Microwave Irradiated Acetylation of p-Anisidine: A Step towards Green Chemistry

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Mousumi Chakraborty ◽  
Vaishali Umrigar ◽  
Parimal A. Parikh
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Green Chemistry ◽  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Organic Solvent ◽  
Reaction Times ◽  
Microwave Energy ◽  
Operating Parameters ◽  
Feed Composition

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.

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

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Jyoti Prajapati ◽  
Mangalshree Dulawat ◽  
Prakash Prajapat ◽  
Renu Rathore ◽  
Shiv S. Dulawat
Keyword(s):  
Reaction Time ◽  
Green Chemistry ◽  
Microwave Irradiation ◽  
Spectral Data ◽  
Elemental Analysis ◽  
Phenyl Ring ◽  
Ring System ◽  
Short Reaction Time ◽  
Highly Efficient

<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>

scholarly journals Synthesis Chalones and Their Isomerization into Flavanones and Azaflavanones

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
Keyword(s):  
Organic Chemistry ◽  
Reaction Time ◽  
Green Chemistry ◽  
Microwave Irradiation ◽  
Aldol Condensation ◽  
Chemistry Laboratory ◽  
Efficient Catalyst ◽  
Theoretical Concepts ◽  
Catalyst Systems ◽  
Organic Chemistry Laboratory

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.

Green Synthesis of 4-aryl-3,4-Dihydrochromeno[3,4-e][1,3]Oxazine-2,5-Dione in Aqueous Media by Condensation of 4-Hydroxycoumarin with Aromatic Aldehydes and Methyl Carbamate

2017 ◽  
Vol 41 (3) ◽  
pp. 136-138 ◽  
Author(s):  
Sabereh Bougan ◽  
Alireza Hassanabadi
Keyword(s):  
Green Chemistry ◽  
Organic Solvent ◽  
Green Synthesis ◽  
Aqueous Media ◽  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Efficient Synthesis ◽  
One Pot ◽  
Three Component Reaction ◽  
High Yields

A green and efficient synthesis of the title compounds has been achieved in a one-pot, three-component reaction of 4-hydroxycoumarin and aromatic aldehydes with methyl carbamate catalysed by p-toluenesulfonic acid in aqueous media to afford 4-aryl-3,4-dihydrochromeno[3,4-e][1,3]oxazine-2,5-diones in excellent yields. The salient features of this protocol are: short reaction times, high yields and absence of any hazardous organic solvent. Consequently, this procedure could be classified as green chemistry.

Synthesis of a series of novel 2,3-dihydrofuranonaphthoquinone derivatives

2017 ◽  
Vol 41 (8) ◽  
pp. 448-451 ◽  
Author(s):  
Maryam Salari ◽  
Mohammad H. Mosslemin ◽  
Alireza Hassanabadi
Keyword(s):  
Reaction Time ◽  
Green Chemistry ◽  
Organic Solvent ◽  
Aromatic Aldehyde ◽  
Efficient Synthesis ◽  
One Pot ◽  
Short Reaction Time ◽  
Highly Efficient ◽  
One Pot Condensation ◽  
High Yields

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.

scholarly journals Three-Component One-Pot Condensation of 2-Hydroxy-1,4-Naphthoquinone with Aromatic Aldehydes and Methyl Carbamate: Synthesis of 4-aryl-3,4-Dihydronaphtho[3,4-e][1,3]Oxazine-2,5,10-Trione in Aqueous Media

2018 ◽  
Vol 42 (6) ◽  
pp. 291-293
Author(s):  
Nooshin Ghaffari-Nia ◽  
Alireza Hassanabadi
Keyword(s):  
Green Chemistry ◽  
Organic Solvent ◽  
Efficient Method ◽  
Aqueous Media ◽  
Reaction Times ◽  
Aromatic Aldehydes ◽  
One Pot ◽  
One Pot Condensation ◽  
Oxazine Ring ◽  
High Yields

