- Starbon acids in alkylation and acetylation reactions: Effect of the Broensted-Lewis acidity
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Various Starbon supported solid acids were prepared and investigated in two test reactions, namely the acetylation of 5-acetyl-methylsalicylate and the alkylation of phenol with cyclohexene. Starbon-SO3H materials exhibited in general an optimum balance of Lewis and Bronsted acid sites, making them ideal catalysts for the investigated processes. Starbon acids were comparably active and differently selective compared to similar solid acids utilised in the proposed acid catalysed processes including commercial sulphated zirconia and beta zeolite. Materials were also highly reusable under the different reaction conditions, preserving their activities almost unchanged after 4 reuses.
- Luque, Rafael,Budarin, Vitaly,Clark, James H.,Shuttleworth, Peter,White, Robin J.
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- Nanocrystalline hierarchical ZSM-5: An efficient catalyst for the alkylation of phenol with cyclohexene
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In this paper, authors report the synthesis of nanocrystalline hierarchical zeolite ZSM-5 and its application as a heterogeneous catalyst in the alkylation of phenol with cyclohexene. The catalyst was synthesized by vacuum-concentration coupled hydrothermal technique in the presence of two templates. This synthetic route could successfully introduce pores of higher hierarchy in the zeolite ZSM-5 structure. Hierarchical ZSM-5 could catalyse effectively the industrially important reaction of cyclohexene with phenol. We ascribe the high efficiency of the catalyst to its conducive structural features such as nanoscale size, high surface area, presence of hierarchy of pores and existence of Lewis sites along with Br?nsted acid sites. The effect of various reaction parameters like duration, catalyst amount, reactant mole ratio and temperature were assessed. Under optimum reaction conditions, the catalyst showed up to 65% selectivity towards the major product, cyclohexyl phenyl ether. There was no discernible decline in percent conversion or selectivity even when the catalyst was re-used for up to four runs. Kinetic studies were done through regression analysis and a mechanistic route based on LHHW model was suggested.
- Radhika,Selvin, Rosilda,Kakkar, Rita,Roselin, L. Selva
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- Carbon supported Pd nanocrystals as high efficient catalyst for regioselective hydrogenation of p-phenylphenol to p-cyclohexylphenol
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A series of Pd based nanocrystals were used to catalyze regioselective hydrogenation of p-phenylphenol (p-PP) to p-cyclohexylphenol (p-CP). The polar solvents such as THF, methanol and ethanol offered much higher selectivity to p-CP than nonpolar solvent. Concerning the effect of supports, the active carbon supported Pd nanocrystals show the best performance probably due to its hydrophobicity and high surface area. The best result with high selectivity (89.1 %) was obtained by using Pd/active carbon as catalyst when p-PP was 100 % converted. Springer Science+Business Media, LLC 2012.
- Liu, Chengyun,Lu, Lianhai,Rong, Zeming,Liang, Changhai,Wang, Yue,Qu, Qingping
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- Hexagonal zirconium phosphate nanoparticles as an efficient and recyclable catalyst for selective solvent-free alkylation of phenol with cyclohexanol
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A facile synthesis of hexagonal α-zirconium phosphate (ZP) nanoparticles as an effective, eco-friendly and recyclable solid acid catalyst was studied. Polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) were used as the organic matrix which were the dispersing agents and acted as a template for the nanoparticles. It seems H-bonds between ZP and PVA or PVP along polymer chains lead to a better dispersion of in situ formed ZP. Pure ZP nanoparticles with hexagonal shape were obtained after calcination of PVA/ZP or PVP/ZP. The catalysts were characterized by several physico-chemical techniques such as BET, ICP-OES, XRD, FT-IR, SEM and TEM. The TPD-NH3 analysis suggests the presence of a reasonable amount of Br?nsted acid sites. The acidic properties were studied in the alkylation of phenol with cyclohexanol under solvent-free conditions which produced 2-cyclohexylphenol (2-CP), 4-cyclohexylphenol (4-CP) and 2,4-dicyclohexylphenol (2,4-DCP). This alkylation reaction was also performed over P2O5/Al2O 3, P2O5/SiO2, α-ZrP (prepared in the absence of the polymers) and various ionic liquids using cyclohexanol and cyclohexene as the alkylating agents. When the hexagonal ZP nanoparticles were used as the catalyst, under optimized reaction conditions, excellent conversion of phenol and selectivity toward 4-CP were obtained. The catalyst was recovered easily from the reaction mixture, regenerated and reused at least four times without significant loss in its catalytic activity.
