3-(Adamantan-1-yl)-1-[(4-ethylpiperazin-1-yl)methyl]-4-[(E)-(4-hydroxybenzylidene)amino]-1H-1,2,4-triazole-5(4H)-thione

In the title thione, C26H36N6OS, the 1,2,4-triazole ring is planar (r.m.s. deviation = 0.020 Å) and the benzene ring is twisted out of this plane [dihedral angle = 62.35 (12)°]. Supramolecular zigzag chains feature in the crystal packing. These are sustained by O—H⋯N(piperazine) hydrogen bonds, and are connected into the three-dimensional crystal structure by C—H⋯S and C—H⋯O interactions. The crystal studied was a racemic twin.


Tiekink Comment
Derivatives of adamantane have long been known for their diverse biological activities including anti-viral activity against the influenza (Vernier et al., 1969) andHIV viruses (El-Emam et al., 2004). Moreover, adamantane derivative were recently reported to exhibit marked anti-bacterial and anti-inflammatory activities (Kadi et al., 2007(Kadi et al., , 2010. In continuation of our interest in the chemical and pharmacological properties of adamantane derivatives, and as a part of on-going structural studies of adamantane derivatives (Kadi et al., 2011;Al-Tamimi et al., 2010) we synthesized the title compound (I) as potential chemotherapeutic agent.
The structure determination of (I), Fig. 1, confirms the presence of the thione in the solid-state. The central 1,2,4triazole ring is planar [r.m.s. deviation = 0.020 Å] and the benzene ring is twisted out of this plane [dihedral angle = 62.35 (12)°]. Globally, the plane of the five-membered ring bisects the adamantyl group with the benzene and piperazine substituents lying to one side.
In the crystal packing, supramolecular zigzag chains are formed via O-H···N(piperazine) hydrogen bonds, Fig. 2 and Table 1. These are connected into the three-dimensional crystal structure by C-H···S and C-H···O interactions, Fig. 3 and Table 1.

Refinement
Carbon-bound H atoms were placed in calculated positions [C-H = 0.95 to 1.00 Å, U iso (H) = 1.2 to 1.5 U eq (C)] and were included in the refinement in the riding model approximation. The hydroxy H atom was located in a difference Fourier supplementary materials sup-2 Acta Cryst. (2012). E68, o657-o658 map, and was refined with a distance restraint of O-H = 0.84±0.01 Å, and U iso was refined.
The crystal is a racemic twin; the Flack parameter was explicitly refined.
There is a significant Hirshfeld rigid-bond alert for the C7-C8 bond. Their displacement factors are somewhat large, indicating some disorder. However, no model for the disorder was resolved.