1: ethanol / 0.25 h / Heating 2: pyridine 3: 1.) potassium hydroxide 2.) 72percent hydrazine hydrate / 1.) methanol, reflux, 20 min 2.) methanol, reflux, 30 min 4: 86.5 percent / pyridine 5: ethanol / 2 h / Heating View Scheme

1: urea / 0.33 h / 150 - 160 °C 2: ethanol / 0.25 h / Heating 3: pyridine 4: 1.) potassium hydroxide 2.) 72percent hydrazine hydrate / 1.) methanol, reflux, 20 min 2.) methanol, reflux, 30 min 5: 86.5 percent / pyridine 6: ethanol / 2 h / Heating View Scheme

1: acetic anhydride / 0.08 h / Heating 2: urea / 0.33 h / 150 - 160 °C 3: ethanol / 0.25 h / Heating 4: pyridine 5: 1.) potassium hydroxide 2.) 72percent hydrazine hydrate / 1.) methanol, reflux, 20 min 2.) methanol, reflux, 30 min 6: 86.5 percent / pyridine 7: ethanol / 2 h / Heating View Scheme

1: pyridine 2: 1.) potassium hydroxide 2.) 72percent hydrazine hydrate / 1.) methanol, reflux, 20 min 2.) methanol, reflux, 30 min 3: 86.5 percent / pyridine 4: ethanol / 2 h / Heating View Scheme

1: 1.) potassium hydroxide 2.) 72percent hydrazine hydrate / 1.) methanol, reflux, 20 min 2.) methanol, reflux, 30 min 2: 86.5 percent / pyridine 3: ethanol / 2 h / Heating View Scheme

1: 61.6 percent / 0.5 h / Heating 2: 86.5 percent / pyridine 3: ethanol / 2 h / Heating View Scheme

1: 86.5 percent / pyridine 2: ethanol / 2 h / Heating View Scheme

1: 50.7 percent / 1percent HCl / 1 h / Heating 2: 61.6 percent / 0.5 h / Heating 3: 86.5 percent / pyridine 4: ethanol / 2 h / Heating View Scheme

in ethanol 2 h; Heating; Yield given;