- Synthesis, characterization and cytotoxicity evaluation of a novel magnetic nanocomposite with iron oxide deposited on cellulose nanofibers with nickel (Fe3O4@NFC@ONSM-Ni)
-
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
-
p. 17413 - 17430
(2021/05/25)
-
- One-pot synthesis of 1,4-dihydropyridine derivatives using the Fe2ZnAl2O7 catalyzed Hantzsch three-component reaction
-
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
-
p. 1310 - 1316
(2021/02/16)
-
- Green synthesis and characterization of novel Mn-MOFs with catalytic and antibacterial potentials
-
This study focused on the synthesis of a new manganese-based metal-organic framework and the investigation of its application aspects. A Mn-MOF nanostructure, namely UoB-4, was prepared using a Schiff base organic linker (H2bbda: 4,4′-[benzene-
- Aryanejad, Sima,Bagherzade, Ghodsieh,Moudi, Maryam
-
p. 1508 - 1516
(2020/02/06)
-
- Ferric Sulfasalazine Sulfa Drug Complex Supported on Cobalt Ferrite Cellulose; Evaluation of Its Activity in MCRs
-
Abstract: The green and nano catalyst was simply prepared through the reaction of ferric sulfasalazine with nanomaterial CoFe2O4-cellulose as a magnetic biopolymer surface. This novel heterogeneous organometallic catalyst was charact
- Rostamizadeh, Shahnaz,Daneshfar, Zahra,Khazaei, Ali
-
p. 2091 - 2114
(2020/01/31)
-
- 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
-
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
-
-
- σ-Bond initiated generation of aryl radicals from aryl diazonium salts
-
σ-Bond nucleophiles and molecular oxygen transform aryl diazonium salts into aryl radicals. Experimental and computational studies show that Hantzsch esters transfer hydride to aryl diazonium species, and that oxygen initiates radical fragmentation of the diazene intermediate to produce aryl radicals. The operational simplicity of this addition-fragmentation process for the generation of aryl radicals, by a polar-radical crossover mechanism, has been illustrated in a variety of bond-forming reactions.
- Chan, Bun,McErlean, Christopher S. P.,Nashar, Philippe E.,Tatunashvili, Elene
-
supporting information
p. 1812 - 1819
(2020/03/17)
-
- 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
-
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
-
p. 6806 - 6814
(2019/05/10)
-
- Compatibility of supported ionic liquid phase catalysts under ultrasonication
-
Various supported ionic liquid phase (SILP) catalysts containing hexafluorophosphate anion have been prepared by covalent grafting of imidazolium ionic liquid in the matrix of cellulose, silica and Merrifield resin followed by anion metathesis reaction. T
- Jagadale, Megha,Kale, Dolly,Salunkhe, Rajashri,Rajmane, Mohan,Rashinkar, Gajanan
-
p. 525 - 535
(2018/06/26)
-
- Facile template-free route to fabricate core–shell Fe3O4@PANI-SO3H urchin-like nanoparticles as reusable catalyst for Hantzsch reaction: change morphology upon sulfonation
-
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
-
p. 6649 - 6666
(2018/06/25)
-
- Fe3O4@SiO2 supported aza-crown ether complex cation ionic liquids: preparation and applications in organic reactions
-
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
-
p. 4237 - 4242
(2017/02/05)
-
- Hollow Fe3O4@DA-SO3H: an efficient and reusable heterogeneous nano-magnetic acid catalyst for synthesis of dihydropyridine and dioxodecahydroacridine derivatives
-
Abstract: In this work, for the first time, a highly stable and efficient super-paramagnetic catalyst, H-Fe3O4@DA-SO3H, involving hollow morphology of Fe3O4 as core and dopamine as shell was prepared
- Mirhosseyni, Marzie sadat,Nemati, Firouzeh,Elhampour, Ali
-
p. 791 - 801
(2017/02/26)
-
- Synthesis, docking simulation, biological evaluations and 3D-QSAR study of 1,4-dihydropyridines as calcium channel blockers
-
Resurgence to target L-type voltage-dependent calcium channels has been applied by the synthesis of two series of nifedipine analogues where the ortho- or a meta-nitrophenyl ring is retained. A pre-synthetic molecular docking study with a receptor model followed by molecular alignment has been performed on 47 compounds to predict the most active member. The IC50 values revealed that some of the compounds are similar to or more active than nifedipine. Substitution of groups at the 3- and 5-positions of the dihydropyridine (DHP) ring gave 3k, which is more active than nifedipine. Our valid three-dimensional quantitative structure–activity relationship (3D-QSAR) model prefigures the influence of lipophilicity, bulkiness and chelating effects of the C3 and C5 substituents. Bulky groups interfere with ring-to-ring hydrophobic interaction with tyrosine (Tyr)4311 and limit the efficiency of increasing the length of the hydrocarbon chain of esters at the 3- and 5-positions of the DHP ring as an approach to increasing the activity. The presence of a chelating substituent on the phenyl ring at the 4-position of the DHP ring ensures strong binding to the receptor and hence stabilization of the closed-channel conformation. The validation of 3D-QSAR model indicated its proficiency in predicting activity of newly compounds belonging to the same chemical class.
