scholarly journals A Task-Specific Ionic-Liquid-Mediated Solvent-Free Protocol for Direct Access to Dimethyl Acetal Protected Benzimidazole 2-Carboxaldehydes

SynOpen ◽  
2020 ◽  
Vol 04 (04) ◽  
pp. 89-95
Author(s):  
Swapan Majumdar ◽  
Barnali Deb ◽  
Ankita Chakraborty ◽  
Jewel Hossain

AbstractA robust and straightforward protocol has been developed for the synthesis of a diverse array of dimethyl acetal protected benz­imidazole-2-carboxaldehydes by reacting various 2-amino aniline derivatives with methyl 4,4-dimethoxy-3-oxobutanoate using the task-specific­ imidazolium ionic liquid (HBIm·TFA) as a promoter for N-C/C-N annulation processes. The present protocol offers several advantages over existing protocols, such as single-step process, short reaction times, very mild reaction conditions, high yields, ease of purification, recovery and reusability of the catalyst, and scale-up of the reaction.

2012 ◽  
Vol 90 (10) ◽  
pp. 798-804 ◽  
Author(s):  
Sara Sobhani ◽  
Razieh Nasseri ◽  
Moones Honarmand

A new and convenient method for the synthesis of bis(pyrazolyl)methanes by one-pot tandem Knoevenagel–Michael reaction of 3-methyl-1-phenyl-5-pyrazolone with aryl, heteroaryl, or alkyl aldehydes in the presence of 2-hydroxyethylammonium acetate (2-HEAA) as a task-specific ionic liquid is described. This method was also successfully applied for the synthesis of 2-pyrazolyl-1-nitroalkanes by Michael addition of 3-methyl-1-phenyl-5-pyrazolone with β-nitrostyrenes in short reaction times. The present protocol offers several advantages such as using a reusable and cost-effective ionic liquid, an environmentally benign reaction media, being amenable to scale-up and good to high yields of the products.


2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Alireza Hasaninejad ◽  
Abdolkarim Zare ◽  
Ahmad Reza Moosavi-Zare ◽  
Fatemeh Khedri ◽  
Rahimeh Rahimi ◽  
...  

Aza-conjugate addition of phthalimide to α,β-unsaturated esters efficiently achieves in the presence of catalytic amount of Cs2CO3 and ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br) under mild reaction conditions (70°C) to afford N-alkyl phthalimides in high yields and relatively short reaction times.


2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Kobra Nikoofar ◽  
Fatemeh Shahriyari

AbstractA simple, straightforward, and ultrasound-promoted method for the preparation of some highly functionalized tetrahydropyridines reported via pseudo five-component reaction of (hetero)aromatic aldehydes, different anilines, and alkyl acetoacetates in the presence of [N-CH2CO2H-3-pic]+HSO4−, as a novel ionic liquid, in green aqueous medium. The IL was synthesized utilizing simple and easily-handled substrates and characterized by FT-IR, 1H NMR, 13C NMR, GC-MASS, FESEM, EDX, and TGA/DTG techniques. The procedure contains some highlighted aspects which are: (a) performing the MCR in the presence of aqua and sonic waves, as two main important and environmentally benign indexes in green and economic chemistry, (b) high yields of products within short reaction times, (c) convenient work-up procedure, (d) preparing the new IL via simple substrates and procedure.


2017 ◽  
Vol 13 ◽  
pp. 694-702 ◽  
Author(s):  
Gabriel P Costa ◽  
Natália Seus ◽  
Juliano A Roehrs ◽  
Raquel G Jacob ◽  
Ricardo F Schumacher ◽  
...  

The use of sonochemistry is described in the organocatalytic enamine–azide [3 + 2] cycloaddition between 1,3-diketones and aryl azidophenyl selenides. These sonochemically promoted reactions were found to be amenable to a range of 1,3-diketones or aryl azidophenyl selenides, providing an efficient access to new ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones in good to excellent yields and short reaction times. In addition, this protocol was extended to β-keto esters, β-keto amides and α-cyano ketones. Selanyltriazoyl carboxylates, carboxamides and carbonitriles were synthesized in high yields at short times of reaction under very mild reaction conditions.


