JPS6059883B2 - Fungicide for agriculture and horticulture - Google Patents

Description

[Detailed description of the invention] The present invention relates to general formula (I) C R゛(I) ”/R2 N, ・R.

(However, in the formula, R1 represents a lower alkyl group or a phenyl group, R2 represents an alkyl group, a cycloalkyl group, or a phenyl group, in which case the phenyl group may be substituted with a lower alkyl group or a halogen atom, and R3
is hydrogen or an alkyl group, and R2 and R3 may be combined with adjacent nitrogen atoms to form a heterocycle.

Some of the compounds represented by the general formula (I) have been described in the Takeda Institute Annual Report, Volume 2, pp. 27-46 (1961), Japanese Patent Publication No. 39-4491, and Japanese Patent Publication No. 39-4493. It is known to have anti-tuberculosis, antibacterial, and antitumor effects.

In addition, compounds similar to these include 2-(3・5-
dimethyl-1-pyrazolyl)-4-methyl-6-hydroxypyrimidine, 2-(3●5-dimethyl-1-pyrazolyl)-4-phenyl-6-hydroxypyrimidine and 2-(3,5-dimethyl-1-pyrazolyl)-4-methyl- Takeda Research Institute Annual Report No. 2, No. 250 shows that 6-thiocyanopyrimidine causes severe chemical damage to useful plants such as rebellious rice, which has control activity against rice blast.
~258 Top (1965). The present inventors synthesized a large number of pyrazolylpyrimidine compounds and conducted extensive studies on their practicality as agricultural and horticultural fungicides.

As a result, it was discovered that a specific group of compounds represented by the general formula (1) has extremely significant control activity against rice blast, sesame leaf blight, cucumber powdery mildew, etc. . These series of compounds are extremely excellent bactericidal agents because they do not cause any phytotoxicity to useful plants, and they can be used safely without toxicity to animals or fish. These characteristics of the present invention are difficult for even a person skilled in the art to deduce from the technical knowledge described in the above-mentioned technical documents, and the agricultural and horticultural fungicides of the present invention are highly expected to have practical utility. It is an excellent drug.

The compound of general formula (1) can be produced according to the method described in the above-mentioned technical literature. Reference production examples are shown below. Reference Production Example 1 2-(3,5-dimethyl-1-pyrazolyl)-4-methyl-6-isopropylaminopyrimidine (compound NO.
5) Dissolve 1.11' (5 mmol) of the corresponding 6-chlor compound in 4 ml of ethanol, and add 1.1 ml of isopropylamine.
Add 8y (20 mmol) and warm at 600C for 6 hours.

The reaction solution was concentrated under reduced pressure, about 20 ml of water was added, and 2.5% H
The oil formed after neutralization with Cl is extracted with 30 ml of ether. After drying the ether extract with anhydrous sodium sulfate,
Distill ether. Np. 0.93y of white crystals with a temperature of 133-1°C are obtained. When this is recrystallized from 17ml of ligroin, M. p. Colorless columnar crystals at 38-139°C 0.8
1fI (66.4%). The elemental analysis results for Cl3H and 9N5 are as follows. Actual value: 63.44
7.7028.86 Reference production example 2 2-(3,5-dimethyl-1-pyrazolyl)-4-phenyl-6-isopropylaminopyrimidine (compound NO.
．． l7) Corresponding 6-chlor compound 4fI (14 mmol)
was dissolved in 30 ml of ethanol, and 4 ml of isopropylamine was added.
．． Add 12y (70 mmol) and warm at 6Crc for 6 hours.

The reaction solution was concentrated under reduced pressure, 20 ml of water was added, and an oily substance insoluble in water was extracted with 40 nt of ether. After drying the extract over anhydrous sodium sulfate, the ether is distilled off. M. p. l
2.25y of brown crystals with a temperature of 48-1°C are obtained. This is TH
Recrystallized from 25 ml of F-hexane (1:3) to obtain M. p
．． 2.05f pale red columnar crystals of l54-1553 (47.
5%). The elemental analysis results for Cl8H21N5 are as follows.

