Versatile Quinazolinone Synthesis: N‐Bromosaccharin‐Catalyzed Divergence in 2,3‐Dihydroquinazolin‐4(1H)‐one and Quinazolin‐4(3H)‐one Formation

Abstract

AbstractIn this research, we present an innovative and eco‐friendly methodology for the synthesis of a diverse array of 2,3‐dihydroquinazolin‐4(1H)‐ones, featuring the use of catalytic N‐Bromosaccharin (NBSac). This novel approach is not limited to just one product; it extends to the efficient synthesis of quinazolin‐4(3H)‐ones by harnessing visible light alongside stoichiometric N‐Bromosaccharin (NBSac) as a multifunctional heterogeneous oxidant. By uniting cyclocondensation and oxidation into a one‐pot sequential process, direct access to quinazolin‐4(3H)‐ones is achieved. The developed protocol is characterized by its user‐friendliness, metal‐free operation, wide applicability across diverse substrates, and the ability to recycle the catalyst, making it an appealing and sustainable method for quinazolinone synthesis.