- New fenclorim synthesis process
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The invention discloses a new fenclorim synthesis process, which includes the following steps: adding 3,4-dihydro-3-methyl-2H-1,4-benzoxazine and a solvent into a reaction kettle, stirring and dissolving, connecting the reaction kettle with a tail gas absorption device, dripping dichloroacetyl chloride after heating to reflux, and performing a reflux reaction after dripping to obtain a reaction solution; and distilling the obtained reaction solution under reduced pressure, dehydrating the solvent to obtain a crude product, and recrystallizing with methanol to obtain the fenclorim. According tothe new fenclorim synthesis process, the dichloroacetyl chloride is dripped by a high-temperature reflux method, tail gas absorbs hydrogen chloride gas at the same time, and the absorbed hydrogen chloride gas is dissolved in water to prepare hydrochloric acid as a by-product. About 0.5 tons of 30% hydrochloric acid can be simultaneously obtained by synthesizing one ton of oxadiazon; the content of the fenclorim is over 99%, and the yield is over 95%; and the new fenclorim synthesis process avoids the generation of a large amount of waste brine, can reduce the production cost, has simple operation and is easy for industrial production.
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Paragraph 0037-0062
(2019/08/07)
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- Synthesis, crystal structure and biological activity of ndichloroacetyl- 3,4-dihydro-3-methyl-2h-1,4-benzoxazines
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A three-step sequence was developed for synthesizing N-dichloroacetyl-3,4-dihydro- 3-methyl-2H-1,4-benzoxazine. Compounds 4 were obtained via O-alkylation, reduction, cyclization and acylation with o-nitro phenol and chloroacetone as the starting material. The structures of the compounds were characterized by IR, 1H NMR, 13C NMR, MS spectroscopy and elemental analysis. The configuration of 4a was determined by Xray crystallography. The preliminary biological test showed that the compounds could protect maize against injury by acetochlor in some extent.
- Fu, Ying,Wang, Jiao,Zhao, Qing-Shan,Wang, Xin-Ming,Xing, Zhi-Yong,Ye, Fei
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- PROCESS FOR PREPARING ACYL AMIDE COMPOUNDS
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A process for preparing acyl amide compounds is described, in which a recrystallized o-nitrophenoxy carbonyl compound is hydrogenated with hydrogen gas in the presence of a nickel sponge metal catalyst with ring closure to form a benzoxazine, which is then reacted with an acyl halide to give the corresponding acyl amide compound.
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Page/Page column 5
(2010/09/07)
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- Composition for the protection of cultivated plants against the phytotoxic action of herbicides
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4-Dichloroacetyl-2,3-dihydro-3-methyl-1,4-benzoxazine is suitable for use as a counter-agent, "antidote" or "safener" for protecting cultivated plants against the phytotoxic action of herbicides. Crops suitable in this respect are preferably millet, cereals, rice, maize and soya, and suitable herbicides are chloroacetanilides and thiolcarbamates.
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