Reaktion #9620

Reaktionsgleichung

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

sodium hydroxide

→

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

Ausbeute 65.0%

Lösungsmittel

acetone

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeSolvent was then removed under reduced pressure via rotary evaporation
2. 2
   Einengenthe 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
   Temperaturthe solution was heated at 80° C. for 2.5 h
5. 5
   TemperaturThe mixture was cooled to rt
6. 6
   workup.ADDITIONdiluted with ethyl acetate
7. 7
   Waschenwashed with water
8. 8
   TrocknenThe organic layer was dried over anhydrous sodium sulfate
9. 9
   Einengenconcentrated under high vacuum
10. 10
    SonstigeThe resulting residue was purified by flash chromatography (Biotage flash 75, 10:90 ethyl acetate/hexane)

Vorschrift

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).

Quelle