苯胺重氮盐与间苯二酚的偶合反应

Azo-Coupling Reaction between Benzenediazonium Chloride and Resorcinol

苯胺重氮盐与间苯二酚的偶合反应会生成一个由一偶氮物、二偶氮物和三偶氮物组成的混合物,其中二偶氮物(4,6-二苯基偶氮间苯二酚)是合成4,6-二氨基间苯二酚的关键中间体,因此控制偶合反应的条件,高选择性地得到4,6-二苯基偶氮间苯二酚是非常有意义的。考察了反应温度、间苯二酚与苯胺重氮盐的摩尔比、间苯二酚与NaOH的摩尔比对生成4,6-二苯基偶氮间苯二酚的影响。研究发现,当反应温度在-7℃～-5℃,间苯二酚∶苯胺重氮盐的摩尔比=1∶2.3,间苯二酚∶NaOH的摩尔比=1∶16.8时,反应产物未经纯化处理,其4,6-二苯基偶氮间苯二酚的含量即可达92%以上,收率80%左右。

A mixture consisting of 4-phenylazoresorcinol, 4,6-bisphenylazoresorcinol and 2,4,6-triphenylazoresorcinol may obtained from the azo-coupling reaction of benzenediazonium chloride and resorcinol. The 4,6-bisphenylazoresorcinol was a key intermediate in synthesis of 4,6-diaminoresorcinol. It was significant to obtain 4,6-bisphenylazoresorcinol in high regioselectivity that control the condition of azo-coupling reaction.The main factors that affect the azo-coupling reaction, such as reaction temperature, molar ratio of benzenediazonium chloride and resorcinol as well as resorcinol and sodium hydroxide, were investigated. The study showed that the content of 4,6-bisphenylazoresorcinol in product without purification was up to 92% and its yield was about 80% under the conditions of the reaction temperature was -7℃ to -5℃, the molar ratio of resorcinol to benzenediazonium chloride was 1∶2.3 and the molar ratio of resorcinol to sodium hydroxide was 1∶16.8.