Crystal structure of 3-[(4-benzylpiperazin-1-yl)methyl]-5-(thiophen-2-yl)- 2,3-dihydro-1,3,4-oxadiazole-2-thione

The title 1,3,4-oxadiazole-2-thione derivative, C18H20N4OS2, crystallized with two independent molecules (A and B) in the asymmetric unit. The 2-thienyl rings in both molecules are rotationally disordered over two orientations by approximately 180� about the single C—C bond that connects it to t...

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Bibliographic Details
Main Authors: Al-Omary, Fatmah A. M., El-Emam, Ali A., Ghabbour, Hazem A., C. S., Chidan Kumar, Ching, Kheng Quah, Fun, Hoong Kun
Format: Article
Language:English
Published: International Union of Crystallography 2015
Subjects:
Online Access:http://eprints.usm.my/38583/
http://eprints.usm.my/38583/1/Crystal_structure_of_3-%5B%284-benzylpiperazin-1-yl%29methyl%5D-5-%28thiophen-2-yl%29-.pdf
Description
Summary:The title 1,3,4-oxadiazole-2-thione derivative, C18H20N4OS2, crystallized with two independent molecules (A and B) in the asymmetric unit. The 2-thienyl rings in both molecules are rotationally disordered over two orientations by approximately 180� about the single C—C bond that connects it to the oxadiazole thione ring; the ratios of site occupancies for the major and minor components were fixed in the structure refinement at 0.8:0.2 and 0.9:0.1 in molecules A and B, respectively. The 1,3,4-oxadiazole-2-thione ring forms dihedral angles of 7.71 (16), 10.0 (11) and 77.50 (12)� (molecule A), and 6.5 (3), 6.0 (9) and 55.30 (12)� (molecule B) with the major and minor parts of the disordered thiophene ring and the mean plane of the adjacent piperazine ring, respectively, resulting in approximately V-shaped conformations for the molecules. The piperazine ring in both molecules adopts a chair conformation. The terminal benzene ring is inclined towards the mean plane of the piperazine ring with N—C— C—C torsion angles of �58.2 (3) and �66.2 (3)� in molecules A and B, respectively. In the crystal, no intermolecular hydrogen bonds are observed. The crystal packing features short S� � �S contacts [3.4792 (9) A ° ] and �–� interactions [3.661 (3), 3.664 (11) and 3.5727 (10) A ° ], producing a threedimensional network.