Venlafaxine besylate monohydrate

Abstract

The title compound {systematic name: [2-(1-hydroxycyclohexyl)-2-(4-methoxyphenyl)ethyl]dimethylazanium benzene­sulfonate monohydrate}, C17H28NO2+·C6H5O3S-·H2O, is a besylate salt hydrate of the anti­depressant drug venlafaxine. In the crystal, besylate anions and water mol­ecules self-assemble, forming hydrogen-bonded dimers linked around inversion centers, with graph set R44(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...[pi] inter­actions. This is the first example of a venlafaxine cation with a closed conformation, as it features an intra­molecular N-H...O inter­action involving the protonated N atom.