Rapid generation of N,NÃÂ-diacylhydrazines by I2 or Br2/hydrazine hydrate: A facile route to 1,3,4-oxadiazoles

We report the rapid preparation of symmetrical aldazines, ketazines and N,N’-Diacylhydrazines byNH2NH2 .H2O in presence ofmolecular iodine or bromine at 0–10oC. This method afforded an exceedingly convenient route to the preparation of 1,3,4-Oxadiazoles. The reactions are safe, affording excellent yields of high purity products in shorter durations and the workup procedure involves no solvent extraction, which is environmentally acceptable.