N-Bromo Reagent Mediated Oxidation of Urazoles to Their Corresponding Triazolinediones under Mild and Heterogeneous Conditions

Silica‐bonded S‐Sulfonic Acid: A Recyclable Catalyst for the Synthesis of Trisubstituted Imidazoles under Solvent‐free Conditions

“…In our continued interest in the development of a highly expedient methodology for the synthesis of fine chemicals and heterocyclic compounds of biological importance, [30][31][32][33][34][35] we report here the synthesis of trisubstituted imidazoles in the presence of SBSSA under solvent-free conditions (Scheme 2).…”

Silica‐bonded S‐sulfonic Acid as a Recyclable Catalyst for Synthesis of 2,3‐Dihydroquinazolin‐4(1H)‐ones

“…During our studies towards the development of new routes to the synthesis of highly substituted heterocycles and the usage of solid acid catalysts, [28][29][30][31][32] we wish to report a valid and an efficient procedure for synthesis of 2,3-dihydroquinazolinones via one-pot condensation of isatoic anhydride and aldehydes with NH 4 OAc or primary amine in the presence of silica-bonded S-sulfonic acid (SBSSA) as an inexpensive solid acid catalyst (Scheme 2).…”

Organic Solid Acid/NaNO2: An Efficient System for the Oxidation of Urazoles and Bis-Urazoles under Mild and Heterogeneous Conditions

“…reagents [14,[16][17][18], the following mechanism for the oxidation reaction via in situ generation of NO + may be suggested (Scheme 3).…”

“…It have been demonstrated that application of heterogeneous systems, for the above reported oxidations, has many advantages over their liquid phase counterparts such as simple experimental procedures, mild reactions conditions and minimization of chemical waste materials [14,18].…”