reported to date.

The reaction formula of the method for producing the metal compound (PI) of the present invention studied by the present inventors is as follows.

(V) (■ Mu) (Vll (IVI) The reaction shown in the above reaction step (3) is an addition/cyclization reaction of both ethyl hydrazi/(V) and ethoxymethylene (17fR diethyl ester). The corresponding 1-ethyl-4
-Ethoxycarbonyl-5-hydroxypyra/- (This reaction shows an interesting reaction. This reaction can be carried out without a solvent, but it should be carried out in an organic medium (e.g. methanol, ethanol, etc.) It is desirable that the reaction temperature is low at the start of the reaction, and as it approaches the end of the reaction it is desirable to heat it to promote the ring-closing reaction.Reaction formula (
The reaction shown in 4) is obtained by reaction formula (3). Using the compound (■) as a raw material, this compound and a mineral acid are heated in the presence of water.

This figure shows a reaction in which the compound tPi1 of the present invention is obtained by simultaneously performing hydrolysis and decarboxylation. At the end of the reaction, the metal compound of the present invention is obtained in the form of a mineral acid salt, but by neutralizing it with an appropriate base, one compound of the present invention can be easily obtained.

As mentioned above, nine compounds of the present invention (II and (IVI)
It is highly useful and novel, and its production method is also completely new, and it is thought to have an 11ffi value.

The present invention will be described below with specific examples. However, the present invention is not limited to these only.

Synthesis of 1-ethyl-5-hydroxypyrazole Ethoxymethylene c1] M/+diethyl ester 1α
A 20 m ethanol solution of at(aos mol 1) was cooled to 0°C, and 10 f of a 50X aqueous solution of ethylhydrazine (α05 mol) was added dropwise while keeping the reaction temperature below t-5°C. After the dropwise addition was completed, the mixture was stirred at room temperature for 1 hour. The mixture was then refluxed for 5 hours.

After the reaction was completed, the solvent was distilled off under reduced pressure and fs condensed, and then 55X hydrochloric acid was added to the residue to carry out hydrolysis and decarboxylation reactions at reflux temperature for 5 hours.

After the reaction was completed, the solvent was distilled off under reduced pressure and the residue was dried to obtain 5.5F of the target 1-ethyl-5-hydroxypyrazole as a hydrochloride.

Yield 72N Otori F (-NMRlδIT) pn low, CD0L, -
DM day 0-d, 11.4215FI, t, , T-7
E4Z, OH,l, 4.20 +2[(,q.

Jx7Eiz, c6-cu, l, 5.91 (
IH, do J”5Hz@Piracy A/l, 7.
84 ilH, d, Jx5Hz*pyrazole i, 1
2.4 (2H, broadsl Example 2 4-(2,
Synthesis of 4-dichlorobenzoyl)-1-ethyl-5-hydroxypyrazole Hydrochloride of 1-ethyl-5-hydroxypyrazole 148
5Ft11 mol), potassium hydroxide (purity 85X11
Add 52f (12 mol) little by little to an aqueous solution dissolved in 55d of water while stirring under water cooling, and after neutralization, add potassium salt. After that, add 60m of Riaroform and 2
While keeping the temperature below 5℃, add 2.4-
Dikulupe/zoyl chloride 2 (L95r (rL 1 mol 1) was added dropwise at room temperature for 2 hours, and then the temperature was raised to 40°C and stirred for 1 hour to complete the reaction. After cooling the reaction solution, the organic layer was separated. After sequentially washing with 5X aqueous sodium hydrogen carbonate solution, water, and saturated brine, drying over anhydrous sodium sulfate, distilling off the solvent under reduced pressure and drying,
-(2,4-cyp-lupenzoyloxy)-1-ethylpyrazole composition. Subsequently, 10 ad of 1,4-dioxane was added to the ester mixture obtained above, and after dissolution, the reaction temperature was raised to 120°C, and anhydrous potassium carbonate 2
The reaction mixture was solidified by adding α7f (0.15 mol) and heating under pressure for about 1 hour while stirring. To the obtained solid, 50% of water was added, heated to dissolve, then returned to room temperature, and hydrochloric acid was added to set the pFI (1). By crystallization, the desired 4-12.4-dipalbe/zoyl 1-1-ethyl-5-hydroxypyrazole is converted to 215F
Obtained.

