Integrated synthetic method of 2-amino-4,6-dimethoxypyrimidine

A technique for the synthesis of dimethoxypyrimidine and its synthesis method, which is applied in the field of synthesis of one-system 2-amino-4,6-dimethoxypyrimidine, which can solve the problem of affecting product yield and quality, unfriendly process environment, and drying equipment. Complexity and other issues, to achieve the effect of saving reaction equipment, improving operating environment conditions, and reducing synthesis costs

CN107629009AActive Publication Date: 2018-01-26YINGKOU YINGXIN CHEM TECH CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2018-01-26

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Abstract

The invention provides an integrated synthetic method of 2-amino-4,6-dimethoxypyrimidine, belongs to the technical field of organic synthesis, and provides a synthetic route using malononitrile, methanol, acetyl chloride, cyanamide and alkali liquid as raw materials. The integrated synthetic method comprises the following steps: dropwise adding acetyl chloride into a system of malononitrile and methanol to directly obtain 1,3-dimethyl propadiamidine dihydrochloride, and then performing reaction on 1,3-dimethyl propadiamidine dihydrochloride and the alkali liquid and cyanamide to obtain 3-amino-3-methoxyl-N-nitril-2-propa-amidine; directly heating, evaporating solvent and performing distillation to obtain 2-amino-4,6-dimethoxypyrimidine. According to the synthetic method disclosed by the invention, a synthetic process and equipment of 1,3-dimethyl propadiamidine dihydrochloride are simple, moisture control of the system is extremely low, the quality of the product is stable, and the yield is high. By adopting the integrated synthetic process, the synthetic process is reduced, distillation is carried out under reduced pressure so as to obtain 2-amino-4,6-dimethoxypyrimidine, and thepurity of the product is up to 99.99 percent.
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Description

technical field

[0001] The invention relates to a synthesis method of one-system 2-amino-4,6-dimethoxypyrimidine, which belongs to the technical field of organic synthesis. Background technique

[0002] In the development of pesticides, heterocyclic compounds have become the mainstream of research and development of new pesticides. Pyrimidine compounds are an important class of biologically active substances, which are widely used in insecticides, herbicides, fungicides and pharmaceutical intermediates and have attracted people's attention. In the production of sulfonylurea herbicides, 2-amino-4,6-dimethoxypyrimidine is an important intermediate in its synthesis, and there are many varieties of sulfonylurea herbicides prepared from it.

[0003] The structure and synthetic route of 2-amino-4,6-dimethoxypyrimidine have been reported in the literature. At present, 2-amino-4,6-dimethoxypyrimidine uses guanidine nitrate, dimethyl malonate, three Synthesis of raw materials such ...

Examples

Embodiment 1

[0023] The synthetic method of 2-amino-4,6-dimethoxypyrimidine, the steps are as follows:

[0024] (1) Synthesis of 1,3‐dimethylmalonamidine dihydrochloride

[0025] Put 66g of malononitrile and 176g of anhydrous methanol into the reaction kettle, slowly drop 235.5g of acetyl chloride into the kettle, control the reaction temperature at 0-5°C, and add the time for 5 hours. After the addition, continue the insulation reaction for 1 hour, extract the hydrogen chloride in the solvent under reduced pressure to obtain 1,3-dimethylmalonamidine dihydrochloride mixed solution.

[0026] (2) Synthesis of 3-amino-3-methoxy-N-cyano-2-propionamidine

[0027] Add lye (sodium bicarbonate 20g, sodium hydroxide 30g, water 500g) and concentration to 1,3-dimethylpropamidine dihydrochloride mixed solution and be the cyanamide solution 110g of 50wt%, control reaction temperature -5-0°C, the reaction pH value is 5-6, the molar ratio of the feed is such that the temperature in the kettle slowly ri...

Embodiment 2

[0032] The synthetic method of 2-amino-4,6-dimethoxypyrimidine, the steps are as follows:

[0033] (1) Synthesis of 1,3‐dimethylmalonamidine dihydrochloride

[0034] Put 66g of malononitrile and 204.8g of anhydrous methanol into the reaction kettle, slowly drop 353.25g of acetyl chloride into the kettle, control the reaction temperature at 10-15°C, and add the time for 8 hours. After the addition, continue the insulation reaction After 2 hours, the hydrogen chloride in the solvent was extracted under reduced pressure to obtain a mixed solution of 1,3-dimethylmalonamidine dihydrochloride.

[0035] (2) Synthesis of 3-amino-3-methoxy-N-cyano-2-propionamidine

[0036] Add lye (sodium bicarbonate 20g, sodium hydroxide 30g, water 500g) and concentration to 1,3-dimethylpropamidine dihydrochloride mixed solution and be the cyanamide solution 101g of 50wt%, control reaction temperature 0-3°C, the reaction pH value is 6-7, the molar ratio of the feed is such that the temperature in th...