Tungstate sulfuric acid: preparation, characterization, and application in catalytic synthesis of novel benzimidazoles

2012 ◽  
Vol 66 (7) ◽  
Author(s):  
Bahador Karami ◽  
Saeed Khodabakhshi ◽  
Zahra Haghighijou
Keyword(s):  
Sulfuric Acid ◽  
Ftir Spectroscopy ◽  
Condensation Reaction ◽  
Direct Synthesis ◽  
Catalytic Synthesis ◽  
Solvent Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solvent Free Conditions ◽  
Work Up

AbstractTungstate sulfuric acid (TSA) was prepared, characterized, and applied for direct synthesis of novel and known benzimidazoles through a condensation reaction of o-phenylenediamines with orthoesters under solvent-free conditions. TSA was characterized by powdered X-ray diffraction (XRD), X-ray fluorescence (XRF), and FTIR spectroscopy. This novel and eco-friendly method is very cheap and has many advantages such as excellent yields, recyclable and eco-friendly catalyst, and simple work-up procedure.

scholarly journals Rapid four-component synthesis of dihydropyrano[2,3-c]pyrazoles using nano-eggshell/Ti(IV) as a highly compatible natural based catalyst

BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Arefeh Dehghani Tafti ◽  
Bi Bi Fatemeh Mirjalili ◽  
Abdolhamid Bamoniri ◽  
Naeimeh Salehi
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Reaction Times ◽  
Diffraction Field ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solvent Free Conditions ◽  
High Yields ◽  
Work Up

AbstractNano-eggshell/Ti(IV) as a novel naturally based catalyst was prepared, characterized and applied for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives. The characterization of nano-eggshell/Ti(IV) was performed using Fourier Transform Infrared spectroscopy, X-ray Diffraction, Field Emission Scanning Electron Microscopy, Energy-Dispersive X-ray Spectroscopy, and Thermo Gravimetric Analysis. Dihydropyrano[2,3-c]pyrazoles were synthesized in the presence of nano-eggshell/Ti(IV) via a four component reaction of aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate at room temperature under solvent free conditions. The principal affairs of this procedure are mild condition, short reaction times, easy work-up, high yields, reusability of the catalyst and the absence of toxic organic solvents.

Catalytic acetylation of (+)-cedrol with heterogeneous catalyst H2SO4/SiO2 under solvent free conditions

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Acetic Anhydride ◽  
Heterogeneous Catalyst ◽  
Silica Gel ◽  
Solvent Free ◽  
Molar Ratio ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solvent Free Conditions ◽  
Bet Method

Heterogeneous catalyst, H2SO4/SiO2 was synthesized by immobilizing sulfuric acid on silica gel as solid support. Silica gel was prepared from kaolin, originating from Belitung island Indonesia. The synthesized catalyst was characterized by various techniques such as X-ray diffraction, scanning electron microscopy, Fourier transform Infrared spectroscopy and BET method and was applied for the acetylation of (+)-cedrol compound using acetic anhydride under solvent free conditions. The optimum conditions for catalytic acetylation were found at 353 K for 20 h reaction period, the molar ratio (+)-cedrol/acetic anhydride 1:10 in the presence of 5%-w of catalyst converted 88,7% (+)-cedrol into cedryl acetate. Results revealed catalyst could possibly be used for cedryl acetate synthesis from (+)-cedrol.

scholarly journals Ni(II)-Aroylhydrazone Complexes as Catalyst Precursors Towards Efficient Solvent-Free Nitroaldol Condensation Reaction

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 554 ◽  
Author(s):  
Manas Sutradhar ◽  
Tannistha Roy Barman ◽  
Armando J. L. Pombeiro ◽  
Luísa M.D.R.S. Martins
Keyword(s):  
Condensation Reaction ◽  
Solvent Free ◽  
Ionization Mass ◽  
Spectroscopic Techniques ◽  
Keto Form ◽  
X Ray ◽  
X Ray Crystallography ◽  
Solvent Free Conditions ◽  
Coordination Behavior ◽  
Nitroaldol Condensation

The aroylhydrazone Schiff bases 2-hydroxy-(2-hydroxybenzylidene)benzohydrazide and (2,3-dihydroxybenzylidene)-2-hydroxybenzohydrazide have been used to synthesize the bi- and tri-nuclear Ni(II) complexes [Ni2(L1)2(MeOH)4] (1) and [Ni3(HL2)2(CH3OH)8]· (NO3)2 (2). Both complexes have been characterized by elemental analysis, spectroscopic techniques [IR spectroscopy and electrospray ionization-mass spectrometry (ESI-MS)], and single-crystal X-ray crystallography. The coordination behavior of the two ligands is different in the complexes: The ligand exhibits the keto form in 2, while coordination through enol form was found in 1. Herein, the catalytic activity of 1 and 2 has been compared with the nitroaldol condensation reaction under various conditions. Complex 2 exhibits the highest activity towards solvent-free conditions.

