- Phenol compound ortho-position direct fluorination method
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The invention relates to a phenol compound ortho-position direct fluorination method which comprises the following steps: reacting a phenol compound shown in a formula (1A) with a fluorination reagentin a solvent under the action of a photocatalyst and a light source at room temperature, and separating and purifying a reaction mixture after the reaction to obtain a fluorinated phenol compound shown in a formula (2A). The advantages are as follows: the method for directly fluorinating phenol by organic photocatalysis is simple in operation process; raw materials are commercialized and easy toobtain; the photocatalyst is low in price, easy to obtain and environmentally friendly; the reaction condition is mild; the site selectivity is high; the reaction is efficient; and a fluorinated phenol derivative can be prepared only through one step.
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Paragraph 0058-0060
(2020/04/17)
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- Vanadate-dependent bromoperoxidases from Ascophyllum nodosum in the synthesis of brominated phenols and pyrroles
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Bromoperoxidases from the brown alga Ascophyllum nodosum, abbreviated as VBrPO(AnI) and VBrPO(AnII), show 41% sequence homology and differ by a factor of two in the percentage of α-helical secondary structures. Protein monomers organize into homodimers for VBrPO(AnI) and hexamers for VBrPO(AnII). Bromoperoxidase II binds hydrogen peroxide and bromide by approximately one order of magnitude stronger than VBrPO(AnI). In oxidation catalysis, bromoperoxidases I and II turn over hydrogen peroxide and bromide similarly fast, yielding in morpholine-4-ethanesulfonic acid (MES)-buffered aqueous tert-butanol (pH 6.2) molecular bromine as reagent for electrophilic hydrocarbon bromination. Alternative compounds, such as tribromide and hypobromous acid are not sufficiently electrophilic for being directly involved in carbon-bromine bond formation. A decrease in electrophilicity from bromine via hypobromous acid to tribromide correlates in a frontier molecular orbital (FMO) analysis with larger energy gaps between the π-type HOMO of, for example, an alkene and the σ*Br,X-type LUMO of the bromination reagent. By using this approach, the reactivity of substrates and selectivity for carbon-bromine bond formation in reactions mediated by vanadate-dependent bromoperoxidases become predictable, as exemplified by the synthesis of bromopyrroles occurring naturally in marine sponges of the genera Agelas, Acanthella, and Axinella. The Royal Society of Chemistry.
- Wischang, Diana,Radlow, Madlen,Hartung, Jens
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p. 11926 - 11940
(2013/09/02)
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- PROCESS FOR PRODUCING 1,2-DIALKOXY-3-FLUOROBENZENE
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The present invention relates to a process for producing a 2-fluoro-6-halophenol as an intermediate; a process for producing a 2-alkoxy-3-fluorophenol and further a 1,2-dialkoxy-3-fluorobenzene from the 2-fluoro-6-halophenol; a second process for producing a 1,2-dialkoxy-3-fluorobenzene from the 2-fluoro-6-halophenol; and a 2-alkoxy-3-fluorophenol. The 2-fluoro-6-halophenol can be obtained using a 2-fluorophenol as a starting material and through a sulfonation reaction, a halogenation reaction, and a deprotection reaction. The 2-fluoro-6-halophenol is alkyl-etherified, and subsequently the halogen atom is converted into a hydroxyl group to obtain the 2-alkoxy-3-fluorophenol, which is further alkyl-etherified to thereby obtain the 1,2-dialkoxy-3-fluorobenzene. Alternatively, a 1,2-dialkoxy-3-fluorobenzene is also obtained by converting the halogen atom of the 2-fluoro-6-halophenol into a hydroxyl group to thereby form 3-fluorocatechol and subsequently alkyl-etherifying two hydroxyl groups thereof. The processes of the invention realize low production costs and high process yields, and thus are suitable for industrial production of a 1,2-dialkoxy-3-fluorobenzene.
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Page/Page column 7
(2009/06/27)
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- Process for producing 1,2-dialkoxy-3-fluorobenzene
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The present invention relates to a process for producing a 2-fluoro-6-halophenol as an intermediate; a process for producing a 2-alkoxy-3-fluorophenol and further a 1,2-dialkoxy-3-fluorobenzene from the 2-fluoro-6-halophenol; a second process for producing a 1,2-dialkoxy-3-fluorobenzene from the 2-fluoro-6-halophenol; and a 2-alkoxy-3-fluorophenol. The 2-fluoro-6-halophenol can be obtained using a 2-fluorophenol as a starting material and through a sulfonation reaction, a halogenation reaction, and a deprotection reaction. The 2-fluoro-6-halophenol is alkyl-etherified, and subsequently the halogen atom is converted into a hydroxyl group to obtain the 2-alkoxy-3-fluorophenol, which is further alkyl-etherified to thereby obtain the 1,2-dialkoxy-3-fluorobenzene. Alternatively, a 1,2-dialkoxy-3-fluorobenzene is also obtained by converting the halogen atom of the 2-fluoro-6-halophenol into a hydroxyl group to thereby form 3-fluorocatechol and subsequently alkyl-etherifying two hydroxyl groups thereof. The processes of the invention realize low production costs and high process yields, and thus are suitable for industrial production of a 1,2-dialkoxy-3-fluorobenzene.
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Page/Page column 5
(2009/09/26)
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- Preparation of monofluorophenols via the reaction of difluorobenzene derivatives with potassium trimethylsilanoate
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An efficient synthesis of monofluorophenols via the reaction of difluorobenzene derivatives with potassium trimethylsilanoate in moderate to excellent yields is described. High regioselectivity was observed in some cases. Georg Thieme Verlag Stuttgart.
- Li, Jianqing,Smith, Daniel,Qiao, Jennifer X.,Huang, Stella,Krishnananthan, Subramaniam,Wong, Henry S.,Salvati, Mark E.,Balasubramanian, Balu N.,Chen, Bang-Chi
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scheme or table
p. 633 - 637
(2009/07/01)
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- MACROCYCLIC GHRELIN RECEPTOR MODULATORS AND METHODS OF USING THE SAME
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The present invention provides novel conformationally-defined macrocyclic compounds that can function as selective modulators of the ghrelin receptor (growth hormone secretagogue receptor, GHS-R1a and subtypes, isoforms and variants thereof). Methods of synthesizing the novel compounds are also described herein. These compounds are useful as agonists of the ghrelin receptor and as medicaments for treatment and prevention of a range of medical conditions including, but not limited to, metabolic and/or endocrine disorders, gastrointestinal disorders, cardiovascular disorders, obesity and obesity-associated disorders, central nervous system disorders, bone disorders, genetic disorders, hyperproliferative disorders and inflammatory disorders.
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Page/Page column 36; 44
(2008/12/07)
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- Synthesis of halogenated phenols by directed ortho-lithiation and ipso-iododesilylation reactions of O-aryl N-isopropylcarbamates
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The regioselective synthesis of halogenated phenols via directed ortho-lithiation reactions of in situ N-silylated O-aryl N-isopropylcarbamates is reported. This protocol is complemented by ipso-iododesilylation reactions of C-silylated carbamates and iodine-magnesium exchange reactions, which are facilitated by the adjacent carbamoyl group. These methods provide an entry into a series of o-fluoro-, o-iodo-, and o,o′-diiodophenols in high yields which are otherwise difficult to obtain. Georg Thieme Verlag Stuttgart.
- Kauch, Matthias,Hoppe, Dieter
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p. 1578 - 1589
(2007/10/03)
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