RUTHENIUM CATALYZED SYNTHESIS OF QUINOLINE DERIVATIVES FROM NITROARENES AND ALIPHATIC ALCOHOLS.

Article abstract of DOI:10.1246/bcsj.57.435

Nitroarenes are reductively converted into quinoline derivatives with aliphatic alcohols in the presence of a catalytic amount of ruthenium compound at 180 degree C. Ruthenium(III) chloride is the most effective catalyst. The reaction of nitrobenzene with 1-propanol and 1-butanol gave 2-ethyl-3-methylquinoline and 3-ethyl-2-propylquinoline in 65 and 70% yields respectively. p-Methoxynitrobenzene gave 3-ethyl-6-methoxy-2-propyquinoline in 70% yield with 1-butanol. The reaction appears to include the redox reaction between the nitroarenes and the alcohols, that is, a catalytic hydrogen transfer reaction which generates the aminoarenes and aldehydes. Thus, the alcohol plays roles as both a reductant and an aldehyde precursor.