Silica-supported barium chloride (SiO2–BaCl2) — Efficient and heterogeneous catalyst for the environmentally friendly preparation of N,N′-alkylidene bisamides under solvent-free conditions

2011 ◽  
Vol 89 (5) ◽  
pp. 555-561 ◽  
Author(s):  
Mohammad Reza Mohammad Shafiee
Keyword(s):  
Heterogeneous Catalyst ◽  
Aromatic Aldehyde ◽  
Environmentally Friendly ◽  
Barium Chloride ◽  
Solvent Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phenyl Acetylene ◽  
Solvent Free Conditions

A series of N,N′-alkylidene bisamides were prepared via a green and environmentally friendly synthetic protocol from the reaction of phenyl acetylene or hex-1-yne, aromatic aldehyde, and benzamide or acetamide. Silica-supported barium chloride (SiO2–BaCl2) catalyzes the process of the reaction. The prepared catalysts were characterized by X-ray diffraction, and the products were obtained with high conversions and yields.

scholarly journals 1D Zn(II) Coordination Polymers as Effective Heterogeneous Catalysts in Microwave-Assisted Single-Pot Deacetalization-Knoevenagel Tandem Reactions in Solvent-Free Conditions

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 90
Author(s):  
Anup Paul ◽  
Anirban Karmakar ◽  
M. Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro
Keyword(s):  
Carboxylic Acid ◽  
Diffraction Analysis ◽  
Heterogeneous Catalysts ◽  
Topological Analysis ◽  
Solvent Free ◽  
Tandem Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Assisted ◽  
Solvent Free Conditions

The new 1D CPs [Zn(L1)(H2O)4]n.nH2O (1) and [Zn(L2)(H2O)2]n (2) [L1 = 1,1′-(ethane-1,2-diyl)bis(6-oxo-1,6-dihydropyridine-3-carboxylic acid); L2 = 1,1′-(propane-1,3-diyl)bis(6-oxo-1,6-dihydropyridine-3-carboxylic acid)] were prepared from flexible dicarboxylate pro-ligands (H2L1 and H2L2). Both CPs 1 and 2 were characterized by elemental, FTIR, and powder X-ray diffraction analysis. Their geometry and the structural features were unveiled by single-crystal X-ray diffraction analysis. The underlying topology of the CPs was illustrated by the topological analysis of the H-bonded structure of CP 1, which revealed a 3,4,6-connected trinodal net. On the other hand, topological analysis on the hydrogen-bonded network of CP 2 showed a 2,3,3,4,6,7-connected hexanodal net. The thermal stability of the CPs was investigated by thermogravimetric analysis. CPs 1 and 2 act as heterogeneous catalysts in one-pot tandem deacetalization–Knoevenagel condensation reactions under environmentally mild conditions. CPs 1 exhibits a yield of ca. 91% in a microwave-assisted solvent-free medium, whereas a slightly lower yield was obtained for CP 2 (87%) under the same experimental protocol. The recyclability of catalyst 1 was also assessed. To our knowledge, these are the first Zn(II)-based CPs to be applied as heterogeneous catalysts for the above tandem reactions under environmentally friendly conditions.

scholarly journals Rapid Four-component Synthesis of Dihydropyrano[2,3-c]pyrazoles using Nano-egg Shell/Ti(IV) as a Highly Compatible Natural Based Catalyst

2020 ◽  
Author(s):  
Arefeh Dehghani Tafti ◽  
Bi BiFatemeh Mirjalili ◽  
Abdolhamid Bamoniri ◽  
Naeimeh Salehi
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Reaction Times ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solvent Free Conditions ◽  
Ft Ir ◽  
Egg Shell ◽  
High Yields ◽  
Work Up

Abstract Nano-egg shell/Ti(IV) (NEST) as a novel naturally based catalyst was prepared, characterized and applied for the synthesis of dihydropyrano[2,3-c]pyrazole [DHPP] derivatives. The characterization of NEST was performed using Fourier Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive X-ray Spectroscopy (EDX), and Thermo Gravimetric Analysis (TGA). DHPPs were synthesized in the presence of NEST via a four component reaction of aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate at room temperature under solvent free conditions. The principal affairs of this procedure are easy work-up, high yields of pure products without the use of any toxic organic solvents, mild condition and short reaction times.

