scholarly journals Synthesis of 3-amino-2-(2-chlorophenyl)quinazolin-4(3H)-one by Conventional heating and Microwave Irradiation

2022 ◽  
Vol 6 (2) ◽  
pp. 84-87
Luthfi Ahmad Muchlashi

This study aims to compare conventional heating with microwave irradiation in order to obtain the optimal method for 3-amino-2-(2-chlorophenyl)quinazolin-4(3H)-one synthesis. For the compound to be completely synthesised, one needs to carry out much heating for a long period of time. 10 hours are required for the reaction using conventional heating; yet it takes only 5 minutes using microwave with 800 watts of power. It was found in this study that there was an improvement in percent yields of 3-amino-2-(2-chlorophenyl)quinazolin-4(3H)-one, 87 %  using microwave irradiation compared to 79 % using reflux. Therefore, microwave-assisted method is a quicker, higher yielding method for 3-amino-2-(2-chlorophenyl)quinazolin-4(3H)-one synthesis.

2019 ◽  
Vol 16 (3) ◽  
pp. 194-201 ◽  
Renu Bala ◽  
Vandana Devi ◽  
Pratibha Singh ◽  
Navjot Kaur ◽  
Pawandeep Kaur ◽  

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.

2020 ◽  
Vol 7 (3) ◽  
pp. 183-195
Musa Özil ◽  
Emre Menteşe

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.

2007 ◽  
Vol 72 (8) ◽  
pp. 1014-1024 ◽  
Pedro Cintas ◽  
Katia Martina ◽  
Bruna Robaldo ◽  
Davide Garella ◽  
Luisa Boffa ◽  

The Huisgen 1,3-dipolar cycloaddition of azides and acetylenes catalyzed by Cu(I) salts, leading to 1,2,3-triazoles, is one of the most versatile "click reactions". We have developed a series of optimized protocols and new applications of this reaction starting from several substrates, comparing heterogeneous vs homogeneous catalysis, conventional heating vs microwave irradiation or simultaneous microwave/ultrasound irradiation. Both non-conventional techniques strongly promoted the cycloaddition (bromide → azide → triazole), that could be conveniently performed in a one-pot procedure. This was feasible even with such bulky molecules as functionalized β-cyclodextrins (β-CD), starting from 61-O-tosyl-β-CD or from heptakis[6-O-(tert-butyldimethylsilyl)]-21-O-propargyl-β-CD. "Greener" heterogeneous catalysis with charcoal-supported Cu(II) or Cu(I) (prepared under ultrasound) was advantageously employed.

2014 ◽  
Vol 86 (11) ◽  
pp. 1695-1706 ◽  
Jacques Desbrières ◽  
Charlotte Petit ◽  
Stéphanie Reynaud

Abstract Polysaccharides are a natural and renewable feed stock for synthesizing high performance macromolecular materials. However, their structure does not allow reaching all properties required for specific applications and chemical modifications are necessary to reach such objectives. Despite the use of natural polymers, the chemistry and processes employed are not environment-friendly due to the nature of chemicals, solvents or because the conventional chemical process are energy-consuming. On the other hand, microwave assisted processes were developed in organic chemistry since the 1980s and more recently for polymer chemistry (polymer formation and modification). Within the chemistry of natural polymers, the use of microwave irradiation has been exploited in the past two decades to alleviate limitations in the synthesis of graft modified polysaccharide materials. Microwave heating is described as more homogeneous, selective and efficient as compared to conventional heating resulting in faster reactions with fewer or no side products as example. Different results reported within the recent literature will be discussed considering the role of microwave irradiation and its consequence on the reaction parameters and properties of final materials. Grafting of polysaccharides, specific modification of polysaccharides or fibers particularly for preparing smart textiles or medical products as well as reactions of polysaccharides to valuable bio-platform molecule will be discussed.

