12benzopyridine

12-benzopyridine is not a widely used, discrete chemical name in standard nomenclature. In practice, it is often used loosely to refer to compounds in the benzo-pyridine family, of which the best known member is quinoline, systematically named 1,2-benzopyridine. The term can reflect ambiguous or nonstandard indexing of fused-ring systems.

The core structure of benzo-pyridines is a benzene ring fused to a pyridine ring, yielding an extended, planar heteroaromatic system. The nitrogen atom in the pyridine ring imparts basicity and a site for coordination chemistry, while the fused aromatic framework contributes to rich spectroscopic properties. Substitution on either ring allows a wide range of derivatives with varying physical and chemical characteristics.

Nomenclature and ambiguity are common with this class. The “12-” prefix is not part of a consistent IUPAC scheme for benzo-pyridines, and different texts may index fusion points differently. This can lead to confusion with other benzo-fused pyridine isomers, such as quinoline (1,2-benzopyridine) or isoquinoline (another fused isomer).

Applications and significance: benzo-pyridine derivatives are important scaffolds in medicinal chemistry, agrochemistry, dyes, and materials science. Their extended conjugation makes them useful in ultraviolet-visible spectroscopy and, in many derivatives, as ligands or pharmacophores. Substituents and ring fusion patterns modulate basicity, reactivity, and biological activity.

Synthesis and preparation: these compounds are typically prepared by heterocyclic annulation or cyclization reactions that join a benzene fragment to a pyridine precursor, with classical routes exemplified by quinoline-forming methods and related strategies, under diverse catalytic or acidic conditions. See also quinoline, isoquinoline, and related benzo-pyridine isomers.