Heteroaromatic compounds

Aromatic heterocycles are a class of organic molecules that form ring structures incorporating at least one non-carbon atom. They possess aromatic characteristics, which arise from the presence of a heteroatom – such as nitrogen, oxygen, or sulfur – within a planar, conjugated π system.

Common Heteroaromatic Compounds

Compound	Structure Type	Heteroatom(s)	Notes
Pyrrole	Five-membered ring	Nitrogen	Found in porphyrins (e.g., heme group in hemoglobin)
Thiazole	Five-membered ring	Sulfur, Nitrogen	Found in vitamin B1 (thiamine)
Isoquinoline	Fused ring system	Nitrogen	Found in alkaloids and synthetic drugs
Indole	Fused ring system	Nitrogen	Found in tryptophan and serotonin