Collect. Czech. Chem. Commun. 2009, 74, 347-362
Published online 2009-02-18 15:00:16

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

Jaroslav Havlíčeka,*, Zuzana Mandelováa, Ruediger Weisemannb, Ivo Střeleca, Lukáš Plačeka and Stanislav Rádla

a Zentiva, U kabelovny 130, 102 37 Prague 10, Czech Republic
b Bruker BioSpin GmbH, Silberstreifen, 76287 Rheinstetten, Germany


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.

Keywords: Candesartan cilexetil; Impurity identification; Impurity synthesis; Tetrazoles; Benzimidazoles; NMR spectroscopy; 1H-15N HMBC; MS.

References: 8 live references.