Method for preparing S-4-methoxymandelic acid through splitting S-1-phenylethylamine

Abstract

The invention discloses a method for preparing S-4-methoxymandelic acid through splitting. The method concretely includes the steps that in alcohol solvent, racemic 4-methoxymandelic acid is used as a raw material, S-1-phenylethylamine is used as a splitting agent for reaction, then S-1-phenylethylamine salt of S-4-methoxymandelic acid is obtained through cooling, crystallizing and separating, and S-4-methoxymandelic acid is obtained through acid freeing after salt recrystallization is performed; after the solution containing the splitting agent is mixed, alcohol is removed through evaporation, after cooling, water and alkaline are added for freeing, and the splitting agent which is S-1-phenylethylamine is obtained through extracting, drying and concentrating. The method for preparing S-4-methoxymandelic acid through splitting has the advantages that conditions are mild, operation is easy, the product yield is good, optical purity is high, and the splitting agent can be recycled, and is quite suitable for preparing and producing S-4-methoxymandelic acid.

Description

technical field [0001] The invention relates to a method for splitting and preparing chiral α-hydroxy carboxylic acid, in particular to a method for splitting and preparing S-4-methoxymandelic acid. Background technique [0002] 4-Methoxymandelic acid, as a chiral α-hydroxy carboxylic acid, has two enantiomeric configurations of R-type and S-type, and has important applications in many fields such as pharmaceutical production and asymmetric synthesis. In current reports, the methods for preparing S-4-methoxymandelic acid can be divided into asymmetric hydrolysis and chemical resolution. Asymmetric hydrolysis uses D-4-methoxymandelic acid methyl ester as a raw material to obtain S-4-methoxymandelic acid through enzyme-catalyzed asymmetric hydrolysis (Journal of the Chemical Society, p.2069-2072), while The chemical resolution method is to use (2S,3S)-2,3-dibenzyloxy-1,4-bis(hydroxylamine)butane as a resolving agent to resolve 4-methoxymandelic acid to obtain S- 4-Methoxyman...

AI Technical Summary

Problems solved by technology

The two reported methods have the disadvantages of low optical purity of the product, expensive bioresolution catalysts and chemical resolution agents, and difficulty in obtaining them.