An Aniline-Mediated Regioselective Synthesis of Quinoxalin-2-ones via the Condensation of α-Ketimine Esters with 2-Aminoanilines

A highly regioselective method for the condensation of α-ketimine esters with 2-aminoanilines for the construction of quinoxalin-2-one derivatives is described. The substrate scope with 2-aminoaniline derivatives and different α-keto esters is explored with yields ranging from 44 to 90% and typical isolated regioselectivities between 6.4 to >25:1.