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Search for "benzoic acid" in Full Text gives 160 result(s) in Beilstein Journal of Organic Chemistry.

Organocatalytic cascade aza-Michael/hemiacetal reaction between disubstituted hydrazines and α,β-unsaturated aldehydes: Highly diastereo- and enantioselective synthesis of pyrazolidine derivatives

  • Zhi-Cong Geng,
  • Jian Chen,
  • Ning Li,
  • Xiao-Fei Huang,
  • Yong Zhang,
  • Ya-Wen Zhang and
  • Xing-Wang Wang

Beilstein J. Org. Chem. 2012, 8, 1710–1720, doi:10.3762/bjoc.8.195

Graphical Abstract
  • ). Soluble organic bases were also tested and failed to increase the yields (Table 1, entries 11 and 12). When benzoic acid (5a) was used as an additive, the yield was slightly improved to 77% (Table 1, entry 13). With the increase of the acidity, the yield was noticeably decreased (Table 1, entry 13 versus
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Published 09 Oct 2012

Organocatalytic tandem Michael addition reactions: A powerful access to the enantioselective synthesis of functionalized chromenes, thiochromenes and 1,2-dihydroquinolines

  • Chittaranjan Bhanja,
  • Satyaban Jena,
  • Sabita Nayak and
  • Seetaram Mohapatra

Beilstein J. Org. Chem. 2012, 8, 1668–1694, doi:10.3762/bjoc.8.191

Graphical Abstract
  • sieves (4 Å) in the reaction (Scheme 2). Wang et al. [44] investigated the same tandem reaction of salicylaldehydes 1 and α,β-unsaturated aldehydes 2 employing TES-protected diphenylprolinol Ie as organocatalyst with high catalyst loading (30 mol %). With benzoic acid as cocatalyst and dichloroethane as
  • )-diphenylpyrrolinol silyl ether (Ia) as organocatalyst and benzoic acid as cocatalyst in toluene at room temperature (Scheme 18). The protocol provides good yield and high enantioselectivity of the desired products. The yield of the reactions does not reduce appreciably when substituents are present on the aromatic
  • of diphenylprolinol trimethylsilyl ether Ib as catalyst and benzoic acid as additive, provides 1,2-dihyroquinolines 53 with high yields (90%) and high ee (>99%) (Scheme 27). Various enal substituents, such as aryl, alkyl and ester groups, are readily tolerated in the reaction. However, with β-alkyl α
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Published 04 Oct 2012

Organocatalytic C–H activation reactions

  • Subhas Chandra Pan

Beilstein J. Org. Chem. 2012, 8, 1374–1384, doi:10.3762/bjoc.8.159

Graphical Abstract
  • Brønsted acids as catalysts was screened for this reaction, and the best reaction efficiency in terms of yield and reaction time was achieved with benzoic acid (10 mol %). The scope of the reaction was investigated and was found to tolerate a wide variety of functional groups including nitro, nitriles
  • -membered lactols, δ-hydroxypyrroles 8 were achieved as the products in good yields (Scheme 6). Later, Pan and Seidel independently extended this methodology to indolines using benzoic acid as the catalyst, conducting the reaction under reflux and microwave irradiation conditions, respectively, to generate
  • explanation is the formation of azomethine ylide intermediate 11 (Scheme 8) [19][20]. The carbanion of ylide 11 is then protonated by benzoic acid, and the resulting benzoate anion supports the aromatization process. In fact, Seidel and co-workers provided the experimental evidence for the existence of
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Published 27 Aug 2012

Recyclable fluorous cinchona alkaloid ester as a chiral promoter for asymmetric fluorination of β-ketoesters

  • Wen-Bin Yi,
  • Xin Huang,
  • Zijuan Zhang,
  • Dian-Rong Zhu,
  • Chun Cai and
  • Wei Zhang

