JPS5885872A - Dihalopyrazine derivative and agricultural and gardening fungicide - Google Patents

Abstract

NEW MATERIAL:A compound shown by the formulaI(X and Y are halogen; R<1> is H, 1-3C acyl, benzoyl, etc.; R<2> is lower alkyl or cycloalkyl; with the proviso that R<2> is not methyl when R<1> is H). EXAMPLE:Methyl-3-amino-5,6-dichloropyrazinecarboxylate. USE:An agricultural and gardening fungicide. Effective especially against downy mildew, powdery mildew and damping-off of cucumbers, scab of apples, blight of rice plants, tomato blights, etc. PROCESS:A compound shown by the formula II is halogenated with a chlorine gas, bromine gas, sulfinyl chloride, etc., to give a compound shown by the formulaI.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel compound and its use, and specifically relates to a compound of the general formula (wherein X and Y are halogen atoms, R1 is a hydrogen atom,
R2 represents a lower alkyl group or a cycloalkyl group; a C1 to S acyl group, a benzoyl group, or a benzoyl group mono- or di-substituted with a rogen atom, a nitro group, an alkoxy group, or a lower alkyl group; ) and agricultural and horticultural fungicides containing the compounds as active ingredients.

A large number of pesticides are used to control crop diseases during the cultivation of agricultural crops, but their v1 eradication efficacy may be insufficient or their use may be restricted due to the emergence of drug-resistant bacteria. There are many fungicides that cannot be said to be satisfactory because they may cause contamination of plants, or they may have a strong affinity for animals and fish11. do not have. Therefore, there is a strong demand for a drug that has fewer such drawbacks and can be used safely.

The present inventors conducted research on a large number of chemical compounds with the above-mentioned drawbacks in mind, and as a result, the group of compounds represented by the above general formula (1) exhibits excellent control effects against various plant diseases. After discovering this, they conducted further pharmaceutical research, completed the present invention, and now provide a novel fungicide for agricultural fields.

The O fungicide of the present invention exhibits control effects against a wide range of plant diseases, but is particularly effective against downy mildew, powdery mildew, Phytophthora blight, apple blight, rice blast, and tomato late blight. It has an excellent nine-effect relationship.

Among the metal compounds according to the present invention, IN is a hydrogen atom, and R
Compound proboscis where 1 is a methyl group, J-Msd-ch@Ken・
1066-71S (1967) and U.S. Patent λ! Although they are known as intermediates for pharmaceuticals, etc., in No. 684 and No. 11 Kame 063, their bactericidal activity has not been reported.

The compound of the present invention is produced by halogenating a compound represented by the general formula (wherein R1 and R2 are the same as above). As the halogenating agent, chlorine gas, bromine gas, sulfinyl chloride, etc. are used.

Next, production examples of the compounds of the present invention will be shown.

Production Example 1 Production of methyl 3-amino-5,6-cyclopyrazinecarpoxylate A 250mt solution of methyl 3-aminopyrazinecarboxylate 1αOf in acetonitrile was heated at 50 to 60% while adding chlorine 17f for 2 hours. Introduced. After the reaction, the precipitated crystals were separated and recrystallized from chloroform to obtain pale yellow methyl 3-amino-5,6-cyclopyrazinecarboxylate (11.2F).

Gas de 231-2° Yield 7f, 1 bag Production Example 2 Production of methyl 3-acetamido-5,6-cyclopyrazinecarboxylate Methyl 3-acetamido-5,6-cyclopyrazinecarboxylate 1
Chlorine was introduced into 2 tons of acetonitrile solution for 1 hour at 40°C. The acetonitrile was distilled off, and the residual liquid was recrystallized with a mixed solvent (ethyl acetate-n-hexane) to obtain white crystals of methyl 3-acedoardanedo & 6-cyclorubi 2-diycarboxylate α5t. Ta.

