2,6-Lutidine → 5-Hydroxy-2-methyl-benzofuran-7-carboxylic acid methyl ester

関与物質

反応手順

BBr3 (10 mL, 10.08 mmol, 1.0 M in CH2Cl2) was added drop-wise to a solution of 5-methoxy-2-methyl-benzofuran-7-carboxylic acid methyl ester (4c) (951 mg, 4.31 mmol) and 2,6-lutidine (1.17 mL, 10.08 mmol) in CH2Cl2 (20 mL) at 0° C. The mixture was stirred and warmed to RT overnight. The mixture was quenched with H2O (60 mL) and extracted with CH2Cl2 (2×60 mL). The combined organic layers were dried over MgSO4 and concentrated. The residue was purified by flash column chromatograph eluting with 5% CH3OH/CH2Cl2 to afford a white solid (746 mg, 83%). 1H NMR (400 MHz, CDCl3) δ 7.40 (d, J=2.53 Hz, 1 H) 7.13 (d, J=2.53 Hz, 1 H) 6.33 (d, J=1.01 Hz, 1 H) 5.50 (s, 1 H) 4.00 (s, 3 H) 2.49 (d, J=1.01 Hz, 3 H).

情報源と証拠