Radiosynthesis of high effective specific-activity [123I]SCH 23982 for dopamine D-1 receptor-based SPECT imaging

The high yield, high-specific activity radiosynthesis of the dopaminergic D-1 receptor-binding ligand [¹²³I]SCH 23982 is described. Using no-carrier-added iododeprotonation of the des-iodo precursor SKF 83692 and column-switching HPLC, [¹²³I]SCH 23982 was isolated in 35–40% radiochemical yield with an effective specific activity of 2250–4000 Ci/mmol and an overall preparation time of 90 min. The procedure outlined here can be employed for the clinical production of [¹²³I]SCH 23982 as a SPECT radiopharmaceutical, as well as [¹²⁵I]SCH 23982 to be used for in vitro receptor-binding applications.