Addition of 4- Phenyltriazolinedione toCarbonyl Compounds: The Formation of alpha-Urazolylcarbonyl Compounds
Journal of Organic Chemistry
N-Phenyltriazolinedione (PTAD) adds to a variety of carbonyl compounds to form -urazolylcarbonyl compounds. With highly enolized carbonyl systems, this type of substitution reaction can occur rapidly even in the absence of a catalyst. However, with simple carbonyl systems, the reaction is greatly accelerated by an acid catalyst such as trifluoroacetic acid. Unsymmetrical ketones afford isomeric ��- and ��'-urazolyl ketones, and the initially formed monourazoles can be further urazolated to the diurazoles through the application of more than 1 equiv of PTAD.
R. M. Wilson, A. C. Hengge, A. Ataei, N. Chantarasiri. “Addition of 4- Phenyltriazolinedione to Carbonyl Compounds: The Formation of alpha-Urazolylcarbonyl Compounds.” J. Org. Chem., 1990, 55, 193-197.