Organic Synthesis of Precursor and Radiolabelling of ¹¹C-Carfentanil as Opiate Receptor Imaging Agent

The ［¹¹C］-methyl 1-phenethyl-4-(N-phenylpropanamido)piperidine-4-carboxylate (¹¹C-Carfentanil) as μ opiate receptor imaging agent and its precursor have been synthesized. The precursor has been confirmed by 1H NMR and MS. ¹¹C-Carfentanil was prepared without using HPLC purification. Labeling yields, radiochemistry purity and specific activity are (67.3±2.3)%(n=3), 98% and 1.67×10¹⁴ Bq/g (66.6 PBq/mol) respectively.