title: Nucleophilic Substitution on 2-Monosubstituted Quinoxalines Giving 2,3-Disubstituted Quinoxalines: Investigating the Effect of the 2-Substituent.
abstract: An investigation on the effect of substituent at the 2-position of mono-substituted quinoxalines in the synthesis of di-substituted quinoxaline derivatives via nucleophilic substitution reactions, is reported. Di-substituted quinoxalines bearing aryl-alky, aryl-aryl, aryl-heteroaryl, aryl-alkynyl, and amino-alkyl substituents were prepared in moderate to good yields. 2-Monosubstituted quinoxalines bearing a phenyl and butyl substituent reacted readily with alkyl-, aryl-, heteroaryl- and alkynyl- nucluephiles, giving di-substituted quinoxalines. 2-Monosubstituted quinoxalines bearing an amine and alkynyl substituent only reacted with alkyl nucleophiles. Oxidative rearomatization to give 2,3-disubstituted quinoxaline products occurred in atmospheric O₂.
authors.affiliation: Department of Chemistry, Faculty of Science and Agriculture, University of Limpopo, Private Bag X 1106, Sovenga 0727, South Africa. nthami001@gmail.com.
authors.forename: Ndumiso Thamsanqa
authors.initials: NT
authors.lastname: Ndlovu
authors.affiliation: Department of Chemistry, Faculty of Science and Agriculture, University of Limpopo, Private Bag X 1106, Sovenga 0727, South Africa. winston.nxumalo@ul.ac.za.
authors.forename: Winston
authors.initials: W
authors.lastname: Nxumalo
mesh_terms: D018384:Oxidative Stress; D011810:Quinoxalines / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D011810:Quinoxalines
keywords: 2,3-disubsituted quinoxaline; nucleophilic substitution; oxidative rearomatization