Metal-free C3-H acylation of quinoxalin-2(1H)-ones with α-oxo-carboxylic acids

Direct C3-H acylation of quinoxalin-2(1H)-ones with α-oxocarboxylic acids under thermo conditions promoted by PIDA has been achieved in moderate to good yield. Mechanistic study revealed that the reaction proceeds via radical process. This work represents a simple, convenient and efficient synthesis of 3-acylated quinoxalin-2(1H)-ones.