JPH0717624B2 - Dithiazinone derivatives and fungicides for agriculture and horticulture - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a 2-dicyanovinylidene-1,3,5-diaazin-6-one derivative represented by the following general formula and a bactericide containing the compound as an active ingredient.

3) General formula (However, R ₁ : C _{1 to} C ₆ alkyl, cycloalkyl, and aryl and phenyl groups (however, the phenyl group may be substituted with C ₁ ), R ₂ : H and C _{1 to} C ₆ alkyl, A cycloalkyl group and a phenyl group are shown.) Table 1 shows typical examples of the compounds represented by the above general formula.

The compound of the present invention can be prepared, for example, by dicarbamoylcyanovinylidene dimercaptan alkali metal salt and a compound of the formula Carbamoyl chloride represented by (wherein R ₁ and R ₂ are the same as above) is reacted in an organic solvent such as acetone, ethyl acetate, ethanol, chloroform, dichloromethane, dimethyl sulfoxide and N, N-dimethylformamide. Alternatively, dicarbamoylcyanovinylidene dimercaptan alkali metal salt solution and formula A benzene, toluene or xylene solution of carbamoyl chloride represented by (wherein R ₁ and R ₂ are the same as above) may be added dropwise at room temperature and atmospheric pressure for the reaction. In this case, when tetranormal butyl ammonium bromide is used as the phase transfer catalyst, the reaction often proceeds smoothly.

The reaction temperature is from 10 ° C to the boiling point of the solvent. When the reaction is carried out in an organic solvent, the reaction solvent is distilled off under reduced pressure and the residue is extracted with dichloromethane or the like. Saturated saline solution,
The extract is washed with saturated aqueous sodium carbonate solution, dried over anhydrous sodium sulfate, the solvent is distilled off, and the residue is recrystallized from ethanol. When reacted with water and a mixed solvent system such as benben, toluene or xylene, the organic layer is separated and saturated saline solution,
After washing with a saturated sodium carbonate aqueous solution and drying over anhydrous sodium sulfate, the solvent is distilled off and the residue is recrystallized from ethanol to obtain the compound of the present invention.

Hereinafter, a representative example of the method for synthesizing the compound of the present invention will be shown and described more specifically.

Synthesis Example 1 5-Normal butyl-2-dicyanovinylidene-1,3,5
Dithiazin-6-one dicarbamoylcyanovinylidene Dimercaptan potassium salt 11.7 g (0.05 M) was dissolved in 50 ml of water and stirred at room temperature with stirring N-normalbutyl-N-chloromethylcarbamoyl chloride 9.3 g (0.05 M). M) and tetranormabutylammonium bromide 1g benzene 80ml solution
Drip in 30 minutes. After the dropping, the mixture is stirred for 2 hours at room temperature, further heated to 60 ° C., and stirred for 2 hours. The reaction system is returned to room temperature, the organic layer is separated, washed with saturated brine and saturated aqueous sodium carbonate solution, and dried over anhydrous sodium sulfate.

The organic solvent is distilled off under reduced pressure, and the residue is recrystallized from ethanol to obtain the desired product (Compound 5). Yield 6.7 g Synthesis Example 2 2-dicyanovinylidene-5-phenyl-1,3,5-dithiazin-6-one dicarbamoylcyanovinylidene Dimercaptan potassium salt-water salt 11.7 g (0.05 M) was dissolved in 100 ml of water. With stirring at room temperature, a solution of 10.3 g (0.05 M) of N-chloromethyl-N-phenylcarbamoyl chloride and 1 g of tetranormabutylammonium bromide in 100 ml of toluene is added dropwise over 30 minutes. After stirring for 3 hours at room temperature, the precipitated crystals are separated by filtration, washed with water and recrystallized from ethanol to give the desired compound (compound
12) is obtained. Yield 9.3 g Synthesis Example 3 2-Dicyanovinylidene-4-phenyl-5-phenyl
1,3,5-Dithiazin-6-one Dicarbamoylcyanovinylidene Dimercaptan potassium salt hydrate 4.7 g (0.03 M) was suspended in acetone 100 ml and stirred at 40 ° C. with N- (1-chloro- 1
A solution of 8.43 g (0.03 M) of -phenyl) methyl-N-phenylcarbamoyl chloride in 50 ml of acetone was added dropwise over 30 minutes. After dropping, the mixture is stirred at 40 ° C. for 2 hours, the solvent is distilled off under reduced pressure, and cold water is added to the residue to crystallize. Recrystallization from methanol gives the desired product. (Compound 16) Yield 2.8 g Synthesis Example 4 2-Dicyanovinylidene-5-methyl-1,3,5-dithiazin-6-one dicarbamoylcyanovinylidene dimercaptan potassium salt-hydrate 23.4 g (0.1 M) Suspended in 150 ml of ethanol and stirred at room temperature with N-chloromethyl-N
-Methylcarbamoyl chloride 17.8g (0.125M) is added dropwise over 30 minutes. The mixture is stirred at room temperature for 3 hours, the solvent is distilled off under reduced pressure, and cold water is added to the residue to crystallize. The desired product is obtained by suctioning the crystals and recrystallizing from ethanol (Compound 1) Yield 14.5 g. The compounds of the present invention are effective in controlling diseases of a wide range of agricultural and horticultural crops, and the main ones are as follows. The following are listed.

