Any of a large class of compounds characterized by a five-membered ring which contains an atom of nitrogen and at least one other noncarbon atom (nitrogen, oxygen, sulphur). The prefixes
furo-,
thio, and
pyrro- are used to distinguish three subclasses of azoles, which may be regarded as derived respectively from furfuran, thiophene, and pyrrol by replacement of the
CH group by nitrogen;
as, furo-monazole. Names exactly analogous to those for the azines are also used;
as, oxazole, diazole, etc.(Org. Chem.)