A nitration system comprising nitric acid, propanoic anhydride and zeolite Hb has been developed for dinitration of toluene to give 2,4-dinitrotoluene in 98% yield, with a 2,4-:2,6‑dinitrotoluene ratio of over 120. This represents the most selective quantitative method for 2,4‑dinitration of toluene; the catalyst is re-usable, solvent is not needed and an aqueous work-up is not required.