Design, synthesis and pharmacological evaluation of 4-(piperazin-1-yl methyl)-N1-arylsulfonyl indole derivatives as 5-HT6 receptor ligands

4-(Piperazin-1-yl methyl)-N1-arylsulfonyl indole derivatives were designed and synthesized as 5-HT6 receptor (5-HT6R) ligands. The lead compound 6a, from this series shows potent in vitro binding affinity, good PK profile, no CYP liabilities and activity in animal models of cognition.