Regioselective Synthesis of Mononitrochlorobenzene (I)Nitration with Nitric Acid

The solid acid catalysts of SO 2- 4/TiO 2 and SO 2- 4/ZrO 2 and a series of SO 2- 4/TiO 2 ZrO 2 catalysts have been prepared and characterized by XRD, FTIR and TG DTA. The regioselectivities of chlorobenzene in mononitration with these catalysts were investigated. It was found that chlorobenzene is nitrated with high para selectivity in the presence of acetic anhydride using the solid acid as catalyst and a stoichiometric quantity of nitric acid. Over SO 2- 4/TiO 2 ZrO 2(atom ratio 1∶2) catalyst, nitration of chlorobenzene gives a 70 2% yield of mononitro compounds, with an ortho para isomer ratio 0 29, greatly below 0 57 as sulfonitric acid as catalyst. The process is rapid, and the catalysts can be repeatedely used 4 times without reduction of ortho/para ratio of product.