JPH11292863A - 2-substituted-1,2,5-thiadiazole-3-thione derivative and germicide for agriculture and holiculture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new compound which has an excellent controlling activity against various disease injuries such as blast of Oryza sativa and seed disease injury, and is useful as a germicide for agriculture and holiculture. SOLUTION: This compound shown by formula I (R1 is H or Cl; R2 is a 1-18C alkyl) (e.g. 2-methyl-1,2,5-thiadiazole-3-thione) is obtained by treating a compound shown by formula II (e.g. 2-methyl-1,2,5-thiadiazole-3-one) with diphosphorus pentasulfide or Lawesson's reagent in a solvent such as toluene, for example, at 80 deg.C for 40 min. This compound is useful as a germicide for seeds such as rice, wheat, and barley.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel 2-substituted-1,2,2,1,2,1,2,1,2,3,4,4,4,5,6,9,12,13,12,13,12,13,12,13 agent, or bactericidal agent which have an excellent bactericidal effect against agricultural and horticultural diseases such as rice blast. The present invention relates to a 5-thiadiazole-3-thione derivative and an agricultural and horticultural fungicide containing the same as an active ingredient.

[0002]

2. Description of the Related Art As a 2-substituted-1,2,5-thiadiazole derivative, there are several 2-substituted-1,2,5-thiadiazol-3-one derivatives as shown in the following. Are known.

[0003] The Journal of Organic Chemistry (J. Org. Chem.), Vol. 44, p. 1118 (1979) shows the following formula: (Wherein, R ₁ represents a hydrogen atom or a chlorine atom, and R ₂ represents a methyl group, an n-propyl group, a phenyl group, a benzyl group,
2-substituted-1,2,5-thiadiazol-3-one derivatives represented by n-dodecyl group) are described, and their synthesis methods are described.

JP-A-49-12034 discloses the following general formula: (Wherein, R represents an alkyl group having 1 to 4 carbon atoms, and X represents a chlorine atom or a bromine atom).
A 2-substituted-1,2,5-thiadiazol-3-one derivative is described, and a method for controlling phytopathogenic bacteria using the derivative is described.

[0005] US Pat. No. 4,362,877 discloses the following general formula: Wherein R is an alkyl group having 1 to 18 carbon atoms,
A phenyl group or substituted phenyl group, R ₁
Represents an alkyl group having 1 to 18 carbon atoms, an alkoxyalkyl group, a tetrahydrofuran-2-ylmethyl group or a phenylalkyl group).
A thiadiazol-3-one derivative is described, and an agricultural fungicide containing the same as an active ingredient is described.

JP-A-6-305914 discloses the following general formula: (Wherein X and Y are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a nitro group, a trifluoromethyl group, and a carboxyl group. Or R 1 represents an alkoxycarbonyl group having 1 to 4 carbon atoms, and R represents an alkyl group having 1 to 6 carbon atoms). And a fungicide for agricultural and horticultural use containing as an active ingredient.

[0007] JP-A-6-306063 discloses the following general formula: (Wherein, R represents a methyl group, a t-butyl group or a methoxy group), and describes a wheat having the active ingredient as a 2-substituted-1,2,5-thiadiazol-3-one derivative. Eyedrop control agents and medical antifungal agents are described.

[0008] JP-A-6-306064 discloses the following general formula: Wherein X, Y and Z are the same or different;
Each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group or a nitro group having 1 to 4 carbon atoms, and R represents an alkyl group having 1 to 6 carbon atoms)
A 2-substituted-1,2,5-thiadiazol-3-one derivative is described, and a fungicide containing the same as an active ingredient is described.

[0009] Swiss Patent No. 680220 discloses the following general formula: (Wherein R ₁ represents an alkyl group, a cycloalkyl group, a phenyl group or an alkylphenyl group, and R ₂ represents a hydrogen atom, an alkyl group, an amino group, a nitro group or an alkoxy group) -1,2,5-thiadiazole-3-
On derivatives are described, and a microbicide containing the same as an active ingredient is described.

On the other hand, as shown below, only one example of a 2-substituted-1,2,5-thiadiazol-3-thione derivative is known.

