2,4,6-Trichlorobenzoyl chloride is prepared by reacting 2,4,6-trichloroaniline with N-butyllithium in a carbon dioxide atmosphere. This produces 2,4,6-trichlorobenzoic acid, which can then be refluxed in thionyl chloride to form 2,4,6-trichlorobenzoyl chloride.
Since 2,4,6-trichlorobenzoic acid is produced as a by product of the esterification process, it can be refluxed again to recreate 2,4,6-trichlorobenzoyl chloride.