نتایج جستجو برای: solvent free conditions
تعداد نتایج: 1355934 فیلتر نتایج به سال:
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 ...
Brønsted acidic ionic liquid triethylamine-bonded sulfonic acid {[Et3N-SO3H]Cl} efficiently catalyzes the one-pot multi-component condensation of 2-naphthol with arylaldehydes and dimedone (5,5-dimethylcyclohexane-1,3-dione) under solvent-free conditions to afford 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-ones in high yields and relatively short reaction times.
An efficient green route for the preparation of naphthoxazinones, applying a three-component one-pot condensation reaction of 2-naphthol, aromatic aldehyde and urea in the presence of nano silica supported ferric chloride under solvent-free conditions has been developed. The present procedure offers several advantages such as short reaction time, simple workup, recovery and reusability of the c...
Nano-silica supported boron trifluoride (BF3.SiO2) is an efficient, reusable and eco-friendly catalyst for chemoselective thioacetalization of aldehydes and ketones. So, this catalyst was applied for transthioacetalization of acetals and acylals into their corresponding 1,3-dithiolanes or 1,3-dithianes in good to excellent yields. The reactions were carried out at room temperature under solven...
A novel, simple and environmentally friendly method is reported for the preparation of 1,8-dioxo-octahydroxanthene derivatives by the reaction of dimedon with various aromatic aldehydes, using thiamine chloride as a recyclable catalyst under solvent-free conditions. This procedure has following benefits; simple workup, moderate reaction times, good yields, and completely compatible with enviro...
A series of 2-amino pyridine-3-carbinitrile derivatives incorporated coumarin moiety has developed via multicomponent condensation of 3-acetyl-2H-chromen-2-one, arylaldehydes, malononitrile and ammonium acetate utilizing Brønsted acidic ionic liquid, (4-sulfobutyl)tris(4-sulfophenyl)phosphonium hydrogen sulfate as catalyst under solvent-free conditions. Good yields, short reaction times, straig...
The direct three component modified Mannich reaction via condensation of aldehydes, 2-naphthol or 2,7-naphthalendiol and piperidine to generate Betti bases has been carried out over L-proline (20 mol%) with high efficiency under solvent free conditions at 70 OC. Also, the reaction of aromatic aldehyde and 4-hydroxycoumarin in the presence of L-proline (20 mol%) in the ethanol under reflux condi...
An efficient protocol for the synthesis of 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives via multi-component coupling reaction of aromatic aldehydes, β-ketoester and urea or thiourea under solvent-free conditions using Silica Supported Barium Chloride as a catalyst is described. All prepared compounds with melting points, IR,1H NMR and 13C NMR were identified. High yields, mild conditi...
Copper (II) phthalocyanine and 2, 9, 16, 23 tetrakis nitro copper (II) phthalocyanine has been synthesized respectively from phthalonitrile and 4-nitro phthalonitrile under solvent-free condition using two different catalysts over nanodimensional zeolites. 4-Nitro phthalonitrile synthesized from phthaimide in three steps. The newly prepared compounds have been characterized by IR, UV-Vis,1H N...
phenytoine derivatives were synthesized , via the pinacol condensation with the reaction of 1,3- diphenyl- propane- 1,3- dione (benzyl) analogs with urea or thiourea in presence of slica gel and solid KOH as Solid phase catalyst in the mortar / pestle at room temperatures. The reaction was completed at short reaction times (approximately 15min) and pure products were obtained with high yiel...
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