[0011] Zh. Org. Khim., Vol. 29, p. 491 (1993)
Has the following formula: Are described, and a method for synthesizing the derivative is described.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel fungicide for agricultural and horticultural use having excellent control activity against a wide range of diseases such as rice blast and seed disease in the agricultural and horticultural field. It is assumed that.

[0013]

Means for Solving the Problems In order to achieve the above object, the present inventors have synthesized various kinds of 1,2,5-thiadiazole derivatives and made various studies. As a result, a new
2-substituted-1,2,5-thiadiazole-3-thione derivatives have been found to have excellent control activity against a wide range of agricultural and horticultural diseases such as rice blast and seed diseases, and have completed the present invention. Was.

That is, according to the first gist of the present invention,
The following general formula (I): (Wherein, R ₁ represents a hydrogen atom or a chlorine atom, and R ₂ represents an alkyl group having 1 to 18 carbon atoms).
A 5-thiadiazole-3-thione derivative is provided.

According to a second aspect of the present invention, there is provided a 2-substituted-1,2,5-thiadiazole represented by the above general formula (I).
A fungicide for agricultural and horticultural use characterized by containing a -3-thione derivative as an active ingredient.

Next, specific examples of the 2-substituted-1,2,5-thiadiazole-3-thione derivative of the present invention are shown in Table 1. The compound number is also referred to in the following description.

[0017]

The 2-substituted-1,2,5-thiadiazole-3-thione derivative represented by the above general formula (I) of the present invention can be produced according to the following reaction formula. (Wherein R ₁ or R ₂ has the above-mentioned meaning) That is, 2-substituted-1,2,5 represented by the above general formula (II)
The 2-substituted-1,2,5-thiadiazole-3-thione derivative represented by the general formula (I) can be produced by treating the -thiadiazol-3-one derivative with diphosphorus pentasulfide or Lawesson's reagent.

The starting material for the above reaction, 2-substituted-1,2,5
The thiadiazol-3-one derivative (II) is a known compound, and can be produced, for example, by the method described in Journal of Organic Chemistry (J. Org. Chem.), Vol. 44, p. 1118 (1979).

The agricultural and horticultural fungicide of the present invention comprises a 2-substituted-1,2,5-thiadiazole-3-thione derivative represented by the above general formula (I) as an active ingredient. It can be in the form of a composition containing a solid carrier commonly used in horticultural fungicides, such as clay, talc, bentonite, kaolin and the like, or a liquid carrier such as water, alcohols and the like. This composition contains the compound represented by the general formula (I) as an active ingredient in an amount of 0.01 to 95%, preferably 0.5 to 95%.
It can be blended at a ratio of up to 70% (by weight) and can be formulated into conventional dosage forms such as emulsions, powders, wettable powders, solutions, aerosols and the like.

The fungicides for agricultural and horticultural use of the present invention include rice blast ( Pyricularia oryzae ) and cucumber downy mildew ( Pseudopero ).
nospora cubensis ), Tomato gray blight ( Phytophthora in
festans ) and other host plant diseases, grape brown spot ( C)
ladosporium cladosporioides ), rice seedling blight ( Tric)
hoderma viride ), apple leaf spot disease ( Alternaria ),
Sweet potato vine rot ( Fusarium oxysporum ), onion black mold ( Aspergillus niger ), sweet potato soft rot ( Rhizopus nigricans ), rice blight seedling ( Gibberella fu
jikuro i), barley and wheat powdery mildew ( Erysiphe grami)
nis ), cucumber powdery mildew ( Sphaerotheca flugin)
a ), apple powdery mildew ( Podosphaera leucotricha ),
Grape powdery mildew ( Uncinula necator ), and other host plant powdery mildew, wheat rust ( Puccina recondit)
a ), oat crown rust ( Puccina coronate ) and other rusts of host plants, and are particularly useful as a seed disinfectant for rice, wheat, barley and the like.

