Abstract: A process for preparing poly{[benzo (1,2-d:5,4-d')bisthiazole-2,6-diyl]-1,4-phenylene} or one of the reactants used in the preparation of such polymer by the use of an electrolytic cell. In the process, thiocyanate ions are oxidized to thiocyanogen in the anode chamber of the cell. In a preferred embodiment, the cathode chamber of the same electrolytic cell is used to reduce 4,6-dithiocyanobenzene-1,3-diamine to form the dithio radical of 4,6-diaminobenzene-1,3-dithiol. Upon hydrogenation, the dithiol or its acid salt may be used to react with terephthalic acid to form the polymer.