- El-Moselhy, Tarek Fathy,Sidhom, Peter Ayoub,Esmat, Eman Ahmed,El-Mahdy, Nageh Ahmed
-
p. 893 - 903
(2018/10/31)
-
- 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
-
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
-
p. 336 - 344
(2016/05/09)
-
- Tetraethylammonium 2-(carbamoyl)benzoate as a bifunctional organocatalyst for one-pot synthesis of Hantzsch 1,4-dihydropyridine and polyhydroquinoline derivatives
-
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
-
p. 1779 - 1787
(2016/09/28)
-
- Silica functionalized sulphonic acid coated with ionic liquid: An efficient and recyclable heterogeneous catalyst for the one-pot synthesis of 1,4-dihydropyridines under solvent-free conditions
-
Silica-supported sulphonic acid catalysts were prepared and coated with ionic liquid, and their catalytic activities were evaluated for the one-pot synthesis of 1,4-dihydropyridines. Different catalysts with an ionic liquid layer (SCILLs) have been prepared with a view to determine the most active catalyst. Silica sulphonic acid coated with [BMIM][PF6] was found to be the most active catalyst and can be recycled for several runs without the loss of significant activity. It was characterized using SEM, TEM, TGA and FTIR.
- Sharma, Pankaj,Gupta, Monika
-
p. 1100 - 1106
(2015/03/04)
-
- N-Propyl-4-aza-1-azoniabicyclo[2.2.2]octane chloride-SBA-15 (SBA-DABCO) as basic mesoporous catalyst for the synthesis of 1,4-dihydropyridine hetrocyclic compounds
-
Regarding the green chemistry's goals, the development of mesoporous silica materials as attractive candidates in the search for supporting of catalysts is currently a subject of increasing interest. Therefore, in the present research n-propyl-4-aza-1-azo
- Kiasat, Ali Reza,Davarpanah, Jamal
-
p. 179 - 182
(2015/07/07)
-
- Urease: A highly biocompatible catalyst for switchable Biginelli reaction and synthesis of 1,4-dihydropyridines from the in situ formed ammonia
-
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
-
-
- Air-stable zirconocene bis(perfluorobutanesulfonate) as a highly efficient catalyst for synthesis of N-heterocyclic compounds
-
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
-
-
- Comparative study of catalytic potential of TBAB, BTEAC, and CTAB in one-pot synthesis of 1,4-dihydropyridines under aqueous medium
-
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
-
p. 574 - 582
(2014/01/23)
-
- New magnetic nanocomposites of ZrO2-Al2O 3-Fe3O4 as green solid acid catalysts in organic reactions
-
A series of magnetic solid acid nano-catalysts were designed and prepared through a facile co-precipitate approach. The original nanocomposites ZrO 2-Al2O3-Fe3O4 were characterized by means of ICP-AES
- Wang, Anqi,Liu, Xiang,Su, Zhongxing,Jing, Huanwang
-
-
- Synthesis, anticonvulsant activity and molecular properties prediction of dialkyl 1-(di(ethoxycarbonyl)methyl)-2,6-dimethyl-4-substituted-1,4- dihydropyridine-3,5-dicarboxylates
-
The synthesis and anticonvulsant properties of new N-diethylmalonyl derivatives of nifedipine and other isosteric analogues (7a-7n) were described. Anticonvulsant screening was performed by subcutaneous pentylenetetrazole (scPTZ) and maximal electroshock (MES) induced seizures tests. Majority of the compounds were effective in scPTZ and MES screens. Compound 7k showed good activity displaying maximum protection, which may be due to the presence of styryl moiety at position 4 of 1,4-dihydropyridine nucleus and the methyl groups of diester functionality. Compounds 7a-7d, 7g, 7i and 7k obeyed the Lipinski's "rule of five" and have drug-likeness. Based on computational prediction of molecular and pharmacokinetic properties, it was found that the compounds have good oral absorption.
