3-(Arylsulfonyl)-1-(azacyclyl)-1H-indoles are 5-HT6 receptor modulators

Novel 3-(arylsulfonyl)-1-(azacyclyl)-1H-indoles 6 were synthesized as potential 5-HT6 receptor ligands, based on constraining a basic side chain as either a piperidine or a pyrrolidine. Many of these compounds had good 5-HT6 binding affinity with Ki values <10 nM. Depending on substitution, both agonists (e.g., 6o: EC50 = 60 nM, Emax = 70%) and antagonists (6y: IC50 = 17 nM, Imax = 86%) were identified in a 5-HT6 adenylyl cyclase assay.