During process optimization of Escitalopram oxalate novel impurities, 6 and 7 were observed, which were isolated and characterized, and the proposed structure was confirmed by chemical synthesis. Investigation of the cause of impurities formation improved the yield and purity of the drug product during the bulk API synthesis.

An efficient scalable synthesis for dronedarone hydrochloride (2) via Friedel−Craft acylation of 2-(-2-butyl-1benzofuran-5-yl)-1H-isoindole-1,3(2H)dione ( 12) with 4-(3-chloropropoxy) benzoic acid (13) in good yield and high purity has been developed by using Eaton's reagent instead of hazardous and toxic metal halide catalyst like AlCl 3 or SnCl 4 .