(2,6-Difluorophenyl)(4-methylpiperidin-1-yl)methanone

In the title compound, C13H15F2NO, the piperidine ring adopts a chair conformation. The dihedral angle between the least-squares plane of the piperidine ring and the benzene ring is 48.75 (7)°. In the crystal structure, the molecules are connected via C—H⋯O hydrogen bonds, forming a zigzag chain along the b axis.

In the title compound, C 13 H 15 F 2 NO, the piperidine ring adopts a chair conformation. The dihedral angle between the leastsquares plane of the piperidine ring and the benzene ring is 48.75 (7) . In the crystal structure, the molecules are connected via C-HÁ Á ÁO hydrogen bonds, forming a zigzag chain along the b axis.

Comment
The piperidine nucleus is present in a wide range of biologically active compounds. For example, the binding properties of 4-diphenyl acetoxy-N-methylpiperidine methiodide (4-DAMP) and its analogs have been evaluated on muscarinic receptors in human neuroblastoma NB-OK1 cells (M1 receptor subtype), rat heart (M2 subtype), rat pancreas (M3 subtype) and the putative M4 receptor subtype in striatum (Waelbroeck et al., 1992). NMDA receptor antagonist properties of piperidine-2carboxylic acid derivatives have also been reported (El Hadri et al., 1995). Due to their biological importance of piperidine derivatives, herein, we have present the crystal structure of the title compound (I).
In the crystal structure, the molecules are connected via C-H···O hydrogen bonds (Table 1) forming one-dimensional supramolecular chains along the b axis (Fig. 2).

Experimental
In a round bottom flask, 25ml of toluene was mixed with 4-methylpiperidine (0.01 mol, 1.0 g) with stirring. Drops of 2,6-difluorobenzylchloride (0.01 mol, 1.7g) dissolved in toluene was then added. The reaction mixture was refluxed for 30 min. The yellow precipitate formed was washed with chloroform and with water. The precipitate was then dissolved in methanol at room temperature. After few days, colourless needle-shaped crystals were formed by slow evaporation.

Special details
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s 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 > 2σ(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.