JP2946686B2 - Thiadiazole derivative and herbicide containing the same as active ingredient - Google Patents

Description

The present invention relates to a novel thiadiazole derivative and a herbicide containing the same as an active ingredient.

[Prior Art] Conventionally, many herbicides have been used. However, there have generally been problems such as insufficient herbicidal activity, narrow herbicidal spectrum, and phytotoxicity of crops.

Conventionally, the herbicidal activity of 2,1,3-benzothiadiazole derivatives and 1,2,4- or 1,3,4-thiadiazole derivatives is well known, but as shown in the general formula [I].
It is not known that 1,2,5-thiadiazole derivatives have herbicidal activity.

[Problems to be Solved by the Invention] Accordingly, an object of the present invention is to provide a novel compound having high herbicidal activity and high safety against crops when used as a herbicide, and a novel herbicide containing the same as an active ingredient. It is to be.

[Means for Solving the Problems] As a result of intensive studies, the present inventors have found that a novel thiadiazole derivative has extremely excellent herbicidal activity and selectivity, and have completed the present invention.

That is, the present invention provides a compound represented by the general formula [I]: [Wherein, Y is an oxygen atom or a sulfur atom, Χ is a hydrogen atom, a halogen atom, a lower alkyl group, a lower haloalkyl group, a lower alkoxy group, a hydroxy group or a nitro group,
V and Z are the same or different and are substituted with a halogen atom, a lower alkyl group, a lower haloalkyl group, a lower alkoxy group, a hydroxy group or a nitro group, and A is substituted with a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group or an alkoxy group. May be an alkoxyalkyl group, an alkylthioalkyl group, -SO ₂ R ¹ (R ¹ is a lower alkyl group optionally substituted with a halogen atom or a phenyl group optionally substituted with a lower alkyl group, or a lower alkyl group. Represents a substituted amino group), (N is 0 or 1, B is CH or a nitrogen atom, R ² and R ³ are the same or different and represent a hydrogen atom, a halogen atom, a lower alkoxy group, a nitro group or a lower alkyl group which may be substituted with a halogen atom. ^{), - SiR 4 R 5 R} 6 (R 4, R 5, R 6 are the same or different and a lower alkyl ^{group), - CHR 7 COOR 8 (} R 7
Represents a hydrogen atom or a lower alkyl group, R ⁸ represents a hydroxy group or an amino group (which may be substituted with a lower alkyl group and / or a phenyl group), —C (＝ W) OR
⁹ (W is an oxygen atom or a sulfur atom, R ⁹ is an alkyl group which may be substituted with a halogen atom, an alkoxyalkyl group,
A benzyl group, a phenyl group, a tetrahydrofurfuryl group or an alkylideneamino group), -COR ¹⁰ (R ¹⁰ is a lower alkyl group, a cycloalkyl group, (a halogen atom, a lower alkyl group, a lower haloalkyl group, a lower alkoxy group,
A phenyl group which may be substituted with a nitro group or a cyano group), -C (= W) NR ¹¹ R ¹² (W is an oxygen atom or a sulfur atom, R ¹¹ and R ¹² are the same or different and are a hydrogen atom A lower alkyl group, a cycloalkyl group, a lower alkoxy group,
An alkoxyalkyl group, a phenyl group which may be substituted with an alkoxy group, or (R ¹³ and R ¹⁴ are the same or different and each represents a lower alkyl group or a lower alkoxy group)) or R ¹¹ and R ¹² are (E is CH ₂ or an oxygen atom, m is 0 or 1, R ¹⁵ and R ¹⁶ are the same or different and each represents a hydrogen atom or a lower alkyl group).

The present invention also provides a herbicide containing the compound of the present invention represented by the above general formula [I] as an active ingredient.

[Effect of the Invention] According to the present invention, a novel compound having an excellent herbicidal activity and a broad herbicidal spectrum as a herbicide is provided. Herbicides containing the compound of the present invention as an active ingredient can control various weeds from before emergence until the growing season, and are highly safe for crops in paddy fields, various cereal fields,
It can be effectively used for weed control in various vegetable fields, fruit trees, mulberry fields, and non-cultivated lands. In particular, it can be effectively used for weed control in paddy fields.

