JPH0667930B2 - Benzothiazolone derivative and herbicide containing the same as active ingredient - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel benzothiazolone derivative, a method for producing the same, and a herbicide containing the same as an active ingredient.

<Prior Art> A herbicide marketed under the general name of benazoline having a benzothiazolone skeleton is known.

[Harbicide Handbook of the Weed
Science Society of America Fifth Edition
Page 40 (1983) (Herbicide Handbook of the Weed Scien
ce Society of America)].

<Problems to be Solved by the Invention> However, the above herbicide benazoline is not sufficient in terms of its herbicidal effect and is not necessarily satisfactory.

<Means for Solving Problems> In view of such circumstances, the present inventors have conducted various studies to develop a compound having an excellent herbicidal effect, and as a result, 2H-isoindole-1,3-dione- The inventors have found that a benzothiazolone derivative having 2-yl as a substituent at the 5-position is a compound having extremely excellent herbicidal effect, and have reached the present invention.

That is, the present invention has the general formula (In the formula, R ¹ represents a lower alkoxy group, a lower cycloalkoxy group, a lower haloalkoxy group, a lower alkoxyalkoxy group, a lower alkoxycarbonylalkoxy type, a lower alkylamino group or a lower dialkylamino group, and R ₂ represents a hydrogen atom or Represents a lower alkyl group, n
Represents 1 or 2. ), A method for producing the same, and a herbicide containing the same as an active ingredient.

The compound of the present invention, in the treatment of foliage and soil in the field, various weeds that are problematic, for example, buckwheat vine, sanaetade, purslane, chickweed, white lobster, aogate,
Japanese radish, red-bellied rape, nazuna, horned hemlock, Ebisugusa, hornbill, American stag deer, field pansy, yaemgra, malaba morning glory, western bindweed, white-billed morning glory, dog physalis, red-nosed foxglove, monarch, sunflower, cornflower, cornflower. It has herbicidal activity against broad-leaved weeds, barnyardgrass, barnyardgrass, green locust, broomgrass, bluegrass, bluegrass, oats, oats, oats, sorghum and cyperaceae such as Kogomegayatsu, and some of the present invention. The compound is corn,
It does not show any harmful effects on major crops such as sorghum, wheat, barley, rice, soybean, peanut, ivy, etc.

Further, the compound of the present invention, in the flooding treatment of paddy fields, various weeds that are problematic, for example, grass weeds such as Taenia japonicus, asena, broad-leaved weeds such as Azena, Kishigusa, Mizohakobe, cyperaceae, weeds such as matsubai. It has a herbicidal effect on eels, eels and urchins, and does not show any harmful phytotoxicity on rice.

Therefore, the compound of the present invention can be used as a herbicide in paddy fields, uplands, orchards, meadows, lawns, forests, non-agricultural lands, etc. by soil treatment, foliar treatment or flooding treatment.

The compound of the present invention has a general formula (Wherein R ¹ , R ² and n have the same meanings as described above), and 1 equivalent of an aminobenzothiazolone derivative represented by
It can be prepared by reacting ˜3 equivalents of 3,4,5,6-tetrahydrophthalic anhydride in a solvent.

In the production method of the present invention, the reaction temperature and the reaction time of the reaction are 80 to 200 ° C. and 1 to 24 hours, respectively.

Solvents used in the reaction include benzene, toluene,
Examples thereof include aromatic hydrocarbons such as xylene, ethers such as dioxane, ethylene glycol and dimethyl ether, lower fatty acids such as formic acid and acetic acid, water and the like, or a mixture thereof.

After the reaction is completed, the reaction solution is added with water and then subjected to usual post-treatment operations such as extraction with an organic solvent and concentration, and if necessary,
The compound of the present invention can be obtained by purification by operations such as chromatography and recrystallization. The aminobenzothiazolone derivative represented by the general formula (II), which is the starting material compound for the compound of the present invention, can be obtained by the following route.

