2-p-Tolyl-2,3-dihydroquinolin-4(1H)-one

In the title molecule, C16H15NO, the tetrahydropyridine ring is in a sofa conformation with the methine C atom forming the flap. The dihedral angle between the benzene rings is 80.85 (8)°. In the crystal, molecules are arranged in alternating double layers parallel to (100) and are connected along [001] by N—H⋯O hydrogen bonds. In addition, weak C—H⋯π interactions are observed.

In the title molecule, C 16 H 15 NO, the tetrahydropyridine ring is in a sofa conformation with the methine C atom forming the flap. The dihedral angle between the benzene rings is 80.85 (8) . In the crystal, molecules are arranged in alternating double layers parallel to (100) and are connected along [001] by N-HÁ Á ÁO hydrogen bonds. In addition, weak C-HÁ Á Á interactions are observed.

Experimental
The substituted 2′-aminochalcone (0.5 mmol) and [bmim]BF4 (1 g) were heated at 423K for 2.5 h. Under these conditions, the title compound was successfully synthesized in good yield (92%). Single crystals suitable for the X-ray diffraction analysis were obtained by dissolving the pure compound in an Et 2 O/CHCl 3 mixture and allowing the solution to slowly evaporate at room temperature.

Refinement
All non-H atoms were refined with anisotropic atomic displacement parameters. Approximate positions for all the H atoms were first obtained from the difference electron density map. However, the H atoms were situated in idealized positions and the H-atoms were refined in a riding-motion approximation. The applied constraints were as follow: C aryl -H aryl = 0.95 Å; C methylene -H methylene = 0.99 Å; C methyl -H methyl = 0.98 Å; and C methine -H methine = 1.0 Å; The idealized methyl sup-2 Acta Cryst. (2014). E70, o214-o215 group was allowed to rotate about the C-C bond during the refinement by application of the command AFIX 137 in SHELXL97 (Sheldrick, 2008). U iso (H methyl ) = 1.5U eq (C methyl ) or U iso (H aryl , methylene , methine ) = 1.2 U eq (C aryl , methylene and methine ).
Atom H1N was found in a difference electron density map and refined isotropically with U iso (H) = 1.2U eq (N)

Figure 1
The molecular structure of (I) with displacement ellipsoids drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radius.  The crystal packing showing alternating double layers parallel to (100) viewed along the c axis. 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.