反应详情

To a dichloromethane (80 ml) solution of 4-cyano-4-(3-methoxyphenyl)-3,4,5,6-tetrahydro-2H-pyran (2.32 g, 10.35 mmol) cooled to 0° C. was added boron tribromide (3.15 ml, 33.3 mmol) dropwise over 10 min. The ice-bath was removed and the reaction mixture stirred at ambient temperature for 19 h, and then at reflux for 4 h. The reaction mixture was cooled and poured into water (150 ml). The organic layer was separated and the aqueous layer was extracted with ethyl acetate (50 ml×3). The combined organic extracts were washed with brine (50 ml), dried (MgSO4) and concentrated in vacuo. The crude product was crystallized from isopropyl ether to afford titled compound as off-white solids (1.43 g, 66%).

1. customThe ice-bath was removed
2. temperatureat reflux for 4 h
3. temperatureThe reaction mixture was cooled
4. additionpoured into water (150 ml)
5. customThe organic layer was separated
6. extractionthe aqueous layer was extracted with ethyl acetate (50 ml×3)
7. washThe combined organic extracts were washed with brine (50 ml)
8. dry with materialdried (MgSO4)
9. concentrationconcentrated in vacuo
10. customThe crude product was crystallized from isopropyl ether