2-Amino-7,7-dimethyl-5-oxo-4-[3-(trifluoromethyl)phenyl]-1,4,5,6,7,8-hexahydroquinoline-3-carbonitrile

In the title molecule, C19H18F3N3O, the dihydropyridine and cyclohexene rings both adopt sofa conformations. The five essentially planar atoms of the dihydropyridine ring [maximum deviation = 0.039 (2) Å] form a dihedral angle of 88.19 (8)° with the benzene ring. The F atoms of the trifluoromethyl group were refined as disordered over two sets of sites in a 0.840 (3):0.160 (3) ratio. In the crystal, N—H⋯O and N—H⋯N hydrogen bonds link molecules into a two-dimensional network parallel to (100).

In the title molecule, C 19 H 18 F 3 N 3 O, the dihydropyridine and cyclohexene rings both adopt sofa conformations. The five essentially planar atoms of the dihydropyridine ring [maximum deviation = 0.039 (2) Å ] form a dihedral angle of 88.19 (8) with the benzene ring. The F atoms of the trifluoromethyl group were refined as disordered over two sets of sites in a 0.840 (3):0.160 (3) ratio. In the crystal, N-HÁ Á ÁO and N-HÁ Á ÁN hydrogen bonds link molecules into a two-dimensional network parallel to (100).

Deshmukh Comment
The nucleus containing 1,4-dihydropyridine (DHP) nucleus act as a versatile intermediate for the synthesis of several pharmaceuticals together with those of cardiovascular drugs and as a calcium channel modulators, laser dyes and photo initiators (Leon et al., 2008). The design and synthesis of 1,4-dihydropyridines has attracted much attention over the past 30 years due to the calcium antagonist effect they display (Mayler, 1989). The establishment of the pharmacological action as drugs for the treatment of cardiovascular diseases such as angina, hypertension or arrhythmia was mainly based on the structural studies carried out by X-ray diffraction on differently substituted 1,4-dihydropyridines (Triggle et al., 1989). In this paper, we report the crystal structure of the title compound, (I).

Experimental
In a 50 ml round bottom flask 5,5-dimethylcyclohexane-1,3-dione (1 mmol) and ammonium acetate (3.5 mmol) were taken in water (10 ml). The reaction mixture was stirred at 373K for 40 min. Then malononitrile (1 mmol), 3-trifluoro methyl benzaldehyde (1 mmol) were charged, and the mixture was heated at 373K for 30 min. After the completion of reaction (monitored by TLC), the reaction mixture was stirred at RT for 15 min. The separated solid was then filtered off and recrystallized from ethanol to afford pure product as crystals suitable for X-ray diffraction. M.P.: 558-560 K, Yield:

Refinement
All H atoms were positioned geometrically and were treated as riding on their parent C atoms, with C-H distances of 0.93-0.98 Å, N-H distances of 0.86 and with U iso (H) = 1.2U eq (C/N) or 1.5U eq (methyl C).

Figure 1
The molecular structure of the title compound with ellipsoids drawn at the 40% probability level. H atoms are shown as small spheres of arbitrary radii. The F atoms are disorded over two sets of sites.  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. (