- PPA-SiO 2 catalyzed one-pot synthesis of 1,4-dihydropyridines under solvent-free conditions
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Silica gel-supported polyphosphoric acid (PPA-SiO2) was found to be an efficient catalyst for the one-pot condensation reaction of aryl aldehydes, ethyl acetoacetate, and ammonium acetate to afford the corresponding 1,4-dihydropyridines in excellent yields. The main advantages of the present approach are short reaction times, clean reaction profiles, and simple experimental and work-up procedures.
- Khojastehnezhad, Amir,Moeinpour, Farid,Shams, Alireza
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- Basicity and stability of urea deep eutectic mixtures
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The stability and basicity origin of some common urea based deep eutectic mixtures/solvents (DES) were studied. We have observed an unexpected Hantzsch dihydropyridine reaction in sorbitol/urea DES, where the source of ammonia was found not to be originated from the individual ingredients of the DES. Our results showed that decomposition of urea occurs in DES at lower than expected temperatures, namely below 100 °C and is enhanced in diol DES by the formation of carbonates causing their unexplained basicity. Carbohydrates and choline chloride (ChCl) DES exhibit lower rates of decomposition, while no decomposition was observed from neat urea or MeOH and EtOH urea solutions.
- Simeonov,Afonso, Carlos A. M.
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- One-pot, three-component synthesis of 1,4-dihydropyridines in PEG-400
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A series of Hantzsch 1,4-dihydropyridines were synthesized by one-pot condensation of aldehyde, β-dicarbonyl compound, and ammonium acetate in polyethylene glycol (PEG-400) at 90°C. This method has the advantages of good yields, less pollution, and simple reaction conditions. Copyright
- Wang, Xicun,Gong, Haipeng,Quan, Zhengjun,Li, Lei,Ye, Helin
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- A convenient ferric chloride catalyzed synthesis of 5-alkoxycarbonyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones under microwave irradiation
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A series of ethyl 4-aryl-6-methyl-1,2,3,4-tetrahydropyrimidin-2-one-5-carboxylates 4 were synthesized by the condensation of aromatic aldehydes, ethyl acetoacetate and urea in the presence of ferric chloride hexahydrate under microwave irradiation. The reactions were completed in 4-6 min with 87-92% yield.
- Tu, Shu-Jiang,Zhou, Jian-Feng,Cai, Pei-Jun,Wang, Hai,Feng, Jun-Cai
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- An Efficient Synthesis of 4-Aryl-1,4-dihydropyridines Via VB1 Catalyzed Hantzsch Reaction
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An environmentally rapid and benign protocol for the synthesis of 4-aryl-1,4-dihydropyridines compounds using VB1 as a catalyst under microwave irradiation and solvent-free conditions has been achieved. The procedure is operationally simple, giving good to high product yield.
- Fan, Chuangang,Song, Mingzhi
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- A new magnetically recoverable catalyst promoting the synthesis of 1,4-dihydropyridine and polyhydroquinoline derivatives via the Hantzsch condensation under solvent-free conditions
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In the current study, 1,4-dihydropyridine and polyhydroquinoline derivatives were efficiently synthesized under solvent-less conditions with a magnetic catalyst containing novel acidic ionic liquid functionalized silica modified Fe3O4 nanoparticles through a four component combination of β-ketoester, aldehydes and ammonium acetate (1, 2, 2). Several approaches have been reported for synthesizing these derivatives, while each of these approaches have some weaknesses including long time of reaction, excess of volatile organic solvent, low efficiency, costly reagents, complex operation, high temperatures, production of a number of side products, and difficult catalyst recovery. The simple operation, short time of reaction (5–30?min) and the high efficiency (80–94%) are the special advantages of this technique. The immobilized catalyst exhibited an appropriate thermal stability and excellent recyclability. Different methods such as FT-IR, SEM, EDX, TGA-DTA, and VSM were used to confirm and characterize the catalyst.
- Taheri, Narges,Heidarizadeh, Fariba,Kiasat, Alireza
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- Hybrid pharmacophore-based drug design, synthesis, and antiproliferative activity of 1,4-dihydropyridines-linked alkylating anticancer agents
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Two series of novel substituted 1,4-dihydropyridine derivatives incorporating nitrogen mustard pharmacophore hybrids without spacer DHP-M (4a-4d) and with ethyl spacer DHP-L-M (8a-8g) were designed and synthesized. They were subjected to in silico ADME prediction study to check their drug-like properties and evaluated for their cytotoxicity against: A 549 (lung), COLO 205 (colon), U 87 (glioblastoma), and IMR-32 (neuroblastoma) human cancer cell lines in vitro using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay against chlorambucil and docetaxel. Majority of the test compounds exhibited moderate to significant cytotoxic activity. The highest activity in all the investigated cancer cells was displayed by DHP-M (4a). This may be due to the less steric hindrance offered by 4a.
- Singh, Rajesh K.,Prasad,Bhardwaj
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- Urease: A highly biocompatible catalyst for switchable Biginelli reaction and synthesis of 1,4-dihydropyridines from the in situ formed ammonia
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Urease is a superior biocompatible catalyst for switching from the Biginelli reaction to urea-based synthesis of 1,4-dihydropyridines in water, where 100% switching occurs at 0.02 g/mL of enzyme. Hantzsch reaction with ammonium acetate (NH4OAc) is inefficiently catalyzed by urease (70%, 4 h), and heavy metal ions inhibit the urease-catalyzed reactions with urea or NH4OAc. Promotion of the urea-based Hantzsch reaction by urease and its inhibition with Hg2 + supports specificity of urease for in situ generation of ammonia, whereas the role of urease in further transformations is not so specific. The features of this enzymatic method are reusability, mild reaction conditions, biocompatibility, generality, and high yield of products.
- Tamaddon, Fatemeh,Ghazi, Somayeh
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- One-pot synthesis of 1,4-dihydropyridine derivatives using the Fe2ZnAl2O7 catalyzed Hantzsch three-component reaction
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A facile, low-cost, and effective one-pot method was developed for the synthesis of 1,4-dihydropyridine derivatives with high yields through the three-component reaction of ammonium acetate, ethyl acetoacetate, and aromatic aldehydes using Fe2ZnAl2O7 as catalyst. The reaction was conducted at 70–80°C temperature under solvent free conditions. The developed method had some great advantages, including safe and clean reaction conditions, high to excellent product yields, short reaction time, and a novel and powerful heterogeneous catalyst. The developed heterogeneous solid catalyst had high efficiency and reusability in one-pot multi-component syntheses such that it was easily reused four to five times without significant loss in efficiency and product yield. The catalyst was characterized by scanning Electron Microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction techniques. N2 sorption isotherms of the prepared nanocomposite exhibited surface area 2.1313E+01 m2/g and total pore volume of 3.0957E-02 cm3/g. Substituted dihydropyridine derivatives were characterized and confirmed using 1H NMR and 13C NMR, and elemental spectral data.
- Zargarzadeh, Reza,Akbari Dilmaghani, Karim,Nikoo, Abbas
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- Design, solvent free synthesis, and antimicrobial evaluation of 1,4 dihydropyridines
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Here in, we report the usage of cellulose sulfuric acid as a heterogeneous eco friendly catalyst for the synthesis of 1,4 dihydropyridines under solvent free conditions via Hantzsch three component reaction of an aldehyde, ethyl acetoacetate and ammonium acetate at 100 °C for 2-5 h. In silico studies were performed on twenty two possible 1,4 dihydropyridines (DHPs) analogues against K+ channel receptor (KcsA). In order to validate in silico studies, thirteen compounds were synthesized and evaluated as antibacterials against twenty seven ESBL isolates of Klebsiella pneumoniae and Escherichia coli.
