A kind of method that takes caprolactam as raw material to synthesize hexamethylene diamine

A technology of caprolactam and hexamethylene diamine, which is applied in the preparation of carboxylic acid amides, chemical instruments and methods, preparation of organic compounds, etc. Equipment requirements are easy, post-processing is convenient, and the reaction conditions are mild.

Active Publication Date: 2022-07-12
ZHENGZHOU UNIV
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] There are very few reports on the synthesis of hexamethylenediamine from caprolactam. It was first reported in US2234566 and US2181140 patents that caprolactam reacted with ammonia gas under a dehydration catalyst and severe temperature to obtain 6-aminocapronitrile, and unreacted caprolactam was separated by distillation. Aminocapronitrile is synthesized into hexamethylenediamine by catalytic hydrogenation of aminocapronitrile subsequently on nickel or cobalt catalyst, but the yield of hexamethylenediamine is not disclosed in the patent; The method of caprolactam synthesis 6-aminocapronitrile reported in patent CN107739318A, CN107602416A and patent US2234566 The method of reporting is almost the same
Among them, the gas phase method reported by patent CN107602416A uses caprolactam to prepare 6-aminocapronitrile. The reaction temperature is about 350 ° C, and the contact time between caprolactam and ammonia is extremely short within 1 second, which is difficult to control; while the liquid phase method reported by patent CN107739318A Although the reaction temperature in the method of synthesizing 6-aminocapronitrile with caprolactam as a raw material is mild at about 280°C, its yield is not high, and its yield is about 50% analyzed from examples

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A kind of method that takes caprolactam as raw material to synthesize hexamethylene diamine
  • A kind of method that takes caprolactam as raw material to synthesize hexamethylene diamine
  • A kind of method that takes caprolactam as raw material to synthesize hexamethylene diamine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] A method for synthesizing hexamethylene diamine with caprolactam as a raw material, comprising the following steps:

[0032] 1) Add 10g of caprolactam into a 250ml single-neck bottle, add 11g of sodium hydroxide and 25ml of water, reflux at 130°C for 3 hours and then cool to room temperature to obtain 6-aminocaproic sodium salt; the molar ratio of the caprolactam to sodium hydroxide is about is 1:3; the molar ratio of caprolactam to the amount of water added is 1:15.8;

[0033] 2) then add 9ml acetic anhydride (amino protecting group, the amount of amino protecting group is 1 times of caprolactam equivalent) in the single-necked bottle of step 1), then to 47 ℃, add concentrated hydrochloric acid after stirring reaction for 2 hours to adjust The pH value of the solution is at 2, and the precipitated solid is recrystallized with water to obtain 6-acetamidocaproic acid;

[0034] 3) drying the product of step 2) to obtain 12g solid; get the product after drying 5g and 0.15...

Embodiment 2

[0037] A method for synthesizing hexamethylene diamine with caprolactam as a raw material, comprising the following steps:

[0038] 1) Add 10g of caprolactam into a 250ml single-neck bottle, and add 13g of sodium tert-butoxide and 32ml of water, reflux at 150° C. for 2 hours and then cool to room temperature to obtain 6-aminocaproic sodium salt; the moles of caprolactam and sodium tert-butoxide are obtained. The ratio is about 1:1.5; the molar ratio of caprolactam to the amount of added water is 1:20;

[0039]2) Then slowly add 18ml benzyl chloroformate (the amino protecting group, the amount of the amino protecting group is 1.5 times the caprolactam equivalent) into the single-necked bottle of step 1), and add to the reaction solution after stirring for 2 h at room temperature. 30ml diethyl ether was used to extract the by-products in the reaction, repeat the operation twice, then add concentrated hydrochloric acid to the extracted aqueous layer solution under ice bath to adj...

Embodiment 3

[0043] A method for synthesizing hexamethylene diamine with caprolactam as a raw material, comprising the following steps:

[0044] 1) Add 10g of caprolactam into a 250ml single-neck bottle, add 7g of sodium hydroxide and 16ml of water, reflux at 100°C for 4h and then cool to room temperature to obtain 6-aminocaproic sodium salt; the molar ratio of the caprolactam to sodium hydroxide is about is 1:2; the molar ratio of caprolactam to the amount of water added is 1:10;

[0045] 2) Then slowly add 15ml of tetrahydrofuran and 20ml of benzyl chloride (the amino protecting group, the amount of the amino protecting group is 2 times the equivalent of caprolactam) into the single-necked bottle of step 1), react under reflux at 70°C for 10h, and cool to room temperature , and concentrated hydrochloric acid was added to the obtained solution to adjust the pH value of the solution to 3; after the reaction, 20 ml of ethyl acetate was added to extract the product, and the operation was rep...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a method for synthesizing hexamethylenediamine using caprolactam as a raw material, comprising the following steps: 1) after mixing caprolactam, alkali and water, heating and refluxing to obtain 6-aminocaproate; 6-aminocaproic acid salt introduces amino protecting group to protect terminal amino group, then adds acid and neutralizes to generate aminocaproic acid with amino protecting group; 3) after drying the product obtained in step 2), add dehydration catalyst for amide And heating reaction in the presence of ammonia source converts carboxylic acid group into cyano group to obtain product nitrile; 4) The product nitrile obtained in step 3) is extracted and purified, catalytically hydrogenated to generate corresponding amine, and then the protective group is removed to obtain target product.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a method for synthesizing hexamethylenediamine by using caprolactam as a raw material. Background technique [0002] Hexamethylenediamine is an important chemical raw material, which is often used to synthesize important industrial products such as nylon 66, nylon 610, HDI, etc. However, there is no production facility for hexamethylenediamine synthetic raw material adiponitrile in my country, and it is completely dependent on imports. , the development of new synthetic methods is crucial. At present, there are not many methods for synthesizing hexamethylene diamine, and the industry is mainly the catalytic hydrogenation of adiponitrile, and the synthesis method of the raw material adiponitrile is butadiene and acrylonitrile method. The production of adiponitrile by the butadiene method is further divided into the chlorinated cyanation method of butadiene a...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): C07C209/62C07C211/12
CPCC07C209/62C07C227/22C07C231/02C07C253/22C07C231/12C07C211/12C07C229/08C07C233/47C07C255/29C07C233/36Y02P20/55Y02P20/52
Inventor 赵清香王帅辉刘民英付鹏庞新厂崔喆赵海涛张晓朦赵蔚
Owner ZHENGZHOU UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap