- Synthesis of coumarin derivatives in a microfluidic flow system employing the Pechmann condensation: A case study
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For the synthesis of coumarin derivatives using the Pechmann condensation scheme, an acidic ionic liquid catalyst, abbreviated as [EBsImH][HSO4], was prepared from the ring opening of 1,4-butanesultone by 1-ethylimidazole, followed by the addition of 1 equiv. H2SO4(c). The [EBsImH][HSO4]-catalyzed Pechmann condensation reactions proceeded smoothly in a batch setup, with recyclable [EBsImH][HSO4] showing great catalytic activity. The acidic ionic liquid catalyst [EBsImH][HSO4] was recovered from EtOAc/H2O extraction of the product mixture, where the H2O layer was worked up and dried for reuse in consecutive runs of the Pechmann condensation reactions, maintaining >85% conversion for four times. The catalytic reactions were also carried out in a microfluidic flow setup. The flow parameters, the reactant molar amounts, and the additional H2SO4 as a modifying acid catalyst were optimized in the current case study. A minimum conversion rate of 2.8 g/hr of coumarin derivatives was demonstrated.
- Liu, Ling-Kang,Deng, Jhao-Hong,Guo, Yang-Ming
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- CuFe2O4 nanoparticles: A magnetically recoverable and reusable catalyst for the synthesis of coumarins via pechmann reaction in water
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The synthesis of coumarins by hydroxyalkylation of phenols with ethyl acetoacetate (via Pechmann reaction) is attempted using magnetically separable and reusable CuFe2O4 nanoparticles in water. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.] Copyright
- Baghbanian, Seyed Meysam,Farhang, Maryam
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- Sulfonated core-shell magnetic nanoparticle (Fe3O4@SiO2@PrSO3H) as a highly active and durable protonic acid catalyst; Synthesis of coumarin derivatives through pechmann reaction
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Sulfonic acid supported silica coated magnetic nanoparticles (Fe3O4@SiO2@PrSO3H), was prepared by using low cost precursors and a facile immobilization technique. The final catalyst, which was characterized by XRD, FT-IR, vibrating sample magnetometer (VSM), TEM, and TGA techniques, was found to be an efficient and environmentally benign solid acid for the Pechmann condensation of substituted phenols with ethyl acetoacetate leading to the formation of coumarin derivatives. After the reaction, the catalyst could be effortlessly separated by external magnet and reused for 22 consecutive runs, without any significant loss in catalytic efficiency. The catalytic system presented offers a reusable strategy for the efficient synthesis of coumarin, simplicity in operation, and a green reaction profile by avoiding toxic conventional catalysts and solvents. Green earth and blue sky: Herein, we wish to disclose a simple bench top procedure for the synthesis of sulfonated core-shell magnetic nanoparticles (SMNPs) (Fe3O4@SiO2@PrSO3H) and discuss its performance as a very strong solid acid in the Pechmann condensation reaction.
- Esfahani, Farhad Kabiri,Zareyee, Daryoush,Yousefi, Reza
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- Meglumine sulfate catalyzed solvent-free one-pot synthesis of coumarins under microwave and thermal conditions
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A convenient method has been developed for the Pechmann reaction of phenols and β-keto esters catalyzed by meglumine sulfate. Solvent-free conditions, inexpensive catalyst, short reaction times, high yield, and ease of purification of the products are the advantages of this protocol. This novel catalytic system is expected to contribute to the development of more benign Pechmann condensation reactions of phenols with β-keto esters.
- Moradi, Leila,Rabiei, Khadijeh,Belali, Fateme
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- Polyvinylpolypyrrolidone-bound boron trifluoride (PVPP-BF3); A mild and efficient catalyst for synthesis of 4-metyl coumarins via the Pechmann reaction
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Polyvinylpolypyrrolidone-supported boron trifluoride has been studied for synthesis of 4-methyl coumarin by the Pechmann reaction. The reaction proceeded smoothly with hydroxyl phenols and ethyl acetoacetate in good yields in ethanol at reflux conditions. The polyvinylpolypyrrolidone-boron trifluoride complex is a non-corrosive and stable solid catalyst elevated Lewis acid property.
- Mokhtary, Masoud,Najafizadeh, Faranak
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- SnCl4 grafted on silica gel: an efficient catalyst for solvent-free synthesis of coumarins via the Pechmann condensation
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A facile synthesis of substituted coumarins via Pechmann condensation catalyzed by SnCl4 grafted on silica gel is described, which was conducted under solvent-free condition in high yields. The catalyst is noncorrosive and can be easily prepared and separated from the reaction mixture. This methodology offers some advantages with regard to yield of products, simplicity in operation and green aspects.
- Sun, Rui,Gao, Yanjuan,Ma, Ying,Yang, Guangde,Li, Yiping
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- The Effects of Exposed Specific Facets and Sulfation on the Surface Acidity of Cu2O Solids
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Cuprous oxide microcrystals with {111}, {111}/{100}, and {100} exposed facets were synthesized. 31P MAS NMR using trimethylphosphine as the probe molecule was employed to study the acidic properties of samples. It was found that the total acidic density of samples increases evidently after sulfation compared with the pristine cuprous oxide microcrystals. During sulfation, new {100} facets are formed at the expense of {111} facets and lead to the generation of two Lewis acid sites due to the different binding states of SO4 2? on {111} and {100} facets. Moreover, DFT calculation was used to illustrate the binding models of SO4 2? on {111} and {100} facets. Also, a Pechmann condensation reaction was applied to study the acidic catalytic activity of these samples. It was found that the sulfated {111} facet has better activity due to its higher Lewis acid density compared with the sulfated {100} facet.
- Wu, Yanan,Huang, Daofeng,Fu, Yingyi,Zhang, Li,Liu, Shixi,Tang, Gangfeng,Ren, Yuanhang,Ye, Lin,Chen, Xueying,Yue, Bin,He, Heyong
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- Selectfluor: A simple and efficient catalyst for the synthesis of substituted coumarins under solvent-free conditions
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Selectfluor is used as an alternative catalyst to conventional catalysts for the synthesis of substituted coumarins via Pechmann condensation of phenols with β-ketoesters under solvent-free conditions at 120 °C. This method of synthesis is simple, cost-effective, requires short reaction time, solvent-free and gives good yields.
- Kumar, B. Sunil,Reddy, Y. Thirupathi,Reddy, P. Narsimha,Kumar,Rajitha
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- Novel traceless liquid-phase synthesis of coumarin derivatives on poly(ethylene glycol) support
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Coumarin derivatives were prepared by the von Pechmann reaction of PEG-bound acetoacetate reagent with phenols in the presence of TiCl4 in excellent yield and purity with a facile workup procedure. The polymer reagent could be recycled two to four times without diminishing the yield or purity. Copyright Taylor & Francis Group, LLC.
- Sheng, Shou-Ri,Huang, Pei-Gang,Wang, Qiong,Huang, Ren,Liu, Xiao-Ling
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- Photo-cross-linked poly(ether amine) micelles for controlled drug release
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In order to improve the stability of micelles and decrease the burst release of loaded drugs, photo-cross-linked micelles were prepared via photodimerization of the coumarin moiety on amphiphilic poly(ether amine) (PEAC). The structures of the obtained monomer and polymers were confirmed by Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), 1H NMR and 13C NMR (Nuclear Magnetic Resonance, NMR). PEAC could self-assemble into micelles by directly dispersing in water with a hydrophobic coumarin core and a hydrophilic poly(ethylene glycol) (PEG) shell. The photo-cross-linking process of the PEAC micelles was monitored by UV-vis spectroscopy. The morphology and size distribution of the micelles was characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Anticancer drug doxorubicin (DOX) was loaded into the micelles during the process of micelle formation. Photo-cross-linked micelles showed slower drug release and cellular uptake in comparison with the uncross-linked micelles. And both DOX-loaded micelles displayed pH-sensitive release behaviours. Moreover, the DOX-loaded photo-cross-linked micelles exhibit comparative anticancer efficacy as free DOX. These results indicated that photo-cross-linked PEAC micelles can be used as potential drug carriers for intelligent drug delivery.
