JPS604164A - Cyanodithioacetate derivative and agricultural and horticultural fungicide - Google Patents

Abstract

NEW MATERIAL:The compound of formula (R1 is H or Cl; R2 is alkyl, benzyl, alkylcarbamoyl, alkoxycarbonyl, etc.). EXAMPLE:S-(p-Chlolo-2-cyano-1-methylthio)styryl(N-methyl)thiocarbamate. USE:An agricultural and horticultural fungicide. Effective to rice blast, leaf spot of beans, scab and powdery mildew of fruits, downey mildew, gray mold, etc. of vegetables, etc. PREPARATION:The compound of formula is produced by reacting methyl-2-(substituted phenyl)-2-cyanodithioacetate with a reaction reagent corresponding to the objective compound, e.g. isocyanate, acid chloride, chloroformate, carbamoyl chloride, diethylthiophosphoric acid chloride, etc. in a solvent such as ethanol, tetrahydrofuran, etc. in the presence of a base (e.g. triethylamine) at room temperature or under heating.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cyanodithioacetate derivative having the following general formula and an agricultural and horticultural fungicide containing the compound as an active ingredient.

Hydrogen or chlorine atom, R2 is an alkyl group (which may contain an oxo group), a benzyl group, an alkylcarbamoyl group (which may contain a cyclized alkyl group), an alkyl group, an alkoxycarbonyl group, or a diethoxythiophosphoryl group. represents a group. ) Representative examples of the compounds represented by the above general formula are shown in Table 1. In addition, the display of the compound is expressed by the substituents R, FL2 in the above general formula, and in the column of physical properties, "NMR" indicates the nuclear magnetic resonance spectrum, and the number in parentheses indicates the solvent, and the display method is the conventional method. I followed□
J It is an infrared absorption spectrum, and the measurement method is shown in parentheses (7, only the wave number of the main purple heater is shown.

To obtain the compounds of the invention, for example, methyl-2-(f
A reaction reagent corresponding to the desired compound such as fi-substituted phenyl)-2-cyanodithioacetate and incyanate, acid chloride, chloroformate, carbamoyl chloride, diethylthiophosphoric acid chloride, etc., is mixed with an appropriate reaction agent such as ethanol, tetrahydrofuran, benzene, etc. in a solvent,
If necessary, it can be synthesized by a method of reacting for one hour to several days at room temperature or with heating (in the presence of an appropriate base such as triethylamine, sodium alcoholade, potassium carbonate, etc.).

Typical synthesis examples will be shown below and explained in more detail.

Synthesis Example S-Synthesis of (parachloro-2-cyano-1-methylthio)styryl (N-methyl)thiocarbamate.

Dissolve 3.6 g of methyl 2-(parachlorophenyl)-2-cyanodithioacetate in cyclohexane and benzene, add 10 g of methyl isocyanate and 3 drops of triethylamine, and let stand at room temperature for 4 days. Decant the solvent and
The nine precipitated crystals were collected and washed with benzene to obtain 3 g of transparent crystals of the desired product.

The compounds of the present invention are effective in controlling a wide range of diseases of agricultural and horticultural crops, and the main ones include the following.

Paddy rice: potato leaf blight, sesame leaf blight; beans: brown spot; fruit trees: apples: black spot, monilia disease, powdery mildew; citrus: black spot, scab; pear: red star, scab; peach: thin leaf, black star, scab; brown Anthrax, mochi, rope blast; persimmon anthracnose, defoliation, powdery mildew; vegetables cucumber downy mildew, carbon, black star, gray mold, powdery mildew, vine warp; tomato blight, leaf mold, gray mold; radish Yellow blight; beet brown spot; potato late blight; melon anthracnose, vine blight, etc.

There are no restrictions on the amount of spraying, but when spraying on fields where crops are grown, the amount of active ingredient compounds (A,
1. ) as 50 to 1000V Oa, and 2 to 8 kgA when applied to soil; 1. /10a is appropriate. Of course, this is just a guideline, and it may be adjusted as necessary, taking into account factors such as the type of crop, the type and degree of damage, the season, the weather, and the dosage form of the drug.

