Synthesis of deuterium labelled analogues of S-oxidative metabolites of thioridazine

The tetradeuterated analogues of the 2-methylsulfinyl (mesoridazine) and 2-methylsulfonyl (sulforidazine) metabolites of (±)-10-[2-(1-methyl-2-piperidinyl)ethyl]-2-methylthio-10H-phenothiazine (thioridazine) were obtained by treatment of the appropriate 2-substituted phenothiazine with the synthon, 2-(2-chloro[1,1,2,2-2H4]-ethyl)-1-methylpiperidine. Selective ring sulfur oxidation using nitrous acid of these deuterated products as well as the previously reported analogous isotopomer of thioridazine gave the tetradeuterated analogues of the 5-sulfoxide metabolites of thioridazine, mesoridazine and sulforidazine. (author)