Method for recycling by-products in metronidazole production process

A production process and cyclic technology, applied in the direction of chemical instruments and methods, alkali metal compounds, alkali metal sulfite/sulfite, etc., can solve the problem that the utilization rate of ethylene oxide does not exceed 25%, and achieve reduction The effect of increasing the dosage, increasing the utilization rate, and solving the pollution of waste liquid

Inactive Publication Date: 2017-11-07
HUANGGANG NORMAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the above three patents have increased the chance of contact reaction between ethylene oxide and materials to varying degrees, the utilization rate of ethylene oxide still does not exceed 25%.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] 1) Add 2-methyl-5-nitroimidazole to the reaction kettle, add 85% industrial formic acid solvent dropwise to dissolve 2-methyl-5-nitroimidazole, add ethylene oxide successively at 30-40℃, And add 98% sulfuric acid in the middle of the feed, after the addition, react for 1h to obtain the hydroxylated liquid;

[0021] 2) Add a low-carbon alcohol in excess, control the temperature to be 10°C higher than the boiling point of the corresponding formate, perform reactive distillation, and condense the steam to obtain the formate product;

[0022] 3) The temperature rises below 10°C above the boiling point of the added lower alcohol, and the excess lower alcohol is obtained by distillation;

[0023] 4) After the hydroxylation solution is cooled to 10°C, the pH is adjusted to 10 with sodium hydroxide solution, placed to cool, crystallized, and filtered to obtain metronidazole;

[0024] 5) Evaporate the filtrate, cool, crystallize, and filter to obtain a solid sodium sulfate product;

[00...

Embodiment 2

[0030] 1) Add 2-methyl-5-nitroimidazole to the reaction kettle, add 85% industrial formic acid solvent dropwise to dissolve 2-methyl-5-nitroimidazole, add ethylene oxide successively at 30-40℃, And add 98% sulfuric acid in the middle of the feed, after the addition, react for 1h to obtain the hydroxylated liquid;

[0031] 2) Add a low-carbon alcohol in excess, control the temperature to be 10°C higher than the boiling point of the corresponding formate, perform reactive distillation, and condense the steam to obtain the formate product;

[0032] 3) The temperature rises below 10°C above the boiling point of the added lower alcohol, and the excess lower alcohol is obtained by distillation;

[0033] 4) After the hydroxylation solution is cooled to 10°C, the pH is adjusted to 10 with sodium hydroxide solution, placed to cool, crystallized, and filtered to obtain metronidazole;

[0034] 5) Evaporate the filtrate, cool, crystallize, and filter to obtain a solid sodium sulfate product;

[00...

Embodiment 3

[0040] 1) Add 2-methyl-5-nitroimidazole to the reaction kettle, add 85% industrial formic acid solvent dropwise to dissolve 2-methyl-5-nitroimidazole, add ethylene oxide successively at 30-40℃, And add 98% sulfuric acid in the middle of the feed, after the addition, react for 1h to obtain the hydroxylated liquid;

[0041] 2) Add a low-carbon alcohol in excess, control the temperature to be 10°C higher than the boiling point of the corresponding formate, perform reactive distillation, and condense the steam to obtain the formate product;

[0042] 3) The temperature rises below 10°C above the boiling point of the added lower alcohol, and the excess lower alcohol is obtained by distillation;

[0043] 4) After the hydroxylation solution is cooled to 10°C, the pH is adjusted to 10 with sodium hydroxide solution, placed to cool, crystallized, and filtered to obtain metronidazole;

[0044] 5) Evaporate the filtrate, cool, crystallize, and filter to obtain a solid sodium sulfate product;

[00...

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PUM

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Abstract

The invention discloses a method for recycling by-products in a metronidazole production process, and solves problems that by-products such as ethylene glycol and ethers thereof are not used frequently and pollute the environment, and the utilization rate of ethylene oxide is low in prior art. In the method disclosed by the invention, the by-products such as ethylene glycol and ethers thereof generated in metronidazole synthesis process are recycled, measures for reducing the use amount of a formic acid solvent, increasing the concentration of formic acid and sulfuric acid, and the like are adopted, and the bring-in amount of water is reduced, so that the utilization rate of ethylene oxide is increased. In the method, the by-products such as ethylene glycol and ethers thereof are partially used as the solvents, so that the use amount of the formic acid solvent is reduced, the utilization rate of ethylene oxide is increased, and a problem of waste liquid pollution is also solved.

Description

Technical field [0001] The invention belongs to the fields of organic synthesis, resource recovery and environmental protection, and particularly relates to a method for recycling by-products in the metronidazole production process. Background technique [0002] Metronidazole is a white or slightly yellow crystal or crystalline powder, used to treat intestinal and extraintestinal amoebiasis (such as amoebic liver abscess, pleural amoebiasis, etc.). It can also be used to treat vaginal trichomoniasis, small bagworm disease and skin leishmaniasis, guinea worm infection, etc. At present, it is also widely used in the treatment of anaerobic infections, and is regarded by the World Health Organization (WHO) as the drug of choice against anaerobic bacteria. [0003] The current process for synthesizing metronidazole is to dissolve 2-methyl-5-nitroimidazole in formic acid, add ethylene oxide successively at 30-40°C, and add sulfuric acid in the middle of the feed. After the addition, th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D233/94C01D5/00
CPCC01D5/00C07D233/94Y02P20/10
Inventor 曾舟华曾彩红刘晓晖冉敬文黄林勇杨水彬
Owner HUANGGANG NORMAL UNIV
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