反应详情

5-Formylsalicylic acid (3.0 g, 17 mmol), conc. sulfuric acid (1 mL) and absolute ethanol (100 mL) were heated at reflux for 3.5 days with stirring under N2. The reaction was cooled, then carefully quenched by adding saturated sodium bicarbonate (40 mL). Solvent was removed in vacuo, and the resulting mixture was acidified with 1 M HCl (50 mL), then extracted with EtOAc. The organic phase was extracted with water, then brine, and dried (MgSO4). Removal of solvent and chromatography on silica gel, eluting with 0% to 25% EtOAc in hexanes gave a colorless crystalline solid (2.3 g), mp 67°-69° C., after solvent removal. 1H-NMR(300 MHz, CDCl3): 11.49 (s, 1H), 9.90 (s, 1H), 8.40 (d, 1H, J=2 Hz), 8.00 (dd, 1H, J=8,2 Hz), 7.11 (d, 1H, J=8 Hz), 4.48 (q, 2H, J=7 Hz), 1.46 (t, 3H, J=7 Hz). IR (KBr): cm-1 3186, 1684.

1. temperatureat reflux for 3.5 days
2. temperatureThe reaction was cooled
3. customcarefully quenched
4. additionby adding saturated sodium bicarbonate (40 mL)
5. customSolvent was removed in vacuo
6. extractionextracted with EtOAc
7. extractionThe organic phase was extracted with water
8. dry with materialbrine, and dried (MgSO4)
9. customRemoval of solvent and chromatography on silica gel
10. washeluting with 0% to 25% EtOAc in hexanes