3-(2-Nitrobenzyl)quinoxalin-2-ones, and pyrido- and 1,2,5-oxadiazolo-fused 2-(2-nitrobenzyl)pyrazin-3-ones in the synthesis of bi-, bis- and condensed heterocyclic systems

It is shown that the products of reduction of the nitro group in 3-(2-nitrobenzyl)quinoxalin-2-ones, and pyrido-and 1,2,5-oxadiazolo-fused 3-(2-nitrobenzyl)pyrazinones with sodium dithionite (Na2S2O4) undergo in the first two cases in an acidic medium Mamedov rearrangement, and in the third case - intramolecular condensation with the formation of rare bi-, bis-and condensed heterocyclic systems, respectively, difficult to obtain by other methods.

Automated summary

Reduction of 3-(2-nitrobenzyl)quinoxalin-2-ones, pyrido-, and 1,2,5-oxadiazolo-fused 3-(2-nitrobenzyl)pyrazinones with sodium dithionite (Na2S2O4) in an acidic medium leads to Mamedov rearrangement in the first two cases, and intramolecular condensation in the third case, resulting in the formation of rare bi-, bis-, and condensed heterocyclic systems that are difficult to obtain by other methods.