104809-67-8Relevant articles and documents
Remarkable product selectivity during photo-Fries and photo-Claisen rearrangements within zeolites
Pitchumani,Warrier,Ramamurthy
, p. 9428 - 9429 (1996)
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Tewari,Tripathi
, p. 613 (1956)
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Change of Selectivity in the Photo-Fries Rearrangement of Phenyl Acetate Induced by β-Cyclodextrin
Veglia, Alicia V.,Sanchez, Ana M.,Rossi, Rita H. de
, p. 4083 - 4086 (1990)
The photolysis of phenyl acetate (1) in water and in solutions containing β-cyclodextrin (CD) leads to p-hydroxyacetophenone (2), o-hydroxyacetophenone (3), and phenol (4).There is a decrease in the total amount of rearrangement products when the reactions are carried out in the presence of oxygen, but the inhibition is less marked in the presence of CD.The / and /( + ) ratios increase from 2.4 to 3.7 and from 0.21 to 0.76 respectively when the CD concentration changes from 0 to 10 mM.These changes are due to the increase in the quantum yield for theformation of 3 and 4 in solutions containing CD.Under the conditions of this study, the substrate reacted in the bulk solution and in the cavity of CD.The quantum yields for the formation of 3 and 4, ΦCD3 and ΦCD4, are higher for the included substrate than the corresponding values for the free substrate.This effect is attributed to the fact that the reaction is taking place in a less polar microenvironment.Besides, ΦCD4 also increases due to the availability of hydrogens bonded to secondary carbons in the cavity of cyclodextrin.
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So et al.
, p. 262 (1975)
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Kalmus et al.
, p. 449,450, 451 (1974)
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Sullivan,Jones
, p. 312 (1974)
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Ligand-Promoted Pd-Catalyzed Oxime Ether Directed C-H Hydroxylation of Arenes
Liang, Yu-Feng,Wang, Xiaoyang,Yuan, Yizhi,Liang, Yujie,Li, Xinyao,Jiao, Ning
, p. 6148 - 6152 (2015)
An efficient Pd-catalyzed oxime ether directed ortho C-H hydroxylation of arenes under neutral conditions has been developed. The efficiency of this hydroxylation is significantly improved by a ligand. Oxone, an inexpensive, readily available, and safe reagent, was employed as terminal oxidant and oxygen source. The challenging electron-deficient substrates could also be monohydroxylated in high efficiency. Drug modification with this protocol was also successfully demonstrated.
Synthesis of 4-(monoalkylamino)-coumarins
Ivanov,Karagiosov,Manolov
, p. 61 - 62 (1991)
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Synthesis and anti-inflammatory activity of 2-oxo-2H-chromenyl and 2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates
Bhimapaka, China Raju,Karri, Shailaja,Kuncha, Madhusudana,Kurma, Siva Hariprasad,Sistla, Ramakrishna
, (2020)
Cycloaddition reaction of 4-chloro-2-oxo-2H-chromene-3-carbaldehydes (3a-g) and 4-chloro-2H-chromene-3-carbaldehydes (7a-h) with activated alkynes (4a-b) provided the 2-oxo-2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates (5a-n) and 2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates (8a-p). All the prepared compounds were screened for anti-inflammatory activity. In vitro anti-inflammatory activity data demonstrated that the compounds 5g, 5i, 5k-l and 8f are effective among the tested compounds against TNF-α (1.108 ± 0.002, 0.423 ± 0.022, 0.047 ± 0.001, 0.070 ± 0.002 and 0.142 ± 0.001 μM) in comparison with standard compound Prednisolone (0.033 ± 0.002 μM). Based on in vitro results, three compounds (5i, 5k and 8f) have been selected for in vivo experiments and these compounds are identified as better compounds with respect to anti-inflammatory activity in LPS induced mice model. Compound 5i was identified as potent and showed significant reduction in TNF-α and IL-6.
Zirconium tetrachloride as a mediator for ambient temperature ortho-Fries rearrangements
Harrowven, David C.,Dainty, Richard F.
, p. 7659 - 7660 (1996)
Zirconium tetrachloride has been found to be an excellent mediator of the Fries reaction. Rearrangements occur at ambient temperature and are highly selective; giving the acetophenone derived from acetyl migration to the sterically least encumbered adjacent carbon.
