Sulfur trioxide → Difluoromalonyl fluoride

Participants

Reaction Steps

3-Methoxytetrafluoropropionyl fluoride (F. S. Fawcett, C. W. Tullock and D. D. Coffman, J. Amer. Chem. Soc., 84, 4275 (1962)) (81 g, 0.45 mol) was slowly added to sulfur trioxide (80 g, 1.0 mol) at 40° C., and the product difluoromalonyl difluoride, bp -9° C., was continuously removed by distillation through a low temperature still, yield 58 g (0.40 mol, 90%). The product structure was confirmed by: λmax 1860 cm-1 (COF), 19F NMR (no solvent), +17.1 ppm (t J=10 Hz), 2F, COF and -114.2 ppm (t J=10 Hz) 2F, CF2.

Provenance & Evidence