PROCESS FOR BROMINATING UNSATURATED ORGANIC COMPOUNDS WITH REMOVAL OF QUATERNARY AMMONIUM OR QUATERNARY PHOSPHONIUM MONOCHLORIDES

摘要

Unsaturated organic compounds are brominated with a quaternary ammonium tribromide or a quaternary phosphonium tribromide, especially when the bromination is conducted in a chlorinated solvent. A quaternary ammonium or quaternary phosphonium monobromide salt is produced in the reaction, together with some amount of quaternary ammonium or quaternary phosphonium monochloride salt. The monochloride salt is converted to the corresponding quaternary ammonium monobromide salt by reacting it with a source of bromide ions. The monobromide salt is then reacted with bromine to regenerate the quaternary ammonium or phosphonium tribromide, which is recycled into the bromination reaction. This process reduces the amount of chlorine that is incorporated into the brominated product.