Aromatic organic compound with the chemical formula C9H7N is quinoline, which belongs to the class of heterocyclic compounds. This strong-smelling liquid is colorless and hygroscopic.

A weak tertiary base, quinoline or benzo[b]pyridine, is a heterocyclic aromatic compound that contains nitrogen. It can form salts with acids and undergoes electrophilic substitution reactions, as well as reactions similar to those of pyridine and benzene.

Quinoline, a tertiary amine base, has chemical properties that allow it to form acid salts and participate in both electrophilic and nucleophilic substitution reactions.

Quinoline finds application in the production of dyes, the synthesis of hydroxyquinoline sulfate and niacin, as well as functioning as a solvent for resins and terpenes.

Quinoline-based drugs are commonly used to treat malaria. Alkaloids such as quinine, which is derived from quinoline and found naturally in plants, are also effective in combating the disease.