Synthesis and antiviral activity of novel imidazo[2,1‐b]thiazoles coupled with morpholine and thiomorpholines

Abstract Herein described the synthesis and antiviral evaluation of a novel series of morpholine and thio‐morpholine coupled imidazo[2,1‐ b ]thiazoles. The three‐step reaction sequence involving the condensation of 1,3‐dichloroacetone with thiourea followed by coupling with morpholine and thiomorpholine and finally cyclization with substituted α‐bromoacetophenones yielded the desired imidazothiazoles 7(a–l) . Screening of all the new compounds for their in vitro antiviral activity against influenza virus A/Puerto Rico/8/34 (H1N1) in MDCK cells, resulted in two potent analogs, 7d (IC 50 : 1.1 μM, C 50 : >300 μM, SI = 273) and 7e (IC 50 : 2.0 μM, C 50 : >300 μM, SI = 150), with a favorable toxicity profile and are the best anti‐influenza hit analogs for further structural optimization.