Thiazolopyrimidine 2 was obtained from the reaction of dihydropyrimidinone with chloroacetic acid and benzaldehyde. Thiazolopyrimidine 2 containing an α,β-unsaturated ketonic function [-CH=CH-CO-] has been used as a component of Michael addition with an equimolar amount of dinucleophiles to give a series of novel tetracyclic pyrimidine derivatives. Treatment of thiazolopyrimidine 2 with uracil, aminotriazole, cyanoacetic acid hydrazide, o-phenylenediamine or diaminopyridine afforded the corresponding pyridopyrimidine, triazolopyrimidine, pyrazolone, benzodiazepine and triazepine derivative, respectively. The detailed synthesis, spectroscopic data, and antitumor activity for synthesized compounds were reported.
