8-Methyl-2-oxo-4-(thiophen-2-yl)-1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile

In the title compound, C15H14N2OS, the pyridinone ring in the fused-ring system is nearly planar (r.m.s. deviation = 0.011 Å) and the cyclohexene ring has a twisted half-boat conformation with the methylene C atom adjacent to the methine C atom deviating by 0.592 (7) Å from the plane defined by the remaining five atoms (r.m.s. deviation = 0.108 Å). The thienyl ring is disordered over two almost coplanar positions of opposite orientation in a 0.649 (4):0.351 (4) ratio, and forms dihedral angles of 51.4 (3) (major component) and 54.2 (3)°, respectively, with the pyridinone ring. In the crystal, inversion-related molecules associate via an eight-membered {⋯HNCO}2 synthon and these are linked into a linear supramolecular chain along the a axis by weak π–π interactions that occur between centrosymmetrically related pyridinone rings [centroid–centroid distance = 3.889 (2) Å].

In the title compound, C 15 H 14 N 2 OS, the pyridinone ring in the fused-ring system is nearly planar (r.m.s. deviation = 0.011 Å ) and the cyclohexene ring has a twisted half-boat conformation with the methylene C atom adjacent to the methine C atom deviating by 0.592 (7) Å from the plane defined by the remaining five atoms (r.m.s. deviation = 0.108 Å ). The thienyl ring is disordered over two almost coplanar positions of opposite orientation in a 0.649 (4):0.351 (4) ratio, and forms dihedral angles of 51.4 (3) (major component) and 54.2 (3) , respectively, with the pyridinone ring. In the crystal, inversionrelated molecules associate via an eight-membered {Á Á ÁHNCO} 2 synthon and these are linked into a linear supramolecular chain along the a axis by weakinteractions that occur between centrosymmetrically related pyridinone rings [centroid-centroid distance = 3.889 (2) Å ].

T. Tiekink Comment
The title compound (I) is a member of a series of cyano-pyridinones that have been evaluated for their cardiotonic (Behit & Baraka, 2005) and anti-inflammatory (Girgis et al., (2007) properties. Herein, the crystal and molecular structures of (I) are described.
In (I), Fig. 1, the pyridyl ring in the fused ring system is planar [r.m.s. deviation = 0.011 Å] and the cyclohexene ring has a twisted half-boat conformation with the methylene-C3 atom lying -0.592 (7)  resembles that found in a literature structure with the exception of the C2-C3 conformation which is fused to a benzene ring (Asiri et al., 2011).

Refinement
Carbon-bound H-atoms were placed in calculated positions [C-H = 0.95-0.99 Å, U iso (H) = 1.2-1.5U eq (C)] and were included in the refinement in the riding model approximation. The N-bound H-atom was treated similarly with N-H = 0.88 Å and with U iso (H) = 1.2U eq (N). The thienyl ring is disordered over two positions [co-planar and opposite orientation] in a 0.649 (4):0.351 (4) ratio. Pairs of 1,2-related distances were restrained to within 0.01 Å of each other, and the rings were restrained to be within 0.01 Å of a plane. The anisotropic displacement parameters, restrained to be nearly isotropic, of the primed atoms were set to those of the unprimed ones. The maximum and minimum residual electron density peaks of 1.02 and -0.78 e Å -3 , respectively, were located 0.14 Å and 0.39 Å from the C15′ and C13 atoms, respectively.

Figure 1
The molecular structure of (I) showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.   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.

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