Abstract: | The title compounds, tert‐butyl 6‐benzyl‐2‐(3,3‐diethylureido)‐4,5,6,7‐tetrahydrothieno2,3‐c]pyridine‐3‐carboxylate, C24H33N3O3S, (I), 7‐benzyl‐2‐diethylamino‐5,6,7,8‐tetrahydro‐3‐oxa‐9‐thia‐1,7‐diazafluoren‐4‐one, C20H23N3O2S, (II), and N‐(7‐benzyl‐4‐oxo‐5,6,7,8‐tetrahydro‐4H‐3,9‐dithia‐1,7‐diazafluoren‐2‐yl)benzamide, C23H19N3O2S2, (III), form monoclinic crystal systems. In (I) and (II), the molecules are linked into a three‐dimensional framework by weak intermolecular C—H?O=C hydrogen bonds, whereas in (III) stronger intermolecular N—H?O=C interactions are observed. The conformation of (I) is further stabilized by an intramolecular N—H?O=C hydrogen bond, which effects the planarity of the ureidothiophenecarboxylate moiety. |