- Carboxylation of o-, m-, and p-chlorophenols with sodium ethyl carbonate
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The possibility for the synthesis of 5-chloro-2-hydroxybenzoic, 4-chloro-2-hydroxybenzoic, and 3-chloro-2-hydroxybenzoic acids via regioselective carboxylation of p-, m-, and o-chlorophenols, respectively, with sodium ethyl carbonate has been demonstrated
- Suerbaev, Kh. A.,Chepaikin,Kudaibergenov, N. Zh.
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Read Online
- Biosynthesis of Chlorflavonin in Aspergillus candidus. 13C- and 14C-Labelling Evidence for a New Route to the Flavonoid Structure
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Aspergillus candidus growing in glucose-leucine-salts medium synthesized chlorflavonin (1) from isotopically labelled phenylalanine, cinnamate, benzoate, or acetate.Radioactivity from cinnamic acid and benzoic acid was incorporated less efficiently than that from L-phenylalanine but decarboxylation of 3-chlorosalicylic acid (3) formed by alkaline degradation of the chlorflavonin samples located all of the radioactivity at C-2 in the flavonoid. 4,5-Dimethoxyresorcinol (2), obtained by alkaline degradation of chlorflavonin labelled from sodium acetate and cinnamic acid, accounted for only part of the radioactivity.The label from both precursors was distributed between ring A and one or more of the C-3, C-4, and C-3 methoxy-carbon atoms. 13C N.m.r. spectrometry of chlorflavonin labelled from sodium acetate showed 13C incorporation into C-4, C-5, C-7, and C-8a.Sodium 0;1;1,2-13C1;0;1>acetate was incorporated intact into (C-3,C-4) and all adjacent pairs of ring-A carbon atoms.The results indicate a pathway of flavonoid biosynthesis differing from that of higher plants in that a C6-C1 precursor unit is condensed with four C2 units.In the route proposed, the heterocyclic ring is formed befor ring A is substituted at C-8 and while it is free to rotate at the enzyme surface.
- Burns, Michael K.,Coffin, Jane M.,Kurobane, Itsuo,Vining, Leo C.,McInnes, A. Gavin,et al.
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- Synthesis of salicylic acid derivatives from the corresponding 2-chlorobenzoic acid using water as solvent
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An improved synthesis of salicylic acid using water as solvent can be achieved using the Ullmann-Goldberg reaction conditions in presence of pyridine as cocatalyst. A number of salicylic acids were prepared in good yield.
- Pellon Comdom, Rolando F.,Docampo Palacios, Maite L.
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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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- Carboxylation of Phenols with CO2 at Atmospheric Pressure
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A convenient and efficient method for the ortho-carboxylation of phenols under atmospheric CO2 pressure has been developed. This method provides an alternative to the previously reported Kolbe-Schmitt method, which requires very high pressures of CO2. The addition of a trisubstituted phenol has proved essential for the successful carboxylation of phenols with CO2 at standard atmospheric pressure, allowing the efficient preparation of a broad variety of salicylic acids.
- Luo, Junfei,Preciado, Sara,Xie, Pan,Larrosa, Igor
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supporting information
p. 6798 - 6802
(2016/05/11)
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- 3,6-DICHLOROSALICYLIC ACID COMPOUNDS AND RELATED SYNTHETIC PROCESSES
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The present disclosure relates, in general, to 5-halo-3,6-dichlorosalicylic acid compounds, 5-halo-3,6-dichlorosalicyaldehyde compounds, processes for preparing 5-halo-3,6-dichlorosalicylic acid compounds, processes for preparing 5-halo-3,6- dichlorosalicyaldehyde compounds, processes for preparing 3,6-dichlorosalicylic acid compounds, and processes that employ such compounds as intermediates in the preparation of the herbicide dicamba.
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- General method for the synthesis of salicylic acids from phenols through palladium-catalyzed silanol-directed C-H carboxylation
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A silanol-directed, palladium-catalyzed C-H carboxylation reaction of phenols to give salicylic acids has been developed. This method features high efficiency and selectivity, and excellent functional-group tolerance. The generality of this method was demonstrated by the carboxylation of estrone and by the synthesis of an unsymmetrically o,o′-disubstituted phenolic compound through two sequential C-H functionalization processes.
