Green synthesis of 1,3-dihydrobenzimidazol-2-ones from aromatic diamines by microwave in a tetrabutylammonium bromide–ethanol molten salt paste

Aghapoor, Kioumars; Mohsenzadeh, Farshid; Sayahi, Hani; Rastgar, Saeed; Darabi, Hossein Reza

doi:10.1007/s10311-018-0733-8

Cited by 9 publications

(7 citation statements)

References 53 publications

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“…Aghapoor et al [ 69 ] developed a simple, rapid, microwave-assisted protocol for the efficient synthesis of 1,3-dihydrobenzimidazol-2-ones ( 12 ) from the reactions of urea ( 9 ) and o -phenylenediamines ( 10 ) using TBAB as a catalyst in ethanol. Under the optimized reaction conditions, pyridine-2,3-diamine ( 11 ) also reacted with urea ( 9 ) and afforded the corresponding 1 H -imidazo [4,5- b ]pyridin-2(3 H )-one ( 13 ) with 68% yield ( Scheme 6 ).…”

Section: Applications Of Tbab For the Synthesis Of Bioactive mentioning

confidence: 99%

Tetrabutylammonium Bromide (TBAB) Catalyzed Synthesis of Bioactive Heterocycles

Banik

Banerjee²,

Kaur³

et al. 2020

Molecules

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During the last two decades, tetrabutylammonium bromide (TBAB) has gained significant attention as an efficient metal-free homogeneous phase-transfer catalyst. A catalytic amount of TBAB is sufficient to catalyze various alkylation, oxidation, reduction, and esterification processes. It is also employed as an efficient co-catalyst for numerous coupling reactions. It has also acted as an efficient zwitterionic solvent in many organic transformations under molten conditions. In this review, we have summarized the recent developments on TBAB-catalyzed protocols for the efficient synthesis of various biologically promising heterocyclic scaffolds.

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Section: Applications Of Tbab For the Synthesis Of Bioactive mentioning

confidence: 99%

Tetrabutylammonium Bromide (TBAB) Catalyzed Synthesis of Bioactive Heterocycles

Banik

Banerjee²,

Kaur³

et al. 2020

Molecules

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“…Based on the interaction of urea with Zn 2+ ion, it was thought urea had no keto‐enolic form; thus no biuret formation was possible. Indeed, the biuret test revealed to be negative …”

Section: Optimization Of the Reaction Conditions On The Model Reactionmentioning

confidence: 99%

“…In this regard, recently, we have successfully synthesized 2‐benzimidazolone derivatives from arene‐1,2‐diamines and urea using a tetrabutylammonium bromide – ethanol biphasic system under microwave irradiation . In the course of this study, we found out that a meticulous optimization of the molar ratio of the reactants is required in order to obtain the best yield of products with a negative biuret test.…”

Section: Optimization Of the Reaction Conditions On The Model Reactionmentioning

confidence: 99%

“…[65,66] In this regard, recently, we have successfully synthesized 2benzimidazolone derivatives from arene-1,2-diamines and urea using a tetrabutylammonium bromide -ethanol biphasic system under microwave irradiation. [67] In the course of this study, we found out that a meticulous optimization of the molar ratio of the reactants is required in order to obtain the best yield of products with a negative biuret test. Based on our experience in the design of novel biphasic systems for the synthesis of N,N-heterocyclic compounds, [67][68][69][70] we herein wish to introduce an environmentally friendly procedure for the synthesis of 2-benzimidazolones and 2-imidazolones in the presence of ZnCl 2 /urea type IV eutectic as a green sustainable reaction media.…”

