- Resonating valence bond and σ-charge density wave phases in a benzannulated phenalenyl radical
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We report the preparation of the first benzannulated phenalenyl neutral radical conductor (18), and we show that the compound displays unprecedented solid state behavior: the structure is dominated by two sets of intermolecular interactions: (1) a π-chain
- Bag, Pradip,Itkis, Mikhail E.,Pal, Sushanta K.,Donnadieu, Bruno,Tham, Fook S.,Park, Hyunsoo,Schlueter, John A.,Sieghst, Theo,Haddon, Robert C.
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Read Online
- STRONGLY LEWIS ACIDIC METAL-ORGANIC FRAMEWORKS FOR CONTINUOUS FLOW CATALYSIS
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Lewis acidic metal-organic framework (MOF) materials comprising triflate-coordinated metal nodes are described. The materials can be used as heterogenous catalysts in a wide range of organic group transformations, including Diels-Alder reactions, epoxide-ring opening reactions, Friedel-Crafts acylation reactions and alkene hydroalkoxylation reactions. The MOFs can also be prepared with metallated organic bridging ligands to provide heterogenous catalysts for tandem reactions and/or prepared as composites with support particles for use in columns of continuous flow reactor systems. Methods of preparing and using the MOF materials and their composites are also described.
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Paragraph 0216-0219; 0225; 0239; 0255
(2021/02/26)
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- Strongly Lewis Acidic Metal-Organic Frameworks for Continuous Flow Catalysis
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The synthesis of highly acidic metal-organic frameworks (MOFs) has attracted significant research interest in recent years. We report here the design of a strongly Lewis acidic MOF, ZrOTf-BTC, through two-step transformation of MOF-808 (Zr-BTC) secondary building units (SBUs). Zr-BTC was first treated with 1 M hydrochloric acid solution to afford ZrOH-BTC by replacing each bridging formate group with a pair of hydroxide and water groups. The resultant ZrOH-BTC was further treated with trimethylsilyl triflate (Me3SiOTf) to afford ZrOTf-BTC by taking advantage of the oxophilicity of the Me3Si group. Electron paramagnetic resonance spectra of Zr-bound superoxide and fluorescence spectra of Zr-bound N-methylacridone provided a quantitative measurement of Lewis acidity of ZrOTf-BTC with an energy splitting (?E) of 0.99 eV between the ?x? and ?y? orbitals, which is competitive to the homogeneous benchmark Sc(OTf)3. ZrOTf-BTC was shown to be a highly active solid Lewis acid catalyst for a broad range of important organic transformations under mild conditions, including Diels-Alder reaction, epoxide ring-opening reaction, Friedel-Crafts acylation, and alkene hydroalkoxylation reaction. The MOF catalyst outperformed Sc(OTf)3 in terms of both catalytic activity and catalyst lifetime. Moreover, we developed a ZrOTf-BTC?SiO2 composite as an efficient solid Lewis acid catalyst for continuous flow catalysis. The Zr centers in ZrOTf-BTC?SiO2 feature identical coordination environment to ZrOTf-BTC based on spectroscopic evidence. ZrOTf-BTC?SiO2 displayed exceptionally high turnover numbers (TONs) of 1700 for Diels-Alder reaction, 2700 for epoxide ring-opening reaction, and 326 for Friedel-Crafts acylation under flow conditions. We have thus created strongly Lewis acidic sites in MOFs via triflation and constructed the MOF?SiO2 composite for continuous flow catalysis of important organic transformations.
- Ji, Pengfei,Feng, Xuanyu,Oliveres, Pau,Li, Zhe,Murakami, Akiko,Wang, Cheng,Lin, Wenbin
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supporting information
p. 14878 - 14888
(2019/10/02)
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- Arylation of Aldehydes to Directly Form Ketones via Tandem Nickel Catalysis
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A nickel-catalyzed arylation of both aliphatic and aromatic aldehydes proceeds with air-stable (hetero)arylboronic acids, with an exceptionally wide substrate scope. The neutral condition tolerates acidic hydrogen and sensitive polar groups and also preserves α-stereocenters of some chiral aldehydes. Interestingly, this nickel(0) catalysis does not follow common 1,2-insertion of arylmetal species to aldehydes and β-hydrogen elimination.