- Wang, Yang,Gevorgyan, Vladimir
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supporting information
p. 2255 - 2259
(2015/02/19)
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- Regioselective ortho-carboxylation of phenols catalyzed by benzoic acid decarboxylases: A biocatalytic equivalent to the Kolbe-Schmitt reaction
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The enzyme catalyzed carboxylation of electron-rich phenol derivatives employing recombinant benzoic acid decarboxylases at the expense of bicarbonate as CO2 source is reported. In contrast to the classic Kolbe-Schmitt reaction, the biocatalytic equivalent proceeded in a highly regioselective fashion exclusively at the ortho-position of the phenolic directing group in up to 80% conversion. Several enzymes were identified, which displayed a remarkably broad substrate scope encompassing alkyl, alkoxy, halo and amino- functionalities. Based on the crystal structure and molecular docking simulations, a mechanistic proposal for 2,6-dihydroxybenzoic acid decarboxylase is presented.
- Wuensch, Christiane,Gross, Johannes,Steinkellner, Georg,Lyskowski, Andrzej,Gruber, Karl,Glueck, Silvia M.,Faber, Kurt
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p. 9673 - 9679
(2014/03/21)
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- Iron-promoted ortho-And/or ipso-hydroxylation of benzoic acids with H 2O2
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Regioselective hydroxylation of aromatic acids with hydrogen peroxide proceeds readily in the presence of iron(II) complexes with tetradentate aminopyridine ligands [FeII(BPMEN)-(CH3CN) 2](ClO4)2 (1) and [FeII(TPA)- (CH3CN)2](OTf)2 (2), where BPMEN=N, N'-dimethyl-N, N'-bis(2-pyridylmethyl)-1,2-ethylenediamine, TPA=tris-(2- pyridylmethyl)amine. Two cis-sites, which are occupied by labile acetonitrile molecules in 1 and 2, are available for coordination of H2O 2 and substituted benzoic acids. The hydroxylation of the aromatic ring occurs exclusively in the vicinity of the anchoring carboxylate functional group: ortho-hydroxylation affords salicylates, whereas ipso-hydroxylation with concomitant decarboxylation yields phenolates. The outcome of the substituent directed hydroxylation depends on the electronic properties and the position of substituents in the molecules of substrates:3-substituted benzoic acids are preferentially ortho-hydroxylated, whereas 2-and, to a lesser extent, 4-substituted substrates tend to undergo ipso-hydroxylation/decarboxylation. These two pathways are not mutually exclusive and likely proceed via a common intermediate. Electron-withdrawing substituents on the aromatic ring of the carboxylic acids disfavor hydroxylation, indicating an electrophilic nature for the active oxidant. Complexes 1 and 2 exhibit similar reactivity patterns, but 1 generates a more powerful oxidant than 2. Spectroscopic and labeling studies exclude acylperoxoiron(III) and FeIV=O species as potential reaction intermediates, but strongly indicate the involvement of an FeIII-OOH intermediate that undergoes intramolecular acid-promoted heterolytic O-O bond cleavage, producing a transient iron(V) oxidant.
- Makhlynets, Olga V.,Das, Parthapratim,Taktak, Sonia,Flook, Margaret,Mas-Balleste, Ruben,Rybak-Akimova, Elena V.,Que Jr., Lawrence
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experimental part
p. 13171 - 13180
(2010/07/03)
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- INHIBITORS OF STEAROYL-COA DESATURASE
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Provided herein are compounds of the formula (I): as well as pharmaceutically acceptable salts thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment of diseases such as, for example, obesity.
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- ortho-Hydroxylation of benzoic acids with hydrogen peroxide at a non-heme iron center
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The iron-assisted hydroxylation of benzoic acid to salicylic acid by 1/H2O2 has been achieved in good yield under mild conditions (where 1 is [Fe(II)(BPMEN)(CH3CN)2](CIO 4)2 and BPMEN = N,N-dimethyl-N,N-bis(2- pyridylmethyl)ethane-1,2-diamine); the product of this reaction is a novel mononuclear iron(m) complex with a chelating salicylate. The Royal Society of Chemistry 2005.
