How is 2,5-Dichlorobenzoyl chloride (CAS: 2905-61-5) typically synthesized?

2,5-Dichlorobenzoyl chloride is typically synthesized by the reaction of 2,5-dichlorobenzoic acid with thionyl chloride. Commonly, thionyl chloride is added to a solution of 2,5-dichlorobenzoic acid and the mixture is heated under reflux to enhance the reaction. The yield is generally high, and the process is conducted under mild conditions to avoid overoxidation of the aromatic ring.