Superior methodology for the nitration of simple aromatic compounds

Simple aromatic compounds such as benzene, alkylbenzenes and halogenobenzenes are nitrated in quantitative yield and with high para-selectivity in a solvent free process by use of a stoichiometric quantity of nitric acid and acetic anhydride at 0-20 degrees C in the presence of zeolite beta as catalyst; the zeolite can be recycled and the only by-product is acetic acid, which is easily separated from the nitration product by distillation; the process is inexpensive and highly convenient and represents the best currently available methodology for the clean syntheses of a range of simple nitroaromatic compounds.