The reaction of 1,1-Dichloro-2,2-di(p-chlorophenyl)ethane (DDD) with sodium thiophenoxide in ethanol

Abstract

The reaction of 1,1-dichloro-2,2-di(p-chlorophenyl)ethane (DDD) with sodium thiophenoxide in ethanol yields the unexpected product Ar₂C=CHSPh (Ar = p-ClC₆H₄) by a second-order process. Elimination-addition- decomposition; elimination-substitution; and direct disubstitution- decomposition mechanisms have been considered. The absence of a β- deuterium isotope effect in the reaction (contrasted with k_H/k_D = 4.6 for the E2 elimination using sodium ethoxide as the base) argues for direct S_N2 substitution of both aliphatic chlorines of DDD followed by decomposition of Ar₂CHCH(SPh)₂ (which was not detected) to the observed product and thiophenol.