Beilstein J. Org. Chem. 2012, 8, 1233–1240, doi:10.3762/bjoc.8.138

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  • determined by chiral phase HPLC analysis on an SHIMADZU LC-20AD system. Synthesis of fluorous quinine ester C-1 Thionyl chloride (1.19 g, 10 mmol) was added to a mixture of (1H,1H,2H,2H-perfluorooctyl)benzoic acid (0.468 g, 1 mmol) and pyridine (75 mg, 1 mmol). After stirring of the mixture for 4 h at 50 °C
  • , 101.4, 114.5, 118.9, 121.8, 127.0, 131.8, 141.7, 143.5, 144.8, 147.4, 149.6, 157.9, 170.0, 199.5, 200.2; ACPIMS m/z: 367.2 (M+ + 1). Synthesis of fluorous pyrrolidine ester C-6 N,N'-Dicyclohexylcarbodiimide (DCC) (0.206 g, 1 mmol) was added to a mixture of (1H,1H,2H,2H-perfluorooctyl)benzoic acid (0.468
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Published 03 Aug 2012

Synthesis of diverse indole libraries on polystyrene resin – Scope and limitations of an organometallic reaction on solid supports

  • Kerstin Knepper,
  • Sylvia Vanderheiden and
  • Stefan Bräse

Beilstein J. Org. Chem. 2012, 8, 1191–1199, doi:10.3762/bjoc.8.132

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  • benzoic acids on Merrifield resin: In a three-necked round-bottom flask equipped with a mechanical stirrer, 5 equiv of cesium carbonate are suspended in DMF (mL/mmol) and are stirred for 30 min at 50 °C. Next, 5 equiv of benzoic acid are added and the mixture is stirred for another 30 min. Afterwards, one
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Published 26 Jul 2012

Parallel solid-phase synthesis of diaryltriazoles

  • Matthias Wrobel,
  • Jeffrey Aubé and
  • Burkhard König

Beilstein J. Org. Chem. 2012, 8, 1027–1036, doi:10.3762/bjoc.8.115

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  • potential inhibitors of protein–protein interactions. Results and Discussion Synthesis of azide-functionalized Wang resins Two azide-functionalized resins were prepared for the solid-phase synthesis of diaryl-triazoles. The commercially available 4-(bromomethyl)benzoic acid (5) was converted into azide 6 in
  • phenyl ring of the benzoic acid as constant structural elements and the third ring consisting either of substituted benzenes, heteroarenes or a polycyclic aromatic compound. Lower product yields were obtained in this series of compounds, ranging from 21 to 63%. The lower reactivity of the aromatic azide
  • of regioisomers in reaction 3. Instead of the 1,4-disubstituted triazoles obtained from copper(I) catalysis, the complex pentamethylcyclopentadienylbis(triphenylphosphine)ruthenium(II) chloride leads to 1,5-disubstituted triazole compounds [19]. 4-(Azidomethyl)benzoic acid functionalized Wang resin 7
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Published 06 Jul 2012

Building photoswitchable 3,4'-AMPB peptides: Probing chemical ligation methods with reducible azobenzene thioesters

  • Gehad Zeyat and
  • Karola Rück-Braun

Beilstein J. Org. Chem. 2012, 8, 890–896, doi:10.3762/bjoc.8.101

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  • for the application in ligation studies. AMPB = (aminomethylphenylazo)benzoic acid. Structure of the glycine-linked auxiliary conjugates 7 and 8. Structural differences between the trans- and the cis-state of azopeptides with a SKV PDZ binding motif. Solid-phase synthesis of the ligation-mediating
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Published 18 Jun 2012

meta-Oligoazobiphenyls – synthesis via site-selective Mills reaction and photochemical properties

  • Raphael Reuter and
  • Hermann A. Wegner

Beilstein J. Org. Chem. 2012, 8, 877–883, doi:10.3762/bjoc.8.99

Graphical Abstract
  • ) was oxidized with potassium permanganate in a 1:1 solvent mixture of pyridine/H2O, to the corresponding benzoic acid 5. The reaction proceeded with an acceptable yield of 66%. However, the resulting highly deactivated aromatic system 5 did not react even under harsh bromination conditions with NBS in
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Published 13 Jun 2012

