JPH06247891A - Cyclohexanedione derivative and herbicide - Google Patents

Abstract

PURPOSE:To obtain the subject derivative consisting of a cyclohexanedione derivative containing substituted benzoyl group, exhibiting excellent herbicidal effect on weeds of paddy field and plowed land, free from phytotoxicity to crops, nontoxic to man, beast and fish and useful for herbicide, etc. CONSTITUTION:The derivative of formula IV useful for herbicide, etc., is produced by adding a cyclohexanedione derivative of formula I (R1 and R2 are H or lower alkyl) (e.g. 1,3-cyclohexanedione) to a benzoyl halide derivative of formula II (R is lower alkyl, lower alkenyl, lower alkynyl, lower alkoxy-lower alkyl or lower alkylthio-lower alkyl; X is Cl or Br; Y is halogen) (e.g. 2,4- dibromo-3-methoxybenzoyl chloride) in a solvent (e.g. chloroform) in the presence of triethylamine, etc., under ice cooling, reacting the components with each other for 1hr and reacting the obtained intermediate of formula III using a cyanide source (e.g. acetone cyanhydrin) as a catalyst.

Description

Detailed Description of the Invention

[0001]

[Object of the Invention]

FIELD OF THE INVENTION The present invention relates to a novel cyclohexanedione derivative and a herbicide containing the derivative as an active ingredient.

Accordingly, the present invention is useful in the chemical industry as well as agriculture, especially in the agrochemical manufacturing industry.

[0003]

2. Description of the Related Art The following compounds are similar in chemical structure to the cyclohexanedione derivative of the present invention, and all are known to have herbicidal activity.

[Patent Document 1] JP-A-4-501726 General formula

[Chemical 3]Where R Represents a chlorine atom or a bromine atom, R₁, R₂,
R₃Is a hydrogen atom or C 1-C 4 alkyl group, R_Four
Is a hydroxyl group, hydrogen atom or C 1-C 4 alkyl group is shown
And R₁, R₂, R_FiveAnd R₆Is all C 1-C 4 Archi
R when R is₃And R_FourAre both carbonyl groups, R
_FiveIs a hydrogen atom or C 1-C 4 alkyl group, R₆Is
Hydrogen atom, C 1-C 4 alkyl group, C 1-C 4-alkyl
Thio group or C 1-C 4 alkylsulfonyl group is shown,
R ₇Represents a methyl group or an ethyl group, R₈Is a halogen source
X, oxygen atom or sulfur atom
Indicates.

US Pat. No. 5,092,919 Specification

[Chemical 4]Where R ₁~ R₃Is a hydrogen atom, C 1-C 4 alkyl groups
Show, R _FourIs a hydroxyl group, hydrogen atom, C 1-C Alkyl of 4
Group, etc. _FiveIs a hydrogen atom, C 1-C Alkyl of 4
Group, R₆Is a hydrogen atom, C 1-C 4 alkyl groups
Which shows R ₇Represents a methyl group or an ethyl group, R₈Is
Indicates a halogen atom, nitro group, etc.

US Pat. No. 5,110,979, general formula

[Chemical 5]Where R ₁Is C 1-C 4 alkyl groups, C 1-C C of 4
Alkyl group, methoxyethyl group or ethoxyethyl
Group, R₇~ R₁₂Is a hydrogen atom or C1-C4
Represents a rutile group, Q is a halogen atom or a nitro group, etc.
Indicates.

WIPO 92/19107 gazette General formula

[Chemical 6]In the formula, R represents a halogen atom or the like, R₁, R₂, R₃,
R _Four, R_Five, R₆Is a hydrogen atom or C 1-C Alkyl of 2
Group, R₇, R₈Is a halogen atom, methoxyethyl group
Alternatively, it represents an ethoxyethyl group or the like.

[0008]

However, the compounds described in these documents are not always effective in herbicidal activity or cause phytotoxicity to crops, as shown in the test examples described below. It is hard to say that we should be satisfied. Therefore, development of a herbicide without such a defect is desired.

The present invention is intended to provide a cyclohexanedione derivative having excellent herbicidal activity and safety against crops, and a herbicide for paddy rice and field crops containing the same, instead of these compounds.

