- Sol-gel synthesis of ceria-zirconia-based high-entropy oxides as high-promotion catalysts for the synthesis of 1,2-diketones from aldehyde
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Efficient Lewis-acid-catalyzed direct conversion of aldehydes to 1,2-diketones in the liquid phase was enabled by using newly designed and developed ceria–zirconia-based high-entropy oxides (HEOs) as the actual catalysts. The synergistic effect of various cations incorporated in the same oxide structure (framework) was partially responsible for the efficiency of multicationic materials compared to the corresponding single-cation oxide forms. Furthermore, a clear, linear relationship between the Lewis acidity and the catalytic activity of the HEOs was observed. Due to the developed strategy, exclusively diketone-selective, recyclable, versatile heterogeneous catalytic transformation of aldehydes can be realized under mild reaction conditions.
- Dinjar, Kristijan,Djerdj, Igor,Koj?inovi?, Jelena,Kukovecz, ákos,Markovi?, Berislav,Mileti?, Aleksandar,Nagy, Sándor Balázs,Sapi, Andras,Stenzel, David,Széchenyi, Aleksandar,Szenti, Imre,Tang, Yushu,Tatar, Dalibor,Varga, Gábor,Ziegenheim, Szilveszter
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- Preparation method of acyloin compounds
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The invention relates to a preparation method of acyloin compounds, and belongs to the field of fine chemical industry. A new catalyst 1-n butyl benzimidazole hydrochloride is provided for synthesis of the acyloin compounds, and the products have the advantages of good quality and less side reactions; deficiencies existed in the prior art are overcome.
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Paragraph 0018; 0019; 0023; 0024
(2017/08/27)
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- Tandem hydroformylation/acyloin reaction - The synergy of metal catalysis and organocatalysis yielding acyloins directly from olefins
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A novel, atom efficient, orthogonal tandem catalysis was developed yielding acyloin products (α-hydroxy ketones) directly from olefins under hydroformylation conditions. The combination of a metal-catalysed hydroformylation and an organocatalysed acyloin reaction provides three atom efficient C-C bond formations to linear, multifunctional molecules via linkage of the intermediate n-aldehydes. Additionally, the rhodium catalyst system gives a high n/bra ratio with an exclusive conversion of the terminal double bond in the hydroformylation and the n-aldehydes are converted selectively to their acyloins.
- Ostrowski, Karoline A.,Fassbach, Thiemo A.,Vorholt, Andreas J.
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supporting information
p. 1374 - 1380
(2015/07/07)
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- Efficient Domino Hydroformylation/Benzoin Condensation: Highly Selective Synthesis of α-Hydroxy Ketones
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An improved domino hydroformylation/benzoin condensation to give α-hydroxy ketones has been developed. Easily available olefins are smoothly converted into the corresponding α-hydroxy ketones in high yields with excellent regioselectivities. Key to success is the use of a specific catalytic system consisting of a rhodium/phosphine complex and the CO2 adduct of an N-heterocyclic carbene. 2 for 1: An improved domino hydroformylation/benzoin condensation of olefins has been developed in the presence of a specific catalytic system consisting of a rhodium/phosphine complex and the CO2 adduct of an N-heterocyclic carbene.
- Dong, Kaiwu,Sang, Rui,Soule, Jean-Francois,Bruneau, Christian,Franke, Robert,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 18033 - 18037
(2015/12/24)
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- Synthesis of thermoregulated phase-separable triazolium ionic liquids catalysts and application for Stetter reaction
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A series of polyether-substituted triazolium ionic liquids catalysts have been first synthesized for resolving the problem of separation and reuse of Stetter catalysts. The catalysts possess the properties of critical solution temperature (CST) and inverse temperature-dependent solubility in toluene/heptane solvents. Based on these properties, the catalysts can achieve the catalytic process named as thermoregulated phase-separable catalysis (TPSC) with the characteristic of homogeneous reaction at higher temperature and phase-separation at lower temperature. The novel TPSC system has been successfully applied for Stetter reaction of furfural or butanal with ethyl acrylate. The experimental results have showed that the novel catalysts exhibit excellent TPSC with high recycling efficiency.
- Yu, Feng-Li,Zhang, Rui-Li,Xie, Cong-Xia,Yu, Shi-Tao
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experimental part
p. 9145 - 9150
(2011/01/12)
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- Polyether-substituted thiazolium ionic liquid catalysts - A thermoregulated phase-separable catalysis system for the Stetter reaction
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A series of polyether-substituted thiazolium ionic liquids have been synthesized and used as catalysts in the Stetter reaction. The ionic liquids are a thermoregulated phase-separable catalysis (TPSC) system, because they possess the properties of critical solution temperature (CST) and inverse temperature-dependent solubility in toluene-heptane. The results showed that the novel TPSC system exhibits high recycling efficiency, and provides a potential route for a environmentally benign Stetter reaction. The Royal Society of Chemistry 2010.
