WO1995018106A1 - 4-trifluoromethylpyridine derivative and process for producting the same - Google Patents

Abstract

A 4-trifluoromethylpyridine derivative represented by general formula (I) and useful as a herbicide wherein X represents halogen, hydrogen, hydrogen or lower alkoxy; R1 represents hydrogen or lower alkoxycarbonyl; and R2 represents lower alkanesulfonyl, benzenesulfonyl or -CO-R3, wherein R3 represents alkyl, haloalkyl, lower-alkoxy-substituted lower alkyl, lower-alkoxycarbonyl-substituted lower alkyl, carboxyl-substituted lower alkyl, cycloalkyl, phenyl (which may be substituted by one to five lower alkyl, halogen, trifluoromethyl, nitro, cyano or lower alkoxy groups), pyridyl, furyl, thienyl, amino or di(lower alkyl)amino.

Description

 W Description

 4. Trifluoromethylpyridine derivatives and their production

 The present invention provides a compound represented by the general formula (I):

[Wherein, X represents a halogen atom, a hydrogen atom or a lower alkoxy group, R ¹ represents a hydrogen atom or a lower alkoxycarbonyl group, R ² represents a lower alkanesulfonyl group, a benzenesulfonyl group or the following formula:

-C 0-R ³

(Wherein, R ³ is an alkyl group, a haloalkyl group, a lower alkoxy-substituted lower alkyl group, a lower alkoxycarbonyl group-substituted lower alkyl group, a carboxyl group-substituted lower alkyl group, a cycloalkyl group, a phenyl group (the phenyl group) A lower alkyl group, a halogen atom, a trifluoromethyl group, a nitro group, a cyano group or a lower alkoxy group, which may be substituted by 1 to 5), a pyridyl group, a furyl group, a phenyl group, It represents an amino group or a di-lower alkylamino group. And a method for producing the same. The compounds of the present invention are useful as herbicides, and exhibit high herbicidal activity, particularly against various annual weeds in paddy fields or fields. Background art

In recent years, a number of herbicides have been developed, contributing to labor saving in agricultural work and improvement in productivity. However, these herbicides are not necessarily sufficient in terms of herbicidal effect and safety in actual use, and the emergence of improved herbicides is desired. You. Journal of Organic Chemistry, 39, pp. 3956, the following formula in 1973 (N 0 _{2) n}

〉 ー 0 N H C〇

で示される化合物力記載されている。 し力 し、 この化合物は除草活性を何ら有し ていないか、 有していてもわずかで除草剤としての有用性は認められない。 フランス公開特許第 2 5 4 1 2 8 2号には、 次式：

The compounds represented by are described. However, this compound has no or no herbicidal activity, and its usefulness as a herbicide is not recognized. French published patent no. 25 4 1 2 82 contains the following formula:

 A r-0-N H-R

Wherein Ar represents an optionally substituted aromatic or heteroaromatic compound (having one or more 〇, N and S), and R represents a hydrogen atom, an alkyl substitution force Various hydroxylamine derivatives used as a growth factor for plants represented by the following are disclosed. And ^¾ to force, not described in detail for 4 one triflumizole Ruo b-piperidine lysine derivative of a specific structure of the present invention. Disclosure of the invention

 The present inventors have synthesized a large number of various compounds for the purpose of developing a herbicide, and have conducted extensive screening tests. As a result, a novel 4-trifluoromethylpyridine derivative having a specific substituent has been obtained. Showed high herbicidal activity, and completed the present invention.

 The present invention provides a compound represented by the general formula (I):

[式中、 Xはハロゲン原子、 水素原子又は低級アルコキシ基を表し、 R¹ は水素 原子又は低級アルコキシカルボ二ル基を表し、 R² は低級アルカンスルホニル 基、 ベンゼンスルホニル基又は次式：

[Wherein, X represents a halogen atom, a hydrogen atom or a lower alkoxy group, R ¹ represents a hydrogen atom or a lower alkoxycarbonyl group, R ² represents a lower alkanesulfonyl group, a benzenesulfonyl group or the following formula:

