JPS6259699B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [] BACKGROUND TECHNICAL FIELD OF THE INVENTION The present invention relates to novel compounds and their uses. More specifically, the present invention relates to a novel benzisothiazoline derivative and a plant disease control agent containing the same as an active ingredient. Antibiotics, which are currently widely used to control bacterial blight, have been reported to be resistant to bacteria in various places, or lack efficacy, and there are growing concerns about their continued use in the future. .
On the other hand, Asozin, an arsenic agent, is also used as a blight control agent, but its use is being regulated due to its toxicity to humans and livestock and environmental pollution, as it contains heavy metal compounds in its active ingredients. There are many drawbacks to existing insecticides, such as the presence of insecticides, and there is a strong demand from various fields for the development of new types of insecticides. [] Summary of the Invention The present invention seeks to solve the above-mentioned problems by providing a novel benzisothiazoline derivative. Therefore, the 3-imino-1,2-benzisothiazoline-1,1-dioxide derivative according to the invention has the general formula (wherein R represents an ethyl group or an isopropyl group, respectively). Furthermore, the plant disease control agent according to the present invention has the general formula (In the formula, R represents an ethyl group or an isopropyl group, respectively) as an active ingredient. Effects The novel compound according to the present invention generally exhibits control activity against a wide range of agricultural and horticultural crop diseases, but has particularly excellent control effects against rice blight and damping-off of tomatoes and cucumbers. This new compound is an extremely low-toxic synthetic compound that does not contain heavy metals, has no practical toxicity to humans, livestock, or fish, and has no phytotoxicity to crops. Therefore, this compound is considered to have sufficient activity to compensate for the drawbacks of the existing drugs mentioned above. [] Detailed Description of the Invention 1 Compound The compound according to the present invention is represented by the general formula (). (In the formula, each R represents an ethyl group or an isopropyl group. The same applies to each of the following formulas.) Among the compounds of general formula (), those in which R is both an ethyl group and an isopropyl group, that is, the following compounds ( 1) and (2) are typical. Compound (1) 2-(2',6'-diethylphenyl)-3-imino-1,2-benzisothiazoline-1,1
-dioxide compound (2) 2-(2',6'-diisopropylphenyl)-3
-Imino-1,2-benzisothiazoline-
Preparation of 1,1-dioxide 2 compound The compound of the present invention can be synthesized by any method suitable for introducing or forming a desired substituent or bond in formula (). One suitable synthesis method is by the reaction shown in the following reaction formula (A), in which a reactive derivative with respect to the hydroxyl group of 2-cyanobenzenesulfonic acid,
For example, the desired product (2) is obtained by reacting a halide, particularly chloride (2), with 2,6-dialkylaniline (2). The intermediate () may or may not be created intentionally. Since the reaction between compounds () and () involves the generation of hydrogen halide, it is preferably carried out in the presence of an acid scavenger of various organic or inorganic bases. Also, the reaction is the compound () ~
(2) and at least one of the optionally used acid scavenger can be dissolved or dispersed to a desired concentration and can be carried out in the presence of a solvent or dispersion medium that does not substantially inhibit this reaction. In that case, an excess amount of the compound () can be used as an acid scavenger and also as a solvent or a dispersion medium. Specific reaction conditions and other details for carrying out this reaction can be found in the experimental examples below and in J.Chem.Soc. 82 ,
1594 (1960) (Reference 1) or Khim.Geterotsikl.
It may be appropriately selected according to the method of Soedin. No. 12, 1632 (1978) (Reference 2). Note that the compound (), which is one of the raw materials, is
It can be synthesized according to the method described in Handbuch der organischen Chemie XI , 376 (Reference 3). Another suitable synthesis method is by the reaction shown in the following reaction formula (B), in which 2 of the formula () is
-Cyano-N-(2',6'-dialkyl phenyl)-
This is a method for obtaining the target product () by ring-closing reaction of benzenesulfonic acid amide. This ring-closing reaction can be carried out by heating or by using an acid or a base as a reaction catalyst. As in the case of reaction A, a suitable solvent or dispersion medium can be used. Specific reaction conditions and other conditions may be appropriately selected according to the description of the experimental examples described later and the method of the above-mentioned document 1. 3. Usefulness of Compound - Plant Disease Control Agent The plant disease control agent according to the present invention is employed as an agricultural and horticultural agent, especially a fungicide, except that the active ingredient is the above-mentioned compound (). It can take any possible form or usage mode. Specifically, for example, the compound of the present invention may be used as it is, or diluted with a solid powder or other suitable carrier, and if necessary, an auxiliary agent such as a spreading agent may be added thereto, or the compound may be used in the production of agricultural chemicals. Hydration is achieved by mixing various liquid or solid carriers according to methods commonly used in It can be used in the form of formulations such as tablets, liquids, emulsions, powders, and granules. In producing these preparations, the liquid carrier used is one that serves as a solvent for the compound of the present invention, or one that can be dispersed or dissolved with the aid of an auxiliary agent. For example, kerosene, dioxane, acetone, dimethyl sulfoxide, animal and vegetable oils, and surfactants, and solid carriers such as clay, kaolin, talc, diatomaceous earth, silica, calcium carbonate, calcium bicarbonate, and the like are used. The content of active ingredient in the preparations thus obtained can be varied within a wide range. For example, when used as a liquid agent, the concentration in the liquid is
Approximately 10 ppm to 500 ppm is appropriate, and in the case of powders or granules, it is desirable to contain the compound of the present invention in a range of approximately 1% to 20%. It goes without saying that the formulation can be formulated at a higher concentration than this and diluted before use.
