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CN-118878541-B - Green production method of 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidine-5 (1H) -ketone

CN118878541BCN 118878541 BCN118878541 BCN 118878541BCN-118878541-B

Abstract

The invention provides a green production method of 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidine-5 (1H) -ketone, which comprises the following steps of (a) adding an organic solvent, 3, 5-diamino-1, 2, 4-triazole and methyl dimethoxy propionate into a reaction container, heating to 50-115 ℃, adding sodium methoxide, continuously heating to reflux to perform cyclization reaction to obtain a reaction mixture, (b) carrying out negative pressure distillation on the reaction mixture to distill out fraction, concentrating until no liquid is distilled out, C) adding water into the product of the step (b) to form a solution, regulating the pH value of the solution to 5-6 by using acid, cooling, suction filtering or centrifuging to obtain filtrate and filter residues, drying and packaging the filter residues, d) standing the filtrate for layering to obtain an upper layer liquid and a lower layer liquid, and applying the upper layer liquid and the fraction to the step (a), and applying the lower layer liquid to the step (C). The reaction solvent can be recycled in the whole process, the mother solution can be used mechanically, no high-nitrogen wastewater is discharged, the environment is protected, and the production cost is greatly reduced.

Inventors

  • Han Juquan
  • QIAN WEIWEN
  • DAI JIAYING
  • LI YUAN

Assignees

  • 湖南吴赣药业有限公司

Dates

Publication Date
20260505
Application Date
20240712

Claims (4)

  1. 1. A green production method of 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidine-5 (1H) -ketone, which is characterized by comprising the following steps: (a) Adding an organic solvent, 3, 5-diamino-1, 2, 4-triazole and dimethoxy-2-methyl propionate into a reaction container, heating to 50-115 ℃, adding sodium methoxide, and continuously heating to reflux to perform cyclization reaction to obtain a reaction mixture, wherein the organic solvent is n-butanol, and the reaction time of the cyclization reaction is 4 hours; (b) Subjecting the reaction mixture to negative pressure distillation to distill out a fraction, concentrating until no liquid is distilled out; (c) Adding water into the product of the step (b) to form a solution, and adjusting the pH value of the solution to 5-6 by using acid; (d) Standing and layering the filtrate to obtain an upper layer liquid and a lower layer liquid, applying the upper layer liquid and the fraction to the step (a), and applying the lower layer liquid to the step (c).
  2. 2. The green production method of 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidine-5 (1H) -ketone according to claim 1, wherein in the step (a), the molar ratio of 3, 5-diamino-1, 2, 4-triazole, dimethoxy-2-methylpropionate and sodium methoxide is 1:0.8-1.4:1-3.
  3. 3. A green process for the production of 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidin-5 (1H) -one according to claim 1, characterized in that in step (c) the product of step (b) is added with an amount of water equal to the mass of the organic solvent in step (a).
  4. 4. The green production method of 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidine-5 (1H) -ketone, which is characterized in that in the step (C), the temperature is reduced to 10-25 ℃ for suction filtration or centrifugation.

Description

Green production method of 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidine-5 (1H) -ketone Technical Field The invention belongs to the technical field of agricultural intermediates, relates to a production method of a paraquat emetic triazolopyrimidinone intermediate, and in particular relates to a green production method of 2-amino-6-methyl-1, 2, 4-triazol [1,5-a ] pyrimidine-5 (1H) -one. Background Triazolopyrimidinone is an important organic synthesis and pharmaceutical intermediate, can synthesize a plurality of derivative products, is also an important active emetic ingredient for medical and veterinary use, and is also used for preventing bronchospasm, slimming medicine and the like. The triazolopyrimidinone can be used as a special functional auxiliary agent for quick-contact herbicides 1-dimethyl-4, 4' -bipyridinium salt dichloride and 1, 2-ethylene-2, 2-bipyridinium salt bipyridinium herbicides. 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidine-5 (1H) -ketone is an intermediate for synthesizing triazolopyrimidinone. The Chinese patent publication No. CN106749271B discloses a class of [1,2,4] -triazolo [1,5-a ] pyrimidinone heterocyclic compounds, their preparation method and use, which react with acyl chloride (or acid, ester) as starting material under the action of catalyst (p-toluenesulfonic acid). The yield of the reaction product in the application is only 50-75%, and the requirement of industrial mass production is not met. Disclosure of Invention In order to solve the technical problems, the invention aims to provide a green production method of 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidine-5 (1H) -ketone. In order to realize the technical problems, the invention provides a green production method of 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidine-5 (1H) -ketone, which comprises the following steps: (a) Adding an organic solvent, 3, 5-diamino-1, 2, 4-triazole and methyl dimethoxy propionate into a reaction vessel, heating to 50-115 ℃, adding sodium methoxide, and continuously heating to reflux to perform cyclization reaction to obtain a reaction mixture; (b) Subjecting the reaction mixture to negative pressure distillation to distill out a fraction, concentrating until no liquid is distilled out; (c) Adding water into the product of the step (b) to form a solution, and adjusting the pH value of the solution to 5-6 by using acid; (d) Standing and layering the filtrate to obtain an upper layer liquid and a lower layer liquid, applying the upper layer liquid and the fraction to the step (a), and applying the lower layer liquid to the step (c). Optimally, the organic solvent is an alcohol or ether solvent layered with water. Further, the organic solvent is n-butanol. Optimally, in the step (a), the molar ratio of the 3, 5-diamino-1, 2, 4-triazole, the dimethoxy methyl propionate and the sodium methoxide is 1:0.8-1.4:1-3. Further, the reaction time of the cyclization reaction is 2-18 h. Optimally, in step (c), the amount of water added to the product of step (b) is equal to the mass of the organic solvent in step (a). Further, in the step (C), the temperature is reduced to 10-25 ℃ for suction filtration or centrifugation. The green production method of 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidine-5 (1H) -ketone can obtain the product with the yield of more than or equal to 90 percent by precisely controlling the types of organic solvents, the proportion of reaction raw materials and other conditions and circularly applying the supernatant, the subnatant and the fraction, and the reaction solvent can be recycled in the whole process, the mother liquor can be applied, high-nitrogen wastewater is not discharged, the green production method is environment-friendly, and the production cost is greatly reduced. Drawings FIG. 1 is a process flow diagram of a green process for the production of 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidin-5 (1H) -one according to the invention. Detailed Description The invention relates to a green production method of 2-amino-6-methyl-1, 2, 4-triazole [1,5-a ] pyrimidine-5 (1H) -ketone, which is shown in figure 1 and comprises the following steps of (a) adding an organic solvent, 3, 5-diamino-1, 2, 4-triazole and methyl dimethoxy propionate into a reaction container, heating to 50-115 ℃, adding sodium methoxide, continuously heating to reflux to carry out cyclization reaction to obtain a reaction mixture, (b) carrying out negative pressure distillation on the reaction mixture to distill out fraction, concentrating until no liquid is distilled out, C) adding water into the product of the step (b) to form a solution, regulating the pH value of the solution to 5-6 by using acid, cooling, suction filtering or centrifuging to obtain filtrate and filter residues, drying and packaging the filter residues, d) standing and layering the filtrate to obtain an upper layer liquid and a lower layer liquid, and mechanically applying the upper lay