- He, Haozhe,Ren, Yanrong,Dou, Yuge,Ding, Tao,Fang, Xiaomin,Xu, Yuanqing,Xu, Hao,Zhang, Wenkai,Xie, Zhigang
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p. 105880 - 105888
(2015)
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- Periodic mesoporous silica chloride (PMSCl) as an efficient and recyclable catalyst for the Pechmann reaction
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Periodic mesoporous silica chloride (PMSCl) with 2D P6mm hexagonal structure which can be prepared by a simple procedure is reported to act as an efficient and recyclable catalyst for the conversion of a variety of phenols into their corresponding coumarins through Pechmann reaction. The reactions were conducted under solvent-free conditions in good to excellent yields.
- Karimi, Babak,Behzadnia, Hesam
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- Synthesis of the coumarins via pechmann method in the presence of environmentally friendly Y(NO3)3×6H2O
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Several substituted coumarins can be prepared in high yield and purity by direct reaction of β-keto esters and phenol derivatives in the presence of a catalytic amount Y(NO3)3×6H2O as Lewis acid and at ambient temperature under solvent-free conditions. Several substituted coumarins can be prepared in high yield and purity by direct reaction of β-keto esters and phenol derivatives in the presence of a catalytic amount Y(NO3)3×6H2O as Lewis acid and at ambient temperature under solvent-free conditions. This method that is based on Pechmann condensation is very easy and rapid reaction for the synthesis of coumarin derivatives. Copyright
- Karami, Bahador,Kiani, Mahtab
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- Sulphamic acid - An efficient and cost-effective solid acid catalyst for the pechmann reaction
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Sulphamic acid (H2NSO3H, SA) is used as an alternative to conventional acid catalysts in the Pechmann condensation of phenols with β-ketoester leading to the formation of substituted coumarin. The method is simple, cost-effective, solvent-free and gives good yields in a short reaction time.
- Singh, Pankajkumar R.,Singh, Devendrapratap U.,Samant, Shriniwas D.
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- Synthesis of coumarin derivatives using glutamic acid under solvent-free conditions
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An efficient,simple and one-pot protocol for synthesis of coumarin derivatives on the basis condensation reaction of phenols with ethyl acetoacetate employing glutamic acid as a novel catalyst is described.
- Sabetpoor, Setareh,Hatamjafari, Farhad
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- Dually activated organo- and nano-cocatalyzed synthesis of coumarin derivatives
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A wide range of substituted coumarin derivatives were synthesized by refluxing in acetonitrile, ethyl acetoacetate, and ethyl benzoyl acetate with a wide range of structurally diverse phenol derivatives within a short reaction time with a catalytic combination of pyridine dicarboxylic acid as organocatalyst and nanocrystalline ZnO.
- Goswami, Papori
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- Nanosilica molybdic acid: synthesis, characterization and application as a green and reusable catalyst for the Pechmann condensation
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Abstract: Nanosilica molybdic acid (SMA NPs) was founded as an efficient and recyclable nanocatalyst for the synthesis of coumarin derivatives in excellent yields with good purity. Nano-SMA as a new solid acid was characterized by X-ray fluorescence, X-ray diffraction, energy-dispersive X-ray analyzer, transmission electron microscopy and Fourier transform infrared spectroscopy. Coumarin derivatives were obtained via the Pechmann condensation reaction of phenols and β-ketoesters at 80?°C under solvent-free conditions. The main advantages of the present procedure are high yields, shorter reaction time and green chemistry procedure, simple work-up and inexpensive and reusability of the catalyst. Graphical Abstract: [Figure not available: see fulltext.]
- Kiani, Mahtab,Karami, Bahador
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- Synthesis and bioactive evaluation of a novel series of coumarinazoles
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A series of novel coumarinazoles were designed, synthesized, and characterized by IR, NMR, MS and HRMS spectra. The bioactive assay for the newly prepared compounds against six bacteria and five fungi manifested that most new compounds exhibited good or even stronger antibacterial and antifungal activities in comparison with reference drugs Chloromycin, Norfloxacin and Fluconazole. Bis-azole alcohols 7a and 7d-e showed better anti-Candida utilis activity than mono-azole derivatives 4a and 4d-e at the tested concentrations, and they were more potent than the clinical Fluconazole. While triazole alcohol 7a gave comparable anti-Candida albicans and anti-Candida mycoderma activity to Fluconazole and better anti-MRSA activity than mono-triazole one 4a and clinical Norfloxacin. 1H-Benzoimidazol-2-ylthio coumarin derivatives 4e and 7e gave the strongest anti-Escherichia coli JM109 efficacy. Oxiran-2-ylmethoxy moiety was found to be a beneficial fragment to improve antibacterial and antifungal activity to some extent.
- Damu, Guri L.V.,Cui, Sheng-Feng,Peng, Xin-Mei,Wen, Qin-Mei,Cai, Gui-Xin,Zhou, Cheng-He
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- Bismuth(III) nitrate pentahydrate - A mild and inexpensive reagent for synthesis of coumarins under mild conditions
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Bismuth(III) nitrate pentahydrate is found to be an efficient catalyst for the Pechmann condensation reaction of phenols and β-ketoesters under solvent-free conditions. The reaction protocol is simple and is followed by aqueous work-up leading to the formation of the corresponding coumarin derivatives in good yield and high purity.
- Alexander, Varughese M.,Bhat, Ramakrishna P.,Samant, Shriniwas D.
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- B(C6F5)3-catalyzed synthesis of coumarins via Pechmann condensation under solvent-free conditions
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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.]
- Prajapti, Santosh Kumar,Rao, S. Prakash
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- Pechmann reaction in chloroaluminate ionic liquid
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Substituted coumarins were synthesized in good yields via the Pechmann reaction in chloroaluminate ionic liquid. 1-Butylpyridinium chloroaluminate ionic liquid was used as a solvent cum catalyst for this condensation reaction.
- Khandekar,Khadilkar
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- Design of a highly efficient and water-tolerant sulfonic acid nanoreactor based on tunable ordered porous silica for the von Pechmann reaction
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(Figure Presented) Among a number of different sulfonic acid nanoreactors prepared, 5 having both acidic sites and phenyl groups located inside the mesochannels of SBA-15 was shown to be the most active and reusable catalyst in the von Pechmann reaction. The mesochannels, and covalently anchored organic groups, provide a synergistic means of an efficient approach of the reactants to acidic sites, enough space for the subsequent cyclization, and suitable hydrophobicity to drive out the water byproduct.
- Karimi, Babak,Zareyee, Daryoush
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- Solvent free synthesis of coumarins using environment friendly solid acid catalysts
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Solid acid catalysts, ZrPW (Zirconium(IV) Phosphotungstate) and 12-TPA/ZrO2 [12-Tungstophosphoric acid (12-TPA) supported onto ZrO2] have been synthesized. The catalysts have been characterized for chemical stability, elemental analysis by ICP-AES, TGA, FTIR, SEM, EDX, XRD, surface area (BET) and surface acidity (NH3-TPD). The performance of these materials as solid acid catalysts has been explored by studying Pechmann condensation as a model reaction, wherein phenols have been treated with methyl acetoacetate to give coumarins, under solvent free conditions using conventional heating as well as microwave heating. Catalytic activity of both the solid acid catalysts have been compared and correlated with surface properties of the materials.