One CO-R ³

(Wherein, R ³ is an alkyl group, a haloalkyl group, a lower alkoxy-substituted lower alkyl group, a lower alkoxycarbonyl group-substituted lower alkyl group, a carboxyl group-substituted lower alkyl group, a cycloalkyl group, a phenyl group (the phenyl group) The alkyl group may be substituted with 1 to 5 lower alkyl groups, halogen atoms, trifluoromethyl groups, nitro groups, cyano groups or lower alkoxy groups), pyridyl groups, furyl groups, chenyl groups, amino groups Or a di-lower alkylamino group). 4] -Trifluoromethylpyridine derivative represented by the formula:

 Further, the present invention provides a compound represented by the following general formula (II):

(Wherein X has the same meaning as described above, and Ha 1 represents a halogen atom.) And a compound represented by the following general formula (III):

H0NHC0R ³ (III)

(Wherein, R ³ has the same meaning as described above.) Wherein the compound is reacted with a hydroxamic acid represented by the following general formula (Ia):

(式中、 X及び R³ は前記と同じ意味を表す。 ） で示される 4一トリフルォロメ チルピリジン誘導体の製造方法に関するものである。

(Wherein, X and R ³ have the same meanings as described above.) The present invention relates to a method for producing a 4-trifluoromethylpyridine derivative represented by the following formula:

 Further, the present invention provides a compound represented by the following general formula (IV):

(Wherein X and R ¹ have the same meanings as described above) and a compound represented by the general formula (V):

Ha l-R ² (V)

(Wherein, R ² and Ha 1 have the same meanings as described above.) A compound represented by the general formula (I):

(Wherein, X, R ¹ and R ² have the same meanings as described above.) A method for producing a 4-trifluoromethylpyridine derivative represented by the following formula:

 Further, the present invention provides a compound represented by the general formula (VI):

CF

Υ

(V I)

X ', _Ν .

Hi, R (Wherein, X and R ² have the same meanings as described above, and Y represents a lower alkoxycarbonyl group.) The compound represented by the formula (Ib):

(I-Ib)

(Wherein, X and R ² have the same meanings as described above.) The present invention relates to a process for producing a 4-trifluoromethylpyridine derivative represented by the following formula:

 The compound represented by the general formula (I) will be described.

 In the above general formula (I), X represents a halogen atom, a hydrogen atom or a lower alkoxy group. Here, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and among them, a chlorine atom is preferable. As the lower alkoxy group, an alkoxy group having 1 to 4 carbon atoms, for example, methoxy group, ethoxy group, π-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group or t-butoxy group Among them, a methoxy group is preferred. X is preferably a halogen atom, particularly a chlorine atom.

R ¹ represents a hydrogen atom or a lower alkoxycarbonyl group. As the lower alkoxycarbonyl group, an alkoxycarbonyl group having 2 to 5 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an isopropoxycarbonyl group, an n-butoxycarbonyl group, an isobutoxycarbonyl group, Examples thereof include a sec-butoxycarbonyl group and a t-butoxycarbonyl group.

R ² is a lower alkanesulfonyl group, a benzenesulfonyl group or the following formula:

-C 0-R ³

Represents a group represented by Here, examples of the lower alkanesulfonyl group include an alkanesulfonyl group having 1 to 4 carbon atoms, such as a methanesulfonyl group and an ethanesulfonyl group.

Group 1 CO— In R ³ , R ³ is an alkyl group, haloalkyl group, lower alkoxy C-substituted lower alkyl group, lower alkoxycarbonyl group-substituted lower alkyl group, methoxyl-substituted lower alkyl group, cycloalkyl group, phenyl group (the phenyl group is a lower alkylyl group, a halogen atom, a trifluoromethylyl group, a nitro group) , A cyano group or a lower alkoxy group which may be substituted by 1 to 5), a pyridyl group, a furyl group, a phenyl group, a phenyl group, an amino group or a di-lower alkylamino group.

Examples of the alkyl group represented by R ³ include an alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. Group, n-pentyl group, isopentyl group, t-pentyl group, neopentyl group, n-hexyl group, π-heptyl group, π-octyl group, n-nonyl group, π-decyl group, etc. it can.

