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A kind of pretreatment method of tetramethylpiperidone and the synthetic method of tetramethylpiperidinamine

A synthetic method, tetramethyl technology, applied in the field of hindered amine light stabilizer intermediates, can solve the problems of poor thermal stability and affecting product quality, and achieve high thermal stability and simple operation

Active Publication Date: 2021-07-02
HENGSHUI KAIYA CHEM +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, a small amount of 2,2,6,6-tetramethyl-4-piperidinone remained in the 2,2,6,6-tetramethyl-4-piperidinamine product prepared by the above preparation method, resulting in 2 ,2,6,6-Tetramethyl-4-piperidinamine has poor thermal stability, which affects product quality

Method used

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Experimental program
Comparison scheme
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preparation example Construction

[0028] The present invention also provides a kind of synthetic method of tetramethyl piperidine amine, comprises the following steps:

[0029] The preoxidized tetramethylpiperidinone obtained by the pretreatment method described in the above technical scheme is mixed with a metal catalyst, ammonia, an inorganic base and an oxygen-containing solvent, and an amination reaction is carried out to obtain tetramethylpiperidinimine;

[0030] Under a protective atmosphere, the tetramethylpiperidinimine and hydrogen are subjected to a reduction reaction to obtain tetramethylpiperidinamine.

[0031] In the invention, the preoxidized tetramethylpiperidone is mixed with a metal catalyst, ammonia, an inorganic base and an oxygen-containing solvent for amination reaction to obtain tetramethylpiperidinimine. In the present invention, the metal catalyst preferably includes framework nickel, framework copper, cobalt catalyst, palladium catalyst or platinum catalyst. In the present invention, ...

Embodiment 1

[0048] (1) Add 250 g of 2,2,6,6-tetramethyl-4-piperidone into the reaction kettle, add 1 g of hydrogen peroxide with a concentration of 50 wt % at 30° C., mix, and perform a pre-oxidation reaction for 30 hours to obtain Preoxidized 2,2,6,6-tetramethyl-4-piperidone;

[0049] (2) Add 40g of skeleton nickel, 12.5g of NaOH and 200g of water to the reactor under stirring and 40°C, add 30g of liquid ammonia to the reactor after heating up to 50°C, control the pressure of the kettle to 0.4MPa, and then raise the temperature After reaching 60°C, carry out amination reaction for 0.5h to obtain 2,2,6,6-tetramethyl-4-piperidinimine;

[0050] (3) Under the condition of 100°C, hydrogen gas is introduced into the kettle until the pressure of the kettle is 1.5 MPa, hydrogen gas is passed into the kettle for 2 hours to carry out the reduction reaction, and then the temperature is lowered to 60℃, then the stirring is stopped, and the skeleton nickel is allowed to settle for 1 hour, and the sup...

Embodiment 2

[0053] (1) Add 250 g of 2,2,6,6-tetramethyl-4-piperidone into the reaction kettle, add 2 g of hydrogen peroxide with a concentration of 27.5 wt % at 50° C., mix, and perform a pre-oxidation reaction for 10 h, Obtain preoxidized 2,2,6,6-tetramethyl-4-piperidone;

[0054] (2) Under the condition of stirring and 35°C, add 40g of skeleton copper, 25g of NaOH and 300g of ethanol in the reactor, add ammonia gas 40g in the reactor after heating up to 40°C, control the pressure of the kettle to be 0.3MPa, then heat up to After 50°C, the amination reaction was carried out for 1 hour to obtain 2,2,6,6-tetramethyl-4-piperidinimine;

[0055] (3) Under the condition of 120°C, hydrogen gas was introduced into the kettle until the pressure of the kettle was 2.0 MPa, hydrogen gas was passed into the kettle for 5 hours to carry out the reduction reaction, and then the temperature was lowered to 90℃, then the stirring was stopped, and the skeleton copper was allowed to settle for 2 hours, and t...

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Abstract

The invention provides a pretreatment method of tetramethylpiperidone and a synthesis method of tetramethylpiperidinamine, belonging to the technical field of hindered amine light stabilizer intermediates. The tetramethylpiperidone pretreatment method provided by the present invention comprises the following steps: performing a preoxidation reaction on the tetramethylpiperidone and an oxidizing agent to obtain preoxidized tetramethylpiperidone. After the treatment method provided by the invention oxidizes the tetramethylpiperidone, the easily discolored substances in the tetramethylpiperidone are oxidized, and the obtained preoxidized tetramethylpiperidone can be directly used in the preparation of Tetramethylpiperidinamine. Moreover, the tetramethylpiperidinamine prepared by using the preoxidized tetramethylpiperidone as a raw material is not easy to change color and has high thermal stability. Moreover, the synthesis method is simple to operate and is suitable for industrial production.

Description

technical field [0001] The invention relates to the technical field of hindered amine light stabilizer intermediates, in particular to a pretreatment method for tetramethylpiperidone and a synthesis method for tetramethylpiperidinone. Background technique [0002] Tetramethylpiperidinamine (i.e. 2,2,6,6-tetramethyl-4-piperidinamine), is an important hindered amine light stabilizer intermediate and pharmaceutical intermediate, especially in hindered amine light stabilizer It is an important raw material for bonded and polymerized high molecular weight hindered amine light stabilizers. [0003] Tetramethylpiperidinamine synthesis methods mainly include catalytic reductive amination and electrochemical reduction. Among them, the electrochemical reduction method uses tetramethylpiperidone as a raw material, reacts on a strong acid medium and different cathode materials, and generates tetramethylpiperidinamine under normal pressure. The electrochemical reduction method is easy ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D211/44C07D211/58
CPCC07D211/44C07D211/58
Inventor 张开用于国宁曹乐乐张文静代广星王涛王慧君
Owner HENGSHUI KAIYA CHEM