JPH022877B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel compound 3-chloro-2,6-difluorobenzonitrile. This product is useful as a raw material for various agricultural chemicals and medicines.

The compound of the present invention can be easily produced by the method described below.

That is, 3-chloro,2,6-difluorobenzonitrile is prepared by combining 2,3,6-trichlorobenzonitrile and potassium fluoride with dimethylsulfoxide, dimethylsulfone, sulfolane, 1,3-
It is obtained by reacting in an aprotic polar solvent such as dimethyl-2-imidazolidinone at a temperature of 120 to 220°C for 0.5 to 5 hours.

The raw material 2,3,6-trichlorobenzonitrile is produced by mixing 2,3,6-trichlorotoluene with air and ammonia gas at a temperature of 350 to 400°C in the presence of a catalyst such as vanadium-iron. It can be easily obtained by gas phase reaction.

Next, specific synthesis examples of the compounds of the present invention will be described.

Synthesis Example 3 - Synthesis of chloro-2,6-difluorobenzonitrile (1) Synthesis of 2,3,6-trichlorobenzonitrile An air-cooled receiver is attached to the outlet of the reaction tube, and a catalyst flow system with two raw material supply pipes A catalyst (element weight ratio; Al:
2,3,6-trichlorotoluene was dissolved in benzonitrile and vaporized from one supply pipe, and further diluted with nitrogen gas (molar ratio: 2, 3,6-trichlorotoluene:benzonitrile:nitrogen=0.5:
0.5:5) was supplied at a rate of 19.5 g/hour of 2,3,6-trichlorotoluene, and a mixed gas of ammonia and air (molar ratio; ammonia:air = 10:16) was supplied from the other supply pipe. 360°C by supplying ammonia at a rate of 36g/hour
The reaction was carried out at a temperature of The residence time of the reaction mixture in the tube at this time was 25 seconds.

After continuing the reaction for 10 hours, the reaction product in the receiver was extracted with methylene chloride, the extracted layer was washed with water, concentrated, and the concentrate was recrystallized with n-hexane. 85g of material was obtained.

(2) Synthesis of 3chloro-2,6-difluorobenzonitrile 206.5 g of 2,3,6-trichlorobenzonitrile obtained by the method (1) above was dissolved in 800 g of dimethyl sulfoxide to form a solution, and in this Add 145.3g of potassium fluoride and heat to 170℃ while stirring.
The reaction was carried out at a temperature of 1.5 hours. After the reaction was completed, the reaction mixture was poured into water and extracted with methylene chloride. After the solvent is distilled off, the boiling point is 95℃/
166.6 g of the target product was obtained at 11 mmHg.

The 3-chloro-2,6-difluorobenzene of the present invention can be chemically converted into a highly physiologically active substance. Therefore, it was confirmed that these derivatives are useful as intermediates for synthesizing compounds having agricultural and pharmaceutical activities.

For example, 2,6-difluorobenzonitrile is obtained by dissolving 3-chloro-2,6-difluorobenzonitrile in methanol and reacting it in the presence of a palladium carbon catalyst and triethylamine at a hydrogen pressure of 5 kg/cm ² . This product is heated and dissolved at 70°C, added dropwise to 90°C sulfuric acid, and reacted at 70-80°C to obtain 2,6-difluorobenzamide. Further, this product was dissolved in 1,2-dichloroethane, oxalyl chloride was added dropwise thereto at 20 to 40°C, and the mixture was reacted under reflux.
- difluorobenzoyl isocyanate, and a pre-prepared 3,5-
A dioxane solution of dichloro-4-(3-chloro-5-trifluoromethyl-2-pyridyloxy)aniline was added dropwise at 40 to 50°C to react with N-
(2,6-difluorobenzoyl)-N′-[3,5
-dichloro-4-(3-chloro-5-trifluoromethyl-2-pyridyloxy)phenyl]urea (melting point 203-205°C) can be obtained.

This derivative is effective in controlling various harmful insects, especially harmful insects, as described in JP-A-54-125677.

Claims (1)

[Claims] 1 3-chloro-2,6-difluorobenzonitrile.