جستجوی مقالات مرتبط با کلیدواژه "پیریمیدین" در نشریات گروه "شیمی"

Azolo-annulated pyrimidines have attracted continuing interest due primarily to their structural similarity to heterocyclic bases of DNA and RNA. As a consequence, these compounds can act as antimetabolites, being effective biologically active compounds. Numerous advantageous properties of azolopyrimidines such as important industrial, agrochemical and pharmaceutical applications, especially in biological science, material chemistry and medicinal chemistry impelled us to design and synthesis of a number of various and interesting derivatives of 3-alkyl-9-methyl-tetrazolo[1,5-a][1,2,3]triazolo[4,5-d]pyrimidine as a novel heterocyclic system which has not been reported previously. In the present work, initially the reaction of 2,4-dichloro-6-methylpyrimidin-5-amine (1) with different primary amines in refluxing i-PrOH gave the corresponding sec-amino derivatives (2a-e) which were consequently treated with NaNO2/HCl solution to yield quantitatively the corresponding diazo derivatives of 5-chloro-3-alkyl-7-methyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine (3a-e). Further reaction of compounds (3a-e) with NaN3 in EtOH was resulted in various derivatives of novel heterocyclic system of tetrazolo[1,5-a][1,2,3]triazolo[4,5-d]pyrimidine (4a-e) that are in equilibrium with azide forms.

In this study, N-heterocyclic carbene palladium complex containing pyrimidine supported on a periodic mesoporous organosilica (Pd-Pym-NHC@PMO) was synthesized from 2-aminopyrimidine in four reaction steps. Structure and Physico-chemical properties of Pd-Pym-NHC@PMO was characterized by different techniques of spectroscopic analysis such as XRD, CP-MAS-NMR, AAS, TGA, and BET porosimetry. After full characterization, its catalytic activity in the synthesis of biaryls via the Suzuki–Miyaura cross-coupling was evaluated under the different conditions such as solvent, temperature, and the molar ratio of the reactants. It was observed that the nanocatalyst Pd-Pym-NHC@PMO exhibited excellent activity. Furthermore, the nanocatalyst can be reused and handled at least eight consecutive without any loss of catalytic activity. The present work is a novel, very mild and environmentally friendly method.

In this research, Fe3O4@Propylsilane-Pyridine[HSO4] magnetic nanoparticles were synthesized via functionalization of Fe3O4 by tri-methoxy silyl propyl amine, pyridine-2-carbaldehyde and sulfuric acid. The structures of the synthesized nanoparticles at different stages were confirmed by FT-IR spectroscopy. Also, the crystal structure, morphology and thermal stability of the nanoparticles were investigated using XRD, SEM, TEM and TGA analyzes. Finally, dihydropyrido[3,2-d: 5,6-d'] dipyrimidine derivatives were synthesized by using of these nanoparticles as an effective catalysts. Comparison of the performance of this catalyst with other catalysts showed that the nano-catalysts made in this research, significantly increase the yield and reaction rate compared to other catalysts.