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Synthesis of 1-methylhydrazine

A kind of technology of monomethylhydrazine and synthesis method, applied in the directions of hydrazine preparation, organic chemistry, etc., can solve the problem of high price of methylation reagents, and achieve the effects of short production cycle, simple operation and high yield

Inactive Publication Date: 2009-04-08
SHANDONG UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0013] Use dimethyl phosphite or dimethyl carbonate as a methylating reagent, and directly synthesize methylhydrazine with hydrazine hydrate under normal pressure conditions. According to some literature reports, the optimal reaction conditions for this process synthesis, the The yield reaches 50%, but the price of the same selected methylation reagent is relatively high

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Add 63g of 80% hydrazine hydrate (1mol) in a 500ml four-necked flask equipped with a thermometer, stirrer and reflux condenser, add 110g of 36.5% concentrated hydrochloric acid (1.1mol) dropwise, add 0.63g of tetrabutyl Ammonium bromide, after stirring for 20 minutes, slowly add 126g (1mol) dimethyl sulfate dropwise, control the dropping rate to prevent bumping, after the addition, the reaction temperature is kept at 115-125°C, react for 2 hours, add 40% sodium hydroxide solution to adjust pH value to 11, cooled to 5°C and filtered the formed inorganic salt, washed the filter cake with cold water, combined the filtrate and washing liquid and rectified, collected 81g of components between 102-110°C, used methyl red as indicator, acid The content was measured by alkali titration, the mass fraction of monomethylhydrazine was 27.6%, and the yield was 48.6%.

[0032] Adjustment method of product concentration: Add 30ml of isopropyl ether to the above product aqueous solution...

Embodiment 2

[0033] Embodiment 2: the mol ratio of hydrochloric acid and hydrazine is 1.8: 1

[0034] Add 63g of 80% hydrazine hydrate in a 500ml four-necked flask equipped with a thermometer, agitator and reflux condenser, add 180g of 36.5% concentrated hydrochloric acid dropwise, add 0.63g of tetrabutylammonium bromide after the dropwise, and stir for 20min Slowly add 126g of dimethyl sulfate dropwise, control the dropping speed to prevent bumping, keep the reaction temperature at 115-125°C after the addition, react for 2h, add 40% sodium hydroxide solution to adjust the pH value to 11, cool to 5°C and filter The generated inorganic salts, wash the filter cake with cold water, combine the filtrate and washing liquid and then rectify, collect 87g of components between 102-110°C, use methyl red as indicator, titrate its content with acid and alkali, the content of monomethylhydrazine The mass fraction is 26.9%, and the yield is 50.9%.

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Abstract

The invention relates to a synthesis method for methyl hydrazine, which comprises the following steps: causing hydrazine hydrate and dimethyl sulfate to react at a temperature of 115 and 125 DEG C by using hydrochloric acid as a protecting agent and tetrabutyl ammonium bromide as a catalyst, adding alkali to neutralize and dissociate out the methyl hydrazine, cooling and removing salt, and rectifying the filter liquor to obtain an aqueous solution of the methyl hydrazine. The synthesis method has the advantages of low raw material cost, simple production equipment, quick reaction rate, high yield, and the like.

Description

technical field [0001] The invention relates to a synthesis method of monomethylhydrazine, which belongs to the field of chemical synthesis. technical background [0002] Monomethylhydrazine is an important energy material in the field of space technology, and it is also an important intermediate for the synthesis of some high-quality pesticides and medicines. According to existing literature reports, there are mainly the following methods for the synthesis of monomethylhydrazine: [0003] 1. Racifer [0004] The Raschig method is the earliest synthetic method used in industry, also known as the chloramine method, which uses sodium hypochlorite to react with ammonia, and then reacts with monomethylamine to generate monomethylhydrazine. The reaction formula is: [0005] NaOCl+NH 3 =NH 2 Cl+NaOH [0006] NH 2 Cl+NaOH+CH 3 NH 2 =CH 3 NNH 3 +NaCl+H 2 o [0007] This technology is mature, and there are many people who use this process to produce monomethylhydrazine at ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C243/14C07C241/02
Inventor 杨延钊刘德强
Owner SHANDONG UNIV
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