Patent ID: 7126011

Claim:
A process for the preparation of at least one thioxanthone represented by Formula I: which process comprises adding a reactant mixture of a 2-chlorothiobenzoyl chloride represented by Formula II: and an aromatic compound represented by Formula III: to a slurry of a Friedel-Crafts catalyst in an organic Friedel-Crafts solvent, wherein: R 1 and R 2 are each independently selected from hydrogen, halogen, C 1-10 -alkyl, C 6-12 -aryl or C 1-10 -alkoxy radicals, R 3 , R 4 and R 5 are each independently selected from hydrogen, halogen, hydroxyl, C 1-10 -alkyl, C 5-8 -cycloalkyl, C 6-12 -aryl, C 1-10 -alkoxy, —X 1 —C(O)OR 6 , —C(O)R 7 , —C(O)OR 8 or —C(O)NR 9 R 10 , or R 3 and R 4 together form a fused ring having from 5 to 7 ring members, X 1 is C 1-10 -alkylene, R 6 , R 7 and R 8 are independently selected from C 1-10 -alkyl, C 6-12 -aryl or C 7-11 -aralkyl, and R 9 and R 10 are independently selected from hydrogen, C 1-10 -alkyl, C 6-12 -aryl or C 7-11 -aralkyl.