ammonium hydroxide 18 h; Ambient temperature;

1: 89 percent / pyridine / 16 h 2: 80 percent / conc. NH3 / 18 h / Ambient temperature View Scheme

1: 94 percent / (dimethylamino)borane / acetic acid / 0.33 h / 20 °C 2: 89 percent / pyridine / 16 h 3: 80 percent / conc. NH3 / 18 h / Ambient temperature View Scheme