Rearrangement of 3-ethoxycarbonyl-5-hydroxyimino-2-methyl-4-oxonaphtho[1,2-b]furan and 3-ethoxycarbonyl-5-hydroxyimino-2-methyl-4-oxo-1-phenylbenzo[g]indole by the action of benzenesulfonyl chloride in an alkaline medium

Abstract

The treatment of 3-ethoxycarbonyl-2-methyl-4,5-dioxonaphtho[1,2-b]furan 5-monoximes and also the similarly substituted benzo[g]indole with benzenesulfonyl chloride in an alkaline medium give 5-(2-cyanophenyl)-3-ethoxycarbonyl-2-methylfuran-4-carboxylic and pyrrole-4-carboxylic acids with high yields as a result of a second-order Beckmann rearrangement. The structures of the initial and final compounds were confirmed by analysis of their mass spectra.