Three-Component, One-Pot Sequential Synthesis of 1,3-Disubstituted 5-Arylhydantoins
Francesca Olimpieri, Alessandro Volonterio*, Matteo Zanda
*Dipartimento di Chimica, Materiali e Ingegneria Chimica ‘Giulio Natta', Politecnico di Milano, Via Mancinelli 7, 20131 Milano, Italy, Email: alessandro.volonteriopolimi.it
F. Olimpieri, A. Volonterio, M. Zanda, Synlett, 2008, 3016-3020.
Reaction of carbodiimides with α-Br(Cl)-aryl acetic acids produces N,N′-substituted 5-arylhydantoins under very mild conditions and high yields. When the carbodiimides are generated in situ by Staudinger reaction, the process becomes a one-pot, three-component sequential synthesis of libraries of differently substituted 5-arylhydantoins.
Some carbodiimides afford a mixture of hydantoin and N-acyl urea. However, in situ addition of a 2 M aqueous NaOH solution promotes the cyclization of the N-acyl urea under Schotten-Baumann conditions.
proposed reaction pathway
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