- Hajipour, Abdol Reza,Karimi, Hirbod
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- Synthesis of cyclohexylphenols
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Catalytic alkylation of phenols with cyclohexanol gives o- and p-cyclohexylphenols as the major products. The effect of temperature, catalyst nature, and reactant concentration on the reaction outcome was studied.
- Postnova,Koshel',Lebedeva,Kuznetsova,Koshel'
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Read Online
- Synthesis of cyclohexylphenol via phenol hydroalkylation using Co2P/zeolite catalysts
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Cyclohexylphenol (CHP) is a high added-value chemical, extensively used for the preparation of dyes, resins and biocides. This molecule is currently synthetized by phenol alkylation with cyclohexene/cyclohexanol using highly polluting mineral Br?nsted acids as catalysts. The present contribution reports the one-pot production of cyclohexylphenol via hydroalkylation, using phenol as the only organic reactant, over a number of bifunctional catalysts consisting of Co2P (5 wt% Co) supported over different zeolites (ferrierite, mordenite, beta and MCM-22). Phenol conversion increased in the order: Co2P/Mordenite (30%) 2P/Ferrierite (65%) 2P/Beta (77%) 2P/MCM-22 (90%), which reflects enhancing dispersion of cobalt phosphide phase and accessibility of acid centres with evolving external surface in nanocrystalline zeolite supports. On the other hand, remarkable differences were observed between the catalysts in terms of CHP formation. The highest values of CHP yield and selectivity (YCHP=43% and SCHP=56%) were attained over the Co2P/Beta catalyst, due to the combination of three-dimensional microporosity, large external surface area (as a consequence of its nanocrystalline nature) and highly dispersed Co2P nanoparticles. In addition, it is envisaged that the formation of CoAlPO phases might favour a balanced performance of metal and acid sites for the CHP production.
- ?ejka, J.,Coronado, J. M.,Gutiérrez-Rubio, S.,Moreno, I.,Serrano, D. P.,Shamzhy, M.
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- Method for promoting iron-catalyzed oxidation of aromatic compound carbon - hydrogen bond to synthesize phenol by ligand
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The method comprises the following steps: iron is used as - a catalyst metal; a sulfur-containing amino acid or cystine-derived dipeptide is a ligand; and under the common action of hydrogen peroxide as an oxidizing agent, an aromatic compound is synthesized to prepare a phenol. Under the action of an acid as an accelerant and hydrogen peroxide as an oxidizing agent, the aryl carbon - hydrogen bond is directly hydroxylated to form a phenolic compound, and the method for preparing the phenol by the catalytic oxidation reaction has a plurality of advantages. The reaction raw materials, the oxidant and the promoter are wide in source, low in price, environment-friendly and good in stability. The aromatic compound carbon - hydrogen bonds directly participate in the reaction to react in one step to form phenol. The reaction condition is mild, the functional group compatibility and the application range are wide. The reaction selectivity is good; under the optimized reaction conditions, the target product separation yield can reach 85%.
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Paragraph 0060-0061; 0127
(2021/09/21)
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- Palladium-Catalyzed Hydroxylation of Aryl Halides with Boric Acid
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Boric acid, B(OH)3, is proved to be an efficient hydroxide reagent in converting (hetero)aryl halides to the corresponding phenols with a Pd catalyst under mild conditions. Various phenol products were obtained in good to excellent yields. This transformation tolerates a broad range of functional groups and molecules, including base-sensitive substituents and complicated pharmaceutical (hetero)aryl halide molecules.
- Song, Zhi-Qiang,Wang, Dong-Hui
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supporting information
p. 8470 - 8474
(2020/11/18)
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- Enantiospecific sp2–sp3 Coupling of ortho- and para-Phenols with Secondary and Tertiary Boronic Esters
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The coupling of ortho- and para-phenols with secondary and tertiary boronic esters has been explored. In the case of para-substituted phenols, after reaction of a dilithio phenolate species with a boronic ester, treatment with Ph3BiF2 or Martin's sulfurane gave the coupled product with complete enantiospecificity. The methodology was applied to the synthesis of the broad spectrum antibacterial natural product (?)-4-(1,5-dimethylhex-4-enyl)-2-methyl phenol. For ortho-substituted phenols, initial incorporation of a benzotriazole on the phenol oxygen atom was required. Subsequent ortho-lithiation and borylation gave the coupled product, again with complete stereospecificity.
