- Pd(OH)2/C, a Practical and Efficient Catalyst for the Carboxylation of Benzylic Bromides with Carbon Monoxide
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A simple, efficient, cheap, and broadly applicable system for the carboxylation of benzylic bromides with carbon monoxide and water is reported. Upon simple reaction with only 2.5 wt % of Pearlman's catalyst and 10 mol % of tetrabutylammonium bromide in tetrahydrofuran at 110 °C for 4 h, a range of benzylic bromides can be smoothly converted to the corresponding arylacetic acids in good to excellent yields after simple extraction and acid-base wash. The reaction was found to be broadly applicable, scalable, and could be successfully extended to the use of ex situ-generated carbon monoxide and applied to the synthesis of the nonsteroidal anti-inflammatory drug diclofenac.
- Wakuluk-Machado, Anne-Marie,Dewez, Damien F.,Baguia, Hajar,Imbratta, Miguel,Echeverria, Pierre-Georges,Evano, Gwilherm
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p. 713 - 723
(2020/02/04)
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- Efficient and Convenient Method for Synthesis of Benzofuran-3-acetic Acids and Naphthafuran-acetic Acids
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Herein, we report an efficient and convenient method for synthesis of benzofuran-3-acetic acids and naphthafuran-acetic acids 5a-p by the reaction of substituted-4-bromomethylcoumarins with aqueous sodium hydroxide at refluxing temperature. The obtained products are characterized by infrared, 1H NMR, 13C NMR, and mass spectral data. Structures 5a and 5e are confirmed by their single x-ray diffraction studies. The advantages of this method are good yields, easy workup, and no chromatographic purifications.
- Basanagouda, Mahantesha,Narayanachar,Majati, Iranna B.,Mulimani, Shiddappa S.,Sunnal, Satish B.,Nadiger, Rohit V.,Ghanti, Ashok S.,Gudageri, Siddeshwar F.,Naik, Ravi,Nayak, Akshata
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supporting information
p. 2195 - 2202
(2015/09/22)
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- Benzofurans as efficient dienophiles in normal electron demand [4 + 2] cycloadditions
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Dearomatization of electron-poor benzofurans is possible through involvement of the aromatic 2,3-carbon-carbon double bond as dienophile in normal electron demand [4 + 2] cycloadditions. The tricyclic heterocycles thereby produced bear a quaternary center at the cis ring junction, a feature of many alkaloids such as morphine, galanthamine, or lunaridine. The products arising from the reaction have been shown to depend on different factors among which the type of the electron-withdrawing substituent of the benzofuran, the nature of the reacting diene, and the method of activation. In the presence of all-carbon dienes, the reaction yields the expected Diels-Alder adducts. When thermal activation is insufficient, a biactivation associating zinc chloride catalysis and high pressure is required to generate the cycloadducts in good yields and high stereoselectivities, for instance, when cyclohexadiene is involved in the process. The use of more functionalized dienes, such as those bearing alkoxy or silyloxy substituents, also shows the limits of the thermal activation, and hyperbaric conditions are, in this case, well-suited. The involvement of Danishefsky's diene induces a competition in the site of reactivity. The aromatic 2,3-carbon-carbon double bond is unambiguously the most reactive dienophile, and the 3-carbonyl unit becomes a competitive site of reactivity with benzofurans bearing substituents prone to heterocyloaddition, in particular under Lewis acid activation. The sequential involvment of both the aromatic double bond and the carbonyl moiety as dienophiles is then possible by using an excess of diene under high-pressure activation. In line with the experimental results, DFT computations suggest that the Diels-Alder process involving the aromatic double bond is preferred over the hetero-Diels-Alder route through an asynchronous concerted transition state. However, Lewis acid catalysis appears to favor the heterocycloaddition pathway through a stepwise mechanism in some cases. 2009 American Chemical Society.
- Chopin, Nathalie,Gerard, Helene,Chataigner, Isabelle,Piettre, Serge R.
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scheme or table
p. 1237 - 1246
(2009/07/04)
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- 2-(4-Chlorobenzyl)-3-hydroxy-7,8,9,10-tetrahydrobenzo[H] quinoline-4-carboxylic acid (PSI-697): Identification of a clinical candidate from the quinoline salicylic acid series of P-selectin antagonists
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P-selectin-PSGL-1 interaction causes rolling of leukocytes on the endothelial cell surface, which subsequently leads to firm adherence and leukocyte transmigration through the vessel wall into the surrounding tissues. P-selectin is upregulated on the surface of both platelets and endothelium in a variety of atherosclerosis-associated conditions. Consequently, inhibition of this interaction by means of a small molecule P-selectin antagonist is an attractive strategy for the treatment of atherosclerosis. High-throughput screening and subsequent analoging had led to the identification of compound 1 as the lead candidate. Herein, we report the continuation of this work and the discovery of a second-generation series, the tetrahydrobenzoquinoline salicylic acids. These compounds have improved pharmacokinetic properties, and a number of them have shown oral efficacy in mouse and rat models of atherogenesis and vascular injury. The lead 31 (PSI-697), is currently in clinical development for the treatment of atherothrombotic vascular events.
