Transition-metal-free direct C-3 alkylation of quinoxalin-2(1H)-ones with ethers

A convenient and efficient transition-metal-free protocol for the synthesis of 3-alkyl quinoxalin-2(1H)-ones from the radical reaction of quinoxalin-2(1H)-ones with ethers was developed with moderate to good yields. The methodology shows broad substrate scope, excellent functional group tolerance, high atom economy and high efficiency, thus enabling the preparation of diverse potentially valuable 3-alkyl quinoxalin-2(1H)-one derivatives.