三相相转移催化法精制粗间二硝基苯

以氯甲基聚苯乙烯树脂分别与三甲胺、三乙胺、三丁胺、三乙醇胺、吡啶5种叔胺反应,制备了不同的聚合物三相相转移催化剂,并用于间二硝基苯精制,考察了催化剂、氢氧化钠、甲醇的用量及催化剂种类对邻、对二硝基苯转化率的影响,得到了适宜的精制工艺条件为:m(粗间二硝基苯)∶m(甲醇)∶m(NaOH)∶m(聚苯乙烯吡啶树脂)=1∶0.8∶0.1∶0.12,反应温度76～78℃,反应时间2 h。在该条件下,邻对二硝基苯的转化率在99.5%以上,精制后的间二硝基苯经色谱分析后其色谱纯度达99.8%,间二硝基苯的收率在99%左右,聚苯乙烯吡啶树脂催化剂可重复使用7次以上。

Purification of m-Dinitrobenzene by Triphrase Transfer Catalysis

A variety of polymeric phase transfer catalysts with quaternary ammonium active center was synthesized by means of quarterisation of tertiary amine and chloromethylated polystyrene polymer,and then was used in the purification of crude m-dinitrobenzene,where p-dinitrobenzene and o-dinitrobenzene were tranferred into nitrodiphenyl ether.The optimum process conditions and the best catalyst were determined on the basis of the reaction yields with different regents and catalysts.It was concluded that polystyrene polymer pyridine and methnol were the best catalyst and oxyalkylation reagent for this reaction.Under the optimum process conditions of m(crude m-dinitrobenzene)∶ m(methnol)∶ m(sodium hydroxide)∶ m(polystyrene polymer pyridine) being 1∶ 0.8∶ 0.1∶ 0.12,and temperature and reaction time being 76~78 ℃ and 2 h,the conversion rate of m-dinitrobenzene reached 99.5%,and the purity of the refined m-dinitrobenzene was 99.8% with its yield being about 99%.Polystyrene polymer pyridine resin was very easy to prepare and could be repeatedly used for at least 7 times.