- Ghodke, Shrinivas,Chudasama, Uma
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- Synthesis of substituted coumarins catalyzed by sawdust-SO3H. An efficient and environmentally benign solid acid catalyst under solvent-free conditions
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The sulfonated sawdust (SD-SO3H) was easily prepared by treatment of sawdust, a biomass waste material, with chlorosulfonic acid and characterized by elemental analysis, SEM and TGA. The bio-degradable solid acid catalyst has been applied to the Pechmann condensation reaction of phenols with β-ketoesters for the synthesis of coumarin derivatives under solvent-free conditions. This environmentally benign and inexpensive method has such advantages as simplicity in operation, high yields, low catalyst loading and short reaction time. The catalyst can be efficiently recycled with insignificant loss of activity.
- Tahanpesar,Sarami
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- Chlorosulfonic acid-catalysed one-pot synthesis of coumarin
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Chlorosulfonic acid is used as an alternative to conventional acid catalysts in the von Pechmann condensation of phenol with β-ketoester leading to the formation of substituted coumarin.
- Kotharkar, Sandeep A.,Bahekar, Sushilkumar S.,Shinde, Devanand B.
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- Cux2 (x =cl, br) as catalysts for pechmann reaction: Synthesis of 4-substituted coumarins
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CuX2 (X=Cl, Br) are found to be efficient catalysts (10 mol%) for the Pechmann condensation reaction of phenols and b-ketoesters to give 4-substituted coumarins under solvent-free conditions. The yields of coumarin derivatives obtained via this
- Wang, Yi,Xu, Feng,Tian, You-Ping,Li, Hui-Li,Wang, Jian-Jun
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- ZrOCl2.8H2O/SiO2: An efficient and recyclable catalyst for the preparation of coumarin derivatives by Pechmann condensation reaction
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Silica gel supported zirconyl chloride octahydrate was found to be an efficient and recyclable catalyst for the synthesis of a series of biologically important molecules in high turnover numbers and rates. Several substituted coumarins can be prepared in high yield and purity by direct reaction of β-keto esters and phenol derivatives in the presence of a catalytic amount of ZrOCl2.8H2O/SiO2 as Lewis acid and at ambient temperature under solvent-free conditions. This method which is called Pechmann condensation is a very easy and a rapid reaction for the synthesis of coumarin derivatives.
- Karami, Bahador,Kiani, Mahtab
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- Expeditious approach to coumarins via pechmann reaction catalyzed by molecular iodine or AgOTf
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An efficient and facile route for the synthesis of coumarins via the Pechmann reaction catalyzed by molecular iodine or AgOTf was described. Copyright Taylor & Francis Group, LLC.
- Wu, Jie,Diao, Tianning,Sun, Wei,Li, Yizhe
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- Coumarin syntheses via Pechmann condensation in Lewis acidic chloroaluminate ionic liquid
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1-Butyl-3-methylimidazolium chloroaluminate, [bmim]Cl·2AlCl3 ionic liquid is used as an alternative to conventional acid catalysts in the Pechmann condensation of phenols with ethyl acetoacetate leading to the formation of coumarin derivatives. The reaction time is reduced drastically even at ambient conditions. The ionic liquid plays the dual role of solvent and Lewis acid catalyst providing a quick and efficient route to the syntheses of coumarins.
- Potdar, Mahesh K.,Mohile, Swapnil S.,Salunkhe, Manikrao M.
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- Acceleration of the Pechmann Reaction by Microwave Irradiation: Application to the Preparation of Coumarins
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Substituted coumarins are synthesised from methyl acetoacetate and substituted phenols using microwaves in excellent yields.
- Singh, Vasundhara,Singh, Jasvinder,Kaur, Kanwal Preet,Kad, Goverdhan L.
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- Diazabicyclo[2.2.2]octane stabilized on Fe3O4 as catalysts for synthesis of coumarin under solvent-free conditions
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Fe3O4-diazabicyclo[2.2.2]octane (Fe3O 4-DABCO) magnetic nanoparticles (MNPs) catalyst was readily prepared from inexpensive starting materials in aqueous media which catalyzed the synthesis of coumarin. FTIR spectroscopy, X-ray diffraction, transmission electron micrographs were employed to characterize the properties of the synthesized Fe3O4-DABCO MNPs. High catalytic activity and ease of recovery from the reaction mixture using external magnet, and several reuse times without significant losses in performance are additional eco-friendly attributes of this catalytic system.
- Nasseri, Mohammad Ali,Sadeghzadeh, Seyed Mohsen
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- Poly(4-vinylpyridine)-supported sulfuric acid: An efficient solid acid catalyst for the synthesis of coumarin derivatives under solvent-free conditions
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Poly(4-vinylpyridine)-supported sulfuric acid is an efficient catalyst for the Pechmann condensation of acetoacetic esters with phenols, leading to the formation of coumarins in good yields within a few minutes under solvent-free microwave conditions. The catalyst used can be recovered and reused after activation. Springer-Verlag 2011.
- Borah, Kalyan Jyoti,Borah, Ruli
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- Pechmann reaction in non-chloroaluminate acidic ionic liquids under solvent-free conditions
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Four non-chloroaluminate acidic ionic liquids have been used as catalysts for Pechmann condensations of phenols under solvent-free conditions. SO 3H-functionalized trifluoromethanesulfonate imidazolium ionic liquid has proved to be the most active catalyst. Ionic liquid loads as low as 5 mol % can be used leading to high yields with activated phenols at an oil bath temperature of 80°C. The acidities of the four ionic liquids have also been tested using the Hammett method in dichloromethane. The results are consistent with their catalytic activities as observed in the Pechmann reaction of resorcinol. This methodology offers significant improvements for the synthesis of coumarins with regard to yield of products, simplicity in operation, and green aspects by avoiding toxic catalysts and solvents.
- Gu, Yanlong,Zhang, Juan,Duan, Zhiying,Deng, Youquan
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- Role of basicity, calcinations, catalytic activity and recyclability of hydrotalcite in eco-friendly synthesis of coumarin derivatives
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An efficient and simple protocol is described for synthesis of coumarin derivatives using Mg-Al-CO3 and Ca-Al-CO3 hydrotalcite as an environmental friendly and reusable heterogeneous catalyst under solvent free conditions. The catalysts were characterized by Hammett titration, SEM and XRD data. Present study revealed that catalytic activity and basicity depend on compositions of hydrotalcite. The calcined hydrotalcite with an Mg/Al of 3:1 derived from calcinations at 750 K was found to be suitable catalyst that gives the highest basicity and the best catalytic activity for this reaction. Catalyst allows short reaction time, high catalytic activity, easy to work up and is reusable. Step economy, atom efficiency and solvent free conditions are some important salient features of this protocol.
- Sahu, Pramod K.,Sahu, Praveen K.,Agarwal, Dau D.
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- Br?nsted-acidic imidazolium ionic liquid [bmim(SO 3H)][OTf]: A mild catalyst for highly efficient synthesis of coumarins
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The use of Br?nsted-acidic imidazolium ionic liquid [bmim(SO 3H)][OTf] as a catalyst for the high yielding synthesis of a wide variety of coumarins under mild conditions via Pechmann condensation has been demonstrated. This method is simple and has benefits from the easy way to isolate coumarins in good yields. In comparison with the classical Pechmann condensation, this new method consistently has the advantage of high yields and good purity.
