Abstract: | The crystal structures of three angiotensin-II receptor antagonists involving different spacer groups (CO, CONH and NHCO) between the aryl rings are presented, namely 2-{4-(3-butyl-1,4-dioxo-2,3-diazaspiro4.4]non-2-yl)methyl]benzoyl}benzoic acid, C26H28N2O5, (I), 2-{4-(3-butyl-1,4-dioxo-2,3-diazaspiro4.4]non-2-yl)methyl]benzamido}benzoic acid, C26H29N3O5, (II), and 2-{4-(3-butyl-1,4-dioxo-2,3-diazaspiro4.4]non-2-yl)methyl]anilinocarbonyl}benzoic acid monohydrate, C26H29N3O5·H2O, (III). The aryl rings of (II) are almost coplanar, in contrast with compounds (I) and (III). The conformation of (II) is induced by an intramolecular N—H⋯O hydrogen bond between the amide and carboxylic acid groups. |