Preparation electrochimique de derives de la quinoleine—I. Electroreduction de composes o-nitrobenzoyles monofonctionnalises

Abstract

Controlled potential electrolysis at a mercury cathode, carried on at a working potential corresponding to the first polarographic wave of o-nitrobenzoyl compounds ( o-NO 2C 6H 4COCH 2Y) is a convenient way to prepare quinoline derivatives. o-Nitrobenzoylacetic acid (Y  CO 2H) or the parent methyl ester gives rise to a N-hydroxyquinoline. Nevertheless simultaneous formation of anthranil derivatives is observed when the reductions are carried out in an acidic media, whereas the latter is the sole product isolated at the term of electrolysis of the acid in a basic media. Quinoline N-oxides can be obtained by reduction of o-nitrobenzoylacetonitrile (Y  CN) or o-nitrobenzoylacetone (Y  COCH 3). Anthranil formation is again evidenced after electrolysis of the nitrile in acidic media, whereas reduction of the ketone in a basic media gives rise to simultaneous formation of the expected quinoline N-oxide and of an indolinone derivative.