A class of heterocyclic compounds that include a two-ring fused structure. Both aromatic and non-aromatic ring structures are included in this category.
Also Known As:
Heterocyclic Compounds, 2-Ring; Fused Heterocyclic Compounds, Two-Ring; Two Ring Heterocyclic Compounds; Fused Heterocyclic Compounds, Two Ring; Heterocyclic Compounds, 2 Ring