An Efficient, Green, and Solvent‐free Multi‐component Synthesis of Benzimidazolo/Benzothiazolo Quinazolinone Derivatives Using Sc (OTf)<sub>3</sub> Catalyst Under Controlled Microwave Irradiation

Gajaganti, Somaiah; Kumari, Savita; Kumar, Dhirendra; Allam, Bharat Kumar; Srivastava, Vandana; Singh, Sundaram

doi:10.1002/jhet.3314

Cited by 28 publications

(18 citation statements)

References 38 publications

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“…Microwave radiation is used to intensify many reactions in organic chemistry. From this point of view, the implementation of the process as shown in Scheme 36 under microwave irradiation conditions without solvent and catalysts, 97 as well as under the conditions of catalysis by Sc(OTf) 3 98 is of great synthetic importance.…”

Section: Construction Of Pyrimidobenzimidazole Structure By Multicomponent Reactionsmentioning

confidence: 99%

Pyrimido[1,2-a]benzimidazoles: synthesis and perspective of their pharmacological use

Fedotov

Русинов

Ulomsky

et al. 2021

Chem Heterocycl Comp

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Nitrogen-containing heterocyclic compounds are the basis of many natural and synthetic biologically active substances. 1 More than two-thirds of the known drugs used in clinical practice contain heterocyclic and, above all, nitrogen-containing fragments within their structure. Over the past decades, the chemistry of aza-heterocycles has received considerable attention due to the wide spectrum of their biological activity and numerous therapeutic applications in medicine.Of nitrogenous heterocycles, azoloazines containing fragments similar to the natural heterocycles purines and pyrimidines are currently of great practical importance. Thus, non-natural nucleosides abacavir, famciclovir, remdesivir are known, which are the products of structural modifications of all the components of the nucleotide exhibiting excellent indicators of antiviral action (Fig. 1). [2][3][4] In addition to the generally accepted nucleoside forms, the azoloazines themselves are relevant in the search for means of combating diseases on a global scale. Nitroazolo- [5,1-c][1,2,4]triazines and nitroazolo [1,5-a]pyrimidines, a new family of antiviral compounds has been found. 5 The

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Section: Construction Of Pyrimidobenzimidazole Structure By Multicomponent Reactionsmentioning

confidence: 99%

Pyrimido[1,2-a]benzimidazoles: synthesis and perspective of their pharmacological use

Fedotov

Русинов

Ulomsky

et al. 2021

Chem Heterocycl Comp

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“…The fused substituted benzothiazolo/benzimidazoloquinazolinones 167 was achieved by Singh and co-workers [142] from aldehyde 5, cyclic 1,3-diketones 6a,b and 2-aminobenzoazoles 104 as the structural fragments with Sc(OTf) 3 as catalyst under microwave irradiation in solvent-free conditions (Scheme 67). The catalytic activity of the catalyst was evident to remain intact even with three successive runs and provided with an environmentally benign and cost effective approach towards the construction of fused quinazolinones.…”

Section: Fused Quinazolinonesmentioning

confidence: 99%

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

Gulati¹,

John²,

Shankaraiah³

2021

Beilstein J. Org. Chem.

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Microwave-assisted (MWA) multicomponent reactions (MCRs) have successfully emerged as one of the useful tools in the synthesis of biologically relevant heterocycles. These reactions are strategically employed for the generation of a variety of heterocycles along with multiple point diversifications. Over the last few decades classical MCRs such as Ugi, Biginelli, etc. have witnessed enhanced yield and efficiency with microwave assistance. The highlights of MWA-MCRs are high yields, reduced reaction time, selectivity, atom economy and simpler purification techniques, such an approach can accelerate the drug discovery process. The present review focuses on the recent advances in MWA-MCRs and their mechanistic insights over the past decade and shed light on its advantage over the conventional approach.

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“…Of special interest for synthesizing drugs are C-3 oxo-substituted imidazoheterocycles. An example of green synthesis is Sc(OTf) 3 -catalyzed MW-assisted atom-economy three-component reaction of 2-aminobenzothiazole, aromatic aldehydes and 1,3-diketones, leading to annulated products 38 bearing pharmacophore motifs (Scheme 30) [60]. The reaction proceeds as the CO-activation, Knoevenagel condensation reaction, and nucleophilic addition of azole followed by intramolecular cyclization.…”

Section: Annulation Reactionsmentioning

confidence: 99%

Modern Approaches to the Synthesis and Transformations of Practically Valuable Benzothiazole Derivatives

2021

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The review is devoted to modern trends in the chemistry of 2-amino and 2-mercapto substituted benzothiazoles covering the literature since 2015. The reviewed heterocycles belong to biologically active and industrially demanded compounds. Newly developed synthesis methods can be divided into conventional multistep processes and one-pot, atom economy procedures, realized using green chemistry principles and simple reagents. The easy functionalization of the 2-NH2 and 2-SH groups and the benzene ring of the benzothiazole moiety allows considering them as highly reactive building blocks for organic and organoelement synthesis, including the synthesis of pharmacologically active heterocycles. The review provides a summary of findings, which may be useful for developing new drugs and materials and new synthetic approaches and patterns of reactivity.

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An Efficient, Green, and Solvent‐free Multi‐component Synthesis of Benzimidazolo/Benzothiazolo Quinazolinone Derivatives Using Sc (OTf)₃ Catalyst Under Controlled Microwave Irradiation

Cited by 28 publications

References 38 publications

Pyrimido[1,2-a]benzimidazoles: synthesis and perspective of their pharmacological use

Pyrimido[1,2-a]benzimidazoles: synthesis and perspective of their pharmacological use

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

Modern Approaches to the Synthesis and Transformations of Practically Valuable Benzothiazole Derivatives

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An Efficient, Green, and Solvent‐free Multi‐component Synthesis of Benzimidazolo/Benzothiazolo Quinazolinone Derivatives Using Sc (OTf)3 Catalyst Under Controlled Microwave Irradiation

Cited by 28 publications

References 38 publications

Pyrimido[1,2-a]benzimidazoles: synthesis and perspective of their pharmacological use

Pyrimido[1,2-a]benzimidazoles: synthesis and perspective of their pharmacological use

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

Modern Approaches to the Synthesis and Transformations of Practically Valuable Benzothiazole Derivatives

Contact Info

Product

Resources

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An Efficient, Green, and Solvent‐free Multi‐component Synthesis of Benzimidazolo/Benzothiazolo Quinazolinone Derivatives Using Sc (OTf)₃ Catalyst Under Controlled Microwave Irradiation