JPH01272565A - N-benzenesulfonylamidine derivative and pesticide for rice blast containing the same derivative as active component - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (R<1> is H, 1-4C alkyl or halogen; R<2> and R<3> are H, 1-4C alkyl, phenyl, pyridyl or together form piperazino; R<4> is 1-18C alkyl, alkenyl, haloalkyl, cycloalkyl, aryl, quinoxalyl, furyl, thienyl, benzothiazolyloxymethyl, etc.). EXAMPLE:N-(4-methylbenzenesulfonyl)-N',N'-diethyl-n-pentylamidine. USE:A pesticide for rice blast. PREPARATION:The compound of formula I can be produced by reacting a compound of formula II with a compound of formula III in an organic solvent (e.g., benzene) or in the absence of solvent at 50-150 deg.C for 10min-50hr. The reaction system may be incorporated with a Lewis acid such as BF3.ether or aluminum chloride to accelerate the reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a novel N-benzenesulfonylamidine derivative and an anti-rice blast agent containing the same as an active ingredient.

' Techniques and challenges Blast disease is one of the important diseases of rice, and various drugs have been proposed for its control.

For example, JP-A No. 56-164103 describes the general formula: [wherein Ro is a hydrogen atom or a methyl group, R1 is a carbon number 1
R3 represents an alkyl group or an alkenyl group having 1 to 10 carbon atoms, and R3 represents an alkyl group having 1 to 6 carbon atoms. ] It is described that the 3-benzenesulfonylisothiourea derivative shown in the following is an agricultural and horticultural fungicide, and in particular has an excellent control effect against rice blast. Also, JP-A-5
No. 6-164164 has the general formula: [wherein R1 is an alkyl group having 4 to 10 carbon atoms (n-
(excluding butyl group) or methyl group, and R' is R1
When R1 is the former, it is a methyl group, and when R1 is the latter, it is an alkyl group having 4 to 16 carbon atoms. It has been described that the sulfonylisothiourea derivative represented by () has an excellent control effect on agricultural and horticultural fungicides, especially against rice blast. However, there is a desire to develop a drug that is even more effective against rice blast disease.

The present inventors synthesized a number of new N-benzenesulfonylamidine derivatives and investigated the anti-blast activity of each of them in order to develop a drug with excellent anti-blast disease activity. As a result, - up to: [wherein R1 is hydrogen, alkyl having 1 to 4 carbon atoms or halogen; R2 and R3 are hydrogen, alkyl having 1 to 4 carbon atoms, optionally substituted phenyl or pyridyl or R1; R3 may be taken together to form optionally substituted piperazino; R4 is C1-C18 alkyl, alkenyl, haloalkyl, cycloalkyl, optionally substituted aryl, phenylalkyl, quinoxalyl, furyl; Represents thienyl, thienylmethyl or benzothiazolyloxymethyl. It has been found that a novel N-benzenesulfonylamidine derivative represented by the following formula has strong anti-rice blast activity. Certain N-benzenesulfonylamidine derivatives are described, for example, in U.S. Pat. No. 3,953,492.
Although it has been reported that N-benzenesulfonylamidine derivatives have anthelmintic activity in No. 2003, no N-benzenesulfonylamidine derivatives having anti-blast disease activity have been reported so far.

Therefore, the present invention provides a novel N-benzenesulfonylamidine derivative represented by (1) above and an anti-rice blast agent containing the same as an active ingredient.

In the above-mentioned maximum (1), examples of the alkyl having 1 to 4 carbon atoms represented by R1 include methyl, ethyl, isopropyl, t-butyl, etc., and examples of the halogen include fluorine, chlorine, bromine, and iodine. Can be mentioned. Examples of the alkyl having 1 to 4 carbon atoms represented by R1 and R3 include methyl, ethyl, isopropyl, and t-
Examples of substituents of optionally substituted phenyl or pyridyl include butyl, halogen,
Examples of optionally substituted piperazino include alkyl, alkoxy, etc. alone or in combination of two or more, and examples of optionally substituted piperazino include 3-methylpiperazino, 4
-Methylpiperazino and the like. Examples of the alkyl having a carbon number of t-tS represented by R4 include methyl,
Ethyl, isopropyl, isobutyl, t-butyl, n-
Examples of alkenyl include pentyl, n-hexyl, n-hebutyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-tridecyl, low-pentadecyl, n-octadecyl, etc., and examples of alkenyl include allyl, , l-propenyl, etc.; examples of haloalkyl include bromoethyl, dichloropropyl, trifluorobutyl, etc.; examples of cycloalkyl include cyclopropyl, cycloalkyl, cycloheptyl, etc., and optionally substituted As the aryl,
Examples include phenyl, α-naphthyl, β-naphthyl, substituted phenyl, substituted pyridyl (substituents include halogen, alkyl, alkoxy, diethylcarbamoyl, etc. alone or in combination of two or more). Examples of phenylalkyl include benzyl and phenethyl.

