1: 30 percent / acetic anhydride / 3 h / Heating 2: 76 percent / H2O; dimethylformamide / 3 h / 100 °C 3: 84 percent / Raney Ni, conc. HCl / ethanol / 4 h / Heating 4: 40 percent / NaH / tetrahydrofuran / Heating View Scheme