Patent ID: 6420601
Filing Date: 2002-07-16
Classification: C07C

Abstract:
A process for the preparation of 3,5-bis(trifluoromethyl)benzoyl chlorides of formula (I) wherein X is hydrogen, fluorine, or chlorine, comprising (1) converting 3,5-dimethylbenzoic acids of formula (V) wherein X has the meaning given for formula (I), into the corresponding acid chlorides of formula (IV) wherein X has the meaning given for formula (I), (2) completely free-radically chlorinating the acid chlorides of formula (IV) in the side chains to give 3,5-bis(trichloromethyl)benzoyl chlorides of formula (III) wherein X has the meaning given for formula (I), (3) fluorinating the 3,5-bis(trichloromethyl)benzoyl chlorides of formula (III) with anhydrous hydrogen fluoride and/or antimony pentafluoride to give 3,5-bis(trifluoromethyl)benzoyl fluorides of formula (II) wherein X has the meaning given for formula (I), and (4) reacting the 3,5-bis(trifluoromethyl)benzoyl fluorides of formula (II) with silicon tetrachloride in the presence of a further Lewis acid to give the compounds of the formula (I).