JPS606660A - 2,3-dimethyl-n-phenylmaleimide derivative and agricultural and horticultural fungicide - Google Patents

Abstract

NEW MATERIAL:2,3-Dimethyl-N-phenylmaleimide of formula I (R1 is difluoromethoxy; R2 and R3 are H, alkyl, difluoromethoxy or halogen). EXAMPLE:N-(3-Chloro-4-difluoromethoxyphenyl)-2,3-dimethylmaleimide. USE:An agricultural and horticultural fungicide having low toxicity and strong fungicidal activity. Effective for the control of a wide variety of the blights of agricultural and horticultural plants such as rice blast, Fusarium yellow of radish, melanose of citrus fruit, black spot of pear, etc. PREPARATION:The compound of formula I can be prepared in high yield, by reacting the 2,3-dimethylmaleic anhydride of formula II with the nucleus-substituted aniline of formula III in a solvent such as toluene preferably at 40- 120 deg.C for 1-3hr.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a novel 2,3-dimethyl-N-71-nylmaleimide having the following general formula and an agricultural fungicide characterized by containing this compound as an active ingredient. It is related to.

(In the formula, R+ is a dinorormeth4 di group, R2, R3
[Represents hydrogen, an alkyl group, a difluoryl-1-oxy group, or a halogen. ) Among the 2,3-dimethyl-N-phenylmaleimide derivatives, there are many known compounds, but the compounds of the present invention are new compounds, have low toxicity, and are completely different from other related compounds. It was found to have a powerful and extremely broad-spectrum bactericidal efficacy.

The compound of the present invention can be produced, for example, by the method shown by the following formula. However, in the following formula, each substituent is as described above.

When carrying out the above reaction, it is desirable to use a suitable solvent. Examples of solvents include aromatic hydrocarbons such as benzene, chitoluene, and ticilene, hydrogenated alkanes such as chloroform and carbon tetrachloride, ketones such as acetone and methyl ethyl ketone, and lower fatty acids such as acetic acid.
Various other solvents such as diAxane can also be used.

The amount of the nuclear-substituted aniline may be used in an equimolar amount to 2,3-dimethylphosphoryne'M anhydride, but it may be adjusted slightly if necessary. The reaction temperature is preferably 40 to 1
Selected from a range of 20°C. The reaction time may generally be 1 to 3 hours. After the reaction, if the solvent used is water-soluble,
Pour reactants into water. Alternatively, when the solvent is insoluble in water, crystals are precipitated by a method such as reducing and distilling off the solvent. If the crude crystals thus obtained are recrystallized from an organic solvent such as acetonyl-1-lyl, the desired compound can be obtained in good yield.

Next, the method of the present invention will be further demonstrated on the hY fence using a synthetic example.

Synthesis Example 1 N-(3-chloro-4-difuralmethoxylinyl)
-Production of 2,3-dimethylmaleimide.

2.2 g (0.1 mol) of 2.3-dimethylmaleic anhydride is dissolved in 1 to 200 d of toluene and heated to reflux with stirring. Add 1 drop of 1-toluene 507 solution of 3-chloro-4-difuralmethoxyaniline 19.3+I+ to it.
After dropping, heating is continued until no water is distilled off by azeotropy. After reacting for another 30 minutes, the solvent is distilled off under reduced pressure. The precipitated crystals are recrystallized from ethanol with a melting point of 128. ~128.5'N-(3-ri['-4-difuralmethoxyphenyl)-2,3
-Dimethylmaleimide 28.60 are obtained as white crystals (yield 97%).

Various compounds having formula (I) could be produced by the same method as in Example 1.

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

Paddy rice, blast disease; fruit trees, rot, black spot 1, scab disease: apples, black star, spotted defoliation, monilia disease; pears, black star, black spot, red star disease; peach, black star, gray star disease: grapes, , late rot;
Black pox disease: Vegetables, gray mold, sclerotia, seedling blight; cucumbers,
Downy mildew, anthracnose, vine splitting, powdery mildew: Melon, vine blight, Nidomad, Phytophthora, ring spot: Phytophthora, Phytophthora; beet, brown spot, etc.

There are no restrictions on spraying m, but when spraying on fields where crops are usually grown, active ingredient compounds (A,
I) Toshite 50-1000g/10a, or 2-8kgA, I when applied in soil.

