Heterocycle-to-heterocycle route to quinoline-4-amines: Reductive heterocyclization of 3-(2-nitrophenyl)isoxazoles

Abstract

A variety of quinoline-4-amines were synthesized from substituted 3-(2-nitrophenyl)isoxazoles utilizing Zn0 or Fe0 dust and HOAc using a reductive heterocyclization process. The starting isoxazoles were synthesized from readily available starting materials. A brief survey of functional groups tolerated in this reductive heterocyclization was performed and several 10-amino-3,4-dihydrobenzo[b][1,6]naphthyridin-1(2H)-one and 9-amino-3,4-dihydroacridin-1(2H)-one examples were synthesized. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.