Electrochemistry provides very versatile means for the electrosynthesis, mechanistic and kinetic studies. [1]. On the other hand solvents can have a significant effect on solubility, stability and reaction rates and choosing the appropriate solvent allows for thermodynamic and kinetic control over a chemical reaction. Different solvents can affect the equilibrium constant of a reaction by differential stabilization of the reactant or product. Recently, we have dealt with the electrochemical oxidation of 4-(Piperazin-1-yl)phenols (1a,b) in aqueous solution [2]. The oxidation of these compounds is followed by many chemical reactions such as hydrolysis, hydroxylation, and/or dimerization reaction [3]. In this work the electrochemical oxidation of 4- (Piperazin-1-yl)phenols was studied in the water, acetonitrile and nitromethan by means of cyclic voltammetry and controlled-potential coulometry. The results revealed that p-quinone-imine generated of oxidation 4-(Piperazin-1-yl)phenols after the hydrolysis reaction participate in Michael-addition reactions with released piperazine of hydrolysis reaction of p-quinone imines. The present work has led to the development of a facile and environmentally friendly electrochemical method for the synthesis of some new derivatives of p-benzoquinone under green conditions. In addition, the effect of water as a solute on the electrochemical response of 4- (Piperazin-1-yl)phenols (1a,b) was examined in the acetonitrile (AN) and nitromethane (NM) solvent.
