Nitrogen-bridged donor-acceptor multifused dithienopyrrolobenzothiadiazole (DTPBT) and dibenzothiadiazolopyrrolothiophene (DBTPT) were successfully synthesized by intramolecular Cadogan annulation. The electron-deficient benzothiadiazole unit in DTPBT can be converted to benzoselenadiazole and quinoxaline moieties through reduction/cyclization to generate dithienopyrrolobenzoselenadiazole (DTPB...

The asymmetric unit of the title compound, C(8)H(6)N(2)O(4), contains one half-mol-ecule; a twofold rotation axis bisects the molecule. The quinoxaline ring is planar, which can be attributed to electron delocalization. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds link the mol-ecules into R(2) (2)(10) motifs, leading to layers, which inter-act via phen-yl-phenyl inter-actions ...

The title compound, C(16)H(10)N(2)S, is almost planar (r.m.s. deviation for all non-H atoms = 0.080 Å). The dihedral angle between the three fused-ring system and the phenyl ring is 9.26 (3)°. The S atom and the opposite C atom of the thio-phene ring are mutually disordered with an occupancy ratio of 0.7706 (19):0.2294 (19).

In the title compound, C35H27N3O3S, the spiro-linked five-membered rings both adopt twisted conformations. The pyrrolidine ring makes dihedral angles of 80.5 (1) and 77.4 (9)° with the benzo-thio-phene ring system and the quinoxaline ring system, respectively. The S atom and C=O unit of the benzo-thio-phene ring system are disordered over two opposite orientations in a 0.768 (4):0.232 (4) ratio...

In the title compound, [Fe(C5H5)(C31H24N3O)], the pyrrolidine ring adopts a twist conformation. The pyrrolidine ring is almost perpendicular to the indeno-quinoxaline ring system, making a dihedral angle of 84.44 (5)°. The cyclo-penta-dienyl rings of the ferrocene moiety adopt an eclipsed conformation. The crystal packing features weak C-H⋯N and C-H⋯π inter-actions.

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.

The aim of this work was the simultaneous determination of both ketoacids and dicarbonyl compounds in wine. To detect ketoacid compounds in wine, a method based on the quinoxaline derivatives by the reaction with diaminobenzene, currently employed to detect alpha-dicarbonyl compounds, was developed. The quinoxaline derivatives were detected by RP-HPLC with UV detection, which allows the determi...

An efficient synthesis of trialkyl (E)-3-(3-Oxo-2-3,4-dihydro-2-(1H)-quinoxalinylidene)-prop-1-ene-1,2,3-tricarboxylate derivatives via a simple three-component reaction between benzene-1,2-diamines with dialkyl acetylenedicarboxylates in the presence of K2CO3-PEG catalytic system at 100 oC was reported. The desired products were obtained in excellent yields (88-92%). Various benzene-1,2-diamin...

The quinoxaline antibiotics are cyclic depsipeptides characterized by the presence of two heterocyclic aromatic chromophores and a cross-bridge, which is either a dithioacetal (quinomycins) or a disulphide (triostins). In the naturally-occurring members of this class the chromophores are both quinoxaline-2-carboxyl (shown as the parent acid in 1). There are natural variants in the class due to ...