反应详情

温度

80 °C

Methyl 2-ethyl-3,5-dihydroxyphenylacetate (2.0 g, 9.7 mmol) obtained in Example 7, Step 2 was suspended in boron trifluoride diethyl etherate (40 mL), and 3-hydroxy-4-methoxybenzoic acid (1.7 g, 11 mmol) was added thereto, followed by stirring at 80° C. for 5 hours. After cooling to room temperature, the reaction mixture was added dropwise to ice-cold water, and the resulting mixture was extracted with ethyl acetate. The organic layer was washed successively with a saturated aqueous solution of sodium hydrogencarbonate and a saturated aqueous solution of sodium chloride, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (ethyl acetate/hexane=1/4-9/1) to obtain methyl 2-ethyl-3,5-dihydroxy-6-(3-hydroxy-4-methoxybenzoyl)phenylacetate (2.2 g, 65%).

1. temperatureAfter cooling to room temperature
2. additionthe reaction mixture was added dropwise to ice-cold water
3. extractionthe resulting mixture was extracted with ethyl acetate
4. washThe organic layer was washed successively with a saturated aqueous solution of sodium hydrogencarbonate
5. dry with materiala saturated aqueous solution of sodium chloride, dried over anhydrous sodium sulfate
6. concentrationconcentrated under reduced pressure
7. customThe resulting residue was purified by silica gel column chromatography (ethyl acetate/hexane=1/4-9/1)