Compound (1) of the present invention can be produced, for example, by the method shown in the reaction formula below.

(II) (II
I) [In the formula, R', R'', R3 and R4 have the same meanings as above.] That is, obtained by reacting the amide compound (It) and the N-benzenesulfonyl isocyanate compound ([1)] This reaction is carried out in an organic solvent or without a solvent. Examples of organic solvents include benzene,
Examples include toluene, quinolene, hexane, chloroform, methylene chloride, ethyl ether, dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, and acetonitrile. The reaction may be carried out at -50°C to 200°C, preferably 50 to 150°C, for 10 minutes to 50 hours.

Lewis acids such as BP, ether, aluminum chloride, etc. may be added to accelerate the reaction.

Amide compound (n) and N used as raw materials
-Benzenesulfonyl isocyanate compound (III)
are commercially available or can be obtained by known methods.

The compound of formula (1) thus obtained can be isolated by conventional separation means such as recrystallization, chromatography, etc.
Can be purified.

The compound (1) of the present invention has extremely strong antibacterial activity and is a useful compound that can be widely used as a fungicide for agricultural and horticultural purposes. It exhibits particularly strong antibacterial activity against rice blast.

The compound (1) of the present invention can be used alone or in combination with one or more of solid carriers, liquid carriers, surfactants, and other formulation auxiliaries to produce agricultural and horticultural preparations such as emulsions, wettable powders, powders, etc. It can be used as a chemical suitable for disinfectants. Each formulation contains the compound of the present invention as an active ingredient in an amount of 01 to 99.9 wt%, preferably 2 to 99.9 wt%, based on the total amount of the composition.
Contains 80wt%. These formulations can be prepared according to conventional methods.

Examples of solid carriers include talc, clay, kaolin, diatomaceous earth, and silica; examples of liquid carriers include:
Examples include water, methanol, ethanol, acetone, dimethylformamide, and ether. Examples of surfactants include nonionic surfactants (polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, etc.), anionic surfactants (alkylbenzene sulfonate, lignin sulfonate, dinaphthyl methanesulfonic acid) salt, etc.), polyvinyl alcohol, CMC, gum arabic, etc.

The compounds of the invention may also be used in combination with other fungicides, insecticides, seed disinfectants, and the like.

The preparation thus obtained is applied as is or diluted with water according to a conventional method. It varies depending on the application rate, purpose of use, etc., but for example, when used in rice fields for the purpose of blast control, hydrating powder (active ingredient 4
0%) and 100 to 1600 times diluted solution to 50 to 400
g, 50 to 400 Q of a 200 to 8000 times diluted emulsion (20% active ingredient) may be sprayed.

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, Test Examples, and Formulation Examples, but the present invention is not limited thereto.

Example I N-(4-methylbenzenesulfonyl)-N',N'-
Preparation of diethyl-n-pentylamidine (compound number 39) N,N-diethylpentylamidine o, 59 (0,002
7 mol) of anhydrous toluene, 0.63 g of 4-methylbenzenesulfonyl isocyanate (0.00
32 mol) was added thereto and heated under reflux for 15 hours. After the reaction was completed, water 503112 was added, extracted with methylene chloride, and dried over sodium sulfate. After distilling off methylene chloride,
The residue was subjected to silica gel column chromatography and eluted with methylene chloride-ethyl acetate (20:1 v/v) to obtain 880 (96%) of the title compound as an oil. n
"4-1.5351 Example 2 N-(4-methylbenzenesulfonyl)-N', N'-
Preparation of diethylcyclohexylamidino (compound no. 53) N,N-diethylcyclohexylamide 2.09 (0,
0109 mol) in anhydrous toluene 30x (!) and 4
-Methylbenzenesulfonyl isocyanate 4.39
(0,022 mol) was added, and the mixture was heated under reflux for 24 hours. After the reaction was completed, water 502Q was added and extracted with methylene chloride.
Dry with sodium sulfate.

