- Influence of the type of halogen substituent on in vivo and in vitro phase II metabolism of 2-fluoro-4-halophenol metabolites formed from 3-halo-fluorobenzenes
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The influence of a change in the type of halogen substituent on phase II metabolism of 2-fluoro-4-halophenol metabolites formed from 3-halo-fluorobenzenes was studied in vivo and in vitro using 19F nmr and spectroscopic assays. The ratio of sulphation to glucuronidation of 2-fluoro-4-halophenol metabolites formed from 3-halofluorobenzenes decreased from 48 to 13 to 6 when the halogen substituent varied from fluorine to chlorine to bromine. When the 2-fluoro-4-halophenols themselves were administered to the rats, the ratio of sulphation to glucuronidation was not affected by the type of halogen substituent at C4 and at a constant value of 0.6, i.e. significantly lower. Kinetic data for P450 catalysed hydroxylation of the 3-halo-fluorobenzenes and for sulphation and glucuronidation of their 2-fluoro-4-halophenol metabolites were obtained from in vitro microsomal and cytosolic incubations. These data demonstrate that the effects of varying the halogen substituent on phase II metabolism of the 2-fluoro-4-halophenol metabolites can be mainly ascribed to an apparently decreased K(m) for the glucuronidation of the 2-fluoro-4-halophenols with a change in the halo substituent from fluorine to chlorine to bromine. Results from calculations on electronic and structural characteristics of the three 4-halo-2-fluorophenols demonstrate that the best explanation for the decrease in the apparent K(m) of the glucuronidation from 2,4-difluoro- to 4-chloro-2-fluoro- to 4-bromo-2-fluorophenol might be an increase in the hydrophobicity of the phenol. An increase in the hydrophobicity of the phenol would provide an increased possibility for substrate accumulation in the hydrophobic membrane environment of the UDP-glucuronyltransferases, resulting in an apparently decreased K(m).
- Soffers,Veeger,Rietjens
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- A convenient and efficient H2SO4-promoted regioselective monobromination of phenol derivatives using N-bromosuccinimide
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A convenient, rapid H2SO4-promoted regioselective monobromination reaction with N-bromosuccinimide was developed. The desired para-monobrominated or ortho-monobrominated products of phenol derivatives were obtained in good to excellent yields with high selectivity. Regioselective chlorination and iodination were also achieved in the presence of H2SO4 using N-chlorosuccinimide and N-iodosuccinimide, respectively.
- Wu, Yong-Qi,Lu, Hai-Jia,Zhao, Wen-Ting,Zhao, Hong-Yi,Lin, Zi-Yun,Zhang, Dong-Feng,Huang, Hai-Hong
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supporting information
p. 813 - 822
(2020/02/15)
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- Regioselective monobromination of phenols with KBr and ZnAl–BrO3?–layered double hydroxides
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The regioselective mono-bromination of phenols has been successfully developed with KBr and ZnAl–BrO3?–layered double hydroxides (abbreviated as ZnAl–BrO3?–LDHs) as brominating reagents. The para site is much favorable and the ortho site takes the priority if para site is occupied. This reaction featured with excellent regioselectivity, cheap brominating reagents, mild reaction condition, high atom economy, broad substrate scope, and provided an efficient method to synthesize bromophenols.
- Wang, Ligeng,Feng, Chun,Zhang, Yan,Hu, Jun
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supporting information
(2020/02/22)
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- Novel pleconaril derivatives: Influence of substituents in the isoxazole and phenyl rings on the antiviral activity against enteroviruses
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Today, there are no medicines to treat enterovirus and rhinovirus infections. In the present study, a series of novel pleconaril derivatives with substitutions in the isoxazole and phenyl rings was synthesized and evaluated for their antiviral activity against a panel of pleconaril-sensitive and -resistant enteroviruses. Studies of the structure-activity relationship demonstrate the crucial role of the N,N-dimethylcarbamoyl group in the isoxazole ring for antiviral activity against pleconaril-resistant viruses. In addition, one or two substituents in the phenyl ring directly impact on the spectrum of antienteroviral activity. The 3-(3-methyl-4-(3-(3-N,N-dimethylcarbamoyl-isoxazol-5-yl)propoxy)phenyl)-5-trifluoromethyl-1,2,4-oxadiazole 10g was among the compounds exhibiting the strongest activity against pleconaril-resistant as well as pleconaril-susceptible enteroviruses with IC50 values from 0.02 to 5.25 μM in this series. Compound 10g demonstrated markedly less CYP3A4 induction than pleconaril, was non-mutagenic, and was bioavailable after intragastric administration in mice. These results highlight compound 10g as a promising potential candidate as a broad spectrum enterovirus and rhinovirus inhibitor for further preclinical investigations.
