1: hydrogenchloride / ethanol; water / 12 h / 25 °C 2: triethylamine / dichloromethane / 1 h / 0 °C 3: sodium azide / N,N-dimethyl-formamide / 3 h / 80 °C 4: hydrogen / ethanol / 20 °C View Scheme

1.1: zirconium tetrachloride; isopropyl alcohol / 4 h / 50 °C 2.1: hydrogen azide; triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran; benzene / 10 - 20 °C 3.1: hydrogen / ethanol 3.2: 50 °C View Scheme

1: zirconium tetrachloride; isopropyl alcohol / 4 h / 50 °C 2: hydrogen azide; triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran; benzene / 10 - 20 °C View Scheme