[Specific description of the invention] The compound of the present invention can be prepared by the method described in Journal of Organic Chemistry, 2823.
, (1967)), and can be produced by reacting the corresponding amino acid amide or a hydrogen halide thereof represented by the general formula [II] with sulfur monochloride or thionyl chloride.

(Wherein, Χ, V, and Z have the same meanings as described above, and Q represents a halogen atom.) This reaction is usually carried out in a solvent at 20 to 100 ° C. for 1 to 24 hours. A compound can be obtained.

Preferred examples of the solvent used in the reaction include benzene, aromatic hydrocarbons such as toluene, ethers such as tetrahydrofuran, halogenated hydrocarbons such as chloroform, nitromethane, acetonitrile, and polar compounds such as N, N-dimethylformamide. Solvents and the like can be mentioned.

The amount of the reagent used for the reaction is usually the amount of amino acid amide 1
Sulfur monochloride is 3 to 4 equivalents to equivalents.

In addition, the compound of the present invention may be prepared by reacting a thiadiazole derivative represented by the general formula [III] with AQ (A and Q have the same meanings as described above), R ⁹ OC (＝ O) OR ⁹ (where R ⁹
Represents the same meaning as described above) or R ¹⁰ C (＝ O) OC (＝ O) R ¹⁰ (where R ¹⁰ has the same meaning as described above).

(However, Χ, Y, Z, and V have the same meanings as described above.) This reaction is usually performed in a solvent in the presence of a base in the range of 0 to 150.
The compound of the present invention can be obtained by conducting the reaction at a temperature of several minutes to 48 hours.

Preferred examples of the solvent used in the reaction include acetone, ketones such as methyl ethyl ketone, benzene, toluene, aromatic hydrocarbons such as xylene, diethyl ether, tetrahydrofuran, ethers such as dioxane,
Halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane, chlorobenzene, tertiary amines such as pyridine, triethylamine, N, N-diethylaniline, acetonitrile, N, N-dimethylformamide, dimethylsulfoxide, 1, 3-dimethyl-2
Polar solvents such as imidazolidinone and hexamethyltriamide phosphate;

Examples of preferred bases used in the reaction include:
Organic bases such as pyridine, triethylamine and N, N-dimethylaniline; inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and sodium hydroxide; alkali metal alkoxides such as sodium methoxide and sodium ethoxide; Is mentioned.

The amount of the reagent used for the reaction is usually AQ, 1 equivalent to 1 equivalent of the thiadiazole derivative represented by the general formula [III].
R ⁹ OC (＝ O) OR ⁹ or R ¹⁰ C (＝ O) OC (＝ O) R ¹⁰ is 1 to
2 equivalents, 1 to 5 equivalents of base.

When A is —C (＝ W) OR ⁹ or —C (＝ W) NR ¹¹ R ¹² in the general formula [I], first, the general formula [III]
In the presence or absence of a reaction solvent, a thiadiazole derivative and phosgene, thiophosgene, trichloromethylchloroformate, or any of bis (trichloromethyl) carbonate represented by 0 to 100 ° C. in the presence or absence of a base, Incubate for a few minutes to 48 hours. Preferred examples of the solvent used in the reaction include benzene, aromatic hydrocarbons such as toluene, dichloromethane, chloroform,
Examples thereof include halogenated hydrocarbons such as carbon tetrachloride. Examples of preferable bases used in the reaction include organic bases such as pyridine, triethylamine and N, N-dimethylaniline, and inorganic bases such as sodium hydrogen carbonate and sodium carbonate.

Next, the corresponding alcohols or amines in the presence or absence of a base in a solvent or without solvent,
The compound of the present invention can be obtained by reacting at 0 to 150 ° C. for several minutes to 48 hours.

Preferred examples of the solvent used in the reaction include acetone, ketones such as methyl ethyl ketone, benzene, toluene, aromatic hydrocarbons such as xylene, diethyl ether, tetrahydrofuran, ethers such as dioxane,
Dichloromethane, chloroform, dichloroethane, halogenated hydrocarbons such as carbon tetrachloride, pyridine, triethylamine, N, tertiary amines such as N-dimethylaniline,
Acetonitrile, N, N-dimethylformamide, acetonitrile, dimethylsulfoxide, 1,3-dimethyl-2
And polar solvents such as imidazolidinone. Preferred examples of the base used in the reaction include organic bases such as pyridine and triethylamine, and inorganic bases such as sodium hydroxide, calcium carbonate and sodium hydrogen carbonate.