[0010]

Means for Solving the Problems The present inventors have synthesized many cyclohexanedione derivatives in order to achieve the above-mentioned object, and have made earnest studies on their usefulness. As a result, the novel cyclohexanedione derivative represented by the following general formula (1) does not cause phytotoxicity to crops, and has excellent herbicidal effect with low dose on weeds of paddy rice and upland crops, especially main weeds of paddy field. Found to show.

Therefore, the gist of the first aspect of the present invention lies in the general formula (1)

[Chemical 7] (In the formula, R represents a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower alkoxy lower alkyl group or a lower alkylthio lower alkyl group, R ₁ and R ₂ represent a hydrogen atom or a lower alkyl group, and X represents chlorine. Represents a atom or a bromine atom)).

In the compound represented by the general formula (1),
In the definition of R, R ₁ and R ₂ , the lower alkyl group has 1 to 6 carbon atoms and may be linear or branched, and examples thereof include a methyl group, an ethyl group and an n-propyl group. , Isopropyl group, n-butyl group, isobutyl group, s
Examples thereof include ec-butyl group, t-butyl group, pentyl group, neopentyl group, isopentyl group, hexyl group and isohexyl group. The lower alkenyl group has 2 to 6 carbon atoms and may be linear or branched. For example, vinyl group, 1-propenyl group, allyl group,
Examples thereof include a 1-methylvinyl group, a 2-methylallyl group, a 1-butenyl group, a 2-butenyl group, a 2-pentenyl group and a 2-hexenyl group. The lower alkynyl group has 2 to 6 carbon atoms and may be linear or branched. For example, ethynyl group, propargyl group, 1-
Examples thereof include a methylpropargyl group, a 2-butynyl group and a 1-methylbutynyl group. The lower alkoxy lower alkyl group is a lower alkyl group substituted with a linear or branched alkoxy group having 1 to 6 carbon atoms, and includes, for example, methoxyethyl group, ethoxyethyl group, n-propoxyethyl group, isopropoxy group. Ethyl group, n-butoxyethyl group, t-butoxyethyl group, n-pentyloxyethyl group, n-hexyloxyethyl group, 2-methoxypropyl group, 2-ethoxypropyl group, 3-n-propoxypropyl group, 3 -Isopropoxypropyl group, 4-methoxybutyl group, 6-methoxyhexyl group and the like can be mentioned. The lower alkylthio lower alkyl group is a lower alkyl group substituted with a linear or branched alkylthio group having 1 to 6 carbon atoms, and examples thereof include a methylthioethyl group, an ethylthioethyl group, and an isopropylthioethyl group. Can be mentioned.

The gist of the second aspect of the present invention is a herbicide containing the compound of formula (1) as an active ingredient.

Next, Table 1 shows typical examples of the compound of the general formula (1) of the present invention.

Compound No. Is also referred to in the following examples and test examples.

General formula (1)

[Chemical 8]

[0017]

[Table 1]

[0018]

The compound of the general formula (1) of the present invention is a novel compound. And the compound of this general formula (1) is
Acts as an active ingredient for controlling various weeds in upland fields.

[0019]

EXAMPLES (Production Method of the Compound of the Present Invention) Next, the production method of the compound of the present invention will be described in detail. That is, the general formula (2) is used as a starting material.

[Chemical 9](In the formula, R ₁, R ₂Represents the above meaning. )
Cyclohexanedione derivative and general formula (3)

[Chemical 10](Wherein, X and R Represents the above meaning, and Y represents halogen.
Represents an atom. ) And a benzoyl halide derivative
By reacting the compound of the general formula (4)

[Chemical 11](In the formula, R , R ₁, R ₂And X have the above-mentioned meanings. )
Is obtained, and then a cyanide source is used as a catalyst.
Then, by reacting the compound of the general formula (1)

[Chemical 12](In the formula, R , R ₁, R ₂And X have the above-mentioned meanings. )
The compound of the present invention represented by is obtained.

In the step of reacting the compound of the formula (2) with the compound of the formula (3), an equivalent amount of the reaction components is used, and in the presence of one equivalent or more of the dehydrohalogenating agent, a suitable solvent is used. React inside. Reaction temperature is 0-50
The mixture is stirred until a suitable temperature is reached and the reaction is substantially complete.

As the dehydrohalogenating agent, organic bases such as triethylamine, pyridine and N, N-diethylaniline, and inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate and sodium hydrogen carbonate can be used.

