Our research group focus on the development of mono and bis-arylation reactions of pyrimidinones including thiazolo[5,4-f]quinazolin-9-(8H)-ones, mainly conceived as potential kinase inhibitors. During the last decade, diaryliodoniums salts appeared as efficient electrophilic and non-toxic reagents for late-stage arylation. In this context, Cu-catalyzed C-H arylation process using diaryliodonium salts was investigated under microwave irradiation. This sustainable methodology, allowing the introduction of (het)aryl groups on C2 atom of the thiazole moiety, was successfully extended to various fused pyrimidinones. A short library of potential inhibitors of kinases is described.