Decomposition Reactions of a Cis-Diacyl Diimide. 4-Phenyl-1,2,4-triazoline-3,5-dione

Article abstract of DOI:10.1021/jo00223a032

The cis-diacyl diimide 4-phenyl-1,2,4-triazoline-3,5-dione (1) was decomposed in a variety of solvent systems.In nonnucleophilic solvents under 80 deg C 1 underwent nitrogen evolution and was converted to 2,6-diphenyltriazolo<1,2-a>-s-triazole-1,3,5,7-tetrone (2).At higher temperatures 1 gave phenyl isocyanate (3).In nucleophilic solvent systems (acetic acid, alcohols, or water) 1 underwent loss of nitrogen and formed mixtures containing varying amounts of 2, 1-(N-phenylcarbamoyl)-4-phenylurazole (5), 4-phenylurazole (11), diphenylurea (12), N-phenylcarbamtes (13), and 1-(alkoxycarbonyl)-4-phenylurazoles (14), depending on the decomposition conditions employed.The mechanistic pathways leading to the various products are discussed.