Regioselective nitration of aromatics under phase-transfer catalysis conditions

Abstract: Mononitration of aromatics was performed in a two-phase system using phase-transfer catalyst. The most advantageous conditions for the nitration were determined (temperature, reaction time, the type and amount of phase transfer catalyst, nitrification strength of the nitro-sulfuric acid). From the results, a significant improvement in the selectivity and conversion of the nitration of xylene was observed: the ratio of 4-nitro-m-xylene to 2-nitro-m-xylene was unprecedented increased up to 91.3%:7.7%, the ratio of 4-nitro-o-xylene to 3-nitro-o-xylene was also increased to 71.1%:27.2%; both the conversions were over 96%. [Copyright &y& Elsevier]