1: 94 percent / NaN3 / dimethylformamide / 4 h / 85 °C 2: 84 percent / pyridine / 26 h / 0 - 20 °C 3: trimethylsilyl triflate / acetonitrile / 22 h / -40 - 20 °C 4: ammonia / methanol / 16 h / Ambient temperature View Scheme

1: 94 percent / NaN3 / dimethylformamide / 4 h / 85 °C 2: 84 percent / pyridine / 26 h / 0 - 20 °C 3: trimethylsilyl triflate / acetonitrile / 24.5 h / -40 - 20 °C 4: ammonia / methanol / 16 h / Ambient temperature View Scheme

1: 94 percent / NaN3 / dimethylformamide / 4 h / 85 °C 2: 84 percent / pyridine / 26 h / 0 - 20 °C 3: 1.) (NH4)2SO4, hexamethyldisilazane, 2.) trimethylsilyl triflate / 1.) reflux, overnight, 2.) MeCN, from -40 deg C to 0 deg C, 4 h 4: ammonia / methanol / 16 h / Ambient temperature View Scheme