Crystal structure of azilsartan methyl ester ethyl acetate hemisolvate

Abstract

The title compound, C26H22N4O5 (systematic name: methyl 2-ethoxy-1-{4-[2-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)phenyl]benzyl}-1H-1,3-benzodiazole-7-carboxylate ethyl acetate hemisolvate), was obtained via cyclization of methyl (Z)-2-ethoxy-1-{(2′-(N′-hydroxycarbamimidoyl)-[1,1′-biphenyl]-4-yl)methyl}-1H-benzo[d]imidazole-7-carboxylate with diphenyl carbonate. There are two independent molecules (A and B) with different conformations and an ethyl acetate solvent molecule in the asymmetric unit. In molecule A, the dihedral angle between the benzene ring and its attached oxadiazole ring is 59.36 (17); the dihedral angle between the benzene rings is 43.89 (15) and that between the benzene ring and its attached imidazole ring system is 80.06 (11)°. The corresponding dihedral angles in molecule B are 58.45 (18), 50.73 (16) and 85.37 (10)°, respectively. The C—O—C—Cm (m = methyl) torsion angles for the ethoxy side chains attached to the imidazole rings in molecules A and B are 93.9 (3) and −174.6 (3)°, respectively. In the crystal, the components are linked by N—H...N and C—H...O hydrogen bonds, generating a three-dimensional network. Aromatic π–π stacking interactions [shortest centroid–centroid separation = 3.536 (3)Å] are also observed.

Keywords

• crystal structure
• azilsartan
• azilsartan methyl ester
• antihypertension