Electrochemical reduction of quinoxalino[2,3-b]quinoxaline

Abstract

. Can. J. Chem. 60,2797Chem. 60, (1982. We have been interested for some time in the very low solubility in usual solvents (methanol, electrochemical reduction of heterocyclic com-acetonitrile, dimethylsulphoxide, dimethylformapounds with two 1,4-nitrogen atoms in a six-mem-mide). It can be dissolved in hot acetic acid or in bered ring. We now report the electrochemical cold trifluoroacetic acid. Our first attempts aimed reduction in protic and aprotic medium of the at obtaining an unambiguous determination of the 1 quinoxalino[2,3-blquinoxaline, 1. This compound structure by X-ray crystallography, but we were 1 possesses two conjugated unable to obtain suitable crystals from CH3COOH 1 -N=c-c=N-or CF,COOH solutions. An nmr spectrum re-I I corded in CF3COOH shows a single AA'BB' patsystems and it seemed interesting to investigate tern for the eight aromatic protons, which gives no how the conjugation of two systems would indication on the structure of fluoflavine the proinfluence their electrochemical behaviour. A single tons of the benzenic rings being equivalent because study of 1 has been published (1); of the protonation of the nitrogen atoms and the fast however, its conclusions are erroneous. exchange of these protons. As we shall see later on, the electrochemical

An extensive study of electrochemical behavior of brimonidine and its determination at glassy carbon electrode

“…Based on the electrochemical study of BRIM at BDDE, it was shown that the reduction occurred in one-step quasi-reversible mechanism, involving the transfer of two electrons and two protons. Accordingly, it was concluded that the reduction happened at the quinoxaline ring confirming the same mechanism as for other quinoxaline derivatives [10,11]. We have also reported electrochemical study and the method for determination of varenicline, the quinoxaline derivative, in tablets and in spiked plasma, at BDDE, glassy carbon (GCE) and hanging mercury electrode [10].…”

N-Heteropentacenes and N-Heteropentacenequinones: From Molecules to Semiconductors

“…31 The true structure of compound 6 was first determined in 1987 as benzenoid rather than quinonoid based on the AA¢XX¢ patterns for the protons of the terminal benzene rings in the corresponding 1 H NMR spectroscopic data. 32,33 Unfortunately, dihydrotetraazapentacene 6 has often been shown as the erroneous quinonoid structure in the literature until recently. [34][35][36] In connection with the debated structure of compound 6, our group found that the methylation of 6 yielded both benzenoid and quinonoid heteropentacenes 7 and 8 4b (Figure 4).…”

Synthesis, Photophysical, Electrochemical and Thermal Studies of Triarylamines based on benzo[g]quinoxalines

“…On cathodic sweep, one reversible wave was observed for all the compounds (see supplementary information) corresponding to the reduction of benzo[g]quinoxaline segment. 50 On cathodic sweep an irreversible wave was observed for compound 5 at −1.30 V which may be due to the reduction of -NO 2 group.…”