1: 4-(N,N-dimethlyamino)pyridine / tetrahydrofuran / 20 °C / Inert atmosphere 2: sodium cyanoborohydride / tetrahydrofuran; acetic acid / 2.08 h / 20 - 60 °C 3: hydrogenchloride; water / Reflux 4: sulfuric acid / 2 h / Reflux View Scheme

1: 4-(N,N-dimethlyamino)pyridine / tetrahydrofuran / 20 °C / Inert atmosphere 2: sodium cyanoborohydride / tetrahydrofuran; acetic acid / 2.08 h / 20 - 60 °C 3: hydrogenchloride; water / Reflux View Scheme

1: 4-(N,N-dimethlyamino)pyridine / tetrahydrofuran / 20 °C / Inert atmosphere 2: sodium cyanoborohydride / tetrahydrofuran; acetic acid / 2.08 h / 20 - 60 °C 3: hydrogenchloride; water / Reflux 4: sulfuric acid / 2 h / Reflux 5: Ba(OH)2 / tetrahydrofuran; methanol / 18 h / 20 °C View Scheme

1: With sodium azide in acetone T=0 - 20°C; 4 h; 2: in acetone; toluene T=65°C;

ammonia in toluene 1 h;