scholarly journals An Ecofriendly Synthesis of 2-oxazolidinone From 2-aminoethanol and Urea Under Solvent-free Condition Using CeO2 Nanoparticles

2021 ◽  
Author(s):  
ALI NEMATI KHARAT ◽  
Mehrnaz Aliahmadi
Keyword(s):  
Gas Adsorption ◽  
Sol Gel ◽  
Solvent Free ◽  
X Ray Diffraction ◽  
Nitrogen Gas ◽  
X Ray ◽  
Solvent Free Condition ◽  
Solvent Free Conditions ◽  
Adsorption Desorption ◽  
Desorption Method

Abstract Cerium dioxide nanoparticles were prepared by the sol-gel method using cellulose as a template and used in the synthesis of 2-oxazolidinone from urea and 2-aminoethanol under solvent-free conditions. All the reaction parameters were optimized to obtain the best selectivity and conversion. The selectivity of 100 % to 2-oxazolidinone with a pretty complete conversion of about 98.4 % was achieved. The prepared catalyst was characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and volumetric isothermal nitrogen gas adsorption-desorption method (BET).

Friedel–Crafts alkylation of 4-hydroxycoumarin over silica-bonded 1,4-diaza-bicyclo[2.2.2] octane-sulfonic acid chloride as nanostructured heterogeneous catalyst

2017 ◽  
Vol 95 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Ehsan Noroozizadeh ◽  
Ahmad Reza Moosavi-Zare ◽  
Mohammad Ali Zolfigol ◽  
Abdolkarim Zare ◽  
Mahmoud Zarei
Keyword(s):  
Heterogeneous Catalyst ◽  
Acid Chloride ◽  
Sulfonic Acid ◽  
Condensation Reaction ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
Efficient Catalyst ◽  
X Ray ◽  
Solvent Free Conditions

A novel nanostructured heterogeneous catalyst, namely silica-bonded 1,4-diaza-bicyclo[2.2.2]octane-sulfonic acid chloride (SBDBSAC), has been synthesized and fully characterized by several techniques, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG), scanning electron microscope (SEM), and energy dispersive X-ray analysis (EDX). Afterward, the nanostructured catalyst was utilized as an efficient catalyst for the synthesis of bis-coumarin derivatives by the condensation reaction of arylaldehydes with 4-hydroxycoumarin at 70 °C under solvent-free conditions.

Facile synthesis of pyrazole derivatives using reusable Fe3O4@MCM-41-SO3H

2021 ◽  
pp. 1-8
Author(s):  
Samanehsadat Sharifi ◽  
Malek Taher Maghsoudlou ◽  
Nourallah Hazeri
Keyword(s):  
Acid Catalyst ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
X Ray ◽  
Solvent Free Conditions ◽  
Lewis Acid Catalyst ◽  
High Yields ◽  
Work Up ◽  
Mcm 41 ◽  
Scanning Electron

In this research, Fe3O4-MCM-41-SO3H was synthesized as a magnetically reusable Lewis acid catalyst and used in the cyclization reaction of 3-acylcoumarins or 3-chromonecarboxylic acid with arylhydrazine derivatives for the synthesis of pyrazoles in high yields under solvent-free conditions and with a simple work-up process. Fe3O4-MCM-41-SO3H was characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analyses.

Magnetically recyclable silica-coated magnetite-molybdate nanocatalyst and its applications in N-formylation reactions under solvent-free conditions-

2022 ◽  
Vol 19 ◽  
Author(s):  
Runjhun Tandon ◽  
Shripad Patil ◽  
Nitin Tandon ◽  
Pushpendra Kumar
Keyword(s):  
Catalytic Activity ◽  
Solvent Free ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solvent Free Conditions ◽  
Ft Ir ◽  
Co Precipitation ◽  
Coated Nanoparticle ◽  
Scanning Electron

Abstract: A novel magnetite silica-coated nanoparticle-supported molybdate nanocatalyst has been prepared successfully by a simple co-precipitation method. Prepared nanocatalyst has been characterized by different techniques like Fourier Transmission Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM) and Energy Dispersive X-ray Spectroscopy (EDX). Further, the catalytic activity of the nanocatalyst was explored for N-formylation reactions under solvent-free conditions. Interestingly, the catalyst could be reused for 10 cycles and only 2 mol % of the catalyst was sufficient to catalyze the N-formylation reaction at 700C under solvent-free conditions.

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