Further, in the general formula [I], A is -C (= W) NR
^{In the} case of ¹¹ R ¹² , the thiadiazole derivative represented by the general formula [III] and the corresponding isocyanate are added in the presence or absence of a solvent, in the presence or absence of a base, in the presence or absence of 0 to 0.
The compound of the present invention can be obtained by reacting at 150 ° C. for several minutes to 48 hours.

In this case, preferred examples of the solvent used in the reaction include aromatic hydrocarbons such as benzene, toluene, and xylene; ethers such as diethyl ether, tetrahydrofuran and dioxane; and halogenated hydrocarbons such as dichloromethane, chloroform and carbon tetrachloride. , Pyridine, triethylamine, N, N-dimethylformamide, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone,
Examples thereof include polar solvents such as hexamethyltriamide phosphate.

Examples of preferred bases used in the reaction include:
Organic bases such as pyridine, triethylamine and N, N-dimethylaniline, and inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydride and the like can be mentioned.

Furthermore, in the general formula [I], Y is a sulfur atom, A
When is a hydrogen atom, the compound of the present invention can be obtained by subjecting the corresponding thionocarbamate to heat transfer to give the corresponding thiolcarbamate, followed by hydrolysis.

This reaction is carried out under a nitrogen atmosphere under an inorganic solvent at 130 to 200
After a reaction at a temperature of several minutes to 24 hours, hydrolysis is carried out.

Furthermore, in the general formula [I], when at least one of Ｖ, V and Z is a nitro group, the general formula [IV]
Thiadiazole derivative and concentrated sulfuric acid-concentrated nitric acid-
It can be produced by reacting at 10 to 100 ° C. for several minutes to 24 hours.

(In the formula, Χ and V have the same meanings as described above.) The amount of the reagent to be subjected to the reaction is usually based on 4 parts by weight of the thiadiazole derivative represented by the general formula [IV].
10 to 100 parts by weight, concentrated nitric acid is 1 to 100 parts by weight.

The herbicide of the present invention containing the compound of the present invention as an active ingredient shows excellent herbicidal effect, but hardly affects crops. That is, the herbicide of the present invention, in the field, various weeds that are problematic, for example, Aoubiyu, Purslane, Onamomi, Sendangusa, Ragweed, Shiroza, Oitanuta, Hakobe, Nazuna, Minamigusa, Shirobanachosenasagao, Acacia catechu, Malva Morning Glory, Dogwood Butterfly, Hotokezaza, Plantain, Ichibiki, Okabami, Yaegura, Sobakazura, Oolechinogiku, Himekasashimogi, Himezion, Inubie, Enokorogusa, Meishishiba, Suzumeokashira, Suzumeokasimo, Sasaenoboshimo, Suzumekoboshimo, Suzumekoboshimo, Suzumekoboshimo, Suzumekoboshimo, Suzumeboshimomo Various weeds of interest, such as, for example, red foxtails, azaleas, kikasigusa, tamayatsuri, fireflies, pine trees, serrata, konagi,
It has a weed effect in pre-emergence treatment and growing season treatment of weeds against urikawa, etc., and corn, wheat,
It does not show any phytotoxicity that would be a problem for major crops such as rice, soybean, tawa and sugar beet.

The herbicide of the present invention can be used in combination with or in combination with other pesticides, for example, fungicides, insecticides, herbicides, plant growth regulators, fertilizers, soil amendments, and the like. In particular, by mixing and using other herbicides, not only labor saving can be brought about, but also an expansion of the herbicidal spectrum and a higher herbicidal effect can be expected.

