نتایج جستجو برای: 34 dihydropyrimidin 21h one
تعداد نتایج: 2090666 فیلتر نتایج به سال:
in this work, the ionic liquid triethylamine-bonded sulfonic acid {[et3n–so3h]cl}, n,n-diethyl-n-sulfoethanammonium chloride was used as a green acidic homogeneous catalyst to synthesis of 3,4-dihydropyrimidin-2(1h)-ones and 3,4-dihydropyrimidin-2(1h)-thiones as two categories of heterocycles, from aldehyde, dicarbonyl compound and urea or thiourea throughout the one-pot three components cycloc...
Several 5-alkyl, 5-alkenyl, 5-iso-alkyl, 5-halo, 5-aminomethyl and 5-carboxy derivatives of S-DABOs (dihydro-alkyl (or cyclo-alkyl)thio-benzyloxopyrimidines), DATNOs (dihydro-alkylthionaphthylmethyl-oxopyrimidines) and F2-S-DABOs (dihydro-alkyl (or cyclo-alkyl)thio-2,6-difluorobenzyl-oxopyrimidines) have been prepared and tested as anti-HIV-1 agents. S-DABO derivatives bearing at C-6 position m...
It is demonstrated that even unsubstituted cationic ligands, namely the known diazoniadibenzochrysenes (, ) and the so far unreported tetraazoniapentaphenopentaphene (), stabilize quadruplex DNA upon association; the ligand exhibits essentially the same affinity towards the quadruplex as does 5,10,15,20-tetrakis(1-methyl-4-pyridyl)-21H,23H-porphine, however, with a significantly higher selectiv...
The PM3 quantum-mechanical method is able to model the magic water clusters (H20),, and (H20)&+. Results indicate that the H30+ ion is tightly bound within the (H20),, cluster by multiple hydrogen bonds, causing deformation to the symmetric (HzO),, pentagonal dodecahedron structure. The structures, energetics, and hydrogen bond patterns of six local minima (H20)21H+ clusters are presented.
an efficient and simple one-pot approach for the synthesis of 3,4-dihydropyrimidin-2-(1h)-one derivatives using antimony trichloride (sbcl3) as a mild catalyst by means of three-component biginelli reaction between β-keto esters, aldehyde derivatives and urea/thiourea under thermal and solvent-free conditions with excellent yields and short reaction times is reported. this methodology offers se...
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 importan...
An improved, simple, and facile synthesis of 3,4-dihydropyrimidin-2(1H)-ones by employing three-component, one-pot condensation reaction of β-keto ester, aromatic aldehydes, and urea or N-methylurea using LaCl3/ClCH2COOH as an inexpensive and green chemistry catalyst system under solvent-free conditions described. Compared with the classicalBiginelli reaction conditions, this method has the adv...
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