JPS6241562B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to agricultural fungicides with high fungicidal activity. For more information, see the general formula: (In the formula, A is a pyridyl group, and X is an oxygen atom or a sulfur atom.) The present invention relates to an agricultural fungicide characterized by containing a benzisothiazole compound represented by the following formula as an active ingredient. Before the application for this invention, the Japanese patent application was already published in the Showa period.
Publication No. 29297 of 1947 describes the general formula: (However, R is −CH ₂ ≡CI or

It is stated that the compound represented by the following formula has biological activity as a fungicide for fruit trees. The present inventors have been studying compounds having a benziisothiazole ring skeleton in order to develop highly bactericidal agents. The present inventors have now discovered that the benzisothiazole compound represented by the general formula () has excellent and significant bactericidal activity. That is, the compound of the present invention has an unsubstituted pyridyl group attached to the carbon atom at the 3-position of 1,2-benziisothiazole 1,1-dioxide via an oxygen atom or a sulfur atom, as represented by the general formula (). are combined, and in this case expresses surprisingly significant bactericidal activity. The compound of the present invention also exhibits a significantly superior activity value when compared with the compound represented by the above general formula (). The agricultural fungicide of the present invention represented by the general formula () has excellent bactericidal and growth-inhibiting power against plant pathogenic bacteria, and can be applied to eradicate plant diseases caused by a wide variety of fungi. It is particularly effective against rice blast disease. The active compounds of the invention can be used against pathogens that parasitize the above-ground parts of plants, pathogens that invade plants from the soil and cause tracheomycosis, seed-borne pathogens, and soil-borne pathogens. In addition, these compounds have low toxicity to warm-blooded animals and good affinity for higher plants, which means that they do not harm cultivated plants at normal concentrations, so they are used as agricultural and horticultural agents to treat pathogenic bacteria. It can be used quite advantageously against plant diseases caused by. That is, as fungicides, archaeal bacteria (Archimycetes), algae (Phycomycetes), ascomycetes (Ascomycetes), basidiomycetes (Basidiomycetes), and Deuteromycota (Fungi fungi) are used as fungicides. It can be effectively used against various plant diseases caused by Fungi Imperfecti and other bacteria. In particular, it has surprising activity against the blast fungus (Pyricularia oryzae), which is an important pathogen for rice. The benzisothiazole compound represented by the general formula () in the present invention is synthesized by the following general method (a), and when X in the general formula () is a sulfur atom, it is further synthesized by the method (b). ) can also be synthesized. (In the formula, A ^, Examples include 3-chloro-1,2-benziisothiazole-1,1-dioxide. Further, the compound represented by the general formula () specifically includes: 2-mercaptopyridine or an alkali metal salt thereof, 2-hydroxypyridine or a silver salt thereof, 3-mercaptopyridine or an alkali metal salt thereof, 3- Hydroxypyridine or an alkali metal salt thereof, 4-mercaptopyridine or an alkali metal salt thereof, 4-hydroxypyridine or a silver salt thereof can be mentioned. Next, the above manufacturing method will be specifically explained using representative examples. The method of the invention is preferably carried out using a solvent or diluent. All inert solvents and diluents can be used for this purpose. Such solvents or diluents include water; aliphatic cycloaliphatic and aromatic hydrocarbons (which may optionally be chlorinated) such as hexane, cyclohexane, petroleum ether, ligroin, benzene, toluene, xylene. , methylene chloride,
Chloroform, carbon tetrachloride, ethylene chloride and trichloroethylene, chlorobenzene;
Other ethers such as diethyl ether,
Methyl ethyl ether, di-iso-propyl ether, dibutyl ether, propylene oxide dioxane, tetrahydrofuran; ketones such as acetone, methyl ethyl ketone, methyl-iso