Complex induced proximity effect enhancement in α-silyl carbanion generation. A general conversion of 2-silyl benzamides into 2-fluorosilylacetophenones
Brough, Paul A.,Fisher, Stephen,Zhao, Baoping,Thomas, Ryan C.,Snieckus, Victor
, p. 2915 - 2918 (1996)
LDA treatment of 2-silylated benzamides 1 affords 2-fluorosilylated acetophenones 3 in a general process likely driven by CIPE-facilitated α-silyl carbanion formation and rearrangement; oxidation (H2O2) of the products given 2-hydroxyacetophenones and catechols.
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Donnelly,Murphy
, p. 2596 (1970)
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Synthesis of 3-(3-alkyl-5-thioxo-1H-4,5-dihydro-1,2,4-triazol-4-yl) aminocarbonylchromones
Cao, Linghua,Zhang, Lin,Cui, Pengyuan
, p. 635 - 640 (2004)
A series of 3-(3-alkyl-5-thioxo-1H-4,5-dihydro-1,2,4-triazol-4-yl) aminocarbonylchromones has been prepared by oxidation of 3-formylchromone with Jones' reagent followed by reaction with 3-alkyl-4-amino-4,5-dihydro-1,2,4- triazole-5(1H)-thione in the presence of POCl3. The structures of the compounds were confirmed by IR, LC-MS, and 1H NMR spectra and elemental analyses.
Reductive dehalogenation of aryl bromides and chlorides and their use as aryl blocking groups
Ramanathan, Ahalya,Jimenez, Leslie S.
, p. 217 - 220 (2010)
Bromo and chloro substituents serve as excellent blocking groups on aromatic rings. When a halo substituent is para to an ortho,para-directing group, the ortho positions can be easily functionalized, and the halo group can be subsequently removed by catalytic hydrogenation under neutral conditions. As expected, bromides are reduced more quickly than chlorides and the reaction requires the use of less catalyst. Bromides can be selectively reduced in the presence of nitro, chloro, cyano, keto, or carboxylic acid groups. Georg Thieme Verlag Stuttgart.
Nickel-catalysed electroreductive cleavage of propargyl compounds
Olivero, Sandra,Dunach, Elisabet
, p. 6193 - 6196 (1997)
The selective reduction of propargyl esters and aryl ethers, involving the cleavage of the propargyl-oxygen bond, affords the corresponding carboxylic acids and phenols in good yields. The reaction proceeds through electrosynthesis combined with the catalysis by Ni(II)-bipyridine complexes, under mild conditions.
C-H Alkenylation of Heteroarenes: Mechanism, Rate, and Selectivity Changes Enabled by Thioether Ligands
Gorsline, Bradley J.,Wang, Long,Ren, Peng,Carrow, Brad P.
, p. 9605 - 9614 (2017)
Thioether ancillary ligands have been identified that can greatly accelerate the C-H alkenylation of O-, S-, and N-heteroarenes. Kinetic data suggest thioether-Pd-catalyzed reactions can be as much as 800× faster than classic ligandless systems. Furthermore, mechanistic studies revealed C-H bond cleavage as the turnover-limiting step, and that rate acceleration upon thioether coordination is correlated to a change from a neutral to a cationic pathway for this key step. The formation of a cationic, low-coordinate catalytic intermediate in these reactions may also account for unusual catalyst-controlled site selectivity wherein C-H alkenylation of five-atom heteroarenes can occur under electronic control with thioether ligands even when this necessarily involves reaction at a more hindered C-H bond. The thioether effect also enables short reaction times under mild conditions for many O-, S-, and N-heteroarenes (55 examples), including examples of late-stage drug derivatization.
Hafnium trifluoromethanesulfonate (Hf(OTf)4) as an efficient catalyst in the Fries rearrangement and direct acylation of phenol and naphthol derivatives
Kobayashi, Shue,Moriwaki, Mitsuhiro,Hachiya, Iwao
, p. 2053 - 2056 (1996)
Hafnium trifluoromethanesulfonate (hafnium triflate, Hf(OTf)4) was found to be an efficient catalyst in the Fries rearrangement of acyloxy benzene or naphthalene derivatives. The reactions proceeded smoothly in the presence of 5-20 mol% Hf(OTf)4. Regioselective direct acylation of phenol and naphthol derivatives with acid chlorides was also achieved by using Hf(OTf)4 as a catalyst.
