Water-Mediated Green Synthesis of Benzimidazoles Using Pyruvic Acid: A Comparable Study of Ultra-sonication versus Conventional Heating

2021 ◽  
Vol 18 ◽  
Author(s):  
Santosh Rangnath Deshmukh ◽  
Archana Subhash Nalkar ◽  
Shankar Ramchandra Thopate
Keyword(s):  
Pyruvic Acid ◽  
Reaction Times ◽  
Acid Catalyst ◽  
Aromatic Aldehydes ◽  
Ultrasound Irradiation ◽  
Conventional Heating ◽  
Benzimidazole Derivatives ◽  
Green Protocol ◽  
Catalyst Metal ◽  
Wide Range

: An efficient and green protocol has been introduced for the synthesis of benzimidazole derivatives using a pyruvic acid catalyst in the presence of water. Pyruvic acid catalyses the reaction of aromatic aldehydes with o-phenylenediamine efficiently, and products were obtained in good to excellent yields under sonication (50 oC) or under conventional heating (50 oC). The advantages of this synthetic methodology are the use of eco-friendly, commercially cheap, biodegradable catalyst, metal-free and Lewis acid-free mild reaction conditions with excellent yields, short reaction times, and compatible with a wide range of electronically diverse substrates. Pyruvic acid in water as a catalyst under ultrasound irradiation can be a better alternative to synthesize benzimidazole derivatives than some of the traditional methods.

scholarly journals Ferrocene-Containing Ionic Liquid Supported on Silica Nanospheres (SiO2@Imid-Cl@Fc) as a Mild and Efficient Heterogeneous Catalyst for the Synthesis of Pyrano[3,2-b]Pyran Derivatives Under Ultrasound Irradiation

2018 ◽  
Vol 42 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Reza Teimuri-Mofrad ◽  
Somayeh Esmati ◽  
Masoumeh Rabiei ◽  
Mahdi Gholamhosseini-Nazari
Keyword(s):  
Ionic Liquid ◽  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Ultrasound Irradiation ◽  
Xrd Analysis ◽  
Catalytic Performance ◽  
Significant Loss ◽  
One Pot ◽  
X Ray ◽  
Three Component Reaction

A novel heterogeneous silica nanosphere-supported ferrocene-containing ionic liquid catalyst (SiO2@Imid-Cl@Fc) was designed and synthesised and was systematically characterised by Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis. The catalytic activity of the SiO2@Imid-Cl@Fc catalyst was tested in a one-pot, three-component reaction of malononitrile and kojic acid with 15 aromatic aldehydes at room temperature under ultrasound irradiation. The products were pyrano[3,2-b]pyran derivatives, four of which are new. The catalyst exhibited good catalytic performance over short reaction times (15–20 min) and could be recycled at least five times without significant loss of activity.

Ultrasonic Activated, Highly Efficient and Regioselective Synthesis of a Novel Pyrrole- Linked benzo[f]chromene Scaffold in a Green Media

2018 ◽  
Vol 15 (6) ◽  
pp. 872-880 ◽  
Author(s):  
Fateme Tavakoli ◽  
Manouchehr Mamaghani ◽  
Mehdi Sheykhan ◽  
Narjes Mohammadipour ◽  
Mehdi Rassa
Keyword(s):  
Antibacterial Activity ◽  
Single Molecule ◽  
Aromatic Aldehydes ◽  
Model Reaction ◽  
Conventional Heating ◽  
Initial Attempt ◽  
One Pot ◽  
Green Protocol ◽  
Three Component Reaction ◽  
The Impact