- Yu, Fengli,Zhang, Ruili,Xie, Congxia,Yu, Shitao
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experimental part
p. 1196 - 1200
(2010/10/20)
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- Thiazolium salt immobilized on ionic liquid: An efficient catalyst and solvent for preparation of α-hydroxyketones
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Aldehydes were efficiently converted to acyloins and benzoins using a new ionic liquid, 3-[2-(1-butyl-1H-imidazol-1,3-ium-3-yl)ethyl]-4,5-dimethyl-1,3- thiazol-3-ium dibromide 1. This ionic liquid is introduced as a catalyst and a solvent. Acyloins and benzoins were easily isolated from the reaction mixture via simple extraction, and the ionic liquid could be recycled for further use. Also, -hydroxy ketones with an aromatic and aliphatic substituent were prepared starting from aromatic and aliphatic aldehydes in the presence of ionic liquid 1.
- Mohanazadeh, Farajollah,Aghvami, Majid
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p. 2467 - 2475
(2008/02/10)
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- Product selectivity in the electroreduction of thioesters
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The electroreduction of differently substituted aromatic and aliphatic thioesters (RCOSR′) led to regioselective reactions depending on the nature of the substituents. Thus, the cleavage between the carbonyl group and the SR′ group afforded α-diketones an
- We?wer,Olivero,Du?ach
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p. 1709 - 1714
(2007/10/03)
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- Convenient preparation of metals deposited on solid supports and their use in organic synthesis
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'High-surface alkali metals' can be conveniently prepared via deposition of corresponding metals on various supports such as sodium chloride, polyethylene, polypropylene and cross-linked polystyrene from their solutions in liquid ammonia. Alkali metals deposited on polymeric supports can be stored in form of stable suspensions in inert solvents and used for the acyloin and Dieckmann condensations and for preparation of organolithiums. Addition of the suspension of supported alkali metal to a solution of zinc chloride gave an active zinc on polymeric support, which can be used for the Reformatski and Barbier reactions.
- Majkosza, Mieczyslaw,Nieczypor, Piotr,Grela, Karol
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p. 10827 - 10836
(2007/10/03)
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- Convenient Preparation of 'High-Surface Sodium' in Liquid Ammonia: Use in the Acyloin Reaction
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'Sodium on solid support' (5-20 wt.% of Na on NaCl, glass powder, poly(ethylene) and poly(propylene)) can be conveniently prepared via low-temperature (-33°C) deposition of sodium from its solution in liquid ammonia. Use of this reagent in the acyloin reaction of carboxylic esters gave the corresponding products in good yields.
- Makosza, Mieczyslaw,Grela, Karol
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p. 267 - 268
(2007/10/03)
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- Carbonylation of dialkylcyanocuprates with carbon monoxide: Synthesis of α-hydroxyketones
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Dialkylcyanocuprates, prepared from copper(I) cyanide and the corresponding alkyllithium or Gringard reagents, readily react with carbon monoxide in the presence of tri-n-butylphosphine at -78°C in THF to give α-hydroxyketones in high yields (65-85%).
- Kabalka, George W.,Li, Nan-Sheng,Yu, Su
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p. 2203 - 2206
(2007/10/03)
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- Diastereoselective reduction of acyclic hydroxyketones and diketones with an indium hydride reagent
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Hydroxyketones and diketones have been reduced with lithium indium hydride to give meso-diols selectively. α-Hydroxyketones and α-diketones are reduced to meso-1,2-diols with high diastereoselectivities, whereas the selectivities of β-hydroxyketones and β-diketones are less satisfactory.
- Yamada, Masafumi,Horie, Tomoaki,Kawai, Masao,Yamamura, Hatsuo,Araki, Shuki
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p. 15685 - 15690
(2007/10/03)
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- Oxidation of Alkynes by Hydrogen Peroxide Catalyzed by Methylrhenium Trioxide
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The oxidation of alkynes with hydrogen peroxide is catalyzed by methylrhenium tioxide.The reactions can be rationalized by postulating that an oxirene intermediate is formed between a rhenium peroxide and the alkyne.Internal alkynes yield α-diketones and carboxylic acids, the latter from the complete cleavage of the triple bonds.Rearrangement products were observed only for aliphatic alkynes.Terminal alkynes gave carboxylic acids and their derivatives and α-keto acids as the major products, but their yields varied with the solvent used.
- Zhu, Zuolin,Espenson, James H.