Paddy rice blast, white leaf blight, sesame leaf blight; wheat spot disease, powdery mildew disease; potato blast disease, summer plague disease; soybean downy mildew disease, spot disease disease, brown spot disease; tobacco red spot disease, wildfire disease, plague disease; tea Red burn disease, rice blast disease, rice blast disease, anthracnose disease, ring spot disease; beet downy mildew disease, brown spot disease, seedling wilt disease; vegetable tomato spot bacterial disease, epidemic disease, gray mold disease, leaf mold disease, wilt Disease, seedling blight, ring spot disease; cucumber downy mildew, gray blight, gray mold, scab, seedling blight, anthracnose, vine wilt vine split, powdery mildew; (radish) black Rot, soft rot, downy mildew, chlorosis, kanran black spot; onion soft rot, downy mildew, gray rot, rust; lettuce downy mildew, soft rot; fruit citrus gray mold, canker , Black spot disease, Scab disease; Apple monili disease, scab, spotted leaf spot, powdery mildew; Oyster, gray mold disease, lobster leaf spot, charcoal Soybean disease, Horn blotch leaf spot; Pear Red spot disease, Black spot disease, Black spot disease; Peach ash spot disease, Black spot disease, Fuomopress rot disease, Bacterial boring disease; Grape downy mildew disease, Black wilt disease, Gray mold disease, Rust disease , Powdery mildew, late rot, etc.

The compounds of the present invention are used as agricultural and horticultural fungicides as described above, but they are generally used in powders, granules, wettable powders, emulsions, oils and other agrochemical formulations as they are or as a mixture with carriers (diluents) Used as an agent. In this case, a spreading agent, an emulsifying agent, a wetting agent, a fixing agent, etc. are appropriately used, if necessary, and can be used in combination with other kinds of fungicides, insecticides, herbicides, fertilizers and the like.

Example 1 Dust powder Compound in the table 3 parts Clay 40 parts Talc 57 parts Example 2 Wettable powder Compound in the table 75 parts Polyoxyethylene alkyl allyl ether 9 parts White carbon 16 parts There is no necessarily limitation on the amount of spraying. However, when it is usually applied to the field where the crop grows, the active ingredient compound (A.
I.) is 50 to 1,000 g / 10a, and when applied in soil, about 2 to 8 kgA.I./10a is suitable. Of course, this is one guideline, and may be appropriately adjusted as necessary in consideration of factors such as the type of crop, the type of disease and the degree of damage, the time, the weather, the dosage form of the drug, and the like.

Hereinafter, typical test examples will be shown in order to specifically describe the effects of the compound of the present invention. However, it goes without saying that these are merely examples and the application examples of the present invention are not limited to these.

Test Example-1 Antibacterial activity test against plant disease-causing bacteria <Test method> Conidia of plant disease-causing bacteria cultured in a predetermined medium are uniformly mixed with PSA medium, and a certain amount is poured into a predetermined container to form a uniform plate. . After solidification, a fixed amount of a certain amount of the drug is absorbed and air-dried, and a diameter of an inhibition circle formed after 48 hours of culture is measured by placing an 8 mm diameter paper.

However, the number of stations is two.

PO: Rice blast fungus XC: Citrus canker disease DC: Citrus sunspot FO: Cucumber wilt disease AK: Pear black spot fungus Cl: Citrus anthracnose BC: Vegetable gray mold fungus Test example-2 against pear black spot fungus Spore germination inhibition test <Test method> Alternaria Kikuchian cultured in apricot medium for 7-10 days
Mix the conidia of a and the drug solution, and use about 100 times a microscope for 1 field of view.
Adjust so that there are 20 pieces.

0.02 ml of this mixed suspension was dropped on a slide glass,
After keeping at a temperature of 27 ° C and a humidity of 100% for 20 hours, it is examined under a microscope and examined for spore germination.

Repeat two times for each, and examine the degree of germination of about 200 spores.