Reference production example 3 2-(3●5-dimethyl-1-pyrazolyl)-4-phenyl-6-hexylaminopyrimidine (compound NO.
9) 1.14y (4 mmol) of the corresponding 6-hexylamine and 2.02y (20 mmol) of n-hexylamine are heated at 600C for 1 hour in 10 ml of ethanol.

After concentrating the reaction solution, about 10 ml of water was added, neutralized with 10% HCl, and insoluble matter was collected. M. p. l36-14
1.37y of product is obtained at 0°C. When this was recrystallized from 5 ml of 95% ethanol, M. p. l39~140.5
1.15 f1 (82.1%) of colorless platelet crystals are obtained. C
The elemental analysis results for 2lH27N5 are as follows.

Reference production example 4 2-(3●5-dimethyl-1-pyrazolyl)-4-phenyl-6-anilinopyrimidine (compound NO.2O) corresponding 6-chlor compound 1.14y (4 mmol) and aniline 1.86f (20 mmol) and 10 ml of ethanol
After heating for 1 hour at 6 (generations) in a medium, the mixture is refluxed at 85° C. for 3 hours.

After concentrating the reaction solution, 10 ml of water was added, and the resulting oil was extracted with 25 ml of chloroform. After drying the extract over anhydrous sodium sulfate, chloroform is distilled off. M. p. l
1.06y of brown crystals with a temperature of 73-175°C are obtained. This was recrystallized from 7 mt of ethanol to obtain Mp. l73~174℃
0.85y (62.0%) of colorless columnar crystals were obtained. C2l
The elemental analysis results for Hl9N5 are as follows.

Compounds produced by such a method are exemplified, and the compound numbers are also referred to in the following Examples and Test Examples.

In order to use the agricultural and horticultural fungicide of the present invention for controlling diseases of agricultural and horticultural crops, the compound of the present invention may be used as it is, or it may be diluted with water, solid powder or other suitable carrier, and a spreading agent may be added if necessary. or by mixing with various liquid or solid carriers by methods commonly used in agricultural chemical manufacturing, and if necessary, wetting agents, spreading agents, dispersing agents, emulsifiers, fixing agents, etc. It can be used in various formulation forms such as wettable powders, solutions, emulsions, powders, granules, and fine granules by adding auxiliary agents such as powders.

In producing these preparations, examples of liquid carriers include water, aromatic hydrocarbons, aliphatic hydrocarbons, alcohols, esters, ketones, highly polar dimethylformamide, dimethyl sulfoxide, etc. Examples of solvents and solid carriers include mineral powders such as clay, talc, kaolin, bentonite, diatomaceous earth, calcium carbonate, and silicic acid;
Wood flour or other organic powders can be used, and adjuvants include nonionic, anionic, cationic or amphoteric surfactants, ligninsulfonic acid or its salts, cams,
Thickening agents such as fatty acid salts and methylcellulose are mentioned.

Furthermore, if necessary, other pesticides or fertilizers such as fungicides, insecticides, herbicides, plant growth regulators, and nematicides can be mixed and used. The agricultural and horticultural fungicide of the present invention can be used by directly spraying on crops for which disease control is desired, and if necessary, it can also be applied to crop growing environments such as water surfaces and soil surfaces. They can also be used in combination.

When the agricultural and horticultural fungicide of the present invention is used as a liquid, the compound of the present invention is usually contained in the spray solution in an amount of 1.0 to 1000 p.
It is desirable to contain it at a concentration of pm, and in cases of concentrated small-volume spraying, aircraft spraying, etc., it can be used as a more concentrated spraying liquid as necessary, and it can be used as a powder, granule, fine granule, etc. In some cases, the content is preferably 0.3 to 30%. Next, examples of the agricultural and horticultural fungicide of the present invention will be shown, but the present invention is not limited thereto.

Example 1 Wettable powder compound NO. By uniformly pulverizing and mixing 20 parts by weight of the compound No. 2, 5 parts by weight of polyoxyethylene alkylaryl ether, 3 parts by weight of calcium lignin sulfonate, and 7 parts by weight of diatomaceous earth, a wettable powder containing 20% of the active ingredient is obtained. .

