反应详情

A solution of [2-(4-bromo-2-fluoro-benzylcarbamoyl)-4-nitro- phenoxy]-acetic acid tert-butyl ester in dichloromethane (11mL, 0.2 M) was treated with trifluoroacetic acid (3.0 mL, 4.44 g. 39.0 mmol) and stirred for 24 h. The reaction was diluted with H2O and extracted with ethyl acetate (3×). The combined organic extracts were washed with H2O (2×), saturated aq NaCl, dried over MGSO4, filtered and concentrated to a crude solid that was recrystallized from heptane and ethyl acetate to give [2-(4-bromo-2-fluoro-benzylcarbamoyl)-4-nitro-phenoxy]-acetic acid as a white crystalline solid (0.98 g, 92%); Rf 0.10 (10% ethyl acetate in dichloromethane); 1H NMR (DMSO-d6, 300 MHz) δ 9.14 (br t, J=6.0 Hz, 1H), 8.58 (d, J=3.3 Hz, 1H), 8.34 (dd, J1=9.0 Hz, J2=3.0 Hz, 1H), 7.52 (br dd, J1=9.3 Hz, J2=3.0 Hz, 1H), 7.43-7.32 ( m, 3H), 5.02 (s, 2H), 4.52 (d, J=6.0 Hz, 2H). ESI-LC/MS m/z calcd for C16H12BrFN2O6: 426.0 found 427.0 (M+1)+. Anal. calcd for C16H12BrFN2O6: C, 25 44.99; H, 2.83; N, 6.56. Found C, 44.97; H, 2.83; N, 6.47.

1. extractionextracted with ethyl acetate (3×)
2. washThe combined organic extracts were washed with H2O (2×), saturated aq NaCl
3. customdried over MGSO4
4. filtrationfiltered
5. concentrationconcentrated to a crude solid that
6. customwas recrystallized from heptane and ethyl acetate