Preparation method of D,L-2-hydroxy-4-methylthiobutyrate

A technology of methylthiobutyrate and methylthiobutyronitrile, which is applied in the field of chemical industry, can solve the problems of increasing production cost and increasing separation and purification steps, and achieve the effects of improving production efficiency, reducing reaction steps and stabilizing properties

Active Publication Date: 2014-01-22
NINGXIA UNISPLENDOUR TIANHUA METHIONINE CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Compared with the first two methods, this preparation method has fewer steps and improved product purity, but this reaction requires additional addition of a large amount of organic solvent as a reaction medium, resulting in increased production costs and increased separation and purification steps.

Method used

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  • Preparation method of D,L-2-hydroxy-4-methylthiobutyrate
  • Preparation method of D,L-2-hydroxy-4-methylthiobutyrate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] The hydrogen cyanide gas mixture I from the hydrocyanic acid synthesis tower was tested. The composition of the hydrogen cyanide gas mixture I was: hydrogen cyanide gas 8.87%, water vapor 3.88%, ammonia 1.64%, hydrogen 1.13%, nitrogen 76.01%, oxygen 1.48%, carbon monoxide 5.67%, carbon dioxide 1.13%, methane 0.39%.

[0045] Hydrocyanic acid mixed gas I passes through a 75% sulfuric acid tower to absorb ammonia and water vapor in the mixed gas to obtain hydrocyanic acid mixed gas II. After testing, its composition is: hydrocyanic acid gas 9.35%, hydrogen 1.57%, Nitrogen is 79.44%, oxygen is 1.71%, carbon monoxide is 5.79%, carbon dioxide is 1.50%, and methane is 0.64%.

Embodiment 2

[0047] The hydrogen cyanide mixed gas II was passed into 223.3g of 94.5% methylthiopropionaldehyde, and the methylthiopropionaldehyde contained 3.3g pyridine. The reaction was performed under normal pressure, the reaction temperature was controlled to be 45°C, the aeration rate was 300L / min, the tail gas was absorbed by sodium hydroxide, and the residual amount of methylthiopropionaldehyde was monitored by HPLC. When the residual amount of methionylpropionaldehyde is less than 0.5%, it is the end of the reaction, and the flow can be stopped. A total of 270.64 g of light yellow liquid was obtained, the content of 2-hydroxy-4-methylthiobutyronitrile was 98%, and the residual hydrocyanic acid was 0.5%. Divide the obtained 2-hydroxy-4-methylthiobutyronitrile together with the reaction solution (ie 2-hydroxy-4-methylthiobutyronitrile reaction system) into two parts. Add 8.5g of water to one part and keep it at 3℃ for 120 days without decomposition; the other part is added with 8.5g...

Embodiment 3

[0049] The hydrogen cyanide mixed gas II was passed into 223.3g of 94.5% methylthiopropionaldehyde, and the methionylpropionaldehyde contained 2.2g pyridine and 10g water. Under 0.15MPa, the reaction temperature was controlled to 42°C, the aeration rate was 280L / min, the tail gas was absorbed by sodium hydroxide, and the residual amount of methylthiopropionaldehyde was monitored by HPLC. When the residual amount of methionylpropionaldehyde is less than 0.5%, it is the end of the reaction, and the flow can be stopped. A total of 279.54 g of light yellow liquid was obtained, the content of 2-hydroxy-4-methylthiobutyronitrile was 98%, and the residual hydrocyanic acid was 0.07%. The obtained 2-hydroxy-4-methylthiobutyronitrile together with the reaction liquid was equally divided into two parts. One part was stored at 3°C ​​for 120 days without decomposition; the other part was acidified with 85% sulfuric acid to pH 3, and stored at 20°C for 130 days, 2-hydroxy-4-methylthiobutyl ...

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Abstract

The invention aims at the chemical industry field, and relates to a preparation method of D,L-2-hydroxy-4-methylthiobutyrate. The method comprises the following steps: fully reacting a hydrocyanic acid gas mixture prepared through an Andrussow method with methylthiopropionaldehyde under the catalysis of an alkali to obtain a 2-hydroxy-4-methylthiobutyronityile reaction system; and mixing the 2-hydroxy-4-methylthiobutyronityile reaction system with alcohol, and carrying out hydrolysis and esterification reactions under the catalysis of an inorganic acid to prepare the D,L-2-hydroxy-4-methylthiobutyrate. Initial raw materials which are not rectified or purified, and are cheap and easily available, an intermediate obtained through a reaction has stable properties, few reaction steps are realized, and a finally obtained product is simply separated and purified to obtain high-purity and high-yield D,L-2-hydroxy-4-methylthiobutyrate.

Description

Technical field [0001] The invention is aimed at the chemical industry and relates to a preparation method of D,L-2-hydroxy-4-methylthiobutyrate. Background technique [0002] Methionine hydroxy analog is a newly synthesized liquid substance with methionine biological activity this year. In addition to methionine function, it also has functions such as acidulant. D,L-2-Hydroxy-4-methylthiobutyric acid is a liquid methionine hydroxy analog. Although it does not have an amino group, it can still participate in the metabolism and synthesis of L-methionine in the body. Amino action can also use free ammonia in the blood, increase ammonia deposits in the body, improve ammonia utilization efficiency, reduce ammonia excretion, and reduce environmental pollution. D,L-2-Hydroxy-4-methylthiobutyric acid has the effect of promoting fiber degradation and acetic acid growth in the body, but it is easier to be degraded by microorganisms in the body, the residence time in the body is short, an...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C323/52C07C319/20
Inventor 吴传隆朱小莉秦岭丁永良朱丽利杨帆任星宇陈宏杨王用贵李欧
Owner NINGXIA UNISPLENDOUR TIANHUA METHIONINE CO LTD
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