Syntheses and Biological Activities of Tricyclic-fused Quinoxaline Ring Systems (A Review). Part I: Thienoquinoxalines

Abstract

Quinoxaline derivatives are an interesting class of heterocyclic compounds in drug discovery. It is rare in natural state, but their synthesis is easy to perform coupling between benzene and pyrazine rings. In addition, quinoxaline nucleus has received notable attention as an important pharmacophore that has broad-spectrum applications, especially in the fields of pharmaceutics and medicine. This review spotlights the biological activities and the different methods of preparation of three isomers of thienoquinoxalines, namely thieno[2,3-b]quinoxaline, thieno[3,4-b]quinoxaline, and thieno[2,3-g]quinoxaline. It is hoped that this mini-review will supply a broad perspective and insights among readers in the development of new quinoxalines scaffolds with rich biological applications.. KEYWORDS :Biological activities, Quinoxalines, Thieno [2,3-g]quinoxaline, Thieno[2,3-b]quinoxaline, Thieno[3,4 -b] quinoxaline, Tricyclic-fused quinoxaline.