反应详情

Thionyl chloride (10 mL) was added to isonicotinic acid (370 mg, 3 mmol) and the mixture was stirred at reflux for 6 hr. Thionyl chloride was evaporated under reduced pressure and the residues was dried in vacuum to get isonicotinoyl chloride. 3-Hydroxyanthranilic acid (153 mg, 1.0 mmol) and pyridine (240 mg, 3.0 mmol) were added to toluene (10 mL) and the mixture was stirred at room temperature for 30 min. Then isonicotinoyl chloride (420 mg, 3.0 mmol) was added. The mixture was stirred at room temperature for 30 min and then at 80° C. for 2 hr. The resulting mixture was extracted with ethyl acetate (100 mL×4) and concentrated. The crude product was purified by column chromatography (silica gel, PE: ethyl acetate 20:1 to 5:1) to obtain 3-hydroxy-2-(isonicotinamido)benzoic acid as a solid (200 mg, yield 77%). LC-MS (ESI) m/z 259 [M+1]−.

1. stirringThe mixture was stirred at room temperature for 30 min
2. waitat 80° C. for 2 hr
3. extractionThe resulting mixture was extracted with ethyl acetate (100 mL×4)
4. concentrationconcentrated
5. customThe crude product was purified by column chromatography (silica gel, PE: ethyl acetate 20:1 to 5:1)