A Convenient Synthesis of New Substituted 1,2,4-Triazolo[4,3-c]Pyrimidines by Oxidative Cyclisation using 1,3-Dibromo-5,5-Dimethyl Hydantoin as Oxidant

A series of new 1,2,4-triazolo[4,3-c]pyrimidines 3(a-h) have been synthesized by oxidative intramolecular cyclisation of heterocyclic hydrazones using 0.51 eq of 1,3-dibromo-5,5-dimethyl hydantoin as oxidant in chloroform with good yield. The purity of novel compounds was confirmed by elemental analyses. The chemical structures of the synthesized compounds were confirmed by FT-IR, 1H NMR and mass spectral studies. The reaction is extremely fast and the reagent utilizes a commercially inexpensive and easily handled oxidant.