- Palladium-catalyzed ortho-C-H hydroxylation of benzoic acids
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A simple Pd(OAc)2 catalyzed ortho-hydroxylation of benzoic acids using TBHP as the sole oxidant has been explored. This protocol features relatively broad substrate scope and operational simplicity. The compatibility of ortho-substituted substrates is an effective complement to the previous ortho-hydroxylation reaction.
- Luo, Feihua,He, Shuhua,Gou, Quan,Chen, Jinyang,Zhang, mingzhong
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- Synthesis of Polysubstituted 2-Naphthols by Palladium-Catalyzed Intramolecular Arylation/Aromatization Cascade
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A palladium-catalyzed intramolecular α-arylation and defluorinative aromatization strategy for the synthesis of polysubstituted 2-naphthols is reported. With ortho-bromobenzyl-substituted α-fluoroketones as the substrates and palladium acetate/triphenylphosphine as the catalyst, this method features good functional group tolerance, readily available catalyst and starting materials, and high yields. The applications of the strategy are demonstrated by the synthesis of useful building blocks, such as naphtha[2,3-b]furan, naphthol AS-D, and ligands/catalysts. (Figure presented.).
- Cai, Jinhui,Hu, Xu-Dong,Liu, Wen-Bo,Wang, Zhen-Kai,Yao, Fei,Zhang, Yun-Hao
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supporting information
(2020/02/25)
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- Practical, mild and efficient electrophilic bromination of phenols by a new I(iii)-based reagent: The PIDA-AlBr3 system
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A practical electrophilic bromination procedure for phenols and phenol-ethers was developed under efficient and very mild reaction conditions. A broad scope of arenes was investigated, including the benzimidazole and carbazole core as well as analgesics such as naproxen and paracetamol. The new I(iii)-based brominating reagent PhIOAcBr is operationally easy to prepare by mixing PIDA and AlBr3. Our DFT calculations suggest that this is likely the brominating active species, which is prepared in situ or isolated after centrifugation. Its stability at 4 °C after preparation was confirmed over a period of one month and no significant loss of its reactivity was observed. Additionally, the gram-scale bromination of 2-naphthol proceeds with excellent yields. Even for sterically hindered substrates, a moderately good reactivity is observed.
- Satkar, Yuvraj,Ramadoss, Velayudham,Nahide, Pradip D.,García-Medina, Ernesto,Juárez-Ornelas, Kevin A.,Alonso-Castro, Angel J.,Chávez-Rivera, Ruben,Jiménez-Halla, J. Oscar C.,Solorio-Alvarado, César R.
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p. 17806 - 17812
(2018/05/28)
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- A solvent method for producing continuous carbonization 2-naphthol, cogeneration 2,3 acid method and device (by machine translation)
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The invention discloses a method for producing continuous carbonization solvent the 2 [...] naphthol, cogeneration 2,3 acid method and device. Method is to adopt continuous carbonization and 2,3 the new process [...] acid, has changed the traditional production process and method, to naphthalene series dye, pigment and derivatives an important intermediate for the production of new production technologies; the device of this invention includes 2 the system and outputs natphthol [...] the 2 [...] hydroxy -3 the output system [...] formic acid, 2 the system includes extracting [...] natphthol chromophore outputs, mixer, and the rectifying tower A, carbonization reaction kettle, 2 the crude distillation tower [...] naphthol, 2 the finished natphthol [...] the rectifying tower and the slice-packaging device, the 2 [...] hydroxy -3 the formic acid [...] output system includes a stationary separation system, and filter-pressing apparatus, dyeworks acidified system, centrifugal-washing and drying-packing device, extraction chromophore mixer connected in sequence, and the rectifying tower A, carbonization reaction kettle, 2 the crude distillation tower [...] naphthol, 2 the product natphthol [...] the rectifying tower and the slice-packing device, 2 the bottom material distillation tower tower[...] naphthol crude product (2,3 the acid [...] double-sodium salt) are connected in sequence still separation system, and filter-pressing apparatus, dyeworks acidified system, centrifuge and dry packing device. (by machine translation)
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Page/Page column 7-9
(2018/02/04)
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- A versatile approach for the synthesis of para -substituted arenes via palladium-catalyzed C-H functionalization and protodecarboxylation of benzoic acids
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While a great number of ortho C-H functionalization reactions have been developed and several breakthroughs have been achieved in meta C-H activation, para C-H functionalization is still in its infancy stage. In this article, a versatile strategy for the synthesis of para-substituted arenes has been developed via a tandem process consisting of palladium-catalyzed C-H functionalization and subsequent copper-catalyzed protodecarboxylation of benzoic acids. Both electron-withdrawing and electron-donating functionalities can be introduced into the para positions of arenes bearing a variety of substituents.
