C.I.颜料红177中间体的制备工艺改进

本文较为系统地研究了铜粉催化剂加入方式对C.I.颜料红177中间体4,4'-二氨基-1,1'-二蒽醌-3,3'-二磺酸(DAS)合成过程中的乌尔曼偶联反应速率的影响规律。 研究结果表明,在55 ℃较佳反应温度下,先加入与溴氨酸钠质量比为2:5的铜粉,反应一段时间后再加入与溴氨酸钠的质量比为1:5的铜粉,与一次性加入与溴氨酸钠的质量比为3:5的铜粉相比较,综合反应时间可节省2~3 h。 另外,对于DAS中混有的铜盐,采取在制备过程中加入柠檬酸的方法予以去除,此举可提高DAS的纯度。 当铜粉与柠檬酸的质量比为6:1时,可使DAS中铜盐的含量小于0.001%。 此外还探究了蒸馏后滤液的剩余量对DAS收率的影响,结果表明,滤液的剩余量在20 mL时,DAS的收率在95%以上。 基于本文的研究结果提出,欲进一步提高该反应的收率,需要寻找更高效的催化剂。

An Efficient Method for Improved Preparation of C.I.Pigment Red 177 Intermediate

The effect of batch addition of the catalyst(copper powder)on the reaction rate during the synthesis of 4,4′-diamino-1,1′-dianthraquinone-3,3′-disulfonic acid(DAS)was investigated systematically.The results indicate that 55℃is the preferred reaction temperature.Copper powder and sodium bromate with a mass ratio of of 2∶5 are first added,and the second portion of catalyst with a mass ratio of 1∶5 copper powder to sodium bromate is then added during the reaction.The reaction time could be saved for 2~3 h compared to adding copper powder at one time(the mass ratio of copper powder to sodium bromate is 3∶5).The copper salt mixed in DAS could be removed efficiently by addition of citric acid during the preparation process,which can improve the purity of DAS.When the mass ratio of copper powder to citric acid is 6∶1,the content of copper salt in DAS is less than 0.001%.In addition,the influence of the residual amount of the filtrate after distillation on the yield of DAS is also explored and the yield of DAS is above 95%when the remaining amount of filtrate is 20 mL.The results of this study also indicate that to further improve the yield of the reaction,more efficient catalyst is needed.