Trimethylolethane → (5-Methyl-2-oxo-1,3-dioxan-5-yl)methyl perfluorophenyl carbonate

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Reaction Steps

To a 100 mL round bottom flask, 1,1,1-tris(hydroxymethyl)ethane (2.0 g, 16.7 mmol) was combined with bis(pentafluorophenyl)carbonate (15.1 g, 38.3 mmol, 2.3 eq.) and cesium fluoride (0.76 g, 5.0 mmol, 0.3 eq.) in anhydrous tetrahydrofuran (THF) (11.9 mL) and stirred for four hours at room temperature. Initially the reaction was heterogeneous, but after one hour the reaction formed a clear homogeneous solution. The reaction was concentrated in vacuo (100 mm Hg, 30° C.) and the residue was dissolved in methylene chloride (˜50 mL). Upon standing (˜10 min), the pentafluorophenol byproduct precipitated from solution and was recovered by filtration. The mother liquor was washed with aqueous sodium bicarbonate (3×50 mL) until the pH of aqueous layer was ˜8 and then with brine (1×50 mL). The organic layer was separated and dried over anhydrous sodium sulfate. The solution was concentrated to give the crude product that was purified by recrystallization. The crude product was dissolved in ethyl acetate (24 mL) at 65° C. n-Hexane (35 mL) was added at the same temperature, and the resulting solution was allowed to cool to room temperature. After stirring the solution overnight, the white crystalline product TMCPFP was separated by filtration (4.0 g, 67% yield). m.p. 130-131° C. 1H NMR (CDCl3, 400 Hz) 1.22 (s, 3H), 4.23 (d, 2H, J=11 Hz), 4.37 (s, 2H), 4.38 (d, 2H, J=11 Hz). 19F NMR (CDCl3, 376 Hz) −154.3-154.3 (m, 2F), −157.8 (t, 1F, J=22 Hz), −162.6˜-162.7 (m, 2F). 13C NMR (CDCl3, 100 Hz) 16.8, 32.6, 70.3, 73.0, 125.4, 137.9, 140.1, 141.3, 147.4, 151.1.

Provenance & Evidence