反应详情

To a solution of trifluoroacetic anhydride (26.2 mL, 0.19 mol) in DCM (100 mL) at 0° C. was added, dropwise, hydrogen peroxide (50% in water, 12.9 mL, 0.17 mol) and the reaction mixture was stirred at 0° C. for 1.5 h. 2,4-Difluoro-3-methoxyphenylamine (3 g, 18.9 mmol) was added as a solution in DCM (20 mL) and the reaction mixture stirred at RT for 3 h. The reaction mixture was diluted with brine and extracted with DCM (3×30 mL). The combined organic fractions were washed with sat. aq. NaHCO3 solution, dried (MgSO4) and concentrated in vacuo. The resultant residue was subjected to flash chromatography (SiO2, eluting with 0-100% Et2O in cyclohexane) to give the title compound as a colourless solid (2.03 g, 57%). 1H NMR 400 MHz δ (CDCl3): 7.83-7.76 (1H, m), 7.03 (1H, td, J=9.4, 2.5 Hz), 4.08 (3H, t, J=1.1 Hz).

1. extractionextracted with DCM (3×30 mL)
2. washThe combined organic fractions were washed with sat. aq. NaHCO3 solution
3. dry with materialdried (MgSO4)
4. concentrationconcentrated in vacuo
5. washThe resultant residue was subjected to flash chromatography (SiO2, eluting with 0-100% Et2O in cyclohexane)