- Prasanthi,Prasad,Bharathi
-
-
- 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
-
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
-
p. 401 - 409
(2014/05/06)
-
- BF3.SiO2 nanoparticles: A solid phase acidic catalyst for efficient one-pot Hantzsch synthesis of 1,4-dihydropyridines
-
The solvent-free Hantzsch reaction between ethyl acetoacetate or 1,3-indandione, an aromatic aldehyde and ammonium acetate catalysed by BF 3.SiO2 nanoparticles provided an efficient one-step synthesis of 1,4-dihydropyridines in excellent yields.
- Sadeghi, Bahareh,Namakkoubi, Ashraf,Hassanabadi, Alireza
-
-
- A magnetic nanoparticle supported Ni2+-containing ionic liquid as an efficient nanocatalyst for the synthesis of Hantzsch 1,4-dihydropyridines in a solvent-free dry-system
-
The highly efficient synthesis of 1,4-dihydropyridines (1,4-DHPs) is reported via the condensation reaction of aldehydes, ethyl acetoacetate and ammonium acetate, using an environmentally benign Ni2+-containing 1-methyl-3-(3-trimethoxysilylprop
- Safari, Javad,Zarnegar, Zohre
-
p. 26094 - 26101
(2013/12/04)
-
- Hantzsch 1,4-dihydropyridine synthesis in aqueous ethanol by visible light
-
A highly efficient environment-friendly Hantzsch 1,4-dihydropyridine synthesis under visible light in aqueous ethanol has been achieved in excellent yield via a one-pot three component reaction of various types of aliphatic and aromatic aldehydes with ethyl acetoacetate and ammonium hydroxide solution.
- Ghosh, Somnath,Saikh, Forid,Das, Jhantu,Pramanik, Arun Kumar
-
supporting information
p. 58 - 62
(2013/02/21)
-
- PEG-mediated catalyst-free synthesis of Hantzsch 1,4-dihydropyridines and polyhydroquinoline derivatives
-
Hantzsch 1,4-dihydropyridines and polyhydroquinoline derivatives were synthesized in good yields by PEG-mediated, catalyst-free synthesis under solvent-free conditions. The products were directly recrystallized from hot methanol. The reaction gave excellent yields with low- as well as high-molecular-weight polyethylene glycols. Taylor & Francis Group, LLC.
- Siddaiah,Basha, G. Mahaboob,Rao, G. Padma,Prasad, U. Viplava,Rao, R. Suryachendra
-
experimental part
p. 627 - 634
(2011/12/22)
-
- Zn[(L)-proline], as a recyclable and green catalyst for efficient and one-pot three-component synthesis of 1,4-Dihydro- pyridines under solvent-free and microwave irradiation conditions
-
Zn[(L)-proline], was faund to be efficient, green, and recyclable catalyst for the synthesis of 1,4-dihydropyridines by condensation reaction of aldehydes, ethyl acetoacetate, and ammonium acetate in high to excellent yields under solvent-free and microwave irradiation conditions. The present methodology offers several advantages, such as a simple procedure with an easy workup, high yields, and the absence of any volatile and hazardous organic solvent. Morever, the catalyst can be easily recovered and reused at least three time with only slight reduction in its catalytic activity.
- Montazeri, Naser,Pourshamsian, Khalil,Zoghi, Rozita,Mahjoob, Saber
-
experimental part
p. 103 - 107
(2012/08/07)
-
- A new In-SiO2 composite catalyst in the solvent-free multicomponent synthesis of Ca2+ channel blockers nifedipine and nemadipine B
-
An In-SiO2 composite was prepared by the sol-gel method and was applied as a heterogeneous Lewis acid catalyst in the multicomponent Hantzsch synthesis of symmetrical and non-symmetrical 1,4-DHPs. The Ca2+ channel blockers nifedipine and nemadipine B were synthesized in a single step through a solvent-free protocol. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2012.
