反应详情

A mixture of cis-1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid anhydride (70.0 g), 99.5% ethanol (16.6 g) and benzene (1000 ml) was heated under reflux for 2 hours. The reaction mixture (about 600 ml) was concentrated under ordinary pressure. The residue was stirred overnight with n-hexane (200 ml). Crystals produced were filtered and dried under reduced pressure to yield racemic cis-1,3-dibenzyl-5-ethoxycarbonyl-2-oxoimidazolidine-4-carboxylic acid (76.2 g), which were recrystallized from toluene. M.P. 110°-111° C.

1. temperaturewas heated
2. temperatureunder reflux for 2 hours
3. concentrationThe reaction mixture (about 600 ml) was concentrated under ordinary pressure
4. customCrystals produced
5. filtrationwere filtered
6. customdried under reduced pressure