Oxidative Radical Skeletal Rearrangement Induced by Molecular Oxygen: Synthesis of Quinazolinones

Oxidative skeletal rearrangement of 5-aryl-4,5-dihydro-1,2,4-oxadiazoles into quinazolinones is induced by molecular oxygen (under a dry air atmosphere) that likely proceeds via transient iminyl radical species. Concise syntheses of biologically active quinazolinone derivatives were demonstrated using the present strategy.