Synthesis of new potentially bioactive bicyclic 2-pyridones

Three convenient methods of reduction of the nitro group of 5-nitroimidazoles and 5-nitrothiazole that bear a diethylmethylene malonate group in an ortho-like position with respect to the nitro group and cyclization of the resulting amino derivatives are reported. These reactions afforded the target bicyclic 2-pyridones in good to excellent yields.