偏苯三酸酐酰氯的合成

以偏苯三酸酐(TMA),二氯亚砜(SOC l2)为原料,CMA为催化剂,1,2-二氯乙烷(DCE)为溶剂,用减压蒸馏方法制备了偏苯三酸酐酰氯(TMAC)。其中,m(TMA)/m(SOC l2)=1.34;CMA、DCE的质量分别为TMA和SOC l2总质量的0.28%,37.5%;反应温度100℃;反应时间10.5 h。用FTIR对TMAC的结构进行了表征,测定其熔点为66.5~67.5℃,HPLC分析其质量分数≥99%。在同一反应器中可循环进行3次合成操作,TMAC的平均收率≥95%,而TMAC纯度不受影响。溶剂和过量的SOC l2可全部回收直接再次使用,循环反应时CMA补加原用量的1/10。该工艺可操作性强,已进入100 t/a中试实验阶段。

Synthesis of Trimellitic Anhydride Chloride

Trimellitic anhydride chloride(TMAC) was synthesized by reaction of trimellitic acid anhydride(TMA) with thionyl chloride(SOCl2),using CMA as catalyst and 1,2-dichloroethane(DCE)as solvent.TMAC was separated from the reaction system by vacuum distillation.The mass ratio of TMA with SOCl2,the ratios of CMA and DCE(based on total mass of TMA and SOCl2),reaction temperature and reaction time were 1.34,0.28%,37.5%,100 ℃ and 10.5 h,respectively.The structure was confirmed by means of FTIR technique.The melting point of TMAC prepared was 66.5～67.5 ℃,and the molar fraction was >99% as determined by HPLC.The process could be conducted 3 times in the same reaction vessel,and the average yield of TMAC was above 95%.Moreover,the purity kept unchanged during the circulation process.The solvent and excess SOCl2 could be completely reused without further disposal,and additional 1/10 of the original mass of CMA was needed to compensate the loss of CMA when circulation process was conducted.The technique was simple and came into pilot-scale trial of 100 t/a.