反应详情

温度

7.5 °C

To a solution of 4-[2-(2-ethoxycarbonyl-ethyl)-3-(6-hydroxy-hexyl)-phenoxy]-butyric acid ethyl ester (0.85 mmol, 349 mg) and carbon tetrabromide (1.26 mmol, 423 mg) in dichloromethane (10 mL) was added triphenylphosphine (1.07 mmol, 281 mg) at ˜0° C. The resulting colorless solution was stirred for 3 h at 5-10° C. Then, the solvent was removed under vacuum and the crude was tried to dissolve in a mixture of ethyl acetate and hexanes (1:3, 50 mL). As a result, a cloudy solution containing some precipitate was formed and the cloudy solution was transferred into a separatory funnel and was washed with a mixture of methanol and water (2:1, 150 mL). The aqueous layer was extracted one more time with ethyl acetate and hexanes (1:3, 50 mL). The combined organic extracts were washed with brine solution (100 mL) and the organic solution was dried over anhydrous magnesium sulfate. Filtration of the drying agent and the removal of the solvent gave a colorless oil which was purified by using a Biotage™ (40M) column chromatography eluting with 10% ethyl acetate in hexanes to obtain the desired 4-[3-(6-bromo-hexyl)-2-(2-ethoxycarbonyl-ethyl)-phenoxy]-butyric acid ethyl ester (350 mg, 87.5%) as a colorless oil: ES(+)-HRMS m/e calculated for C23H35BrO5 (M+Na)+ 493.1560, found 493.1560.

1. customThen, the solvent was removed under vacuum
2. dissolutionto dissolve in a mixture of ethyl acetate and hexanes (1:3, 50 mL)
3. additionAs a result, a cloudy solution containing some precipitate
4. customwas formed
5. customthe cloudy solution was transferred into a separatory funnel
6. washwas washed with a mixture of methanol and water (2:1, 150 mL)
7. extractionThe aqueous layer was extracted one more time with ethyl acetate and hexanes (1:3, 50 mL)
8. washThe combined organic extracts were washed with brine solution (100 mL)
9. dry with materialthe organic solution was dried over anhydrous magnesium sulfate
10. filtrationFiltration of the drying agent
11. customthe removal of the solvent
12. customgave a colorless oil which
13. customwas purified
14. washeluting with 10% ethyl acetate in hexanes