反应详情

1,2,3-Trifluoro-5-methylbenzene (40 mmol) was added to conc. H2SO4 (50 ml) at 0-5° C. Then the reaction mixture was slowly treated with conc. HNO3 (3.39 ml, 48.44 mmol, 90%) while maintaining the internal temperature below 20° C. The reaction mixture was stirred at room temperature for 16 h and poured onto ice (300 g) and the oily layer was extracted with CH2Cl2 (2×125 ml). The organic layer was washed with water (2×200 ml), brine (200 ml) and dried (MgSO4) and evaporated to obtain the crude product which was purified over flash silica gel chromatography to obtain the title product (6.5 g, 85%). 1H-NMR (300 MHz, CDCl3): δ 6.96 (septet, 1H), 2.39 (s, 3H). 19FNMR (CDCl3): δ −128.18, −141.50, −159.05.

1. temperaturewhile maintaining the internal temperature below 20° C
2. additionpoured onto ice (300 g)
3. extractionthe oily layer was extracted with CH2Cl2 (2×125 ml)
4. washThe organic layer was washed with water (2×200 ml), brine (200 ml)
5. dry with materialdried (MgSO4)
6. customevaporated
7. customto obtain the crude product which
8. customwas purified over flash silica gel chromatography