- Murthy,Rajack, Abdul,Taraka Ramji,Jeson Babu,Praveen, Ch.,Aruna Lakshmi
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- Facile template-free route to fabricate core–shell Fe3O4@PANI-SO3H urchin-like nanoparticles as reusable catalyst for Hantzsch reaction: change morphology upon sulfonation
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Abstract: This paper describes a novel and effective approach to fabricate the core–shell Fe3O4@PANI-SO3H urchin-like morphology in a self-assembly method as nano-magnetic solid acid catalyst. The Fe3O4@PANI microspheres were synthesized via an in situ surface polymerization of aniline monomer in an acidic condition, using ammonium persulfate as the oxidant. It was found that upon sulfonation of polyaniline (PANI), the morphology changes to morphology similar to urchin confirming the transmission electron microscopy and field emission scanning electron microscopy results. The as-prepared solid acid catalyst was also carefully analyzed by energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and vibrating sample magnetometry. This new magnetic core–shell material was shown to have high catalytic performance for one–pot synthesis of 1,4-dihydropyridine derivatives. In addition, the catalyst can be easily separated using an external magnet. Recyclability and reusability for several runs, facile accessibility, and simple handling are the merits of this magnetic-heterogeneous acid catalyst. Graphical Abstract: [Figure not available: see fulltext.].
- Shahamat, Zahra,Nemati, Firouzeh,Elhampour, Ali
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- One-Pot Three-Component Synthesis of Hantzsch 1,4-Dihydropyridines Promoted by Dimethyl Phosphate Ionic Liquids
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A one-pot three-component reaction of ethyl acetoacetate, AcONH4, and different aldehydes has been successfully performed in the presence of ionic liquids (ILs) possessing a (MeO)2PO2- counterion. The impact of electronic and steric effects of the substituents of aromatic aldehydes, as well as the influence of different anions of ILs on the product yield, have been investigated. The application of dimethyl phosphate ILs in the synthesis of Hantzsch 1,4-dihydropyridines presents a simple method for obtaining structurally diverse products in moderate to high yields without using any additional catalyst.
- Priede, Elina,Zicmanis, Andris
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- Highly effective Br?nsted base/lewis acid cooperative catalysis: A new Cd metal-organic framework for the synthesis of Hantzsch 1,4-DHPs at ambient temperature
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A new 3D metal-organic framework {[Cd3(BDC)3(OPP)(DMF)2]·2DMA}n (TMU-33) has been synthesized using a novel V-shaped imine-functionalized ligand, N,N′-(oxybis(4,1-phenylene))bis(1-(pyridin-4-yl)methanimine) (OPP), terephthalic acid (H2BDC), and Cd(NO3)2·4H2O and has been fully characterized. The function of the imine moiety of the OPP ligand as a Br?nsted base and open Cd site as a Lewis acid in this framework was investigated to determine the role of the cooperative catalyst in the synthesis of Hantzsch 1,4-dihydropyridines simultaneously and separately at ambient temperature. In addition, nanorods and nanoplates of TMU-33 were synthesized via a sonochemical reaction by the coordination modulation method, and the effect of the nanostructure on the relative accessibility of the catalytic site was studied. Moreover, the catalytic performance of TMU-33 with different morphologies was evaluated in this reaction. Efficient catalytic activity was observed for the nanoscale catalysts at ambient temperature, and the acidic sites in the cooperative catalyst were found to be more effective than the existing basic sites in the structure. TMU-33 can be reused by washing with ethanol at least four times with no significant degradation of the catalytic activity (less than 7%).
- Rouhani, Farzaneh,Morsali, Ali
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- Synthesis of diethyl 4-(phenyl-substituted)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylates catalyzed by CoCl2/K-10 montmorillonite in water and their antimicrobial activity
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A simple and efficient method of one pot synthesis of 1,4-dihydropyridine by three components reaction of aromatic aldehydes with 1,3-dicarbonyl compound, ammonium acetate and catalytic amount of CoCl2 based on the Hantszch reaction is developed. The process is catalysis by an inexpensive catalyst in water medium, gives high yield of products and involves no volatile organic solvents. Some synthesized compounds demonstrated antimicrobial activity.
- Bajaj,Mahodaya,Tekade,Patil,Kukade, Suraj D.
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- Synthesis of some C-3,4,5-substituted 2,6-dimethyl-1,4-dihydropyridines (4-DHPs)
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A series of C-3,4,5-substituted 2,6-dimethyl-1,4-dihydropyridines (1,4-DHPs) with pharmacological properties were prepared by a variation from the classical Hantzsch synthesis. The procedure involves treatment of the respective aldehyde with either ethyl-3-aminocrotonate or 3-aminocrotonitrile in anhydrous acetic acid at temperatures not exceeding 60°C, thus minimizing by-product formation. The structures of title compounds were elucidated by 1H NMR, 13C NMR, FTIR, and elemental analysis. Copyright Taylor & Francis Group, LLC.
- Navarrete-Encina, Patricio A.,Squella, Juan A.,Carbajo,Conde,Nunez-Vergara, Luis J.
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- One-pot synthesis of 1,4-dihydropyridines via a phenylboronic acid catalyzed Hantzsch three-component reaction
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A simple, inexpensive, and efficient one-pot synthesis of 1,4-dihydropyridine derivatives was achieved in good yields via the three-component reaction of aromatic aldehydes, ethyl acetoacetate, and ammonium acetate using PhB(OH)2 as catalyst. Georg Thieme Verlag Stuttgart.
- Debache, Abdelmadjid,Boulcina, Raouf,Belfaitah, Ali,Rhouati, Salah,Carboni, Bertrand
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- Boosting the catalytic performance of manganese (III)-porphyrin complex MnTSPP for facile one-pot green synthesis of 1,4-dihydropyridine derivatives under mild conditions
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In this study, the metal complex (5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin manganese (III) chloride; denoted as MnTSPP) represents a promising efficient and reusable heterogeneous solid catalyst for facile and highly efficient one-pot synthesis of 1,4 dihydropyridine derivatives via three-component condensation reaction of aromatic aldehyde, ethyl acetoacetate, and ammonium acetate under green and mild reaction conditions. The simple operation, short reaction time (15 min), and the high efficiency (99%) are the special advantage of this protocol. Furthermore, the green aspects of this synthetic protocol were more studied by examination of the reusability of MnTSPP for four consecutive cycles without a significant loss of catalytic activity. Remarkably, the new synthesis presented advantages in terms of safety, commercially available catalyst, simplicity, stability, mild conditions, short reaction time, and excellent yields, using a mixture of H2O and C2H5OH environmental-friendly solvent, operationally facile, wide tolerance of starting materials, and excellent recoverable of the catalyst.
- Ali El-Remaily, Mahmoud Abd El Aleem Ali,Hamad, Hesham A.,Soliman, Ahmed M. M.,Elhady, Omar M.
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- CoFe2O4@SiO2-NH2-CoII NPs catalyzed Hantzsch reaction as an efficient, reusable catalyst for the facile, green, one-pot synthesis of novel functionalized 1,4-dihydropyridine derivatives
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A magnetically heterogeneous CoFe2O4@SiO2-NH2-CoII nanoparticle was synthesized by the immobilization of Co (II) complex onto CoFe2O4@SiO2 nanoparticles, and the heterogeneous magnetic nanocatalyst was characterized by XRD, TEM, TGA, EDX, and FT-IR techniques. Then, the green and reusable method was introduced for a multicomponent synthesis of 1,4-dihydropyridine derivatives via Hantszch reaction. The synthesis of 1,4-dihydropyridine derivatives was proceeded by the reaction of aldehyde, ethyl acetoacetate, and ammonium acetate in the presence of this magnetic nanocatalyst in EtOH/Water (1:1). Simple work-up, short reaction times, excellent yields (60–96percent) as well as green solvent are some advantages of this novel approach, and the corresponding products were purified with no need for chromatographic separation.
- Allahresani, Ali,Mohammadpour Sangani, Mehri,Nasseri, Mohammad Ali
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- Sulfated polyborate: An efficient and reusable catalyst for one pot synthesis of Hantzsch 1,4-dihydropyridines derivatives using ammonium carbonate under solvent free conditions
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A simple and efficient method for the synthesis of four-component 1,4-dihydropyridines of various aldehydes, β-ketoesters and ammonium carbonate catalyzed by sulfated polyborate with high yields under a solvent free condition at 90?°C is described. The key advantages of the present method are high yields, short reaction time, solvent free condition, easy workup, recyclability of catalyst and ability to tolerate a variety of functional groups which gives economical as well as ecological rewards.
