in neat (no solvent) 135-140°C; fractionation;

byproducts: THF; from -196°C to 0°C, 6 h stirred at 0°C; volatiles destilled out at 0°C, chromatographed on silica-gel in CHCl3, vacuum sublimation at 78°C, vacuum fractional destillation at 70°C;

15 days 23°C; fractionated through traps, elem. anal.;

in neat (no solvent) 135-140°C; fractionation;