1: 7.17 g / sodium borohydride / methanol / 6.5 h / 20 °C 2: pyridine; 4-(dimethylamino)pyridine / 5 h / 20 °C 3: trifluoroacetic acid / H2O / 6 h / 20 °C 4: 5.84 g / pyridine; 4-(dimethylamino)pyridine / 40 h / 20 °C 5: 71 percent / N,O-bis(trimethylsilyl)acetamide; trimethylsilyl triflate / acetonitrile / 24 h / 60 °C 6: 74 percent / NH3 / methanol / 46 h / 20 °C View Scheme

1: 7.17 g / sodium borohydride / methanol / 6.5 h / 20 °C 2: pyridine; 4-(dimethylamino)pyridine / 5 h / 20 °C 3: trifluoroacetic acid / H2O / 6 h / 20 °C 4: 5.84 g / pyridine; 4-(dimethylamino)pyridine / 40 h / 20 °C 5: 90 percent / N,O-bis(trimethylsilyl)acetamide; trimethylsilyl triflate / acetonitrile / 21 h / 60 °C 6: 77 percent / NH3 / methanol / 46 h / 20 °C View Scheme