Method and device for preparing L-selenocystine by using sodium triacetoxyborohydride as reducing agent

Abstract

The invention belongs to the field of chemical conversion, and particularly discloses a method and a device for preparing selenocystine under mild conditions. The method specifically comprises the following steps: mixing selenium powder, a strong alkaline substance, water and sodium triacetoxyborohydride, adding a 3-chloro-L-alanine aqueous solution, and carrying out a stirring reaction; and afterthe reaction is finished, adding an acid, filtering, adding an alkali into the obtained filtrate to adjust the pH value, and carrying out standing filtering to obtain filter residues, ie., selenocystine. According to the invention, the method has the advantages of few side reactions, high raw material utilization rate, and almost no generation of hydrogen or other undesired reactions; and a sodium diselenide solution is prepared by using sodium triacetoxyborohydride as a reducing agent under a strong alkaline condition, so that the reaction is mild, safe and reliable, the operation is simpleand feasible, the reaction process is mild and controllable, and the method has good application prospect.

Description

technical field [0001] The invention belongs to the field of chemical transformation, and in particular relates to a method and a device for preparing selenocystine by using sodium triacetoxyborohydride as a reducing agent. Background technique [0002] Selenium is an essential trace element to maintain human health, and the state of "selenium deficiency" or "low selenium" can lead to the occurrence of various diseases. Supplementing selenium is an effective way to solve the problem of "selenium deficiency" or "low selenium". It is generally believed that organic selenium compounds have higher bioavailability and less toxicity than inorganic selenium compounds, and are more suitable as selenium supplements. Selenocystine is an important representative of organic selenium compounds and has a wide range of biological activities. It can also be used as an important raw material for the synthesis of L-selenium-methylselenocysteine. Therefore, the market demand for selenocystine...

AI Technical Summary

Problems solved by technology

The first five methods are not used by manufacturers at home and abroad because of difficult sources of raw materials, high prices, difficult separation and purification of products, or low yields.

The last method, using chloroalanine hydrochloride and sodium diselenide to react to synthesize L-selenocystine is a promising preparation method, but there are also very obvious deficiencies: 1) sodium diselenide is generally For immediate use, use flammable and explosive NaBH 4 Reduced selenium powder, because selenium powder is insoluble in water, NaBH 4 It is difficult to directly contact with selenium powder; in order to ensure sufficient reduction of selenium powder, NaBH 4 Serious excessive use is required, generally more than 10 times the theoretical equivalent, so the reaction is very violent and the risk is high; excessive NaBH 4 Instead of reacting selenium powder, it reacts with solvent water to produce a large amount of hydrogen gas. The post-processing of the gas is troublesome and has potential safety hazards.

2) Because NaBH in the reaction process 4 The reactivity of the four hydrogens in the molecule is inconsistent. In the later stage of the reaction, the relative reactivity is slightly insufficient, and heating is required to make it completely reacted. Therefore, the requirements for the reaction equipment are relatively high in medium-scale preparations. There are large-scale manufacturers of L-selenocysteine

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