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Preparation process of methyl mercaptothiadiazole

A technology of methyl mercaptothiadiazole and preparation process, which is applied in the field of medicine and chemical industry, can solve the problem of no waste acid treatment and the like, and achieve the effects of reducing usage amount, wide source of raw materials and mild reaction conditions

Inactive Publication Date: 2020-11-13
SHANDONG JINCHENG KERUI CHEMICAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The biggest disadvantage of the above reaction is that a large amount of concentrated sulfuric acid is used in the cyclization reaction, and a large amount of waste acid is generated, which puts a huge pressure on both equipment and environmental protection, and the relevant patents do not have any protection against the generated waste acid. How to deal with it, it's a huge hole

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] A kind of preparation technology of methylmercaptothiadiazole is carried out as follows:

[0026] (1) Take 62.5g of 80% hydrazine hydrate and put it in a three-necked flask, control the reaction temperature at 25°C, add 80g of carbon disulfide dropwise for 2h, keep it at 25°C for 1h, filter, and dry the wet HDF product in vacuum at 55°C for 4h , to obtain a white crystalline powder;

[0027] (2) Control the temperature at 30°C, add dried HDF into the reaction bottle, then add 61.2g of glacial acetic acid, add 122g of 36% concentrated hydrochloric acid dropwise, add dropwise for 2h, heat up to 50°C, react for 3h, cool down to 0-5 ℃, 30% sodium hydroxide solution to adjust the pH=8.5, and filter to obtain the crude product of methylmercaptothiadiazole (MMTD);

[0028] (3) Add the crude product of MMTD to 750g of distilled water, raise the temperature to 90°C, reflux for 1h, slowly cool down to 45°C, stir for 1h, continue to cool down to 0-5°C, stir for 1h, filter to obta...

Embodiment 2

[0030] A kind of preparation technology of methylmercaptothiadiazole is carried out as follows:

[0031] (1) Take 62.5g of 80% hydrazine hydrate and put it in a three-necked flask, control the reaction temperature at 25°C, add 80g of carbon disulfide dropwise for 2h, keep it at 25°C for 1h, filter, and dry the wet HDF product in vacuum at 55°C for 4h , to obtain a white crystalline powder;

[0032] (2) Control the temperature at 25°C, add dried HDF into the reaction bottle, add 61.2g of glacial acetic acid, add 199g of phosphorus oxychloride dropwise, add dropwise for 2 hours, heat up to 60°C, react for 3 hours, and cool down to 0-5 ℃, 30% sodium hydroxide solution to adjust the pH=8.5, and filter to obtain the crude product of methylmercaptothiadiazole (MMTD);

[0033] (3) Add the crude MMTD to 800g of distilled water, raise the temperature to 95°C, reflux for 1h, slowly cool down to 45°C, stir for 1h, continue to cool down to 0-5°C, stir for 1h, filter to get the wet MMTD p...

Embodiment 3

[0035] A kind of preparation technology of methylmercaptothiadiazole is carried out as follows:

[0036] (1) Take 62.5g of 80% hydrazine hydrate and put it in a three-necked flask, control the reaction temperature at 25°C, add 80g of carbon disulfide dropwise for 2h, keep it at 25°C for 1h, filter, and dry the wet HDF product in vacuum at 55°C for 4h , to obtain a white crystalline powder;

[0037] (2) Control the temperature at 25°C, add dried HDF into the reaction bottle, add 61.2g of glacial acetic acid, add 107.8g of 98% concentrated sulfuric acid dropwise, add dropwise for 1.5h, heat up to 60°C, react for 3h, and cool down to 0 ~5°C, adjust the pH to 8.5 with 30% sodium hydroxide solution, and filter to obtain the crude product of methylmercaptothiadiazole (MMTD);

[0038] (3) Add the crude MMTD to 800g of distilled water, raise the temperature to 95°C, reflux for 1h, slowly cool down to 45°C, stir for 1h, continue to cool down to 0-5°C, stir for 1h, filter to get the we...

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Abstract

The invention discloses a preparation process of methyl mercaptothiadiazole, and relates to the technical field of pharmaceutical chemicals. The preparation process comprises the following steps: (1)reacting hydrazine hydrate serving as a raw material with carbon disulfide to prepare hydrazino dithioformic acid (HDF); (2) carrying out cyclization between HDF and acetic acid under the action of anacid catalyst to generate a methyl mercaptothiadiazole (MMTD) crude product; and (3) refining to obtain an MMTD product. Compared with the traditional process, the process greatly reduces or even avoids the use of concentrated sulfuric acid, is green and pollution-free, has simple process steps, greatly improves the cyclization reaction rate, improves the cyclization reaction conversion rate, saves time and energy, and is suitable for industrial production.

Description

technical field [0001] The invention relates to the technical field of medicine and chemical engineering, in particular to a preparation process of methylmercaptothiadiazole. Background technique [0002] Methylmercaptothiadiazole is an important intermediate for the production of cefazolin, cefocanide, cefazidone, cephalosporin, cefprosporin, cephalosporin BL-S339, cephalosporin and other medicines Because of their broad-spectrum antibacterial properties, good absorption, few side effects, and especially suitable for oral absorption, they are widely used clinically. [0003] At present, the preparation process of methylmercaptothiadiazole is obtained by hydrazination, addition, and cyclization of ethyl acetate. The specific steps are: hydrazine hydrate and ethyl acetate are refluxed for 5 hours to obtain acetyl hydrazide; acetyl hydrazide is added to potassium hydroxide or Ammonia ethanol solution, add carbon disulfide dropwise at low temperature, react for 3 hours, filter...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D285/125
CPCC07D285/125
Inventor 李家全张林宋广慧邱化齐
Owner SHANDONG JINCHENG KERUI CHEMICAL CO LTD
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