Research On Regioselective Nitration Of Toluene In Sulophuric Acid

The progress of regioselective research for aromatic nitration was one of most popular topic. In this paper, the effect of different nitrating system, temperature, nitrification intensity and catalysts on the regioselectivity and the conversion of the nitration of toluene were investigated.Usually three isomers were included by nitration of toluene:o-nitrotoluene(60%), m-nitrotoluene(4%), p-nitrotoluene(36%). Market demands of m-nitrotoluene and p-nitrotoluene had apparently risen recently. And the purpose of the paper was to improve the percentage of these two isomers.Through a large number of experiments, a series of researches have done on the regioselective nitration of toluene in sulophuric acid. The results imply that in the mixed acid-phosphoric acid system, when the mole ratio of H2SO4:N2O5:P2O5=0.2:9.1:2.5 and the reaction temperature was 60℃, the m-nitrobenzene increased to 4.7%,O/P valued of 1.62.In the sulfuric acid-urea nitrate system, solid urea nitrate was used as catalyst. Whlie changed the reaction temperature and the amount of sulfuric acid, the m-nitrobenzene increased to5.2%, O/P valued of 1.85. By using amides, conditions including reaction temperature, nitrification intensity, dosage of amides. When using N, N-Dimethylformamide, the percent of m-nitrobenzene became 4.3%, O/P valued of 1.26. As formamide was applied, the percent was 5.3%, O/P valued of 1.59. While using acetamide as catalyst, the m-nitrobenzene increased to 4.2% and O/P valued of 1.48. In this paper, ionic liquids were attempted as catalyst for nitration of toluene. And three SO3H-functionalized ionic liquids were discussed. The results in different reaction temperature, nitrification intensity and dosage of ionic liquids were obtained. As we made use of [p-SABPy] HSO4, the percent of m-nirotoluene was 5.3% and O/P valued of 1.27.