反应详情

温度

15 °C

Sodium hydrogen carbonate (27.63 g, 0.329 mol, 1.25 eq) and a saturated solution of sodium hydrogen carbonate (333 ml) were added to a stirred solution of 4-bromo-3-fluoroaniline (50.0 g, 0.263 mol, 1 eq) in acetone (660 ml). The resulting mixture was cooled to 15° C. and benzyl chloroformate (39 ml, 0.276 mol, 1.05 eq) was added gradually, taking care that the reaction temperature did not exceed 22° C. The mixture was stirred over 90 mins at room temperature and the acetone was removed under vacuum. The aqueous layer was then extracted with ethyl acetate (3×150 ml). The combined organic layers were then washed with a saturated sodium chloride solution, and dried over MgSO4. After filtration, the solvent was removed, and n-hexane added. The mixture was stirred during 30 min at room temperature, the crystals were filtrated and washed with hexane to give the first crop of solid. The filtrate was evaporated, and the solid mixed with heptane at 0° C. and stirred during 30 min. The product was again filtered, to give the second crop of solid. The two crops were then combined, to give the product (85.3 g, quantitative) as of solid.

1. customdid not exceed 22° C
2. customthe acetone was removed under vacuum
3. extractionThe aqueous layer was then extracted with ethyl acetate (3×150 ml)
4. washThe combined organic layers were then washed with a saturated sodium chloride solution
5. dry with materialdried over MgSO4
6. filtrationAfter filtration
7. customthe solvent was removed
8. additionn-hexane added
9. stirringThe mixture was stirred during 30 min at room temperature
10. filtrationthe crystals were filtrated
11. washwashed with hexane
12. customto give the first crop of solid
13. customThe filtrate was evaporated
14. additionthe solid mixed with heptane at 0° C.
15. stirringstirred during 30 min
16. filtrationThe product was again filtered
17. customto give the second crop of solid
18. customto give the product (85.3 g, quantitative) as of solid