Examples of the solvent include hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as chloroform, dichloromethane and chlorobenzene, ethers such as diethyl ether, tetrahydrofuran and dioxane, ketones such as acetone and methyl ethyl ketone. , Acetonitrile and the like can be used.

After completion of the reaction, the reaction solution is added with water, extracted with an organic solvent, subjected to usual post-treatments such as concentration, and if necessary, purified by operations such as chromatography and recrystallization. it can.

Examples of production by this method are shown in Examples 1 and 2.

Next, the step of rearrangement reaction of the compound of formula (4), that is, the enol ester intermediate, is carried out by using an excess (preferably about 2 equivalents) of base and a catalytic amount (preferably 0.01).
(About 0.1 equivalent) in the presence of a cyanide source in a suitable solvent. The reaction temperature is close to the boiling point of the solvent, preferably 20 to 40 ° C., and the mixture is stirred until the rearrangement is substantially completed.

As the base, organic bases such as triethylamine, triethanolamine and pyridine, and inorganic bases such as potassium carbonate and trisodium phosphate can be used.

Examples of the cyanide source include alkali metal cyanides such as sodium cyanide and potassium cyanide, cyanohydrins of methylalkylketones such as acetone cyanohydrin, methyl isobutyl ketone cyanohydrin, cyanohydrins of benzaldehyde, acetaldehyde cyanohydrin, and propionaldehyde cyanohydrin. Cyanhydrin which is a different aliphatic aldehyde, zinc cyanide, trimethylsilyl cyanide and the like can be used.

Examples of the solvent include hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as chloroform, dichloromethane, 1,2-dichloroethane and chlorobenzene, ethers such as diethyl ether, tetrahydrofuran and dioxane, and acetone. , Ketones such as methyl ethyl ketone, acetonitrile, ethyl acetate, dimethylformamide and the like can be used.

After completion of the reaction, a usual post-treatment is carried out, and if desired, the desired product can be purified by a procedure of chromatography and recrystallization.

The compound represented by the general formula (2), which is the starting material, is a known compound. In addition, the general formula (3)
Is a novel compound, which can be synthesized by a known method, and its production examples are shown in Reference Production Examples 1 and 2.

[0031]

【Example】

Example 1 Preparation of 2- (2 ′, 4′-dibromo-3′-methoxymethoxybenzoyl) -1,3-cyclohexanedione (Compound No. 22) 1,3-Cyclohexanedione 6.1 g, triethylamine 6.6 g Then, to a mixture of 70 ml of chloroform, 17.9 g of 2,4-dibromo-3-methoxymethoxybenzoyl chloride was added under ice cooling, and the mixture was stirred at room temperature for 1 hour. Then, the reaction solution was added with a 5% hydrochloric acid aqueous solution and 5
% Aqueous sodium hydrogen carbonate solution, the chloroform layer was dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The crude composition of the enol ester was dissolved in 70 ml of 1,2-dichloroethane, and 10.1 g (2 equivalents) of triethylamine and 0.3 g (0.07 equivalents) of acetone cyanohydrin were added thereto, and the mixture was added at 40 ° C. for 1 hour. Dried. Then, the reaction solution is washed with a 5% hydrochloric acid aqueous solution,
The organic layer was dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the residue was purified by silica gel chromatography (eluent, toluene: acetone = 15: 1).
15.4 g of the title compound as white crystals, mp 80-82 ° C.
(Yield 71%) was obtained.

Example 2 Preparation of 2- (2 ', 4'-dichloro-3'-ethoxymethoxybenzoyl) -1,3-cyclohexanedione (Compound No. 2) 1,3-Cyclohexanedione 6.1 g, triethylamine To a mixture of 6.6 g and 70 ml of chloroform, 14.2 g of 2,4-dichloro-3-ethoxymethoxybenzoyl chloride was added under ice cooling, and the mixture was stirred at room temperature for 30 minutes. Then, the reaction solution was washed with a 5% aqueous solution of hydrochloric acid and a 5% aqueous solution of sodium hydrogen carbonate, the chloroform layer was dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure. The crude composition of the enol ester was dissolved in 70 ml of acetonitrile, and triethylamine 10.
1 g (2 equivalents) and acetone cyanohydrin 0.3
g (0.07 equivalent) was added, and the mixture was stirred at room temperature for 5 hours.
Then, the reaction solution was concentrated under reduced pressure, and chloroform 70
ml was added, the mixture was washed with a 5% aqueous hydrochloric acid solution, and the chloroform layer was dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the residue was purified by silica gel chromatography (eluent, toluene: ethyl acetate = 15: 1) to give 13.6 g of the title compound as a pale yellow oil (n ²³ _D = 1.57).
88, yield 76%) was obtained.

