hydrogen bromide in acetic acid T=70°C; 12 h;

1: 74.2 percent / triethylamine, pyridine / 1 h / 0 °C 2: 74 percent / toluene / Heating 3: 91 percent / lithium borohydride / tetrahydrofuran / 0 - 25 °C 4: 86 percent / pyridine / 2 h / 10 °C 5: 90 percent / toluene / 9 h / Heating 6: 89 percent / HBr / acetic acid / 12 h / 70 °C View Scheme

1: 91 percent / lithium borohydride / tetrahydrofuran / 0 - 25 °C 2: 86 percent / pyridine / 2 h / 10 °C 3: 90 percent / toluene / 9 h / Heating 4: 89 percent / HBr / acetic acid / 12 h / 70 °C View Scheme

1: 74 percent / toluene / Heating 2: 91 percent / lithium borohydride / tetrahydrofuran / 0 - 25 °C 3: 86 percent / pyridine / 2 h / 10 °C 4: 90 percent / toluene / 9 h / Heating 5: 89 percent / HBr / acetic acid / 12 h / 70 °C View Scheme

1: 86 percent / pyridine / 2 h / 10 °C 2: 90 percent / toluene / 9 h / Heating 3: 89 percent / HBr / acetic acid / 12 h / 70 °C View Scheme

1: 90 percent / toluene / 9 h / Heating 2: 89 percent / HBr / acetic acid / 12 h / 70 °C View Scheme