[0022]

Next, production examples of the compound of the present invention will be specifically described. Example 1 Preparation of 2-methyl-1,2,5-thiadiazol-3-thione (Compound No. 1)
Dissolved in 25 ml. 5 g of diphosphorus pentasulfide was added to the resulting solution at room temperature, and the mixture was stirred at 80 ° C. for 40 minutes. The supernatant was filtered off from the obtained reaction solution, and the residue was diluted with 30 ml of hot toluene.
After extraction twice, the extract was washed with saturated saline and dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure. The obtained crystals were recrystallized from methanol to give 1.4 g (yield 50%) of the title compound [melting point 105-106 ° C, mass spectrometry value m / e 132
(M ⁺ )].

Example 2 Preparation of 2 -methyl-4-chloro-1,2,5-thiadiazole-3-thione (Compound No. 2) 2-Methyl-4-chloro-1,2,5-thiadiazole-3 -1.5g on
Was dissolved in 50 ml of toluene. 2.2 g of Lawesson's reagent [2,4-bis (4-methoxyphenyl) -1,3-dithia-2,4-diphosphetane-2,4-disulfide] was added to the resulting solution, and 100
Stirred at C for 30 minutes. After evaporating the solvent from the obtained reaction solution under reduced pressure, the residue was purified by silica gel column chromatography (eluent: toluene / acetone 100: 1) to obtain 0.8 g (yield 47%) of the title compound. [Melting point 96-99 ° C., mass spectrometry value m / e166 (M ⁺ )].

Example 3 Preparation of 2-n-octyl-1,2,5-thiadiazole-3-thione (Compound No. 11) 1.5 g of 2-n-octyl-1,2,5-thiadiazol-3-one Was dissolved in 30 ml of xylene. 1.5 g of diphosphorus pentasulfide to the resulting solution
Was added and stirred at 80 ° C. for 2 hours. The supernatant was filtered off from the obtained reaction solution, the residue was extracted three times with 30 ml of xylene, the extract was washed twice with 30 ml of saturated saline, dried over anhydrous sodium sulfate, and the solvent was distilled off. The residue was purified by silica gel column chromatography (eluent: toluene) to obtain 0.6 g (yield: 38%) of the title compound [melting point: 28 to 30 ° C, mass spectrometry value: m / e230 (M ⁺ )] ].

Example 4 2-n-octyl-4-chloro-1,2,
Preparation of 5-thiadiazole-3-thione (Compound No. 12) 2-n-octyl-4-chloro-1,2,5-thiadiazol-3-one 2
g was dissolved in 20 ml of toluene. 2 g of diphosphorus pentasulfide was added to the resulting solution and stirred at 80 ° C. for 2 hours. The residue obtained by treating in the same manner as in Example 3 was subjected to silica gel column chromatography (eluent: n-hexane / acetone 20: 1).
To give 1.3 g of the title compound (62% yield).
25-27 ° C, mass spec m / e 264 (M ⁺ )].

Next, some formulation examples of the agricultural and horticultural fungicide of the present invention will be described. It goes without saying that the amount of the fungicide and the type of auxiliary agent can be changed. Compound No. 1
Can be similarly formulated by changing Compound Nos. To Compound Nos. 2 to 14. All parts in the formulation examples are parts by weight.

Formulation Example 1 Emulsion 10 parts of Compound No. 1 is dissolved in 40 parts of dimethylformamide, and 50 parts of xylene and 10 parts of polyoxyethylene nonylphenyl ether are added to this solution and mixed well to obtain an emulsion. Was.

Formulation Example 2 Powder 2 parts of Compound No. 2 were dissolved in 10 parts of acetone, and 68 parts of clay and 30 parts of talc were added to the solution and mixed uniformly. Thereafter, acetone was evaporated off to obtain a powder.

Formulation Example 3 Wettable powder 40 parts of Compound No. 3, 56 parts of clay, 3 parts of sodium lauryl alcohol sulfonate and 1 part of polyvinyl alcohol are uniformly mixed in a mixer, and ground with a hammer mill. A wettable powder was obtained.

Formulation Example 4 Oil-soluble preparation 2 parts of Compound No. 11 was dissolved in 2 parts of dimethylformamide, and 96 parts of solvent naphtha was added to obtain an oil.

