SYNTHESIS AND CHARACTERIZATION OF NOVEL AND POTENTIALN IMPURITIES OF DARIFENACIN, A POTENT MUSCARINIC M3 RECEPTOR ANTAGONIST

Darifenacin Hydro bromide (Enablex) is a potent muscarinic M3 receptor antagonist, used for the treatment of overactive bladder with symptoms of urge urinary incontinence. During the large scale synthesis of darifenacin hydro bromide, four potent impurities were observed viz.., darifenacin acid, darifenacin desnitrile, darifenacin vinyl phenol, darifenacin ether. The present work describes the synthesis and characterization of these four impurities.