1: 58 percent / 1.5 h / 260 - 263 °C / 0.02 Torr 2: 75 percent / dichloromaleic anhydride / 200 °C 3: 77 percent / AlI3 / CS2 / Heating 4: 96 percent / 2 M KOH / ethanol / Heating View Scheme

T=260 - 263°C; P=0.02 Torr; 1.5 h;