scholarly journals Microwave Induced Synthesis of Pyrazoline Compounds Containing Substituted Benzyloxy Phenyl Ring System

Author(s):  
Jyoti Prajapati ◽  
Mangalshree Dulawat ◽  
Prakash Prajapat ◽  
Renu Rathore ◽  
Shiv S. Dulawat

<div><p><em>Green chemistry uses highly efficient and environmental benign synthetic procedures to synthesize various bioactive heterocyclic frameworks which are the useful synthons for the synthesis of medicines, plastics, petrochemicals, agrochemicals, cosmetics and many more hence the green chemistry is the need of the day. In this methodology pyrazolines have been synthesized under microwave irradiation<sup>1</sup> using ethanol /alumina. The structures of these compounds were established by elemental analysis and spectral data. The method has several advantages in comparison with conventional synthesis including clean reaction procedure, easy workup, and short reaction time giving excellent yields of product.</em></p></div>

2017 ◽  
Vol 41 (8) ◽  
pp. 448-451 ◽  
Author(s):  
Maryam Salari ◽  
Mohammad H. Mosslemin ◽  
Alireza Hassanabadi

A green and highly efficient synthesis of 12 novel trans-2-(4-chlorobenzoyl)-3-aryl-2,3-dihydronaphtho[2,3- b]furan-4,9-diones has been achieved via a three-component, one-pot condensation of 2-[2-(4-chlorophenyl)-2-oxoethyl)]isoquinolinium bromide with 2-hydroxy-1,4-naphthoquinone and an aromatic aldehyde in the presence of catalytic amounts of choline hydroxide in water under reflux conditions. The advantages of this method are a short reaction time, high yields and the avoidance of any hazardous organic solvent. Therefore, this procedure can be classified as green chemistry.


2020 ◽  
Vol 7 (2) ◽  
pp. 145-156
Author(s):  
Pravinkumar Patil ◽  
Gangadhar Bhopalkar ◽  
Sainath Zangade

Background: The various industrial processes have a diverse effect on the environment through pollution. In view of these observations, some environmentally benign synthetically protocols have developed under green chemistry. For rapid and sustainable synthesis, the microwave irradiation (MI) has gained popularity as a powerful tool compared to conventional synthesis. The present study describes the synthesis of novel substituted 1, 3-diaryl-2-propene-1-one derivative using alumina supported K3PO4-MWI combination. Objective: Chalcones are important compounds which are widely spread in nature like in fruits, vegetables, tea, spices, etc. The 2’-hydroxy derivative of chalcones plays an important role in the synthesis of bioactive compounds. The present communication deals with a convenient and rapid synthesis of 1, 3-diaryl-2-propene-1-one under the support of alumina-tripotassium phosphate and microwave irradiation. Our efforts are focused on the introduction of typical and easier route for the synthesis of title compounds using a microwave. All synthesized chalcones have been screened and evaluated for the antioxidant activity by DPPH and nitric oxide radical scavenging. Some of these compounds are found to be more potent scavengers and may lead to the development of a new class of antioxidants. Methods: The α, β-unsaturated carbonyl functionality contains two electrophilic centers allowing them to undergo addition and cyclization reactions with different nucleophiles. In the literature survey, we found that Chalcones were synthesized using tripotassium phosphate catalyst under refluxing by a conventional method. A novel method for the synthesis of 1, 3-diaryl-2-propene-1-one via Claisen Schmidt has been introduced by reacting substituted 2’- hydroxyl acetonaphthones with substituted aromatic aldehydes under the support of basic alumina –tripotassium phosphate via microwave radiations. Formation of corresponding Chalcones was confirmed by spectral studies followed by their screening for antioxidant activity. The scavenging activity is expressed in terms of % inhibition and IC50 value (μg/ml). Results: The structures of newly synthesized Chalcones were confirmed and in good agreement with obtained spectral analysis such as IR, NMR, Mass and elemental analysis. Commercially available basic alumina and tripotassium phosphate in combination of microwave were utilized and found to be effective, convenient route for the synthesis of 1, 3-diaryl-2-propene-1-one derivatives with desirable yields in short reaction time (5-12 min). The results of antioxidant activity revealed that the IC50 value for compounds 3a, 3d, 3e, 3f, 3g, 3h, 3j, 3l and 3n are lower than that of standard ascorbic acid to scavenge DPPH radical. This indicates that these compounds are more significant scavengers in comparison with standard drug. On the other hand, compounds 3a, 3b, 3c, 3d, 3g, 3l and 3n are more potent scavengers for NO free radical. Conclusion: We have introduced an efficient, ecofriendly, simple and fast microwave assisted method using basic alumina-tripotassium phosphate for the synthesis of 1, 3-diaryl-2-propene-1- one derivatives. Microwave irradiation provides an effective way for the preparation of Chalcones in terms of several advantages as a simple procedure, short reaction time, milder reaction condition, cleaner reaction and excellent yield. The scavenging activity of chalcones against DPPH and NO free radicals showed excellent properties of antioxidants.


