1: With phosphorus pentachloride in chloroform T=60°C; 2: With potassium hydroxide in diethyl ether; chloroform T=20°C; 0.5 h;

1.1: thionyl chloride / 3 h / Heating 2.1: Et3N / CHCl3 / 0.25 h / 20 °C 2.2: CHCl3 / 0.75 h / 20 °C 3.1: 70 percent / phosphorus pentachloride / CHCl3 / 60 °C View Scheme