N, N –Disubstituted piperazines and homopiperazines: Synthesis and affinities at α4β2* and α7* neuronal nicotinic acetylcholine receptors.

A series of N, N– disubstituted piperazines and homopiperazines were prepared and evaluated for binding to natural α4β2* and α7* neuronal nicotinic acetylcholine receptors (nAChRs) using whole brain membrane. Some compounds exhibited good selectivity for α4β2* nAChRs and did not interact with the α7* nAChRs subtype. The most potent analogs were compounds 8-19 (Ki = 10.4 μM), 8–13 (Ki = 12.0 μM), and 8–24 (Ki = 12.8 μM). Thus, linking together a pyridine π-system and a cyclic amine moiety via a homopiperazine ring affords compounds with low affinity but with good selectivity for α4β2* nAChRs. [ABSTRACT FROM AUTHOR]