On water catalyst-free synthesis of benzo[d]imidazo[2,1-b] thiazoles and novel N-alkylated 2-aminobenzo[d]oxazoles under microwave irradiation

Narasimharao Mukku; Barnali Maiti

doi:10.1039/c9ra08929b

“On water” synthesis of highly functionalized 4H-chromenes via carbon–carbon bond formation under microwave irradiation and their antibacterial properties

RSC Advances ◽

10.1039/c5ra01301a ◽

2015 ◽

Vol 5 (37) ◽

pp. 28958-28964 ◽

Cited By ~ 22

Author(s):

L. Chandrasekhara Rao ◽

N. Satish Kumar ◽

V. Dileepkumar ◽

U. S. N. Murthy ◽

H. M. Meshram

Keyword(s):

Microwave Irradiation ◽

Bond Formation ◽

Antibacterial Properties ◽

Microwave Assisted Synthesis ◽

Carbon Bond ◽

Microwave Assisted ◽

Catalyst Free ◽

Carbon Carbon Bond

Microwave assisted synthesis catalyst-free synthesis water as a solvent anti bacterial properties.

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A facile, practical and metal-free microwave-assisted protocol for mono- and bis-[1,2,4]triazolo[1,5-a]pyridines synthesis utilizing 1-amino-2-imino-pyridine derivatives as versatile precursors

RSC Advances ◽

10.1039/d0ra02256j ◽

2020 ◽

Vol 10 (26) ◽

pp. 15554-15572 ◽

Cited By ~ 3

Author(s):

Hamada Mohamed Ibrahim ◽

Haider Behbehani ◽

Wael Abdelgayed Ahmed Arafa

Keyword(s):

Energy Source ◽

Microwave Irradiation ◽

Green Energy ◽

Pyridine Derivatives ◽

Metal Free ◽

Microwave Assisted ◽

Highly Efficient

A novel and highly efficient, protocol for synthesizing mono- and bis-[1,2,4]triazolo[1,5-a]pyridines has been established utilizing the readily attainable 1-amino-2-imino-pyridines and microwave irradiation as green energy source.

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Highly efficient Synthesis of per-substituted amino-cyclodextrins under Microwave Irradiation in a closed Cavity

MRS Proceedings ◽

10.1557/opl.2013.176 ◽

2013 ◽

Vol 1492 ◽

pp. 177-182 ◽

Cited By ~ 1

Author(s):

Giancarlo Cravotto ◽

Katia Martina ◽

Marina Caporaso ◽

Georgios Heropoulos ◽

László Jicsinszky

Keyword(s):

Microwave Irradiation ◽

High Efficiency ◽

Dielectric Heating ◽

Efficient Synthesis ◽

Closed Vessel ◽

Amino Groups ◽

Closed Cavity ◽

Microwave Assisted ◽

Highly Efficient ◽

Green Criteria

ABSTRACTSynthetic chemists are paying ever more attention to enabling technologies as a means to opening the paths towards the double goal of achieving high efficiency and meeting green criteria. Non-conventional techniques that create unique environments which promote selective modification have been investigated by many as part of the search for more highly efficient synthetic derivatization of cyclodextrins (CD). A few optimized microwave-assisted protocols have so far been developed for the preparation of selective per-alkylated aminocyclodextrin. In this work, a series of β-CD derivatives, whose primary hydroxyls were all replaced by amino groups, has efficiently been synthesized from per-(6-iodo-6-deoxy)-β-CD via nucleophilic substitution with amines under microwave irradiation in closed vessel (N2 pressure). The reduction of per-(6-azido-6-deoxy)-β-CD to per-(6-amino-6-deoxy)-β-CD via catalytic hydrogenation has also been successfully carried out under dielectric heating.

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Microwave assisted aminocatalyzed [3 + 2] annulation between α-iminonitriles and succinaldehyde: synthesis of pyrrole-3-methanols and related polycyclic ring systems

RSC Advances ◽

10.1039/c6ra06831f ◽

2016 ◽

Vol 6 (46) ◽

pp. 39741-39749 ◽

Cited By ~ 12

Author(s):

Nisar A. Mir ◽

Sachin Choudhary ◽

Panduga Ramaraju ◽

Deepika Singh ◽

Indresh Kumar

Keyword(s):

Microwave Irradiation ◽

Efficient Method ◽

Ring Systems ◽

Microwave Assisted ◽

Highly Efficient ◽

High Yields

A quick and highly efficient method for the synthesis of substituted pyrrole-3-methanols from α-iminonitriles and succinaldehyde under microwave irradiation is reported with good to high yields (up to 75%).

