Crystal structure of 2,4-bis(2-chlorophenyl)-7-tert-pentyl-3-azabicyclo[3.3.1]nonan-9-one

The title compound, C25H29Cl2NO, which is a chloro analog of 2,4-bis(2-bromophenyl)-7-(tert-pentyl)-3-azabicyclo[3.3.1]nonan-9-one [Park, Ramkumar & Parthiban (2012). Acta Cryst. E68, o2946], exists in a twin-chair conformation with an equatorial orientation of the 2-chlorophenyl groups. The tert-pentyl group on the cyclohexanone adopts an exocyclic equatorial position and is disordered between two orientations in a ratio 0.520 (8):0.480 (8). The crystal packing shows no directional contacts beyond van der Waals contacts.

The chloro substituted benzene rings of the title compound is oriented very similar to that of its bromo analog. The benzene rings are inclined to each other with an angle of 29.38°, where as the orientation of bromo analog is 29.6 (3)°.
Based on the complete crystallographic analysis, it is concluded that the title compound, C 25 H 29 Cl 2 NO, exists in a twinchair conformation with an equatorial orientation of the 2-chlorophenyl groups.
The mixture was gently warmed on a hot plate at 303-308 K (30-35° C) with moderate stirring till the complete consumption of the starting materials, which was monitored by TLC. At the end, the crude azabicyclic ketone was separated by filtration and gently washed with 1:5 cold ethanol-ether mixture. X-ray diffraction quality crystals of the title compound were obtained by slow evaporation from ethanol.

S3. Refinement
All hydrogen atoms were fixed geometrically and allowed to ride on the parent carbon atoms with aromatic C-H = 0.93 Å, aliphatic C-H = 0.98 Å, methylene C-H = 0.97 Å. The displacement parameters were set for phenyl, methylene and aliphatic H atoms at U iso (H) = 1.2U eq (C), methyl H atoms at U iso (H) = 1.5U eq (C) and the hydrogen atoms were fixed geometrically and allowed to ride on the parent nitrogen atom with N-H = 0.86 Å and the displacement parameter was supporting information set at U iso (H)= 1.2U eq (N). The tert-pentyl group attached to the carbon atom (C4) is disordered in two orientations in a ratio 0.520 (8):0.480 (8).

Figure 1
View of the title molecule showing the atomic numbering and 30% probability displacement ellipsoids. For clarity, only major component of the disordered group is shown.