A green and efficient method for oxazine ring formation is established using the reaction of 2-hydroxy-1,4-naphthoquinone and aromatic aldehydes with methyl carbamate catalysed by p-toluenesulfonic acid in aqueous media to afford 4-aryl-3,4-dihydronaphtho[3,4- e][1,3] oxazine-2,5,10-triones in excellent yields. The salient features of this protocol are short reaction times and high yields while avoiding any hazardous organic solvent. Therefore, this procedure could be classified as green chemistry.

scholarly journals 2-[3-(Trifluoromethyl)phenyl]furo[3,2-b]pyrroles: synthesis and reactions

2005 ◽  
Vol 3 (2) ◽  
pp. 311-325 ◽  
Author(s):  
Peter Gajdoš ◽  
Soňa Pavlíková ◽  
Filip Bureš ◽  
Alžbeta Krutošíková
Keyword(s):  
Reaction Time ◽  
Carboxylic Acid ◽  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Hydrazine Hydrate ◽  
Methyl Iodide ◽  
Benzyl Chloride ◽  
Hydrazine Derivatives ◽  
Condensation Reactions ◽  
Hydrolysis Of

AbstractThe synthesis and reactions of methyl 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole-5-carboxylate (1a) are described. Upon reaction with methyl iodide, benzyl chloride, or acetic anhydride, this compound gave N-substituted products 1b-d. By hydrolysis of compounds 1a-c, the corresponding acids 2a-c were formed, or by reaction with hydrazine-hydrate, the corresponding carbohydrazides 3a-c were formed. By heating 2-[3-(trifluoromethyl)phenly]-4H-furo[3,2-b]pyrrole-5-carboxylic acid (2a) in acetic anhydride, 4-acetyl-2-[3-(trifluoromethyl)phenyl]furo[3,2-b]pyrrole (4) was formed. By hydrolysis of 4, 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole (5a) was formed, and reactions with methyl iodide or benzyl chloride gave N-substituted products 5b-c. The reaction of 4 with dimethyl butynedioate gave substituted benzo[b]furan 6. Compound 3a reacted with triethyl orthoesters giving 7a-c, which afforded with phosphorus (V) sulphide the corresponding thiones 8a-c. The thiones 8a-c reacted with hydrazine hydrate to form hydrazine derivatives 9a-c. The reaction of triethyl orthoformiate with compounds 9a-c led to furo[2′,3′: 4,5]pyrrolo[1,2-d][1,2,4]triazolo[3,4-f][1,2,4]triazines 10a-c. Hydrazones 11a-c were formed from 3a-c and 5-[3-(trifluoromethyl)phenyl]furan-2-carboxaldehyde. The effect of microwave irradiation on some condensation reactions was compared with “classical” conditions. The results showed that microwave irradiation shortens the reaction time while affording comparable yields.

scholarly journals Efficient Eco-Friendly Solvent-Free Obtaining Bis-Selenium-Alkenes with High Biological Potential

2020 ◽  
Vol 2 (1) ◽  
pp. 20
Author(s):  
Pâmella Cordeiro ◽  
Matheus Silva Prado ◽  
José Neto ◽  
Vanessa Nascimento
Keyword(s):  
Green Chemistry ◽  
Microwave Irradiation ◽  
Reaction Times ◽  
13C Nmr Spectroscopy ◽  
Conventional Heating ◽  
Diphenyl Diselenide ◽  
Organoselenium Compounds ◽  
1H And 13C Nmr ◽  
Reaction Optimization ◽  
Biological Potential

