A two-stage process for the production of m- or p-phenylenediamine by chlorinating a dilute aqueous mineral acid suspension of the corresponding initial iso- or tere-phthalamide reactant in a first stage, the dilution being sufficient to retain hydrogen chloride being formed substantially completely dissolved in the reaction mixture, and then converting the N,N'-dichloro-isophthalamide or N,N'-dichloro-terephthalamide intermediate product into the corresponding m- or p-phenylenediamine in a second stage by reaction with an aqueous solution of an alkali or alkaline earth metal hydroxide. The diamine products are of known utility, especially as intermediates in the synthesis of azo dyes.
展开▼
