scholarly journals Microwave assisted synthesis of five membered nitrogen heterocycles

RSC Advances ◽  
2020 ◽  
Vol 10 (59) ◽  
pp. 36031-36041
Author(s):  
Gopinadh Meera ◽  
K. R. Rohit ◽  
Salim Saranya ◽  
Gopinathan Anilkumar
Keyword(s):  
Reaction Time ◽  
Nitrogen Heterocycles ◽  
Product Formation ◽  
Microwave Assisted Synthesis ◽  
Short Reaction Time ◽  
Microwave Assisted ◽  
High Yields

Microwave assisted synthesis of N-heterocycles with short reaction time, high yields and high product purities along with a decrease in the rate of by-product formation.

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.

Nucleophilic Acylation with Aromatic Aldehydes to 2 Bromoacetonitrile: An Umpolung Strategy for the Synthesis of Active Methylene Compounds

2020 ◽  
Vol 17 (7) ◽  
pp. 518-524
Author(s):  
Shailesh Singh ◽  
Jyoti Tiwari ◽  
Deepali Jaiswal ◽  
Amit Kumar Sharma ◽  
Jaya Singh ◽  
...  
Keyword(s):  
Reaction Time ◽  
Ambient Temperature ◽  
Aromatic Aldehydes ◽  
Product Formation ◽  
One Pot ◽  
Short Reaction Time ◽  
Salient Features ◽  
High Yields ◽  
Operational Simplicity ◽  
Nucleophilic Acylation

Background: A novel one-pot N-heterocyclic carbene (NHC)-catalysed acylation of 2- bromoacetonitrile with aromatic aldehydes is reported. The protocol involves carbonyl umpolung reactivity of aldehydes in which the carbonyl carbon attacks nucleophilically (as d1 nucleophile) on the electrophilic terminal of 2-bromoacetonitrile to afford 3-aryl-3-oxopropanenitrile. The salient features of this procedure are short reaction time, operational simplicity, ambient temperature, no by-product formation and high yields. Materials and Methods: A flame-dried round bottom flask was charged with Imidazolium salts (3a) (0.20 mmol). Aldehyde 1a (1.0 mmol), 2-bromoacetonitrile 2 (1.0 mmol), and THF / t-BuOH 5 mL; 10:1) were added at positive nitrogen pressure followed by the addition of DBU (0.15 mmol) through stirring. The resulting yellow- orange solution was stirred at room temperature for 5-6 h. After completion of the reaction (TLC monitored), the reaction mixture was concentrated under reduced pressure. The product was purified using hexane / EtOAc (10:1) as an eluent to provide analytically pure compound 4a. Physical data of representative compounds and the NMR spectroscopic data are in agreement with the literature value. Results and Discussion: The salient features of this procedure are short reaction time, operational simplicity, ambient temperature, no by-product formation and high yields. Conclusion: To sum up, we have developed a convenient, efficient and one-pot route for 3-oxo-3- phenylpropanenitrile synthesis from NHC promoted direct nucleophilic acylation of aromatic aldehydes using 2- bromoacetonitrile. This method provided a wide range of products and good yields. To best of our knowledge, this is the new report for the synthesis of 3-oxo-3-phenylpropanenitrile through NHC promoted nucleophilic acylation of aromatic aldehyde.

scholarly journals Rapid and Economic Access to Some NSAIDS-Based Bioactive Heterocycles

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
A. V. Chavan ◽  
R. R. Somani ◽  
P. P. Kalantri ◽  
D. T. Makhija
Keyword(s):  
Reaction Time ◽  
Microwave Synthesis ◽  
Microwave Energy ◽  
The Other ◽  
Microwave Assisted Synthesis ◽  
Simple Method ◽  
Short Reaction Time ◽  
Microwave Assisted ◽  
Target Molecules ◽  
Bioactive Heterocycles

The use of microwave energy for the synthesis is considered as one of the alternate strategies. The present work includes the synthesis of some newer 2,5-disubstituted-1,3,4-oxadiazole analogues using both conventional and alternate rapid methods.The conventional method involves the synthesis of the target molecules by using cyclodehydrating agent like POCl3, while the other method consists of using some catalytic reagents like PbO2. Also, the short reaction time provided by microwave synthesis makes it ideal for the reaction. Hence, this project describes an efficient and operationally simple method for the microwave-assisted synthesis of some bioactive heterocycles based on NSAIDs.

scholarly journals A Simple and Green Protocol for 2H-Indazolo[2,1-b]phthalazine-triones Using Grinding Method

