JPH03193773A - Thiadiazole derivative, its production and herbicide with same as active ingredient - Google Patents

Abstract

NEW MATERIAL:A compound of formula I [R<1> and R<2> are each H or halogen; R<3> and R<4> are each H, lower alkyl or -COR<5> (R<5> is lower alkyl or amino) or linked to each other into phthaloyl]. EXAMPLE:3-Amino-4-(2,6-dichlorophenyl)-1,2,5-thiadiazole. USE:A herbicide; in particular, effective for controlling paddy weeds such as Cyperus difformis, Scirpus juncoides and Monochoria vaginalis. PREPARATION:The objective compound of the formula I can be obtained by reaction at 60-150 deg.C between a thiadiazole derivative of formula II and an amine of formula NHR<6>R<7> (R<6> and R<7> are each H or 1-6C lower alkyl) in a solvent such as methanol in the presence or absence of copper and/or cuprous chloride.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel thiadiazole derivative, a method for producing the same, and a herbicide containing the same as an active ingredient.

[Prior Art] Many herbicides have been used in the past, but they generally have problems such as insufficient herbicidal activity, narrow herbicidal spectrum, and chemical damage to crops.

Furthermore, the herbicidal activity of 2,1,3-benzothiadiazole derivatives and 1,2,4- or 1,3,4-thiadiazole derivatives has been known, but 1. It is not known that 2,5-thiadiazole derivatives have herbicidal activity.

[Problems to be Solved by the Invention] Therefore, an object of the present invention is to provide a novel compound with high herbicidal activity and high safety for crops, a method for producing the compound, and a novel herbicide containing the compound as an active ingredient. It is.

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

That is, the present invention is based on the general formula [1] [wherein RR2 are the same or different; .

Thiadiazole derivatives (hereinafter referred to as compounds of the present invention) represented by R (R5 represents a lower alkyl group, an amino group optionally substituted with a lower alkyl group) or R3R4 are linked to each other and represent a phthaloyl group], general A method for producing a thiadiazole derivative represented by the formula [n] [wherein RR2R6R7 has the same meaning as above], the general formula [■]) [wherein RR2 has the same meaning as above] The thiadiazole derivative shown above is reacted with an amine represented by the general formula [■CoNHR6R7[III] [wherein RR7 is the same or different and represents a hydrogen atom or a C-C6 lower alkyl group]. General formula [IV] 2 [wherein RR represents the same meaning as above] General formula [V] characterized by reacting a thiadiazole derivative represented by the above formula with potassium phthalimide [ A method for producing a thiadiazole derivative represented by the general formula [V]\/2 [wherein RR represents the same meaning as above]; General formula [VI]\/ characterized by hydrolyzing the derivative [wherein R and R2 have the same meanings as above]
The present invention provides a method for producing a thiadiazole derivative represented by the formula [I], and a herbicide containing the thiadiazole derivative represented by the general formula [I] as an active ingredient.

[Detailed Description of the Invention] To specifically describe the compound of the present invention represented by the general formula [11], RR2 are the same or different from each other. hydrogen atom, lower alkyl group, -COR(R5
represents a lower alkyl group, an amino group which may be substituted with a lower alkyl group) 4 or RR is connected to each other to represent a phthaloyl group, and the halogen atom of R and R2 is replaced by a fluorine atom, a chlorine atom, , bromine atom, iodine atom, etc., and lower alkyl groups of R3R4R5 include methyl, ethyl, n-propyl, isopropyl, n
-butyl, isobutyl, 5ec-butyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl and other straight-chain or branched alkyl groups of 01 to CB can be mentioned.

67 In addition, the C1 to C6 lower alkyl group of RR in general formula [III] includes methyl, ethyl, n-propyl,
Isopropyl, n-butyl, isobutyl, 5ec-butyl, tert-butyl, n-pentyl, isopentyl,
Straight chain or branched alkyl groups such as n-hexyl and isohexyl can be mentioned.

