JP2730021B2 - 3-Benzyloxyalkanoic acid derivative, its production method and herbicide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a herbicide containing a novel 3-benzyloxyalkanoic acid derivative as an active ingredient.

[0002]

2. Description of the Prior Art Many herbicides have been developed so far in order to save labor in agricultural work and improve productivity of agricultural products. However, conventional herbicides cannot be said to have a sufficient selective herbicidal effect on crops such as soybeans, and it is hard to say that they sufficiently satisfy the problem of safety for living organisms. Therefore, in order to solve these issues,
The development of new herbicides is desired. The 3-benzyloxyalkanoic acid derivative of the present invention is a novel compound, and its herbicidal effect has not been known.

[0003]

The object of the present invention is to provide a novel 3-
An object of the present invention is to provide a benzyloxyalkanoic acid derivative, a method for producing the same, and a herbicide containing the same as an active ingredient.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, a novel 3-benzyloxyalkanoic acid derivative has been found to be an excellent choice for crops such as soybean. The present inventors have found that the present invention has an effective herbicidal effect, and have completed the present invention. That is, the present invention is as follows. The first invention has the following formula:

[0005]

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(Wherein R ¹ represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group, a cyano group, a halo-lower alkyl group, a lower alkylthio group or a lower alkylsulfonyl group; R ² , R ³ or R ⁴ each independently represents a hydrogen atom or a lower alkyl group;
⁵ represents a lower alkyl group or a lower alkoxy group; R ⁶
Represents a lower alkoxy group; X represents an oxygen atom or a sulfur atom; n represents an integer of 1 to 5. )). The second invention has the following formula:

[0007]

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(Wherein R ¹ , R ² , R ³ , R ⁴ , X and n are as defined above) and the following formula:

[0009]

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Wherein R ⁵ and R ⁶ have the same meanings as described above, and react with a compound represented by the formula (I). The present invention relates to a method for producing a derivative. A third invention provides the following formula:

[0011]

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Wherein R ¹ , R ² , R ³ and R ⁴ have the same meanings as described above, and R ⁷ represents a lower alkyl group, a substituted phenyl group or a halo-lower alkyl group. And the following equation:

[0013]

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Wherein R ⁵ and R ⁶ have the same meanings as described above, and are reacted with a compound represented by the formula (I). The present invention relates to a method for producing a derivative. A fourth invention provides the following formula:

[0015]

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(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ ,
R ⁶ and n have the same meanings as described above, and R ⁸ represents a lower alkyl group. The present invention relates to a process for producing a 3-benzyloxyalkanoic acid derivative represented by the above formula (I), wherein the compound represented by the formula (I) is hydrolyzed. The fifth invention relates to a herbicide containing a 3-benzyloxyalkanoic acid derivative represented by the above formula (I) as an active ingredient.

Hereinafter, the present invention will be described in detail. In the above-mentioned target compound, the novel 3-benzyloxyalkanoic acid derivative (I) and the production raw materials thereof (II) to (VI), R ¹ , R ² , R ³ , R ⁴ , R ⁵ ,
R ⁶ , R ⁷ , R ⁸ , X and n are as follows.

Examples of R ¹ include a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group, a cyano group, a halo-lower alkyl group, a lower alkylthio group and a lower alkylsulfonyl group; The number of carbon atoms in the group, lower alkoxy group, halo-lower alkyl group, lower alkylthio group, lower alkylsulfonyl group, etc. is preferably 1 to 6 in a linear or branched form, more preferably 1 to 4 (for example, methyl Group, ethyl group, n-propyl group, i-propyl group, n-
A butyl group, an i-butyl group, a sec-butyl group, a t-butyl group and the like; a halogen atom or a halogen in a halo-lower alkyl group (for example, a fluorine atom, a chlorine atom,
As a bromine atom and an iodine atom, a fluorine atom and a chlorine atom are preferable.

R ² , R ³ or R ⁴ is a hydrogen atom,
The lower alkyl group may have 1 to 6 carbon atoms, preferably linear or branched, preferably 1 to 4 (for example, 1 to 4 as described above).
The lower alkyl group is more preferably a methyl group for R ² and R ³ , and an ethyl group for R ⁴ .

