Microwave-supported one-pot reaction for the synthesis of 5-alkyl/arylidene-2-(morpholin/thiomorpholin-4-yl)-1,3-thiazol-4(5H)-one derivatives over MgO solid base

In this study, we synthesized 5-alkyl/arylidene-2-(morpholin/thiomorpholin-4-yl)-1,3-thiazol-4(5H)-one through a one-pot reaction using all starting materials in a microwave oven. The presence of the solid base MgO catalyzed the reaction in the eco-friendly solvent of ethanol as a green chemistry approach owing to the noticeable advantages of short reaction times to save energy and less toxic starting materials for environmental friendliness. This indicates that the one-pot reaction makes the process simpler, in which the reaction time (1 h) is shorter than that of conventional methods (10 h). The yield of the reactions reached 55–76% for 18 final products consisting of 17 derivatives of morpholine or thiomorpholine with various aldehydes and one extended moiety of the primary amine, of which 13/18 final compounds were new. The purification procedure was performed without using polluting solvents. The structures were confirmed using IR, 1H-NMR, 13C-NMR, and MS analyses.