To specifically explain the method for producing the compound of the present invention, Method A2 The compound of the present invention is a thiadiazole derivative represented by the general formula [■] \/ [wherein R1 and R2 have the same meanings as above]. In the presence of a solvent, copper and/or It can be produced by reacting at 60 to 150°C for several minutes to 48 hours in the presence or absence of cuprous chloride. Solvents used in the reaction include alcohols such as methanol and ethanol, polar solvents such as N,N-dimethylformamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, and hexamethyltriamide phosphate; Examples include water. The amount of reagents used in the reaction is 1 to 100 equivalents of the amine represented by the general formula [III], 1 to 10 equivalents of copper, and cuprous chloride per 1 equivalent of the thiadiazole derivative represented by the general formula [II]. It is 1 to 10 equivalents.

Method B: The compound of the present invention is prepared by combining a thiadiazole derivative represented by the general formula [1] [wherein R12 R represents the same meaning as above] and potassium phthalimide at 80 to 150°C for several minutes in the presence of a solvent. ~
It can be produced by reacting for 48 hours.

Solvents used in the reaction include alcohols such as methanol and ethanol, N,N-dimethylformamide,
Examples include polar solvents such as dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, and hexamethyltriamide phosphate, and water. The amount of the reagent used in the reaction is 1 to 10 equivalents of potassium phthalimide per 1 equivalent of the thiadiazole derivative represented by the general formula [11].

Method C 2 The compound of the present invention can be further produced by reacting a thiadiazole derivative represented by the general formula [V] with an acid or hydrazine at 50 to 100°C for several minutes to 24 hours in the presence of a solvent. can. Examples of the solvent used in the reaction include alcohols such as methanol and ethanol, and water. The acid is hydrochloric acid,
Examples include sulfuric acid. The amount of the reagent used in the reaction is 1 to 100 equivalents of the acid or hydrazine per 1 equivalent of the thiadiazole derivative represented by the general formula [V].

Method D 2 The compound of the present invention can also be prepared by the general formula [■] [wherein R and R2 have the same meanings as above [however, in the formula, R1
, R2 represents the same meaning as above, R8 represents a hydrogen atom or a lower alkyl group] and X-COR (X is a halogen atom, R5 represents the same meaning as above) in a base and a solvent. in the presence of 40-1
It can be produced by reacting at 50°C for several minutes to 24 hours. Solvents used in the reaction include ketones such as acetone and methyl ethyl ketone, aromatic hydrocarbons such as benzene, toluene and xylene, ethers such as diethyl ether, tetrahydrofuran and dioxane,
Halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane, chlorobenzene, tertiary amines such as pyridine, triethylamine, N5N-dimethylaniline, acetonitrile, N, N-dimethylformamide, dimethylsulfoxide, 1.3- Examples include polar solvents such as dimethyl-2-imidazolidinone and hexamethyltriamide phosphate. Examples of bases 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 hydride, and sodium methoxide and sodium ethoxide. Examples include alkali metal alkoxides. The amount of the reagent used in the reaction is -X-C
OR51-5 equivalents, base 1-10 equivalents.

The herbicide of the present invention containing the compound of the present invention as an active ingredient is
While it exhibits excellent herbicidal effects, it has almost no effect on crops. That is, the herbicide of the present invention can be applied to various problematic weeds in upland fields, such as blueberry, purslane, Japanese fir, Japanese lily, Japanese knotweed, whiteweed, Japanese knotweed, chickweed, shepherd's purse, waterweed, white-spotted weed, American hornwort, Maruba morning glory, Japanese broom, Hotokenoza, plantain, Ichibi,
It is effective against various weeds that can be problematic in rice fields, such as oxalis, commonweed, buckwheat, Japanese sagebrush, sagebrush, sycamore, Japanese millet, foxtail grass, silverwort, sycamore, oat, oat, sorghum, etc. Azena, Kikashigusa, Japanese cypress,
It has a herbicidal effect on weeds such as bulrushes, pine beetles, Japanese cypress, Japanese cypress, and weeds during pre-emergence and growing season treatments, and is also effective against major crops such as corn, wheat, rice, soybean, cotton, and sugar beet. It does not show any harmful chemical effects.

The herbicide of the present invention may be used in combination with other agricultural chemicals, such as fungicides, insecticides,
It can be mixed or used in combination with herbicides, plant growth regulators, fertilizers, soil conditioners, etc. In particular, when used in combination with other herbicides, it can be expected not only to save labor, but also to expand the herbicidal spectrum and to have even higher effects. Herbicides that can be used in combination include 2,4-bis(ethylamino)-6-ethylthio-1,3,5-triazine [generic name: simetrine], 2,4-bis(isopropylamino)-6-methylthio -1゜3.5-triazine [generic name: promethrin], 2-(1,2-dimethylpropylamino)-4-ethylamino-6-methylthio-1,3,5-triazine [generic name: dimethamethrin], etc. triazine herbicide; 5-4-chlorobenzyl-N, N-diethylthiocarbamate [generic name: Benthiocarb] S-α, α-dimethylbenzyl-N.

