Displacement reaction of 2,3-dichloroquinoxaline with secondary amines in boiling ethanol afforded it`s mono aminoquinoxaline derivatives. Further reaction of the latter compounds with sodium azide in warm dimethylsulfoxide achieved a group of 4-amino tetrazolo[1,5-a]quinoxaline derivatives. 1HNMR spectra of these compounds are discussed.

A novel and simple HCl-mediated, photocatalytic method for quinoxaline(on)es C3-H arylation with arylhydrazine under transition metal catalyst- oxidant-free conditions is presented. Various underwent this transformation smoothly, demonstrating a broad substrate tolerance providing the corresponding aryl products in moderate to excellent yields. Mechanistic studies indicated that radical pathway...

Quantum chemical calculations using the density functional theory (DFT) at the B3LYP/6-31G(d,p) level were performed ontwo quinoxaline derivatives named: 1-ethyl-3-methylquinoxalin-2(1H)-one (Et-N-Q=O) and 1benzyl-3-methylquinoxalin-2(1H)-one (Bz-N-Q=O) in order to correlate the structural and electronic properties, such as HOMO, LUMO energy values, frontier orbital energy gap, molecular dipole...

The mean (N-O) bond dissociation enthalpies were derived for three 2-methyl-3-(R)-quinoxaline 1,4-dioxide (1) derivatives, with R = methyl (1a), ethoxycarbonyl (1b), and benzyl (1c). The standard molar enthalpies of formation in the gaseous state at T = 298.15 K for the three 1 derivatives were determined from the enthalpies of combustion of the crystalline solids and their enthalpies of sublim...

The synthesis and cyclization of acyclic quinoxaline, pyridine, and pyrimidine enediynes (1-3) are described. These compounds were prepared using palladium(0) coupling of trimethylsilyl acetylene to o-dihaloor o-halotriflic heteroarenes. All compounds were prepared in modest to good yields. The enediynes prepared were shown to undergo Bergman cyclization. Kinetics over a minimum of 3 half-lives...

Two isomers were isolated during the reaction between 3-methyl-quinoxalin-2-one and bis-(2-chloro-ethyl)amine hydro-chloride. The crystal structure of one isomer has already been reported [Caleb, Bouhfid, Essassi & El Ammari (2009). Acta Cryst. E65, o2024-o2025], while that of the second isomer is the subject of this work. The title compound, C(14)H(15)N(3)O(3), has a new structure containing o...

Mequindox (MEQ) is a quinoxaline-N,N-dioxide antibiotic used in food-producing animals. MEQ residue in animal-derived foods is a food safety concern. The tissue distribution of MEQ and its marker residue 1,4-bisdesoxymequindox (M1) were determined in swine following oral gavage or intramuscular injection twice daily for 3 days. The experimental data were used to construct a flow-limited physiol...

DNA triple helices offer new perspectives toward oligonucleotide-directed gene regulation. However, the poor stability of some of these structures might limit their use under physiological conditions. Specific ligands can intercalate into DNA triple helices and stabilize them. Molecular modeling and thermal denaturation experiments suggest that benzo[f]pyrido[3, 4-b]quinoxaline derivatives inte...