Electrochemical Study of Bromide in the Presence of 1,3-Indandione. Application to the Electrochemical Synthesis of Bromo Derivatives of 1,3-Indandione

The electrochemical oxidation of bromide in the presence of 1,3-indandione (1) in water/acetic acid and methanol/acetic acid mixtures has been studied by cyclic voltammetry and controlled-potential coulometry. The results indicate the participation of 1,3-indandione in the bromination reaction. On the basis of the electroanalytical and preparative results a reaction mechanism including electron transfer, chemical reaction and regeneration of bromide was discussed. The electrochemical synthesis of bromo derivatives of 1,3-indandione (2-3) has been successfully performed at constant current, in an undivided cell, in good yield and purity.