Thionyl Chloride → 2,3,4,5-Tetrafluorobenzoyl chloride

Participants

Reaction Steps

In a 1000 ml three-neck flask with thermometer, reflux condenser, 50 ml dropping funnel, mechanical stirrer, bubble counter, exhaust pipe and oil bath 0.5 ml of dimethylformamide were added with stirring to a suspension of 97.05 g of 2,3,4,5-tetrafluorbenzoic acid (8; 0.5 mol) in 100 ml of n-hexane. In the course of 10 min. 44 ml of thionyl chloride (0.61 mol) were added, and the reaction mixture was heated for 17 hours at reflux temperature. After cooling to room temperature, the n-hexane was evaporated off at 55° C. and increasing vacuum for 30 min. (at the end 3 min. at 55° C./40 torr). 104.8 g of 2,3,4,5-tetrafluoro-benzoic acid chloride (9) were obtained as a yellow, clear liquid, which was directly used in the next step.

Provenance & Evidence