Lewis酸催化对甲酚与异丁烯合成对叔丁氧基甲苯

Synthesis of 1-tert-butoxy-4-methylbenzene with p-cresol and isobutene catalyzed by Lewis acid

以Lewis酸为催化剂,对甲苯酚与异丁烯经O-烷基化反应合成对叔丁氧基甲苯。考察了催化剂种类、催化剂用量、反应温度、物料比等因素对反应的影响。实验表明适宜的工艺条件是对甲酚与结晶氯化铁的质量比为11.8∶1,异丁烯与对甲酚的物质的量为1.6∶1,异丁烯通过耐压恒压滴液漏斗滴加,反应温度为30℃,反应时间为9 h,收率达76%,纯度为99.6%。探讨了Lewis酸催化O-烷基化反应的机理。该方法具有原子经济性好,O-烷基化反应选择性高特点。

1-tert-Butoxy--4-methylbenzene was prepared through O-alkylation of p-cresol and isobutene catalyzed by Lewis acid. The effects of reaction conditions such as type of catalyst,the amount of catalyst, temperature, and mole ratios between materials on O-alkylation were optimized. The yield of product can be 76% with content of 99.6% when weight ratio of p-cresol/crystal ferric chloride is 11.8：1 ,molar ratio of isobutene/p-cresol 1.6 ： 1, reaction temperature30℃ , re- action time 9 h, condensed isobutene dropped with iresistant and constant pressure dropping funnel. The reaction mechanism of O-alkylation catalyzed by Lewis acid was discussed. The method is characterized by excellent atom economy and high selectivity of O-alkylation.