Crystal structures of two pyrrolidin-1-yl derivatives of cathinone: α-PVP and α-D2PV

Two cathinones found on the market for legal highs have been characterized using X-ray crystallography. These are 1-(1-oxo-1-phenylpentan-2-yl)pyrrolidin-1-ium chloride monohydrate, C₁₅H₂₂NO⁺·Cl^-·H₂O (α-PVP·HCl·H₂O), with erythritol [(2R,3S)-butane-1,2,3,4-tetrol, C₄H₁₀O₄] as diluent in the sample, and 1-(2-oxo-1,2-diphenylethyl)pyrrolidin-1-ium chloride, C₁₈H₁₈NO⁺·Cl^- (α-D2PV·HCl or A-D2PV·HCl). The intermolecular interactions occurring in the various crystal structures of these compounds have been described. The two arene rings of α-D2PV participate in the formation of π-π bonds (with parallel-displaced geometries of the π-π interactions). In addition, one of the rings forms a C-H...π interaction with an arene ring participating in an adjacent π-π bond, resulting in a linear arrangement of the molecules in the crystal. In the hydrated α-PVP salt, the molecules form a structure, the so-called `corral', in which two water molecules and two chloride ions are confined. The whole is held together by intermolecular hydrogen bonds. The structure of the chloride salt of α-D2PV described here lacks water molecules, which automatically allows for the formation of other types of intermolecular interactions. This structure was compared with the previously published hydrated form.