A regioselective nitration process for diphenyl compounds which can be carried out at about ambient temperature in which each ring of the diphenyl compound is selectively nitrated in the para position to form the corresponding di(4-nitrophenyl) compound. Such compounds as diphenyl carbonate, 2,2-diphenylpropane, 2,2-diphenylhexafluoropropane, diphenyl sulfide, diphenyl ketone, diphenyl sulfone, and the like can be converted to an isomeric mixture containing an enhanced amount of the corresponding di(4-nitrophenyl) compound, which mixture may be reduced or purified and reduced to the di(4-aminophenyl) analogues for use in the manufacture of polyamides, polyimides, and polyamide-imides.
一种区域选择性硝化过程,适用于二苯基化合物,可在大约室温下进行,在该过程中,二苯基化合物的每个环被选择性地硝化到对位位置,形成相应的二(4-
硝基苯基)化合物。例如,二
苯基碳酸酯、
2,2-二苯基丙烷、2,2-二苯基
六氟丙烷、二苯基
硫醚、二苯基酮、二苯基磺酮等化合物可以转化为含有增强量的相应二(4-
硝基苯基)化合物的异构体混合物,该混合物可以被还原或纯化并还原为二(4-
氨基苯基)类似物,用于制造聚酰胺、聚
酰亚胺和聚酰胺-
酰亚胺。