Visible light-induced cascade N -alkylation/amidation reaction of quinazolin-4(3 H )-ones and related N-heterocycles.

An efficient and visible light-promoted cascade -alkylation/amidation of quinazolin-4(3)-ones with benzyl halides and allyl halides has been described for the first time to provide a convenient access to quinazoline-2,4(1,3)-diones. This cascade -alkylation/amidation reaction shows good functional group tolerance and could also be applied to N-heterocycles such as benzo[]thiazoles, benzo[]imidazoles, and quinazolines. Control experiments show that KCO plays an important role in this transformation.