- Pd(ii)-Catalyzed alkyne annulation through allylic isomerization: synthesis of spiro-cyclopentadiene pyrazolones
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The Pd(ii)-catalyzed activation of Csp2-H bond and double alkyne annulation which proceedsviaallylic isomerization is reported for the first time. This reaction of antipyrines with alkynes provides an efficient synthetic route for the biologically important spiro-cyclopentadiene pyrazolones. In the presence of Lawesson's reagent, this Pd(ii)-catalyzed annulation reaction affords another spiro-cyclopentadiene pyrazolone which displays very good fluorescence properties.
- Changmai, Sumi,Sultana, Sabera,Sarma, Bipul,Gogoi, Sanjib
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supporting information
p. 6027 - 6030
(2021/06/21)
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- Metal-Free Direct C–H Thiolation and Thiocyanation of Pyrazolones
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Metal-free approach for direct C–H thiolation and thiocyanation of N-substituted pyrazolones with disulfides and thiocyanate salts, respectively, are developed. These reactions allow the C–S bond coupling to proceed effectively under mild conditions, providing useful and convenient methods for preparation of a series of 4-thio-substituted pyrazolone analogues, which have potential applications in organic, medicinal and material chemistry. Preliminary mechanistic investigation suggested that radical processes are likely to involve in these transformations.
- Kittikool, Tanakorn,Yotphan, Sirilata
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supporting information
(2020/02/13)
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- Copper-catalyzed acylation of pyrazolones with aldehydes to afford 4-acylpyrazolones
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Copper-catalyzed direct acylation of the alkenyl C-H bond in 1,2-dihydro-3H-pyrazol-3-ones has been developed, affording a series of 4-acylpyrazolones in moderate to good yields. Notably, this protocol involves readily accessible substrates and reagents, which have good functional group tolerance leading to pyrazolone derivatives under mild reaction conditions.
- Xiao, Yan,Wu, Xiaopeng,Teng, Jiangang,Sun, Song,Yu, Jin-Tao,Cheng, Jiang
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supporting information
p. 7552 - 7557
(2019/08/20)
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- On/Off O2 Switchable Photocatalytic Oxidative and Protodecarboxylation of Carboxylic Acids
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Photoredox catalysis in recent years has manifested a powerful branch of science in organic synthesis. Although merging photoredox and metal catalysts has been a widely used method, switchable heterogeneous photoredox catalysis has rarely been considered. Herein, we open a new window to use a switchable heterogeneous photoredox catalyst which could be turned on/off by changing a simple stimulus (O2) for two opponent reactions, namely, oxidative and protodecarboxylation. Using this strategy, we demonstrate that Au@ZnO core-shell nanoparticles could be used as a switchable photocatalyst which has good catalytic activity to absorb visible light due to the localized surface plasmon resonance effect of gold, can decarboxylate a wide range of aromatic and aliphatic carboxylic acids, have multiple reusability, and are a reasonable candidate for synthesizing both aldehydes/ketones and alkane/arenes in a large-scale set up. Some biologically active molecules are also shown via examples of the direct oxidative and protodecarboxylation which widely provided pharmaceutical agents.
- Bazyar, Zahra,Hosseini-Sarvari, Mona
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p. 13503 - 13515
(2019/10/11)
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- DABCO-catalyzed silver-promoted direct thiolation of pyrazolones with diaryl disulfides
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A highly efficient protocol for a direct thiolation of N-substituted pyrazolones with diaryl disulfides is described. Using a combination of DABCO and silver(i) acetate, the C-S bond formation proceeds smoothly at room temperature under mild and easy to handle conditions. This synthetic strategy offers a convenient and direct modification of antipyrine and other pyrazolone substrates, giving a series of aryl sulfide-substituted pyrazolone products in moderate to excellent yields.
