Preparation method of N,N-diethylenediamine

Abstract

The invention belongs to the technical field of chemical synthesis and relates to a preparation method of N,N-diethylenediamine. The preparation method of the N,N-diethylenediamine comprises the following steps: (1) preparing 2-diethylamine-based chloroethane hydrochloride: performing heat-preserving reaction on a chlorinating agent and diethylamine ethanol in a reaction solvent, concentrating a reaction solvent after the heat-preserving reaction, adding low molecular alcohol or ester after concentrating, performing recrystallization to obtain a 2-2-diethylamine-based chloroethane hydrochloride wet product and drying to obtain a 2-diethylamine-based chloroethane hydrochloride dry product; (2) preparing the N,N-diethylenediamine: performing heat-preserving and pressure-maintaining reactionon the 2-diethylamine-based chloroethane hydrochloride and excessive liquid ammonia for more than or equal to 4 hours under the conditions that the pressure is 0 to 10 MPa and the temperature is 10 to100 DEG C, recycling the residual ammonia gas after the reaction, adding alkali into the reaction liquid, performing cooling alkali analysis, separating out the lower layer of alkaline liquid, rectifying an organic layer and collecting the fraction with the temperature of 143 to 148 DEG C, to obtain the N,N-diethylenediamine. The N,N-diethylenediamine prepared according to the method provided bythe invention has the advantages of high yield, high content, simplicity in operation, low raw material cost and the like.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and relates to a preparation method of N,N-diethylethylenediamine. Background technique [0002] N,N-Diethylethylenediamine is a colorless transparent liquid with a boiling point of 145.2°C. There are not many manufacturers of this product in China, and the price is gradually rising. It is a very important fine chemical intermediate and can be used as an important pharmaceutical intermediate, surfactant, auxiliary agent, curing agent, etc. The pharmaceutical industry can use it to produce the antiarrhythmic drug procainamide, the local anesthetic cinbucaine hydrochloride, the antiemetic drug metoclopramide, the myasthenia gravis drug Enzyme, and the chorea treatment tiapride hydrochloride, etc.; in the textile industry It can be used to synthesize cationic surfactants and BCH additives of Sebimin; it can also be used as a curing agent for epoxy powder coatings. [0003] Generally spe...

AI Technical Summary

Problems solved by technology

The yield of this method is still relatively high, but the price of using bromoethylamine bromate is more expensive, and the copper sulfide used is not easy to handle, which is not conducive to industrialization

The third is that diethylamine and 2-chloroethylamine hydrochloride are used as raw materials in CN103012156A, and sodium methoxide methanol solution is used as an acid-binding agent, and cuprous chloride is used as a catalyst to carry out high-temperature and high-pressure reaction in an autoclave to obtain a reaction solution, adding Alkali analysis of saturated sodium hydroxide aqueous solution, rectification of the oil layer to obtain N,N-diethylethylenediamine, the yield is 78.6%, and the purity is 99.2%. The yield and purity are relatively high, but the 2-chloroethane used in this reaction The price of amine hydrochloride is relatively expensive, and the reaction is high temperature and high pressure, and sodium methoxide is also used, which is relatively dangerous and not conducive to industrial production

The fourth is ethylenediamine monoacetylation, alkylation, and then hydrolysis to obtain the target product. The raw material cost of this method is high and the highly toxic substance dialkyl sulfate is used, which is relatively dangerous. Big, not conducive to mass production

The fifth is other methods: it is obtained from acrylonitrile through hydrolysis, addition, and degradation; it is obtained by hydrogenation of ethylenediaminoacetonitrile. These two methods have high raw material costs and cumbersome operations. They require high temperature and high pressure reactions and are not easy to operate.

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