反应详情

温度

52.5 °C

A solution or 5-bromo-2-fluorophenyl phenyl ether (8.01 g, 30 mmol) in tetrahydrofuran is added dropwise over 30 minutes to a mixture of magnesium turnings (0.0802 g, 33 mmol), a crystal of iodine and a few drops of 1,2-dibromoethane in tetrahydrofuran at 50-55° C. under nitrogen. After the addition is complete, the reaction mixture is stirred at 50-55° C. for 70 minutes and cooled to room temperature. The cooled mixture is added over 25 minutes to a solution of trimethyl borate (4.09 mL, 36 mmol) in diethyl ether at dry ice/acetone bath temperature. After the addition is complete, the mixture is stirred at dry ice/acetone bath temperature for 20 minutes, allowed to warm to -10° C. over 25 minutes, diluted sequentially with acetic acid and water, stirred at room temperature for 30 minutes, and extracted with ether. The organic extract is washed with water, dried over anhydrous sodium sulfate and concentrated in vacuo to obtain a residue. A mixture of the residue in water is heated over a steam bath for 30 minutes, cooled to room temperature and filtered to obtain a solid which is washed with hexanes and dried to give the title product as a colorless solid (5.7 g, mp 177-180° C., 82% yield).

1. customat 50-55° C.
2. additionAfter the addition
3. temperaturecooled to room temperature
4. additionAfter the addition
5. stirringthe mixture is stirred at dry ice/acetone bath temperature for 20 minutes
6. temperatureto warm to -10° C. over 25 minutes
7. stirringstirred at room temperature for 30 minutes
8. extractionextracted with ether
9. extractionThe organic extract
10. washis washed with water
11. dry with materialdried over anhydrous sodium sulfate
12. concentrationconcentrated in vacuo
13. customto obtain a residue
14. temperatureis heated over a steam bath for 30 minutes
15. temperaturecooled to room temperature
16. filtrationfiltered
17. customto obtain a solid which
18. washis washed with hexanes
19. customdried