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confidence: 99%

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ZnCl₂/Urea Eutectic Solvent as Stable Carbonylation Source for Benign Synthesis of 2–Benzimidazolones and 2–Imidazolones: An Effective Strategy for Preventing NH₃ Gas Evolution

et al. 2019

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The synthesis of 2‐benzimidazolone and 2‐imidazolone derivatives from urea as an inexpensive widely available carbonyl source is usually performed in high boiling organic solvents accompanied by ammonia evolution, due to urea decomposition. In this paper, a sustainable method has been introduced for the synthesis of these N,N‐heterocycles by employing zinc chloride:urea (1 : 3.5) type IV eutectic mixture under mild reaction conditions. No urea was used directly in the reaction owing to the fact that the eutectic mixture (containing urea itself) suffice to provide the carbonylation source. This new concept allowed the smooth conversion of a range of arene‐1,2‐diamines and benzoins to the corresponding N,N‐heterocycle in efficient yields. The remarkable advantage of this green protocol over other conventional heating procedures is that all reactions are conducted under open‐vessel conditions due to the absorption of the evolved ammonia by the eutectic mixture during the reaction process. (© WILEY‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

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“…Up to now, cycloaddition reaction of o-phenylenediamine and carbon source molecule seems to be an effective method for the synthesis of benzimidazoles. The carbon source generally involves a carboxylic acid, 9,11 aldehyde, 1,3,10 ketone, 12 amide, 11,13,14 and carbon dioxide 2,15,16 (Scheme 1). As a special amide, N,N-dimethylformamide (DMF) is not only a carbon source but also an effective polar solvent for the synthesis of benzimidazoles.…”

Section: Introductionmentioning

confidence: 99%

CO2 Improved Synthesis of Benzimidazole with the Catalysis of a New Calcium 4-Amino-3-hydroxybenzoate

Gao¹,

Gao²,

Zhu³

et al. 2021

ACSi

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In this paper, we explored the synthesis of benzimidazole by the reaction of DMF and o-phenylenediamine. In the process of catalyst screening, we found that 4-amino-3-hydroxybenzoic acid, benzoic acid, and benzene-1,3,5-tricarboxylic acid could catalyze the reaction. Moreover, the calcium 4-amino-3-hydroxybenzoate and CO2 could more effectively catalyze the reaction, the synergistic effect of CO2 and 4-amino-3-hydroxybenzoic acid calcium salt can increase the yield of benzimidazole from 28% to 94%.

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Green synthesis of 1,3-dihydrobenzimidazol-2-ones from aromatic diamines by microwave in a tetrabutylammonium bromide–ethanol molten salt paste

Cited by 9 publications

References 53 publications

Tetrabutylammonium Bromide (TBAB) Catalyzed Synthesis of Bioactive Heterocycles

Tetrabutylammonium Bromide (TBAB) Catalyzed Synthesis of Bioactive Heterocycles

ZnCl₂/Urea Eutectic Solvent as Stable Carbonylation Source for Benign Synthesis of 2–Benzimidazolones and 2–Imidazolones: An Effective Strategy for Preventing NH₃ Gas Evolution

CO2 Improved Synthesis of Benzimidazole with the Catalysis of a New Calcium 4-Amino-3-hydroxybenzoate

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Green synthesis of 1,3-dihydrobenzimidazol-2-ones from aromatic diamines by microwave in a tetrabutylammonium bromide–ethanol molten salt paste

Cited by 9 publications

References 53 publications

Tetrabutylammonium Bromide (TBAB) Catalyzed Synthesis of Bioactive Heterocycles

Tetrabutylammonium Bromide (TBAB) Catalyzed Synthesis of Bioactive Heterocycles

ZnCl2/Urea Eutectic Solvent as Stable Carbonylation Source for Benign Synthesis of 2–Benzimidazolones and 2–Imidazolones: An Effective Strategy for Preventing NH3 Gas Evolution

CO2 Improved Synthesis of Benzimidazole with the Catalysis of a New Calcium 4-Amino-3-hydroxybenzoate

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ZnCl₂/Urea Eutectic Solvent as Stable Carbonylation Source for Benign Synthesis of 2–Benzimidazolones and 2–Imidazolones: An Effective Strategy for Preventing NH₃ Gas Evolution