(S)-(-)-6-(4-Bromo-phen-yl)-2,3,5,6-tetra-hydro-thia-zolo[2,3-b]imidazolium hydrogen oxalate

Acta Crystallogr Sect E Struct Rep Online. 2008 Sep 17;64(Pt 10):o1954. doi: 10.1107/S1600536808029085.

Abstract

The structure of the title compound, C(11)H(12)BrN(2)S(+)·C(2)HO(4) (-) (common name 6-bromo-levamisole hydrogen oxalate), is stabilized mainly by hydrogen bonds. Hydrogen oxalate anions form parallel coplanar chains via O-H⋯O hydrogen bonds, while there are N-H⋯O hydrogen-bonding inter-actions between the 6-bromo-levamisole cations and oxalate anions. Both five-membered rings from the 6-bromo-levamisole mol-ecule have a twist conformation. The mol-ecule has an extended conformation, with the 4-bromo-phenyl substituent positioned equatorially with N-C-C-C and C-C-C-C torsion angles of 39.8 (3) and 100.4 (3)°, respectively.