Example 2 Granule Compound No. 5 parts by weight of the compound No. 7, 1 part by weight of calcium ligninsulfonate, 3 parts by weight of bentonite and 64 parts by weight of clay were uniformly ground and mixed, then an appropriate amount of water was added and kneaded, then granulated and dried. This gives granules containing 5% of the active ingredient.

Example 3 Powder Compound No. 3 parts by weight of the compound No. 6 and 0.0 parts by weight of silicic anhydride fine powder.
5 parts by weight of calcium stearate, 0.5 parts by weight of calcium stearate, 5 parts by weight of clay and 4 parts by weight of talc are uniformly ground and mixed to obtain a powder containing 3% of the active ingredient.

Example 4 Emulsion compound NO. By uniformly dissolving and mixing 20 parts by weight of the compound No. 2, 3 parts by weight of dimethylformamide, 35 parts by weight of xylene and 15 parts by weight of polyoxyethylene alkylaryl ether, an emulsion containing 20% of the active ingredient is obtained.

Test Example 1 Rice blast control effect test (prevention) A test chemical solution diluted to a predetermined concentration was sprayed on third-leaf stage seedlings of paddy rice (variety Asahi) grown in clay pots with a diameter of 9C7I in a greenhouse.

One day after the spraying, a spore suspension of the blast fungus was inoculated by spraying.
After inoculation, leave overnight under humid room conditions (humidity 95-100%, temperature 24%).
~25°C). Five days after inoculation, the number of lesions per leaf on the third leaf was investigated, and the control value was calculated using the following formula. In addition, chemical damage to rice was investigated using the following indicators. The results are shown in Table 2. In the drug injury investigation index table, comparative drug 1 contains 2-(3,5-dimethyl-1-pyrazolyl)-4-methyl-6-hydroxypyrimidine,
Comparative drug 2 is 2-(3.5-dimethyl-1-pyrazolyl)-4-phenyl-6-hydroxypyrimidine, and comparative drug 3 is 2-(3.5-dimethyl-1-pyrazolyl)-4-methyl-6-thio. Comparative agent 4 is a commercially available fungicide (trade name: Kitazine P emulsion) containing 0.0-diisopropyl S-benzyl phosphorothiolate.

Test Example 2 Paddy rice blast control effect test (treatment) Paddy rice (variety
Asahi) seedlings at the third leaf stage were spray inoculated with a spore suspension of the blast fungus.

After inoculation, overnight under humid room conditions (temperature 95-100%, temperature 24%)
~Article 25C). One day after inoculation, a test chemical solution diluted to a predetermined concentration was sprayed. Five days after spraying, the control value and degree of chemical damage were investigated in the same manner as in Test Example 1. Comparative drugs 1 and 2
, 3 and 4 used the same drugs as in Test Example 1.

The test results are shown in Table 3. Test Example 3 Paddy rice top leaf blight control effect test Diameter in greenhouse: 9cm! Paddy rice cultivated in soil in RL clay pots (
A drug solution diluted to a certain concentration was sprayed on seedlings at the fourth true leaf stage of the cultivar Asahi (variety Asahi), and one day after the spraying, a conidial suspension of rice seedlings with leaf blight was spray inoculated.

Five days after inoculation, the number of lesions per leaf on the fourth leaf was investigated, and the control value was calculated using the following formula. In addition, chemical damage to rice was investigated using the same method as in Test Example 1. The results are shown in Table 4. Comparative agents 1, 2, and 3 were the same as in Test Example 1, and comparative agent 4 was a commercially available fungicide containing the compound name 2,4-dichloro6-(0-chloroanilino)-1●3,5 triazine. (generic name triazine) was used.

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. The group may be substituted with a lower alkyl group or a halogen atom, and R_3 is hydrogen or an alkyl group, and also R_
An agricultural and horticultural fungicide containing a pyrazolylpyrimidine derivative represented by (2 and R_3 may be combined with adjacent nitrogen atoms to form a heterocycle) as an active ingredient.