The haloalkyl group represented by R ^3, the exemplary similar 1-5-substituted number 1-2 alkyl carbon with a halogen atom, specifically Furuoromechiru group, chloromethyl group, dichloromethyl group Trifluoromethyl group, 1-fluoroethyl group, 1-chloroethyl group, 2-fluoroethyl group, 2-chloroethyl group, trichloroethyl group, trifluoroethyl group, and pentafluoroethyl group. be able to.

Examples of the lower alkoxy-substituted lower alkyl group represented by R ³ include an alkyl group having 1 to 4 carbon atoms substituted with an alkoxy group having 1 to 4 carbon atoms, specifically, a methoxymethyl group and a 1-methoxyethyl group. , 2-methoxyl, 3-methoxypropyl, 4-methoxybutyl, 2-ethoxyl, isopropoxymethyl, 41-t-butoxybutyl and the like.

As the lower alkoxycarbonyl group-substituted lower alkyl group represented by R ^3, there can be mentioned an alkyl group having 1 to 4 carbon atoms, which is substituted by an alkoxyl group having 2 to 5 carbon atoms, specifically, a methoxycarbonylmethyl group. , 2-methoxycarbonylethyl, 3-methoxycarbonylpropyl, 4-methoxycarbonylbutyl, 2-ethoxycarbonylethyl, isopropoxycarbonylmethyl, 4-t-butoxycarbonyl A butyl group and the like can be mentioned.

As the carboxyl group-substituted lower alkyl group represented by R ³ , a carboxyl group-substituted alkyl group having 1 to 4 carbon atoms, such as carboxymethyl group, Examples include a boxyshethyl group, a 3-carboxypropyl group, and a 4-carboxybutyl group.

The cycloalkyl group represented by R ³ can be exemplified a cycloalkyl group having 3 to 6 carbon atoms, specifically, cyclopropyl group, cyclobutyl group, cyclopentyl group, a key sill group cyclohexylene.

In the phenyl group represented by R ³ , the lower alkyl group to be substituted includes an alkyl group having 1 to 4 carbon atoms, specifically the same as those described above, and the lower alkoxy group has 1 carbon atom. And the same alkoxy groups as described above in Examples 4 to 4 can be mentioned, and the halogen atom can be the same as described above.

Examples of the pyridyl group represented by R ³ include a 2-pyridyl group, a 3-pyridyl group and a 4-pyridyl group. Examples of the furyl group include a 2-furyl group and a 3-furyl group. Examples of the phenyl group include a 2-phenyl group and a 3-phenyl group. Examples of the di-lower alkylamino group include an amino group substituted with an alkyl group having 1 to 4 carbon atoms, such as a dimethylamino group, a getylamino group, a di-n-propylamino group, a diisopropylamino group, a di-n-butylamino group, Diisobutylamino group, di-sec-butylamino group, di-t-butylamino group and the like.

Among the compounds represented by formula (I), preferred compounds include, for example, the compounds shown in Table 1.

Nil

Table 1.

—The general formula (Ia) corresponds to the case where R ^{1 in the} general formula (I) is a hydrogen atom and R ² is —CO—R ³ .

The general formula (Ib) corresponds to the case where R ^{1 in the} general formula (I) is a hydrogen atom.

—X in the general formula (II) is the same as described above. H a1 represents a halogen atom, and includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

—X and R ^{1 in} the general formula (III), general formula (IV), and X and R ^{2 in} the general formula (VI) in the general formula (V) are the same as described above. As the lower alkoxycarbonyl group represented by Y in the general formula (VI), the same as those exemplified for R ′ can be mentioned.

