Synthesis of Substituted Pyrimidines from Chromones

Significance

A one-pot synthesis of 2,4,5-tri­substituted pyrimidines from chromones is reported. In this heterocyclic ring interconversion process, an initial Suzuki coupling is followed by reaction with amidines to afford the pyrimidine derivatives. The well-known Michael acceptor and 1,3-dicarbonyl equivalent properties of chromones are rationally exploited in this reaction. Combinations of five different boronic acids and six amidines were used to provide 30 different pyrimidines. The electronic influences of the arylboronic acid and amidine substituents appear not to play a significant role, as evidenced by the yields of the reactions.