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Search for "tosylate" in Full Text gives 126 result(s) in Beilstein Journal of Organic Chemistry.

Synthesis of imidazo[1,5-a]pyridines via cyclocondensation of 2-(aminomethyl)pyridines with electrophilically activated nitroalkanes

  • Dmitrii A. Aksenov,
  • Nikolai A. Arutiunov,
  • Vladimir V. Maliuga,
  • Alexander V. Aksenov and
  • Michael Rubin

Beilstein J. Org. Chem. 2020, 16, 2903–2910, doi:10.3762/bjoc.16.239

Graphical Abstract
  • , 1466, 1436, 1423, 1273, 1208, 1129, 1069 cm−1; HRESIMS (TOF) m/z: [M + H]+ calcd for C12H10BrN2O, 276.9971; found, 276.9974. Biologically active imidazo[1,5-a]pyridines. Activation of nitroalkanes towards nucleophilic attack by amines. Mechanistic rationale. Reaction of the N-tosylate 17 with
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Published 26 Nov 2020

Syntheses of spliceostatins and thailanstatins: a review

  • William A. Donaldson

Beilstein J. Org. Chem. 2020, 16, 1991–2006, doi:10.3762/bjoc.16.166

Graphical Abstract
  • -methyl-3-buten-1-yl tosylate in the presence of Grubbs’ 2nd generation catalyst yielded 59, which, upon elimination with potassium tert-butoxide led to the diene 50. The reductive amination of 50 afforded an inseparable mixture of the C-14 amines (6:1 ratio). However, the amidation of this mixture with
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Published 13 Aug 2020

Facile synthesis of 7-alkyl-1,2,3,4-tetrahydro-1,8-naphthyridines as arginine mimetics using a Horner–Wadsworth–Emmons-based approach

  • Rhys A. Lippa,
  • John A. Murphy and
  • Tim N. Barrett

Beilstein J. Org. Chem. 2020, 16, 1617–1626, doi:10.3762/bjoc.16.134

Graphical Abstract
  • available iodide 29. The formation of compound 30 proceeded in 21% yield, with alcohol 31 and dimer 32 also formed in 20% and 5% yield, respectively (Scheme 9). Indeed, when iodide 29 was replaced with bromide 33 and tosylate 34 no formation of compound 30 was observed, with alcohol 31 and dimer 32
  • formation of dimer 28. Conditions: KOt-Bu, THF, 1 h, 68% yield. Alkylation of phosphoramidate 13 by iodide 29 to afford compound 30 and byproducts alcohol 31 and dimer 32. Use of bromide 33 or tosylate 34 afforded only compounds 31 and 32. Conditions: (i) s-BuLi (1.3 equiv), iodide 29, THF, −78 °C, 30 min
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Published 08 Jul 2020

Recent synthesis of thietanes

  • Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

Graphical Abstract
  • ring-opening followed by an intramolecular substitution to afford chiral thietane 175 [61]. 2.2.6 Synthesis via the nucleophilic ring-opening of three-membered heterocycles and subsequent displacement from aziridine-2-methyl tosylate: (1R,2S,6R)-6-Methyl-7-tosyl-7-azabicyclo[4.1.0]heptan-2-yl tosylate
  • (179) is a derivative of aziridine-2-methyl tosylate. After the ring-opening with ammonium tetrathiomolybdate and subsequent intramolecular cyclization, the compound was converted into a bridged thietane 183 in 75% yield. The results indicated that, in the ring-opening step, tetrathiomolybdate
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Published 22 Jun 2020

Recent advances in Cu-catalyzed C(sp3)–Si and C(sp3)–B bond formation

  • Balaram S. Takale,
  • Ruchita R. Thakore,
  • Elham Etemadi-Davan and
  • Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

Graphical Abstract
  • an attempt to determine the existence of radical behavior of PhMe2Si-MgMe (2), they studied the reaction of this Grignard reagent with dodecyl tosylate (1, X = OTs), which led to the formation of dodecyl silane 3 (20%) along with tridecane 4 (3%) and dodecane 5 (36%). Similarly, dodecyl bromide (1, X
  • the Oestreich group in 2016 [27]. The reaction could be performed using CuCN as catalyst in the absence of a ligand. A wide variety of triflates 9, including some containing a remote tosylate, bromide, alkene, or alkyne functionality, afforded the desired alkylsilanes 10–16 in fair to good yields
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Published 15 Apr 2020

