Anodic oxidation of n-acylazacycloalkanes in methanol

The electrochemical properties of three cyclic amides of the type N-acylazacycloalkanes (5-, 6- and 7-membered rings) have been investigated in acetonitrile by cyclic voltammetry. Their preparative scale oxidation in methanol at C anodes under various electrochemical conditions (current density, electricity consumption and supporting electrolytes) has been performed. The outcome indicates that four major products were formed by all three substrates: cyclic eneamides (c), α-methoxy, cyclic α'-eneamide (c), α-methoxy- (b) and α,α'-dimethoxy (d) cyclic amides. Their relative ratio was found to be highly dependent on the nature of the electrolyte used and current density.