scholarly journals Synthesis of 3,4-Dihydropyrimidin-2(1H)-one-phosphonates by the Microwave-Assisted Biginelli Reaction

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 45
Author(s):  
Nóra Popovics-Tóth ◽  
Ádám Tajti ◽  
Evelyn Hümpfner ◽  
Erika Bálint
Keyword(s):  
Biginelli Reaction ◽  
Aromatic Aldehydes ◽  
Model Reaction ◽  
Molar Ratio ◽  
Type Synthesis ◽  
Reaction Parameters ◽  
Urea Derivatives ◽  
Aliphatic Aldehydes ◽  
Heating Method ◽  
Microwave Assisted

The synthesis of novel 3,4-dihydropyrimidin-2(1H)-one-phosphonates was elaborated by the microwave (MW)-assisted three-component Biginelli reaction of β-ketophosphonates, aromatic or aliphatic aldehydes and urea derivatives. The condensation was optimized on a selected model reaction in respect of the reaction parameters, such as the heating method, the type of the catalyst and solvent, the temperature, the reaction time and the molar ratio of the starting materials. The fast and solvent-free MW-assisted procedure was then extended for the preparation of further new 3,4-dihydropyrimidin-2(1H)-one-phosphonate derivatives starting from different aromatic aldehydes, β-ketophosphonates and urea derivatives to prove the wide scope of the process. As a novel by-product of the Biginelli-type synthesis of 3,4-dihydropyrimidin-2(1H)-one-phosphonates, the 5-diethoxyphosphoryl-4-phenyl-6-styryl-3,4-dihydropyrimidin-2(1H)-one was also isolated and characterized. Our MW-assisted method made also possible the condensation of aliphatic aldehydes, diethyl (2-oxopropyl)phosphonate and urea, which reaction was previously reported to be impossible in the literature.

scholarly journals Microwave Assisted Solvent-Free Synthesis of Some Imine Derivatives

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Yunus Bekdemir ◽  
Kürşat Efil
Keyword(s):  
Microwave Heating ◽  
Aromatic Amines ◽  
Environmentally Friendly ◽  
Aromatic Aldehydes ◽  
Solvent Free ◽  
Molar Ratio ◽  
Microwave Assisted ◽  
Solvent Free Conditions ◽  
Solvent Free Synthesis ◽  
Environmentally Friendly Method

Some imine derivatives (1a–7d) were synthesized using a rapid and an environmentally friendly method with reaction of aromatic aldehydes (a–d) and aromatic amines (1–7) (in 1 : 1 molar ratio) in the presence of β-ethoxyethanol as a wetting reagent (2 drops) under solvent-free conditions using microwave heating.

scholarly journals Investigation of methanol electro-oxidation on graphene supported platinum–tungsten catalyst

Chemija ◽  
2019 ◽  
Vol 30 (3) ◽  
Author(s):  
Teofilius Kilmonis ◽  
Antanas Nacys ◽  
Dijana Šimkūnaitė ◽  
Loreta Tamašauskaitė-Tamašiūnaitė ◽  
Aldona Balčiūnaitė ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Molar Ratio ◽  
Heating Method ◽  
Molar Ratios ◽  
Microwave Assisted ◽  
Oxidation Of Methanol ◽  
Supported Platinum ◽  
Density Values ◽  
Electro Oxidation ◽  
Cv Measurements

The graphene (GR) supported platinum–tungsten (PtW) catalysts with Pt:W molar ratios, equal to 1.6:1, 2.3:1 and 7.1:1, were prepared by a rapid microwave-assisted heating method. The activity of the catalysts was investigated for the electro-oxidation of methanol in an alkaline medium by means of cyclic voltammetry (CV) and chronoamperometry (CA). It has been determined that the rate of methanol oxidation depends on the Pt:W molar ratio in the PtW/GR catalysts. From the CV measurements it follows that the highest current density values, specific and mass activities are obtained for the PtW/GR catalyst with the Pt:W molar ratio equal to 1.6:1. Similarly, the chronoamperometry measurements point to the best performance of the PtW/GR catalyst with the same Pt:W molar ratio. Moreover, in all cases the synthesized PtW/GR catalysts, regardless of different Pt:W molar ratio, show an enhanced electrocatalytic activity towards the direct electro-oxidation of methanol when compared with that for the bare Pt/GR and W/GR catalysts.

