Metal‐Free, Visible‐Light Promoted Intramolecular Azole C−H Bond Amination Using Catalytic Amount of I2: A Route to 1,2,3‐Triazolo[1,5‐a]quinazolin‐5(4H)‐ones

A metal‐free, visible‐light promoted intramolecular azole C−H bond amination for the rapid and efficient synthesis of pharmaceutical important 1,2,3‐triazolo[1,5‐a]quinazolin‐5(4H)‐ones has been developed. Employing 2‐(1,2,3‐triazol‐1‐yl)benzamides as the easily available precursors and catalytic amount of I2 as an initiator, the desired product were isolated in moderate to excellent yiels with a broad substrate scope and good functional group tolerance. Furthermore, this protocol features mild conditions, operational simplicity, and easy scale‐up. Preliminary mechanistic studies suggested that a radical pathway might be involved during the reaction.