- Egorova, Anna,Ekins, Sean,Jahn, Birgit,Kazakova, Elena,Makarov, Vadim,Schmidtke, Michaela
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- 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 0052-0054
(2020/04/17)
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- Mild and Regioselective Bromination of Phenols with TMSBr
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In this work, an unexpected promoting effect of by-product thioether was observed, leading to a mild and regioselective bromination of phenols with TMSBr. This method can tolerate a series of functional groups such as the reactive methoxyl, amide, fluoro, chloro, bromo, aldehyde, ketone and ester groups, and has the potential to recycle the by-product thioether and isolate the desired product under column chromatography-free conditions. Mechanism studies revealed that O–H···S hydrogen bond may be formed between phenol and by-product thioether. Possibly owing to the steric hindrance effect from by-product thioether, the electrophilic bromination at para-position of phenols is much favorable.
- Ma, Xiantao,Yu, Jing,Jiang, Mengyuan,Wang, Mengyu,Tang, Lin,Wei, Mengmeng,Zhou, Qiuju
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supporting information
p. 4593 - 4596
(2019/07/05)
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- Intermolecular Aryl C?H Amination through Sequential Iron and Copper Catalysis
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A mild, efficient and regioselective method for para-amination of activated arenes has been developed through a combination of iron and copper catalysis. A diverse range of products were obtained from an operationally simple one-pot, two-step procedure involving bromination of the aryl substrate with the powerful Lewis acid iron(III) triflimide, followed by a copper(I)-catalysed N-arylation reaction. This two-step dehydrogenative process for the regioselective coupling of aromatic C?H bonds with non-activated amines was applicable to anisole-, phenol-, aniline- and acetanilide-type aryl compounds. Importantly, the arene substrates were used as the limiting reagent and required no protecting-group manipulations during the transformation.
- Mostafa, Mohamed A. B.,Calder, Ewen D. D.,Racys, Daugirdas T.,Sutherland, Andrew
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supporting information
p. 1044 - 1047
(2017/02/05)
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- Synthesis of 2 - fluoro phenol compounds
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The present invention provides a method for synthetizing a 2-fluoro phenol compound shown in a formula IV. The phenol compound shown in the formula I is prepared into a 2-pyridine oxygroup arene compound shown in a formula II through an Ullmann reaction, the 2-pyridine oxygroup arene compound shown in the formula II is mixed with a palladium catalyst, a fluorinating reagent, an additive and an organic solvent, the mixture is stirred under the temperature of 30-160 DEG C to perform a fluorination reaction to obtain an ortho-position fluoridated 2-pyridine oxygroup arene compound shown in a formula III, and the ortho-position fluoridated 2-pyridine oxygroup arene compound shown in the formula III is prepared into the 2-fluoro phenol compound shown in the formula IV through the action of alkali. The method provided by the present invention has the advantages of mild reaction conditions, simplicity in operations, good substrate adaptability, high fluorination selectivity and the like. The 2-fluoro phenol compound is shown in the figure below.
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- Selective C-H bond fluorination of phenols with a removable directing group: Late-stage fluorination of 2-phenoxyl nicotinate derivatives
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A facile and site-selective C-H bond fluorination of phenols using removable 2-pyridyloxy group as an auxiliary was developed. Alternatively, late-stage C-H bond fluorination of bioactive 2-phenoxyl nicotinate derivatives and diflufenican were also feasible under the present strategy.