7F・115°-6° Yield 3391 Production Example 3 Production of methyl 3-penzoylamide 2-do-5,6-cyclolopidzinecarboxylate Methyl 3-penzoylamidobiradi 7carboxylate)
6. Dimethylformand α5 mt was added to a solution of 320 units of carbon tetrachloride, and chlorine was introduced for 3 hours while maintaining the temperature at about 60°C. Carbon tetrachloride was distilled off, and the residue was recrystallized from chloroform to obtain white crystals of methyl 3-bensyylamide-5,6-dithyaruvirazine carpoxylate 54f.

%ψ, 163-5 Yield 71.1 Production Example 4 Production of cyclohexyl 3-benzoylamidopyrazinecarboxylate Cyclohexyl 3-benzylamidopyrazinecarboxylate) Add dimethylformamide 0 to 25Wlt solution of 1.9 f carbon tetrachloride. .1 ml was added, and chlorine was introduced at about 60° C. for 1 hour. After distilling off carbon tetrachloride, the residue was purified by silica gel column chromatography (Wakogel C-200, developing solvent was chloroform:
cc74=1:2) to obtain 1.5 of white crystals of cyclohexyl 3-benzoylamide-56-cyclopyrazine carboxylate.

m no!・136-7° *Rate 65.11
Table G shows the compounds and physical constants according to the present invention.

The fungicide of the present invention can be used as a pure active ingredient compound, and for the purpose of use as an agricultural chemical, it can be used in the form of general agricultural products, such as wettable powders, granules, powders, and emulsions. It can also be used in the form of , water solvent, air sol, etc. As additives and carriers, when the purpose is a wUW agent, vegetable powder such as soybean flour and wheat flour, diatomaceous earth, apatite,
Fine mineral powders such as gypsum, talc, pyrophyllite, and clay are used. For liquid O-type formulations, use kerosene, mineral oil, petroleum, or turbent naphtha.

xylene, cyclohexane, cyclonon, dimethylformamide, dimethylsulfonate, alcohol,
Use acetone, water, etc. as a solvent. In these preparations, if necessary to obtain a uniform and stable form,
Surfactants can be added. The nine powders and emulsions obtained in this way are diluted with water to a predetermined concentration to form a suspension or emulsion, and the powders and granules are used as they are by spraying them on plants.

Next, some examples of compositions of the present invention are shown, but the additives and their addition ratios are not limited to these examples and can be varied over a wide range.

Example 1 Wettable powder compound 3 40 parts □ Diatom ± 53 parts Primary-r alcohol sulfate ester 4 parts Alkylnaphthalene sulfonic acid If 3 parts or more are mixed uniformly and pulverized finely, the active ingredient 40
% hydration agent.

Example 2 Emulsion compound 7 30 parts xylene 33 parts dimethylformide If 30 parts or more are mixed and dissolved, an emulsion with the active ingredient SOS is obtained.Example 3 Powder compound 9 10 partsMerck 89 parts or more If mixed well and finely ground, the active ingredient will be 10
- obtain a powder.

Next, some test examples regarding the efficacy of the fungicide of the present invention will be shown.

Test Example 1 Chieuribe and disease control test A chemical solution of a predetermined concentration of a wettable powder of the present compound was sprayed on seedlings of Chiecuri (cultivar "Satsukindori") grown for about 3 weeks, and after air-drying, the infected leaves of Chieuribe and disease were collected. Inoculated with sodium bicarbonate zoospore suspension, kept in an inoculation box at 25℃ and humidity of 100℃ for 2 days, then transferred to a greenhouse, and examined the degree of disease onset on each leaf 78 days after inoculation. The control value was calculated based on the following. The results are shown in Table 2.

