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Ferric hydrogensulfate catalyzed synthesis of aryl 14H-dibenzo[a,j] xanthene derivatives under thermal and solvent-free conditions
Shaterian, Hamid Reza;Ghashang, Majid;
Journal of the Brazilian Chemical Society , 2008, DOI: 10.1590/S0103-50532008000500034
Abstract: ferric hydrogensulfate as catalyst has been used for the one-pot preparation of aryl 14h-dibenzo[a,j]xanthene derivatives by cyclocondensation of β-naphthol and substituted benzaldehydes under solvent-free and thermal conditions. this method has the advantages of high yields, a cleaner reaction, simple methodology, short reaction times, easy workup and greener conditions.
One-Pot Chemoenzymatic Multicomponent Synthesis of Thiazole Derivatives  [PDF]
Hui Zheng,Yi-Jia Mei,Kui Du,Xian-Ting Cao,Peng-Fei Zhang
Molecules , 2013, DOI: 10.3390/molecules181113425
Abstract: A novel chemoenzymatic one-pot multicomponent synthesis of thiazole derivatives was developed. A series of thiazole derivatives were synthesized with high yields up to 94% under mild enzyme-catalyzed conditions. The blank and control experiments reveal that trypsin from porcine pancreas (PPT) displayed great catalytic activity to promote this reaction and showed a wide tolerance range towards different substrate amines. This trypsin-catalyzed multicomponent conversion method provides a novel strategy to synthesize thiazole derivatives and expands the application of enzymes in organic synthesis.
Ecofriendly and Facile One-Pot Multicomponent Synthesis of Thiopyrimidines under Microwave Irradiation  [PDF]
Biswa Mohan Sahoo,B. V. V. Ravi Kumar,Jnyanaranjan Panda,S. C. Dinda
Journal of Nanoparticles , 2013, DOI: 10.1155/2013/780786
Abstract: A rapid, improved, and ecofriendly synthesis of thiopyrimidines is carried out via one-pot multicomponent reaction of ethylcyanoacetate, substituted benzaldehydes, and thiourea in presence of ethanolic K2CO3 using microwave irradiation heating method. Excellent yields, shorter reaction time, and easy workup are the major advantageous features of this green protocol. So the application of multicomponent reactions involves the combination of multiple starting materials with different functional groups leading to the highly efficient and environmentally friendly construction of multifunctional drug molecules. The structures of the newly synthesized products were assigned on the basis of IR and 1HNMR spectral data. 1. Introduction One-pot multicomponent organic reactions (MCORs) have emerged as an efficient tool for benign synthesis by virtue of their convergence, productivity, facile execution, and generation of highly diverse and complex products from easily available starting materials in a single operation. MCORs are now being tuned for synthesizing various heterocyclic compounds due to their diverse biological activities [1]. The environmental acceptability of the process is improved if the multicomponent strategy is applied under microwave irradiation (MWI) technology [2]. For an organic synthesis, a major adverse effect on the environment is the consumption of energy for heating. To overcome this problem, it is highly desirable to develop suitable methods of heating that use microwave irradiation. So, the synthetic methodologies nowadays should be designed in such a way to use and generate substances that possess little or no toxicity to human health and the environment. Microwave heating provides a valuable tool to perform reactions faster with enhanced product yields with high purity by reducing unwanted formation of byproducts [3]. From an environmental and economic perspective, it is becoming obvious that the traditional methods of performing chemical synthesis are unsustainable and have to be changed. Multicomponent coupling reactions provide a solution since they are more efficient, cost effective, and less wasteful than traditional methods. The achievement of making multiple bonds in a one-pot multicomponent coupling reaction promotes a sustainable synthetic approach to develop new drug molecule in a drug discovery process. Microwave (MW) irradiation facilitates better thermal management of chemical reactions. The rapid MW heat transfer allows reactions to be carried out very much faster compared to conventional heating methods often resulting
Tris(diisopropylammonium) hydrogensulfate sulfate
Gholamhossein Sh. Mohammadnezhad,Mostafa M. Amini,Hamid Reza Khavasi,Seik Weng Ng
Acta Crystallographica Section E , 2008, DOI: 10.1107/s160053680802237x
Abstract: The cations and anions of the title salt, 3C6H16N+·HSO4 ·SO42 , are linked by N—H...O and O—H...O hydrogen bonds into a three-dimensional network. The hydrogensulfate ion, with a single S—O(H) bond of 1.563 (2) , forms a short O—H...O hydrogen bond [O...O = 2.609 (2) ] to the sulfate ion. The hydrogensulfate ion accepts two hydrogen bonds from two cations, whereas the sulfate ion, as an acceptor, binds to four cations. The sulfate ion is disordered approximately equally over two sites related by rotation around one of the O—S bonds.
