1,2,3-三氯苯的硝化反应研究

Study on Nitration of 1,2,3-Trichlorobenzene

对1,2,3-三氯苯(TCB)经硝化反应合成4,6-二硝基三氯苯进行了研究,考察了其在硝酸/硫酸、硝酸钾/硫酸和有机溶剂中的硝化反应;在混酸体系中,考察了物料配比、反应温度、反应时间对4,6-二硝基三氯苯收率的影响。在65%硝酸/98%硫酸体系中,确定了较优的反应条件为:n(TCB)∶n(硫酸)∶n(硝酸)=1∶11.3∶2.3、反应温度65℃、反应时间4.5 h,在此条件下,4,6-二硝基三氯苯的收率最高,达93.95%。为循环利用废酸,考察了在65%硝酸/95%硫酸体系中1,2,3-三氯苯的硝化反应,在反应温度为85℃、反应时间为4.5 h的条件下,目标产物收率达90.34%,可实现废酸的循环利用,减轻环境污染。而在硝酸钾/硫酸和有机溶剂中的1,2,3-三氯苯硝化反应,仅能得到部分目标产物和一硝化产物。目标化合物的结构经红外、高效液相色谱和元素分析进行表征。

The nitration of 1,2,3-trichlorobenzene were explored in the nitration system of nitric acid/sulfu- ric acid, potassium nitrate/sulfuric acid and organic solvent. The effects of molar ratio of raw materials, reaction temperature and reaction time on the 4,6-dinitro-1,2,3-trichlorobenzene yield were evaluated in the system of nitric acid/sulfuric acid. The optimum conditions were selected in the system of 65% nitric acid/98% sulfuric acid as follows：molar ratio of 1,2,3-trichlorobenzene to sulfuric acid to nitric acid of 1 ： 11.3： 2.3, reaction temperature of 65℃ and reaction time of 4.5 h. The yield of 4,6-dinitro-1,2,3-trichlorobenzene was 93.95% under above conditions. The nitration of 1,2,3-trichlorobenzen was studied in the system of 65 % nitric acid/ 95% sulfuric acid,the results showed that the yield could reach 90.34% at the reaction temperature of 85 ℃ with the reaction time of 4.5 h. Through this method, all the waste acid could be recovered, and environment pollution could be reduced. Part of compounds of dinitration and mononitration could be obtained in the system of potassium nitrate/sulfuric acid and organic solvent. The structure of target product was characterized by IR, HPLC and elemental analysis.