Herbicides that can be used in combination include 2,4-bis (ethylamino) -6-ethylthio-1,3,5-triazine [generic name: simetryn], 2,4-bis (isopropylamino)
-6-methylthio-1,3,5-triazine [generic name: promethrin], 2- (1,2-dimethylpropylamino)-
Triazine herbicides such as 4-ethylamino-6-methylthio-1,3,5-triazine [generic name: dimethamethrin]: S-4-chlorobenzyl = N, N-diethylthiocarbamate [generic name: benthiocarb]; S-α, α-dimethylbenzyl = N, N-pentamethylenethiocarbamate [generic name: dimepiperate], S-benzyl = N-ethyl-N- (1,2-dimethylpropyl) thiocarbamate [generic name: esprocalp] , S-ethylhexahydro-1H-azepine-1-carbothioate [generic name: molinate], O-3-tert-butylphenyl = N- (6-
Carbamate herbicides such as methoxy-2-pyridyl) -N-methylthiocarbamate [generic name: pyributicarb]: 2,4-D, CMPB, 2- (2-naphthyloxy) propionanilide [generic name: naproanilide], 2, − (2,4
Phenoxy herbicides such as -dichloro-3-methylphenoxy) propionanilide [generic name: clomeprop]; 2,4,6-trichlorophenyl 4-nitrophenyl ether [generic name: chloronitrophen], 2,4-dichlorophenyl = 3-methoxy-4-nitrophenyl ether [generic name: chloromethoxynil], 2,4-dichlorophenyl = 3-methoxycarbonyl-4-nitrophenyl ether [generic name: bifenox], 2-chloro-4-
Diphenyl ether-based herbicides such as trifluoromethylphenyl 4-nitro-3- (tetrahydropyran-3-yloxy) phenyl ether [test name: MT-124]; N
-Butoxymethyl-2-chloro-2 ', 6'-diethylacetanilide [generic name: butachlor], N-propoxyethyl-2-chloro-2', 6'-diethylacetanilide [generic name: pretilachlor], N-methyl -2-
(2-benzothiazolyloxy) acetanilide [generic name: mefenacet], 2 ', 3'-dichloro-4-ethoxymethoxybenzanilide [test name: HW-52], N-
(Α, α-dimethylbenzyl) -2-bromo-3,3-dimethylbutyramide [generic name: bromobutide], 3 ′,
Amide-based herbicides such as 4'-dichloropropionanilide [generic name: propanil]; 1- (α, α-dimethylbenzyl) -3- (4-methylphenyl) urea [generic name: Daimulon], 1- (2 -Chlorobenzyl) -3- (α,
urea herbicides such as α-dimethylbenzyl) urea [test name: JC-940]; quinone herbicides such as 2-amino-3-chloro-1,4-naphthoquinone [generic name: ACN]; 4- ( 2,4-
Dichlorobenzoyl) -1,3-dimethyl-5-pyrazolyl p-toluenesulfonate [generic name: pyrazolate], 4- (2,4-dichlorobenzoyl) -1,3-dimethyl-5-phenacyloxypyrazole [general Name: pyrazoxifene], 4- (2,4-dichloro-3-methylbenzoyl) -1,3-dimethyl-5- (4-methylphenacyloxy) pyrazole [generic name: benzofenap],
5-benzyloxy-4- (2,4-dichlorobenzoyl) -1-methylpyrazole [Test name: NC-310], 5-
tert-butyl-3- (2,4-dichloro-5-isopropoxyphenyl) -1,3,4-oxadiazole-2- (3
H) -one [generic name: oxadiazone], 3,7-dichloro-8-quinolinecarboxylic acid [generic name: quinclorac], 3-chloro-2- [2-fluoro-4-chloro-
5- (1-propynyloxy) phenyl] -4,5,6,7-
Tetrahydro-2H-indazole [Test name: S-27
5], 3-isopropyl-2,1,3-benzothiadiazinone-4) -2,2-dioxide [generic name: bentazone], 1
-(3-methylphenyl) -5-phenyl-1H-1,2,4
-Triazole 3-carboxamide [Test name: KNW-24
2] and other heterocyclic herbicides; 0,0-diisopropyl-2-
(Benzenesulfonamide) ethylenedithiophospho-
G [generic name: SAP] and other organic phosphorus herbicides; methyl 2
-[[[[[(4,6-Dimethoxypyrimidin-2-yl) amino] carbonyl] amino] sulfonyl] methyl] benzoate [generic name: Rondax], ethyl
5- [3- (4,6-dimethoxypyrimidin-2-yl)
Ureidosulfonyl] -1-methylpyrazole-4-carboxylate [generic name: pyrazosulfuron-ethyl]
And the like, but are not limited thereto.

