反应详情

Thionyl chloride (70 ml) is added to 2-bromo-4,5-difluorobenzoic acid (39.5 g), and the mixture is allowed to stand at room temperature for one hour and then refluxed for one hour. After completion of the reaction, the excess thionyl chloride is distilled off under reduced pressure. The oily residue is distilled under reduced pressure to give 2-bromo-4,5-difluorobenzoyl chloride (37.8 g) as a pale yellow oily substance, b.p. 121°-123° C. (32 mmHg).

1. temperaturerefluxed for one hour
2. customAfter completion of the reaction
3. distillationthe excess thionyl chloride is distilled off under reduced pressure
4. distillationThe oily residue is distilled under reduced pressure