- Wilson, Claire M.,Ganesh, Venkataraman,Noble, Adam,Aggarwal, Varinder K.
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p. 16318 - 16322
(2017/12/04)
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- METHOD FOR PRODUCING AN ARENE WITH AN AROMATIC C-N BOND ORTHO TO AN AROMATIC C-O BOND
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A method for producing an arene with an aromatic C—N bond ortho to an aromatic C—O bond from a hydroxy arene comprising said aromatic C—O bond is provided. This method comprising the steps a) ortho-oxygenating the hydroxy arene to produce an ortho-quinone, b) condensating the ortho-quinone with a nitrogen nucleophile to generate a compound of Formula (IVa) or (IVb), and c) allowing 1,5-hydrogen atom shift of the compound of Formula (IVa) or (IVb), thereby producing arenes with a C—N bond ortho to a C—O bond of Formula (Va) and (Vb), respectively:
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Paragraph 0375; 0376; 0376; 0463
(2017/03/28)
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- Iron-catalyzed arene alkylation reactions with unactivated secondary alcohols
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A simple, iron-based catalytic system allows for the inter- and intramolecular arylation of unactivated secondary alcohols. This transformation expands the substrate scope beyond the previously required activated alcohols and proceeds under mild reaction conditions, tolerating air and moisture. Furthermore, the use of an enantioenriched secondary alcohol provides an enantioenriched product for the intramolecular reaction, thereby offering a convenient approach to nonracemic products.
- Jefferies, Latisha R.,Cook, Silas P.
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supporting information
p. 2026 - 2029
(2014/05/06)
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- Chemoselective O-Versus C-Alkylation of substituted phenols with cyclohexene over mesoporous ZSM-5
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Chemoselective O- versus C-alkylation of substituted phenols such as phenol, p-cresol, and guaiacol with cyclohexene were investigated over various ZSM-5 catalysts with different degree of mesoporosity and external acidity such as mesoporous ZSM-5 synthesized by microwave induced assembly via electrostatic interaction between sulfonic acid, functionalized or non-functionalized ZSM-5 nanozeolites and counter cationic surfactant, and hydrothermal synthesized microporous ZSM-5 with or without sulfonic acid functionalization and surfactant. The selectivity of O- and C-alkylated products varied with different degree of mesoporosity. The selectivity of C-alkylated products increased with increasing mesopore volume and external acid sites, whereas that of O-alkylated product decreased. The mesoporous ZSM-5 synthesized under microwave via sulfonic acid functionalization showed not only the highest mesoporosity and external acid sites but also the best catalytic activity and selectivity of C-alkylated products, whereas the other ZSM-5 catalysts mainly produced O-alkylated products due to diffusion limitation of bulky product.
- Jin, Hailian,Ansari, Mohd Bismillah,Park, Sang-Eon
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p. 184 - 190
(2014/02/14)
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- Titanium salalen catalysts based on cis-1,2-diaminocyclohexane: Enantioselective epoxidation of terminal non-conjugated olefins with H 2O2
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Terminal, non-conjugated olefins, such as 1-octene, are difficult to epoxidize asymmetrically. Ti salalen complexes based on cis-1,2- diaminocyclohexane catalyze this demanding reaction giving high yields and enantioselectivities (up to 95 % ee), with H2O2 as the oxidant. The X-ray structures of the μ-oxo and peroxo complexes shed light on the coordination behavior of this novel class of ligands.
- Berkessel, Albrecht,Guenther, Thomas,Wang, Qifang,Neudoerfl, Joerg-M.