Yield near 9X Melting point = 144-146℃ 'H-NMR (δ, ppm, coat, +: t4
s (5H, t, Js7[(z.

-OQ, ), 404 (2H,q, Jx7Hz,
-05,-).

7.50-7.47 (4H-m L'-5711H
211,-OH1" 1 mouth 1L 4-+2.4-jiku HA
Synthesis of spe/diyl)-1-ethyl-5-bearazyloxypyrazole 4-(2,4-dichlorobenzoyl)-1-ethyl-5
-Hydroxypyrazole 1.45 fl 1005 mol li
In addition to 50% of triethylamine, 0.0% of triethylamine was added.
51F ([1005 mol)] was added to form a homogeneous solution.

In the above solution, benzyl bromide (LI36Fl(L
After adding 5 moles of OO) with stirring at room temperature, the mixture was heated and expanded at reflux S degree for 4 hours.

After cooling the reaction mixture, the produced salt was separated by furnace, and the resulting penze/solution was mixed with 5X charcoal t'll sodium hydrogen aqueous solution,
After washing successively with water and saturated brine and drying over anhydrous sodium sulfate, benzene was distilled off under reduced pressure to obtain an oily residue. The obtained oil was purified by silica gel column chromatography using eluent: be/ze/1 to obtain the desired 4-(2,4-dikuαrubet/zoyl 1-1-ethyl-5-be/zyl). Oxypyrazole as a colorless oil 1.41 f.

Yield near 5'H-NMRIJ, ppm, C! DC41: 1
．． 1913f(,t, ,T-7Hz.

-(f(,l, i85 (2F(,t, !-7FI
! , -0Fj* CHll *5.48 (2H,a
, -0EI, O-1, 7,20~7.40 (m,
9B+ Next, examples of compounds included in the present invention synthesized by the same method as Examples 2 and 3 are shown in Table 1 below, including the compounds of Examples 2 and 5. It is not limited to these.

Table 1 False Hs For application of the compounds of the invention as herbicides, suitable carriers 9, such as clays, are generally used.

Solid carriers such as talc, bentonite, diatoms, water, alcohols (methanol, ethanol, etc.), aromatic hydrocarbons; (ethyl acetate, etc.), acid amides (dimethylformamide, etc.), and if desired, a surfactant 1
Dispersant! V! By adding a clouding agent, a penetrating agent, a spreading agent, a stabilizer, etc., it can be put to practical use in any desired dosage form such as an emulsion, a wettable powder, or a powder.

In addition, other types of herbicides [e.g. Farm Chemical He/Dobuk 7Q, <19
841].

It may be applied in combination with various insecticides, fungicides, synergists, etc.

Next, specific formulation examples of formulations using the compounds of the present invention will be shown. Parts indicate weight. However, the formulation examples of the present invention are not limited to these only.

After uniformly pulverizing the above-mentioned gold, a small amount of water was added, the mixture was stirred and kneaded, and the mixture was granulated using an extrusion type granulator.

Dry and make into granules.

Ezu Katsuto Eternal Powder (White Carbon: Shionogi #Shu brand name) or more is uniformly ground into powder to form a wettable powder. When using, dilute the above irrigation agent 50 to 1000 times with water until the amount of active ingredient is 1.
Spray at a rate of 11010-10 kg per hectare thal.

Next, the effects of the herbicide composition of the present invention will be specifically explained by giving test examples.

Test Example 1 Weeding effect test under flooded conditions 115000
Alluvial soil was placed in Earl's Hugnerbot, and then water was added to create a water depth of 2e11.

