Preparation method of levocarnitine intermediate

Abstract

The invention discloses a preparation method of a levocarnitine intermediate. The preparation method comprises the following steps: taking S-epichlorohydrin as a starting raw material; firstly, takingS-epichlorohydrin and trimethylamine hydrochloride to be subjected to amination reaction, so as to obtain L-3-chloro-2-hydroxypropyltrimethyl ammonium chloride; then taking L-3-chloro-2-hydroxypropyltrimethyl ammonium chloride and sodium cyanide to be subjected to cyanation reaction to obtain the levocarnitine intermediate, i.e., L-3-cyano-2-hydroxypropyltrimethyl ammonium chloride. After the cyanation reaction is finished, a complexing agent is used for treating a reaction system; preferably, the complexing agent is phytic acid; after the cyanation reaction is finished, an adsorbent is usedfor treating the reaction system; preferably, the adsorbent is activated carbon. According to the method disclosed by the invention, the complexing agent is added to treat after the amination reaction, so that the color of an L-quaternary ammonium salt solution can be remarkably improved, and furthermore, the color of L-nitrile can be remarkably improved and the impurity content of L-nitrile is reduced. According to the method disclosed by the invention, the adsorbent is added to treat after the cyanation reaction, so that the color of L-nitrile can be remarkably improved, and furthermore, theimpurity content of L-nitrile is reduced.

Description

technical field [0001] The invention belongs to the technical field of preparation of pharmaceutical intermediates, in particular to a method for preparing levocarnitine intermediates. Background technique [0002] L-carnitine is an essential natural substance in the energy metabolism of mammals, and its main function is to promote lipid metabolism. It can not only bring long-chain fatty acids into the mitochondrial matrix, promote their oxidation and decomposition, provide energy for cells, but also export short-chain fatty acyl groups produced in mitochondria. The supplementation of this product can relieve the fat metabolism disorder caused by the deficiency in the body, and the dysfunction of skeletal muscle and cardiac muscle and other tissues. [0003] At present, the most common production method of levocarnitine is to use S-epichlorohydrin as the starting material, and first perform amination reaction with trimethylamine hydrochloride to obtain L-chlorinated 3-chlor...

AI Technical Summary

Problems solved by technology

[0004] The main problem that this method exists at present is: the L-quaternary ammonium salt solution color that amination reaction obtains is dark brown, and then the L-nitrile compound color and luster that cyanide reaction obtains is khaki or tan, and impurity content is obviously more, like this Directly affect the final product quality of L-carnitine