反应详情

To a solution of 4-chloro-3-(trifluoromethyl)benzoic acid (200 g, 891 mmol) in MeOH (600 mL, 14.8 mol), sulfuric acid (27 mL, 445 mmol) was added. The mixture was stirred at reflux for 6 h, allowed to cool and the solvent evaporated under reduce pressure. The resulting liquid residue (−250 mL) was poured onto ice water whereby a white suspension formed. The solid was filtered and washed with 0.05 N NaOH (3×200 mL) followed by H2O (3×200 mL). The solid was dried under vacuum for 16 h followed by 4 h at 40° C. to give the title compound as an off-white solid (197.0 g). 1H NMR (400 MHz, CDCl3) δ ppm, 3.98 (s, 3H), 7.62 (d, J=8.4 Hz, 1H), 8.16 (dd, J=8.8 Hz, 2.0 Hz, 1H), 8.39 (d, J=2.0 Hz, 1H).

1. temperatureat reflux for 6 h
2. temperatureto cool
3. customthe solvent evaporated
4. additionThe resulting liquid residue (−250 mL) was poured onto ice water whereby a white suspension
5. customformed
6. filtrationThe solid was filtered
7. washwashed with 0.05 N NaOH (3×200 mL)
8. customThe solid was dried under vacuum for 16 h