- Haldorai, Yuvaraj,Kalkhambkar, Rajesh G.,Shim, Jae-Jin
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- Gallium triiodide-catalyzed organic reaction: A convenient procedure for the synthesis of coumarins
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Gallium triiodide, which was generated in situ by the reaction of gallium metal and iodine, was used as an efficient catalyst in the Pechmann condensation of phenols with ethyl acetoacetate, leading to the formation of coumarins. The reaction proceeded in dichloromethane at room temperature with good to excellent yields. Copyright Taylor & Francis, Inc.
- Sun, Peipei,Hu, Zhixin
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- Microwave assisted convenient one-pot synthesis of coumarin derivatives via Pechmann condensation catalyzed by FeF3 under solvent-free conditions and antimicrobial activities of the products
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A rapid and efficient solvent-free one-pot synthesis of coumarin derivatives by Pechmann condensation reactions of phenols with ethyl acetoacetate using FeF3 as a catalyst under microwave irradiation is described. This one-pot synthesis on a solid inorganic support provides the products in good yields. The newly synthesized compounds were systematically characterized by IR, 1H-NMR, 13C-NMR, MS and elemental CHN analyses. The proposed solvent-free microwave irradiation method using the environmentally friendly catalyst FeF3 offers the unique advantages of high yields, shorter reaction times, easy and quick isolation of the products, excellent chemoselectivity, and a one-pot, green synthesis. The products were screened for antimicrobial activity, and the results showed that the compounds reacted against all the tested bacteria.
- Vahabi, Vahid,Hatamjafari, Farhad
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- PEG-SO3H: A mild and efficient recyclable catalyst for the synthesis of coumarin derivatives
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A simple and efficient synthesis of coumarin derivatives through condensation reaction of substituted phenols and dicarbonyl compounds using PEG-SO3H as a recyclable catalyst under solvent-free conditions is described.
- Nazeruddin,Pandharpatte,Mulani
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- Recyclable cellulose nanocrystal supported Palladium nanoparticles as an efficient heterogeneous catalyst for the solvent-free synthesis of coumarin derivatives via von Pechmann condensation
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2-Amino pyrimidine nanocellulose-supported Palladium nanoparticles (CNC-AMPD-Pd) as a novel bio supported nanocatalyst was prepared and characterized by ICP-AES, FT-IR, XRD, SEM, TEM, TGA and EDX techniques. The nanocatalyst demonstrated outstanding performance in Pechmann condensation between different substituted phenols and ethyl acetoacetate to obtain coumarin derivatives in good to excellent yields. The catalyst is easily recycled and reused without loss of the catalytic activity. The combined merits of reusable catalyst and solvent-free reaction conditions make the condensation with safe operation, no leaching of pd into environment, low pollution, rapid access to products and simple workup.
- Mirosanloo, Atieh,Zareyee, Daryoush,Khalilzadeh, Mohammad A.
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- Use of a highly efficient and recyclable solid-phase catalyst based on nanocrystalline titania for the pechmann condensation
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Nanocrystalline titania-based sulfonic acid was used as an efficient and reusable catalyst for the synthesis of coumarins. The clean, mild acidity condition, the quantitative yields of products, the short reaction time, and the low reaction temperature are attractive features of this method, making it suitable for heat- or acid-sensitive substrates, particularly in drug synthesis. In practice, this method affords an advantageous combination of satisfactory yields, easy product isolation and purification.
- Atghia, Seyyed Vahid,Beigbaghlou, Somayyeh Sarvi
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- Environmentally sustainable magnetic solid sulfonic acid: An efficient and reusable catalyst for the Pechmann reaction
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Abstract An environmentally benign sulfonic acid nanocomposite based on Fe3O4@SiO2 core-shell magnetic nanoparticles, Fe3O4@SiO2@Et-PhSO3H, was prepared and the acidity and utility of the catalyst were explored for the synthesis of a diverse range of coumarin derivatives under solvent-free conditions. The catalyst shows potential for scale up in the synthesis of coumarins with high purity and was easily separated by using an external magnet. The recovered catalyst was reused in seven cycles without any significant loss of activity.
- Mobaraki, Akbar,Yasham, Shahriar,Movassagh, Barahman
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- Alum (KAl(SO4)2·12H2O) catalyzed one-pot synthesis of coumarins under solvent-free conditions
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Alum (KAl(SO4)2·12H2O) is used as an efficient catalyst in the Pechmann condensation of phenol derivatives with β-keto esters leading to the formation of coumarins in excellent yields under solvent-free conditions. This methodology offers significant improvements for the synthesis of coumarins with regard to the yield of products, simplicity in operation, and green aspects by avoiding toxic catalysts and solvents.
- Dabiri, Minoo,Baghbanzadeh, Mostafa,Kiani, Shadi,Vakilzadeh, Yasamin
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- Microwave-assisted synthesis of coumarins via pechmann condensation in wet phosphoric acid imidazolium dihydrogenphosphate
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Phosphoric acid imidazolium dihydrogenphosphate was found to work well as a catalyst and excellent reaction medium in the Pechmann condensation of substituted phenols or α-naphthol with ethyl acetoacetate to give 4-methyl coumarins under microwave irradiation. This method is simple, cost effective, requires short reaction times, and gives very good to excellent yields.
- Valizadeh, Hassan,Kordi, F. Mahmoodi,Gholipur, Hamid,Amiri, Mohammad
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- Photo-stimulated self-healing polyurethane containing dihydroxyl coumarin derivatives
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A novel polyurethane was synthesized, which consisted of isophorone diisocyanate, polyethylene glycol and photo-reversible moiety 5,7-bis(2-hydroxyethoxy)-4-methylcoumarin. By taking advantage of reversible photodimerization and photocleavage habit of coumarin, the polyurethane can be repeatedly crosslinked and de-crosslinked under successive UV irradiations at 350 and 254 nm. More importantly, damages in crosslinked version of the polyurethane can be re-bonded through chain reconnection on fracture surfaces resulting from the photochemical reactions, as characterized by mechanical strength restoration tests. Compared to the previous proof-of-concept trial with monohydroxyl coumarin derivatives as the photosensitive groups, the application of dihydroxyl coumarin derivatives in the present work prevented the undesirable gelation during synthesis and enabled properties-oriented structure adjustment of polymerization products. Besides, structure-performance relationship study of the polyurethane revealed that rubbery domains resulting from microphase separation were necessary for the photo-remending with high efficiency.
- Ling, Jun,Rong, Min Zhi,Zhang, Ming Qiu
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- MoO3/Al2O3: An efficient and reusable heterogeneous catalyst for solvent-free synthesis of coumarins via pechmann condensation
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16 wt % alumina supported MoO3 has been found to be an efficient catalyst for the synthesis of various substituted coumarins via Pechmann condensation. This method offers several advantages like high yields, facile recovery and reusability of the catalyst without loss in activity, nearly neutral and solvent free condition.
- Singhal, Sweety,Jain, Suman L.,Sain, Bir
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- 1-Nicotinoylbenzotriazole: A Convenient Tool for Site-Selective Protection of 5,7-Dihydroxycoumarins
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1-Nicotinoylbenzotriazole (NicBt) was uncovered as an efficient protecting agent for the site-selective acylation of resorcinol-type phenolic groups with almost equal reactivity. The use of NicBt allows selective protection of the 7-OH group in 5,7-dihydr
- Charushin, Valery N.,Chupakhin, Oleg N.,Fatykhov, Ramil F.,Inyutina, Anna K.,Kartsev, Victor G.,Khalymbadzha, Igor A.,Slepukhin, Pavel A.