- Lei, Chuanhu,Zhu, Daoyong,Tangcueco, Vicente Iii Tiu,Zhou, Jianrong Steve
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supporting information
p. 5817 - 5822
(2019/08/26)
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- Hydrogen bond donor solvents enabled metal and halogen-free Friedel–Crafts acylations with virtually no waste stream
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We have developed a metal and halogen-free Friedel–Crafts acylation protocol with virtually no waste stream generation. We propose a hydrogen bonding donor solvent will form a hydrogen bonding network and may provide significant rate enhancement for Friedel–Crafts reactions. Trifluoroacetic acid is one of the strongest H-bond donor solvents, which is also volatile and can be easily recovered by distillation without need for reaction workup. Our protocol is a ‘green’ Friedel–Crafts acylation process: 1) the catalyst can be recovered and reused; 2) using halogen free starting material (carboxylic acids anhydride or carboxylic acids); 3) no need for aqueous reaction work-up; 4) minimum or no waste steam generation.
- Liu, Guangchang,Xu, Bo
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supporting information
p. 869 - 872
(2018/02/09)
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- Metal-free oxidation of alcohols to their corresponding carbonyl compounds using NH4NO3/Silica sulfuric acid
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A metal-free and efficient procedure for the oxidation of alcohols into the corresponding carbonyl compounds has been described using ammonium nitrate in the presence of silica sulfuric acid under mild and heterogeneous conditions. The use of non-toxic and inexpensive materials, simple and clean work-up, short reaction times and good yields of the products are among the advantages of this method.
- Zarei, Amin
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experimental part
p. 2149 - 2155
(2012/08/29)
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- Polyaniline-supported zinc oxide (ZnO) nanoparticles: An active and stable heterogeneous catalyst for the Friedel-Crafts acylation reaction
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We report herein the synthesis of zinc oxide (ZnO) nanoparticles incorporating a polyaniline (PANI) matrix in aqueous medium and its catalytic performance toward Friedel-Crafts acylation reactions. The acylation reactions demonstrate that polyaniline/ nano-ZnO composites are very active catalysts and are able to activate the reactant at ambient temperature. The obtained nanocatalyst was characterized by Fourier transform-infrared, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller, X-ray diffraction, and particle-size analysis techniques. The catalyst was reusable for five cycles without appreciable loss in activity. Copyright Taylor & Francis Group, LLC.
- Rezaei, Seyed Jamal Tabatabaei,Nabid, Mohammad Reza,Hosseini, Seyedeh Zahra,Abedi, Mahvash
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experimental part
p. 1432 - 1444
(2012/04/17)
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- Friedel-crafts acylation of arenes with carboxylic acids using polystyrene-supported aluminum triflate
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Cross-linked polystyrene-supported aluminum triflate (Ps-Al(OTf) 3) has been shown to be a mild, efficient, and chemoselective heterogeneous Lewis acid catalyst for the acylation of aromatic compounds. The catalyst can be easily prepared from cheap starting materials, is stable (as a bench top catalyst) and is reusable.
- Boroujeni, Kaveh Parvanak,Parvanak, Kamran
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experimental part
p. 155 - 163
(2012/01/02)
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- Friedel-Crafts acylation of arenes with carboxylic acids using silica gel supported AlCl3
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Aromatic compounds react smoothly with carboxylic acids in the presence of silica gel supported aluminium trichloride to afford the corresponding ketones with high regioselectivity in high to excellent yields. The catalyst is stable (as a bench top catalyst) and can be easily recovered and reused without appreciable change in its efficiency. tuebitak.
- Parvanak Boroujeni, Kaveh
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experimental part
p. 621 - 630
(2010/11/04)
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- Polystyrene supported Al(OTf)3: An environmentally friendly heterogeneous catalyst for Friedel-Crafts acylation of aromatic compounds
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Stable and non-hygroscopic polystyrene supported aluminium triflate (Ps-Al(OTf)3), which is prepared easily from cheap and commercially available compounds was found to be an environmentally friendly heterogeneous catalyst for Friedel-Crafts acylation of arenes using acid chlorides in the absence of solvent under mild reaction conditions. The catalyst can be reused up to five times after simple washing with dichloromethane.
- Boroujeni, Kaveh Parvanak
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experimental part
p. 3156 - 3158
(2012/05/20)
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- Anti-influenza drug discovery: Structure-activity relationship and mechanistic insight into novel angelicin derivatives
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By using a cell-based high throughput screening campaign, a novel angelicin derivative 6a was identified to inhibit influenza A. (H1N1) virus induced cytopathic effect in Madin-Darby canine kidney cell culture in low micromolar range. Detailed structure-activity relationship studies of 6a revealed that the angelicin scaffold is essential for activity in pharmacophore B, while meta-substituted phenyl/2-thiophene rings are optimal in pharmacophore A and C. The optimized lead 4-methyl-9-phenyl-8-(thiophene-2-carbonyl)-furo[2,3-h] chromen-2-one (8g, IC50 = 70 nM) showed 64-fold enhanced activity compared to the high throughput screening (HTS) hit 6a. Also, 8g was found effective in case of influenza A (H3N2) and influenza B virus strains similar to approved anti-influenza drug zanamivir (4). Preliminary mechanistic studies suggest that these compounds act as anti-influenza agents by inhibiting ribonucleoprotein (RNP) complex associated activity and have the potential to be developed further, which could form the basis for developing additional defense against influenza pandemics.
