Synthesis and biological evaluation of benzimidazolone bridged triheterocyclic compounds

A new series of benzimidazolone bridged triheterocyclic compounds bearing thiosemicarbazide, thiadiazole, triazole, moieties was synthesized and then screened for their in vitro urease, α-glucosidase, and acetylcholinesterase inhibition properties for the first time. All the synthesized compounds showed an outstanding urease inhibitory effect when compared with standards. Compounds 1 , 4 , 5b , 5d , 6b , 6d , 7b , and 7d showed significant acetylcholinesterase inhibitory activity with IC₅₀ values between 7.32 ± 0.58 and 12.52 ± 0.13 μg/ml comparable to donepezil (15.12 ± 0.20 μg/ml). Compound 5c , having thiosemicarbazide moiety at the positions N-1 and N-3 of benzimidazolone nucleus, showed the highest α-glucosidase inhibitory activity (IC₅₀ = 11.42 ± 0.11 μg/ml).