Novel 2,4,5-trisubstituted oxazole derivatives: synthesis and antiproliferative activity.

Microwave irradiation promotes the rapid O,N-acylation-cyclodehydration cascade reaction of oximes and acid chloride. Twenty novel 2,4,5-trisubstituted oxazole derivatives containing heterocycle moiety were synthesized and evaluated for their antiproliferative activity. The twenty compounds are all first reported and their structures were established by elemental analysis, (1)H NMR and (13)C NMR spectra. The bioassay tests showed that compounds 2-(2-(2-fluorophenyl)-4-(2,3,4-trimethoxyphenyl)oxazol-5-ylthio)benzo[d]thiazole (6af), 2-(2-(pyridin-3-yl)-4-(2,3,4-trimethoxyphenyl)oxazol-5-ylthio)pyrimidine (6bg) and 2-(2-(2-fluorophenyl)-4-(2,3,4-trimethoxyphenyl)oxazol-5-ylthio)-5-methyl-1,3,4-thiadiazole (6cf) displayed good antiproliferative activity in vitro, which were comparable to the positive control (5-fluorouracil).