4,4′-二甲基二苯醚的合成

Synthesis of 4,4′-Dimethyl Diphenyl Ether

以对甲酚和对氯甲苯为原料,经Ullmann常压缩合醚化合成了4,4′-二甲基二苯醚。研究了物料配比、反应时间、催化剂用量、碱类型、加料方式等对反应的影响。实验发现,碱的类型和对氯甲苯的滴加方式是常压醚化成败的关键。较佳工艺条件是n(对氯甲苯)∶n(对甲酚)∶n(氢氧化钾)∶n(氯化亚铜)=1．0000∶1．4200∶0．8400∶0．0125,反应时间10 h。在此条件下,产品对氢氧化钾的收率为67．3%,产品中目的产物的质量分数为99．7%。

4,4＇-Dimethyl diphenyl ether was synthesized using p-cresol and p-chlorotoluene as starting materials through Ullmann etherification under normal pressure. The effects of ratio of starting materials, reaction time, dosage of catalyst, kinds of alkali and adding mode on the reaction were discussed. According to the experiment, kinds of alkali and adding mode of p-chlorotoluene were the key factors for the etherification. The optimum conditions were n（p-chlorotoluene） ： n（p-cresol） ： n（potassium hydroxide） ： n（CuCl） = 1.0000： 1.420 0：0.840 0 ： 0.012 5, reaction time 10h. Under above conditions, the yield based on potassium hydroxide was 67. 3%, the purity was 00.7%.