3Nitropyridine

3-Nitropyridine is an aromatic heterocycle consisting of a pyridine ring bearing a nitro group at the 3-position. Its chemical formula is C5H4N2O2 and its molecular weight is about 124.1 g/mol. At room temperature it is typically a colorless to pale yellow liquid or solid, depending on purity and how it is stored.

Synthesis and occurrence: 3-Nitropyridine is usually prepared by nitration of pyridine under controlled acidic conditions to favor the 3-nitro isomer. The process can yield mixtures of nitro isomers, requiring purification by distillation or crystallization. In some routes, the nitro group can be introduced via oxidation or other transformations on pre-formed pyridine derivatives, but direct nitration remains the common route.

Uses and reactions: 3-Nitropyridine is a valuable building block in organic synthesis. It is used to prepare a range of 3-pyridyl compounds found in pharmaceuticals, agrochemicals, and materials. The nitro group can be reduced to give 3-aminopyridine, a versatile starting material for amide coupling, heterocycle formation, and further functionalization. The nitro substituent also enables various other transformations, including nucleophilic aromatic substitutions under suitable conditions.

Safety and handling: Nitroaromatic compounds can be toxic and may present hazards such as sensitivity to shock or heat under certain conditions. They should be handled in a well-ventilated area with appropriate personal protective equipment, stored away from reducing agents and oxidizers, and treated as hazardous organic chemicals according to applicable regulations.

See also: 2-nitropyridine, 4-nitropyridine.