- A practical and improved copper-catalyzed synthesis of the central intermediate of diafenthiuron and related products
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A bioinspired Cu(I)/N-methylimidazole catalyst system is used for the synthesis of the diaryl ether part of diafenthiuron, a widely used insecticide. The convenient protocol proceeds smoothly with high selectivity and quantitative yield. Applying the optimized procedure various diaryl ether analogs are synthesized in good to excellent yield.
- Schareina, Thomas,Zapf, Alexander,Cotte, Alain,Mueller, Nikolaus,Beller, Matthias
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- Synthesis method of diafenthiuron impurities A and B
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The invention provides a preparation method of the diafenthiuron impurities A and B. 2, 6-isopropylaniline, phenol, triphosgene, tert-butylamine and tert-butyl formamidine hydrochloride are used as raw materials, a material basis is provided for normatively researching the impurities, and the method can also be used for qualitative and quantitative analysis of the impurities in diafenthiuron production. And the impurities are controlled within a safe and reasonable limit range, so that the quality standard of the diafenthiuron can be improved, and important guiding significance is provided for safe medication of the masses.
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- Synthesis method of diafenthiuron impurity D
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The invention provides a preparation method of the diafenthiuron impurity D. According to the preparation method of the diafenthiuron impurity D, 2, 6-isopropylaniline, phenol, CS2 and the like are used as raw materials, a material basis is provided for regularly researching the impurities, and the method can also be used for qualitative and quantitative analysis of the impurities in diafenthiuron production. And the impurities are controlled within a safe and reasonable limit range, so that the quality standard of the diafenthiuron can be improved, and important guiding significance is provided for safe medication of the masses.
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- CuI/oxalamide catalyzed couplings of (hetero)aryl chlorides and phenols for diaryl ether formation
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Couplings between (hetero)aryl chlorides and phenols can be effectively promoted by CuI in combination with an N-aryl-N′-alkyl-substituted oxalamide ligand to proceed smoothly at 120 °C. For this process, N-aryl-N′-alkyl-substituted oxalamides are more effective ligands than bis(N-aryl)-substituted oxalamides. A wide range of electron-rich and electron-poor aryl and heteroaryl chlorides gave the corresponding coupling products in good yields. Satisfactory conversions were achieved with electron-rich phenols as well as a limited range of electron-poor phenols. Catalyst and ligand loadings as low as 1.5 mol % are sufficient for the scaled-up variants of some of these reactions. Aryl and alkyl: N-Aryl-N′-alkyl-substituted oxalamide ligands promote the CuI catalyzed coupling of (hetero)aryl chlorides and phenols at 120 °C more effectively than bis(N-aryl)-substituted oxalamides. A wide range of electron-rich and electron-poor aryl and heteroaryl chlorides were converted into the corresponding coupling products in good yields.
- Fan, Mengyang,Zhou, Wei,Jiang, Yongwen,Ma, Dawei
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supporting information
p. 6211 - 6215
(2016/05/24)
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- PROCESS FOR THE CATALYTIC SYNTHESIS OF DIARYL ETHERS
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Described is a process for preparing diaryl ethers of the formula (I) [in-line-formulae]Ar—O—Ar′??(I)[/in-line-formulae]In which Ar is an aryl or substituted aryl group and Ar′ is an aryl, substituted aryl, heteroaryl or substituted heteroaryl group,by reacting an aryl of formula (II) or a aryloxy salt of formula (III) [in-line-formulae]Ar—OH ??(II)[/in-line-formulae] [in-line-formulae]Ar—OR ??(III)[/in-line-formulae]In which Ar has the same meaning as in formula (I) and R is an alkali metal,with an aryl or heteroaryl bromide of formula (IV) [in-line-formulae]Ar′—Br ??(IV)[/in-line-formulae]In which Ar′ has the same meaning as in formula (I),characterized in that the reaction is carried out in the presence of a copper(I)salt and a 1-substituted imidazole as catalyst system.
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Page/Page column 3; 5
(2009/06/27)
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- Process for the preparation of isothiocyanates
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There is disclosed a process for the preparation of isothiocyanates of formula STR1 wherein R1 and R2 are each independently of the other C1 -C6 alkyl and R3, R4 and R5 are each independently of the other hydrogen, halogen, C1 -C4 alkyl, C1 -C4 alkoxy, trifluoromethyl or nitro, which process comprises an amine of formula STR2 with ammonium thiocyanate or an alkali metal thiocyanate, in the presence of acid and an inert solvent, to the thiourea of formula STR3 and cleaving said thiourea by heating. The essential feature of this process consists in carrying out the reaction of the amine of the above formula with ammonium thiocyanate or an alkali metal thiocyanate in the presence of 0.5-5% by weight of water, based on the total weight of the reaction mixture. The isothiocyanates of the above formula are intermediates for the synthesis of pesticidal compounds.
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- Phenoxyphenylisothioureas, production thereof and use thereof in pest control, and phenoxyphenylthioureas as intermediates for the production of the phenoxyphenylisothioureas and use thereof in pest control
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The invention relates to N-phenoxyphenylisothioureas of the formula STR1 wherein each R1, R2 and R3 is hydrogen, halogen, C1 -C4 alkyl, C1 -C4 alkoxy, trifluoromethyl or nitro, each of R4 and R5 is C2 -C4 alkyl, R6 is C1 -C6 alkyl, C3 -C6 alkenyl or C3 -C5 alkynyl, R7 is C1 -C10 alkyl, C3 -C5 alkenyl or C3 -C6 cycloalkyl, and R8 is hydrogen or C1 -C10 alkyl. The invention further relates to the production of these compounds and their use in pest control, as well as to phenoxyphenylthioureas as intermediates for the production of the N-phenoxyphenylisothioureas of the invention.
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