IMPROVED PROCESS FOR SYNTHESIS OF MACITENTAN ABSTRACT: Disclosed herein is an improved and industrially feasible process for synthesis of Macitentan, N-[5-(4-Bromophenyl)-6-[2-[(5-bromo-2-pyrimidinyl)oxy]-ethoxy]-4-pyrimidinyl]-N- propyl sulfamide and its intermediates thereof in good yield and purity.