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Search for "dehydration" in Full Text gives 263 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

  • Marcus Baumann and
  • Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

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  • the scaled synthesis of NBI-75043 (3) [41], a continuous dehydration process to deliver over 5 kg of dehydropristane 4, a precursor of the immunoactivating agent pristane [42] or the flow synthesis of hydroxamic acids by a procedure that was also applied to the preparation of suberoylanilide
  • under the acidic conditions promotes dehydration. The product is isolated as the in situ formed hydrochloride salt of amitriptyline (127). Solution delivery As the previous examples have demonstrated, the development of an efficient flow process is often the result of designing and implementing a new
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Published 17 Jul 2015

Novel carbocationic rearrangements of 1-styrylpropargyl alcohols

  • Christine Basmadjian,
  • Fan Zhang and
  • Laurent Désaubry

Beilstein J. Org. Chem. 2015, 11, 1017–1022, doi:10.3762/bjoc.11.114

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  • Christine Basmadjian Fan Zhang Laurent Desaubry Laboratory of Therapeutic Innovation (UMR 7200), University of Strasbourg - CNRS, Faculty of Pharmacy, 67401 Illkirch, France 10.3762/bjoc.11.114 Abstract The dehydration and subsequent cyclization reactions of 1-styrylpropargyl alcohols was
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Published 15 Jun 2015

A new and convenient synthetic way to 2-substituted thieno[2,3-b]indoles

  • Roman A. Irgashev,
  • Arseny A. Karmatsky,
  • Gennady L. Rusinov and
  • Valery N. Charushin

Beilstein J. Org. Chem. 2015, 11, 1000–1007, doi:10.3762/bjoc.11.112

Graphical Abstract
  • conventional path [32] (Path C) leading to the aldol adduct 9a (which was further used without purification in all our experiments), its dehydration into 10a, reduction of the latter to indolin-2-ones 11a, and finally cyclization of 11a by action of Lawesson’s reagent (LR), resulting in the formation of the
  • the corresponding acetylated (hetero)arenes 8a–m. Dehydration of the initially obtained aldol-type adducts into 3-(2-oxo-2-(hetero)arylethylidene)indolin-2-ones 10 has been carried out in acetic acid solution with addition of hydrochloric acid (method A), or in CH2Cl2 solution with an excess of SOCl2
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Published 11 Jun 2015

Trifluoromethyl-substituted tetrathiafulvalenes

  • Olivier Jeannin,
  • Frédéric Barrière and
  • Marc Fourmigué

Beilstein J. Org. Chem. 2015, 11, 647–658, doi:10.3762/bjoc.11.73

Graphical Abstract
  • MeOH gives the corresponding primary amide 7 in 63% yield. Its dehydration with POCl3 in sulfolane gives 2ac in 60% yield. A similar phosphite-based cross-coupling reaction between the bis(trifluoromethyl)-1,3-dithiole-2-one derivative 9cc and the diester derivative 10bb gave the TTF 3bc in 15% yield
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Published 06 May 2015

Further exploration of the heterocyclic diversity accessible from the allylation chemistry of indigo

  • Alireza Shakoori,
  • John B. Bremner,
  • Mohammed K. Abdel-Hamid,
  • Anthony C. Willis,
  • Rachada Haritakun and
  • Paul A. Keller

Beilstein J. Org. Chem. 2015, 11, 481–492, doi:10.3762/bjoc.11.54

Graphical Abstract
  • negative charge for subsequent cyclisation onto the carbonyl forming the 7-membered ring. In Path A, dehydration and cyclisation onto the activated iminium cation 25 could form 17. Path B describes the base-induced deprotonation to form the neutral product 26. While dehydration of 26 could conceivably also
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Published 15 Apr 2015

Attempts to prepare an all-carbon indigoid system

  • Şeref Yildizhan,
  • Henning Hopf and
  • Peter G. Jones

Beilstein J. Org. Chem. 2015, 11, 363–372, doi:10.3762/bjoc.11.42

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  • a dehydration reaction. In both cases only minute amounts of products could be obtained. When trying to purify these by column chromatography on silica gel, the stationary phase turned blue, but no defined products could be isolated. Since it might have been the central conjugated butenedione core
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Published 18 Mar 2015

