对羟基苯乙酸酯还原法制备对羟基苯乙醇的工艺研究

对羟基苯乙醇是一种重要的医药中间体,但目前的合成方法存在着成本高、难以工业化等不足。研究了硼氢化钾系列的多种还原体系将对羟基苯乙酸甲酯还原为对羟基苯乙醇的反应。研究发现,KBH4-ZnCl2体系在对羟基苯乙酸甲酯的还原中显示出较好的实验结果,其优惠工艺条件为n(对羟基苯乙酸甲酯)∶n(硼氢化钾)=1∶1.5,n(硼氢化钾)∶n(氯化锌)=1.5∶1,反应时间为6h,反应温度66℃(回流)。此工艺条件下对羟基苯乙醇的收率为82.7%,纯度为98.6%。

Preparation Methods for p-Hydroxyphenylethyl Alcohol by Reduction of Methyh p-Hydroxyphenylacetate

p-Hydroxyphenylethyl alcohol is an important medicine intermediate.At present,the synthetic methods of p-hydroxyphenylethyl alcohol are not suitable for large-scale industrial application due to the long synthetic route,low overall yield,rigorous reaction conditions and high cost.In this paper,various of modified potassium borohydride systems were studied in the reduction of p-hydroxyphenylacetate methyl.KBH4-ZnCl2 displayed high reduction activity,and the optimum conditions were determined:n(KBH4):n(p-hydroxyphenylacetate methyl)=1.5:1,n(ZnCl2):n(KBH4)=1:1.5,reaction temperature 66℃(reflux),reaction time 6 h.The yield was 82.7% and the purity was 98.6% under the optimum conditions.