2,2′,3,3′-联苯四酸二酐的合成与表征

Synthesis and Characterization of 2,2′,3,3′-Biphenyltetracarboxylic Dianhydride

研究了以3-氯-邻苯二甲酸酐为原料,经甲胺化、偶联、水解和脱水反应制备2,2,′3,3′-联苯四酸二酐(i-BPDA)的工艺过程,偶联反应以三苯基膦(PPh3)为配位体的镍络合物为催化剂、锌粉为还原剂、碘化钠为促进剂。采用红外光谱、氢核磁共振对i-BPDA及反应中间产物的结构进行了表征,并用高效液相色谱测定了i-BPDA的纯度。实验结果表明,中间产物N-甲基-3-氯-邻苯酰亚胺(C8H6NO2C l)偶联反应的收率受催化剂的种类、催化剂配比、反应时间和反应温度的影响,其中当催化剂中的镍化合物为无水N iC l2时,催化剂的活性最高;最佳偶联条件为:n(C8H6NO2C l)∶n(N iC l2)∶n(PPh3)∶n(Zn)=1∶1∶4∶1.1,反应时间5h,反应温度110℃。在此条件下,偶联产物的收率为69.0%。i-BPDA的平均纯度大于98%。

2,2′, 3,3′-biphenyltetracarboxylic dianhydride （ i-BPDA）, used in synthesis of polyimide, was prepared through a series of reactions：firstly,reaction of methylamine with 3-chlorophthalimide to N-methyl-3-chlorophthalimide; secondly, coupling of N-methyl-3-chlorophthalimide（ CsH6NO2CI ） with previously prepared triphenylphosphine （PPh3）-nickel chloride as catalyst, zinc powder as reducing agent and sodium iodide as promoting agent;thirdly, hydrolysis of product in basic solution;finally, dehydration of product. The coupling was key reaction. Structures of i-BPDA and coupling intermediate were confirmed by means of IR and 1H NMR. Purity of i-BPDA was measured by HPLC. Effects of catalyst types, and ratios of catalyst to reducing agent and promoting agent on coupling yield of N-methyl-3-chlorophthalimide were investigated. When Ni compound in catalyst was anhydrous NiCl2, its catalytic activity was the highest. Under optimal coupling reaction conditions： n（C8H6NO2CI） ： n（NiCl2） ： n（PPh3） ： n（Zn） 1 ： 1：4 ： 1.1,110℃ and 5 h,coupling yield of Nmethyl-3-chlorophthalimide could reach 69.0%. Average purity of i-BPDA was more than 98%.