A kind of synthetic method of 4-amino-2.6-dimethoxypyrimidine

A technology of dimethoxypyrimidine and a synthesis method, which is applied in the field of synthesis of 4-amino-2.6-dimethoxypyrimidine, can solve the problems of increased process risk, low yield in the chlorination step, a large amount of phosphorus-containing waste water and the like , to avoid emissions, reduce environmental pollution, and save costs

Active Publication Date: 2022-07-05
YANGZHOU TIANHE PHARM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method synthetic route is simple, and by-product is few, but the yield of chlorination step is relatively low (being 44% to 81%), and the highly toxic phosphorus oxychloride is used in the preparation process, aftertreatment can produce a large amount of phosphorus-containing waste water, Not only increased the risk of the process, but also caused environmental pollution

Method used

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  • A kind of synthetic method of 4-amino-2.6-dimethoxypyrimidine
  • A kind of synthetic method of 4-amino-2.6-dimethoxypyrimidine
  • A kind of synthetic method of 4-amino-2.6-dimethoxypyrimidine

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Experimental program
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Effect test

Embodiment 1

[0031] A synthetic method of 4-amino-2.6-dimethoxypyrimidine, comprising the steps:

[0032] (1) 300ml of water, 26.5g of 28% ammonia water were added in a 500mL four-necked reaction flask, 40g of 4,6-dichloropyrimidine-5-carboxylic acid was added under stirring, and then the temperature was kept at 30°C and reacted for 6 hours to obtain 4-amino- 6-chloropyrimidine-5-carboxylic acid;

[0033] (2) after the reaction finishes, adjust the pH of 4-amino-6-chloropyrimidine-5-carboxylic acid to 3 with hydrochloric acid, feed about 15g of chlorine, and the logical chlorine process control temperature is between 10~40 ℃, and the logical chlorine finishes, Adjust pH to 4~5 with liquid alkali, filter below 20℃ to obtain 4-amino-2,6-dichloropyrimidine-5-carboxylic acid tidal product;

[0034] (3) add 1000ml water in 2L pressure reaction kettle, drop into the 4-amino-2,6-dichloropyrimidine-5-carboxylic acid obtained in step (2), be warming up to 150 ℃, react for 2 hours, complete the rea...

Embodiment 2

[0037] A synthetic method of 4-amino-2.6-dimethoxypyrimidine, comprising the steps:

[0038] (1) 300ml of water, 32.7g of 28% ammonia water were added to the 500mL four-necked reaction flask, 40g of 4,6-dichloropyrimidine-5-carboxylic acid was added under stirring, and then the temperature was kept at 50°C and reacted for 12 hours to obtain 4-amino- 6-chloropyrimidine-5-carboxylic acid;

[0039] (2) after the reaction finishes, adjust the pH of 4-amino-6-chloropyrimidine-5-carboxylic acid to 3 with hydrochloric acid, feed about 15g of chlorine, and the logical chlorine process control temperature is between 10~40 ℃, and the logical chlorine finishes, Adjust pH to 4~5 with liquid alkali, filter below 20℃ to obtain 4-amino-2,6-dichloropyrimidine-5-carboxylic acid tidal product;

[0040] (3) add 1000ml water in 2L pressure reactor, drop into the 4-amino-2,6-dichloropyrimidine-5-carboxylic acid wet product that step (2) obtains, be warming up to 110 ℃, react 4 hours, reaction fin...

Embodiment 3

[0043] A synthetic method of 4-amino-2.6-dimethoxypyrimidine, comprising the steps:

[0044] (1) 300ml of water, 32.7g of 28% ammonia water were added to the 500mL four-necked reaction flask, 40g of 4,6-dichloropyrimidine-5-carboxylic acid was added under stirring, and then the temperature was kept at 50°C and reacted for 12 hours to obtain 4-amino- 6-chloropyrimidine-5-carboxylic acid;

[0045](2) after the reaction finishes, adjust the pH of 4-amino-6-chloropyrimidine-5-carboxylic acid to 3 with hydrochloric acid, feed about 15g of chlorine, and the logical chlorine process control temperature is between 10~40 ℃, and the logical chlorine finishes, Adjust pH to 4~5 with liquid alkali, filter below 20℃ to obtain 4-amino-2,6-dichloropyrimidine-5-carboxylic acid tidal product;

[0046] (3) add 1000ml water in 2L pressure reactor, drop into the 4-amino-2,6-dichloropyrimidine-5-carboxylic acid wet product that step (2) obtains, be warming up to 110 ℃, react 4 hours, reaction fini...

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Abstract

The invention discloses a method for synthesizing 4-amino-2.6-dimethoxypyrimidine in the technical field of medicine. The synthetic method comprises the following steps: (1) ammonolysis reaction: put 4,6-dichloropyrimidine-5-formic acid into ammonia water to carry out ammonolysis reaction to obtain 4-amino-6-chloropyrimidine-5-formic acid; ( 2) chlorination reaction: the 4-amino-6-chloropyrimidine-5-formic acid obtained in step (1) is dissolved in dilute acid water, and then chlorination reagent is added to obtain 4-amino-2,6-chloropyrimidine -5-formic acid; (3) decarboxylation reaction: in a solvent, the 4-amino-2,6-chloropyrimidine-5-formic acid obtained in step (2) is subjected to high temperature decarboxylation to obtain 4-amino-2,6- Chloropyrimidine; (4) Methoxylation: put the 4-amino-2,6-chloropyrimidine obtained in step (3) into a methoxylation reagent, and obtain 4-amino-2.6-dimethoxyl through methoxylation base pyrimidine. The present invention adopts a new synthetic route, avoids the generation of a large amount of phosphorus-containing waste water, and the method provided by the present invention is environmentally friendly and has obvious social benefits.

Description

technical field [0001] The invention relates to the technical field of medicine, in particular to a method for synthesizing 4-amino-2.6-dimethoxypyrimidine. Background technique [0002] 4-Amino-2.6-dimethoxypyrimidine, CAS No.: 3289-50-7, Molecular formula: C 6 H 9 N 3 O 2 , molecular weight: 155.15, white crystal, melting point: 149-152 ℃, is an important intermediate for the synthesis of sulfa drugs sulfadimethoxine. Sulfadimethoxine has low toxicity, and is particularly effective for upper respiratory tract and urinary tract infections. It has minimal irritation to the kidneys, and the concentration in the blood can be maintained for a long time, so the number and dose of administration can be large. reduce. Therefore, it is of practical significance to study the synthesis of the drug. [0003] There are two main methods for synthesizing 4-amino-2,6-dimethoxypyrimidine: [0004] (1) Barbituric acid method, that is, using phosphorus oxychloride to act on barbituric...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D239/52
CPCC07D239/52
Inventor 张玉朱林飞王小龙
Owner YANGZHOU TIANHE PHARM CO LTD
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