Table 2 *Commercial agent "Dako Ale" (Tetrachloroisophthalene nitrile) 75-Water powder Test Example 2 Apple scab control test Apple seedlings grown in 25-inch pots (variety "Kunimitsu", 3-4
A chemical solution of a predetermined concentration of a hydrating powder of the compound of the present invention is sprayed during the leaf stage), and after air-drying, apple scab fungus (vllD) is grown.
After inoculating with conidia of Neet n
The disease was maintained at a warm temperature of 15°C and the degree of disease onset was investigated, and the control value was calculated based on the disease onset in the untreated control plot. The results are shown in Table 3.

Table 3 *Commercially available product “Cabtan” (N-()cyclodimethylthio)-4-cyclohexene-1,2-dicarboximide) SOIs hydrating agent Test Example 3 Curcumin udon Zeta disease spinning test Compounds of the present invention At the hydrating agent ji! Spray Oken IIK on potted seedlings of Chie cucumber (variety "Sacchi Dentori") and let it air dry.
K*caFull-ginam) was inoculated, and the disease onset was investigated after 10 days at a temperature of around 25° C., and the control value was calculated based on the disease severity in the untreated control plot. The result is number 41! l! Shown below.

Table 4 This commercially available agent "Molestan" (8-8-6-methylquinoxaline-23-diyldithiocarbonate) 25-hydrating agent Test Example 4 Tomato late blight pot test '') seedlings (3 to 4 g stage) were sprayed with a predetermined concentration of an irrigation agent containing the compound of the present invention, air-dried at room temperature for about 1 day, and grown tomato late blight (L. h
Conidia of tho-1JDuJIL1) were inoculated, kept at 28°C for about 1 day, and then placed in the temporary greenhouse (25-
28°C) and kept for 5 days to investigate the degree of subsequent disease. Control value (%) was calculated based on the degree of disease onset in the untreated area. The results are shown in Table WN2.

Table 5 This commercially available agent "Daconyl" (tetrachloroisophthalonitrile) 75-Water powder test example 5 Rice blast control test Tin pot (10X5aJX10aa height') Km cultivated nine rice (variety: 1 Shihikari) Young seedlings (311th season) K
A chemical solution of a predetermined concentration of a hydrating powder of a one-time printing compound was sprayed, and the next day, conidia of the rice blast fungus (Pricular 1ior esiri) were inoculated, and the mixture was heated at 26°C for 24 hours at high temperature 1.
[After holding at warm mK for 6 days, investigate the number of diseased hook spots in each group, and calculate the control value based on the disease onset in the untreated control plot.] The results are shown in Table 6.

Table 6: This commercially available agent “Rabside = (4,5,6t 7-teto-2 chlorophthalide) 501 water use agent test example 6. Pot test for damping-off (caused by vicinium soda) pot test? Five chestnut seeds (item 1!L "1 leaf") were sown and Ahanldermatum was added to the Ahanldermatum which had been cultured in soil, bran, and rice husk medium in advance.
), and after covering the soil, a chemical solution of a predetermined concentration of a hydrating powder of the invention compound was injected into the soil, and 6 days later, the degree of disease onset was investigated, and the control value was calculated based on the 1 onset of disease in the untreated control plot. Calculated. The results are shown in Section 71I.

Table 7 This commercially available agent “Tachigarey” (3-hydroxy-5-methylinquinazole) 40-liquid

Claims (1)

[Claims] 1. General formula (in the formula, X and Y are halogen atoms, R1 is a water volume
, a C1-3 acyl group, a benzoyl group, or a benzoyl group mono- or di-substituted with a halogen atom, a nitro group, an alkyl group, or a lower alkyl group, and Rf is a lower alkyl group or a cycloalkyl group. show. However, when R1 is a hydrogen atom, R1 is not a methyl group. ) Compound 2 general formula (wherein, X and Y are halogen atoms, R1 is hydrogen atom 01
~3 acyl group, benzoyl group, or benzoyl group mono- or di-substituted with a halogen atom, nitro group, alkoxy group, or lower alkyl group, and R2 represents a lower alkyl group or a cycloalkyl group. ) Agricultural and horticultural fungicide containing the compound represented by as an active ingredient