Quinoxalines, also known as benzopyrazines, are heterocyclic compounds containing a ring complex consisting of a benzene ring and a pyrazine ring. It has isomerism with other naphthalene compounds such as quinazoline, phthalazine, cinnamine, etc. Fusion N-heterocyclic compounds are widely used as valuable entities for the expansion of important pharmacological agents and are considered to be an advantageous scaffold material. Among the numerous fused N-heterocyclic compounds, cinnoline, quinoxaline and quinazoline are important pharmacological agents. In medicinal chemistry, these N-heterocyclic compounds have a wide range of biological properties and can be used as synthetic intermediates, potential drug candidates and chemical probes.
Tetrahydroisoquinoline is an organic compound with the chemical formula C9H11N. It is classified as a secondary amine, obtained from isoquinoline by hydrogenation. The tetrahydroisoquinoline moiety forms the backbone of several natural, synthetic and semi-synthetic drugs approved for the treatment of cancer, pain, gout and various neurodegenerative diseases.