1: 91 percent / Cl2 / various solvent(s) / 0.33 h / Ambient temperature 2: 95 percent / n-Butyllithium/hexane / diethyl ether / 0.5 h / Heating 3: hexamethylphosphoric acid triamide / 20 h / 100 °C 4: 66 percent / n-Butyllithium / diethyl ether / 0.5 h / Heating 5: 99 percent / Ethanethiol, NaH / dimethylformamide / 3 h / Heating View Scheme