Quinolin

Quinoline is a heterocyclic aromatic organic compound with the chemical formula C₉H₇N. It is a colorless hygroscopic liquid with a strong odor. Quinoline is a benzene and pyridine fused ring compound, with the benzene ring fused to the pyridine at two adjacent carbon atoms.

History

Quinoline was first extracted from coal tar in 1834 by the German chemist Friedlieb Ferdinand Runge. It was later synthesized by Charles Adolphe Wurtz in 1842.

Structure and Properties

Quinoline is a planar molecule with a fused ring structure. The nitrogen atom in the pyridine ring contributes to the basicity of the compound. Quinoline has a boiling point of 238°C and a melting point of -15°C. It is slightly soluble in water but highly soluble in organic solvents such as ethanol and ether.

Synthesis

Quinoline can be synthesized through several methods, including the Skraup synthesis, the Doebner-Miller reaction, and the Friedländer synthesis. The Skraup synthesis is the most commonly used method and involves the reaction of aniline, glycerol, and sulfuric acid in the presence of an oxidizing agent.

Applications

Quinoline and its derivatives are used in the production of dyes, antiseptics, and pharmaceuticals. They are also used as intermediates in the synthesis of other chemicals. Quinoline derivatives have been studied for their potential use as antimalarial and antibacterial agents.

Toxicity and Safety

Quinoline is toxic and can cause skin and eye irritation. Prolonged exposure can lead to liver damage and other health issues. It is important to handle quinoline with care and use appropriate safety measures, such as wearing protective clothing and working in a well-ventilated area.

Related Compounds

• Isoquinoline
• Quinoxaline
• Quinazoline
• Cinchona alkaloids

See Also

• Heterocyclic compound
• Aromaticity
• Coal tar