2005 ◽  
Vol 60 (2) ◽  
pp. 231-241 ◽  
Willi Kantlehner ◽  
Gerhard Simchen ◽  
Jochen Mezger ◽  
Edmont V. Stoyanov ◽  
Ralf Kreß ◽  

The diformylation of the dinitriles 4 and diesters 7 with the Bredereck-Simchen reagent HC[N(CH3)2]2[OC(CH3)3] (1) under microwave irradiation give the bis-enamines 6 and 8 with dramatically reduced reaction times and improved yields compared to conventional heating. The condensation products formed can be easily converted to bis-pyrazole and bis-isoxazole derivatives 13 and 20, respectively. Methyl anthranilate reacts on prolonged heating with the orthoamide 21 to give ketene aminal 23 in low yield (8 %). Under microwave irradiation the same reagents lead to a mixture of 23 (14 %) and dihydropyrane 24 (28 %).

2016 ◽  
Vol 45 (8) ◽  
pp. 3268-3271 ◽  
Xiang-xiao Jin ◽  
Wei-dong Yu ◽  
Yan-Mei Nie ◽  
Meng-Shu Liu ◽  
Jun Yan

A redox active layered shape [(HPO3)6Mo21O60(H2O)4]8− with a phosphite template is synthesised by a microwave-assisted method and characterized.

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Sheauly Khatun ◽  
M. Z. H. Khan ◽  
Khodeza Khatun ◽  
M. A. Sattar

An efficient synthesis of arylidene acetophenones have been achieved by using the microwave heating in comparison to the conventional heating. In this work compound 1-phenyle-3-(4-droxyphenyle)-2-propen-1-one, 1-(4-chlorophenyle)-3-phenyle-2-propen-1-one, and 1-(4-chlorophenyle)-3-(4-hydroxyphenyle)-2-propen-1-one have been synthesized by the condensation reaction between aromatic aldehydes and substituted acetophenones under microwave irradiation. The compounds of aldehydes and acetophenones were used as benzaldehyde, parahydroxybenzaldehyde, acetophenone, and parachloroacetophenone. The result shows that the time taken for the reaction was reduced from the conventional 1-2 hours to 60–120 seconds. The yield of the compounds in the conventional heating was moderate while the highest yield of 90–98% was observed in MWI method. The structure of the compounds was characterized by their IR,1H-NMR spectral data.

2016 ◽  
Vol 81 (8) ◽  
pp. 851-858 ◽  
Dongamanti Ashok ◽  
Velagapuri Rao ◽  
Rangu Kavitha

A series of new benzodiazepines 4a-h have been synthesized by Michael addition of chalcones 3a-h with o-phenylenediamine (OPDA) in presence of sodium acetate under conventional heating and microwave irradiation. Structures of the newly synthesized benzodiazepines 4a-h have been established on the basis of IR, 1H & 13C NMR and mass spectral data and tested for antimicrobial activity.

2018 ◽  
Vol 18 (1) ◽  
pp. 53
Ratnaningsih Eko Sardjono ◽  
Iqbal Musthapa ◽  
Iis Rosliana ◽  
Fitri Khoerunnisa ◽  
Galuh Yuliani

A new versatile macromolecule cyclic C-3,7-dimethyl-7-hydroxycalix[4]resorcinarene (CDHHK4R) has been synthesized from a fragrance agent, 7-hydroxycitronellal, via microwave irradiation. The reaction utilized a domestic microwave oven at various irradiation time and power to yield an optimum condition. As a comparison, the conventional heating method was also employed for the synthesis of the same calix[4]resorcinarene. Compared to the conventional method, microwave-assisted reaction effectively reduced the reaction time, the amount of energy consumption and the waste production. It is found that the synthesis of CDHHK4R by microwave irradiation yielded 77.55% of product, higher than by conventional heating which was only 62.17%.

2019 ◽  
Vol 16 (6) ◽  
pp. 491-494
Dinesh S. Gavhane ◽  
Aniket P. Sarkate ◽  
Kshipra S. Karnik ◽  
Shritesh D. Jagtap ◽  
Sajed H. Ansari ◽  

A proficient, microwave mediated methodology using CuFe2O4 nanoparticle as the catalyst for S-arylation of substituted benzene boronic acids with thiophenol has been developed. In this method, the substituted thioethers were easily obtained through a C-S bond formation using microwave irradiation technique as well as conventional heating in the presence of CuFe2O4 nanoparticles with modest to excellent yields with the less reaction time. The ligand free microwave technique helped in the preparation of substituted thioethers in measurable amount within 10 mins. The same results were obtained with conventional heating in 12h. The reported method is economically efficient and an alternative to the initial existing method for the preparation of substituted thioethers.

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