Abstract The formation of 2-benzhydrylidene-4, 4-diphenyl-[1, 3] oxathiolan-5-one (1) was performed by cathodic reduction of 2-bromo-2, 2-diphenylacetyl bromide in dichloromethane tetraethylammonium bromide on graphite cathode in the presence of inorganic sulphur compounds from the anodic compartment.