Preparation method of L-Se-methylselenocysteine

Abstract

The invention provides a preparation method of L-Se-methylselenocysteine. The preparation method comprises the following steps: A) carrying out a nucleophilic substitution reaction on methyl hydroselenide sodium salt with N-acetyl-3-chloro-L-serine methyl ester to obtain N-acetyl-3-selenium methyl-L-selenocysteine methyl ester; and B) hydrolyzing the N-acetyl-3-selenium methyl-L-selenocysteine methyl ester obtained in the step A) in a hydrochloric acid solution to obtain the L-Se-methylselenocysteine. According to the invention, the N-acetyl-3-chloro-L-serine methyl ester is used as a chiral source reagent, and the obtained product is a single optically active substance, so that complex and tedious splitting process can be overcome. The process has the advantages that raw materials are easily available and cheap, operation is convenient, reaction conditions are mild, the product is single, separation is easy, the yield is high, and the method is suitable for industrial production.

Description

Technical field [0001] The invention belongs to the technical field of organic fine chemical synthesis, and particularly relates to a preparation method of L-selenomethylselenocysteine. Background technique [0002] Selenium is an essential trace element for the human body and an important part of various enzymes in the human body. It has many functions such as anti-oxidation, anti-cancer, detoxification, promoting growth, and improving immunity. Once the body lacks selenium, it will directly lead to cardiovascular and cerebrovascular diseases. The occurrence of more than 40 diseases such as, hypertension, metabolic syndrome, gastrointestinal diseases, diabetes, asthma, Parkinson’s disease, liver disease, cancer, etc., which indirectly leads to the occurrence of more than 400 diseases. Therefore, selenium has a great impact on human health. The effect is irreplaceable by other substances. According to the data released by the World Health Organization, there are more than 40 cou...

AI Technical Summary

Problems solved by technology

[0008] (1) Sodium diselenide method: first react chloroalanine with sodium diselenide to generate selenocystine, then reduce and cleavage the Se-Se bond with metallic sodium / liquid ammonia (-70°C), and then methyl Selenomethylselenocysteine ​​is obtained by chemical reaction. The reaction conditions of this method are harsh, and metal sodium and liquid ammonia are used at ultra-low temperature. Special reaction equipment is required, which is not conducive to large-scale production.

[0009] (2) Sodium methyl selenide method: replace the chlorine in chloroalanine or chloroalanine methyl ester with sodium methyl selenate to obtain selenomethylselenocysteine. This method is due to the raw material source of chloroalanine Difficult, high production cost, low yield, not conducive to large-scale production

In this method, the preparation of the substrate dibromopropionitrile is obtained by addition of acrylonitrile and liquid bromine, but a large amount of volatile and toxic liquid bromine is used, which makes the operation difficult and requires high equipment, while serious pollution and environmental protection costs High; the nucleophilic substitution reaction of selenoxide and substrate has poor selectivity and low yield; the final product is a racemate, which needs to be resolved to obtain an optically active substance of a single configuration, so the process is cumbersome, tedious, and the yield is low. Low, only suitable for laboratory preparation and not for industrial production

[0014] In summary, the current synthesis methods of L-selenomethylselenocysteine ​​mainly have difficulties in raw material sources and high prices; complex synthesis processes and low yields; harsh reaction conditions and high equipment requirements; involving highly toxic raw materials, Severe environmental pollution; and the target product is a racemate (DL-configuration), which needs to be resolved, etc.

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