反応 #59117

反応方程式

2-[2-(4-bromophenyl)-2-oxoethyl]-2-propylmalonate

acetone

sodium hydroxide

→

ethyl 2-[2-(4-bromophenyl)-2-oxoethyl]pentanoate

収率 20.0%

溶媒

ethanol

反応条件

後処理

1. 1
   濃縮The clear, orange-red reaction mixture was then concentrated under reduced pressure
2. 2
   workup.DISSOLUTIONthe residue was redissolved in dimethoxyethane (30 mL)
3. 3
   温度The mixture was heated to 80° C. for 3 h
4. 4
   温度The reaction mixture was cooled to rt
5. 5
   workup.ADDITIONdiluted with ethyl acetate (100 mL) and water (100 mL)
6. 6
   抽出was extracted into the organic layer
7. 7
   その他The layers were separated
8. 8
   抽出the aqueous layer extracted with additional ethyl acetate (75 mL)
9. 9
   洗浄The combined organic layers were washed with saturated aqueous sodium chloride solution (75 mL)
10. 10
    乾燥dried over anhydrous sodium sulfate
11. 11
    濃縮concentrated under reduced pressure
12. 12
    その他to afford an orange oil
13. 13
    その他The crude product was purified by flash chromatography (10:1 hexane:ethyl acetate)

実験手順

To a 200 mL flask was added crude 2-[2-(4-bromophenyl)-2-oxoethyl]-2-propylmalonate (7.62 g, 19.2 mmol), acetone (21 mL), and ethanol (19 mL), followed by addition of 1 N aqueous sodium hydroxide solution (19.1 mL). The reaction mixture was heated to 55° C. for 3 h. The clear, orange-red reaction mixture was then concentrated under reduced pressure and the residue was redissolved in dimethoxyethane (30 mL). The mixture was heated to 80° C. for 3 h. The reaction mixture was cooled to rt, diluted with ethyl acetate (100 mL) and water (100 mL), and stirred for 15 minutes until almost all color was extracted into the organic layer. The layers were separated and the aqueous layer extracted with additional ethyl acetate (75 mL). The combined organic layers were washed with saturated aqueous sodium chloride solution (75 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to afford an orange oil. The crude product was purified by flash chromatography (10:1 hexane:ethyl acetate) to afford ethyl 2-[2-(4-bromophenyl)-2-oxoethyl]pentanoate (1.33 g, 20%). LC-MS ret. time 3.60 min, m/z 326.05 (MH+); 1H NMR (300 MHz, CDCl3) δ 0.87 (t, 3H), 1.25 (t, 3H), 1.29-1.43 (m, 2H), 1.57-1.73 (m, 2H), 2.90-3.08 (m, 2H), 3.34-3.47 (m, 2H), 4.15 (q, 2H), 7.59 (d, 4H), 7.82 (d, 2H).

出典