Formulation Example 5 2 parts of the aerosol compound No. 12 and 0.5 part of fragrance were added to deodorized kerosene 40
And dissolved in an aerosol container. After mounting the valve, 58 parts of liquefied petroleum gas was charged under pressure to obtain an aerosol.

Next, the effect of the present invention as an agricultural and horticultural fungicide will be described with reference to test examples. Test Example 1 Rice Blast Control Test Formulation Example 3 was applied to the third leaf stage seedling of paddy rice (cultivar: Asahi) cultivated in soil in a greenhouse in a plastic pot having a diameter of 6 cm.
The wettable powder prepared according to the above was diluted with water so that the active ingredient concentration became 200 ppm, and sprayed 10 ml per pot using an automatic spraying device. On the day after the drug treatment, conidia of Pyricularia oryzae ( Pyricularia oryzae ) previously formed on an oatmeal agar medium were adjusted to a spore concentration of 5 ppm with a 50 ppm aqueous solution of a spreading agent (polyoxyethylene alkyl ether). × 10 ⁵ Spore count (pieces) / m
The above seedlings were spray-inoculated using a spray gun. After being kept in an inoculation box at 24 ° C and 100% humidity overnight, they were transferred to a greenhouse at 24 ° C to promote disease. Five days after inoculation of the rice blast fungus, the number of rice blast spots per leaf of the third leaf of the rice was examined, and the control value (%) was calculated by the following equation. The test was performed in a three-pot system, and the average control value (%) was determined. In addition, phytotoxicity to rice was investigated according to the criteria shown below as the phytotoxicity index. Table 2 shows the obtained results. Investigation index of phytotoxicity 5: severe 4: severe 3: many 2: slightly 1: slight 0: none.

Test Example 2 Rice seed disinfection effect test A wettable powder prepared according to Formulation Example 3 was diluted with water to adjust the concentration of the active ingredient to 1000 ppm, and the mixture was added to a test solution of Gibberella fujikuroi. ) Was immersed at 20 ° C for 24 hours. The paddy treated in this manner is taken out of the chemical solution, and this is further poured into tap water at 20 ° C.
And germinated at 30 ° C. for 24 hours. The seeds after germination were seeded on seedling cultivation soil and allowed to emerge at 32 ° C. for 2 days. Three weeks after sowing, the diseased seedling rate was investigated, and the control value (%) was calculated by the following formula in comparison with the untreated plot. The test was performed in three sections, and the average control value (%) was determined. Further, phytotoxicity was investigated according to the same criteria as in Test Example 1. Table 2 shows the obtained results.
The control value was calculated by the following equation.

[0034]

Test Example 3 Test for Controlling Cucumber Downy Mildew The second leaf stage seedling of a cucumber (cultivar: Sagami Hanjiro) cultivated in a greenhouse in a plastic pot having a diameter of 6 cm was cultivated.
The wettable powder prepared according to Formulation Example 3 was diluted with water to have an active ingredient concentration of
Dilute to 200 ppm and use an automatic spraying device
10 ml was sprayed per pot. On the day after the chemical treatment, the spores of the cucumber downy mildew ( Pseudoperonospora cubensis ) formed on the cucumber leaves in advance were dissolved in a 50 ppm aqueous solution of a spreading agent (polyoxyethylene alkyl ether). 5x1
0 ⁵ spores number (pieces) was adjusted to / ml, which was inoculated by spraying to the cucumber seedlings with a spray gun. 20 ℃, 100% humidity
After being kept in the inoculation box overnight, they were transferred to a greenhouse at 24 ° C. to promote the disease. Six days after the inoculation of the cucumber downy mildew fungus, the percentage of the cucumber downy disease spot per leaf of the second leaf (%) was investigated.
The control value (%) was calculated by the following equation. The test was performed in a three-pot system, and the average control value (%) was determined. In addition, phytotoxicity to cucumber was investigated according to the same criteria as in Test Example 1. Table 3 shows the obtained results.