Test Example-3 Pear black spot disease efficacy test <Test method> 20 ml of a drug solution diluted to a predetermined concentration was spray-sprayed on developed leaves of pear (variety: twentieth century) per five leaves and air-dried indoors. After air-drying, conidia of Alternaria Kikuchiana cultivated in apricot medium were spray-inoculated, and immediately allowed to stand for 3 days at 25 ° C. and 100% humidity, and the diseased area was examined 3 days later.

However, the number of stations is 5.

Test Example-4 Spore germination inhibition test against black spotted citrus fungus <Test method> Conidia of Diaporthe citri cultivated on citrus dead branches are mixed with a drug solution, and the number is adjusted to about 20 per 1 field of view with a microscope 100 times.

0.02 ml of this mixed suspension was dropped on a slide glass,
After keeping the temperature at 27 ° C and the humidity at 100% for 20 hours, the cells are inspected for spore germination.

Repeat two times for each, and examine the degree of germination of about 200 spores.

Test Example-5 Citrus black spot disease efficacy test <Test method> At the time of developing new shoots of potted mandarin orange (variety: summer citrus), a sufficient amount of a chemical solution diluted to a predetermined concentration was sprayed and then air-dried in a greenhouse. Immediately after spray-inoculation with conidia of Diaporthe citri cultivated on mandarin orange branches, the temperature was 23 ° C and the humidity was 100%.
Kept in the dark for 2 days. Two days later, it was left in the greenhouse, and 30 days after the inoculation, the degree of disease onset was investigated.

However, the number of stations is three.

Test Example-6 Citrus canker disease, efficacy test <Test method> At the time of developing a new shoot of a potted mandarin orange (variety: summer citrus), a sufficient amount of a chemical solution diluted to a predetermined concentration was sprayed and then air-dried in a greenhouse. Xanthomonas citri cultured on mandarin orange branches
Immediately after spray inoculating the suspension of
% Darkness for 2 days. Leave it in the greenhouse two days later,
The degree of disease onset was investigated 30 days after the inoculation.

However, the number of stations is three.

Test Example-7 Cucumber seedling wilting efficacy test <Test method> Soil artificially contaminated with the Pythium aphanidermatum of cucumber seedling wilt is filled in a clay pot with a diameter of 15 cm. Cucumber seeds pre-germinated on the surface (variety: Sagamihanjiro)
After seeding 20 seeds per pot, cover the soil with contaminated soil and immediately pour 3 ml / m ^{2 of} a chemical solution diluted to a predetermined concentration uniformly on the surface. After irrigation, it was lightly watered and left in the greenhouse.
During the test, appropriate irrigation was performed, and 14 days after the treatment, the germination number and the inverted number were examined, and the control value was calculated as follows.

However, the number of stations is 5 stations. Test Example-8 Radish Yellows Efficacy Test <Test Method> Soil artificially contaminated with thick film spores of radish yellow rot fungus (Fusarium oxysporum f.raphani) is filled in a clay pot with a diameter of 15 cm. 10 seeds of radish seeds (variety: Aojumiya Shige) that have been germinated on the surface are sown per pot and covered with contaminated soil.
Immediately, a chemical solution diluted to a predetermined concentration is uniformly poured onto the surface, and then lightly watered. Then, the pots are left in the greenhouse and watered appropriately.

After 60 days of treatment, the presence / absence of disease will be investigated according to the following criteria.

However, the number of stations is 5.

Test Example-9 Rice blast efficacy test In a three-leaf stage of potted rice (variety: ten stones), 200 l / 10a of a drug solution having a predetermined concentration is sprayed and sprayed. Microscopic examination of conidia of rice blast fungus (Pyricularia oryzae) cultivated after air-drying
The suspension was inoculated by spraying with a suspension which was adjusted to 40 per 100-fold visual field.

Immediately after inoculation, 48 in dark conditions with temperature 23 ° C and humidity 100%.
After keeping it for a while, it was left in a greenhouse, and 10 days after the inoculation, the disease degree and degree were examined according to the following criteria, and the disease degree was calculated.

However, the number of stations is three.

Claims (2)

[Claims] 1. A general formula (However, R ₁ : C _{1 to} C ₆ alkyl, cycloalkyl, and aryl and phenyl groups (however, the phenyl group may be substituted with C ₁ ), R ₂ : H and C _{1 to} C ₆ alkyl, 2-dicyanovinylidene-1,3,5-dithiazin-6-one derivative represented by a cycloalkyl group and a phenyl group. 2. General formula (However, R ₁ : C _{1 to} C ₆ alkyl, cycloalkyl, and aryl and phenyl groups (however, the phenyl group may be substituted with C ₁ ), R ₂ : H and C _{1 to} C ₆ alkyl, And a 2-dicyanovinylidene-1,3,5-dithiazin-6-one derivative represented by the formula (1), which represents a cycloalkyl group and a phenyl group.) As an active ingredient.