melamine trisulfonic acid (mtsa) as an efficient heterogeneous catalyst has been used for the one-pot preparation of triazolo[1,2-a]indazole-1,3,8-trione and 2h-indazolo[2,1-b]phthalazine-1,6,11-trione derivatives by the three-component condensation reaction of urazoles or phthalhydrazide, dimedone or 1,3-cyclohexanedione, and aldehydes under solvent-free conditions in good to excellent yields ...

this study represents a highly efficient and regioselective ring-opening of epoxides with acetic anhydride in the presence of naoac·3h2o at solvent-free conditions. the ring-opening of different classes of epoxides were carried in oil bath (70-80 °c) to afford 1,2-diacetates in high to excellent yields

sulfonic acid functionalized sba-15 as a nanoporous acid catalyst was used in the synthesis of 2-aryl benzoxazoles 4 by the condensation of 2-aminophenol 1 and benzoyl chlorides 2 under microwave irradiation in solvent free reaction conditions. the advantages of this methodology are good product yields (60-98%), being environmentally benign, short reaction times and easy work up.

nano silica-h2so4 is an efficient and mild catalysis system for the regeneration of aldehyde from aldoximes. ketoximes are converted to amides by beckmann rearrangement in the presence of nano silica-h2so4. the reactions are carried out in solvent-free conditions under microwave irradiation (600 w) within 50-120 sec in good yields.

a simple, fast, efficient and environmentally friendly method for synthesis of benzimidazole and its 2-alkyl, aryl and heteroaryl substituted derivatives was developed using zeolite hy. two component cyclolcondensation of 1,2-phenylenediamine (o-phenylenediamine) and commercially available carboxylic acids catalyzed by zeolite hy without any solvent, under microwave irradiation led to formation...

as benzimidazole ring is an important pharmacophore in modern drug discovery and benzimidazoles are very important intermediates in organic reactions, the preparation of benzimidazoles has gained considerable attention in recent years. here, a comparative study on the synthesis of benzimidazoles from aromatic, aliphatic and heterocyclic carboxylic acid, benzonitrile and o-phenylenediamine under...

cellulose bonded n-propyl diethylene tetra sulfamic acid (cbpdetsa) was successfully applied as a green and recyclable acidic catalyst for the synthesis of tetrahydrobenzo [a] xanthene-11-one as an important class of potentially bioactive compounds. the products are obtained by the coupling of 2-naphtol , cyclohexadione and aldehyde derivatives in good to high yields (70- 92%) under solvent-fre...

a mild, efficient and fast method for the oxidation of alcohols and trimethylsilyl and tetrahydropyranyl ethers to their corresponding carbonyl compounds using cro3 in the presence of sulfonic acid functionalized ordered nanoporous na+-montmorillonite (sanm) and under solvent-free conditions is reported. all reactions were performed at room temperature in high to excellent yields. ease of the p...

nanosilica periodic acid (nano-spia) is found to be a new, powerful, and reusable heterogeneous catalyst for the rapid synthesis of 2-naphtholazo dyes via diazotization of aromatic amines and followsazo coupling with 2-naphthol under solvent-free conditions at room temperature by grinding. eco-friendly, heterogeneous reaction conditions, high stability of diazonium salt, simple experimental pro...