反应详情

A mixture of 2,3-dihydroxybenzoic acid (3.8 g, 24.6 mmol) in methanol (300 ml) was treated dropwise with conc. Sulfuric acid (4.2 g) and the resultant solution was heated at reflux temperature overnight. Upon cooling the solvent was evaporated and the residue poured into ice-water. The mixture was extracted with dichloromethane (3×50 ml) and the combined organic fractions dried (Na2SO4) and concentrated to yield a pale tan solid (4.05 g).

1. temperatureat reflux temperature overnight
2. temperatureUpon cooling the solvent
3. customwas evaporated
4. additionthe residue poured into ice-water
5. extractionThe mixture was extracted with dichloromethane (3×50 ml)
6. dry with materialthe combined organic fractions dried (Na2SO4)
7. concentrationconcentrated