反应详情

The product from Step B (3.00 g, 8.85 mmol) was added in small portions over 5 minutes to concentrated H2SO4 (30 mL) and the mixture was stirred at ambient temperature for 2 hours (homogeneous after 5 minutes). The solution was slowly added to chilled H2O (300 mL) with stirring and the mixture was extracted with EtOAc. The combined EtOAc portions were washed with H2O, 1M Na2CO3 and saturated NaCl. The EtOAc solution was dried over MgSO4/activated carbon, filtered through a packed Celite pad and concentrated to give a white foam. The foam was dissolved in minimal CH2Cl2 and hexane was added to induce formation of a white precipitate. The mixture was concentrated to provide the title compound as a flowing white solid after drying in vacuum (2.80 g, 92%). MS (apci) m/z=344.1 (M+H).

1. additionThe solution was slowly added
2. stirringwith stirring
3. extractionthe mixture was extracted with EtOAc
4. washThe combined EtOAc portions were washed with H2O, 1M Na2CO3 and saturated NaCl
5. dry with materialThe EtOAc solution was dried over MgSO4/activated carbon
6. filtrationfiltered through a packed Celite pad
7. concentrationconcentrated
8. customto give a white foam
9. concentrationThe mixture was concentrated