1: 57 percent / NaBH4 / ethanol / 3 h 2: 82 percent / NaH / tetrahydrofuran / 24.5 h / Heating 3: 49 percent / 4.5M HCl / H2O / 24 h / Heating View Scheme

1: 57 percent / NaBH4 / ethanol / 3 h 2: 95 percent / pyridine / 24 h 3: 63 percent / dimethylformamide / 13 h / 60 - 65 °C 4: 72 percent / hydrazine / 2-methyl-propan-2-ol / 3 h / Heating 5: 83.5 percent / diisopropylamine,n-BuLi / tetrahydrofuran / 1 h / -45 °C 6: 68 percent / 4.5M HCl / 30 h / Heating View Scheme