نتایج جستجو برای: solvent free condition
تعداد نتایج: 857817 فیلتر نتایج به سال:
In the present work, we have planned a new magnetically recoverable nanocatalyst. The obtained nanocatalyst designated as Fe3O4@SiO2@DOPisatin-Ni (II) was characterized by FTIR, XRD, SEM, EDAX, VSM, AAS and TGA techniques. It was found that Fe3O4@SiO2@DOPisatin-Ni (II) successfully catalyses the synthesis of 2,3-dihydroquinazolin-4(1H)-ones, polyhydroquinoline and 5-substituted 1H-tetrazoles in...
methoxymethylation of a variety of alcohols was performed using formaldehyde dimethyl acetal in the presence of 1,3-dichloro-5,5-dimethyl hydantoin [dcdmh] and poly n,n′-dibromo-n-ethyl naphthyl-2,7-disulfonamide [pbns] as catalysts at room temperature and under solvent-free conditions. our experiments show that primary and secondary alcohols can be smoothly converted into the corresponding mom...
2-amino-substituted ketones react with α-methylene ketones under solvent-free conditions at 90 °c in thepresence of a catalytic amount of zirconium dodecylphosphonate to create the corresponding quinolinesin excellent yields. this procedure recommends numerous advantages such as easy work-up, use of mild,reusable and safe catalyst, short reaction timeand high yields. the new compounds have been...
abstract in first part of this project, the use of a new and biguanid-like catalyst supported on silica as a recyclable catalyst provides a new route for the synthesis of a variety of arylalkylidene rhodanine derivatives through knoevenagle reaction in at present of solvent at room temperature. rhodanine derivatives and especially arylalkylidene rhodanines have proven to be attractive compound...
Coumarins play an important role in drug development with diverse biological applications. Herein, we present the synthesis of coumarin through Pechmann reaction by using zirconia-based heterogeneous catalysts (ZrO2-TiO2, ZrO2-ZnO, and ZrO2/cellulose) in a solvent-free condition at room temperature. ZrO2-TiO2, ZrO2-ZnO, and ZrO2/cellulose were identified through spectroscopic techniques such as...
the treatment equimolar quantities of carboxylic acids with acid chlorides in the presence of zno brings abouthighly efficient unsymmetrical anhydrides at room temperature in solvent-free condition. reactivity trendsfavored formation of the product using both electron deficient and rich aryl acids and acid chlorides.
the acetylation of various alcohols and phenols was performed successfully using acetic anhydride in the presence of citric acid coated magnetite nanoparticles as catalyst under solvent-free condition and at 45 °c. the catalyst showed high thermal stability and was recovered and reused at least 5 times without any considerable loss of activity. the present process is environmentally benign and ...
silica supported phosphorus pentoxide (p2o5·sio2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.
hydrochlorothiazide (hct) is a diuretic agent which is shown to be effective in the treatment of hypertension. literature reports have demonstrated that urinary excretion data may be used to assess the bioavailability of various formulations containing this thiazide. also hct consumption by the athletes is one of the drugs which should be regulated by world anti-doping agency (wada), because of...
Flavanone was synthesized through the Claisen–Schmidt condensation between benzaldehyde and acetophenone and subsequent intramolecular Michael addition over aminopropyl-functionalized SBA-15 materials. The catalysts with well-ordered hexagonally arranged mesopores were synthesized by one-pot co-condensation of tetraethoxysilane and aminopropyltriethoxysilane using amphiphilic block copolymer as...
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