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Preparation method of N-methyl piperazine

A technology of methylpiperazine and methyliminodiacetonitrile is applied in the field of preparation of N-methylpiperazine, and can solve the problems of incomplete conversion of piperazine, low conversion rate of piperazine, and yield of N-methylpiperazine. It can reduce the probability of polymerization side reactions and improve the selectivity.

Active Publication Date: 2015-04-29
WANHUA CHEM GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

In this patent, there are shortcomings such as high content of various piperazine derivatives and incomplete transformation of piperazine
[0007] The preparation of the above-mentioned N-methylpiperazine all adopts piperazine as a raw material, and there are generally disadvantages such as high price of raw material piperazine, low conversion rate of piperazine, low yield of N-methylpiperazine, and many by-products.

Method used

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  • Preparation method of N-methyl piperazine
  • Preparation method of N-methyl piperazine
  • Preparation method of N-methyl piperazine

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0045] The preparation of embodiment 1 carrier

[0046] 161g ZrOCl 2 ·8H 2 O was dissolved in water, and after the hydrolysis was complete, about 430 g of MCM-41 molecular sieve was added, and after soaking for 1 hour, ammonia water with a mass fraction of 20 wt % was added dropwise under stirring conditions to adjust the pH value to about 9. The precipitate was suction filtered and washed with a large amount of distilled water until it was free of chloride ions. The filter residue was dried at 100°C, impregnated with a certain concentration of sulfuric acid for 2 hours, dried at 100°C, and then calcined at high temperature for 3 hours to obtain a carrier.

[0047] Determination of the acid ratio between B acid and L acid: under vacuum conditions, the infrared spectrogram of the carrier after desorption at 300 ° C, the L acid center (1446.2cm -1 ), B acid center (1546.2cm -1 ).

[0048] The acid strength H of different carriers measured by the indicator method o , the pr...

Embodiment 2

[0051] Embodiment 2 catalyst preparation

[0052] According to the ratio, the active metal salt is made into a solution, impregnated on the carrier by dipping method, dried under infrared lamp for 24 hours, layered into strips, and dried at a certain temperature for a period of time for later use. The specific preparation conditions and results are shown in Table 2.

[0053] Table 2 catalyst preparation conditions and results

[0054]

Embodiment 3

[0055] Embodiment 3 prepares N-methyliminodiacetonitrile

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Abstract

The invention relates to a preparation method of N-methyl piperazine. The preparation method comprises the following steps: (1) carrying out reaction on iminodiacetonitrile (IDAN) and methanal under the acidic condition to prepare N-methyl iminodiacetonitrile; and (2) carrying out hydrogenation reaction on N-methyl iminodiacetonitrile at the temperature of 70-140 DEG C and the pressure of 2-8MPa, wherein a molecular-sieve modified zirconium-based superacid serves a carrier, and one or two or more of the active metals of Fe, Co, Ni, Ru and Rh serves / serve as a hydrogenation catalyst. Compared with the prior art, the preparation method provided by the invention has the advantages of high yield due to the adoption of the catalyst and low equipment investment. In addition, the raw materials for preparing the N-methyl piperazine are low in cost and are easy to obtain.

Description

technical field [0001] The invention relates to a preparation method of N-methylpiperazine. Background technique [0002] N-Methylpiperazine is one of the derivatives of piperazine and is an important fine chemical product, mainly used as drugs such as ofloxacin, clozapine, sildenafil, turidin, and zopiclone It can also be used as an intermediate in pesticides, dyes, plastics and other industries. [0003] The synthetic method of N-methylpiperazine mainly contains two kinds at present: [0004] Method 1: react piperazine and hydrochloric acid to generate piperazine hydrochloride, separate the salt and then react with a mixture of formic acid and formaldehyde to obtain N-methylpiperazine hydrochloride, then add sodium hydroxide to neutralize, and distill , In water-containing N-methylpiperazine. Add benzene and heat to reflux with water, fractional distillation, and collect fractions at 132-140°C to obtain anhydrous N-methylpiperazine with a yield of only 50%. This proces...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D295/03C07D295/023B01J29/03B01J29/04
CPCB01J29/0333B01J2229/18C07D295/023C07D295/03
Inventor 丁可陈长生李付国李昂信勇崔兵胡江林刘运海舒磊曾伟王坤曹善健黎源
Owner WANHUA CHEM GRP CO LTD