反应详情

Methyl 3,5-diallyloxy-2-ethylphenylacetate (1.0 g, 3.3 mmol) obtained in Example 5, Step 3 was dissolved in trifluoroacetic acid (9.0 mL), and 4-hydroxybenzoic acid (1.4 g, 10 mmol) and trifluoroacetic anhydride (1.2 mL) were added thereto, followed by stirring at room temperature for 20 hours. To the mixture were further added 4-hydroxybenzoic acid (0.92 g, 6.6 mmol) and trifluoroacetic anhydride (1.4 mL), followed by stirring for 6 hours. The reaction mixture was added dropwise to a saturated aqueous solution of sodium hydrogencarbonate (0.10 L), and the resulting mixture was extracted with ethyl acetate (50 mL×4). The organic layer was dried over anhydrous sodium sulfate and then concentrated under reduced pressure. The resulting residue was dissolved in a 7 mol/L solution of ammonia in methanol (100 mL), followed by stirring at room temperature for 1 day. After the reaction mixture was concentrated under reduced pressure, 3 mol/L hydrochloric acid (40 mL) was added thereto, followed by extraction with ethyl acetate (50 mL×3). The organic layer was washed with water, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (ethyl acetate/hexane=1/10-1/2) to obtain methyl 3,5-diallyloxy-2-ethyl-6-(4-hydroxybenzoyl)phenylacetate (0.84 g, 57%).

1. stirringby stirring for 6 hours
2. extractionthe resulting mixture was extracted with ethyl acetate (50 mL×4)
3. dry with materialThe organic layer was dried over anhydrous sodium sulfate
4. concentrationconcentrated under reduced pressure
5. dissolutionThe resulting residue was dissolved in a 7 mol/L solution of ammonia in methanol (100 mL)
6. stirringby stirring at room temperature for 1 day
7. concentrationAfter the reaction mixture was concentrated under reduced pressure, 3 mol/L hydrochloric acid (40 mL)
8. additionwas added
9. extractionfollowed by extraction with ethyl acetate (50 mL×3)
10. washThe organic layer was washed with water
11. dry with materialdried over anhydrous sodium sulfate
12. concentrationconcentrated under reduced pressure
13. customThe resulting residue was purified by silica gel column chromatography (ethyl acetate/hexane=1/10-1/2)