Hofmann reaction-involving annulation of o-(pyridin-2-yl)aryl amides selectively and rapidly leads to potential potocatalytic active 6H-pyrido[1,2-c]quinazolin-6-one derivatives

A highly efficient PIFA-mediated Hofmann reaction of o-(pyridin-2-yl)aryl amides has been developed to selectively and rapidly construct various potential potocatalytic active 6H-pyrido[1,2-c]quinazolin-6-ones. The use of nontoxic and eco-friendly organoiodine reagent, operationally simplicity, short reaction time and mild reaction conditions, broad substrate scope and high functional group tolerance, and excellent yields make this protocol very simple, practical, and easy to handle. It provides a feasible platform for developing novel organic fluorophore structures. Preliminary research for this purpose shows that the N5-methylated pyridoquinazolinone 3a could be used as a photocatalyst in several organic transformations, indicating it is a very promising lead fluorophore for developing new superior photocatalysts.