Examples of R ⁵ include a lower alkyl group and a lower alkoxy group. The number of carbon atoms in the lower alkyl group and the lower alkoxy group is preferably 1 to 6 in a linear or branched state. Preferably 1 to 4 (for example, 1 to 4 described above) are preferred; a more preferred lower alkyl group is a methyl group; a more preferred lower alkoxy group is a methoxy group.

Examples of R ⁶ include lower alkoxy groups and the like; the number of carbon atoms is preferably linear or branched, and is preferably 1 to 6, and preferably 1 to 4 (for example, 1 to 4 as described above). To 4) is preferred; a methoxy group is more preferred.

R ⁷ includes a lower alkyl group, a substituted phenyl group, a halo-lower alkyl group, and the like;
The number of carbon atoms in the lower alkyl group is linear or branched and preferably 1 to 6, preferably 1 to 4 (for example, 1 to 4 described above); more preferably methyl The substituent of the substituted phenyl group is preferably a lower alkyl group [The number of carbon atoms in the lower alkyl group is preferably linear or branched and is preferably 1 to 6, and preferably 1 to 4 (for example, 1-4 described above
And more preferably a methyl group].

R ⁸ is a lower alkyl group (for example,
1 to 4 described above) and the like.

X includes an oxygen atom, a sulfur atom and the like. n can be an integer of 1 to 5; preferably 1 or 2.

The novel 3-benzyloxyalkanoic acid derivative (I), which is the target compound, includes optical isomers based on asymmetric carbon atoms. Compound (I)
Can be produced, for example, by the following production methods 1 to 3.

(Production Method 1)

[0027]

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(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ ,
R ⁶ , X and n are as defined above. ) The compound (I) is usually prepared by mixing the starting compound (II) and the starting compound (I
It is preferred to react the compound with II) in a solvent in the presence of a base.

When X is an oxygen atom, the compound (II) may be, for example, [Tetrahedron Letter]
No. 36, 3761 (1972)] or [Or
g. Syn. IV, p. 459], and can be easily produced by reacting an epoxy alkanoic acid ester produced by the method described in [IV] with an acid catalyst (sulfuric acid, paratoluenesulfonic acid, etc.) in an alcohol as shown below. it can.

[0030]

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(In the formula, R ¹ , R ² , R ³ and R ⁸ have the same meanings as described above.) When X is a sulfur atom, the compound (II) is, for example, as follows: As described above, the compound (IV) can be easily produced by reacting the compound (IV) with sodium bisulfide in a polar solvent.

As the compound (II), for example,
Compound Nos. 1, 3, 611, 14, 1 shown in 10
6,18,20,22,24,26,28,30,3
2,36,39,42,45,47,51,54,5
6, 59, 63, 73, each compound consisting of each type of substituent [compounds (II) ₁ , (II) ₃ ,
(II) ₆ , (II) ₁₁ , (II) ₁₄ , (II)
₁₆ , (II) ₁₈ , (II) ₂₀ , (II) ₂₂ ,
(II) ₂₄ , (II) ₂₆ , (II) ₂₈ , (II)
₃₀ , (II) ₃₂ , (II) ₃₆ , (II) ₃₉ ,
(II) ₄₂ , (II) ₄₅ , (II) ₄₇ , (II)
₅₁ , (II) ₅₄ , (II) ₅₆ , (II) ₅₉ ,
(II) ₆₃ and (II) ₇₃ . [For example, compound (I) corresponding to compound No. 1
I) is referred to as Compound (II) ₁ . The compound (II) ₁ is defined as (R ¹ ) _n , R in the compound (II).
² and R ³ are H, R ⁴ is C ₂ H ₅ , and X is O. ]. Compound (III) is described, for example, in JP-A-63-2
It can be easily produced according to the method described in No. 3870.