Test Example 4 Test for controlling tomato ring spot disease Tomato (cultivar: Toko K) at the third leaf stage of tomato cultivated in a greenhouse in a plastic pot having a diameter of 6 cm in accordance with Formulation Example 3 The active ingredient concentration is 200ppm with the prepared wettable powder with water.
And then sprayed 10 ml per pot using an automatic spraying device. On the day after the drug treatment, spores of Alternaria solani ( Alternaria solani ), which had been formed on a potato decoction medium in advance, were treated with a spreading agent (polyoxyethylene alkyl ether) 50pp.
The spore concentration was adjusted to 5 × 10 ⁵ spores (number) / ml with an aqueous solution of m, and this was sprayed and inoculated to the tomato seedlings using a spray gun. After being kept in an inoculation box at 24 ° C and 100% humidity overnight, they were transferred to a greenhouse at 24 ° C to promote disease. Five days after the inoculation of the tomato ring spot fungus, the percentage (%) of the area of the tomato ring spot disease per second leaf and the third leaf was examined, and the control value (%) was calculated by the following formula. The test was conducted in a three-pot system,
The average control value (%) was determined. Further, phytotoxicity to tomatoes was investigated according to the same criteria as in Test Example 1. Table 3 shows the obtained results.

[0037]

Test Example 5 Tomato spot bacterial disease Tomato (variety: Toko K) at the 4th leaf stage seedling cultivated in soil in a greenhouse in a plastic pot having a diameter of 6 cm.
A predetermined concentration diluted solution of the wettable powder prepared according to 3 was sprayed by 10 ml per pot using an automatic spraying device. The day after the drug treatment, in advance, tomato spot bacteria fungus cultured on a potato decoctions medium (Xanthomonas campestris pv. V
esicatoria : A cell of Zantomonas campestris pv. vesicatria) was prepared as a suspension of 5 × 10 ⁷ CFU (colony formation unit) / ml with a 50 ppm aqueous solution of a spreading agent (polyoxyethylene alkyl ether). ,
This was sprayed and inoculated to the above tomato fungus using a spray gun. After overnight in an inoculation box at 24 ° C and 100% humidity,
It was transferred to a greenhouse at ℃ to promote the onset of the disease. Seven days after the inoculation of the bacterial spot of the tomato spot, the area of the bacterial spot of the bacterial spot of the tomato spot (%) per third to fourth leaves was investigated, and the average spot area (%)
And the control value (%) was calculated by the following formula. Test 3
The pot control was performed, and the average control value (%) was determined. Also,
The phytotoxicity to tomatoes was investigated according to the same criteria as in Test Example 1. Table 4 shows the obtained results.

[0039]

[0040]

Industrial Applicability The 2-substituted-1,2,5-thiadiazole-3-thione derivative represented by the general formula (I) of the present invention and a fungicide for agricultural and horticultural use containing the same as an active ingredient are rice blast. ,
Known 2-substituted-1,2,5-thiadiazol-3-one derivatives against cucumber downy mildew, tomato ring spot, tomato spot bacterial disease and rice scab disease and agricultural and horticultural products containing the same as an active ingredient It has a feature that the bactericidal effect is remarkably higher than that of a fungicide for agricultural use, and can be widely used as a fungicide for agricultural and horticultural use.

Continued on the front page (72) Inventor Kiyoshi Hirasawa 3-8 Central View Heights 3-8 Morinosato, Atsugi City, Kanagawa Prefecture (72) Inventor Seiichi Kutsuma 1-5-9-901, Tsumada Higashi, Atsugi City, Kanagawa Prefecture

Claims (2)

[Claims] 1. The following general formula (I): (Wherein, R ₁ represents a hydrogen atom or a chlorine atom, and R ₂ represents an alkyl group having 1 to 18 carbon atoms).
2,5-thiadiazole-3-thione derivative. 2. The following general formula (I): (Wherein, R ₁ represents a hydrogen atom or a chlorine atom, and R ₂ represents an alkyl group having 1 to 18 carbon atoms).
An agricultural and horticultural fungicide comprising a 2,5-thiadiazole-3-thione derivative as an active ingredient.