4,6-二胺基间苯二酚盐酸盐的合成工艺研究

Study on the Synthetical Technology of 4,6-Diaminoresorcinol Dichloride

4,6-二胺基间苯二酚盐酸盐(DADHB)是制备聚对苯撑苯并双噁唑(PBO)的单体之一,今以改进的 1,2,3-三氯苯路线由硝化、水解、催化加氢反应制得了各步反应的中间体和最终单体,并对中间体和单体进行了 FT-IR、元素分析、1H NMR、13C NMR 等分析。用优化原料配比直接过滤出水解物的工艺方法,简化了乙酸乙酯提取工艺中难以操作的缺点;并用 HAc 介质路线彻底解决了传统 HAc/NaAc 加氢工艺中易引入无机盐杂质的问题。

Diaminoresorcinol dichloride (DADHB) is one of the monomers for the production of poly (p-phenylene benzobisoxazole) (PBO), which has an excellent combination property, such as high tensile strength, high stiffness, high thermal stability and others. Beginning from the raw material ?? 1,2,3-trichlorobenzene, the traditional route of DADHB production consists of three reaction steps ?? nitration, hydrolization and catalytic hydrogenation and this traditional route suffers some defects, such as it is hard to control the operation during the hydrolytic stage and the final product DADHB is easily contaminated by NaCl formed in the hydrogenation stage. Pointing to these defects, some improvements were proposed. For the hydrolytic stage, the suitable adding mole ratio of NaOH to 1,2,3chloro-4,6-dinitobanzeno is taken as 4:1 and filtrate the hydrolysate directly other than using ethyl acetate as extractant; for the hydrogenation stage, instate of in HAc/NaAc buffer soulution, the 2-chloro-4,6-dinitro-resorcinol is hydrogenated in HAc aqueous solution and no NaAc is added. Meanwhile the final product DADHB and the intermediate products of each step were analysed by FT-IR, elemental analhsis, HNMR 1 13C NMR and others, respectively. The results show that the modified process proposed overcomes the defects of the traditional route well.