A preparing method of 2,2,6,6-tetramethyl-4-piperidylamine by a catalytic amination method

Abstract

A preparing method of 2,2,6,6-tetramethyl-4-piperidylamine by a catalytic amination method is disclosed. The preparing method includes following steps of: (1) adding 2,2,6,6-tetramethyl-4-piperidone, sodium hydroxide, ammonia water and a skeleton nickel catalyst into a high-pressure kettle having a condenser, a pressure gage, a stirrer and a thermocouple, feeding nitrogen to replace air in the kettle, feeding hydrogen until the pressure is 2.5 MPa, stirring, heating to 110 DEG C, and reacting for 30 min; and (2) after the reaction is completed, cooling to room temperature, stopping stirring, venting, taking reaction materials out, filtering, subjecting filtrate to distillation under atmospheric pressure to distill ammonia gas and water, subjecting the residue in the kettle to vacuum distillation, and collecting a fraction that is the 2,2,6,6-tetramethyl-4-piperidylamine. The preparing method adopts the skeleton nickel as the catalyst, synthesizes the 2,2,6,6-tetramethyl-4-piperidylamine by hydrogenation and amination, and is high in yield and purity of products.

Description

[0001] technical field [0002] The invention relates to a preparation method of a hindered amine light stabilizer intermediate, in particular to a preparation method of 2,2,6,6-tetramethyl-4-piperidinamine. [0003] Background technique [0004] 2,2,6,6-Tetramethyl-4-piperidinamine is an important intermediate used to synthesize a series of hindered amine light stabilizers with excellent performance. The commonly used synthesis methods in the world mainly include catalytic amine Chemical method and electrochemical reduction method, etc. The electrochemical reduction method to synthesize 2,2,6,6-tetramethyl-4-piperidinamine has the advantages of easy control of the process, easy realization of continuous operation, less reaction by-products, easy separation of products, The reaction conditions are mild, etc., but the energy consumption is high and the equipment investment is large, so it is difficult to realize industrial production. [0005] Contents of the invention ...

AI Technical Summary

Problems solved by technology

[0004] 2,2,6,6-Tetramethyl-4-piperidinamine is an important intermediate used to synthesize a series of hindered amine light stabilizers with excellent performance. The commonly used synthesis methods in the world mainly include catalytic amine Chemical method and electrochemical reduction method, etc. The electrochemical reduction method to synthesize 2,2,6,6-tetramethyl-4-piperidinamine has the advantages of easy control of the process, easy realization of continuous operation, less reaction by-products, easy separation of products, Mild reaction conditions and other advantages, but high energy consumption, large investment in equipment, difficult to achieve industrial production