1H-Benzimidazole, 2,2'-(1,2-ethanediyl)bis(5-(4,5-dihydro-1H-imidazol-2-yl)- 2,2'-(1,2-Ethanediyl)bis(5-(4,5-dihydro-1H-imidazol-2-yl)-1H-benzimidazole) 77838-87-0