- Affeldt, Ricardo F.,Benvenutti, Edilson V.,Russowsky, Dennis
-
experimental part
p. 1502 - 1511
(2012/07/30)
-
- An Efficient Synthesis of 4-Aryl-1,4-dihydropyridines Via VB1 Catalyzed Hantzsch Reaction
-
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
-
scheme or table
p. 707 - 711
(2012/06/01)
-
- Silica sulfuric acid: An efficient heterogeneous catalyst for the one-pot synthesis of 1,4-dihydropyridines under mild and solvent-free conditions
-
A series of 1,4-dihydropyridines have been prepared by a one-pot condensation of aldehydes, ethyl acetoacetate, and ammonium acetate in the presence of a heterogeneous catalyst silica sulfuric acid at room temperature under solvent-free condition. This new protocol has the advantage of short reaction time and excellent yields, and is an environmentally benign route to the synthesis of 1,4-dihydropyridines.
- Datta, Bandita,Pasha, M. Afzal
-
experimental part
p. 1180 - 1184
(2012/06/04)
-
- Silica Sulfuric Acid: An Efficient Heterogeneous Catalyst for the One-Pot Synthesis of 1,4-Dihydropyridines under Mild and Solvent-Free Conditions
-
A series of 1,4-dihydropyridines have been prepared by a one-pot condensation of aldehydes, ethyl acetoacetate, and ammonium acetate in the presence of a heterogeneous catalyst silica sulfuric acid at room temperature under solvent-free condition. This new protocol has the advantage of short reaction time and excellent yields, and is an environmentally benign route to the synthesis of 1,4-dihydropyridines.
- Datta, Bandita,Pasha, M. Afzal
-
p. 1180 - 1184
(2016/04/10)
-
- One-pot synthesis of hantzsch dihydropyridine catalyzed by ionic liquid (BmimOAc) and the oxidative aromatization of dihydropyridine using FeCl 3·6H2O
-
A series of 1,4-dihydropyridines were synthesized in one pot synthesis with the yield of 80-93 % using ionic liquid [bmim]OAc as catalyst and DMF as solvent. The ionic liquid could be repeatedly utilized 5 times with no decrease of the yield. The aromatization of these dihydropyridines (4a, 4b, 4d, 4f, 4h and 4i) were executed by the action of iron chloride and the post-processing was simplified using ethanol instead of water in dissolving dihydropyridines.
- Liu, Ruidong,Zhang, Jian
-
experimental part
p. 1743 - 1746
(2011/12/22)
-
- Synthesis of 1,4-dihydropyridines using Ce(SO4)2-SiO2 as catalyst under solvent-free conditions
-
A facile and efficient one-pot synthesis of 1,4-dihydropyridines from aldehyde, 1,3-dicarbonyl compounds and ammonium acetate in the presence of Ce(SO4)2-SiO2 at 80 °C under solvent-free conditions is described. Compared with the classical Hantzsch reaction, this novel method consistently has the advantages of excellent yields and short reaction time.
- Pei, Wen,Wang, Qin,Li, Xiaonian,Sun, Li
-
experimental part
p. 483 - 486
(2010/10/02)
-
- Synthesis of 3,4-dihydropyrimidin-2(1H)-ones and 1,4-dihydropyridines using ammonium carbonate in water
-
Various known and new 3,4-dihydropyrimidin-2(1H)-ones and 1,4-dihydropyridines are prepared efficiently via Biginelli and Hantzsch reactions using ammonium carbonate in water. Competition between Biginelli and Hantzsch reactions is observed with pyridine carbaldehydes. Using this methodology, Hantzsch esters are synthesized in higher yields and purities than with other procedures without the use of a catalyst or an organic solvent.
- Tamaddon, Fatemeh,Razmi, Zahra,Jafari, Abbas Ali
-
experimental part
p. 1187 - 1189
(2010/04/23)
-
- Sulfonic acid-functionalized silica: A remarkably efficient heterogeneous reusable catalyst for the one-pot synthesis of 1, 4-dihydropyridines
-
An efficient one-pot method for the synthesis of 1, 4-dihydropyridines from β-dicarbonyl compounds, aldehyde, and ammonium acetate is reported using sulfonic acid-functionalized silica at 90 ° C under solvent-free conditions with good to excellent yields. The catalyst is easily prepared, stable (up to 300 ° C), reusable, and efficiently used under reaction conditions. tuebitak.
- Mohammadi, Behzad,Hosseini Jamkarani, Sayyed Mohammad,Kamali, Taghi A.,Nasrollahzadeh, Mahmoud,Mohajeri, Ali
-
experimental part
p. 613 - 619
(2010/11/05)
-
- CeCl3·7H2O-Catalyzed One-Pot Synthesis of Hantzsch 1,4-Dihydropyridines at Room Temperature
-
An efficient synthesis of a series of 1,4-dihydropyridines was accomplished at room temperature by the reaction of aldehydes with ammonium acetate and ethyl acetoacetate catalyzed by CeCl3·7H2O.