Aim and Objective: Chromene scaffold is one of the most famous oxygen heterocycles that have widely found in plants playing pivotal roles in medicinal and synthetic chemistry. This study was undertaken to provide a green protocol for the synthesis of novel functionalized chromen-pyrrole hybrids by a regioselective three-component reaction via both conventional and sonochemical methods. Because of fascinating features of these individual cores, a hybride molecular structure comprising of pyrrole and chromene moieties could result in a novel single molecule with increased efficacy. Materials and Methods: The synthesis of novel functionalized chromen-pyrrole hybrids was accomplished by regioselective three-component reaction of β-naphthol, 3-(1-methyl-1H-pyrrol-2-yl)-3-oxopropanenitrile and diverse aromatic aldehydes catalyzed by triethylamine in H2O-EtOH via both conventional and sonochemical methods. The impact of some variants such as solvents, catalysts and temperature was also probed under both conventional heating and sonochemical methods to accomplish the optimized reaction condition. The synthesized products were screened for antibacterial activity against Gram positive (Ml, Bs, Sa) and Gram negative bacteria (Ps, Ec). Results: In initial attempt, the reaction of equimolar amounts of 2-fluorobenzaldehyde, 3-(1-methyl-1H-pyrrol- 2-yl)-3-oxopropanenitrile and β-naphthol was selected as a model reaction. The role of various solvents, temperature and different acidic and basic catalysts on the model reaction was examined. The optimized condition was the use of 20 mol% triethylamine in H2O-EtOH (1:1) under ultrasound irradiation at 65°C. The scope of this reaction was screened with respect to various substituted aromatic aldehydes. Considering the results, the electronic features of substituents affected the performance of this condensation. The reaction with aromatic aldehydes containing electron-withdrawing groups proceeded in lower reaction time, affording the productds in high to excellent yields while aldehydes with electron-donating groups reacted more slowly. This three-component reaction also provided a suitable procedure for the synthesis of bis-(chromen-pyrrole) in excellent yield. All of the synthesized products had significant antibacterial activity against the screened bacteria (Ml, Bs, Sa, Ps, Ec). Conclusion: A streamlined, regioselective and ecofriendly ultrasonic-promoted procedure for the synthesis of novel substituted benzo[f]chromenes from one-pot condensation of β-naphthol, 3-(1-methyl-1H-pyrrol-2-yl)-3- oxopropanenitrile and structurally diverse aldehydes catalyzed by triethylamine was developed. This green protocol furnishes all the products in reduced reaction times and high yields. In addition, the synthesized novel compounds showed narrow to wide spectral activity against the tested strains.

The Discovery of Ultrasound Irradiation as a Useful Tool for Accelerating Petasis Three-component Reaction: Synthesis of α-Arylglycines

2018 ◽  
Vol 15 (2) ◽  
pp. 256-266 ◽  
Author(s):  
Fan Yun ◽  
Chunhui Cheng ◽  
Jingxuan Li ◽  
Pingwah Tang ◽  
Qipeng Yuan
Keyword(s):  
Reaction Time ◽  
Glyoxylic Acid ◽  
Reaction Times ◽  
Ultrasound Irradiation ◽  
Secondary Amines ◽  
One Pot ◽  
Petasis Reaction ◽  
Three Component Reaction ◽  
Wide Range ◽  
High Yields

Aim and Objective: α-Arylglycines belong to an important class of non-proteinogenic amino acids. Petasis 3-component, one-pot reaction lends itself to be suitable for the synthesis of α-Arylglycines. Because of the low reactivity, Petasis reaction requires long reaction time. Our objective is to use ultrasound irradiation to accelerate this versatile Petasis' synthesis of α-Arylglycines. Materials and Methods: Ultrasound irradiation as a physical tool to accelerate the Petasis 3-component reaction without any auxiliary catalyst can significantly shorten the reaction time. The operation is simple. It can be applied to a wide range of substrates. In order to highlight the remarkable utility of the ultrasound in Petasis reaction, we have compared side-by-side the reactivity between the reaction with ultrasound and the one without ultrasound. Results: Using ultrasound, the reaction times of Petasis reactions with various amine substrates including primary and secondary amines, heterocyclic amines, with a wide variety of boronic acids having different substituents (activating and deactivating groups) in the phenyl rings, and with glyoxylic acid and salicylic aldehyde were shortened from 5 to more than 20-fold. Conclusion: We have discovered the first examples of an efficient ultrasound-promoted approach for Petasis reaction to prepare a series of α-arylglycines in high yields and in excellent purities. The low reactivity of the reactions in this study were significantly enhanced by the ultrasound irradiation. By virtue of the acceleration and the operational simplicity, the present ultrasound assisted Petasis reaction can find applications in the synthetic areas of the already widely used Petasis three-component reaction.

