246Trimethylpyridine

2,4,6-Trimethylpyridine, commonly referred to as collidine, is an aromatic amine formed by a pyridine ring bearing methyl substituents at the 2, 4, and 6 positions. Its chemical formula is C8H11N. The three methyl groups give collidine a distinctly aliphatic character, while the pyridine nitrogen provides basicity.

In terms of properties, 2,4,6-trimethylpyridine is a colorless to pale liquid with a characteristic pyridine-like odor. It is sparingly soluble in water and more readily soluble in organic solvents. As a tertiary amine, it acts as a base and forms salts with acids, such as the hydrochloride and hydrobromide, which can be isolable solids. Compared with unsubstituted pyridine, collidine is generally less basic due to steric effects from the methyl groups, although it remains sufficiently basic for many synthetic applications.

Preparation and availability: 2,4,6-trimethylpyridine is commercially available and can be produced by methods used for substituted pyridines, often involving regioselective alkylation or oxidation steps on pyridine substrates. Its production is oriented toward use as a reagent and intermediate in organic synthesis rather than as a bulk chemical.

Applications: The compound is primarily used as a non-nucleophilic organic base in acylations and other reactions, where its bulk helps suppress side reactions. It also serves as a ligand or building block in coordination chemistry and can function as a versatile intermediate in the synthesis of specialty chemicals and pharmaceuticals.

Safety: Collidine is a flammable liquid and an irritant. It should be handled with appropriate PPE, in a well-ventilated area, and stored away from oxidizers. Like other tertiary amines, it can be harmful if inhaled or ingested and may cause skin and eye irritation.