Reaktion #9626

Reaktionsgleichung

sodium carbonate

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

4-nitro-phenyl boronic acid

→

ethyl 2-(2-methoxyethyl)-4-(4′-nitro-1,1′-biphenyl-4-yl)-4-oxobutanoate

Ausbeute 88.0%

Lösungsmittel

dioxane

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeTo a 150 mL 3-neck flask fitted with a reflux condenser
2. 2
   workup.ADDITIONwas added
3. 3
   Sonstigeof degassing
4. 4
   Temperaturto cool
5. 5
   workup.ADDITIONwas diluted with ethyl acetate (75 mL) and saturated aqueous sodium chloride solution (75 mL)
6. 6
   SonstigeThe layers were separated
7. 7
   Extraktionthe aqueous layer was extracted twice with ethyl acetate (50 mL)
8. 8
   Waschenthe combined organic layers were washed with saturated aqueous sodium chloride solution (75 mL)
9. 9
   Trocknendried over anhydrous magnesium sulfate
10. 10
    Filtrationfiltered in vacuo through 2 cm Celite®/2 cm silica
11. 11
    EinengenThe filtrate was concentrated in vacuo
12. 12
    Sonstigeleaving a dark red-brown oil, that
13. 13
    Sonstigewas purified by flash chromatography (4:1 hexane/ethyl acetate

Vorschrift

To a 150 mL 3-neck flask fitted with a reflux condenser was added ethyl 4-(4-bromophenyl)-2-(2-methoxyethyl)-4-oxobutanoate (1.06 g, 3.09 mmol) and 4-nitro-phenyl boronic acid (0.62 g, 3.70 mmol) dissolved in toluene (30 mL) and dioxane (8.50 mL), followed by addition of saturated aqueous sodium carbonate solution (8.50 mL). A thin-gauge needle was inserted into the bi-phasic mixture and degassed with argon over 30 minutes, at which point 1,2-bis[(diphenylphosphino) ferrocene] dichloropalladium(II) (0.13 g, 0.15 mmol) was added, followed by an additional 15 minutes of degassing. The reaction mixture was heated at 85° C. for 16 h, and then the resulting dark-colored reaction mixture was allowed to cool, and was diluted with ethyl acetate (75 mL) and saturated aqueous sodium chloride solution (75 mL). The layers were separated, the aqueous layer was extracted twice with ethyl acetate (50 mL), and the combined organic layers were washed with saturated aqueous sodium chloride solution (75 mL), dried over anhydrous magnesium sulfate, and filtered in vacuo through 2 cm Celite®/2 cm silica. The filtrate was concentrated in vacuo, leaving a dark red-brown oil, that was purified by flash chromatography (4:1 hexane/ethyl acetate, then 3:1 hexane/ethyl acetate, then 2:1 hexane/ethyl acetate) to afford ethyl 2-(2-methoxyethyl)-4-(4′-nitro-1,1′-biphenyl-4-yl)-4-oxobutanoate (1.04 g, 88%). LC-MS ret. time 3.38 min, m/z 385.9 (MH+); 1H NMR (300 MHz, CDCl3) δ 1.27 (t, 3H), 1.80–1.95 (m, 1H), 1.95–2.10 (m, 1H), 3.10–3.25 (m, 2H), 3.40–3.58 (m, 3H), 4.17 (q, 2H), 7.67–7.82 (2d, 4H), 8.10 (d, 2H), 8.33 (d, 2H).

Quelle