- Yeh, Jiann-Yih,Coumar, Mohane Selvaraj,Horng, Jim-Tong,Shiao, Hui-Yi,Kuo, Fu-Ming,Lee, Hui-Ling,Chen, In-Chun,Chang, Chun-Wei,Tang, Wen-Fang,Tseng, Sung-Nain,Chen, Chi-Jene,Shih, Shin-Ru,Hsu, John T.-A.,Liao, Chun-Chen,Chao, Yu-Sheng,Hsieh, Hsing-Pang
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experimental part
p. 1519 - 1533
(2010/08/20)
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- Simple and efficient procedure for the friedel-crafts acylation of aromatic compounds with carboxylic acids in the presence of P2O5/AL2O3 under heterogeneous conditions
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An efficient and chemoselective method for the Friedel-Crafts acylation of aromatic compounds using P2O5/Al2O3 and carboxylic acids. Both aromatic and aliphatic carboxylic acids reacted easily to afford the corresponding aromatic ketones in good yields.
- Hajipour, Abdol R.,Zarei, Amin,Khazdooz, Leila,Ruoho, Arnold E.
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experimental part
p. 2702 - 2722
(2009/12/06)
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- Friedel-Crafts acylation of aromatic compounds with carboxylic acids in the presence of P2O5/SiO2 under heterogeneous conditions
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A convenient and efficient procedure for the Friedel-Crafts acylation of aromatic compounds with carboxylic acids in the presence of P2O5/SiO2 is described. Both aromatic and aliphatic carboxylic acids reacted easily to afford the corresponding aromatic ketones. The use of non-toxic and inexpensive materials, simple and clean work-up, short reaction times and good yields of the products are the advantages of this method.
- Zarei, Amin,Hajipour, Abdol R.,Khazdooz, Leila
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scheme or table
p. 6715 - 6719
(2009/04/07)
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- An efficient method for aromatic Friedel-Crafts acylation reactions
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Friedel-Crafts acylation of aromatic compounds was carried out using FeCl3-based ionic liquid. This liquid serves as an efficient media as well as a Lewis acid catalyst. The significant advantages of this methodology are excellent yields, short reaction times, mild reaction conditions, environmentally friendly method, simple work-up procedure, low cost, and easy preparation and handling of the catalyst. Copyright
- Khodaei, Mohammad Mehdi,Bahrami, Kiumars,Shahbazi, Fomeida
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p. 844 - 845
(2008/12/22)
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- Tf2O as a rapid and efficient promoter for the dehydrative Friedel-Crafts acylation of aromatic compounds with carboxylic acids
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The Friedel-Crafts acylation of aromatic compounds with carboxylic acids was investigated in the presence of Tf2O. The reaction was carried out efficiently and very rapidly under mild reaction conditions without the need of any catalyst.
- Khodaei, Mohammd Mehdi,Alizadeh, Abdolhamid,Nazari, Ehsan
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p. 4199 - 4202
(2008/02/05)
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- Acylation of naphthalenes and anthracene on sulfated zirconia
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Sulfated zirconia (SZ) exhibits a high catalytic performance in the benzoylation of 1-methoxynaphthalene. Therefore, it was used as heterogeneous catalyst in the acylation of methoxynaphthalenes, methylnaphthalenes, naphthalene, and anthracene with benzoic anhydride, benzoyl chloride, and acetic anhydride to synthesize aromatic ketones. The rate of product formation on SZ was dependent on the respective aromatic, on the solvent used, and on the ratio of aromatic to acylating agent.
- Deutsch,Prescott,Mueller,Kemnitz,Lieske
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p. 269 - 278
(2007/10/03)
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- Aluminum dodecatungstophosphate (AlPW12O40) as a non-hygroscopic Lewis acid catalyst for the efficient Friedel-Crafts acylation of aromatic compounds under solvent-less conditions
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Stable and non-hygroscopic aluminum dodecatungstophosphate (AlPW 12O40), which is prepared easily from cheap and commercially available compounds was found to be an effective catalyst for Friedel-Crafts acylation reactions using carboxylic acids, acetic anhydride and benzoyl chloride in the absence of solvent under mild reaction conditions.
