Thionyl Chloride → 4-Bromo-2,5-difluorobenzoic acid chloride

Participants

Reaction Conditions

Reaction Steps

A total of 2075 g (8.79 moles) of crude 4-bromo-2,5-difluorobenzoic acid from step (b) was treated with thionyl chloride (2.0 L), and the resulting slurry was slowly heated to reflux (90° C. internal) to obtain a solution. After removal of excess thionyl chloride, the product was collected at 85°-95° C. (oil pump, vacuum not measured), leaving a solid residue. The distillate afforded 2045 g (91%) of a liquid which was used directly in the next step.

Provenance & Evidence