The role of acid catalysis in the electrosynthesis of <Emphasis Type="Italic">N</Emphasis>-(2,5-dimethoxyphenyl)azoles

The influence of the acid components of the medium on the anodic 2,5-dimethoxy-phenylation of various azoles at the nitrogen atom was studied for constant-current electrolysis of the mixture azole—1,4-dimethoxybenzene in an undivided cell. Elimination of azole functions in the key steps of the process can be catalyzed by such electrophilic species as Brønsted (AcOH) and Lewis acids (ZnCl₂) and even the radical cation generated in the anodic oxidation of 1,4-dimethoxybenzene. The data obtained provided evidence for the existence of the arenonium cation as a key reaction intermediate.