JPH01197477A - Substituted thenylsulfonamide derivative, production thereof and selective herbicide - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I [X and Y are halogen, lower alkyl or haloalkyl) n is 0-2; m is 0 or 1; R is lower alkyl, lower alkoxyalkyl, haloalkyl, lower alkenyl or lower alkynyl; R1 is CONH2, CSNH2, CN or CONH-R2 (R2 is alkoxycarbonyl or alkylcarbonyl)]. EXAMPLE:N-Ethyl-N-carbamoylmethyl-2,5-dibromo-3-thenylsulfonamide. USE:An active ingredient o selective herbicides, completely safe for directly sown rice plant, having extremely advanced selectivity between the genuses Oryza-Echinochloa and powerful barnyard grass weeding activity and capable of completely exterminating barnyard grass in the germination stage and of advanced growth with a wide suitable period for use. PREPARATION:A substituted thenylsulfonyl halide expressed by formula III (Z is halogen) is reacted with a compound expressed by formula IV in the presence of a basic substance in excess in a solvent to afford the aimed compound expressed by formula I.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is based on the general formula [■] (where X and Y independently represent a halogen atom, a lower alkyl group, or a haloalkyl group, and n is 0.1 .2
, m represents 0.1, R represents a lower alkyl group, lower alkoxyalkyl group, haloalkyl group, lower alkenyl group or lower alkynyl group, R1 C0NHz, C
3NH2, -CN or -CONLL, and R2 represents an alkoxycarbonyl group or an alkylcarbonyl group. ) substituted tenylsulfonamide derivatives (
(hereinafter referred to as the compound of the present invention), its production method, and a selective herbicide containing the compound as an active ingredient.

[, Conventional technology]

In order to protect agricultural crops from weed damage and increase yields, various systems of compounds are being researched, and many types of herbicides are used in practical situations, and it is known that they are making a significant contribution to increasing agricultural productivity. ing. However, most of these herbicides have so-called selectivity between rice and barnyard grass, which shows a strong activity against barnyard grass, which is a harmful weed in rice cultivation, and a high degree of safety for rice, especially in direct-seeding cultivation methods. It's not something you have.

It is known that sulfonamide-based compounds of the following types have selectivity between the genus Rice and Millet (Japanese Patent Application Laid-open No. 44543/1983).
No. JP-A-53-145916).

However, its herbicidal activity is not satisfactory.

[Problem to be solved by the invention]

The present invention simultaneously solves various problems such as selectivity between rice and barnyard grass, herbicidal activity against barnyard grass, and its effective period of use in paddy rice cultivation, especially in direct sowing cultivation, which is a labor-saving and low-cost modern agricultural form. The objective is to provide a new herbicide that

[Means to solve the problem]

With the aim of developing a useful herbicide that solves the above-mentioned problems, the present inventors have conducted extensive research, especially on sulfonamide compounds, and have found that the compound of the present invention exhibits selectivity between rice and barnyard grass species, and kills the barnyard grass herbicide. The present inventors have discovered that it has satisfactory properties in terms of activity and suitable period of use, etc., and have completed the present invention.

That is, the present invention relates to (1) general formula [■] (wherein X and Y independently represent a halogen atom, a lower alkyl group, or a haloalkyl group, and n is 0.1.2
, m represents 0.1, R represents a lower alkyl group, lower alkoxyalkyl group, haloalkyl group, lower alkenyl group or lower alkynyl group, R1 represents -CONH2, -
C3N)+2, -CN or -CONfl R2, and R2 represents an alkoxycarbonyl group or an alkylcarbonyl group. ) Substituted tenyl sulfonamide derivatives.

(2) General formula [■] (In the formula, X and Y independently represent a halogen atom, a lower alkyl group, or a haloalkyl group, and n is 0.1.2
, m represents 0.1, and Z represents a halogen atom. ) and the substituted tenylsulfonyl halide represented by the general formula [
III) (In the formula, R represents a lower alkyl group, a lower alkoxyalkyl group, a haloalkyl!, a lower alkenyl group, or a lower alkynyl group, and R1 is -CONH2, C3NH2, -C
It represents N or -CONH-R2, and R2 represents an alkoxycarbonyl group or an alkylcarbonyl group. ) (wherein X, YSnSmSR, R+ have the same meanings as above) A method for producing a substituted thenylsulfonamide derivative.

(3) A selective weed killer characterized by containing a substituted thenylsulfonamide derivative represented by the general formula [13 (wherein, XSY, nSm, R, R, have the same meanings as above) as an active ingredient. provide the agent.

The compound of the present invention is a novel compound synthesized by the present inventors for the first time and has not been described in any literature.

