p-Toluenesulfonic Acid Coated Natural Phosphate as an Efficient Catalyst for the Synthesis of 2-Substituted Benzimidazole

2018 ◽  
Vol 42 (12) ◽  
pp. 614-617
Author(s):  
Soumia Belkharchach ◽  
Hanane Elayadi ◽  
Hana Ighachane ◽  
Said Sebti ◽  
Mustapha Ait Ali ◽  
...  

2-Substituted benzimidazoles are selectively synthesised in high yields via the condensation of o-phenylenediamine derivatives with aldehyde derivatives using catalytic amount of p-toluenesulfonic acid coated natural phosphate (NP/PTSA) under mild conditions. The use of NP/PTSA as a reusable catalyst makes this process simple, convenient, and environmentally friendly.

2014 ◽  
Vol 989-994 ◽  
pp. 83-86
Author(s):  
Xuan Yan Liu ◽  
Zhi Gao Yang

3,4-Dihydropyrimidin-2(1H)-ones derivatives were synthesized in moderate to high yields in one-pot three component reaction from the corresponding aldehydes, 1,3-dicarbonyl compounds and urea, Coconut shell char sulfonic acid (CSCSA) used as a reusable, and efficient catalyst. Compared to the classical acid catalyst, This new protocol for the Biginelli reaction includes the following important features: excellent yields, non-toxic, inexpensive and easily available reagent.


2011 ◽  
Vol 8 (4) ◽  
pp. 1626-1631 ◽  
Author(s):  
Liqiang Wu ◽  
Xiao Wang

An efficient solvent-free procedure for the preparation of 4,4′-epoxydicoumarins via the ondensation of 4-hydroxycoumarin with aldehydes in the presence of catalytic amount of phosphorus pentoxide/silica gel at 110°C is described. The advantages of this method are generality, high yields, short reaction times, ease of product isolation, low cost and ecologically friendly.


2019 ◽  
Author(s):  
Yichen Wu ◽  
Tao liu ◽  
Dongping Chen ◽  
Daoming Wang ◽  
Peng Wang

Herein, we reported a nickel catalyzed hydrogenation of alkenes with water as the sole hydrogen source. Employing Zn as reductant and water as solvent in the presence of a catalytic amount of nickel catalyst led to direct hydrogenation of a series of electron-rich and electron-deficient alkenes in high yields. This protocol features unprecedented heterocycle and functional group tolerance under facile and mild conditions. Selective hydrogenation of the substrates containing additional reducible functionalities, such as alkenyl, alkynyl, chloride, ketone, and benzyl group etc, was also realized.


2019 ◽  
Vol 16 (11) ◽  
pp. 915-921
Author(s):  
Nafiseh Yaltaghian-Khiabani ◽  
Shahrzad Abdolmohammadi ◽  
Sepehr Sadegh-Samiei

Pyridopyrimidines represent a highly important class of compounds which exhibit a wide spectrum of biological properties. Nanoscale metal oxide catalysts have been extensively studied for their application in organic reactions owing to their special features such as high surface area and pore sizes as supports. Titanium dioxide nanoparticles (TiO2 NPs) are an attractive candidate for readily available cheap nanocatalysts, due to their unique properties such as being non-toxic, moisture stable and reusable catalyst. 7-amino-2,4-dioxo-5-aryl-1,2,3,4-tetrahydropyrido[2,3-d]pyrimidine-6-carbonitriles were synthesized through the reaction of 4(6)-aminouracil, aromatic aldehydes, and malononitrile using calcined TiO2-SiO2 nanocomposite as a reusable catalyst in water at ambient temperature. All the synthesized compounds were well characterized by their elemental analyses, IR, 1H and 13C NMR spectroscopy. The synthesized catalyst was fully characterized by the powder X-ray diffraction (XRD), the scanning electron microcopy (SEM), the transmission electron microscopy (TEM), and the x-ray fluorescence (XRF) techniques. The reaction proceeded through calcined TiO2-SiO2 nanocomposite catalyzed three-component reaction affording twelve target compounds in high yields. This method introduced a novel protocol to provide 7-amino-2,4-dioxo-5-aryl-1,2,3,4-tetrahydropyrido[2,3- d]pyrimidine-6-carbonitrile derivatives and offer several advantages like very simple operation, using inexpensive, recyclable and non-toxic catalyst, mild reaction conditions, high yields of products (92- 98%), short reaction times (2.5-4 h), and green aspects by avoiding toxic catalysts and hazardous solvents.