- Lou, Shao-Jie,Chen, Qi,Wang, Yi-Feng,Xu, Dan-Qian,Du, Xiao-Hua,He, Jiang-Qi,Mao, Yang-Jie,Xu, Zhen-Yuan
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p. 2846 - 2849
(2015/05/20)
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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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- Bromination of phenols in bromoperoxidase-catalyzed oxidations
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Phenol and ortho-substituted derivatives furnish products of selective para-bromination, if treated with sodium bromide, hydrogen peroxide, and the vanadate(V)-dependent bromoperoxidase I from the brown alga Ascophyllum nodosum. Relative rates of bromination in morpholine-4-ethane sulfonic acid (MES)-buffered aqueous tert-butanol (pH 6.2) increase by a factor 32, as the ortho-substituent in a phenol changes from F via Cl, OCH3, C(CH 3)3, and H to CH3. The polar effect in phenol bromination by the enzymatic method, according to a Hammett-correlation (ρ=-3), compares to reactivity of molecular bromine under identical conditions (ρ=-2). Hypobromous acid is not able to electrophilically substitute bromine for hydrogen at pH 6.2 in aqueous tert-butanol. The tribromide anion behaves in MES-buffered aqueous tert-butanol as electrophile (ρ～-3), showing a similar polar effect in phenol bromination as molecular bromine.
- Wischang, Diana,Hartung, Jens
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supporting information
p. 9456 - 9463
(2012/11/07)
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- P-Hydroxyphenacyl photoremovable protecting groups Robust photochemistry despite substituent diversity
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A broadly based investigation of the effects of a diverse array of substituents on the photochemical rearrangement of p-hydroxyphenacyl esters has demonstrated that common substituents such as F, MeO, CN, CO2R, CONH2, and CH3 have little effect on the rate and quantum efficiencies for the photo-Favorskii rearrangement and the release of the acid leaving group or on the lifetimes of the reactive triplet state. A decrease in the quantum yields across all substituents was observed for the release and rearrangement when the photolyses were carried out in buffered aqueous media at pHs that exceeded the ground-state pKa of the chromophore where the conjugate base is the predominant form. Otherwise, substituents have only a very modest effect on the photoreaction of these robust chromophores.
- Givens, Richard S.,Stensrud, Kenneth,Conrad, Peter G.,Yousef, Abraham L.,Perera, Chamani,Senadheera, Sanjeewa N.,Heger, Dominik,Wirz, Jakob
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scheme or table
p. 364 - 384
(2011/06/22)
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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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- New oxabispidine compounds for the treatment of cardiac arrhythmias
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There is provided compounds of formula I, wherein R1, R2, R3, R41 to R46, X, Y and Z have meanings given in the description, which compounds are useful in the prophylaxis and in the treatment of arrhythmias, in particular atrial and ventricular arrhythmias.
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Page/Page column 58
(2008/06/13)
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- PROCESS FOR THE PREPARATION OF N,N′- DISUBSTITUTED OXABISPIDINES
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There is provided a process for the preparation of a sulfonic acid salt of formula I, or a solvate thereof, which process comprises hydrogenating a sulfonic acid salt of formula II,. or a solvate thereof; in the presence of a solvent system consisting essentially of water, a C3-5 secondary alkyl alcohol and no more than 15% v/v of another organic solvent, wherein the sulfonic acid salt of formula I is optionally, without isolation, converted to a compound of formula IX, or a pharmaceutically-acceptable derivative thereof, wherein R1, R2, R3, R6, R7, R8, A, B and D have meanings given in the description.
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Page/Page column 33
(2010/11/25)
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- NOVEL OXABISPIDINE COMPOUNDS AND THEIR USE IN THE TREATMENT OF CARDIAC ARRHYTHMIAS
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There is provided compounds of formula (I), wherein R1, R2, R3, R4, R 41 to R46, A, B and G have meanings given in the description, which are useful in the prophylaxis and in the treatment of arrhythmias, in particular atrial and ventricular arrhythmias.