- Taktak, Sonia,Flook, Margaret,Foxman, Bruce M.,Que Jr., Lawrence,Rybak-Akimova, Elena V.
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p. 5301 - 5303
(2007/10/03)
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- The site-selective functionalization of halogen-bearing phenols: An exercise in diversity-oriented organometallic synthesis
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The organometallic approach to diversity-oriented organic synthesis was subjected to a further test, this time in the phenol series. The model compounds selected were 2,3,6-trifluorophenol, the three isomers of (trifluoromethoxy) phenol and the three isomers of chlorophenol. A combination of optionally site selective metalations and protective group-controlled metalations enabled the selective generation of several isomeric intermediates in each case and their subsequent conversion into functionalized derivatives, in particular hydroxybenzoic acids.
- Marzi, Elena,Schlosser, Manfred
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p. 3393 - 3401
(2007/10/03)
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- A short and efficient preparation of methyl-[1,2,4]oxadiazolium derivatives with plant-inducing activity
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A short and efficient preparation of methyl-[1,2,4]oxadiazolium derivatives with plant-inducing activity is discussed. A concise and efficient synthetic method leading to structurally diverse array of oxadiazolium derivatives, starting from halogenated phenols is also developed. The starting point of the synthesis is the Lewis acid mediated addition of isocyanates to phenols. The strategy also involves a new and rapid access to all meta-halogenated salicylic acids, compounds of high synthetic value.
- Dobler, Markus R.
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p. 963 - 964
(2007/10/03)
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- Process for the preparation of 5-chloro-1-(4-fluorophenyl)-3-(1,2,3,6-tetrahydropyridin-4-yl)indole and method of manufacturing sertindole
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A process of manufacturing sertindole comprising reacting 5-chloro-1-(4-fluorophenyl)indole with 4-piperidone in a mixture of an acetic acid and concentrated HCl; reduction of the resulting 5-chloro-1-(4-fluorophenyl)-3-(1,2,3,6-tetrahydropyridin-4-yl)indole and reaction of this compound with 1-(2-chloroethyl)-2-imidazolidinon in order to obtain sertindole.
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- Method of manufacturing sertindole
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The present invention relates to a new method of manufacturing the compound 1-[2-[4-[5-chloro-1-(4-fluorophenyl)-1-H-indol-3-yl]-1-piperidinyl]ethyl]-2-imidazolidinone having the recommended INN name sertindole and a new method of manufacturing the intermediates, N-(4-fluorophenyl)-N-(2-carboxy-4-chlorophenyl)glycine and 5-chloro-1-(4-fluorophenyl)-3-(1,2,3,6-tetrahydropyridin-4-yl)indole used in the method.
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Page column 5; 6
(2010/01/30)
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- A highly efficient strategy for the synthesis of 3-substituted salicylic acids by either directed ortho-lithiation or halogen-metal exchange of substituted mom protected phenols followed by carboxylation
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A highly efficient synthesis of various 3-substituted salicylic acids is described starting from inexpensive starting materials and requiring no special apparatus.
- Lau, Stephen Y.W.,Keay, Brian A.
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p. 1541 - 1545
(2007/10/03)
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- Highly Selective Aromatic Chlorinations. Part 2. The Chlorination of Substituted Phenols, Anisoles, Anilines, and Related Compounds with N-Chloroamines in Acidic Solution
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Phenols, anisoles, anilines, and related compounds are chlorinated in trifluoroacetic acid at room temperature by N-chlorodialkylamines and N-chlorotrialkylammonium salts.With monsubstituted compounds and their 2- and 3-substituted derivatives the reaction occurs efficiently and selectively at the 4-position.The reactivity of these substrates and the selectivity of their chlorinations are determined by electronic rather than steric effects of the substituent.Blocking the reaction with a substituent at the 4-position generally leads to only poor or moderate yields of the 2-chlorinated product.Evidence for radical and cation radical intermediates has been obtained in the reactions of some of the 4-substituted reactants and the mechanism of chlorination is discussed in the light of these findings.The reactions of selected substrates have been scaled up to give laboratory syntheses.