Reference Production Example 1 Production of 2,4-dibromo-3-n-propoxymethoxybenzoyl chloride t-butylamine 73.0 g, dichloromethane 50
0 ml of mixture with dry ice / acetone at about -50 ° C
After cooling to 80.0 g, bromine was slowly added over 1 hour. After the addition, the mixture was stirred at about -50 ° C for 1 hour, then ethyl 3-hydroxybenzoate 41.5
g was added at once. The mixture was left at room temperature overnight. The white solid formed is filtered off, washed with a little dichloromethane and 500 ml of dichloromethane and 500 ml of 1 are added.
Using a 0% aqueous hydrochloric acid solution, 60.8 g (yield 75%) of free phenol (ethyl 2,4-dibromo-3-hydroxybenzoate) was obtained as white crystals.

27.6 g of potassium carbonate and 13.1 of n-propoxymethyl chloride were added to a mixture of 32.4 g of the above-obtained phenol and 200 ml of dimethylformamide. After that, the mixture was stirred at 70 ° C. for 2 hours, 300 ml of toluene was added to the reaction mixture, and ordinary post-treatment was performed to obtain ethyl 3,4-dibromo-3-n-propoxymethylbenzoate (33.3 g, yield 84%). Obtained as a brown oil.

The above-obtained ester 19.8 g, 15
2.6 g of sodium hydroxide was added to 0 ml of a mixture of 80% methanol / water, and the mixture was stirred at room temperature for 5 hours, then 300 m.
l of ether was added and the organic layer was extracted 3 times with 100 ml of 5% aqueous sodium hydroxide solution. The extracts were combined and acidified with hydrochloric acid, and then extracted twice with dichloromethane. The organic layer was dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and 16.9 g (yield 92%) of 2,4-dibromo-3-n-propoxymethoxybenzoic acid was obtained as white crystals (m).
p. 98-98.5 ° C).

5 drops of DMF were added to a mixture of 11.0 g of the above product and 100 ml of dichloromethane, and 5.7 g of oxalyl chloride was slowly added. After the addition was completed, the solution was refluxed for 1 hour, and the solvent was distilled off under reduced pressure to obtain 11.0 g (yield 100%) of the title compound as a light brown oil.

Reference Production Example 2 Production of 2,4-dichloro-3-isopropoxymethoxybenzoyl chloride Reflux to a mixed solution of ethyl 3-hydroxybenzoate 41.5 g, diisopropylamine 0.5 g and 1,2-dichloroethane 500 ml. Chlorine under 88.6g
Was added over 5 hours and cooled to room temperature. 20 after cooling
0 ml of 5% aqueous sodium bisulfite solution, then 20
It was washed with 0 ml of water, the organic layer was dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. Recrystallization of the residue from ether / pentane gave free phenol (ethyl 2,4
-Dichloro-3-hydroxybenzoate) was obtained as white crystals (74.0 g, yield 63%).

To the resulting mixture of 23.5 g of phenol and 100 ml of dimethylformamide, 27.6 g of potassium carbonate and 13.1 g of isopropoxymethyl chloride were added. Then, the mixture was stirred at 80 ° C. for 2 hours, 300 ml of toluene was added to the reaction mixture, and ordinary post-treatment was performed to obtain 27.7 g of ethyl 2,4-dichloro-3-isopropoxymethylbenzoate (yield 90%).
Was obtained as a light brown oil.

15.4 g of the above-obtained ester, 15
2.6 g of sodium hydroxide was added to 0 ml of a mixture of 80% methanol / water, and the mixture was stirred at room temperature for 5 hours and then 300 ml.
Of ether was added, the organic layer was dried with 100 ml of 5% sodium hydroxide, and extracted three times with an aqueous solution. The extracts were combined, acidified with hydrochloric acid, and then extracted twice with chloroform. The organic layer was dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and 13.0 g (yield 93%) of 2,4-dichloro-3-isopropoxymethoxybenzoic acid was obtained as white crystals (mp 66). ˜69 ° C.).