- Pan, Shulei,Zhou, Bo,Zhang, Yanghui,Shao, Changdong,Shi, Guangfa
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supporting information
p. 277 - 281
(2016/01/20)
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- Production of aromatic hydroxycarboxylic acid
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PROBLEM TO BE SOLVED: To provide an environment-friendly method for producing aromatic hydroxycarboxylic acid in high yield even under low temperature reaction conditions. SOLUTION: The method for producing aromatic hydroxycarboxylic acid includes a process of reacting an alkali metal salt of an aromatic hydroxy compound with carbon dioxide in a medium, where the reaction is performed in the presence of 0.01-1.0 mole of one or more alcohol compounds and/or ether compounds for 1 mole of the alkali metal salt of the aromatic hydroxy compound. COPYRIGHT: (C)2013,JPOandINPIT
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Paragraph 0047
(2018/07/14)
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- Production of aromatic hydroxycarboxylic acid
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PROBLEM TO BE SOLVED: To provide a production method capable of obtaining aromatic hydroxycarboxylic acid at high yield even under a reaction condition at low temperature. SOLUTION: The method for production of aromatic hydroxycarboxylic acid includes a process of reacting an alkali metal salt of aromatic hydroxy compounds with carbon dioxide in a medium. The method is characterized by performing the above reaction in the presence of a ligand alone or as its metal complex of 0.01-1.0 mol based on 1 mol of the alkali metal salt of the aromatic hydroxy compound. COPYRIGHT: (C)2012,JPOandINPIT
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Paragraph 0065-0067; 0069-0070; 0071-0072
(2018/05/17)
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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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p. 2255 - 2259
(2015/02/19)
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- PD(II)-CATALYZED HYDROXYLATION OF ARENES WITH O2 OR AIR
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Pd (II) -catalyzed ortho-hydroxylat ion of variously substituted aromatic carboxylic acids under O2 or air is achieved under non-acidic conditions. Extensive labeling studies support a direct oxygenation of aryl C-H bonds with molecular oxygen.
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Page/Page column 14
(2011/04/24)
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- Ni-catalyzed reduction of inert C-O bonds: A new strategy for using aryl ethers as easily removable directing groups
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An efficient Ni-catalyzed protocol for the reductive cleavage of inert C-O bonds has been developed. The method is characterized by its simplicity and wide scope, thereby allowing the use of aryl ethers as easily removable directing groups in organic synthesis.
- Alvarez-Bercedo, Paula,Martin, Ruben
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supporting information; scheme or table
p. 17352 - 17353
(2011/02/23)
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- Importance of equilibrium fluctuations between most stable conformers in the control of the reaction mechanism
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Hydrolysis of closely related compounds show how subtle structural differences markedly change reaction mechanisms. While in the hydrolysis of 3-acetoxy-2-naphthoic acid (3AC2NA) the reacting groups rotate freely, favoring intramolecular general base catalysis, the 1-acetoxy-2-naphthoic acid (1AC2NA) isomer is caged in an energy wall that freezes a conformation suitable for intramolecular nucleophilic attack, in contrast to the results expected for reactions governed largely by electronic effects. The results highlight the importance of the dynamics of equilibrium fluctuations between most stable conformers in the control of the reaction mechanism, (i) promoting the nucleophilic attack in 1AC2NA by allowing the most stable conformers to equilibrate only via rotation in a direction that intercepts the reaction coordinate and (ii) favoring a general base-catalyzed water attack in 3AC2NA by favoring equilibration via rotation that allows inclusion of a water molecule in a proper position for reaction.
