- Practical synthesis of 2,3,4,5-tetramethoxytoluene
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The title compound, a key material for synthesis of coenzyme Q 10 , was effectively prepared in high yield by a reaction sequence starting from 3,4,5-trimethoxybenzadehyde via Wolff-Kishner reduction, Vilsmeier-Haack reaction, Dakin reaction, and methylation. Copyright Taylor & Francis Group, LLC.
- Ji, Yafei,Xu, Wanmei,Jin, Wenhu,Weimin, Yue
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- A novel and convenient synthesis of coenzyme Q1
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A convenient and efficient synthetic route to Coenzyme Q1 (6) starting from 3,4,5-trimethoxytoluene (1) is described. The key features of this synthesis include the Diels-Alder reaction of 2,3-dimethoxy-1,4-benzoquinone (3) with cyclopentadiene and the introduction of a C5 side chain to 4,5-dimethoxy-2-methyltricyclo[6.2.1.02,7]undeca-4,9-diene-3,6-dione (4) under mild conditions, (6) was obtained in overall 60% yield.
- Lu, Liang,Chen, Fener
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- Synthesis of oxygenated orthomethylbenzaldehydes via aryne [2+2] cycloaddition and benzocyclobutenol ring opening
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Herein, a two-step procedure for the preparation of oxygenated ortho-methylbenzaldehyde derivatives, starting from commercially available bromoarenes, is described. The synthesis features the simultaneous and highly regioselective installation of both the methyl and the formyl group onto the benzene core via benzyne [2+2] cycloadditions with acetaldehyde lithium enolate to give the corresponding benzocyclobutenols in high yields. Bond-selective ring opening of the benzocyclobutenols under basic conditions in methanol delivers the title compounds.
- Maturi, Mark M.,Ohmori, Ken,Suzuki, Keisuke
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p. 870 - 873
(2019/01/21)
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- Fluorogenic Ubiquinone Analogue for Monitoring Chemical and Biological Redox Processes
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We report herein the synthesis and characterization of a fluorogenic analogue of ubiquinone designed to reversibly report on redox reactions in biological systems. The analogue, H2B-Q, consists of the redox-active quinone segment found in ubiquinone, 2,3-dimethoxy-1,4-benzoquinone, coupled to a boron-dipyrromethene (BODIPY) fluorophore segment that both imparts lipophilicity in lieu of the isoprenyl tail of ubiquinone, and reports on redox changes at the quinone/quinol segment. Redox sensing is mediated by a photoinduced electron transfer intramolecular switch. In its reduced dihydroquinone form, H2B-QH2 is highly emissive in nonpolar media (quantum yields 55-66%), while once oxidized, the resulting quinone H2B-Q emission is suppressed. Cyclic voltammetry of H2B-Q shows two reversible, 1-electron reduction peaks at -1.05 V and -1.37 V (vs ferrocene) on par with those of ubiquinone. Chemical reduction of H2B-Q by NaBH4 resulted in >200 fold emission enhancement. H2B-QH2 is shown to react with peroxyl radicals, a form of reactive oxygen species (ROS) as well as to cooperatively interact with chromanol (the active segment of α-tocopherol). Kinetic analysis further shows the antioxidant reactivity of the nonfluorescent intermediate semiquinone. We anticipate that the H2B-Q/H2B-QH2 off/on reversible couple may serve as a tool to monitor chemical redox processes in real-time and in a noninvasive manner.
- Greene, Lana E.,Godin, Robert,Cosa, Gonzalo
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p. 11327 - 11334
(2016/11/05)
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- Alternative synthesis of 5-chloromethyl-2,3-dimethoxy-6-methyl-1, 4-benzoquinone: A key intermediate for preparing coenzyme Q analogues
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The title compound, a key intermediate for preparing Coenzyme Qn family, was prepared in high yield by a reaction sequence starting from the commercially available 3, 4, 5-trimethoxy-benzadehyde via Wolff-Kishner reduction, Vilsmeier-Haack reaction, Blanc chloromethylation reaction, Dakin reaction and oxidation.
- Wang, Jin,Yang, Jian,Yang, Bo,Sun, Jia-Qiang,Yang, Tao
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experimental part
p. 724 - 725
(2011/04/24)
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- New efficient synthesis of ubiquinones
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A strategy for the ecofriendly and high-yielding synthesis of ubiquinones starting from simple materials and using mild conditions is reported. CoQ1, CoQ2, CoQ3, and CoQ9 were prepared. Copyright Taylor & Francis Group, LLC.
- Bovicelli, Paolo,Borioni, Giorgio,Fabbrini, Danilo,Barontini, Maurizio
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p. 391 - 400
(2008/04/01)
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- Radical-scavenging polyphenols: New strategies for their synthesis
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New strategies for the synthesis of polyphenols, compounds with antioxidant properties contained in every kind of plants, are discussed. Syntheses of different classes of polyphenols, namely ubiquinones, present in many natural systems in which electron-transfer mechanisms are involved, hydroxytyrosol, one of the main components of the phenol fraction in olives, and flavonoids, widespread in the plant kingdom, were approached by simple and environmentally sustainable methods.
- Bovicelli, Paolo
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p. 1703 - 1710
(2008/03/11)
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- Benzoylpyridine derivative or its salt, fungicide containing it as an active ingredient, its production process and intermediate for producing it
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The present invention relates to a fungicide containing a novel benzoylpyridine derivaitive or its salt. The present invention provides a fungicide containing a benzoylpyridine derivative represented by formula (I) or its salt: wherein X is a halogen atom, a nitro group, a substitutable alkoxy group, a substitutable aryloxy group, a substitutable cyclo(alkoxy group, a hydroxyl group, a substitutable hydrocarbon group, a substitutable alkylthio group, a cyano group, a carboxyl group which may he esterified or amidated, or at substitutable amino group; n is 1, 2, 3 or 4; R1 is a substitutable alkyl group, R2 is a substitutable alkyl group, it substitutable alkoxy group, a substitutable aryloxy group, a substitutable cycloalkoxy group or a hydroxyl group; and m is 1, 2, 3 or 4, provided that when m is at least 2, R2 may contain an oxygen atom to form a condensed ring.
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Page/Page column 14
(2008/06/13)
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- Synthetic studies on naturally occurring coumarins. II. Synthesis of 6,7-dimethoxy- and 7,8-dimethoxy-5-[(E)-3-oxo-1-butenyl]coumarins
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In connection with studies on the structure elucidation of the so-called Reisch's coumarin isolated from Toddalia asiatica, syntheses of two coumarins (4 and 5) were accomplished via the routes shown in Charts 2 and 3, respectively. Melting points and NMR data of the synthesized coumarins (4 and 5) and of related coumarins (5-methoxysuberenon, toddalenone, and Reisch's coumarin) are given in Table I, suggesting that so-called Reisch's coumarin might be 4.
- Ishii,Ishikawa,Wada,Miyazaki,Kaneko,Harayama
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p. 2614 - 2619
(2007/10/02)
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