反应详情

2-Bromofluorobenzene (1.85 g) was dissolved in toluene (30 ml), and tetrahydrofuran (10 ml) was added. n-Butyllithium (2.73 M; 3.68 ml) was added dropwise at −78° C. 2-Fluorophenyllithium was prepared by stirring at the same temperature for one hour. A boron trifluoride-ether complex (1.26 ml) was added to a solution of 3,3a,4,5-tetrahydro-7H-pyrano[3,4-c]isoxazole (630 mg) in toluene (70 ml) at −78° C. After stirring at the same temperature for 10 minutes, 2-fluorophenyllithium prepared above was added to the reaction mixture through a cannula. After stirring at the same temperature for one hour, an ammonium chloride solution was added. The reaction mixture was returned to room temperature, and the aqueous layer was extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure and the residue was purified by silica gel column chromatography to obtain the title compound (1.26 g).

1. stirringAfter stirring at the same temperature for 10 minutes
2. additionabove was added to the reaction mixture through a cannula
3. stirringAfter stirring at the same temperature for one hour
4. customwas returned to room temperature
5. extractionthe aqueous layer was extracted with ethyl acetate
6. washThe organic layer was washed with brine
7. dry with materialdried over anhydrous magnesium sulfate
8. customThe solvent was evaporated under reduced pressure
9. customthe residue was purified by silica gel column chromatography