- Preparation of a novel bridged bis(β-cyclodextrin) chiral stationary phase by thiol-ene click chemistry for enhanced enantioseparation in HPLC
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A bridged bis(β-cyclodextrin) ligand was firstly synthesized via a thiol-ene click chemistry reaction between allyl-ureido-β-cyclodextrin and 4-4′-thiobisthiophenol, which was then bonded onto a 5 μm spherical silica gel to obtain a novel bridged bis(β-cyclodextrin) chiral stationary phase (HTCDP). The structures of HTCDP and the bridged bis(β-cyclodextrin) ligand were characterized by the 1H nuclear magnetic resonance (1H NMR), solid state 13C nuclear magnetic resonance (13C NMR) spectra spectrum, scanning electron microscope, elemental analysis, mass spectrometry, infrared spectrometry and thermogravimetric analysis. The performance of HTCDP in enantioseparation was systematically examined by separating 21 chiral compounds, including 8 flavanones, 8 triazole pesticides and 5 other common chiral drugs (benzoin, praziquantel, 1-1′-bi-2-naphthol, Tr?ger's base and bicalutamide) in the reversed-phase chromatographic mode. By optimizing the chromatographic conditions such as formic acid content, mobile phase composition, pH values and column temperature, 19 analytes were completely separated with high resolution (1.50-4.48), in which the enantiomeric resolution of silymarin, 4-hydroxyflavanone, 2-hydroxyflavanone and flavanone were up to 4.34, 4.48, 3.89 and 3.06 within 35 min, respectively. Compared to the native β-CD chiral stationary phase (CDCSP), HTCDP had superior enantiomer separation and chiral recognition abilities. For example, HTCDP completely separated 5 other common chiral drugs, 2 flavanones and 3 triazole pesticides that CDCSP failed to separate. Unlike CDCSP, which has a small cavity (0.65 nm), the two cavities in HTCDP joined by the aryl connector could synergistically accommodate relatively bulky chiral analytes. Thus, HTCDP may have a broader prospect in enantiomeric separation, analysis and detection. This journal is
- Gong, Bolin,Guo, Siyu,Zhang, Ning
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p. 35754 - 35764
(2021/12/02)
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- Preparation and evaluation of a triazole-bridged bis(β-cyclodextrin)–bonded chiral stationary phase for HPLC
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A triazole-bridged bis(β-cyclodextrin) was synthesized via a high-yield Click Chemistry reaction between 6-azido-β-cyclodextrin and 6-propynylamino-β-cyclodextrin, and then it was bonded onto ordered silica gel SBA-15 to obtain a novel triazole-bridged bis (β-cyclodextrin)–bonded chiral stationary phase (TBCDP). The structures of the bridged cyclodextrin and TBCDP were characterized by the infrared spectroscopy, mass spectrometry, elemental analysis, and thermogravimetric analysis. The chiral performance of TBCDP was evaluated by using chiral pesticides and drugs as probes including triazoles, flavanones, dansyl amino acids and β-blockers. Some effects of the composition in mobile phase and pH value on the enantioseparations were investigated in different modes. The nine triazoles, eight flavanones, and eight dansyl amino acids were successfully resolved on TBCDP under the reversed phase with the resolutions of hexaconazole, 2′-hydroxyflavanone, and dansyl-DL-tyrosine, which were 2.49, 5.40, and 3.25 within 30 minutes, respectively. The ten β-blockers were also separated under the polar organic mode with the resolution of arotinolol reached 1.71. Some related separation mechanisms were discussed preliminary. Compared with the native cyclodextrin stationary phase (CDSP), TBCDP has higher enantioselectivity to separate more analytes, which benefited from the synergistic inclusion ability of the two adjacent cavities and bridging linker of TBCDP, thereby enabling it a promising prospect in chiral drugs and food analysis.
- Shuang, Yazhou,Liao, Yuqin,Wang, Hui,Wang, Yuanxing,Li, Laisheng
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p. 168 - 184
(2019/11/25)
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- Continuous preparation method of flutriafol
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The invention relates to a continuous preparation method of flutriafol. 1,2,4-triazole and 1-(2-fluorophenyl)-1-(4-fluorophenyl) ethylene oxide react in a microchannel continuous flow reactor in the presence of an organic solvent and a soluble alkali to obtain the flutriafol. The method is short in reaction time and high in automatic production level, promotes the competitiveness of an enterprise,is small in safety hazard in the process of synthesizing the target product, reduces the risk coefficient, is high in yield of the target product, simple in post treatment and little in solid waste,and realizes a cleaner and environment-friendly production process.
