Identification, synthesis and structural determination of some impurities of candesartan cilexetil

All principal candesartan cilexetil impurities and/or degradation products were synthesized and identified. The differentiation of N-1 and N-2 ethylated candesartan cilexetil derivatives was performed using 1D and 2D NMR experiments. The influence of the magnetic field on the resolution and sensitivity of NMR experiments is shown. Selective hydrolysis of these compounds then provided corresponding producrs of hydrolysis of the ethoxy group.