反应详情

1-[3,5-difluoro-4-(methylthio)phenyl]ethanone (4.84 g, 23.9 mmol) was dissolved in diethyl ether (200 mL). Sodium methoxide (24 mL of 25% in methanol, 30 mmol) was added and stirred 10 min at ambient temperature. Ethyl trifluoroacetate (3.79 g, 23.9 mmol) was added. The solution was stirred for 1 hour then aqueous hydrochloric acid was added (100 mL, 1 M). The layers were separated and the organic layer collected. The organic layer was washed with water (2×100 mL), saturated ammonium chloride (2×200 mL) and dried over sodium sulfate. The solvent was removed in vacuo to afford a yellow oil. The 1-[3,5-difluoro-4-(methylthio)phenyl]-4,4,4-trifluorobutane-1,3-dione was isolated by crystallization from ethyl acetate and hexanes (5.50 g, 77%). 1H NMR (CDCl3/300 MHz) 7.49 (m, 2H), 6.50 (s, 1H), 2.62 (s, 3H). ESHRMS m/z 297.0012 (M+H+, Calcd 297.0009). Anal. Calcd for C11H7F5O2S: C, 44.30; H, 2.37; Found: C, 44.36; H, 2.26.

1. stirringThe solution was stirred for 1 hour
2. customThe layers were separated
3. customthe organic layer collected
4. washThe organic layer was washed with water (2×100 mL), saturated ammonium chloride (2×200 mL)
5. dry with materialdried over sodium sulfate
6. customThe solvent was removed in vacuo
7. customto afford a yellow oil