When the compound of the present invention is used as an active ingredient of a herbicide, it is usually mixed with a solid carrier, a liquid carrier, a surfactant, and other auxiliaries for formulation, an emulsion, a wettable powder, a flowable,
It can be formulated into granules, powders and the like and used.

Examples of the solid carrier include kaolin, clay, bentonite, diatomaceous earth, acid clay, white carbon, pumice powder and the like. Further, as a liquid carrier, xylene, aromatic hydrocarbons such as methylnaphthalene, isopropanol, ethylene glycol, alcohols such as cellosolve, acetone, ketones such as cyclohexanone, mineral oil, dimethyl sulfoxide, N, N-dimethylformamide, Acetonitrile, water and the like can be mentioned.

Examples of the surfactant include anionic surfactants such as alkyl sulfates, alkyl sulfonates, and aryl sulfonates; and nonionics such as polyoxyethylene glycol ethers, polyoxyethylene glycol esters, and polyhydric alcohol esters. Surfactants and the like can be mentioned.

Other formulation auxiliaries include polyvinyl alcohol, lignin sulfonate, gum arabic and the like.

The preparation obtained as described above contains the compound of the present invention as an active ingredient in an amount of 0.1 to 90% by weight, preferably 1 to 80% by weight.

The application rate of the herbicide of the present invention varies depending on climatic conditions, formulation form, treatment time, application method, application place, target weed, target crop, and the like.
10a, preferably 2 to 500 g / 10a.

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples.
The present invention is not limited to only these examples.

Example 1 3- (2,6-dichlorophenyl) -4-hydroxy-1,
Production of 2,5-thiadiazole (Compound No. 11) 2,6-dichlorophenylglycinamide hydrobromide 1
4.5 g was dissolved in N, N-dimethylformamide, 19.5 g of sulfur monochloride was added, and the mixture was stirred at room temperature for 12 hours. The reaction mixture was poured into water, made alkaline with sodium hydroxide, and then insolubles were removed by filtration. The filtrate was acidified with hydrochloric acid and the precipitate was extracted with ether. The ether layer was washed twice with dilute hydrochloric acid and twice with saturated saline, and then dried over anhydrous sodium sulfate. The crystals obtained by removing the solvent were recrystallized from chloroform to obtain 9.5 g of 3- (2,6-dichlorophenyl) -4-hydroxy-1,2,5-thiadiazole.

mp 194-195 ° C ¹ H-NMR (solvent: CDCl ₃ , unit: δ ppm) 7.3-7.6 (m) IR (KBr, cm ^-1 ) 3200-2400,1540,1505,1435,1230,880,790,775 Elemental analysis (%) : Calculated: C; 38.88, H; 1.63, N; 11.33 Found: C; 39.00.H; 1.48, N; 11.53 Example 2 4- (2,6-dichlorophenyl) -1,2,5-thiadiazole- Preparation of 3-yl N, N-dimethylcarbamate (Compound No. 7) 3- (2,6-dichlorophenyl) -4-hydroxy-
A suspension of 0.25 g of 1,2,5-thiadiazole and 0.15 g of potassium carbonate in acetonitrile was added to dimethylcarbamoyl chloride.
0.12 g was added and the mixture was heated under reflux for 12 hours. After cooling, the reaction mixture was poured into water and extracted with ether. The ether layer was washed twice with a dilute aqueous sodium hydroxide solution, water, and saturated saline. After drying over anhydrous sodium sulfate, concentration and purification by silica gel column chromatography, 4- (2,6
-Dichlorophenyl) -1,2,5-thiadiazole-3-
0.25 g of yl N, N-dimethyl carbamate was obtained.

