نتایج جستجو برای: pyrimidines

تعداد نتایج: 6345  

Journal: :Polycyclic Aromatic Compounds 2023

A straightforward and effective strategy for the synthesis of novel 7-cyano-4-imino-3-phenyl-6-(pyrrolidin-1-yl)-2-substituted-3,4-dihydroselenopheno[3,2-d]pyrimidines have been accomplished through a base-promoted cascade addition/cyclization sequence employing phenyl isothiocyanate followed by S-alkylation obtained fused Se-containing heterocyclic framework with various alkyl halides. Free ra...

Journal: :The Journal of organic chemistry 2013
David Tejedor Sara López-Tosco Fernando García-Tellado

A novel approach to the synthesis of fully substituted pyrimidine derivatives armed with an oxy-functionalized acetate chain at the ring is described. The manifold uses amidines as the nitrogen source and activated skipped diynes as the electrophilic reactive partners in a coupled domino strategy. In the first domino reaction, two consecutive aza-Michael additions assemble the six-membered ring...

2012
Cyril Párkányi

Distribution (partition) of an organic substance between two liquid phases, usually water and an or­ ganic solvent, plays an important role in extraction, partition chromatography, and various other separa­ tion processes used in many areas of chemistry. Partition (distribution) coefficient, P, which is the quantity used to characterize the distribution of a solute between two immiscible solven...

2017
Elisandra Scapin Paulo R S Salbego Caroline R Bender Alexandre R Meyer Anderson B Pagliari Tainára Orlando Geórgia C Zimmer Clarissa P Frizzo Helio G Bonacorso Nilo Zanatta Marcos A P Martins

An efficient synthesis methodology for a series of tetrazolo[1,5-a]pyrimidines substituted at the 5- and 7-positions from the cyclocondensation reaction [CCC + NCN] was developed. The NCN corresponds to 5-aminotetrazole and CCC to β-enaminone. Two distinct products were observed in accordance with the β-enaminone substituent. When observed in solution, the compounds can be divided into two grou...

2006
Gry Mine Berg Niels O. G. Jørgensen

Nucleotide bases are ubiquitous in living organisms, but the fate of these compounds in natural environments is poorly understood. Here we studied the metabolism of selected purines and pyrimidines in estuarine bacterial assemblages from the Øresund, Denmark. Depletion of nucleotide bases in the incubations was followed by the appearance of urea. The purine guanine and the catabolic intermediat...

2017

Nucleotide metabolism results in the synthesis of the four nucleotides that form DNA. These are further divided in two categories: purines and pyrimidines. Their construction and degradation takes place in a progression of single steps, while different enzymes and cofactors are involved in the process. Beside degradation, there is also a form of reprocessing purine and pyrimidine nucleotides, d...

2018

Nucleotide metabolism results in the synthesis of the four nucleotides that form DNA. These are further divided in two categories: purines and pyrimidines. Their construction and degradation takes place in a progression of single steps, while different enzymes and cofactors are involved in the process. Beside degradation, there is also a form of reprocessing purine and pyrimidine nucleotides, d...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید