Aromatic heterocyclics - production and uses

The industrial chemistry of the heterocyclic aromatics is extraordinarily diverse. A large number of mono- and polynuclear heterocyclics (vide infra) is present in coal tar and can be recovered from this source. Synthetic means of production, principally from petroleum-derived feedstocks have been added to the coal-derived raw materials since the fifties. 

In addition to heterocyclics with one hetero-atom, aromatic compounds with several hetero-atoms are also commercially important. They are generally not produced by recovery from crude aromatic mixtures, but by synthesis from smaller building blocks. These heterocyclic compounds are used in substituted form predominantly as pesticides, dyes and pharmaceuticals. 

---