- Method for preparing trifluridine
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The invention discloses a method for preparing trifluridine. The method comprises the following steps of performing halogenation on ribose fully protected by hydroxyl, performing condensation on the halogenated ribose and 5-(trifluoromethyl)uracil, performing deprotection to generate an intermediate namely 5-trifluoromethyl uridine, and then performing dehydrating, halogenation and a reduction reaction so as to obtain the trifluridine. According to the method disclosed by the invention, the fully protected ribose is used as a raw material, so that the cost of raw materials can be notably reduced; besides, in the condensation reaction process of the ribose protected by 2-site acyl groups, due to effects of neighboring group participation, the beta-stereoselectivity of the condensation reaction is notably increased; the 5-(trifluoromethyl)uracil is used as a raw material, and high-toxicity trifluoromethylating reagents are avoided, so that the method is environmentally-friendly; and a compound as shown in a formula VI begins to use continuous operations, separation and purification on the intermediate are not needed, and final products can be directly generated, so that production and operation are greatly convenient, the production efficiency is improved, and the cost of human resources is reduced.
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Paragraph 0053; 0054
(2020/06/20)
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- Organic semiconductor photocatalyst can bifunctionalize arenes and heteroarenes
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Photoexcited electron-hole pairs on a semiconductor surface can engage in redox reactions with two different substrates. Similar to conventional electrosynthesis, the primary redox intermediates afford only separate oxidized and reduced products or, more rarely, combine to one addition product. Here, we report that a stable organic semiconductor material, mesoporous graphitic carbon nitride (mpg-CN), can act as a visible-light photoredox catalyst to orchestrate oxidative and reductive interfacial electron transfers to two different substrates in a two- or three-component system for direct twofold carbon–hydrogen functionalization of arenes and heteroarenes. The mpg-CN catalyst tolerates reactive radicals and strong nucleophiles, is straightforwardly recoverable by simple centrifugation of reaction mixtures, and is reusable for at least four catalytic transformations with conserved activity.
- Ghosh, Indrajit,Khamrai, Jagadish,Savateev, Aleksandr,Shlapakov, Nikita,Antonietti, Markus,K?nig, Burkhard
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p. 360 - 366
(2019/08/15)
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- THERMOSTABLE BIOCATALYST COMBINATION FOR NUCLEOSIDE SYNTHESIS
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The present invention relates to a transglycosylation method for the preparation of natural and synthetic nucleosides using a uridine phosphorylase (PyNPase, E.C. 2.4.2.3), a purine nucleoside phosphorylase (PNPase, E.C. 2.4.2.1), or a combination thereof. These biocatalysts may be used as such, or by means of host cells transformed with vectors comprising recombinant DNA gene derived from hyperthermophilic archaea and encoding for the PyNPase and PNPase enzymes.
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Paragraph 0088-0089
(2016/08/17)
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- Simple and Clean Photoinduced Aromatic Trifluoromethylation Reaction
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We describe a simple, metal-and oxidant-free photochemical strategy for the direct trifluoromethylation of unactivated arenes and heteroarenes under either ultraviolet or visible light irradiation. We demonstrated that photoexcited aliphatic ketones, such as acetone and diacetyl, can be used as promising low-cost radical initiators to generate CF3 radicals from sodium triflinate efficiently. The broad utility of this strategy and its benefit to medicinal chemistry are demonstrated by the direct trifluoromethylation of unprotected bidentate chelating ligand, xanthine alkaloids, nucleosides, and related antiviral drug molecules.
- Li, Lu,Mu, Xiaoyue,Liu, Wenbo,Wang, Yichen,Mi, Zetian,Li, Chao-Jun
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supporting information
p. 5809 - 5812
(2016/06/09)
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- Direct One-Pot Synthesis of Nucleosides from Unprotected or 5-O-Monoprotected d -Ribose
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New, improved methods to access nucleosides are of general interest not only to organic chemists but to the greater scientific community as a whole due their key implications in life and disease. Current synthetic methods involve multistep procedures employing protected sugars in the glycosylation of nucleobases. Using modified Mitsunobu conditions, we report on the first direct glycosylation of purine and pyrimidine nucleobases with unprotected d-ribose to provide β-pyranosyl nucleosides and a one-pot strategy to yield β-furanosides from the heterocycle and 5-O-monoprotected d-ribose.
- Downey, A. Michael,Richter, Celin,Pohl, Radek,Mahrwald, Rainer,Hocek, Michal
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supporting information
p. 4604 - 4607
(2015/09/28)
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- One-flow, multistep synthesis of nucleosides by Bronsted acid-catalyzed glycosylation
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Nucleosides in flow: A general, scalable method of Bronsted acid-catalyzed nucleoside formation is described. Because of the high reaction temperatures readily available to the flow reaction format, mild Bronsted acids, particularly pyridinium triflates, can be used. A one-flow multistep synthesis of unprotected nucleosides is also reported (see scheme).
- Sniady, Adam,Bedore, Matthew W.,Jamison, Timothy F.
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supporting information; experimental part
p. 2155 - 2158
(2011/04/23)
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- NUCLEIC ACID BASE HAVING PERFLUOROALKYL GROUP AND METHOD FOR PRODUCING THE SAME
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Provided is a simple and efficient production process of a nucleobase having a perfluoroalkyl group. A nucleobase (for example, uracils, cytosines, adenines, guanines, hypoxanthines, xanthines, or the like) is reacted with a perfluoroalkyl halide in the presence of a sulfoxide, a peroxide and an iron compound to produce a perfluoroalkyl-substituted nucleobase, which is useful as an intermediate for medical drugs, economically.
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Page/Page column 42
(2008/12/07)
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- Lipid esters of nucleoside monophosphates and their use as immunosuppressive drugs
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The present invention is directed to new nucleoside monophosphate derivatives of lipid ester residues of general formula (I) wherein R1 represents an optionally substituted alkyl chain having 1-20 carbon atoms; R2 represents hydrogen, an optionally substituted alkyl chain having 1-20 carbon atoms; R3, R4 and R5 represent hydrogen, hydroxy, azido, amino, cyano, or halogen; X represents a valence dash, oxygen, sulfur, a sulfinyl or sulfonyl group; Y represents a valence dash, an oxygen or sulfur atom; B represents a purine and/or pyrimidine base; with the proviso that at least one of the residues R3 or R5 is hydrogen; to their tautomers and their physiologically acceptable salts of inorganic and organic acids and/or bases, as well as to processes for their preparation, and to drugs containing said compounds.
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- Studies on Organic Fluorine Compounds. Part 35. Trifluoromethylation of Pyrimidine- and Purine-nucleosides with Trifluoromethyl-Copper Complex
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Halogenated nucleoside derivatives were trifluoromethylated using a solution of a trifluoromethyl-copper complex, which was prepared by shaking trifluoromethyl iodide and copper powder in hexamethylphosphoric triamide and filtering off the excess of copper powder.The following trifluoromethylated nucleosides were obtained in moderate to good yields: 5-trifluoromethyl-uridine, -deoxyuridine, -cytidine, -deoxycytidine, and arabinosylcytosine; 8-trifluoromethyl-adenosine, -deoxyadenosine, and -inosine; and 6-trifluoromethylribofuranosylpurine.This procedure offers simple synthesis of many trifluoromethyl compounds.
- Kobayashi, Yoshiro,Yamamoto, Kenjiro,Asai, Toyohira,Nakano, Masanori,Kumadaki, Itsumaro
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p. 2755 - 2761
(2007/10/02)
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