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A simple and eco-sustainable method for the sulfonylation of amines under microwave-assisted solvent-free conditions

RSC Advances ◽

10.1039/c4ra01346h ◽

2014 ◽

Vol 4 (31) ◽

pp. 16027-16032 ◽

Cited By ~ 18

Author(s):

Salah Lakrout ◽

Hacène K'tir ◽

Aïcha Amira ◽

Malika Berredjem ◽

Nour-Eddine Aouf

Keyword(s):

Microwave Irradiation ◽

Reaction Times ◽

Solvent Free ◽

Environmentally Benign ◽

Microwave Assisted ◽

Catalyst Free ◽

Solvent Free Conditions

A new environmentally benign, simple, and efficient protocol for the sulfonylation of amines using microwave irradiation under solvent- & catalyst-free conditions is reported. The corresponding sulfonamides were obtained in excellent yields within short reaction times.

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Natural Phosphate-supported Palladium: A Highly Efficient and Recyclable Catalyst for the Suzuki-Miyaura Coupling Under Microwave Irradiation

Current Organic Chemistry ◽

10.2174/1385272819666141117234222 ◽

2015 ◽

Vol 18 (24) ◽

pp. 3141-3148 ◽

Cited By ~ 14

Author(s):

Ayoub Hassine ◽

Mohamed Bouhrara ◽

Said Sebti ◽

Abderrahim Solhy ◽

Remi Mahfouz ◽

...

Keyword(s):

Microwave Irradiation ◽

Recyclable Catalyst ◽

Natural Phosphate ◽

Highly Efficient ◽

Supported Palladium

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Regioselective Synthesis of Potent 4,5,6,7-Tetrahydroindazole Derivatives via Microwave-assisted Vilsmeier-Haack Reaction and their Antioxidant Activity Evaluation

Letters in Organic Chemistry ◽

10.2174/1570178615666180919120329 ◽

2019 ◽

Vol 16 (3) ◽

pp. 194-201 ◽

Cited By ~ 2

Author(s):

Renu Bala ◽

Vandana Devi ◽

Pratibha Singh ◽

Navjot Kaur ◽

Pawandeep Kaur ◽

...

Keyword(s):

Antioxidant Activity ◽

Microwave Irradiation ◽

Biological Activities ◽

Reaction Times ◽

Conventional Heating ◽

High Chemical ◽

Microwave Assisted ◽

Work Up ◽

Active Methylene ◽

By Products

Background: Tetrahydroindazole, a member of the fused-pyrazole system, is a least studied class of heterocyclic compounds owing to its scarcity in nature. However, a large number of synthetically prepared tetrahydroindazoles are known to show a variety of biological activities such as interleukin- 2 inducible T-Cell kinase inhibitors, AMPA receptor positive allosteric modulators, antitumor, antituberculosis, anti-inflammatory and antimicrobial activities. Vilsmeier-Haack reaction is one of the most important chemical reactions used for formylation of electron rich arenes. Even though Vilsmeier- Haack reaction was studied on a wide variety of hydrazones derived from active methylene compounds, literature lacks the examples of the use of 4-substituted cyclohexanones as a substrate for the synthesis of 4,5,6,7-tetrahydroindazoles. The study of the reaction of Vilsmeier-Haack reagent with hydrazones derived from cyclic keto compounds having active methylene has been considered the interested topic of investigation. In the present study, ethyl cyclohexanone-4-carboxylate was treated with one equivalent of various hydrazines for two hours and the resulted hydrazones were further treated with an OPC-VH reagent (Vilsmeier-Haack reagent isolated from phthaloyl dichloride and N,Ndimethylformamide) afforded 4,5,6,7-tetrahydroindazoles in excellent yields. The synthesized compounds 4a-f and 5a-f were screened for their antioxidant activities using the DPPH radical scavenging assay. The target compounds were synthesized regioselectively using 4+1 approach in excellent yields. A number of experiments using both conventional heating as well as microwave irradiation methods were tried and on comparison, microwave irradiation method was found excellent in terms of easy work up, high chemical yields, shortened reaction times, clean and, no by-products formation. Some of the synthesized compounds showed significant antioxidant activity. The microwave assisted synthesis of 4,5,6,7-tetrahydroindazoles from ethyl cyclohexanone-4-carboxylate has been reported under mild conditions in excellent yield. Easy work up, high chemical yield, shortened reaction times, clean and no by-products formation are the major advantages of this protocol. These advantages may make this method useful for chemists who are interested in developing novel 4,5,6,7-tetrahydroindazole based drugs.

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Microwave-assisted Synthesis of Benzoxazoles Derivatives

Current Microwave Chemistry ◽

10.2174/2213335607999200518094114 ◽

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.

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