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Page/Page column 84 - 85
(2008/06/13)
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- Potent, novel in vitro inhibitors of the Pseudomonas aeruginosa deacetylase LpxC
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Deacetylation of uridyldiphospho-3-O-(R-hydroxydecanoyl)-N-acetylglucosamine by LpxC is the first committed step in the Pseudomonas aeruginosa biosynthetic pathway to lipid A; homologous enzymes are found widely among Gram-negative bacteria. As an essential enzyme for which no inhibitors have yet been reported, the P. aeruginosa LpxC represents a highly attractive target for a novel antibacterial drug. We synthesized several focused small-molecule libraries, each composed of a variable aromatic ring, one of four heterocyclic/spacer moieties, and a hydroxamic acid and evaluated the LpxC inhibition of these compounds against purified P. aeruginosa enzyme. To ensure that the in vitro assay would be as physiologically relevant as possible, we synthesized a tritiated form of the specific P. aeruginosa glycolipid substrate and measured directly the enzymatically released acetate. Several of our novel compounds, predominantly those having fluorinated substituents on the aromatic ring and an oxazoline as the heterocyclic moiety, demonstrated in vitro IC50 values less than 1 μM. We now report the synthesis and in vitro evaluation of these P. aeruginosa LpxC inhibitors.
- Kline, Toni,Andersen, Niels H.,Harwood, Eric A.,Bowman, Jason,Malanda, Andre,Endsley, Stephanie,Erwin, Alice L.,Doyle, Michael,Fong, Susan,Harris, Alex L.,Mendelsohn, Brian,Mdluli, Khisimuzi,Raetz, Christian R. H.,Stover, C. Kendall,Witte, Pamela R.,Yabannavar, Asha,Zhu, Shuguang
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p. 3112 - 3129
(2007/10/03)
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- Elemental fluorine Part 12. Fluorination of 1,4-disubstituted aromatic compounds
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Direct fluorination of a series of 1,4-disubstituted benzene derivatives in acid reaction media at convenient temperature leads, in many cases, to selectively fluorinated aromatic products in preparatively useful conversions and yields.
- Chambers, Richard D.,Hutchinson, John,Sparrowhawk, Matthew E.,Sandford, Graham,Moilliet, John S.,Thomson, Julie
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p. 169 - 173
(2007/10/03)
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- Chiral cyclohexyl compounds
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The present invention describes liquid crystal compounds which are suitable for use in liquid crystal devices including those which exploit the electroclinic effect.
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- Insecticidal ethers
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This invention relates to novel fluorinated ethers, useful as insecticides and acaricides, to processes and intermediates for their preparation, to insecticidal and acaricidal compositions thereof and to methods of combating and controlling insect and acarine pests therewith.
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- Phenoxyphenoxypropionates, intermediates thereof and methods of preparation
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A method for preparing substituted phenoxyphenols which are useful in the preparation of herbicidal (phenoxyphenoxy)propionates is disclosed. The process involves the oxidation of substituted phenoxyphenones to the corresponding phenoxyphenyl esters and their conversion to the desired phenoxyphenol. Novel intermediates for the process are similarly disclosed.
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- Azolyl substituted aralkyl compounds and pesticidal use thereof
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Compounds of the formula: STR1 The compounds are useful as pesticides, particularly insecticides.
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- Fluorophenoxyphenoxypropionates and derivatives thereof
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Novel fluorophenoxyphenoxypropionates and derivatives thereof possess herbicidal activity selectively in the presence of broadleaf crops. Preemergent and postemergent applications are contemplated.
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- Fluorophenoxyphenoxypropionates and derivatives thereof
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Novel intermediates useful in the preparation of fluorophenoxyphenoxypropionates and derivatives thereof which possess herbicidal activity selectively in the presence of broadleaf crops.
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- Fluorophenoxyphenoxypropionates and derivatives thereof
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Novel intermediates useful in the preparation of fluorophenoxyphenoxypropionates and derivatives thereof which possess herbicidal activity selectively in the presence of broadleaf crops.
