N,N-DIBROMOBENZENESULFONAMIDE: A USEFUL REGENRABLE REAGENT FOR BROMINATION OF VARIOUS CARBANIONIC SUBSTRATES

N,N-Dibromobenzenesulfonamide(dibromoamine-B), which is prepared easily in high yield, has been employed as effective brominating agent for carbanionic substrates under mild conditions. β-Diketones and β-ketoesters were brominated by this reagent without using any bases. The reagent can be recovered, rebrominated, and reused several times.