Crystal structures of two hydrazide derivatives of mefenamic acid, 3-(2,3-di-methyl-anilino)- N'-[(E)-(furan-2-yl)methyl-idene]benzohydrazide and N'-[(E)-benzyl-idene]-2-(2,3-di-methyl-anilino)benzo-hydrazide

Acta Crystallogr E Crystallogr Commun. 2021 Feb 12;77(Pt 3):242-246. doi: 10.1107/S2056989021001353. eCollection 2021 Mar 1.

Abstract

The conformation about the central benzene ring in the mol-ecule of (I), C20H19N3O2, is partially determined by an intra-molecular N-H⋯O hydrogen bond. In the crystal, chains parallel to the c axis are generated by inter-molecular N-H⋯O hydrogen bonds with the chains assembled into a three-dimensional network structure by inter-molecular C-H⋯O hydrogen bonds and C-H⋯π(ring) inter-actions. The mol-ecule of (II), C22H21N3O, differs from (I) only in the substituent at the hydrazide N atom where a phenyl-methyl-ene moiety for (II) is present instead of a furan-methyl-ene moiety for (I). Hence, mol-ecules of (I) and (II) show similarities in their mol-ecular and crystal structures. The conformation of the central portion of the mol-ecule of (II) is also therefore partially determined by an intra-molecular N-H⋯O hydrogen bond and inter-molecular 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) inter-actions.

Keywords: C—H⋯π(ring); NSAIDs; benzohydrazide; crystal structure; hydrogen bond; mefenamic.

Grants and funding

This work was funded by National Science Foundation grant 1228232. Tulane University grant .