The compound (I) of the present invention can be synthesized by the following three methods. The first method (hereinafter referred to as “method a” :) is represented by the general formula (Π): CF

(I I)

 H a 1

(Wherein X represents the same meaning as described above, and Ha represents a halogen atom.) And a compound represented by the general formula (III):

HONHCO R ³ (III)

(Wherein R ³ has the same meaning as described above.) By reacting with a hydroxamic acid represented by the following formula (Ia):

(Wherein, X and R ³ have the same meanings as described above.) A method for producing a 4-trifluoromethylpyridine derivative represented by the following formula:

 In this reaction, it is preferable to use a base. Examples of the base to be used include sodium hydroxide, alkali metal hydroxides such as hydroxide hydroxide, alkali metal alkoxides such as sodium methoxide, sodium ethoxide and potassium t-butoxide, and sodium hydride. Metal hydrides such as hydrogen hydride and the like are preferred. The amount of the base to be used is generally 0.5 to 5 mol, preferably 0.8 to 3 mol, particularly preferably 1 to 2 mol, per 1 mol of the compound represented by the formula (III).

 The reaction is carried out in the presence of hydrocarbons such as benzene and toluene, ethers such as methyl ether, tetrahydrofuran and dioxane, alcohols such as methanol, ethanol, isopropanol and t-butanol, or N, N-dimethylform. Amid

1 〇 (DMF), dimethylsulfoxide, dimethylacetamide, tetramethylurea, and the like, it is preferable to carry out in a nonprotonic polar solvent.

 The reaction temperature is usually from 20 ° C to 150 ° C, preferably from 0 ° C to 120 ° C, particularly preferably from 10 ° C to 100 ° C. In this reaction, the compound represented by the formula (III) is usually used in an amount of 0.5 to 3 mol, preferably 0.7 to 2 mol, particularly preferably 0.1 to 2 mol per mol of the compound represented by the formula (II). Use 9 to 1.5 moles.

 In addition, the compound (I) of the present invention can be produced by the second method (hereinafter, referred to as “method b”) in addition to the above method a.

 This method b has the general formula (IV):

(Wherein X and R ¹ have the same meanings as described above.) And a compound represented by the general formula (V):

Ha 1 -R ² (V)

(Wherein, R ² and Ha 1 have the same meaning as described above. By reacting with an acid halide represented by the general formula (I):

(Wherein, X, R ¹ and R ² have the same meanings as described above.) A method for producing a 4-trifluoromethylpyridine derivative represented by the following formula:

In this reaction, the use of a base is preferred. The base used is Amines such as gin, bicholine, lutidine, dimethylaminopyridine, trimethylamine and triethylamine; alkali metal carbonates such as carbon dioxide, sodium carbonate and sodium bicarbonate; sodium hydroxide; Alkali metal hydroxides such as potassium thiocyanate; alkaline earth metal hydroxides such as calcium hydroxide; alkali metal alkoxides such as sodium methoxide, sodium ethoxide and potassium t-butoxide; Amines such as picoline and triethylamine are preferred.

 The amount of the base to be used is generally 0.5 to 10 mol, preferably 0.8 to 8 mol, particularly preferably 1.0 to 6 mol, per 1 mol of the compound represented by the general formula (IV). The reaction is carried out without solvent or in a solvent such as halogenated hydrocarbons such as dichloromethane, dichloroethane, and chloroform, hydrocarbons such as benzene and toluene, and ethers such as dimethyl ether, tetrahydrofuran, and dioxane. Is preferred.

 The reaction temperature is usually from 150 ° C to 100 ° C, preferably from −30 ° C to 80 ° C. C, particularly preferably 0 ° C to 60 ° C. In this reaction, the compound represented by the formula (V) is usually 0.5 to 8 mol, preferably 1.0 to 6 mol, particularly preferably 1.0 to 1 mol of the compound represented by the formula (IV). Use 5-4 moles.

 Furthermore, compound (I) of the present invention can also be produced by a third method (hereinafter, referred to as “method c”). This method c has the general formula (VI):

(Wherein, X and R ² have the same meanings as described above, and Y represents a lower alkoxycarbonyl group.) By hydrolyzing the compound represented by the formula (I-b): (I-Ib)

(Wherein, X and R ² have the same meanings as described above.) A method for producing a 4-trifluoromethylpyridine derivative represented by the following formula:

 For this reaction, it is preferable to use a base. Examples of the base include alkali metal hydroxides such as hydroxydium hydroxide and potassium potassium hydroxide, and alkaline earth metal hydroxides such as calcium hydroxide. Alkali metal alkoxides such as sodium methoxide, sodium ethoxide and potassium t-butoxide, and alkali metal hydrides such as sodium hydride and potassium hydride are preferred. The amount of base used is the general formula

The amount is generally 0.5 to 30 mol, preferably 1 to 15 mol, particularly preferably 3 to 10 mol, per 1 mol of the compound represented by (VI).

