Method for catalytic synthesis of tetraacetylethylenediamine by utilizing supported lithium chloride

Abstract

The invention provides a method for catalytic synthesis of tetraacetylethylenediamine by utilizing supported lithium chloride. Specifically, the method comprises the following steps: (1) sufficientlymixing a lithium chloride solution, a grinding aid dispersant and a carrier under stirring at room temperature, performing high-temperature drying, and performing grinding to obtain the supported lithium chloride solid acid catalyst; (2) quickly adding anhydrous acetic acid dropwise into ethylenediamine and a conventional catalyst; performing heating, performing a heat preservation reaction, and separating water; and adding acetic anhydride and the lithium chloride catalyst, continuing heating, and performing a reaction; and (3) performing cooling, performing crystallization, performing washing, and performing drying to obtain the tetraacetylethylenediamine. The method provided by the invention utilizes the supported lithium chloride solid acid to catalyze the synthesis of the tetraacetylethylenediamine by the ethylenediamine and an acylating reagent, and the catalyst is beneficial for recovering and can be recycled and has less pollution to the environment; the catalytic efficiency ishigh, the reaction time is effectively shortened, and the product yield can reach 90% or more; and the preparation method of the catalyst is simple, has low costs, and facilitates realizing industrial production and application of the 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...

AI Technical Summary

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