Nitration of nitrotoluene employing ionic liquids

Ionic liquids (ILs) can function as "green " solvents owing to their stability and low vapor pressure. These features help prevent the ignition of a reaction and therefore ensures its safety. In this study, the application of ILs in the synthesis of energetic materials was examined; this was accomplished using nitration reactions in an IL, i.e. 1-butyl-3- methylimidazolium trifluoromethanesulfonate [BMIM][OTf] to determine its effect on runaway reactions. In this study, the nitration process generated o-, m-, and p-nitrotoluene (NT) with by-products; the major by-product was benzoic acid (BA), and the ratio of the weight of the NTs to the BA was-90 %. Furthermore, the presence of oxygen facilitated the production of BA. The amount decreased to 0.45 % under nitrogen atmosphere in a closed instrument. This investigation showed that oxygen was one of the key factors to the generation of BA, which was considered a characteristic feature of the nitration in [BMIM][OTf]. The presence of BA reduces the temperature required to initiate the exothermic reaction of the NTs. However, neither the benzoic-acid-induced temperature decrease nor the heat-of-reaction-induced adiabatic temperature increase facilitated the attainment of a temperature that triggered the decomposition of NTs or IL.