TY - JOUR AU - Zarrad, Fadi AU - Zlatopolskiy, Boris AU - Krapf, Philipp AU - Zischler, Johannes AU - Neumaier, Bernd TI - A Practical Method for the Preparation of 18F-Labeled Aromatic Amino Acids from Nucleophilic [18F]Fluoride and Stannyl Precursors for Electrophilic Radiohalogenation JO - Molecules VL - 22 IS - 12 SN - 1420-3049 CY - Basel PB - MDPI75390 M1 - FZJ-2017-08436 SP - 2231 - PY - 2017 AB - In a recent contribution of Scott et al., the substrate scope of Cu-mediated nucleophilic radiofluorination with [18F]KF for the preparation of 18F-labeled arenes was extended to aryl- and vinylstannanes. Based on these findings, the potential of this reaction for the production of clinically relevant positron emission tomography (PET) tracers was investigated. To this end, Cu-mediated radiofluorodestannylation using trimethyl(phenyl)tin as a model substrate was re-evaluated with respect to different reaction parameters. The resulting labeling protocol was applied for 18F-fluorination of different electron-rich, -neutral and -poor arylstannyl substrates in RCCs of 16–88%. Furthermore, this method was utilized for the synthesis of 18F-labeled aromatic amino acids from additionally N-Boc protected commercially available stannyl precursors routinely applied for electrophilic radiohalogenation. Finally, an automated synthesis of 6-[18F]fluoro-l-m-tyrosine (6-[18F]FMT), 2-[18F]fluoro-l-tyrosine (2-[18F]F-Tyr), 6-[18F]fluoro-l-3,4-dihydroxyphenylalanine (6-[18F]FDOPA) and 3-O-methyl-6-[18F]FDOPA ([18F]OMFD) was established furnishing these PET probes in isolated radiochemical yields (RCYs) of 32–54% on a preparative scale. Remarkably, the automated radiosynthesis of 6-[18F]FDOPA afforded an exceptionally high RCY of 54 ± 5% (n = 5). LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000419242400196 C6 - pmid:29244780 DO - DOI:10.3390/molecules22122231 UR - https://juser.fz-juelich.de/record/841351 ER -