Synthesis and monoamine transporter affinity of 2β-carbomethoxy-3β-(4′-p-substituted phenyl)-piperidine analogs of cocaine

A series of novel piperidine based analogs of cocaine was synthesized and evaluated in vitro against the three monoamine transporters to develop new potential selective SERT radiotracers. Modification of the phenyl substitution with five-membered heterocyclic groups resulted in a wide affinity and selectivity scale. Radiolabeling and mouse in vivo study was performed on the piperidine analog of ZIENT, which crossed the blood–brain barrier but failed to selectively accumulate in the regions of the brain rich in SERT.