Post-treatment method for preparing 1,3-dimethyl-4-iminourazine

A technology of imidecarbazine and dimethylcyanoacetylurea, which is applied in the field of chemical technology, can solve the problems of increased environmental protection treatment costs, increased sulfuric acid consumption, poor control stability, etc., and achieves the goal of improving internal quality and reducing unit consumption Effect

Inactive Publication Date: 2020-05-19
JILIN SHULAN SYNTHETIC PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] 2. When the condensation reaction synthesizes 1,3-dimethylcyanoacetylurea, the stability of the raw material cyanoacetic acid used in the synthesis is general. When the control stability of the reaction process is not good, certain by-product impurities will be produced. These by-product impurities will have a great impact on the final The content and distribution of caffeine impurities have a certain influence, which in turn affects the quality of caffeine products
[0008] 3. The residual liquid alkali in the feed solution after the cyclization reaction increases the consumption of sulfuric acid during the nitrosation reaction and produces a large amount of sulfate. These separated high-salt waste liquids increase the difficulty of wastewater treatment and increase the cost of environmental protection treatment. Increase

Method used

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  • Post-treatment method for preparing 1,3-dimethyl-4-iminourazine
  • Post-treatment method for preparing 1,3-dimethyl-4-iminourazine
  • Post-treatment method for preparing 1,3-dimethyl-4-iminourazine

Examples

Experimental program
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Effect test

Embodiment 1

[0041] Transfer 1200L dimethylcyanoacetylurea into the cyclization reaction tank, adjust the base temperature of the cyclization reaction to 40°C, add 45L liquid sodium hydroxide to carry out the cyclization reaction to obtain DM·4AU, and the pH value at the end of the cyclization reaction is 9.2-9.4, The end point temperature is 90°C;

[0042] After the closed loop is completed, keep the temperature at 90°C, keep the temperature for 0.5 hours, and test the pH value during the heat preservation process to stabilize the pH value at 9.2 to 9.4 and keep it unchanged;

[0043]After the heat preservation is completed, cool down to 20°C for centrifugation, specifically: centrifuge 6 times, each centrifugation speed is 1500 rpm, and each centrifugation time is 20 minutes. After separation, 1,3-dimethyl-4- Urazine mother liquor and 460kg1,3-dimethyl-4-carbazine solid;

[0044] Sewage treatment of 1,3-dimethyl-4-imide ureazine mother liquor, 460kg of 1,3-dimethyl-4-imide ureazine soli...

Embodiment 2

[0046] Transfer 1200L dimethyl cyanoacetylurea into the cyclization reaction tank, adjust the base temperature of the cyclization reaction to 45°C, add 50L liquid sodium hydroxide to carry out the cyclization reaction to obtain DM·4AU, and the pH value at the end of the cyclization reaction is 9.2-9.4, The end point temperature is 95°C;

[0047] After the closed loop is completed, keep the temperature at 95°C for 0.5 hours and test the pH value during the heat preservation process to stabilize the pH value at 9.2 to 9.4 and keep it unchanged;

[0048] After the heat preservation is completed, cool down to 25°C for centrifugation, specifically: centrifuge 7 times, each time at a speed of 1500 rpm, and each time of centrifugation for 20 minutes, after separation, 1,3-dimethyl-4- Urazine mother liquor and 480kg1,3-dimethyl-4-carbazine solid;

[0049] Sewage treatment of 1,3-dimethyl-4-imide ureazine mother liquor, 480kg of 1,3-dimethyl-4-imide ureazine solid was put into the tra...

Embodiment 3

[0051] Transfer 1200L dimethyl cyanoacetylurea into the cyclization reaction tank, adjust the base temperature of the cyclization reaction to 42°C, add 54L liquid sodium hydroxide to carry out the cyclization reaction to obtain DM·4AU, and the pH value at the end of the cyclization reaction is 9.2-9.4, The end point temperature is 92°C;

[0052] After the closed loop is completed, keep the temperature at 92°C for 0.5 hours and test the pH value during the heat preservation process to stabilize the pH value at 9.2 to 9.4 and keep it unchanged;

[0053] After the heat preservation is completed, cool down to 22°C for centrifugation, specifically: centrifuge 6 times, each centrifugation speed is 1500 rpm, and each centrifugation time is 20 minutes. After separation, 1,3-dimethyl-4- Aminocarbazine mother liquor and 470kg1,3-dimethyl-4-imazinocarbazine solid;

[0054] Sewage treatment of 1,3-dimethyl-4-imide ureazine mother liquor, 470kg of 1,3-dimethyl-4-imide ureazine solid was p...

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Abstract

The invention provides a post-treatment method for preparing 1,3-dimethyl-4-iminourazine, belonging to the technical field of chemical processes. The method comprises the following steps: adding dimethyl cyanoacetylurea into a cyclization reaction tank, and adding liquid sodium hydroxide for a cyclization reaction; carrying out a heat-preserved reaction at a final temperature to obtain a crude 1,3-dimethyl-4-iminourazine product; carrying out centrifugal separation on the crude 1,3-dimethyl-4-iminourazine product to obtain a 1,3-dimethyl-4-iminourazine mother solution and a 1,3-dimethyl-4-iminourazine solid; and carrying out sewage treatment on the 1,3-dimethyl-4-iminourazine mother solution obtained in the step 3, putting the 1,3-dimethyl-4-iminourazine solid into a transfer tank, addingdrinking water to a constant volume, and carrying out beating and mixing to form a turbid liquid. The total impurity content of a finished caffeine product obtained by the treatment method is greatlyreduced, and the variety of impurities is greatly reduced.

Description

technical field [0001] The invention belongs to the technical field of chemical technology, and in particular relates to a post-treatment method for preparing 1,3-dimethyl-4-imidecarbazine. Background technique [0002] In the caffeine production process, the cyclization reaction is the main reaction step, and the reaction is that 1,3-dimethylcyanoacetylurea is cyclized under the action of liquid sodium hydroxide to obtain 1,3-dimethyl-4- The process of semicarbazine (DM·4AU), this DM·4AU is the main intermediate product of the subsequent synthesis of caffeine, and the product quality of DM·4AU has a great influence on the quality of the final caffeine product. [0003] As my country's GMP management has become more stringent this year, the requirements for drug quality have become higher and higher, especially the control of impurities. And 80% of our company's caffeine is exported to Europe, America, Latin America and Southeast Asia, especially in Europe and the United St...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D239/46C07D473/12
CPCC07D239/46C07D473/12
Inventor 郭跃民齐万良许海波张英勋李立冬
Owner JILIN SHULAN SYNTHETIC PHARMA
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