in N,N-dimethyl-formamide 1 h; Heating;

1: 82 percent / 3 h / Heating 2: 78 percent / AcOH / 3 h / Heating 3: 62 percent / N2H4*H2O / 3 h / 20 °C 4: 4 mmol / Na / ethanol / 0.5 h / 20 °C 5: 82 percent / 0.33 h / 100 °C View Scheme

1: 78 percent / 3 h / Heating 2: 4 mmol / Na / ethanol / 0.5 h / 20 °C 3: 0.33 h / 100 °C View Scheme