scholarly journals Microwave-assisted synthesis followed by a reduction step: making persistent phosphors with a large storage capacity

2020 ◽  
Vol 49 (14) ◽  
pp. 4518-4527 ◽  
Author(s):  
José Miranda de Carvalho ◽  
David Van der Heggen ◽  
Lisa I. D. J. Martin ◽  
Philippe F. Smet
Keyword(s):  
Microwave Irradiation ◽  
Storage Capacity ◽  
Microwave Assisted Synthesis ◽  
Persistent Luminescence ◽  
Reduction Step ◽  
Microwave Assisted

Microwave irradiation leads to highly homogeneous emitting sites, and large storage capacity in persistent luminescence materials after the reducing step.

Microwave-assisted Synthesis of Benzoxazoles Derivatives

2020 ◽  
Vol 7 (3) ◽  
pp. 183-195
Author(s):  
Musa Özil ◽  
Emre Menteşe
Keyword(s):  
Microwave Irradiation ◽  
Reaction Medium ◽  
Pharmaceutical Chemistry ◽  
Conventional Heating ◽  
High Yield ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Optical Brighteners ◽  
Chemistry Research ◽  
Extensive Class

Background: Benzoxazole, containing a 1,3-oxazole system fused with a benzene ring, has a profound effect on medicinal chemistry research owing to its important pharmacological activities. On the other hand, the benzoxazole derivative has exhibited important properties in material science. Especially in recent years, microwave-assisted synthesis is a technique that can be used to increase diversity and quick research in modern chemistry. The utilization of microwave irradiation is beneficial for the synthesis of benzoxazole in recent years. In this focused review, we provide a metaanalysis of studies on benzoxazole in different reaction conditions, catalysts, and starting materials by microwave technique so far, which is different from conventional heating. Methods: Synthesis of different kind of benzoxazole derivatives have been carried out by microwave irradiation. The most used method to obtain benzoxazoles is the condensation of 2-aminophenol or its derivatives with aldehydes, carboxylic acids, nitriles, isocyanates, and aliphatic amines. Results: Benzoxazole system and its derivatives have exhibited a broad range of pharmacological properties. Thus, many scientists have remarked on the importance of the synthesis of different benzoxazole derivatives. Conventional heating is a relatively inefficient and slow method to convey energy in orientation to the reaction medium. However, the microwave-assisted heating technique is a more effective interior heating by straight coupling of microwave energy with the molecules. Conclusion: In this review, different studies were presented on the recent details accessible in the microwave- assisted techniques on the synthesis of the benzoxazole ring. It presents all examples of such compounds that have been reported from 1996 to the present. Benzoxazoles showed an extensive class of chemical substances not only in pharmaceutical chemistry but also in dyestuff, polymer industries, agrochemical, and optical brighteners. Thus the development of fast and efficient achievement of benzoxazoles with a diversity of substituents in high yield is getting more noteworthy. As shown in this review, microwave-assisted synthesis of benzoxazoles is a very effective and useful technique.

Microwave-assisted synthesis of quinolones and 4H-1,4-benzo thiazine 1,1-dioxides

2005 ◽  
Vol 2005 (1) ◽  
pp. 27-28 ◽  
Author(s):  
Jaime Charris ◽  
Arthur Barazarte ◽  
José Domínguez ◽  
Neira Gamboa
Keyword(s):  
Microwave Irradiation ◽  
Rapid Method ◽  
Solvent Free ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Solvent Free Conditions

A rapid method for the preparation of N-aryl-2-methylthio-4-oxo-1,4-dihydro quinoline-3-carbonitriles (2a–e) and N-aryl-3-methylthio-4H-1,4-benzothiazine-2-carbonitrile 1,1-dioxides (2f–o) is reported. The cyclization is accelerated by microwave irradiation under solvent free conditions in the presence of K2CO3.

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.

scholarly journals Microwave Assisted Synthesis of 4-Phenylquinazolin-2(1H)-one Derivatives that Inhibit Vasopressor Tonus in Rat Thoracic Aorta

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1467
Author(s):  
Rafaela Teixeira ◽  
Talita Menengat ◽  
Gabriel Andrade ◽  
Bruno Cotrim ◽  
Cristiano Ponte ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Thoracic Aorta ◽  
Mtt Assay ◽  
Maximum Concentration ◽  
Vascular Reactivity ◽  
Microwave Assisted Synthesis ◽  
Pharmacological Effects ◽  
Microwave Assisted ◽  
Ic50 Values ◽  
Rat Thoracic Aorta

Quinazolinones have pharmacological effects on vascular reactivity through different mechanisms. We synthesized 4-phenylquinazolin-2(1H)-one derivatives under microwave irradiation and tested them on the rat thoracic aorta. The prepared compounds 2a–2f were obtained in about 1 h with suitable yields (31–92%). All derivatives produced vasorelaxant effects with IC50 values ranging from 3.41 ± 0.65 µM to 39.72 ± 6.77 µM. Compounds 2c, 2e and 2f demonstrated the highest potency in endothelium-intact aorta rings (IC50 4.31 ± 0.90 µM, 4.94 ± 1.21 µM and 3.41 ± 0.65 µM respectively), and they achieved around 90% relaxation (30 μM). In aorta rings without an endothelium, the effect of compound 2f was abolished. Using the MTT assay to test for cell viability, only compound 2b induced cytotoxicity at the maximum concentration employed (30 µM). The results show that vasorelaxation by 4-phenylquinazolin-2(1H)-one derivatives might depend on the activation of a signalling pathway triggered by endothelium-derived factors.