N-pentamethylene thiocarbamate [generic name: dimebiperate], S-benzyl-N-ethyl-N-(1,2
-dimethylpropyl) thiocarbame) (common name di-esbrocarb) S-ethylhexahydro-IH-azepine-1-carbothioate (common name dimolinate), 0
Carbamate herbicides such as -3-tert-butylphenyl-N-(6-medoxy-2-pyridyl)-N-methylthiocarbamate [generic name: pyributicarb]; 2゜4-D, MCPB, 2-(2-naphthyl) oxy)propionanilide [generic name: nabroanilide] 2- (2,
Phenoxy herbicides such as 4-dichloro-3-methylphenoxy)propionanilide [generic name: clomeprop], 2,4.6-dolichlorophenyl-4-nitrophenyl ether)kc, 2
．． 4-dichlorophenyl-3-meth)4-cy-4-nitrophenyl ether [generic name: chromethoxynil], 2.
4-dichlorophenyl-3-methoxycarbonyl-4-
Nitrophenyl ether [generic name: Bifenox],
2-chloro-4-trifluoromethylphenyl-4-nitro-3-(tetrahydropyran-3-yloxy)phenyl ether [Test name: diphenyl ether herbicide such as MT-1241; N-butoxymethyl-2-chloro- 2',6'-diethylacetanilide [common name: butachlor], N-propoxyethyl-2-chloro-2
°, 6'diethylacetanilide [generic name: dibretilachlor], 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], Amide herbicides such as 3',4°-dichloropropionanilide [generic name: propanil]; 1-(α,α-dimethylbenzyl)-3
- Urea herbicides such as (4-methylphenyl)urea [generic name: Daimeron], 1-(2-chlorobenzyl)-3-(α,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: virazolate], 4-(2,4-dichlorobenzoyl)-1,3-dimethyl-5-phena Siloxypyrazole [-generic name: pyrazoxyfen), 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-oxadiazol-2-(3H)-one [generic name: oxacyacin], 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: pentacine], 1-(3-methylphenyl)-5-phenyl-
IH-1,2゜4-triazole-3-carboxamide [Test name: Heterocyclic herbicide such as KNW-2421; 0,
0-diisopropyl-2-(benzenesulfonamide)
Organophosphorus herbicides such as ethylene dithiophosphate [generic name: 5AP]; methyl 2-[[[[[(4,6-cymethoxypyrimidin-2-yl)amino]carbonyl]
Amino]sulfonyl]methyl]benzoate [generic name:
rondax], ethyl 5-[3-(4,6-cymethoxypyrimidin-2-yl)ureidosulfonyl]-
Examples include, but are not limited to, sulfonylurea herbicides such as 1-methylpyrazole-4-carboxylate [generic name: virazosulfuron-ethyl].

When using the compound of the present invention as an active ingredient of a herbicide,
Usually, it can be mixed with solid carriers, solvents, surfactants, and other formulation auxiliaries to formulate emulsions, wettable powders, flowables, granules, powders, and the like.

Solid carriers include kaolin, clay, bentonite,
Diatomaceous earth, acid clay, white carbon, pumice powder, etc. can be mentioned. In addition, as a solvent, xylene,
Aromatic hydrocarbons such as methylnaphthalene, alcohols such as isopropanol, ethylene glycol, and cellosolve, ketones such as acetone and cyclohexanone, mineral oil,
Dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile, water and the like can be mentioned.

Examples of surfactants include anionic surfactants such as alkyl sulfate salts, alkyl sulfonate salts, and aryl sulfonate salts, polyoxyethylene glycol ethers,
Examples include nonionic surfactants such as polyoxyethylene glycol esters and polyhydric alcohol esters.

Other formulation aids 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.
Contains % by weight.

Further, the application amount of the herbicide of the present invention varies depending on climatic conditions, formulation form, treatment time, application method, application location, target weeds, target crops, etc., but usually the amount of active ingredient is 1 to 1000.
g/10a, preferably 2-500 g/10a
It is.