In addition, if circumstances permit, other compatible agricultural and horticultural chemicals or fertilizers may be mixed into the formulation. The pesticidal agent according to the present invention can be used by spraying on the foliage of crops, and can also be applied to water surfaces, water, soil surfaces, and soil.
In this case, compatible agricultural and horticultural chemicals or fertilizers may be used. Such agricultural and horticultural chemicals include, for example, fungicides, insecticides, herbicides, and plant growth regulators. The amount of application varies depending on the type and severity of the target disease, the type of target crop, the mode of application, etc., but an example when applying to soil is 0.1 kg per 10 ares.
Application rates of ~10Kg are generally appropriate. 4 Experimental Example 1 Synthesis of Compound Synthesis Example 1 Synthesis of Compound (1) 2-cyanobenzenesulfonic acid chloride 2.01g
and 1.5 g of 2,6-diethylaniline were added to 6 ml of pyridine, and heated under reflux for 1 hour with stirring. Methanol was added to the residue obtained by distilling off pyridine under reduced pressure under ice cooling, the precipitated white crystals were filtered, washed with a small amount of methanol, and 2-(2',6'-
1.1 g of (diethylphenyl)-3-imino-1,2-benzisothiazoline-1,1-dioxide
(yield 35%). (1) Melting point: 136-137°C (recrystallization solvent: methanol). (2) Infrared absorption spectrum (Nujol) (cm ^-1 ) 3230 (NH), 1651 (C=N), 1348, 1328,
1270, 1249, 1216, 1170, 1122, 1074, 967,
860, 808, 776, 758, 747 (3) NMR spectrum (DMSO-d6-TMS) δ 8.48-6.98 (7H, multiplet and broad signal,
aromatic ring proton), 2.51 (4H, quartet, J=7.5
Hz, −CH ₂ −CH ₃ ×2), 1.08 (6H, triple line,
J=7.5Hz, −CH ₂ −CH ₃ ×2) (4) Elemental analysis value (%) C ₁₇ H ₁₈ N ₂ O ₂ S (314.4) Calculated value C64.95, H5.77, N8.91 Analysis Values C64.56, H5.63, N8.92 (5) Mass spectrum m/e 314 (M ⁺ ), 285 (MC ₂ H ₅ ), 235, 91. Synthesis Example 2 Synthesis of compound (1) 2-cyanobenzenesulfonic acid chloride 2.01g
was mixed with 3.0 g of 2,6-diethylaniline,
It was heated to 150°C with stirring. The reaction was exothermic and the clear solution soon solidified. Immediately stop heating and allow to cool, add methanol, filter the precipitated crystals and wash with a small amount of methanol to remove the compound.
1.3 g of 2-cyano-N-(2',6'-diethylphenyl)-benzenesulfonamide (compound where R=ethyl group in general formula ()), which is the intermediate of (1)
I got it. (1) Melting point: 131.5-133°C (recrystallization solvent: methanol). (2) Infrared absorption spectrum (Nujol) (cm ^-1 ) 3230 (NH), 2260 (C≡N), 1660, 1586,
1406, 1334, 1264, 1197, 1158, 1132, 1068,
1038, 971, 946, 684, 606 (3) NMR spectrum (DMSO-d6-TMS) δ 8.05-6.78 (7H, multiplet, aromatic ring proton), 2.30 (4H, quartet, J = 7Hz, -C H ₂ −
CH ₃ ×2), 0.93 (6H, triple line, J=7Hz, -
CH ₂ −CH ₃ ×2) (4) Mass spectrum m/e 314 (M ⁺ ) (5) Elemental analysis value (%) C ₁₇ H ₁₈ N ₂ O ₂ S (314.4) Calculated value C64.95, H5 .77, N8.91 Analysis value C64.87, H5.80, N8.88 200 mg of the obtained intermediate was added to 3 ml of dioxane.
