An efficient cascade synthesis of various 2H-1,4-benzoxazin-3-(4H)-ones from o-halophenols and 2-halo-amides catalyzed by CuI

A novel and efficient one-pot cascade synthesis of 2H-1,4-benzoxazin-3-(4H)-ones has been developed through copper-catalyzed coupling of o-halophenols and 2-halo-amides. Various 2H-1,4-benzoxazin-3-(4H)-ones with diversity at three substituents on their scaffold have been synthesized conveniently in good to excellent yields.