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.
Tetrahydroquinoline is one of the most important simple nitrogen heterocycles, widely found in nature and in a variety of pharmacologically active compounds. Tetrahydroquinoline is an important structure for the synthesis of various biologically active derivatives.