8.4 g of the above product, chloroform
4.3 g of thionyl chloride was added to 100 ml of the mixture, the solution was refluxed for 1 hour, and the solvent was distilled off under reduced pressure to obtain 8.8 g (yield 99%) of the title compound as a pale brown oily substance.

Example (Method for formulating herbicide) When the compound of the present invention is used as an active ingredient of a herbicide,
Usually, it is mixed with solid carrier, liquid carrier, surfactant, and other auxiliaries for preparations, and emulsions, wettable powders, liquids, flowable (sol) agents, powders, driftless agents, granules, and fine particles are prepared by a conventional formulation. It can be prepared in an appropriate form such as an agent or a tablet.

The carrier used here may be either solid or liquid as long as it is commonly used for agricultural and horticultural agents, and is not limited to a particular one. ,
For example, these carriers include mineral powders (kaolin,
Bentonite, clay, montmorillonite, talc, diatomaceous earth, mica, vermiculite, gypsum, calcium carbonate, apatite, white carbon, slaked lime, silica sand, ammonium sulfate, urea, etc., vegetable powder (soybean flour, wheat flour, wood flour,
Tobacco powder, starch, crystalline cellulose, etc., polymer compounds (petroleum resin, polyvinyl chloride, ketone resin, dammal gum, etc.), alumina, silicates, sugar polymers, highly dispersible silicic acid, waxes, etc. . Further, as the liquid carrier, water, alcohols (methyl alcohol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, butanol, ethylene glycol,
Benzyl alcohol), aromatic hydrocarbons (toluene, benzene, xylene, ethylbenzene, methylnaphthalene, etc.), halogenated hydrocarbons (chloroform,
Carbon tetrachloride, dichloromethane, chloroethylene, monochlorobenzene, trichlorofluoromethane, dichlorofluoromethane, etc.), ethers (ethyl ether, ethylene oxide, dioxane, tetrahydrofuran, etc.), ketones (acetone, methyl ethyl ketone, cyclohexanone, methyl isobutyl) Ketones, isophorone, etc., Esters (ethyl acetate, butyl acetate, ethylene glycol acetate, amyl acetate, etc.), Acid amides (dimethylformamide, dimethylacetamide, etc.), Nitriles (acetonitrile, propionitrile, acrylonitrile, etc.), sulfoxides (Dimethylsulfoxide, etc.), Alcohol ethers (Ethylene glycol monomethyl ether, Ethylene glycol monoethyl ether, etc.) Aliphatic or alicyclic hydrocarbons (n- hexane, cyclohexane, etc.), industrial gasoline (petroleum ether, solvent naphtha, etc.), petroleum fractions (paraffins, kerosene, etc. gas oil) and the like.

In the preparation of emulsions, wettable powders, flowable agents, etc., various surfactants (or emulsifiers) are used for the purpose of emulsification, dispersion, solubilization, wetting, foaming, lubrication, spreading and the like. . Such surfactants include nonionic type (polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ester, etc.), anionic type (alkylbenzene sulfonate, alkyl sulfosuccinate, alkyl sulfate, polysulfate). Oxyethylene alkyl sulfate, aryl sulfonate, etc.), cationic type [alkyl amines (lauryl amine, stearyl trimethyl ammonium chloride, alkyl dimethyl benzyl ammonium chloride, etc.), polyoxyethylene alkyl amines], amphoteric type [carboxylic acid (betaine type ), Sulfate ester salts, etc.]
Of course, it is not limited to these examples.

In addition to these, polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC),
Various auxiliary agents such as gum arabic, polyvinyl acetate, sodium alginate, gelatin and tragacanth gum can be used.

In the present invention, when the above-mentioned various preparations are produced, the compound of the present invention is added in an amount of 0.001% to 95%.
(% By weight; the same applies hereinafter), preferably 0.01% to 75%
It can be formulated so as to contain in the range of. For example, in the case of powder, DL powder, and fine powder (F),
0.01% to 5%, in the case of granules 0.01% to 10%
%, Wettable powders, emulsions, and liquid preparations can be contained in the range of 1% to 75%.

In the case of granules, for example, the thus-prepared preparation may be sprayed as it is on the soil surface, in the soil or in water in an amount of about 0.3 g to 300 g per 10 ares as an active ingredient amount. In the case of a wettable powder, an emulsion, a sol and the like, they may be diluted with water or a suitable solvent and diluted in the range of about 0.3 to 300 g per 10 ares as an active ingredient amount.

