反应详情

To a stirred solution of ethyl 3-(4-methoxyphenyl)isoxazole-5-carboxylate (1 g, 4.04 mmol, prepared according to literature method Tet. Lett 2009, 50(27), 3948-3951) in 8 mL DCM, Boron tribromide 1 M solution in DCM (8.0 mL, 8.08 mmol) was added dropwise at −78° C. After complete addition reaction mixture was allowed to warm slowly and further stirred for 16 hrs at RT. After completion of the reaction, solvent was removed under reduced pressure. The reaction mixture was diluted with ice cold water (20 mL) and extracted with ethyl acetate (3×50 mL). The combined organic layer was washed with water, brine and dried over sodium sulfate, filtered and concentrated under reduced pressure to get ethyl 3-(4-hydroxyphenyl)isoxazole-5-carboxylate (0.7 g).

1. additionAfter complete addition reaction mixture
2. temperatureto warm slowly
3. customAfter completion of the reaction, solvent
4. customwas removed under reduced pressure
5. additionThe reaction mixture was diluted with ice cold water (20 mL)
6. extractionextracted with ethyl acetate (3×50 mL)
7. washThe combined organic layer was washed with water, brine
8. dry with materialdried over sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure