- Photocatalytic Degradation of 4,4′-Isopropylidenebis(2,6-dibromophenol) on Magnetite Catalysts vs. Ozonolysis Method: Process Efficiency and Toxicity Assessment of Disinfection By-Products
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Flame retardants have attracted growing environmental concern. Recently, an increasing number of studies have been conducted worldwide to investigate flame-retardant sources, environmental distribution, living organisms’ exposure, and toxicity. The presented studies include the degradation of 4,4′-isopropylidenebis(2,6-dibromophenol) (TBBPA) by ozonolysis and photocatalysis. In the photocatalytic process, nano-and micro-magnetite (n-Fe3 O4 and μ-Fe3 O4) are used as a catalyst. Monitoring of TBBPA decay in the photocatalysis and ozonolysis showed photocatalysis to be more effective. Significant removal of TBBPA was achieved within 10 min in photocatalysis (ca. 90%), while for ozonation, a comparable effect was observed within 70 min. To determine the best method of TBBPA degradation concentration on COD and TOC, the removals were examined. The highest oxidation state was obtained for photocatalysis on μ-Fe3 O4, whereas for n-Fe3 O4 and ozonolysis, the COD/TOC ratio was lower. Acute toxicity results show noticeable differences in the toxicity of TBBPA and its degradation products to Artemia franciscana and Thamnocephalus platyurus. The EC50 values indicate that TBBPA degradation products were toxic to harmful, whereas the TBPPA and post-reaction mixtures were toxic to the invertebrate species tested. The best efficiency in the removal and degradation of TBBPA was in the photocatalysis process on μ-Fe3 O4 (reaction system 1). The examined crustaceans can be used as a sensitive test for acute toxicity evaluation.
- Balawejder, Maciej,Barylyak, Adriana,Bobitski, Yaroslav,Kisa?a, Joanna,Tomaszewska, Anna
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- Halogenated method of aromatic compound
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The invention belongs to the field of organic synthesis, and particularly relates to synthesis of aromatic halogens, in particular to arylamine. The invention discloses a synthesis method of a corresponding ortho-halogenated product from aromatic compounds such as carbazole and phenol. The method comprises the following steps: adding a metal sulfonate salt catalyst, aromatic amine, carbazole, phenol and other hydrogen - heteroatom-containing aromatic compound reaction substrates, a halogenation reagent and a reaction solvent at a specific reaction temperature. After the drying agent is dried, the yield of the reaction product and the nuclear magnetic characterization determining structure are determined by column chromatography. The reaction product yield is determined by gas chromatography. By adopting the method, under the cheap metal salt catalyst, a plurality of ortho-substituted brominated and chloro products can be obtained with moderate to excellent yield.
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Paragraph 0205-0207
(2021/11/10)
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- Green halogenation reactions for (hetero)aromatic ring systems in alcohol, water, or no solvent
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A new method of brominating aromatic and heteroaromatic ring systems is investigated. The combination of hydrobromic acid as the halogen source, hydrogen peroxide as the oxidant, and ethanol, water, or no solvent are evaluated as greener conditions than those that have been previously published. The new conditions give high yields and good regioselectivity for a variety of substrates when the ring is activated by electron-donating groups or heteroatoms. Phenols, anisole, thiophenes, and pyrrole give comparable or superior results when compared to a traditional bromination by N-bromosuccinimide in tetrahydrofuran. Other nitrogen-containing heterocycles do not react under the conditions because they are protonated and hence deactivated; similarly, substrates with electron-withdrawing groups are not brominated. The reaction is very tolerant of a variety of functional groups.
- Kajorinne, Jessie K.,Steers, Jennifer C.M.,Merchant, Marnie E.,MacKinnon, Craig D.
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p. 1087 - 1091
(2018/11/25)
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- Method of preparing styrenated phenol derivatives
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The present invention relates to a method for selectively producing a di-styrenated phenol derivative. According to the present invention, the method for selectively producing the di-styrenated phenol derivative enables the selective production of the di-styrenated phenol derivative ensuring thermal stability and discoloration stability. Additionally, it is also possible to increase reaction yields by minimizing residual reaction materials. To this end, the method for selectively producing the di-styrenated phenol derivative comprises the following steps: a first step for producing a dihalo-substituted phenol derivative represented by chemical formula 3; and a second step for producing the di-styrenated phenol derivative represented by chemical formula 1.COPYRIGHT KIPO 2017
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Paragraph 0056-0059
(2017/05/12)
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- A highly selective synthetic method for distyrenated phenol
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Styrenated phenol is an antioxidant synthesized by catalytic reaction of a Bronsted acid and Lewis acid Composition ratio of compound varies based on the amounts source material and catalyst. In this study the composition of the styrenated phenol of monomer, dimer, trimer product synthesized by designing on experiment for increasing selectively. These styrenated phenol were analyzed using a MALDI-TOF MS, FT/IR Spectrometer, 1H(13C)-NMR, and Gas Chromatography (GC).
