1-Methylquinoxalinium iodide

Methylquinoxalinium iodide (217) with diethylamine gave 2-diethylamino-1-methyl-1,2-dihydroquinoxaline (218) (EtaO, 20°C, 5 min 91%) and thence either 5-methyl-l,2,3,4,4a,5,10,10a-octahydropyrazino[2,3-/7]qui-... 

Cyclization of 1-methylquinoxalinium iodide by o-HXC6H4NH2 (X = NH, O) in ethanolic dimethylamine at room temperature gives 53% and 70% yields of the corresponding quinox-alino[2,3-6]quinoxalines <84KGS706>. 

This effect is also shown in the proton spectra of 1-methyl-pyrazinium iodide (9), 2,4-dimethylpyrazinium (lOA), 2 amino-4-methylpyra-zinium iodide (lOB) and 1-methylquinoxalinium iodide (11) in deuterium oxide solution at 100 Me./sec.The reduction of the... 

The UV and H NMR spectral properties of 1-methylquinoxalinium iodide suggest that at pH 9-12, the pseudo base 10 is in equilibrium with the covalent hydrate 11 formed by addition of a molecule of water across the C-3, N-4 bond. At higher pH the anion 12 is formed, and this is less susceptible to covalent hydration across the C-3, N-4 bond. ... 

Among the recently (as of 2003) described reactions of such quaternary salts, reduction to dihydroquinoxalines has been exemplified toward the end of Section 2.2.4 treatment of the diquaternary compound, 1,4,6,7-tetramethylquinox-alinediium bis(tetrafluoroborate) (215), with sodium iodide gave a well-characterized product that appears in X-ray studies to have the cation radical structure (216) ""° and a fundamental spectrophotometric study on the addition of hydroxyl and methoxyl ions to the 1-methylquinoxalinium cation has been reported. ... 

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