2bromopyridines

2-Bromopyridine is an organobromine compound in which a bromine atom substitutes hydrogen at the 2-position of the pyridine ring. Its molecular formula is C5H4BrN. It is typically a colorless to pale yellow solid or liquid at room temperature and is used as a versatile building block in organic synthesis. Like other aryl bromides, it exhibits reactivity in cross-coupling and related transformations, but the pyridine nitrogen can influence catalyst performance and selectivity.

Preparation methods for 2-bromopyridine include selective bromination of pyridine derivatives, or lithiation at the C-2 position followed by quenching with a brominating agent. Direct bromination of unsubstituted pyridine tends to favor other positions, so selective strategies often employ directing groups or prefunctionalized substrates such as N-oxide derivatives to achieve C-2 bromination.

In synthetic chemistry, 2-bromopyridine is valued for its use in palladium-catalyzed cross-coupling reactions, including Suzuki-Miyaura,Negishi, and related couplings. These reactions enable the installation of various aryl, vinyl, or alkyl groups at the 2-position, yielding 2-substituted pyridines that are important motifs in pharmaceuticals, agrochemicals, and materials science. The compound also serves as a starting material for further functionalization of the pyridine ring.

Safety and handling considerations include irritant and potential acute toxicity properties associated with brominated pyridines. Appropriate precautions include working in a well-ventilated hood, with gloves and eye protection, and proper waste disposal in accordance with regulations. See also the isomeric 3- and 4-bromopyridines for related reactivity patterns.