- Souza, Bruno S.,Nome, Faruk
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supporting information; experimental part
p. 7186 - 7193
(2011/01/12)
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- Photoarylation/alkylation of bromonaphthols
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The photochemistry of 6-bromo-2-naphthols has been studied in acetonitrile, aqueous acetonitrile, and isopropyl alcohol in the absence and in the presence of triethylamine by product distribution analysis, laser flash photolysis (LFP), fluorescence, phosp
- Pretali, Luca,Doria, Filippo,Verga, Daniela,Profumo, Antonella,Freccero, Mauro
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experimental part
p. 1034 - 1041
(2009/07/04)
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- Pd(II)-catalyzed hydroxylation of arenes with 1 atm of O2 or air
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(Chemical Equation Presented) Pd(II)-catalyzed ortho-hydroxylation of variously substituted benzoic acids under 1 atm of O2 or air is achieved under nonacidic conditions. Extensive labeling studies support a direct oxygenation of aryl C-H bonds with molecular oxygen.
- Zhang, Yang-Hui,Yu, Jin-Quan
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supporting information; experimental part
p. 14654 - 14655
(2010/01/06)
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- Synthesis, characterization and kinetics properties of chromium(III) complex [Cr(3-HNA)(en)2]Cl · H2O · CH3OH
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The reaction of chromium(III) chloride, 3-hydroxy-2-naphthoic acid (3-HNA) and ethylenediamine (en) led to the formation of complex [Cr(3-HNA)(en)2]Cl · H2O · CH3OH, Bis(ethylenediamine-κ2N,N′)(3-hydroxy-2-napht
- Liu, Bin,Li, Ying-qi,Yang, Bin-Sheng
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p. 367 - 370
(2008/10/09)
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- Process for dehydrating hydrous sodium Beta-naphtholate
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The present invention provides a process for dehydrating hydrous sodium β-naphtholate comprising: the step of heating the hydrous sodium β-naphtholate or a mixture of the hydrous sodium β-naphtholate and β-naphthol which comprises no more than 0.2 mole of β-naphthol per one mole of sodium β-naphtholate in a solvent at a temperature of 260-300°C under an inert gas. The process makes it possible to dehydrate hydrous sodium β-naphtholate thoroughly in a short time with less production of tarry components.
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Page/Page column 7
(2010/02/10)
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- Carboxylation of naphthols with sodium ethyl carbonate
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The carboxylation of α- and β-naphthols with sodium ethyl carbonate was studied. Conditions for the regioselective carboxylation of α-naphthol in the 2- and 4-positions and β-naphthol in the 3-position were found. Simple and convenient methods for the preparation of 1-hydroxy-2-naphthoic, 1-hydroxy-4-naphthoic, and 2-hydroxy-3-naphthoic acids were developed. Copyright
- Suerbaev, Kh. A.,Mikhnenko,Akhmetova,Shalmagambetov,Chepaikin
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p. 335 - 337
(2007/10/03)
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- Toning agent
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A toning agent for an azo pigment, an azo pigment with a modified tone, and process for preparing the same are provide. 2-hydroxynaphthalene-3,6-dicarboxylic acid or a derivative thereof is admixed with a primary coupler component for an azo pigment and the mixed coupler composition and an aromatic diazonium are coupled.
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- Crystal of 2-hydroxynaphthalene-3-carboxylic acid and process for the preparation thereof
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The present invention provides crystalline 2-hydroxynaphthalene-3-carboxylic acid (BON) characterized in that the average particle size is equal to or more than 157 μm and the proportion of the particles of which particle size is less than 74 μm is equal to or less than 14%. The crystalline composition of the present invention can be prepared by a process comprising the step of recrystallizing BON, especially at a high temperature, or by carrying out the acid precipitation step in the method for preparing BON at a high temperature.