An Efficient One-Pot Multicomponent Synthesis of 4-Aza-Podophyllotoxin Derivatives in Ionic Liquid  [PDF]
Hossein Naeimi,Zahra Rashid,Amir Hassan Zarnani,Ramin Ghahremanzadeh
Journal of Chemistry , 2013, DOI: 10.1155/2013/169695
Abstract: A simple, green, and efficient procedure for the synthesis of 4-aza-podophyllotoxin derivatives by using a one-pot three-component reaction of benzaldehydes, 1,3-cyclohexanediones, and anilinolactones in the presence of catalytic amount of alum in 1-butyl-3-methylimidazolium triflate as green media is described. This reaction proceeded under mild conditions with the use of an inexpensive and readily available catalyst, high to excellent yields, and simple workup procedure. 1. Introduction Multicomponent reactions (MCRs) are one-pot processes in which three or more reactants come together in a single reaction vessel to give a final product containing substantial elements of all the reactants [1–4], and in recent year much attention has been directed toward the one-pot multicomponent reactions, because of their wide range of applications in pharmaceutical chemistry for the production of structural scaffolds and combinatorial libraries for drug discovery [5–8]. The strategies of MCRs offer significant advantages over conventional linear-type syntheses because of high degree of atom economy, high selectivity, and procedural simplicity due to formation of carbon-carbon and carbon-heteroatom bonds in one-pot procedure [9–11]. MCRs, particularly those performed in green and eco-friendly media, have become increasingly useful tools for the synthesis of chemically and biologically important compounds because of their environmentally friendly atom economy and green characteristics, and the “greening” of global chemical processes has became a major issue in the chemical industry [12, 13]. Organic reactions in ionic liquid (IL) media have received the considerable attention of synthetic organic chemists in recent years; IL is an environmentally friendly solvent with unique properties such as high ionic conductivity, nonvolatility, high thermal stability, nonflammability, and miscibility with organic compounds, especially with the heterocyclic compounds [14–17]. Because of these useful properties numerous works have been published in the last decades reporting the possibility to perform several organic reactions and catalyzed processes in these green media [18–20]. 1,4-Dihydropyridine compounds are molecules based upon pyridine and this nucleus is one of the significant core structures among the most extensively natural and unnatural heterocyclic compounds, have been recognized as vital drugs for the treatment of cardiovascular diseases, and are well known as calcium channel modulators [21, 22]. 1,4-Dihydropyridine derivatives exhibit a variety of biological
Benign Methodology and Efficient Catalysis for the One-Pot Multicomponent Synthesis of Dihydropyrimidinones and Thiones: A New Key for Old Lock  [PDF]
Parvez Ali,Naziyanaz Pathan,Taibi Ben Hadda
Journal of Applied Chemistry , 2014, DOI: 10.1155/2014/835758
Abstract: In the present communication, under the influence of microwaves, cuprous chloride has been demonstrated to be safe, mild, efficient, and inexpensive catalyst for the Biginelli discovered multicomponent reaction (MCR) between aromatic aldehydes, urea/substituted urea, and ethyl acetoacetate to produce structurally diverse dihydropyrimidin-2(1H)-ones (DHPMs) and thiones in an ecofriendly solvent-free protocol. The practical and simple protocol led to excellent yields of the dihydropyrimidin-2(1H)-one derivatives under mild reaction conditions and within short span of reaction times with easy reaction workup by maintaining excellent atom economy. 