反应详情

温度

40 °C

A 5M solution of sodium hydroxide (6.5 mL; 32.5 mmol; 3 eq.) was added to a solution of 2-ethoxy-4-fluoro-benzoic acid ethyl ester (2.3 g; 10.8 mmol; 1 eq.) in EtOH (46 mL) and the resulting mixture was stirred at 40° C. for 18 hours then concentrated in vacuo. The residue was taken up in water and the pH made acidic with 5M HCl. The precipitate was filtered off, washed with water and dried to afford the title compound (1.8 g, 90%) as a white solid. 1H NMR (DMSO-d6) δ 12.56 (s, 1H), 7.71 (dd, J=7.0, 8.6 Hz, 1H), 7.01 (dd, J=2.4, 11.7 Hz, 1H), 6.80 (dt, J=2.4, 8.5 Hz, 1H), 4.09 (q, J=7.0 Hz, 2H), 1.32 (t, J=7.0 Hz, 3H). HPLC (max plot) 99.3%; Rt 2.71 min. UPLC/MS: (MS+) 185.2 ([M+H]+).

1. concentrationthen concentrated in vacuo
2. filtrationThe precipitate was filtered off
3. washwashed with water
4. customdried