反应详情

4-(4-(3-(4-chloro-3-(trifluoromethyl)phenyl)ureido)-3-fluorophenoxy)picolinic acid (1 g, 2.13 mmol) was suspended in methanol (20 mL). Concentrated sulfuric acid (5 mL) was added at room temperature. The resulted mixture was refluxed for 3 h. The solvent was removed under reduced pressure, and the residue was purified by column chromatography (dichloromethane: methanol=10:1) to give methyl 4-(4-(3-(4-chloro-3-(trifluoromethyl)phenyl)ureido)-3-fluorophenoxy)picolinate B8 (0.83 g, purity 97%, yield 80%) as a white solid.

1. temperatureThe resulted mixture was refluxed for 3 h
2. customThe solvent was removed under reduced pressure
3. customthe residue was purified by column chromatography (dichloromethane: methanol=10:1)