A method of manufacturing of 2-ethoxy-1-((2'-((hydroxyamino)iminomethyl) biphenyl-4-yl)methyl)-1H-benzodimidazole-7-carboxylic acid and its esters, key intermediates of azilsartan synthesis

摘要

A method of manufacturing of 2-ethoxy-1-((2'-((hydroxyamino)iminomethyl) biphenyl-4-yl)methyl)-1H-benzo[d]imidazole-7-carboxylic acid and its esters of Formula I, wherein R is either H or an (un)branched C1-C4 alkyl, ArCH2, Ar2CH, or Ar3C, wherein Ar is a (un)substituted phenyl, the key intermediates for the synthesis of azilsartan, the reaction of the corresponding nitrile of formula IV being carried out with aqueous hydroxylamine in a polar aprotic solvent, or in a mixture of such solvents.