反应详情

A mixture of 2,4-bis-benzyloxy-5-bromo-benzoic acid benzyl ester (503 mg, 1 mmol) and 5-isopropyl-2-methoxy-phenylboronic acid (388 mg, 2 mmol) was heated in a mixture of toluene (5 ml), ethanol (5 ml) and saturated NaHCO3 (5 ml) under nitrogen in the presence of a catalytic amount of Pd(PPh3)4 (60 mg, 0.052 mmol) at 80° C. for 2-3 h. After the reaction was complete, the reaction mixture was extracted with ethyl acetate (25 ml×3), and the combined organics were washed with water and brine and dried over Na2SO4. After filtration and concentration, the residue was purified by flash chromatography on silica gel to provide 4,6-bis-benzyloxy-5′-isopropyl-2′-methoxy-biphenyl-3-carboxylic acid benzyl ester (481 mg, 84%). M.p.: 139-141° C.; 400 MHz 1H NMR (CDCl3) δ: 7.44-7.22 (m, 16H), 7.17 (dd, J=8.0, 2.4 Hz, 1H), 7.11 (d, J=2.4 Hz, 1H), 6.87 (d, J=8.4 Hz, 1H), 6.58 (s, 1H), 5.32 (s, 2H), 5.11 (s, 2H), 5.04 (s, 2H), 3.71 (s, 3H), 2.87 (hept, J=7.2 Hz, 1H), 1.23 (d, J=7.6 Hz, 6H); LCMS: 573 [M+H].

1. extractionthe reaction mixture was extracted with ethyl acetate (25 ml×3)
2. washthe combined organics were washed with water and brine
3. dry with materialdried over Na2SO4
4. filtrationAfter filtration and concentration
5. customthe residue was purified by flash chromatography on silica gel