Mononuclear heterocyclic rearrangements. Part 10. Kinetic study of the amine-catalysed rearrangement of the Z-p-nitrophenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole into 4-benzoylamino-2-p-nitrophenyl-5-phenyl-1,2,3-triazole in benzene

Abstract

The kinetics of the title reaction have been measured in the presence of primary, secondary, and tertiary amines and of primary diamines. The following relationships have been observed: k_A=k_IV[B]³ with primary amines and with 1,6-diaminohexane, k_A=k_III[B]² with secondary cyclic amines and the other primary diamines, and k_A=k_II[B] with diazabicyclo[2.2.2]octane (DABCO). The reaction has also been studied in the presence of pairs of amines [butylamine (piperidine) and triethylamine (DABCO)], in which case ‘mixed’ terms such as k′_IV[BuA][DABCO]² and k′_III[PIP][DABCO] also occur. On the basis of the results the kinetic laws observed have been ascribed to catalysis of catalysis which depends on the nature and the structure of the amine used.