As the compound (III), for example, Table 1
Compound Nos. 1, 3, 611, 14, 1 shown in
6,18,20,22,24,26,28,30,3
2,36,39,42,45,47,51,54,5
6, 59, 63, 73, each compound consisting of the type of each substituent [compound (III) ₁ , (II
I) ₃ , (III) ₆ , (III) ₁₁ , (III)
₁₄ , (III) ₁₆ , (III) ₁₈ , (III)
₂₀ , (III) ₂₂ , (III) ₂₄ , (III)
₂₆ , (III) ₂₈ , (III) ₃₀ , (III)
₃₂ , (III) ₃₆ , (III) ₃₉ , (III)
₄₂ , (III) ₄₅ , (III) ₄₇ , (III)
₅₁ , (III) ₅₄ , (III) ₅₆ , (III)
₅₉ , (III) ₆₃ and (III) ₇₃ . [For example, compound (III) corresponding to compound No. ₁ is referred to as compound (III) ₁ . And
The compound (III) ₁ means that R ⁵ and R ⁶ in the compound (III) are OCH ₃ . ].

The solvent is not particularly limited as long as it does not directly participate in the present reaction. Methyl ethyl ketone. Ketones such as methyl isobutyl ketone; nitriles such as acetonitrile; dipolar aprotic solvents such as N, N-dimethylformamide, N, N-dimethyl-2-imidazolidinone, dimethylsulfoxide; water; Can be mentioned.

As the base, for example, organic bases such as triethylamine, pyridine, N, N-diethylaniline and the like; inorganic bases such as sodium amide, sodium hydroxide, potassium hydroxide, potassium carbonate, sodium carbonate, sodium hydride and the like And the like.

The method for producing the compound (I) has a reaction concentration of 5 to 5.
It can be performed at 100%. In the production method, the ratio of the starting compound (II) to the starting compound (III) is based on 1 mol of the starting compound (II) and the starting compound (III).
It can be added at a ratio of 0.5 to 2 mol, but preferably 1 to 1.5 mol.

The reaction temperature is not particularly limited as long as the reaction is carried out at a temperature not higher than the boiling point of the solvent used, but it is preferably 10 to 100 ° C., preferably 30 to 60 ° C.

The reaction time varies depending on the above-mentioned concentration and temperature, but can usually be carried out for 1 to 12 hours.
As the compound (I), for example, each compound consisting of the types of the substituents corresponding to the compound numbers 1 to 74 shown in Tables 1 to 10 [referred to as compounds 1 to 74. [For example, Compound (I) corresponding to Compound No. 1 is referred to as Compound 1. The compound 1 means (R ¹ ) _n , R ² and R ³ in compound (I) are H, R ⁴ is C ₂ H ₅ , R ⁵ and R ⁶ are OCH ₃ , and X is O. ].

(Production method 2)

[0040]

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(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ ,
R ⁶ , R ⁷ and n are as defined above. ) Compound (I) is obtained by the same reaction in Production Method 1 except that (IV) is used instead of (II) as the starting compound and (V) is used instead of (III) as the starting compound. be able to.

The compound (IV) can be easily produced, for example, by reacting the compound (II) with a sulfonyl chloride in an appropriate solvent in the presence of a base catalyst as shown below.

[0043]

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(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁷ and n have the same meanings as described above.)

As the compound (IV), for example,
Each compound consisting of the types of the substituents corresponding to the compound numbers 38, 49, and 50 shown in FIG.
V) ₃₈ , (IV) ₄₉ and (IV) ₅₀ . [For example, compound (IV) corresponding to compound number ₅₀ is referred to as compound (IV) ₅₀ . And
The compound (IV) ₅₀ means that (R ¹ ) _n in the compound (IV) is 2-Cl, R ² , R ³ and R ⁴ are H and R ⁷
Is paratoluene. ].

Compound (V) is, for example, compound (II)
I) can be easily produced by adding sodium bisulfide in water or alcohol and heating and stirring as shown below.

[0047]

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(In the formula, R ⁴ and R ⁵ have the same meanings as described above.)

As the compound (V), for example, Tables 1 to 1
Compounds consisting of the types of the substituents corresponding to the compound numbers 38 and 4950 shown in 0 (referred to as compounds (V) ₃₈ , (V) ₄₉ , and (V) ₅₀ , respectively). [For example, compound (V) corresponding to compound number ₅₀ is referred to as compound (V) _50] . The compound (V) ₅₀ is defined as R ⁵ and R ⁶ in the compound (V).
Is OCH ₃ . ].

