反应详情

Phosphorus tribromide (PBr3, 1.57 mL, 16.7 mmol) was added to a solution of 3,4-diethoxy-2-fluoro-6-(hydroxymethyl)benzonitrile (38.0 g, 33.4 mmol) in 1,2-dimethoxyethane (DME) (80 mL) on ice, followed by 3 hours of stirring at room temperature. After the reaction solution was cooled on ice, ethyl acetate and water were added. The organic layer was separated, and the aqueous layer was extracted further with ethyl acetate. The combined extract solutions were washed with saturated aqueous sodium hydrogen carbonate solution and saturated brine, and after addition of activated charcoal, were dried over anhydrous magnesium sulfate. After filtration, the solvent was distilled off, followed by addition of n-heptane (100 mL) to the residue, and the solvent was distilled off again. n-Heptane (100 mL) was added to the residue, and this was cooled on ice. Precipitated crystals were collected by filtration, and washed with n-heptane to give 9.1 g of the subject compound (yield: 90.1%).

1. additionwere added
2. customThe organic layer was separated
3. extractionthe aqueous layer was extracted further with ethyl acetate
4. extractionThe combined extract solutions
5. washwere washed with saturated aqueous sodium hydrogen carbonate solution and saturated brine
6. additionafter addition of activated charcoal
7. dry with materialwere dried over anhydrous magnesium sulfate
8. filtrationAfter filtration
9. distillationthe solvent was distilled off
10. additionfollowed by addition of n-heptane (100 mL) to the residue
11. distillationthe solvent was distilled off again
12. additionn-Heptane (100 mL) was added to the residue
13. temperaturethis was cooled on ice
14. customPrecipitated crystals
15. filtrationwere collected by filtration
16. washwashed with n-heptane