Affiliations 

  • 1 Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, PO Box 2457, Riaydh 11451, Saudi Arabia
  • 2 Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, PO Box 2457, Riaydh 11451, Saudi Arabia ; King Abdullah Institute for Nanotechnology (KAIN), King Saud University, Riyadh 11451, Saudi Arabia
  • 3 Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
  • 4 X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia ; Department of Chemistry, Alva's Institute of Engineering & Technology, Mijar, Moodbidri 574 225, Karnataka, India
  • 5 X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
  • 6 Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, PO Box 2457, Riaydh 11451, Saudi Arabia ; X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
Acta Crystallogr E Crystallogr Commun, 2015 Mar 1;71(Pt 3):o175-6.
PMID: 25844234 DOI: 10.1107/S2056989015002273

Abstract

The title 1,3,4-oxa-diazole-2-thione derivative, C18H20N4OS2, crystallized with two independent mol-ecules (A and B) in the asymmetric unit. The 2-thienyl rings in both mol-ecules are rotationally disordered over two orientations by approximately 180° about the single C-C bond that connects it to the oxa-diazole 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 mol-ecules A and B, respectively. The 1,3,4-oxa-diazole-2-thione ring forms dihedral angles of 7.71 (16), 10.0 (11) and 77.50 (12)° (mol-ecule A), and 6.5 (3), 6.0 (9) and 55.30 (12)° (mol-ecule B) with the major and minor parts of the disordered thio-phene ring and the mean plane of the adjacent piperazine ring, respectively, resulting in approximately V-shaped conformations for the mol-ecules. The piperazine ring in both mol-ecules 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 mol-ecules A and B, respectively. In the crystal, no inter-molecular hydrogen bonds are observed. The crystal packing features short S⋯S contacts [3.4792 (9) Å] and π-π inter-actions [3.661 (3), 3.664 (11) and 3.5727 (10) Å], producing a three-dimensional network.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.