After distilling off methylene chloride, it was subjected to silica gel column chromatography, and methylene chloride-ethyl acetate (9:I
v/v) to give the title compound 3.09 (86%). Melting point 102-105°C Example 3 N-(4-methylbenzenesulfonyl)-N', N'-
Preparation of dimethyl-(4-methoxyphenyl)amidine (compound number 3) N,N-dimethyl-4-methoxybenzamide 2.49
(0,0134 mol) was dissolved in anhydrous toluene 24xQ and 4-methylbenzenesulfonylisocyanate 5.3
9 (0,0268 mol) was added, and the mixture was heated under reflux for 5 hours. After the reaction was completed, 100 liters of water was added, extracted with 100×f2 ethyl acetate, and dried over sodium sulfate. After distilling off the solvent, it was subjected to silica gel column chromatography, eluted with methylene chloride-ethyl acetate (1:1 v/v), and then recrystallized from ethyl acetate to obtain the title compound 2.
゜39 (52%) was obtained. Melting point 132-133°C Example 4 N-(4-methylbenzenesulfonyl)-N'-methyl-No-phenylphenylaminone (Compound No. 17)
Preparation of 0.59 (0,0024 mol) of N-methylbenzanilide in 7 M 1 liter of anhydrous toluene! 4-methylbenzenesulfonyl isocyanate 1.419 (0,007
1 mol) was added thereto, and the mixture was heated under reflux for 13 hours. After the reaction was completed, the solvent was distilled off and subjected to silica gel column chromatography using methylene chloride-ethyl acetate (4:1 v
/v), the title compound was 0.759 (87%)
I got it. Melting point 106-107°C Example 5 Production of N-(4-methylbenzenesulfonyl)-N”-methyl-N′-(2-pyridyl)methylamidine (Compound No. 24) N-methyl-N-(2-pyridyl ) Acetamide 0.4
69 (0,0031 mol) was dissolved in anhydrous toluene 7zQ and 4-methylbenzenesulfonyl isocyanate 1.
839 (0,0093 mol) was added, and the mixture was heated under reflux for 16 hours. After the reaction was completed, the solvent was distilled off and subjected to silica gel column chromatography and eluted with methylene chloride-ethyl acetate (1: I v/v) to obtain the title compound 0.
．． 759 (80%). Melting point: 115-116°C The following compound of the present invention was produced in the same manner as above.

Next, a rice blast control effect test was conducted to examine the antibacterial activity of the compound of the present invention.

Test method (spraying application) 300 rice seedlings (variety: Aichi Asahi) grown for 2 weeks after sowing
The seedlings were transplanted into zg cups and grown for another two weeks.

After that, a test solution with a concentration of 500 ppm was sprayed, and 24 hours later, rice blast fungus (Pyricularia oryza) was detected.
The cells were inoculated by spraying a conidial suspension of icularia oryzae). Then, after keeping the rice in an inoculation room at 28°C for 7 days, the number of lesions on the rice leaves was investigated, and the control rate was calculated using the following formula. The results are shown in Table 1.

Test method (water surface application) Rice (variety, Aichi Asahi) was sown in a 300 mg cup, and 2
Seedlings were raised for a week. A sample of midges dissolved in acetone was dropped into the rice field water in this cup so that the concentration in the water was 00 ppm. After the treatment, seedlings were raised for another 7 days, and pathogenic bacteria were inoculated in the same manner as above, the number of lesions was investigated, and the control rate was calculated. The results are shown in Table 2.

Table 1 Table 2 Next, examples of formulations of the anti-rice blast agent of the present invention will be shown.

Formulation Example 1 3 parts by weight of the compound of the present invention, 85 parts by weight of clay and 12 parts by weight of talc are thoroughly ground and mixed to form a powder.

Formulation Example 2 25 parts by weight of the compound of the present invention, 8 parts by weight of polyoxyethylene alkylphenyl ether, 2 parts by weight of sodium alkylbenzenesulfonate and 65 parts by weight of xylene are mixed and dissolved to prepare an emulsion.

Formulation Example 3 50 parts by weight of the compound of the present invention, 6 parts by weight of sodium alkylbenzene sulfonate, 4 parts by weight of sodium lignin ζ sulfonate
Part by weight and 40 parts by weight of clay are thoroughly mixed and ground to prepare a wettable powder.

Effects of the Invention According to the present invention, a novel N-benzenesulfonylamine derivative having anti-rice blast activity and an anti-rice blast agent containing the same as an active ingredient are provided.

Claims (2)

[Claims] (1) General formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R^1 is hydrogen, alkyl having 1 to 4 carbon atoms, or halogen; R^2 and R^3 are hydrogen, having 1 to 4 carbon atoms. 4 alkyl, each optionally substituted phenyl or pyridyl or R^2 and R^3 may be taken together to form an optionally substituted piperazino; R^4
is an alkyl, alkenyl, haloalkyl, cycloalkyl, optionally substituted aryl having 1 to 18 carbon atoms,
Phenylalkyl, quinoxalyl, furyl, thienyl,
Represents thienylmethyl or benzothiazolyloxymethyl. ] A compound represented by. (2) General formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R^1 is hydrogen, alkyl having 1 to 4 carbon atoms, or halogen; R^2 and R^3 are hydrogen, having 1 to 4 carbon atoms. 4 alkyl, each optionally substituted phenyl or pyridyl or R^2 and R^3 may be taken together to form an optionally substituted piperazino; R^4
is an alkyl, alkenyl, haloalkyl, cycloalkyl, optionally substituted aryl having 1 to 18 carbon atoms,
Phenylalkyl, quinoxalyl, furyl, thienyl,
Represents thienylmethyl or benzothiazolyloxymethyl. ] An anti-rice blast agent characterized by containing a compound represented by the following as an active ingredient.