Author(s):  
Mousumi Chakraborty ◽  
Vaishali Umrigar ◽  
Parimal A. Parikh

The present study aims at assessing the effect of microwave irradiation against thermal heat on the production of N-acetyl-p-anisidine by acetylation of p-anisidine. The acetylation of p-anisidine under microwave irradiation produces N-acetyl-p-anisidine in shorter reaction times, which offers a benefit to the laboratories as well as industries. It also eliminates the use of excess solvent. Effects of operating parameters such as reaction time, feed composition, and microwave energy and reaction temperature on selectivity to the desired product have been investigated. The results indicate as high as a 98% conversion of N-acetyl-p-anisidine can be achieved within 12-15 minutes using acetic acid. The use of acetic acid as an acetylating agent against conventionally used acetic anhydride eliminates the handling of explosive acetic anhydride and also the energy intensive distillation step for separation of acetic acid. Organic solvent like acetic anhydride are not only hazardous to the environment, they are also expensive and flammable.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Feray Aydogan ◽  
Cigdem Yolacan

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.


2006 ◽  
Vol 84 (5) ◽  
pp. 819-824 ◽  
Author(s):  
Guirong Qu ◽  
Suhui Han ◽  
Zhiguang Zhang ◽  
Mingwei Geng ◽  
Feng Xue

An efficient and green procedure for the synthesis of purine acyclic nucleosides through microwave-assisted alkylation of various purine nucleobases with 2-oxa-1,4-butanediol diacetate in the absence of solvent and catalyst is described. The advantages of using this method include its environmental friendliness, simple manipulation, short reaction time, high regioselectivity, and good yields.Key words: acyclic nucleosides, microwave irradiation, regioselectivity, alkylation, 2-oxa-1,4-butanediol diacetate.


RSC Advances ◽  
2017 ◽  
Vol 7 (63) ◽  
pp. 39502-39511 ◽  
Author(s):  
Ensieh Safari ◽  
Ammar Maryamabadi ◽  
Alireza Hasaninejad

A green, efficient, multi-component protocol has been developed for synthesis of novel bis-spirooxindoles in short reaction time, easy workup and excellent yields.


2019 ◽  
Vol 2 (3) ◽  
pp. 70 ◽  
Author(s):  
Djenisa H. A. Rocha ◽  
Patrícia A. A. M. Vaz ◽  
Diana C. G. A. Pinto ◽  
Artur M. S. Silva

Flavanones [2-aryl-2,3-dihydrochromen-4(1H)ones] and 2-aryl-2,3-dihydroquinolin-4(1H)-ones are valuable precursors in the synthesis of important pharmacological scaffolds, so efficient methodologies towards their synthesis are important in the medicinal chemistry context. Their synthesis also involves theoretical concepts such as aldol condensation, isomerization, and catalysis that make it useful in an undergraduate organic chemistry laboratory. The use of both microwave irradiation as a source of energy to promote reactions and efficient catalysts are considered within green chemistry principles, mostly because the reaction yields are improved and reaction time decreased. In this paper, the efficiency of microwave irradiation use in the synthesis of chalcone derivatives and efficient catalyst systems to promote their isomerization into flavanones and 2-aryl-2,3-dihydroquinolin-4(1H)-ones is demonstrated.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Biswa Mohan Sahoo ◽  
B. V. V. Ravi Kumar ◽  
Jnyanaranjan Panda ◽  
S. C. Dinda

A rapid, improved, and ecofriendly synthesis of thiopyrimidines is carried out via one-pot multicomponent reaction of ethylcyanoacetate, substituted benzaldehydes, and thiourea in presence of ethanolic K2CO3 using microwave irradiation heating method. Excellent yields, shorter reaction time, and easy workup are the major advantageous features of this green protocol. So the application of multicomponent reactions involves the combination of multiple starting materials with different functional groups leading to the highly efficient and environmentally friendly construction of multifunctional drug molecules. The structures of the newly synthesized products were assigned on the basis of IR and 1HNMR spectral data.


2021 ◽  
Vol 16 (9) ◽  
pp. 1934578X2110458
Author(s):  
Le Nhat Thuy Giang ◽  
Dang Thi Tuyet Anh ◽  
Hoang Thi Phuong ◽  
Nguyen Ha Thanh ◽  
Nguyen Thi Quynh Giang ◽  
...  

For the first time the 4-dimethylaminopyridine (DMAP) catalyzed straightforward and efficient procedure has been developed for the synthesis of 3,3′-(arylmethylene) bis(2-hydroxynaphthalene-1,4-dione) derivatives starting from lawsone (2-hydroxy-1,4-naphthoquinone) and a variety of (hetero)aromatic aldehydes in ethanol under microwave irradiation. Three of nine synthesized compounds are new. This method provides notable advantages over existing procedures including use of non-traditional basic catalyst and environmentally benign solvent, mild reaction conditions, excellent yields, short reaction time and simple workup.


2017 ◽  
Vol 41 (7) ◽  
pp. 380-383
Author(s):  
Maryam Salari ◽  
Alireza Hassanabadi ◽  
Mohammad H. Mosslemin

We report a green and efficient method for the synthesis of trans-[3-(aryl)-2,3-dihydrofuro[3,2- h]quinolin-2-yl]-(4-chlorophenyl) methanones from the condensation of 2-[2-(4-chlorophenyl)-2-oxoethyl)]isoquinolinium bromide with 8-hydroxyquinoline and an aromatic aldehyde in the presence of catalytic amounts of choline hydroxide in water at reflux conditions. This new protocol employing choline hydroxide, which is a green and inexpensive catalyst, offers advantages such as mild reaction conditions, short reaction time, high yields and does not involve any hazardous solvent. Therefore, this procedure can be classified as green chemistry.


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