Powder X‐ray study of racemic (2RS,3RS)‐5‐amino‐3‐[4‐(3‐methoxyphenyl)piperazin‐1‐yl]‐1,2,3,4‐tetrahydronaphthalen‐2‐ol

The structure of the title benzovesamicol analogue, C₂₁H₂₇N₃O₂, an important compound for the diagnosis of Alzheimer's disease, has been determined by X‐ray powder diffraction. The title compound was firstly synthesized and characterized by spectroscopic methods (FT–IR, and ¹³C and ¹H NMR). The compound is a racemic mixture of enantiomers which crystallizes in the monoclinic system in a centrosymmetric space group (P2₁/c). Crystallography, in particular powder X‐ray diffraction, was pivotal in revealing that the enantio‐resolution did not succeed. The piperazine ring is in a chair conformation, while the cyclohexene ring assumes a half‐chair conformation. The crystal packing is dominated by intermolecular O—H...N hydrogen bonding which links molecules along the c direction.