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p. 7728 - 7732
(2007/10/03)
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- Synthesis and antithyroid activity of 1,4,5-trialkyl 2-thioimidazole derivatives
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A series of compounds based on the structure of MTI (1-methyl-2-thioimidazole) were synthesized by condensation of α-hydroxyketones and alkylthioureas. The α-hydroxyketones were obtained by a radical reaction in the presence of sodium and the alkyl ester, while the alkylthioureas were prepared by nucleophilic addition of ammonia on an alkylisothiocyanate. The antithyroid activity of the 13 compounds prepared was evaluated in vitro by determination of the concentrations which led to a 50% inhibition (IC50) of the activity of thyroid peroxidase, and in vivo by assay of thyroid hormones levels and histological examination of the thyroid gland in rats treated chronically with the compounds. 1-methyl-4,5-dipropyl 2-thioimidazole (compound 10) was found to have the highest antithyroid activity of the 13 compounds synthesized.
- Fatimi,Lagorce,Chabernaud,Comby,Buxeraud,Raby
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p. 253 - 257
(2007/10/02)
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- Synthesis and inhibitory effects of 1,4,5-trialkyl-2-thioimidazole derivatives on platelet aggregation
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New 1,4,5-trialkyl-2-thioimidazole have been synthesized by the condensation of α-hydroxyketones and alkylthioureas. The in vitro platelet aggregation inhibiting effect of prepared compounds on human platelets was studied in the presence of ADP and collagen as inducers. The formation of thromboxane B2 (TXB2) was inhibited. 1-isopropyl-4,5-dimethyl-2-thioimidazole has the greatest aggregation inhibiting effect, about 4 times that of aspirin. It highly inhibits the production of TXB2 (68,5% for a final concentration of 0,04 M).
- Fatimi,Lagorce,Chabernaud,Buxeraud,Raby
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p. 151 - 155
(2007/10/02)
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- Catalytic action of azolium salts. VI. Preparation of benzoins and acyloins by condensation of aldehydes catalyzed by azolium salts
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Benzoins 4 (2-hydroxyethanones substituted with aryl groups at the 1- and 2-positions) were prepared by self-condensation of aromatic aldehydes 3 using catalytic amounts of azolium salts 1 and 2 in excellent yields. 1,3-Dimethylbenzimidazolium iodide (2) was an effective catalyst for the preparation of acyloins 6 (2-hydroxyethanones substituted with alkyl groups at the 1- and 2-positions) by self-condensation of aliphatic aldehydes 5. On the other hand, an attempt at the condensation of hexanal (5d) catalyzed by 1,3-dimethylimidazolium iodide (1) failed to yield the acyloin 6d, and instead the aldol-type condensed product 8d was obtained.
- Miyashita,Suzuki,Iwamoto,Higashino
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p. 2633 - 2635
(2007/10/02)
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- Process for producing α-hydroxyketones
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A process for producing an α-hydroxyketone represented by formula (I): STR1 wherein R1 represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or an alkoxycarbonyl group; and R2 and R3 each represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aralkyl group, provided that they do not simultaneously represent a hydrogen atom; or a pair of R1 and R2, a pair of R1 and R3, or a pair of R2 and R3 is taken together to form a ring; and the pair of R1 and R2 and the pair of R2 and R3 may form a ring simultaneously, is disclosed, comprising reacting a compound represented by formula (II): STR2 wherein R1, R2, and R3 are as defined above, with an oxidizing agent in the presence of a ruthenium compound and water. α-Hydroxyketones useful as physiologically active substances are produced with good selectivity and in high yield.
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- Direct Catalytic Transformation of Olefins into α-Hydroxy Ketones with Hydrogen Peroxide Catalyzed by Peroxotungstophosphate
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Aliphatic olefins were directly converted into α-hydroxy ketones with acidic aqueous hydrogen peroxide in the presence of catalytic amount of peroxytungstophosphate (PCWP) under the biphasic system using chloroform as a solvent.The acidic medium was necessary to open the resulting epoxide to vic-diol which was subsequently oxidized to α-hydroxy ketones.
- Sakata, Yasuyuki,Katayama, Yuji,Ishii, Yasutaka
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p. 671 - 674
(2007/10/02)
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- AZO ANIONS IN SYNTHESIS. PT 1. t-BUTYLHYDRAZONES AS ACYL-ANION EQUIVALENTS
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The lithium salts of aldehyde t-butylhydrazones react with electrophiles (aldehydes, ketones, alkyl halides, crotonates) to form C-trapped t-butylazo-compounds; tautomerisation and hydrolysis gave α-hydroxy ketones, ketones, and γ-keto esters in good yield, thereby providing a convenient new acyl-anion equivalent.Reaction of these lithium salts with aldehydes and ketones, followed by elimination provided a new route to azo alkenes.
