2-Amino-4-(2-chlorophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile ethanol monosolvate

In the title compound, C16H13ClN2O2·C2H6O, the fused cyclohexene and pyran rings adopt envelope and flattened boat conformations, respectively. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds link the chromene and ethanol solvent molecules into infinite chains along the c axis, and N—H⋯N hydrogen bonds link these chains into a three-dimensional framework. Weak C—H⋯π interactions are also present.

In the title compound, C 16 H 13 ClN 2 O 2 ÁC 2 H 6 O, the fused cyclohexene and pyran rings adopt envelope and flattened boat conformations, respectively. In the crystal, N-HÁ Á ÁO and O-HÁ Á ÁO hydrogen bonds link the chromene and ethanol solvent molecules into infinite chains along the c axis, and N-HÁ Á ÁN hydrogen bonds link these chains into a threedimensional framework. Weak C-HÁ Á Á interactions are also present.

Comment
The present investigation is a continuation of our work that includes syntheses and structural studies of polyfunctionalized substituted pyran derivatives, owing to their biological activities (Lokaj et al., 1990;Marco et al., 1993).We obtained the title compound, (I), and reported here its crystal structure in the paper.
In the crystal structure, there exist typical intermolecular N-H···N, N-H···O, O-H···O hydrogen bonds and weak C-H···π interactions (Table 1.). Intermolecular N-H···O and O-H···O hydrogen bonds link the molecules and ethanol solvent into infinite chain along c-axis and intermolecular hydrogen bonds link these chains forming three-dimensional framework.

Experimental
Malononitrile (5 mmol), 1,3-cyclohexanedione (5 mmol) and 2-chorobenzaldehyde (5 mmol) was dissolved in 20 ml DMF in a round-bottom flask. The mixture was warmed, with agitation, to 423 K over a period of 6 h. The resulting solution was cooled. Crystal of (I) suitable for X-ray diffraction analysis were obtained by recrystallized from ethanol.

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. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq