A method of manufacturing 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.
