scholarly journals Microwave-Assisted Synthesis of Arylidene Acetophenones

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
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.

2011 ◽  
Vol 8 (2) ◽  
pp. 945-951 ◽  
Author(s):  
P. Y. Pawar ◽  
P. M. Gaikwad ◽  
P. H. Balani

The reaction of resorcinol with ethylacetoacetate yielded the 7-hydroxy-4-methyl coumarin (1), which on treatment with benzidine gives 1-(4ʹ-amino-biphenyl-4-yl)-7-hydroxy-4-methyl-1H-quinolin-2-one (2). 1-{4ʹ-[(Substituted benzylidene)-amino]-biphenyl-4-yl}-7-hydroxy-4-methyl-1H-quinolin-2-one (3a-j) were obtained by reacting 1-(4ʹ-amino-biphenyl-4-yl)-7-hydroxy-4-methyl-1H-quinolin-2-one (2) with different substituted aromatic aldehydes in presence of glacial acetic acid by microwave irradiation. The compound 1-{4ɴ-[(substituted benzylidene)-amino]-biphenyl-4-yl}-7-hydroxy-4-methyl-1H-quinolin-2-one (3a-j) on cyclization with chloro acetyl chloride in presence of triethylamine as catalyst under microwave irradiation furnished 1-{4ʹ-[3-chloro-2-(substituted phenyl)-4-oxo-azetidin-1-yl]-biphenyl-4-yl}-7-hydroxy-4-methyl-1H-quinolin-2-one (4a-j). Purity of synthesized compounds was checked by TLC and the structures were elucidated by their IR,1H NMR, Mass and elemental analysis data. The synthesized compounds were screened for anticonvulsant activity.


2009 ◽  
Vol 6 (2) ◽  
pp. 323-331
Author(s):  
D. Ashok ◽  
K. Aravind

A series of 1-{2, 4-dihydroxy-5-[5-(aryl)-1-pyridine/pyrimidine-4-carbonyl)-4, 5-dihydro-1H-pyrazol-3-yl]-phenyl}-3-(aryl)-propenones (2a-h) have been synthesized from 1-[2,4-dihydroxy-5-(aryl acryloyl)phenyl]-aryl propenones(1a-h)by Micheal addition with isoniazide/pyrazinic acid hydrazide under microwave irradiation and classical heating. The synthesized compounds were characterized by IR,1H-NMR,13C-NMR and Mass spectral data. All the compounds were screened for their Antibacterial activity.


2009 ◽  
Vol 64 (7) ◽  
pp. 826-830 ◽  
Author(s):  
Hatem A. Abdel-Aziz ◽  
Sobhi M. Gomha

We report herein on the utility of the Pfitzinger reaction in a facile two-step synthesis of the new heterocyclic ring system 6-arylbenzo[4,5]imidazolo[2,1-b]quino[4,3-e]-1,3-thiazin-14-one using microwave irradiation (MWI) and/or conventional heating. Microwave irradiation was used for a rapid and efficient synthesis of quinoline-4-carboxylic acids 6a - d from the reaction of isatin with 2-(1Hbenzimidazol- 2-ylthio)-1-arylethanones 3a - d. Cyclization of cinchoninic acids 6a - d afforded the fused title compounds 7a - d.


2020 ◽  
Vol 7 (3) ◽  
pp. 183-195
Author(s):  
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.


2016 ◽  
Vol 81 (8) ◽  
pp. 851-858 ◽  
Author(s):  
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.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nur Atiqah Mohamad Aziz ◽  
Robiah Yunus ◽  
Hamidah Abd Hamid ◽  
Alsultan Abdul Kareem Ghassan ◽  
Rozita Omar ◽  
...  

AbstractMicrowave-assisted synthesis is known to accelerate the transesterification process and address the issues associated with the conventional thermal process, such as the processing time and the energy input requirement. Herein, the effect of microwave irradiation on the transesterification of palm oil methyl ester (PME) with trimethylolpropane (TMP) was evaluated. The reaction system was investigated through five process parameters, which were reaction temperature, catalyst, time, molar ratio of TMP to PME and vacuum pressure. The yield of TMP triester at 66.9 wt.% and undesirable fatty soap at 17.4% were obtained at 130 °C, 10 mbar, sodium methoxide solution at 0.6 wt.%, 10 min reaction time and molar ratio of TMP to PME at 1:4. The transesterification of palm oil-based methyl ester to trimethylolpropane ester was 3.1 folds faster in the presence of microwave irradiation. The total energy requirement was markedly reduced as compared to the conventional heating method. The findings indicate that microwave-assisted transesterification could probably be an answer to the quest for a cheaper biodegradable biolubricant.


