CN108997356B

CN108997356B - Method for synthesizing 2-methyl triethylene diamine by catalyzing ethylene imine and 2-methyl piperazine

Info

Publication number: CN108997356B
Application number: CN201810790778.5A
Authority: CN
Inventors: 张前; 杨建明; 王为强; 余秦伟; 赵锋伟; 惠丰; 袁俊; 梅苏宁; 李亚妮; 李江伟; 吕剑
Original assignee: Xian Modern Chemistry Research Institute
Current assignee: Xian Modern Chemistry Research Institute
Priority date: 2018-07-18
Filing date: 2018-07-18
Publication date: 2021-08-20
Anticipated expiration: 2038-07-18
Also published as: CN108997356A

Abstract

The invention discloses a method for synthesizing 2-methyl triethylene diamine by catalyzing ethylene imine and 2-methyl piperazine, and aims to solve the problems of multiple synthesis steps and low product selectivity of the existing method. The method is applied to the reaction for synthesizing the 2-methyl triethylene diamine by one-step catalysis by taking the ethylene imine and the 2-methyl piperazine as raw materials and taking the Pentasil zeolite as a catalyst, and has the advantages of few synthesis steps and high product selectivity.

Description

Method for synthesizing 2-methyl triethylene diamine by catalyzing ethylene imine and 2-methyl piperazine

Technical Field

The invention belongs to the field of fine chemical engineering, and particularly relates to a method for synthesizing 2-methyl triethylene diamine by catalyzing ethylene imine and 2-methyl piperazine.

Background

2-methyl triethylene diamine is also called 2-methyl-1, 4-diazabicyclo [2.2.2] octane, and is a novel polyurethane foaming amination catalyst. Compared with the traditional catalyst triethylene diamine, the 2-methyl triethylene diamine has higher boiling point (184-186 ℃) and lower melting point (less than 0 ℃), small hygroscopicity, simple production method and wider application range, and is expected to become a perfect substitute of triethylene diamine.

Currently, the synthesis of 2-methyltriethylenediamine mainly uses hydroxyethyl piperazine derivatives as reactants, such as CN103641836, CN201610761294.9, US4754036 and JP2016199471A disclose the synthesis of 2-methyltriethylenediamine using one or two of 1-hydroxyethyl-3-methylpiperazine, 1-hydroxyethyl-2-methylpiperazine, N- β -hydroxypropyl piperazine and N- α -methyl- β -hydroxyethyl piperazine as reaction raw materials, but the raw materials are relatively expensive.

Compared with the synthesis of 2-methyl triethylene diamine by taking hydroxyethyl piperazine derivatives as raw materials, the synthesis method has the advantages of lower cost and obvious economic advantage. Trejbal and the like firstly synthesize 2-methyl piperazine by using ethylenediamine and 1, 2-propylene glycol as raw materials through hydrogenation, and then synthesize 2-methyl triethylene diamine through the reaction with ethylenediamine or an ethylenediamine solution of piperazine, but the product selectivity is not more than 19.8% (Petroleum & Coal 2012,54(4), 335-; xianrong uses 2-methyl piperazine and ethylene oxide as raw materials to synthesize hydroxyethyl methyl piperazine in toluene, and then uses phenylphosphonic acid as a catalyst to synthesize 2-methyl triethylene diamine in a mixed solvent of biphenyl and diphenyl ether (southeast university, Master academic thesis, 2012). However, the reaction process is carried out slowly under the ice bath condition by introducing ethylene oxide, and after the intermediate hydroxyethyl methyl piperazine is obtained by synthesis, reduced pressure distillation and purification are carried out, and then 2-methyl triethylene diamine is synthesized under the condition of 325 ℃ under the catalysis of organic acid, so that the synthesis steps are multiple, and the reaction condition is harsh; yakhontov et al take 2-methylpiperazine as a raw material to react with hydrogen chloride to generate corresponding chloride, then react with sodium nitrite to obtain azide, reduce with lithium aluminum hydride to obtain primary amine, then react with dibromoethane to obtain bromide, and then hydrogenate under the action of palladium-carbon catalyst to obtain 2-methyl triethylene diamine. Although the reaction substrate is 2-methylpiperazine, the raw material is single, five steps are needed to obtain the target product, the synthesis steps are multiple, and the reaction process is complex (Khimiko-farattshecheski Zhurnal,1989,23(1), 30-35).