The reaction can be carried out using the solvent, base, reaction temperature and reaction time described in Production Method 1. (Production method 3)

[0051]

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(Wherein R ¹ , R ² , R ³ , R ⁵ , R ⁶ ,
R ⁸ and n are as defined above. ) Compound (I)
Can be obtained by reacting compound (VI) in a solvent in the presence of a base.

As the compound (VI), for example,
Compound Nos. 2, 7, 1012, 15, 1 shown in 10
7,19,21,23,25,27,29,31,3
3,34,35,37,40,41,43,44,4
6,48,52,53,55,57,58,60,6
1, 62, 64, 65, 66, 72, and 74, each compound consisting of each type of substituent [each compound (V
I) ₂ , (VI) ₇ , (VI) ₁₀ , (VI) ₁₂ ,
(VI) ₁₅ , (VI) ₁₇ , (VI) ₁₉ , (VI)
₂₁ , (VI) ₂₃ , (VI) ₂₅ , (VI) ₂₇ ,
(VI) ₂₉ , (VI) ₃₁ , (VI) ₃₃ , (VI)
₃₄ , (VI) ₃₅ , (VI) ₃₇ , (VI) ₄₀ ,
(VI) ₄₁ , (VI) ₄₃ , (VI) ₄₄ , (VI)
₄₆ , (VI) ₄₈ , (VI) ₅₂ , (VI) ₅₃ ,
(VI) ₅₅ , (VI) ₅₇ , (VI) ₅₈ , (VI)
₆₀ , (VI) ₆₁ , (VI) ₆₂ , (VI) ₆₄ ,
(VI) ₆₅ , (VI) ₆₆ , (VI) ₇₂ , (VI)
_{No. 74} . [For example, compound (VI) corresponding to compound number ₂ is referred to as compound (VI) _2] . The compound (VI) ₂ is a compound (V
In (I), it means that (R ¹ ) _n , R ² and R ³ are H, R ⁵ and R ⁶ are OCH ₃ , and R ⁸ is C ₂ H ₅ . ].

The solvent is not particularly limited as long as it does not directly participate in the present reaction. Methyl ethyl ketone. Ketones such as methyl isobutyl ketone; alcohols such as methanol and ethanol; ethers such as tetrahydrofuran and 1,4-dioxane; water;

Examples of the base include sodium hydroxide and potassium hydroxide.

The production method of compound (I) is such that the reaction concentration is 5 to 5.
It can be performed at 100%.

The reaction temperature is not particularly limited as long as the reaction is carried out at a temperature not higher than the boiling point of the solvent used, but it is preferably from 10 to 70 ° C, preferably from 20 to 50 ° C.

The reaction time varies depending on the above-mentioned concentration and temperature, but can usually be carried out for 0.5 to 12 hours.

Herbicides containing compound (I) as an active ingredient include:
It has high selectivity for soybeans and so on, and shows an excellent herbicidal effect. That is, the herbicide of the present invention exhibits an excellent herbicidal effect on annual weeds and perennial weeds that occur in paddy fields, fields, etc., and the herbicidal effect is particularly high for annual grasses (for example, Mehishiba, Nobie, And annual broadleaf weeds (eg, morning glory, shiroza,
It is prominent in perennial weeds (for example, fireflies, urikawa, and jyonsonras).
Further, the herbicide of the present invention exhibits an excellent herbicidal effect on the above-mentioned weeds, but does not show any phytotoxicity to field crops (for example, cotton) at such a treatment concentration.

The herbicide of the present invention contains at least one compound (I) as an active ingredient. Compound (I)
Can be used alone, but usually, a carrier, a surfactant, a dispersant, an auxiliary agent, etc. are blended by a conventional method (for example, powders, emulsions, fine granules, granules, wettable powders, oil-based It is preferably prepared as a composition such as a suspension or an aerosol.)