- Firouzabadi, Habib,Iranpoor, Nasser,Nowrouzi, Farhad
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p. 10843 - 10850
(2007/10/03)
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- Reactions on a solid surface. A simple, economical and efficient Friedel-Crafts acylation reaction over zinc oxide (ZnO) as a new catalyst
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Zinc oxide (ZnO) brings about a rapid Friedel-Crafts acylation of a range of activated and unactivated aromatic compounds such as anisole and chlorobenzene with acid chlorides in solvent-free conditions at room temperature. The ZnO powder can be reused up to three times after simple washing with dichloromethane.
- Sarvari, Mona Hosseini,Sharghi, Hashem
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p. 6953 - 6956
(2007/10/03)
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- Solvent-free Friedel-Crafts acylation of aromatic compounds with carboxylic acids in the presence of trifluoroacetic anhydride and aluminum dodecatungstophosphate
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The stable and non-hygroscopic aluminum dodecatungstophosphate (AlPW12O40), was found to be an effective catalyst (3 mol%) for the solvent-free Friedel-Crafts acylation of aromatic compounds with carboxylic acids in the presence of trifluoroacetic anhydride under mild reaction conditions.
- Firouzabadi, Habib,Iranpoor, Nasser,Nowrouzi, Farhad
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p. 5343 - 5345
(2007/10/03)
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- Method for acylation or sulphonylation of an aromatic compound
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The present invention relates to a process for the acylation or sulphonylation of an aromatic compound. More particularly, the invention relates to a process for the acylation or sulphonylation of an activated or deactivated aromatic compound. The invention is applied to the preparation of aromatic ketones or sulphones. The process for the acylation or sulphonylation of an aromatic compound which consists in reacting at least one aromatic compound with an acylating or sulphonylating agent, in the presence of a Friedel-Crafts catalyst is characterized in that the acylation or sulphonylation reaction is carried out in liquid phase under microwave irradiation.
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Page column 22,23
(2008/06/13)
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- Acylation of aromatic compounds using moisture insensitive InCl3 impregnated mesoporous Si-MCM-41 catalyst
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Acylation of aromatic compounds (benzene, toluene, p-xylene, mesitylene, anisole, naphthalene, methylnaphthalene and methoxynaphthalene) by an acyl chloride (benzoyl chloride, phenylacetyl chloride, propionyl chloride or butyryl chloride) in high yield, in a short reaction period (3 h), even in the presence of moisture in the aromatic substrate or solvent (dichloroethane), can be accomplished at low temperature (80±1°C) using an InCl3 impregnated Si-MCM-41 catalyst in low catalyst concentration.
- Choudhary, Vasant R.,Jana, Suman K.,Patil, Nilesh S.
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p. 1105 - 1107
(2007/10/03)
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- Acylation of aromatic compounds using moisture insensitive mesoporous Si-MCM-41 supported Ga2O3 catalyst
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Mesoporous Si-MCM-41 supported Ga2O3 is a highly active catalyst for the acylation of aromatic compounds with different acyl chlorides. Moreover, this catalyst is not deactivated by water and hence does not require moisture-free reaction conditions.
- Choudhary, Vasant R.,Jana, Suman K.
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p. 2843 - 2848
(2007/10/03)
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- Regiospecific acylations of aromatics and selective reductions of azobenzenes over hydrated zirconia
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Hydrated zirconia has been found to be an efficient and reusable catalyst for the regiospecific acylations of arenes and selective reductions of azobenzenes to produce benzophenones and hydrazabenzenes respectively.
- Patil,Jnaneshwara,Sabde,Dongare,Sudalai,Deshpande
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p. 2137 - 2140
(2007/10/03)
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- Acylation of 2-Methoxynaphthalene with Acyl Clorides in the Presence of a Catalytic Amount of Lewis Acids
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The regiochemistry of the reaction of 2-methoxynaphthalene 1 with benzoyl chloride 2a using a catalytic amount of Lewis acid is strongly influenced by the identity of the acid catalyst employed as well as by the reaction temperature.By using InCl3, FeCl3, SnCl4 or ZnCl2 and heating at 160 deg C, 2-benzoyl-6-methoxynaphthalene 4a is selectively produced along with 1-benzoyl-7-methoxynaphthalene 5a, while in the case of AlCl3, SbCl5 or TiCl4, 1-benzoyl-2-methoxynaphthalene 3a is the major product. 2-Acyl-6-methoxynaphthalenes 4b-e can be selectively obtained using InCl3 and the corresponding acyl chlorides 2b-e in place of 2a.In the presence of a stoichiometric amount of InCl3, the reaction of 1 with 2a also gives 4a as the predominant product along with 5a even at 50 deg C.This reaction appears to involve isomerisation of 3a to 4a and 5a.
- Pivsa-Art, Sommai,Okuro, Kazumi,Miura, Masahiro,Murata, Satoru,Nomura, Masakatsu
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p. 1703 - 1708
(2007/10/02)
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