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Preparation method of medical intermediate semicarbazlde hydrochloride

A technology of semicarbazide hydrochloride and intermediates, which is applied in the field of preparation of pharmaceutical intermediates semicarbazide hydrochloride, which can solve problems such as difficulty in achieving scale, high equipment requirements, and harsh reaction conditions, and achieve improved utilization, low equipment requirements, and easy operation. simple effect

Inactive Publication Date: 2018-11-23
SUZHOU GAIDE FINE MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Both of the above two processes use gas as raw material, which requires high equipment and harsh reaction conditions, making it difficult to achieve large-scale

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] The preparation method of pharmaceutical intermediate semicarbazide hydrochloride comprises the following steps:

[0021] (1) Divide urea into three equal parts, add hydrazine hydrate into the three-necked flask, slowly raise the temperature to 90°C, then add one part of urea into the three-necked flask, stir for 30 minutes after adding, and then continue to add the remaining two parts in batches For urea, add sodium acetate after the addition is complete, then heat up to 100-105°C, and keep warm for 1 hour; wherein, the molar ratio of urea to hydrazine hydrate is 1:1; the mass ratio of urea to sodium acetate is 3:1 ;

[0022] (2) After the above reaction is finished, cool down to 60°C, add dropwise a hydrochloric acid solution with a mass concentration of 20% in a three-necked flask, stir while adding dropwise, and continue stirring for 30 minutes after the dropwise addition, and cool to room temperature after the reaction Filtration, and then the obtained precipitate...

Embodiment 2

[0024] The preparation method of pharmaceutical intermediate semicarbazide hydrochloride comprises the following steps:

[0025] (1) Divide urea into three equal parts, add hydrazine hydrate into the three-necked flask, slowly raise the temperature to 90°C, then add one part of urea into the three-necked flask, stir for 30 minutes after adding, and then continue to add the remaining two parts in batches After adding urea, add sodium acetate, then heat up to 100-105°C, and keep warm for 3 hours; wherein, the molar ratio of urea to hydrazine hydrate is 1.4:1; the mass ratio of urea to sodium acetate is 4.5:1 ;

[0026] (2) After the above reaction is finished, cool down to 80°C, add dropwise a hydrochloric acid solution with a mass concentration of 35% in a three-necked flask, stir while adding dropwise, after the dropwise addition, continue to stir for 50 minutes, and cool to room temperature after the reaction Filtration, and then the obtained precipitate was redissolved with...

Embodiment 3

[0028] The preparation method of pharmaceutical intermediate semicarbazide hydrochloride comprises the following steps:

[0029] (1) Divide urea into three equal parts, add hydrazine hydrate into the three-necked flask, slowly raise the temperature to 90°C, then add one part of urea into the three-necked flask, stir for 30 minutes after adding, and then continue to add the remaining two parts in batches After adding urea, add sodium acetate, then heat up to 100-105°C, and keep warm for 1.5h; wherein, the molar ratio of urea to hydrazine hydrate is 1.1:1; the mass ratio of urea to sodium acetate is 3.5: 1;

[0030] (2) After the above reaction is finished, cool down to 65°C, add dropwise a hydrochloric acid solution with a mass concentration of 25% in a three-necked flask, stir while adding dropwise, continue stirring for 30 minutes after the dropwise addition, and cool to room temperature after the reaction Filtration, and then the obtained precipitate was redissolved with me...

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PUM

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Abstract

The invention discloses a preparation method of a medical intermediate semicarbazlde hydrochloride, and relates to the field of organic synthesis. The method comprises the following steps that firstly, hydrazine hydrate and urea are used as raw materials for preparing semicarbazide, in the preparation process, the urea are divided into three equal parts before being added in batch, and in a reaction process, a moderate amount of sodium acetate is added so that reaction can be effectively promoted, after the reaction is completed, a hydrochloric acid solution is added, and by effectively controlling the dropping speed of the hydrochloric acid solution, the crystallization speed is controlled, and a prepared target product is high in yield and purity.

Description

Technical field: [0001] The invention relates to the field of organic synthesis, in particular to a method for preparing a pharmaceutical intermediate semicarbazide hydrochloride. Background technique: [0002] Semicarbazide hydrochloride, also known as semicarbazide hydrochloride. It is an organic ionic compound with urea as its molecular matrix, so its structure is very stable. Melting point 175-177 ℃, toxic. Its pure product is white flake or prism crystal. Semicarbazide hydrochloride is an important chemical intermediate. As a pharmaceutical raw material, it can be used to prepare nitrofurans, etc. In the field of chemical analysis, it can be used as a reagent for the determination of ketones and aldehydes, as well as chromatographic analysis and separation of hormones. Solvent; At the same time, it can also be used in the production of pesticides, photosensitive materials and other products. [0003] Many synthetic routes of semicarbazide hydrochloride have been rep...

Claims

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Application Information

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IPC IPC(8): C07C281/06
CPCC07C281/06
Inventor 李晓明
Owner SUZHOU GAIDE FINE MATERIALS CO LTD
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