Nitration is one of the most studied and best understood of organic reactions. Both aromatic and aliphatic compounds can be nitrated by various methods such as heterolytic (electrophilic and nucleophilic) and radical nitrations. Aromatic nitration is most frequently electrophilic, aliphatic is free radical. Nitroaromatic compounds are of substantial use as intermediates in the synthesis of plastics, pharmaceuticals, dyes, explosives, insecticides, etc. Nitroaliphatics are used as solvents and synthons in organic synthesis. The most common nitrating mixtures are the nitric acid and sulfuric acid combinations, but many different ways are known from the literature.
Nowadays, the subject of nitration is still of substantial interest and activity, therefore, to find more effective and selective nitration methods are investigated continuously. Selectivity can be a challenge in nitrations because as a rule, more than one compound may result but only one is desired, so alternative products act as contaminants or are simply wasted. Accordingly, it is desirable to design syntheses with suitable selectivity, for example, by controlling the reaction conditions.
The flow technology, especially ThalesNano’s IceCube Reactor, is one of the tools to revise the current knowledge from nitration. Due to the advantages of continuous flow technology, the time-consuming acid mixture preparation can be managed on an easy and continuous way, and the proper control of the residence time gives the chance to produce more selectively nitrated products than previously.
Nitration with the IceCube Reactor