One pot synthesis of 4-(1,2-dihydro-2-oxobenzodimidazol-3-yl)butanoic acid, a key intermediate of zilpaterol

摘要

The present invention relates to one pot process for the preparation of 4-(1,2-dihydro-2-oxobenzo[d]imidazol-3-yl)butanoic acid of Formula-I, which is a key intermediate and its use in the preparation of Zilpaterol, which comprises condensation of methyl-4-chloro butyrate with 1-(prop-1-en-2-yl)-1H-benzo[d]imidazol-2(3H)-one in presence of a base and suitable solvent to give corresponding ester derivative, further hydrolyzation and acidification in presence of inorganic solvent to obtain Formula-I.;