Oxadiazole

Oxadiazole is a heterocyclic aromatic chemical compound with the molecular formula C₂H₂N₂O. There are four isomers of oxadiazole:

• 

  1,2,3-oxadiazole

• 

  1,2,4-oxadiazole

• 

  1,2,5-oxadiazole
  (furazan)

• 

  1,3,4-oxadiazole

1,2,4-Oxadiazole, 1,2,5-oxadiazole, and 1,3,4-oxadiazole are known, but the 1,2,3-isomer is unstable and reverts to the diazoketone tautomer.^[1] The stable oxadiazoles appear in a variety of pharmaceutical drugs including raltegravir, butalamine, fasiplon, oxolamine, and pleconaril.

References

1. Heterocyclic Chemistry, 3rd Edition, J. A. Joule, K. Mills, and G.F. Smith, page 452