Novel biphenyl-substituted 1,2,4-oxadiazole ferroelectric liquid crystals: synthesis and characterization

  • Mahabaleshwara Subrao,
  • Dakshina Murthy Potukuchi,
  • Girish Sharada Ramachandra,
  • Poornima Bhagavath,
  • Sangeetha G. Bhat and
  • Srinivasulu Maddasani

Beilstein J. Org. Chem. 2015, 11, 233–241, doi:10.3762/bjoc.11.26

Graphical Abstract
  • The synthesis of 1,2,4-oxadiazoles involves [30] a single stage dehydration of O-acylated amidoximes via a reaction between amidoximes and derivatives of carbonyl compounds (esters, amides, acids, acid chlorides, aldehydes, etc.). Otherwise, the reaction is based on the 1,3-dipolar cycloaddition of N
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Published 11 Feb 2015

Inclusion of trans-resveratrol in methylated cyclodextrins: synthesis and solid-state structures

  • Lee Trollope,
  • Dyanne L. Cruickshank,
  • Terence Noonan,
  • Susan A. Bourne,
  • Milena Sorrenti,
  • Laura Catenacci and
  • Mino R. Caira

Beilstein J. Org. Chem. 2014, 10, 3136–3151, doi:10.3762/bjoc.10.331

Graphical Abstract
  • oil and the DSC trace shows a corresponding broad endotherm accompanying the dehydration. However, a sharp endotherm subsequently developed, peaking at ca. 110 °C, interpreted as commencement of complex fusion which overlaps the dehydration process. This coincides with the melting observed in HSM at
  • molecules per 1:1 complex unit. The endotherm observed over the range of 30–120 °C appears sharper than expected for solvent loss alone, suggesting simultaneous melting of the complex. The HSM photographs confirm that dehydration is accompanied by complex fusion, the latter spanning a wide temperature range
  • -precipitation method and fully characterized by thermal and single crystal X-ray diffraction methods. For the complexes containing the fully methylated hosts TMA and TMB, thermal analysis revealed dehydration overlapping with fusion of the anhydrous complex, followed by final decomposition, whereas the DMB
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Published 29 Dec 2014

Modification of physical properties of poly(L-lactic acid) by addition of methyl-β-cyclodextrin

  • Toshiyuki Suzuki,
  • Ayaka Ei,
  • Yoshihisa Takada,
  • Hiroki Uehara,
  • Takeshi Yamanobe and
  • Keiko Takahashi

Beilstein J. Org. Chem. 2014, 10, 2997–3006, doi:10.3762/bjoc.10.318

Graphical Abstract
  • observed, except for PLLA. For MeCD, this weight loss arises from dehydration [41][42]. For PL-MCD samples, the weight loss begins at higher temperatures than for MeCD. The weight loss is caused by desorption of chloroform from the MeCD cavity. This weight loss may not be observed if PLLA is included in
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Published 16 Dec 2014

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

  • Véronique Nardello-Rataj and
  • Loïc Leclercq

Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273

Graphical Abstract
  • , Dong et al. published on the inclusion of ciprofloxacin by grafting β-CD on cellulose fibers (Figure 8) [65]. The β-CD-grafted cellulose was prepared by the formation of CA-β-CD obtained after the dehydration of the two adjacent carboxyl groups of the citric acid (CA) to form a cyclic anhydride, which
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Published 07 Nov 2014

Formal total syntheses of classic natural product target molecules via palladium-catalyzed enantioselective alkylation

  • Yiyang Liu,
  • Marc Liniger,
  • Ryan M. McFadden,
  • Jenny L. Roizen,
  • Jacquie Malette,
  • Corey M. Reeves,
  • Douglas C. Behenna,
  • Masaki Seto,
  • Jimin Kim,
  • Justin T. Mohr,
  • Scott C. Virgil and
  • Brian M. Stoltz

