- Microwave-assisted Pechmann reaction on P2O5/molecular sieves. Application to the preparation of 4-substituted coumarins
-
4-Substituted coumarins were efficiently and rapidly synthesised via Pechmann condensation of phenols with ethyl acetoacetate catalyzed by P2O5/molecular sieves in satisfactory yields.
- Shockravi, Abbas,Valizadeh, Hassan,Heravi, Majid M.
-
-
Read Online
- Synthesis, computational studies and antiproliferative activities of coumarin-tagged 1,3,4-oxadiazole conjugates against MDA-MB-231 and MCF-7 human breast cancer cells
-
A novel library of coumarin tagged 1,3,4 oxadiazole conjugates was synthesized and evaluated for their antiproliferative activities against MDA-MB-231 and MCF-7 breast cancer cell lines. The evaluation studies revealed that compound 9d was the most potent molecule with an IC50 value of 50 = 7.07 μM), in Estrogen Negative (ER?) cells than Estrogen Positive (ER+) cells. Structure–activity relationship (SAR) studies revealed that conjugates bearing benzyl moieties (9b, 9c and 9d) had superior activities compared to their alkyl analogues. The most potent compound 9d showed ~1.4 times more potent activity than tamoxifen against MCF-7 cell line; while the introduction of sulfone unit in compounds 11a, 11b and 11c resulted in significant cytotoxicity against both MCF-7 and MDA-MB-231 cell lines. These results were further supported by docking studies, which revealed that the stronger binding affinity of the synthesized conjugates is due to the presence of sulfone unit attached to the substituted benzyl moiety in their pharmacophores.
- Dhawan, Sanjeev,Kerru, Nagaraju,Awolade, Paul,Singh-Pillay, Ashona,Saha, Sourav Taru,Kaur, Mandeep,Jonnalagadda, Sreekantha B.,Singh, Parvesh
-
-
Read Online
- B(C6F5)3-catalyzed synthesis of coumarins via Pechmann condensation under solvent-free conditions
-
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
-
p. 469 - 473
(2021/03/26)
-
- Synthesis of coumarin derivatives in a microfluidic flow system employing the Pechmann condensation: A case study
-
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
-
p. 2208 - 2215
(2020/11/30)
-
- Synthesis, Cytotoxicity and Antimicrobial Evaluation of New Coumarin-Tagged β-Lactam Triazole Hybrid
-
A series of coumarin-tagged β-lactam triazole hybrids (10a–10o) were synthesized and tested for their cytotoxic activity against MDA-MB-231 (triple negative breast cancer), MCF-7 (estrogen receptor positive breast cancer (ER+)) and A549 (human lung carcinoma) cancer cell lines including one normal cell line, HEK-293 (human embryonic kidney). Two compounds 10b and 10d exhibited substantial cytotoxic effect against MCF-7 cancer cell lines with IC50 values of 53.55 and 58.62 μm, respectively. More importantly, compounds 10b and 10d were non-cytotoxic against HEK-293 cell lines. Structure–activity relationship (SAR) studies suggested that the nitro and chloro group at the C-3 position of phenyl ring are favorable for anticancer activity, particularly against MCF-7 cell lines. Furthermore, antimicrobial evaluation of these compounds revealed modest inhibition of examined pathogenic strains with compounds 10c and 10i being the most promising antimicrobial agents against Pseudomonas aeruginosa and Candida albicans, respectively.
- Awolade, Paul,Cele, Nosipho,Dhawan, Sanjeev,Jonnalagadda, Sreekantha B.,Kaur, Mandeep,Kisten, Prishani,Pillay, Ashona-Singh,Saha, SouravTaru,Singh, Parvesh
-
-
- N-Doped Carbon Wrapped Polyoxometalate Derived from POM-IL Hybrid: A Heterogeneous Catalyst for the Synthesis of Coumarin Derivatives under Solvent-Free Conditions
-
Vanadium substituted Keggin type polyoxometalate loaded N-doped carbon was prepared from polyoxometalate ionic liquid hybrid by carbonization process. The decomposition of organic part generates various functional groups leaving polyoxometalate part intact. The catalyst was characterized by elemental analysis, FTIR, MAS 13C NMR, XPS and electron microscopy studies. The presence of carboxylic acids, aromatic and hetero-aromatic groups in the catalyst was confirmed by 13C NMR. The high resolution C1s and O1s XPS analysis further confirmed the presence of these groups. Various oxidation states of nitrogen were confirmed by deconvoluted N1s XPS spectra. Pyridine adsorption study confirms the presence of Bronsted and Lewis acid sites in the catalyst. Layered structure of the catalyst was confirmed by HR TEM analysis. The hybrid material displayed excellent catalytic activity towards the synthesis of coumarin derivatives under solvent-free conditions.