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Xiao-chuan Jia ◽  
Jing Li ◽  
Yu Ding ◽  
Bin Zhang ◽  
Na Wang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Sulfonic Acid ◽  
Catalytic Amount ◽  
Solvent Free ◽  
Short Reaction Time ◽  
Green Protocol ◽  
Simple Operation ◽  
Grinding Method ◽  
Toluene Sulfonic Acid ◽  
High Yields

A robust, facile, and solvent-free route for the three-component synthesis of 2H-indazolo[2,1-b]phthalazine-triones in the presence of a catalytic amount ofp-toluene sulfonic acid utilizing grinding has been developed. Short reaction time, simple operation, and high yields are the advantages of this protocol.

Size-Controlled Microwave-Assisted Synthesis of Water-Dispersible Cd(Se,S) Quantum Dots for Potential Biological Applications

2015 ◽  
Vol 1784 ◽  
Author(s):  
E. Calderón-Ortiz ◽  
S. Bailón-Ruiz ◽  
L. Alamo-Nole ◽  
J. Rodriguez-Orengo ◽  
O. Perales-Perez
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Quantum Confinement Effect ◽  
Reactive Oxygen Species Generation ◽  
Size Control ◽  
Average Crystallite Size ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted

ABSTRACTNanomedicine is fostering significant advances in the development of platforms for early detection and treatment of diseases. Nanoparticles (NPs) like quantum dots (QDs) exhibit size-dependent optical properties for light-driven technologies, which might become important in bio-imaging, sensing and photo-dynamic therapy (PDT) applications. The present research addresses the synthesis of water-stable Cd-based QDs via a Microwave-Assisted synthesis approach using cadmium sulfate salt, and thioglycolic acid as Cd- and S-precursors, respectively. Selenide ions were available by reductive leaching of metallic Selenium in Sodium bisulfite solution. The size control and the tunability of the optical properties were achieved by a suitable control of the reaction temperature (in the 140°C- 190°C range) and reaction time (10 minutes-40 minutes). X-ray diffraction analyses suggested the development of a CdSe,S face cubic centered structure; the broadening of the diffraction peaks indicated the presence of very small nanocrystals in the samples. The average crystallite size was estimated at 5.50 nm ± 1.17nm and 3.72 nm ± 0.04 nm, for nanoparticles synthesized at 180°C after 40 minutes or 10 minutes of reaction, respectively. HRTEM images confirmed the crystalline nature and the small size of the synthesized nanocrystals. In turn, the exciton was red-shifted from 461nm to 549 nm when the reaction temperature was prolonged from 140°C to 190 °C, suggesting the crystal growth. The corresponding band gap values were approximately 2.2 eV, confirming the quantum confinement effect (bulk value 1.74eV). This red shift was also evidenced in PL measurements where the main emission peak was shifted from 507 nm to 564 nm when the samples were excited at 420 nm. A narrow size-tunable emission also was supported by the full width at half maximum (∼ 45 nm) for the synthesized nanocrystals. The reactive oxygen species generation capability of as-synthesized QDs was also investigated. The correlation between the particle size and the generation of (ROS) by the degradation of methylene blue was evident with a reduction of MB concentration from 10μM to 7.5μM and 6.7μM after 15 minutes of UV irradiation for reaction time of 10 min. and 40 min. respectively. No additional degradation was noticed after 60 minutes of irradiation.

A Convenient Synthesis of 1,5-Fused 1,2,4-Triazoles from N-Arylamidines via Chloramine-T Mediated Intramolecular Oxidative N–N Bond Formation

Synthesis ◽  
2019 ◽  
Vol 51 (20) ◽  
pp. 3883-3890
Author(s):  
Ashish Bhatt ◽  
Rajesh K. Singh ◽  
Ravi Kant ◽  
Bhupendra K. Sarma
Keyword(s):  
Reaction Time ◽  
Bond Formation ◽  
Available N ◽  
Short Reaction Time ◽  
Metal Free ◽  
Convenient Synthesis ◽  
Chloramine T ◽  
High Yields ◽  
Short Time

A convenient synthesis of 1,5-fused 1,2,4-triazoles from readily available N-arylamidines is reported. The reaction is efficiently promoted by chloramine-T to afford the desired products mostly in high yields and in relatively short time, through direct metal-free oxidative N−N bond formation. The mild nature of the synthesis and short reaction time are notable advantages of the developed protocol. This protocol is effective toward various substrates having different functionalities.