2021 ◽  
Author(s):  
Bishwajit Changmai ◽  
Kalyani Rajkumari ◽  
diparjun das ◽  
Samuel Lalthazuala Rokhum

Synthesis and application of acid-functionalized mesoporous polymer catalyst for the synthesis of 3,4-Dihydropyrimidin-2(1H)-ones via Biginelli condensation reaction under microwave irradiation is investigated. Several analytical techniques such as FT-IR, BET, TEM, SEM and EDX were employed to characterize the synthesized polymeric catalyst. High acidity (1.15 mmol g-1 ), high surface area (90.44 m2 g -1 ) and mesoporous nature of the catalyst effectively promoted the synthesis of 3,4-Dihydropyrimidin-2(1H)-ones. Microwave irradiation shows higher yield (89-98 %) as compared to conventional heating (15-25 % yield) under our optimized reaction conditions such as 1:1:1.2 molar ratio of aldehyde/ethylacetoacetate/urea, catalyst loading of 6 wt.% (with respect to aldehyde), the temperature of 80 °C and microwave power of 50 W. The synthesized Biginelli products were fully characterized by 1H and 13C NMR. The reusability of the catalyst was investigated up to 5 successive cycles and it showed great stability towards the synthesis of 3,4-Dihydropyrimidin-2(1H)-ones without any significant depreciation in yields.


2019 ◽  
Vol 84 (3) ◽  
pp. 237-244
Author(s):  
Dongamanti Ashok ◽  
Rangu Kavitha ◽  
Srinivas Gundu ◽  
Madderla Sarasija

A new series of 6-[3-aryl-1-phenyl-4?,5?-dihydro[4,5?-bi-1H-pyrazol]-3?-yl]-2H-chromen-5-ol derivatives was synthesized by Michael addition of chalcones 5a?j with hydrazine hydrate in presence of sodium acetate under conventional heating and microwave irradiation. Structural assignment of the products was confirmed based on IR, 1H-NMR, 13C-NMR, MS and analytical data. All the synthesized compounds 6a?j were screened for their antimicrobial activity against various bacterial and fungal strains. Most of the compounds exhibited variable range of antimicrobial activity and compounds 6c?f and 6i showed promising antimicrobial potency.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
L. Achutha ◽  
R. Parameshwar ◽  
B. Madhava Reddy ◽  
V. Harinadha Babu

Quinoxaline-incorporated Schiff bases(4a–j)were synthesized by the condensation of 2-[(3-methylquinoxalin-2-yl)oxy]acetohydrazide(3)with indole-3-carbaldehyde, furfuraldehyde, 5-(4-nitrophenyl)-2-furfuraldehyde, and substituted benzaldehydes under conventional and microwave irradiation methods. The microwave method was found to be remarkably successful with higher yields, less reaction time, and environmentally friendly compared to conventional heating method. The chemical structures of the synthesized compounds have been confirmed by analytical and spectral data. All the compounds have been evaluated for antitubercular and anti-inflammatory activities.


2006 ◽  
Vol 3 (4) ◽  
pp. 307-312 ◽  
Author(s):  
Prashant Kriplani ◽  
Pawan Swarnkar ◽  
Rinku Maheshwari ◽  
K. G. Ojha

Synthesis of some biologically active benzothiazolotriazine derivatives by microwave irradiation is reported. 2-Amino-6-substituted benzothiazoles1on treatment with benzaldehyde in anhydrous ethanol afforded 2-benzylidenoimino-6-substitutedbenzothiazoles2which underwent cyclisation with ammoniumthiocyanate in dioxane to give 2-phenyl benzothiazolo [3,2-α]-s-triazine-4-[3H] thiones3.These both steps were carried out in microwave. Compound3with benzoyl chloride in anhydrous pyridine gave 2-phenyl-3-(benzoyl) benzothiazolo [3,2-α]-s-triazine-4-thiones4in good yields. The structure of all these compounds have been supported by their elemental analysis and their spectral data. All synthesized compounds were tested for their antibacterial activity using standard drug.


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