Abstract: In accordance with the present invention, aromatic ketones are prepared by the acylation of aromatic reactants using boron trifluoride as a catalyst and in a solvent medium comprising anhydrous liquid sulfur dioxide. The acylation proceeds in accordance with the equation I: ##STR1## wherein n ranges from 5 to 9, Ar is phenylene and n is 5, naphthalene and n is 7, or a bis phenylene radical having the structure: ##STR2## and n is 9; wherein Z is selected from the group consisting of a covalent carbon to carbon bond, O, S, SO.sub.2, C.dbd.O and C.sub.1 to C.sub.3 alkylene or alkylidene, X is selected from the group consisting of H, OH, halogen, C.sub.1 to C.sub.6 alkyl C.sub.1 to C.sub.6 alkoxy and combinations thereof, R is an alkyl group containing from 1 to about 16 carbon atoms and Y is selected from the group consisting of hydroxy, acyloxy and halogen.