An Improved and Efficient Process for the Production of Dronedarone Hydrochloride, an Antiarrhythmia Drug

An improved, high-yielding, and efficient process for the production of dronedarone hydrochloride (1), a class III antiarrhythmia drug for the prevention of cardiac arrhythmias such as atrial fibrillation (AF) is described. The developed process avoids isolation of unstable intermediates at several stages by telescoping the steps upon individual optimization, thereby minimizing the turnaround time of the batch cycle and increasing the throughput. Potential impurities (byproducts) arise during the reaction at various stages, and carry-over impurities from starting materials were controlled selectively by designing reaction conditions and suitable workup procedures, resulting in an increased overall yield from 33% (as per processes reported in the literature) to 66%.