Nickel nanoparticles assisted regioselective synthesis of pyrazoloquinolinone and triazoloquinazolinone derivatives

Abstract

Biologically important pyrazoloquinolinone and triazoloquinazolinone derivatives were synthesized by the condensation reaction of 3-amino-1H-1,2,4-triazole/3-amino-5-methyl-1H-pyrazole, dimedone and aryl aldehydes using catalytic amount of magnetically retrievable nickel nanoparticles under reflux condition. This protocol eliminates the usage of toxic reagents, complex work-up conditions, etc., with the added benefit of reusability of the catalyst without compromising the yield or purity of the product. Results and discussionOur present work deals with the synthesis of triazoloquinazolinones/pyrazoloquinolinones through a simple method in

Regenerable Acidity of Graphene Oxide in Promoting Multicomponent Organic Synthesis

“…Ethanol could provide both sufficient polarity for homogeneous 1xGO dispersion and higher solubility for the reactants when compared to the other solvents. According to the previous reports, acid promoted synthesis of 4a was typically carried out in acetonitrile, a more toxic solvent compared to ethanol 36,37 . The amount of 1xGO used in the reaction affects the yields.…”

“…In the past decade, efforts have been made to synthesize triazoloquinazolinone using different acid catalysts in MCR approach 32–35 , where Lewis acids were proved to be important in facilitating reaction yields. For example, the Lewis acidities of nickel nanoparticles, molecular iodine, and hydrotalcites have been shown to promote the multicomponent synthesis of triazoloquinazolinones effectively 36–38 . However, the drawbacks of non-reusable promoters, toxic solvents, corrosive homogenous acid promoters, and complicated catalysts were involved.…”

α-Aminoazoles/azines: key reaction partners for multicomponent reactions

“…The products were isolated after 12–20 min in excellent yields. 74 To date, various practical approaches have been developed, wherein the same starting materials are being reacted in the presence of catalysts such as Fe 3 O 4 @chitosan, 75 Fe 3 O 4 @clay nanocomposite, 76 choline chloride:glycerol as a deep eutectic solvent, 77 1-methyl-1-sulfonic acid pyrrolidinium chloride [MPyrrSO 3 H]Cl/4-methyl-4-sulfonic acid morpholinium chloride [MMorSO 3 H]Cl, 78 Sc(OTf) 3 , 79 Brönsted acidic ionic liquid supported on rice husk ash (RHA-[pmim]HSO 4 ), 80 montmorillonite KSF as a heterogeneous catalyst, 81 nickel nanoparticles, 82 CAN, 83 microwave irradiation at 150 W, 84 hydrotalcite (Mg–Al–CO 3 ), 85 chitosan, 86 nanosheets AlPO 4 (SO 3 H), 87 graphene oxide (GO), 88 γ-Fe 2 O 3 @SiO 2 @[bis-APTES]Cl 2 nanoparticles, 89 and catalyst- and solvent-free conditions at 160–170 °C 90 by various research groups. All these methods were proven to be highly efficient, giving the products in excellent yields in a shorter time ( Scheme 24 ).…”

The Recent Progress on Supported and Recyclable Nickel Catalysts towards Organic Transformations: A Review

“…The retrievable Ni‐nanocatalysts are employed in the regioselective Hantzsch and Biginelli type reactions through MCRs to construct biologically important heterocyclic skeletons like triazoloquinazolinones and pyrazoloquinolinones [62] . The Supported Ni catalyzed region‐selective formation of pyrazoloquinolinones (Hantzsch‐type product) from substituted aminopyrazole was observed by the authors rather than Biginelli‐type product.…”