Novel Assembling of Furano-Fused Azepinone Derivatives for Inhibition of Acetylcholinesterase Responsible for Alzheimer’s Disease: Synthesis, Molecular Docking, DFT, In Vitro, and In Silico Studies

A new assembly of furano-fused azepinone derivatives was carried out in two steps, i.e., 3 + 2 cycloaddition followed by hydroxylammonium-<i>O</i>-sulfonic acid (HOSA)-assisted Beckmann rearrangement in aqueous conditions. This methodology uses a readily available starting synthon, dimedone, to synthesize five- and six-membered condensed furano-azepinone derivatives <b>5(a-n)</b>, and their structures were validated by spectral techniques. In vitro antiacetylcholinesterase (AchE) activity revealed that compound <b>5n</b> (IC₅₀= 2.38 ± 0.02 nM) showed higher inhibitory activity than reference drugs galantamine (IC₅₀ = 2.84 ± 0.01 nM). Later, cytotoxicity studies of the synthesized compounds were conducted on SHSY5Y cell lines, indicating the concentration-dependent inhibition, i.e., the highest cell viability at 25 μM, whereas the lowest viability at 400 μM. Further intracellular ROS measurements indicate that <b>5n</b> exhibits superior ROS-scavenging capabilities in fluorescence-based assays. Molecular docking and density functional theory (DFT) analyses were applied to further validate the binding interactions of the compounds with the AchE active site. The combined experimental and computational investigation revealed that <b>5n</b> exhibits significant anti-AchE activity and warrants further exploration for its medicinal utility in Alzheimer's disease and related challenges. The design, synthesis, and AchE inhibitory properties of the synthesized furano-azepinone derivatives were patented under Indian patent number 202511048244.