Method for preparing D-valine by asymmetric transformation process

Abstract

The invention belongs to the technical field of preparation of D-amino acid compounds, and particularly relates to a method for preparing D-valine by an asymmetric transformation process. The method comprises the following steps: carrying out asymmetric transformation on a chiral resolution reagent D-diacetyl tartaric acid and DL-valine in a glyoxalic acid solution, and crystallizing to precipitate the target double salt; and separating the double salt, washing, and dissociating to obtain the D-valine, wherein the total yield is greater than 92%, and the resolution reagent D-diacetyl tartaric acid can be recycled. The method saves the step of DL step in the chemical resolution simple to operate, has the advantage of high resolution efficiency, avoids the phenomenon of entrapped precipitation in the chemical resolution method, and ensures the high optical purity of the D-valine (>99.5%ee). The recycling of the chiral reagent greatly lowers the production cost, and is suitable for industrial production.

Description

technical field [0001] The invention relates to a method for preparing D-valine by an asymmetric conversion method, and belongs to the technical field of preparation of chiral amino acid compounds. Background technique D-valine (D-Val for short) is an important organic chiral source, mainly used in the synthesis of chiral drugs, chiral additives, chiral auxiliary agents and other compounds, such as pharmaceutical raw materials And pharmaceutical intermediates, but also used in the synthesis of sweetener Alatan. Due to its own biochemical properties, D-valine can be used to synthesize new high-efficiency pesticides pyrethroids and halvalerate, and the valine pyrethrins prepared from it are a kind of broad-spectrum promising It is an insecticide and acaricide, which can inhibit the activity of insect enzyme system to play a contact and stomach poisoning effect, and can effectively control the main pests of cotton, fruit trees, vegetables and other crops, including Lepidopte...

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Problems solved by technology

Induced crystallization method to prepare D-valine has a long period, low yield and low optical purity

The preparation of D-valine by chemical resolution method has also been reported at home and abroad, such as 1. D.F.Holmes used menthol to synthesize the chiral reagent L-menthol oxyethylphthalein chloride to resolve helical valine; domestic patents are also useful for diphenyl The chemical resolution of formyl tartaric acid as a chiral reagent, the induced crystallization method and the chemical resolution method have the characteristics of low cost, but the optical purity of the product is low, and multiple recrystallizations are required to meet the requirements, and the maximum single yield is 50%

There are a lot of reports on the microbial asymmetric conversion method, but the concentration of the conversion process is too low, resulting in a lot of waste of water resources