1: triethylamine / tetrahydrofuran / 1 h / -20 °C 2: NaN3 / tetrahydrofuran; H2O / -10 - 20 °C 3: benzene / 2 h / Heating 4: triethylamine / CH2Cl2 / 4 h / Heating 5: 98 percent / H2 / Pd/C / methanol / 20 °C View Scheme