反应详情

Compound 7 (124 mg, 0.20 mmol) was azeotroped three times with anhydrous pyridine. This was dissolved in anhydrous pyridine (2.0 ml), and 38 μl (0.40 mmol) of acetic anhydride was further added thereto. The resulting mixture was stirred at room temperature for 2 days. The mixture was poured into water (50 ml) and extracted with methylene chloride (50 ml×3). After drying over Na2SO4, the solvent was distilled off under reduced pressure. The residue was dissolved in 20 ml anhydrous methylene chloride, and 200 μl dichloroacetic acid was added thereto at 0° C. After stirring at 2° C. for 15 minutes, the mixture was poured into 8 ml saturated aqueous sodium bicarbonate, diluted with 42 ml water, and then extracted with methylene chloride (50 ml×3). After drying over Na2SO4, the solvent was distilled off under reduced pressure. The residue was purified by flash silica gel chromatography using methylene chloride:ethyl acetate (9:1 to 3:2) as an elution solvent to give 65 mg of Compound 9 in a yield of 88%.

1. extractionextracted with methylene chloride (50 ml×3)
2. dry with materialAfter drying over Na2SO4
3. distillationthe solvent was distilled off under reduced pressure
4. dissolutionThe residue was dissolved in 20 ml anhydrous methylene chloride
5. addition200 μl dichloroacetic acid was added
6. customat 0° C
7. stirringAfter stirring at 2° C. for 15 minutes
8. additionthe mixture was poured into 8 ml saturated aqueous sodium bicarbonate
9. additiondiluted with 42 ml water
10. extractionextracted with methylene chloride (50 ml×3)
11. dry with materialAfter drying over Na2SO4
12. distillationthe solvent was distilled off under reduced pressure
13. customThe residue was purified by flash silica gel chromatography