Electrochemical oxidation of aminophenols in the presence of benzenesulfinate

The anodic oxidation of aminophenols and their amino-protected derivatives was investigated by using cyclic voltammetry and preparative electrolysis methods. The results showed that like the catechols the amino-protected aminophenol could also undergo Michael addition, and that the benzenesulfonate group was regioselectively introduced at the meta-position of the amino group. In contrast, the expected products were not formed from the oxidation of unprotected aminophenols. Finally, a reaction mechanism is proposed.