Zeolite-Assisted Regioselective Nitration of Toluene in Acetonitrile with Nitric Acid/Acetic Anhydride

摘要

p-Nitrotoluene widely used pharmaceutical and dyestuff intermediates was selectively prepared with nitric acid under the promotion of acetic anhydride in the presence of zeolite catalysts. The ratio of onitrotoluene isomer to β-nitrotoluene could reach 0.553 in a moderate total yield of 62.8 % when the reaction was carried out in acetonitrile with 1.89 mmol toluene, 5.67 mmol nitric acid, 5.67 mmol acetic anhydride and 0.13 g HBEA-280 at reflux temperature. The zeolite catalyst has a strong influence on the reaction and could be easily regenerated.