JPH0417187B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is based on the general formula [In the formula, R represents a lower alkyl group, a lower alkenyl group, or a lower alkynyl group, and X represents a chlorine atom or a bromine atom. ] The present invention relates to 5-amino-4-fluoro-2-halophenyl sulfide (hereinafter referred to as the compound of the present invention) represented by the following and a method for producing the same. General formula that can be produced by reacting the compound of the present invention with 3,4,5,6-tetrahydrophthalic anhydride [In the formula, R and X have the same meanings as above. ] 5-phenyl-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione derivatives are harmful to major crops such as corn, wheat, rice, and soybean. It shows no chemical damage and has sufficient herbicidal efficacy against many weeds. Compounds of the invention typically have the general formula [In the formula, R and X have the same meanings as above. ] 5-(N-acetylamino)-4-fluoro-2-halophenyl sulfide shown in a solvent using an excess amount of mineral acid at 80°C to 100°C for 1 hour to
It can be produced by reacting for 10 hours and then hydrolyzing. Solvents that can be used in the above production method include:
methanol, ethanol, isopropanol, t
-Alcohols such as butanol, octanol, cyclohexanol, methyl cellosolve, ethylene glycol, glycerin, water, etc., or mixtures thereof. Further, examples of mineral acids include hydrochloric acid, hydrobromic acid, and sulfuric acid. After completion of the reaction, the reaction solution can be subjected to conventional post-treatments such as extraction and concentration with an organic solvent, or further purified by operations such as chromatography and recrystallization as necessary, to achieve the objective of the present invention. A compound is obtained. Note that 5-(N-acetylamino)-4-fluoro-2-halophenyl sulfide of the general formula [], which is a raw material compound in the above method, can be efficiently produced by the following method. That is, the general formula [In the formula, X represents the same meaning as above. ] 2-fluoro-4-haloacetanilide and an equivalent to an excess amount of oleum in the absence of a solvent or in concentrated sulfuric acid at 0°C to 100°C.
By reacting at ℃ for 0.5 to 5 hours and sulfonation, the general formula [In the formula, X represents the same meaning as above. ] 5-(N-acetylamino)-4-fluoro-2-halobenzenesulfonic acid shown by is produced, and then an alkali metal salt such as sodium or potassium or an organic base salt such as pyridine and the
1.0 to 5 equivalents of chlorinating agent such as phosphorus pentachloride or phosphorus oxychloride in a solvent or without solvent at 0°C to 200°C.
By reacting for 0.5 to 5 hours and chlorinating, the general formula [In the formula, X represents the same meaning as above. ] 5-(N-acetylamino)-4-fluoro-2-halobenzenesulfonyl chloride is produced, and then it is reduced by a conventional method of reducing benzenesulfonyl chlorides to benzenethiols, for example, sulfuric acid-zinc , by reacting with a reducing agent such as hydrochloric acid-stannic chloride, acetic acid-zinc, etc. at room temperature to 120°C for 15 minutes to 12 hours to obtain the general formula [In the formula, X represents the same meaning as above. ] 5-(N-acetylamino)-4-fluoro-2-halobenzenethiol is produced, and this is further combined with the general formula RY [] [wherein, R represents the same meaning as above, and Y represents a halogen represents an atom. ] It can be produced by reacting the halides shown in the following in a solvent in the presence of a dehydrohalogenating agent at 0°C to 80°C for 0.5 to 5 hours. In addition, 2-fluoro-4-haloacetanilide of the general formula [], which is a raw material compound, is
It can be produced by the production method described in Japanese Patent No. 51521. The present invention will be explained in more detail below using production examples and reference examples. Production Example (Production of Compound 5 of the Present Invention) 11.7 g of N-[4-bromo-2-fluoro-5-(2-propylthio)phenyl]acetamide was suspended in 30 ml of ethanol, and 7.5 ml of concentrated hydrochloric acid was added.
Stirred at 80°C for 2 hours. The reaction solution was concentrated, the residue was dissolved in water, neutralized with potassium carbonate, extracted with ethyl acetate, and the extract was dried and concentrated to give 4-
10 g of bromo-2-fluoro-5-(2-propynylthio)aniline was obtained. n ³¹ _D 1.6235 Some of the compounds of the present invention that can be produced by such a production method are shown in Table 1.

