反应详情

To a solution of tert-butyl (3-bromo-2-fluorophenyl)carbamate (7.23 g, 24.9 mmol) in EtOAc (125 mL) was added 4 M HCl/EtOAc (62 mL) at 0° C. The mixture was stirred at room temperature for 12 h and concentrated in vacuo. The residue was diluted with 6 M HCl aqueous solution (62 mL). To the suspension was added a solution of NaNO2 (2.06 g, 29.9 mmol) in water (5 mL) at 0° C. To a suspension of methyl 4-methoxy-3-oxobutanoate (3.22 mL, 24.9 mmol) and NaOAc (92.9 g) in EtOH (84 mL) was added the above mixture at 0° C. The mixture was stirred at 0° C. for 20 min. The precipitates were collected by filtration, diluted with EtOAc, washed with NaHCO3 aqueous solution, dried over MgSO4, filtered and concentrated in vacuo to yield the title compound (5.36 g, 62% yield) as a brown solid: 1H NMR (DMSO-d6, 300 MHz): δ ppm 3.30 (3H, s), 3.75-3.94 (3H, m), 4.56-4.71 (2H, m), 7.15-7.34 (1H, m), 7.37-7.59 (1H, m), 7.63-7.80 (1H, m), 12.26 (1H, s).

1. concentrationconcentrated in vacuo
2. additionThe residue was diluted with 6 M HCl aqueous solution (62 mL)
3. additionwas added the above mixture at 0° C
4. stirringThe mixture was stirred at 0° C. for 20 min
5. filtrationThe precipitates were collected by filtration
6. additiondiluted with EtOAc
7. washwashed with NaHCO3 aqueous solution
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated in vacuo