反应详情

To a 0.497M solution of (2,4-difluorophenyl)magnesium bromide (32.4 g, 149 mmol) in THF at 0° C. was carefully added cyclopentanone (13.23 mL, 149 mmol). Upon the end of the addition, the reaction mixture was heated at reflux for 2 h. Ice (10 g) and 6N aqueous hydrochloric acid were added. The reaction mixture was extracted with ether. The combined organic extracts were washed with a saturated aqueous solution of sodium hydrogen sulfite, a saturated aqueous solution of sodium bicarbonate and water. The organic layer was dried over anhydrous magnesium sulfate and filtered. The solvent was removed in vacuum and the residue was purified by column chromatography on silica gel to give 1-cyclopentenyl-2,4-difluorobenzene (7.064 g, 39.2 mmol, 26.3% yield) as colorless oil. LC-MS (M+H)+=181.0. 1H NMR (500 MHz, CDCl3) δ ppm 7.22-7.31 (1H, m), 6.75-6.85 (2H, m), 6.26-6.31 (1H, m), 2.68-2.74 (2H, m), 2.51-2.58 (2H, m), 1.93-2.02 (2H, m).

1. customat 0° C.
2. additionUpon the end of the addition
3. temperaturethe reaction mixture was heated
4. temperatureat reflux for 2 h
5. extractionThe reaction mixture was extracted with ether
6. washThe combined organic extracts were washed with a saturated aqueous solution of sodium hydrogen sulfite
7. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
8. filtrationfiltered
9. customThe solvent was removed in vacuum
10. customthe residue was purified by column chromatography on silica gel