- Sabitha, Gowravaram,Arundhathi,Sudhakar,Sastry,Yadav
-
experimental part
p. 2843 - 2851
(2009/12/03)
-
- Assessment and use of two silicon carbide multi-well plates for library synthesis and proteolytic digests using microwave heating
-
The use of two silicon carbide plates is reported for the preparation of three libraries of organic molecules using microwave heating. In addition, a preliminary study has been carried out, showing that one of the plates can also be used in a proteomics setting. Both the 24-position and 48-position plates heated evenly when irradiated with microwave energy. The 48-position plate was used to prepare a library of N-aryl functionalized β-amino esters via an aza-Michael reaction between anilines and Michael acceptors. The 24-position plate was used to prepare a library of biaryls via a Suzuki coupling methodology and a library of 1,4-dihydropyridines via a Hantzsch synthesis. The 48-position plate was also used to perform the proteolytic digestion of insulin chain B by trypsin. The Royal Society of Chemistry 2009.
- Stencel, Lauren M.,Kormos, Chad M.,Avery, Keri B.,Leadbeater, Nicholas E.
-
experimental part
p. 2452 - 2457
(2009/09/26)
-
- Efficient synthesis of Hantzsch esters and polyhydroquinoline derivatives in aqueous micelles
-
Hantzsch 1,4-dihydropyridine and polyhydroquinoline derivatives were synthesized in excellent yields in aqueous micelles. The reaction is catalyzed by PTSA and strongly accelerated by ultrasonic irradiation. Georg Thieme Verlag Stuttgart.
- Kumar, Atul,Maurya, Ram Awatar
-
p. 883 - 885
(2008/12/22)
-
- Barium nitrate catalyzed one pot synthesis of 1,4-dihydropyridines under solvent free conditions at room temperature
-
(Chemical Equation Presented) Barium nitrate acts as an efficient catalyst for the three-component one pot synthesis of 1,4-dihydropyridines. Barium nitrate is a safe chemical, and reaction without the use of organic solvents makes the process eco-friendly.
- Sharma, Mukul,Agarwal, Nisha,Rawat, Diwan S.
-
p. 737 - 739
(2008/09/21)
-
- Magnesium nitride as a convenient source of ammonia: preparation of dihydropyridines
-
(Chemical Equation Presented) Magnesium nitride (Mg3N 2) has been investigated for the preparation of dihydropyridines. This is a commercially available, bench-stable solid that generates ammonia upon treatment with protic solvents. The main features of the process are the facile reaction setup and good yields obtained in the majority of cases.
- Bridgwood, Katy L.,Veitch, Gemma E.,Ley, Steven V.
-
supporting information; experimental part
p. 3627 - 3629
(2009/05/07)
-
- COMPOUNDS AND COMBINATIONS THEREOF FOR INHIBITING BETA-AMYLOID PRODUCTION AND METHODS OF USE THEREOF
-
Provided are compounds which can be used in combination for treating diseases associated with a condition associated with cerebral accumulation of Alzheimer’s amyloid, such as Alzheimer’s disease. Also provided are methods of treating or reducing the risk of developing β-amyloid production, β-amyloid deposition, β-amyloid neurotoxicity (including abnormal hyperphosphorylation of tau) and microgliosis associated with cerebral accumulation of Alzheimer’s amyloid by administering therapeutically effective amounts of compounds which in combination can decrease β-amyloid production and capacitative calcium entry in cells. Further provided are methods for diagnosing diseases associated with cerebral accumulation of Alzheimer’s amyloid in animals or humans by administering diagnostically effective amounts of the compounds.
- -
-
Page/Page column 123
(2010/11/29)
-
- Aromatization of 1,4-dihydropyridines using tetraethylammonium bromate as an oxidizing agent
-
Quaternary ammonium bromate have been prepared from the corresponding bromide and used as a mild and efficient oxidizing agent for the aromatization of Hantzsch esters and related compounds to pyridine derivatives.
