反应详情

温度

0 °C

Methanesulfonic acid (140 ml) was added dropwise, under ice cooling, to a solution consisting of 4-tert-butyl-5-hydroxybenzofuran [J. Org. Chem., 53, 4135 (1988 ); 35 g, 0.18 mol], tert-butyl alcohol (70 g, 0.84 mol) and chloroform (50 ml). After stirring at 0° C. for 20 min, the mixture was poured into ice water. Subsequently, the mixture was neutralized with an aqueous solution of N sodium hydroxide and subjected to extraction with ethyl acetate. The extracted layer was washed with a saturated aqueous solution of sodium hydrogen carbonate, dried over anhydrous magnesium sulfate, and concentrated. The concentrate was purified by silica gel chromatography (n-hexane) to afford 2,4,6-tri-tert-butyl-5-hydroxybenzofuran [10.87 g (yield, 20%)]. Also obtained, though in low yield, was 4,6-di-tert-butyl-5-hydroxybenzofuran.

1. extractionsubjected to extraction with ethyl acetate
2. washThe extracted layer was washed with a saturated aqueous solution of sodium hydrogen carbonate
3. dry with materialdried over anhydrous magnesium sulfate
4. concentrationconcentrated
5. customThe concentrate was purified by silica gel chromatography (n-hexane)