-Pyropylketone, methyl-iso-butylketone; Nitriles such as acetonitrile, propionitrile, acrylonitrile; Esters such as ethyl acetate, amyl acetate; Acid amides such as dimethylformamide, dimethylacetamide; Sulfones, sulfoxides such as dimethylsulfoxide , sulfolane; and bases, e.g.
Examples include pyridine. Moreover, the reaction of the present invention can be carried out in the presence of an acid binder. Such acid binders include commonly used alkali metal hydroxides,
Carbonates, bicarbonates and alcoholates, etc., and tertiary
Examples of the class amines include triethylamine, diethylaniline, and pyridine. However, when producing a compound in which X is an oxygen atom in the general formula (), the raw material compound of the general formula () is 2-hydroxypyridine, 4-
In the case of hydroxypyridine, it is necessary to use silver oxide as the acid binder (reactive base). The method of the invention can be carried out within a wide temperature range. It is generally carried out between -20°C and the boiling point of the mixture, preferably between 0 and 100°C. Further, although the reaction is preferably carried out under normal pressure, it is also possible to operate under increased pressure or reduced pressure. (In the formula, A and Hal are the same as above. ^M2 represents a hydrogen atom or an alkali metal atom.) In the above reaction formula, the compound represented by the general formula () is specifically 3-mercapto-1, 2-
Examples include benzisothiazole-1,1-dioxide or its alkali metal salts such as sodium and potassium. Further, specific examples of the compound represented by the general formula () include 2-chloropyridine, 3-chloropyridine, and 4-chloropyridine, and also bromine compounds instead of chlorine compounds. Next, the above manufacturing method will be specifically explained using representative examples. To carry out the above method, the same solvents or diluents as mentioned above can be used, and the reaction can be carried out in the presence of the same acid binders as mentioned above. As before, this reaction can be carried out within a wide temperature range. It is generally carried out between -20°C and the boiling point of the mixture, preferably between 0 and 100°C. Although the reaction is preferably carried out under normal pressure, it can be operated under increased pressure or reduced pressure. When using the agricultural fungicide of the present invention, it can be used directly as it is after being diluted with water, or it can be made into various formulations by using agricultural chemical adjuvants and methods commonly used in the field of agricultural chemical manufacturing. be able to. In actual use, these various formulations can be used directly or diluted with water to a desired concentration. Examples of pesticide adjuvants mentioned here include diluents (solvents, fillers, carriers), surfactants (solubilizers, emulsifiers, dispersants, wetting agents), stabilizers, fixing agents, and propellants for aerosols. , synergists. Solvents include water: organic solvent; hydrocarbons [e.g., n-hexane, petroleum ether, naphtha, petroleum fractions (paraffin wax, kerosene, light oil, medium oil, heavy oil), benzene, toluene, xylenes], halogenated Hydrocarbons [e.g. chlormethylene, carbon tetrachloride, trichlorethylene, ethylene chloride, ethylene dibromide, chlorobenzene chloroform], alcohols [e.g. methyl alcohol, ethyl alcohol, propyl alcohol, ethylene glycol], ethers , [e.g. ethyl ether, ethylene oxide, dioxane],
Alcohol ethers, [e.g., ethylene glycol monomethyl ether, etc.], ketones, [e.g., acetone, isophorone, etc.], esters, [e.g., ethyl acetate, amyl acetate, etc.], amides, [e.g., dimethylformamide, dimethylacetamide, etc.] ], sulfoxides [for example, dimethyl sulfoxide, etc.]. Inorganic granules as fillers or carriers; sulfur, slaked lime, magnesium lime, gypsum, calcium carbonate, silica, perlite, pumice, calcite, diatomaceous earth, amorphous silicon oxide, alumina, zeolite,
