Concise and Scalable Radiosynthesis of (+)-[(18)F]MDL100907 as a Serotonin 5-HT(2A) Receptor Antagonist for PET

[Image: see text] 5-Hydroxytryptamine (5-HT(2A)) receptors play an important role in several psychiatric disorders. In order to investigate the serotonin (5-HT) receptor in vivo, reliable syntheses are required for positron emission tomography (PET) 5-HT radioligands. Owing to the excellent in vivo properties of [(18)F]MDL100907 for PET, there has been great interest to develop a novel synthetic route for [(18)F]MDL100907. Here, we report a highly efficient, scalable, and expedient synthesis for [(18)F]MDL100907. The radiofluorination was performed on a (18)F-labeling boron pinacol ester precursor, which is synthesized using the Liebeskind–Srogl cross-coupling reaction as a key step. Our method is practically more suitable to employ late-stage Cu-mediated radiofluorination and facilitate the production of the [(18)F]MDL100907 radioligand in excellent decay-corrected RCY of 32 ± 10% (n = 7) within 60 min. We prepared [(18)F]MDL100907 in high molar activity (2.1 Ci/μmol) and compared it to [(11)C]MDL100907 in the brain of a nonhuman primate.