- Production process for improving quality of sulfonyl isocyanate
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The invention discloses a production process for improving the quality of sulfonyl isocyanate. The production process comprises the steps of mixing a sulfanilamide raw material and xylene according toa certain ratio to form a sulfanilamide solution, adding a certain amount of xylene into a synthesis kettle, heating, controlling the temperature at 110 to 115 DEG C, adding the sulfanilamide solution into the synthesis kettle through a transfer pump at a certain rate; dropwise adding a catalyst and introducing gaseous phosgene at the same time, paying attention to that the catalyst must be dropwise added 2 hours before the sulfanilamide solution is well converted, reducing the phosgene flow until the process requirement cumulant is reached, transferring a product into a light breaking kettleafter heat preservation is performed for 2 hours, removing redundant phosgene by using nitrogen, and finally obtaining a finished product after qualified sampling and analyzing. According to the invention, the synthesis system of sulfonyl isocyanate is optimized, the yield of sulfonyl isocyanate is improved, and meanwhile, the synthesized tail gas and the gas-driving tail gas are innovatively condensed by a condenser and then flow back to the synthesis kettle, so that the tail gas is recycled, and the reaction rate and content of the product are improved.
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Paragraph 0031-0036
(2021/03/30)
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- Research on controllable degradation of sulfonylurea herbicides
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In order to seek ecologically safer and environmentally benign sulfonylurea herbicides (SU), insight into the structure/bioassay/soil degradation tri-factor relationship was first established. With the introduction of various groups (alkyl, nitro, halogen, cyano etc.) at the 5th position of its benzene ring, structural derivatives of chlorsulfuron were designed, synthesized, and evaluated for their herbicidal activity. The structures of the title compounds were confirmed by infrared spectroscopy, ultraviolet spectroscopy, 1H and 13C NMR, mass spectrometry, elemental analysis and X-ray diffraction. Bioassay results confirmed that most derivatives retained their superior herbicidal activities in comparison with chlorsulfuron. After investigating the soil degradation behavior of each molecule under set conditions, it was found that structures with electron-withdrawing substituents at the 5th position of the benzene ring retained their long degradation half-lives, yet the introduction of electron-donating substituents accelerated the degradation rate. These results will provide a valuable clue to further explore the potential controllable degradation of SU and other herbicides, and to discover novel herbicides that are favorable for environmentally and ecologically sustainable development.
- Hua, Xue-Wen,Chen, Ming-Gui,Zhou, Shaa,Zhang, Dong-Kai,Liu, Ming,Zhou, Sha,Liu, Jing-Bo,Lei, Kang,Song, Hai-Bin,Li, Yong-Hong,Gu, Yu-Cheng,Li, Zheng-Ming
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p. 23038 - 23047
(2016/03/12)
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- Process for preparing arylsulfonyl isocyanates by phosgenation of arylsulfonamides
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An improved process for preparing arylsulfonyl isocyanates by phosgenation of arylsulfonamides in the presence of a catalytic quantity of a hydrocarbyl isocyanate and a catalytic quantity of a tertiary amine base. The sulfonyl isocyanates are useful inter
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