Venlafaxine besylate monohydrate

The title compound {systematic name: [2-(1-hydroxycyclohexyl)-2-(4-methoxyphenyl)ethyl]dimethylazanium benzene-sulfonate monohydrate}, C17H28NO2 (+)·C6H5O3S(-)·H2O, is a besylate salt hydrate of the anti-depressant drug venlafaxine. In the crystal, besylate anions and water mol-ecules self-assemble, forming hydrogen-bonded dimers linked around inversion centers, with graph set R 4 (4)(6). The crystal packing features a chain of alternate dimers and venlafaxine cations in the b-axis direction with the components linked by O-H⋯O hydrogen bonds and C-H⋯O and C-H⋯π inter-actions. This is the first example of a venlafaxine cation with a closed conformation, as it features an intra-molecular N-H⋯O inter-action involving the protonated N atom.