反应详情

温度

65 °C

Concentrated sulfuric acid (36N, 50 mL) is added dropwise at room temperature to a stirred suspension of 3-hydroxy-6-methoxyquinoline-4-carboxylic acid (14.5 g, 66.15 mmol, 1.0 eq) in methanol (250 mL) and the resulting mixture is heated at 65° C. for 36 hours. Solvent is then evaporated and the residue is quenched with the dropwise addition at 0° C. of saturated sodium hydrogen carbonate aqueous solution. The resulting precipitate is collected by filtration and dried under vacuum to afford 3-hydroxy-6-methoxyquinoline-4-carboxylic acid methyl ester as an off-white powder (15.0 g, 97% yield).

1. customSolvent is then evaporated
2. customthe residue is quenched with the dropwise addition at 0° C. of saturated sodium hydrogen carbonate aqueous solution
3. filtrationThe resulting precipitate is collected by filtration
4. customdried under vacuum