HZSM-5 Assisted Clean Nitration of Toluene with Dinitrogen Pentoxide

In order to solve the problem of synthesizing p-mononitrotoluene involving the concentrated mineral acids as the catalysts,produces huge amounts of wastes along with a large amount of undesired o-MNT due to the nonselective nitration of toluene,the nitration of toluene by N_2O_5 has been investigated with solid acids catalysts HZSM-5.By the use of new nitrating agent,the reaction eliminated the use of concentrated sulfuric acid and was environmental friendly with high atom economy.The excellent selectivity of HZSM-5 makes the ratio of p-mononitrotoluene increase greatly.Effects of reaction temperature,reaction time,amount of catalyst and the ratio of Si/Al on the nitration were investigated,showing that under optimum conditions,the yield of nitration of toluene was 42%,and para-selectivity was 78.9%.