Dimethyl Sulfate → 1,1,2,2,4,4,5,5-Octafluoro-1,3,3,5-tetramethoxypentane

Participants

Reaction Conditions

Reaction Steps

A mixture of 27.0 g (0.50 mol) of sodium methoxide, 56.0 g (0.62 mol) of dimethyl carbonate, and 100 ml of dry tetrahydrofuran was agitated in a 350 ml tube under 1-3 atm of tetrafluoroethylene. Tetrafluoroethylene was pressured in as consumed until 110 g (1.1 mol) had been added. The mildly exothermic reaction kept the temperature near 35° C.; after the addition, the reaction mixture was heated at 40° C. for 1 hour. The viscous solution from this reaction was treated directly with 75.6 g (0.60 mol) of dimethyl sulfate at 40° C. for 15 hours. Filtration and distillation afforded 87.6 g (52%) of 1,3,3,5-tetramethoxyoctafluoropentane, bp 54° C. (0.3 mm Hg), nD24 1.3605, whose structure was confirmed by IR 3.29, 3.33, and 3.42 (satd CH) 8-9μ (CF, COC). Nmr (CCl4) 'H δ 3.68 (s, 1, CF2OCH3) and 3.57 (p, JHF 1.3 Hz, 1, C (OCH3)2); 19F -88.2 (m, l, CR2O) and -116.5 ppm (m, l, CF2).

Provenance & Evidence