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- Effects of alkali and alkaline earth metals on the Kolbe-Schmitt reaction
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It was found that the carboxylations of magnesium, calcium, and barium phenoxides with carbon dioxide at 260 °C produced salicylic acid and dicarboxylic acids (4-hydroxyisophthalic acid and 2-hydroxyisophthalic acid) in very high yields (80-100%), exceeding that of the ordinary Kolbe-Schmitt reaction. The orientation (ortho/para ratio) was controlled not only by chelations of the intermediate with alkaline earth metal (Mg, Ca, Ba) ions, resulting in salicylic acid, but also by the sizes of metal ions (Rb, Cs), giving p-hydroxybenzoic acid in a much higher ratio than the widely used method with potassium or sodium phenoxide. These alkaline earth metals worked to produce 3-hydroxy-2-naphthoic acid by the reaction of 2-naphthoxide with carbon dioxide, but the yield of 6-hydroxy-2-naphthoic acid was comparable to that of 3-hydroxy-2-naphthoic acid when cesium or rubidium 2 naphthoxide was employed. Considerably high yields (～60%) of 6-hydroxy-2-naphthoic acid, a monomer of one of the best liquid-crystal polymers, was attained by the carboxylation of cesium or rubidium 2-naphthoxide in the presence of potassium or sodium carbonate, where the alkali metal ion was supposed to increase the reactivity of the substrate. The formation of "binol" was observed in the preparation of 2-naphthoxides with metal hydroxides, especially with copper(II) ion.
- Rahim, Mohammad Abdur,Matsui, Yoshihisa,Kosugi, Yoshio
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p. 619 - 622
(2007/10/03)
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- COMPOSITIONS AND METHODS FOR THE TREATMENT OF IMMUNOMEDIATED INFLAMMATORY DISORDERS
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Compositions and methods for the prevention and treatment of immunomediated inflammatory disorders, especially for those disorders associated with the respiratory tract, are provided. More particularly, a tryptase inhibitor, typically a hydroxyaroyl or hydroxyheteroaroyl substituted dipeptide, is administered. Also provided by this invention are pharmaceutical compositions, typically aerosol or topical, as well as aerosol devices for administering these compositions intranasally.
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- Process for preparing aromatic hydroxycarboxylic acids
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A process for preparing aromatic hydroxycarboxylic acids or di-salts thereof by reaction of alkali metal phenolates or naphtholates with carbon dioxide, in the presence or absence of a further alkali metal salt, which comprises introducing the solid phenolate or naphtholate starting materials and, if desired, the alkali metal salt into the reaction mixture batchwise or continuously, separately or together, in the form of a dispersion in an inert organic liquid. The process of the invention makes possible the preparation of aromatic hydroxycarboxylic acids in good yields and with high chemical selectivity. Additional measures for increasing the selectivity, as are described for the Kolbe-Schmitt reaction in, for example, EP-A 0 053 824, EP-A 0 081 753 and EP-A 0 254 596, can be omitted.
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- NON CONCERTED PATHWAY IN THE GENERATION OF DEHYDROARENES BY THERMAL DECOMPOSITION OF DIARYLIODONIUM CARBOXYLATES.
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1,3-Dehydrobenzene, 1,4-dehydrobenzene and 2,3-dehydronaphthalene are generated in the thermal decomposition of appropriate diaryliodonium carboxylates as demonstrated by the use of the three phase test.Intermediate species C6H4CO2 for m- and p-benzyne and C10H6CO2 for 2,3-naphthalyne have been unambiguously trapped in the same way, showing how non-concerted processes are the main pathway for generation of arynic intermediates from those iodonium salts.
- Luis, S. V.,Gavina, F.,Ferrer, P.,Safont, V. S.,Torres, M. C.,Burguete, M. I.
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p. 6281 - 6296
(2007/10/02)
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- Process for producing aromatic hydroxycarboxylic acids
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This invention provides a process for selectively producing aromatic hydroxycarboxylic acids, which comprises subjecting a liquid mixture consisting of a polycyclic aromatic hydrocarbon, an alkali metal salt of an aromatic hydroxy compound and a free aromatic hydroxy compound to a reaction with carbon dioxide. The process permits the production of the intended product with enhanced selectivity.
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- Process for separation of 2-hydroxynapthalene-3-carboxylic acid from the reaction mixtures of alkali metal salts of 2-hydroxynaphthalene and carbon dioxide
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In the carboxylation of 2-alkali metal naphtholates under pressure and at temperatures of above 200° C., apart from the alkali metal salt of 2-naphthol-3-carboxylic acid and free 2-naphthol considerable amounts of resinous by-products are obtained which according to the hitherto known processes have to be separated and removed in a very expensive manner. According to this invention, the alkali-soluble acidic resins are separated from this carboxylation melt after its solution in water during the work-up of the carboxylation product by means of a cationic quaternary ammonium compound. These surface-active compounds precipitate the alkali-soluble acidic resins in such a manner that they can be easily removed from the alkali metal salts of 2-hydroxynaphthalene-3-carboxylic acid dissolved in water.
