Crystal structures of 3-methoxy-4-{[5-(4-methoxyphenyl)-1,3,4-oxadiazol-2-yl]methoxy}benzonitrile and N-(4-{[5-(4-chlorophenyl)-1,3,4-oxadiazol-2-yl]methoxy}phenyl)acetamide

The title compounds, C18H15N3O4 and C17H4ClN3O3, are heterocyclic 1,3,4-oxadiazole derivatives which differ from each other in the groups attached to the carbon atoms: a methoxyphenyl ring and a benzonitrile group in (I) and a chlorophenyl ring and an acetamide group in (II). Short intramolecular C-H center dot center dot center dot O hydrogen bonds occur in both molecules. The crystal structure of (I) features C-H center dot center dot center dot N hydrogen bonds, while in the crystal structure of (II), N-H center dot center dot center dot N, C-H center dot center dot center dot N and C-H center dot center dot center dot O hydrogen bonds are observed.