1. Introduction In multicomponent reactions (MCRs), three or more reactants come together in a single reaction vessel to form new products that contain portions of all the components [1–5]. In this dynamic era of chemistry where a premium effort is put on speed, diversity, and efficiency in the drug discovery process [6], MCR strategies offer significant advantages over conventional linear-type synthesis [1–5]. One such MCR that belongs to this category is the venerable Biginelli dihydropyrimidinones synthesis. In 1893, Italian chemist Pietro Biginelli reported the acid catalyzed cyclocondensation reaction of ethyl acetoacetate (1), benzaldehyde (2), and urea (3) [7]. The reaction was carried out by heating a mixture of the three components by dissolving it in ethanol with a catalytic amount of HCl at reflux temperature. The product of this novel one-pot, three-component synthesis that precipitated on cooling of the reaction mixture was identified correctly by Biginelli as 3,4-dihydropyrimidin-2(1H)-one 4 (Scheme 1) [8, 9]. Scheme 1: Traditional Biginelli reaction. Owing to their remarkable pharmacological properties such as calcium channel blockers, antitumor, and anti-inflammatory activities, dihydropyrimidinones and their derivatives have increasingly attracted the attention of synthetic chemists [10–15]. Moreover, the dihydropyrimidine-5-carboxylate core has been found in several marine natural products which are potent HIVgp-120-CD4 inhibitors [16, 17]. However, despite the potential utility of dihydropyrimidinones as bioactive compounds, their antifungal activities are also studied [18]. Thus, due to immense pharmacological profile of this class of compounds, research interest towards this area is growing day by day. This in turn increases the attempts to develop various versatile, safe, and quick processes for their synthesis. The classical Biginelli condensation protocol suffers from the drawbacks like
O-iodoxybenzoic acid in water: optimized green alternative for multicomponent one-pot synthesis of 2-amino-3,5-dicarbonitrile-6-thiopyridines
Takale, Santosh;Patil, Jaidas;Padalkar, Vikas;Pisal, Rajaram;Chaskar, Atul;
Journal of the Brazilian Chemical Society , 2012, DOI: 10.1590/S0103-50532012000500024
Abstract: a multicomponent one-pot reaction of aromatic aldehyde, malononitrile and thiophenol in the presence of iodoxybenzoic acid (ibx) in aqueous media furnished 2-amino-3,5-dicarbonitrile-6-thiopyridine in good to excellent yield. eventually, a catalyst could be easily recovered and reused without loss of its catalytic property.
L-proline catalyzed an efficient multicomponent one-pot synthesis of poly substituted pyridines  [PDF]
B. Janardhan,V. Ravibabu,Peter. A. Crooks,B. Rajitha
Organic Communications , 2012,
Abstract: A series of poly substituted pyridines (3,11-disubstituted-7-aryl-5,6,8,9-tetrahydro-dibenzo[c,h]acridines) were synthesized by the multicomponent condensation of 6-substituted-1-tetralone, aromatic aldehydes and ammonium acetate in ethanol using L-proline as an efficient organocatalyst. This methodology is mild, efficient, high yielding and the catalyst is inexpensive, easily recovered from the reaction mixture and reused for five times without losing its activity.
One-Pot Tandem Synthesis of 2-Arylquinazolines by a Multicomponent Cyclization Reaction  [PDF]
Leping Ye,Lin Yu,Lijun Zhu,Xiaodong Xia
Molecules , 2013, DOI: 10.3390/molecules181113860
Abstract: A series of 2-arylquinazolines have been synthesized in moderate to excellent yields by one-pot tandem reaction of (2-aminophenyl)methanols, aldehydes and ceric ammonium nitrate (CAN). The utility of this transformation was demonstrated by its compatibility with a wide range of functional groups. Thus, the method represents a simple and practical procedure to access 2-arylquinazolines.
Nano aluminium nitride as a solid source of ammonia for the preparation of hantzsch 1,4-dihydropyridines and bis-(1,4-dihydropyridines) in water via one pot multicomponent reaction
Ghorbani-Choghamarani, Arash;Zolfigol, Mohammad Ali;Hajjami, Maryam;Goudarziafshar, Hamid;Nikoorazm, Mohsen;Yousefi, Somaieh;Tahmasbi, Bahman;
Journal of the Brazilian Chemical Society , 2011, DOI: 10.1590/S0103-50532011000300016
Abstract: nano aluminium nitride in the presence of water acts as solid source of ammonia, which is used for the preparation of 1,4-dihydropyridines and bis-(1,4-dihydropyridines). an efficient and simple procedure for the one-pot synthesis of 1,4-dihydropyridine and bis-(1,4-dihydropyridine) derivatives was achieved by combination of methyl acetoacetate or ethyl acetoacetate with aldehydes or dialdehydes and aluminium nitride at 80 oc in water in high purity and good yields
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