Dissolve it, add 0.1ml of triethylamine, and make 1
Heat to reflux for an hour. The oil obtained by evaporation of the solvent crystallized shortly after. This crystal corresponded to compound (1) obtained previously in Synthesis Example 1. Yield 200
mg. Synthesis Example 3 Synthesis of Compound (1) 10 g of 2-cyanobenzenesulfonic acid chloride and 7.5 g of 2,6-diethylaniline were mixed in dioxane.
Dissolve in 40ml, add 6g of triethylamine,
The mixture was heated under reflux for 3 hours. The brown oil obtained by distilling off the solvent was washed several times with water, and finally diluted with methanol 30
ml was added to cause crystallization, which was filtered and washed with a small amount of methanol to obtain 8 g of crude compound (1).
1 g of the crude compound (1) thus obtained was taken and dissolved in 30 ml of methanol while hot, insoluble matter was removed by heating, the liquid was cooled on ice, and the precipitated white crystals were filtered. The solid obtained by concentrating the liquid to dryness was recrystallized from aqueous methanol to obtain 56 mg of the desired product. This substance corresponded to compound (1) obtained in Synthesis Examples 1 and 2. Synthesis Example 4 Synthesis of compound (2) 2-cyanobenzenesulfonic acid chloride 2.1g
and 1.77 g of 2,6-diisopropylaniline were dissolved in 30 ml of pyridine and heated under reflux at a bath temperature of 180°C for 2 hours. 15 ml of methanol was added to the brown oil obtained by distilling off the pyridine, and the mixture was stirred under ice cooling. The precipitated white crystals were filtered, washed with a small amount of methanol, phenyl)-3
-imino-1,2-benzisothiazoline-1,
1.5 g of 1-dioxide was obtained. (1) Melting point: 195-196°C (recrystallization solvent: methanol). (2) Infrared absorption spectrum (Nujol) (cm ^-1 ) 3320 (NH), 1651 (C=N), 1467, 1368,
1353, 1332, 1320, 1270, 1187, 1160, 1110,
1063, 927, 862, 842, 806, 773, 753, 651,
608, 588, 553. (3) NMR spectrum (DMSO-d6-TMS) δ 8.44-7.08 (7H, multiplet, aromatic ring proton), 2.90 (2H, multiplet, J=7Hz, -CH
(CH ₃ ) ₂ × 2), 1.16 (6H, double line, J = 7Hz,
-CH( _CH3 ) ₂ ), 1.02(6H, double line, J=
7Hz, -CH( _CH3 ) ₂ ) (4) Mass spectrum m/e 342(M ⁺ ), 299(M-CH( _CH3 ) ₂ ), 235. (5) Elemental analysis value (%) C ₁₉ H ₂₂ N ₂ O ₂ S (342.46) Calculated value C66.63, H6.48, N8.18 Analysis value C66.67, H6.48, N8.18 Synthesis example 5 Synthesis of compound (2) 6.48g of 2,6-diisopropylaniline and 2-
4.2 g of cyano-benzenesulfonic acid chloride was mixed with the mixture and heated with stirring at a bath temperature of 140°C. The clear solution gradually solidified. When the internal temperature reaches 120℃ and the contents are completely solidified, stop heating, leave to cool, add 30ml of methanol to make a slurry, filter out the colorless crystals that have precipitated, and wash with cold methanol.2.8 g of 2-cyano-N-(2',6'-diisopropylphenyl)-benzenesulfonamide crystals were obtained. (1) Melting point 175-176.5 (decomposed) (recrystallization solvent methanol). (2) Infrared absorption spectrum (Nujol) (cm ^-1 ) 3240 (NH), 2260 (C≡N), 1589, 1408,
1339, 1260, 1185, 1161, 1131, 1104, 1066,
928, 804, 773, 756, 703, 688, 625, 600,
571. (3) NMR spectrum (DMSO-d6-TMS) δ 8.05-6.82 (7H, multiplet, aromatic ring proton), 2.97 (2H, septet, J=6.5Hz, -CH
(CH ₃ ) ₂ × 2), 0.91 (12H, double line, J = 6.5
Hz, -CH( _CH3 )×2). (4) Elemental analysis value (%) C ₁₉ H ₂₂ N ₂ O ₂ S (342.46) Calculated value C66.63, H6.48, N8.18 Analysis value C66.56, H6.52, N8.13 (5) Mass spectrum m/e 342 (M ⁺ ), 299 (M-CH (CH ₃ ) ₂ ), 176 2-cyano-N-(2',6'-diisopropylphenyl)-benzenesulfone obtained here 500 mg of amide was dissolved in 10 ml of dioxane, 0.3 ml of triethylamine was added, and the mixture was heated under reflux for 1 hour. The oil obtained by evaporation of the solvent crystallized shortly after. This crystal corresponded to compound (2) obtained in Synthesis Example 4. Yield 500mg. 2 Formulation Formulation Example 1 Wettable powder 2-(2',6'-dialkyl phenyl)-3-imino-1,2-benzisothiazoline-1,1-
Dioxide 20 parts by weight Clay 10 〃 Diatomaceous earth 65 〃 Lignosulfonic acid 3 〃 Polyoxyethylene alkyl allyl ether
2〃 Make a wettable powder composition by uniformly mixing and pulverizing the above component materials, and prepare a wettable powder composition with a predetermined concentration of 100 to 100% per 10 ares.
