反应详情

Methyl 2-acetyl-3,5-diallyloxyphenylacetate (22 g, 72 mmol) obtained in Example 5, Step 2 was dissolved in 1,4-dioxane (0.20 L). To the solution were added ammonium formate (18 g, 0.29 mol) and bis(triphenylphosphine)palladium (II) dichloride (2.5 g, 3.6 mmol), followed by stirring for 8 hours under heating and reflux. After cooling to room temperature, the reaction mixture was made acidic by addition of 3 mol/L hydrochloric acid (0.20 L) and then concentrated under reduced pressure. The resulting residue was extracted with a mixed solvent of ethyl acetate and methanol (ethyl acetate/methanol=4/1, 0.20 L×4). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (ethyl acetate/hexane=1/2) to obtain methyl 2-acetyl-3,5-dihydroxyphenylacetate (6.2 g, 39%).

1. temperatureunder heating
2. temperaturereflux
3. concentrationconcentrated under reduced pressure
4. extractionThe resulting residue was extracted with a mixed solvent of ethyl acetate and methanol (ethyl acetate/methanol=4/1, 0.20 L×4)
5. dry with materialThe organic layer was dried over anhydrous sodium sulfate
6. concentrationconcentrated under reduced pressure
7. customThe resulting residue was purified by silica gel column chromatography (ethyl acetate/hexane=1/2)