Synthesis and antibacterial evaluation of new pyrido[3',2':4,5]thieno[3,2-d ]pyrimidin-4(3H)-one hybrids linked to different heteroarene units

A three-component protocol involving the reaction of 3-aminothieno[2,3-b]pyridine-2-carboxylate, Me₂NCH(OMe)₂ and heteroaryl (bis)amines in dioxane under microwave irradiation yielded a new series of pyrimidinones. The target hybrids were formed by an initial formamidine formation,Pyrazole-linked pyrimidinones displayed the best antibacterial activity against all the gram-positive and negative strains tested.