9H-Carbazole Derivatives Containing the N-Benzyl-1,2,3-triazole Moiety as New Acetylcholinesterase Inhibitors.

A series of triazole-containing carbazole derivatives were designed as new anti-acetylcholinesterase (AChE) agents. The target compounds 6a-q were simply prepared via a one-pot three-component click reaction of N-propargyl-9H-carbazole, sodium azide, and an appropriate benzyl halide. The in vitro anti-cholinesterase assay showed that the unsubstituted benzyl derivative 6p along with the 2-F, 2-Me, 3-Me, 3-MeO, and 3-F analogs (6a, 6c, and 6g-i) had significant anti-AChE activity (IC50s ≤ 3.8 μM). Among them, the 2-methylbenzyl derivative 6c with an IC50 value of 1.9 μM was the most active compound. The SAR studies revealed that small halogen atoms such as the fluorine atom or electron-donating groups such as methyl or methoxy at the ortho or meta positions of the benzyl pendent group could be tolerated or improved the anti-AChE activity.