As shown in the test examples below, the compound of the present invention has a high degree of selectivity between rice and barnyard grass species that is completely safe even for directly sown rice, has strong herbicidal activity in barnyard grass, and has a strong effect on the germination period and the progress of growth. It has the property of being an excellent herbicide with a wide range of suitable periods of use, as it can completely kill even the common barnyard grass.

The compound of the present invention can be synthesized by the method shown in the reaction formula below. X5YSn, m of the following formula.

ZSR,R, has the same meaning as above.

The compound of the present invention can be easily obtained by reacting a combination of the respective reagents in a solvent in the presence of an excess of a basic substance.

As the solvent, ketones such as acetone, ethers, ethers such as tetrahydrofuran, acetonitrile, aromatic hydrocarbons, chlorinated hydrocarbons, alcohols, water, etc. can be used alone or in combination.

As the basic substance, for example, an inorganic base such as potassium carbonate, sodium carbonate, hydroxide, etc., and an organic base such as pyridine, tertiary amine, etc. are used, and an excess amount is usually used, but preferably 1. A ratio of 1 to 3 moles is appropriate. The reaction temperature can be arbitrarily set from -20°C to room temperature, but preferably -5° to 10°C. Sulfonyl chloride is suitable as the sulfonyl halide, and the amount of the amine used is preferably in excess of the sulfonyl chloride, usually 1.1 to 1.5 moles, and the deoxidizing agent is also used in an amount of 2 moles. You can also use more than that. In Table 1, representative compounds of the present invention are exemplified and synthesis examples are given to explain the method for producing the compounds of the present invention in more detail.

[Example 1] Synthesis of N-ethyl-N-rubamoylmethyl-2,5-dichloro-3-thenylsulfonamide N'-ethylaminoacetamide 2.24 g Tetrahydrofuran solution 3
2.70 g of 2.5-dichloro-3-thenylsulfonyl chloride was added to 10
m1! Tetrahydrofuran solution was added dropwise. The mixture was stirred as it was for 1 hour, and further stirred at room temperature for 1 hour, then poured into ice-cold water, and the oily substance was extracted with dichloromethane. The solvent was distilled off, and the resulting crude product was purified by silica gel column chromatography to obtain Compound No. 10 with a melting point of 113-116°C.
1.03 g of the target product was obtained.

[Example 2] Synthesis of N-ethyl-N-rubamoylmethyl-2,5-dibromo-3-thenylsulfonamide 2.24 g of N'-ethylaminoacetamide 20 g of tetrahydrofuran
mj! The liquid was cooled to 0 to 10°C, and a solution of 3.55 g of 2,5-dibromo-3-thenylsulfonyl chloride in 10 ml of tetrahydrofuran was added dropwise while stirring. As is 1
After stirring for an hour and further stirring at room temperature for 1 hour, the mixture was poured into ice-cold water and the oil was extracted with dichloromethane. Distill the solvent,
(The obtained crude product was purified by silica gel column chromatography to obtain 1.18 g of the target compound No. 4 with a melting point of 156-158°C.

Although the compounds of the present invention may be used as is, - generally,
It is advantageous to use it in the form of emulsions, wettable powders, granules, fine granules, powders, etc.

Liquid or solid carriers can be used in making these formulations. Examples of the liquid carrier include organic solvents, such as xylene, chlorobenzene, methylnaphthalene, cyclohexanone, isophorone, alcohols, dimethylformamide, N-methylpyrrolidone, and the like. Examples of solid carriers include kaolin, talc, bentonite, diatomaceous earth, clay, and synthetic compounds such as alumina and silicates. When preparing formulations, various auxiliary agents such as emulsifiers,
Dispersants, spreading agents, wetting agents, penetrants, etc. can be used.

It can also be used in combination with other herbicides for the purpose of reducing spraying labor or expanding the range of grass species that can be effectively controlled. In particular, since the compound of the present invention is weakly effective against broad-leaved weeds, it is meaningful to mix it with a herbicide effective against these weeds, and is important in practical situations.

Next, formulation examples and herbicidal activity test examples of herbicides containing the compound of the present invention as an active ingredient will be shown, but the present invention is of course not limited to these. Parts indicate parts by weight.

Example 3 Emulsion 15 parts of isophorone and 60 parts of xylene were added to 20 parts of emulsion compound No. 4, and to this were added 1.5 parts of polyoxyethylene alkyl ether, 2 parts of alkylbenzene sulfonate, and 1.5 parts of polyoxyethylene sorbitan alkylate as emulsifiers. 5 parts were added and mixed and dissolved to obtain a 20% emulsion.