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supporting information
p. 8467 - 8471
(2013/09/02)
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- Acid catalyzed alkylation of phenols with cyclohexene: Comparison between homogeneous and heterogeneous catalysis, influence of cyclohexyl phenyl ether equilibrium and of the substituent on reaction rate and selectivity
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The reactivity of several phenols toward liquid phase alkylation with cyclohexene in the presence of heterogeneous and homogeneous acid catalyst at 358 K is studied. The comparison between Amberlyst 15 and CH3SO 3H, as examples of heterogeneous and homogeneous systems, shows a higher activity of the former with different behavior of selectivity between the two systems, anyway, in both systems O-alkylation and ring alkylations occur. A remarkable difference in the selectivity of the ring alkylation between heterogeneous and homogeneous systems is observed: Amberlyst 15 shows a constant ortho/para ratio close to 2, while in the presence of CH3SO 3H ortho/para is variable from 3 to 5, suggesting an involvement of the cyclohexyl phenyl ether rearrangement. This is proved also by a direct relationship between the ortho/para ratio and the concentration of the cyclohexyl phenyl ether when CH3SO3H is used as a catalyst. The formation of cyclohexyl aryl ethers is reversible; on the contrary, ring alkylation appears irreversible. The reactivity of the dimethylphenols shows a strong influence of the steric hindrance of the substituent on the electrophilic attack of the cyclohexyl cation, which is poorly influenced by the inductive effect of the methyl group.
- Ronchin,Vavasori,Toniolo
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scheme or table
p. 134 - 141
(2012/03/09)
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- Kinetics and mechanism of acid catalyzed alkylation of phenol with cyclohexene in the presence of styrene divinylbenzene sulfonic resins
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The kinetics of phenol cyclohexylation catalyzed by sulfonic resins is studied taking into account equilibria and side reactions observed in the reaction media. The influence of different sulfonic resins has been tested and only small variation of the catalyst activity, referred to the acid amount, has been observed. Besides, the selectivity is unaffected by varying the type of the catalyst. The effect of reagent concentration on the reaction rate has been also studied, together with the reactivity of the cyclohexyl phenyl ether as intermediate. The etherification equilibrium of cyclohexyl phenyl ether has been analyzed in the presence of methanesulfonic acid, and the adsorption equilibria on a sulfonic resin of reagents and intermediates are measured, too. Starting from the evidences obtained from these studies an Eley-Rideal type kinetic model has been proposed and the fitting of the experimental data allows obtaining the kinetic constant of each stage. Good reliability of the model with the experimental data has been observed, also at high conversion, and the values of the fitting parameters are substantially constant by varying the operative variable, which is a further proof of the goodness of the model.
- Ronchin,Quartarone,Vavasori
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experimental part
p. 192 - 203
(2012/03/09)
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- Zirconia-modified superacid UDCaT-5: An efficient and versatile catalyst for alkylation reactions under solvent-free conditions
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UDCaT-5, a modified version of zirconia, efficiently catalyzes alkylation of phenols with alcohols under environmentally safe, heterogeneous reaction conditions with high selectivity and in excellent yields. The high content present in UDCaT-5 with preservation of tetragonal phase of zirconia was responsible for the superactivity. Several phenolic compounds carrying either electron-sulfer releasing or electron-withdrawing substituents in the ortho, meta, and para positions afforded high yields of the products. Copyright Taylor & Francis Group, LLC.
- Yadav, Ganapati D.,Pathre, Ganesh S.
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p. 2684 - 2691
(2008/12/22)
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- Cyclohexylation of phenol over a solid acid catalyst comprising 12-tungstophosphoric acid and hydrous zirconia
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The Friedel-Crafts alkylation (cyclohexylation of phenol with cyclohexene) has been carried out over 12-tungstophosphoric acid supported on hydrous zirconia under mild conditions. The catalyst shows high activity and selectivity for 2-cyclohexyl phenol, an important product used as intermediate in dyestuff preparation as well as in preparation of 2-phenyl phenol which is used as disinfectant and fungicide. In addition, the catalyst can be recycled and reused.
- Bhatt, Nikunj,Patel, Anjali
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p. 387 - 389
(2008/09/20)
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- ALKYLATION OF HYDROXYARENES WITH OLEFINS, ALCOHOLS AND ETHERS IN IONIC LIQUIDS
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Hydroxyarenes are alkylated using an ionic liquid catalyst system with olefins, alcohols, or ethers as alkylating agents. The ionic liquid catalyst system comprises chloroindate (III) anions. The reactions may be conducted at moderate temperatures and pressures to yield commercially relevant alkylated hydroxyarene compounds.
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(2008/06/13)
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- (2R)-2-Methylchromane-2-carboxylic acids: Discovery of selective PPARα agonists as hypolipidemic agents
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A SAR study was conducted on chromane-2-carboxylic acid toward selective PPARα agonisim. As a result, highly potent, and selective PPARα agonists were discovered. The optimized compound 43 exhibited robust lowering of total cholesterol levels in hamster and dog animal models.
