H3R antagonist 2 (Compound 23) is a multitarget histamine H3 receptor antagonist. It exhibits inhibitory effects on acetylcholinesterase, butyrylcholinesterase, and human monoamine oxidase B (hMAO B) with IC50 values of 180 nM, 880 nM, and 775 nM, respectively. With a Ki of 170 nM for hH3R, H3R antagonist 2 demonstrates favorable anti-neuropathic pain and memory-enhancing effects. Additionally, it can cross the blood-brain barrier (BBB) [1].