Intramolecular animation of p-benzoquinones: formation of 1,2,3,5-tetrahydrobenzo[1,2-b:4,5-b′]dipyrroles and 1,2,3,4-tetrahydropyrido-[2,3-g]quinolines

Abstract

2,5-Bis-(2-amirioethyl)hydroquinones undergo intramolecular condensation in neutral or slightly alkaline aqueous solution in air to form 1,2,3,5-tetrahydrobenzo[1,2-b:4,5-b′]dipyrroles. Under similar conditions 2,5-bis-(3-aminopropyl)hydroquinones yield 1,2,3,4-tetrahydropyrido[2,3-g]quinolines. Tentative structures for some of the intermediates involved in these reactions are discussed in the light of spectroscopic data.