N-(2-(Piperazin-1-yl)phenyl)arylamide Derivatives as β-Secretase (BACE1) Inhibitors: Simple Synthesis by Ugi Four-Component Reaction and Biological Evaluation

A novel series of N-(2-(piperazin-1-yl) phenyl) aryl carboxamide derivatives were simply synthesized by Ugi-multicomponent reaction as beta-secretase (BACE1) inhibitors. The BACE1 inhibitory activity of the synthesized compounds was examined using a Forester resonance energy transfer (FRET)-based assay. Among the tested compounds, the N-(5-bromo-2-(4-phenylpiperazine-1-yl) phenyl) thiophenecarboxamide derivative 14 containing the N-cyclohexyl indole acetamide moiety showed superior BACE1 inhibition at 10 and 40 mu M. The results of the molecular docking study indicated that compound 14 establishes favorable hydrogen bonding interactions with the catalytic amino acid residues Asp228 and Thr72 and could be well accommodated in the flap region and P2 and P'2 pockets of the BACE1 active site.