FLUOROALKANESULFONYL CHLORIDES

A simple and effective synthesis of CH2FSO2Cl and CHF2SO2Cl has been achieved, both in 49% overall yield. The (di)fluoromethyl chlorides are converted into the (di)fluoromethyl benzyl sulfides by NaOH-benzyl mercaptan in DMF. Oxidative chlorination in cold water yields the (di)fluoromethanesulfonyl chlorides. Despite identical conditions and yields, the reactions of benzyl mercaptide with CH2FCl and CHF2Cl proceed through SN2 and carbene paths, respectively, as indicated by alkylation in NaOD. The oxidative chlorination of CHF2SCH2Ph occurs at least 50% via the sulfoxide. In situ generation of benzyl mercaptide gave a 39% overall yield of CHF2SO2Cl. tert-Butyl mercaptan proved inferior in the difluoromethylation step. © 1979, American Chemical Society. All rights reserved.