Regio- and stereoselective oxidation of unactivated C–H bonds with Rhodococcus rhodochrous

  • Elaine O’Reilly,
  • Suzanne J. Aitken,
  • Gideon Grogan,
  • Paul P. Kelly,
  • Nicholas J. Turner and
  • Sabine L. Flitsch

Beilstein J. Org. Chem. 2012, 8, 496–500, doi:10.3762/bjoc.8.56

Graphical Abstract
  • 29% of p-chlorobenzoic acid. The isolation of the benzoic acid derivative suggests that benzylic hydroxylation takes place, leading to cleavage of the unstable acetal [19][20]; however, this was not investigated further and the oxidation products were not characterised. The most interesting
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Published 03 Apr 2012

Derivatives of phenyl tribromomethyl sulfone as novel compounds with potential pesticidal activity

  • Krzysztof M. Borys,
  • Maciej D. Korzyński and
  • Zbigniew Ochal

Beilstein J. Org. Chem. 2012, 8, 259–265, doi:10.3762/bjoc.8.27

Graphical Abstract
  • yields. It is worth noting that we encountered significant difficulties while applying the Philips method for the cyclization of diamine 9 with benzoic acid and 4-chlorobenzoic acid. The expected benzimidazole was not formed, and only the substrates were isolated from the reaction mixture. Therefore we
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Published 15 Feb 2012

Efficient, highly diastereoselective MS 4 Å-promoted one-pot, three-component synthesis of 2,6-disubstituted-4-tosyloxytetrahydropyrans via Prins cyclization

  • Naseem Ahmed and
  • Naveen Kumar Konduru

Beilstein J. Org. Chem. 2012, 8, 177–185, doi:10.3762/bjoc.8.19

Graphical Abstract
  • the solvent of choice at reflux temperature (Table 1, entries 5, 6, 8–10). Similarly, various acids like trifluoroacetic acid (TFA), benzoic acid, acetic acid, benzylphosphonic acid, and O,O’-diethyl dithiophosphate were tried as catalysts but all of them failed to give the desired product. We
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Published 01 Feb 2012

Laterally substituted symmetric and nonsymmetric salicylideneimine-based bent-core mesogens

  • Sonja Findeisen-Tandel,
  • Wolfgang Weissflog,
  • Ute Baumeister,
  • Gerhard Pelzl,
  • H. N. Shreenivasa Murthy and
  • Channabasaveshwar V. Yelamaggad

Beilstein J. Org. Chem. 2012, 8, 129–154, doi:10.3762/bjoc.8.15

Graphical Abstract
  • benzoic acids 2 and hydrogenolytic deprotection of the hydroxy group according to [47]. The final products OH 1a–c were obtained by esterification of the phenols 3 with 4-(4-dodecyloxy-2-hydroxybenzylideneamino)benzoic acid (4), which exhibits a liquid-crystalline phase itself (Cr 204 N 269 I) [42]. It
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Published 24 Jan 2012

Synthesis and characterization of new diiodocoumarin derivatives with promising antimicrobial activities

  • Hany M. Mohamed,
  • Ashraf H. F. Abd EL-Wahab,
  • Ahmed M. EL-Agrody,
  • Ahmed H. Bedair,
  • Fathy A. Eid,
  • Mostafa M. Khafagy and
  • Kamal A. Abd-EL-Rehem

Beilstein J. Org. Chem. 2011, 7, 1688–1696, doi:10.3762/bjoc.7.199

Graphical Abstract
  • ), 170 (COOH); MS m/z (% relative intensity): 533 (M+, 45), 425 (M+ – NH-C6H4-OH, 100), 341 (16), 214 (10), 171 (17), 87 (63). 2-(6,8-Diiodocoumarin-3-carboxamido)benzoic acid (10). Yellow crystals: Yield 91%; mp 315 °C; Anal. calcd for C17H9I2NO5: C, 36.37; H, 1.60; N, 2.50; found: C, 36.39; H, 36.39; N
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Published 19 Dec 2011