 The reaction includes alcohols such as methanol, ethanol, isopropanol and t-butanol, water, halogenated hydrocarbons such as dichloromethane and dichloroethane, ethers such as dimethyl ether, tetrahydrofuran and dioxane, N, N-dimethylformamide, It is preferable to carry out the reaction in a solvent such as an aprotic polar solvent such as N, N-dimethylacetamide.

 The reaction temperature is usually from 0 ° C to 150. Z, preferably from 10 ° C to 50 ° C, particularly preferably from 20 ° C to 40 ° C.

 To use the compound of the present invention as a herbicide, the compound of the present invention alone, or a carrier, a surfactant, a dispersing agent, an auxiliary agent, and the like, and a wettable powder, an emulsion, a powder, a fine granule, or a granule in combination with the compound of the present invention And dilute it to an appropriate concentration before spraying or applying directly.

The compound of the present invention or a preparation containing the compound can be used as a surface treatment or admixed with soil, which can be directly sprayed and used on weeds. The application rate is about 10 to 400 _g / ha as a normally active ingredient amount that varies depending on the type of target weed, the type of target crop, and the mode of application. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, the present invention will be described more specifically with reference to Examples and Test Examples, but the scope of the present invention is not limited thereto.

 (Example 1)

 Synthesis of N- (6-chloro-4-1-trifluoromethyl-2-pyridyloxy) acetamide (Compound No. 1)

 In a 10 Oml flask equipped with a thermometer and a dropper, 4.32 g of 2,6-dichloro-4-trifluoromethylpyridine (20 liters) and 1.5 g of acetate hydroxamic acid (20 liters) 2 Ommol) and 7 Otnl of ethanol. While stirring with C, 3 Oml of an ethanol solution of 2.64 g (20 conceivable) of 85% potassium hydroxide was added dropwise over 25 minutes. After the addition was completed, the mixture was further kept at 20 ° C. for 1 hour. Then, 3.6 g of acetic acid was added, and most of the ethanol in the reaction mixture was distilled off under reduced pressure. 200 ml of water was added to the obtained residue, and extraction was performed twice with 20 ml of ethyl acetate. The ethyl acetate extract was washed with saturated saline, dried over anhydrous magnesium sulfate, and then ethyl acetate was distilled off under reduced pressure. The obtained residue was recrystallized from toluene-hexane to give 2.79 g of the desired product (yield 55%).

 Melting point: 122-123 ° C

 MS (Field Desorption (FD) method): 254 (M +)

 I R (KB r tablets, cm-ri:

 3190, 1665, 1575, 1393, 1335, 1201,

 1 138, 1078, 860, 703

 Ή-NMR (CDC 13, ppm):

 2.16 (3 H, s), 7.12 (1 H, s), 7.27 (1 H, s), 9.8 (1Η, broad s)

 (Example 2)

The compounds shown in Table 2 were synthesized according to the method of Example 1 (corresponding to method a in the text of the specification). 9 T

 ζ

LSZZ0IP6d £ fIDd 90I8I / S6 OAS. Table 2 (continued)

 (Example 3)

 Synthesis of N- (6-chloro-4-1-trifluoromethyl-2-pyri.ziloxy) -N-ethoxycarbonemethanesulfonamide (Compound No. 33)

1.43 g (5 mmo 1) of N- (6-chloro-4-1-trifluoromethyl-2-pyrroloxy) ethyl rubinate, 3.03 g (30 mmo 1) of triethylamine and 20 ml of tetrahydrofuran in 100 ml eggplant The batch was charged into a flask, stirred at room temperature under nitrogen for 5 minutes, and then a solution of 1.73 g (15 mmo 1) of methanesulfonyl chloride in tetrahydrofuran (10 ml) was added dropwise over 3 minutes. Was. After further reacting for 10 minutes, 30 ml of ethyl acetate and 30 ml of water were added and extracted.The ethyl acetate layer was washed with 30 ml of water, dried over anhydrous sodium sulfate, concentrated, rinsed with 20 ml of hexane, filtered, By vacuum drying, 1.74 g (96% yield) of N- (6-chloro-4-1-trifluoromethyl-2-pyridyloxy) -1-N-ethoxycarbonyl-methanesulfonamide was obtained as pale yellow crystals.

