Potassium Carbonate → 2-tert-Butoxycarbonylamino-3-(4'-dibenzofuran-4-yl-biphen-4-yl)-propanoic acid methyl ester

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Reaction Steps

A solution of 2-tert-Butoxycarbonylamino-3-(4-iodophenyl)-propanoic acid methyl ester (1.22 g, 3 mmol), 4-(4-dibenzofuranyl)benzeneboronic acid (0.906 g, 3.15 mmol) and Pd(PPh3)4 (160 mg, 5 mol %) in toluene (25 mL) and ethanol (6.0 mL) was treated with 2 M K2CO3 (4.5 mL). The reaction mixture was heated to reflux for 2 h, cooled to room temperature, diluted with ethyl acetate (100 mL). The organic layer was washed successively with 2% aq HCl and sat. aq NaCl, dried over MgSO4 and concentrated. Purification by flash column chromatography (2-10% ethyl acetate in heptane) gave 2-tert-Butoxycarbonylamino-3-(4′-dibenzofuran-4-yl-biphen-4-yl)-propanoic acid methyl ester (1.1 g, 70%) as an oil. 1H NMR (CDCl3), δ 7.98 (d, J=9 Hz, 2H), 7.96 (d, J=8 Hz, 2H), 7.74 (d, J=9, 2H), 7.66 (m, 4H), 7.42 (m, 5H), 5.04 (d, J=9 Hz, 1H), 4.66 (m, 1H), 3.73 (s, 3H), 3.15 (m, 2H), 1.57 (s, 9H). LCMS 422 (M+−100).

Provenance & Evidence