反应详情

4-Bromo-2-methylphenyl methyl carbonate (4.0 g, 16.32 mmol) was added portion-wise to H2SO4 (12.0 mL) to generate a homogeneous solution. This solution was then cooled to 0° C. internal temperature and KNO3 (2.0 g, 19.6 mmol) was added portion-wise maintaining the internal temperature below 5° C. The reaction was stirred for 2 h and then poured over ice. The aqueous layer was extracted with dichloromethane, washed with saturated NaHCO3 and water, dried over Na2SO4, and concentrated. Purification by silica gel chromatography (0-5% ethyl acetate/hexanes) provided 4-bromo-2-methyl-5-nitrophenyl methyl carbonate (3.4 g, 71% yield). 1H NMR (400.0 MHz, DMSO-d6) δ 8.11 (s, 1H), 7.95 (s, 1H), 3.88 (s, 3H), 2.25 (s, 3H).

1. additionwas added portion-wise
2. temperaturemaintaining the internal temperature below 5° C
3. additionpoured over ice
4. extractionThe aqueous layer was extracted with dichloromethane
5. washwashed with saturated NaHCO3 and water
6. dry with materialdried over Na2SO4
7. concentrationconcentrated
8. customPurification by silica gel chromatography (0-5% ethyl acetate/hexanes)