Preparation of iodine-123 labeled AM251: A potential SPECT radioligand for the brain cannabinoid CB1 receptor

✍ Scribed by Ruoxi Lan; S. John Gatley; Alexandros Makriyannis

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: French
• Weight: 361 KB
• Volume: 38
• Category: Article
• ISSN: 0022-2135
• DOI: 10.1002/(sici)1099-1344(199610)38:10<875::aid-jlcr908>3.0.co;2-g

✦ Synopsis

We report the synthesis and labeling with iodine-123 of N-(piperidin-1-yl)-5-(4-iodophenyl)-l-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251). This compound is an analog of the recently described cannabinoid receptor antagonist, SR1417164 in which a 4-chlorophenyl group is replaced by 4-iodophenyl. Labeling in good yield (62%) and radiochemical purity (> 95%), and high specific activity (> 2500 Ci/mmol) was achieved by an iododestannylation reaction using the tributyltin precursor, no canier added 1-123 iodide, and chloramine-T.