Design, synthesis, and biological evaluation of 5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester derivatives as a novel series of acetylcholinesterase inhibitors

Acetylcholinesterase inhibitors are the most frequently prescribed anti-Alzheimer's drugs. A series of 5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester derivatives as the novel acetylcholinesterase inhibitors was designed based on virtual screening methods. The target compounds were synthesized with Biginelli reaction and Hantzsch-type condensation of dihydropyrimidines with substituted phenacyl chlorides, and were characterized with elemental analysis, IR, MS, 1H NMR, and 13C NMR. The biological evaluation against human acetylcholinesterase in vitro indicated all the target compounds show more than 50% inhibition at 10 μmol/L by means of the Ellman method. The results provide a starting point for the development of novel drags to treat Alzheimer's disease and lay the foundation of searching for improved acetylcholinesterase inhibitors with the novel scaffolds.