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A kind of method of low temperature synthetic metronidazole

A metronidazole and low-temperature technology, applied in the field of low-temperature synthesis of metronidazole, can solve the problems of low yield of metronidazole, low utilization rate of ethylene oxide, large amount of waste water, etc., so as to improve the utilization rate and the yield. , the effect of reducing production costs

Active Publication Date: 2022-02-18
南京甘倍加生物科技有限责任公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to overcome above-mentioned technical deficiency, propose a kind of method for synthesizing metronidazole at low temperature, solve the technical problem of low utilization rate of ethylene oxide, large amount of waste water, low yield of metronidazole in the prior art

Method used

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  • A kind of method of low temperature synthetic metronidazole
  • A kind of method of low temperature synthetic metronidazole
  • A kind of method of low temperature synthetic metronidazole

Examples

Experimental program
Comparison scheme
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Embodiment 1

[0022] Add 2-methyl-5-nitroimidazole and formic acid into the reactor, stir at room temperature until completely dissolved, then add activated carbon-supported phosphotungstic acid catalyst (the immobilized amount of phosphotungstic acid is 0.2, that is, 1g activated carbon 0.2g phosphotungstic acid), lower the temperature of the reaction system to -10°C, then slowly add ethylene oxide, control the reaction temperature below 10°C, keep the reaction at 5°C to 9°C for 6 hours after adding ethylene oxide, The activated carbon-supported phosphotungstic acid catalyst is recovered by suction filtration, and the filtrate is concentrated at 70°C to 85°C and the vacuum degree is 0.085MPa to 0.095MPa to recover formic acid; the recovered concentrate is added with the equivalent of 2-methyl-5- 1.5 times of nitroimidazole in water, stir and mix well, adjust the pH to 3 with a mass fraction of 30% sodium hydroxide solution, then suction filter, recover the filter cake to obtain 2-methyl-5-n...

Embodiment 2～4

[0025] The difference between Examples 2-4 and Example 1 lies in the weight ratio of 2-methyl-5-nitroimidazole to formic acid, see Table 1 for details.

[0026] Table 1 Effect of the weight ratio of 2-methyl-5-nitroimidazole to formic acid on the reaction results

[0027]

[0028] As can be seen from Table 1, when the weight ratio of 2-methyl-5-nitroimidazole and formic acid is 1:4, a higher yield can be obtained, and if formic acid is continued to be added, the yield of metronidazole crude product will not increase significantly.

Embodiment 5～12

[0030] Compared with Example 1, the difference between Examples 5-12 lies in the use of different immobilized heteropolyacid catalysts, see Table 2 for details.

[0031] The impact of different heteropolyacid catalysts and different solid loadings on the reaction results in table 2

[0032]

[0033] ("g / g" in the solid loading refers to the mass ratio of heteropolyacid to carrier.)

[0034] From the above data, it can be seen that the phosphotungstic acid catalyst has the best effect, and the immobilization amount of the catalyst is 0.2g of phosphotungstic acid immobilized on 1g of activated carbon. The subsequent increase of the immobilization amount of phosphotungstic acid does not significantly improve the yield.

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Abstract

The invention discloses a method for synthesizing metronidazole at low temperature, comprising the following steps: mixing 2-methyl-5-nitroimidazole and formic acid, stirring at room temperature until completely dissolved, then adding a solid-supported heteropolyacid catalyst, and cooling to -20°C to -5°C, then feed ethylene oxide, and control the temperature at 0°C to 10°C. After the completion of the feed of ethylene oxide, continue the heat preservation reaction. After the reaction, separate to obtain metronidazole. The present invention synthesizes metronidazole by reacting ethylene oxide in liquid form with 2-methyl-5-nitroimidazole under low temperature conditions, which greatly improves the utilization rate of ethylene oxide; The heteropolyacid catalyst replaces the existing sulfuric acid, the catalytic effect is remarkable, there is no large amount of waste water, it is environmentally friendly, the catalyst can be recycled and no regeneration is required; the invention can greatly increase the yield, reduce production costs, and is safe and simple to operate .

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a method for synthesizing metronidazole at low temperature. Background technique [0002] Metronidazole, chemical name 1-(2-hydroxyethyl)-2-methyl-5-nitroimidazole, white or yellowish crystal or crystalline powder. As an antibiotic and antiprotozoal, metronidazole is used in the treatment of intestinal and parenteral amoebiasis, pelvic inflammatory disease, bacterial vaginosis, piriformis and oral anaerobic infection, etc., and is essential in basic medical care medicine. [0003] The existing synthesis technique of metronidazole is to take the mixed acid of formic acid and sulfuric acid as solvent, under heating condition (reaction temperature is 90 ℃), adopts 2-methyl-5-nitroimidazole and ethylene oxide reaction synthesis, This synthetic technique has following shortcoming: [0004] (1) The utilization rate of ethylene oxide is low: the reaction temperature of this...

Claims

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Application Information

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IPC IPC(8): C07D233/94B01J31/18B01J31/16
CPCC07D233/94B01J27/188B01J23/30
Inventor 吴洪元徐双喜
Owner 南京甘倍加生物科技有限责任公司