Ethyl 2-cyano-2-{(Z)-2-[2,2-dicyano-1-(4-methylphenyl)ethyl]cyclohexylidene}acetate

In the crystal of the title cyclohexylidene derivative, molecules associate via C—H⋯N hydrogen bonds, forming a three-dimensional network.


Structure description
Cyclohexylidene derivatives possess a wide range of biological activities including antibacterial (Gupta & Narayana, 1997), antiviral (Ulusoy Guzeldemirci et al., 2016), antituberculatic and anti-inflammatory (Kabir et al., 2008). As part of our studies in this area, we have undertaken a single-crystal X-ray diffraction study for the title compound, and the results are presented here.

Synthesis and crystallization
A mixture of 2-amino-4-(p-tolyl)octahydronaphthalene-1,3,3(2H)-tricarbonitrile (0.01 mol), formic acid (5 mL) and a catalytic amount of concentrated HCl was refluxed for 16 h and the reaction mixture was allowed to cool. The reaction mixture was poured onto crushed ice and the solid that separated was filtered, dried and recrystallized using ethanol and water as mixed solvents.

Figure 2
The crystal packing of the title compound viewed down the a axis. The C-HÁ Á ÁN hydrogen bonds (see Table 1) are shown as dashed lines. For clarity, H atoms not involved in these interactions have been omitted.

Figure 3
The two-dimensional fingerprint plot for the title compound depicting the overall contribution by the various contacts.

Figure 5
The two-dimensional fingerprint plot for the title compound depicting the contribution of the CÁ Á ÁH contacts.

Figure 4
The two-dimensional fingerprint plot for the title compound depicting the contribution of the NÁ Á ÁH contacts.  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.38 e Å −3 Δρ min = −0.31 e Å −3 Special details 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. Refinement. H atoms were placed in idealized positions and allowed to ride on their parent atoms: C-H = 0.93-0.98 Å, with U iso (H) = 1.5U eq (C) for methyl H atoms and 1.2U eq (C) for other H atoms.