- Rekunge, Deelip S.,Khatri, Chetan K.,Chaturbhuj, Ganesh U.
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- Comparative study of catalytic potential of TBAB, BTEAC, and CTAB in one-pot synthesis of 1,4-dihydropyridines under aqueous medium
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Convenient and straightforward tetrabutylammonium bromide (TBAB), benzyltrienthylammonium chloride (BTEAC), and cetyltrimethylammonium bromide (CTAB) catalyzed synthesis of 1,4-dihydropyridines (1,4-DHPs) in water was established for the first time. The catalytic potential of phase-transfer catalysts (PTCs) in three different concentrations was envisioned. Aryl aldehydes and hetero aryl aldehydes afforded good yields of 1,4-DHPs in TBAB and BTEAC reactions. In particular, furfuraldehyde and thienyl-2-carbaldehyde produced excellent yields. Isolation of the products through nonchromatographic methods, good to excellent yields, and benign reaction conditions are the major advantages of this protocol.
- Ananda Kumar, T. Durai,Mohan,Subrahmanyam,Satyanarayana
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- Solvent-free efficient one-pot synthesis of Biginelli and Hantzsch compounds catalyzed by potassium phthalimide as a green and reusable organocatalyst
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The usage of potassium phthalimide (PPI) for the simple and green one-step multicomponent synthesis of Hantzsch 1,4-dihydropyridines, polyhydroquinolines, 3,4-dihydropyrimidin-2(1H)-ones/thiones, and octahydroquinazolinones under solventless conditions at 120°C is reported. The method is operationally simple, environmentally benign, and has relatively high yields. The other merits of this method include efficient, clean, green, and catalyst reusability.
- Kiyani, Hamzeh,Ghiasi, Maryam
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- A simple and efficient approach for synthesis of 1,4-dihydropyridines using nano-crystalline solid acid catalyst
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A simple highly versatile and efficient synthesis of various 1,4-dihydropyridines in the condensation of aromatic aldehydes with β-dicarbonyl compounds and ammonium acetate in the presence of nano-sulfated zirconia, nano-structured ZnO, nano-γ-alumina and nano-ZSM-5 zeolites, as catalyst in the ethanol at moderate temperature is presented. The advantages of method are short reaction times and milder conditions and easy work-up. The catalysts can be recovered for the subsequent reactions and reused without any appreciable loss of efficiency.
- Teimouri, Abbas,Ghorbanian, Leila,Moatari, Athar
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- Fe3O4@SiO2 supported aza-crown ether complex cation ionic liquids: preparation and applications in organic reactions
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A series of aza-crown ether ionic liquids supported on magnetic Fe3O4@SiO2 core-shell particles were designed, synthesized and characterized by elemental analysis, TEM, TG and FT-IR. These new aza-crown ether complex cation ionic liquids were utilized as heterogeneous acidic catalysts in Friedel-Crafts alkylation and Hantzsch reaction in good yields under convenient reaction conditions. Moreover, these magnetic particle supported IL catalysts could be readily recovered by an external magnet and reused five times without obvious loss of activity.
- Li, Dandan,Wang, Jinyuan,Chen, Fengjuan,Jing, Huanwang
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- Recyclable Bi2WO6-nanoparticle mediated one-pot multicomponent reactions in aqueous medium at room temperature
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Different types of multicomponent reactions (MCRs) are reported using Bi2O3, BiVO4, and Bi2WO6 (nanoparticle) as heterogeneous catalysts. Among these, Bi2WO6 nanoparticles showed excellent reactivity for the synthesis of functionalized dihydropyridine, polyhydroquinoline, 4H-chromene and 2-amino-4H-benzo[b]pyran derivatives at ambient temperature in aqueous medium. All the reactions gave good to excellent yields in 10-45 minutes in the presence of 5 mol% (optimized) of the catalyst. The catalyst was regenerated and reused up to 5 times without losing catalytic activity. The gram scale synthesis of dihydropyridine gave the desired product in 82% yield in 2 h. This journal is
- Paplal, Banoth,Nagaraju,Veerabhadraiah, Palakollu,Sujatha, Kodam,Kanvah, Sriram,Vijaya Kumar,Kashinath, Dhurke
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- The First Recyclable, Nanocrystalline CdS Thin Film Mediated Eco-benign Synthesis Of Hantzsch 1, 4 Dihyropyridines, 1, 8-Dioxodecahydroacridine and Polyhydroquinolines derivatives
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In the present study, we report a recyclable, nanocrystalline CdS thin film mediated efficient one-pot, three component synthesis of Hantzsch 1, 4 Dihydropyridine in good yields. The catalyst is also effective for the efficient synthesis of Polyhydroquinoline and 1, 8-dioxodecahydroacridine derivatives in good to excellent yields. The CdS thin film catalyst was prepared by chemical bath deposition (CBD) technique. The cadmium sulphide thin film was characterized by powder XRD and FT-IR studies. The average crystallite size (D) was calculated from powder XRD by using Scherrer formula and SEM analysis. The elemental composition of the CdS thin film was established by EDS analysis. The effect of temperature, substituent's, catalyst loading and mole ratio on the reaction was also studied. All the products were thoroughly characterized by 1H-NMR, 13C-NMR, FT-IR, Mass spectral and CHN analysis. A plausible mechanism for the CdS thin film catalyzed synthesis of 1, 4 DHP's is proposed. The heterogeneous catalyst could be easily recovered from the reaction mixture and successively reused at least five times without loss of activity.
- Lavanya,Venkatapathy,Magesh,Perumal,Sathishkumar,Amudha
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- A novel method for synthesis of 1,4-dihydropyridines using robust laterite catalyst under ultrasonic irradiation
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An efficient method for the synthesis of 1,4-dihydropyridine derivatives from various aryl or heteroaryl aldehydes, β-ketoester and ammonium acetate in presence of laterite catalyst in ethanol under ultrasonication is reported. Catalyst study done with wet chemical analysis, FT-IR, XRD, SEM and EDS techniques. The catalyst can be recovered and reused without noticeable loss of activity even after five cycles.
- Chine,Patil
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- Air-stable Organobismuth(V) Bisperfluorooctanesulfonate as an Efficient Catalyst for the Synthesis of N-Containing Compounds
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Triphenyl bismuth bisperfluorooctanesulfonate is an air- and water-stable Lewis acid. It exhibits high catalytic efficiency for the synthesis of nitrogen heterocycles such as diindolylmethane derivatives, dihydropyrimidinones, dihydropyridines and 1,2-disubstitued benzimidazoles under mild condition. Furthermore, it can be reused without loss of activity in a test of five cycles.This catalytic system affords a simple and efficient way for the synthesis of N-containing compounds.
- Wang, Penghui,Wang, Jinying,Au, Chak-Tong,Qiu, Renhua,Xu, Xinhua,Yin, Shuang-Feng
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- β-Cyclodextrin-polyurethane polymer: A neutral and eco-friendly heterogeneous catalyst for the one-pot synthesis of 1,4-dihydropyridine and polyhydroquinoline derivatives via the Hantzsch reaction under solvent-free conditions
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An efficient synthesis of 1,4-dihydropyridine and polyhydroquinoline derivatives using a β-cyclodextrin-polyurethane polymer (β-CDPU) as a stationary micro-vessel and neutral heterogeneous catalyst via a four component coupling of aldehydes, β-ketoester (2 mol) and ammonium acetate under solvent-free conditions is described. Compared with the classical Hantzsch reaction, this new method has the advantages of good yield, short reaction time and methodological simplicity. β-CDPU was proved to be an efficient heterogeneous catalyst that could be easily handled and removed from the reaction mixture by simple filtration, and also recovered and reused without loss of reactivity.
