The mass spectra of 2-ethylbenzimidazole (1), 2-(alpha-hydroxyethyl)-benzim
idazole (2), 2-acetylbenzimidazole (3) 2-(alpha-hydroxybenzyl)-benzimidazol
e (4), 2-benzoylbenzimidazole (5) and; benzimidazole-2-carboxylic acid (6)
along with that of 3-methylbenzo-1H-dihydropyrazine -2-one (7) have been cr
itically studied with increasing levels of oxidation at the a-carbon of 2-s
ubstitutedbenzimidazoles.