“…In recent years, quinoxalin-2(1 H )-one has been prominently studied [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Furthermore, the direct acid-catalyzed C–H bond functionalization of quinoxalin-2(1 H )-one based on a nucleophilic aromatic substituted hydrogen approach (S N H -reaction) is of equal interest [ 25 , 26 , 27 , 28 , 29 ]. Several reviews summarize the C-3 functionalization of quinoxalin-2(1 H )-one and were published between 2019 and 2021 [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ].…”