一种有效制备2-(2-羟基苯基)-2-氧乙酸乙酯的方法

以环己酮和乙醛酸乙酯为原料,首先经酸性催化的Aldol缩合得中间体2-羟基-2-(2'-氧环己基)乙酸乙酯(Ⅶ),接着Ⅶ在碘酸-二甲基亚砜(HIO3-DMSO)体系下氧化、芳构化制得2-(2-羟基苯基)-2-氧乙酸乙酯(Ⅰ)。得到的最佳工艺条件为:以三氟乙酸为催化剂,n(乙醛酸乙酯)∶n(环己酮)=1∶10时,Ⅶ的收率为65.4%;氧化、芳构化反应中,n(HIO3)/n(Ⅶ)=2.0时,产物Ⅰ的收率为60.0%;对Ⅰ的结构进行了1HNMR,13CNMR和MS表征。

A Facile Preparation of Ethyl 2-(2-Hydroxyphenyl)-2-oxoacetate

2-(2-Hydroxyphenyl)-2-oxoacetate(I) is obtained from cyclohexanone and ethyl glyoxylate in two steps. Firstly, the condensation of cyclohexanone and ethyl glyoxylate furnished ethyl 2-hydroxy-2-(2-oxocyclohexyl)acetate(VII), then the final product I was synthesized through the oxidization and aromatization of VII with HIO3-DMSO. The reaction condition of each step was studied. The optimal process condition is that the yield of product VII is up to 65.4% when the catalyst is trifluoroacetic acid and the ratio of glyoxylate ethyl ester and cyclohexanone is 1:10 and the yield of I is 60.0% when HIO3-DMSO was two equivalents of VII. The structure of product I is confirmed by 1H NMR, 13C NMR spectra and MS.