申请人:Yoshida Hiroshi
公开号:US20050090686A1
公开(公告)日:2005-04-28
The present invention provides a process for more efficiently producing an α-hydroxycarboxylic acid ester wherein side reactions due to the α-hydroxycarboxylic acid ester are inhibited or prevented in comparison with prior art production processes. The invention provides a process for producing an α-hydroxycarboxylic acid ester comprising Steps 1 to 3: Step 1. reacting, in the presence of oxygen, (i) a 1,2-diol with a 1,2-diol or (ii) a 1,2-diol with an alcohol to obtain a reaction product containing an α-hydroxycarboxylic acid ester; Step 2. separating the α-hydroxycarboxylic acid ester from the reaction product obtained in Step 1 by distillation under reduced pressure; and Step 3. feeding Step 1 with a mixture obtained by partially or entirely removing water from the reaction product, wherein the mixture contains an unreacted 1,2-diol and/or alcohol.
本发明提供了一种比现有生产工艺更高效地生产α-羟基羧酸酯的过程,其中由于α-羟基羧酸酯引起的副反应被抑制或预防。该发明提供了一种生产α-羟基羧酸酯的过程,包括步骤1至3:步骤1。在氧气存在下,反应(i) 1,2-二醇与1,2-二醇或(ii) 1,2-二醇与醇,以获得含有α-羟基羧酸酯的反应产物;步骤2。通过减压蒸馏将α-羟基羧酸酯从步骤1获得的反应产物中分离出来;步骤3。将步骤1与从反应产物中部分或完全去除水而得到的混合物一起加入,其中混合物含有未反应的1,2-二醇和/或醇。