Cas Number


Other Names



The formula



Pyridine is a basic heterocyclic organic compound. It is structurally related to benzene, with one methine group (=CH−) replaced by a nitrogen atom. The pyridine ring occurs in many important compounds, including azines and the vitamins niacin and pyridoxine.

Physical and Chemical Properties
Physical state and Appearance: Yellow liquid
Odor: obnoxious odor
Molecular Weight: 79.1 g mol−1
pH (1% soln/water): 8.5
Boiling Point: 116 °C
Melting Point: -43.6 °C
Specific Gravity: 0.983 @ 77 °F
Vapor Pressure: 10 mm Hg
Vapor Density: 2.72
Water, % by wt: 0.007

Pyridine is an important solvent and reagent in organic synthesis. It is used as a solvent in Knoevenagel condensations. It is the precursor to myriad insecticides, herbicides, pharmaceuticals, food flavorings, dyes, rubber chemicals, adhesives, paints, explosives and disinfectants.

Pyridine is a widely used polar but aprotic solvent. It is miscible with a broad range of solvents including hexane and water. Deuterated pyridine, called pyridine-d5, is a common solvent for1H NMR spectroscopy.

Pyridine is also used as a denaturant for antifreeze mixtures, for ethyl alcohol, for fungicides, and as a dyeing aid for textiles.