反应详情

To a solution of 3-bromo-2-fluoro-6-methyl-5-nitrobenzoic acid (2.41 g, 8.67 mmol) in N,N-Dimethylformamide (25 ml) at room temperature and under nitrogen was added K2CO3 (2.4 g, 17.34 mmol) followed by iodomethane (0.7 ml, 11.27 mmol). The reaction mixture was stirred at room temperature for 2 hours before being diluted with deionized water (100 ml) and extracted with EtOAc (3×50 ml). The combined organic phases were washed with saturated NaHCO3(aq) (50 ml) and then dried over MgSO4, filtered and concentrated under reduced pressure. The residue was purified twice by FCC (50 g silica, Isolute cartridge, gradient of eluents; 98:2 Heptane:EtOAc to 9:1 Heptane:EtOAc) to give 2.43 g (89%) of methyl 3-bromo-2-fluoro-6-methyl-5-nitrobenzoate as a white solid. LC-MS 99%, 2.18 min (3 minute LC-MS method), m/z=no ionization, 1H NMR (500 MHz, Chloroform-d) δ ppm 8.22 (d, J=6.2 Hz, 1H), 4.00 (s, 3H), 2.48 (s, 3H).

1. extractionextracted with EtOAc (3×50 ml)
2. washThe combined organic phases were washed with saturated NaHCO3(aq) (50 ml)
3. dry with materialdried over MgSO4
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified twice by FCC (50 g silica, Isolute cartridge, gradient of eluents; 98:2 Heptane:EtOAc to 9:1 Heptane:EtOAc)