反应详情

A solution of 3-bromo-4-methylaniline (5.00 g, 26.9 mmol), N-iodosuccinimide (4.53 g, 20.2 mmol) and bis(pyridine)iodonium tetrafluoroborate (2.70 g, 7.26 mmol) in DCM (100 mL) was stirred at room temperature overnight. The mixture was diluted with DCM, washed sequentially with saturated aqueous NaHSO3 and water, and dried and concentrated. The residue was purified by column chromatography on silica gel, eluting with EtOAc-hexanes (sequentially 1%, 2% and 3%), to provide 5-bromo-2-iodo-4-methylaniline as a yellow solid (5.27 g, 63% yield). Mass spectrum m/z 312, 314 (M+H)+. 1H NMR (500 MHz, CDCl3) δ 7.49 (d, J=0.6 Hz, 1H), 6.94 (s, 1H), 4.17-3.91 (br.s, 2H), and 2.25 (s, 3H).

1. washwashed sequentially with saturated aqueous NaHSO3 and water
2. customdried
3. concentrationconcentrated
4. customThe residue was purified by column chromatography on silica gel
5. washeluting with EtOAc-hexanes (sequentially 1%, 2% and 3%),