Disclosure of Invention

The invention aims to solve the technical problems of multiple synthesis steps and low product selectivity in the prior art, and provides a method for synthesizing 2-methyltriethylenediamine by one-step catalysis of ethyleneimine and 2-methylpiperazine, which is shown as the following formula:

the method for synthesizing 2-methyl triethylene diamine by catalyzing ethylene imine and 2-methyl piperazine is characterized in that the ethylene imine and the 2-methyl piperazine are used as raw materials, solid acid hydrogen type Pentasil zeolite is used as a catalyst, ring opening is carried out on the ethylene imine ternary nitrogen heterocycle, and then intermolecular deamination reaction is carried out on the ethylene imine and the activated 2-methyl piperazine to finally generate the target product 2-methyl triethylene diamine.

The Pentasil zeolite contains at least one bivalent, trivalent or tetravalent metal M heteroatom besides a silica framework, wherein M is one or more of Mn, Mg, Fe, B, Al, Co, Ni, Mo, La, Sn, Cr, Ga, Ti, Zr and Ge, preferably one of Al, Mn, Fe, Ti, B and Cr, and further preferably one of Al, Mn and Fe, and the Si/M molar ratio is 100-1000. When M is Al, the Si/Al molar ratio is 80-200; when M is Mn, the molar ratio of Si/Mn is 120-600; when M is Fe, the Si/Fe molar ratio is 100 to 300.

The Pentasil zeolite is ZSM-5 or ZSM-11 or the mixed structure of the two, and the Pentasil zeolite needs to be completely or partially in a hydrogen form and can be prepared by a conventional ion exchange method.

The present invention employs a continuous operation wherein the ratio of ethyleneimine in the feed stream: 2-methylpiperazine: the mass ratio of the solvent is 5-50: 10-30: 10 to 80 parts. The solvent is one or more selected from water, ammonia water, methanol, N-methylpyrrolidone, benzene, toluene, xylene, trimethylbenzene and chloroform. In view of the subsequent rectification purification process, one of water, ammonia water and methanol is preferred, and water is further preferred.

The reaction temperature is 330-420 ℃, and preferably 350-400 ℃; the absolute pressure in the reactor is 0.1-10 bar, and the reaction is preferably carried out at normal pressure; the liquid volume airspeed is 0.05-3 h^-1Preferably 0.2 to 1 hour^-1。

The invention adopts a fixed bed or a fluidized bed reactor to carry out gas-solid phase catalytic reaction to synthesize the 2-methyl triethylene diamine, and the fixed bed is preferred.

The invention has the beneficial effects that:

in the prior art, the synthesis method using 2-methylpiperazine as a reaction substrate has more steps, usually two-step to five-step reaction, and the selectivity of the target product 2-methyltriethylenediamine is relatively low (less than or equal to 19.8%), while the synthesis method has less synthesis steps, is one-step reaction, and has the selectivity of the 2-methyltriethylenediamine reaching 75.8% and obvious advantages.

Detailed Description

The present invention is further illustrated by the following examples, but is not limited thereto.

Example 1

A fixed bed reactor is adopted, and the size of the reactor is 700mm multiplied by phi 40mm multiplied by 6 mm. The reaction was carried out at normal pressure using HZSM-5(n (Si/Al) ═ 200) as the catalyst, a loading of 30mL, and an aqueous ethyleneimine solution of 2-methylpiperazine as the starting material, wherein the ethyleneimine: 2-methylpiperazine: the mass ratio of water is 5: 20: 80, passing through a constant flow pump, preheating by a preheater and then entering a fixed bed reactor, wherein the reaction temperature is 370 ℃, and the liquid space velocity is 1h^-1. After the reaction is stable for 6 hours, sampling analysis shows that the conversion rate of the 2-methylpiperazine is 51.1 percent, and the selectivity of the 2-methyltriethylenediamine is 75.8 percent.