mp 115-116 ° C ¹ H-NMR (solvent: CDCl ₃ , unit: δ ppm) 2.87 (s, 3H), 2.93 (s, 3H), 7.2-7.45 (m, 3H) IR (KBr, cm ⁻¹ ) 1735, 1365, 1235, 1150, 785 Elemental analysis (%): Calculated: C; 41.52, H; 2.85, N; 13.20 Found: C; 41.58.H; 2.86, N; 13.04 Example 3 4- (2, 6 Preparation of-(dichlorophenyl) -1,2,5-thiadiazol-3-yl acetate (Compound No. 66) 3- (2,6-dichlorophenyl) -4-hydroxy-
0.5 g of 1,2,5-thiadiazole and 0.18 g of pyridine were dissolved in ether, 0.23 g of acetic anhydride was added, and the mixture was stirred at room temperature for 3 hours. The reaction mixture was poured into water and extracted with ether. Washing was performed twice each with a dilute aqueous solution of sodium hydroxide, water, and saturated saline. After drying over anhydrous sodium sulfate, concentration and purification by silica gel column chromatography, 4-
(2,6-dichlorophenyl) -1,2,5-thiadiazole-
0.41 g of 3-yl acetate was obtained.

mp 56-59 ° C. ¹ H-NMR (solvent: CDCl ₃ , unit: δ ppm) 2.17 (s, 3H), 7.15-7.4 (m, 3H) IR (KBr, cm ⁻¹ ) 1795, 1430, 1175, 780 Elemental analysis (%): Calculated: C; 41.54, H; 2.09, N; 9.68 Found: C; 41.23.H; 2.27, N; 9.84 Example 4 4- (2,6-dichlorophenyl) -1,2,5 Preparation of -Thiadiazol-3-yl N- (3-methoxypropyl) -N-methylcarbamate (Compound No. 62) 3- (2,6-dichlorophenyl) -4-hydroxy-
Dissolve 0.49 g of 1,2,5-thiadiazole and 0.21 g of bis (trichloromethyl) carbonate in benzene and add
After adding 0.2 g and stirring at room temperature for 12 hours, 0.41 g of N-methyl-N- (3-methoxypropyl) amine was further added and the mixture was stirred at room temperature for 12 hours. The reaction mixture was poured into water and extracted with ether. The ether layer was washed three times each with a dilute aqueous sodium hydroxide solution and dilute hydrochloric acid, and further twice each with water and a saturated saline solution. After washing with anhydrous sodium sulfate and concentration, purification was performed by silica gel column chromatography, and 4- (2,6-dichlorophenyl) -1,2,5-thiadiazol-3-yl N- (3-methoxypropyl) was purified.
0.38 g of -N-methyl carbamate was obtained.

n ^25.0 : 1.5638 ¹ H-NMR (solvent: CDCl ₃ , unit: δ ppm) 1.4-2.0 (m, 2H), 2.92 (broad s, 3H), 3.1-3.6 (m, 7H), 7.25-7.5 (m, 3H) IR (KBr, cm ^-1 ) 1745,1430,1385,1230,1120,790 Elemental analysis (%): Calculated: C; 44.69, H; 4.01, N; 11.16 Actual: C; 44.34.H; 4.05, N; 13.92 Example 5 Preparation of 4- (2,6-dichlorophenyl) -1,2,5-thiadiazol-3-yl N, N-dimethylthiolcarbamate (Compound No. 35) 4- (2,6- Dichlorophenyl) -1,2,5-thiadiazol-3-yl N, N-dimethylthionocarbamate
1.34 g was heated to 180 ° C. under a nitrogen atmosphere. After allowing to cool, the reaction mixture was purified by silica gel column chromatography, and 4- (2,6-dichlorophenyl) -1,2,5-thiadiazol-3-yl N, N-dimethylolcarbamate
0.8 g was obtained.

mp 168-170 ° C. ¹ H-NMR (solvent: CDCl ₃ , unit: δ ppm) 2.93 (s, 6H), 7.2-7.45 (m, 3H) IR (KBr, cm ⁻¹ ) 1690, 1430, 1090, 785 Elemental analysis (%): Calculated: C; 39.52, H; 2.71, N; 12.57 Found: C; 39.38.H; 2.83, N; 12.79 Example 6 3- (2,6-Dichlorophenyl) -4-mercapto-1 ,
Production of 2,5-thiadiazole (Compound No. 38) 4- (2,6-dichlorophenyl) -1,2,5-thiadiazol-3-yl-N, N-dimethylthiolcarbamate
0.6 g and potassium hydroxide 0.28 g ethanol 15 ml, water 0.3 ml
And the mixture was heated under reflux for 15 hours. Ethanol was removed from the reaction mixture, ethanol was removed from the dilute aqueous sodium hydroxide solution, and a dilute aqueous sodium hydroxide solution was added, followed by washing with ether. The aqueous layer was acidified with hydrochloric acid and extracted with ether. The ether layer was washed twice each with dilute hydrochloric acid and saturated saline, dried over anhydrous sodium sulfate, and then the solvent was removed. 0.4 g of 3- (2,6-dichlorophenyl) -4-mercapto-1,2,5-thiadiazole I got

