1: Et3N / butan-1-ol / 20 h / Heating 2: conc. HCl / 42 h / Ambient temperature 3: 70 percent / liquid NH3 / methanol / 18 h / 60 °C 4: 50 percent / 1 M BCl3 / CH2Cl2; hexane / 2.5 h / -75 °C View Scheme

1: ethanol / 0.67 h / Heating 2: 33 g / triethylamine / ethanol / 18 h / Heating 3: 71 percent / lithium hydroxide monohydrate / methanol / 2 h / Ambient temperature 4: 71 percent / cuprous oxide, 1,10-phenanthroline / quinoline / 0.25 h / 170 °C 5: 64 percent / Lawesson's reagent / hexamethylphosphoric acid triamide / 2.45 h / 100 °C 6: 64 percent / ammonia / methanol / 18 h / 60 °C 7: 62 percent / boron trichloride / CH2Cl2 / 2.5 h / -78 °C View Scheme