(In the formulae, R ¹ , R ² and n have the same meanings as described above, and X
Represents a chlorine atom, a bromine atom or an iodine atom. ) That is, first, 6-fluoro-2 represented by the formula (III)
By reacting (3H) -benzothiazolone with a nitrating agent, 6-fluoro-5-nitro-2 (3H) -benzothiazolone represented by the formula (IV) is obtained.

In the reaction, examples of the nitrating agent include a sulfuric acid-nitric acid mixture.

The reaction temperature of this reaction is −10 ° C. to 10 ° C., the reaction time is instantaneous to 5 hours, and the amount of the reagent used for the reaction is sulfuric acid based on 1 equivalent of 6-fluoro-2 (3H) -benzothiazolone. Is 1 equivalent to a large excess amount, and nitric acid is 1 to 1.2 equivalents.

After completion of the reaction, the reaction solution is poured into ice water, the generated crystals are separated, and a usual post-treatment such as washing with water is performed, and recrystallization is performed if necessary.
Purification by an operation such as chromatography gives 6-fluoro-5-nitro-2 (3H) -benzothiazolone.

Then, the obtained 6-fluoro-5-nitro-2 (3H)
3-substituted 3-benzothiazolone, which is the case where n = 1 in the compound represented by the general formula (VII), by reacting the α-haloacetic acid derivative represented by the general formula (V) in the presence of a base. 6-Fluoro-5-nitro-2 (3H)
-Benzothiazolone (VII) can be obtained.

The reaction temperature of this reaction is 0 ° C to 80 ° C, preferably 10 ° C to 50 ° C.
The reaction time is 30 minutes to 24 hours, and the amount of the reagent used in the reaction is represented by the general formula (V) with respect to 1 equivalent of 6-fluoro-5-nitro-2 (3H) -benzothiazolone. The amount of α-haloacetic acid and base is 1.0 to 1.5 equivalents, respectively.

This reaction is usually carried out in a solvent, and the solvent used for the reaction includes toluene, aromatic hydrocarbons such as benzene, N,
Examples thereof include amides such as N-dimethylformamide, sulfur compounds such as dimethylsulfoxide, nitriles such as acetonitrile, water and the like, or a mixture thereof.

Examples of the base include sodium hydride, potassium carbonate, sodium hydroxide, potassium hydroxide and the like.

After completion of the reaction, the reaction solution is added with water, and then subjected to usual post-treatments such as extraction with an organic solvent and concentration, and if necessary, recrystallization,
The 3-substituted-6-fluoro-5-nitro-2 (3H-benzothiazolone) represented by the general formula (VII) can be obtained by purification by an operation such as chromatography.
Similarly, by reacting 6-fluoro-5-nitro-2 (3H) -benzothiazolone with an acrylic acid derivative represented by the general formula (VI) in the presence of a base, a compound represented by the general formula (VII) can be obtained. 3-Substituted-6-fluoro-5-nitro-2 (3H) -benzothiazolone is obtained, where n = 2.

The reaction temperature of this reaction is 50 ° C to 100 ° C, and the reaction temperature is 30 ° C.
The amount of the reagent used for the reaction is 6-
Fluoro-5-nitro-2 (3H) -benzothiazolone 1
The amount of the acrylic acid derivative represented by the general formula (VI) is 1.0 equivalent to a large excess, and the amount of the base is 1.0 to 3.0 equivalents. This reaction is usually carried out in a solvent, and as the solvent used in the reaction, toluene, aromatic hydrocarbons such as benzene, amides such as N, N-dimethylformamide, sulfur compounds such as dimethyl sulfoxide, acetonitrile and the like. Examples thereof include nitriles, water and the like or a mixture thereof.

Examples of the base include benzyltrimethylammonium hydroxide and the like.

After completion of the reaction, the reaction solution is added with water, and then subjected to usual post-treatments such as extraction with an organic solvent and concentration, and if necessary, recrystallization,
The 3-substituted-6-fluoro-5-nitro-2 (3H) -benzothiazolone represented by the general formula (VII) can be obtained by purification by an operation such as chromatography. Then, the 3-substituted-6-fluoro-5-nitro-2 (3H) -benzothiazolone thus obtained is reacted with a reducing agent to obtain an aminobenzothiazolone derivative represented by the general formula (II). To be

Examples of the reducing agent include iron powder.