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- Silica sulfuric acid as an efficient and reusable catalyst for the pechmann synthesis of coumarins under solvent-free conditions
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Silica sulfuric acid is used as an efficient catalyst in the Pechmann condensation of phenols with β-keto-esters leading to the formation of coumarin derivatives in excellent yields under solvent-free conditions. It was found that the catalyst could be recycled and reused for several runs.
- Dabiri, Minoo,Salehi, Peyman,Zolfigol, Mohammad Ali,Baghbanzadeh, Mostafa
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- Pegylated enzyme entrapped in poly(vinyl alcohol) hydrogel for biocatalytic application
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A procedure for enzyme entrapment into matrices suitable for biocatalytic applications is reported. The method, which takes advantage of the stable formation of polyvinyl alcohol (PVA) hydrogels by freezing and thawing PVA aqueous solutions, was assayed using lipase as model enzyme. The leakage of lipase was minimised by using high molecular weight PVA and by previous conjugation of the enzyme to PEG. The immobilised PEG enzyme maintained its catalytic activity in organic solvents also, thus allowing enzymatic activity towards water insoluble substrates. The activity was largely increased reducing the diffusional constrain by cutting the matrices into slices of micron size. Matrix-entrapped lipase-PEG, when used in the hydrolysis of acetoxycoumarins, showed a conversion rate of about 10 times lower than the enzyme-PEG in the free form, and maintained regioselectivity when a diacetylated product was used as substrate.
- Veronese, Francesco Maria,Mammucari, Cristina,Schiavon, Franco,Schiavon, Odolone,Lora, Silvano,Secundo, Francesco,Chilin, Adriana,Guiotto, Adriano
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- KAl(SO4)2·12H2O (alum) a reusable catalyst for the synthesis of some 4-substituted coumarins via Pechmann reaction under solvent-free conditions
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A simple, efficient, and practical procedure for the Pechmann condensation using KAl(SO4)2·12H2O (alum) as a non-toxic, reusable, inexpensive, and easily available catalyst is described under solvent-free condition at 65°C. These improved reaction conditions allow the preparation of a wide variety of some new substituted coumarins in high yields (86-96%) and purity under mild reaction conditions. Compared to the classical Pechmann condensation, this new method consistently has the advantage of high yields.
- Azizian, Javad,Mohammadi, Ali A.,Bidar, Ilyar,Mirzaei, Peiman
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- Pentafluorophenylammonium triflate (PFPAT): An efficient, metal-free and reusable catalyst for the von Pechmann reaction
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Pentafluorophenylammonium triflate (PFPAT) is used as an efficient catalyst in the von Pechmann condensation of phenols with β-ketoesters leading to the formation of coumarin derivatives. Short reaction times, easy and quick isolation of the products, excellent chemoselectivity, excellent yields and ease of catalyst recovery with consistent activity makes this protocol efficient and environmentally benign.
- Montazeri, Naser,Khaksar, Samad,Nazari, Akbar,Alavi, Seyedeh Soghra,Vahdat, Seyed Mohammad,Tajbakhsh, Mahmood
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- Vanadium(III) chloride as an effective catalyst for the Pechmann reaction
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Good yields of substituted coumarins were obtained by a synthetic method involving the Pechmann reaction using vanadium(III)chloride (VCl3) reagent to effect this condensation under solvent-free conditions. 2006 Springer Science+Business Media, Inc.
- Sunil Kumar,Kumar,Srinivasulu,Rajitha,Thirupathi Reddy,Narsimha Reddy,Udupi
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- Multicomponent click polymerization for the synthesis of coumarin containing 1,4-polytriazoles and their application as dye adsorbent
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The synthesis of heterocycle-based polymers have remained an important area of research in polymer chemistry. Herein we report a one-pot synthesis of a set of novel coumarin containing regioselective 1,4-polytriazols by multicomponent click polymerization using Cs2CO3 as a base and copper(I) acetate as a catalyst in DMF medium. In this one-pot process, O-alkylation followed by a three-component click reaction between the coumarin-linked dialkyne, sodium azide and alkyl/benzyl dibromides provide novel polymers having coumarin-triazole-linker (C-T-L) units. Ten novel polymers have been synthesized with high molecular weights (Mw = 20,080–46,340 g/mol) and very good yields (83–93%). All the polymers were well characterized by IR, NMR, and GPC. The dye removal capacities of these polymers were evaluated for methylene blue (MB), rhodamine B (RB), methyl orange (MO), and congo red (CR). Polymers P1, P2, and P3 showed very high affinity towards methylene blue dye and among them, P2 showed the highest dye removal efficiency (971 mg/g) for MB. The reusability of P2 was checked and found excellent removal efficiency (RE = 96%) up to the eighth cycle.
- Bhaumick, Prabhas,Choudhury, Lokman H.
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- Investigation of the cytotoxicity of bioinspired coumarin analogues towards human breast cancer cells
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Abstract: Coumarins possess a wide array of therapeutic capabilities, but often with unclear mechanism of action. We tested a small library of 18 coumarin derivatives against human invasive breast ductal carcinoma cells with the capacity of each compound to inhibit cell proliferation scored, and the most potent coumarin analogues selected for further studies. Interestingly, the presence of two prenyloxy groups (5,7-diprenyloxy-4-methyl-coumarin, 4g) or the presence of octyloxy substituent (coumarin 4d) was found to increase the potency of compounds in breast cancer cells, but not against healthy human fibroblasts. The activity of potent compounds on breast cancer cells cultured more similarly to the conditions of the tumour microenvironment was also investigated, and increased toxicity was observed. Results suggest that tested coumarin derivatives could potentially reduce the growth of tumour mass. Moreover, their use as (combination) therapy in cancer treatment might have the potential of causing limited side effects. Graphic abstract: [Figure not available: see fulltext.].
- Gkionis, Leonidas,Kavetsou, Eleni,Kalospyros, Alexandros,Manousakis, Dimitris,Garzon Sanz, Miguel,Butterworth, Sam,Detsi, Anastasia,Tirella, Annalisa
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p. 307 - 321
(2020/05/06)
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- Preparation of a novel, efficient, and recyclable magnetic catalyst, Cu(II)-OHPC-Fe3O4 nanoparticles, and a solvent-free protocol for the synthesis of coumarin derivatives
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Cu(II) supported on 5-oxo-4,5-dihydro-pyrrole-3-carboxylic acid functionalized Fe3O4 nanoparticles (Cu(II)-OHPC-Fe3O4) as a new magnetic nanocatalyst was prepared and characterized by ICP-AES, FT-IR, XRD, SEM, TEM, TGA, XRD, VSM and EDX techniques. Prepared nanocatalyst (Cu(II)-OHPC-Fe3O4) is employed for Pechmann reactions between different substituted phenols and ethyl acetoacetate to obtain new products of coumarin derivatives in good to excellent yields. This green catalyst was easily removed, reused several times with no significant loss of its activity and provided clean synthesis with excellent yield and reduced time.
- Yuan, Jingjing,Mohammadnia, Majid
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p. 2327 - 2343
(2021/07/26)
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- Synthesis of novel coumarin containing conjugated fluorescent polymers by Suzuki cross-coupling reactions and their chemosensing studies for iron and mercury ions
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Conjugated fluorescent polymers are very useful materials for chemical and biochemical sensors. Herein we report the synthesis of four novel conjugated coumarin-containing fluorescent co-polymers (P1–P4) by palladium catalyzed Suzuki-Miyaura cross-couplin
- Bhaumick, Prabhas,Jana, Asim,Choudhury, Lokman H.
