Acetone → 6-Hydroxybenzofuran

Participants

Reaction Steps

NaBH4 (6.0 g, 160 mmol) was added to a solution of 6-(tert-butyldimethylsilyloxy)benzofuran-3(2H)-one (40.0 g, 151 mmol) in MeOH (800 mL) at room temperature. After stirring at room temperature for 2 h, the reaction mixture was treated with acetone. Subsequently 4N HCl were added to the mixture and the stirring was continued for 3 h at room temperature. The mixture was diluted with water and extracted with ethyl acetate (3×1000 mL). The extract was washed with brine, dried, concentrated in vacuo and purified by column chromatography on silica gel (5-10% ethyl acetate in petroleum ether) to afford the pure product (17.0 g, 85.5% yield). 1H NMR (300 MHz, CDCl3) δ: 7.51 (d, J=2.1, 1H), 7.41 (d, J=8.4, 1H), 7.02 (d, J=1.8, 1H), 6.81 (dd, J=8.4, 2.1, 1H), 6.68 (dd, J=2.1, 0.9, 1H), 5.5 (br s, 1H).

Provenance & Evidence