- Das, Pranab J.,Baruah, Akashi
-
experimental part
p. 1568 - 1571
(2009/04/07)
-
- Covalently anchored sulfonic acid on silica gel as an efficient and reusable heterogeneous catalyst for the one-pot synthesis of Hantzsch 1,4-dihydropyridines under solvent-free conditions
-
A highly efficient one-pot synthesis of Hantzsch 1,4-dihydropyridines under solvent-free conditions catalyzed by sulfonic acid covalently anchored onto the surface of silica gel is reported here. All types of aldehydes, including aromatic, unsaturated, and heterocyclic aldehydes, gave excellent yields. The silica gel/sulfonic acid catalyst (SiO2-SO3H) is completely heterogeneous and can be recycled for eight consecutive runs without significant loss of activity. Georg Thieme Verlag Stuttgart.
- Gupta, Raman,Gupta, Rajive,Paul, Satya,Loupy, Andre
-
p. 2835 - 2838
(2008/03/13)
-
- Synthesis of Hantzsch 1,4-dihydropyridines under solvent-free condition using Zn[(L)proline]2 as Lewis acid catalyst
-
The present short communication describes a Lewis acid (Zn[(L)proline] 2) catalysed one pot synthesis of Hantzsch 1,4-dihydropyridine (DHP) derivatives under solvent-free condition by conventional heating and microwave irradiation. The Lewis acid catalyst Zn[(L)proline]2 used in this reaction afford moderate to good yield. The catalyst is reusable upto five cycles without appreciable loss of its catalytic activity.
- Sivamurugan,Kumar, R. Suresh,Palanichamy,Murugesan
-
p. 969 - 974
(2007/10/03)
-
- PROCESS FOR THE PREPARATION OF 1,4-DIHYDROPYRIDINES AND NOVEL 1,4-DIHYDROPYRIDINES USEFUL AS THERAPEUTIC AGENTS
-
The present invention provides a process for the preparation of 1,4-dihydropyridines of the formula (1), wherein R1 is H, NO2, Cl, OAc, OH, R2 is H, NO2, Cl, -O-CH2-O-, OMe, OAc, OEt, OH, R3 is H, NO2, Cl, N(Me)2, -O- CH2 -O-, OMe, OAc, OH, R4 is H, OMe, OAc, OH, R5 is H, Cl, I, and R6 and R7 are either methyl, ethyl or both by preparing a mixture of an aromatic aldehyde, alkyl acetoacetate and a source of ammonia, adsorbing the prepared mixture and adsorbent till adsorbent becomes free flowing, heating the material so obtained under microwave irradiation, cooling the reaction mixture and recovering the compound of formula (1). The present invention also relates to novel 1,4-dihydropyridines with cardiovascular activity.
- -
-
-
- A convenient hantzsch synthesis of 1,4-dihydropyridines using tetraethyl orthosilicate
-
Hantzsch dihydropyridine synthesis using tetraethyl orthosilicate as a water scavenger is described. With this method reaction time was drastically shortened in comparison with conventional methods. Generally, the obtained yields were good or excellent. S
- Litvic, Mladen,Cepanec, Ivica,Vinkovic, Vladimir
-
p. 385 - 390
(2007/10/03)
-
- Chemical compounds having ion channel blocking activity for the treatment of immune dysfunction
-
The present invention relates to chemical compounds having inhibitory activity on an intermediate conductance Ca 2+ activated potassium channel (IK Ca), and the use of such compounds for the treatment or alleviation of diseases or conditions relating to immune dysfunction. Moreover, the invention relates to a method of screening a chemical compound for inhibitory activity on an intermediate conductance Ca 2+ activated potassium channel (IK Ca).
- -
-
-
- Rearrangement of o-nitrobenzaldehyde in the Hantzsch reaction
-
The reaction of 5-hydroxy-2-nitrobenzaldehyde with ethyl acetoacetate in ammonia gave the two expected isomeric 1,4- and 1,2-dihydropyridines resulting from the normal Hantzsch reaction. However, the combination of 2-nitrobenzaldehyde with ethyl acetoacet
- Angeles,Santillan,Menconi,Martinez,Ramirez,Velazquez,Lopez-Castanares,Martinez
-
p. 683 - 693
(2007/10/03)
-
- An efficient and fast procedure for the Hantzsch dihydropyridine synthesis under microwave conditions
-
Abstract: A single-mode microwave cavity synthesizer with temperature and pressure control was used to accelerate the Hantzsch synthesis of 4-aryl and 4-alkyl-2,6-dimethyl-1,4-dihydro-3,5-pyridinedicarboxylates. In comparison with both conventional method
- ?hberg,Westman
-
p. 1296 - 1298
(2007/10/03)
-