Crystal structures and absolute configurations of dexmedetomidine and its tosyl derivative

Abstract X-ray diffraction data were used to determine the absolute configuration of dexmedetomidine, a new member of a class of drugs with 4-arylalkyl-1H-imidazole structure. When the anomalous effect of the parent compound proved to be too small for determination of the absolute configuration the tosyl derivative, with the same configuration, was synthesised and used as a reference. Stability of the stereogenic center was verified by HPLC technique. The absolute configuration of the compounds is S. Complete crystal structures are reported for both compounds. Co radiation was used for measurements.