A kind of preparation method of piperazine

Abstract

The invention discloses a preparation method of piperazine, comprising: diethanolamine in Co-Ni-Mo / Al 2 o 3 Under the action of catalyst, continuous gas-solid phase reaction is carried out to prepare piperazine. The invention can directly generate piperazine through diethanolamine, the catalyst has a long service life, the reaction conditions are mild, and the gas-solid phase reaction is adopted, which avoids the corrosion of the reaction equipment by the liquid phase material under high temperature and high pressure conditions. Continuous production; high single-pass conversion rate of raw materials, good product selectivity; and the incidental output of monoethanolamine and hydroxyethylpiperazine can continue to participate in the reaction to convert it into piperazine and ethylenediamine, or make it as a by-product, Increased selectivity for monoethanolamine and hydroxyethylpiperazine.

Description

technical field [0001] The invention relates to the technical field of piperazine, in particular to a method for preparing piperazine using diethanolamine as a raw material. Background technique [0002] Piperazine is an important organic chemical intermediate, which is widely used in the fields of medicine, pesticides, dyes and surfactants; piperazine can be used as a raw material to synthesize lomefloxacin hydrochloride, sparfloxacin and other drug intermediates. [0003] The research on piperazine is relatively extensive abroad, and there are mainly the following types according to the different synthesis methods of the raw materials used: [0004] JP4911712 and JP74125375, etc. have reported the process route of preparing piperazine by hydrogenation and cyclization of N-β-hydroxyethylethylenediamine as raw material. This type of method uses metal oxides such as copper, chromium, and manganese as catalysts, and has by-products Less, the advantage of high yield; But its t...

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Problems solved by technology

[0004] JP4911712 and JP74125375, etc. have reported the process route of preparing piperazine by hydrogenation and cyclization of N-β-hydroxyethylethylenediamine as raw material. This type of method uses metal oxides such as copper, chromium, and manganese as catalysts, and has by-products Less, the advantage of high yield; But its technology is intermittent production, and production efficiency is low;

[0005] Patents such as SU368219 report the process of preparing piperazine by deamination of diethylenetriamine as raw material under high temperature and catalyst action. The yield of this method is relatively high; but the high price of raw materials restricts the industrialization of this process;

[0006] EP16325304 etc. have reported the process of synthesizing piperazine with aminoethanol as raw material under the action of high temperature, high pressure and catalyst to co-produce ethylenediamine; but the yield of piperazine is low;

[0007] The preparation of other piperazines also generally has the problem of high cost or short catalyst life, so it is necessary to carry out research on new piperazine synthesis processes