When the compound of the present invention is used as a herbicide, its applicability can be expanded by mixing it with a known herbicide, insecticide or plant regulator, and in some cases, a synergistic effect is expected. You can also do it.

Regarding the method for formulating the compound of the present invention represented by the general formula (1) as a herbicide, the following Examples 3 to 6 are given.
Explain. However, the present invention is not limited only to these examples, it can be mixed with various other additives in any proportion, and other herbicides and the like can be mixed in any proportion to prepare a formulation. You can also

Compound No. Are those shown in Table 1 above, and all parts in the examples are parts by weight.

Example 3 (Granule) Compound No. Compound 1 of 3, lauryl sulphate 1 part, calcium lignin sulfonate 1 part, bentonite 30 parts and white clay 67 parts were added with 15 parts of water and kneaded with a kneader, then granulated with a granulator, and then fluidized dryer. And dried to obtain granules containing 1% of active ingredient.

Example 4 (Wettable powder) Compound No. 16 parts of compound, 15 parts of white carbon, 3 parts of calcium lignin sulfonate, 3 parts of polyoxyethylene nonylphenyl ether, 5 parts of diatomaceous earth and 60 parts of clay are uniformly mixed with a pulverizer to contain 15% of active ingredient. Obtain a wettable powder.

Example 5 (Emulsion) Compound No. 21 compounds, 20 parts, Solpol 700
20 parts of H (Emulsifier manufactured by Toho Chemical Industry Co., Ltd.) and 60 parts of xylene are mixed to obtain an emulsion containing 20% of the active ingredient.

Example 6 (powder) Compound No. 14 parts of compound 0.5 parts, silicic acid fine powder 0.5 parts, calcium stearate 0.5 parts, clay 50 parts and talc 48.5 parts were uniformly mixed and pulverized to obtain a powder containing 0.5% of active ingredient. obtain.

Next, Test Examples 1 to 3 are shown to demonstrate the herbicidal effect of the compound of the present invention. Test Example 1. Herbicidal effect test and phytotoxicity test for transplanted paddy rice A rice pot soil (planting loam soil) is filled in a plastic pot with a size of 1 / 5,000 are, and water is added to perform scavenging, and 50 Tainubier seeds are sown on the surface layer of 0 to 2 cm Then
Two-leaf stage paddy rice was planted at a depth of 2 cm, 2 plants per strain, 3 plants per pot, and the water depth was kept at 3 cm.

The drug treatment was carried out in the second leaf stage of the sea bream, Example 5.
Dilute the emulsion prepared in accordance with the procedure of 1.
ml (1.3g per are in terms of the amount of active ingredient used)
(Equivalent) was added dropwise.

This test was carried out in duplicate for each chemical concentration group, and 21 days after the chemical treatment, the herbicidal effect and the phytotoxicity of paddy rice were investigated based on the following evaluation indexes. The results are shown in Tables 2 and 3.

Evaluation value of herbicidal effect Herbicidal rate (%) 5 100% 4 80 to less than 100% 3 60 to less than 80% 2 40 to less than 60% 1 20 to less than 40% 0 less than 20% Evaluation of phytotoxicity 5 Death 4 Drug damage 3 Drug damage Medium 2 Drug damage 1 Drug damage Minor 0 Drug damage No

[0058]

[Table 2]

[0059]

[Table 3]

[0060]

Embedded image Comparative drug A; (Compounds described in JP-A-4-501726)

[0061]

Embedded image Comparative drug B; (Compounds described in JP-A-4-501726)

[0062]

Embedded image Comparative drug C; (Compounds described in US Pat. No. 5,092,919)

[0063]

Embedded image Comparative drug D; (Compounds described in US Pat. No. 5,110,979)

Test Example 2. Herbicidal effect test for paddy field weeds and phytotoxicity test for transplanted paddy rice Paddy soil (planting soil) is filled in a plastic pot with a size of 1 / 5,000 are, and rice paddy, broad-leaved weeds (Azena, Kishigusa, Mizohakobe) and firefly seeds are filled. 30 seeds were seeded at a depth of 1-2 cm.
One day after sowing, the water was flooded to keep the water depth at 2 cm. Three days after sowing, paddy rice at the 2.5 leaf stage was transplanted and grown in a greenhouse. One day after transplanting the paddy rice, the emulsion prepared according to Example 5 was diluted with water to a predetermined amount to obtain a spray solution,
0 ml was dropped.

