sodium azide in water; N,N-dimethyl-formamide T=90 - 100°C; 12 h;

sodium in methanol debenzoylation; 1 h;

1: 92.4 percent / pyridine / -10 °C 2: 93 percent / aq. AcOH / 20 h / 64 °C 3: 86 percent / pyridine / 48 h / -15 °C 4: 72 percent / NaN3 / dimethylformamide / 24 h / 100 °C 5: 89 percent / Na / methanol / 1 h View Scheme

1: 48 percent / H2SO4 / acetone / 20 °C 2: 92.4 percent / pyridine / -10 °C 3: 93 percent / aq. AcOH / 20 h / 64 °C 4: 86 percent / pyridine / 48 h / -15 °C 5: 72 percent / NaN3 / dimethylformamide / 24 h / 100 °C 6: 89 percent / Na / methanol / 1 h View Scheme

1.1: pyridine; 1H-imidazole; 4-(N,N-dimethlyamino)pyridine / 2 h / 0 - 20 °C / Inert atmosphere 2.1: triethylamine / dichloromethane / 0.25 h / 0 °C / Inert atmosphere 3.1: hydrogenchloride / methanol; water / 2 h / 0 - 20 °C 3.2: 3 h / 0 - 20 °C 4.1: hydrogen bromide / acetic acid; acetone / 0.5 h / 0 °C / Inert atmosphere 5.1: palladium 10 on activated carbon; formic acid; hydrogen / methanol / 2 h / 20 °C 6.1: sodium azide / water; N,N-dimethyl-formamide / 12 h / 90 - 100 °C View Scheme

1: hydrogen bromide / acetic acid; acetone / 0.5 h / 0 °C / Inert atmosphere 2: palladium 10 on activated carbon; formic acid; hydrogen / methanol / 2 h / 20 °C 3: sodium azide / water; N,N-dimethyl-formamide / 12 h / 90 - 100 °C View Scheme