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Preparation method of 4-nitroimidazole

A technology of nitroimidazole and imidazolium disulfate, applied in organic chemistry and other directions, can solve the problems of difficult control, long time, and high reaction temperature, and achieve the effects of reducing the generation of waste acid, reducing reaction time, and reducing reaction temperature

Inactive Publication Date: 2015-05-06
JIANGSU CALE NEW MATERIALS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] There is following shortcoming in the above-mentioned method: method one, the nitric acid amount used is bigger, and the high time of technological reaction temperature is long, and yield is low; Method two, unsteady reaction is difficult to control, and used nitric acid amount is bigger; Method three, reaction temperature is high, high energy consumption

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Preparation of imidazolium sulfate:

[0030] Add 25.8mL of 98% concentrated sulfuric acid into a 250mL three-necked flask and ice-bath to 5°C, add 13.6g of imidazole, and stir at 20°C for 20min after the addition is complete to obtain imidazolium disulfate solution.

[0031] Preparation of nitrating agent:

[0032] Add 40ml 10% oleum in a 250mL three-necked flask and ice-bath to 5°C, then slowly add 8.53mL of 86% concentrated nitric acid and 1.85g of dinitrogen pentoxide to the three-necked flask and keep stirring to obtain N 2 o 5 - Mixed acid nitrating agent.

[0033] Preparation of 4-nitroimidazole:

[0034] Heat the imidazolium disulfate solution in a water bath to 50 °C, and slowly add N at this temperature 2 o 5 - Mix the acid nitrating agent and keep stirring. The molar ratio of concentrated nitric acid to imidazole is 0.8:1. After the addition is complete, stir at 50°C for 30 minutes to make the reaction complete. Cool the reaction system to 0°C, add 7mL o...

Embodiment 2

[0036] Preparation of imidazolium sulfate:

[0037] Add 25.8mL of 98% concentrated sulfuric acid into a 250mL three-necked flask and bathe it in water to 5°C, add 13.6g of imidazole under constant stirring, keep warm at 20°C and stir for 20min after the addition, to obtain imidazolium disulfate solution.

[0038] Preparation of nitrating agent:

[0039] Take 40ml of fuming sulfuric acid in a 250mL three-necked flask and ice-bath to 5°C, slowly add 10.7mL of 86% concentrated nitric acid and 1g of dinitrogen pentoxide under stirring to obtain N 2 o 5 - Mixed acid nitrating agent.

[0040] Preparation of 4-nitroimidazole:

[0041] Heat the water bath of imidazolium sulfate solution to 55 °C, slowly add N at this temperature 2 o 5 - Mix the acid nitrating agent and keep stirring. The molar ratio of concentrated nitric acid to imidazole is not 1:1. After adding, keep stirring for 30 minutes to make the reaction complete. Then cool the reaction solution to 0°C, add 7mL of ice-...

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PUM

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Abstract

The invention discloses a preparation method of 4-nitroimidazole. The preparation method comprises the steps of preparing disulfated imidazole salt from concentrated sulfuric acid and imidazole, and adding an N2O5<-1> mixed acid nitrating agent, so as to prepare 4-nitroimidazole. Compared with the prior art, the preparation method has the beneficial effects that the reaction yield is high and can reach 95.5%; meanwhile, nitrification of partial concentrated nitric acid is replaced by nitrogen pentoxide, so that the consumption of concentrated nitric acid is reduced, the reaction temperature is decreased, the reaction time is reduced, the generation of waste acid is reduced, the cost is saved, meanwhile, the environmental friendliness is achieved, and the industrialization of 4-nitroimidazole is facilitated.

Description

technical field [0001] The invention relates to the field of chemical synthesis, in particular to a preparation method of 4-nitroimidazole. Background technique [0002] 4-Nitroimidazole is an important intermediate in the synthesis of a class of anti-inflammatory drugs in the pharmaceutical field. It is mostly used in the synthesis of antifungal drugs and is also used as an intermediate in the preparation of cardiovascular drugs. Such as the synthesis of antibacterial antiprotozoal ronidazole, etc., in the energetic materials in the military field, 4-nitroimidazole is the synthesis of 2,4-dinitroimidazole, 4,5-dinitroimidazole, 2,4, An important synthetic intermediate of high-energy explosives such as 5-trinitroimidazole. 4-Nitroimidazole can also be used as a feed additive, and can also be used for polymerization and polycondensation reactions in the polymer chemical industry, especially for epoxy compound reactions, aldol condensation reactions, ethyl malonate or ethyl a...

Claims

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Application Information

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IPC IPC(8): C07D233/92
CPCC07D233/92
Inventor 沈健
Owner JIANGSU CALE NEW MATERIALS