Nitration of Substituted Benzenes Catalyzed by Metal Bis[(perfluoroalkyl)sulfonyl]imides in Quaternary Ammonium Ionic Liquids

The nitrations of substituted benzenes proceeded rapidly and cleanly with very good yields in Cu(N(C 4 F 9 SO 2 ) 2 ) 2 / [N 4446 ][Tf 2 N] or In(NTf 2 ) 3 /[N 4446 ][Tf 2 N] catalyst system, in which HNO 3 /Ac 2 O was used as the nitrating agent. For the nitration of chlorobenzene when 2 mol% catalyst was used at room temperature for 10 min, 87.6% and 90.6% of conversion of chlorobenzene were achieved, respectively and the para / ortho ratios of products were about 4.3–4.8. The catalyst systems with ionic liquid could be recovered easily and reused more than 5 times.