Regioselective Syntheses of 2,7-(Het)Arylpyrido[2,3-d]pyrimidines by an Orthogonal Cross-Coupling Strategy

An efficient and easy access to 2,7-disubstituted pyrido[2,3- d ]pyrimidine derivatives is reported. These derivatives were obtained using two orthogonal palladium-catalyzed cross-coupling reactions via successive C-7 chlorine and C-2 methylsulfur releases.