 Melting point: 112-114. C

 Ή-NMR (CDC 13, ppm):

 1.33 (3H, t, J = 7Hz) 3.57 (3H, s

 4.39 (2H, q, J = 7Hz) 7.22 (1H, s

 7.39 (1 H, s)

 (Example 4)

The same operation was performed in the same manner as in Example 3 except that methanesulfonyl chloride was replaced with acetyl, propionyl chloride, isobutyryl chloride, bivaloyl chloride, nonanoyl chloride, ethanesulfonyl chloride, or benzenesulfonyl chloride. The results and physical properties data are shown in Table 3 (mp: ° C) o

Table 3

 (Example 5)

 Synthesis of N— (6-chloro 4-trifluoromethyl-2-pyridyloxy) methanesulfonamide (Compound No. 15)

1.08 g (3 mmo 1) of N— (6—black mouth—4—trifluoromethyl-2-pyridyloxy) —N—ethoxycarbonylmethanesulfonamide synthesized in Example 3 was converted to methanol 10 m After dissolving in water, add 10 ml of a 20% aqueous hydroxide solution at room temperature, stir for 30 minutes, concentrate, extract with 50 ml of ethyl acetate and 5 Oml of water, and wash the ethyl acetate layer with 50 ml of water. Concentrate by drying over anhydrous sodium sulfate. Rinse the concentrate with 1 Om 1 of hexane and vacuum dry to obtain N- (6-chloro-4-trifluoromethyl-12-pyridyloxy) methanesulfone. 0.75 g of the amide was obtained as pale yellow crystals (86% yield).

 Melting point: 109 ~ 1 10 ° C

 Ή-NMR (CDC 13, ppm):

 2.92 (3H, s), 7.14 (1H, s), 7.63 (1H, s) (Example 6)

 Synthesis of N- (6-chloro-4-1-trifluoromethyl-12-pyridyloxy) ethanesulfonamide (Compound No. 16) and N- (6-chloro-4-1-trifluoromethyl-2-pyridyloxy) benzenesulfonamide (Compound No. 17) N- (6-chloro-4-trifluoromethyl-2-pyridyloxy) -N-ethoxycarbonyl-2-methanesulfonamide of Example 5 was converted to N- (6-chloro-4-trifluoromethyl-2-pyridyloxy)- The same procedure was carried out in place of N-ethoxycarbonyl-2-ethanesulfonamide and N- (6-chloro-4-trifluoromethyl-2-pyridyloxy) -1-N-ethoxycarbonyl-2-benzenesulfonamide. As a result, the desired product was obtained as pale yellow crystals in 41% yield (compound No. 16, melting point: 60-61 ° C) and 67% (compound No. 17, melting point: 57-58 ° C, deliquescent). Was. The data of 'Η-NMR spectrum of each compound are shown below. .

Compound No. _{16 (CDC 1 3, ppm)} :

 1.31 (3H, t, J = 7Hz), 4.29 (2H, q, J = 7Hz), 7.21 (1H, s), 7.30 (1H, s),

 7.5 to 7.9 (1H, br)

 Compound No. 17 (CDC 13, ppm):

 5.0—6.0 (1H, br), 6.69 (1H, s),

 6.77 (1H, s), 6.8 to 7.4 (3H, m),

 7.74 (2 H, d, J = 8 Hz)

 (Example 7) Wetting agent

 A wettable powder was prepared by uniformly mixing and grinding 10% of the compound of the present invention, 3% of a sodium salt of a higher alcohol sulfate and 87% of kaolin.

(Example 8) Emulsion An emulsion was prepared by uniformly dissolving 20% of the compound of the present invention, 10% of polyoxyethylene alkylaryl ether, 30% of cyclohexanone and 40% of xylene.