The reaction temperature of this reaction is 60 ° C to 120 ° C, the reaction time is 10 minutes to 12 hours, and the amount of the reagent supplied to the reaction is 3-substituted-6-fluoro-5-nitro-2 (3H)-. Iron powder is 3 to 30 equivalents, preferably 5 to 20 equivalents, relative to 1 equivalent of benzothiazolone.
It is equivalent. Furthermore, this reaction is usually carried out in acetic acid water, preferably in the presence of a cosolvent such as ethyl acetate.

After the reaction is completed, the reaction solution is separated from the residue, extracted with an organic solvent, washed with water, aqueous sodium hydrogen carbonate, etc., and then subjected to usual post-treatments such as concentration, or if necessary, re-treatment. The aminobenzothiazolone derivative represented by the general formula (II) can be obtained by purification by operations such as crystallization and chromatography.

In addition, 6-fluoro-2, which is the starting compound for the above method
(3H) -Benzothiazolone is G.Mazzone & G.Pappalard
o, Farmaco, Ed. Sc., 32 (5) 348 (1977).

Hereinafter, the present invention will be described in more detail with reference to Examples and Reference Examples.

<Example> (Production of compound 2 of the present invention) 5-amino-3-ethoxycarbonylmethyl-6-fluoro-2 (3H) -benzothiazolone 140 mg and 3,4,5,6-tetrahydrophthalic anhydride 90 mg The suspension was suspended in 3 m of acetic acid and heated under reflux for 5 hours. After the reaction mixture had cooled, water was added and the mixture was extracted with ethyl acetate. The extract was washed with water, washed with sodium hydrogen carbonate, dried, and concentrated. The residue thus obtained was subjected to silica gel thin layer chromatography (developing solvent; ethyl acetate:
Purified with hexane = 1: 2), 2- [3-ethoxycarbonylmethyl-6-fluoro-2 (3H) -benzothiazolone-5-yl] -4,5,6,7-tetrahydro-1H-isoindole- 40 mg of 1,3 (2H) -dione was obtained. mp155.5−
156.5 ° C. Table 1 shows some of the compounds of the present invention which can be produced by such a production method.

<Reference Example 1> [6-Fluoro-5-nitro-2 (3H)-
Production Example of Benzothiazolone] 6-Fluoro-2 (3H) -benzothiazolone (47.58 g)
It was dissolved in 760 m of 00% sulfuric acid. This was cooled to 0 ° C to 5 ° C, and 18.79 g of 98% fuming nitric acid (d = 1.52) was gradually added dropwise at 0 ° C to 5 ° C, followed by stirring at the same temperature for 60 minutes. The reaction mixture was poured into ice water, and the obtained crystals were washed with water and air-dried to give light brown crystalline 6-fluoro-5-nitro-2 (3
(H) -benzothiazolone (48.48 g) was obtained.

mp180-182 ° C. <Reference Example 2> (Production example of nitrobenzothiazolone derivative) 0.21 g of 50% oily sodium hydride was suspended in 5 m of N, N-dimethylformamide and cooled to 0 ° C. 6-fluoro-5-nitro-2 (3H9-benzothiazolone 1.0g
Was added little by little at 0 ° C, and the mixture was stirred at 0 ° C for 30 minutes. Ethyl bromoacetate (0.86 g) was added at 0 ° C and the temperature was gradually raised to 50-60.
The mixture was stirred at 0 ° C for 3 hours. After the reaction mixture had cooled, water was added, and the mixture was extracted with ethyl acetate, washed with water, dried and concentrated. The residue thus obtained was purified by silica gel thin layer chromatography (developing solvent; ethyl acetate: toluene = 1: 9) to give 3-ethoxycarbonylmethyl-6-fluoro-5.
0.35 g of -nitro-2 (3H) -benzothiazolone was obtained.
mp139.0-140.0 ° C <Reference Example 3> 6-fluoro-5-nitro-2 (3H) -benzothiazolone 1.0 g, methyl acrylate 5 m, and benzyltrimethylammonium hydroxide 40% methanol solution 1.95 g are heated under reflux for 2 hours. did. After the reaction mixture cooled, water was added and the mixture was extracted with ethyl acetate. The extract is washed with water, dried and concentrated to give 6-
Fluoro-3- (2-methoxycarbonyl) ethyl-5
1.12 g of -nitro-2 (3H) -benzothiazolone was obtained.

