Reaktion #59119

Reaktionsgleichung

sodium hydroxide

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

→

ethyl 4-(4-bromophenyl)-2-(2-methoxyethyl)-4-oxobutanoate

Ausbeute 86.0%

Lösungsmittel

ethanol

acetone

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenThe reaction mixture was concentrated in vacuo
2. 2
   Sonstigeto remove solvents
3. 3
   workup.DISSOLUTIONthe residue redissolved in dimethoxyethane (32 mL)
4. 4
   Temperaturthe reaction mixture heated at 80° C. for 3 h
5. 5
   TemperaturThe reaction mixture was cooled to rt
6. 6
   workup.ADDITIONdiluted with ethyl acetate (50 mL) and water (50 mL)
7. 7
   Extraktionwas extracted into the organic layer
8. 8
   SonstigeThe layers were separated
9. 9
   Extraktionthe aqueous layer was extracted with additional ethyl acetate (50 mL)
10. 10
    Waschenthe combined organic layers were washed with saturated aqueous sodium chloride solution (50 mL)
11. 11
    Trocknendried over anhydrous sodium sulfate
12. 12
    Einengenconcentrated in vacuo

Vorschrift

To a 150 mL flask was added diethyl 2-[2-(4-bromophenyl)-2-oxoethyl]-2-(2-methoxyethyl)malonate (1.59 g, 3.59 mmol) dissolved in acetone (16 mL) and ethanol (16 mL), followed by addition of 1N aqueous sodium hydroxide solution (3.6 mL). The reaction mixture was then heated at 55° C. for 3 h. The reaction mixture was concentrated in vacuo to remove solvents, the residue redissolved in dimethoxyethane (32 mL), and the reaction mixture heated at 80° C. for 3 h. The reaction mixture was cooled to rt, diluted with ethyl acetate (50 mL) and water (50 mL), and stirred for 15 minutes until almost all color was extracted into the organic layer. The layers were separated, the aqueous layer was extracted with additional ethyl acetate (50 mL), and the combined organic layers were washed with saturated aqueous sodium chloride solution (50 mL), dried over anhydrous sodium sulfate, and concentrated in vacuo, to afford ethyl 4-(4-bromophenyl)-2-(2-methoxyethyl)-4-oxobutanoate (1.06 g, 86%). No further purification of this material was required. LC-MS ret. time 3.18 min, m/z 342.8 (MH+); 1H NMR (300 MHz, CDCl3) δ 1.35 (t, 3H), 1.77-1.92 (m, 1H), 1.94-2.10 (m, 1H), 3.05-3.2 (m, 2H), 3.35-3.50 (m, 3H), 4.09-4.25 (m, 2H), 7.60 (d, 2H), 7.83 (d, 2H).

Quelle