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- Fluorophenoxyphenoxypropionates and derivatives thereof
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Novel fluorophenoxyphenoxypropionates and derivatives thereof possess herbicidal activity selectively in the presence of broadleaf crops. Preemergent and postemergent applications are contemplated.
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- The Synthesis and Liquid Crystal Properties of Some Laterally Fluorinated trans-Cyclohexane-1-carboxylate and Benzoate Esters
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A large number of laterally fluorinated 4-n-alkyl- and -alkoxy-phenyl 4'-n-alkyl- and -alkoxy-bezoates and 4-n-alkylphenyl trans-4'-n-alkyl- and -alkoxy-cyclohexane-1-carboxylates were synthesised.In these compounds, the lateral fluoro-substituent was situated in either the phenol or the carboxylic acid moiety of the molecules for the benzoate esters, but only in the phenol moiety for the trans-cyclohexane-1-carboxylate esters.The nematic thermal stabilities for the fluorophenyl bezoate and trans-cyclohexane-1-carboxylate esters and the fluorobenzoate esters were compared with those for the corresponding non-fluorinated analogues.A nematic thermal efficiency order was derived for the 4-n-alkyl-fluorophenyl 4-n-alkylbezoate and trans-4-n-alkylcyclohexane-1-carboxylate esters, but only in the case of the latter esters, which were extensively examined, was the smectic tendency of the system investigated.Explanations are given for the observed nematic and smectic thermal stabilities of the titled esters, and some of their physical properties are discussed.
- Gray, G. W.,Hogg, C.,Lacey, D.
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- Etude des complexes du cobalt (II) transporteurs d'oxygene: Nouvelle synthese du fluoro-3 hydroxy-2 benzaldehyde
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Synthetic chelates of cobalt (II) derived from Schiff bases have remarkable behavior of reversibly absorbing and releasing molecular oxygene.Among these, bis (3-fluorosalicylaldehydeethylenediimide) Co (II) (fluomine: Formula A, X=F) is most interesting in allowing to isolate pure oxygen from air, because it absorbs with extreme rapidity 4.43percent of its weight of oxygen.Fluomine is easily prepared from 3-fluorosalicylaldehyde (3FSA), ethylenediamine and cobalt (II) chloride; but substances such as 3-substituted salicylaldehydes have proven to be extremely difficult to prepare in other than small laboratory quantities from the corresponding ortho-substituted phenol.Many author have prepared 3-fluorosalicylaldehyde, as described in patents, but often these syntheses are very long and the yields are generally less than 20percent.We now describe a new synthesis from o-fluorophenol.Nitration of o-fluorophenol with liquid nitrogen dioxide is convenient: - on the one hand, ortho-substitution to the hydroxyl group, is easy, -on the other hand, the para substituted by-product, is reinserted in the course of the synthesis, so that it is possible to minimize loss of the starting phenol, an expensive product. o-Fluorophenol 1 in solution in pentane, at about 0 deg C, is treated with liquid nitrogen dioxide (slight excess).The reaction is rapid and leads to 2-fluoro 6-nitrophenol 2 which remains in solution, and 2-fluoro 4-nitrophenol 7 which cristallizes rapidly (approximatively 50percent of each one). 2-Fluoro 6-nitrophenol 2 is converted into the anisole 3, the NO2 group of which is catalytically reduced by hydrogen into 3-fluoro 2-methoxy-aminobenzene 4.This amine 4 is diazotized, and treated with formaldoxime to lead to 3-fluoro 2-methoxybenzaldehyde 5 (Eb12 = 82 deg C). 3FSA is finally obtained by heating under reflux anisole 5 and a solution of hydrobromic acid (48percent). 2-Fluoro 4-nitrophenol 7 is converted in five steps into 3-fluoro 2-methoxyaminobenzene 4 by the same reactions as these used for its isomer.Finally the total yield of amine 4 from o-fluorophenol is 73percent, and 3FSA is obtained in 25percent yield.No primary amines are required during the isolation, so that no possible contamination of the final product is possible and therefore the fluomine prepared therefrom is not contaminated and deactivated.
- Aymes, Daniel J.,Paris, Michel R.
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p. 175 - 178
(2007/10/02)
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