- Kiasat, Ali Reza,Nazari, Simin,Davarpanah, Jamal
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- Tetrabutylammonium hexatungstate [TBA]2[W6O 19]: A novel heterogeneous catalyst for one-pot synthesis of Hantzsch 1,4-dihydropyridines in solvent-free conditions
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A new method for one pot synthesis of Hantzsch 1,4-dihyropyridines was achieved by the reaction of aromatic aldehydes, ethyl acetoacetate and ammonium acetate at 80 °C in the presence of an isopoly tungstate, tetrabutylammonium hexatungstate [TBA]2[W6O19], as an effective and environmentally friendly catalyst. An important advantage of this catalyst is the ease of separating it from the reaction mixture, as well as the fact that it could be recycled a number of times.
- Tavakoli-Hoseini, Niloofar
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- A novel series of 1, 4-Dihydropyridine (DHP) derivatives bearing thiazolidin-4-one: From synthesis to structure
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A novel series of 1, 4-Dihydropyridine (DHP) thiazolidin-4-one compounds derived from dihydropyridine hydrazones Schiff bases with thioglycolic acid were synthesized through an efficient Hantzsch reaction and experimentally characterized by spectral methods using IR, 1H NMR, 13C NMR, and mass spectroscopic methods. Herein, DHPs were synthesized by an improved Hantzsch procedure in the excellent yields by three different conditions including reflux condensation, fusion, and the microwave irradiation. An additional comparison of applied methodology routes was used to confirm the advantages including short reaction time, good yields, and operational simplicity. Furthermore, the structural and electronic properties of the studied molecules were theoretically investigated by performing density functional theory (DFT) to access reliable results to the experimental values. The molecular geometry, HOMO, and LUMO of the studied compounds were calculated. The theoretical 13C chemical shift results were also calculated using the gauge independent atomic orbital (GIAO) approach and their respective linear correlations were obtained.
- Bade, Tahseen S.,Ebrahimi, Hossein Pasha,Alsalim, Tahseen A.,Titinchi, Salam J.J.,Abbo, Hanna S.,Bolandnazar, Zeinab,Ebrahimi, Amirpasha
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- Synthesis of 1,4-dihydropyridine esters using low-melting sugar mixtures as green solvents
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Several low-melting sugar mixtures (LMMs) were synthesized and used for preparation of 1,4-dihydropyridines with aldehydes, 1,3-dicarbonyl compounds, and a nitrogen source as starting materials. Good yields, low reaction times, recyclability of LMMs, and catalyst-free methodology are some of the highlights of this new protocol.
- Kumar, J. Ashwin,Shridhar, Gomathi,Ladage, Savita,Ravishankar, Lakshmy
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- One-step, synthesis of Hantzsch esters and polyhydroquinoline derivatives using new organocatalyst
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Herein we report an efficient organocatalyst for the multicomponent Hantzsch reaction under mild condition. The product easily isolated by simple filtration and catalyst can be recovered.
- Baghbanian, Seyed Meysam,Khaksar, Samad,Vahdat, Seyed Mohammad,Farhang, Maryam,Tajbakhsh, Mahmood
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- Cu-doped ZnO nanocrystalline powder as a catalyst for green and convenient multi-component synthesis of 1,4-dihydropyridine
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Abstract A simple, efficient, and convenient one-step method for synthesis of Hantzsch 1,4-dihydropyridine, using Cu-doped ZnO nanocrystalline powder as a catalyst is reported. The method offers several advantages including excellent yields, green solvent, easy work-up, simplicity in operation and catalyst reusability.
- Alinezhad, Heshmatollah,Mohseni Tavakkoli, Sahar
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- Solvent free, environment benign synthesis of 1,4-dihydropyridines and polyhydroquinolines by using heterogeneous Zn/MCM-41 catalyst
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Heterogeneous catalysis has been utilized in number of efficient reactions with higher selectivity of the product, more stable, reusable and easy for separation as compared to homogeneous catalysts. Generally, heterogeneous catalysts are prepared by using mesoporous materials, microporous materials, metal oxides and metal organic framework. The mesoporous materials have small particle size and high surface area as compared to the microporous materials. The adsorbent mesoporous materials have highly efficient for the therapeutic applications in chemistry hence it has best as compared to other heterogeneous materials. Herein, we have reported synthesis of 1,4-dihydropyridines and polyhydroquinolines at solvent free and environmental benign condition in the presence of Zn/MCM-41 catalyst. The present protocol gives excellent yield (89–96%) of the product within short reaction time by easy work up procedure and no need of further purification of product. The catalyst was characterized by XRD diffractometer, SEM, EDAX, TGA-DTA, BET surface area analysis and FT-IR Spectroscopy. The synthesized organic compounds were characterized by FT-IR, 1H NMR, 13C NMR, LC–MS spectrometry. Graphical abstract: [Figure not available: see fulltext.]
- Dhengale, Shankar D.,Naik, Vaibhav M.,Kolekar, Govind B.,Rode, Chandrashekhar V.,Anbhule, Prashant V.
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- Poly(vinylimidazolum acetic acid)-entrapped nanozeolite: efficient heterogeneous catalyst for synthesis of polyhydroquinolines and 1,4-dihydropyridines
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An effective method for synthesis of substituted 1,4-dihydropyridines and polyhydroquinoline derivatives by Hantzsch reaction using poly(ionic liquid)-based nanozeolite (NZ@PIL-COOH) catalyst under simple conditions is described. The new solid acid catalyst was prepared by polymerization of 3-carboxymethyl-1-vinylimidazolium in presence of modified nanozeolite, and characterized by Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD) analysis, and transmission electron microscopy (TEM). The resulting heterogeneous catalyst displayed high catalytic performance under mild reaction condition in short reaction time. The catalyst was recycled eight times without any loss in reactivity or yield.
- Amoli, Tabassom,Baghbanian, Seyed Meysam
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- Synthesis, anticonvulsant and anti-inflammatory studies of new 1,4-dihydropyridin-4-yl-phenoxyacetohydrazones
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The present work involves design and synthesis of new substituted 1,4-dihydropyridin-4-yl-phenoxyacetohydrazones (4a-s, 5a-h), starting from 4-hydroxybenzaldehyde. The final compounds were screened for their in vivo anticonvulsant activity by MES, scPTZ and 6 Hz methods, while their anti-inflammatory screening was performed by Carrageenan induced Paw Edema method. The results indicated that compounds carrying electron donating groups are anticonvulsant active, while most of the tested compounds exhibited significant anti-inflammatory activity. Compounds 4k, l, 4p-s, and 5c showed rapid anti-inflammatory activity within 30 min and appeared as lead compounds. Further, Neurotoxicity study revealed that all the tested compounds are non-toxic up to 300 mg/kg doses. Selected compounds were also subjected to analgesic screening following Tail immersion method and they exhibited good activity.
- Ulloora, Shrikanth,Shabaraya, Ramakrishna,Ranganathan, Rajesh,Adhikari, Airody Vasudeva
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- In-vitro metabolic inhibition and antifertility effect facilitated by membrane alteration: Search for novel antifertility agent using nifedipine analogues
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In search of non-hormonal male contraceptives, analogues of nifedipine, which causes reversible infertility, have been synthesized and their interaction at molecular level with model membrane has been probed. Analogues act differently with respect to their antifertility action. This is achieved by altering the cell metabolism thereby directly affecting the motility which is responsible for fertility. Secondly, these drugs bind differently to the interior of the cell-membrane affecting the membrane fluidity, architecture and dynamics. Sulfasalazine and D4 interact to a larger extent and alter the lipid bilayer phase to a hexagonal. D1, D2 and D 3 do not have considerable effect. D4 is the most promising candidate as a lead compound for the development of novel non-hormonal male antifertility agents.
