反应详情

A mixture of 26.4 g of glyoxylic acid propyl ester propyl hemiacetal (0.15 mol), 30.0 g of urea (0.5 mol), 600 g of propanol and 7.5 g of 8% strength propanolic sulfuric acid was heated under reflux for 4 hours. Thereafter, the reaction had ended and the reaction mixture was cooled to room temperature, whereupon a colorless precipitate separated out, which was filtered off, washed with methanol and dried in vacuo at 50° C. 13.6 g, that is to say 42% of theory, of crystalline allantoin acid propyl ester were obtained by this reaction.

1. temperaturewas heated
2. temperatureunder reflux for 4 hours
3. customseparated out
4. filtrationwhich was filtered off
5. washwashed with methanol
6. customdried in vacuo at 50° C