Synthesis of some 3,4-disubstituted-6,7-dihydro-imidazo[2,1-b][1,3]thiazole and 3,4-disubstituted-7,8-dihydro-6H-imidazo[2,1-b][1,3]thiazine derivatives and evaluation of their cytotoxicities against F2408 and 5RP7 cells

Synthesis and cytotoxic activity of some novel N-pyridinyl-2-(6-phenylimidazo[2,1-b]thiazol-3-yl)acetamide derivatives

A series of novel compounds bearing imidazo[2,1-b]thiazole scaffolds were designed and synthesized based on the optimization of the virtual screening hit compound N-(6-morpholinopyridin-3-yl)-2-(6-phenylimidazo[2,1-b]thiazol-3-yl)acetamide (5a), and tested for their cytotoxicity against human cancer cell lines, including HepG2 and MDA-MB-231. The results indicated that the compound 2-(6-(4-chlorophenyl)imidazo[2,1-b]thiazol-3-yl)-N-(6-(4-(4-methoxybenzyl)piperazin-1-yl)pyridin-3-yl)acetamide (5l), with slightly higher inhibition on VEGFR2 than 5a (5.72% and 3.76% inhibitory rate at 20 μM, respectively), was a potential inhibitor against MDA-MB-231 (IC₅₀ = 1.4 μM) compared with sorafenib (IC₅₀ = 5.2 μM), and showed more selectivity against MDA-MB-231 than HepG2 cell line (IC₅₀ = 22.6 μM).