Photohydration via Intramolecular Proton Transfer to Carbon in Electronically Excited States
Isaks, Martin,Yates, Keith,Kalanderopoulos, Peter
, p. 2728 - 2730 (1984)
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Investigation of the molecular dynamics of some phenols and their acetyl isomers in solutions by NMR relaxation
Mamedov,Magerramov,Bairamov,Mamedova
, p. 2182 - 2186 (2010)
The dynamics of relaxations and Fries rearrangements in phenol acetates and their acetyl isomers was studied by the NMR relaxation technique in acetone-d 6. The results of 13C and 1H spin-lattice nuclear relaxation measurements show that these experiments can be used for determining the mobility and activation energies of the molecular motions of compounds in different systems.
The Catalytic Fries Rearrangement and o-Acylation Reactions Using Group 3 and 4 Metal Triflates as Catalysts
Kobayashi, Shue,Moriwaki, Mitsuhiro,Hachiya, Iwao
, p. 267 - 273 (1997)
Group 3 and 4 metal triflates (Sc(OTf)3, TiCl(OTf)3, Zr(OTf)4, and Hf(OTf)4) were found to be efficient catalysts in the Fries rearrangement of phenyl or 1 -naphthyl acylates. It was also found that the o-acylation (direct acylation) reactions of phenols and 1-naphthols with acid chlorides proceeded smoothly in the presence of the triflates. Both reactions were successfully carried out using small amounts of the triflates (catalytically), and comparison of catalytic activities of these metal triflates in these reactions is discussed.
Biochemical Studies of Mycobacterial Fatty Acid Methyltransferase: A Catalyst for the Enzymatic Production of Biodiesel
Petronikolou, Nektaria,Nair, Satish K.
, p. 1480 - 1490 (2015)
Summary Transesterification of fatty acids yields the essential component of biodiesel, but current processes are cost-prohibitive and generate waste. Recent efforts make use of biocatalysts that are effective in diverting products from primary metabolism to yield fatty acid methyl esters in bacteria. These biotransformations require the fatty acid O-methyltransferase (FAMT) from Mycobacterium marinum (MmFAMT). Although this activity was first reported in the literature in 1970, the FAMTs have yet to be biochemically characterized. Here, we describe several crystal structures of MmFAMT, which highlight an unexpected structural conservation with methyltransferases that are involved in plant natural product metabolism. The determinants for ligand recognition are analyzed by kinetic analysis of structure-based active-site variants. These studies reveal how an architectural fold employed in plant natural product biosynthesis is used in bacterial fatty acid O-methylation. Mycobacterial fatty acid methyltransferases are employed as biocatalysts for the production of biodiesel. Petronikolou and Nair describe structural and biochemical characterization of a mycobacterial fatty acid methyltransferase, reveal an unexpected homology to enzymes involved in plant primary metabolism, and provide insights into substrate preference.
Bismuth triflate-catalyzed fries rearrangement of aryl acetates
Ollevier, Thierry,Desyroy, Valerie,Asim, Muhammad,Brochu, Marie-Christine
, p. 2794 - 2796 (2004)
Bismuth triflate was found to be an efficient catalyst in the Fries rearrangement of phenyl or 1-naphthyl acetates. Both reactions proceeded smoothly with a catalytic amount of bismuth triflate (10 mol%) to afford the corresponding hydroxyaryl ketone in moderate to good yields in most cases.