Japanese millet, broad-leaved weeds (Japanese cabbage, Japanese azalea, Japanese grass)
, the seeds of each type of firefly were mixed in the above pot,
In addition, I placed Urikawa lump violet, Mizugaya Tsuri lump violet, and Kurogwai lump violet as friends. Furthermore, Z, 5-leaf stage rice mt-transplanted, pot t? Place in a greenhouse at 20-25°C to grow plants,
7 days after sowing, when the barnyard grass was at the one-leaf stage, a diluted solution of the drug was added dropwise with a measuring pipette so that the amount of the drug was a predetermined amount.

Five weeks after dropping the chemical solution, the herbicidal effect on various weeds was investigated according to the following criteria.

The results are shown in Table 2.

Judgment Criterion 5: Weed killing rate 903 or higher (almost complete death) 4...
・ 1 70-90X 5... 1 40-70X 2... 120-40X 1... I 5-20X O-, # 5X or less (almost no effect) However,
The above-mentioned weed killing rate was estimated by measuring the weight of above-ground grass in the chemically treated area and above-ground grass in the untreated area using the following formula.

Table 2 Test Example 2 Herbicidal effect test under flooded conditions J 7500
After putting alluvial soil into 0 are Hugnerbot,
Water was added to set the irrigation conditions of 1 water depth and 2 water depths.

Seeds of Japanese millet and Nagi were placed in the pots described above, and the pots were placed in a greenhouse at 20 to 25°C to grow the plants.

When the barnyard grass was at the 2-leaf stage and the Japanese grasshopper was at the 1-2 leaf stage, a diluted drug solution was dropped onto the water surface of the rice fields using a measuring pipette so that the amount of the drug was a predetermined amount.

Three weeks after the chemical solution treatment, the herbicidal effect on various weeds was investigated according to the same criteria as in Test Example 1 above. The result is the third
Shown in the table.

Table 3 Test Example 3 Weeding effect and phytotoxicity test on direct-seeded paddy rice Alluvial soil was placed in a 115,000 are Hugnerbot, and then water was added to mix and watering conditions were set at a water depth of α51.

Japanese millet, broad-leaved weeds (Japanese cabbage, Japanese azalea, Japanese grass)
, the seeds of each type of firefly were mixed in the above pot,
Furthermore, 5 rice seeds coated with calcium peroxide (trade name: Calper 1) were sown at a depth of 11, and 5 seeds not coated with calcium peroxide were sown at a depth of 01.Fr-20 to 25℃ The plants were grown in a greenhouse, and on the first day after sowing, a diluted drug solution was dropped onto the surface of the rice paddy water using a measuring pipette to reach a predetermined amount of the drug. After 58 days, the water was flooded to a depth of 21 degrees.

Five weeks after the chemical solution treatment, the herbicidal effect on various weeds was investigated according to the same criteria as in Test Example 1 above. The result is the 4th
Shown in the table.

Table 4 The structural formulas of the comparative metal compounds fA) to (F) used in Test Examples 1 to 3 are as follows.

(Metallic compound described in JP-A-5A-1ASS6A Publication No. 4) Patent applicant Nissan Chemical Industries, Ltd. Procedural amendment September 3, 1985 l Indication of the case 1985 Patent Application No. 98905 2 Name of the invention Pyrazole Derivatives, their manufacturing methods, and selective herbicides 3 Relationship with the case of the person making the amendment Patent applicant address 3-7-1 Kanda Nishiki-cho, Chiyoda-ku, Tokyo 101 Name (398) Nissan Chemical Industries, Ltd. 4 Date of amendment order Voluntary action Amendment 5 Subject of amendment 6, Contents of amendment (1) The statement stated on page 27, line 9 of the specification is corrected as follows.

(2) Stated on page 27, line 13 of the specification (3
(4) The following items are inserted between lines 11 and 12 of page 51 of the specification.

After uniformly mixing and pulverizing the granules, add a small amount of water, stir and knead, then granulate with an extrusion granulator and dry to make granules.

