Electrochemical Oxidation of p-Aminoacetanilide in Aqueous Solutions: A Green Electrochemical Protocol for the Synthesis of Azo Dyes

For the first time, this paper presents the results of electrochemical oxidation of p-aminoacetanilide in aqueous solution with different pH values. The data indicate that electrochemically generated p-quinone-diimine is unstable in acidic and alkaline solution. It is hydrolyzed in acidic (pH range of 1-6) and alkaline (pH range of 12-13) media and it is dimerized and trimerized in intermediate pH values. The observed homogeneous rate constants (k(obs)) of the coupling reaction of p-aminoacetanilide with electrochemically generated p-quinone-diimine, was estimated by comparison of the experimental cyclic voltammograms with the digital simulated results in the pH range 7-9. In addition, based on electrochemical data, a green electrochemical protocol for the synthesis of a new yellow azo dye involving electrochemical oxidation of p-aminoacetanilide in aqueous phosphate buffer and in an undivided cell, using carbon anode is described. (C) 2016 The Electrochemical Society. All rights reserved.