Regioselective mononitration of aromatic compounds using Brønsted acidic ionic liquids as recoverable catalysts Original Research Article

Some novel acyclic Brønsted acidic task-specific ionic liquids (TSILs) that bear an alkane sulfonic acid group in an acyclic trialkanylammonium cation were synthesized and their uses as halogen-free catalysts for regioselective mononitration of aromatic compounds were investigated. The reactions were carried out at 60–80 °C with reasonable to good yields and improved para-selectivities for halogenobenzenes compared to those in the absence of the catalysts. In addition, the TSILs could be recovered and reused without noticeably decreasing the catalytic activity.