Synthesis of a radioiodinated analog of epibatidine: (±)-exo-2-(2-iodo-5-pyridyl)-7-azabicyclo [2.2.1]heptane for in vitro and in vivo studies of nicotinic acetylcholine receptors

John L. Musachio, Andrew Horti, Edythe D. London, Robert F Dannals

Research output: Contribution to journalArticle


[125I] or [123I] labeled (±)-exo-2-(2-iodo-5-pyridyl)-7-azabicyclo[2.2.1]heptane (IPH), an analog of the high-affinity nicotinic acetylcholine receptor ligand, epibatidine, was prepared by a nucleophilic non-isotopic exchange reaction. Treatment of the 2-bromo pyridyl precursor with radioiodide and in situ generated Cu(I) at high temperature (200-220°C) gave [125I] or [123I]IPH that was purified by reverse phase HPLC. Radiochemical yields ranged from 31-50% for the [125I] labeling (average = 37%, n = 7) and 20% for [123I]. Both [125I]IPH and [123I]IPH were of high radiochemical purity (> 96%) and high specific activity (average of 1540 mCi/μmol (57 GBq/μmol) for [125I]IPH and >1750 mCi/μmol (65 GBq/μmol) for [123I]IPH).

Original languageEnglish (US)
Pages (from-to)39-48
Number of pages10
JournalJournal of Labelled Compounds and Radiopharmaceuticals
Issue number1
Publication statusPublished - Jan 1997



  • I
  • I
  • Brain imaging
  • Copper-assisted halogen-exchange
  • Epibatidine
  • Nicotinic receptors
  • Single photon emission computed tomography

ASJC Scopus subject areas

  • Clinical Biochemistry
  • Molecular Medicine
  • Analytical Chemistry
  • Organic Chemistry
  • Drug Discovery
  • Pharmacology

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