Method and special device for heterogeneous catalyzed synthesis of triacetonamine

Abstract

The invention belongs to the technical field of preparation of hindered amine light stabilizer midbody and pharmaceutical midbody triacetonamine, and particularly relates to a method and a special device for heterogeneous catalyzed synthesis of triacetonamine. The technical scheme is that a cone base reaction kettle consisting of a straight cylinder section and a cone cylinder section is applied, and a water knockout drum formed by a tubular type membrane tube is arranged in the cone base reaction kettle; heterogeneous catalyst and acetone are added in the reaction kettle; after stirring and heating, ammonia gas is filled for reaction; the procedures of separating water by the water knockout drum, cooling, stopping mixing, separating water and standing are carried out, and reaction fluid is discharged and filtered to obtain a crude product of triacetonamine; finally, the crude product is rectified to obtain the high-purity triacetonamine product. In the invention, the heterogeneous catalyst is applied to replace the homogeneous catalyst, thus the separating difficulty of the catalyst is reduced, the high saline-alkali waste water generated from separation process of homogeneous catalyst is avoided; the reaction water is separated from the reaction process, the yield of triacetonamine is improved, and the water separating cost of the rectifying technique is reduced. The content of organic matters in separated water of the water knockout drum is low, and water disposal cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of preparation of hindered amine light stabilizer intermediates and pharmaceutical intermediates triacetonamine, and in particular relates to a method and special equipment for heterogeneously catalyzed synthesis of triacetonamine. Background technique [0002] The chemical name of triacetonamine is 2,2,6,6-tetramethylpiperidone, which is an important hindered amine light stabilizer intermediate and pharmaceutical intermediate, especially in the field of hindered amine light stabilizer, triacetonamine It is the only parent nucleus of the hindered amine light stabilizer piperidine derivatives, and is an important raw material for the synthesis of tetramethylpiperidinol, tetramethylpiperidinamine and polymerization inhibitor 702. The synthetic method of triacetonamine mainly contains two-step method and one-step method. [0003] The two-step method first uses acetone and ammonia as raw materials to synthesize...

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Problems solved by technology

In this one-step synthesis process, its yield is lower than that of the two-step method, but the catalyst is cheap and easy to obtain, and the raw materials are easy to recycle and apply mechanically, which has a greater cost advantage; but the catalyst used in the one-step method is generally ammonium nitrate, ammonium chloride, and calcium chloride. , organic ammonium salt and other homogeneous catalysts soluble in water or acetone, the separation and recovery of homogeneous catalysts is difficult, and a large amount of high-salinity wastewater is produced at the same time, which is difficult to treat

[0005] In addition, whether the above-mentioned one-step or two-step synthesis of triacetone amine will produce water as a by-product during the reaction process, thus forming a reaction balance, the yield is not high, and the process of separating water after the reaction is mainly concentrated alkali water separation and Distillation divides water, causing alkali and energy consumption, and at the same time produces difficult-to-treat high-salinity organic wastewater

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