反应详情

温度

-78 °C

Dissolve 5-[5-(5-chloro-2-methoxy-phenyl)-oxazol-2-yl]-pentanoic acid methyl ester (4.174 g, 12.89 mmol) in 50 mL of CH2Cl2 and cool the solution to −78° C. Add boron tribromide (48.9 mL of a 1M solution in CH2Cl2) dropwise to the reaction and allow it to warm to ambient temperature and allow it to stir for 27 hours. Cool the reaction to −78° C. and quench it by adding 100 mL of MeOH dropwise to the reaction mixture. Allow the reaction to warm to ambient temperature and stir for 19 hours. Concentrate the reaction mixture in vacuo. Dissolve the residue in CH2Cl2 and wash it with saturated aqueous NaHCO3 and brine. Dry the organic layer with MgSO4. Filter off the drying agent and concentrate in vacuo to afford a crude residue. Purify the residue using silica gel chromatography eluting with hexanes/ethyl acetate mixtures to afford 3.26 g of the titled product (82%): mass spectrum: m/z=310.09 (M+H).

1. temperatureto warm to ambient temperature
2. temperatureCool
3. customthe reaction to −78° C.
4. customquench it
5. additionby adding 100 mL of MeOH dropwise to the reaction mixture
6. customthe reaction
7. temperatureto warm to ambient temperature
8. stirringstir for 19 hours
9. concentrationConcentrate the reaction mixture in vacuo
10. dissolutionDissolve the residue in CH2Cl2
11. washwash it with saturated aqueous NaHCO3 and brine
12. dry with materialDry the organic layer with MgSO4
13. filtrationFilter off the drying agent
14. concentrationconcentrate in vacuo
15. customto afford a crude residue
16. customPurify the residue
17. washeluting with hexanes/ethyl acetate