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

  • Bernd Strehmel,
  • Christian Schmitz,
  • Ceren Kütahya,
  • Yulian Pang,
  • Anke Drewitz and
  • Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

Graphical Abstract
  • anions promoting the solubility in organic surroundings. Representative anions in the case of cationic absorbers relate to tosylate [5], [n-C12H25-Ph-SO3−] [5], FAP ([(C2F5)3PF3]−)[71], NTf2 ([(CF3SO2)2N]−) [5] or aluminates ([Al(t-C4F9O)4]−) [6] – just to count a few possible examples. Thus, replacement
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Published 18 Mar 2020

Architecture and synthesis of P,N-heterocyclic phosphine ligands

  • Wisdom A. Munzeiwa,
  • Bernard Omondi and
  • Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

Graphical Abstract
  • chiral acetal ligands have been reported by Lyle et al. where the fluorine–metal exchange was achieved by treatment with potassium tert-butoxide for a relatively long period (24 h) (Scheme 4) [65]. Acid-catalyzed condensation of compound 20 with enantiomerically pure C2-symmetric 1,2-tosylate analogs 21
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Published 12 Mar 2020

Oligomeric ricinoleic acid preparation promoted by an efficient and recoverable Brønsted acidic ionic liquid

  • Fei You,
  • Xing He,
  • Song Gao,
  • Hong-Ru Li and
  • Liang-Nian He

Beilstein J. Org. Chem. 2020, 16, 351–361, doi:10.3762/bjoc.16.34

Graphical Abstract
  • designable structure, tunable properties as well as superior solubility [26][27]. Furthermore, the thermal stability and negligible vapor pressure of ILs can facilitate the product separation after reaction. To the best of our knowledge, the IL 1-butylsulfonic-3-methylimidazolium tosylate ([HSO3-BMim]TS) can
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Published 10 Mar 2020

A chiral self-sorting photoresponsive coordination cage based on overcrowded alkenes

  • Constantin Stuckhardt,
  • Diederik Roke,
  • Wojciech Danowski,
  • Edwin Otten,
  • Sander J. Wezenberg and
  • Ben L. Feringa

Beilstein J. Org. Chem. 2019, 15, 2767–2773, doi:10.3762/bjoc.15.268

Graphical Abstract
  • formed revealing that a chiral self-sorting process takes place. In addition, two of the cage isomers can bind a tosylate anion in solution by formation of a host–guest complex. Results and Discussion Ligands Z-1 and E-1 (Scheme 1) were synthesized by a Suzuki cross-coupling reaction of 3
  • -sorting. Next, we were interested in the guest binding abilities of cages Pd2(stable Z-1)4 and Pd2(stable E-1)4. The tosylate anion was chosen as it has the appropriate size to fit inside the cages. A Job plot analysis revealed a 1:1 binding stoichiometry between both cage isomers and OTs− (Figures S3–S5
  • , Supporting Information File 1), which corresponds to the model in which OTs− serves as a guest molecule which is encapsulated inside the cages [55][56]. 1H NMR titrations with tetrabutylammonium tosylate revealed that both cages are able to bind OTs−, showing similar binding strengths (KB = 1604 ± 39 M−1 for
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Published 15 Nov 2019

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

  • Iwona E. Głowacka,
  • Aleksandra Trocha,
  • Andrzej E. Wróblewski and
  • Dorota G. Piotrowska

Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168

Graphical Abstract
  • )-7 (Scheme 6) which was found to be an effective inhibitor of the mitotic kinesin. The biologically active enantiomer of mexiletine (R)-24 was efficiently synthesized from the alcohol (2R,1'R)-7 (Scheme 7) [45]. When the respective tosylate (2R,1'R)-25 was treated with 2,6-dimethylphenoxide two
  • )-24 was obtained. On the other hand, alkylation of 2,6-dimethylphenol with the tosylate (2S,1'R)-25 proceeded regioselectively to give (2S,1'R)-26, a precursor to (S)-24. (−)-Cathinone ((S)-27) is an alkaloid acting as a central nervous system stimulant found in leaves of Catha edulis. It was
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Published 23 Jul 2019

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

  • Gagandeep Kour Reen,
  • Ashok Kumar and
  • Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

