1: 75 percent / propan-2-ol / 110 h / 120 °C 2: 89 percent / sodium hydride, di-imidazolyl sulphone / dimethylformamide / 1.5 h / 50 °C 3: 91 percent / propan-2-ol / 4 h / 80 °C 4: 75 percent / H2 / Ranei nickel T-4 / dioxane; ethanol / 6 h / 60 °C 5: 86 percent / aq. 80percent acetic acid / 9 h / 50 °C 6: 61 percent / imidazole / CHCl3 / 48 h / Heating 7: 84 percent / silver trifluoromethanesulphonate, 1,1,3,3-tetramethylurea / CH2Cl2 / 10 h / Ambient temperature 8: liquid ammonia, sodium / tetrahydrofuran / 6 h / -78 °C View Scheme