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Preparation method of methylhydrazine

A technology of methylhydrazine and methanol, applied in the preparation of hydrazine, organic chemistry, etc., can solve the problems of high energy consumption, many reaction steps, and high requirements, and achieve the effects of lower reaction temperature, high selectivity, and energy saving

Active Publication Date: 2017-03-29
石家庄金派医药化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method has many reaction steps, requires recovery of solvent and catalyst, high energy consumption, and hydrochloric acid is corrosive, which requires high equipment requirements.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Put 360g of methanol and 625g of hydrazine hydrate with a concentration of 80% into the reactor, then add 53g of sodium bisulfite and 82g of sodium p-toluenesulfonate into the reactor, close the reactor, start stirring, and heat up to 86°C. After reacting for 5 hours, the temperature of the reaction solution was lowered to 60°C, and the reaction solution was transferred to a rectification kettle and the temperature was raised to 65-70°C, 87g of methanol was distilled off, and the temperature was further raised to 90-110°C, and 393g of methylhydrazine was distilled off. After the rectification finished, the still bottom contained 55 g of hydrazine hydrate, and the yield of methylhydrazine was 96.1%.

Embodiment 2

[0021] The methyl alcohol 87g that rectification reclaims among the embodiment 1 and the still bottom that contains hydrazine hydrate 55g are transferred in the reactor, supplement 393g methyl alcohol and 742g concentration and be the hydrazine hydrate of 60%, then 33g sodium bisulfite and 25g p-toluene Sodium sulfonate is added to the reaction kettle, the reaction kettle is closed, the stirring is started, and the temperature is raised to 98°C. After reacting for 3 hours, the temperature of the reaction solution is lowered to 60°C, and the reaction solution is transferred to the rectification kettle and the temperature is raised to 65-70°C. Distill 196g of methanol, continue to heat up to 90-110°C, distill 405g of methylhydrazine. After the rectification finished, the still bottom contained 48g of hydrazine hydrate, and the yield of methylhydrazine was 97.3%.

Embodiment 3

[0023] 196g of methanol recovered by rectification in Example 2 and the bottoms containing 48g of hydrazine hydrate were transferred to the reactor, and 284g of methanol and 753g of hydrazine hydrate with a concentration of 753g were added, the reactor was closed, stirring was started, and the temperature was raised to 95°C After 3 hours of reaction, the temperature of the reaction solution was lowered to 60°C, the reaction solution was transferred to a rectification kettle and the temperature was raised to 65-70°C, 200g of methanol was distilled off, and the temperature was continued to rise to 90-110°C, and 399g of methylhydrazine was distilled off. After rectification, the still bottom contained 52g of hydrazine hydrate, and the yield of methylhydrazine was 96.9%.

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PUM

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Abstract

The invention discloses a method for one-step preparation of methylhydrazine. The method comprises that under the protection of inert gas, hydrazine hydrate and methanol are subjected to alkylation reaction under an action of a catalyst for one-step synthesis of methylhydrazine, excess methanol is kept in the reaction process, and a mixed solution after the reaction is finished is rectified to obtain a high-purity methylhydrazine solution. The method has the following advantages of short process route, simple operation, high reaction yield, high selectivity of the catalyst, mild reaction conditions, and fewer by-products and side reactions; the catalyst and unreacted methanol and hydrazine can be recycled for use in the alkylation reaction, no solvents are used, no three wastes are generated, and the method is green and environmentally friendly.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a preparation method of methylhydrazine. Background technique [0002] Methylhydrazine is an important energy material, and at the same time, it is also an important intermediate for the synthesis of some high-quality pesticides and medicines. The preparation method report for methylhydrazine is a lot, mainly contains following several preparation methods according to existing literature: [0003] Chloramine method: Patent US4192819 first disclosed the process of synthesizing methylhydrazine by chloramine method, which mainly uses sodium hypochlorite and ammonia to react to produce chloramine, and then reacts chloramine and monomethylamine to generate methylhydrazine. This technology is mature, but the subsequent separation of this route is difficult, the energy consumption of the production process is high, and the cost of equipment is high. [0004] Hyd...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C241/02C07C243/14
CPCC07C241/02C07C243/14
Inventor 李亚杉
Owner 石家庄金派医药化工有限公司
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