反应详情

To a mixture of the compound from Step A (0.90 g, 2.23 mmol), potassium carbonate (0.40 g, 2.90 mmol) in acetone (80 mL) was added ethyl bromoacetate (0.484 g, 0.32 mL, 2.90 mmol) with stirring. The mixture was heated at reflux temperature for 3 h and evaporated to dryness. The residue was mixed with water (100 mL) and extracted with EtOAc (3×60 mL). The combined extracts were dried over magnesium sulfate, filtered and evaporated to dryness. Chromatography on silica eluting with a gradient of 10% to 30% EtOAc/hexane gave a solid (0.92 g, 84%): mp 89-90° C.; LCMS (+APCI) 490, 492 (M+H).

1. temperatureThe mixture was heated
2. temperatureat reflux temperature for 3 h
3. customevaporated to dryness
4. additionThe residue was mixed with water (100 mL)
5. extractionextracted with EtOAc (3×60 mL)
6. dry with materialThe combined extracts were dried over magnesium sulfate
7. filtrationfiltered
8. customevaporated to dryness