Microwave assisted synthesis of novel Pyrazole derivatives and their biological evaluation as anti-bacterial agents

2020 ◽  
Vol 23 ◽  
Author(s):  
Hadis Khodadad ◽  
Farhad Hatamjafari ◽  
Khalil Pourshamsian ◽  
Babak Sadeghi
Keyword(s):  
Antibacterial Activity ◽  
Aromatic Aldehydes ◽  
Catalytic Amount ◽  
Antibacterial Activities ◽  
Structural Features ◽  
Biological Evaluation ◽  
Aureus Strain ◽  
Microwave Assisted Synthesis ◽  
Pyrazole Derivatives ◽  
Microwave Assisted

Aim and Objective: Microwave-assisted condensation of acetophenone 1 and aromatic aldehydes 2 gave chalcone analogs 3, which were cyclized to pyrazole derivatives 6a-f via the reaction with hydrazine hydrate and oxalic acid in the presence of the catalytic amount of acetic acid in ethanol. Materials and Methods: The structural features of the synthesized compounds were characterized by melting point, FT-IR, 1H, 13C NMR and elemental analysis. Results: The antibacterial activities of the synthesized pyrazoles was evaluated against three gram-positive bacteria such as Enterococcus durans, Staphylococcus aureus, Bacillus subtilis and two gram-negative bacteria such as Escherichia coli and Salmonella typhimurium. Conclusion: All the synthesized pyrazoles showed relatively high antibacterial activity against S. aureus strain and none of them demonstrated antibacterial activity against E. coli.

1, 1’-Sulfinyldiethylammonium Bis (Hydrogen Sulfate) as a Recyclable Dicationic Ionic Liquid Catalyst for the Efficient Solvent-free Synthesis of 3, 4-Dihydropyrimidin-2(1H)-ones via Biginelli Reaction

2020 ◽  
Vol 23 (2) ◽  
pp. 157-167
Author(s):  
Zainab Ehsani-Nasab ◽  
Ali Ezabadi
Keyword(s):  
Ionic Liquid ◽  
Biginelli Reaction ◽  
Aromatic Aldehydes ◽  
Solvent Free ◽  
Hydrogen Sulfate ◽  
One Pot ◽  
Acidic Ionic Liquid ◽  
Brønsted Acidic Ionic Liquid ◽  
Solvent Free Conditions ◽  
Dicationic Ionic Liquid

Objective: A facile and efficient method for synthesis of 3, 4-dihydropyrimidin-2(1H)-ones via Biginelli reaction catalyzed by a novel dicationic Brönsted acidic ionic liquid, [(EtNH2)2SO][HSO4]2, has been successfully developed. Material and Method:: 3, 4-Dihydropyrimidin-2(1H)-ones were synthesized through one-pot condensation of aromatic aldehydes, ethyl acetoacetate, and urea under solvent-free conditions using [(EtNH2)2SO][HSO4]2 as a novel catalyst. The progress of the reaction was monitored by thin-layer chromatography (ethyl acetate / n-hexane = 1 / 5). The products have been characterized by IR, 1H NMR, 13C NMR, and also by their melting points. Results: In this research, a library of dihydropyrimidinone derivatives was synthesized via Biginelli reaction under solvent-free conditions at 120oC using [(EtNH2)2SO][HSO4]2 as a catalyst. Various aromatic aldehydes, as well as heteroaromatic aldehydes, were employed, affording good to high yields of the corresponding products and illustrating the substrate generality of the present method. In addition, the prepared dicationic Brönsted acidic ionic liquid can be easily recovered and reused. Conclusion: 1, 1’-Sulfinyldiethylammonium bis (hydrogen sulfate), as a novel dicationic ionic liquid, can act as a highly efficient catalyst for the synthesis of 3, 4-dihydropyrimidin-2(1H)-ones under solvent-free conditions.

Microwave Assisted Synthesis of Schiff Bases: A Green Approach

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Mousumi Chakraborty ◽  
Sanjay Baweja ◽  
Sunita Bhagat ◽  
TejpalSingh Chundawat
Keyword(s):  
Microwave Irradiation ◽  
Microwave Power ◽  
Mass Spectra ◽  
Molar Ratio ◽  
Microwave Assisted Synthesis ◽  
Schiff’S Bases ◽  
Microwave Assisted ◽  
Green Approach ◽  
Schiff's Bases ◽  
Effects Of Temperature

Abstract In the present study Schiff’s bases are synthesized by the conventional as well as by microwave irradiation. Excellent yield within short reaction time is obtained using microwave irradiation along with other advantages like mild reaction condition, non-hazardous and safer environmental conditions. The effects of temperature, reactant molar ratio, and microwave power variation on yield are observed. Mathematical model has been developed using matlab software to obtain the yield as a function of microwave power. Kinetic study of the reaction has also been attempted. Schiff’s bases structures are confirmed by IR, 1HNMR, Mass Spectra and elemental analysis.

