反応 #9620

反応方程式

diethyl 2-[2-(4-bromophenyl)-2-oxoethyl]-2-(2-phenylethyl)malonate

sodium hydroxide

→

ethyl 4-(4-bromophenyl)-4-oxo-2-(2-phenylethyl)butanoate

収率 65.0%

溶媒

acetone

ethanol

反応条件

後処理

1. 1
   その他Solvent was then removed under reduced pressure via rotary evaporation
2. 2
   濃縮the resulting residue was further concentrated under high vacuum for 1 h
3. 3
   workup.DISSOLUTIONThe residue was redissolved in dimethoxyethane (18.5 mL)
4. 4
   温度the solution was heated at 80° C. for 2.5 h
5. 5
   温度The mixture was cooled to rt
6. 6
   workup.ADDITIONdiluted with ethyl acetate
7. 7
   洗浄washed with water
8. 8
   乾燥The organic layer was dried over anhydrous sodium sulfate
9. 9
   濃縮concentrated under high vacuum
10. 10
    その他The resulting residue was purified by flash chromatography (Biotage flash 75, 10:90 ethyl acetate/hexane)

実験手順

To a solution of diethyl 2-[2-(4-bromophenyl)-2-oxoethyl]-2-(2-phenylethyl)malonate (7.89 g, 17.1 mmol) in acetone (18.5 mL) and ethanol (17.0 mL) was added 1 N aqueous sodium hydroxide solution (17.1 mL), and the resulting solution was heated at 50° C. for 3 h. Solvent was then removed under reduced pressure via rotary evaporation and the resulting residue was further concentrated under high vacuum for 1 h. The residue was redissolved in dimethoxyethane (18.5 mL) and the solution was heated at 80° C. for 2.5 h. The mixture was cooled to rt, diluted with ethyl acetate, and washed with water. The organic layer was dried over anhydrous sodium sulfate and concentrated under high vacuum. The resulting residue was purified by flash chromatography (Biotage flash 75, 10:90 ethyl acetate/hexane) to afford ethyl 4-(4-bromophenyl)-4-oxo-2-(2-phenylethyl)butanoate (4.32 g, 65%). LC-MS ret. time 3.79 min, m/z 389.2 (MH+); 1H NMR (300 MHz, CDCl3) δ 1.20 (t, 3H), 1.78–1.94 (m, 2H), 2.62 (t, 2H), 2.86–3.01 (m, 2H), 3.26–3.36 (m, 1H), 4.10 (q, 2H), 7.05–7.11 (m, 3H), 7.18–7.23 (m, 2H), 7.51 (d, 2H), 7.72 (d, 2H).

出典