Anthony R. Butler and Elizabeth Leitch
J. Chem. Soc., Perkin Trans. 2, 1977, 1972-1976
DOI:
10.1039/P29770001972,
Paper
Urea and N-methylurea react with benzil and substituted benzils in alkaline conditions to form 5,5-diphenylhydantoins, or the appropriately substituted compounds. The mechanism of reaction is rate-determining attack by the urea anion on benzil, rapid cyclisation, and slow rearrangement. The mechanism was deduced from a kinetic study, With NN′-dimethylurea the product is a diol.
