A kind of synthetic method of one-system 2-amino-4,6-dimethoxypyrimidine

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.

Description

Technical field [0001] The invention relates to a one-system 2-amino-4,6-dimethoxypyrimidine synthesis method, which belongs to the technical field of organic synthesis. Background technique [0002] In the development of pesticides, heterocyclic compounds have become the mainstream of new pesticide research and development. Pyrimidine compounds are an important class of biologically active substances, which are widely used in pesticides, 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 synthesis 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, and three Phosphorus oxychloride, sodium methoxide and...

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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

After the synthesis of the first step 1,3‐dimethylmalonamidine dihydrochloride is completed, during the process of separating the solvent, the equipment is cumbersome, and the product has been deteriorated in contact with moisture and air, which affects the product yield and quality; in 3-amino- In the 3-methoxy-N-cyano-2-propionamidine ring-closing process, the prior art will filter, Washing, drying, further dissolving in an organic solvent and heating to close the ring to obtain 2-amino-4,6-dimethoxypyrimidine, the process is relatively complicated and the equipment is cumbersome

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