scholarly journals Microwave Assisted One Pot Synthesis of 3,4-Dihydropyrano[c]chromene Derivatives using [Emim]OH Ionic Liquid as Novel Catalyst

2019 ◽  
Vol 31 (4) ◽  
pp. 829-833
Author(s):  
D.S. Bhagat ◽  
S.G. Pande ◽  
M.V. Katariya ◽  
R.P. Pawar ◽  
P.S. Kendrekar
Keyword(s):  
Ionic Liquid ◽  
Reaction Time ◽  
High Yield ◽  
Reaction Conditions ◽  
One Pot ◽  
Short Reaction Time ◽  
Aryl Aldehydes ◽  
Microwave Assisted ◽  
Novel Catalyst ◽  
Work Up

One-pot efficient protocol to the synthesis of 2-amino-5-oxo-4,5-dihydropyrano(3,2-c)chromene-3-carbonitrile derivatives via condensation of various aryl aldehydes, dicyanomethane and 4-hydroxycoumarin in presence of Emim hydroxide as an excellent homogeneous liquid catalyst. The key advantages of this methodology are mild reaction conditions, novel catalyst, short reaction time, eco-friendly, easy work-up procedure and high yield of isolation of derivatives.

scholarly journals Clauson Kaas Pyrrole Synthesis Catalyzed by Acidic Ionic Liquid under Microwave Irradiation

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Feray Aydogan ◽  
Cigdem Yolacan
Keyword(s):  
Ionic Liquid ◽  
Reaction Time ◽  
Microwave Irradiation ◽  
Product Formation ◽  
High Yield ◽  
Pyrrole Derivatives ◽  
Short Reaction Time ◽  
Acidic Ionic Liquid ◽  
Clean Product

A new procedure to synthesize the N-substituted pyrrole derivatives by Clauson Kaas reaction catalyzed by acidic ionic liquid under microwave irradiation was developed. This procedure provides several advantages such as high yield, clean product formation, and short reaction time.

A Convenient One-Pot and Rapid Microwave-Assisted Synthesis of Biologically Active s-Triazolo[3,4-b][1,3,4]Thiadiazine and s-Triazolo[3,4-b][1,3,4]Thiadiazole Nanoarchitectonics

2020 ◽  
Vol 20 (5) ◽  
pp. 2917-2929
Author(s):  
Ahmed F. M. EL-Mahdy ◽  
Hassan A. H. EL-Sherief ◽  
Zeinab A. Hozien ◽  
Shiao-Wei Kuo
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Reaction Time ◽  
Catalytic Amount ◽  
Biologically Active ◽  
Microwave Assisted Synthesis ◽  
One Pot ◽  
Microwave Assisted ◽  
Work Up ◽  
Temperature Time

A rapid and efficient one-pot protocol has been developed for the synthesis of s-triazolo[3,4-b][1,3,4]thiadiazine and s-triazolo[3,4-b][1,3,4]thiadiazole nanoarchitectonics through the reaction of s-triazoles with ketones and nitriles in acetic acid containing a catalytic amount of sulfuric acid under microwave irradiation in excellent yields. With this catalytic reaction, the cheap sulfuric acid as well as other acids were examined as catalysts and the highly toxic and irritating haloketones and halonitriles were avoided to form. The effects of microwave power, temperature, time, solvent and catalyst were examined. This method achieved a better performance; e.g., higher yields, shorter reaction time and easier work-up as compared to other conventional methods. Therefore, the proposed method will be readily applicable to the synthesis of biologically important compounds containing s-triazolo[3,4-b][1,3,4]thiadiazine and s-triazolo[3,4-b][1,3,4]thiadiazole framework.

scholarly journals A Green, Expeditious, One-Pot Synthesis of 3, 4-Dihydropyrimidin-2(1H)-ones Using a Mixture of Phosphorus Pentoxide-Methanesulfonic Acid at Ambient Temperature

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Amulrao Borse ◽  
Mahesh Patil ◽  
Nilesh Patil ◽  
Rohan Shinde
Keyword(s):  
Reaction Time ◽  
Ambient Temperature ◽  
Room Temperature ◽  
Simple Procedure ◽  
Methanesulfonic Acid ◽  
Phosphorus Pentoxide ◽  
One Pot ◽  
Short Reaction Time ◽  
Solvent Free Conditions ◽  
High Yields

An expeditious, one-pot method for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones using a mixture of phosphorus pentoxide-methanesulfonic acid (Eaton’s reagent) at room temperature under solvent-free conditions is described. The salient features of this method include short reaction time, green aspects, high yields, and simple procedure.

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