Clay minerals (e.g. pyrophyllite, talcum, montmorillonite, beidellite, vermiculite, kaolinite, mica): Vegetable granules; Grain flour, starch, modified starch, sugar, glucose, crushed plant stems: Synthetic resins Powder: Examples include phenolic resin, urea resin, and vinyl chloride resin. Examples of surfactants include anionic surfactants; alkyl sulfates, [e.g., sodium lauryl sulfate, etc.], arylsulfonic acids, [e.g., alkylarylsulfonates, sodium alkylnaphthalenesulfonates], and succinates. , polyethylene glycol alkylaryl ether sulfate salts: cationic surfactants; alkylamines [e.g., laurylamine, stearyltrimethylammonium chloride, alkyldimethylbenzylammonium chloride, etc.], polyoxyethylene alkylamines: non- Ionic surfactants; polyoxyethylene glycol ethers, [e.g., polyoxyethylene alkylaryl ethers and condensates thereof], polyoxyethylene glycol esters, [e.g., polyoxyethylene fatty acid esters], polyhydric alcohol esters , [for example, polyoxyethylene sorbitan monolaurate], : ampholytic surfactant, and the like. In addition, stabilizers, fixing agents [e.g., agricultural soap, caseinate lime, sodium alginate, polyvinyl alcohol (PVA), vinyl acetate adhesives, acrylic adhesives], propellants for aerosols [e.g., trichlorofluoromethane, Dichlorofluoromethane, 1,2,2-trichlor-1,1,2
-Trifluoroethane, chlorobenzene,
LNG, lower ethers]: Combustion regulators (for smokers) [e.g., nitrites, zinc dust, dicyandiamide]: Oxygen yielding agents, [e.g., chlorates, dichromates]: Reducing chemical damage Agents [e.g. sulfuric acid, zinc, ferrous chloride, copper nitrate]: Potency extenders: Dispersion stabilizers [e.g. casein, tragacanth, carboxymethylcellulose (CMC),
Polyvinyl alcohol (PVA)]: A synergist can be mentioned. The agricultural fungicide of the present invention can be manufactured into various formulations by methods generally used in the agricultural chemical manufacturing field. Forms of preparations include emulsions, oils, wettable powders, suspensions, powders, aqueous solutions, granules, powders, smoking agents, tablets, aerosols, pastes, capsules, etc. can. The agricultural fungicide of the present invention contains the active ingredient at 0.1
It can contain up to 95% by weight, preferably 0.5 to 90% by weight. In actual use, the various formulations and spray preparations described above (ready-to-use)
The active compound content in the preparation is generally
0.0001-20% by weight, preferably 0.005-10% by weight
A range of is appropriate. The content of these active ingredients can be changed as appropriate depending on the form of the preparation, the method of application, purpose, timing, location, and occurrence of plant diseases. The agricultural fungicide of the present invention may further contain other agricultural chemicals, such as insecticides, bactericidal agents, acaricides, nematicides, antiviral agents, herbicides, plant growth regulators, attractants, (For example, organic phosphate compounds, carbamate compounds, dithio (or thiol) carbamate compounds, organic chlorine compounds, dinitro compounds, organic sulfur or metal compounds, antibiotics, substituted diphenyl ether compounds, urea compounds, compounds, triazine compounds] or/and fertilizers, etc. Various formulations or preparations for spraying (ready-to-use) containing the active ingredients of the present invention may also be present.
Preparation) refers to application methods commonly used in the field of agrochemical manufacturing, such as spraying, spraying, misting, atomizing, dusting, granulation, water surface application, and pouring. : Fumigation: Soil application, [e.g.
This can be accomplished by mixing, sprinkling, vaporing, irrigation, etc. Also, the so-called ultra-high concentration small amount spraying method (ultra-
It can also be used with low-volume). In this way it is possible to have 100% active ingredient content. The application rate per unit area is approximately 0.03 to 10 Kg of active compound per hectare, preferably 0.3 to 10 Kg of active compound per hectare.
6Kg is used. However, in special cases it is possible, and sometimes even necessary, to exceed or fall below these ranges. The present invention comprises a compound of the general formula () as an active ingredient, and further contains a diluent (solvent and/or filler and/or carrier) and/or surfactant, and if necessary, a stabilizer, a fixing agent, etc. An agricultural fungicidal composition comprising a synergist is provided. Furthermore, the present invention provides a method for applying the compound of the general formula () alone to plant pathogenic bacteria and/or their locations,
