反应详情

To a mixture of nitronium tetrafluoroborate (11.6 g, 87.0 mmol) and CH2Cl2 (60.0 mL) was added 2-bromo-5-fluoro toluene (15.0 g, 10.0 mL, 79.0 mmol) over 5 minutes. After refluxing for 4.5 h, the mixture was cooled to room temperature and poured into ice water (150 mL). The mixture was extracted with CH2Cl2 (3×50 mL). The combined organic layers were washed with brine (100 mL), dried over Na2SO4, filtered and concentrated to give 18.3 g of crude product. The crude product was treated with hexane and cooled to −70° C. then the hexane was decanted away from the resulting solid to give the desired product as a semi-solid (9.77 g, 53% yield). The mother liquors were evaporated and purified by column chromatography (silica gel, 2% EtOAc in Hexane) to give 1.0 g of the desired product. 1H NMR (CDCl3) δ 8.26 (d, J=6.9 Hz, 1H), 7.20 (d, J=11.7 Hz, 1H), 2.48 (s, 3H).

1. temperatureAfter refluxing for 4.5 h
2. extractionThe mixture was extracted with CH2Cl2 (3×50 mL)
3. washThe combined organic layers were washed with brine (100 mL)
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. customto give 18.3 g of crude product
8. temperaturecooled to −70° C.
9. customthe hexane was decanted away from the resulting solid