Quinoline compound

Quinoline and isoquinoline are the two isomers of benzopyridine, both present in coal tar. They themselves and many substituted derivatives can be prepared by cyclization of a benzene derivative into a ring. The synthesis method of the ring of the quinoline compound is carried out by heating aniline and glycerin together with sulfuric acid, an oxidizing agent (nitrobenzene, etc.), that is, synthesizing into quinoline. Since glycerin is dehydrated to become acrolein, an addition reaction occurs with aniline. Therefore, a quinoline compound having a substituent on the ring can be synthesized by using various aniline derivatives and other α,β-unsaturated carbonyl compounds. For example, 4-methylquinoline (Leptidin) is prepared from aniline and methyl-vinyl ketone. The synthesis method of other quinoline compounds is a condensation method of o-aminobenzaldehyde and a ketone. For example, 2-methylquinoline (quinaldine) is prepared by condensing o-aminobenzaldehyde with acetone. The quinoline compound refers to quinoline and its homologues and is a nitrogen-containing (hetero) bicyclic aromatic hydrocarbon. Quinoline compounds are commonly referred to as heavy pyridines. Together with pyridine bases, they are collectively referred to as tar bases. They are a basic product of high temperature coal tar processing, mainly including quinoline, isoquinoline, methylquinoline and dimethylquinoline. The quinoline compounds are concentrated in the naphthalene oil fraction and the wash oil fraction of the coal tar. The content of the quinoline compound in the coal tar is about 0.3 to 0.5%. Quinoline compounds have a special odor and become darker when exposed to air or sunlight. Quinoline compounds can be used in the preparation of medicines, dyes, photographic materials, rubbers, solvents and chemical agents. Quinoline is mainly used in medicine to manufacture three major classes of drugs: nicotinic acid, 8-hydroxyquinoline and quinine. Niacin-based drugs include nicotinic acid amines, cardiotonic agents, stimulants and tsutsugamushi drugs; 8-hydroxyquinoline can be used to manufacture medicinal amoebic drugs and wound disinfectants, as well as fungicides and textile auxiliaries; Berprimin, quinine chloride and hydroxyaminoquine are synthetic malaria drugs. Isoquinolines can be used in the manufacture of insecticides, antimalarials, rubber vulcanization accelerators, and chemical agents for the determination of rare metals. Methylquinoline can be used in the manufacture of color film sensitizers and dyes, as well as solvents, impregnants, corrosion inhibitors, quinines and insecticides. The extraction process of quinoline compounds is described by heavy pyridine purification.