【摘要】 以Brφnsted酸性离子液体[Hmim][CF3COO](三氟乙酸根甲基咪唑盐)和[Hmim][HSO4](硫酸氢根甲基咪唑盐)作为溶剂和催化剂,硝酸铵为硝化剂,研究了烷基苯和卤苯等芳香化合物的硝化反应。在0℃到室温的硝化条件下,烷基苯和卤苯都能被硝化成一硝基化合物,收率为40%~80%。甲苯等烷基苯的硝化选择性与硝硫混酸中的硝化选择性相当;卤苯硝化的对位选择性则远高于硝硫混酸中的硝化结果。其中氯苯在18℃下反应8 h,三氟乙酸酐(TFAA)/硝酸铵为4时产物的对邻比达到6.2,而溴苯在0℃下反应8 h,TFAA/硝酸铵为5时产物的对邻比可达到14.0,并且生成的对硝基溴苯可以从反应液中析出,得到对硝基溴苯含量为98%的产物。更多还原

【Abstract】 Various aromatic compounds,including alkyl and halo benzenes,were nitrated to mononitro compounds in reasonable yields(40%-80%) with NH4NO3 from 0 ℃ to room temperature in Brφnsted acidic ionic liquids with [CF3COO] and as solvent and catalyst respectively.The isomer ratios for nitration of toluene in Brnsted acidic ionic liquids were comparable to that obtained in mixed acid nitration.Isomer ratios for the nitration of halo benzenes in Brφnsted acidic ionic liquids are different from that obtained in mixed acid nitration,usually,with higher para selectivity.The para-/ortho-product isomer ratio is 6.2 for the nitration of chlorobenzene at 18 ℃ for 8 h with n(TFAA)/n(NH4NO3)=5.The para-/ortho-product isomer ratio is 14.0 for the nitration of bromobenzene at 0 ℃ for 8 h with n(TFAA)/n(NH4NO3)=5.The para-product,p-nitrobromobenzene,from the nitration of bromobenzene in under 0 ℃ precipitates with 98% purity,which facilitates the separation of the pure isomert.更多还原