or a diluent (solvent and/or filler and/or carrier) and/or surfactant, and if necessary, a method for controlling plant diseases, which is applied in combination with, for example, a stabilizer, a fixing agent, a synergist. Ru. EXAMPLES Next, the content of the present invention will be specifically explained with reference to Examples, but the present invention should not be limited thereto. Example 1 (Wettable powder) Compound No. 1 of the present invention, 15 parts, mixture of powdered diatomaceous earth and powdered clay (1:5), 80 parts, sodium alkylbenzenesulfonate, 2 parts, sodium alkylnaphthalenesulfonate formalin condensation thing,
Three parts were ground and mixed to form a wettable powder. This is diluted with water and sprayed onto plant pathogens and/or their growth areas. Example 2 (Emulsion) Compound No. 2 of the present invention, 15 parts, methyl ethyl ketone
70 parts of polyoxyethylene alkyl phenyl ether, 8 parts of calcium alkylbenzenesulfonate, and 7 parts of calcium alkylbenzenesulfonate were mixed and stirred to prepare an emulsion. This is diluted with water and sprayed onto plant pathogens and/or their growth areas. Example 3 (Powder) Compounds No. 1 and 2 of the present invention and 98 parts of powdered clay were pulverized and mixed to prepare a powder. This is sprinkled on plant pathogens and/or their growth areas. Example 4 (Powder) 1.5 parts of Compound No. 2 of the present invention, 0.5 parts of isopropyl hydrogen phosphite (PAP), and 98 parts of powdered clay were ground and mixed to make a powder, and the powder was sprinkled on plant pathogenic bacteria and/or their growth areas. do. Example 5 (Granules) To a mixture of 10 parts of the present compound No. 3, 30 parts of bentonite (montmorillonite), 58 parts of talc, and 2 parts of lignin sulfonate, 25 parts of water was added. 10 to 40 by extrusion type granulator.
It is dried in the form of mesh granules at 40 to 50°C to form granules. This is sprinkled on plant pathogens and/or their growth areas. Example 6 (Granules) Clay mineral particles having a particle size distribution of 0.2 to 2 mm, 95
5 parts of Compound No. 1 of the present invention dissolved in an organic solvent are sprayed onto the mixer and dried at 40 to 50°C to form granules. This is sprinkled on plant pathogens and/or their growth areas. When compared with active compounds of similar structure and compounds of similar active form already known from the literature, the novel compounds according to the invention demonstrate a substantially improved efficacy and a very high toxicity for warm-blooded animals. This compound is characterized by a low oxidation rate, and therefore has very high utility value. The unexpected superiority and remarkable efficacy of the active compounds of the present invention can be seen from the following test results against rice blast fungi. Test Example 1 Preparation of test compound for foliar spray efficacy test against rice blast disease Active compound: 50 parts by weight Carrier: Mixture of diatomaceous earth and kaolin (1:5)
45 parts by weight Emulsifier: 5 parts by weight of polyoxyethylene alkyl phenyl ether A wettable powder is prepared by grinding and mixing the above-mentioned amounts of the active compound, carrier and emulsifier, and diluting the predetermined amount with water. Test method Paddy rice (variety: Asahi) was grown in clay pots with a diameter of 12 cm, and at the 3rd to 4th leaf stage, 50 ml of a diluted solution of the test compound prepared as described above at a predetermined concentration was sprayed per 3 pots. The next day, a suspension of artificially cultured rice blast fungus spores was spray inoculated (twice) at 25℃ and 100% relative humidity.
were kept in a damp room and infected. Seven days after inoculation, the degree of disease per pot was graded and evaluated according to the following criteria, and the control value (%) was determined. At the same time, drug damage was also investigated. Morbidity Spot area ratio (%) 0 0 0.5 2 or less 1 3 to 5 2 6 to 10 3 11 to 20 4 21 to 40 5 41 or more Control value (%) = (Severity of disease in untreated area - in treated area Morbidity level / Morbidity level in untreated area) x 100 This test is the result of 3 pots in 1 area. The results are shown in Table 1.