- Waghmare, Abhijeet,Kanyalkar, Meena,Joshi, Mamata,Srivastava, Sudha
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- Oxidation of C4-hydroxyphenyl 1,4-dihydropyridines in dimethylsulfoxide and its reactivity towards alkylperoxyl radicals in aqueous medium
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This work reports the electrochemical oxidation of three newly synthesized C4-hydroxyphenyl-substituted 1,4-dihydropyridine derivatives in dimethylsulfoxide. The reactivity of the compounds with ABAP-derived alkylperoxyl radicals in aqueous buffer pH 7.4, was also studied. The oxidation mechanism involves the formation of the unstable dihydropyridyl radical, which was confirmed by controlled-potential electrolysis (CPE) and ESR experiments. The final product of the CPE, that is, pyridine derivative, was identified by GC-MS technique for the three derivatives. A direct reactivity of the synthesized compounds toward ABAP-derived alkylperoxyl radicals was found. The pyridine derivative was identified by GC-MS as the final product of the reaction. Results reveal that this type of 1,4-DHPs significantly reacts with the radicals, even compared with commercial 1,4-DHP drugs with a well-known antioxidant ability.
- Nunez-Vergara, Luis J.,Salazar,Camargo,Carbajo,Conde,Navarrete-Encina,Squella
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- Green synthesis of benzimidazoloquinazolines and 1,4-dihydropyridines using magnetic cyanoguanidine-modified chitosan as an efficient heterogeneous nanocatalyst under various conditions
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Abstract: In the present study, we demonstrated the synthesis of magnetic cyanoguanidine-modified chitosan (MCGC) as an efficient and green retrievable heterogeneous nanocatalyst for one-pot three-component synthesis of benzimidazoloquinazolines (from 2-aminobenzimidazole, aromatic aldehydes, and dimedone) and 1,4-dihydropyridines (via Hantzsch-type condensation of ethyl acetoacetate, aromatic aldehydes, and ammonium acetate) under the ultrasonic irradiation and reflux conditions. The structure of the catalyst was fully confirmed using Fourier transform infrared spectroscopy, vibrating sample magnetometer, field emission scanning electron microscopy, energy dispersive spectroscopy, and thermogravimetric analysis. Increased amount of amino groups that are generated by modifying the surface of chitosan with cyanoguanidine as well as presence of hydroxyl groups determined the catalytic activity of MCGC. Furthermore, as experimental results confirmed, the ultrasonic-promoted reactions gave the better results in terms of reaction time, yield, and purity of isolated products. Cost effectiveness, mild conditions, low catalyst loading, convenient work-up, and ecofriendly solvent are some of the remarkable advantages of this protocol.
- Javanmiri, Kaveh,Karimian, Ramin
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- One-step, synthesis of Hantzsch esters and polyhydroquinoline derivatives in fluoro alcohols
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Hantzsch 1,4-dihydropyridine, polyhydroquinoline and 1,8-dioxodecahydroacridines derivatives were synthesized in excellent yields in trifluoroethanol (TFE). The solvent (TFE) can be readily separated from reaction products and recovered in excellent purity for direct reuse.
- Heydari, Akbar,Khaksar, Samad,Tajbakhsh, Mahmood,Bijanzadeh, Hamid Reza
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- Synthesis, characterization and cytotoxicity evaluation of a novel magnetic nanocomposite with iron oxide deposited on cellulose nanofibers with nickel (Fe3O4@NFC@ONSM-Ni)
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A heterogeneous, magnetically recoverable nanocomposite, Fe3O4@NFC@ONSM-Ni(ii) was prepared by immobilization of a novel Ni(ii) Schiff base complex on Fe3O4@NFC nanoparticles followed by treatment with melamine. This trinuclear catalyst has been characterized using several analytical techniques including FT-IR, TEM, Fe-SEM, EDX, DLS, ICP, TGA, VSM, and XRD. It was used as an efficient catalyst for one-pot solvent-free synthesis of 1,4-dihydropyridine and poly-hydro quinoline derivatives through Hantzsch reaction. This catalyst showed remarkable advantage over previously reported catalysts due to suitable conditions, short reaction time, high efficiency and lower catalyst load and timely recovery of the magnetic catalyst. Moreover, the effects of Fe3O4@NFC@ONSM-Ni(ii) nanoparticles on thein vitroproliferation of human leukemia cell line (k562) and human breast cancer cells (MDA-MB-231) were investigated. The results of MTT and Hochest assays suggested that the nanoparticles could effectively inhibit the proliferation of these cancer cells in a time- and concentration-dependent manner.
- Ghamari Kargar, Pouya,Noorian, Maryam,Chamani, Elham,Bagherzade, Ghodsieh,Kiani, Zahra
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- Solvent-free synthesis of dihydropyridines and acridinediones via a salicylic acid-catalyzed hantzsch multicomponent reaction
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A multicomponent Hantzsch synthesis of 1,4-dihydropyridines and acridinediones from commercially available aldehydes, ammonium acetate, and ethyl acetoacetate or dimedone, in the presence of salicylic acid as an efficient catalyst, in good yield and short reaction time is reported. [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.]
- Khodja, Imene Amine,Ghalem, Wassima,Dehimat, Zineb Imene,Boulcina, Raouf,Carboni, Bertrand,Debache, Abdelmadjid
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- Chitosan nanoparticles as a green and renewable catalyst in the synthesis of 1,4-dihydropyridine under solvent-free conditions
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In the present study, chitosan nanoparticles were obtained by the gelation of chitosan by heptamolybdate anions and dried with dry CO2 for 30 minutes. Chitosan nanoparticles efficiently proceeded the Hantzsch reaction at 80 °C under metal and solvent free conditions. The present method offers several advantages such as a simple procedure, green conditions, excellent yields and short reaction time.
- Safari, Javad,Azizi, Fatemeh,Sadeghi, Masoud
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- Synthesis and anticonvulsant activity of some 1,4-dihydropyridine derivatives
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A series of asymmetrical 4-alkyl/aryl-2,6-dimethyl-3-N-(aryl/heteroaryl)-carbamoyl-5-ethoxycarbonyl-1, 4-dihydropyridines 3a-d and symmetrical 4-alkyl/aryl-2,6-dimethyl-3,5-bis-(ethoxycarbonyl)-1,4-dihydropyridines 4a and 4b have been prepared by the condensation of various benzaldehydes, ethylacetoacetate, 2-aminopyridine or p-toludine in ethanol (Hantzch method). The structures of all the synthesized 1,4-dihydropyridine derivatives have been confirmed by spectral data (IR,1H NMR) and elemental analysis. Compounds 3a-c, 4a and 4b (10 mg/kg) have been evaluated for their anticonvulsant effect against pentylenetetrazole- induced convulsions with phenytoin (4 mg/kg) as the standard. The anticonvulsant potential of the newly synthesized compounds have been assessed on the basis of increase in latency (onset time) to induce convulsions; decrease in number of convulsions and increase in latency of death compared to control and standard.
- Begum, Safia,Sirisha, Kalam
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p. 433 - 438
(2021/09/28)
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- [Fesipmim]Cl as highly efficient and reusable catalyst for solventless synthesis of dihydropyridine derivatives through Hantzsch reaction
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Abstract: In the present investigation, magnetic ferrite nanoparticles (ferrite NPs) were synthesized and coated with silica (ferrite?SiO2NPs) by using the sol-gel method. After that, silica propylmethylimidazolium chloride ionic liquid [Sipmim]Cl was prepared and linked with the above-prepared ferrite?SiO2NPs to synthesize ferrite silica propylmethylimidazolium chloride [Fesipmim]Cl catalyst. The formation of [Fesipmim]Cl catalyst was confirmed by Fourier-transform infrared (FT-IR) spectroscopy analysis. X-ray diffraction (XRD) analysis confirmed the structure of ferrite NPs and ferrite?SiO2 NPs. Transmission electron microscopy (TEM) evidenced the successful formation of ferrite NPs and ferrite?SiO2 NPs. Scanning electron microscopy (SEM) results revealed the change in morphology of ferrite NPs, ferrite?SiO2NPs and [Fesipmim]Cl. The magnetic properties of [Fesipmim]Cl catalyst were measured by vibrating sample magnetometer (VSM). The efficiency of the [Fesipmim]Cl catalyst was checked by using it for the synthesis of different derivatives of dihydropyridine through Hantzsch reaction via a three-component coupling reaction of substituted benzaldehydes, ethyl/ methyl acetoacetate and ammonium acetate. The formation and structures of all the synthesized compounds were confirmed by FT-IR, 1HNMR, 13C NMR spectral analyses. The reusability of the catalyst [Fesipmim]Cl was checked up to seven cycles and found to have excellent activity up to five cycles. Graphic abstract: [Figure not available: see fulltext.].
