HYDROLYSIS OF N-PHENYLALKANESULFINAMIDES IN AQUEOUS MINERAL ACIDS

Abstract

The acid-catalyzed hydrolysis of N-phenylalkanesulfinamides (RSONHPh; 1, R = (i)Pr; 2, R = (t)Bu; 3, R = 1-adamantyl) has been studied in aqueous mineral acids. Hydrolysis was found to proceed via a slow spontaneous (uncatalyzed) pathway, an A-2 (bimolecular) acid-catalysis pathway, and an acid-dependent nucleophilic catalysis pathway, the last of which predominates in hydrobromic and hydrochloric acid solutions. A mechanistic switch over from A-2 to A-1 was detected for compounds 2 and 3 in concentrated sulfuric acid. Order of catalytic activity, effect of added salts, Arrhenius parameters, kinetic solvent isotope, and solvent effects are all consistent with the proposed mechanisms.