反应详情

温度

0 °C

A solution of NaNO2 (7.9 g, 115 mmol) in H2O (20 mL) was added dropwise at 0° C. to a mixture of 4-bromo-2,5-difluoroaniline (20 g, 96 mmol) and 6 M HCl aqueous solution (96 mL, 576 mmol). After stirring for 15 min, the resulting aqueous solution was added to a suspension of methyl 4-methoxyacetoacetate (12.4 mL, 96 mmol) and NaOAc (34 g, 576 mmol) in MeOH (165 mL) pre-cooled at 0° C. The precipitate was collected by filtration, washed with water, and dried at room temperature to give the title compound (37 g, 100% yield) as a red solid: 1H NMR (300 MHz, DMSO-d6): δ ppm 3.34 (3H, s), 3.83 (3H, s), 4.68 (2H, s), 7.70 (1H, dd, J=9.7, 7.0 Hz), 7.89 (1H, dd, J=10.6, 6.1 Hz), 12.16 (1H, s).

1. filtrationThe precipitate was collected by filtration
2. washwashed with water
3. customdried at room temperature