The biological functions of heterocyclic amines vary, including vitamins and carcinogens. Monomer scope for cationic polymerization is limited to two main types&colon; alkene and heterocyclic monomers. Carbazole is an aromatic heterocyclic organic compound. Benzimidazole is a heterocyclic aromatic organic compound. Isoquinoline is a heterocyclic aromatic organic compound. Isoindole in heterocyclic chemistry is a benzo-fused pyrrole. Ring opening in the indole heterocyclic ring could generate new amine and keto functions. This aromatic diamine is an important precursor to many heterocyclic compounds. Indole is an aromatic heterocyclic organic compound with formula CHN. Pyrrole is another compound made up of molecules with a five-membered heterocyclic ring. Cooking proteins at high temperature can lead to the formation of heterocyclic amines (HCAs). It is one of the methyl derivative of a heterocyclic compound quinoline. These compounds are important in the synthesis of heterocyclic compounds. The reactivity of heterocyclic monomers depends on their ring strain. Pyrones or pyranones are a class of heterocyclic chemical compounds.