- Preparation method of 1, 2, 4-trifluorobenzene
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The invention relates to the technical field of preparation of chemical drug intermediates, and particularly discloses a preparation method of 1, 2, 4trifluorobenzene. The preparation method comprisesthe following steps: step 1, preparing 2, 4-diamino fluorobenzene: carrying out hydrogenation reduction on 2, 4-dinitrofluorobenzene and a catalyst to obtain 2, 4-diamino fluorobenzene with a reaction formula shown in the specification; step 2, preparation of fluoroboric acid diazonium salt: 2, 4-diamino fluorobenzene obtained in the step 1 is subjected to diazotization reaction with a fluoroboric acid aqueous solution and a sodium nitrite aqueous solution in sequence, a fluoroboric acid diazonium salt intermediate is obtained, and the reaction formula is shown in the specification; and step3, preparation of 1, 2, 4-trifluorobenzene: heating and decomposing the fluoroboric acid diazonium salt intermediate obtained in the step 2 to obtain 1, 2, 4-trifluorobenzene, nitrogen and boron trifluoride gas, and the reaction formula is shown in the specification. The method has the advantages that the raw materials are cheap and easy to obtain, the preparation cost is low, the yield is high, few three wastes are produced during preparation, and the economic value of byproducts is high.
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Paragraph 0037
(2021/01/28)
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- Gas-liquid flow hydrogenation of nitroarenes: Efficient access to a pharmaceutically relevant pyrrolobenzo[1,4]diazepine scaffold
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Using a Tube-in-Tube device based on the amorphous Teflon AF-2400 fluoropolymer, a series of nitroarenes was hydrogenated to afford the corresponding aniline compounds. The system was then applied to the construction of a pyrrolobenzo[1,4]diazapene scaffold through a tandem hydrogenation-condensation-hydrogenation sequence.
- Dimitriou, Eleni,Jones, Richard H.,Pritchard, Robin G.,Miller, Gavin J.,O'Brien, Matthew
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p. 6795 - 6803
(2018/10/15)
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- A 4, 4 - dimethoxy - 2, 2 - bipyridyl silver catalytic hydrogenation of aromatic nitro compound synthesis of aromatic amines (by machine translation)
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The invention discloses a 4, 4 - dimethoxy - 2, 2 - bipyridyl silver catalytic hydrogenation of aromatic nitro compound synthesis of aromatic amines, the method uses a cheap, easy synthesis of 4, 4 - dimethoxy - 2, 2 - bipyridyl silver as catalyst, in order to green, environmental protection, non-toxic as the hydrogen source, the aromatic nitro compound in the relatively mild reaction conditions, one-step reaction can synthesize aromatic amine. The invention has simple operation, catalyst is cheap and easy and small consumption, mild reaction conditions, to substrate demonstrates better functional group tolerant, high product yield, industrial manufacturing cost, it has very good application prospect. (by machine translation)
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Paragraph 0016; 0069; 0072
(2017/07/19)
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- Novel diamine having perfluorodecylthio group, preparation method thereof and fluorinated polyimid film prepared therefrom
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The present invention relates to a novel diamine having a perfluorodecylthio group for preparing a novel fluorinated polyimide film, a method for preparing the same, and a novel fluorinated polyimide film having a perfluorodecylthio group obtained from the diamine. The polyimide film obtained from the novel diamine having a perfluorodecylthio group according to the present invention comprises a perfluorodecylthio side group, and thus reduces a CTC effect between polymer chains and improves optical transparency through a steric hindrance effect and an induction effect of the perfluorodecyl side group (electron-donating effect of the diamine), improves solubility, provides increased hydrophobicity and shows improved physical properties, including low water absorbability and a low dielectric constant. Thus, the film according to the present invention can be used advisably instead of the existing polyimide films.COPYRIGHT KIPO 2017
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Paragraph 0105; 0106; 0107
(2017/08/26)
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- Synthesis and characterization of highly transparent and hydrophobic fluorinated polyimides derived from perfluorodecylthio substituted diamine monomers
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Two new perfluorodecylthio substituted aromatic diamines, namely 2,4-diamino-1-(1H,1H,2H,2H-perfluorodecathio) benzene (DAPFB) and 2,2′-Bis((1H,1H,2H,2H-perfluorodecyl) thio)[1,1′-biphenyl]4,4′-diamine (BPFBD) were synthesized and polycondensed with 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) to produce two new perfluorinated polyimides (PI2 and PI4). The chemical structures of these polyimides were confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy and elemental analysis. Two other polyimides (PI1 and PI3) were also synthesized from 6FDA and analogous perfluorodecylthio unsubstituted diamines to investigate the incorporation effect of perfluorodecylthio group on various physical and chemical properties of the synthesized PIs. Compared with PI1 and PI3, PI2 and PI4 exhibited improved solubility, optical transparency, and hydrophobicity, lower moisture absorption, dielectric constant, and thermo-mechanical stabilities owing to the presence of the perfluorodecylthio side group in the polymer chain. Even though thermo-mechanical properties of PI2 and PI4 (Td5: 413 and 404 °C, Tg: 220 and 209 °C, tensile strength of 101 and 76 MPa, tensile modulus of 1.7 and 1.5 GPa and elongation at break of 8 and 10%, respectively) were reduced in comparison to PI1 and PI3 but still were good enough for most of the practical applications. Most importantly, the presence of the perfluorodecylthio side group in BPFBD considerably reduced the dielectric constant of PI4 to 2.71 which was quite low as aromatic polyimide.
- Tapaswi, Pradip Kumar,Choi, Myeon-Cheon,Nagappan, Saravanan,Ha, Chang-Sik
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p. 479 - 488
(2015/03/03)
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- One-pot reductive conversion of nitroarenes to N-arylacetamides mediated by metallic samarium
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Nitroarenes can be reduced and then converted to N-arylacetamides by metallic samarium in the presence of acetic anhydride, acetic acid and methanol in excellent yields by a one pot-procedure.
- Zhang, Yandong,Zhang, Yongmin
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p. 596 - 598
(2007/10/03)
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- Synthesis of 5- and 6-membered heterocycles by a strategy combining SNAr and SRN1 reactions
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The SRN1 mechanism is compatible with many substituents on the benzenic substrate and allows SRN1 reactions to be combined with SNAr reactions in a strategy which brings together their corresponding synthetic advantages.Thus, compounds containing benzene fused to 5- or 6-membered heterocycles containing N (indoles), N and P (benzazaphospholes) and N and S (benzothiazines) are readily obtained. nucleophilic aromatic substitution / SRN1 / SNAr / benzene-fused heterocycles
- Beugelmans, Rene,Chbani, Mohamed
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p. 306 - 313
(2007/10/02)
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- 7-(1-Pyrrolyl) derivatives of 1-ethyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acids and 1-ethyl-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acids and their use as antimicrobial agents
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The present invention relates to new derivatives of 7-(1-pyrrolyl)-1-ethyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid and 7-(1-pyrrolyl)-1-ethyl-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid of general formula I: STR1 in which: X represents a carbon atom or a nitrogen atom, and R represents a hydrogen atom or a fluorine atom, as well as their physiologicaly acceptable alkali metal salts or alkaline earth metal salts. The derivatives of the present invention are advantageously used as antimicrobial agents, espcially as anti-bacterial and anti-fungal agents.
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