Tetrachlorobenzene

Tetrachlorobenzene is any of three isomeric chlorobenzenes with the molecular formula C6H2Cl4. They differ by the positions of the chlorine atoms around the ring. Tetrachlorobenzenes are colorless crystalline compounds.

Synthesis
1,2,4,5-Tetrachlorobenzene can be produced by electrophilic halogenation of benzenes and some chlorobenzenes. 1,2,3,4-Tetrachlorobenzene can only be produced by chlorination of 1,3,5-trichlorobenzene.

Uses
1,2,4,5-tetrachlorobenzene once was used as intermediates in the production of pesicides, specifically trichlorophenols. This method has been discontinued because it also produced 2,3,7,8-tetrachlorodibenzo-p-dioxin.