[Effects of the Invention] The present invention provides a novel compound having excellent herbicidal activity and a wide herbicidal spectrum as a herbicide, and a method for producing the same. In addition, the herbicide containing the compound of the present invention as an active ingredient can control various weeds from before emergence to the growing season, and is highly safe for crops, such as paddy fields, various grain fields, various vegetable fields, fruit trees, It can be effectively used for weed control in mulberry gardens and non-agricultural lands. In particular, it can be effectively used to control weeds in rice fields.

[Examples] Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited only to these Examples.

[Example 1] 3-Amino-4-(2,6-dichlorophenyl)=1.
2. Preparation of 5-thiadiazole (compound number 1) 3-chloro-4-(2,6-dichlorophenyl)-1,
2,5-thiadiazole 5.31g, copper powder 1.91g,
Add 2.97 g of cuprous chloride and a methanol solution saturated with ammonia gas to a stainless steel container, and after sealing,
Stirred at ℃ for 24 hours.

After cooling, the reaction mixture was filtered to remove insoluble materials.

The filtrate was concentrated and then purified by silica gel column chromatography to obtain 2.19 g of 3-amino-4-(2,6-dichlorophenyl)-1,2,5-thiadiazole.

m, p, 95-97°C 'H-NMR (solvent: CDCl, unit: δppm
)4.52(s, 21ri, 7.2~7.5(m, 31D
I R (KB r, cm-1) 3425.3325.3210.1620.1535.
1490.14101420.790.780 M5 (m/z): 245 (M) [
Example 2] 3-(4-chlorophenyl)-4-phthalimide-1,
Production of 2,5-thiadiazole 3-chloro-4-(4-
Chlorophenyl)-1゜2.5-thiadiazole 1.1
1.11 g of potassium phthalimide was added to 6 g of N,N-dimethylformamide solution, and the mixture was heated under reflux at 110° C. for 12 hours. After cooling, the reaction mixture was poured into water and extracted with ether. The ether layer is a dilute aqueous sodium hydroxide solution,
It was washed twice with water and saturated saline, respectively.

The residue was dried over anhydrous sodium sulfate, concentrated, and purified by silica gel column chromatography to obtain 0.85 g of 3-(4-chlorophenyl)-4-phthalimido-1°2.5-thiadiazole.

m, p, 152-153°C 'H-NMR (solvent: CDCl, unit: δppm
) 7.1-7.4 (m, 2H), 7.4-7.7 (Akebono, 211) 7.7-8.0 (■, 411) I R (K B r s cm-') 1790 .1725.1440.1180.885,7
15M5 (s/z): 34 1 (M
) [Example 3] 3-Amino-4-(4-chlorophenyl)-1°2.5
-Production of thiadiazole 3-(4-chlorophenyl)-4-phthalimide-1,
To a solution of 0.41 g of 2,5-thiadiazole in ethanol was added 0605 g of an 80% aqueous hydrazine solution, and the mixture was heated under reflux for 1 hour. After cooling, the reaction mixture was poured into water and extracted with ether. The ether layer was made of water and saturated saline at 2 times each.
Washed twice.

After drying with anhydrous sodium sulfate, concentrating, and purifying with silica gel column chromatography, 3-amino-4-(
4-chlorophenyl)-1,2,5-thiadiazole 0
．． 21 g was obtained.

m, I), 132-133°C'H-NMR (solvent: Acetone-d, unit:
δpp ■) 5.40 (bs, 2H), 7.2 to 7.5 (m, 2M)
7.5-7.8 (so-called, 2H) I R (KB r, co-') 3410.3310.3190.1620, 1515.
1495.14351400.1090.830 MS (m/z): 211 (M) [Example 4
] Production of 3-(2,6-dichlorophenyl)-4-methylamino-1,2,5-thiadiazole (compound number 2) 3-chloro-4-(2,6-dichlorophenyl)-1,
5.31 g of 2,5-thiadiazole and 100 ml of a 40% methylamine aqueous solution were added to a stainless steel container, and the container was sealed and stirred at 120° C. for 12 hours.

After cooling, the reaction mixture was poured into water and extracted with ether.