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Published 19 Jul 2019

An improved synthesis of adefovir and related analogues

  • David J. Jones,
  • Eileen M. O’Leary and
  • Timothy P. O’Sullivan

Beilstein J. Org. Chem. 2019, 15, 801–810, doi:10.3762/bjoc.15.77

Graphical Abstract
  • form alcohol 4 and further base-mediated alkylation with tosylate 5 affords phosphonate ester intermediate 6. Subsequent dealkylation of 6 using trimethylsilyl bromide (TMSBr) gives adefovir (1). The related analogue tenofovir, developed as an anti-HIV agent, may be prepared in a similar manner [37][38
  • ]. The poor solubility of adenine and its derivatives in most organic solvents restricts the choice of solvent for this and subsequent reactions to polar aprotic solvents such as DMF, NMP and DMSO [38]. The choice of base for the alkylation of alcohol 4 with tosylate 5 has been the subject of recent
  • tosylate 5 remained the superior alkylating agent under these conditions. The reaction of 4 with iodide 7 afforded only a trace amount of the phosphonate, with mostly unreacted starting material evident in the 1H and 31P NMR spectra of the crude reaction mixture. The reaction with triflate 8 resulted in a
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Published 29 Mar 2019

Syntheses and chemical properties of β-nicotinamide riboside and its analogues and derivatives

  • Mikhail V. Makarov and
  • Marie E. Migaud

Beilstein J. Org. Chem. 2019, 15, 401–430, doi:10.3762/bjoc.15.36

Graphical Abstract
  • synthesis may be partially explained by the fast mutarotation of 2′,3′-O-isopropylidene-D-ribofuranosylamine and its tosylate. This mutarotation is solvent-dependent. For example, according to 1H NMR data presented in the work of Cusack et al. [40], compound 23 exists essentially as the pure β-anomer in
  • chloroform whereas in dimethyl sulfoxide and water solutions, mixtures of α- and β-anomers are observed, with α/β ratio being 1:1.7 and 1:1.5, respectively. Moreover, mutarotation of the tosylate 23 is very fast in aqueous basic solution, being almost instantaneous in aqueous 2 M Na2CO3 as emphasized by the
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Published 13 Feb 2019

Learning from B12 enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis

  • Keishiro Tahara,
  • Ling Pan,
  • Toshikazu Ono and
  • Yoshio Hisaeda

Beilstein J. Org. Chem. 2018, 14, 2553–2567, doi:10.3762/bjoc.14.232

Graphical Abstract
  • methyl tosylate (TsOCH3) as the methyl donor [72]. Kräutler et al. found an equilibrium methyl transfer between methylcobalamin and the methylated complex of 1 resulting in cob(II)alamin and β-methyl heptamethyl cob(III)yrinate. Such a thermal equilibration takes 16 days at room temperature [73]. Keese
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Published 02 Oct 2018

Synthesis of a leopolic acid-inspired tetramic acid with antimicrobial activity against multidrug-resistant bacteria

  • Luce Mattio,
  • Loana Musso,
  • Leonardo Scaglioni,
  • Andrea Pinto,
  • Piera Anna Martino and
  • Sabrina Dallavalle

Beilstein J. Org. Chem. 2018, 14, 2482–2487, doi:10.3762/bjoc.14.224

Graphical Abstract
  • tosylate in the presence of 18-crown-6 ether [15]. The synthesis of benzyl tosylate was accomplished using benzyl alcohol and freshly recrystallized p-toluenesulfonyl chloride in the presence of anhydrous trimethylamine and DMAP, in anhydrous dichloromethane [25]. At this stage, all attempts to obtain the
  • key intermediate 13 removing the p-methoxybenzyl group [24][26][27][28] from 11 failed. Finally, compound 13 was successfully obtained by modifying the sequence of reactions. Deprotection of compound 10 with TFA [24], followed by selective alkylation with benzyl tosylate as previously described
  • to rt, 1 h, 8a: 81%, 8b: 66%; e) dodecanoyl chloride, TEA, CHCl3, 0 °C to rt, 3 h, 90%; f) t-BuOK 1 M in THF, THF, reflux, 1.5 h, 65%; g) benzyl tosylate, KHMDS 0.5 M in toluene, crown ether 18-crown-6, THF, 0 °C to rt, 3 h, 35%; h) TFA, 60 °C, 2h; i) CAN, CH3CN/H2O (3:1), 0 °C to rt, 1h; j) benzyl
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Published 24 Sep 2018

Synthesis of 1,4-imino-L-lyxitols modified at C-5 and their evaluation as inhibitors of GH38 α-mannosidases

