title: Iodonium ylide-mediated radiofluorination of 18F-FPEB and validation for human use.
abstract: Translation of new methodologies for labeling nonactivated aromatic molecules with (18)F remains a challenge. Here, we report a one-step, regioselective, metal-free (18)F-labeling method that uses a hypervalent iodonium(III) ylide precursor, to prepare the radiopharmaceutical (18)F-3-fluoro-5-[(pyridin-3-yl)ethynyl]benzonitrile ((18)F-FPEB).
  
  
  METHODS
  Automated radiosynthesis of (18)F-FPEB was achieved by reaction of the ylide precursor (4 mg) with (18)F-Et4NF in dimethylformamide at 80°C for 5 min and formulated for injection within 1 h.
  
  
  RESULTS
  (18)F-FPEB was synthesized in 20% ± 5% (n = 3) uncorrected radiochemical yields relative to (18)F-fluoride, with specific activities of 666 ± 51.8 GBq (18 ± 1.4 Ci)/μmol at the end of synthesis and was validated for human use.
  
  
  CONCLUSIONS
  Radiofluorination of iodonium (III) ylides proved to be an efficient radiosynthetic strategy for synthesis of (18)F-labeled radiopharmaceuticals.
authors: Division of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Boston, Massachusetts; and Department of Radiology, Harvard Medical School, Boston, Massachusetts.
authors: Nickeisha A
authors: NA
authors: Stephenson
authors: Department of Radiology, Harvard Medical School, Boston, Massachusetts.
authors: Jason P
authors: JP
authors: Holland
authors: Division of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Boston, Massachusetts; and.
authors: Alina
authors: A
authors: Kassenbrock
authors: Division of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Boston, Massachusetts; and.
authors: Daniel L
authors: DL
authors: Yokell
authors: Division of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Boston, Massachusetts; and Department of Radiology, Harvard Medical School, Boston, Massachusetts.
authors: Eli
authors: E
authors: Livni
authors: Division of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Boston, Massachusetts; and Department of Radiology, Harvard Medical School, Boston, Massachusetts.
authors: Steven H
authors: SH
authors: Liang
authors: Division of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Boston, Massachusetts; and Department of Radiology, Harvard Medical School, Boston, Massachusetts vasdev.neil@mgh.harvard.edu.
authors: Neil
authors: N
authors: Vasdev
mesh_terms: D001331:Automation; D004583:Electrons; D005462:Fluorine Radioisotopes / Q000737:chemistry*; D006801:Humans; D006868:Hydrolysis; D007455:Iodine / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry*; D009861:Onium Compounds / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D049268:Positron-Emission Tomography; D011725:Pyridines / Q000138:chemical synthesis / Q000737:chemistry*; D011854:Radiochemistry; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000737:chemistry; D013696:Temperature; D013997:Time Factors
chemical_list: C527000:3-fluoro-5-((pyridin-3-yl)ethynyl)benzonitrile; D005462:Fluorine Radioisotopes; D009570:Nitriles; D009861:Onium Compounds; D011725:Pyridines; D019275:Radiopharmaceuticals; D007455:Iodine; D010100:Oxygen
keywords: 18F-FPEB; PET; fluorination; iodonium ylide; mGlu5
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