Synthesis of New 2,3-diarylquinoxaline and Quinoxaline Oxide Derivatives as Potential Anticancer and Anti-microbial Agents

Background and Quinoxaline derivatives are standing interest of people who work on anti-cancer drugs. There are many reports about using these agents as DNA cleaving, transglutaminase 2 inhibitor, topoisomerase II inhibitor and tumor antibiotic. Other drugs used in treatment of tuberculosis such as isoniazid, pyrazinamide and rifampin have similar structures to quinoxaline and quinoxaline 1, 4-di-N-oxide derivatives. This study aimed to prepare 2, 3 diaryl quinoxaline and quinoxaline oxide as potential anticancer and antituberculosis compounds. The first step involved the conversion of benzaldehyde to benzoine in the presence of sodium cyanide. Direct oxidation of related benzoines to 1,2-diketon compounds were performed using nitric acid which then underwent a nucleophilic attack by phenylenediamine that led to quinoxaline derivatives in high yield. Subsequently, anhydride acetic acid and hydrogen peroxide was employed for the oxidation quinoxaline derivatives to desired 1,4- N-oxide quinoxaline. The 2,3-diarylquinoxaline and quinoxaline oxide derivatives were synthesized and their chemical structures were confirmed using1H-NMR and IR spectroscopy. In this study an efficient method was developed for the preparation of novel derivatives of quinoxaline and 1,4- N-oxide quinoxaline as potential anticancer and antituberculosis agents.