O-Phenylisourea Synthesis and Deprotonation: Carbodiimide Elimination Precludes the Reported Chapman Rearrangement.

The kinetics of the addition of phenol to diisopropylcarbodiimide, and reaction of the resulting N, N′-diisopropyl- O-phenylisourea with hydroxide, are reported. The isourea is generated by a slow overall termolecular equilibrium process, inhibited by isourea-phenol salt generation. In contrast to an earlier report, reaction of the isourea with hydroxide does not induce a synthetically useful 1,3-O-N (Chapman) rearrangement. Instead, deprotonation results in solvolysis by carbodiimide elimination. [ABSTRACT FROM AUTHOR]