【table】

[Table] Reference example 1 173.2 g of N-(4-bromo-2-fluorophenyl)acetamide was suspended in 80 ml of concentrated sulfuric acid and heated at 10°C.
After dropping 340ml of 60% oleum at ~20℃,
Stir for hours. After that, the reaction solution was added dropwise to 500 g of ice water at 10°C to 20°C, the precipitated crystals were removed, and the mixture was cooled with cold water.
Washed with 400ml. The crystals are dried under reduced pressure and heat,
175.8 g of 5-(N-acetylamino)-2-bromo-4-fluorobenzenesulfonic acid was obtained. m.
p.300°C or higher In the same manner, 5-(N-acetylamino)-2-chloro-4-fluorobenzenesulfonic acid was obtained from N-(4-chloro-2-fluorophenyl)acetamide. mp300℃ or higher Reference example 2 5-(N-acetylamino)-2-bromo-4-
175.8g of fluorobenzenesulfonic acid and pyridine
130 g was added and stirred for 1 hour, and the precipitated crystals were collected and washed with diethyl ether. 199.5 g of the pyridine salt of the sulfonic acid thus obtained
was suspended in 560 ml of chloroform, and 140.7 g of phosphorus pentachloride was added.
After adding, the mixture was stirred at 60°C to 70°C for 1 hour. The reaction solution was allowed to cool, added with water, extracted with chloroform,
The extract was dried and concentrated to obtain 73.25 g of 5-(N-acetylamino)-2-bromo-4-fluorobenzenesulfonyl chloride. mp155℃~156
℃ In a similar manner, 5-(N-acetylamino)-
From 2-chloro-4-fluorobenzenesulfonic acid, 5-(N-acetylamino)-2-chloro-4
-Fluorobenzenesulfonyl chloride was obtained.
mp138℃～139℃ Reference example 3 5-(N-acetylamino)-2-bromo-4-
After dissolving 73.25 g of fluorobenzenesulfonyl chloride in 630 ml of acetic acid and adding 289.7 g of zinc,
Refluxed for an hour. The reaction solution was allowed to cool, water was added, and extraction was performed with ethyl acetate. The extract was washed with water, neutralized with an aqueous sodium bicarbonate solution, dried, and concentrated to give 5-(N-acetylamino)- 2-bromo-4
-31.38 g of fluorobenzenethiol was obtained. m.
p.157℃～158℃ In the same manner, 5-(N-acetylamino)-
5-(N-acetylamino)-2-chloro-4-fluorobenzenethiol was obtained from 2-chloro-4-fluorobenzenesulfonyl chloride.
mp156℃～158℃ Reference example 4 5-(N-acetylamino)-2-bromo-4-
After suspending 10.46 g of fluorobenzenethiol in 80 ml of 3% sodium hydroxide and adding 0.13 g of tetrabutylammonium bromide, 1-bromo-2
- 8.48 g of propyne was added dropwise. After stirring at room temperature for 12 hours, extraction was performed with ethyl acetate, and the extract was dried and concentrated to give N-[4-bromo-2-fluoro-5-(2
-propynylthio)phenyl]acetamide
11.74g was obtained. mp106°C to 107°C The following compound was obtained in a similar manner.

[Table] Next, 2-phenyl-4,5 of the general formula [],
6,7-tetrahydro-2H-isoindole-
Production examples and test examples of 1,3-dione derivatives are shown for reference. Reference example 5 10 g of 4-bromo-2-fluoro-5-(2-propynylthio)aniline and anhydrous 3,4,5,6-
6 g of tetrahydrophthalic acid was dissolved in 40 ml of acetic acid, and the mixture was stirred at 100°C to 110°C for 1 hour. The reaction solution was allowed to cool, water was added, extracted with ethyl acetate, the extract was neutralized with an aqueous sodium hydrogen carbonate solution, and then dried.
Concentrate to give 2-[4-bromo-2-fluoro-5-
(2-propynylthio)phenyl]-4,5,6,
7-tetrahydro-2H-isoindole-1,
6.5 g of 3-dione was obtained. mp115.5℃ Reference example 6 Fill a pot with an area of 30 x 23 cm ² and a depth of 11 cm with field/soil, sow soybean, cotton, Japanese mulberry morning glory, Japanese fir tree, Japanese cabbage, white grass, corn, wheat, goldenrod, and foxtail grass, 1 The soil was covered with soil to a thickness of ~2 cm. The test compound was made into an emulsion, a predetermined amount of which was diluted with water equivalent to 10 liters per are, and applied to the soil surface using a small sprayer. 20 after processing
The plants were grown in a greenhouse for one day and their herbicidal efficacy was investigated. The results are shown in Table 3.

[Table] The herbicidal efficacy is determined by visually observing the degree of budding and growth inhibition of the test plants during the survey, and ``0'' indicates that there is no or almost no difference from when no compound is used. A rating of 0 to 5 indicates that the plant is withering or its growth is completely inhibited.
It is evaluated in 6 stages of 5, and is shown as 0, 1, 2, 3, 4, and 5. Reference Example 7 A cylindrical plastic pot with a diameter of 8 cm and a depth of 12 cm was filled with rice paddy soil, and seeds of Japanese millet, broad-leaved weeds (Azeena, Azalea, Chickweed), and firefly were mixed in at a depth of 1 to 2 degrees. After flooding the fields to create a paddy field, tubers of Urikawa were buried at a depth of 1 to 2 cm, and then rice at the two-leaf stage was transplanted and grown in a greenhouse. Six days later (at the beginning of the emergence of each weed), the test compound was made into an emulsion, a predetermined amount of the emulsion was diluted with 5 milliliters of water, and the solution was applied to the water surface. After treatment, they were grown in a greenhouse for 20 days and their herbicidal efficacy was investigated. The results are shown in Table 4.

【table】

Claims (1)

[Claims] 1. General formula [In the formula, R represents a lower alkyl group, a lower alkenyl group, or a lower alkynyl group, and X represents a chlorine atom or a bromine atom. ] 5-amino-4-fluoro-2-halophenyl sulfide shown. 2 General formula [In the formula, R represents a lower alkyl group, a lower alkenyl group, or a lower alkynyl group, and X represents a chlorine atom or a bromine atom. ] A general formula characterized by hydrolyzing 5-(N-acetylamino)-4-fluoro-2-halophenyl sulfide represented by [In the formula, R and X have the same meanings as above. ] A method for producing 5-amino-4-fluoro-2-halophenyl sulfide.