Beilstein J. Org. Chem. 2014, 10, 2501–2512, doi:10.3762/bjoc.10.261

Graphical Abstract
  • , terminal alcohol silylation, and tertiary alcohol dehydration, affording methylene cyclohexane (−)-20. Treatment of this silyl ether with Jones reagent simultaneously cleaved the silyl group and oxidized the resulting alcohol, furnishing carboxylic acid (−)-12 in 65% yield. With this enantioenriched acid
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Published 28 Oct 2014

Phosphinocyclodextrins as confining units for catalytic metal centres. Applications to carbon–carbon bond forming reactions

  • Matthieu Jouffroy,
  • Rafael Gramage-Doria,
  • David Sémeril,
  • Dominique Armspach,
  • Dominique Matt,
  • Werner Oberhauser and
  • Loïc Toupet

Beilstein J. Org. Chem. 2014, 10, 2388–2405, doi:10.3762/bjoc.10.249

Graphical Abstract
  • in apical (top) or equatorial (bottom) position. Complexation of a "PdCl(dmba)" unit by HUGPHOS ligands. Reaction of HUGPHOS-1 with [MCl2(PhCN)2] complexes (M = Pd, Pt). Only one isomer with a given MeO–M bond has been drawn. Synthesis of complexes 3–5. Dehydration of Pd(II) complex 5. Synthesis of
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Published 15 Oct 2014

Visible light photoredox-catalyzed deoxygenation of alcohols

  • Daniel Rackl,
  • Viktor Kais,
  • Peter Kreitmeier and
  • Oliver Reiser

Beilstein J. Org. Chem. 2014, 10, 2157–2165, doi:10.3762/bjoc.10.223

Graphical Abstract
  • produced by thermal dehydration of acetic acid [12], the overall sequence to the benzoylated starting material 6e does not require any type of activation reagents such as thionyl chloride or DCC that are often used for ester formation, but ultimately only requires energy in form of heat. After the
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Published 10 Sep 2014

Photorelease of phosphates: Mild methods for protecting phosphate derivatives

  • Sanjeewa N. Senadheera,
  • Abraham L. Yousef and
  • Richard S. Givens

Beilstein J. Org. Chem. 2014, 10, 2038–2054, doi:10.3762/bjoc.10.212

Graphical Abstract
  • the 5- and 8-positions by H–D exchange [19]. Furthermore, dehydration of 5-(1-hydroxyethyl)-1-naphthol (34) is very efficient, leading to quinone methide 35 which is trapped by solvent MeOH (Scheme 8). The corresponding 4-(1-hydroxyethyl)-1-naphthol, however, is unreactive. Comparisons of the two
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Published 29 Aug 2014

Five-membered ring annelation in [2.2]paracyclophanes by aldol condensation

  • Henning Hopf,
  • Swaminathan Vijay Narayanan and
  • Peter G. Jones

Beilstein J. Org. Chem. 2014, 10, 2021–2026, doi:10.3762/bjoc.10.210

Graphical Abstract
  • dehydration experiment described below. The most plausible mechanism for the above aldol reaction also favors the discussed structural assignments. As shown above in Scheme 2, the starting material 9 favors a conformation in the solid state in which all carbonyl groups point towards the “inner” space of the
  • aldols, we next dehydrated them under acidic conditions. When the syn-isomer 12 was treated with p-toluenesulfonic acid in toluene at room temperature, three dehydration products 18–20 were produced in approximately equal yields. The products were separated by preparative plate chromatography, and the
  • , and also furnishes three dehydration products, the anti-configurated diketones 21–23, produced in a 1:3:1 ratio. Again the fully or partially conjugated isomers are deeply colored (intense yellow) and display absorption maxima at 389 and 358 nm, respectively (Scheme 6). For 21 yellow single crystals
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Published 28 Aug 2014

Facile synthesis of 1-alkoxy-1H-benzo- and 7-azabenzotriazoles from peptide coupling agents, mechanistic studies, and synthetic applications

