A green and efficient trinitration system for aromatic compounds with Bi(NO3)3·5H2O/[HMIM]ClO4 as catalyst in HNO3/Ac2O

To investigate the green trinitration method of aromatic compounds, with Lewis acid/ionic liquid as catalyst and HNO 3 /Ac 2 O as nitration reagent, a Lewis acid/ionic liquid/HNO 3 /Ac 2 O system was established. In various combinations of Lewis acids and ionic liquids, Bi(NO 3 ) 3 ·5H 2 O/[HMIM]ClO 4 proved to be a very efficient catalyst for the trinitration of activated aromatic compounds and reusable for 3 times. Reaction conditions for the trinitration were optimized and yields of the trinitro products were from mild to excellent. This sulfuric acid-free system has the advantages of strong trinitration ability, low environment pollution, low toxicity, low cost and high potential for industrial application.