1,3-Dihydro-5,6-dichlorobenzo(c)thiophene-S,S-dioxide1,3-dihydro-5,6-dichlorobenzo(c)thiophene-S,S-dioxide is an intermediate in the synthesis of 2,3,6,7-Tetrachloronaphthalene which is a polychlorinated naphthalene (PCN) with dioxin-like toxic properties that can lead to increased risk of liver disease. It is a potential carcinogen.