Crystal structure of 4-methyl-N-{[1-(4-methylbenzoyl)piperidin-4-yl]methyl}benzamide

In the title compound, C22H27N2O2, the piperidine ring adopts a half-chair conformation with the benzene rings inclined in a trans orientation with respect to the piperidine ring [dihedral angle between the benzene rings = 89.1 (1)°]. In the crystal, a three-centre asymmetric N—H⋯O/C—H⋯O hydrogen-bonding interaction leads to the formation of chains extending along the a-axis direction.


Related literature
For the synthesis of the title compound, see: Prathebha et al. (2013Prathebha et al. ( , 2014. For the biological activity of piperdine derivatives, see: Prostakov & Gaivoronskaya (1978); O'Hagan (2000); Pinder (1992 Table 1 Hydrogen-bond geometry (Å , ). the medical field due to their wide range of pharmacological activities. The piperidine ring system is a ubiquitous structural component of naturally occurring alkaloid and pharmaceuticals (O′Hagan et al., 2000;Pinder et al., 1992). We report in this communication, the synthesis and crystal structure of a new piperidine derivative, the title compound In the title compound ( Fig. 1 In the crystal, the molecules are linked by a asymmetric three-centre cyclic hydrogen-bonding interaction involving N1 -H and C21-H donors and O1 i (Table 1), giving an R 1 2 (7) motif and forming a chain which extends along the a axis ( Fig. 2).

S2. Experimental
The procedure (Prathebha et al., 2013; adopted in the synthesis of a typical diamide is re-presented here (Fig. 3). 4-Aminomethylpiperidine (0.03 mol) was placed in a 250 mL round-bottomed flask and 120 mL of ethyl methyl ketone was added and the mixture was stirred at room temperature. After 10 minutes, triethylamine (0.06 mol) was added and the mixture was stirred for a further 15 minutes. 4-Methylbenzoyl chloride (0.06 mol) was then added and the reaction mixture was stirred at room temperature for about 3 h. A white precipitate of triethylammonium chloride was generated which was filtered and the filtrate was evaporated to obtain the crude product which was recrystallized twice from ethyl methyl ketone, giving the title compound: yield: 79%.

S3. Refinement
H atoms were positioned geometrically and treated as riding on their parent atoms with C-H = 0.93-0.98 Å and N-H = 0.86 Å, with U iso (H) = 1.5U eq (C-methyl) or 1.2U eq (N, C) for other H atoms.  The molecular structure of the title compound showing atom numbering, with displacement ellipsoids drawn at the 30% probability level.

Figure 2
The packing of the molecules in the crystal structure. Unassociated H-atoms are omitted and dashed lines indicate the hydrogen bonds.  Experimental procedure

4-Methyl-N-{[1-(4-methylbenzoyl)piperidin-4-yl]methyl}benzamide
Crystal data Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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 > 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 C22 0.6965 (2