10-(4-Chlorophenyl)-9-(4-fluorophenyl)-3,3,6,6-tetramethyl-3,4,6,7,9,10-hexahydroacridine-1,8(2H,5H)-dione

The title compound, C29H29ClFNO2, was synthesized by the reaction of 4-fluorobenzaldehyde, 5,5-dimethylcyclohexane-1,3-dione and 3-(4-chlorophenylamino)-5,5-dimethylcyclohex-2-enone in an ionic liquid (1-butyl-3-methylimidazolium bromide). X-ray analysis reveals that the 1,4-dihydropyridine ring adopts a boat conformation, while each of the attached partially saturated six-membered rings adopts a half-chair conformation. The structure is stabilized by weak C—H⋯O and C—H⋯F hydrogen bonds. The molecule has approximate mirror symmetry; the largest deviation from this symmetry concerns the fluoro- and chlorophenyl rings.

The 4-fluorophenyl ring is nearly perpendicular to the plane defined by the atoms C1-C2-C4-C5, forming a dihedral angle of 87.9 (1)°. The molecule has an approximate mirror symmetry. For example, the atoms C14 and C20 of the acridine groups are deviated by about 0.25Å. (The calculation has been carried out with the help of JANA2000 (Petříček et al., 2000).
The largest deviation from this symmetry concerns the fluoro-and the chlorophenyl rings whose planes contain 9.3 (1)°.
The weak hydrogen bonds of C-H···O and C-H···F are listed in Table 1. The weak intermolecular hydrogen bonds of C-H···O and C-H···F link the molecules (Fig. 2).

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
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 Rfactors(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.