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- Process for producing 2 hydroxy-naphthalene-3-carboxylic acid
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A process for producing 2-hydroxynaphthalene-3-carboxylic acid comprising reacting carbon dioxide with a homogeneous liquid mixture comprising an alkali metal salt of β-naphthol, β-naphthol and a specific alkylbenzene is disclosed.
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- Amino-substituted imidazo[1,2-a:3,4-a']diquinolin-15-ium salts compositions and method of use
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Amino-substituted imidazo[1,2-a:3,4-a']diquinolin-15-ium salts having the formula I: STR1 wherein R1 is hydrogen, lower alkyl, C4 -C6 cycloalkyl, di(lower alkyl)amino, 1-azetidinyl, 1-pyrrolidinyl, 1-piperidinyl, methyl-1-pyrrolidinyl, methyl-1-piperidinyl, 4-morpholinyl or 2,2-dimethylhydrazino; R2 is hydrogen, lower alkyl, lower alkylamino, di(lower alkyl)amino, C4 -C6 cycloalkylamino, lower alkoxy(lower alkyl)amino, 1-azetidinyl, 1-pyrrolidinyl, 1-piperidinyl, methyl-1-pyrrolidinyl, methyl-1-piperidinyl, hexahydro-1H-azepin-1-yl, 4-morpholinyl, benzylamino, N-methylbenzylamino or 2-phenylethylamino; R3 is hydrogen or methyl; X is an anion; with the proviso that at least one of R1 and R2 is other than hydrogen, lower alkyl or C4 -C6 cycloalkyl; and with the further proviso that when R2 is dimethylamino, at least one of R1 and R3 is other than hydrogen, and intermediates used in the preparation thereof are disclosed. The compounds of the invention are prepared by amination of the corresponding chloro or fluoro-substituted imidazo [1,2-a:3,4-a']diquinolin-15-ium salts; either the halo substituted intermediates or the amino substituted salts may be further treated, typically using ion exchange techniques to obtain a variety of physiologically acceptable amino-substituted [1,2-a:3,4-a']diquinolin-15-ium salts which exhibit antifungal activity.
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- Process for preparing 2-hydroxynaphthalenecarboxylic acids
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A process for preparing 2-hydroxynaphthalenecarboxylic acids which comprises reacting a liquid mixture of 1 mole of an alkali β-naphtholate, 0.05 to 3 moles of β-naphthol, and 0.1 to 5 times the weight of the alkali β-naphtholate of light oil or kerosene with carbon dioxide under a carbon dioxide pressure of not more than 15 kg/cm2.G at a temperature of at least 180° C.
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- Production of 2-hydroxynaphthalene-3-carboxylic acid
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The production of 2-hydroxynaphthalene-3-carboxylic acid by heating sodium β-naphtholate in the presence of an araliphatic compound containing two aromatic radicals and/or in the presence of an aromatic ether having at least one aromatic radical etherified with an aliphatic, cycloaliphatic or araliphatic radical at a temperature of at least 200° C, reaction with carbon dioxide and reaction of the salt formed with acid. The resultant 2-hydroxy-naphthalene-3-carboxylic acid is a starting material for the production of dyes, a coupling component of surface coating colors and chrome dyes and also a developer for diazotizable dyes.
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- Production of 2-hydroxynaphthalene-3-carboxylic acid
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2-HYDROXYNAPHTHALENE-3-CARBOXYLIC ACID IS PRODUCED BY HEATING A MIXTURE OF POTASSIUM β-NAPHTHOLATE AND SODIUM β-NAPHTHOLATE TO A TEMPERATURE OF AT LEAST 180° C, reacting it with carbon dioxide and treating the salt formed with an acid. The product is a dye intermediate, a coupling component of surface coating dyes and chrome dyes, and a developer for diazo dyes.
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- Production of 2-hydroxynaphthalene-3-carboxylic acid
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2-Hydroxynaphthalene-3-carboxylic acid is prepared by the reaction of sodium-β-naphtholate with carbon dioxide, extraction of the reaction mixture in the presence of water with benzene or a benzene derivative in a specific ratio and separation of the end product from the extracted mixture. The product is a starting material for the production of dyes and a coupling component in the manufacture of azo dyes.
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