2-Amino-6-(pyrrolidin-1-yl)-4-p-tolylpyridine-3,5-dicarbonitrile

In the title compound, C18H17N5, the pyrrolidine ring adopts an envelope conformation. The pyrrolidine ring is disordered over two sets of sites with occupancy factors of 0.648 (6) and 0.352 (6). The dihedral angles between the pyrrolidine and pyridine rings are 14.6 (3)° for the major component and 16.2 (6)° for the ninor component. The crystal structure is stabilized by intermolecular N—H⋯N and C—H⋯N interactions.

In the title compound, C 18 H 17 N 5 , the pyrrolidine ring adopts an envelope conformation. The pyrrolidine ring is disordered over two sets of sites with occupancy factors of 0.648 (6) and 0.352 (6). The dihedral angles between the pyrrolidine and pyridine rings are 14.6 (3) for the major component and 16.2 (6) for the ninor component. The crystal structure is stabilized by intermolecular N-HÁ Á ÁN and C-HÁ Á ÁN interactions.
The crystal structure is stabilized by N-H···N and C-H···N intermolecular interactions (Table 1). For the symmetry codes, see Table 1 too. The packing view of the reported compound is shown in Fig. 2.

Experimental
Initially a mixture of 4-methylbenzaldehyde (2 mmoL,0.24 g), malononitrile (3 mmoL, 0.198 g), pyrrolidine (1.5 mmoL, 0.1 g) and 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 x 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
The H atoms were placed in idealized positions and allowed to ride on the parent atoms, with C-H bond lengths fixed to 0.93Å (Aromatic H), 0.96Å (methyl H), 0.97Å (methylene H), 0.86Å (N-H) and U iso (H) = 1.2-1.5U eq (C,N).
supplementary materials sup-2 Figures Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at 30% probability level. H atoms are present as small spheres of arbitary radius. Only major moiety of pyrrolidine is presented for clarity.