A novel electrochemical method for the synthesis of 2,4-diamino-6-hydroxybenzofuro[2,3-b]pyridine-3-carbonitrile derivatives

The electrochemical oxidation of hydroquinones has been studied in the presence of 2-aminoprop-1-ene-1,1,3-tricarbonitrile as a nucleophile in aqueous solution using cyclic voltammetry and controlled potential coulometry. The results indicate that the quinones derived from hydroquinones participate in Michael addition and then intramolecular nucleophilic addition to yield benzofuro[2,3-b]pyridine derivatives. The electrochemical synthesis of these new 2,4-diamino-6-hydroxybenzofuro[2,3-b]pyridine-3-carbonitrile derivatives has been performed successfully at a carbon-rod electrode in an undivided cell in good to excellent yields at room temperature.