scholarly journals One-pot Three-component Synthesis of β-amino Carbonyl Compounds Using Nanocrystalline Solid Acid Catalyst

2013 ◽  
Vol 1 ◽  
pp. 194308921350716 ◽  
Author(s):  
Abbas Teimouri ◽  
Leila Ghorbanian
Keyword(s):  
Carbonyl Compounds ◽  
Organic Molecules ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Reaction Times ◽  
Acid Catalyst ◽  
Aromatic Aldehydes ◽  
Efficient Synthesis ◽  
One Pot ◽  
The Mannich Reaction

This study presents a simple highly versatile and efficient synthesis of various β-amino carbonyl compounds in the Mannich reaction of acetophenone with aromatic aldehydes and aromatic amines in the presence of nanosulfated zirconia, nanostructured ZnO, nano-γ-alumina, and nano-ZSM-5 zeolites as the catalyst in ethanol at moderate temperature. The optical properties of the nanostructured organic molecules were studied. The advantages of methods are short reaction times, milder conditions, easy workup, and purification of products by nonchromatographic methods. The catalysts can be recovered for the subsequent reactions and reused without any appreciable loss of efficiency.

scholarly journals One-Pot Synthesis of Tetrasubstituted Imidazoles Catalyzed by Preyssler-Type Heteropoly Acid

2011 ◽  
Vol 8 (2) ◽  
pp. 547-552 ◽  
Author(s):  
Ali Javid ◽  
Majid M. Heravi ◽  
F. F. Bamoharram ◽  
Mohsen Nikpour
Keyword(s):  
Heteropoly Acid ◽  
Ammonium Acetate ◽  
Reaction Times ◽  
Acid Catalyst ◽  
Aromatic Aldehydes ◽  
Primary Amines ◽  
One Pot ◽  
High Yields ◽  
Work Up ◽  
Tetrasubstituted Imidazoles

A simple one-pot four-component synthetic method was reported for the preparation of tetrasubstituted imidazole derivatives from benzil, aromatic aldehydes, primary amines and ammonium acetate in the presence of Preyssler-type heteropoly acid catalyst. This method was proved to be eco-benign, easy work-up, convenient, relatively short reaction times and the products were isolated with high yields.

scholarly journals Comparative Study on Conventional and Ultrasound Irradiation Promoted Synthesis of 2,3-Disubstitutedquinoxaline Derivatives

2018 ◽  
Vol 28 (3) ◽  
pp. 141
Author(s):  
Ahmed Mutanabbi Abdula ◽  
Ghazwan Ali Salman ◽  
Hamid H. Mohammed
Keyword(s):  
13C Nmr ◽  
Ultrasonic Irradiation ◽  
Reaction Times ◽  
Ultrasound Irradiation ◽  
Conventional Heating ◽  
Heating Method ◽  
Quinoxaline Derivatives ◽  
Ft Ir ◽  
Ultrasound Assisted ◽  
Good Percentage

A series of ten chalcone-substituted quinoxalines (4a-e), (3a-e) starting from 1-(phenylquinoxalin-2-yl)ethanone and 1-(3-methylquinoxalin-2-yl)ethanone have been synthesized using conventional heating and ultrasound-assisted methods. Furthermore, novel of five quinoxaline derivatives including pyrazoline, isoxazole, pyrimidin-2-one, N-acylpyrazoline and pyridin-2-one moieties were also prepared from the reaction of chalcone compound 4a with different cyclization reagents using the same strategy. The structures of all synthesized compounds were established on the basis of FT-IR, 1H-NMR and 13C-NMR. The ultrasonic irradiation method provide several advantages over conventional heating method, including shorter reaction times (30-90 min.) and good percentage yields (65% - 88%), comparing with conventional protocol (5 to 20 hrs. with 30% to 55% reaction yields).

