4-(4-Chlorophenyl)-4-hydroxypiperidinium 2-(2-phenylethyl)benzoate

In the title compound, C11H15ClNO+·C15H13O2 −, the piperidinium ring adopts a chair conformation. In the crystal, cations and anions are connected by intermolecular O—H⋯O and N—H⋯O hydrogen bonds, forming two-dimensional networks parallel to the bc plane. Furthermore, the crystal structure is stabilized by weak C—H⋯π interactions.

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009  (neuroleptic drug used to treat patients with psychotic illnesses, extreme agitation, or Tourette's syndrome) and loperamide, which is a synthetic piperidine derivative, is a drug effective against diarrhea resulting from gastroenteritis or inflammatory bowel disease. A review on the synthesis and biological activity of uncondensed cyclic derivatives of piperidine has been reported (Vartanyan, 1984).
Experimental 4-(4-Chlorophenyl)-piperidin-4-ol (2.12 g, 0.01 mol) was dissolved in 10 ml of methanol and 2-(2-phenylethyl)benzoic acid (2.26 g, 0.01 mol) was dissolved in 10 ml of methanol. The solutions were mixed and stirred in a beaker at 333 K for 30 minutes. The mixture was kept aside for three days at room temperature. The formed salt was filtered and dried in vacuum desiccator over phosphorous pentoxide. Crystals suitable for X-ray analysis were obtained by slow evaporation of a N,N-dimethylformamide solution (m. p.: 445-448 K).

Special details
Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.
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 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq  (12)