bromine in acetic acid T=50 - 80°C; 2 h;

1: 1.) Br2, 2.) NaOAc / 1.) AcOH, 80 deg C, 2 h, 2.) AcOH, reflux, 1 h 2: phosphorus oxychloride / 4 h / 85 - 95 °C 3: hydrazine hydrate / butan-1-ol / 6 h / 100 °C 4: H2 / Raney Ni / methanol / 20 °C / 760 Torr View Scheme

1: 1.) Br2, 2.) NaOAc / 1.) AcOH, 80 deg C, 2 h, 2.) AcOH, reflux, 1 h 2: phosphorus oxychloride / 4 h / 85 - 95 °C View Scheme

1: 1.) Br2, 2.) NaOAc / 1.) AcOH, 80 deg C, 2 h, 2.) AcOH, reflux, 1 h 2: phosphorus oxychloride / 4 h / 85 - 95 °C 3: hydrazine hydrate / butan-1-ol / 6 h / 100 °C View Scheme

Multi-step reaction with 2 steps 1: NaOH, H2O / ethanol / 50 °C2: hydrazine hydrate / ethanol / 4 h / Heating