Highly selective catalytic nitration of 1-nitronaphthalene with NO2 to 1,5-dinitronaphthalene over solid superacid SO42−/ZrO2 promoted by molecular oxygen and acetic anhydride under mild conditions

A simple and efficient method for liquid-phase catalytic nitration of 1-nitronaphthalene with NO2 to 1,5-dinitronaphthalene under mild conditions has been developed. The results indicated that the sulfated zirconia (SO42−/ZrO2) as solid superacid catalyst exhibits superior catalytic performance with dioxygen and acetic anhydride. 93.8% conversion of 1-nitronaphthalene and 52.8% 1,5-dinitronaphthalene selectivity were achieved. Furthermore, the physicochemical properties of SO42−/ZrO2 were determined by XRD, Py-FT-IR, BET, FT-IR, Raman spectroscopy and ICP-OES technologies. The possible nitration reaction mechanism over SO42−/ZrO2 catalyst was proposed. The present work provides an easy-to-implement, mild and eco-friendly approach for the efficient preparation of valuable 1,5-dinitronaphthalene, which has extensive industrial application prospects.