1: in diethyl ether T=20°C; 16 h; 2: With manganese(IV) oxide; potassium hydroxide in ethanol 10 h; Heating; 3: T=600°C; P=0.007501 - 0.015001 Torr; Title compound not separated from byproducts;

T=600°C; P=0.01 - 0.02 Torr; 2 h;