反应详情

To a mixture of compound 17 (7.3 g, 21.6 mmol) in methanol (180 mL) was added water (18 mL) and NaOH (8.64 g, 216 mmol). The solution was heated and maintained at reflux for 3 days. The solvent was evaporated in vacuo and the residue was dissolved in 140 mL of water. Then the solution was acidified to pH 2 by the addition of 2N HCl. The aqueous phase was extracted with ethyl acetate (100 mL×3), and the combined organic phases were washed with water and brine, dried over anhydrous Na2SO4 and then concentrated to give compound 18 as a yellow solid, which was used in the next reaction without further purification.

1. temperatureThe solution was heated
2. temperaturemaintained
3. temperatureat reflux for 3 days
4. customThe solvent was evaporated in vacuo
5. dissolutionthe residue was dissolved in 140 mL of water
6. additionThen the solution was acidified to pH 2 by the addition of 2N HCl
7. extractionThe aqueous phase was extracted with ethyl acetate (100 mL×3)
8. washthe combined organic phases were washed with water and brine
9. dry with materialdried over anhydrous Na2SO4
10. concentrationconcentrated