نتایج جستجو برای: condensation reaction
تعداد نتایج: 440835 فیلتر نتایج به سال:
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...
5(6)-carboxy-rhodamine 110 isomers were rapidly synthesized by condensation of 3-aminophenol and trimellitic anhydride using microwave irradiation as heating method. after esterification of the two isomers, separation and hydrolyzation provided target products,5-carboxy-rhodamine 110 and 6-carboxy-rhodamine 110, in high yields. the results shows microwave irradiation can effectively reduce the ...
alkali and alkaline earth metals hydrogen sulfate catalyzed the one-pot three component condensation reactions of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1h)-ones in high yields at 80 °c. our results showed that biginelli reaction not only is ph dependent, but the cation of catalyst plays an important role.
benzazolo [2,1-b]quinazolinones and triazolo[2,1-b]quinazolinones were synthesized in high yields by the condensation reaction of an aldehyde and a cyclic β-diketone with 2 - aminobenzimidazole, 2 - aminobenzothiazole or 1, 2, 4 - triazole derivatives in 1 - butyl - 3 -methylimidazolium bromide as an ionic liquid under classic heating conditions within 5-60 minutes.
1,3-dipolar cycloaddition reaction of 1 mol or 2 mol of dibenzalaceton with 1 mol of non-stabilized azomethinylides generated in situ by decarboxylative condensation of isatin and proline or sarcosine give the novel new spiro-oxindolo(pyrrolizidines/ pyrrolidines) instead of bis-spirooxindolo( pyrrolizidines/ pyrrolidines).
A practical and new method for the synthesis oxindole substituted pyrrolo[2,3-d]pyrimidines by the condensation of isatin, acetophenone and 6-amino-uracil under ultrasound irradiation conditions at 60 °C was described. The reaction was developed via a sequential tandem process to afford the oxindole substituted pyrrolo[2,3-d]pyrimidines in good to excellent yields. All reactions performed effic...
A simple, efficient procedure for the one-pot Biginelli condensation reaction of aldehydes, beta-ketoesters and urea or thiourea employing copper(II) sulfamate as a novel catalyst is described. Compared to the classical Biginelli reaction conditions, the present method has the advantages of good yields, short reaction times and experimental simplicity.
a practical and new method for the synthesis oxindole substituted pyrrolo[2,3-d]pyrimidines by the condensation of isatin, acetophenone and 6-amino-uracil under ultrasound irradiation conditions at 60 °c was described. the reaction was developed via a sequential tandem process to afford the oxindole substituted pyrrolo[2,3-d]pyrimidines in good to excellent yields. all reactions performed effic...
the three components one pot synthesis of 2-amino-4h-benzo-[b] -pyran derivatives were obtained in good to excellent yields within short reaction time by condensing dimedone, aldehydes and malanonitrile or ethylcyanoacetate using a catalytic amount of (diacetoxyiodo)benzene as hypervalent iodine in aqueous ethanol under reflux conditions have been discussed. this aqua mediated knoevenagel-cyclo...
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...
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