1: 78 percent / 0.33 h / 140 °C 2: 78 percent / 99percent N2H4*H2O / ethanol / 8 h / Heating 3: 70 percent / glacial AcOH / ethanol / 5 h / Heating 4: 1) glacial AcOH, HCl, NaNO2 2) pyridine / 1) water, 0-5 deg C 2) r.t., overnight View Scheme

1: 78 percent / 0.33 h / 140 °C 2: 78 percent / 99percent N2H4*H2O / ethanol / 8 h / Heating 3: 65 percent / glacial AcOH / ethanol / 5 h / Heating 4: 1) glacial AcOH, HCl, NaNO2 2) pyridine / 1) water, 0-5 deg C 2) r.t., overnight View Scheme

sodium carbonate 4 h; Heating; Yield given;