Post-treatment method of sucrose-6-carboxylic ester chlorination reaction liquid

Abstract

The invention provides a post-treatment method of sucrose-6-carboxylate chlorination reaction liquid. The post-treatment method comprises the following steps: adding ammonia water or water into the sucrose-6-carboxylate chlorination reaction liquid to carry out primary neutralization reaction; introducing ammonia gas into the obtained reaction solution at a preset temperature, adjusting the pH value to an alkaline preset range, and continuously keeping the reaction for a period of time at the reaction temperature; and adding acid into the reaction solution obtained in the ammonia neutralization step, and regulating the pH value to a preset acidity range. A small amount of ammonia water or water is added, so that the subsequent ammonia gas absorption efficiency can be effectively improved,and the ammonia gas utilization rate is increased; generation of a sucrose-6-carboxylate hydrolysis side reaction is avoided, and the conversion rate and selectivity of the reaction are improved; theorganic solvent recovered by subsequent distillation can be directly recycled only by simple treatment, so that tedious procedures such as dehydration and rectification treatment on the organic solvent are reduced. The problems of generation of a large amount of wastewater, wastewater treatment and the like are avoided, and the production cost is greatly reduced.

Description

Technical field[0001]The invention relates to the technical field of fine chemical manufacturing, in particular to a post-treatment method of a sucrose-6-carboxylate chlorination reaction liquid.Background technique[0002]Sucralose has high sweetness, good taste, and high safety. It has been widely used; it does not have any calories and can be provided to obese patients, diabetic patients, cardiovascular disease patients and the elderly; it does not cause caries and is helpful Healthy teeth.[0003]The synthetic methods of sucralose include full group protection method and single group protection method. Among them, the full group protection method has many production processes and high production costs, which is not suitable for mass production. The single-group protection method has economical and easy-to-obtain raw materials, high selectivity, simple production process, and is widely used in existing technology production. In the single-group protection method, the chlorination rea...

AI Technical Summary

Problems solved by technology

Neutralization with an alkaline solution such as ammonia or sodium hydroxide will cause a side reaction of hydrolysis, resulting in a reduction in the yield of sucralose-6-ester, and due to the presence of a large amount of water in the reaction solution, the subsequent concentrated organic solvent needs to be dehydrated It can be recycled after treatment; at the same time, a large amount of waste water is generated after dehydration of organic solvents, which needs to be recycled before being discharged, which increases the cost of recycling

And directly use ammonia gas (patent CN108047283A) to neutralize because the solubility of ammonia gas in the system is small thereby absorption efficiency is low, waste ammonia gas; Carried out under conditions, the reaction is slow, and the progress is not easy to control, resulting in insufficient reaction, which reduces the yield of sucralose-6-carboxylate