Nano Rice Husk Ash Modified with Acidic Ionic Liquid Bridge: An Efficient Promoter for the Synthesis of 1,2,4-Triazolo Quinazolinones

In this study, a new heterogeneous catalyst was obtained easily and simply from the preparation and consolidation of bis-3-(trimethoxysilylpropyl)-ammonium hydrogen sulfate on nano rice husk ash [RHA-[bip]-NH2+ HSO4–]. After identification this reagent using different techniques including FT-IR, XRD, FESEM, TEM, and TGA, its application as an efficient catalyst was investigated in the acceleration of the preparation of 1,2,4-triazolo quinazolinones. All reactions using this catalyst were performed under solvent-free conditions and all products were obtained in suitable times with high isolated yields without the formation of any by-products. Furthermore, the reusability of the catalyst was investigated during successive three runs.</p

Introduction of PEG-SANM nanocomposite as a new and highly efficient reagent for the promotion of the silylation of alcohols and phenols and deprotection of the silyl ethers

<p>Poly (ethylene glycol)-sulfonated sodium montmorillonite (PEG-SANM) nanocomposite was prepared by a simple method and characterized using XRD, TGA, SEM, TEM, and FT-IR techniques. After preparation and characterization, this reagent was used as a highly efficient and reusable solid acid catalyst for the chemoselective silylation of alcohols and phenols and deprotection of the obtained silyl ethers. The method offers several advantages including high to excellent yields of the products, short reaction times, easy preparation of the catalyst and easy work-up procedure. In addition, the catalyst can be recycled and reused at least for five times without significant decrease in the catalytic activity.</p

Sustainable, Scalable, and One-Pot Synthesis of Isoxazol-5(4<i>H</i>)-One and 1,2,4-Triazoloquinazolinone Derivatives Using a Natural Deep Eutectic Solvent

In this work, a sustainable and efficient procedure for the synthesis of isoxazol-5(4H)-one and 1,2,4-triazoloquinazolinone derivatives via multi-component reactions using a natural deep eutectic solvent prepared from choline chloride and glutamic acid is described. The proposed methodology is capable of providing the requested products during acceptable reaction times in good to high yields under green conditions. The utilization of affordable, readily available, non-toxic, and bio-compatible reagents for the synthesis of the catalyst, a straightforward procedure for the preparation of the catalyst and products, simple work-up, and applicability in large-scale synthesis are the prominent features of this method. Also, the catalyst can be recovered easily and reused several times in the studied reactions.</p

Introduction of a New Ionic Liquid Catalyst for the Trimethylsilyl and Tetrahydropyranyl Protection of Alcohols

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Novel, One-Pot, Three-Component, Regioselective Synthesis of Fluorine-Containing Thiazole and Bis-3<i>H</i>-thiazole Derivatives Using Polyvinyl Pyridine as Heterogeneous Catalyst, and Evaluation of Their Antibacterial Activity

<div><p></p><p>A convenient, one-pot, three-component regioselective synthesis of novel 2,2′-(1,4-phenylene)-bis-(3-aryl-2-substituted imino-4-aryl-3H-thiazole) derivatives from 1,4-phenylene diisothiocyanate, aryl amines, and various phenacyl bromide, and also the regioselective synthesis of 3-alkyl-2-(aryl imino)-4-cyclopropyl-5-(2′-fluorophenyl)-thiazole derivatives from alkylisothiocyanate, aryl amines, and 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone in the presence of poly-4-vinyl pyridine as heterogenous basic catalyst are described. This efficient method produced the products at room temperature with excellent yields (82–96%). The structures of all products were characterized by spectral and elemental analyses. The antimicrobial activity of the synthesized compounds was evaluated against <i>Salmonella enterica, Micrococcus luteus, Bacillus subtilis</i>, and <i>Pseudomonas aeruginosa</i>.</p></div