Present invention is to provide in-situ preparation of intermediates, Dronedarone and pharmaceutically acceptable salts thereof in higher yield and purity starting from 2-n-butyl-3-(4-hydroxybenzoyl)-5-nitrobenzofuran. The said process is carried out without isolation and purification of intermediates and is particularly advantageous as far as environment, yields, productivity and purity of the resulting Dronedarone and pharmaceutically acceptable salts thereof. Further, the entire reaction sequence is carried out in solo solvent. Such a process eliminates time consuming steps for isolation or purification of intermediates and save time on avoiding solvent changes, solvent distillation in the process, thus making the process more efficient and with a high production capacity.