” (5) “Compound number (20)” in Table 2 on page 53 of the specification
Insert the following information between the J line and the "Control Compound (A)" line.

(6) “Compound No. (2)” in Table 3 on page 55 of the specification
Insert the following information between the line ``0)'' and the line ``Control compound (E).''

(7) “Compound No. (2)” in Table 4 on page 57 of the specification
Insert the following information between the line ``0)'' and the line ``Control compound (E).''

Claims (5)

[Claims] (1) General formula (I): ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) [In the formula, X represents a halogen atom, nitro group, lower alkyl group, trifluoromethyl group, or methanesulfonyl group, and n represents an integer from 1 to 5. If n is 2 or more,
X may be the same or different. Z is a lower alkyl group that may be substituted with a halogen atom, a lower alkenyl group that may be substituted with a halogen atom, a lower alkynyl group that may be substituted with a halogen atom, a cyanomethyl group, the following formula: ▲ Numerical formula, chemical formula, table etc.▼ (In the formula, R represents a hydrogen atom or a lower alkyl group,
m represents an integer of 0 or 1. R^1 represents a phenyl group or a lower alkyl group which may be substituted with up to 5 same or different substituents selected from a lower alkyl group, a halogen atom, a nitro group, and a trifluoromethyl group. represent. ) or an organic acid residue. ] A compound represented by (2) General formula (II): ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (In the formula, X represents a halogen atom, a nitro group, a lower alkyl group, a trifluoromethyl group, or a methanesulfonyl group, and a represents an integer from 1 to 5. If a is 2 or more,
may be the same or different. ) and a compound represented by
General formula (III): Hal-Z (III) [In the formula, Z is a lower alkyl group that may be substituted with a halogen atom, a lower alkenyl group that may be substituted with a halogen atom, or a lower alkenyl group that may be substituted with a halogen atom. Lower alkynyl group, cyanomethyl group, the following formula: ▲Mathematical formula, chemical formula, table, etc.▼ (In the formula, R represents a hydrogen atom or a lower alkyl group,
m represents an integer of 0 or 1. R^1 represents a phenyl group or a lower alkyl group which may be substituted with up to 5 same or different substituents selected from a lower alkyl group, a halogen atom, a nitro group, and a trifluoromethyl group. represent. ) or an organic acid residue. Hal represents a halogen atom. ] is reacted with a compound represented by the general formula ( I
): ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, X, n, and Z have the same meanings as above.) A method for producing a pyrazole derivative represented by the following. (3) General formula (I): ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) [In the formula, X represents a halogen atom, nitro group, lower alkyl group, trifluoromethyl group, or methanesulfonyl group, and n represents an integer from 1 to 5. If n is 2 or more,
X may be the same or different. Z is a lower alkyl group that may be substituted with a halogen atom, a lower alkenyl group that may be substituted with a halogen atom, a lower alkynyl group that may be substituted with a halogen atom, a cyanomethyl group, the following formula: ▲ Numerical formula, chemical formula, table etc.▼ (In the formula, R represents a hydrogen atom or a lower alkyl group,
m represents an integer of 0 or 1. R^1 represents a phenyl group or a lower alkyl group which may be substituted with up to 5 same or different substituents selected from a lower alkyl group, a halogen atom, a nitro group, and a trifluoromethyl group. represent. ) or an organic acid residue. A selective herbicide characterized by containing one or more of the compounds represented by the following as an active ingredient. (4) Formula (IV): ▲There are mathematical formulas, chemical formulas, tables, etc.▼(IV) A pyrazole derivative represented by (5) Ethylhydrazine represented by the following formula (V): C_3H_3-NHNH_3(V) and the following formula (VI) C_2H_5OCH=C(CHHC_2H_5)_2
Formula (IV) is characterized by a condensation and cyclization reaction with the compound represented by (VI), followed by heating, hydrolysis, and decarboxylation with a mineral acid: ▲Contains mathematical formulas, chemical formulas, tables, etc. ▼(IV) A method for producing a pyrazole derivative represented by.