How is 2,4,5-Trifluorobenzoyl chloride (CAS: 88419-56-1) typically synthesized?

2,4,5-Trifluorobenzoyl chloride is typically synthesized by the chlorination of 2,4,5-trifluorobenzoic acid in the presence of thionyl chloride. This process involves the use of a catalytic amount of thionyl chloride to facilitate the introduction of the chlorine atom at the benzylic position. The reaction is carried out under anhydrous conditions to minimize side reactions.