Organocalcogenides, in particular, organoselenium compounds, have been widely studied due to their large number of synthetic and biological applications. Among organoselenium compounds, a class of bis-selenide-alkene derivatives has attracted attention. Recently, some studies have been developed for the synthesis of vinyl chalcogen derivatives, since these are also highly valuable intermediates in several synthetic applications. However, the methodologies developed so far have extensive reaction times, and use toxic solvents as well as heavy metals. Therefore, there is an emerging need to develop protocols for the synthesis of these molecules that are in accordance with the principles of green chemistry. In this work, we developed an alternative synthesis of bis-selenium-alkene derivatives, through an environmentally appropriate methodology. Reaction optimization was evaluated from the diphenylacetylene and diphenyl diselenide, using I2/DMSO as a catalytic system under microwave irradiation or conventional heating. The variations of these conditions were carried out through different equivalences between the reagents, the amount of catalyst (I2), temperature, DMSO and the reaction process (Microwave or conventional). Even now, it was found that the best established condition was using diphenylacetylene, diphenyl diselenide, 30 mol% I2 in DMSO, under microwave irradiation at 100 °C for 10 min. In this condition, the product was obtained in 82% yield and its characterization was performed using 1H and 13C NMR spectroscopy. Therefore, the methodology that is being developed, in addition to perfectly attending to the principles of green chemistry, will allow to evaluate the reaction scope using different alkenes and diselenides or even disulfides and ditellurides.

scholarly journals Reactions of 4-hydroxycoumarin with heterocyclic aldehydes

2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Renáta Gašparová ◽  
Katarína Kotlebová ◽  
Margita Lácová
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Sodium Hydroxide ◽  
Acid Medium ◽  
Sodium Acetate ◽  
Toluenesulfonic Acid ◽  
Heterocyclic Aldehydes

Reactions of 4-hydroxycoumarin 1 with heterocyclic aldehydes 2-4 led to bis-4-hydroxycoumarin derivatives 5-7 under microwave irradiation as well as under the classical heating. The subsequent reactions of products 5-7 are described. 4,4’-Epoxydicoumarins 8, 9 were prepared by the reaction of 5-7 in acetic acid / p-toluenesulfonic acid medium. Compound 10 was prepared by the reaction of 5 in acetic anhydride in the presence sodium acetate. Dioxocine-1,15-dione 11 was prepared by the reaction of 6 with dichloromethane in sodium hydroxide-toluene.

scholarly journals Expeditious synthesis of 1,3,4-oxadiazole derivatives via sydnones

2008 ◽  
Vol 73 (2) ◽  
pp. 131-138 ◽  
Author(s):  
Ravindra Kamble ◽  
B.S. Sudha ◽  
D.G. Bhadregowda
Keyword(s):  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Hydrazine Hydrate ◽  
Reaction Times ◽  
Elemental Analyses ◽  
Oxadiazole Derivatives

The clean cyclization of chalcones (1a-c/2a-c) with hydrazine hydrate under microwave irradiation afforded pyrazolines derivatised with sydnone (3d-i/4d-i), which underwent 1,3-dipolar cyclo-addition with acetic anhydride to form pyrazolines appended with 1,3,4-oxadiazoles (5g-l/6g-l). The newly synthesized compounds were confirmed by spectral and elemental analyses. In comparison to classical heating, the results indicate that microwave irradiation affords higher yields, shorter reaction times (4-12 min) and cleaner reactions.

scholarly journals ACETYLATION OF ANISOLE IN GREEN CHEMISTRY CONDITIONS

2010 ◽  
Vol 13 (2) ◽  
pp. 62-70
Author(s):  
Thu Thi Hoang ◽  
Phuong Hoang Tran ◽  
Thach Ngoc Le
Keyword(s):  
Green Chemistry ◽  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Solvent Free ◽  
High Yield ◽  
Free Condition ◽  
Solvent Free Condition ◽  
Bismuth Triflate ◽  
Short Time ◽  
New Generation

In this study, acetylation of anisole by acetic anhydride, catalyzed by bismuth triflate are described. The reaction was taken place under new generation monomode microwave irradiation (Discover oven), solvent-free condition. High yield was obtainted in short time. Good selectivities for the para- products were observed. Bismuth(III) triflate could be recycled and reused effectively.

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