 (Example 9) Granules

 5% of the inventive compound of the present invention, 40% of bentonite, 50% of clay and 5% of sodium ligninsulfonate are uniformly mixed and pulverized, kneaded by adding water, granulated and dried by granulation. Agent.

 (Example 10) Powder

 3% of the compound of the present invention and 97% of clay were uniformly mixed and pulverized to obtain a powder. Next, the herbicidal effect of the compound of the present invention will be described with reference to test examples.

 (Test example)

 Filter paper (2 sheets) was spread over a petri dish with a lid of 9 cm in diameter, and seeds of Nobie, Mehishiba, Aobu and Alfalpha were sown. 20 ml of a diluted aqueous solution of liquid fertilizer and a wettable powder of a test compound (prepared according to Example 7) were diluted with water at a rate of 1 OOg / lha as an active ingredient and sprayed. After 10 days at 30 ° C under light irradiation (3000 lux), the herbicidal effect was visually evaluated based on the criteria shown in Table 4.

 Table 4 Index Weeding effect

5 Complete withering

 4. 5 9% to 99%

 4 80% or more and up to 89%

 3.5 5% or more up to 79%

 3 60% or more and up to 69%

 2.5 5% to 59%

 2 40% or more up to 49%

 1, 5 30% or more up to 39%

 1 20% to 29%

 0.5 19% or less 1% or less

0 None Result _c shown in Table 5 Table 5

* Comparative compound 1 using a known compound represented by the following formula

0 ₉ N

Comparative compound 2

〇 ₂ N

Industrial applicability

 According to the present invention, a novel 4-trifluoromethylpyridine derivative is provided. The 4-trifluoromethylpyridine derivative of the present invention is useful as a herbicide, and particularly exhibits a high herbicidal effect on various annual weeds in paddy fields or fields.

Claims

1. —General formula (

Wherein X represents a halogen atom, a hydrogen atom or a lower alkoxy group, and R ¹ is hydrogen  car R ² represents a lower alkanesulfonyl group, a benzenesulfonyl group or the following formula: -C0-R ³ Wherein R ³ is an alkyl group, a haloalkyl group, a lower alkoxy-substituted lower alkyl group, a lower alkoxycarbonyl group-substituted lower alkyl group, a carboxyl group-substituted lower alkyl group, a cycloalkyl group, a phenyl group (the The group may be substituted with 1 to 5 lower alkyl groups, halogen atoms, trifluoromethyl groups, nitro groups, cyano groups or lower alkoxy groups), pyridyl groups, furyl groups, chenyl groups, amino groups or It represents a di-lower alkylamino group. ] 4-trifluoromethylpyridine derivative represented by the formula: 2. General formula (II):

(Wherein, X represents the same meaning as described above, and Ha 1 represents a halogen atom.) And a compound represented by the following general formula (ΠΙ): HONHCO R ³ (III) (Wherein, R ³ represents the same meaning as described above.) A general formula (g) characterized by reacting with a hydroxamic acid represented by the following formula: C F 3 H  , Ν. (I-a) , Ν '〇', C〇R 3 (Wherein, X and R ³ have the same meanings as described above.) A method for producing a 4-trifluoromethylpyridine derivative represented by the following formula:  3. The method according to claim 2, wherein the reaction is carried out in the presence of a 3-base. 4. General formula (IV): χ

(Wherein X and R ¹ have the same meanings as described above) and a compound represented by the general formula (V): Ha l-R ² (V) (Wherein, R ² and Ha 1 have the same meanings as described above.) A compound represented by the general formula (I):

(Wherein, X, R ¹ and R ² have the same meanings as described above.) A method for producing a 4-trifluoromethylpyridine derivative represented by the following formula:  5. The method according to claim 4, wherein the reaction is carried out in the presence of a base. 6. General formula (VI):

(Wherein, X and R ² have the same meaning as described above, and Y represents a lower alkoxycarbonyl group.) A compound represented by the general formula (Ib): (I-Ib)

(Wherein, X and R ² have the same meanings as described above.).  7. The method according to claim 6, wherein the reaction is carried out in the presence of a base.