Ene reaction of 4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione with dicyclopentadiene

Abstract

© 2015 Pleiades Publishing, Ltd. The kinetics of the ene reaction of endo-dicyclopentadiene with 4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione in benzene, toluene, acetonitrile, 1,2-dichloroetane, and chloroform have been studied. The reaction volumes and enthalpies have been determined, and the activation volume in toluene has been calculated from the pressure kinetic data. The "anomalous" ratio ΔV<inf>corr</inf>^≠/ΔV<inf>r</inf> = 1.34 corresponds to a concerted cyclic transition state, though the addition product has acyclic structure.