Brønsted Acidic Dicationic Ionic Liquid Immobilized on Fe₃O₄@SiO₂ Nanoparticles as an Efficient and Magnetically Separable Catalyst for the Synthesis of Bispyrazoles

Abstract

In this research article, brønsted acidic dicationic ionic liquid immobilized on silica-coated iron oxide support and its catalytic activity was investigated in the synthesis of bispyrazol-5-ols under solvent-free conditions. The prepared catalyst was characterized by different analytical tools such as XRD, FT-IR, TGA, TEM, and SEM techniques. The catalyst can be recycled at least five times with the remaining of its catalytic activity. The easy recovery, reusability, and excellent activity of the catalyst as well as easy workup are other remarkable advantages of this method.

Synthesis of Imidazolium‐Based Ionic Liquid on Modified Magnetic Nanoparticles for Application in One‐Pot Synthesis of Trisubstituted Imidazoles

“…Also, the effect of diverse temperatures on the model reaction was tested. The results show that the reaction yield was improved when the reaction temperature increased from 25°C to 100°C (Table 1, entries [5][6][7][8].…”

“…Imidazole derivatives were paid much attention owing to their chemical and biological activities such as antibacterial, antitumor, and antiviral properties. Also, the wide range of imidazoles have been used for the preparation of N‐heterocyclic carbenes and ionic liquids in organometallic chemistry and green chemistry. During the past few years, numerous synthetic methods and catalysts have been established for the substituted imidazoles.…”

Greener and practical synthesis of 4,4′‐(arylmethylene)bis(3‐methyl‐1‐phenyl‐1H‐pyrazol‐5‐ol)s through a conventional heating and a mechanochemical procedure

“…Also, the reaction of cyclohexanecarboxaldehyde with ethyl acetoacetate and phenyl hydrazine gave the corresponding product in 75% yield under optimal conditions. The known products were approved by comparing their melting point and 1 H NMR with authentic reports in the literature 4,13,14,32,33 . New products were characterized by melting point, FTIR, 1 H NMR and 13 C NMR, and MS analysis.…”

Green Synthesis of Bis(pyrazol‐5‐ole) and Pyrazolopyranopyrimidine Derivatives through Mechanochemistry Using Chitosan as a Biodegradable Catalyst

“…in the synthesis of bis(pyrazol‐5‐ole) and amine@functionalized poly‐3,3‐bis(chloromethyl) oxetane, meglumine, β ‐dextrine, etc. in the synthesis of pyrazolopyranopyrimidine (Table 1) have been reported earlier but they have many drawbacks [31–38] …”

“…in the synthesis of pyrazolopyranopyrimidine (Table 1) have been reported earlier but they have many drawbacks. [31][32][33][34][35][36][37][38] The current aim of an organic chemist is to maintain the protocol of Green Chemistry and the basics of the area can be smoothened or improved by the transition from traditional, solution-based chemistry to mechanochemical, atom economic and solvent-free conditions. So, we planned to exploit chitosan as a biodegradable catalyst for the multi-component synthesis of each of bis(pyrazol-5-ole) and pyrazolopyranopyrimidine using pestle and mortar under solvent-free conditions (Scheme 1).…”