Electrochemical synthesis of amino-substituted 1,2-benzoquinone derivatives

The electrooxidation of 3-substituted catechols (1) has been studied in the presence of dibenzylamine (3) in water + acetonitrile (90/10) solution, using electrochemical and spectroelectrochemical methods. The o-benzoquinones (2) derived from catechols (1) participate in Michael addition reactions with dibenzylamine (3) to form the corresponding monoamino-substituted o-benzoquinones (5). We propose a mechanism for the electrode process. An efficient electrochemical synthesis of amino-substituted 1,2-benzoquinone derivatives (5) has been performed at a carbon rod electrode in a two-compartment cell.