Electroselective α-bromination of acetophenone using in situ bromonium ions from ammonium bromide

摘要

A greener and expeditious method for the side chain bromination of acetophenone using in situ generated bromonium ions from NH _(4) Br and a catalytic amount of H _(2) SO _(4) as a supporting electrolyte in a H _(2) O:CH _(3) CN medium at ambient temperature has been developed in an undivided cell equipped with a Pt/Pt electrode. This method results in a good yield (80%) of α-bromo acetophenone with high selectivity when only 2 F of electricity was passed. Optimization studies such as variation of the current density, charge passed, solvent, solvent/water ratio, acid, acid strength, bromide salt, bromide salt concentration, etc. , are carried out and reported.