2-巯基苯并咪唑锌盐合成新工艺的研究

Study on new synthesis process of 2-mercaptobenzimidazole zinc salt

以邻苯二胺、二硫化碳为原料,在4-二甲氨基吡啶(DMAP)催化下合成了2-巯基苯并咪唑,然后加入氧化锌得到2-巯基苯并咪唑锌盐。考察了不同催化剂及其质量分数、反应介质、反应原料的摩尔比、成盐条件等对2-巯基苯并咪唑锌盐合成工艺的影响。结果表明,反应的最优工艺条件是:以水为反应介质,加入理论产量的1.0‰DMAP催化剂,反应原料n(邻苯二胺)∶n(二硫化碳)∶n(氧化锌)=1∶1.5∶0.52,成盐反应温度为125~130℃。相对于传统工艺,该工艺反应时间短、操作简单、三废少,适合工业化规模生产。

2-Mercaptobenzimidazole is synthesized from 1,2-diaminobenzene and carbon disulfide under the catalysis of DMAP(4-dimethylaminopyridine),and reacts with zinc oxide to obtain 2-mercaptobenzimidazol zinc salt.The effects of the types and dosages of catalyst,the reaction medium,the molar ratio of raw materials and salt-forming conditions on the synthesis of 2-mercaptobenzimidazol zinc salt are investigated.The optimum conditions are obtained as follows:water as the reaction medium,the dosage of DMAP catalyst is 0.1%of theoretical yield,n(1,2-diaminobenzene)∶n(carbon disulfide)∶n(zinc oxide)=1∶1.5∶0.52,and salt-forming reaction temperature is in the range of 125-130℃.Compared with traditional process,this process needs short reaction time,operates easily,generates less wastes,and is suitable for industrial scale production.