- Son, Seokhwan,Kim, Jinhyun,Ahn, Hogeun,Jang, Mikyeong,Kwak, Wonbong,Jung, Sunghun,Chung, Minchul
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p. 2703 - 2706
(2017/03/09)
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- Thermal Protodeboronation of hydroxyarene Boronic Acids and Its Application to ortho- and meta- Functionalization of hydroxyarene Using Boronic Acids as Blocking and Directing Groups
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The present invention refers to hydroxy arene boron acid compounds that thermal de borohydride of phenolic compounds using functional groups in ortho-or meta-position with hydroxy [...] manufacturing method relates to, more particularly boron position and outputs ortho of phenol then substituted acid, ortho-or meta-position boron arene hydroxy then introduced to a functional groups in making and compounds, thermal de using borohydride said boron acid by removing phenol from ortho-or meta-position functional groups in have been introduced method for preparing the compounds of arene hydroxy relates to. Manufacturing method of arene compound hydroxy the present invention according to such as iridium or a palladium metal catalyst-free, a stronger acid than the acid or base conditions, a low-temperature reaction acid and acetic anhydride the microbeam generating reactions, by causing or permitting a condition without requiring a step of client and, simply phenol from ortho-or meta-position for introducing functional groups to hydroxy arene compound can be produced.
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Paragraph 0128; 0129; 0131-0133
(2016/10/27)
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- Room-temperature Pd-catalyzed C-H chlorination by weak coordination: One-pot synthesis of 2-chlorophenols with excellent regioselectivity
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A room-temperature Pd(ii)-catalyzed regioselective chlorination reaction has been developed for a facile one-pot synthesis of a broad range of 2-chlorophenols. The reaction demonstrates an excellent regioselectivity and reactivity for C-H chlorination. This reaction represents one of the rare examples of mild C-H functionalization at ambient temperature.
- Sun, Xiuyun,Sun, Yonghui,Zhang, Chao,Rao, Yu
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p. 1262 - 1264
(2014/02/14)
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- Hydrodebromination of 2,4,6-tribromophenol in aqueous solution using Devarda's alloy
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The effectiveness of application of aluminium and its alloys and mixtures with copper was studied for complete hydrodebromination of 2,4,6-tribromophenol to phenol in aqueous NaOH solution at room temperature. Dissolved metals were removed using precipita
- Weidlich, Tomá?,Krej?ová, Anna,Proke?, Lubomír
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p. 155 - 162
(2013/07/27)
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- Debromination of 2,4,6-tribromophenol coupled with biodegradation
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The application effect of aluminium and their alloys and mixtures with nickel was studied for the complete hydrodebromination of 2,4,6-tribromophenol (TBP) to phenol in aqueous NaOH solution at room temperature. It was found that the Raney Al-Ni alloy can
- Weidlich, Tomas,Prokes, Lubomir,Pospisilova, Dagmar
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p. 979 - 987
(2014/03/21)
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- Protodeboronation of ortho- and para-phenol boronic acids and application to ortho and meta functionalization of phenols using boronic acids as blocking and directing groups
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The first metal-free thermal protodeboronation of ortho- and para-phenol boronic acids in DMSO was developed. The protodeboronation was successfully applied to the synthesis of ortho- and meta-functionalized phenols using the boronic acid moiety as a blocking group and a directing group, respectively. Mechanistic studies suggested that this protodeboronation proceeds through the coordination of water to the boron atom followed by σ-bond metathesis.
- Lee, Chun-Young,Ahn, Su-Jin,Cheon, Cheol-Hong
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p. 12154 - 12160
(2014/01/06)
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- Enantioselective access to benzannulated spiroketals using a chiral sulfoxide auxiliary
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This article describes our efforts to develop an asymmetric synthesis of bisbenzannulated spiroketals using a chiral sulfoxide auxiliary. Our primary focus was on the synthesis of the 3H-spiro[benzofuran-2,2′-chroman] ring system, the spirocyclic core of the rubromycin family. Our strategy employed the use of lithium-halogen exchange on a racemic bromospiroketal in order to attach a chiral sulfoxide, thus producing two diastereomers. The diastereomers were separable, enabling isolation of each spiroketal enantiomer. Subsequent cleavage of the sulfoxide group from each diastereomer yielded the respective parent spiroketal in high enantiopurity.
