Preparation method of N-alkyloxy oxalyl alanine alkyl ester

Abstract

The invention discloses a preparation method of N-alkyloxy oxalyl alanine alkyl ester, comprising the steps of: subjecting pyruvic acid alkyl ester (2) and oxamic acid alkyl ester (3) to a reductive amination reaction so as to obtain a target compound (1) directly in the following reaction route; or, conducting a dehydration reaction to pyruvic acid alkyl ester (2) and oxamic acid alkyl ester (3) first so as to obtain an intermediate Schiff base (4), which then undergoes a reduction reaction, thus obtaining the target compound (1), with a following reaction route; wherein, R1 and R2 respectively represent methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or t butyl. With the advantages of simple operation, short preparation period, low energy consumption, strong industrial feasibility and the like, the preparation method provided in the invention can satisfy the requirements for large-scale industrial production.

Description

technical field The invention relates to a preparation method of N-alkoxy oxalylalanine alkyl ester, which belongs to the technical field of organic chemical synthesis. Background technique N-alkoxy oxalylalanine alkyl ester is an important intermediate in the synthesis of vitamin B6. According to the record of existing literature, the preparation of N-alkoxy oxalylalanine alkyl ester has the following methods at present: (1) alanine alkyl ester directly or its hydrochloride and alkoxy oxalyl chloride or oxalic acid Dialkyl ester reacts (FR1533817 in the presence of organic base in methylene chloride; JP43010614 (1968); Bull.Chem.Soc.Japan 42 (5), 1435-1457 (1969); CN91103013, J.Heterocyclic.Chem ., 32, 1693-1702(1995); CN200680053471, Bioorg.&Med.Chem.Lett.17(6), 1671-1679(2007)); (2) reaction of alanine and oxalic acid in methanol or ethanol (US3646061 ; JP46002969(1971); Bull.Chem.Soc. Japan 45,1917-1918(1972)); (3) with ethanol as solvent, alanine and oxalic acid react...

AI Technical Summary

Problems solved by technology

In the above method, some raw materials are expensive, such as alkoxy oxalyl chloride as a raw material, which is not suitable for industrial production; some reaction times are too long, such as the direct ester acylation of alanine, and the water separation time of the ester acylation reaction is as long as hundreds of years. hours, a large amount of energy is consumed in the process