One-pot radiosynthesis of [13N]urea and [13N]carbamate using no-carrier-added [13N]NH3

✍ Scribed by Katsushi Kumata; Makoto Takei; Masanao Ogawa; Koichi Kato; Kazutoshi Suzuki; Ming-Rong Zhang

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: French
• Weight: 203 KB
• Volume: 52
• Category: Article
• ISSN: 0022-2135
• DOI: 10.1002/jlcr.1584

✦ Synopsis

Abstract

The aim of this study was to develop a practical labeling method of [^13^N]ligands using no‐carrier‐added [^13^N]NH~3~ with high specific activity. [^13^N]urea analogues [^13^N]1a and [^13^N]2a or [^13^N]carbamate [^13^N]3a were synthesized by reacting isocyanate 5a, carbamoyl chloride 6a or chloroformate 7a with [^13^N]NH~3~. The precursors 5a–7a were prepared by treating amines 8a and 9a and alcohol 10a with triphosgene in situ. These reaction mixtures were not purified and were used directly for [^13^N]ammonolysis, respectively. Using the one‐pot method, we synthesized [^13^N]carbamazepine ([^13^N]4), a putative positron emission tomography ligand for brain imaging. Copyright © 2009 John Wiley & Sons, Ltd.