Table of Contents
What is Quinoline?
Quinoline is a heterocyclic organic compound with the chemical formula C9H7N. It is a colorless liquid that is soluble in organic solvents. Quinoline is used in the manufacture of dyes, pharmaceuticals, and other organic compounds.
Structure of Quinoline
The quinoline molecule is composed of a benzene ring fused to a pyrazole ring. There are two nitrogen atoms located at the R3 and R4 positions on the pyrazole ring, which are responsible for the pharmacological properties of quinoline derivatives.
Preparation Methods of Quinoline
There are various preparation methods of quinoline, which include the following:
1) Reaction of aniline with nitrous acid: In this method, aniline is reacted with nitrous acid to form quinoline. The reaction mixture is then heated to reflux to promote the formation of the quinoline product.
2) Reaction of aniline with paraformaldehyde: In this method, aniline is reacted with paraformaldehyde to form quinoline. The reaction mixture is then heated to reflux to promote the formation of the quinoline product.
3) Reaction of aniline with nitric acid: In this method, aniline is reacted with nitric acid to form quinoline. The reaction mixture is then heated to reflux to promote the formation of the quinoline product.
4) Reaction of aniline with hydrogen chloride: In this method, aniline is reacted with hydrogen chloride to form quinoline. The reaction mixture is then heated to reflux to promote the formation of the quinoline product.
Properties of Quinoline
Quinoline is a heterocyclic aromatic organic compound with the molecular formula C9H7N. It is a colorless liquid with a slightly bitter taste. Quinoline is soluble in water and ethanol, and is slightly flammable.
Two Important derivatives of Quinoline
1) Quinine
2) Quinidine
SAR of Quinolines
The following table provides a summary of the SARs of quinoline derivatives.
SAR of Quinoline Derivatives
Compound
SAR
1-methylquinoline
High affinity for histamine H1 receptors; moderate affinity for serotonin 5-HT2 receptors
2-methylquinoline
Low affinity for histamine H1 receptors; no affinity for serotonin 5-HT2 receptors
3-methylquinoline
High affinity for histamine H1 receptors; moderate affinity for serotonin 5-HT2 receptors
4-methylquinoline
High affinity for histamine H1 receptors; high affinity for serotonin 5-HT2 receptors
5-methylquinoline
High affinity for histamine H1 receptors; high affinity for serotonin 5-HT2 receptors
Quinoline Uses
Quinoline is used as a precursor to other chemicals. It is also used as an antioxidant and a corrosion inhibitor.
