Radiosynthesis and biological evaluation of [18F]R91150, a selective 5-HT2A receptor antagonist for PET imaging

Serotonergic 5-HT2A receptors in cortical and forebrain regions are an important substrate for the neuromodulatory actions of serotonin brain. They have been implicated etiology many neuropsychiatric disorders serve as a target antipsychotic, antidepressant, anxiolytic drugs. Positron emission tomography imaging using suitable radioligands can be applied vivo quantification receptor densities occupancy therapy evaluation. Recently, radiosynthesis selective 5-HT2AR antagonist [18F]R91150 was reported. However, six-step is cumbersome time-consuming with low radiochemical yields (RCYs) <5%. In this work, prepared late-stage Cu-mediated radiofluorination to simplify its synthesis. The detailed protocol enabled us obtain RCYs 14 ± 1%, total synthesis time reduced 60 min. addition, autoradiographic studies rat brain slices revealed typical uptake pattern ligands.