- Koyama, Hiroo,Boueres, Julia K.,Miller, Daniel J.,Berger, Joel P.,MacNaul, Karen L.,Wang, Pei-Ran,Ippolito, Marc C.,Wright, Samuel D.,Agrawal, Arun K.,Moller, David E.,Sahoo, Soumya P.
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p. 3347 - 3351
(2007/10/03)
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- Organic reaction in water. Part 3: A facile method for reduction of aromatic rings using a Raney Ni-Al alloy in dilute aqueous alkaline solution under mild conditions
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Reduction of aromatic rings such as phenol, naphthalenes, biphenyls, acenaphthene, and acenaphthylene was smoothly performed using a Raney Ni-Al alloy in dilute aqueous alkaline solution without any organic solvents at 90°C under atmospheric pressure, and the corresponding reduced compounds were obtained in high yields. (C) 2000 Elsevier Science Ltd.
- Tsukinoki, Takehito,Kanda, Tadashige,Liu, Guo-Bin,Tsuzuki, Hirohisa,Tashiro, Masashi
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p. 5865 - 5868
(2007/10/03)
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- Scandium(III) triflate immobilised in ionic liquids: a novel and recyclable catalytic system for Friedel-Crafts alkylation of aromatic compounds with alkenes
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Scandium(III) triflate catalysed Friedel-Crafts alkylation of aromatic compounds with alkenes proceeded readily in the hydrophobic ionic liquid solvents based on 1,3-dialkylimidazolium salts with easy catalyst/solvent recycling, whereas these reactions did not occur in common organic solvents, water or hydrophilic ionic liquids at all.
- Song, Choong Eui,Shim, Woo Ho,Roh, Eun Joo,Choi, Jung Hoon
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p. 1695 - 1696
(2007/10/03)
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- New 4-aminoquinoline Mannich base antimalarials. 1. Effect of an alkyl substituent in the 5'-position of the 4'-hydroxyanilino side chain
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A new series of 4-aminoquinoline Mannich base derivatives have been synthesized, in which the 3'-diethylamino function of amodiaquine (AQ) is replaced by a 3'-tert-butylamino group and an aliphatic hydrocarbon entity is incorporated into the 5'-position of the 4'-hydroxyanilino side chain. Seven alkyl Mannich base derivatives were screened and found to be active against both chloroquine-sensitive and -resistant strains of Plasmodium falciparum in vitro. The propyl and isopropyl alkyl derivatives were found to be the most active; consequently these derivatives were tested against a nonsensitive strain of Plasmodium berghi in vivo and found to be 3-fold more active than AQ, irrespective of the route of administration (oral or intraperitoneal).
- Raynes, Kaylene J.,Stocks, Paul A.,O'Neill, Paul M.,Park, B. Kevin,Ward, Stephen A.
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p. 2747 - 2751
(2007/10/03)
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- Regioselective alkylation of phenol with cyclopentanol over montmorillonite K10: An efficient synthesis of l-(2-cyclopentylphenoxy)-3-[(l,l-dimethylethyl)amino]propan-2-ol {(S')-penbutolol}
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Regioselective alkylation of phenol with cyclopentanol is achieved over Montmorillonite K10 clay, producing 2-cycIopentylphenol, the key intermediate. The synthesis of optically active (S)-penbutoIol 1, an important antihypertensive drug, is realized in 5 steps from 2-cyclopentylphenol by employing Sharpless asymmetric dihydroxylation. The Royal Society of Chemistry 1999.
- Phukan, Prodeep,Sudalai, Arumugam
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p. 3015 - 3018
(2007/10/03)
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- Alkylation of phenol with olefins in the presence of lignosulfonic acids
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Alkylation of phenol with cyclohexene, 1-octene, dicyclopentadiene, 1,3-cyclopentadiene, and butylene polymer distillate at 100-140°C was studied. The process was performed in the presence of lignosulfonic acids obtained from industrial calcium lignosulfonates.