Example 2

A fixed bed reactor was used, the reactor size being the same as in example 1. The reaction was carried out at normal pressure, using HZSM-11(n (Si/Al) ═ 120) as the catalyst, with a loading of 30mL, and using an aqueous ethyleneimine solution of 2-methylpiperazine as the starting material, wherein the ethyleneimine: 2-methylpiperazine: the mass ratio of water is 10: 18: 70, passing through a constant flow pump, preheating by a preheater and then entering a fixed bed reactor, wherein the reaction temperature is 360 ℃, and the liquid space velocity is 1h^-1. After the reaction is stable for 6 hours, sampling analysis shows that the conversion rate of 2-methylpiperazine is 63.7 percent, and the selectivity of 2-methyltriethylenediamine is 68.6 percent.

Example 3

A fixed bed reactor was used, the reactor size being the same as in example 1. The reaction was carried out at atmospheric pressure, with Mn-ZSM-5(n (Si/Mn) ═ 210) as the catalyst, a loading of 30mL, and an aqueous ethyleneimine solution of 2-methylpiperazine as the starting material, wherein the ethyleneimine: 2-methylpiperazine: the mass ratio of ammonia water is 8: 20: 80, first pass throughThe flow pump is preheated by the preheater and then enters the fixed bed reactor, the reaction temperature is 350 ℃, and the liquid space velocity is 0.8h^-1. After the reaction is stable for 6 hours, sampling analysis shows that the conversion rate of the 2-methylpiperazine is 47.3 percent, and the selectivity of the 2-methyltriethylenediamine is 58.7 percent.

Example 4

A fixed bed reactor was used, the reactor size being the same as in example 1. The reaction was carried out at normal pressure, using HZSM-5(n (Si/Al) ═ 160) as the catalyst, with a loading of 30mL, using an aqueous solution of ethyleneimine of 2-methylpiperazine as the starting material, wherein the ethyleneimine: 2-methylpiperazine: the mass ratio of ammonia water is 5: 30: 70, passing through a constant flow pump, preheating by a preheater and then entering a fixed bed reactor, wherein the reaction temperature is 370 ℃, and the liquid space velocity is 0.5h^-1. After the reaction is stable for 6 hours, sampling analysis shows that the conversion rate of the 2-methylpiperazine is 57.1 percent, and the selectivity of the 2-methyltriethylenediamine is 72.5 percent.

Claims

1. A method for synthesizing 2-methyl triethylene diamine by catalyzing ethylene imine and 2-methyl piperazine is characterized by comprising the following steps:

using ethylene imine and 2-methyl piperazine as raw materials, and using Pentasil zeolite as a catalyst;

in continuous operation, the ratio of ethyleneimine in the feed stream: 2-methylpiperazine: the mass ratio of the solvent is 5-50: 10-30: 10-80;

the Pentasil zeolite contains a bivalent, trivalent or tetravalent metal M heteroatom besides a silicon-oxygen framework, wherein M is one of Mn and Al, and the Si/M molar ratio is 100-1000; the Pentasil zeolite is ZSM-11 or ZSM-5 or a mixed structure of the two, and at least part of the Pentasil zeolite exists in a hydrogen form;

the solvent is one or more of water, ammonia water, methanol, N-methyl pyrrolidone, benzene, toluene, xylene, trimethylbenzene and chloroform;

the reaction temperature is 330-420 ℃;

the absolute pressure in the reactor is 0.1-10 bar;

the liquid volume airspeed is 0.05-3 h^-1；

The reactor adopts a fixed bed or a fluidized bed.

2. The method for synthesizing 2-methyltriethylenediamine by catalyzing ethyleneimine and 2-methylpiperazine according to claim 1, characterized in that when M is Al, the Si/Al molar ratio is 80-200; when M is Mn, the Si/Mn molar ratio is 120 to 600.

3. The method for synthesizing 2-methyltriethylenediamine from ethyleneimine and 2-methylpiperazine under the catalysis of claim 1, characterized in that the solvent in the feed stream is one of water, ammonia water and methanol.