- Agrwal, Akansha,Kasana, Virendra
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- Search for Antimicrobial Activity Among Fifty-Two Natural and Synthetic Compounds Identifies Anthraquinone and Polyacetylene Classes That Inhibit Mycobacterium tuberculosis
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Drug-resistant tuberculosis threatens to undermine global control programs by limiting treatment options. New antimicrobial drugs are required, derived from new chemical classes. Natural products offer extensive chemical diversity and inspiration for synthetic chemistry. Here, we isolate, synthesize and test a library of 52 natural and synthetic compounds for activity against Mycobacterium tuberculosis. We identify seven compounds as antimycobacterial, including the natural products isobavachalcone and isoneorautenol, and a synthetic chromene. The plant-derived secondary metabolite damnacanthal was the most active compound with the lowest minimum inhibitory concentration of 13.07 μg/mL and a favorable selectivity index value. Three synthetic polyacetylene compounds demonstrated antimycobacterial activity, with the lowest MIC of 17.88 μg/mL. These results suggest new avenues for drug discovery, expanding antimicrobial compound chemistries to novel anthraquinone and polyacetylene scaffolds in the search for new drugs to treat drug-resistant bacterial diseases.
- Pollo, Luiz A. E.,Martin, Erlon F.,Machado, Vanessa R.,Cantillon, Daire,Wildner, Leticia Muraro,Bazzo, Maria Luiza,Waddell, Simon J.,Biavatti, Maique W.,Sandjo, Louis P.
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- MIL-101-SO3H metal-organic framework as a Br?nsted acid catalyst in Hantzsch reaction: An efficient and sustainable methodology for one-pot synthesis of 1,4-dihydropyridine
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A straightforward and efficient methodology for the one-pot multicomponent synthesis of 1,4-dihydropyridine has been developed using MIL-101-SO3H metal-organic framework as a solid Br?nsted acid. The presence of the uniformly distributed Br?nsted acidic sulfonic acid sites throughout the framework and the high stability bestow the catalyst with excellent reactivity towards the synthesis of 1,4-dihydropyridine under simple reaction conditions using renewable ethanol as the solvent. The present methodology tolerates various functional groups and allows the synthesis of 1,4-dihydropyridine derivatives in good to excellent yields through Hantzsch reaction. The developed methodology proceeds under mild conditions, avoids corrosive reagents and special reaction conditions, and is amenable to gram scale synthesis. The sustainable nature of the catalyst was proved by the easy recovery and the reusability of the catalyst, as it was reused several times without loss in activity, which was confirmed from the FTIR, PXRD and SEM analyses of the reused catalyst.
- Devarajan, Nainamalai,Suresh, Palaniswamy
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p. 6806 - 6814
(2019/05/10)
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- Preparation method and application of novel ionic beta-naphthol aldehyde Schiff base zirconium complex
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The invention belongs to the technical field of catalytic organic synthesis, and particularly relates to a preparation method and application of a novel ionic beta-naphthol aldehyde Schiff base zirconium complex. Zirconium atoms are coordinated with a beta-naphthol aldehyde Schiff base ligand and water molecules, and two perfluoroalkyl (aryl) sulfonic acid groups are combined with central atom zirconium through covalent bonds and ionic bonds respectively. The preparation method comprises the following steps: dissolving beta-naphthol aldehyde Schiff base zirconium dichloride in a solvent, adding a silver salt under the protection of N2, reacting the mixture for 1-4 hours in a dark place at room temperature, performing filtration, adding n-hexane into filtrate until layering, putting the solution into a refrigerator, and freezing the solution for 24 hours to separate out the beta-naphthol aldehyde Schiff base zirconium complex. The beta-naphthol aldehyde Schiff base zirconium complex hashigh air stability and strong Lewis acidity, and can efficiently catalyze the Hantzsch reaction of aldehyde, beta-ketoester and ammonium acetate to synthesize 1,4-dihydropyridine derivatives.
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Paragraph 0041; 0054-0055
(2019/12/02)
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- Synergistic catalytic effect between ultrasound waves and pyrimidine-2,4-diamine-functionalized magnetic nanoparticles: Applied for synthesis of 1,4-dihydropyridine pharmaceutical derivatives
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A convenient strategy for synthesis of the various derivatives of 1,4-dihydropyridine (1,4-DHP), as one of the most important pharmaceutical compounds, is presented in this study. For this purpose, firstly, magnetic iron oxide nanoparticles (Fe3O4 NPs) were fabricated and suitably coated by silica network (SiO2) and trimethoxy vinylsilane (TMVS). Then, their surfaces were well functionalized with pyrimidine-2,4-diamine (PDA) as the main active sites for catalyzing the synthesis reactions. In this regard, the performance of three different methods including reflux, microwave (MW) and ultrasound wave (USW) irradiations have been comparatively monitored via studying various analyses on the fabricated nanocatalyst (Fe3O4/SiO2-PDA). Concisely, high efficiency of the USW irradiation (in an ultrasound cleaning bath with a frequency of 50 kHz and power of 250 W/L) has been well proven through the investigation of the main factors such as excellent surface-functionalization, core/shell structure conservation, particle uniformity, close size distribution of the particles, and great inhibition of the particle aggregation. Then, the effectiveness of the USW irradiation as a promising co-catalyst agent has been clearly demonstrated in the 1,4-DHP synthesis reactions. It has been concluded that the USW could provide more appropriate conditions for activation of the catalytic sites of Fe3O4/SiO2-PDA NPs. However, high reaction yields (89%) have been obtained in the short reaction times (10 min) due to the substantial synergistic effect between the presented nanocatalyst and USW.
- Taheri-Ledari, Reza,Rahimi, Jamal,Maleki, Ali
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- Anchored sulfonic acid on silica-layered NiFe2O4: A magnetically reusable nanocatalyst for Hantzsch synthesis of 1,4-dihydropyridines
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In this study, the immobilization of sulfonic acid on silica-layered nickel ferrite, NiFe2O4@SiO2@SO3H, was investigated. The sulfonated Ni-nanocatalyst was then characterized using FT-IR, SEM, EDX, XRD and VSM analyses. Catalytic activity of the Ni-nanocomposite was also studied towards Hantzsch synthesis of 1,4-dihydropyridines via one-pot condensation reaction of 1,3-diketones (ethyl acetoacetate or 4-hydroxycoumarin), aromatic aldehydes and aqueous ammonia in H2O (70 °C)as a green solvent. All reactions were carried out within 10–100 min to afford the products in high to excellent yields. The green aspect of this synthetic protocol was more studied by examining the reusability of NiFe2O4@SiO2@SO3H MNPs for seven consecutive cycles without the significant loss of catalytic activity. The current method represents remarkable advantages in terms of mild reaction conditions, using H2O as an environmental-friendly solvent, stability and easy separation of the magnetic nanocatalyst, high yield of products, wide tolerance of starting materials and the perfect reusability of the applied Ni-nanocatalyst.
- Zeynizadeh, Behzad,Rahmani, Soleiman,Eghbali, Elham
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- Silica-supported ceric ammonium nitrate (CAN): a simple, mild and solid-supported reagent for quickest oxidative aromatization of Hantzsch 1,4-dihydropyridines
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An efficient and environmentally benign methodology for the oxidative aromatization of 1,4-dihydropyridines to their corresponding pyridine derivatives is developed. The oxidative aromatization of 1,4-dihydropyridines was explored using silica-supported ceric ammonium nitrate as catalyst in CH3CN with or without sonication at room temperature. This supported catalyst acts as a more efficient oxidising reagent and offers several advantages over other reported reagents in terms of reaction time and yields. The supported reagent is found to be more efficient and selective when compared with its unsupported form. The Belousov–Zhabotinskii reaction was not observed in present reaction. The dealkylation observed in case of 4-n-alkyl/n-alkenyl with other oxidising agents is also not observed in the present case.