Green Synthesis and Biological Study of Pyrimidone derivatives employing Cetyltrimethyl ammonium bromide under solvent free condition

2021 ◽  
Vol 25 (11) ◽  
pp. 38-40
Author(s):  
S.R. Jagtap ◽  
R.P. Yadav ◽  
B.B. Bahule ◽  
D.J. Chaudhari
Keyword(s):  
Condensation Reaction ◽  
Biginelli Reaction ◽  
Aromatic Aldehydes ◽  
Solvent Free ◽  
Environmentally Benign ◽  
Biological Study ◽  
Ammonium Bromide ◽  
Solvent Free Condition ◽  
Cetyltrimethyl Ammonium ◽  
Anti Fungal

In this study, we are reporting a solvent free Biginelli reaction using aromatic aldehydes, ethyl acetoacetate and urea in presence of cetyl tri-methyl ammonium bromide as a catalyst. The reaction is green and environmentally benign. The yield of three component condensation reaction is excellent. The products were screened for anti-bacterial and anti-fungal activity. The method is simple and convenient. The catalyst is novel and easily available, non-expensive and nontoxic.

scholarly journals A practical way to synthesize chiral fluoro-containing polyhydro-2H-chromenes from monoterpenoids

2016 ◽  
Vol 12 ◽  
pp. 648-653 ◽  
Author(s):  
Oksana S Mikhalchenko ◽  
Dina V Korchagina ◽  
Konstantin P Volcho ◽  
Nariman F Salakhutdinov
Keyword(s):  
Aromatic Aldehydes ◽  
Single Step ◽  
Preparative Synthesis ◽  
Aliphatic Aldehydes ◽  
First Time

Conditions enabling the single-step preparative synthesis of chiral 4-fluoropolyhydro-2H-chromenes in good yields through a reaction between monoterpenoid alcohols with para-menthane skeleton and aldehydes were developed for the first time. The BF3·Et2O/H2O system is used both as a catalyst and as a fluorine source. The reaction can involve aliphatic aldehydes as well as aromatic aldehydes containing various acceptor and donor substituents. 4-Hydroxyhexahydro-2H-chromenes were demonstrated to be capable of converting to 4-fluorohexahydro-2H-chromenes under the developed conditions, the reaction occurs with inversion of configuration.

scholarly journals Synthesis of new Cα-tetrasubstituted α-amino acids

2009 ◽  
Vol 5 ◽  
Author(s):  
Andreas A Grauer ◽  
Burkhard König
Keyword(s):  
Amino Acids ◽  
Secondary Structure ◽  
Aromatic Aldehydes ◽  
Building Blocks ◽  
Reaction Conditions ◽  
Peptide Backbone ◽  
Aliphatic Aldehydes ◽  
New Class ◽  
Cyclic Amino Acids

Cα-Tetrasubstituted α-amino acids are important building blocks for the synthesis of peptidemimetics with stabilized secondary structure, because of their ability to rigidify the peptide backbone. Recently our group reported a new class of cyclic Cα-tetrasubstituted tetrahydrofuran α-amino acids prepared from methionine and aromatic aldehydes. We now report the extension of this methodology to aliphatic aldehydes. Although such aldehydes are prone to give aldol products under the reaction conditions used, we were able to obtain the target cyclic amino acids in low to moderate yields and in some cases with good diastereoselectivity.

Heterogeneous Microwave Irradiation Biodiesel Processing of Jatropha Oil

2014 ◽  
Vol 554 ◽  
pp. 500-504 ◽  
Author(s):  
Farid Nasir Ani ◽  
Ahmed Bakheit Elhameed
Keyword(s):  
Reaction Time ◽  
Methyl Ester ◽  
Microwave Irradiation ◽  
Calcium Oxide ◽  
Production Cost ◽  
Catalyst Concentration ◽  
Molar Ratio ◽  
Biodiesel Fuel ◽  
Jatropha Oil ◽  
Reaction Parameters

This paper investigated the three critical reaction parameters including catalyst concentration, microwave exit power and reaction time for the transesterification process of jatropha curcas oil using microwave irradiation. The work is an attempt to reduce the production cost of biodiesel. Similar quantities of methanol to oil molar ratio 6:1 and calcium oxide as a heterogeneous catalyst were used. The results showed that the best yield percentage 96% was obtained using 300W microwave exit power, 8 %wt CaO and 7 min. The methyl ester FAME obtained was within the standard of biodiesel fuel.

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