反应详情

The product of Example 1, i.e., 1-ethoxymethyl-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride (8 mmol) was, without purification, dissolved in methanol (10 ml). To this solution, solid sodium methoxide (0.86 g, 16 mmol) was added at 0° C. The resulting deep orange solution was stirred for 18 h at room temperature, after which the solvent was evaporated in vacuo. After drying for 1 h at 77° C. under reduced pressure, the solid was dissolved in water and heated under reflux for 5 h followed by treatment with charcoal (stirring for 30 min at reflux). Filtration and evaporation under reduced pressure yielded 3-(ethoxymethyl)phthalic acid disodium salt (37%).

1. customafter which the solvent was evaporated in vacuo
2. customAfter drying for 1 h at 77° C. under reduced pressure
3. dissolutionthe solid was dissolved in water
4. temperatureheated
5. temperatureunder reflux for 5 h
6. customfollowed by treatment with charcoal (stirring for 30 min at reflux)
7. filtrationFiltration and evaporation under reduced pressure