Example 4 Wettable powder: 2 parts of white carbon was added to 30 parts of Compound No. 2 and mixed. To this, 3 parts of sodium alkyl ether sulfate and 2 parts of sodium dialkylnaphthalene sulfonate were added as a dispersing wetting agent, and the mixture was ground. 63 parts of clay was added as an auxiliary agent, and the whole was thoroughly mixed and pulverized to obtain a 30% permanent agent.

Example 5 Granules 67 parts of clay and 26 parts of bentonite were added to 3 parts of Compound No. 3, and 0.5 part of alkylbenzenesulfonate and 3.0 parts of sodium likuninsulfonate were added as disintegration aids.
Add 5 parts and mix everything well. Water was added thereto, the mixture was granulated and dried using a mixer, and the granules were sized to obtain 3% granules.

Example 6 Germination period soil treatment test A pot with a surface area of 100 cffI was filled with paddy soil, 50 millet seeds and 10 paddy rice seeds were sown, and the pots were covered with soil to a thickness of 0.5 am. 4. Flooding source when barnyard grass and rice seeds germinate on the soil surface. A predetermined amount of the compound of the present invention was treated as Oam. An investigation was conducted on the 14th day after the drug treatment, and the results shown in Table 2 were obtained using the following formula.

Table-2 Germination stage soil treatment test * Comparative example 5-(4-talolobenzyl)-N,N-diethylthiol carbamate Example 7 Barnyard grass 2.0 leaf stage treatment test In the same manner as in Example 9, barnyard grass seeds were placed in a pot with a surface area of 100 cI11. and paddy rice seeds were sown, and each was grown until it reached the 2.0 leaf stage. When barnyard grass and paddy rice reached the 2.0 leaf stage, a predetermined amount of the compound of the present invention was applied as a flooding source of 4.0 am. An investigation was conducted on the 14th day after the drug treatment, and the results shown in Table 3 were obtained using the above formula.

Table-3 Barnyard grass 2.0 leaf stage treatment test *Comparative example 5-(4-chlorobenzyl)-N,N-diethylthiol carbamate [Effects of the invention] The present invention has extremely high selectivity between rice and barnyard grass genus and strong It is possible to obtain an excellent herbicide that has a high herbicidal activity for barnyard grass and can be used over a wide range of periods.

Claims (3)

[Claims] (1) General formula [I] ▲Mathematical formulas, chemical formulas, tables, etc.▼[I] (In the formula, X and Y independently represent a halogen atom, a lower alkyl group, or a haloalkyl group, and n is 0, 1, 2
, m represents 0 or 1, R represents a lower alkyl group, lower alkoxyalkyl group, haloalkyl group, lower alkenyl group or lower alkynyl group, R_1 is -CONH_2
, -CSNH_2, -CN or -CONH-R_2, and R_2 represents an alkoxycarbonyl group or an alkylcarbonyl group. ) A substituted tenylsulfonamide derivative represented by (2) General formula [II] ▲ Numerical formulas, chemical formulas, tables, etc. ▼ [II] (In the formula, X and Y independently represent a halogen atom, a lower alkyl group, or a haloalkyl group, and n is 0, 1, 2
, m represents 0 or 1, and Z represents a halogen atom. ) and the substituted tenylsulfonyl halide represented by the general formula [
III] ▲There are mathematical formulas, chemical formulas, tables, etc.▼[III] (In the formula, R represents a lower alkyl group, a lower alkoxyalkyl group, a haloalkyl group, a lower alkenyl group, or a lower alkynyl group, and R_1 is -CONH_2, -CSNH_
2, -CN or -CONH-R_2, and R_2 represents an alkoxycarbonyl group or an alkylcarbonyl group. ) General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] (In the formula, X and Y independently represent a halogen atom, a lower alkyl group, or a haloalkyl group) group, n is 0, 1, 2
, m represents 0 or 1, R represents a lower alkyl group, lower alkoxyalkyl group, haloalkyl group, lower alkenyl group or lower alkynyl group, R_1 is -CONH_2
, -CSNH_2, -CN or -CONH-R_2, and R_2 represents an alkoxycarbonyl group or an alkylcarbonyl group. ) A method for producing a substituted tenylsulfonamide derivative represented by (3) General formula [I] ▲Mathematical formulas, chemical formulas, tables, etc.▼[I] (In the formula, X and Y independently represent a halogen atom, a lower alkyl group, or a haloalkyl group, and n is 0, 1, 2
, m represents 0 or 1, R represents a lower alkyl group, lower alkoxyalkyl group, haloalkyl group, lower alkenyl group or lower alkynyl group, R_1 is -CONH_2
, -CSNH_2, -CN or -CONH-R_2, and R_2 represents an alkoxycarbonyl group or an alkylcarbonyl group. ) A selective herbicide characterized by containing a substituted tenylsulfonamide derivative represented by the following as an active ingredient.