反应详情

To a solution of 1E (2.5 g, 8.14 mmol) in EtOH (25 mL) was added 15% aqueous sulfuric acid (25 mL). The resulting mixture was refluxed overnight, then cooled to RT. After removal of most of the EtOH, the mixture was diluted with water (200 mL), extracted with CH2Cl2 (3×50 mL). The aqueous layer was basified with 4N NaOH to pH=10, then extracted with CH2Cl2 (3×50 mL). The combined organics were washed with brine, dried (Na2SO4) and concentrated. The residue was crystallized from EtOAc/hexane to afford the title compound (1.026 g, 73% yield).

1. temperatureThe resulting mixture was refluxed overnight
2. customAfter removal of most of the EtOH
3. additionthe mixture was diluted with water (200 mL)
4. extractionextracted with CH2Cl2 (3×50 mL)
5. extractionextracted with CH2Cl2 (3×50 mL)
6. washThe combined organics were washed with brine
7. dry with materialdried (Na2SO4)
8. concentrationconcentrated
9. customThe residue was crystallized from EtOAc/hexane