Clean preparation method of high-purity methionine hydroxyl analogue calcium salt

Abstract

The invention discloses a clean preparation method of high-purity methionine hydroxyl analogue calcium salt. The clean preparation method comprises the following specific steps: adding water into 2-hydroxy-4-methylthiobutyronitrile serving as a raw material, carrying out a hydration reaction under the catalytic action of solid acid / solid alkali, adding strong acid or strong alkali for hydrolysis to obtain 2-hydroxy-4-methylthiobutyric acid, then adding CaO or Ca(OH)2, carrying out a salt forming reaction to obtain an aqueous solution of a mixture, carrying out chromatographic desalination treatment on the aqueous solution of the mixture to obtain an aqueous solution of a methionine hydroxyl analogue, and finally carrying out spray drying on the aqueous solution of the methionine hydroxyl analogue to obtain a target product. Compared with a traditional method, the method disclosed by the invention has the advantages that the step of neutralizing and alkali washing after the reaction is finished is avoided, the generation of a byproduct, namely inorganic ammonium salt is avoided, reaction is simple, conditions are mild, and the method is safe and environment-friendly; and in addition, a catalyst, namely the solid acid or solid alkali adopted in the method can be recycled, so production cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a clean preparation method of high-purity methionine hydroxyl analogue calcium salt. Background technique [0002] The traditional method for preparing methionine is to use acrolein and methyl mercaptan as raw materials to produce methionine, and then to obtain methionine product through cyanamide reaction. [0003] J.Am used 3,6-bis-(β-chloroethyl)-2,5-diketopiperazine as raw material to react with thiourea and then dimethyl sulfate to obtain a methylthio-substituted intermediate, followed by hydrolysis Get methionine. However, the intermediates of this synthetic route need to use butyrolactone derivatives as raw materials, which can be obtained through multi-step synthetic reactions. The synthetic route is long and the yield is low, and the raw material cost is high and has no industrial value. [0004] Methionine Hydroxy Analogue (MHA) is a highly acid...

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