- Aitken, Harry R. M.,Furkert, Daniel P.,Hubert, Jonathan G.,Wood, James M.,Brimble, Margaret A.
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p. 5147 - 5155
(2013/08/15)
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- Dye molecules for simple co-sensitization process: Fabrication of mixed-dye-sensitized solar cells
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Sensitive kind of dye: Co-sensitization of the TiO2 electrode using PcS15 and the dye D131 results in a dramatic enhancement of the photocurrent response for the entire visible-light region. This method provides a simple design for accessing dye-sensitized solar cells. Copyright
- Kimura, Mutsumi,Nomoto, Hirotaka,Masaki, Naruhiko,Mori, Shogo
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supporting information; experimental part
p. 4371 - 4374
(2012/06/29)
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- Liquid-crystal engineering with anchor-shaped molecules: Honeycombs with hexagonal and trigonal symmetries formed by polyphilic bent-core molecules
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Anchored in hexagons: The molecules shown display two new complex liquid-crystalline phases formed by arrays of hexagonal cylinders, each hexagon comprising either three or six molecules. The phase type can be selected by choosing the right size ratio between the π-conjugated aromatic core (the anchor) and the flexible chain. One of the phases is the first columnar liquid crystal with trigonal symmetry. (Chemical Equation Presented).
- Glettner, Benjamin,Liu, Feng,Zeng, Xiangbing,Prehm, Marko,Baumeister, Ute,Ungar, Goran,Tschierske, Carsten
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supporting information; experimental part
p. 6080 - 6083
(2009/03/11)
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- Simple bromination of activated arenes by IBX amide resin and tetraethyl-ammonium bromide
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A mild and operationally simple method of brominating activated aromatic compounds using a polymer supported IBX reagent (IBX amide resin) and tetraethylammonium bromide (TEAB) was developed. The activated aromatics, when reacted with IBX amide resin in the presence of TEAB, were easily converted into the brominated aromatics in high yields (>80%) at room temperature.
- Kim, Duk-Ki,Chung, Woo-Jae,Lee, Yoon-Sik
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p. 279 - 282
(2007/10/03)
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- Reductive dehalogenation of halophenols in sulfite-bisulfate medium
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The KHSO4-Na2SO3 system is found to be simple and inexpensive for reductive elimination of halogens (Br, I) from the corresponding halophenols under reflux conditions in dry methanol. Under similar conditions the reaction is sluggish with chlorophenols.
- Adimurthy, Subbarayappa,Ramachandraiah, Gadde
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p. 5251 - 5252
(2007/10/03)
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- Bromination by means of sodium monobromoisocyanurate (SMBI)
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A variety of aromatic compounds with both activating and deactivating substituents were brominated with sodium monobromoisocyanurate (SMBI) 1, diethyl ether, diethyl ether-methanesulfonic acid, trifluoroacetic acid, or sulfuric acid were employed as solvents. Thus nitrobenzene was conveniently brominated in sulfuric acid, benzene was readily monobrominated in diethyl ether-methanesulfonic acid, and phenol was selectively brominated at the ortho position under mild conditions in refluxing diethyl ether. With substituents that are easily protonated, trifluoroacetic acid may be employed as solvent in the reaction with 1, in contrast NBS was ineffective in trifluoroacetic acid. This renders 1 a superior reagent relative to NBS. In addition to aromatics, alkenes, ketones and esters were also brominated with 1. Diethyl malonate was brominated with 1 and then subjected to a Bingel reaction with NaH to afford the desired methanofullerene in reasonable yield.
- Okada, Yukihiro,Yokozawa, Masanori,Akiba, Miwa,Oishi, Kazuhiko,O-Kawa, Kyoji,Akeboshi, Tomohiro,Kawamura, Yasuo,Inokuma, Seiichi,Nakamura, Yosuke,Nishimura, Jun
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p. 2506 - 2511
(2007/10/03)
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- A novel application of Hβ-zeolite in catalytic dehalogenation of halophenols
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A new application of Hβ-zeolite for debromination of bromophenols and deiodination of iodophenols is presented in this note. The heterogeneous catalyst can be recovered and recycled effectively for subsequent reactions. The catalyst was found ineffective for similar action on chlorophenols.
- Adimurthy, Subbarayappa,Ramachandraiah, Gadde,Bedekar, Ashutosh V.
