Abstarct: In this research, we report a successful synthesis of 6-amino-2-propargyl thiopyrimidine-4-one (89) from the reaction of 6-amino2-thiouracil (87) with propargyl bromide in the presence of sodium methoxide. When compound (89) was treated in DMF with the aryl iodides (90) and triethylamine in the presence of bis (triphenylphosphine) palladium (II) chloride and copper iodide at 70 °C, the products namely 5-amino-3-benzyl-7H-thiazolo[3,2-a]pyrimidine-7-ones (92a-g) were obtained in good to high yields.