- Kaila, Neelu,Janz, Kristin,Huang, Adrian,Moretto, Alessandro,DeBernardo, Silvano,Bedard, Patricia W.,Tam, Steve,Clerin, Valerie,Keith Jr., James C.,Tsao, Desirée H.H.,Sushkova, Natalia,Shaw, Gray D.,Camphausen, Raymond T.,Schaub, Robert G.,Wang, Qin
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- Cycloaddition chemistry of 2-vinyl-substituted indoles and related heteroaromatic systems
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(Chemical Equation Presented) The intramolecular Diels-Alder cycloaddition reaction (IMDAF) of several N-phenylsulfonylindolyl-substituted furanyl carbamates containing a tethered π-bond on the indole ring were examined as an approach to the iboga alkaloi
- Padwa, Albert,Lynch, Stephen M.,Mejia-Oneto, Jose M.,Zhang, Hongjun
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p. 2206 - 2218
(2007/10/03)
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- 3-AMINO CHOMAN AND 2-AMINO TETRALIN DERIVATIVES
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3-Amino chroman and 2-amino tetralin derivatives and compositions containing such compounds are disclosed. Methods of using the 3-amino chroman and 2-amino tetralin compounds and compositions containing such compounds in the treatment of serotonin disorders, such as depression and anxiety, are also disclosed.
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Page/Page column 83-84
(2010/02/10)
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- Peripherally selective kappa opioid agonists
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PCT No. PCT/US98/06485 Sec. 371 Date Jun. 24, 1999 Sec. 102(e) Date Jun. 24, 1999 PCT Filed Apr. 2, 1998 PCT Pub. No. WO98/49158 PCT Pub. Date Nov. 5, 1998The compounds of the instant invention as those of Formula I or a pharmaceutically acceptable salt t
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- Certain benzofuranyl-N-[pyrrolidin-1-YL]-N-methyl-acetamide derivatives useful as opioid agonists
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PCT No. PCT/US98/07832 Sec. 371 Date Jun. 30, 1999 Sec. 102(e) Date Jun. 30, 1999 PCT Filed Apr. 17, 1998 PCT Pub. No. WO98/49141 PCT Pub. Date Nov. 5, 1998The novel compounds of formula (I) of the instant invention are selective kappa opioid agonists use
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- Selectivity in the tandem cyclization - Carboxylation reaction of unsaturated haloaryl ethers catalyzed by electrogenerated nickel complexes
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The electrochemical reduction of a series of 2-haloaryl ethers containing allyl and propargyl groups under CO2 allows the synthesis of benzofuranacetic acid derivatives. This novel intramolecular cyclization- carboxylation reaction is carried out in single-compartment cells and is catalyzed by [Ni(cyclam)Br2].
- Olivero,Du?ach
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p. 1885 - 1891
(2007/10/03)
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- A convenient synthesis of benzofuran-3-carboxyaldehydes
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The benzofuran-3-acetic acids (3a-c) on treatment with pyridine N-oxide give benzofuran-3-carboxyaldehydes (5a-c) on reduction with NaBH4 in methanol yields naturally occurring benzofuran 6a which is converted into 6b and 6c by the literature method.
- Deshpande, A. R.,Paradkar, M. V.
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p. 526 - 528
(2007/10/02)
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- Vinylindenes and Some Heteroanalogues in the Diels-Alder Reaction. IX. 3-Vinylbenzofuran and 1,4-Naphthoquinone
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3-Vinylbenzofuran and 1,4-naphthoquinone react to give r-5a,6,c-12a,c,12b-tetrahydroanthrabenzofuran-5,13-quinone.This adduct undergoes ring opening to 2-(2-hydroxyphenyl)anthraquinone with base and oxygen, but shows no rearrangement to anthrabenzofuran-5,13-quinone.
- Pearson, James R.,Porter, Quentin N.
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p. 907 - 917
(2007/10/02)
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- Synthesis of 3-(3-Benzofuranyl)coumarins
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The paper describes the synthesis of a new ring system 3-(3-benzofuranyl)coumarins.
- Deshpande, A.R.,Paradkar, M.V.
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p. 809 - 816
(2007/10/02)
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- Syntheses of Furano Compounds: Part XLIV. Syntheses of 2-CarboxybenzoFuran-3-Acetic Acid and 3-CarboxybenzoFuran-2-Acetic Acid
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1-Carboxybenzofuran-3-acetic acid and 3-carboxybenzofuran-acetic acid have been synthesised. A new synthesis of benzofuran-3-acetic acid, a plant hormone is reported.
- Chatterjea, J. N.,Sahai, Radhika Pati
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p. 633 - 636
(2007/10/02)
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