Abstract Efficient, mild syntheses of the three major metabolites 2–4 of the important antipsychotic drug thioridazine (1) have been developed. The cardiotoxic metabolite 2 with a ring sulfoxide moiety was prepared in 96% yield by oxidation of 1 with NaIO 4 under acidic conditions. Four different procedures were elaborated for the selective side-chain sulfide oxidation of 1 to mesoridazine (3), giving rise to yields of up to 91%. Finally, sulforidazine ( ...