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p. 6391 - 6392
(2007/10/03)
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- Process for generating electrophiles from anions by reaction with electrophilic fluorinating agent
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A process includes substituting a substituent on a substrate. The process includes reacting a salt of an anionic form of the substituent with an electrophilic fluorination agent to provide an electrophile containing a cationic form of the substituent. The electrophile is then electrophilically substituted on the substrate. In some aspects of the process, the substrate can be an aromatic or a non-aromatic. The process can be used for a variety of reactions having electrophilic mechanisms, including halogenation, thiocyanation and nitration.
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- Oxidative bromination in a liquid-liquid two-phase system to synthesize organic intermediates: 2-Bromophenol, 2,6-dibromophenol, and 2-bromo-4-methylphenol
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An alternative manufacturing process-scheme was developed to synthesize 2-bromophenol and 2,6-dibromophenol involving oxidative bromination of a substrate protected in the para position in a two-phase system followed by deprotection involving decarboxylation. Thus, selective oxidative bromination of 4-hydroxybenzoic acid in ethylenedichloride with HBr-H2O2, and subsequent decarboxylation in quinoline gave 90-95% yield to the mono- or dibromophenol depending upon the mol ratio of HBr:H2O2 employed in the oxidative bromination. Similarly, 4-methylphenol under identical reaction conditions gave 99.6% selectivity to 2-bromo-4-methylphenol at 89% conversion ratio of 4-methylphenol.
- Mukhopadhyay, Sudip,Ananthakrishnan,Chandalia, Sampatraj B.
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p. 451 - 454
(2013/09/08)
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- Halogenation Using N-Halogenocompounds. I. Effect of Amines on ortho-Bromination of Phenols with NBS
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Primary and secondary amines, especially diisopropylamine and dibutylamine, catalyzed ortho-dibromination of phenol and ortho-monobromination of 2-substituted phenols with NBS in dichloromethane to give selectively 2,6-dibromophenol and 2-bromo-6-sybstituted phenols, respectively.The effective intermediates are inferred to be N-bromoamines.The scope and limitations of the bromination are also presented.
- Fujisaki, Shizuo,Eguchi, Hisao,Omura, Atsushi,Okamoto, Atsushi,Nishida, Akiko
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p. 1576 - 1579
(2007/10/02)
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- Ortho-Specific Bromination of Phenols
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Phenol as well as 3-substituted phenols are brominated exclusively in the ortho positions by N.N-dibromomethylamine, yielding 2.6-dibrominated phenols in excellent yields.Phenols bearing an ortho-substituent need N-bromomethylamine as the brominating agent to take up one bromine atom into the free ortho-position. para-Bromination is not observed in either case. 1-Naphthol gives 2-bromo-1-naphthol, 8-hydroxyquinoline gives 7-bromo-8-hydroxyquinoline with 80percent and 98percent yield respectively. ortho-Specific chlorination of phenols was carried out in some cases using N-chloro-alkylamines.
- Schmitz, Ernst,Pagenkopf, Ingeborg
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p. 998 - 1006
(2007/10/02)
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- ipso Halogenation. II. Bromination of phenols, isomerisation and disproportionation of bromophenols, and dione-phenol rearrangement of bromodienones
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Bromination of p-cresol, bromo-p-cresol, 3,4-dimethylphenol, and mesitol in trifluoromethanesulfonic acid gices as the main product the bromo derivative with bromine meta to hydroxyl, a result attributed to the intermediate formation of a bromodienone and its rearrangement.Phenols does not give m-bromophenol in trifluoromethanesulfonic acid. 4-Bromo-2,4,6-trimethylcyclohexa-2,5-dienone rearranges to 3-bromomesitol in trifluoromethanesulfonic acid and, similarly, 2,4,6-tribromo-4-methylcyclohexa-2,5-dienone rearranges to 3-bromomesitol in trifluoromethanesulfonic acid and, similarly, 2,4,6-tribromo-4-methylcyclohexa-2,5-dienone rearranges to 2,3,6-tribromo-4-methylphenol.Under appropriate conditions debromination of bromodienones is competitive with rearrangement.Tetramethylammonium bromide in trifluoromethanesulfonic acid is an effective reagent for isomerization and disproportionation of bromophenols.Tetramethylammonium iodide in trifluoromethanesulfonic acid is an effective reagent for selective debromination of bromophenols at the ortho and para position.
- Fischer, Alfred,Henderson, George Narayanan
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p. 1045 - 1052
(2007/10/02)
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