反应详情

[4-Amino-2-(4-bromo-2-fluoro-benzylcarbamoyl)-phenoxy] acetic acid (0.62g, 1.56 mmol) was dissolved in allyl alcohol (15 mL, 0.1 M). This solution was treated with 7 drops of concentrated H2SO4 and stirred at room temperature for 48 h. The reaction was concentrated, redissolved in ethyl acetate, washed with H2SO, saturated aq NaCl (3×), dried over Na2SO4 and filtered. The filtrate was treated with decolorizing charcoal, boiled for 10 minutes, cooled to room temperature, filtered and concentrated. The crude solid was recrystallized from heptane and ethyl acetate to give [4-amino-2-(4-bromo-2-fluoro-benzylcarbamoyl)-phenoxy]-acetic acid allyl ester as a light orange solid (0.13 g, 20%). 1H NMR (DMSO-d6, 300 MHz) δ 8.92 (br t, J=5.4 Hz, 1H), 7.49-7.80 (m, 4H); 6.84 (d, J=8.7 Hz, 1 H), 6.63 (br dd, J1=8.7 Hz, J2=2.7 Hz, 1H), 5.95-5.79 (m, 1H), 5.29 (br d, J=17.1 Hz, 1H), 5.19 (br d, J=10.5 Hz, 1 H), 4.91 (br s, 1H), 4.83 (br s, 2H), 4.61 (br d, J=5.4 Hz, 1 H).

1. concentrationThe reaction was concentrated
2. dissolutionredissolved in ethyl acetate
3. washwashed with H2SO, saturated aq NaCl (3×)
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. additionThe filtrate was treated with decolorizing charcoal
7. waitboiled for 10 minutes
8. temperaturecooled to room temperature
9. filtrationfiltered
10. concentrationconcentrated
11. customThe crude solid was recrystallized from heptane and ethyl acetate