Metal & Surfactant-Free Oxidation of Quinoxalin-2(1h)-Ones: Access to Quinoxaline-2,3-Diones

An efficient and direct oxidative reaction for the construction of 1,4-dihydroquinoxaline-2,3-diones has been developed. A range of oxidative products are obtained with satisfactory yields (up to 99%). This practical method features transition metal free, surfactant free, chromatography free, mild reaction conditions, good functional group tolerance and easy scale-up synthesis. Furthermore, it provided a convenient approach for the synthesis of one kind of known inhibitor for α-glucosidase. This mechanistic study shows that this transformation is not a radical process.