Sequential multicomponent synthesis of highly functionalized pyridin-2(1H)-one derivatives

Highly functionalized pyridin-2(1H)-one derivatives were synthesized in high yields by a sequential multicomponent reaction. The mechanism involves the Michael addition of Meldrum's acid to 3-formylchromone, followed by the addition of an amine, intramolecular amidation and elimination of acetone. Depending on the temperature used, decarboxylation can occur. The mechanism of this reaction has been proposed based on the by-products obtained when the reaction was performed using poorly reactive amines. The versatility of this approach has been exemplified using various 3-formylchromones and amines. Analogues of Meldrum's acid were also tested, allowing the synthesis of pyridin-2(1H)-one derivatives with various substituents on the aromatic ring.