Chitosan-attached nano-Fe3O4 as a superior and retrievable heterogeneous catalyst for the synthesis of benzopyranophenazines using chitosan-attached nano-Fe3O4

2019 ◽  
Vol 74 (10) ◽  
pp. 733-738
Author(s):  
Javad Safaei-Ghomi ◽  
Maryam Tavazo ◽  
Hossein Shahbazi-Alavi
Keyword(s):  
Solid Acid Catalyst ◽  
Reaction Times ◽  
Acid Catalyst ◽  
Catalyst Loading ◽  
High Catalytic Activity ◽  
One Pot ◽  
X Ray ◽  
Wide Range ◽  
Nano Fe3o4 ◽  
Low Catalyst Loading

AbstractA simple and rapid method for the preparation of benzopyranophenazines is presented, involving a one-pot four-component reaction of hydroxynaphthoquinone, o-phenylenediamine, benzaldehydes, and malononitrile with nano-Fe3O4@chitosan as an efficient heterogeneous solid acid catalyst under reflux conditions in ethanol. The catalyst is characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), magnetic susceptibility measurements, energy-dispersive X-ray spectroscopy (EDS), and Fourier transform infrared (FT-IR) spectroscopy. Atom economy, high catalytic activity, a wide range of products, excellent yields in short reaction times, and low catalyst loading are some of the important features of this method.

scholarly journals Methanolysis of Jatropha Oil Using Conventional Heating

2011 ◽  
Vol 11 (1) ◽  
pp. 41 ◽  
Author(s):  
Susan A Roces ◽  
Raymond Tan ◽  
Francisco Jose T Da Cruz ◽  
Shuren C Gong ◽  
Rison K Veracruz
Keyword(s):  
Fatty Acid ◽  
Methyl Esters ◽  
Reaction Times ◽  
Acid Catalyst ◽  
Conventional Heating ◽  
Molar Ratio ◽  
Jatropha Oil ◽  
Separation And Purification ◽  
Step Process ◽  
Standard Range

Studies were carried out on the transesterification, also called methanolysis, of oil from the Jatropha curcas L. with methanol using conventional heating for the production of biodiesel. All reactions were carried out in a batch-stirred reactor and in the subsequent separation and purification stages. The high free-fatty acid (FFA) level of Jatropha oil was reduced to less than 1% by a two-step process. The first step was carried out with 12% w/w methanol-to-oil ratio in the presence of 1% w/w HCl as acid catalyst in a 2h reaction at 343K. The second step was carried out with variable parameters: temperatures at 318K and 333K, initial catalyst concentrations at 0.5% and 1.5%, methanol:oil molar ratios at 4:1 and 6:1, and reaction times at 1h and 2h. Gas chromatography analysis was used to determine the fatty acid profile of crude Jatropha oil. Methanolysis of Jatropha oil used the catalysts NaOH and KOH. The high FFA level of Jatropha oil was reduced from 6.1% to 0.7% after the first step process. The highest yield of fatty acid methyl esters (FAME), however, was achieved at 92.7% in 2h at 4:1 methanol:oil molar ratio, 1.5% w/w KOH, and 333K reaction temperature. This method produced biodiesel that met ASTM’s biodiesel standards. Results showed a density of 0.8g/ml that is within 0.86–0.9kg/l standard range and a kinematic viscosity of about 4.1cSt that is within 2–4.5cSt standard range. The flash point of the biodiesel samples fell between 169oC and 179oC while the cloud point averaged at 6oC.