mp224.3 ° C Table 2 shows some of the nitrobenzothiazolone derivatives which can be produced by such a production method.

<Reference Example 4> (Production example of aminobenzothiazolone derivative) 0.29 g of electrolytic iron powder was suspended in 2 m of 5% acetic acid aqueous solution. While heating, 0.31 g of 3-ethoxycarbonylmethyl-6-fluoro-5-nitro-2 (3H) -benzothiazolone
Was added dropwise to 1 m of acetic acid and 1 m of ethyl acetate, and the mixture was heated under reflux for 3 hours. The reaction mixture was filtered through Celite, and the liquid was extracted with ethyl acetate. The extract was washed with water, washed with sodium bicarbonate water, dried and concentrated to give 0.20 g of 5-amino-3-ethoxycarbonylmethyl-6-fluoro-2 (3H) -benzothiazolone.

mp172.5-173.5 ° C Table 3 shows some of the aminobenzothiazolone derivatives which can be produced by such a production method.

When the compound of the present invention is used as an active ingredient of a herbicide,
Usually, it is mixed with a solid carrier, a liquid carrier, a surfactant and other auxiliaries for formulation, and then formulated into an emulsion, a wettable powder, a suspension, a granule and the like.

The compound of the present invention as an active ingredient in a weight ratio of 0.05 to 90%,
Preferably, a formulation containing 0.1 to 80% is provided.

Examples of the solid carrier include kaolin clay, attapulgite clay, bentonite, acid clay, pyrophyllite, talc, diatomaceous earth, calcite, walnut powder, urea, ammonium sulfate, fine powder or particles of synthetic hydrous silicon oxide, and the like. As the liquid carrier, xylene, aromatic hydrocarbons such as methylnaphthalene, alcohols such as isopropanol, ethylene glycol, cellosolve, acetone, cyclohexanone, ketones such as isophorone, soybean oil, vegetable oils such as cottonseed oil, dimethyl sulfoxide, N, N-
Examples include dimethylformamide, acetonitrile, water and the like.

Surfactants used for emulsification, dispersion, wet extension, etc. include alkyl sulfate ester salts, alkyl sulfonates, alkyl aryl sulfonates, dialkyl sulfosuccinates, polyoxyethylene alkyl aryl ether phosphate ester salts. Anionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene polyoxypropylene block copolymer, nonionic surfactants such as sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, etc. To be Examples of the auxiliaries for the formulation include lignin sulfonate, alginate, polyvinyl alcohol, gum arabic, CMC (carboxymethyl cellulose), PAP (isopropyl acid phosphate) and the like.

Formulation examples are shown below. The compounds of the present invention are shown by the compound numbers in Table 1. Parts are parts by weight.

Formulation Example 1 50 parts of the compound (1) or (2) of the present invention, 3 parts of calcium ligninsulfonate, 2 parts of sodium lauryl sulfate and 45 parts of synthetic hydrous silicon oxide are well pulverized and mixed to obtain a wettable powder.

Formulation Example 2 10 parts of the present compound (3) or (5), 14 parts of polyoxyethylene styryl phenyl ether, 6 parts of calcium dodecylbenzene sulfonate, 25 parts of xylene and 45 parts of cyclohexanone are thoroughly mixed to obtain an emulsion.

Formulation Example 3 2 parts of the compound (1) or (14) of the present invention, 1 part of synthetic hydrous silicon oxide, 2 parts of calcium lignin sulfonate, 30 parts of bentonite and 65 parts of kaolin clay are well pulverized and mixed, and water is added and kneaded well. After they are combined, they are granulated and dried to obtain granules.