- Kumar, Parvin,Kadyan, Kulbir,Duhan, Meenakshi,Sindhu, Jayant,Hussain, Khalid,Lal, Sohan
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p. 1153 - 1162
(2019/04/25)
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- A novel three-phenyl bismuth organic (V) complex catalyst and its preparation method and a nitrogen-containing compound in the synthesis of the catalytic application
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The invention provides a novel triphenyl organic bismuth (V) complex catalyst I, a preparation method thereof, and a synthesis method for nitrogen-containing compounds II-V under the catalysis of the novel triphenyl organic bismuth (V) complex catalyst I. The complex I is a cation-type organic bismuth complex, and the molecular formula is Ph3BiX2 (X=OSO2C4F9, OSO2C6F5, OSO2C8F17). The bismuth atom in the complex is connected with three triphenyls to show pentavalence. The other two perfluorooctane sulfonate roots and the cation part of the complex form an ionic bond. The synthesis method is used for synthesizing four types nitrogen-containing compounds, including bis(indolyl)methane II, dihydropyrimidinone III, dihydropyridine IV and beta-alkamine V, by taking the triphenyl organic bismuth compound as a catalyst and a conventional organic solvent as a reaction solvent. The method has the advantages of lower cost, high yield, simplicity and convenience in operation, zero pollution, repeated use of the catalyst and the like, and creates a cheap and environment-friendly way for preparing the nitrogen-containing compounds.
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Paragraph 0136; 0138; 0140; 0142; 0144; 0146; 0150; 0152
(2018/10/19)
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- Synthesis and application of chitosan supported vanadium oxo in the synthesis of 1,4-dihydropyridines and 2,4,6-triarylpyridines: Via anomeric based oxidation
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Chitosan, as a biopolymer, exhibits a strong affinity for complexation with suitable metal ions. Thus, it has received increased attention for the preparation of stable bioorganic-inorganic hybrid heterogeneous catalysts. Herein, a novel chitosan based vanadium oxo (ChVO) catalyst was prepared and fully characterized by several techniques such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), derivative thermal gravimetric (DTG), differential thermal analysis (DTA), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma mass spectrometry (ICP-MS). The synthesized catalyst has been successfully used as a reusable catalyst in the synthesis of dihydropyridines and triarylpyridines.
- Safaiee, Maliheh,Ebrahimghasri, Bahar,Zolfigol, Mohammad Ali,Baghery, Saeed,Khoshnood, Abbas,Alonso, Diego A.
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p. 12539 - 12548
(2018/08/04)
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- A New Type of Magnetically-Recoverable Heteropolyacid Nanocatalyst Supported on Zirconia-Encapsulated Fe3O4 Nanoparticles as a Stable and Strong Solid Acid for Multicomponent Reactions
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Abstract: A novel highly efficient magnetically retrievable catalyst was developed by the immobilization of H3PW12O40 (20–60 wt%) on the surface of zirconia-encapsulated Fe3O4 nanoparticles. The prepared HPW supported on nano-Fe3O4@ZrO2 heterogeneous acid catalyst (or n-Fe3O4@ZrO2/HPW) was fully characterized by several physicochemical techniques such as: Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, vibrating sample magnetometry and thermogravimetric analysis. The FT-IR spectroscopic data revealed that H3PW12O40 molecules on the nano-Fe3O4@ZrO2 support existed in the Keggin structure. The acidity of the catalyst was measured by the help of a potentiometric titration with n-butylamine. It was surprising that this very strong solid acid catalyst exhibited an excellent acid strength which was as a result of possessing a higher number of surface active sites compared to its homogeneous analogues. The catalytic activity of the as-prepared novel nano-Fe3O4@ZrO2/HPW was explored through the one-pot three-component synthesis of different 3,4-dihydropyrimidin-2(1H)-ones (i.e. Biginelli reaction) and 1,4-dihydropyridines (i.e. Hantzsh reaction) under solvent free condition. The sample of 40 wt% showed higher acidity and activity in the catalytic transformation. After the reaction, the catalyst/product isolation could be easily achieved with an external magnetic field and the catalyst could be easily recycled for at least five times without any decrease in its high catalytic activity. The excellent recyclability was attributed to the strong interaction between the hydroxyl groups of the nano-Fe3O4@ZrO2 support and the HPW species. Graphical Abstract: [Figure not available: see fulltext.].
- Zolfagharinia, Somayeh,Kolvari, Eskandar,Koukabi, Nadiya
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p. 1551 - 1566
(2017/05/17)
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- Synthesis and in vitro evaluation of Ca2 + channel blockers 1,4-dihydropyridines analogues against Trypanosoma cruzi and Leishmania amazonensis: SAR analysis
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Drugs containing the1,4-dihydropyridine (DHP) core have recently attracted attention concerning their antiparasitic effect against various species of Leishmania and Trypanosoma. This approach named drugs repositioning led to interesting results, which have prompted us to prepare 21 DHP's analogues. The 1,4-DHP scaffold was decorated with different function groups at tree points including the nitrogen atom (NH and N-phenyl), the aryl group attached to C-4 (various substituted aryl residues) and the carbon atoms 2 and 6 (bearing Ph or Me groups). Moreover, the products were evaluated for their cytotoxicity on three cancer and a non-tumoral cell lines. Only 6 of them were antiproliferative and their weak effect (CC50 comprised between 27 and 98 μM) suggested these DHPs as good candidates against the intracellular amastigote forms of L. amazonensis and T. cruzi. L. amazonensis was sensitive to DHPs 5, 11 and 15 (IC50 values at 15.11, 45.70 and 53.13 μM, respectively) while 12 of them displayed significant to moderate trypanocidal activities against T. cruzi. The best trypanocidal activities were obtained with compounds 2, 18 and 21 showing IC50 values at 4.95, 5.44, and 6.64 μM, respectively. A part of the N-phenylated DHPs showed a better selectivity than their NH analogues towards THP-1 cells. 4-Chlorophenyl, 4-nitrophenyl and 3-nitrophenyl residues attached to the carbon atom 4 turned to be important sub-structures for the antitrypanosomal activity.
- Pollo, Luiz A.E.,de Moraes, Milene H.,Cisilotto, Júlia,Creczynski-Pasa, Tania B.,Biavatti, Maique W.,Steindel, Mario,Sandjo, Louis P.
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p. 789 - 797
(2017/09/23)
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- Synthesis of 2,3-dihydropyrroles by photo rearrangement of Hantzsch 1,4-dihydropyridines with high diastereoselectivity
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The Hantzsch 1,4-dihydropyridines were found to be transforming to the 2,3-dihydropyrroles by photo rearrangement with air under irradiation of LED light (410?nm) with high diastereoselectivity (dr?>?20:1). This reaction includes tandem photo oxidation/rearrangement. The 2,3-dihydropyrroles were obtained in moderate yields with successfully one-pot process starting from aldehydes, ammonium acetate and ethyl acetoacetate.
- Zhong, Qidi,Fan, Qiangwen,Yan, Hong
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supporting information
p. 1292 - 1295
(2017/03/10)
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- Aqua-mediated one-pot synthesis of Biginelli dihydropyrimidinone/thiones (DHPMs), Hantzsch dihydropyridines (DHPs), and polysubstituted pyridines sonocatalyzed by metal-supported nanocatalysts
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In this work, catalyst composition-activity relationship of supported catalysts in Biginelli and Hantzsch reactions was investigated under mild conditions. Biginelli dihydropyrimidinone/thiones were prepared over Fe-Cu/ZSM-5 as an efficient, convenient, and environmentally benign catalyst under ultrasonic irradiation in aqueous media in very good yields. The Fe-Cu/ZSM-5-catalyzed synthesis of 1,4-dihydropyridines and their aromatization to polysubstituted pyridines and also a new one-pot, two-step, and sequential protocol for the synthesis of pyridine derivatives, employing an aldehyde, ethyl acetoacetate, and ammonium acetate under the same green experimental conditions were illustrated. Three-component condensation in the presence of supported reagent with operational simplicity, inexpensive reagents, short reaction time, high yield of products, and use of non-toxic reagents makes this synthetic protocol an attractive one.