Examples of the carrier include talc, mica, bentonite, clay, kaolin, diatomaceous earth, white carbon, vermiculite, dolomite, zeolite, slaked lime, silica sand, silicic anhydride, ammonium sulfate, urea, wood powder,
Solid carriers such as starch and cellulose; hydrocarbons (kerosene, mineral oil, etc.), aromatic hydrocarbons (benzene, toluene, xylene, etc.), chlorinated hydrocarbons (chloroform,
Carbon tetrachloride, etc., ethers (dioxane, tetrahydrofuran, etc.), ketones (acetone, cyclohexanone, isophorone, etc.), esters (ethyl acetate, ethylene glycol acetate, dibutyl maleate, etc.), alcohols (methanol, n-hexanol) ,
Liquid carriers such as ethylene glycol), polar solvents (dimethylformamide, dimethyl sulfoxide, etc.), water; gas carriers such as air, nitrogen, carbon dioxide, and freon (in this case, mixed injection can be performed). I can do it.

Surfactants that can be used to improve the performance of this agent, such as adhesion to plants, improvement in absorption, dispersion, emulsification, and spreading of drugs, include nonionic, anionic, and cationic surfactants. And amphoteric surfactants (eg, alcohol sulfates, alkyl sulfonates, lignin sulfonates, polyoxyethylene glycol ethers, etc.). In order to improve the properties of the preparation, carboxymethylcellulose, polyethylene glycol, gum arabic and the like can be used as adjuvants.

In the preparation of the present agent, in addition to the above-mentioned carriers, surfactants, dispersants, adjuvants, etc., other agricultural chemicals (bactericides, insecticides, etc.), fertilizers, soil conditioners, etc. Depending on each, they can be used alone or in an appropriate combination.

When the compound (I) of the present invention is formulated, the concentration of the active ingredient is usually 1 to 50% by weight for emulsions, usually 0.3 to 25% by weight for powders, and usually 1 to 90% by weight for wettable powders. % For granules, usually 0.5 to 5% by weight for oils, usually 0.5 to 5% by weight for oils, and 0.1 to 5% by weight for aerosols. These preparations can be diluted to an appropriate concentration and applied to various uses by spraying them on plant foliage, soil, or the water surface of paddy fields, or directly applying them, depending on the purpose.

[0065]

The present invention will be described below by way of examples. In addition,
These examples do not limit the scope of the invention.

Embodiment 1

(1) 3-benzyloxy-2- (4,6
Synthesis of ethyl-dimethoxypyrimidin-2-yl) oxybutanoate (Compound 1) The compound (I) of the present invention was synthesized by the method described in (Production Method 1). Ethyl 2,3-epoxybutanoate (13.0 g, 0.1 mol) was added to benzyl alcohol (21.6 g, 0.2 mol), and sulfuric acid (0.5 ml) was added as a catalyst. Stirred for hours. Column chromatography from the reaction solution (Wakogel C-200, n-hexane: ethyl acetate = 3: 1 elution)
Thus, ethyl 3-benzyloxy-2-hydroxybutanoate (19.0 g) was obtained. Next, the obtained ethyl 3-benzyloxy-2-hydroxybutanoate (19.0
g) and 4,6-dimethoxy-2-methylsulfonylpyrimidine (17.4 g, 0.08 mol) were added to N, N-dimethylformamide (150 ml), and potassium carbonate (11.1 g, 0.08 mol) was further added. 6)
Stirred at 0 ° C. for 3 hours.

The obtained reaction solution was added to water and extracted with ethyl acetate. The ethyl acetate layer was washed with saturated saline, dried over sodium sulfate, and ethyl acetate was distilled off under reduced pressure to obtain a residue. By column chromatography (Wakogel C-2)
00, n-hexane: ethyl acetate = 4: 1) and 24.1 g of the target compound as a colorless oil.
(80% yield).

(2) 3-benzyloxy-2- (4,6
Synthesis of -dimethoxypyrimidin-2-yl) oxybutanoic acid (Compound 2) According to the method described in (Production Method 3), target compound (I)
Was synthesized. In ethanol (100 ml), the compound 1 prepared in the above (1) (34.4 g, 0.1 mol) was added.
l) was dissolved. Then, 5N sodium hydroxide (40 ml) was added thereto, and the mixture was stirred at 30 ° C. for 2 hours. Thereafter, ethanol was distilled off under reduced pressure, and 5
N hydrochloric acid (50 ml) was added, and the mixture was extracted with chloroform.
The chloroform layer was washed with water and dried, and chloroform was distilled off under reduced pressure to obtain 26.9 g (yield: 85.0%) of the target compound as white crystals.