Formulation Example 4 25 parts of the compound (5) or (7) of the present invention, 3 parts of polyoxyethylene sorbitan monooleate, 3 parts of CMC, and 69 parts of water are mixed and wet-milled until the particle size of the active ingredient is 5 microns or less. To obtain a suspension.

Formulation Example 5 The present compound (4) or (11) 5 parts, polyoxyethylene styryl phenyl ether 14 parts, calcium dodecylbenzene sulfonate 6 parts, xylene 30 parts and N, N-dimethylformamide 45 parts are mixed well. Obtain an emulsion.

The thus-prepared compound of the present invention can be used as a herbicide by soil treatment, foliage treatment or flooding treatment in a field, paddy field, orchard or the like before or after emergence of weeds. The soil treatment includes a soil surface treatment, a soil admixture treatment, and the like, and the foliage treatment includes a treatment from above the plant body and a local treatment for treating only the weeds so as not to adhere to the crop. In addition, the herbicidal effect can be expected to be enhanced by treating the mixture with other herbicides. Further, it can be treated by mixing with an insecticide, acaricide, nematicide, fungicide, plant growth regulator, fertilizer, soil conditioner and the like.

When the compound of the present invention is used as an active ingredient of a herbicide, the treatment amount is usually 0.05 g to 100 g per 1 are, preferably 0.1 g to 50 g, and emulsions, wettable powders, suspensions, etc.
It can be treated by diluting it with water of 1 liter to 10 liters per one are (adding an auxiliary agent such as a spreading agent if necessary), and the granules and the like can be directly treated without any dilution.

As the spreading agent, in addition to the above-mentioned surfactant, polyoxyethylene resin acid (ester), lignin sulfonate,
Examples thereof include abietic acid salt, dinaphthylmethane disulfonic acid salt, and paraffin.

Next, Test Examples will show that the compound of the present invention is useful as an active ingredient of a herbicide. The compounds of the present invention are shown by the compound numbers in Table 1, and the compounds used for comparison and control are shown by the compound symbols in Table 4.

Regarding the herbicidal efficacy, the degree of budding and growth inhibition of the test plant at the time of the survey was visually observed, and when there was no or almost no difference from when the compound was not tested, the test plant died. Or, the one whose growth is completely inhibited is defined as "5" and evaluated in 6 levels of 0 to 5, 0, 1, 2,
Shown as 3, 4, and 5.

Test Example 1 Upland soil treatment test Field soil was packed in a cylindrical plastic pot having a diameter of 10 cm and a depth of 10 cm, and seeds of green flesh, Malaga morning glory and velvetleaf were sown.
Covered with soil. A predetermined amount of the compound to be tested, which was made into an emulsion according to Formulation Example 2 or 5, was diluted with water equivalent to 10 liters per are, and the soil surface was treated with a small sprayer. After the treatment, the plants were grown in a greenhouse for 20 days and the herbicidal efficacy was investigated. The results are shown in Table 5.

Test Example 2 Field foliage treatment test Field soil was filled in a cylindrical plastic pot having a diameter of 10 cm and a depth of 10 cm, and radish and velvet were sown and grown in a greenhouse for 10 days. Thereafter, a predetermined amount of the test compound, which was made into an emulsion according to Formulation Example 2 or 5, was diluted with water containing 10 liters of spreading agent per are, and the leaves were treated from above the plant with a small sprayer. Grow in the greenhouse for 20 days after treatment,
The herbicidal efficacy was investigated. The results are shown in Table 6.

Test Example 3 Paddy field flooding treatment test: Paddy soil was packed in a cylindrical plastic pot with a diameter of 8 cm and a depth of 12 cm, and seeds of rice ball millet, broad-leaved weeds (Azena, Kishigusa, Mizohakobe) and firefly were mixed at a depth of 1-2 cm. It is. After flooding to make paddy fields, tubers of Urikawa were embedded at a depth of 1 to 2 cm, and rice at the two-leaf stage was further transplanted and grown in a greenhouse. 6 days later (early generation of each weed)
And the test compound which was made into an emulsion according to Formulation Example 2 or 5
It was diluted with milliliter water and treated on the water surface. After processing 20
The plants were cultivated in a greenhouse for one day and the herbicidal efficacy was investigated. The results are shown in Table 7.