- Safa, Kazem D.,Esmaili, Maryam,Allahvirdinesbat, Maryam
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p. 267 - 277
(2016/01/09)
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- Tetraethylammonium 2-(carbamoyl)benzoate as a bifunctional organocatalyst for one-pot synthesis of Hantzsch 1,4-dihydropyridine and polyhydroquinoline derivatives
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Abstract: A green, convenient, and environment-friendly approach for the synthesis of biologically active Hantzsch 1,4-dihydropyridine and polyhydroquinoline derivatives in the presence of tetraethylammonium 2-(carbamoyl)benzoate, as an effective bifunctional metal-free catalyst, has been developed via a one-pot multicomponent reaction of various aldehydes, ethyl acetoacetate or cyclic 1,3-dicarbonyl compounds, and ammonium acetate in EtOH under reflux conditions. The proposed methodology is capable of providing the desired products in good to excellent yields and short reaction time with straightforward work-up and a low-cost procedure. Graphical abstract: [Figure not available: see fulltext.]
- Yarhosseini, Mahsa,Javanshir, Shahrzad,Dekamin, Mohammad G.,Farhadnia, Mohammad
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p. 1779 - 1787
(2016/09/28)
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- A Simple and Efficient One-pot Synthesis of 1,4-dihydropyridines Using Nano-WO3-supported Sulfonic Acid as an Heterogeneous Catalyst under Solvent-free Conditions
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Nano-tungsten trioxide-supported sulfonic acid (n-WSA) was found to be an effective heterogeneous catalyst for the one-pot reaction of aromatic aldehydes, β-dicarbonyl compounds and ammonium acetate to afford 1,4-dihydropyridine derivatives in good to excellent yields. The other main advantages of the present method are short reaction times, simple workup, ease in purification and environmentally benign methodology. The reaction conditions were optimized employing Response Surface Method technique (Central Composite Design (CCD)) which is economically considerable because of the minimum number of experiments required to evaluate the effects of multiple parameters on the response.
- Bitaraf, Mehrnoosh,Amoozadeh, Ali,Otokesh, Somayeh
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p. 336 - 344
(2016/05/09)
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- Heterogeneous bimetallic ZnFe2O4nanopowder catalyzed synthesis of Hantzsch 1,4-dihydropyridines in water
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The mixed metal oxide ZnFe2O4nanopowder, a dual Lewis acid–base combined catalyst is found to efficiently catalyze a multicomponent synthesis of 1,4-dihydropyridines from aldehydes, ethyl acetoacetate, and ammonium acetate in water. This procedure offers several advantages including high yields, short reaction times, a simple work-up procedure, and a benign eco-footprint. This method takes advantage of the fact that water, a green solvent is used in combination with ZnFe2O4nanoparticles as catalyst which can be easily recovered magnetically and reused for further runs.
- Ravikumar Naik,Shivashankar
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supporting information
p. 4046 - 4049
(2016/08/18)
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- Air-stable zirconocene bis(perfluorobutanesulfonate) as a highly efficient catalyst for synthesis of N-heterocyclic compounds
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Zirconocene bis(perfluorobutanesulfonate) is air- and water-stable and proved to be ionic on basis of conductivity measurements. It exhibits high catalytic efficiency for the synthesis of N-heterocyclic compounds under solvent-free condition, such as benzimidazoles, benzodiazepines, dihydropyrimidinones and dihydropyridines under mild condition. Furthermore, it can be reused without loss of activity in a test of five cycles. This catalytic system affords a simple and efficient approach for the synthesis of N-heterocyclic compounds.
- Wang, Jinying,Li, Ningbo,Qiu, Renhua,Zhang, Xiaohong,Xu, Xinhua,Yin, Shuang-Feng
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- Ultrasound-mediated, uranyl nitrate hexahydrate-catalyzed synthesis of 1,4-dihydropyridines under mild conditions
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Abstract Synthesis of 1,4-dihydropyridines by three-component condensation reaction of aldehyde, 1,3-dicarbonyl compounds, and ammonium acetate have been found to be efficiently catalyzed by uranyl nitrate hexahydrate [UO2(NO3)2 ·6H2O] at room temperature under ultrasound irradiation. This novel synthetic method offers the advantages of high yields, short reaction times, simplicity, and easy workup compared to the conventional methods reported in the literature.
- Palakshi Reddy,Sarveswari,Vijayakumar
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p. 6877 - 6883
(2015/08/18)
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- Melamine supported on hydroxyapatite-encapsulated-γ-Fe2O3: A novel superparamagnetic recyclable basic nanocatalyst for the synthesis of 1,4-dihydropyridines and polyhydroquinolines
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In this paper, the preparation and characterization of hydroxyapatite-encapsulated γ-Fe2O3 nanoparticles functionalized with Melamine nanocomposite (γ-Fe2O3@HAp@Melamine) are presented. The resulting nanocomposite was characterized by infrared spectroscopy, scanning electron microscope, thermal gravimetric analysis, X-ray diffraction, vibrating sample magnetometer and elemental analysis. The catalytic activity of γ-Fe2O3@ HAp@Melamine as a magnetic powerful basic nanocatalyst was probed through one-pot synthesis of 1, 4-dihydropyridine and polyhydroquinoline derivatives through Hantzsch condensation reaction under solvent-free thermal conditions. The heterogeneous catalyst could be recovered easily by simple magnetic decantation and reused many times without significant loss of its catalytic activity.
- Igder, Sedighe,Kiasat, Ali Reza,Shushizadeh, Mohamad Reza
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p. 7227 - 7244
(2015/09/29)
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- Alginic acid: A highly efficient renewable and heterogeneous biopolymeric catalyst for one-pot synthesis of the Hantzsch 1,4-dihydropyridines
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Alginic acid, a naturally occurring polysaccharide, in its granular form and without any post-modification was found to be an efficient, environmentally benign, easily recoverable and low-cost catalyst for the clean and rapid synthesis of 1,4-dihydropiridine derivatives (DHPs) just based on its polysaccharide architecture. The Hantzsch pseudo-four-component reaction of ethyl or methyl acetoacetate, ammonium acetate and different aldehydes is catalyzed by alginic acid efficiently under mild conditions to afford the desired products in high to quantitative yields and clean reaction profiles. Avoiding the use of any transition metal, the use of a one-pot and multi-component procedure for the synthesis of DHPs, the reusability of the catalyst and operational simplicity are important features of this methodology.
- Dekamin, Mohammad G.,Ilkhanizadeh, Siamand,Latifidoost, Zahra,Daemi, Hamed,Karimi, Zahra,Barikani, Mehdi
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p. 56658 - 56664
(2015/02/02)
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- Regioselective synthesis of novel 2-chloroquinoline derivatives of 1,4-dihydropyridines
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Highly regioselective reaction of some substituted 2,4-dichloroquinolines with symmetrical 1,4-dihydropyridines, leading to novel quinoline derivatives of DHPs, has been achieved in the presence of powdered K2CO 3, as a mild and efficient base, at moderate temperature. All the synthesized compounds were characterized by use of IR, NMR, and mass spectral data.
- Rajesh,Iniyavan,Sarveswari,Vijayakumar
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p. 1851 - 1866
(2014/05/06)
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- One-pot synthesis of Hantzsch esters and polyhydroquinoline derivatives catalyzed by γ-Al2O3-nanoparticles under solvent-free thermal conditions
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γ-Alumina nanoparticles are used as an effective and reusable catalyst for one-pot synthesis of 1,4-dihydropyridine and polyhydroquinoline derivatives via multicomponent Hantzsch reaction at 90 °C under solventfree conditions. A broad range of structurally diverse aldehydes were applied successfully, and corresponding products were obtained in high yields without any byproduct. Compared with other methods, satisfactory results are obtained with high yields, short reaction times, and simplicity in the experimental procedure. The catalyst could easily be recycled and reused four times without noticeable decrease in catalytic activity.
- Kiasat, Ali Reza,Almasi, Hossein,Saghanezhad, Seyyed Jafar
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