/10a is appropriate. Of course, this is only a guideline, and depends on the type of crop, type of disease, degree of damage, timing, etc.
Factors such as the weather and the dosage form of the drug will be taken into consideration (adjustments will be made as necessary).

As mentioned above, the compound of the present invention is used as a fungicide for agricultural purposes, but it is also used sparingly in powders, granules, wettable powders, emulsions, oils, and other agrochemical preparations, either as is or mixed with a carrier (diluent). -C is used as a suitable agent. In this case, spreading agents, emulsifiers, wetting agents, fixing agents, etc. are used as necessary, and they may also be mixed with other types of fungicides, insecticides, herbicides, fertilizers, etc. can.

Example 1 Powder Compounds in the table 3 parts Clay 40 parts Talc 51 parts Example 2 Wettable powder Compounds in the table 75 parts Polyoxyethylene noryl ether 9 parts White 1-carbon 16 parts or less, the invention Representative test examples are shown to specifically explain the effects of the compounds. However, these are just examples, and it goes without saying that the application examples of the present invention are not limited to these.

Test Example - 1 or 8 Black Spot Disease Control Test Method Immediately after the new leaves of a 4-fi pot of citrus +'l'+ (product: Iris Unshu) develop, a hydrating powder of the compound of the present invention is applied to a predetermined depth (
diluted to 500ppm), 300su/' per pot
After 1 month, a spore suspension of citrus black spot fungus cultured on dead mandarin branches was spray inoculated.

After inoculation, the plants were kept in a cave at 25°C for 2 days, and then left in a greenhouse. Thirty days after inoculation, the disease development was investigated as follows.

Index 01 2 3 4 Test Example 2 Human root yellowing disease control test (F USarlLIm OXySIIOrUm f
, rallllallf ) <Test method> Contaminated soil was packed in a 9 cm pot, and 10 seeds of M-dashishi lJ human root (variety: Aokubi Miyaju) were sown per pot. ? 5 Covered with dyed soil. After lightly watering, a predetermined amount of a chemical solution was injected at 3 liters per d. The plants were left in an irrigation greenhouse, watered appropriately, and 40 days after treatment, they were examined to see if they had developed any disease.

However, the number of runs shall be three.

4 500 30 0 100 - Test Example - 33 Test method for controlling rice blast
The seeds were sprayed at a rate of 200 pieces per acre and air-dried in a greenhouse. After air-drying, the cultured rice was infected with rice blast fungus (pyricul).
aria oryzae) spore suspension (i Microscope 10
40 seeds per field) was spray inoculated, and the temperature was immediately raised to 23°C.
J3 was kept under dark conditions at 100% humidity for 48 hours.

After being exposed to the sun, the specimens were left on a log guide and examined after 10 treatments.

N: Number of leaves investigated 4 11- Test Example 4 Spore germination inhibition test method for citrus black spot fungus J8 was fed to dead branches of citrus l) 1aportl+e
Mix the conidia of cit4 and the drug solution and adjust to about 20 conidia per field using a 100x microscope.

Place 0.02#ll of this mixed suspension on a slide glass.
! After dropping the mixture and keeping it at a temperature of 27°C and a humidity of 100% for 20 hours, the right ya of C spores was examined by microscopic examination.

Each test was repeated twice, and the degree of germination of approximately 200 spores was examined.

Results Test Example-5 Spore germination inhibition test method for pear black spot fungus ΔIternari cultured on apricot garden for 7 to 10 days
aK 1kuchiana conidia and a drug solution were mixed,
Adjust so that there are about 20 pieces per field of view under a 100x microscope.

0.02 d of this mixed suspension is dropped onto a slide glass, maintained at a temperature of 27° C. and a humidity of 100% for 20 hours, and examined under a microscope to check for spore germination.

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

Claims (1)

[Claims] 1) In the general formula hydrogen and alkyl represent halogen. ) 2,3-dimedyru N-71 nilmaleimide. 2) General formula (wherein R1 is a difluoromethoxy group or R21R3
does not represent hydrogen, alkyl groups, difluoromethoxy groups, or halogens. ) with 2,3-dimethyl-N-
An agricultural and horticultural fungicide containing phenylmaleimide as an active ingredient.