反应详情

331 g of Z-4,4'-Stilbene-dicarboxylic acid di-tert.-butyl ester in 1700 ml of absolute toluene are boiled under reflux for 3 hours together with 10.3 g of p-toluene sulphonic acid. The reaction mixture is then concentrated by evaporation and boiled under reflux for 4 hours with 104.2 g of NaOH, 1300 ml of H2O and 1300 ml of ethanol. The reaction mixture is filtered hot after the addition of active charcoal, diluted with about 3 l of H2O and extracted twice, in each case with 1 l of CH2Cl2. Concentrated HCl is then added to the aqueous phase. 230 g of Z-4,4'-stilbene dicarboxylic acid are obtained after suction filtration and drying.

1. concentrationThe reaction mixture is then concentrated by evaporation
2. temperatureunder reflux for 4 hours with 104.2 g of NaOH, 1300 ml of H2O and 1300 ml of ethanol
3. filtrationThe reaction mixture is filtered hot
4. additionafter the addition of active charcoal
5. additiondiluted with about 3 l of H2O
6. extractionextracted twice, in each case with 1 l of CH2Cl2
7. additionConcentrated HCl is then added to the aqueous phase