Process for preparing N-benzyl piperazine

Abstract

The preparation method of N-benzylpiperazine is that piperazine and benzyl halide react under catalyst conditions to generate N-benzylpiperazine, piperazine is dissolved in a solvent, and nitrogen-containing amine salt is dropped into as a catalyst, at 0-100 Add dropwise benzyl halide and piperazine at ℃ to react, keep warm for 0.5-24 hours after the reaction, evaporate the solvent under reduced pressure, add lye to strong alkalinity, extract with extractant, and then distill and rectify to obtain the finished product. The invention has the advantages of minimizing the post-treatment procedure after the reaction, simple operation, high purity of the target product, which can reach more than 99%, and the yield can reach more than 95%.

Description

technical field [0001] The invention relates to a preparation method of a pharmaceutical intermediate, in particular N-benzylpiperidine, an intermediate of pharmaceutical products such as rifamycin for treating tuberculosis infection, dopamine for treating and preventing neuropsychological diseases, and trimetazidine for relaxing blood vessels. The preparation method of oxazine. Background technique [0002] N-benzyl piperazine (N-benzyl piperazine) is an important nitrogen-containing heterocyclic compound and a pharmaceutical intermediate. Its derivatives can be made into a variety of pharmaceutical products, such as rifamycin for the treatment of tuberculosis infection , dopamine for the treatment and prevention of neuropsychological diseases, trimetazidine for dilating blood vessels, and antiallergic drug pyridazinone, etc. The current preparation method of N-benzylpiperazine is formed by condensation of piperazine and benzyl halide under the action of a catalyst. Commo...

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Problems solved by technology

In addition, the main reaction will have some side reactions at the same time. In order to prevent the side reactions, it is often necessary to use an excessive amount or even several times the amount of piperazine to participate in the reaction, so that post-treatment will be carried out after the reaction. Unreacted piperazine and the target product N-benzylpiperazine is separated, the operation is more complicated, the product purity is low, and the yield is very low, which can only reach 60-70%.

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