p-Toluenesulfonic acid → 4,4'-cis-Stilbenedicarboxylic acid

Participants

Reaction Steps

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.

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