An azole is a class of five-membered nitrogen heterocyclic ring compounds containing at least one other noncarbon atom, nitrogen, sulfur or oxygen. The parent compounds are aromatic and have two double bonds; there are successively reduced analogs (azolines and azolidines) with less.

Meet the azoles:

• 1 nitrogen
  • pyrrole
• 2 or more nitrogen atoms
  • pyrazole
  • imidazole, included in histidine
  • triazole, included in Ribavirin
  • tetrazole
• 1 nitrogen atom and 1 oxygen atom
  • oxazole
  • isoxazole
• 1 nitrogen atom and 1 sulfur atom
  • thiazole
  • isothiazole

A "dioxole" is a similar compound with two oxygen atoms in a five membered ring. Dioxolane is a derivative of dioxole.

Azoles