Synthesis process of thiothiamine

Abstract

The invention discloses a synthesis process of thiothiamine. The synthesis process comprises the following steps of dissociating acetamidine hydrochloride with liquid sodium methoxide and then filtering to retain the solution, placing the solution into a reactor, adding alpha-(o-chloroaniline)ylmethenyl-beta-formylaminopropionitrile (enamine), and then recovering methanol and carrying out cyclization reaction to obtain a cyclized solution; adding an aqueous phase to the cyclized solution, distilling, wherein the distillation temperature of vapor is 120 DEG C; after o-chloroaniline is completely stripped out, adding a caustic soda liquid, hydrolyzing and then adding water, adding carbon disulfide, reacting, finally adding gamma-chloro-gamma-acetyl propanol, carrying out condensation and filtering to obtain a thiothiamine crude; dissolving with hydrochloric acid, reacting, adding activated carbon, decolorizing, filtering to remain filtrate, neutralizing with the caustic soda liquid; and after a solid is precipitated, filtering and drying the solid to obtain the finished thiothiamine. The synthesis process of thiothiamine disclosed by the invention has the advantages that the process steps are simple, the yield of thiothiamine is high, the generation of wastes is reduced, the environment friendliness is achieved and the production cost is reduced.

Description

technical field [0001] The invention relates to the technical field of vitamin production, in particular to a synthesis process of thiothiamine. Background technique [0002] The synthetic technology of vitamin B1 at home and abroad, at present relatively mature routes mainly include acrylonitrile acetylpyrimidine route, acrylonitrile formyl pyrimidine route and malononitrile route. In China, the acrylonitrile formyl pyrimidine route is generally used to synthesize vitamin B1. This method mainly includes aminopropionitrile, sodium substitution, enamine, pyrimidine, chlorate, ether hydrochloride, thiothiamine, thiothiamine oxidation, sulfuric acid nitric acid, and sulfuric acid. Amine neutralization, and thiamine hydrochloride and other processes. Wherein thiothiamine is an important intermediate for the synthesis of vitamin B1 by this method, and the above-mentioned preparation method has the following defects: 1. In the preparation process of pyrimidine, after the cyclizat...

AI Technical Summary

Problems solved by technology

Wherein thiothiamine is an important intermediate for the synthesis of vitamin B1 by this method, and the above-mentioned preparation method has the following defects: 1. In the preparation process of pyrimidine, after the cyclization, it needs to be filtered and dried, that is, to separate the solid from the liquid. The operation is cumbersome, and the process is labor-intensive; on the other hand, it is easy to cause the loss of solute and solvent, the combined yield from enamine to thiothiamine is low, and a lot of solid waste is produced, the smell is large, and the energy consumption is high. Larger, not conducive to the protection of the environment