Synthesis of 5'-N-(2-[18F]Fluoroethyl)-carboxamidoadenosine: A promising tracer for investigation of adenosine receptor system by PET technique

Sz Lehel, G. Horváth, I. Boros, P. Mikecz, T. Márián, A. J. Szentmiklósi, L. Trón

Research output: Contribution to journalArticle

19 Citations (Scopus)


5'-N-(2-[18F]Fluoroethyl)-carboxainidoadenosine ([18F]FNECA), a promising 18F-labelled adenosine agonist has been prepared by two different synthetic routes. In the first, [18F]fluoride was reacted with 5'-N,N-ethylene-2',3'-O-isopropylidenecarboxamido-adenosine and after removing the protective group [18F]FNECA was obtained in a low radiochemical yield (1 ± 1%, mean ± sd, n = 7, decay corrected). In the second, 2-[18F]fluoroethylamine was synthesised according to the literature and reacted with 2',3'-O-isopropylideneadenosine-5'-uronic acid in the presence of a coupling agent. The following hydrolysis step provided the [18F]FNECA with a modest radiochemical yield (24 ± 9%, n = 17, based on [18F]fluoride-activity). After purification by preparative reverse phase HPLC 18.9-166.5 MBq (0.51-4.5 mCi) [18F]FNECA was obtained with a specific activity of 2.35 ± 1.14 TBq/mmol (63.5 ± 30.9 Ci/mmol, n = 3). The total synthesis took 200 min and the decay corrected radiochemical yield based on [18F]F- activity was 17 ± 9% (n = 5) with more than 99.9% radiochemical purity. This second route provides sufficient [18F]FNECA for the subsequent biological evaluation using PET-technique.

Original languageEnglish
Pages (from-to)807-815
Number of pages9
JournalJournal of Labelled Compounds and Radiopharmaceuticals
Issue number8
Publication statusPublished - Jan 1 2000



  • Adenosine receptors
  • NECA
  • PET
  • Radiofluorination

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Radiology Nuclear Medicine and imaging
  • Drug Discovery
  • Spectroscopy
  • Organic Chemistry

Cite this