Monomethylation of Aromatic Rings by Friedel-Crafts Reaction with Chloromethyl Sulfide

Abstract

A novel method for the introduction of a methyl group into aromatic rings is described. Friedel-Crafts reactions of ethyl a-(chloromethylthio)acetate (3k) and α-chloromethylthio-γ-butyrolactone (3m) with an arene in the presence of stannic chloride gave ethyl α-(arylmethylthio)-acetate (6) and a-arylmethylthio-y-butyrolactone (7), respectively, which were easily converted to the corresponding methylated arene (8) by reductive desulfurization with Raney nickel or zinc dust-acetic acid. © 1986, The Pharmaceutical Society of Japan. All rights reserved.