@article{oai:repo.qst.go.jp:00083306,
 author = {Ohkubo, Takayuki and Kurihara, Yusuke and Masanao, Ogawa and Nobuki, Nengaki and Masayuki, Fujinaga and Wakana, Mori and Katsushi, Kumata and Masayuki, Hanyu and Kenji, Furutsuka and Hiroki, Hashimoto and Kazunori, Kawamura and Zhang, Ming-Rong and Ohkubo, Takayuki and Kurihara, Yusuke and Masanao, Ogawa and Nobuki, Nengaki and Masayuki, Fujinaga and Wakana, Mori and Katsushi, Kumata and Masayuki, Hanyu and Kenji, Furutsuka and Hiroki, Hashimoto and Kazunori, Kawamura and Zhang, Ming-Rong},
 journal = {EJNMMI Radiopharmacy and Chemistry},
 month = {Jul},
 note = {Background
[ 18 F]Fluoromisonidazole ([ 18 F]FMISO) and 1-[ 18 F]fluoro-3-((2-((1 E ,3 E )-4-(6-(methylamino)pyridine-3-yl)buta-1,3-dien-1-yl)benzo[d]thiazol-6-yl)oxy)propan-2-ol ([18 F]PM-PBB3 or [ 18 F]APN-1607) are clinically used radiotracers for imaging hypoxia and tau pathology, respectively. Both radiotracers were produced by direct 18 F-fluorination using the corresponding tosylate precursors 1 or 2 and [ 18 F]F - , followed by the removal of protecting groups. In this study, we synthesized [ 18F]FMISO and [ 18 F]PM-PBB3 by 18 F-fluoroalkylation using [ 18 F]epifluorohydrin ([ 18 F] 5 ) for clinical applications.
Results
First, [ 18 F] 5 was synthesized by the reaction of 1,2-epoxypropyl tosylate ( 8 )
with [ 18 F]F - and was purified by distillation. Subsequently, [ 18 F] 5 was reacted with 2-nitroimidazole ( 6 ) or PBB3 ( 7 ) as a precursor for 18 F-labeling, and each reaction mixture was purified by preparative high-performance liquid chromatography and formulated to obtain the [ 18 F]FMISO or [ 18 F]PM-PBB3 injection. All synthetic sequences were performed using an automated 18 F-labeling synthesizer. The obtained [ 18 F]FMISO showed sufficient radioactivity (0.83 ± 0.20 GBq at the end of synthesis (EOS); n = 8) with appropriate radiochemical yield based on [ 18F]F - (26 ± 7.5% at EOS, decay-corrected; n = 8). The obtained [ 18 F]PM-PBB3 also showed sufficient radioactivity (0.79 ± 0.10 GBq at EOS; n = 11) with appropriate radiochemical yield based on [ 18 F]F - (16 ± 3.2% at EOS, decay-corrected; n = 11).
Conclusions
Both [ 18 F]FMISO and [ 18 F]PM-PBB3 injections were successfully synthesized with sufficient radioactivity by 18 F-fluoroalkylation using [ 18 F] 5 .},
 title = {Automated radiosynthesis of two 18F-labeled tracers containing 3-fluoro-2-hydroxypropyl moiety, [18F]FMISO and [18F]PM-PBB3, via [18F]epifluorohydrin},
 volume = {6},
 year = {2021}
}