【table】

【table】

[Table] Test 2 Test method for water surface application efficacy test against rice blast Using a pipette, a chemical solution with a predetermined concentration was applied to the water surface at the indicated amount without directly contacting the above-ground parts of the rice plants. Five days later, a suspension of rice blast fungus spores was spray inoculated by a conventional method and kept in an inoculation chamber at a temperature of 23 to 25°C and a relative humidity of 100% for 24 hours. Thereafter, the plants were transferred to a glass greenhouse at a temperature of 20 to 28°C, and 7 days after inoculation, the same investigation as in Test Example 1 was conducted to determine the control value (%). At the same time, drug damage was also investigated. The results are shown in Table 2.

【table】

[Table] Next, a synthesis example will be shown and a method for producing the compound of the present invention will be specifically described. Synthesis example 1 1.11g of 2-mercaptopyridine in 20ml of toluene
Add 1.01 g of triethylamine and stir. Next, add 2.02 g of 3-chloro-1,2-benziisothiazole-1,1-dioxide to this solution.
and stirred at room temperature overnight. After the reaction is complete, water is added to dissolve triethylamine hydrochloride, and precipitated crystals that are insoluble in water and toluene are sucked off. When the crystals are washed with methyl alcohol, the desired product, 3-(2'-pyrdylthio)-1,2-benziisothiazole-1,1-
2.2 g of dioxide are obtained. mp・204～206℃ Synthesis example 2 2.01 g of 3-mercapto-1,2-benziisothiazole-1,1-dioxide, 1.14 g of 4-chloropyridine, and 1.38 g of potassium carbonate were suspended in 30 ml of methyl ethyl ketone, and the suspension was heated on a water bath at 40 to 50°C for 3 hours. Stir. After stirring, the precipitated crystals were removed, and the liquid was concentrated under reduced pressure. The resulting crystals were washed with ethanol to obtain the target product, 3-(4'-pyridylthio)-1,2-benziisothiazole-
2.25 g of 1,1-dioxide are obtained. mp152-154°C Table 3 shows the compounds of the present invention synthesized by almost the same procedure as in Synthesis Example 1 above.

[Table] The present invention, which has been explained in detail in the detailed description of the invention, is specifically summarized as follows. 1 General formula: (In the formula, A is a pyridyl group, and X is an oxygen atom or a sulfur atom.) An agricultural fungicide characterized by containing a benzisothiazole compound represented by the following as an active ingredient. 2 General formula: (In the formula, Hal represents a halogen atom.) A compound represented by the general formula: M'-X-A () (In the formula, A and X are the same as above. M' is a hydrogen atom, a silver atom or an alkali metal atom). 3 General formula: (In the formula, ^M2 represents a hydrogen atom or an alkali metal atom.) A compound represented by the general formula: Hal-A () (In the formula, Hal and A are the same as above.) General formula, characterized by reacting (In the formula, A is the same as above.) A method for producing a benzisothiazole compound represented by the following. 4. A method for controlling plant diseases, which comprises applying a benzisothiazole compound represented by the general formula () to plant pathogenic bacteria and/or their growth sites. 5. Use of the benzisothiazole compound represented by the above general formula () for controlling plant pathogens. 6. An agricultural fungicidal composition characterized in that a benzisothiazole compound represented by the general formula () is mixed with a diluent (solvent and/or filler and/or carrier) and/or surfactant. manufacturing method.

Claims (1)

[Claims] 1. General formula: (In the formula, A represents a pyridyl group, and X represents an oxygen atom or a sulfur atom.) An agricultural fungicide characterized by containing a benzisothiazole compound represented by the following as an active ingredient.