Quinoline N-oxides and hydroxamic acids with antibacterial properties

A number of quinoline N-oxides have been prepared and oxidized by means of lead tetraacetate to quinoline hydroxamic acids (i.e. derivatives of 1-hydroxy-2(1H)-quinolone). Contrary to the findings of other investigators, 1-hydroxy-4-nitro-2(1H)-quinolone (2e) is obtained by treating 4-nitroquinoline 1-oxide with lead tetraacetate. Quinolines with a methyl group in the 8-position could not be oxidized to N-oxides with hydrogen peroxide.The antibacterial properties of the hydroxamic acids and some of the N-oxides were evaluated against S. aureus and E. coli.