5-Piperazinyl-3-sulfonylindazoles as Potent and Selective 5-Hydroxytryptamine-6 Antagonists

As part of our efforts to develop agents for CNS diseases, we have been focused on the 5-HT6 receptor in order to identify potent and selective ligands for cognitive enhancement. Herein we report the identification of a novel series of 5-piperazinyl-3-sulfonylindazoles as potent and selective 5-HT6 antagonists. The synthesis, SAR, and pharmacokinetic and pharmacological activities of some of the compounds including 3-(naphthalen-1-ylsulfonyl)-5-(piperazin-1-yl)-1H-indazole (WAY-255315 or SAM-315) will be described.