Preparation of Quinazolinoquinazolinones via a Cascade Approach

A one-pot synthesis of quinazolino[3,4-a]quinazolin-13-ones was realized from the direct reaction of o-(methoxycarbonyl)benzenediazonium salts, nitriles, and 2-cyanoanilines in moderate to good yields. This method utilizes the in situ generation of reactive N-arylnitrilium ion, which undergoes further amination/tandem cyclization/amidation to deliver the desired polycyclic scaffolds with consecutive formation of four N–C bonds. Flexibility in substitution patterns, mild reaction conditions, and operational simplicity are the salient features of this methodology.