反应详情

Under a nitrogen atmosphere, 46.7 g (1.168 mol) of sodium hydride (60% dispersion in paraffin) were added to 600 ml of tetrahydrofuran. A mixture of 125 g (1.008 mol) of difluoroethyl acetate and 88.7 g (1.010 mol) of ethyl acetate was added dropwise at 35° C., while the temperature was kept below 40° C. The mixture was then further stirred at room temperature overnight. The reaction mixture was carefully poured into 1.7 l of ice water and the pH adjusted to pH 3 by addition of sulphuric acid. The mixture was extracted twice, each time with 500 ml of methyl tert-butyl ether, and the combined organic phases were washed twice with saturated sodium chloride solution, dried over sodium sulphate, concentrated at 40° C. and 150 mbar and distilled at 60 mbar (Vigreux column). The product was obtained at 85-87° C. as a colourless liquid (104 g, 62% of theory with a purity of >99% (GC)).

1. additionwas added dropwise at 35° C., while the temperature
2. customwas kept below 40° C
3. extractionThe mixture was extracted twice
4. washeach time with 500 ml of methyl tert-butyl ether, and the combined organic phases were washed twice with saturated sodium chloride solution
5. dry with materialdried over sodium sulphate
6. concentrationconcentrated at 40° C.
7. distillation150 mbar and distilled at 60 mbar (Vigreux column)
8. customThe product was obtained at 85-87° C. as a colourless liquid (104 g, 62% of theory with a purity of >99% (GC))