(3) 3-benzyloxy-2- (4,6
Synthesis of -dimethoxypyrimidin-2-yl) thiobutanoic acid (Compound 3) The compound (I) of the present invention was synthesized by the method described in (Production Method 1). 1N sodium hydroxide (200m
In 1), 3-benzyloxy-2-mercaptobutanoic acid (22.6 g, 0.1 mol) was dissolved. And, in this, 4,6-dimethoxy-2-methylsulfonylpyrimidine (21.8 g, 0.1 ml) was added to acetone (100 ml).
(1 mol) was added, and the mixture was stirred at room temperature for 1 hour.

A 5N hydrochloric acid aqueous solution (100
ml), and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated saline, dried over sodium sulfate, and the residue obtained by evaporating the ethyl acetate under reduced pressure was subjected to column chromatography (Wakogel C-gel). 200, n-hexane: ethyl acetate: acetic acid = 1: 1: 0.1 elution)
27.2 g of the target compound as a colorless oil (yield: 7
5%).

(4) Synthesis of 3- (2-chlorobenzyl) oxy-2- (4,6-dimethoxypyrimidin-2-yl) thiobutanoic acid (compound 50) Compound (I)
Was synthesized. 3- (2-chlorobenzyl) oxy-2-
Paratoluenesulfonyloxybutanoic acid (36.3 g,
0.1 mol) and 4,6-dimethoxy-2-mercaptopyrimidine (17.2 g, 0.1 mol) by N, N-
Dissolved in dimethylformamide (200 ml), further added potassium carbonate (13.8 g, 0.1 mol) and stirred at 50 ° C. for 2 hours.

A 1N aqueous hydrochloric acid solution (500
ml), and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated saline, dried over sodium sulfate, and the residue obtained by evaporating the ethyl acetate under reduced pressure was subjected to column chromatography (Wakogel C-gel). 200, n-hexane: ethyl acetate: acetic acid = 1: 1: 0.1 elution)
31.8 g of the target compound as white crystals (yield: 80
%)Obtained.

(5) Synthesis of other compounds (I) in Tables 1 to 10 According to any one of the synthesis methods (1) to (4),
The target compound (I) as shown in 10 was obtained.

Embodiment 2

(1) [Preparation of granules] 8 parts by weight of compound 1, 30 parts by weight of bentonite, 59 parts by weight of talc, 1 part by weight of neoperex powder (trade name, manufactured by Kao Corporation) and sodium ligninsulfonate 2 The parts by weight were uniformly mixed and then kneaded by adding a small amount of water, and then granulated and dried to obtain granules.

(2) [Preparation of wettable powder] 50 parts by weight of compound 3, 46 parts by weight of kaolin, 2 parts by weight of Neoperex powder (trade name, manufactured by Kao Corporation) and Demol N
(Product name; manufactured by Kao Corporation) 2 parts by weight are mixed uniformly,
Then, it was pulverized to obtain a wettable powder.

(3) [Preparation of emulsion] 30 parts by weight of compound 36, 60 parts by weight of xylene, 5 parts by weight of dimethylformamide and 5 parts by weight of Solpol 3005X (trade name; manufactured by Toho Chemical Industry Co., Ltd.) were added and mixed uniformly. And dissolved to obtain an emulsion.

(4) [Preparation of dust] A powder was obtained by uniformly mixing 5 parts by weight of compound 50, 50 parts by weight of talc and 45 parts by weight of clay.

