Metronidazole preparation method

A technology for metronidazole and nitroimidazole, applied in the field of preparation of metronidazole, can solve problems such as high cost and low yield, and achieve the effects of promoting reaction, reducing production cost and saving usage amount

Active Publication Date: 2013-02-06
SHANXI TONGJI PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] An object of the present invention is to solve the problems of high cost and low yield in the existing formic acid method for preparing metronidazole bulk drug; another object of

Method used

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Embodiment 1

[0034] A method for preparing metronidazole includes the following steps:

[0035] (1) Mixed acid: Put 100 parts of formic acid with a concentration of 97% (1kg per part, the same applies for the following) into the reaction kettle, add 30 parts of concentrated sulfuric acid to prepare mixed acid for use;

[0036] (2) Synthesis reaction: Put 120 parts of the reaction material 2-methyl-5-nitroimidazole into the reaction tank, add the mixed acid prepared in step (1), control the temperature at 75℃, and wait until 2-methyl-5 -After the nitroimidazole is completely dissolved, keep it for 15 minutes, add 98 parts of ethylene oxide and 8 parts of concentrated sulfuric acid, and generate hydroxylation liquid after the reaction;

[0037] (3) One-time neutralization: Put the hydroxylation solution prepared in step (2) back into the nitrate tank, control the temperature at 28°C, add sodium hydroxide (NaOH) dropwise to neutralize to a pH of 2.0, and then lower the temperature to 15 Perform cry...

Embodiment 2

[0042] A method for preparing metronidazole includes the following steps:

[0043] (1) Mixed acid: Put 100 parts of formic acid with a concentration of 95% (10kg per part, the same below) into the reactor, control the temperature at 20~25℃ and add 27 parts of concentrated sulfuric acid to prepare mixed acid for later use; The main purpose of controlling the temperature between 20~25℃ in concentrated sulfuric acid is to prevent the splash of concentrated sulfuric acid from hurting people when preparing mixed acid;

[0044] (2) Synthesis reaction: Put 115 parts of reaction material 2-methyl-5-nitroimidazole into the reaction tank, add the mixed acid prepared in step (1), control the temperature at 80℃, and wait until 2-methyl-5 -After the nitroimidazole is completely dissolved, keep it for 10 minutes, add 95 parts of ethylene oxide and 7 parts of concentrated sulfuric acid, and generate hydroxylation liquid after the reaction;

[0045] (3) One-time neutralization: Put the hydroxylatio...

Embodiment 3

[0050] A method for preparing metronidazole includes the following steps:

[0051] (1) Mixed acid: Put 100 parts of formic acid with a concentration of 98% (5kg per part, the same applies below) into the reactor, control the temperature between 20 and 25 ℃ and add 25 parts of concentrated sulfuric acid to prepare mixed acid for use;

[0052] (2) Synthesis reaction: Put 110 parts of the reaction material 2-methyl-5-nitroimidazole into the reaction tank, add the mixed acid prepared in step (1), control the temperature at 76°C, wait until 2-methyl-5 -Nitroimidazole is completely dissolved and kept for 17 minutes, 100 parts of ethylene oxide and 8.5 parts of concentrated sulfuric acid are added, and a hydroxylation liquid is generated after the reaction; among them, ethylene oxide is added to the reaction tank in four times and concentrated sulfuric acid in three times , Specifically: add ethylene oxide uniformly for the first time within 40 minutes, add concentrated sulfuric acid for ...

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Abstract

The invention relates to the field of medicine manufacturing techniques, in particular to a metronidazole API preparation method, and solves the problems that a current metronidazole preparation method is high in cost and low in yield. The method comprises the following steps: (1), acid mixing, adding 100 parts (by weight) of formic acid of concentration of 95-99 percent in a reaction kettle for stirring to a temperature of 20 DEG C, then adding 25-35 parts (by weight) of concentrated sulphuric acid, so as to prepare the mixed acid for further use; (2), synthesis reaction, adding 100-120 parts (by weight) of reaction raw materials 2-methyl-5-nitroimidazole into a reaction tank, and adding the mixed acid prepared in the step 1, stirring to a temperature of 75-80 DEG C, completely dissolving the 2-methyl-5-nitroimidazole, and maintaining 10-20 minutes. According to the invention, the design is reasonable; and the mixed acid is adopted to provide an acidic condition, an applicable reaction raw material ratio and an appropriate control reaction parameter, so as to allow the yield of the nitroimidazole to reach 65-70 percent.

Description

technical field [0001] The invention relates to the technical field of medicine manufacturing, in particular to a method for preparing metronidazole. Background technique [0002] Metronidazole is also known as metronidazole, metronidazole, metronidazole, metronidazole, etc., and its chemical name is 2-methyl-5-nitroimidazole-1-ethanol (2-methyl-5- nitroimidazole-1-ethanol), is a nitroimidazole synthetic antibacterial drug. It is widely used in clinical practice and has broad-spectrum anti-anaerobic and antiprotozoal effects. It is mainly used in the prevention and treatment of infections caused by anaerobic bacteria, such as respiratory tract, digestive tract, abdominal cavity and pelvic infection, skin soft tissue, bone and bone joints and other parts. infection and endocarditis, brain abscess, sepsis and meningitis caused by Bacteroides fragilis, and is also widely used in the prevention and treatment of oral anaerobic infection. The nitro group of metronidazole is redu...

Claims

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Application Information

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IPC IPC(8): C07D233/94
Inventor 兰亚朝韩晓平李梅花张海霞吕国婷韩小鹏王庆
Owner SHANXI TONGJI PHARMA
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