The ether layer was washed three times each with water and saturated saline. The residue was dried over anhydrous sodium sulfate, concentrated, and purified by silica gel column chromatography to obtain 2.55 g of 3-(2,6-dichlorophenyl)-4=methylamino-1,2,5-thiadiazole.

m, p, 145-146°C'H-NMR (solvent: CDCl, unit = δppm
) 3.02 (s, 311), 4.1O (bs, 1Il)
,7.15~7.4(o+,311) IR(KBr,.,-1) 3320.1555.1425.790.775M5(
Il/z): 259 (M) [Example 5] Preparation of 3-acetylamino-4-(2,6-dichlorophenyl)-1,2,5-thiadiazole (Compound No. 3) 3-amino-4-( 2,6-dichlorophenyl)-1,
To a solution of 0.49 g of 2,5-thiadiazole and 0.22 g of ethylamine in N,N-dimethylformamide was added 0.20 g of acetyl chloride, and the mixture was stirred at 60°C for 12 hours. After cooling, the reaction mixture was poured into water and extracted with ether. The ether layer was diluted with dilute hydrochloric acid, water, and saturated saline for 2 hours each.
Washed twice.

It was dried over anhydrous sodium sulfate, concentrated, and purified by silica gel column chromatography to obtain 0.25 g of 3-acetylamino-4-(2,6-dichlorophenyl)-1,2,5-thiadiazole.

m, p, 180-185°C 'H-NMR (solvent: CDCl, unit: δppa+
)2.1(s,3)1),7J7(s,3)1),9
．． 47 (bs, IH) IR (KB r, cm') 3290.1B95.1540.1500.1425.
1230.785MS (m/z): 287 (M
) [Example 6] Production of 3-(2,6-dichlorophenyl)-4-phthalimido-1,2,5-thiadiazole (compound number 4) 3-chloro-4-(2,6-dichlorophenyl)-1,
2,5-thiadiazole 2.66 g N.

2.22 g of potassium phthalimide was added to the N-dimethylformamide solution, and the mixture was heated under reflux at 110° C. for 12 hours.

After cooling, the reaction mixture was poured into water and extracted with ether.

The ether layer was washed twice each with dilute aqueous sodium hydroxide solution, water, and saturated brine. After drying with anhydrous sodium sulfate, concentrating, and purifying with silica gel column chromatography, 3-(2,6-dichlorophenyl)-4-
Phthalimide-1,2,5-thiadiazole 1.90g
I got it.

m, p, 214-215°C'H-NMR (solvent: CDC1, unit: δppm) 7
．． 15-7.4 (s, 3!ri, 7.55-7.95 (1
, 411) IR (KBr, es″″I) 1790.1745.1730.1470.14B5,
1430, 14151310.710 M5 (i/z): 375 (M) [
Example 7] 3-(2,6-dichlorophenyl)-4(3゜3-
dimethylureido) -1,2,5-thiadiazole (
Preparation of compound number 5) 3-amino-4-(2,6-dichlorophenyl)-1,
To a solution of 0.49 g of 2,5-thiadiazole and 0.22 g of triethylamine in N,N-dimethylformamide was added 0.24 g of dimethylcarbamoyl chloride, and 12
Stirred at 0°C for 12 hours. After cooling, the reaction mixture was poured into water and extracted with ether. The ether layer consists of dilute hydrochloric acid, water,
Each was washed twice with saturated saline. After drying over anhydrous sodium sulfate, concentrating, and purification using silica gel column chromatography, 0.19 g of 3 (2,6-dichlorophenyl)4 (3,3-dimethylureido)-1,2,5-thiadiazole was obtained. Ta.

m, p, 100-103°C 'H-NMR (solvent: CDCl, unit: δpp11
) 2.83 (s, 311), 3.0O (s, 3H), 7
．． 15-7.45 (11,3H) 8.27 (s, IH) I R (KB r, c+a-') 1630.14B0, 1425.13g0, 1115,
1100,790.775M5 (Il/z): 3
16 (M) [Example 8] 3-isobutyrylamino-4-(2,6-dichlorophenyl)-1,2,5-thiadiazole (compound number 6)
Preparation of 3-amino-4-(2,6-dichlorophenyl)-1,
To a solution of 0.49 g of 2,5-thiadiazole and 0.22 g of ethylamine in N,N-dimethylformamide was added 0.27 g of isobutyryl chloride, and the mixture was stirred at 60°C for 12 hours. After cooling, the reaction mixture was poured into water and extracted with ether. The ether layer was washed twice each with dilute hydrochloric acid, water, and saturated brine. After drying with anhydrous sodium sulfate, concentrating, and purifying with silica gel column chromatography,
0.23 g of -isobutyrylamino-4-(2,6-dichlorophenyl)-1,2,5-thiadiazole was obtained.

