2107-77-9Relevant articles and documents
Coumarins: Facile and expeditious synthesis via keggin-type heteropolycompounds under solvent-free condition
Rafiee, Ezzat,Fakhri, Akram,Joshaghani, Mohammad
, p. 1121 - 1128 (2013)
Different Keggin-type heteropolycompounds were used in Pechmann reaction to obtain biologically active coumarins. Effect of solvent, catalyst loading, and molar ratios of substrates was studied to introduce the best reaction condition. The optimized reaction condition was extended to Pechmann reaction of methylacetoacetate with various monohydric and polyhydric phenols. This rapid procedure afforded structurally diverse coumarins with high to excellent yields. Short reaction times, simple work-up, and mild reaction conditions were advantages of this method. The optimized catalysts were reusable for four runs.
Synthesis of hydroxyderivatives of 4-methylcoumarin
Zav'yalov,Dorofeeva,Rumyantseva,Zavozin
, p. 204 - 205 (1996)
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Reactions of 4-methylchromene-2,7,8-trione with phosphonium ylides. Synthesis and evaluation of fused 1,3-dioxolocoumarins as antioxidants and antiinflammatories
Fylaktakidou, Konstantina C.,Gautam, Daman R.,Hadjipavlou-Litina, Dimitra J.,Kontogiorgis, Christos A.,Litinas, Konstantinos E.,Nicolaides, Demetrios N.
, p. 3073 - 3079 (2001)
4-Methylchromene-2,7,8-trione 1 reacts with stabilized 2a-c and non-stabilized ylides 11a-c bearing an α-methylene group to give 7,8-fused 1,3-dioxolocoumarins 4a-c and 12a-c along with betaine 6 and 7-hydroxycoumarin derivative 9. The reaction of 4,5-fused 1,3-dioxolo-o-benzoquinone 13 with the ylide 14 leads to 4-ethoxycarbonylayapin 18 and benzofuranone 19. Deethoxycarbonylation of 18 gives ayapin 20. Compounds 4b, 12a-c, 18 and 20 were tested for their ability to interact with 1,1-diphenyl-2-picrylhydrazyl stable free radical (DPPH), to scavenge superoxide anion radicals, to compete with DMSO for hydroxyl radicals, and to inhibit proteolysis, β-glucuronidase and soybean lipoxygenase activity in vitro. These compounds were also tested for their effect on the ferrous ion-stimulated peroxidation of linoleic acid. They showed a potent inhibitory effect (55-57%) against inflammation induced by carrageenan in the rat paw edema model. On the contrary their reducing ability was found to be low and no inhibition on soybean lipoxygenase was recorded.
Recyclable CMK-5 supported sulfonic acid as an environmentally benign catalyst for solvent-free one-pot construction of coumarin through Pechmann condensation
Zareyee, Daryoush,Serehneh, Mahshad
, p. 88 - 91 (2014)
Sulfonic acid modified nanostructured CMK-5 is used as an alternative to conventional acid catalysts in the von Pechmann condensation of a neat mixture of substituted phenols with ethyl acetoacetate leading to the formation of coumarin derivatives at 130 °C. In comparison, CMK-5-SO3H showed a greater activity than some other homogeneous and heterogeneous catalysts. Additionally, the catalyst is reused repeatedly for 6 reaction cycles without any evidence of loss of activity, confirming the stability of the covalent bonding of acidic centers. The methodology presented offers reusable strategy for the efficient synthesis of coumarin, simplicity in operation, and green aspects by avoiding toxic conventional catalysts and solvents.
Novel Fe3+-based 1H MRI β-galactosidase reporter molecules
Yu, Jian-Xin,Gulaka, Praveen K.,Liu, Li,Kodibagkar, Vikram D.,Mason, Ralph P.
, p. 370 - 378 (2012)
There is increasing interest in the development of reporter agents to reveal enzyme activity in vivo using imaging in small animals. We have previously demonstrated the feasibility of detecting lacZ gene activity using the commercially available 3,4-cyclohexenoesculetin-β-D-galactopyranoside (S-Gal) as a 1H MRI reporter. Specifically, β-galactosidase (β-gal) releases the aglycone, which forms a magnetic resonance contrast-inducing paramagnetic precipitate in the presence of Fe3+. Contrast was primarily T2-weighted signal loss, but T1 effects were also observed. Since T1-contrast generally provides signal enhancement as opposed to loss, it appeared attractive to explore whether analogues could be generated with enhanced characteristics. We now report the design and synthesis of novel analogues together with characterization of 1H MRI contrast based on both T1 and T2 response to b-gal activity in vitro for the lead agent.
Regioselective IBX-Mediated Synthesis of Coumarin Derivatives with Antioxidant and Anti-influenza Activities
Bizzarri, Bruno M.,Botta, Lorenzo,Capecchi, Eliana,Celestino, Ignacio,Checconi, Paola,Palamara, Anna T.,Nencioni, Lucia,Saladino, Raffaele
, p. 3247 - 3254 (2017)
Different catechol and pyrogallol derivatives have been synthesized by oxidation of coumarins with 2-iodoxybenzoic acid (IBX) in DMSO at 25 °C. A high regioselectivity was observed in accordance with the stability order of the incipient carbocation or radical benzylic-like intermediate. The oxidation was also effective in water under heterogeneous conditions by using IBX supported on polystyrene. The new derivatives showed improved antioxidant effects in the DPPH test and inhibitory activity against the influenza A/PR8/H1N1 virus. These data represent a new entry for highly oxidized coumarins showing an antiviral activity possibly based on the control of the intracellular redox value.
Nano-BFn/cellulose: a bio-based nano-catalyst for synthesis of bio-active 7-hydroxycoumarins
Mirjalili, Bi Bi Fatemeh,Bamoniri, Abdolhamid,Fazeli-Attar, Seyede Azita
, p. 839 - 851 (2022/01/20)
Nano-BFn/cellulose as a modified bio-based nano-catalyst has been synthesized from nanocellulose and boron triflouride via very simple steps. This novel nano-catalyst exhibited many advantages in the synthesis of 7-hydroxycoumarins such as good
Synthesis of C4-substituted coumarins via Pechmann condensation catalyzed by sulfamic acid. Insights into the reaction mechanism by HRMS analysis
Moraes, Maiara C.,Lenard?o, Eder J.,Barcellos, Thiago
, p. 151 - 163 (2022/01/28)
A series of functionalized C4-substituted coumarins were synthesized by exploring the reaction of activated and non-activated phenols and β-ketoesters under solvent-free conditions in the presence of sulfamic acid as a Br?nsted acid catalyst. Fifteen exam
B(C6F5)3-catalyzed synthesis of coumarins via Pechmann condensation under solvent-free conditions
Prajapti, Santosh Kumar,Rao, S. Prakash
, p. 469 - 473 (2021/03/26)
Tris(pentafluorophenyl)borane [B(C6F5)3] catalyzed simple, efficient and environmentally benign protocol has been developed for the Pechmann condensation using variety of phenols and β-ketoesters under solvent-free conditions to afford coumarin derivatives. The present protocol displayed significant advantages such as low catalyst loading, short reaction time, mild reaction conditions, low toxicity, easy work-up, high yields, and compatibility with other functional groups. In addition, it is a convenient, clean, and fast alternative approach for synthesizing variety of coumarin derivatives. Moreover, the applicability of this method towards large-scale synthesis demonstrated its suitability for the industrial application. Graphic abstract: [Figure not available: see fulltext.]
