A kind of method utilizing supported lithium chloride to catalyze the synthesis of tetraacetylethylenediamine

Abstract

The invention provides a method for catalytically synthesizing tetraacetylethylenediamine by using supported lithium chloride. It specifically includes (1) fully stirring and mixing lithium chloride solution, grinding aid dispersant and carrier at room temperature, and then drying and grinding at high temperature to obtain a supported lithium chloride solid acid catalyst; (2) ethylenediamine and conventional catalysts, Quickly add anhydrous acetic acid dropwise; then heat up and keep warm for reaction while separating water; then add acetic anhydride and lithium chloride catalyst to continue heating up and react again; (3) After cooling, crystallization, washing and drying, tetraacetylethylenediamine is obtained. The method utilizes a loaded lithium chloride solid acid to catalyze ethylenediamine and an acylating reagent to synthesize tetraacetylethylenediamine, the catalyst is beneficial to recovery and can be recycled, and has little environmental pollution; the catalytic efficiency is high, the reaction time is effectively shortened, and the product yield is improved. The yield can reach more than 90%; the preparation method of the catalyst is simple and the cost is low, which is beneficial to realize the industrial production and application of tetraacetylethylenediamine.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, in particular to a method for synthesizing tetraacetylethylenediamine, in particular to a method for catalytically synthesizing tetraacetylethylenediamine by using supported lithium chloride. Background technique [0002] Tetraacetylethylenediamine (TAED) is a colorless, odorless, storage-stable solid. As a high-efficiency low-temperature oxygen-based bleaching activator, it has excellent low-temperature bleaching performance, and can promote oxygen-based bleaching agents to fully exert their unique effects of whitening, brightening, detoxification, and sterilization under low temperature conditions. Enzymes have good compatibility with other surfactants. Therefore, tetraacetylethylenediamine is widely used in washing powder, color bleaching powder, dishwashing agent and other various solid washing / detergents. Tetraacetylethylenediamine can also be used as a bleaching activator of hyd...

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Problems solved by technology

Deng Yu et al. used concentrated sulfuric acid as a catalyst to study the synthesis method of tetraacetylethylenediamine by a two-step method (research on the catalytic synthesis of TAED by concentrated sulfuric acid. Printing and Dyeing Auxiliaries, 2002, vol.19 (2): 19-21) ; Lu Hongwu et al. synthesized diacetylethylenediamine, the precursor of tetraacetylethylenediamine, under high temperature conditions by adding 75% phosphoric acid (research on the synthesis process of diacetylethylenediamine. Daily Chemical Science, 2013, vol. 36 (11): 18-21); Zou Lixia et al. (Synthesis of tetraacetylethylenediamine. Process test, 2009, vol.9) and patent CN1255376C both mentioned the use of p-toluenesulfonic acid to catalyze the synthesis of tetraacetylethylenediamine Methods: Yao Fang et al. synthesized a bleach activator TAED by heteropolyacid catalyst (heteropolyacid catalyst synthesis of bleach activator TAED. Chemical Times, 2003, 17 (1): 52-54), specifically using heteropolyacid as a catalyst , the reaction of two-step acylation synthesis of TAED is better, avoiding the corrosion of equipment, reducing the pollution to the environment and the catalyst and recycling, but the preparation process of heteropolyacid is tedious, the cost is high, and the industrial application is limited to a certain extent; Jing Qi et al. used the method of microwave induction to catalyze the acylation reaction to synthesize diacetyldiethylamine (preliminary research on the catalytic synthesis of diacetylethylenediamine induced by microwave. Printing and Dyeing Auxiliaries, 2003, vol.20 (4): 42-44)

The results of the study show that the use of general acid catalysts such as H 2 SO 4 、H 3 PO 4 , HCl and other liquid protonic acids are easy to cause corrosion of equipment and pipelines, and the cost of waste acid treatment is relatively high; while Lewis acid AlCl 3 The use of catalyst waste residue will bring problems such as difficult to deal with, the results are not ideal

Moreover, the above-mentioned catalytic synthesis systems all have the defect of long reaction time; microwave-induced catalysis of DAED can greatly shorten the synthesis time, which is of great significance for improving production efficiency, but it has no obvious effect on the further synthesis of TAED and how to realize industrialization is currently facing research problems