JPS606688A - Imidazopyrazole derivative and agricultural and horicultural fungicide - Google Patents

Abstract

NEW MATERIAL:A compound shown by the formula I (R1 is H, halogen, lower alkyl, lower alkoxy, or halogenoalkoxy; R2 is H, or chlorine). EXAMPLE:2-t-5-(3,5-Dichlorophenyl)imidazo[1,5-b]pyrazole 4,6-dione. USE:Agricultural and horticultural fungicide. PREPARATION:For example, a compound [e.g., 5-t-butyl-N-(3,5-dichlorophenyl)-3- pyrazolecarbonamide, etc.] shown by the formula II is reacted with COCl2(or dimer) usually in a solvent such as ethyl acetate, etc. preferably at 0-40 deg.C for 7-8hr.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an imidazopyrazole derivative represented by the following general formula and a fungicide containing the compound as an active ingredient.

(However, R1: hydrogen, halogen, lower alkyl, lower alkoxy, or halogenoalkoxy, R2: hydrogen or chlorine) The compound of the present invention can be produced, for example, by a general production method shown by the following formula.

When carrying out the above reaction, it is desirable to use a suitable solvent. As the solvent, various solvents can be used, such as aromatic hydrocarbons such as benzene, toluene, and xylene, chlorinated alkanes such as chloroform and carbon tetrachloride, and esters such as ethyl acetate.

The reaction temperature is preferably in the range of 06 to 40°C. After the reaction, the solvent is poured into ice, neutralized with sodium bicarbonate, etc., and the organic solvent is separated and concentrated under reduced pressure to achieve the desired purpose. If necessary, it can be reconsolidated with an organic solvent such as benzene.

Typical examples will be shown below to further explain the synthesis method.

(Synthesis Example 1) 3.5 g of 5-tert-butyl-N-(3,5-dichlorophenyl)-3-pyrazole carbonamide was dissolved in 150 ml of ethyl acetate, and while stirring at room temperature, trichloromethylchloro Drop in the formate tomb.

After the dropwise addition, stirring was continued for 30 minutes, then heated to 40°C on a water bath and reacted for 7 hours.

After cooling, the reaction solution is poured into ice, and sodium hydrogen carbonate is added to neutralize it. After separating the organic layer, it is dried over anhydrous sodium sulfate and concentrated. When the fluorine residue is reconsolidated with benzenehexane, 3.2 g of 2-tert-5-(3,5-dichlorophenyl)imidazo(1,5-b)pyrazole 4,6-dione at m@p 128130°C becomes white. Obtained as crystals.

(Synthesis Example 2) 4 g of 5-tera-butyl-N-phenyl-3-pyrazole carbonamide is dissolved in 100 ml of ethyl acetate, and 10 ml of trichloromethyl chloroformate is added dropwise with stirring at room temperature. After the dropwise addition, stirring was continued at room temperature for another 30 minutes, and the mixture was heated and stirred on a 40°C water bath for 8 hours. Allow to cool, pour the reaction solution into ice, and neutralize by adding powdered sodium hydrogen carbonate. The organic layer is separated, dried over anhydrous sodium sulfate, and the solvent is distilled off. n- in the residue
When hexane is added and crystallized, pure 2-tert-butyl-5-phenylimidazo[1,5-b]
3.9 g of pyrazole 4,6-dione are obtained.

NMR (CDC/3) ((Hereinafter in the margin) 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.

