From 1,2,5-Oxadiazolo[3,4-g]indoles to Pyrrolo[2,3-f]quinoxalines in One Preparative Stage

Pyrrolo[2,3-f]quinoxalines are synthesized by heating 1,2,5-oxadiazolo[3,4-g]indoles with ethanolamine in the presence of p-toluenesulfonic acid.