α-Hydroxyketones undergo MnO2-mediated oxidation followed by in situ trapping with aromatic or aliphatic 1,2-diamines to give quinoxalines or dihydropyrazines, respectively, in a one pot procedure which avoids the need to isolate the highly reactive 1,2-dicarbonyl intermediates. Modifications of the procedure allow the formation of pyrazines and piperazines.
α-羟基酮在
MnO2介导的氧化下,随后与芳香或脂肪族1,2-二胺原位捕获,分别生成
喹喔啉或二氢
吡嗪,这一过程在一个反应釜中完成,避免了分离高度反应性1,2-二酮中间体的需要。对该工艺的修改可以生成
吡嗪和
吡咯啉。