Sodium Carbonate → Ethyl 2-(2-methoxyethyl)-4-(4'-nitro-1,1'-biphenyl-4-yl)-4-oxobutanoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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).

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