JPH0717623B2 - 1.3.5-Dithiazin-6-one derivative and agricultural / horticultural fungicide - Google Patents

Description

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

(However, R ₁ : H, an alkyl or halogen atom of C _{1 to} C ₄ ,
R _2: represents an alkyl of C ₁ -C _6, a cyclohexyl alkenyl or phenyl. ) Typical examples of the compounds represented by the above general formula of the present invention include those shown in Table 1.

The dithiazine derivative (I) of the present invention is, for example, a sodium salt of benzenesulfonyliminocarbodithioate and N-chloromethyl-N-alkyl (or aryl).
It can be produced by reacting with carbamoyl chloride. In this reaction, the both may be mixed in approximately equimolar amounts, or, in some cases, either one may be added in a slightly larger amount.

In order to allow the reaction to proceed smoothly, it is preferably carried out in an organic solvent, and in this case, two solvents, acetone, ketones such as methyl ethyl ketone and aromatic hydrocarbons such as benzenetoluene, and water are used. It is preferable to use a mixed solvent of.

This reaction is usually preferably carried out at 30 to 100 ° C, and in some cases, the reaction may be carried out near the reflux temperature of the solvent.

The reaction time ranges from several hours to several tens of hours.

The presence of a catalyst is not essential for this reaction, but when it is carried out in a mixed solvent of an aromatic hydrocarbon and water, tetra-n-butylammonium bromide, 18-crown-6 or the like may be used as a phase transfer catalyst. .

After completion of the reaction, in the case of a reaction solvent which can be mixed with water, water is added and the obtained crude product is recrystallized or purified by column chromatography. In the case of water and aromatic hydrocarbons,
The organic solvent was separated, washed with saturated saline, then dehydrated,
The solvent can be distilled off.

The crude product is purified by recrystallization or column chromatography.

A typical synthesis example will be shown below and will be described more specifically.

Synthesis Example 1 5-Aryl-2-benzenesulfonylimino-1.3.5-dithiazin-6-one 13.9 g (0.05M) of disodium salt of benzenesulfonyliminocarbodithioate was suspended in 100 ml of methyl ethyl ketone and stirred at room temperature. 20 ml of methyl ethyl ketone containing 7.6 g (0.045 M) of N-aryl-N-chloromethylcarbamoyl chloride are added dropwise.

Stir at room temperature for 1 hour, then stir for 6 hours while refluxing the solvent. After cooling to room temperature, the solvent is distilled off under reduced pressure and the residue is extracted with dichloromethane. Dichloromethane is washed twice with saturated brine and dried over anhydrous sodium sulfate. The solvent was distilled off, and diethyl ether was added to the residue to crystallize. The crystals were separated and washed with a small amount of diethyl ether to obtain the desired product. Yield 4.6 g Synthesis Example 2 2- (p-chlorobenzenesulfonylimino) -5-phenyl-1.3.5-dithiazin-6-one p-chlorobenzenesulfonyliminocarbodithiolate disodium salt 15.6 g (0.05 M) in water 50 ml. While stirring at room temperature, 6.2 g (0.03 M) of N-chloromethyl-N-phenylcarbamoyl chloride and 0.5 g of tetra-n-butylammonium bromide in 100 ml of toluene were added dropwise. After the dropping, the solvent is stirred under reflux for 5 hours. After cooling to room temperature, the toluene layer is separated, washed twice with saturated saline and dried on anhydrous sodium sulfate.

The solvent is distilled off under reduced pressure and the residue is recrystallized from ethanol. Yield 5.1 g The compound of the present invention is effective for controlling diseases of a wide range of agricultural and horticultural crops, and the main ones thereof include the following.

Rice blast, sesame leaf blight Wheat spot disease Potato blight, summer blight Soybean downy mildew, spot disease, brown spot disease Tobacco red scab, epidemic brown tea anthracnose beet downy mildew, brown spot vegetable tomato blight, gray mold Disease, leaf mold, ring spot cucumber downy mildew, gray blight, gray mold scab, anthracnose, vine wilt citrus downy mildew, black spot (radish) onion downy mildew, gray rot Lettuce downy mildew Fruit tree Citrus Gray mold, Black spot, Scab Apple monili disease, Scab, Spotted leaf spot Oyster Gray mold, Enstar leaf spot, Anthracnose, Horn spot leaf spot None Black spot, Black spot Disease thigh ash, scab, phomopsis rot, downy mildew, gray mold, and late rot.

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 also be used in combination with other types of fungicides, insecticides, herbicides, fertilizers, etc. .

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 Polyfoxyethylene alkylallyl ether 9 parts White carbon 16 parts However, when 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 is appropriately adjusted as necessary in consideration of factors such as the type of crop, the type of disease and the extent 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 Spore germination inhibition test against citrus black spot fungus <Test method> Conidia of Diaporthe citri cultivated on citrus dead branches are mixed with a chemical 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 maintaining at a temperature of 27 ° C and a humidity of 100% for 20 hours, the specimen is examined for spore germination.

Each test is repeated twice, and the presence or absence of germination of about 200 spores is examined.

Test Example 2 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 pears (variety: 20th century) per 5 leaves, and air-dried indoors.

Alternaria Kikuchiana cultured in apricot medium after air drying
Was sprayed and inoculated immediately, and allowed to stand immediately under the conditions of 25 ° C. and 100% humidity for 3 days, and the diseased area was investigated 3 days later.

However, the number of stations is 5.

Test Example 3 Spore germination inhibition test against black spot disease fungus <Test method> Alternaria Kikuchi cultivated in apricot medium for 7 to 10 days
The conidia of ana and the drug solution are mixed, 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 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.

Claims (2)

[Claims] 1. A general formula (However, R ₁ : H, an alkyl or halogen atom of C _{1 to} C ₄ ,
R _2: represents an alkyl of C ₁ -C _6, a cyclohexyl alkenyl or phenyl. ) 2-Benzenesulfonylimino-1,3,5-dithiazin-6-one derivative represented by 2. General formula (However, R ₁ : H, an alkyl or halogen atom of C _{1 to} C ₄ ,
R _2: represents an alkyl of C ₁ -C _6, a cyclohexyl alkenyl or phenyl. ) An agricultural and horticultural fungicide containing the 2-benzenesulfonylimino-1,3,5-dithiazin-6-one derivative represented by the formula (1) as an active ingredient.