- Ramalingam, Meenakshi,Mani, Chandhru,Manickam, Sundar,Srinivasalu, Kutti Rani
-
p. 1904 - 1910
(2019/04/01)
-
- Recyclable cellulose nanocrystal supported Palladium nanoparticles as an efficient heterogeneous catalyst for the solvent-free synthesis of coumarin derivatives via von Pechmann condensation
-
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.
-
-
- α-Glucosidase Inhibition, Antioxidant and Docking Studies of Hydroxycoumarins and their Mono and Bis O-alkylated/acetylated Analogs
-
Background: Diabetes Mellitus (DM) is a complex metabolic disease illustrated by abnormally high levels of plasma glucose or hyperglycaemia. Accordingly, several α-glucosidase inhibitors have been developed for the treatment of diabetes and other degenerative disorders. While, a coumarin ring has the privilege to represent numerous natural and synthetic compounds with a wide spectrum of biological activities e.g. anti-cancer, anti-HIV, anti-viral, anti-malarial, anti-microbial, anti-convulsant, anti-hypertensive properties. Besides this, coumarins have also shown potential to inhibit α-glucosidase leading to a generation of new promising antidiabetic agents. However, the testing of O-substituted coumarins for α-glucosidase inhibition has evaded the attention of medicinal chemists. Methods: For O-alkylation/acetylation reactions, the hydroxyl coumarins (A-B) initially activated by K2 CO3 in dry DMF were reacted with variedly substituted haloalkanes at room temperature under nitrogen. The synthesized compounds were tested for their α-glucosidase (from Saccharomyces cerevisiae) inhibitory activity and anti-oxidant activity using DPPH radical scavenging activity. In silico docking simulations were conducted using CDocker module in DS (Accelrys) to explore the binding modes of the representative compounds in the catalytic site of α-glucosidase. Results: All the coumarin analogues (A1, B1, A2-A10, B2-B8) including their precursors (A-B) were evaluated for their in vitro α-glucosidase inhibition using acarbose as a standard inhibitor. All the mono O-alkylated coumarins (except A1) showed significant (p 50 values ranging between 11.084±0.117 to 145.24± 29.22 μg/mL. Compound 7-(benzyloxy)-4, 5-dimethyl-2H-chromen-2-one (A9) bearing a benzyl group (Ph-CH2 -) at position 7 showed a remarkable (p 50 = 11.084±0.117 μg/mL), almost four-fold more than acarbose (IC50 = 40.578±5.999 μg/mL). The introduction of –NO2 group dramatically improved the anti-oxidant activity of coumarin, while the O-alkylation/acetylation decreased the activity. Conclusion: The present study describes the synthesis of functionalized coumarins and their evaluation for α-glucosidase inhibition and antioxidant activity under in vitro conditions. Based on IC50 data, the mono O-alkylated coumarins were observed to be stronger inhibitors of α-glucosidase with respect to their bis O-alkylated analogues. Coumarin (A9) bearing O-benzyloxy group displayed the strongest α-glucosidase inhibition, even higher than the standard inhibitor acarbose. The coumarin (A10) bearing –NO2 group showed the highest anti-oxidant activity amongst the synthesized compounds, almost comparable to the ascorbic acid. Finally, in silico docking simulations revealed the role of hydrogen bonding and hydrophobic forces in locking the compounds in catalytic site of α-glucosidase.
- Singh, Parvesh,Ngcoya, Nomandla,Mopuri, Ramgopal,Kerru, Nagaraju,Manhas, Neha,Ebenezer, Oluwakemi,Islam, Md. Shahidul
-
p. 127 - 135
(2018/03/21)
-
- Synthesis method of coumarin compounds
-
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.
