1: sodium-amalgam; water / staendig mit wss. Schwefelsaeure neutralisieren 2: pyridine View Scheme

1: 4.5 g / H2 / Raney nickel / methanol / 24 h 2: 65 percent / p-toluenesulfonic acid / dimethylformamide / 3 h / 60 °C / 20 Torr 3: 100 percent / pyridine / CH2Cl2 / 0.5 h / -15 °C 4: 1.25 g / NaN3 / dimethylformamide / 5 h / 20 °C View Scheme