Crystal structures of two hydrazide derivatives of mefenamic acid, 3-(2,3-dimethylanilino)-N′-[(E)-(furan-2-yl)methylidene]benzohydrazide and N′-[(E)-benzylidene]-2-(2,3-dimethylanilino)benzohydrazide

Abstract

The conformation about the central benzene ring in the molecule of (I), C20H19N3O2, is partially determined by an intramolecular N—H...O hydrogen bond. In the crystal, chains parallel to the c axis are generated by intermolecular N—H...O hydrogen bonds with the chains assembled into a three-dimensional network structure by intermolecular C—H...O hydrogen bonds and C—H...π(ring) interactions. The molecule of (II), C22H21N3O, differs from (I) only in the substituent at the hydrazide N atom where a phenylmethylene moiety for (II) is present instead of a furanmethylene moiety for (I). Hence, molecules of (I) and (II) show similarities in their molecular and crystal structures. The conformation of the central portion of the molecule of (II) is also therefore partially determined by an intramolecular N—H...O hydrogen bond and intermolecular N—H...O hydrogen bonds form chains parallel to the c axis. Likewise, the chains are connected into a three-dimensional network by C—H...O hydrogen bonds and C—H...π(ring) interactions.