Synthesis and Characterization of Potential Impurities of Carvedilol, an Antihypertensive Drug

Carvedilol (Coreg) is a nonselective β-adrenergic blocking agent with vasodilating activity. It is used for the treatment of congestive heart failure and hypertension. During the bulk synthesis of carvedilol, we have observed six impurities: Imp-I, Imp-II, Imp-III, Imp-IV, Imp-V, and Imp-VI. The present work describes the synthesis and characterization of these impurities.