4-hydroxyquinoline

4-Hydroxyquinoline is an organic compound with the formula C₉H₇NO. It is a derivative of quinoline, featuring a hydroxyl group at the 4-position. This compound is of interest due to its role as a building block in the synthesis of various pharmaceuticals and its biological activity.

Structure and Properties

4-Hydroxyquinoline is a heterocyclic aromatic compound. The presence of the hydroxyl group at the 4-position of the quinoline ring system influences its chemical properties, making it more reactive than quinoline itself. The compound exhibits tautomerism, existing in equilibrium with its keto form, 4-oxo-1,2-dihydroquinoline.

Physical Properties

• Molecular Weight: 145.16 g/mol
• Appearance: White to pale yellow crystalline solid
• Melting Point: 220-225 °C
• Solubility: Slightly soluble in water, soluble in organic solvents such as ethanol and acetone.

Synthesis

4-Hydroxyquinoline can be synthesized through several methods, including the Skraup synthesis, which involves the cyclization of aniline derivatives with glycerol in the presence of an acid catalyst. Another method involves the oxidation of 4-aminoquinoline.

Applications

4-Hydroxyquinoline is used as an intermediate in the synthesis of various pharmaceuticals, including antimalarial and antibacterial agents. It is also used in the preparation of chelating agents and dyes.

Biological Activity

4-Hydroxyquinoline and its derivatives exhibit a range of biological activities. They have been studied for their potential as antimicrobial agents, particularly against bacterial and fungal infections. The compound's ability to chelate metal ions is also of interest in the development of antimalarial drugs.

Safety and Handling

4-Hydroxyquinoline should be handled with care, as it can be irritating to the skin and eyes. Appropriate personal protective equipment, such as gloves and goggles, should be used when handling the compound.

Also see

• Quinoline
• Antimalarial drugs
• Chelating agents
• Heterocyclic compounds