Inexpensive Weight-Reducing Aid (L-Carnitine) as An Efficient Catalyst for Synthesis of Benzimidazoles

2018 ◽  
Vol 21 (8) ◽  
pp. 567-570
Author(s):  
Min Zhang ◽  
Guoling Huang ◽  
Xuefang Zhang ◽  
Zhenyuan Lin ◽  
Yibiao Li ◽  
...  
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Internal Standard ◽  
Aromatic Aldehydes ◽  
Benzimidazole Derivatives ◽  
Metallic Oxide ◽  
Efficient Catalyst ◽  
Excellent Yield ◽  
Wide Range ◽  
Work Up

Aim and Objective: The benzimidazole derivatives have been obtained via weightreducing aid (L-Carnitine) as a cheap catalyst. A wide range of aromatic aldehydes easily undergo condensations with substituted o-phenylendiamine under mild condition to afford the target molecular in excellent yields. Materials and Methods: Melting points were measured on an Electrothemal X6 microscopy digital melting point apparatus. 1H NMR and 13C NMR spectra were recorded in DMSO-d6 on a Bruker AVANCE 400 (400 MHz) instrument with the TMS at d 0.00 ppm as an internal standard. C, H and N analysis were performed by a Perkin-Elmer 2400 CHN elemental analyzer. Chemicals used were of commercial grade without further purification. An equimloar (1.0 mmol) mixture of o-phenylenediamine 1, aromatic aldehyde 2, and L-Carnitine (10 mol%) was vigorously stirred at 60°C in EtOH (3 mL) for the specific time indicated by TLC (petroleum: ethyl acetate ether = 4:1). After completion of the reaction, the mixture was quenched by adding H2O (20 mL), extracted with EtOAc (3 x 10 mL), and the combined extracts were dried by anhydrous MgSO4. The filtrate was evaporated and the corresponding benzimidazole was obtained as the only product. The products 3a–3r were obtained in 82–95% yields. The structures of the products 3 were identified by their IR, 1H NMR, 13C NMR and elemental analysis spectra. Results: The products were obtained in 82–95% yields in 30–80 min. The method has several advantages such as simple, clean and environmentally process, excellent yield and avoiding use of inconvenient preparation of catalyst. Meanwhile, the catalyst L-Carnitine is a kind of weightreducing aid, which might be applied to broad green catalyzed system. Conclusion: A facile synthesis of benzimidazoles comprising the reaction of various aldehydes with substituted o-phenylendiamine in good to excellent yield is provided using L-Carnitine as an efficient catalyst. The protocol overcomes the earlier disadvantages like harsh reaction conditions, tedious work-up, expensive process, wastes generation and the use of metallic oxide, which might be applied to the synthesis of benzimidazoles pharmaceticals in order to meet friendly environmental demands.

Benzimidazole as Ubiquitous Structural Fragment : An Update on Development of its Green Synthetic Approaches

2020 ◽  
Vol 17 ◽  
Author(s):  
Ashish Patel ◽  
Drashti Shah ◽  
Naiya Patel ◽  
Khushbu Patel ◽  
Nidhi Soni ◽  
...  
Keyword(s):  
Condensation Reaction ◽  
Aromatic Aldehydes ◽  
Ultrasound Irradiation ◽  
Heating Time ◽  
Biologically Active ◽  
New Drugs ◽  
Current Status ◽  
Benzimidazole Derivatives ◽  
Structural Fragment ◽  
Short Period

Abstract: The benzimidazole and its derivatives are privileged heterocyclic motif and important building block for the development of the biologically active compound. However, several research reports are produced in a short period of time due to the rapid production of new drugs having a benzimidazole nucleus. In order to understand the current status of the benzimidazole nucleus in medicinal chemistry science, it is therefore important to combine the latest knowledge with earlier information. Hence, synthetic organic chemists concentrated on inventing an effective green methodology for synthesizing benzimidazole derivatives. In addition to this, non-degradable chemical compounds cause the ecosystem to become fragile, damage or irritation as contaminants and pose a danger to the environment. However, conventional methods of synthesis need longer heating time, complicated and tedious apparatus set up which result in high cost and pollution in contrast to greener methods which are inexpensive. In the present review, therefore, we have attempted to shed light on various synthetic strategies leading to the synthesis of different benzimidazole derivatives through the direct condensation reaction between o-phenylenediamine and aromatic aldehydes using green chemistry approaches such as mechanochemistry, ultrasound irradiation, microwave irradiation, environmentally benign solvents/catalysts, reactant immobilized on a solid support and blue light irradiation.

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