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.
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.