pyridine hydrogenfluoride in dichloromethane a) -10 deg C, 15 min, b) RT, 16 h;

1: TEA / CHCl3 / 17 h / Ambient temperature 2: 80 percent aq. formic acid, CuSO4 / 16 h / 80 °C 3: dimethylsulfoxide / 3.5 h / 60 °C 4: 50 percent / HF*pyridine / CH2Cl2 / a) -10 deg C, 15 min, b) RT, 16 h View Scheme

1: TEA / CHCl3 / 17 h / Ambient temperature 2: 80 percent aq. formic acid, CuSO4 / 16 h / 80 °C 3: dimethylsulfoxide / 3.5 h / 60 °C 4: 50 percent / HF*pyridine / CH2Cl2 / a) -10 deg C, 15 min, b) RT, 16 h View Scheme

1: dimethylsulfoxide / 3.5 h / 60 °C 2: 50 percent / HF*pyridine / CH2Cl2 / a) -10 deg C, 15 min, b) RT, 16 h View Scheme

1: 83 percent / pyridine / Ambient temperature 2: 87 percent / dimethylformamide / 7 h / 150 °C 3: 87 percent / ethanolamine / 2 h / 60 °C View Scheme

1: 83 percent / pyridine / Ambient temperature 2: 87 percent / dimethylformamide / 7 h / 150 °C 3: 87 percent / ethanolamine / 2 h / 60 °C 4: toluene / 2 h / Heating 5: KBH4 / methanol / 18 h / Ambient temperature View Scheme