Electrochemical Oxidation of 2,3-dihydrophthalazine-1,4-dione in the Presence of Indole Derivatives

Abstract

The electrochemical oxidation of 2,3-dihydrophthalazine-1,4-dione (1) has been studied in the presence of indole derivatives as nucleophiles in a water/acetonitrile mixture by means of cyclic voltammetry and controlled-potential coulometry. Results indicate that electrogenerated phthalazine-1,4-dione (1ox) participates in a Michael type addition reaction with indole derivatives (2 and 3) via an EC mechanism. In this work, we propose a mechanism for the electrode process. The electrochemical synthesis of indoyl- phthalazines (4 and 5) has been successfully performed at a carbon rod electrode and in an undivided cell.