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.
Thienopyridines are similar in structure to quinoline and isoquinoline, and are a class of heterocyclic compounds with important physiological activity and medicinal value. Thienopyridines are a subclass of antiplatelet drugs that prevent platelet aggregation by binding to selected extracellular cysteine residues on the P2Y12 receptor located on the platelet membrane.