[(3R,4S)-4-(4-Fluorophenyl)-1-methylpiperidin-3-yl]methyl 4-methylbenzenesulfonate

In the title compound, C20H24FNO3S, the piperidine ring adopts a chair conformation. The dihedral angle between the aromatic rings is 47.01 (17)°.

In the title compound, C 20 H 24 FNO 3 S, the piperidine ring adopts a chair conformation. The dihedral angle between the aromatic rings is 47.01 (17) .

Experimental
To a stirred solution of trans-(-)-paroxo (10 g) in dichloromethane (50 ml) triethylamine (7 ml) was added. The mixture was cooled to 268 K. Toluenesulfonyl chloride (12 g) was slowly added and stirred for l h at 268 K. Methanesulfonic acid (4 ml) was then added gradually and the mixture was concentrated at about 323 K at atmospheric pressure. The residue was taken up in toluene, water was added and this was stirred for 30 minutes. The top toluene layer was separated. The pH of the aqueous layer was then adjusted to 9.0 with a saturated NaHCO 3 solution. The product was filtered, washed with water and dried to yield the title compound (13 g) as a white to off-white solid (m.p. 380-381 K).

Refinement
All H atoms were placed in calculated positions, with C-H distances in the range 0.93-0.98 and included in the final cycles of refinement in the riding-model approximation, with U iso (H) = 1.2U eq (C) or U iso (H) = 1.5U eq (C). Fig. 1. The molecular structure of the title compound showing atom labels and 40% probability displacement ellipsoids.

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.
supplementary materials sup-3 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.