Abstarct: In this work, the synthesis of new derivatives of thiazolo[3,2-a] pyrimidine through palladium-catalyzed heteroannulation is reported. Treatment of 2-thiouracil (77) with propargyl bromide (63) in sodium methoxide affords 2-propargylthiopyrimidine-¬4¬-one (78) in good yield. When compound (78) in acetonitril was reacted with aryl iodides and triethylamin in the presence of bis (triphenylphosphine) palladium choloride(II) and cuprous iodide (I) at room temperature, derivatives of 3-aryl-7H-thiazolo[3,2-a]¬¬¬pyrimidine-7-one (79a-f) were obtained. The reactions were carried out under an argon atmosphere, and acetonitrile and triethylamine mixture was degassed prior to use.