Test Example 4 Upland soil treatment test Field soil was packed in a vat having an area of 33 × 23 cm ² and a depth of 11 cm,
Peanut, soybean, cotton, corn, malaga morning glory, velvetleaf, physalis perch, amaranthus, white
Ebisugusa, barnyard grass, green squirrel, and sorghum sorghum were sown, and the soil was covered to a thickness of 1 to 2 cm. A predetermined amount of the compound to be tested, which was made into an emulsion according to Formulation Example 2 or 5, was diluted with water equivalent to 10 liters per are, and the soil surface was treated with a small sprayer. After the treatment, the plants were grown in a greenhouse for 20 days and the herbicidal efficacy was investigated. The results are shown in Table 8.

Test Example 5 Upland field foliage treatment test Field up soil was packed in a vat having an area of 33 × 23 cm ² and a depth of 11 cm,
Maize, Malaga morning glory, giant fir tree, velvetleaf, physalis sycamore, and blue-spotted gall were sowed and cultivated for 18 days.
Then, a predetermined amount of the test compound, which was made into an emulsion according to Formulation Example 2 or 5, was diluted with 5 liters of water per 1 are containing a spreading agent, and the whole foliage portion was applied from above the plant body with a small sprayer. Treated uniformly. At this time, the growth of weeds and crops varies depending on the grass species, but it is 1 to 4 leaf stage and the plant height is 2
It was ~ 12 cm. The herbicidal efficacy was investigated 20 days after the treatment. The results are shown in Table 9. This test was conducted in a greenhouse throughout the entire period.

Test Example 6 Paddy field flooding test 1 / 5000a Wagner pot was filled with paddy field soil, and seeds of Pinus millet and winter buds were mixed to a depth of 1 to 2 cm. After flooding to make it into a paddy field, rice at the 3-leaf stage was transplanted and grown in a greenhouse. Five days later (the germination stage of Laevis mellifera), a predetermined amount of the test compound, which was made into an emulsion according to Formulation Example 2 or 5, was diluted with 10 ml of water and treated on the water surface to a water depth of 4 cm. After the treatment, the plants were grown in a greenhouse for 20 days and the herbicidal efficacy was investigated. The results are shown in Table 10. In addition, from the day after the treatment, water was leaked in an amount corresponding to a water depth of 3 cm per day for 2 days.

<Effects of the Invention> The compound of the present invention has an excellent herbicidal effect and has little chemical damage to crops, and is therefore excellent as an active ingredient of a herbicide.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Ryo Sato 4-2-1 Takashi, Takarazuka-shi, Hyogo Sumitomo Kagaku Kogyo Co., Ltd. (56) Reference JP-A-62-155276 (JP, A) JP JP-A-62-132872 (JP, A) JP-A-62-132873 (JP, A) JP-A-62-132874 (JP, A)

Claims (2)

[Claims] 1. A general formula (In the formula, R ¹ represents a lower alkoxy group, a lower cycloalkoxy group, a lower haloalkoxy group, a lower alkoxyalkoxy group, a lower alkoxycarbonylalkoxy group, a lower alkylamino group or a lower dialkylamino group, and R ² represents a hydrogen atom or Represents a lower alkyl group, n
Represents 1 or 2. ) A benzothiazolone derivative represented by. 2. General formula (In the formula, R ¹ represents a lower alkoxy group, a lower cycloalkoxy group, a lower haloalkoxy group, a lower alkoxyalkoxy group, a lower alkoxycarbonylalkoxy group, a lower alkylamino group or a lower dialkylamino group, and R ² represents a hydrogen atom or Represents a lower alkyl group, n
Represents 1 or 2. ) A benzothiazolone derivative represented by (4) is contained as an active ingredient.