A straightforward approach towards combined α-amino and α-hydroxy acids based on Passerini reactions

  • Ameer F. Zahoor,
  • Sarah Thies and
  • Uli Kazmaier

Beilstein J. Org. Chem. 2011, 7, 1299–1303, doi:10.3762/bjoc.7.151

Graphical Abstract
  • aldehyde group. Therefore, we decided to run the reaction also under neat conditions as reported for the γ-oxo-amino acids. With acetic acid as the acidic component the yield of 6a was comparable to the previous examples. In principle, other acids such as benzoic acid or Cbz-protected glycine can be used
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Published 19 Sep 2011

Use of mixed Li/K metal TMP amide (LiNK chemistry) for the synthesis of [2.2]metacyclophanes

  • Marco Blangetti,
  • Patricia Fleming and
  • Donal F. O'Shea

Beilstein J. Org. Chem. 2011, 7, 1249–1254, doi:10.3762/bjoc.7.145

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  • 4a and 4e, giving purified 4-methyl-2-(3-methylphenethyl)benzoic acid (6f) (Table 1, entry 6). This product is the result of oxidative hetero coupling of benzylic metalated xylene and 2-(methyl-metalated)-4-methylbenzoate. To more clearly illustrate a site selective metalation of 4e for the methyl
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Published 09 Sep 2011

A practical two-step procedure for the preparation of enantiopure pyridines: Multicomponent reactions of alkoxyallenes, nitriles and carboxylic acids followed by a cyclocondensation reaction

  • Christian Eidamshaus,
  • Roopender Kumar,
  • Mrinal K. Bera and
  • Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2011, 7, 962–975, doi:10.3762/bjoc.7.108

Graphical Abstract
  • -protected lactic acid, the corresponding ketoenamides 61 and 62 were isolated in 58% yield. Reaction of lithiated methoxyallene with O-TBS-protected lactic nitrile and benzoic acid furnished 64 in high yield. Heterocyclic moieties were also well tolerated as demonstrated by the efficient reaction of 2
  • and (S)-TBS-lactic nitrile (200 mg, 1.14 mmol) in anhydrous diethyl ether (5 mL) was added to the mixture. After stirring for 4 h, a solution of benzoic acid (0.84 g, 6.88 mmol) in anhydrous DMF (10 mL) was added. The mixture was stirred overnight and slowly allowed to reach r.t. The reaction was
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Published 13 Jul 2011

Isotopic labelling studies for a gold-catalysed skeletal rearrangement of alkynyl aziridines

  • Paul W. Davies,
  • Nicolas Martin and
  • Neil Spencer

Beilstein J. Org. Chem. 2011, 7, 839–846, doi:10.3762/bjoc.7.96

Graphical Abstract
  • proposed mechanism does not account for the formation of 2,4-disubstituted pyrrole without deuterium incorporation at the C-5 position. More information on whether a 1,2-aryl shift occurs was therefore sought using a non-labile 13C label at the aziridine carbon. 13C labelling studies 13C-Enriched benzoic
  • acid was converted into imine 10 and subsequently coupled with 7 to give the aziridine 11, in four steps, as a 1:5 13C:12C mixture (Scheme 6). Two further 13C-enriched alkynyl aziridines, 14 and 15, with different substituents on the alkyne, were later prepared using the sulfonium salts 12 and 13. On
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Published 21 Jun 2011

Continuous flow hydrogenation using polysilane-supported palladium/alumina hybrid catalysts

  • Hidekazu Oyamada,
  • Takeshi Naito and
  • Shū Kobayashi

Beilstein J. Org. Chem. 2011, 7, 735–739, doi:10.3762/bjoc.7.83

Graphical Abstract
  • could also be carried out successfully in water (Scheme 4). The reduction of aqueous maleic acid proceeded quantitatively. Dehalogenation of p-chlorobenzoic acid in basic aqueous solution also proceeded smoothly and benzoic acid was obtained after acid treatment. In the case of p-chlorophenol, the
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Published 31 May 2011