- -
-
Paragraph 0054; 0055; 0057
(2018/06/23)
-
- 7 - aryloxyacetic acetyloxy coumarin compound and its application in pesticide (by machine translation)
-
The invention provides a 7 - aryloxyacetic acetyloxy coumarin compound and its application in pesticide, preparation are as follows: 1, will contain different substituents of the resorcinol add to the reaction bottle of the concentrated sulfuric acid, stirring and dissolving, ice water bath cooling slowly dripping acetoacetate compound, then completing, ice water bath cooling under reaction 1h; reacting at room temperature 24h; violent stirring into ice water in the mixture, a yellow precipitation, filtered, the filter cake is anhydrous ethanol recrystallize to get 7 - hydroxy coumarin compound; 2, 2, 4 - dichloro acid with oxalyl dissolved in CH2 Cl2 In the solvent, dropping N, N - dimethyl formamide, room temperature reaction 2h make acyl chloride; 3, containing 7 - hydroxy coumarin compounds and acyl chloride in the organic solvent, under a certain temperature, adding catalyst, reaction after a period of time, re-crystallization to obtain the 7 - aryloxyacetic acetyloxy coumarin compound. The compounds of the invention have very high herbicidal activity. (by machine translation)
- -
-
Paragraph 0031; 0032; 0033
(2017/07/23)
-
- One-pot synthesis of coumarine derivatives using butylenebispyridinium hydrogen sulfate as novel ionic liquid catalyst
-
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
-
p. 4097 - 4107
(2016/07/06)
-
- Meglumine sulfate catalyzed solvent-free one-pot synthesis of coumarins under microwave and thermal conditions
-
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
-
supporting information
p. 1283 - 1291
(2016/08/16)
-
- Sulfonated core-shell magnetic nanoparticle (Fe3O4@SiO2@PrSO3H) as a highly active and durable protonic acid catalyst; Synthesis of coumarin derivatives through pechmann reaction
-
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
-
p. 3333 - 3337
(2015/04/16)
-
- An efficient synthesis of coumarin derivatives using a SBA-15 supported cobalt(II) nanocatalyst
-
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
-
p. 1621 - 1625
(2019/11/28)
-
- Synthesis of osthole derivatives with grignard reagents and their larvicidal activities on mosquitoes
-
The structure of osthole has been modified to improve its larvicidal activity against mosquitoes. A new efficient synthesis of osthole derivatives with Grignard reagents has been developed, which employs CuI and LiCl as promoters and covers a broad range of substrates to afford the corresponding products in mild to good yields (up to 83%). Bio-activity evaluation showed that several products exhibited better activities than osthole. CuI and LiCl promoted efficient synthesis of osthole derivatives with Grignard reagents has been developed. Bio-activity evaluation showed that several products exhibited far better larvicidal activities against mosquitoes than osthole.
- Liu, Ming,Liu, Yang,Hua, Xuewen,Wu, Changchun,Zhou, Sha,Wang, Baolei,Li, Zhengming
-
supporting information
p. 1353 - 1358
(2016/02/18)
-
- Synthesis and heterogeneous catalytic activity of covalently immobilized hexamine cation as a magnetically-recoverable nanocatalyst
-
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
-
p. 1771 - 1779
(2015/08/06)
-
- 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
-
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
-
p. 13093 - 13103
(2015/02/19)
-
- Recyclable CMK-5 supported sulfonic acid as an environmentally benign catalyst for solvent-free one-pot construction of coumarin through Pechmann condensation
-
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.
- Zareyee, Daryoush,Serehneh, Mahshad
-
-
- CuFe2O4 nanoparticles: A magnetically recoverable and reusable catalyst for the synthesis of coumarins via pechmann reaction in water
-
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
-
p. 697 - 706
(2014/01/17)
-
- Synthesis and nematicidal bioevaluation of substituted 2H-1-benzopyrane-2- ones and their carbamate derivatives against root-knot nematode (Meloidogyne javanica)
-
Synthesis of 7-hydroxy-4,5-methyl/7-hydroxy-4-methyl/7,8-dihydroxy-4- methyl/6-chloro-7-hydroxy-4-methyl-2H-1-benzopyrane-2-ones (VI-IX) have been carried out by Pechmann reaction. The condensation of synthesized 2H-1-benzopyran-2-ones (VI-X) with phenyl isocyanate (XI) gave 4,5-methyl/4-methyl/4-methyl/6-chloro-4-methyl-2-oxo-2H-benzopyran-7yl/7,8-diyl/ 4-yl/phenyl carbamates (XIIXVI). The synthesized compounds were characterized on the basis of analytical and spectral data. All the compounds were evaluated for their nematicidal activity in vitro against second stage juveniles (J2) of root-knot nematode (Meloidogyne javanica).
