Carbon Tetrachloride → Acetic acid 3-chloromethyl-benzofuran-6-yl ester

Participants

Reaction Steps

To a solution of 3-hydroxymethyl-benzofuran-6-ol (4.72 g, 28.6 mmol) in iPrOH (120 mL) was added NaOH (2.30 g, 57.5 mmol) in H2O (25 mL) followed by acetic anhydride (5.4 mL, 57.5 mmol) and the reaction mixture was stirred (rt, 1 h). The reaction was concentrated in vacuo and the resulting residue was partitioned with saturated NaHCO3 (100 mL) and EtOAc (100 mL). The layers were separated and the aqueous layer was extracted with EtOAc (3×100 mL). The organic layers were combined, dried, filtered and concentrated in vacuo. The residue was dissolved in DCM (150 mL) and treated with CCl4(3.2 mL, 32.9 mmol) and triphenylphosphine (8.64 g, 32.9 mmol) as a solution in CH2Cl2 (50 mL) and stirred (rt, 12 h). The reaction mixture was concentrated in vacuo and the resulting residue was purified by silica gel flash chromatography using DCM:hexanes (0-100%) to provide the title compound as a white solid (3.45 g, 65%). MS (ESI): mass calcd. for O11H9Cl3, 224.0; m/z found, 225.0 [M+H]+. 1H NMR (400 MHz, CDCl3): 7.68-7.64 (m, 2H), 7.28 (d, J=2.0, 1H), 7.05 (dd, J=8.5, 2.0, 1H), 4.73 (d, J=0.8, 2H), 2.33 (s, 3H).

Provenance & Evidence