Spread 150 liters. Formulation Example 2 Powder 2-(2',6'-dialkyl phenyl)-3-imino-1,2-benzisothiazoline-1,1-
Dioxide 3 parts by weight Calcium stearate 1 Anhydrous silicic acid powder 1 Clay 48 Talc 47 A powder composition obtained by mixing and pulverizing the above components,
Spray 4 kg per 10 ares. Formulation Example 3 Granules 2-(2',6'-dialkyl phenyl)-3-imino-1,2-benzisothiazoline-1,1
- Dioxide 8 parts by weight Clay 89 〃 Carboxymethyl cellulose 3 〃 The above ingredients are mixed, an appropriate amount of water is added, kneaded into a mold, and then dried to obtain a granule composition, which is powdered at 3 kg per 10 ares. . 3 Medicinal Efficacy Test Test Example 1 Rice Shrinkage Blight Control Efficacy Test A predetermined concentration of the hydrating powder produced in Formulation Example 1 was sprayed on paddy rice (variety Jukoku) at the heading stage grown in a 1/5000 are Wagner pot. The mixture was sprayed at a rate of 70 ml/3 pots using a spray gun (3 kg/cm ² ), a chemical spraying device. Immediately after air-drying the inoculated areas on the same day, the strangulation blight bacteria obtained by flat culture on a peptone-added potato decoction agar medium for 48 hours was punched out using a cork borer with a diameter of 0.5 cm. Inoculation was performed by inserting the tube into the center, 15 cm from the ground surface. In addition, the inoculated areas on the 7th day after spraying, which were carried out to check the effectiveness of preventing invasion, were air-dried after spraying the chemical solution, and then allowed to stand in a glass greenhouse for 7 days, and then treated in the same manner as the inoculated areas on the same day. Inoculation was carried out. After inoculation, each pot was covered with a vinyl cylinder and kept at 30°C during the day and at 24°C at night in both the same-day and 7-day post-inoculation areas to encourage the invasion of strangle blight bacteria.
Let stand in a glass greenhouse at ℃ and inoculate 10
Days later, the lesion length of the disease onset diameter was measured, and the control value was calculated according to the following formula. At the same time, the occurrence of drug damage was also observed. Control value = (1 - average lesion length of treated area/average lesion length of untreated area) x 100 The results were as shown in the table below. [Table] Test Example 2 Seedling damping-off control test Seedling damping-off bacterium (Rhizoctonia type A bacterium) was cultured on a potato decoction agar medium, mixed and ground with three times the amount of rice bran to prepare an inoculum. Ivy. Tomatoes (variety: Hikari) and cucumbers (variety: Satsuki Midori) were used as test crops.
Twenty sprouted seeds per pot were sown in a 5,000 Ahl Wagner pot and covered with soil, and a mixture of equal amounts of the above-mentioned inoculum and sterilized field soil was uniformly spread over the pot for inoculation. After inoculation, store in a constant temperature room at 28℃ for 48 hours.
After standing for a period of time, the compound of the present invention of Formulation Example 1 was adjusted to a predetermined concentration to prepare an irrigation solution, and 100 mg/pot was prepared.
ml of this chemical solution was poured uniformly onto the ground surface using a pipette. Thereafter, in order to facilitate the invasion and progress of the inoculated bacteria, the plants were transported to a glass greenhouse at a temperature of 30°C to 28°C, and the soil in the pot was kept in a slightly dry state to develop the disease. In the investigation, the number of germination and the number of healthy seedlings up to three weeks after sowing were investigated, and the germination rate relative to the number of sown grains and the percentage of healthy seedlings relative to the number of germination were calculated. The results were as shown in the table below. 【table】

Claims (1)

[Claims] 1. General formula 3-imino-1,2- (wherein R represents an ethyl group or an isopropyl group, respectively)
Benzisothiazoline-1,1-dioxide derivative. 2 General formula A plant disease control agent containing a compound represented by the following formula (in which R represents an ethyl group or an isopropyl group) as an active ingredient.