Preparation method of L-valine methyl ester hydrochloride

A technology of valine methyl ester and hydrochloride, which is applied in the field of preparation of amino acid derivatives, can solve the problems of failure to meet the use requirements, low product purity, incompleteness, etc., and achieve few steps, high purity and simple method Effect

Inactive Publication Date: 2010-12-01
张明宝
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

L-valine methyl ester hydrochloride is used as an intermediate for synthesizing high blood pressure drug sartan. In recent years, some studies have been done, but not comprehensively. There are also many shortcomings in its preparation method, for example: the product is not high in purity, and it is difficult to obtain The rate is low, the use requirements cannot be met, etc.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Measure 1 mol of anhydrous methanol and add it into the exhaust gas absorption liquid (prevent SO 2 and HCl gas escape) into a four-necked flask, cooled to about -8~-10°C with an external ice-salt bath, and slowly added 1.3mol of thionous phthalein chloride (SOCl 2 ), the rate of addition is limited by the reaction temperature not exceeding 0°C. After the drop is completed, stir at this temperature for 1h, add 20.5mol L-valine under cooling conditions, heat up to room temperature and stir for 3h, then heat and reflux at 65°C to react 8h, after the end of the reaction, distill under reduced pressure to evaporate most of the methanol and excess SOCl 2 , transfer the residue to a beaker for cooling and crystallization, vacuum filter, collect the crystals, and recrystallize with anhydrous methanol-ether to obtain L-valine methyl ester hydrochloride as white fine powder crystals. The reaction was monitored by thin-layer chromatography, using chloroform:methanol:32% glacial ...

Embodiment 2

[0014] Measure 1 mol of anhydrous methanol and add it into the exhaust gas absorption liquid (prevent SO 2 and HCl gas escape) into a four-neck flask, cooled to about -8~-10°C with an external ice-salt bath, and slowly added 1.5mol of thionous phthalein chloride (SOCl 2 ), the rate of addition is limited by the reaction temperature not exceeding 0°C, after the drop is completed, stir at this temperature for 1.5h, add 21mol L-valine under cooling conditions, heat up to room temperature and stir for 3.5h, then heat and reflux at 70°C Reaction 9h, after reaction finishes, underpressure distillation is to evaporate most of methyl alcohol and excess SOCl 2 , transfer the residue to a beaker for cooling and crystallization, vacuum filter, collect the crystals, and recrystallize with anhydrous methanol-ether to obtain L-valine methyl ester hydrochloride as white fine powder crystals. The reaction was monitored by thin-layer chromatography, using chloroform:methanol:32% glacial calci...

Embodiment 3

[0016] Measure 1 mol of anhydrous methanol and add it into the exhaust gas absorption liquid (prevent SO 2 and HCl gas escape) into a four-neck flask, cooled to about -8~-10°C with an external ice-salt bath, and slowly added 1.0mol of thionous phthalein chloride (SOCl 2 ), the rate of addition is limited by the reaction temperature not exceeding 0°C. After the drop is completed, stir at this temperature for 0.8h, add 20mol L-valine under cooling conditions, heat up to room temperature and stir for 2.5h, then heat and reflux at 60°C Reaction 7h, after the reaction finishes, vacuum distillation is to evaporate most of methyl alcohol and excess SOCl 2 , transfer the residue to a beaker for cooling and crystallization, vacuum filter, collect the crystals, and recrystallize with anhydrous methanol-ether to obtain L-valine methyl ester hydrochloride as white fine powder crystals. The reaction was monitored by thin-layer chromatography, using chloroform: methanol: 32% glacial calciu...

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PUM

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Abstract

The invention discloses a preparation method of L-valine methyl ester hydrochloride, which comprises the following steps of: firstly, adding absolute methanol in a reactor and controlling the temperature between 8 DEG C below zero and 10 DEG C below zero, dripping thionyl phthalyl chloride by stirring, reacting for 0.8-1.5 hours at the temperature, adding L-valine under the cooling condition, raising the temperature to the ambient temperature and stirring for 2.5-3.5 hours, then heating and refluxing, and reacting for 7-9 hours at the temperature of 60-70 DEG C; and secondly, reducing pressure to distill after the reaction, cooling residues for crystallization, carrying out vacuum filtration, and recrystallizing with absolute methyl-ethyl ether to prepare L-valine methyl ester hydrochloride, wherein the reaction materials have the mole ratio that n (L-valine):n (SOC12):n (absolute methanol)=1.0:1-1.5:20-21. The preparation method of the invention is simple, has fewer steps and small economic investment, and only requires commonly-used devices, and the prepared L-valine methyl ester hydrochloride is high in purity and yield and can satisfy the use requirements.

Description

technical field [0001] The invention relates to a preparation method of amino acid derivatives, in particular to a preparation method of L-valine methyl ester hydrochloride. Background technique [0002] The synthesis of amino acids and their derivatives is a new research field that has developed rapidly in recent years. They are widely used in medicine, chemical industry, food, agriculture, etc., and can be used as pharmaceutical intermediates, food additives, and cosmetic additives. , mineral flotation agent and bactericidal insecticide mixture, etc., the application prospect is very broad. It has important theoretical and practical significance to research and develop the preparation technology of amino acid esters and their derivatives with reliable process and reasonable cost. L-valine methyl ester hydrochloride is used as an intermediate for synthesizing high blood pressure drug sartan. In recent years, some studies have been done, but not comprehensively. There are a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C229/08C07C227/18
Inventor 张明宝
Owner 张明宝
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