JOURNAL of the Tunisian Chemical Society

The electrochemical oxidation of p-xylene in acetonitrile is carried out at the electrode and by homogeneous redox catalysis. The mechanistic investigation by means of cyclic voltammetry has shown that the anodic process obeys an ECE (or ECDisp) type mechanism where the first electron transfer is the rate determining step and is followed by a rapid deprotonation of the cation radical obtained in the above step. The preparative electrolysis, carried out at a constant potential located on the first wave, led to a nucleophilic substitution of a lateral methyl group. The products obtained depended on the reaction media. Thus, in the absence of a base, the main product was N-(4-methylbenzyl) acetamide. Alternatively. oxidation of p-xylene by means of homogeneous redox catalysis with organic mediators, allowed the determination of the deprotonation rate constant of p-xylene cation radical. Furthermore, it led to a selective transformation of p-xylene in N-(4-methylbenzy) acetamide with an important energetic gain.

N. Ben Salah, F. Matoussi

electron transfer, p-xylene, deprotonation, homogeneous redox catalysis

Pages 285-294