Synthesis, evaluation and metabolic studies of radiotracers containing a 4-(4-[18F]-fluorobenzyl)piperidin-1-yl moiety for the PET imaging of NR2B NMDA receptors

► Fluorinated antagonists for the NR2B subunit of the NMDA receptors were developed. ► Two PET radiotracers containing the 4-(4-[18F]fluorobenzyl)piperidine moiety were synthesized. ► The in vivo evaluation by PET imaging demonstrated radiodefluorination. ► Metabolism of the 4-(4-[18F]fluorobenzyl)piperidine was studied by LC-MS.