  • Maroš Bella,
  • Sergej Šesták,
  • Ján Moncoľ,
  • Miroslav Koóš and
  • Monika Poláková

Beilstein J. Org. Chem. 2018, 14, 2156–2162, doi:10.3762/bjoc.14.189

Graphical Abstract
  • pyridine or TEA was sluggish. Subsequent substitution of the tosylate in 8 either with Super-hydride® (LiBHEt3) or with a cuprate generated in situ from MeMgBr and CuI afforded pyrrolidines 9 [31] and 12 in 68% and 44% yield, respectively (Scheme 1). In the course of tosylate substitution with the cuprate
  • , 3-methylpiperidine 11 was isolated as a byproduct in 32% yield. A formation of the piperidine 11 proceeds via opening of aziridinium intermediate 10 (Scheme 1) [32]. Interestingly, a product of a ring expansion was not observed during the tosylate substitution with LiBHEt3. Simple acidic hydrolysis
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Published 17 Aug 2018

Metal-free formal synthesis of phenoxazine

  • Gabriella Kervefors,
  • Antonia Becker,
  • Chandan Dey and
  • Berit Olofsson

Beilstein J. Org. Chem. 2018, 14, 1491–1497, doi:10.3762/bjoc.14.126

Graphical Abstract
  • of the desired aryl moiety, and the ortho-effect exerted by the 2-amido substituent was expected to improve the chemoselectivity further. Salt 5a was synthesized in good yield using our reported arylboronic acid methodology [33] (Scheme 3). Attempts to form the corresponding tosylate salt, either
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Published 20 Jun 2018

Imide arylation with aryl(TMP)iodonium tosylates

  • Souradeep Basu,
  • Alexander H. Sandtorv and
  • David R. Stuart

Beilstein J. Org. Chem. 2018, 14, 1034–1038, doi:10.3762/bjoc.14.90

Graphical Abstract
  • (TMP)iodonium tosylate salts. The aryl transfer from the iodonium moiety occurs under electronic control with the electron-rich trimethoxyphenyl group acting as a competent dummy ligand. The yields of N-aryl phthalimides are moderate to high and the coupling reaction is compatible with electron
  • reaction yield, using tosylate (OTs) produced the highest yield in both DCE and toluene as solvent (Table 1, entries 4–8). Given our ability to readily access aryl(TMP)iodonium tosylate salts [12] we continued our optimization with these reagents. We observed a very narrow operating temperature with a
  • (via Mayr nucleophilicity constants) [16] may be useful in developing other coupling reactions with diaryliodonium electrophiles. Conclusion The coupling of both electron-deficient and sterically encumbered aryl groups with a phthalimide anion is achievable with aryl(TMP)iodonium tosylate salts. This
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Published 11 May 2018

Cross-coupling of dissimilar ketone enolates via enolonium species to afford non-symmetrical 1,4-diketones

  • Keshaba N. Parida,
  • Gulab K. Pathe,
  • Shimon Maksymenko and
  • Alex M. Szpilman

Beilstein J. Org. Chem. 2018, 14, 992–997, doi:10.3762/bjoc.14.84

Graphical Abstract
  • competing side reaction was the nucleophilic attack by the tosylate on the enolonium species 4. Only in the rare cases mentioned below homocoupling did take place. The enolonium species 4 (R1 = Ph, R2 = H) reacts readily with both electron-rich and electron-poor TMS enol ethers 5 (Scheme 2). Thus, the cross
  • enolonium species leads it to react faster with the less-hindered tosylate despite its poor electronic nucleophilicity. Thus, when the strategy of converting the least hindered enolate into the enolonium species 4 is used even highly hindered TMS enol ethers 5 may be used with formation of tertiary carbon
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Published 03 May 2018

Mechanochemistry of nucleosides, nucleotides and related materials

  • Olga Eguaogie,
  • Joseph S. Vyle,
  • Patrick F. Conlon,
  • Manuela A. Gîlea and
  • Yipei Liang

Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81

Graphical Abstract
  • achieved within 40 minutes at 25 Hz in the presence of ethyl acetate although the integrity of the vessel was compromised and significant levels of metallic copper were removed from the walls during work-up. Expeditious displacement of tosylate or halides from 5′-derivatised nucleosides was achieved using
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Published 27 Apr 2018

Enantioselective dioxytosylation of styrenes using lactate-based chiral hypervalent iodine(III)