mp 91-94 ° C. ¹ H-NMR (solvent: CDCl ₃ , unit: δ ppm) 3.09 (broad s, 1H), 7.53 (s, 3H) IR (KBr, cm ⁻¹ ) 2550,1430,1345,1175,820,790,785 elements Analysis (%): Calculated: C; 36.51, H; 1.53, N; 10.64 Found: C; 36.82.H; 1.38, N; 10.58 Example 7 4- (2,6-dichlorophenyl) -1,2, 5-thiadiazol-3-yl N-methylcarbamate (Compound No. 7
Preparation of 5) 3- (2,6-dichlorophenyl) -4-hydroxy-
0.25 g of 1,2,5-thiadiazole was dissolved in pyridine, 0.17 g of methyl isocyanate was added, and the mixture was stirred at room temperature for 19 hours.
The reaction mixture was poured into water and extracted with ether. The ether layer was washed twice each with diluted hydrochloric acid and saturated saline. The extract was dried over anhydrous sodium sulfate, concentrated, and purified by silica gel column chromatography to obtain 0.24 g of 4- (2,6-dichlorophenyl) -1,2,5-thiadiazol-3-yl N-methylcarbamate.

mp 118-122 ° C. ¹ H-NMR (solvent: CDCl ₃ , unit: δ ppm) 2.75 (d, J = 5 Hz, 3H), 5.3 (broad s, 1H), 7.2-7.5 (m, 3H) IR (KBr, cm) ^-1 ) 3290, 1760, 1730, 1400, 1225 Elemental analysis (%): Calculated: C; 39.49, H; 2.31, N; 13.81 Found: C; 39.66.H; 2.48, N; 14.13 Example 84 Preparation of-(2,6-dichloro-3-nitrophenyl) -3-ylmethyl carbonate (Compound No. 104) 3- (2,6-dichlorophenyl) -4-hydroxy was added to a mixed acid (concentrated sulfuric acid 9 ml, concentrated nitric acid 9 ml). 2.75 g of -1,2,5-thiadiazole was added and the mixture was stirred at room temperature for 4 hours. The reaction mixture was poured into water and extracted with ether. The ether layer was washed twice each with water and saturated saline. The extract was dried over anhydrous sodium sulfate, and the solvent was distilled off to obtain 3.15 g of 4- (2,6-dichloro-3-nitrophenyl) -3-ylmethyl carbonate.

Viscous oil ¹ H-NMR (solvent: CDCl ₃ , unit: δ ppm) 3.93 (s, 3H), 7.62 (d, J = 8.5 Hz, 1H), 7.59 (d, J = 8.5H)
z, 1H) IR (NaCl, cm ^-1 ): 1785,1540,1530,1250,1220 Elemental analysis (%): Calculated: C; 34.30, H; 1.43, N; 12.00 Actual: C; 34.30.H ; 1.56, N; 11.97 Table 1 shows typical examples of the compound of the present invention obtained by the same method and physical properties thereof.

Example 9 Preparation of wettable powder 10 parts by weight of the compound of the present invention, 86.5 parts by weight of Siglite (trade name: manufactured by Siglite Chemical Mining), Newcalgen NV
2 parts by weight of -406 (trade name: manufactured by Takemoto Yushi) and 1.5 parts by weight of SUSKOL WA (trade name: manufactured by Daiichi Kogyo Seiyaku) were mixed and pulverized to obtain a wettable powder.

Example 10 Preparation of Emulsion An emulsion was obtained by uniformly stirring and mixing 5% by weight of the compound of the present invention, 75 parts by weight of xylene, and 20 parts by weight of Solbol 2806B (trade name, manufactured by Toho Chemical Industry).

