Crystal structure of (E)-2-[3-(tert-butyl)-2-hydroxybenzylidene]-N-cyclohexylhydrazine-1-carbothioamide

The title compound is composed of cyclohexane and benzene rings connected through a hydrazinecarbothioamide moiety. In the crystal, the molecules are connected by N—H⋯S hydrogen bonds.

In the title compound, C 18 H 27 N 3 OS, the cyclohexane ring has a chair conformation. The azomethine C N double bond has an E configuration. The nearly planar hydrazinecarbothioamide moiety and substituted benzene ring are twisted by 31.13 (5) relative to each other. The amide moiety and the cyclohexane ring are almost perpendicular to each other; a similar conformation was previously observed in reported structures. In the crystal, molecules are linked by N-HÁ Á ÁS hydrogen bonds, forming inversion dimers with an R 2 2 (8) ring motif.

Chemical context
The thiosemicarbazone Schiff base is comprised of two soft Lewis bases -the sulfur and nitrogen coordinating sites as well as a hard Lewis base -the oxygen atom (Mohamed et al., 2009). Such Schiff bases are of special interest because of their specific coordinating ability to some metal ions (Arion et al., 2001;Leovac & Č ešljević, 2002;Chandra & Sangeetika, 2004;Singh et al., 2000;Gerbeleu et al., 2008;Mohamed et al., 2009). Several reports have highlighted the importance of the chelate metal complexes of thiosemicarbazone Schiff bases for medicinal applications, particularly against cancer (Paterson & Donnelly, 2011;Ziessel, 2001;Salam et al., 2012;Arafath et al., 2017a). Thus thiosemicarbazones with ONS coordinating sites are important in coordination chemistry because of their strong bonding ability to transition metal ions as well as because of their pharmaceutical uses (Rayati et al., 2007;Alomar et al., 2009;Vieites et al., 2009).
Dihedral is the dihedral angle between the mean planes of the benzylidene ring and the hydrazinecarbothioamide moiety. 5 is the C8-N3-C9-C10 torsion angle.

Figure 1
The molecular structure with the atom-labelling scheme and displacement ellipsoids at the 50% probability level.
5.00 mmol) in 20.0 mL methanol was then added dropwise with stirring to the aldehyde solution. The resulting colourless solution was refluxed for 4 h with stirring. The colourless precipitate that formed was filtered off and washed with 5.0 mL ethanol and 5.0 mL n-hexane. The recovered product was dissolved in acetone for recrystallization. Colourless single crystals suitable for X-ray diffraction was obtained on slow evaporation of the solvent (m.p. 502-503 K, yield 98%). Analysis

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 3

Special details
Experimental. The following wavelength and cell were deduced by SADABS from the direction cosines etc. They are given here for emergency use only: CELL 0.71104 13.523 6.653 20.749 89.939 93.047 89.965 Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 ) x y z U iso */U eq S1