نتایج جستجو برای: 34 dihydropyrimidin 21h ones
تعداد نتایج: 236634 فیلتر نتایج به سال:
Two small cell lung cancer (SCLC) cell lines were established from pericardial and pleural effusions of a patient with histopathologically proven SCLC of the oat cell type. Chemotherapy was administered without response during the 148-day period prior to the establishment of the first cell line, SCLC-22H, and some of the same drugs were administered in the 15 days prior to the establishment of ...
Starting from enantiomeric pure 1-[(3S,5R)- and 1-[(3R,5S)-3-(hydroxymethyl)-2-methylisoxazolidin-5-yl]-5-methylpyrimidine-2,4(1H,3H)-diones (-)7a and (+)7b, obtained by lipase-catalyzed resolution, pure diethyl{[(3S,5R)-2-methyl-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)isoxazolidin-3-yl]methyl}phosphonate (-)12a and diethyl{[(3R,5S)-2-methyl-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidi...
Reaction of ethyl-6-methyl-2-oxo-4-aryl-1,2,3,4-tetrahydropyrimidin-5-carboxylates (1a-i) with hydrazine hydrate yielded 6-methyl-2-oxo-4-aryl-1,2,3,4-tetrahydropyrimidin-5-carbohydrazides (2a-i). These products, on reaction with cyanogen bromide, gave 5-(5-amino-1,3,4-oxadiazol-2-yl)-6-methyl-4-aryl-3,4-dihydropyrimidin-2 (1H)-ones (3a-i). The resultant aminooxadiazolylpyrimidinones were conde...
Different (±)-4-(3/4-acetoxyaryl)-5-ethoxycarbonyl-6-methyl-3,4-dihydropyrimidin-2-ones have been synthesized and subjected to enantioselective deacetylation reactions mediated by different lipases in organic media. Novozyme 435 in tetrahydrofuran:diisopropyl ether was found to be the catalyst of choice for efficient enantioselective deacetylation of dihydropyrimidinones under study. Further, w...
The title compound, C(20)H(32)N(2)OS, was obtained during the course of our investigation on 2-alkylsulfanyl-6-benzyl-3,4-dihydropyrimidin-4(3H)-ones (S-DABOs) showing favourable anti-HIV-1 activity. Both cyclo-hexane rings adopt chair conformations. The angle at the methyl-ene C atom linking the pyrimidine and cyclo-hexane ring is 113.7 (3)°, which is in the range considered optimal for maximu...
the present study aimed to use a method for the synthesis of some 3, 4-dihydropyrimidin-2-(1h) - ones/thiones. the study tried to answer the question whether this reaction can be performed without solvent and with new catalyst or not. to find answer to the question, we described a novel protocol for the efficient synthesis of 3, 4-dihydropyrimidin-2-(1h)-one derivatives using aromatic aldehyde,...
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...
CuO-CeO2 nanocomposite is reported as a green and highly efficient recyclable catalyst for the multicomponent synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones under solvent-free conditions. The catalyst was synthesized by co-precipitation method and characterized by XRD, BET specific surface area, FESEM and EDS analysis.
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