Liquid phase oxidation of acetophenone over rice husk silica vanadium catalyst
Adam, Farook,Chew, Thiam-Seng,Andas, Jeyashelly
, p. 518 - 522 (2012)
Rice husk silica catalyst loaded with 10 wt vanadium was synthesized from agricultural biomass via a sol-gel synthetic route at pH = 9. The catalyst was characterized by different physico-chemical methods. The FTIR spectra showed the formation of Si-O-V and V=O stretching bands. The presence of vanadium was confirmed by EDX elemental analysis. RH-10V possessed a high specific surface area of 276 m2/g and pore volume of 0.83 ml/g. The prepared catalyst possessed a narrow pore size distribution centered around 7.9 nm. The catalytic performance of RH-10V was tested in the oxidation of acetophenone at 70°C. RH-10V was found to be an active catalyst in the oxidation of acetophenone, producing 36.28 conversion efficiency. The products identified were benzoic acid, 2-hydroxyacetophenone, phenol, acetic acid, and 3-hydroxyacetophenone.
DMSO/N2H4·H2O/I2/H 2O/CH3CN: A new system for selective oxidation of alcohols in hydrated media
Gogoi, Pranjal,Sarmah, Gautam Kumar,Konwar, Dilip
, p. 5153 - 5154 (2004)
A new alternative system for the oxidation of secondary alcohols to ketones with DMSO/N2H4·H2O/I2/H 2O/CH3CN in hydrated media has been developed. The system also selectively oxidizes the secondary alcoholic groups to the corresponding ketones in the presence of primary alcoholic groups present within the same molecule in moderate to very good yields at reflux temperature.
Microwave assisted direct ortho-acylation of phenol and naphthol derivatives by BF3·(C2H5)2O
Naeimi, Hossein,Moradi, Leila
, p. 284 - 287 (2005)
The solventless acylation of phenol and naphthol derivatives with various organic acids and BF3·(C2H5) 2O, under microwave conditions, was studied. High yields of the o-acylated products were achieved in a very short time.
Hydration of Alkynes to Ketones with an Efficient and Practical Polyoxomolybdate-based Cobalt Catalyst
Xie, Ya,Wang, Jingjing,Wang, Yunyun,Han, Sheng,Yu, Han
, p. 4985 - 4989 (2021/10/12)
Hydration of alkynes to ketones is one of the most atom economical and universal methods for the synthesis of carbonyl compounds. However, the basic reaction usually requires organic ligand catalysts or harsh reaction conditions to insert oxygen into the C≡C bond. Here, we report an inorganic ligand supported cobalt (III) catalyst, (NH4)3[CoMo6O18(OH)6], which is supported by a central cobalt (III) mononucleus and a ring-shaped pure inorganic ligand composed of six MoVIO6 octahedrons to avoid the disadvantages of expensive and unrecyclable organic ligand catalysts or noble metal catalysts. Under mild conditions, the cobalt (III) catalyst can be used for the hydration of alkynes to ketones. The catalyst is non-toxic, green, and environment friendly. The catalyst can be recycled at least six times with high activity. According to control experiments, a reasonable mechanism is provided.
Preparation method of O-methoxyacetophenone
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Paragraph 0027; 0029, (2021/02/10)
The invention relates to a preparation method of o-methoxyacetophenone. A composite catalyst containing heteropolyacid and Lewis acid is adopted and can effectively catalyze the reaction of dimethyl ether and o-hydroxyacetophenone so that the use of dimethyl sulfate and other highly toxic substances as reaction reagents is avoided, the production cost is lowered, the discharge of highly toxic substances is reduced, and the process is enabled to be greener and more environment-friendly.
Bioactivity study of thiophene and pyrazole containing heterocycles
Athare, Anil E.,Dare, Sushama B.,Kale, Nitin V.,Karale, Bhausaheb K.,Mhaske, Sadhana D.,Salve, Supriya P.,Takate, Sushama J.
, p. 891 - 899 (2021/09/08)
Chalcones 3a-f were prepared by reacting thiophene containing pyrazolyl aldehyde (2) with different 2-hydroxy acetophenones 1a-f. The compounds 3a-f were transformed into different Pyrazolines 4a-f. The formation of chromene derivatives 5a-f occurred from the cyclization of 3a-f, which were then transformed into pyrazole derivatives 6a-f. Newly synthesized compounds have promising antibacterial activity against S. typhii and S. aureus, while weak activity against B. subtilis and E. coli. Compounds 5d and 6d had significant antifungal action towards A. niger, while most of the compounds were moderately active towards T. viride. Some of the synthesized compounds showed promising α-amylase inhibitory activity at 1 mg/mL concentration.
