5 h; Heating;

1: 80 percent / POCl3 2: 75 percent / 90percent hydrazine hydrate / 3 h / Heating 3: 80 percent / phosphorus pentasulfide, pyridine / 4 h / Heating 4: 75 percent / 90percent hydrazine hydrate / 5 h / Heating 5: 90 percent / 5 h / Heating View Scheme

1: 75 percent / 90percent hydrazine hydrate / 3 h / Heating 2: 80 percent / phosphorus pentasulfide, pyridine / 4 h / Heating 3: 75 percent / 90percent hydrazine hydrate / 5 h / Heating 4: 90 percent / 5 h / Heating View Scheme

1: 75 percent / 90percent hydrazine hydrate / 5 h / Heating 2: 90 percent / 5 h / Heating View Scheme