Copper-Catalyzed Cyclization for Access to 6H-Chromeno[4,3-b]quinolin-6-ones Employing DMF as the Carbon Source.

The first example of the copper-catalyzed cyclization of 4-(phenylamino)-2H-chromen-2-ones employing the N-methyl moiety of DMF as the source of the methine (CH) group has been developed, providing an efficient synthetic pathway to access novel functionalized 6H-chromeno[4,3-b]quinolin-6-ones in moderate to good yields.