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Paragraph 0009; 0040-0048
(2019/02/26)
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- Efficient and Enantioselective Rhodium(I)-Catalyzed Arylation of α-Ketoesters: Synthesis of (S)-Flutriafol
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An enantioselective addition of arylboronic acids and α-ketoesters promoted by a Rhodium(I)-chiral diene catalyst is reported. The transformation proceeds regioselectively in the presence of as low as 0.5 mol% of the catalyst generated in situ from a Rhod
- Chang, Chiung-An,Uang, Tsung-Ying,Jian, Jia-Hong,Zhou, Meng-Yi,Chen, Ming-Liang,Kuo, Ting-Shen,Wu, Ping-Yu,Wu, Hsyueh-Liang
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p. 3381 - 3390
(2018/08/06)
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- A synthesis method of flutriafol (by machine translation)
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The invention relates to a synthesis method of flutriafol, the halogenated methane and dimethyl sulfoxide in the 0 - 120 °C reaction under 1 - 48 H-; adding solid alkali and 2, 4' - difluoro benzophenone, temperature control in the 0 - 80 °C, reaction 1 - 25 the H; adding triazole, temperature control in the 50 - 200 °C, reaction 1 - 20 the H, after the reaction, filtered, to remove solvent, washing, crystallization get said teflubenzuron. In the present invention dimethyl sulfoxide is used as the reaction raw material, but also as the solvent, avoiding mixed solvent separation difficulties, and, dimethyl sulfoxide and halogenated methane to replace the existing technology to the environment in the pressure of the dimethyl sulfide and highly toxic chemicals dimethyl sulfate, so that the present invention is friendly to the environment, in addition, the invention mild reaction conditions, the reaction time is short, high yield, high product quality, three waste emissions low, produces only a sole inorganic salt, of the present invention thereby the productivity is high, economic efficiency is good. (by machine translation)
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Paragraph 0034; 0037; 0039-0054
(2019/01/08)
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- FUNGICIDAL MIXTURES
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The present invention relates to fungicidal mixtures comprising, as active components, 1) azolylmethyloxiranes of the general formula I wherein the variables have the meanings described in the application, 2) a fungicidal compound II, and 3) optionally a further fungicidal compound II, where the compounds II of components 2 and 3 independently of one another are selected from the group consisting of the compounds described in the application, with the proviso that components 2 and 3 are not identical, and to the use of the fungicidal mixtures for controlling phytopathogenic fungi and to the compositions comprising them.
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- FUNGICIDAL MIXTURES
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The present invention relates to fungicidal mixtures comprising, as active components, 1) azolylmethyloxiranes of the general formula I in which the variables have the meanings described in the application, and 2) a fungicidal compound II, where the compounds II of component 2 are selected from among the compounds described in the application, and to the use of the fungicidal mixtures for controlling phytopathogenic fungi and to the compositions comprising them.
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- Stereoselective synthesis of (+)-flutriafol
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The stereoselective synthesis of (+)-flutriafol, a triazole fungicide, has been accomplished in seven linear steps from (1S)-[(4R)-2,2-dimethyl-[1,3]-dioxolan-4-yl]-(4-methoxyphenyl)methanol in 15% overall yield. Diastereoselective nucleophilic 1,2-addition was employed as a key step for constructing the requisite chiral 1,2-diol for flutriafol. A high degree of 1,4-asymmetric induction could be realized via a chelation-controlled mechanism during the key alkylation step.
- Chang, Minsun,Kim, Tae Hyun,Kim, Hee-Doo
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p. 1503 - 1507
(2008/12/21)
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- Fungicide compositions
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Compositions of azole fungicides exhibiting reduced eye irritation are prepared by replacing a significant portion of the hydrocarbon solvent with a combination of propylene glycol and a long chain fatty alcohol.
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- Isomerization process
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Transformation of specified 4H-substituted-1,2,4-triazoles into their 1H-substituted isomers by heating at a temperature of 150° C. to 300° C. in the presence of a base and, essentially, in the absence of a polar aprotic solvent.
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- Fungicide compositions
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A fungicide composition having reduced eye irritation comprising in percent by weight based on the weight of the composition 5-50% of an azole fungicide which irritates the eye in combination with an aromatic hydrocarbon, 20-40% propylene glycol, 1-20% fatty alcohol having at least 10 carbon atoms, 10-40% surfactant and less than about 20% aromatic hydrocarbon.
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