反应详情

To a solution of 3,4-difluorobenzoic acid (10 g, 63.3 mmol) in tetrahydrofuran (300 ml) was added 1,1′-carbonylbis-1H-imidazole (11.3 g, 69.6 mmol) and the mixture was stirred at room temperature for 30 min. To the reaction solution was added monoethyl malonate magnesium salt (10 g, 34.8 mmol) and the mixture was stirred at room temperature for 2 hrs. To the reaction solution were added ethyl acetate (50 ml) and water (50 ml), and conc. hydrochloric acid was added until the aqueous layer showed acidic pH. The reaction solution was extracted with ethyl acetate (200 ml×2). The extract was washed with saturated brine, dried over anhydrous magnesium sulfate and evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=4:1) to give ethyl 3-(3,4-difluorophenyl)-3-oxopropionate (10.3 g, 77%) as a brown oil.

1. stirringthe mixture was stirred at room temperature for 2 hrs
2. additionwas added until the aqueous layer
3. extractionThe reaction solution was extracted with ethyl acetate (200 ml×2)
4. washThe extract was washed with saturated brine
5. dry with materialdried over anhydrous magnesium sulfate
6. customevaporated under reduced pressure
7. customThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=4:1)