Covalent organic framework material, preparation method therefor and application of covalent organic framework material in synthesis of hindered amines

Abstract

The invention relates to a covalent organic framework material, a preparation method therefor and a method for synthesizing N,N'-di(2,2,6,6-tetramethyl-4-piperidyl)-1,3-benzenediformamide by using thecovalent organic framework (COFs) catalyst. The method comprises the specific steps: subjecting dimethyl isophthalate and 2,2,6,6-tetramethyl-4-aminopiperidine to a heterogeneous catalytic reaction with stirring in an organic solvent by taking the covalent organic framework material (COFs) as a catalyst, and carrying out aftertreatment after the reaction ends up, thereby obtaining the product. The catalyst has sufficient alkaline loci and can be used for effectively catalyzing the reaction and remarkably increasing yield; and after the catalyst is used, treatment steps are simpler, the emission of salt-bearing wastewater is reduced, heavy-metal pollution is avoided, and the catalyst is environmentally friendly.

Description

technical field [0001] The present invention relates to the synthesis and preparation of a covalent organic framework material (COFs), and the catalytic synthesis of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)- A method for hindered amine light stabilizers such as 1,3-phthalamide belongs to the technical field of organic synthesis. Background technique [0002] With the development of the world's plastics industry, especially the increase in the application range and output of outdoor plastic products, light stabilizers have become one of the fastest growing categories of plastic additives. Among them, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,3-benzenedicarboxamide is a new type of high-efficiency hindered amine light stabilizer, because It can capture free radicals, quench excited oxygen, and decompose hydroperoxides, thereby effectively inhibiting or slowing down the breakage of polymer chemical bonds, showing strong photostability; the effective group can be recycle...

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Problems solved by technology

In prior art CN103508938A, CN104974075A and WO2017 / 024608, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,3- Phthalamide, but because the acid chloride is easily hydrolyzed, an acid-binding agent needs to be used, resulting in extremely cumbersome treatment processes such as subsequent purification and a large amount of waste water; in the prior art CN106905225A, although the isophthalic acid diester is used as a raw material to synthesize N, N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,3-benzenedicarboxamide, but the yield is low because no catalyst is used; adopted in the prior art CN107382828A The solid-supported catalyst and the compounding of organic solvents further increase the yield. At the same time, the catalyst has cycle stability and can be used repeatedly, reducing production costs. However, the catalyst used contains metals, which is easy to cause heavy metal pollution, and After repeated application, the yield will drop significantly

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