  • Mahesh K. Lakshman,
  • Manish K. Singh,
  • Mukesh Kumar,
  • Raghu Ram Chamala,
  • Vijayender R. Yedulla,
  • Domenick Wagner,
  • Evan Leung,
  • Lijia Yang,
  • Asha Matin and
  • Sadia Ahmad

Beilstein J. Org. Chem. 2014, 10, 1919–1932, doi:10.3762/bjoc.10.200

Graphical Abstract
  • previously described the use of (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP) for the dehydration of aldoximes to cyanides [22]. In that work, analysis of the reaction course by 31P{1H} NMR did not show the formation of a new phosphorus signal other than that for HMPA, which
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Published 19 Aug 2014

Multicomponent reactions in nucleoside chemistry

  • Mariola Koszytkowska-Stawińska and
  • Włodzimierz Buchowicz

Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179

Graphical Abstract
  • dehydration and cyclization steps of the reaction owing to its acidic properties. The reaction variant involving the corresponding sugar aldehyde 75, 4-aminopent-3-en-2-one and ethyl 3-oxobutanoate allowed to obtain unsymmetrical products 93. Galactose-6'-aldehyde-derived counterparts of the symmetrical
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Published 29 Jul 2014

Rasta resin–triphenylphosphine oxides and their use as recyclable heterogeneous reagent precursors in halogenation reactions

  • Xuanshu Xia and
  • Patrick H. Toy

Beilstein J. Org. Chem. 2014, 10, 1397–1405, doi:10.3762/bjoc.10.143

Graphical Abstract
  • the dehydration of oximes 12 to form nitriles 13. Capitalizing on the fact that 1 is formed as a byproduct from 3a,b in each of these reactions, Denton and co-workers have recently combined the Masaki–Fukui reaction with many of the functional group transformation outlined in Scheme 2, in one-pot
  • halophosphonium salts in Appel and dehydration reactions [44]. This work utilized a commercially available polymer-supported phosphine oxide based on the Merrifield resin architecture, and it is noteworthy that the reactions reported in this manuscript required a 6-fold excess of the halophosphonium salt compared
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Published 20 Jun 2014

Direct C–H trifluoromethylation of di- and trisubstituted alkenes by photoredox catalysis

  • Ren Tomita,
  • Yusuke Yasu,
  • Takashi Koike and
  • Munetaka Akita

Beilstein J. Org. Chem. 2014, 10, 1099–1106, doi:10.3762/bjoc.10.108

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  • synthesis of CF3-alkenes via sequential photoredox-catalyzed hydroxytrifluoromethylation and dehydration (Scheme 3a) [37] and photoredox-catalyzed trifluoromethylation of alkenylborates (Scheme 3b) [38]. These results prompted us to explore photoredox-catalyzed C–H trifluoromethylation of di- and
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Published 12 May 2014

Aza-Diels–Alder reaction between N-aryl-1-oxo-1H-isoindolium ions and tert-enamides: Steric effects on reaction outcome

  • Amitabh Jha,
  • Ting-Yi Chou,
  • Zainab ALJaroudi,
  • Bobby D. Ellis and
  • T. Stanley Cameron

Beilstein J. Org. Chem. 2014, 10, 848–857, doi:10.3762/bjoc.10.81

Graphical Abstract
  • and Diels–Alder cascade. Concomitant electrophilic aromatic substitution and dehydration resulted in isoquinoloquinoline derivatives [22]. Similarly, isoindoloquinolines were also synthesized via classical Povarov chemistry between furyl aldimines and tert-enamides followed by a N-acryloylation, Diels
  • –Alder reaction [23][24] and dehydration sequence [25][26] (Scheme 1). As mentioned earlier, N-aryl-1-oxo-1H-isoindolium ions (A, Scheme 1) undergo [4 + 2] imino-Diels–Alder cyclization with electron-rich alkenes [11][12][13][14][15][16][17], the steric effects on the outcome of these reactions has not
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Published 14 Apr 2014

