An improved and scale-up synthesis of 6-hydroxybenzofuran
acidified with 2 N HCl to pH 2 and extracted with ethyl acetate three times. The
ethyl acetate phases were combined, washed with water, and dried over sodium
sulfate. The solvent was removed under vacuum and the residue was left overnight
at room temperature to afford 1 as a light brown solid (2.65 kg, 90 % yield, 99.5 %
1
purity), m.p. 54–56 °C. H-NMR (CDCl3, ppm): d 7.55 (s, 1H), 7.44–7.46 (d, 1H),
7.03 (s, 1H), 6.81–6.83 (d, 1H), 6.72 (s, 1H), 5.09 (br, 1H).
Acknowledgments This work was supported by Guangdong Medical College Research Foundation
(Grant JB12020).
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