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- Antagonistic activity of hydroxycoumarin-based antioxidants as possible singlet oxygen precursor photosensitizers
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Coumarins are phenolic-type compounds with efficient antioxidant activity due to their ability to scavenge reactive oxygen species. Nevertheless, their ability to behave as photosensitizers capable of generating reactive oxygen species, such as singlet oxygen, has been less studied. In this work, the photosensitizing ability of seven hydroxycoumarins was evaluated through the photooxidation of ergosterol by quantifying the conversion of ergosterol into ergosterol peroxide. In our experimental conditions, we found that almost every tested antioxidant coumarin promotes the peroxidation of ergosterol. The results suggest that the hydroxycoumarins exhibit potential photosensitizing activity by promoting singlet oxygen generation by a Type II photochemical mechanism. Density functional theory (DFT) calculations were also performed to obtain further insight into the chemical reactivity of tested compounds; the observed tendency in the group of antioxidant coumarins to promote the reaction was their hardness due to the principle of maximum hardness. To evaluate our conclusion, we performed the reaction using a highly polarizable coumarin as a photosensitizer, which resulted in an increased photosensitizing capacity supported with DFT calculations, which reinforces our analysis. Finally, we found that hydroxycoumarins can be potentially pro-oxidants since some of them can act as photosensitizers and generate singlet oxygen in the presence of UV–Vis light, a characteristic that must be considered when these compounds are used as antioxidants.
- Guerrero, Tomás,Vázquez-Ortega, Fernanda,Lagunes, Irene,Ortiz-Blanco, Erik,Sosa-Ortiz, Gabriela,Tovar-Miranda, Ricardo,Medina, Manuel E.,Trigos, ángel
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- Synthesis of C4-substituted coumarins via Pechmann condensation catalyzed by sulfamic acid. Insights into the reaction mechanism by HRMS analysis
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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
- Moraes, Maiara C.,Lenard?o, Eder J.,Barcellos, Thiago
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p. 151 - 163
(2022/01/28)
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- MnSb2O6-chitosan nanocomposite: An efficient catalyst for the synthesis of coumarins via Pechmann reaction
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In this work, MnSb2O6-chitosan nanocomposites were synthesized and have been employed in Pechmann condensation for the synthesis of coumarin derivatives. MnSb2O6-chitosan nanocomposites were characterized by Fou
- Bahramnezhad, Baharak,Ghazanfari, Dadkhoda,Sheikhhosseini, Enayatollah,Akhgar, Mohammad Reza,Ahmadi, Sayed Ali
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supporting information
p. 173 - 181
(2019/11/20)
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- Novel diphenylmethyl compounds having mycobacterium tuberculosis inhibitory activity
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The invention relates to novel diphenylmethyl derivatives having mycobacterium tuberculosis inhibitory activity and a preparation method thereof and particularly relates novel diphenylmethyl derivatives having activity for inhibiting replicative and non-replicating mycobacterium tuberculosis and a preparation method thereof. In particular, the invention relates to compounds shown in the formula (I) or all possible isomers, prodrugs, pharmaceutically acceptable salts, solvates or hydrates thereof, wherein the variables are as described in the specification. The invention also relates to the preparation method of the compounds and their pharmaceutical compositions and a use of the compounds in preparation of drugs for treating mycobacterium tuberculosis infection-caused diseases.
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Paragraph 0866-0869; 0873-0876
(2019/02/13)
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- NO2 functionalized coumarin derivatives suppress cancer progression and facilitate apoptotic cell death in KRAS mutant colon cancer
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Colon cancer is one of the most lethal cancers worldwide even with the significant progress made in screening techniques and therapeutic agents. Genetic mutations in tumors complicated the treatments, and the survival rate remains low for patients at late or metastatic stages. KRAS gene mutation which leads to failure of the EGFR targeted therapies stands for an example of the challenges in clinical sites. Therefore, development of novel agents for colon cancer treatment is in need. Natural and synthetic coumarin derivatives have been suggested with various biological activities with pharmacologic potential including anti-cancer capacity. Here in this study, five coumarin derivatives, include trifluoromethyl-, dimethoxy-, and/or nitro-substitutions at different positions, were synthesized. Their cancer inhibition potential was investigated in various cancer cell lines. Our data demonstrated that one nitro-coumarin derivate, 5,7-Dimethoxy-4-methyl-6-nitro-chromen-2-one, exhibits cytotoxicity specifically towards colon cancer cells under competitive EC50. Our results showed that this compound can effectively suppress colon cancer cells harboring either wild type or mutant KRAS genes, and that it could inhibit short-term proliferation, long term proliferation, and migration capacities of cancer cells. Finally, we demonstrated that this coumarin derivate facilitates cancer cell death through activation of apoptosis pathway. Our results suggest that this coumarin derivate is a promising lead drug worth further investigation and development for future cancer treatment.
- Lin, Mei-Hsiang,Wang, Juo-Shan,Hsieh, Yi-Chen,Zheng, Jia-Huei,Cho, Er-Chieh
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- Synthesis method of coumarin compounds
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The invention relates to a synthesis method of coumarin compounds. The method particularly comprises the following steps: performing reaction for 40 to 120 minutes by taking substituted phenol and beta-keto ester as substrates and DES as a catalyst under the condition of no solvents and at the temperature of 50 to 100 DEG C to prepare the coumarin compounds. In the preparation process of the coumarin compounds, other organic solvents do not need to be added and the DES serves as a reaction catalyst and solvent. The DES can be reused and is environment-friendly, and the catalytic effect basically maintains unchanged after the DES is recovered for four times. The preparation method provided by the invention is simple in process, high in catalytic activity and high in yield; and after reaction, treatment is simple, convenient and environment-friendly.
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Paragraph 0062; 0063; 0065
(2018/06/23)
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- Anionic SO3H-functionalized ionic liquid: An efficient and recyclable catalyst for the Pechmann reaction of phenols with ethyl acetoacetate
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This paper has reported an anionic SO3H-functionalized ionic liquid N-methylimidazolium sulfomethylsulfonate ([Hmim][HO3SCH2SO3]) for the synthesis of coumarins by Pechmann reaction. The [Hmim][HO3SCH2SO3] is easier to prepare by one-step neutralization reaction of N-methylimidazole with methanedisulfonic acid and show high catalytic performance for Pechmann reaction. Besides, the catalyst can simply be separated from the reaction mixture and recycled ten times without noticeable loss of activity.
- Song, Dayong,Chen, Jing,Liang, Yong-Min
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supporting information
p. 692 - 698
(2018/02/16)
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- A green and convenient approach for the one-pot solvent-free synthesis of coumarins and β-amino carbonyl compounds using Lewis acid grafted sulfonated carbon@titania composite
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Abstract: This paper reports an efficient protocol for the synthesis of coumarins via Pechmann reaction, and β-amino carbonyl compounds via aza-Michael reaction using catalytic amount of solid Lewis acid catalyst, C@TiO2–SO3–SbCl2. Six different catalysts were prepared by covalent immobilization of homogeneous Lewis acids onto sulfonated carbon@titania composite derived from amorphous carbon and nano-titania. Among various catalysts tested, C@TiO2–SO3–SbCl2 showed superior catalytic activity. The catalyst could be recycled without significant loss of its catalytic activity and demonstrated versatile catalysis for a wide range of substrates. Graphical abstract: [Figure not available: see fulltext.]