Group-assisted purification (GAP) chemistry for the synthesis of Velcade via asymmetric borylation of N-phosphinylimines

  • Jian-bo Xie,
  • Jian Luo,
  • Timothy R. Winn,
  • David B. Cordes and
  • Guigen Li

Beilstein J. Org. Chem. 2014, 10, 746–751, doi:10.3762/bjoc.10.69

Graphical Abstract
  • , MgSO4 or CaSO4 was chosen as the dehydration reagent together with molecular sieves for imine formation. Under these conditions, complete conversion can be reached after 5 days to give the chiral N-phosphinylimine, which can be directly used for the following asymmetric borylation reaction without
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Published 31 Mar 2014
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  • , the impact of the hydrophobic end-group on the cloud point of the polymer increased with decreasing molecular weight and thus showing an inverse dependency (Figure 4 and Table 2). This is in agreement with the findings of previous studies. As stated by Chung et al. the dehydration of the polymer chain
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Published 19 Mar 2014

Synthesis of complex intermediates for the study of a dehydratase from borrelidin biosynthesis

  • Frank Hahn,
  • Nadine Kandziora,
  • Steffen Friedrich and
  • Peter F. Leadlay

Beilstein J. Org. Chem. 2014, 10, 634–640, doi:10.3762/bjoc.10.55

Graphical Abstract
  • preferentially accepts the 2D,3D-configured precursor, if all four potential stereoisomers of 3-hydroxy-2-methyl-SNAc-pentanoate model substrates are presented [7]. A commonly accepted model suggests that DHs from PKS I systems catalyze the removal of water by syn-dehydration and that a 2D,3D-configured
  • ongoing in our lab. a) Structure of borrelidin (1); b) PKS intermediates are attached to an acyl carrier protein domain (ACP) via a 4'-phosphopantetheine linker, giving acyl-ACPs (2); c) BorDH3 catalyzes the dehydration of ACP-bound 3-hydroxyacylate 3 to one of the ACP-bound enoates 4a or 4b. The
  • configuration of the double bond in the dehydration product is presently unknown. In a previous study, we have shown that BorDH3 only accepts surrogates with the shown 2D,3D-configuration if incubated with simple 3-hydroxy-2-methyl-SNAc pentanoates [7][12]. Retrosynthetic analysis of surrogate substrates for
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Published 11 Mar 2014

Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics

  • Gijs Koopmanschap,
  • Eelco Ruijter and
  • Romano V.A. Orru

Beilstein J. Org. Chem. 2014, 10, 544–598, doi:10.3762/bjoc.10.50

Graphical Abstract
  • library of acyclic products (Scheme 11), in which the isocyanide input 30 was derived from the corresponding amine via an N-formylation/dehydration sequence [52]. An additional palladium-catalyzed cyclization gave the pyrrolidine mimics 32 in excellent yields and modest to good selectivities (de 8–78
  • byproduct. Addition of cyclopropyl isocyanide followed by dehydration of the Passerini-product furnished the third Ugi-component 61. The subsequent Ugi 3-CR of 61, 62 and 57 followed by a final oxidation resulted in 63 (42% from H-Chg-OMe, dr 84:13:4). Even better selectivities were observed using the more
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Published 04 Mar 2014

Direct and indirect single electron transfer (SET)-photochemical approaches for the preparation of novel phthalimide and naphthalimide-based lariat-type crown ethers

  • Dae Won Cho,
  • Patrick S. Mariano and
  • Ung Chan Yoon

Beilstein J. Org. Chem. 2014, 10, 514–527, doi:10.3762/bjoc.10.47

Graphical Abstract
  • corresponding polyether side chain containing the lariat-type azacrown ethers 47a–c exclusively (Scheme 11). As observed in earlier studies [34], the initially formed photoproducts undergo in situ dehydration to produce the vinyl sulfide products 46a–c [82]. The photoreactions shown in Scheme 10 and Scheme 11
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Published 27 Feb 2014
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