A green synthesis method of high-purity 3-methylamino-1,2-propanediol

Abstract

The invention provides a green synthesis method of high-purity 3-methylamino-1,2-propanediol, the method comprising the preparation of glycidol and the synthesis of 3-methylamino-1,2-propanediol; the preparation of glycidol , including adding chloroglycerin, adding sodium methoxide methanol solution, reacting, and distilling; the synthesis of 3-methylamino-1,2-propanediol includes pressure testing, feeding, amination reaction, recovery of monomethylamine, and distillation. The beneficial effects of the present invention are: the product prepared by the present invention has high purity, the content of impurities and water is reduced, the appearance is a colorless transparent viscous liquid, the product purity is 99.87-99.96%, and the yield is 98.52-98.99%; The rate is 92.61‑93.76%, and the purity is 99.25‑99.40%; the production cycle is shortened; it is safe and environmentally friendly; side reactions such as polymerization hardly occur; energy saving and consumption reduction are obvious.

Description

technical field [0001] The invention relates to a green synthesis method of high-purity 3-methylamino-1,2-propanediol, belonging to the field of chemical synthesis. Background technique [0002] Iopromide is a non-ionic contrast agent developed by the French Guerbet pharmaceutical company. It has experienced 90 million clinical applications abroad, which proves that it has good safety and imaging effects. As a water-soluble contrast agent, its water solubility is large, It has low viscosity, good tolerance, and low toxicity of intravenous injection. It is an ideal contrast agent for CT enhanced scanning. Compared with iohexol, both iopromide and iohexol are low-osmotic, non-ionic contrast agents, and their iodine content and osmotic pressure are basically the same, but iopromide is more expensive than iohexol, and the imaging effect is higher than that of iohexol. a little better. Iopromide ranks second in the domestic market share of contrast agents. According to statisti...

AI Technical Summary

Problems solved by technology

These two methods have the following disadvantages: due to the existence of a large amount of monomethylamine hydrochloride in the post-treatment process of the amination solution, the material in the later stage is viscous and difficult to distill, and it needs to be refined with low-carbon alcohols to dissolve, filter and desalinate, and the operation is cumbersome. The salt takes away part of the product, and the presence of a small amount of salt in the rectification of the finished product causes local heat and mass transfer to be uneven, which directly affects the product yield and the amount of distillation residue

The method has long reaction time, low purity, low yield, cumbersome operation, and the introduction of low-toxic toluene, which increases the risk of reaction

[0006] In the prior art, chloroglycerin is directly reacted with monomethylamine to prepare 3-methylamino-1,2-propanediol. This method mainly has the following disadvantages: (1) long operation cycle: use 40% monomethylamine aqueous solution After the reaction is completed, the post-treatment requires flash deamination dehydration, alkali addition, secondary dehydration, distillation and other operations. The operation time of each process ranges from 6 to 18 hours; (2) Large energy consumption: it takes About 3200kg of water is evaporated, and the stirring motor of the kettle reactor keeps running during the subsequent processing operation after the amination is completed, which consumes a lot of energy; (3) The product has low purity and high impurity content: the distillation process of the finished product must steam out low boilers and water in sequence , front fraction, etc. If the distillation time is too long, it will cause quality problems such as low purity, colored appearance, and high impurity content of the product, especially in the late stage of distillation.

The reaction operation of this method is easy to control, but the operation time is long, and dichloromethane is used as the solvent, and the solvent consumption is large