Radiosynthesis of N‐[4‐(4‐fluorobenzyl)piperidin‐1‐yl]‐N′‐(2‐[11C]oxo‐1,3‐dihydrobenzimidazol‐5‐yl)oxamide,a NR2B‐selective NMDA receptor antagonist |
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Authors: | Romain Labas Franck Sobrio Yann Bramoullé Anne‐Sophie Hérard Martine Guillermier Philippe Hantraye Frédéric Dollé Louisa Barré |
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Affiliation: | 1. CEA, I2BM, CINAPS, GDM‐TEP, Caen, France;2. Université de Caen Basse Normandie, UMR 6232 CI‐NAPS, Centre Cyceron, Caen, France;3. CEA, I2BM, SHFJ, LIME, Orsay, France |
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Abstract: | In order to perform in vivo imaging of the NR2B NMDA receptor system by positron emission tomography, a NR2B selective NMDA receptor antagonist has been labelled with carbon‐11 (half‐life: 20 min). N‐4‐(4‐fluorobenzyl)piperidin‐1‐yl]‐N′‐(2‐oxo‐1,3‐dihydrobenzimidazol‐5‐yl)oxamide has been described demonstrating high affinity and selectivity for the NR2B receptors (IC50 of 5 nM in 3H]Ro‐25,6981 binding assay). The labelling precursor and the reference compound were synthesized by coupling the 4‐(4‐fluorobenzyl)piperidine with the corresponding oxalamic acid. The reaction of 11C]phosgene with phenylenediamine precursor led the formation of the 11C]benzimidazolone ring present on the ligand. The labelling occurred in THF or acetonitrile and the decay corrected radiochemical yield was 30–40% from the produced 11C]methane. HPLC purification and formulation led to 2.6–3.7 GBq (70–100 mCi) of radioligand within 30–35 min. The specific radioactivity was 72–127 GBq/µmol (2–3.4 Ci/µmol) at the end of synthesis. Copyright © 2009 John Wiley & Sons, Ltd. |
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Keywords: | carbon‐11 PET NR2B NMDA radiolabelling |
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