Reductive cyclisation of some derivatives of methyl o-nitrophenyl-pyruvate and other keto-esters by catalysed sodium borohydride

Abstract

3-Amino-1-hydroxyquinolin-2(1H)-one (Va) is one of the products when the oxime of methyl o-nitrophenyl-pyruvate is reduced with sodium borohydride and palladium–charcoal. The claim that the same quinolone is one of the products of the catalytic hydrogenation of ethyl o-nitrophenylpyruvate oxime is shown to be erroneous. Reduction of the oximino-, benzylidene, and other derivatives of selected keto-esters with sodium borohydride and palladium–charcoal is described.