Sulfamic Acid-catalyzed One-pot Multicomponent Synthesis of 5-phenyl-2- thioxo-1,2,3,5-tetrahydro-4H-pyrimido[4,5-d][1,3]thiazolo[3,2-a]pyrimidin- 4-ones

Background: A straightforward protocol for the one-pot synthesis of a series of novel thiazolopyrimidine derivatives has been developed. Method: In which multicomponent reaction between thiobarbituric acid, 2-aminothiozole and several substituted aldehydes using sulfamic acid (20 mol%) as a heterogeneous and easily recoverable catalyst in ethanol under reflux condition. Conclusion: This method has several advantages like greener synthetic approach, good to excellent yield (82-91%), cost-effectiveness, easy work-up and atom-economic procedure.