- Pisanenko,Smirnov-Zamkov
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p. 1655 - 1657
(2007/10/03)
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- Metal cation-exchanged montmorillonite (Mn+-mont)-catalysed aromatic alkylation with aldehydes and ketones
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The alkylation of aromatic compounds with aldehydes and ketones in the presence of a variety of metal cation-exchanged montmorillonites (Mn+-mont; Mn+ = Zr4+, Al3+, Fe3+, Zn2+, H+, Na+) has been investigated. Al3+- and Zr4+-Monts are revealed to be effective as catalysts, while no reaction takes place with Na+-mont. Al3+-Mont-catalysed alkylation of phenol with several aldehydes produces mainly or almost solely the corresponding gem-bis(hydroxyphenyl)alkanes (bisphenols) in good yields, while that with several ketones affords selectively the corresponding alkylphenols in moderate to good yields. The alkylation always occurs at the carbonyl carbon without any skeletal rearrangement and the kind of products depends much on the steric hindrance of an electrophilic intermediary carbocation. The alkylation of anisole, veratrole and p-cresol proceeds well, while that of toluene, benzene, chlorobenzene and nitrobenzene scarcely occurs.
- Tateiwa, Jun-Ichi,Hayama, Ei,Nishimura, Takahiro,Uemura, Sakae
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p. 1923 - 1928
(2007/10/03)
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- Non-catalyzed C-alkylation of phenols with cyclic secondary alkyl bromides
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C-Alkylations of phenol with 1-chloro and 1-bromoadamantane, 2-bromoadamantane, cyclohexyl bromide and exo-2-bromonorbornane, and C-alkylations of para-substituted phenol derivatives with 2-bromoadamantane are described.
- Arredondo, Yolanda,Moreno-Manas, Marcial,Pleixats, Roser
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p. 3885 - 3895
(2007/10/03)
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- Rearrangement Alkyl Phenyl Ethers to Alkylphenols in the Presence of Cation-exchanged Montmorillonite (Mn+-Mont)
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The rearrangement of alkyl phenyl ethers such as 4-phenoxybutan-2-one 1, 1-phenoxybutane 2a, 2-phenoxybutane 2b, 2-methyl-2-phenoxypropane 2c and phenoxycyclohexane 2d have been investigated in the presence of cation-exchanged montmorilonite (Mn+-mont; Mn+ = Zr4+, Al3+, Fe3+ and Zn2+).The ether 1 rearranged to 4-(4-hydroxyphenyl)butan-2-one 3 (raspberry ketone), the odour source of rasprerry, in 16-34percent GLC yield, where Zn2+-mont was the most effective catalyst.Similarly, other ethers 2a-d rearranged to the corresponding alkylphenols in up to 75percent isolated yield with good product selectivity, Al3+-mont being the catalyst of choice.Al3+-Mont was regenerated and resulted in the rearrangement of 2b, 2c and 2d.
- Tateiwa, Jun-ichi,Nishimura, Takahiro,Horiuchi, Hiroki,Uemura, Sakae
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p. 3367 - 3372
(2007/10/02)
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- Acid-Catalyzed Hydrolysis of Some Secondary Alkyl Phenyl Ethers in Perchloric Acid: Kinetics and Mechanism
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Hydrolysis rates and products of isopropyl, cyclopentyl and cyclohexyl phenyl ethers were studied in concentrated aqueous perchloric acid solutions.The activation parameters, solvent deuterium isotope effects, dependences of the reaction rates on acid concentration, substituent effects and products were in agreement with the A-1 mechanism.The pKSH+ values (-6.13 to -5.76) and the slope parameters m* (av. 0.98 +/- 0.03) were measured spectrophotometrically by the excess acidity method.They were used to calculate the m++-parameters (1.46-2.01).Comparisons weremade with the hydrolyses of exo- ad endo-2-norbornyl phenyl ethers and secondary alyl methanesulfonates.