- Baldwin, Jack E.,Adlington, Robert M.,Bottaro, Jeffrey C.,Kolhe, Jayant N.,Perry, Matthew W. D.,Jain, Ashok U.
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p. 4223 - 4234
(2007/10/02)
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- THE BEHAVIOUR OF DISUBSTITUTED ALKYNES WITH VARIOUS METAL ION ACETATES
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4-Octyne and diphenylethyne have been treated with some metal ion acetates in methanol and in acetic acid.From this systematic investigation, it appeares that the metal ions play a major role in directing the course of the reaction.The function of the metal is not predictable, since no general trend has been observed.Mercuric acetate was by and large the best reagent for the reaction with alkynes, quantitatively transforming these substrates into vinyl ethers, ketones, and dimethylketals.The reaction was faster in methanol than in acetic acid, and 4-octyne resulted more reactive than diphenylethyne.
- Bassetti, Mauro,Floris, Barbara
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p. 595 - 598
(2007/10/02)
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- Application of Polymer-Bound Thiazolium Salts to the Synthesis of Acyloins and Benzoins: Effects of Solvent and Substituents of the Thiazolium Nucleus
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Covalent immobilization of the thiazole nucleus on a chloromethylated polystyrene copolymer results in the formation of a catalytically active thiazolium salt, capable of repeated acyloin and benzoin condensations.The nature of the solvent and the substituents on the thiazolium nucleus has been found to have marked effects of the rate of catalysis.
- Karimian, Khashayar,Mohanazadeh, Farajolah,Rezai, Shaheen
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p. 1119 - 1122
(2007/10/02)
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- Azo Anions in Synthesis. t-Butylhydrazones as Acyl-anion Equivalents
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The lithium salts of aldehyde t-butylhydrazones react with electrophiles (aldehydes, ketones, alkyl halides) to form C-trapped t-butylazo compounds; isomerisation and hydrolyse gave α-hydroxy ketones and ketones in good yields, thereby providing a convenient new acyl-anion equivalent.
- Adlington, Robert M.,Baldwin, Jack E.,Bottaro, Jeffrey C.,Perry, Matthew W. D.
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p. 1040 - 1041
(2007/10/02)
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- Photochimie en solution. XXIV. Mecanisme de l'addition des aldehydes aux double liaisons ethyleniques activees par des groupements attracteurs d'electrons
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The mechanism of the photochemical addition of aliphatic aldehydes to electron-deficient olefins has been rationalized.No addition to α,β-unsaturated ketones was observed when the latter were excited.The reaction can be explained by a first self-quenching step of the aliphatic aldehyde involving its lowest triplet state, which is reached with a moderate quantum yield (0.5).The radical R-C.=O produced in the self quenching process adds to the olefin at the more positively-charged carbon atom.The reaction ends by a hydrogen atom exchange between the radical produced by this addition and the radical R-C.HOH.The quantum yield of the product formation is much higher with benzaldehyde owing to the almost unity value of the intersystem crossing, but it competes with the formation of benzile.
- Kawenoki, Isabelle,Maurel, Daniele,Kossanyi, Jean
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p. 385 - 390
(2007/10/02)
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- Photochemistry in solution-XX. Triplet reactivity of aliphatic aldehydes
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The triplet self-quenching process of three aliphatic aldehydes has been investigated by inhibition with dienes (taking into account the singlet interaction with the dienes) and by laser flash photolysis. The results obtained for intersystem crossing, the setf-quenching process and product formation have been rationalized. The main reactivity observed for the three aldehydes is the self-quenching process which occurs from both the singlet and triplet state. The laser flash photolysis experiments carried out with butanal show two absorptions of a transient at 320 aod 355 nm; no evidence for two different species could be put forward. The similar decay of the two absorption maximas of the transient, as the concentration of aldehyde is increased, would be indicative of only one single absorbing species which could be either the triplet state of the aldehyde or a radical-pair formed by the self-quenching process or the 1,4-biradical resulting from γ-H abstraction. The fact that both the quenching experiments (by dienes or by 1-methylnaphthalene) and the laser flash measurements lead to about the same lifetime also indicates only one species. The products formed from the triplet setf-quenching process have also been obtained by a different method: excitation of benzophenone at 365 nm in the presence of butanal. The quantum yields for product formation is about the same as those obtained for the triplet by direct irradiation of butanal, except that of octane-4,5-dione which is increased if the photoreaction is carried out at 365 nm in the presence of beazophenone.
- Kossanyi,Sabbah,Chaquin,Ronfart-Haret
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p. 3307 - 3315
(2007/10/02)
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