2009 ◽  
Vol 2009 (8) ◽  
pp. 473-477 ◽  
Author(s):  
Xinying Zhang ◽  
Yingying Qu ◽  
Xuesen Fan ◽  
Xia Wang ◽  
Jianji Wang

The utilisation of an ionic liquid-[bmim][BF4] as both reaction medium and promoter for the reaction between aldehyde and 4-hydroxy-6-methylpyran-2-one is described. Without any added catalyst, this reaction was realised efficiently to give arylbispyranylmethane derivatives in high yields. Alternatively, when this reaction was carried out in the presence of acetic anhydride, fused pyran derivatives were obtained. These two novel procedures have advantages such as an environmentally benign nature, high efficiency, simple operation process and mild reaction conditions. As an application, these procedures were used in the preparation of novel 5-substituted pyrimidine nucleoside derivatives with potential antiviral activities.


Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2084
Author(s):  
Poliane K. Batista ◽  
João Marcos G. de O. Ferreira ◽  
Fabio P. L. Silva ◽  
Mario L. A. A Vasconcellos ◽  
Juliana A. Vale

Tetrahydropyran (THP) rings are common in several natural products, therefore, various strategies are being developed to synthesize these rings. The present work described the study of a one-pot synthesis of 2,4,6-trisubstituted tetrahydropyran compounds promoted by the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6] through a Barbier–Prins reaction between allyl bromide and aldehydes. The use of [BMIM][PF6] gave Prins products from several aldehydes in good yields and reaction times. We also found that the anion, PF6-, accelerates the Barbier reaction when used alone, and the excess SnBr2 from the reaction conditions of the Barbier reaction leads to the formation of the THP rings, thus acting as a catalyst for Prins cyclization. Additionally, we demonstrate that ionic liquid can be recovered and reused five times in the preparation of 4-bromo-tetrahydro-2,6-diphenyl-2H-pyran without significant yield loss.


2005 ◽  
Vol 2005 (9) ◽  
pp. 600-602 ◽  
Author(s):  
Yu-Ling Li ◽  
Mei-Mei Zhang ◽  
Xiang-Shan Wang ◽  
Da-Qing Shi ◽  
Shu-Jiang Tu ◽  
...  

In this paper the preparation of 3,3,6,6-tetramethyl-9-aryl-1,2,3,4,5,6,7,8,9,10- decahydroacridin-1,8-dione derivatives from aromatic aldehydes, 5,5-dimethyl-1,3- cyclohexanedione and ammonium acetate in ionic liquids [bmim+][BF4-] is described. This new method has the advantages of easier work-up, milder reaction conditions, high yields and an environmentally benign procedure compared with other methods.


2011 ◽  
Vol 65 (4) ◽  
Author(s):  
Hossein Eshghi ◽  
Narges Mirzaie

AbstractPolycondensation reactions of phenols with phthalic anhydride were carried out in the presence of ferric hydrogensulphate under melt conditions. The reactions proceeded in short reaction times by using a catalytic amount of Fe(HSO4)3 and the corresponding fluorescein derivatives were obtained in high yields. The simplicity, scale-up, along with the use of an inexpensive, non-toxic, recyclable catalyst of an environmentally benign nature, are other remarkable features of the procedure. The absorption and emission properties of these fluorescein derivatives were studied.


2017 ◽  
Vol 56 (2) ◽  
Author(s):  
Arturo Sánchez ◽  
Fernando Hernández ◽  
Paulo César Cruz ◽  
Yolanda Alcaraz ◽  
Joaquín Tamariz ◽  
...  

A simple, versatile, and efficient synthesis of 4<em>H</em>-pyran derivative compounds is achieved via a three-component cyclocondensation of aldehydes, malononitrile, and ethyl acetoacetate, using ammonium hydroxide as the catalyst, promoted by infrared irradiation. The present method offers several advantages, such as high yields, non hazardous reaction conditions as well as short reaction times.


2018 ◽  
Vol 62 (1) ◽  
Author(s):  
Jabbar Khalafy ◽  
Ramin Javahershenas

<p>A green approach for the synthesis of polyfunctionalized pyrrolo[2,3-<em>d</em>]pyrimidine derivatives was successfully achieved by a one-pot, three-component reaction of arylglyoxals, 6-amino-1,3-dimethyluracil and barbituric acid derivatives in the presence of tetra-<em>n</em>-butylammonium bromide (TBAB) (5 mol%) as the catalyst in ethanol at 50 °C. This protocol has many advantages such as high yields (73-95%), green and simple procedure, short reaction times, easy work-up, mild reaction conditions and general applicability.</p>


Sign in / Sign up

Export Citation Format

Share Document