3-Chloro-2,4,5,6-tetrafluoropyridine

3-Chloro-2,4,5,6-tetrafluoropyridine can be prepared from 3,5-dichloro-2,4,6-trifluoropyridine.

70g of 3,5-dichloro-2,4,6-trifluoropyridine, 22g of anhydrous potassium fluoride were mixed with 150mL of cyclobutanesulfone, and the reaction was stirred at 180C for 2.5h, lowered to room temperature, and samples were taken to monitor the complete conversion of the raw materials, and the reaction solution was decanted into 1L of ice water, and extracted with dichloromethane. The organic phase was washed with water and saturated sodium chloride solution in turn, dried with anhydrous sodium sulfate, concentrated under reduced pressure, the crude product obtained was purified by distillation to obtain 46.5g of colorless liquid, 3-chloro-2,4,5,6-tetrafluoropyridine, GC content of 98.3%, yield 72%.