Preparation and application of 2,6-difluoropyridine_Industrial additives

Preparation and application background of 2,6-difluoropyridine and overview of formyl phenylboronic acid

2,6-Difluoropyridine is widely used in the production of medicines, pesticides, rubber and dyes; it is an important intermediate for pesticide chemicals and is used to prepare herbicides and insecticides. It has important medicinal value and Prospects. 2,6-Difluoropyridine can be obtained by fluorination of 2,6-dichloropyridine.

Preparation and application of 2,6-difluoropyridine

Into the 500L enamel kettle, pump 252.2kg sulfolane (1g/4ml) and 50kg 2,6-dichloropyridine (1.0eq) into the system at one time, then add 43.2g potassium fluoride (2.2eq) at one time ) and 1.5kg 18-crown ether-6 (3%), stir for 20 minutes, then heat the system temperature to 180-188°C, and react at 180-188°C for 6 hours. The product is transferred out of the reaction by distillation during the reaction. The system is used to drive the reaction to completion. The fractions are washed with water, separated into liquids, and the organic phase is dried. After suction filtration, the filtrate is distilled, and the fractions at 122-124°C are collected to obtain 30.4kg of product, with a yield of 78.2% and a gas chromatography purity (GC ): 99.5%.

Preparation and application of 2,6-difluoropyridine

CN201711043007.1 discloses a method for preparing 6-fluoro-2-pyridinesulfonyl chloride, using 2,6-difluoropyridine as the starting material, and passing through the electrodeless sulfur compound Na₂S , NaHS or Na₂S_x and other substances are sulfided to prepare synthetic fluorphlogopite to persulfide, and then the persulfide is oxidized to obtain 6-fluorine-2- Pyridinesulfonyl chloride.

References

[1][China invention, China invention authorization] CN200810154715.7 A synthesis method of 2,6-difluoropyridine

[2][Chinese invention] CN201711043007.1 A method for preparing 6-fluoro-2-pyridinesulfonyl chloride