Dry rice Rice blast, sesame leaf root disease Wheat spot, powdery mildew, rust, potato Phytophthora, summer blight, soybean Downy mildew, spot, brown spot, rust Tobacco Red star blight, Phytophthora rust Blast, blast, anthracnose, ring spot beet downy mildew, brown spot vegetable tomato late blight, gray mold, leaf mold, ring spot cucumber downy mildew, gray blight, gray mold, black spot Diseases, anthracnose, vine blight, powdery mildew downy mildew, black spot onion downy mildew, gray rot, rust Apples Monilia disease, scabrous blight, leaf spot blight, powdery mildew Botrytis blight, Nitten leaf blight, lint blight, inner leaf fall blight, sclerosis, sclerotia, powdery mildew The compounds of the present invention As mentioned above, it is used as a fungicide for agricultural and horticultural purposes, but it can also be used as it is or mixed with a carrier (diluent) as a powder, granule, wettable powder, emulsion, oil, or other suitable agent commonly used in i-medicinal preparations. It will be done. In this case, a spreading agent, an emulsifying agent, a fixing agent, etc. are used as necessary, and it can also be used in combination or mixed with other types of fungicides, insecticides, herbicides, fertilizers, etc.

Example 1 Powder Compounds in the list 3 parts Clay 40 parts Talc 57 parts Example 2 Wettable powder Compounds in the list 75 parts White carbon 16 parts There is no necessarily limit to the amount of spraying, but it is usually sprayed on fields where crops are growing. In some cases, the active ingredient compound (A,
1. ) as 50 to 1,000 g/10a″ii,
2-8 kg A, L/10 when applied in soil
A value of about a is appropriate. Of course, this is just a guideline, and it may be adjusted as necessary, taking into consideration factors such as the type of crop, the type of disease, the degree of damage5, the season, the weather, and the dosage form of the drug.

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

Test Example 1 Rice Blast Efficacy Test <Test Method> An amount equivalent to 2001710a of a chemical solution at a predetermined concentration is sprayed onto potted rice plants (cultivar Futagokata) at the 3-leaf stage. Rice blast fungus (Pyricularia ory) cultured after air drying
A suspension of 40 conidia of Ll) was inoculated per field of view under a microscope at a magnification of 100.

Immediately after inoculation, the seeds were kept under dark conditions at a temperature of 23° C. and a humidity of 100 c$ 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.

N: Number of leaves investigated <Test results> Test example 2 Citrus black spot efficacy test <Test method> A chemical solution diluted to a prescribed concentration on strongly pruned potted citrus (variety: Seedling metamorphosis). After spraying an amount of 50Ai/10a, it was air-dried in a greenhouse.

After air-drying, the citrus black spot fungus (Diaporthe citri), which had been cultured in advance on dead citrus branches, was spray-inoculated and immediately placed in a thermostatic chamber at a temperature of 23°C and a humidity of 100% for 2 hours.
After keeping it for several days, it was left in a greenhouse. Thirty days after inoculation, the onset of disease was investigated as follows.

N: Number of leaves investigated <Test results> Test example 3 Pear black spot disease efficacy test <Test method> As a development plan for pears (variety 220th century), leaf liquid diluted to a specified concentration was sprayed at 20 rall per 5 leaves. and air-dried indoors.

Alterllaria cultured in apricot medium after air drying
Conidia of K1ku-0I-9-I chsan were spray-inoculated and immediately left to stand under conditions of 25° C. and 100% humidity for 3 days, and the diseased area was examined after 3 days.

However, the number of runs shall be 5.

<Test results> Test example: Spore germination inhibition test against pear spot fungus <Test method> Alterna- cultured on apricot medium for 7 to 10 days
The conidia of Ia Kikuchiana and the drug solution are mixed and adjusted so that the number of conidia is about 20 per field of view under a microscope with a magnification of 100.

A drop of 0.02 ml of this mixed suspension is placed on a slide glass, kept at a temperature of 27° C. and a humidity of 100° C. for 20 hours, and examined under a microscope to check for spore germination.

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

Claims (1)

[Scope of Claims] An imidazopyrazole derivative represented by (R1: hydrogen, halogen, lower alkyl, lower alkoxy, or halogenoalkoxy, R2: hydrogen or chlorine). An agricultural and horticultural fungicide containing as an active ingredient an imidazopyrazole derivative represented by (R1: hydrogen, ) rogene, lower alkyl, lower alkoxy or halogenoalkoxy, R2: hydrogen or chlorine.