- Lajunen, Martti,Kaehkoenen, Mika
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p. 726 - 731
(2007/10/02)
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- Equilibria for the isomerization of (secondary-alkyl)phenols and cyclohexylphenols
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Equilibria of a series of isomerizations and trans-alkylations of alkylphenols have been investigated in the liquid phase over a wide range of temperatures.Equilibria of isomerizations connected with the displacement of a substituent on a benzene nucleus were studied for secondary-butyl, -amyl, -hexyl, and cyclohexyl-phenols, and di-(secondary-butyl)phenols.Equilibria of positional isomerization connected with the displacement of an oxyphenyl radical in an alkyl chain were investigated for oxyphenyl-pentanes, -hexanes, -octanes, and -decanes.Trans-alkylation was investigated for di- and tri-(secondary-butyl)phenols.Values of ΔrH0m and ΔrS0m were found for all investigated reactions.An analysis was made of the thermodynamic quantities for the reactions.Enthalpies of formation of isopropylphenols (IPP) in the gaseous state were calculated.The values of ΔfH0m/(kJ * mol-1) were found at 298.15 K: o-IPP, -(175.3 +/- 2.4); p-IPP, -(175.3 +/- 2.4); m-IPP, -(175.3 +/-2.4); 2,4-di-IPP, -(254.1 +/- 2.8); 2,5-di-IPP, -(254.1 +/- 2.8); 2,6-di-IPP, -(254.1 +/- 2.8); 3,5-di-IPP, -(254.1 +/- 2.8); 2,4,6-tri-IPP, -(333.0 +/- 3.1).
- Nesterova, T. N.,Pimerzin, A. A.,Rozhnov, A. M.,Karlina, T. N.
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p. 385 - 396
(2007/10/02)
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- ALKYLATION OF PHENOL BY ALCOHOLS IN THE PRESENCE OF ALUMINUM PHENOLATE
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The reaction of phenol with alcohols in the presence of aluminum phenolate leads to a mixture of 2- and 4-alkylphenols, of which the former predominate in the case of benzyl, tert-butyl, and cyclohexyl alcohols, and the latter in the case of dimethylphenyl- and diphenylmethylcarbinols.Only triphenyl(4-hydroxyphenyl)methane is formed during the alkylation of phenol by triphenylcarbinol.In individual experiments the formation of small amounts of alkyl phenyl ethers and 2,6-dialkylphenols was observed.
- Koshchii, V. A.,Kozlikovskii, Ya. B.,Matyusha, A. A.
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p. 1358 - 1361
(2007/10/02)
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- Hydrogenation of 4-Substituted Biphenyls
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Hydrogenations of 4-hydroxy-(1a), 4-methoxy-, and 4-methylbiphenyls were carried out in the presence of Raney nickel (R-Ni), palladium-on-carbon (Pd-C), or platinum as catalysts under relatively mild conditions.The reaction rates depend primarily on the catalysts and less on the substrates.Hydrogenation with Pd-C or Pt took place predominantly in the phenyl ring, independent of the substituent.On the other hand, hydrogenation with R-Ni caused reduction mainly in the substituted aromatic ring.Hydrogenation of the phenol, 1a, using R-Ni afforded predominantly trans-4-phenylcyclohexanol in preference to the cis isomer, differing from the other reactions examined.
- Minabe, Masahiro,Watanabe, Kousuke,Ayabe, Yooichi,Yoshida, Masaaki,Toda, Takashi
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p. 1745 - 1748
(2007/10/02)
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- Hydroalkylation of Phenol to Cyclohexylphenyl in the Presence of Pd-Al2O3 and NaCl-AlCl3 under Hydrogen Pressure
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The hydroalkylation of phenol (1) in the presence of palladium catalyst and fused salt (NaCl-AlCl3) under hydrogen pressure was carried out.By using 1percent Pd-Al2O3 (1g) and the fused salt (1:1 mol ratio, 6g), 4-cyclohexyphenol (6) was obtained selectively from 1 (30g) in a yield of 31.9 percent at 120 deg C for 4.5 h.Cyclohexylphenols were formed by way of 2-cyclohexen-1-ol and 1.Keywords-hydroalkylation; palladium catalyst; fused salt; phenol; 2-cyclohexylphenol; 4-cyclohexylphenol; 2-cyclohexylcyclohexanone
- Kamiyama, Tsutomu,Enomoto, Saburo,Inoue, Masami
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p. 450 - 454
(2007/10/02)
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- Process for the selective production of dihydroxybenzenes
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The known nuclear hydroxylation of phenol or substituted phenols or phenol ethers with organic solutions of hydrogen peroxide in the presence of a catalyst is carried out in improved manner by employing both (1) a special, practically water free solution of hydrogen peroxide in an organic solvent which forms an azeotrope with water, which azeotrope boils below the boiling point of hydrogen peroxide, and (2) selenium dioxide as a catalyst. Through this, the nuclear hydroxylation is substantially simpler than previously. Besides, for the first time, it is possible to control the ortho to para ratio or the two ortho ratios to each other.
