Method for preparing 4,6-dihydroxypyrimidine

A technology of dihydroxypyrimidine and malonate, applied in the field of medicine, can solve problems such as the yield of only 78%, and achieve the effect of cheap raw materials

Inactive Publication Date: 2013-09-25
YANGZHOU TIANHE PHARM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] According to literature reports, domestic 4,6-dihydroxypyrimidine is currently prepared by reacting formamide and diethyl propionate in sodium ethoxide ethanol solution at 60°C for 4 hours, and the yield is only about 78%.

Method used

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  • Method for preparing 4,6-dihydroxypyrimidine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Put 20g of formamidine hydrochloride, 40g of diethyl malonate, and 12g of sodium hydroxide into methanol, heat up and reflux for 9 hours, cool to 40°C after the reaction is completed, add hydrochloric acid dropwise to adjust the pH to about 7, recover methanol under reduced pressure, and recover After the end, add water to cool, stir and filter to obtain pale yellow crystals, and recrystallize with acetone to obtain 25.3 g of 4,6-dihydroxypyrimidine with a content of 98.9%.

Embodiment 2

[0022] Put 20g of formamidine hydrochloride, 60g of diethyl malonate, and 25g of potassium hydroxide into ethanol, raise the temperature and reflux for 4 hours, cool to 40°C after the reaction is completed, add hydrochloric acid dropwise to adjust the pH to about 7, recover the ethanol under reduced pressure, and recover After the end, add water to cool, stir and filter to obtain pale yellow crystals, and recrystallize with acetone to obtain 27.4 g of 4,6-dihydroxypyrimidine, with a content of 99.2%.

Embodiment 3

[0024] Put 20g of formamidine hydrochloride, 35g of dimethyl malonate, and 15g of sodium methoxide into methanol, heat up and reflux for 8 hours, cool to 40°C after the reaction is completed, add hydrochloric acid dropwise to adjust the pH to about 7, recover methanol under reduced pressure, and the recovery is complete Then add water to cool, stir and filter to obtain pale yellow crystals, and recrystallize with acetone to obtain 26.7g of 4,6-dihydroxypyrimidine, content: 99%.

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Abstract

The invention discloses a method for preparing 4,6-dihydroxypyrimidine, relates to the method for preparing the 4,6-dihydroxypyrimidine, and belongs to the technical field of a medicine. The method comprises the following steps: firstly, feeding formamidine hydrochloride, malonic ester and alkali to a solvent to reflux, agitate and react for 1-12 hours; washing by acid water until the solvent is neutral; adding water, cooling, agitating and filtering so as to obtain pale yellow crystal after recovering the solvent at reduced pressure; finally re-crystallizing the pale yellow crystal by acetone to obtain the white crystal 4,6-dihydroxypyrimidine. According to the method, the 4,6-dihydroxypyrimidine is prepared from formamidine hydrochloride and malonic ester as materials in a cyclization manner; the used materials are cheap; the reaction yield can be up to over 90%; the content of the 4,6-dihydroxypyrimidine after re-crystallization is greater than 98%.

Description

technical field [0001] The invention relates to a method for preparing 4,6-dihydroxypyrimidine, which belongs to the technical field of medicine. [0002] Background technique [0003] 4,6-Dihydroxypyrimidine, the English name is 4,6-Dihydroxypyrimidine, the molecular formula is: C 4 h 4 N 2 o 2 , the structural formula is as follows: [0004] 4,6-dihydroxypyrimidine is the key intermediate for the preparation of sulfamethoxine. [0005] According to literature reports, domestic 4,6-dihydroxypyrimidine is currently prepared by reacting formamide and diethyl propionate in sodium ethoxide ethanol solution at 60°C for 4 hours, and the yield is only about 78%. Contents of the invention [0006] The purpose of the present invention is to propose a method for preparing 4,6-dihydroxypyrimidine with high yield. [0007] The technical scheme of the present invention is: first put formamidine hydrochloride, malonate and alkali into the solvent, reflux and stir for 1-12 hour...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D239/54
Inventor 庄卫东赵云德汪锦琪
Owner YANGZHOU TIANHE PHARM CO LTD
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