反应详情

温度

0 °C

A solution of NaNO2 (2.07 g, 30 mmol) in H2O (5 mL) was added dropwise at 0° C. to a mixture of 4-(benzyloxy)-2-fluoroaniline (5.43 g, 25 mmol) and 6 M HCl aqueous solution (25 mL, 150 mmol). After stirring for 15 min, the resulting aqueous solution was added to a suspension of methyl 4-methoxyacetoacetate (3.24 mL, 24 mmol) and NaOAc (12.3 g, 150 mmol) in MeOH (50 mL) pre-cooled at 0° C. The reaction mixture was poured into water and extracted with AcOEt. The extract was washed with brine, dried over MgSO4, and concentrated under reduced pressure. The residue was recrystallized from hexane/AcOEt to give the title compound (8.48 g, 91% yield) as a yellow solid: 1H NMR (300 MHz, CDCl3): δ ppm 3.500 (3H×0.46, s), 3.502 (3H×0.54, s), 3.88 (3H×0.54, s), 3.92 (3H×0.46, s), 4.65 (2H×0.46, s), 4.68 (2H×0.54, s), 5.06 (2H×0.54, s), 5.07 (2H×0.46, s), 6.75-6.86 (2H, m), 7.32-7.44 (5H, m), 7.53 (1H×0.46, t, J=9.0 Hz), 7.76 (1H×0.54, t, J=9.0 Hz), 13.12 (1H×0.46, brs), 15.13 (1H×0.54, brs).

1. extractionextracted with AcOEt
2. washThe extract was washed with brine
3. dry with materialdried over MgSO4
4. concentrationconcentrated under reduced pressure
5. customThe residue was recrystallized from hexane/AcOEt