| 摘要 |
PURPOSE:To readily obtain high-purity m-phenylenediamine hardly coloring with the lapse of time in high yield by using crude m-dinitrobenzene containing o- and p-isomers as a starting material. CONSTITUTION:Crude m-DNB containing o- or p-DNB is made to react with phenols of formula I and/or formula II (R is H, halogen, OH, alkyl, NH<2>, alkoxy, carboxyl, phenol, etc.; m is 1-5; n is 1-4; X is 1-10C divalent hydrocarbon group, C(CF3)2, CO, S, SO, O, N=N, NH, single bond, etc.) in the presence of a basic compound (preferably sodium hydroxide) and as necessary, a phase transfer catalyst combinedly used to substantially convert only o- and p-DNB into corresponding phenoxynitrobenzenes. Then the resultant reaction mixture is subjected to hydrogenation reaction without separating m-DNB from the reaction mixture and the resultant m-phenylenediamine is separated by distillation. Phenoxyaniline produced by hydrogenation is left as a kettle residue when distilled. |