Embodiment 3

(1) [Paddy field weeding test] A 1/5000 arel Wagner pot was filled with Ube soil (alluvial clay loam), seeds or tubers of weeds (Nobie, Urikawa, Firefly) were planted, and water was added to add water. It was flooded by 3 cm. The wettable powder of the target compound (I) shown in Tables 1 to 10 prepared according to Example 2 was diluted with water, and the effective concentration of the compound (I) in each of these drug solutions was increased at the time of the first leaf leaping. 20g
/ A was dropped using a pipette. And after managing for 3 weeks in a glass room with an average temperature of 25 ° C,
Their herbicidal effects were investigated. The evaluation of the drug effect was performed in six stages [0: harmless (normal development), 1: slight harm, 2: small harm, 3: moderate harm, 4: major harm,
5: complete withering) (-indicates that no study has been conducted). Table 11 shows the results.

(2) [Upland soil treatment test] 1/5000
Earl's Wagner pots were filled with Ube soil (alluvial clay loam), and seeds of soybean, mehishiba, nobie, shiroza and inubiyu were planted and covered. Table 1 prepared according to Example 2
The wettable powder of the target compound (I) shown in Nos. 10 to 10 was diluted with water, and sprayed uniformly on the surface of each soil so that the effective concentration of the compound (I) in each of these chemical solutions was 20 g / a. And after controlling for 3 weeks in a glass room with an average temperature of 25 ° C., their herbicidal effect was investigated. Table 12 shows the evaluation results of the drug effects by the evaluation method described in the paddy field herbicidal effect test (1).

(3) [Field foliage treatment test] 1/5000
Earl's Wagner pot was filled with volcanic ash soil, and seeds of soybean, mehishiba, nobie, shiroza, inubeyu, and morning glory were planted and covered for two weeks. A wettable powder of the target compound (I) shown in Tables 1 to 10 prepared according to Example 2 was used as a spreading agent neoesterin (manufactured by Kumiai Chemical Co., Ltd.).
(500 ppm) diluted to 2000 ppm with water containing
Each of the above plants was sprayed uniformly. And average temperature 2
After three weeks of management in a glass room at 5 ° C., their herbicidal effect was investigated. The results of the determination of the drug effect are shown in Table 13 by the evaluation method described in the paddy field herbicidal effect test (1).

[Effects of the Invention] The novel 3-benzyloxyalkanoic acid derivatives of the present invention exhibit an excellent herbicidal effect on annual and perennial weeds and an excellent selective herbicidal effect on crops such as soybean. Things.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

[Table 8]

[Table 9]

[Table 10]

[Table 11]

[Table 12]

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kunio Shiraishi Examiner at the Ube Research Institute, Ube Research Institute, 1978 Kogushi, Ube City, Ube City, Yamaguchi Prefecture Shinichi Naito

Claims (5)

(57) [Claims] (1) The following formula: (Wherein R ¹ represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group, a cyano group, a halo-lower alkyl group, a lower alkylthio group or a lower alkylsulfonyl group; R ² , R ³ or R ⁴ each independently represent a hydrogen atom or a lower alkyl group; R ⁵ represents a lower alkyl group or a lower alkoxy group; R ⁶ represents a lower alkoxy group; X represents an oxygen atom or a sulfur atom; n is 1
Represents an integer of from 5 to 5. A) 3-benzyloxyalkanoic acid derivative represented by the formula: 2. The following formula: Wherein R ¹ , R ² , R ³ , R ⁴ , X and n are
Is synonymous with the description. And a compound represented by the following formula: (Wherein R ⁵ and R ⁶ have the same meanings as described in claim 1), and the compound is reacted with 3-benzyloxy represented by the formula (I) according to claim 1. A method for producing an alkanoic acid derivative. 3. The following formula: (Wherein R ¹ , R ² , R ³ and R ⁴ have the same meanings as in claim 1 and R ⁷ represents a lower alkyl group, a substituted phenyl group or a halo-lower alkyl group). The following formula: (Wherein R ⁵ and R ⁶ have the same meanings as described in claim 1), and the compound is reacted with 3-benzyloxy represented by the formula (I) according to claim 1. A method for producing an alkanoic acid derivative. 4. The following formula: (Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and n have the same meanings as in claim 1, and R ⁸ represents a lower alkyl group). The method for producing a 3-benzyloxyalkanoic acid derivative represented by the formula (I) according to claim 1, which is decomposed. 5. The compound represented by the formula (I) according to claim 1,
A herbicide containing a benzyloxyalkanoic acid derivative as an active ingredient;