2-amino-4,6-dimethoxypyrimidine synthesis method

Abstract

The invention provides a 2-amino-4,6-dimethoxypyrimidine synthesis method, which belongs to the technical field of organic synthesis. The invention provides a synthetic route which takes malononitrile, methanol, acetyl chloride, hydrogen cyanamide and alkali liquor as raw materials; the method comprises the following steps of dropwise adding the acetyl chloride to a system of the malononitrile andthe methanol, directly obtaining 1,3-dimethylpropanediamidine dihydrochloride, then reacting with the alkali liquor and the hydrogen cyanamide to obtain 3-amino-3-methoxy-N-cyano-2-propylamidine andfurther performing closed-loop rearrangement to obtain 2-amino-4,6-dimethoxypyrimidine. The synthesis method provided by the invention saves the cumbersome synthesis technology and equipment of the 1,3-dimethylpropanediamidine dihydrochloride, and comprises the steps of adding the acetyl chloride into the malononitrile and the methanol to directly obtain the 1,3-dimethylpropanediamidine dihydrochloride. The synthetic route of the 1,3-dimethylpropanediamidine dihydrochloride in the invention has extremely low moisture control, stable product quality and high yield.

Description

technical field [0001] The invention relates to a synthesis method of 2-amino-4,6-dimethoxypyrimidine, belonging 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 as phosphorus o...

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Problems solved by technology

[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 as phosphorus oxychloride and sodium methoxide. Phosphorus oxychloride is harmful to the environment during transportation and use, and the process is not environmentally friendly; the synthesis of 2-amino-4,6-dimethoxypyrimidine Another route in the method uses malononitrile as a raw material with low cost and environmental friendliness, using malononitrile, methanol, anhydrous hydrogen chloride, toluene, cyanamide, sodium bicarbonate raw materials, intermediate 1,3-dimethylpropane There is absolutely no water in the synthesis process of diamidine dihydrochloride, and anhydrous hydrogen chloride gas is one of the necessary raw materials. However, the preparation of anhydrous hydrogen chloride and drying equipment are complicated, the operating cost is high, and the poor quality of anhydrous hydrogen chloride directly affects the product yield. Rate and other issues

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