2-Amino-4-(4-chlorophenyl)-6-(pyrrolidin-1-yl)pyridine-3,5-dicarbonitrile

In the title compound, C17H14ClN5, two C atoms and their attached H atoms of the pyrrolidine ring are disordered over two sets of sites with an occupancy ratio of 0.638 (10):0.362 (10). The benzene and pyridine rings are inclined to one another by 60.57 (8)°. In the crystal, the amino group forms an N—H⋯N hydrogen bond with one of the cyano groups, linking the molecules into chains along [010].

In the title compound, C 17 H 14 ClN 5 , two C atoms and their attached H atoms of the pyrrolidine ring are disordered over two sets of sites with an occupancy ratio of 0.638 (10): 0.362 (10). The benzene and pyridine rings are inclined to one another by 60.57 (8) . In the crystal, the amino group forms an N-HÁ Á ÁN hydrogen bond with one of the cyano groups, linking the molecules into chains along [010].
The effect can also be verified by the shortening of the C12-N2 bond (1.345 (2)Å) relative to a normal single C-N bond (1.483Å for C-N in methaneamine (Atoji & Lipscomb, 1953).
The chlorine atom attached at C1 deviates by -0.0817 (3)Å from the mean plane of the phenyl ring. The title structure exhibits structural similarities with the previously reported structure (Inglebert et al., 2011).
In the crystal structure, the classical intermolecular N2-H2B···N4 i hydrogen bonds link the molecules into chains along the b axis. Symmetry code: (i) x, y+1, z.

Experimental
A mixture of 4-chlorobenzaldehyde (2 mmoL, 0.28 g), malononitrile (3 mmoL, 0.198 g), pyrrolidine (1.5 mmoL, 0.1 g) was stirred without any solvent at room temperature. A solid appeared immediately which has dissolved in a minimum amount (3 ml) of ethanol and the solution was refluxed until completion of the reaction (monitered by TLC). The reaction mixture was cooled. Ethanol was evaporated under reduced pressure and the residue was extracted with dicholoromethane (3×10 ml). Evaporation of solvent left the crude solid which was subjected to silica gel column chromatography [25:75 ethyl acetate/hexane] and the product was recrysallized from dichloromethane.

Refinement
H atoms attached to C atoms were positioned geometrically and constrained to ride on their parent atoms, with C-H = 0.93Å (aromatic H) and C-H = 0.97Å (methylene H) U iso (H) = 1.2U eq (C). H atoms of amino group were located from difference Fourier map and refined freely.   The packing diagram of the title compound, which shows intermolecular N2-H2B···N4 i interactions (dashed lines). H atoms not involved in hydrogen bonds have been omitted for clarity.  (2) Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s 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 > σ(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.