5-HT6R antagonist 3 (compound 15) is an effective and selective 5-HT6R antagonist capable of crossing the blood-brain barrier. It exhibits Ki values of 14 nM for 5-HT6, 3533 nM for 5-HT1A, 35 nM for 5-HT2A, and 1449 nM for 5-HT7. This compound demonstrates anxiolytic-like effects and possesses neuroprotective and cognitive-enhancing properties, indicating potential for Alzheimer's disease research.

5-HT2A receptor:35 nM (Ki), 5-HT1A receptor:3533 nM (Ki), 5-HT7 Receptor:1449 nM (Ki), 5-HT6 receptor:14 nM (Ki)