- Thupyai, Akkharaphong,Pimpasri, Chaleena,Yotphan, Sirilata
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supporting information
p. 424 - 432
(2018/02/06)
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- Copper/Persulfate-Promoted Oxidative Decarboxylative C?H Acylation of Pyrazolones with α-Oxocarboxylic Acids: Direct Access to 4-Acylpyrazolones under Mild Conditions
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A facile and efficient oxidative C?H acylation of N-substituted pyrazolones using α-oxocarboxylic acids as an acyl group source was developed. A combination of Cu(OAc)2 and K2S2O8 enables the reaction to proceed smoothly under air and provides a wide array of 4-acylpyrazolone products in moderate to excellent yields. The mechanism of this transformation is believed to proceed via a copper-induced decarboxylation to form the acyl-copper species. This method provides a convenient and useful route for a direct installation of an acyl moiety into bioactive pyrazolone derivatives, which can be further utilized in many applications. (Figure presented.).
- Kittikool, Tanakorn,Thupyai, Akkharaphong,Phomphrai, Khamphee,Yotphan, Sirilata
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p. 3345 - 3355
(2018/09/10)
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- Design, synthesis, anti-inflammatory activity and molecular docking of potential novel antipyrine and pyrazolone analogs as cyclooxygenase enzyme (COX) inhibitors
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As a part of a directed program for development of new active agents, novel heterocyclic derivatives with antipyrine and pyrazolone moieties -incorporated in- have been designed and synthesized. Starting with 4-arylidene-3-methyl-1-phenyl-5-pyrazolone derivative 2a,b novel Mannich bases derivatives have been synthesized and biologically evaluated for their anti-inflammatory activity. Furthermore, the activity of such compounds has been tested interestingly as COX-1 and COX-2 inhibitors. Structure elucidation of the synthesized compounds was attained by the use of elemental analysis, IR, 1H NMR, 13C NMR, and Mass spectrometry techniques. Compounds 3b, 3d and 4b represent the high % inhibition values for both COX-1 and COX-2. On the other hand, compound 8 showed little selectivity against COX-2 while compound 10 showed good selectivity against COX-1 only. Structure activity relationship has been discussed and the results were confirmed by molecular docking calculations.
- El Sayed, Mardia T.,El-Sharief, Marwa A.M.Sh.,Zarie, Eman S.,Morsy, Nesrin M.,Elsheakh, Ahmed R.,Voronkov, Andrey,Berishvili, Vladimir,Hassan, Ghada S.
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p. 952 - 957
(2018/03/06)
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- Pyrazolone methylamino piperidine derivatives as novel CCR3 antagonists
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The discovery and optimization of a novel class of potent CCR3 antagonists is described. Details of synthesis and SAR are given together with some ADME properties of selected compounds. An optimal balance between activities, physicochemical properties, and in vitro metabolic stability was reached by the proper choice of substituents.
- Pegurier, Cecile,Collart, Philippe,Danhaive, Pierre,Defays, Sabine,Gillard, Michel,Gilson, Frederic,Kogej, Thierry,Pasau, Patrick,Van Houtvin, Nathalie,Van Thuyne, Marc,van Keulen, BerendJan
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p. 4228 - 4231
(2008/02/09)
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- PYRAZOLONE COMPOUNDS AS METABOTROPIC GLUTAMATE RECEPTOR AGONISTS FOR THE TREATMENT OF NEUROLOGICAL AND PSYCHIATRIC DISORDERS
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Compounds of Formula (I), wherein R1, R2, R3, R4, R5, R6, X, and n are as defined for Formula (I) in the description, processes for the preparation of the compounds and new intermediates employed in the preparation, pharmaceutical compositions containing the compounds, and the use of the compounds in the treatment or prevention of neurological and psychiatric disorders associated with glutamate dysfunction.