  • Morifumi Fujita,
  • Koki Miura and
  • Takashi Sugimura

Beilstein J. Org. Chem. 2018, 14, 659–663, doi:10.3762/bjoc.14.53

Graphical Abstract
  • proceed via an SN2 reaction of a cyclic intermediate such as I1, judging from the syn selectivity of the dioxytosylation [52][53]. The attack of the tosylate ion on I1 possibly takes place at the benzylic position or at the methylene carbon atom. The positive charge of I1 may be stabilized by the aryl
  • styrene with 4a–e preferentially gave (S)-3, which forms via an electrophilic addition of the iodane toward the Si face of styrene, followed by an SN2 reaction with the tosylate ion. If an SN1 mechanism were involved in the oxytosylation of I1, the enantiomeric ratio of 3 would decrease owing to the
  • planar structure of the benzylic cation. Thus, the tosylate ion may act as an effective nucleophile for the SN2 reaction of I1. The stereoface-differentiation in the dioxytosylation reaction using the lactate-derived aryl-λ3-iodanes is similar to that in preceding reactions [14], which include the
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Published 20 Mar 2018

Preparation of trinucleotide phosphoramidites as synthons for the synthesis of gene libraries

  • Ruth Suchsland,
  • Bettina Appel and
  • Sabine Müller

Beilstein J. Org. Chem. 2018, 14, 397–406, doi:10.3762/bjoc.14.28

Graphical Abstract
  • advantages of solution chemistry and solid-phase methods. Thus, solid-supported acyl chloride or pyridinium tosylate as the activator of nucleoside-3'-O-H-phosphonates/phosphoramidites, and polystyrene-bound trimethylammonium periodate as oxidation reagent have been demonstrated to be superior for dimer and
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Published 13 Feb 2018

Diels–Alder cycloadditions of N-arylpyrroles via aryne intermediates using diaryliodonium salts

  • Huangguan Chen,
  • Jianwei Han and
  • Limin Wang

Beilstein J. Org. Chem. 2018, 14, 354–363, doi:10.3762/bjoc.14.23

Graphical Abstract
  • cycloaddition reaction of 1-phenylpyrrole (1a) using phenyl(mesityl)iodonium tosylate (2a) as benzyne precursor. To our delight, with LiHMDS as the base in toluene, the Diels–Alder adduct 3aa was obtained in 23% yield at room temperature (Table 1, entry 1). However, when the reaction temperature was increased
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Published 06 Feb 2018

Homologated amino acids with three vicinal fluorines positioned along the backbone: development of a stereoselective synthesis

  • Raju Cheerlavancha,
  • Ahmed Ahmed,
  • Yun Cheuk Leung,
  • Aggie Lawer,
  • Qing-Quan Liu,
  • Marina Cagnes,
  • Hee-Chan Jang,
  • Xiang-Guo Hu and
  • Luke Hunter

Beilstein J. Org. Chem. 2017, 13, 2316–2325, doi:10.3762/bjoc.13.228

Graphical Abstract
  • extend the carbon chain by one atom. The alcohol 11 was first converted into the corresponding tosylate (Scheme 1), but when this tosylate was subsequently treated with cyanide the undesired disubstituted product 14 was formed in 40% yield. Unfortunately, despite varying the reaction stoichiometry it was
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Published 01 Nov 2017

Solid-state mechanochemical ω-functionalization of poly(ethylene glycol)

  • Michael Y. Malca,
  • Pierre-Olivier Ferko,
  • Tomislav Friščić and
  • Audrey Moores

Beilstein J. Org. Chem. 2017, 13, 1963–1968, doi:10.3762/bjoc.13.191

Graphical Abstract
  • terminal group (Figure 1) [20]. The functionalization of mPEG was also corroborated by the observed shift in the 1H NMR signals of the tosylate group protons from 7.92 (2H) and 7.49 (2H) in TsCl to 7.79 and 7.34 ppm, in mPEG–OTs (Figure S1, Supporting Information File 1) [20]. Employing NaOH as a base
  • mPEG with tosylate functionality. TsCl = p-toluenesulfonyl chloride; CEA = chloroethylamine·HCl; Mw = molecular weight. All reactions were ball-milled at an operating frequency of 30 Hz. Surveyed reactions of mechanochemical derivatization to afford mPEG–Br, –SH, –COOH and –NH2 derivatives. Supporting
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Published 18 Sep 2017
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