Quinoline

Quinoline is a heterocyclic aromatic organic compound with the chemical formula C₉H₇N. It is a colorless hygroscopic liquid with a strong odor. Aged samples, if exposed to light, become yellow and later brown. Quinoline is only slightly soluble in cold water but dissolves readily in hot water and most organic solvents. Quinoline itself has few application, but many of its derivatives are useful in diverse applications. A prominent example is quinine, which is found naturally in plants as alkaloids. 4-Hydroxy-2-alkylquinolines (HAQs) are involved in antibiotic resistance.