- Kumari, Sumona,Singh, Rajvir,Kumar, Anil,Walia
-
p. 3139 - 3143
(2014/07/22)
-
- Introduction of poly(4-vinylpyridinium) perchlorate as a new, efficient, and versatile solid acid catalyst for one-pot synthesis of substituted coumarins under ultrasonic irradiation
-
Poly(4-vinylpyridinium) perchlorate, is a supported, recyclable, eco-benign catalyst for synthesis of substituted coumarins via Pechmann reaction using ultrasound irradiation at room temperature and neat condition in high yields with short reaction times. The catalyst was studied by FT-IR, X-ray diffraction, scanning electron microscope, thermo-gravimetric and energy dispersion X-ray analyses. All the products were extensively characterized by 1H NMR, FT-IR, MS and melting point analyses. This methodology offers momentous improvements over various options for the synthesis of coumarins with regard to yield of products, simplicity in operation and green aspects by avoiding toxic catalysts and solvents. Further, the catalyst can be reused and recovered for several times without loss of activity.
- Khaligh, Nader Ghaffari,Shirini, Farhad
-
p. 26 - 31,6
(2012/12/11)
-
- Br?nsted-acidic imidazolium ionic liquid [bmim(SO 3H)][OTf]: A mild catalyst for highly efficient synthesis of coumarins
-
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
-
p. 9379 - 9383
(2013/11/19)
-
- Synthesis and biological investigation of coumarin piperazine (piperidine) derivatives as potential multireceptor atypical antipsychotics
-
The discovery and synthesis of potential and novel antipsychotic coumarin derivatives, associated with potent dopamine D2, D3, and serotonin 5-HT1A and 5-HT2A receptor properties, are the focus of the present article. The most-promising derivative was 7-(4-(4-(6-fluorobenzo[d]isoxazol-3-yl)-piperidin-1-yl)butoxy) -4-methyl-8-chloro-2H-chromen-2-one (17m). This derivative possesses unique pharmacological features, including high affinity for dopamine D2 and D3 and serotonin 5-HT1A and 5-HT2A receptors. Moreover, it possesses low affinity for 5-HT2C and H1 receptors (to reduce the risk of obesity associated with chronic treatment) and hERG channels (to reduce the incidence of torsade des pointes). In animal models, compound 17m inhibited apomorphine-induced climbing behavior, MK-801-induced hyperactivity, and the conditioned avoidance response without observable catalepsy at the highest dose tested. Further, fewer preclinical adverse events were noted with 17m compared with risperidone in assays that measured prolactin secretion and weight gain. Acceptable pharmacokinetic properties were also noted with 17m. Taken together, 17m may constitute a novel class of drugs for the treatment of schizophrenia.
- Chen, Yin,Wang, Songlin,Xu, Xiangqing,Liu, Xin,Yu, Minquan,Zhao, Song,Liu, Shicheng,Qiu, Yinli,Zhang, Tan,Liu, Bi-Feng,Zhang, Guisen
-
p. 4671 - 4690
(2013/07/19)
-
- Synthesis and anti-inflammatory effects of a series of novel 7-hydroxycoumarin derivatives
-
A number of 7-hydroxycoumarins have been synthesised by Pechmann cyclisation using differently substituted resorcinols employing perchloric acid as the condensing agent. All the compounds have been characterised by analytical and spectroscopic methods. The anti-inflammatory properties were tested with LPS-induced inflammation in J774 macrophages. Expression of iNOS and COX-2 was determined by Western blot, NO by nitrite assay and IL-6 by ELISA analyses. Fifteen of the tested 7-hydroxycoumarins also inhibited IL-6 production but none of them had any major inhibitory effect on COX-2 expression.
- Timonen, Juri M.,Nieminen, Riina M.,Sareila, Outi,Goulas, Antonis,Moilanen, Lauri J.,Haukka, Matti,Vainiotalo, Pirjo,Moilanen, Eeva,Aulaskari, Paula H.
