Study On The Synthesis Of Triazolopyrimidine Sulfonamide

With the rapid development of science and technology, herbicide industry entersa rapid and efficient developing times since the successful development ofchlorsulfuron, especially the birth of sulfonylurea, imidazolinone herbicides, etc.,which bring a new world for chemical weed. The recent advent of sulfonamideherbicide, it has brought a new revolutionary change in the international chemicalweed industry. However, the development and start of herbicide in our country arelater than Europe, America, Japan and other developed countries. Therefore, for thespecific circumstances of the current agricultural production, it is very necessary tochoose some generic typical herbicide compounds.Penoxsulam is postemergence herbicide which was exploited by DowAgricultural company, it effect by inhibiting acetolactate synthase, penoxsulam canbe quickly absorbed by soil, and because of its fine features in low toxicity, highefficiency and security, it has been paid much attention. However, due to thecomplexity of the existing synthetic route, low yields, and production process is morecomplex, the herbicide is currently sold expensively in the market.Therefore, this paper aims to the improvements of penoxsulam’syntheticroute and improvements in yield. Moreover, in connection with this process, we alsohave done some related to replace the orientation effect of benzene.On the basis of related article reports,the main results are described as follows:1,triazolopyrimidin amine as the intermediate I has been synthesized throughimproved route: taking methyl2-methoxyacetate and methyl formate as startingmaterials.2, benzenesulfonyl chloride as the intermediate II has been synthesized throughimproved route: taking3-(trifluoromethyl)phenol as starting materials.3, The intermediate I reacts with the intermediate II to produce the targettriazolopyrimidin benzene sulfonamide.Like sulfonamide herbicide,sulfonyl thiourea herbicides also play a pivotal rolein the development of herbicide industry. The key for the synthesis of sulfonamidethiourea is aryl sulfonyl isothiocyanates, our group made some inquiry about the keymolecules aryl sulfonyl isothiocyanates in synthese. For synthses of aryl sulfonyl isothiocyanates,we made aryl sulfonyl chloride asthe starting material, ammoniated, remix, the reaction mixture was kept under anatmosphere of nitrogen at45℃for7.5h, after which brown potassium aryl sulfonylimino dithio carbonates were precipitated. Following filtration and vacuum drying,the above salts were suspended in anhydrous dichloroethane, and then a solution ofBTC in dichloroethane was added dropwise, and the reaction was continued at45℃for15h. The aryl sulfonyl isothiocyanates were obtained in61%～75%yield.Followed by reaction with an amine to obtain aryl sulfonyl thiourea.All intermediate products and the target compound have been fully characterizedby IR、1HMR or MS.