As mentioned above, the compound of the present invention is used as a fungicide for agriculture and horticulture, but it is also commonly used as it is or mixed with a carrier (diluent) in powders, granules, wettable powders, emulsions, oil skewers, and other agrochemical preparations. It is used as an appropriate agent. In this case, spreading agents, emulsifiers, wetting agents, fixing agents, etc. are used as appropriate, and other fungicides, insecticides,
It can also be used or mixed with herbicides, fertilizers, etc.

Example 1 Powder Compounds listed in the table as active ingredients: 3 parts Clay 40 parts Talc 57 parts Example 2 Wettable powder Compounds listed in the table 75 parts Polyoxyethylene alkyl allyl ether 9 parts White carbon 16 parts Below, the effects of the compounds of the present invention were evaluated. For concrete explanation, typical test examples are shown. However, these are merely examples, and it goes without saying that the application examples of the present invention are not limited to these.

Test Example 1 Rice Blast Efficacy Test <Method> An amount equivalent to 2001J/102 of a predetermined concentration of a chemical solution is sprayed onto potted rice plants (variety: Doishi) at the 3-leaf stage. Rice blast fungus (Pyricularia or
yzae) conidia at 40 per field of view under a microscope at 100x magnification.
The suspension was prepared by spray inoculation.

Immediately after inoculation, the plants were kept under dark conditions at a temperature of 23° C. and 100% humidity for 48 hours, and then left in a greenhouse. Ten days after inoculation, the degree of disease onset was determined using the following criteria. However, the number of runs shall be three.

f: Index of disease severity N: Number of investigated leaves Number of lesions per leaf 00 1 2 2-5 3 6-10 4 To 11 Test Example 2 Efficacy test for thick root yellowing disease <Method> Radish Sanga fungus ( Fusariurn oxysqoru
m1. Clay pots with a diameter of 15 Crn are filled with soil artificially contaminated with chlamydospores of A. raptlani.

10 seeds of radish (variety: Aokubi Miyaju) that have been germinated in advance are sown on the surface, and the soil is covered with contaminated soil. Immediately, after uniformly irrigating the surface with a chemical solution diluted to a predetermined concentration,
Water lightly. The pots are then left in the greenhouse and watered accordingly.

60 days after treatment, the presence/absence and severity of disease onset is investigated according to the following criteria.

However, the number of rows is 5.Test Example 3 Citrus black spot efficacy test <Method> When the new shoots of potted mandarin oranges (variety: Natsukan) develop, a sufficient amount of the chemical solution diluted to the specified concentration is sprayed and then air-dried in a greenhouse. did. Diaportbe c cultured on mandarin orange branches
Immediately after spray inoculation with conidia of T. itri, temperature Z3
'C, kept in darkness with 100% humidity for 2 days. Two days later, the plants were left in a greenhouse, and the degree of disease onset was investigated 30 days after inoculation.

However, the number of runs shall be three.

n: Number of leaves by severity of disease N: Number of leaves investigated 0 1 1-3 2 4-6 3 7-10 April Results> Test Example 4 Method for spore germination inhibition test against citrus black spot fungus> On citrus dead branches Cultured Diaporthe citr
Mix the conidia of conidia i and the drug solution, and adjust to about 20 conidia per 1 field of view of a 100x microscope.

Place 0.02 ml of this mixed suspension on a slide glass.
After dropping the solution and keeping it at a temperature of 27° C. and a humidity of 100° C. for 20 hours, it is examined for spore germination by microscopic examination.

Both were repeated twice, and the presence or absence of germination of approximately 200 spores was determined.
Check the degree.

<result>

Claims (1)

[Claims] is a hydrogen or chlorine atom, d: an alkyl group (which may include an oxo group), a benzyl group, an alkylcarbamoyl group (which may include a cyclized alkyl group), an alkyl group, an alkoxycarbonyl group. or diethoxythiophosphoryl group. ) Cyanodithioacetate derivative represented by. is a hydrogen or chlorine atom, 几 is an alkyl group (which may contain an oxo group), a benzyl group, an alkylcarbamoyl group (which may contain a cyclized alkyl group), an alkyl group, an alkoxycarbonyl group, or a diethoxythiophyl group Represents an osphoryl group. ) An agricultural and horticultural fungicide containing a cyanodithioacetate derivative represented by the following as an active ingredient.