This test was carried out in duplicate for each chemical solution concentration group, and 21 days after the treatment, the herbicidal effect and the phytotoxicity of paddy rice were investigated based on the same evaluation indexes as in Test Example 1. The results are shown in Tables 4 to 5.

[0066]

[Table 4]

[0067]

[Table 5]

Test Example 3 Herbicidal effect on upland weeds and phytotoxicity test on crops 1) Herbicidal effect test on weeds Field soil (alluvial loam) was packed in a biscuit pot with a size of 1/5000 are, and a soil of 1 cm surface layer was prepared. Each 50 seeds of various weed seeds, such as crabgrass, green locust, white squirrel, white squirrel, and sardine, were uniformly mixed, and the surface layer was lightly pressed. Two days after sowing, the emulsion prepared according to Example 5 was diluted with water, and 100 liters per 10 ares (corresponding to 100 g per 10 ares in terms of application amount of active ingredient) was sprayed onto the soil surface.

This test is carried out in a double system for each concentration of the chemical solution.
30 days after the chemical treatment, the herbicidal effect was investigated based on the same evaluation index as in Test Example 1.

2) Chemical damage test for crops Field soil (alluvial loam soil) was packed in a pot made of bisque of 1 / 10,000 are, and seeds of each crop (5 soybeans, 5 corns, 10 beets, 10 rapeseed seeds). And wheat 1
(0 grains) were seeded in different pots, and the surface layer was lightly pressed. One day after sowing, the emulsion prepared according to Example 5 was diluted with water, and 100 liters per 10 ares (corresponding to 100 g per 10 ares in active ingredient amount) was sprayed onto the soil surface.

This test is carried out in a double system for each concentration of the chemical solution.
30 days after the chemical treatment, the degree of phytotoxicity to each crop was investigated based on the same evaluation index as in Test Example 1. The results are shown in Tables 6 to 7.

[0072]

[Table 6]

[0073]

[Table 7]

[0074]

INDUSTRIAL APPLICABILITY The compound of the present invention has an excellent herbicidal effect as compared with known similar compounds, and exhibits excellent selectivity between crops and weeds. That is, in flooding treatment of paddy fields, various weeds that are problematic, for example, grass weeds such as Taenia japonicus, azena, yellow grass, broad-leaved weeds such as Mizochabe,
It can act on a wide variety of cyperaceous weeds, such as Pleurotus cornucopiae, firefly, pine nuts, and cyperus edulis, as well as eels and urchins, and can almost completely weed it, but it does not cause any phytotoxicity to paddy rice.

The compounds of the present invention are also problematic in foliage treatment and soil treatment of upland fields, such as buckwheat vine, Aedes persicae,
Broad-leaved weeds such as starfish, chickweed, white lobster, blue-spotted gall, tuna, velvetleaf, and morning glory, Tainubie, Inobie, Enokurogusa, Mejisiba, Scutellaria barbata,
It can act on a wide range of grass weeds such as oats and cyperaceae weeds such as pearl nuts, and can almost completely weed it, and it is also harmful to major crops such as corn, wheat, rice, soybean, rape and beet. Do not give.

Moreover, there is no human animal toxicity or fish toxicity. Therefore, it can be used safely.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuo Hirayama 2385 Toda, Atsugi-shi, Kanagawa Kitakogaku Dormitory (72) Hiromichi Ishikawa 5-40-12 Asahi-cho, Atsugi-shi, Kanagawa (72) Inventor Hirokazu Yoshizawa 1 Clover Heights 303 (72) at 2190 Toda, Atsugi, Kanagawa Prefecture Inventor Takashi Takeuchi 2385, Toda, Atsugi, Kanagawa Prefecture

Claims (2)

[Claims] 1. A general formula: (In the formula, R represents a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower alkoxy lower alkyl group or a lower alkylthio lower alkyl group, R ₁ and R ₂ represent a hydrogen atom or a lower alkyl group, and X represents chlorine. Which represents an atom or a bromine atom). 2. A general formula: (In the formula, R represents a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower alkoxy lower alkyl group or a lower alkylthio lower alkyl group, R ₁ and R ₂ represent a hydrogen atom or a lower alkyl group, and X represents chlorine. Atom or bromine atom) is contained as an active ingredient.