Polarographic study of alkyl benzimidazolyl sulfoxide and the corresponding suldife and sulpfone

2-(5-Methylbenzimidazolyl) 1-(2-pyridyl)ethyl sulfide, 2-(5-methylbenzimidazolyl) 1-(2-pyridyl)ethyl sulfoxide and 2-(5-methylbenzimidazolyl) 1-(2-pyridyl-1-oxide)ethyl sulfone are reduced at a dropping mercury electrode in aqueous ethanol. Coulometric experiments at a mercury pool prove that 2-ethylpyridine and 2-mercapto-5-methylbenzimidazole are formed in the reduction process of the sulfide and the sulfoxide. Coulometric reduction of the sulfone results in some conversion of the pyridine-1-oxide group together with a reductive fission of the ethyl—sulfonyl bond. One of these fission products methyl undergoes secondary reactions. The concentration of 2-benzimidazolyl 2-pyridyl methyl sulfoxide in a pharmaceutical formulation has been determined by differntial pulse polarogarphy.