scholarly journals Microwave Assisted Synthesis of 1,5-Benzothiazepines Using Greener Reaction Medium

2019 ◽  
Vol 31 (5) ◽  
pp. 993-996 ◽  
Author(s):  
Sanjay S. Kotalwar ◽  
Amol D. Kale ◽  
Ram B. Kohire ◽  
Vasant B. Jagrut
Keyword(s):  
Reaction Time ◽  
Microwave Irradiation ◽  
Reaction Medium ◽  
Microwave Assisted Synthesis ◽  
Reaction Conditions ◽  
Renewable Sources ◽  
Microwave Assisted ◽  
High Yields

An efficient and eco-friendly synthesis of 1,5-benzothiazepines has been developed by the reaction of various 2-propen-1-ones with 2-aminothiophenol using microwave irradiation in greener reaction medium, glycerol. The clean reaction conditions, shorter reaction time, high yields and non-toxic, biodegradable reaction medium manufactured from renewable sources are unique features of this method.

scholarly journals Microwave-assisted synthesis of γ-thiolactams from ethyl isocyanoacetate

2018 ◽  
Vol 24 (3) ◽  
pp. 125-128 ◽  
Author(s):  
Massimiliano Lamberto
Keyword(s):  
Microwave Irradiation ◽  
Radical Cyclization ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted

Abstractγ-Thiolactams were synthesized in good yields from ethyl isocyanoacetate through a sequential alkylation/isothiocyanation/radical cyclization under microwave irradiation.

scholarly journals Design and Microwave Assisted Synthesis of Coumarin Derivatives as PDE Inhibitors

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Mahadev N. Kumbar ◽  
Ravindra R. Kamble ◽  
Atulkumar A. Kamble ◽  
Sujith Raj Salian ◽  
Sandhya Kumari ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Inhibitory Activity ◽  
Human Spermatozoa ◽  
Microwave Assisted Synthesis ◽  
Coumarin Derivatives ◽  
Motility Pattern ◽  
Microwave Assisted ◽  
Pde Inhibitors ◽  
Pde Inhibition ◽  
Potent Inhibitory Activity

Coumarins appended to benzimidazole through pyrazole are designed and synthesized using microwave irradiation. These compounds were analyzed for phosphodiesterase (PDE) inhibition indirectly by motility pattern in human spermatozoa. Some of the synthesized compounds, namely, 5d, 5e, 5f, 5g, 5h, and 5k, have exhibited potent inhibitory activity on PDE.

Microwave-assisted synthesis of 1,4-disubstituted thiosemicarbazides and semicarbazides under solvent-free conditions in the absence of catalyst

2005 ◽  
Vol 2005 (1) ◽  
pp. 71-72 ◽  
Author(s):  
Xi-Cun Wang ◽  
Zheng-Jun Quan ◽  
Zheng Li
Keyword(s):  
Microwave Irradiation ◽  
Solvent Free ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Solvent Free Conditions

Thirty-two 1-aroyl/aryloxyacetyl-4-(2-furoyl)thiosemicarbazides and corresponding semicarbazides were synthesised in excellent yields under microwave irradiation and solvent-free conditions without using any catalyst.

Air-exposing microwave-assisted synthesis of CuInS2/ZnS quantum dots for silicon solar cells with enhanced photovoltaic performance

RSC Advances ◽  
2015 ◽  
Vol 5 (124) ◽  
pp. 102682-102688 ◽  
Author(s):  
Ming Hong ◽  
Tongtong Xuan ◽  
Jiaqing Liu ◽  
Ziyao Jiang ◽  
Yiwei Chen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Microwave Irradiation ◽  
Conversion Efficiency ◽  
Photovoltaic Performance ◽  
Composite Films ◽  
Silicon Solar Cells ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Si Solar Cells

CIS/ZnS QDs were synthesized by microwave irradiation in air. The fabricated QDs/PMMA composite films were first applied to Si solar cells to improve the conversion efficiency by 3.8%.

Microwave Assisted Synthesis of N-(ethoxycarbonylmethyl)-nucleobases: Building Blocks for PNAs

2005 ◽  
Vol 2005 (3) ◽  
pp. 167-168 ◽  
Author(s):  
Gui-Rong Qu ◽  
Yong Li ◽  
Su-Hui Han
Keyword(s):  
Microwave Irradiation ◽  
Nucleic Acids ◽  
Peptide Nucleic Acids ◽  
Building Blocks ◽  
Microwave Assisted Synthesis ◽  
Ethyl Bromoacetate ◽  
Microwave Assisted

The synthesis of N1/N9- (Ethoxycarbonylmethyl)pyrimidine/purine using as synthons for peptide nucleic acids has been described. Microwave irradiation provided the desired products by alkylation of the appropriately protected natural and substituted nucleobases with ethyl bromoacetate within 4–7 min in 48–85% yields.

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