- Synthesis of [2,2’]Bifuranyl-5,5’-dicarboxylic Acid Esters via Reductive Homocoupling of 5-Bromofuran-2-carboxylates Using Alcohols as Reductants?
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Herein, we describe an environmentally benign and cost-effective protocol for the synthesis of valuable bifuranyl dicarboxylates, starting with α-bromination of readily accessible furan-2-carboxylates by LiBr and K2S2O8. Furthermore, the bromination intermediate product 5-bromofuran-2-carboxylates were then conducted in a palladium-catalyzed reductive homocoupling reactions in the presence of alcohols to afford bifuranyl dicarboxylates. One of the final products in this protocol, [2,2’]bifuran-5,5’-dicarboxylic acid esters, are essential monomers of poly(ethylene bifuranoate), which can be served as an green and versatile alternative polymer for traditional poly(ethylene terephthalate) that is currently common in technical plastics.
- Jiang, Huanfeng,Luo, Jiajun,Xie, Yi,Yin, Biaolin,Yu, Bin
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- A quick, mild and efficient bromination using a CFBSA/KBr system
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Bromination is a fundamental transformation in organic chemistry and brominated compounds as building blocks are of paramount importance in organic synthesis. In our study, we have developed an efficient method of bromination by using a CFBSA/KBr system at room temperature in a short reaction time. Notably, this approach has been proven to be applicable to a range of substrates including 1,3-diketones and β-keto esters, phenols, aromatic amines and heteroarenes with good to excellent yields.
- Jiang, Pan-Pan,Yang, Xian-Jin
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p. 90031 - 90034
(2016/10/09)
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- Dual role of Rh(III) catalyst enables regioselective halogenation of (electron-rich) heterocycles
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The Rh(III)-catalyzed selective bromination and iodination of electron-rich heterocycles is reported. Kinetic investigations show that Rh plays a dual role in the bromination, catalyzing the directed halogenation and preventing the inherent halogenation of these substrates. As a result, this method gives highly selective access to valuable halogenated heterocycles with regiochemistry complementary to those obtained using uncatalyzed approaches, which rely on the inherent reactivity of these classes of substrates. Furans, thiophenes, benzothiophenes, pyrazoles, quinolones, and chromones can be applied.
- Schr?der, Nils,Lied, Fabian,Glorius, Frank
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p. 1448 - 1451
(2015/02/19)
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- Spirocyclic delta opioid receptor agonists for the treatment of pain: Discovery of N,N-diethyl-3-hydroxy-4-(spiro[chromene-2,4′-piperidine]-4- yl) benzamide (ADL5747)
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Selective, nonpeptidic δ opioid receptor agonists have been the subject of great interest as potential novel analgesic agents. The discoveries of BW373U86 (1) and SNC80 (2) contributed to the rapid expansion of research in this field. However, poor drug-like properties and low therapeutic indices have prevented clinical evaluation of these agents. Doses of 1 and 2 similar to those required for analgesic activity produce convulsions in rodents and nonhuman primates. Recently, we described a novel series of potent, selective, and orally bioavailable delta opioid receptor agonists. The lead derivative, ADL5859 (4), is currently in phase II proof-of-concept studies for the management of pain. Further structure activity relationship exploration has led to the discovery of ADL5747 (36), which is approximately 50-fold more potent than 4 in an animal model of inflammatory pain. On the basis of its favorable efficacy, safety, and pharmacokinetic profile, 36 was selected as a clinical candidate for the treatment of pain.
- Bourdonnec, Bertrand Le,Windh, Rolf T.,Leister, Lara K.,Zhou, Q. Jean,Ajello, Christopher W.,Gu, Minghua,Chu, Guo-Hua,Tuthill, Paul A.,Barker, William M.,Koblish, Michael,Wiant, Daniel D.,Graczyk, Thomas M.,Belanger, Serge,Cassel, Joel A.,Feschenko, Marina S.,Brogdon, Bernice L.,Smith, Steven A.,Derelanko, Michael J.,Kutz, Steve,Little, Patrick J.,Dehaven, Robert N.,DeHaven-Hudkins, Diane L.,Dolle, Roland E.
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experimental part
p. 5685 - 5702
(2010/02/28)
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- IMIDAZOLE DERIVATIVE
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A CB2 receptor modulator comprising an imidazole derivative represented by the general formula (I): [wherein, R1 represents optionally substituted lower alkyl or the like; R2 represents optionally substituted cycloalkyl or the like; R3 represents optionally substituted aryl or the like; and n represents an integer of 0 to 3] or a pharmaceutically acceptable salt thereof as an active ingredient, and the like are provided.
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Page/Page column 71
(2009/09/05)
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- REACTION OF ETHYL 5-SUBSTITUTED-2-FUROYLMALONATES WITH SECONDARY AMINES
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In situ prepared magnesium salts of ethyl malonate react with 5-X-2-furoyl chlorides (X=Br.NO2.C6H5S and C6H5SO2) to give the corresponding ethyl 5-X-2-furoylmalonates.On treatment of these compounds with secondary amines no nucleophilic substitution of the group X in position 5 of the furan nucleus took place but, instead, amides of 5-X-2-furancarboxylic acids were isolated.
- Kada, Rudolf,Brunckova, Jarmila,Bobal, Pavol
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p. 1400 - 1407
(2007/10/02)
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