4-(4-Chlorophenyl)-2,6-bis(1H-indol-3-yl)-1,4-dihydropyridine-3,5-dicarbonitrile ethanol monosolvate

In the title compound, C29H18ClN5·C2H6O, the dihydropyridine ring adopts a strongly flattened envelope conformation, with a maximum deviation of 0.139 (2) Å from its best plane for the Csp 3 atom. The dihedral angles between the dihydropyridine ring plane and the two indole rings in positions 2 and 6 are 34.28 (5) and 40.50 (6)°, respectively. In turn, the benzene ring and the dihydropyridine ring are oriented at a dihedral angle of 74.69 (6)°. An intramolecular C—H⋯Cl hydrogen bond occurs. In the crystal, molecules are linked by N—H⋯N, N—H⋯O and O—H⋯N hydrogen bonds into layers parallel to (001). There are short C—H⋯Cl contacts between molecules in neighboring layers.

In the title compound, C 29 H 18 ClN 5 ÁC 2 H 6 O, the dihydropyridine ring adopts a strongly flattened envelope conformation, with a maximum deviation of 0.139 (2) Å from its best plane for the Csp 3 atom. The dihedral angles between the dihydropyridine ring plane and the two indole rings in positions 2 and 6 are 34.28 (5) and 40.50 (6) , respectively. In turn, the benzene ring and the dihydropyridine ring are oriented at a dihedral angle of 74.69 (6) . An intramolecular C-HÁ Á ÁCl hydrogen bond occurs. In the crystal, molecules are linked by N-HÁ Á ÁN, N-HÁ Á ÁO and O-HÁ Á ÁN hydrogen bonds into layers parallel to (001). There are short C-HÁ Á ÁCl contacts between molecules in neighboring layers.

Song-Lei Zhu and Jun-Nian Zheng Comment
Indole fragments are important moieties of a large number of natural products and medicinal agents (da Silva et al., 2001). Compounds carrying the indole moiety exhibit antibacterial and fungicidal activities (Joshi & Chand, 1982). In addition, 1,4-dihydropyridine compounds are a well-known classe of calcium channel modulators for the treatment of cardiovascular diseases, for example Nifedipin, Felodipin are clinically useful as vasodilators and antihypertensive agents (Janis & Triggle, 1983). Due to the potent and diverse biological activities of indole and 1,4-dihydropyridine derivatives, we investigated a simple and efficient protocol for synthesis of a series of bisindoles derivatives containing 1,4-dihydropyridine units (Zhu et al., 2008). Herein, we report the crystal structure of the title compound.
In the crystal, intermolecular N-H···N, N-H···O and O-H···N hydrogen bonds link the molecules into layers parallel to (0 0 1) ( Table 1, Fig. 2). There are short C-H···Cl contacts between the molecules from neighboring layers.

Experimental
The title compound was prepared by the reaction of 4-chlorobenzaldehyde (1 mmol), 3-cyanoacetyl indole (2 mmol), ammonium acetate (5 mmol) in glycol solvent (3 mL) under microwave irradiation condition. After irradiating for 8 mins at 413 K, the reaction mixture was cooled and washed with small amount of ethanol. The crude product was filtered and single crystals of the title compound were obtained from ethanol solution by slow evaporation at room temperature (yield: 75%, m.p. > 573 K).  The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. The solvent ethanol is not shown for clarity.  A packing diagram of the title compound. Hydrogen bonds are shown as dashed lines.

4-(4-Chlorophenyl)-2,6-bis(1H-indol-3-yl)-1,4-dihydropyridine-3,5-dicarbonitrile ethanol monosolvate
Crystal data C 29 H 18 ClN 5 ·C 2 H 6 O M r = 518.00 Triclinic, P1 Hall symbol: -P 1 a = 9.2133 (17) Å b = 11.611 (2) Å c = 12.473 (2) Å α = 87.714 (7) where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.67 e Å −3 Δρ min = −0.71 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. 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.   (10)