- Kour, Manmeet,Paul, Satya
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p. 327 - 337
(2017/02/10)
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- Preparation of a novel, efficient, and recyclable magnetic catalyst, γ-Fe2O3@HAp-Ag nanoparticles, and a solvent- and halogen-free protocol for the synthesis of coumarin derivatives
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In this protocol, Ag supported on the hydroxyapatite-core–shell magnetic γ-Fe2O3nanoparticles (γ-Fe2O3@HAp-Ag NPs) as a novel, efficient, and magnetically recyclable catalyst is synthesized, and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). The use of the catalyst is described in the synthesis of coumarin derivatives by the Pechmann condensation of various phenols with β-ketoesters under solvent- and halogen-free conditions at 80?°C. This novel and inexpensive method offers advantages, such as recyclability simple experimental protocol, short reaction time, minimal work-up procedure, and excellent yields of products, together with desirable, eco-friendly, green aspects by avoiding toxic elements and solvents, and ease of recovery from the reaction mixture using an external magnet.
- Abbasi, Zahra,Rezayati, Sobhan,Bagheri, Maryam,Hajinasiri, Rahimeh
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- One-pot synthesis of coumarine derivatives using butylenebispyridinium hydrogen sulfate as novel ionic liquid catalyst
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Pechmann condensation reaction of 3-hydroxyphenol and ethyl acetoacetate in the presence of 1,1′‐butylenebispyridinium hydrogen sulfate as an efficient, green, and recyclable catalyst produces 7-hydroxy-4-methylcoumarin in good yield under solvent-free conditions at room temperature. This catalyst has advantages such as the following: good to excellent yields, short reaction times, simplicity in operation, and easy workup procedure.
- Rezayati, Sobhan,Sheikholeslami-Farahani, Fatemeh,Rostami-Charati, Faramarz,Abad, Saeid Afshari Sharif
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p. 4097 - 4107
(2016/07/06)
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- L-ascorbic acid: A green and competent promoter for solvent-free synthesis of flavones and coumarins under conventional as well as microwave heating
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Background: An expeditious approach has been developed for the synthesis of two distinct classes of benzopyrones viz. flavones and coumarins under solvent-free conditions. L-Ascorbic acid was found to be an effective promoter under microwave irradiation and conventional heating. Various benzo-α-pyrones and benzo-γ-pyrones were synthesized with overall good yields. The present protocol is highly facile and needs no column chromatography for purification and therefore it would serve as an effective and compatible method under both microwave irradiation and conventional heating. Results: The catalytic ability of L-ascorbic acid was investigated for the synthesis of flavones and coumarins. For this purpose, cyclodehydration of 1-(2-hydroxyphenyl)-3-aryl-1,3-propanedione and Pechmann coumarin synthesis, reactions were selected. And accordingly, it was observed that one mole of L-ascorbic acid was necessary for the completion of reaction. In all the cases, the desired flavones were smoothly generated with good to excellent yields; indicating its excellent tolerance for various functional groups. However, electron donating groups favors coumarin synthesis under these conditions. All the reaction mixtures were carefully analyzed and NMR indicates high conversions and lack of side products. Conclusion: We have developed L-ascorbic acid-promoted, solvent-free and simple method for the synthesis of benzo-α-pyrones and benzo-γ-pyrone under microwave irradiation as well as conventional heating in good to excellent yields. The notable advantages of this method are solvent-free conditions, inexpensive and efficient eco-friendly promoter, and shorter reaction time and can be carried out under air. This methodology is highly facile and requires no column chromatography for purification. The resulting flavones and coumarins are versatile building blocks in the construction of heterocyclic architectures, dominant in natural products. Further studies of exploiting the efficiency of L-ascorbic acid as a promoter in synthesis of various heterocyclic compounds are in progress.
- Dengale, Rohit Arvind,Thorat, Nitin Madhu,Thopate, Shankar Ramchandra
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p. 734 - 741
(2017/02/05)
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- Natural organic acids promoted green and expeditious synthesis of coumarins under solvent free condition
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Green and highly efficient synthesis of coumarins by Pechmann condensation, using naturally occurring acids under solvent free condition, is described. Various phenols efficiently condensed with ethyl acetoacetate under conventional as well as microwave i
- Rohokale, Sandeep V.,Kote, Santosh R.,Thopate, Shankar R.
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- An efficient synthesis of coumarin derivatives using a SBA-15 supported cobalt(II) nanocatalyst
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The catalytic performance of highly active cobalt(II) supported on mesoporous SBA-15 materials for the Pechmann reaction was investigated. SBA-15 supported cobalt(II) nanocatalyst was found to be efficient and easily recoverable in the Pechmann reaction of phenols and b-ketoesters to their corresponding coumarin derivatives under solvent-free conditions. The supported cobalt catalyst could be easily recovered after reaction completion and reused twelve times with an excellent durability and without any noticeable loss in activity.
- Rajabi, Fatemeh,Feiz, Afsaneh,Luque, Rafael
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p. 1621 - 1625
(2019/11/28)
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- A solvent-free synthesis of coumarins using 1,3-disulfonic acid imidazolium hydrogen sulfate as a reusable and effective ionic liquid catalyst
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Abstract 1,3-Disulfonic acid imidazolium hydrogen sulfate has been used as an effective and reusable ionic liquid catalyst for the synthesis of coumarins from phenol derivatives with β-ketoesters via the Von Pechmann condensation under solvent-free conditions. This method consistently has the advantages of excellent yields, easy and quick isolation of the products, short reaction times, and green aspects by avoiding toxic catalysts and solvents. Further, the catalyst can be recovered and reused for four times without loss of activity.
- Shirini, Farhad,Yahyazadeh, Asieh,Mohammadi, Kamal
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p. 6207 - 6218
(2015/08/18)
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- Perlite: A cheap natural support for immobilization of sulfonic acid as a heterogeneous solid acid catalyst for the heterocyclic multicomponent reaction
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Perlite sulfonic acid (Perlite-SO3H (PeSA)) has been synthesized by grafting the sulfonic groups on the perlite surface as naturally and cheap support to produce novel heterogeneous reusable solid acid catalysts. FT-IR, XRD, SEM, TGA, pH analysis and Hammett acidity function were employed to characterize the properties of the synthesized PeSA. Significantly, the as-prepared PeSA exhibits a high catalytic activity in multicomponent reaction for the one-pot synthesis of heterocyclic compound such as 3,4-dihydropyrimidin-2(1H)-ones, 2,4,5-trisubstituted imidazoles, coumarins and bis(indolyl)methanes. Additionally, the newly synthesized heterogeneous solid acid catalyst can be reused for several times without apparent loss of its catalytic activity, confirming the stability of the covalent bonding of acidic centers. PeSA has advantages such as low cost, ease of preparation, more stability and reusability, low toxicity and ease of handling.
- Kolvari, Eskandar,Koukabi, Nadia,Hosseini, Maliheh M.
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- Synthesis and heterogeneous catalytic activity of covalently immobilized hexamine cation as a magnetically-recoverable nanocatalyst
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Functionalized magnetic core-shell nanoparticles Fe3O4-SiO2-HMTA are prepared by co-precipitation method and characterized by SEM, TEM, FT-IR, XRD, and VSM. The particles are spherical with an average size of approximately 48 nm. The catalytic activity of these nanoparticles was tested in solvent-free synthesis of coumarin derivatives. The catalyst was readily recycled by the use of an external magnetic field and can be reused four times without significant loss of activity or mass.
- Kangari, Sahar,Yavari, Issa,Maasoumi, Bakhshali
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p. 1771 - 1779
(2015/08/06)
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- FeCl3-catalysed ultrasonic-assisted, solvent-free synthesis of 4-substituted coumarins. A useful complement to the Pechmann reaction
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The catalytic activity of FeCl3 for the synthesis of a variety of 4-substituted coumarins using high energy techniques has been investigated. The ultrasonic-assisted conditions provide a useful complement to the Pechmann reaction, affording the coumarin derivatives in excellent yields, under solvent-free conditions, in short reaction times using an inexpensive, mild and benign Lewis acid catalyst.
