Heterocyclic compound
= Heterocyclic compound
= Heterocycle
{synonym}
A <heterocyclic compound> contains a ring with at least one atom other than carbon. Nitrogen, oxygen, and sulfur are common heteroatoms.
For example, <pyrrolidine> has a saturated nitrogen-containing ring, while pyridine is aromatic. Having a heteroatom does not by itself imply aromaticity; ring conjugation and electron occupancy determine that separate property.