نتایج جستجو برای: condensation reaction

تعداد نتایج: 440835  

Journal: :International Journal of Organic Chemistry 2021

Reaction of ethyl (Z)-3-(heteroaryl/aryl)-2-((triphenyl-λ5-phosphaneylidene) amino) acrylates intermediates with 2,3-thiophenedicarboxaldehyde was used in novel Tandem three consecutive reactions: aza-Wittig, imine condensation and electrophilic heteroaromatic cyclization to obtain a series indolizines. A tentative mechanism this reaction is proposed.

A facile and efficient protocol for the synthesis of 1,8-dioxo-octahydroxanthenes has been developed by one-pot Knoevenagel condensation, Michael addition and cyclodehydration reaction of dimedone (active methylene carbonyl compound) with aromatic aldehydes in the presence of Iron (III) sulfate hydrate as a solid acidic catalyst under solvent-free conditions. Various aromatic aldehydes were uti...

Selectfluor [1-(chloro methyl) -4-flouro -1,4-di azonia bicyclo[2,2,2] octane bis (tetraflouro-borate)] catalyzed the preparation of quinoxaline and 2,3-dihydo pyrazine derivatives through one -pot condensation of 1,2-di amines with 1,2-di carbonyls in solvent and under solvent- free conditions. This catalyst is commercially available, inexpensive, reusable, stable to air and moisture, and rela...

A series of arylidine barbituric acid derivatives was synthesized by Knoevenagel condensation reaction of aromatic aldehydes with barbituric acid or thiobarbituric acid using dodecylbenzenesulfonic acid as a Brønsted acid-surfactant catalyst in aqueous media. Regardless of the nature of the substitution (electron-donating and -withdrawing), all the reactions were completed within 15-65 min in w...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1998
mohammad sadegh khajavi parichehr afshani kourosh rad moghadam

the first highly accelerated niementowski reaction of anhranilic acid with some amides or ketones under microwave irradiation leading to quinazolinones and quinoline derivatives is described. these reactions represent some examples of efficient microwave irradiation promoted organic condensation in which the reactions can be carried out in open vessels and provides products of high purity with ...

Journal: :iranian journal of catalysis 2012
farhad shirini somayeh sarvi beigbaghlou seyyed vahid atghia

various types of aldehydes undergo crossed-aldol condensation with ketones in the presence of melamine trisulfonic acid (mtsa) under solvent-free conditions. the reported method is mild, efficient and has the advantages such as using heterogeneous catalysis, short reaction times, high yields of the products and the recyclability of the catalyst.

Journal: :iranian journal of catalysis 2012
abdolkarim zare roghayyeh khanivar maria merajoddin masoud kazem-rostami mohammad mahdi ahmad-zadeh

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.

A new efficient method for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones and spiroquinazolinones via a condensation reaction of aldehydes and ketones with anthranilamide in the presence of nano Fe3O4@SiO2-SO3H as catalyst in ethanol has been described. The reactions are completed in short times, and the corresponding dihydroquinazolinones are produced with high yields. The present procedure...

A. Hashemzehi-Goonaki J. Saffari,

In this work firstly Fe2O3 nanoparticles were synthesized via a simple chemical method. Properties of the product were examined by X-ray diffraction pattern (XRD), Scanning electron microscope (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Vibrating sample magnetometer (VSM) shows nanoparticles exhibit ferromagnetic behavior. To continue some of the 2-naphthol condensed 1,3-oxazinon...

The condensation of benzylamine with glyoxal leads to Hexabenzylhexaazaisowurtzitane (HBIW) in acetonitrile solvent with citric acid as a green catalyst under both conventional stirring and ultrasonic irradiation conditions. The influence of four variables, including the amount of catalyst, solvent, reaction time and ultrasonic power, on the reaction yield was investigated. The results showed t...

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