- Smith, John R. Lindsay,McKeer, Linda C.,Taylor, Jonathan M.
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p. 385 - 392
(2007/10/02)
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- PHOTOREACTION OF BENZOIC ACID WITH SODIUM HYPOCHLORITE IN AQUEOUS ALKALI
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The photoreaction of benzoic acid with sodium hypochlorite in aqueous alkali (pH > 12) has been studied.At a low initial ratio of , e.g, 0.1, hydroxylation and chlorination at the aromatic ring occur simultaneously with ipso-substitution of the carboxylate group to give hydroxy- and chlorobenzoic acids together with phenol.The product distribution depends on the wavelength of the light, which implies the dependence on the concentration of avtive species generated from ClO(1-) and on the light stability of products.At comparable concentrations of ClO(1-) and PhCOO(1-), the products initially formed from the photoreaction react further with ClO(1-) in the dark to give polychlorinated derivatives.The initial steps for the photoreaction are discussed on the basis of the reactivity of the active species, O(3P), O(1D), O(1-)(.), and Cl(.), generated by photolysis of ClO(1-).
- Ogata, Yoshiro,Tomizawa, Kohtaro
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p. 985 - 988
(2007/10/02)
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- Electrophilic Catalysis of Sulphate (-SO3-) Group Transfer: Hydrolysis of Salicyl Sulphates assisted by Intramolecular Hydrogen Bonding
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The hydrolysis of substituted salicyl sulphates has been measured over a range of pH values at 70 deg C to obtain kinetic parameters for hydronium ion (kH) and carboxylic acid (kp) calalysis.A Jaffe treatment of the carboxy-catalysis parameter for a range of nuclear substituents yields ρphenol 1.51; ρcarboxy 0 indicates that the carboxy-function does not ionise on going from the ground- to the transition-state, consistent with hydrogen bonding rather than catalysis through proton transfer.The change in 'effective' charge on the phenol oxygen on going from the ground- to the transition-state confirms less build up of negative charge than in the uncatalysed hydrolysis of aryl sulphates.
- Hopkins, Andrew Ramsay,Green, Adam Llywellyn,Williams, Andrew
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p. 1279 - 1284
(2007/10/02)
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- Dual Fluorescence and Ground State Equilibria in Methyl Salicylate, Methyl 3-Chlorosalicylate, and Methyl 3-tert-Butylsalicylate
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Fluorescence spectra of methyl 3-chlorosalicylate, methyl 3-tert-butylsalicylate, and o-hydroxyacetophenone in cyclohexane and ethanol at room temperature have been measured, together with the corrected dual fluorescence excitation spectra of gas-phase methyl salicylate.Based on these observations a ground state equilibrium between two tautomers is proposed, both having an intramolecular hydrogen bond.This model is consistent with a number of methyl salicylate H-bond energy estimates.It also allowed an interpretation of the multiple fluorescence emitted from these and related compounds either in solution or in gas phase.
- Acuna, A. U.,Amat-Guerri, F.,Catalan, J.,Gonzalez-Tablas, F.
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p. 629 - 631
(2007/10/02)
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- Benzamide derivatives
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Benzamide derivatives of the formula:- STR1 wherein R1 represents a fluorine, chlorine or bromine atom, or an alkyl, alkoxy, alkylthio, alkylsulphonyl, alkanoylamino, alkylamino or alkylsulphamoyl group, each such group containing from 1 to 6 carbon atoms, a dialkylsulphamoyl, dialkylamino or dialkylcarbamoyl group (wherein the two alkyl groups may be the same or different and each contains from 1 to 4 carbon atoms), an alkanoyl, alkoxycarbonyl, alkoxycarbonylamino or alkylcarbamoyl group containing from 2 to 6 carbon atoms, or a hydroxy, formyl, nitro, trifluoromethyl, aryl, benzyloxycarbonylamino, amino, sulphamoyl, cyano, tetrazol-5-yl, carboxy, carbamoyl or aroyl group, and n represents an integer 1, 2 or 3, are new compounds possessing pharmacological properties, in particular properties of value in the treatment of respiratory disorders manifested by the interaction of tissue-fixed antibodies with specific antigens.
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