Abstract

(±)-Trans-Ph/Et and (±)-cis-Ph/Et 1-(2-ethyl-1-phenylcyclohexyl)piperidine were synthesized from 2-ethylcyclohexanone. In contrast to the corresponding trans-substituted 2-methyl compound which is 5x more potent than PCP, the trans-2-ethyl derivative has a 75x lower affinity for the PCP binding site. The cis-2-ethyl isomer is inactive like the cis-2-methyl derivative. (±)-1-(1- Phenylcyclohexyl)-2-methylpiperidine is almost as active as the parent PCP. Reduction of the aromatic ring or quaternization of the piperidine in PCP reduces the affinity for the PCP site.

Keywords: Phencyclidine, Conformations, NMDA receptor, PCP binding site, Bruylants reaction, Ritter reaction