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Page/Page column 50
(2008/06/13)
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- Alkylation of pyrazolones via the mitsunobu reaction
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The reaction of 3-methyl-1-phenyl-2-pyrazolin-5-one and 4-acyl derivatives thereof (R4 = COPh, 2-thienoyl, COCH2CH2Ph, COCH=CHPh) with various alcohols under 'Mitsunobu'-conditions was studied. In many cases selective O-alkylation could be achieved.
- Holzer, Wolfgang,Plagens, Brigitte,Lorenz, Karin
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p. 309 - 314
(2007/10/03)
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- Mucosal adhesive device for long-acting delivery of pharmaceutical combinations in oral cavity
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Mucosal adhesive devices are provided for use in the oral cavity for therapy against infections. The devices are dosage units which comprise a combination of antimicrobial agents such as antifungal agents and anti-inflammatory agents, optionally also a local anesthetic. The dosage units yield a gradual and relatively constant release of the pharmaceuticals over at least a 12-hour period.
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- AN UNUSUAL AROMATIZATION OF HANTZSCH-TYPE 4-ANTIPYRYL-1,4-DIHYDROPYRIDINES
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Under acidic conditions, Hantzsch-type 4-antipyryl-1,4-dihydropyridines undergo an elimination of the 4-substituent to yield 4-unsubstituted pyridines and antipyrine.The mechanism and scope of the reaction are discussed.
- Eynde, Jean-Jacques Vanden,Mayence, Annie,Maquestiau, Andre,Anders, Ernst
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p. 815 - 822
(2007/10/02)
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- Aminopyrine and Antipyrine Free Radical-cations: Pulse Radiolysis Studies of One-electron Transfer Reactions
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Absolute rate constants for the reaction of a variety of electrophilic free radicals with the pyrazoline derivatives aminopyrine and antipyrine have been measured by pulse radiolysis.In the case of aminopyrine the resulting radical cation is a particularly stable species ε325 5.35*103 dm3 mol-1 cm-1).Both compounds are readily oxidised to their respective radical-cations with the one-electron oxidation potential of antipyrine (E0 1.1-1.6 V) being higher than that of aminopyrine (E0 0.26-0.5 V).Studies of the reaction of the radical-cations with reducing agents suggest that aminopyrine in particular may prove to be a useful reference compound in studies of free radical one-electron oxidations.
- Forni, Luigi G.,Mora-Arellano, Victor O.,Packer, John E.,Willson, Robin L.
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p. 1579 - 1584
(2007/10/02)
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- Mechanisms of Heterocycle Ring Formation. Part 5. A Carbon-13 Nuclear Magnetic Resonance Study of Pyrazolinone Synthesis by the Reaction of β-Ketoesters with Substituted Hydrazines
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The 16 reactions between each of four hydrazines and four β-ketoesters have been followed by 13C n.m.r. spectroscopy.Peaks were assigned to starting materials, intermediates, and products, and reaction mechanisms determined and rationalized.Most rections proceed by attack of the least hindered hydrazine nitrogen atom on the keto carbon group of the ketoester.Relative rates of nucleophilic attack determine the build-up of intermediate and in some cases the nature of the products formed.
- Katrizky, Alan R.,Barczynski, Piotr,Ostercamp, Daryl L.
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p. 969 - 976
(2007/10/02)
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- Opthalmic solution
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An ophthalmic solution is provided for treatment of "dry eye", providing lubricating and cushioning effects for traumatized eyes, including trauma caused by the wearing of hard or gel-type contact lenses, and as a carrier for ophthalmic medicaments. The solution is an aqueous solution of polyethylene oxide, optionally polyethylene glycol, and other optional ingredients.
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- Polystyrene sulfonate containing opthalmic solutions
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An opthalmic solution is provided for treatment of "dry eye", providing lubricating and cushioning effects for traumatized eyes, including trauma caused by the wearing of hard or gel-type contact lenses, and as a carrier for opthalmic medicaments. The solution is an aqueous solution of polystyrene sulfonate, optionally and preferably including polyethylene glycol, and other optional ingredients.
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