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

  • Marcus Baumann,
  • Ian R. Baxendale,
  • Steven V. Ley and
  • Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

Graphical Abstract
  • of solvents and the influence of additives was undertaken [40]. It was identified that the use of a specific 23 mol % of benzoic acid significantly increased the cis/trans ratio from a base level of 55:45 to 92:8 (16 h reaction time at ambient temperature) in an overall yield of 86%. It was also
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Published 18 Apr 2011

Regioselective ester cleavage during the preparation of bisphosphonate methacrylate monomers

  • Kamel Chougrani,
  • Gilles Niel,
  • Bernard Boutevin and
  • Ghislain David

Beilstein J. Org. Chem. 2011, 7, 364–368, doi:10.3762/bjoc.7.46

Graphical Abstract
  • 4c and 5c. The two aromatic targets 6c and 7c were prepared from p-(aminomethyl)benzoic acid (17) which was converted into the bisphosphonate 18 in 92% yield under Kabachnik–Fields conditions. This common intermediate 18 was either reduced by diborane to the alcohol 19 followed by esterification by
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Published 25 Mar 2011

Approaches towards the synthesis of 5-aminopyrazoles

  • Ranjana Aggarwal,
  • Vinod Kumar,
  • Rajiv Kumar and
  • Shiv P. Singh

Beilstein J. Org. Chem. 2011, 7, 179–197, doi:10.3762/bjoc.7.25

Graphical Abstract
  • -ketonitriles 16 with a substituted hydrazine in the presence of Et3N in ethanol under reflux conditions. The intermediate 16 was obtained from β-ketoester 15 on treatment with TFA, which in turn was synthesized by condensing 4-(phenylsulfonamidomethyl)cyclohexane carboxylic acid or benzoic acid 13
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Published 09 Feb 2011

Novel 2-(ω-phosphonooxy-2-oxaalkyl)acrylate monomers for self-etching self-priming one part adhesive

  • Joachim E. Klee and
  • Uwe Lehmann

Beilstein J. Org. Chem. 2010, 6, 766–772, doi:10.3762/bjoc.6.95

Graphical Abstract
  • -trimethylbenzoyl)phenyl phosphine oxide and 0.0392 g 4-(N,N-dimethylamino)benzoic acid ethyl ester were dissolved in a solvent mixture of 3.5201 g ethanol and 1.7484 g water. Adhesive compositions 4c–i were prepared from 3c–i in the same manner as described above. The following procedure was applied prior to
  • conditions. The subtraction of these runs from one another removed the effect of different baselines for the dark and the illumination periods. In the monomers were dissolved 0.3 mol % camphorquinone and 0.35 mol % 4-(N,N-dimethylamino)benzoic acid ethyl ester. Adhesion of an adhesive composition 4
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Published 07 Sep 2010

Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

  • Vladimir N. Boiko

Beilstein J. Org. Chem. 2010, 6, 880–921, doi:10.3762/bjoc.6.88

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  • and form 1,3-bis(SCF3) benzene [38][39][40] and 4-SCF3-benzoic acid fluoride, respectively [55]. The use of hydrogen fluoride has some advantages. Due to its low boiling point (+19.4 °C) and good solubility in water, excess HF is easily removed from the reaction mixture. Unlike HF, reactions with SbF3
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Published 18 Aug 2010

Pd-catalyzed decarboxylative Heck vinylation of 2-nitrobenzoates in the presence of CuF2

  • Lukas J. Gooßen,
  • Bettina Zimmermann and
  • Thomas Knauber

Beilstein J. Org. Chem. 2010, 6, No. 43, doi:10.3762/bjoc.6.43

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  • yield 2-nitro-stilbene (3aa) as a model reaction, and investigated the catalytic activity of various combinations of palladium precursors, additives and oxidants (Table 1). The choice of an electron-deficient benzoic acid was motivated by our intention to overcome substrate limitations observed in Myers
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Published 03 May 2010

Molecular recognition of organic ammonium ions in solution using synthetic receptors

  • Andreas Späth and
  • Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

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Published 06 Apr 2010
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