Preparation method of N,N'-bis(3-aminopropyl)-1,2-ethylenediamine

Abstract

The invention discloses a preparation method of N,N'-bis(3-aminopropyl)-1,2-ethylenediamine, which comprises the following steps:1) by using monohydric alcohol as a solvent, heating ethylenediamine and acrylonitrile to react, thereby obtaining an N,N'-bis(cyanoethyl)-1,2-ethylenediamine mixture; and 2) in the presence of solid alkali and Raney nickel catalyst, directly carrying out hydrogenation reaction on the N,N'-bis(cyanoethyl)-1,2-ethylenediamine mixture obtained in the step 1), thereby obtaining the N,N'-bis(3-aminopropyl)-1,2-ethylenediamine. The solvent is added to synthesize the N,N'-bis(cyanoethyl)-1,2-ethylenediamine by a one-step process, the selectivity is high, and the obtained mixture is directly used for hydrogenation of the N,N'-bis(3-aminopropyl)-1,2-ethylenediamine in the step 2), thereby reducing the distillation step and lowering the energy consumption. The recycled Raney nickel catalyst and monohydric alcohol solvent can be reused repeatedly, thereby further lowering the production cost and reducing the discharge amount of waste liquor.

Description

technical field [0001] The invention belongs to the field of organic synthesis, in particular to a preparation method of N, N'-bis(3-aminopropyl)-1,2-ethylenediamine. Background technique [0002] N, N'-bis(3-aminopropyl)-1,2-ethylenediamine, as a special amine, is mainly used in the synthesis of plastic anti-ultraviolet absorbers, and can also be used in the synthesis of insecticides and epoxy resin curing agents , fuel, gasoline and lubricating oil additives, metal corrosion inhibitors, and can also be used in paper and textile industries. It has a wide range of uses. With the development of high-end lubricating oil and fuel industries at home and abroad, the domestic and foreign demand has increased rapidly. [0003] Traditional N, N'-bis(3-aminopropyl)-1,2-ethylenediamine synthesis steps: use ethylenediamine and acrylonitrile as the main raw materials, first synthesize N,N'-bis(cyanoethyl) -1,2-ethylenediamine, and then hydrogenated to synthesize N,N'-bis(3-aminopropyl)...

AI Technical Summary

Problems solved by technology

[0008] The first step is to synthesize N, N'-bis(cyanoethyl)-1,2-ethylenediamine, due to the use of acetic acid, water or other Additives are used to improve the selectivity of cyanoethylation, which will inevitably lead to problems such as equipment corrosion and waste water generation; and the intermediate obtained in the step needs to be purified by rectification, which requires high energy consumption and long cycle;

[0009] The second step is to synthesize N,N'-bis(3-aminopropyl)-1,2-ethylenediamine. The current technology is mainly batch hydrogenation, namely Put all the N, N'-bis(cyanoethyl)-1,2-ethylenediamine, and use the catalyst Raney nickel for high-pressure hydrogenation (the yield is only 60%, which is low), or use LiOH-ModifiedCatalyst for hydrogenation ( high cost); or use semi-continuous hydrogenation, that is, continuously pump N, N'-bis(cyanoethyl)-1,2-ethylenediamine into the autoclave, and continuously feed it under the nickel or cobalt catalyst Hydrogenation of hydrogen to obtain a mixture of N,N'-bis(3-aminopropyl)-1,2-ethylenediamine as the main product (relatively high equipment requirements, difficult to control)

Post-processing obtains high-content N, N'-bis(cyanoethyl)-1,2-ethylenediamine through rectification, which inevitably leads to low yield and high energy consumption

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