Sodium Carbonate → Biphenyl-3-ylacetic acid methyl ester

Beteiligte Stoffe

Reaktionsschritte

Concentrated sulphuric acid (588 μL) was added to a solution of 3-bromophenyl acetic acid (10 g, 46.5 mmol) in methanol (100 mL). The mixture was refluxed for 1.5 h and then cooled to ambient temperature and evaporated under reduced pressure to afford a residue. The residue was redissolved in diethyl ether (500 mL), washed with water (2×100 mL), brine (100 mL), dried (MgSO4) and then evaporated under reduced pressure to afford 3-bromophenyl acetic acid methyl ester (10.65 g). The 3-bromophenyl acetic acid methyl ester was dissolved in toluene (117 mL) then phenyl boronic acid (6.8 g, 55.69 mmol) added, followed by a aqueous solution of sodium carbonate (93 mL, 2M) and tetrakis(triphenylphosphine)palladium (1.6 g, 1.41 mmol). The mixture was stirred overnight then cooled to ambient temperature and an aqueous solution of saturated ammonium chloride (100 mL) added. The mixture was extracted with ethyl acetate (2×200 mL), died (Na2SO4) and evaporated under reduced pressure to afford a residue. Flash chromatography of the residue over silica (200 g) using ethyl acetate:heptane (3:48) as the eluent gave biphenyl-3-yl acetic acid methyl ester, yield 10.5 g, (99%), TLC (single UV spot, Rf=0.24, 10% ethyl acetate in heptane), analytical HPLC Rt=19.55 min, HPLC-MS (single main UV peak with Rt=9.35 min, 227.1 [M+H]+).

Herkunft & Nachweise