Example 11 Preparation of Granules 10 parts by weight of the compound of the present invention, 50 parts by weight of bentonite, 35 parts by weight of Kunilite (trade name: manufactured by Kokumine Kogyo) and 5 parts by weight of Solball 800A (trade name: manufactured by Toho Chemical Industry) are mixed and pulverized. After that, water was added, the mixture was stirred uniformly, and granulated and dried to obtain granules.

Example 12 Paddy Field Flooding Treatment Test A 100 cm ² plastic pot was filled with paddy soil in a scraped state, seeds of weeds shown in Table 2 were sown, and two-leaf rice (cultivar: Yamahoushi) was planted in two pots per pot. The strain was transplanted and maintained in a flooded state of about 2 cm. In the early stage of the emergence of the weeds shown in Table 2, a predetermined amount of the herbicide of the present invention formulated according to Example 9 was dropped on the water surface, and then left standing in a greenhouse to sprinkle water as needed. On the 20th day after the chemical treatment, the herbicidal effect and the phytotoxicity were investigated, and the results shown in Table 2 were obtained. In addition, the evaluation of the herbicidal effect was shown by the number of 0-5 as shown below. In addition, phytotoxicity to crops was shown on the same basis as the herbicidal effect.

Herbicidal effect Weeding rate 0 0-9% 1 10-29% 2 30-49% 3 50-69% 4 70-89% 5 90-100%

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C07D 417/12 239 C07D 417/12 307 307 C07F 7/18 U C07F 7/18 A01N 43/82 103 (56) References JP 55-153774 (JP, A) U.S. Pat. No. 4,555,521 (US, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C07D 285/00-285/38 A01N 47/06 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A compound of the general formula [I] [Wherein, Y is an oxygen atom or a sulfur atom, Χ is a hydrogen atom, a halogen atom, a lower alkyl group, a lower haloalkyl group, a lower alkoxy group, a hydroxy group or a nitro group,
V and Z are the same or different and are substituted with a halogen atom, a lower alkyl group, a lower haloalkyl group, a lower alkoxy group, a hydroxy group or a nitro group, and A is substituted with a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group or an alkoxy group. May be an alkoxyalkyl group, an alkylthioalkyl group, -SO ₂ R ¹ (R ¹ is a lower alkyl group optionally substituted with a halogen atom or a phenyl group optionally substituted with a lower alkyl group, or a lower alkyl group. Represents a substituted amino group), (N is 0 or 1, B is CH or a nitrogen atom, R ² and R ³ are the same or different and represent a hydrogen atom, a halogen atom, a lower alkoxy group, a nitro group or a lower alkyl group which may be substituted with a halogen atom. ^{), - SiR 4 R 5 R} 6 (R 4, R 5, R 6 are the same or different and a lower alkyl ^{group), - CHR 7 COR 8 (} R 7 is a hydrogen atom or a lower alkyl group, R ⁸ is hydroxy Group or an amino group (which may be substituted with a lower alkyl group and / or a phenyl group)), -C (= W) OR
⁹ (W is an oxygen atom or a sulfur atom, R ⁹ is an alkyl group which may be substituted with a halogen atom, an alkoxyalkyl group,
A benzyl group, a phenyl group, a tetrahydrofurfuryl group or an alkylideneamino group), -COR ¹⁰ (R ¹⁰ is a lower alkyl group, a cycloalkyl group, (a halogen atom, a lower alkyl group, a lower haloalkyl group, a lower alkoxy group,
A phenyl group which may be substituted with a nitro group or a cyano group), -C (= W) NR ¹¹ R ¹² (W is an oxygen atom or a sulfur atom, R ¹¹ and R ¹² are the same or different and are a hydrogen atom A lower alkyl group, a cycloalkyl group, a lower alkoxy group,
An alkoxyalkyl group, a phenyl group which may be substituted with an alkoxy group, or (R ¹³ and R ¹⁴ are the same or different and each represents a lower alkyl group or a lower alkoxy group) or R ¹¹ and R ¹² are linked to each other (E is a CH ₂ or oxygen atom, m is 0 or 1, R ¹⁵ and R ¹⁶ are the same or different and each represents a hydrogen atom or a lower alkyl group). 2. A herbicide comprising the thiadiazole derivative according to claim 1 as an active ingredient.