Studies of Sulfinyl Radicals. 1. Thermal Decompositions of Benzhydryl p-Tolyl Sulfoxide and Benzhydryl Methyl Sulfoxide

Article abstract of DOI:10.1021/jo00316a009

The kinetics and mechanism of the thermal decompositions of benzhydryl p-tolyl sulfoxide (BTSO) and benzhydryl methyl sulfoxide (BMSO) were studied.Product analysis, ESR, and CIDNP results showed that both sulfoxides gave p-toluenesulfinyl and methanesulfinyl radicals, respectively, by the scission of carbon-sulfur bonds at 100-130 deg C.The presence of a small amount of a base such as pyridine has been found to suppress the formation of other products than the coupling products (the corresponding thiosulfonates and tetraphenylethane), which may be formed by ionic reactions of BTSO and BMSO.The mechanism of BTSO decomposition is complex, since it is in equilibrium with benzhydryl p-toluenesulfenate (BTSN) at 100-130 deg C.On the other hand, BMSO, showing simple decomposition behavior, indicated that the decomposition rates decreased on the addition of hydroxylic solvents.