2017 ◽  
Vol 14 (6) ◽  
pp. 904-911 ◽  
Author(s):  
Ramin Ghorbani-Vaghei ◽  
Jafar Mahmoodi ◽  
Yaser Maghbooli ◽  
Azadeh Shahriari

Background: The synthesis of 3,4-dihydropyrano[3,2-c]chromenes via the one-pot three-component reactions of various aldehydes, malononitrile, and 4-hydroxycumarin at 60 °C in water as a solvent by the magnetic nanoparticles tag: piperidinium benzene-1,3-disulfonate ionic liquid as a green and efficient catalyst. Some benefits of the presented technique are significant cost impact, impressive catalysis and the ability to reuse of the catalyst. The current procedure offers high yield, short reaction times, neat reaction and simple reusable catalyst. Objective: A magnetic nanoparticles tag: piperidinium benzene-1,3-disulfonate ionic liquid as a green, efficient, reusable and heterogeneous catalyst was used for the synthesis of 3,4-dihydropyrano[3,2-c]chromenes. Method: We have described an efficient and green process for the synthesis of the one-pot three-component synthesis of 3,4-dihydropyrano[3,2-c]chromenes from the reaction between 4-hydroxy-coumarin with malononitrile and aldehydes in the presence of catalytic amount of magnetic nanoparticles tag: piperidinium benzene-1,3-disulfonate ionic liquid as a novel and powerful nano ionic liquid with good to excellent yields and in a short reaction time in water solvent at 60 °C. Result: The main advantage of this process is the simplicity of the work-up and the products can be isolated without chromatography. Conclusion: We suggest that the method has also various additional advantages such as low loading of catalyst, clean reaction, which makes it a suitable and noteworthy approach for the synthesis of 3,4- dihydropyrano[3,2-c]chromenes.


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.


2018 ◽  
Vol 42 (4) ◽  
pp. 210-214
Author(s):  
Bo Chen ◽  
Jiaheng Lei ◽  
Junling Zhao

A mild and efficient catalyst-free method for the rapid synthesis at room temperature of 3-thiomethylated oxindole derivatives has been achieved via the Michael addition of aryl thiols to ring and 1-substituted 3-(2,2,2-trifluoroethylidene)oxindoles in dichloromethane. The method was applicable to a wide range of thiols and variously substituted 3-(2,2,2-trifluoroethylidene)oxindoles under mild conditions as demonstrated by the synthesis in high yields with good diastereoselectivities of 30 3-thiomethylated oxindoles bearing a trifluoromethyl group.


2021 ◽  
Vol 8 (7) ◽  
pp. 210142
Author(s):  
Melina C. Ontivero ◽  
Teodoro S. Kaufman ◽  
Iván Cortés ◽  
Andrea B. J. Bracca

Methoximes are important as a class of intermediates and products, among fine chemicals and specialties. The development of a new, facile and efficient method for their synthesis is reported. The methoximes were properly accessed from the corresponding aromatic aldehydes and ketones in good to excellent yields, under mild conditions, employing the inexpensive and environmentally friendly MnCl 2 .4H 2 O as a catalyst (at low loading and without the addition of ligand), in EtOH at 50°C. The scope of the process was systematically assessed.


2019 ◽  
Author(s):  
Yichen Wu ◽  
Tao liu ◽  
Dongping Chen ◽  
Daoming Wang ◽  
Peng Wang

Herein, we reported a nickel catalyzed hydrogenation of alkenes with water as the sole hydrogen source. Employing Zn as reductant and water as solvent in the presence of a catalytic amount of nickel catalyst led to direct hydrogenation of a series of electron-rich and electron-deficient alkenes in high yields. This protocol features unprecedented heterocycle and functional group tolerance under facile and mild conditions. Selective hydrogenation of the substrates containing additional reducible functionalities, such as alkenyl, alkynyl, chloride, ketone, and benzyl group etc, was also realized.


2007 ◽  
Vol 85 (6) ◽  
pp. 438-444 ◽  
Author(s):  
Abdolkarim Zare ◽  
Alireza Hasaninejad ◽  
Ahmad Reza Moosavi Zare ◽  
Abolfath Parhami ◽  
Hashem Sharghi ◽  
...  

A simple, clean, and efficient procedure for the green synthesis of some N-alkyl derivatives of sulfonamides is described. Microwave-assisted Michael addition of sulfonamides to α,β-unsaturated esters, in the presence of catalytic amount of zinc oxide (ZnO) in 1-butyl-3-methylimidazolium bromide ([bmim]Br), affords the title compounds in high yields and short reaction times.Key words: zinc oxide, green chemistry, microwave, Michael addition, sulfonamide, ionic liquid.


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