Chemical oxidative polymerization of benzocaine

Novel electroactive paramagnetic ortho-coupled aniline oligomers functionalized with ethyl ester groups were synthesized by the oxidation of the 4-carbethoxyaniline, well known anesthetic benzocaine, with ammonium peroxydisulfate in an acidic aqueous medium at room temperature. Oligobenzocaines were characterized by elemental analysis, gel-permeation chromatography, conductivity measurements, FTIR, Raman and EPR spectroscopies, and scanning electron microscopy. Theoretical study of the mechanism of benzocaine oxidation has been based on the AM1 and RM1 semi-empirical quantum chemical computations of the heat of formation and ionization energy of the benzocaine, protonated benzocaine, generated reactive species and reaction intermediates, taking into account influence of pH and solvation effects. Electroactivity of the oligobenzocaines was studied by the cyclic voltammetry.