N-bromosuccinimide reactions of some heterocycles in the presence or absence of water: An overview of ring versus side chain bromination for the synthesis of important brominated heterocyclic synthons

Reactions of various heterocycles 1-6 with N-bromosuccinimide in the presen ce or absence of water have been studied for side chain versus ring bromina tion to afford some new and important heterocyclic synthons. Interestingly, the N-bromosuccinimide reaction in the presence of perchloric acid a new c ondition, affords exclusively the new dibromo aminopicoline 1f, which is no t obtained by other presently studied methods.