Method for preparing 1, 3-cyclohexanediamine by hydrogenation of m-xylylenediamine

A technology of m-xylylenediamine and cyclohexyldimethylamine, which is applied to the hydrogenation of m-xylylenediamine to prepare 1,3-cyclohexanedimethylamine, and the hydrogenation of high-concentration m-xylylenediamine to prepare high-cis isomers In the field of 1,3-cyclohexanedimethylamine content, it can solve the problems of low production efficiency per unit volume of reactor, high energy consumption for product separation, and low concentration of hydrogenation substrate, which is beneficial to scale-up and industrial implementation, improves production efficiency, and reduces Effect of Solvent Dosage

Active Publication Date: 2020-05-08
WANHUA CHEM GRP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0013] In order to overcome the low concentration of the existing m-xylylenediamine hydrogenation substrate, the present invention causes large amount of solvent, high energy consumption for product separation, and low production efficiency of reactor per unit volume Low, and need to increase the cis-isomer content in the 1,3-cyclohexanedimethylamine product through subsequent isomerization reaction, develop a high-concentration m-xylylenediamine hydrogenation to prepare high cis-isomer content1 , the method of 3-cyclohexanedimethylamine, its main features are: (1) by adding a certain quality m-xylylenediamine to the system containing catalyst, solvent, reaction additive and high-pressure hydrogen at a constant rate, by controlling the m-xylylenedia

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0037] Example 1

[0038] In a 2L autoclave, add 100g THF, 6g catalyst sample, 0.04g 2-picoline, install the autoclave, drain the air in the autoclave 3 times with low pressure nitrogen and hydrogen successively, then fill with hydrogen to 3MPa, and heat up to 120°C , then pressurized to 8.0MPa, adjust the stirring rate to be 1000rpm, open the m-xylylenediamine feed pump to feed, the feeding time is 3h, and the total feed amount of m-xylylenediamine is 300g (that is, the feed rate is 100g / h), after feeding the material, continue stirring and reacting for 1h, stop stirring, close the hydrogen inlet valve, cool down, discharge the residual gas in the kettle, filter out the reaction mother liquor with a built-in filter, and use gas chromatography to carry out quantitative analysis of external standard, and obtain the The conversion rate of xylylenediamine was 99.8%, the selectivity of 1,3-cyclohexanedimethylamine was 97.5%, the molar yield was 97.3%, and the ratio of cis-isomer / ...

Example Embodiment

[0039] Example 2

[0040] In a 2L autoclave, add 100g of 1,3-cyclohexanedimethylamine, 15g of catalyst samples, 3g of 3-methylquinoline, put on the autoclave, drain the air in the autoclave 3 times with low-pressure nitrogen and hydrogen successively, and then refill the autoclave. The hydrogen was heated to 3MPa, heated to 100°C, then pressurized to 12MPa, adjusted the stirring rate to 1000rpm, turned on the m-xylylenediamine feed pump to feed, the feeding time was 4h, and the total feed amount of m-xylylenediamine was 400g (that is, the feeding rate is 100g / h), after feeding the material, continue stirring and reacting for 0.8h, stop stirring, close the hydrogen inlet valve, cool down, discharge the residual gas in the kettle, filter out the reaction mother liquor with a built-in filter, and use gas chromatography Quantitative analysis with external standard showed that the conversion rate of m-xylylenediamine was 99.6%, the selectivity of 1,3-cyclohexanedimethylamine was 96...

Example Embodiment

[0041] Example 3

[0042] In a 2L autoclave, add 90g THF, 3g catalyst sample, 0.02g quinoline, install the autoclave, drain the air in the autoclave 3 times with low pressure nitrogen and hydrogen in turn, fill it with hydrogen to 3MPa, heat up to 90°C, and increase the temperature. Press to 14MPa, adjust the stirring speed to be 1000rpm, open the m-xylylenediamine feed pump to feed, the feeding time is 7.5h, and the total feed amount of m-xylylenediamine is 450g (that is, the feed rate is 60g / h) , after feeding the material, continue stirring the reaction for 3.0h, stop stirring, close the hydrogen inlet valve, cool down, discharge the residual gas in the kettle, filter out the reaction mother liquor with a built-in filter, and use gas chromatography for quantitative analysis of external standard to obtain isophthalic acid. The conversion rate of methylamine was 99.4%, the selectivity of 1,3-cyclohexanedimethylamine was 96.5%, the molar yield was 95.9%, and the ratio of cis-i...

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Abstract

The invention relates to a method for preparing 1, 3-butanediol by hydrogenation of m-xylylenediamine. According to the method, hydrogenation of high-concentration m-xylylenediamine can be realized toprepare the high-cis-form-content 1, 3-cyclohexanediamine. The method comprises the following steps: adding a certain mass of m-xylylenediamine into a system containing a catalyst, a solvent, a reaction additive and high-pressure hydrogen at a constant speed so that the m-xylylenediamine is kept at a relatively low concentration in the whole reaction process through controlling the feeding rate of m-xylylenediamine. High-concentration hydrogenation mother liquor can be obtained while high-selectivity selectivity and yield of 1, 3-cyclohexylenediamine are realized. By adding a nitrogen-containing rigid cyclic compound into a reaction system, the content of cis-form bodies in a hydrogenation product 1, 3-cyclohexanediamine can be effectively increased, and a 1, 3-cyclohexanediamine productwith a cis-form body/trans-form body ratio of 80/20 or above is obtained. The method is easy to implement and has an industrial application prospect.

Description

technical field [0001] The invention relates to a method for preparing 1,3-cyclohexanedimethylamine by hydrogenating m-xylylenediamine, in particular to a method for preparing 1,3-cyclohexane with high cis-body content by hydrogenating m-xylylenediamine with high concentration The method for dimethylamine belongs to the field of synthesis of amine compounds. Background technique [0002] 1,3-Cyclohexanedimethylamine is an important fine chemical, which has a wide range of applications in the fields of epoxy curing agent, isocyanate and polyamide. [0003] The main preparation methods of 1,3-cyclohexanedimethylamine include hydrogenation of isophthalonitrile, hydroamination of 1,3-cyclohexanedimethanol and hydrogenation of m-xylylenediamine. Among them, the hydrogenation method of m-xylylenediamine has the advantages of high conversion rate of raw materials, high selectivity of products, and easy separation and purification of products. method. [0004] Patent US5741928 ad...

Claims

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Application Information

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IPC IPC(8): C07C209/72C07C211/17
CPCC07C209/72C07C2601/14C07C211/17
Inventor 龚亚军张聪颖李海龙杨在刚王静郭爱国杨晓坤丁皓
Owner WANHUA CHEM GRP
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