- Prousis, Kyriakos C.,Avlonitis, Nicolaos,Heropoulos, Georgios A.,Calogeropoulou, Theodora
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p. 937 - 942
(2014/02/14)
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- Cholinium ionic liquids as cheap and reusable catalysts for the synthesis of coumarins via Pechmann reaction under solvent-free conditions
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A cheap cholinium ionic liquid N,N′-dimethylaminoethanol hydrosulfate ([N112OH][HSO4]) was found to be an efficient and reusable catalyst for the Pechmann condensation under solvent-free conditions. The coumarin products can be simply separated and the ionic liquid catalyst can be recycled and reused for at least six runs without noticeable decrease in the catalytic activity. The UV-vis studies suggested that the increase of the acidity and the introduction of a hydroxyl group to the cation benefit the existence of the keto tautomer of ethyl acetoacetate, which then leads to the excellent performance of [N112OH][HSO4].
- Zhang, Yuehua,Zhu, Anlian,Li, Qianqian,Li, Lingjun,Zhao, Yang,Wang, Jianji
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p. 22946 - 22950
(2014/06/24)
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- Synthesis of polyacrylonitrile fiber-supported poly(ammonium methanesulfonate)s as active and recyclable heterogeneous br?nsted acid catalysts
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A new polyacrylonitrile fiber-supported Br?nsted acid catalyst has been developed and verified to efficiently (high yield, 10 cycles) mediate Biginelli reactions in ethanol, Pechmann condensations in toluene, Friedel-Crafts alkylations of indoles in water and conversion of fructose in dimethyl sulfoxide (DMSO) and mixed-aqueous system.
- Shi, Xian-Lei,Xing, Xiaoli,Lin, Huikun,Zhang, Wenqin
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supporting information
p. 2349 - 2354
(2014/07/21)
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- Synthesis and bioactive evaluation of a novel series of coumarinazoles
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A series of novel coumarinazoles were designed, synthesized, and characterized by IR, NMR, MS and HRMS spectra. The bioactive assay for the newly prepared compounds against six bacteria and five fungi manifested that most new compounds exhibited good or even stronger antibacterial and antifungal activities in comparison with reference drugs Chloromycin, Norfloxacin and Fluconazole. Bis-azole alcohols 7a and 7d-e showed better anti-Candida utilis activity than mono-azole derivatives 4a and 4d-e at the tested concentrations, and they were more potent than the clinical Fluconazole. While triazole alcohol 7a gave comparable anti-Candida albicans and anti-Candida mycoderma activity to Fluconazole and better anti-MRSA activity than mono-triazole one 4a and clinical Norfloxacin. 1H-Benzoimidazol-2-ylthio coumarin derivatives 4e and 7e gave the strongest anti-Escherichia coli JM109 efficacy. Oxiran-2-ylmethoxy moiety was found to be a beneficial fragment to improve antibacterial and antifungal activity to some extent.
- Damu, Guri L.V.,Cui, Sheng-Feng,Peng, Xin-Mei,Wen, Qin-Mei,Cai, Gui-Xin,Zhou, Cheng-He
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p. 3605 - 3608
(2015/02/19)
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- An efficient synthesis of new khellactone-type compounds using potassium hydroxide as catalyst via one-pot, three-component reaction
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In the present work, three-component synthesis for novel khellactone-type compounds via the reaction of Meldrum's acid, aryl aldehydes and 5,7-dihydroxy benzopyrone derivatives was described. In this reaction 10-aryl substituted-9,10-dihydropyrano[2,3-h]benzopyrone-8-ones as new khellactone analogous in the presence of catalytic amount of potassium hydroxide as cheap and green basic catalyst were obtained in good to excellent yields under refluxing methanol.
- Karami,Eskandari,Khodabakhshi
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p. 631 - 637
(2014/05/20)
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- Magnesium bis(trifluoromethane)sulfonimide: An efficient catalyst for the synthesis of coumarins under solvent-free conditions
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Magnesium bis(trifluoromethane)sulfonimide [Mg(NTf2) 2] is an efficient catalyst for the synthesis of coumarins via the Pechmann condensation reaction of phenols and β-ketoesters under solvent-free conditions.
- Wang, Hongshe
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p. 411 - 414
(2013/05/21)
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- An environmentally friendly, chemoselective, and efficient protocol for the preparation of coumarin derivatives by Pechman condensation reaction using new and reusable heterogeneous Lewis acid catalyst polystyrene-supported GaCl 3
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An environmentally benign Pechman protocol for the one-pot synthesis of 4-substituted coumarins through the condensation reactions of phenol substrates with β-ketoesters using polystyrene-supported GaCl3 (PS-GaCl3) as a highly active and reusable solid Lewis acid catalyst under mild and heterogeneous conditions in good to excellent yields is described. This new protocol is easy, simple, cost-effective, chemoselective, and in addition has the advantages of easy availability, stability, reusability and eco-friendly character of the catalyst, high to excellent yields, simple experimental and work-up procedure.
- Rahmatpour, Ali,Mohammadian, Sara
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p. 271 - 278
(2013/05/08)
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- Succinimide-N-sulfonic acid catalyzed synthesis of bis(indolyl)methane and coumarin derivatives under mild conditions
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A mild and simple procedure is described for the synthesis of bis(indolyl)methane and coumarin derivatives using succinimide-N-sulfonic acid as an efficient, cheap, and reusable catalyst under mild conditions.
- Shirini, Farhad,Khaligh, Nader Ghaffari
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p. 1890 - 1896
(2013/11/19)
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- Ionic-liquid-catalyzed green synthesis of coumarin derivatives under solvent-free conditions
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Broensted acidic ionic liquids, namely 2-pyrrolidonium hydrogen sulfate, N-methyl-2-pyrrolidonium hydrogen sulfate, N-methyl-2-pyrrolidonium dihydrogen phosphate, (4-sulfobutyl)tris(4-sulfophenyl)phosphonium hydrogen sulfate, and triphenyl(propyl-3-sulfonyl)phosphonium toluenesulfonate, catalyzed efficient Pechmann condensation of phloroglucinol with β-keto ethyl/methyl esters. 5,7-Dihydroxy-4-methylcoumarin and 5,7-dihydroxy-4-phenylcoumarin were prepared in good to excellent yields under mild, ambient, and solvent-free conditions. Pyrano[2,3-h]coumarins were then prepared by one-pot three-component reactions of 5,7-dihydroxy-4-subsituted coumarin, malononitrile, and aldehydes in the presence of catalytic amounts of Broensted basic ionic liquids, namely 2-hydroxyethylammonium formate, 3-hydroxypropanaminium acetate, 1-butyl-3-methylimidazolium hydroxide, pyrrolidinium formate, and pyrrolidinium acetate, under thermal solvent-free conditions. The catalysts are environmentally benign and can be easily prepared, stored, and recovered without significant loss of activity.
- Shaterian, Hamid Reza,Aghakhanizadeh, Morteza
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p. 1690 - 1696
(2013/10/21)
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- A green, efficient and recyclable poly(4-vinylpyridine)-supported copper iodide catalyst for the synthesis of coumarin derivatives under solvent-free conditions
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Poly(4-vinylpyridine)-supported copper iodide is reported as a green, efficient and recyclable catalyst for the synthesis of coumarin derivatives by the Pechmann reaction under solvent-free conditions. This catalyst can be recovered by simple filtration and recycled up to eight consecutive runs without any loss of their efficiency.
- Albadi, Jalal,Shirini, Farhad,Abasi, Jafar,Armand, Nezam,Motaharizadeh, Tayebeh
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p. 407 - 411
(2013/07/05)
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