反应详情

温度

80 °C

A mixture of 7-methoxynaphthalene-2-sulfonic acid, sodium salt (8.12 g, 31.1 mmol) in 80 mL of thionyl chloride is heated at 80° C. for 3 hours. A few drops of DMF is added with vigorous bubbling resulting and the mixture is heated for an additional 1.5 hours. The mixture is allowed to cool to room temperature and concentrated in vacuo. The residue is diluted in EtOAc and washed successively with water (2×), 1 N HCl solution and saturated NaCl. The organic layer is dried over anhydrous MgSO4, filtered and concentrated. The crude product is purified by column chromatography eluting with 20% EtOAc/hexanes to afford the title compound (5.2 g, 20.2 mmol) as a white solid.

1. customwith vigorous bubbling
2. customresulting
3. temperaturethe mixture is heated for an additional 1.5 hours
4. temperatureto cool to room temperature
5. concentrationconcentrated in vacuo
6. additionThe residue is diluted in EtOAc
7. washwashed successively with water (2×), 1 N HCl solution and saturated NaCl
8. dry with materialThe organic layer is dried over anhydrous MgSO4
9. filtrationfiltered
10. concentrationconcentrated
11. customThe crude product is purified by column chromatography
12. washeluting with 20% EtOAc/hexanes