m, p, 112-117°C'H-NMR (solvent: CDCl, unit = δppm
) 1.08 (d, J=7Hz, 611), 2.68 (s
eptet, J-7Hz, LH) 7.2-7.45 (w
, 311), 8.10 (bs, Lll) I R (KB
r, em-') 3290.1700.1540.1495,1430.
1145M5 (+e/z): 315 (M
) [Example 9] (Wettable powder) 10 parts by weight of the compound of the present invention, 86.5 parts by weight of Zeeklite (trade name, manufactured by Zeeklite Chemical Mining Co., Ltd.), 221 Calgen NV-406 (trade name, 2 parts by weight (manufactured by Takemoto Yushi) and 1.5 parts by weight of Discsol WA (trade name, manufactured by Dai-Kogyo Seiyaku)
Parts by weight were mixed and ground to obtain a wettable powder.

[Example 10] (Emulsion) 5 parts by weight of the compound of the present invention, 75 parts by weight of xylene, and 20 parts by weight of Tsurupol 2806B (trade name, Toho Chemical Industries type) were uniformly stirred and mixed to obtain an emulsion.

[Example 11] (Granules) 10 parts by weight of the compound of the present invention, 50 parts by weight of bentonite,
After mixing and pulverizing 35 parts by weight of Kunilite (trade name, manufactured by Kunimine Industries) and 5 parts by weight of Tsurupol 800A (trade name, Toho Chemical Industries type), water was added, the mixture was stirred uniformly, and the mixture was granulated and dried to obtain granules. Ta.

[Example 12] Paddy field flooding treatment test 100 cd plastic pots were filled with paddy soil in a paddy state, seeds of the weeds shown in Table 1 were sown, and two-leaf stage paddy rice (variety: Yamahoshi) was planted in each pot. These two strains were transplanted and managed under water-logging conditions of approximately 2 cm+. At the early stage of the emergence of the weeds shown in Table 1, a predetermined amount of the herbicide of the present invention formulated according to Example 9 was dropped onto the water surface, and then the plants were left standing in a greenhouse and watered at appropriate times.

The herbicidal effect and chemical damage were investigated on the 20th day after chemical treatment and Table 1
The results shown are obtained. The herbicidal effect was evaluated using numbers from 0 to 5 as shown below. In addition, chemical damage to crops was shown using the same criteria as herbicidal effects.

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

Claims (5)

[Claims] (1) General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [However, in the formula, R^1 and R^2 are the same or different and are hydrogen atoms, halogen atoms, R^3 , R^4 are the same or different from each other, hydrogen atom, lower alkyl group, -CO
R^5 (R^5 represents a lower alkyl group or an amino group which may be substituted with a lower alkyl group) or R^3, R^
4 are linked to each other to represent a phthaloyl group] A thiadiazole derivative represented by the following. (2) General formula [II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [II] Thiadiazole derivatives represented by [However, in the formula, R^1 and R^2 represent the same meanings as above] and the general formula [III
] NHR^6R^7 [III] [However, R^6 and R^7 are the same or different and represent a hydrogen atom or a lower alkyl group of C_1 to C_6]
[IV] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [IV] [However, in the formula, R^1, R^2, R^6, R ^7 represents the same meaning as above] A method for producing a thiadiazole derivative. (3) General formula [II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [II] [However, in the formula, R^1 and R^2 represent the same meanings as above] Thiadiazole derivative and potassium phthalimide General formula [V] characterized by reacting with ▲There are mathematical formulas, chemical formulas, tables, etc.▼[V] A method for producing thiadiazole derivatives. (4) General formula [V] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [V] [In the formula, R^1 and R^2 have the same meanings as above] Hydrolysis of thiadiazole derivatives Thiadiazole derivatives represented by the general formula [VI] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [VI] [In the formula, R^1 and R^2 have the same meanings as above] manufacturing method. (5) A herbicide containing the thiadiazole derivative according to claim (1) as an active ingredient.