反应详情

A solution of 131g (3.8 g, 13.0 mmol) in 30% H2SO4 (100 mL) was heated at reflux for 16 h. See FIG. 15. The reaction mixture was cooled to room temperature and extracted with dichloromethane (3×200 mL). The combined organic layer was concentrated under reduced pressure and the residue was purified by silica-gel column chromatography eluting with 100:1 dichloromethane/methanol to afford 131h as a yellow solid (1.72 g, 60%). MS-ESI: [M+H]+ 221.0

1. temperatureat reflux for 16 h
2. extractionextracted with dichloromethane (3×200 mL)
3. concentrationThe combined organic layer was concentrated under reduced pressure
4. customthe residue was purified by silica-gel column chromatography
5. washeluting with 100:1 dichloromethane/methanol