Electrochemical synthesis of the new substituted phenylpiperazines

Electrochemical oxidation of 1-(4-(4-hydroxyphenyl)piperazin-1-yl)ethanone (1) has been studied in the presence of arylsulfinic acids (3a–c) as nucleophiles in aqueous solutions using cyclic voltammetry and controlled-potential coulometry methods. The results revealed that quinone-imine derived from oxidation of 1 participates in Michael type addition reaction with 3a–c and via an EC mechanism converts to the corresponding new phenylpiperazine derivatives. The present work has led to the development of a facile and environmentally friendly reagent-less electrochemical method for synthesis of some new phenylpiperazine derivatives in aqueous solutions with high atom economy and safe waste under ambient conditions and in an undivided cell using a carbon electrode.