反应详情

To a solution of the product from Example 266C (3.1 g, 13.00 mmol) in tetrahydrofuran (40 mL) was added potassium tert-butoxide (1.0 Min tetrahydrofuran, 15.7 mL, 15.7 mmol) via syringe under nitrogen, and the resultant mixture was stirred for 15 minutes. Then ethyl 2-bromoacetate (1.59 mL, 14.4 mmol) was added. The reaction mixture was stirred at room temperature overnight. The reaction mixture was concentrated and then diluted with ethyl acetate, washed with water and brine, dried over magnesium sulfate, filtered and concentrated. The resulting residue was dissolved in ethanol/water (4:1, 60 mL) and treated with lithium hydroxide (1.254 g, 52.4 mmol). After stirring for 2 hours at reflux, the reaction was concentrated, diluted with ice/water (150 mL) and neutralized with 2 N HCl. The precipitate formed was filtered, washed with water (50 mL), and dried under vacuum to obtain the title compound. MS (DCI+) m/z 288.1 (M+H)+.

1. concentrationThe reaction mixture was concentrated
2. additiondiluted with ethyl acetate
3. washwashed with water and brine
4. dry with materialdried over magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. dissolutionThe resulting residue was dissolved in ethanol/water (4:1, 60 mL)
8. stirringAfter stirring for 2 hours
9. temperatureat reflux
10. concentrationthe reaction was concentrated
11. additiondiluted with ice/water (150 mL)
12. customThe precipitate formed
13. filtrationwas filtered
14. washwashed with water (50 mL)
15. customdried under vacuum