文摘
In the presence of molecular oxygen and zeolite La-β with Si/Al2 = 260, regioselective mononitration of biphenyl with stoichiometric quantities of liquid nitrogen dioxide occurs at 20 °C to yield mononitrobiphenyl, as the main product, in yields up to 82.7 %. The 2-nitrobiphenyl:4-nitrobiphenyl isomer ratio is 0.34. The process is eco-friendly and inexpensive, and the zeolite is easily regenerated by simple work-up to give results similar to those obtained with the fresh catalyst. Keywords Biphenyl Nitrogen dioxide Mononitration Rare earth cations β-Zeolite Regioselectivity