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- REACTION OF PHENOL WITH CYCLOHEXENE IN THE PRESENCE OF ALUMINUM PHENOLATE
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The reaction of phenol with cyclohexene in the presence of aluminum phenolate leads to a mixture of mono-, di-, and tricyclohexylphenols, in which the ortho-alkylation products predominate.Conditions were found (molar ratio of phenol, cyclohexene, and catalyst 1.0:2.1:0.1, temperature 200 deg C, reaction time 8 h) under which the yield of the desired product (2,6-dicyclohexylphenol) amounted to 65percent.
- Kozlikovskii, Ya. B.,Koshchii, V. A.
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p. 108 - 111
(2007/10/02)
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- REACTION OF PHENOL WITH CYCLOHEXANONE IN THE PRESENCE OF ALUMINUM PHENOLATE
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The reaction of phenol with cyclohexanone in the presence of aluminum phenolate leads to a mixture of products of ether and phenolic character and also a mixture of the dimer and trimer of the initial ketone.As a rule 1-(2-hydroxyphenyl)cyclohexene predominates in the mixture.
- Kozlikovskii, Ya. B.,Chernyaev, B. V.
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p. 1970 - 1973
(2007/10/02)
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- Synthesis and Structure-Activity Relationships among α-Adrenergic Receptor Agonists of the Phenylethanolamine Type
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Nineteen arylethanolamine derivatives related to norepinephrine were prepared and tested for α-adrenergic stimulant activity.In one series the analogues possess a p-hydroxy function, while the meta position is substituted by methyl, ethyl, isopropyl, cyclohexyl, fluoro, chloro, iodo, carboxy, carbomethoxy, and methylsulfamido groups.The other series is meta hydroxylated with the para position substituted by the same groups.The influence of these groups upon the α-adrenergic activity is discussed, and the compounds are compared to octopamine, normetanephrine,norepinephrine, and norphenylephrine.It has been found that the introduction of an isopropyl, cyclohexyl, and fluoro group in the meta position of octopamine improves its affinity by three, five, and six times, respectively, whereas when these groups are introduced in the para position of norphenylephrine their effects are always detrimental.The most active compound, α-(aminomethyl)-(4-fluoro-3-hydroxyphenyl)methanol (44), has about one-hundreth the affinity and the same intrinsic activity as norepinephrine.
- Leclerc, Gerard,Bizec, Jean Claude,Bieth, Nicole,Schwartz, Jean
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p. 738 - 744
(2007/10/02)
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- Process for the production of 2-aryl-2H-benzotriazoles
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A process for the production of 2-aryl-2H-benzotriazoles comprises reducing and cyclizing the corresponding o-nitroazobenzenes with hydrogen at a temperature in the range of about 20° C. to about 100° C. and at a pressure in the range of about 15 psia (1 atmosphere) to about 1000 psia (66 atmospheres) in an alkaline medium at a pH over 10 in the presence of a nickel catalyst, preferably molybdenum-promoted Raney nickel. High yields of pure product are obtained directly with a concomitant reduction of undesired by-product and a reduction in effluent pollution problems.
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- Process for the production of 2-aryl-2H-benzotriazoles
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A process for the production of 2-aryl-2H-benzotriazoles comprises reducing and cyclizing the corresponding o-nitroazobenzenes with carbon monoxide at a temperature in the range of about 20° C. to about 150° C. and at a pressure in the range of about 15 psia (1 atmosphere) to about 1000 psia (66 atmospheres) in an alkaline medium at a pH over 10 in the presence of a copper-amine complex catalyst. High yields of pure product are obtained with a concomitant reduction of undesired by-products and a reduction in effluent pollution problems.
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- Process for the production of 2-aryl-2H-benzotriazoles
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An improved process for the production of 2-aryl-2H-benzotriazoles by the reduction of o-nitroazobenzene intermediates with zinc in alkaline medium comprises employing a ratio of moles of alkali to moles of o-nitroazobenzene intermediate in the range of 0.2-1.7/1 in the presence of less than 150 ppm of iron based on zinc used. The improved process results in higher yields of high purity products with a concomitant reduction in the amount of undesired cleavage amine by-products and a reduction in effluent pollution problems. The process is carried out in a polar/non-polar solvent mixture.
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