| 摘要 |
A 1,3-diphenyltriazene rearrangement product obtained by contacting an aniline solution of the triazene with 0.4-2% of a strong acid, preferably HNO3, which product, at 25-40 DEG C, is a two-phase liquid having (1) an organic phase in which p-aminoazobenzene and water are dissolved in aniline, and (2) an aqueous phase, is separated into organic and aqueous phases, and the organic phase thereafter contacted with an aqueous extracting base, e.g., NH4OH, which reduces the strong acid concentration of the organic phase. The organic phase then is separated and is ready for conversion to p-phenylenediamine by catalytic hydrogenation. Higher catalyst activity and productivity result when the rearrangement product is treated as described prior to the hydrogenation. |