-
supporting information; experimental part
p. 3845 - 3850
(2011/11/13)
-
- Pentafluorophenylammonium triflate (PFPAT): An efficient, metal-free and reusable catalyst for the von Pechmann reaction
-
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
-
experimental part
p. 450 - 452
(2011/08/03)
-
- Design of a highly efficient and water-tolerant sulfonic acid nanoreactor based on tunable ordered porous silica for the von Pechmann reaction
-
(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
-
supporting information; experimental part
p. 3989 - 3992
(2009/06/18)
-
- Novel traceless liquid-phase synthesis of coumarin derivatives on poly(ethylene glycol) support
-
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
-
p. 3175 - 3181
(2007/10/03)
-
- Expeditious approach to coumarins via pechmann reaction catalyzed by molecular iodine or AgOTf
-
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
-
p. 2949 - 2956
(2007/10/03)
-
- An efficient procedure for the synthesis of coumarin derivatives using TiCl4 as catalyst under solvent-free conditions
-
The ability of titanium(IV) chloride as a catalyst to promote the Pechmann condensation reaction with a range of phenols and β-keto esters is described.The reaction was carried out by addition of TiCl4 to a mixture of the phenol and the β-keto ester with thorough stirring in the absence of a solvent and represents an improvement on the classical Pechmann conditions. The yields of coumarins obtained via this novel protocol were significantly higher than those using the conventional method and the reaction duration was reduced to a few minutes or even a few seconds.
- Valizadeh, Hassan,Shockravi, Abbas
-
p. 3501 - 3503
(2007/10/03)
-
- Anti-AIDS agents. 42. Synthesis and anti-HIV activity of disubstituted (3′R,4′R)-3′,4′-di-O-(S)-camphanoyl-(+)-cis- khellactone analogues
-
A series of disubstituted 3′,4′-di-O-(S)-camphanoyl-(+)-cis-khellactone (DCK) analogues (1-10) were synthesized and evaluated for inhibition of HIV-1 replication in H9 lymphocytes. 5-Methoxy-4-methyl DCK (8) was the most promising compound with an EC50 value of 7.21 × 10-6 μM and a therapeutic index of >2.08 × 10,7 which were much better than those of lead compound DCK in the same assay. Another six disubstituted DCK analogues (1-5 and 7) were more potent than AZT but less active than DCK. Conformational analysis suggested that resonance of the coumarin system is an essential structural feature for potent anti-HIV activity. Steric compression of C(4) and C(5) substituents of the coumarin moiety can reduce the overall planarity and thus resonance of the coumarin nucleus, resulting in a decrease or lack of anti-HIV activity.
- Xie,Takeuchi,Cosentino,McPhail,Lee
-
p. 664 - 671
(2007/10/03)
-
- Synthesis of coumarins catalyzed by eco-friendly W/ZrO2 solid acid catalyst
-
Synthesis of substituted coumarins via reactions of resorcinol and substituted resorcinol with ethyl acetoacetate and ethyl α-methylacetoacetate (Pechmann reaction) are reported, in which the production of environmentally harmful waste streams is minimized by the use of a novel solid acid catalyst.
- Reddy,Reddy,Giridhar
-
p. 3603 - 3607
(2007/10/03)
-
- ALKENYLATION OF 5-METHYLRESORCINOL WITH PIPERYLENE AND 4-CHLORO-2-PENTENE
-
The alkenylation of 5-methylresorcinol with 4-chloro-2-pentene and piperylene takes place preferentially at the carbon atom with the formation of alkenyl- and dialkenyl-5-methylresorcinols.The predominance of the product from alkenylation at position 2 or
- Shornik, N. A.,Aleksandrova, E. K.,Komissarova, E. V.,Rossinskii, A. P.,Bunina-Krivorukova, L. I.
-
p. 760 - 765
(2007/10/02)
-
- Furocoumarin for the photochemotherapy of psoriasis and related skin diseases
-
A class of alkyl-substituted angular flurocoumarins, sometimes termed alkylangelicins, useful in the photochemotherapy of psoriasis and in other skin diseases characterized by cellular hyperproliferation or lack of skin pigmentation is disclosed for topical application or systemic administration. Compared with conventional psoralens the described compounds exhibit a lower risk of skin cancer, absence of phototoxicity problems anderithema to the patient so treated. One preferred compound is 5-methylangelicin.
- -
-
-