Category: pyrimidines

Krivokapic, Andre published the artcilePrimary oxidation products of 5-methylcytosine: methyl dynamics and environmental influences, Category: pyrimidines, the main research area is radiolytic oxidation methylcytosine ESR ENDOR methyl group tunneling rotation.

The primary oxidation product in X-irradiated single crystals of 5-methylcytosine hemihydrate and 5-methylcytosine hydrochloride has been studied at 10 K, using ESR, electron-nuclear double resonance (ENDOR), and ENDOR-induced EPR (EIE) spectroscopies. The radical is characterized by large couplings to the Me protons and appears to be deprotonated at N1 in both crystal systems. In the hydrochloride crystal the Me group is completely frozen at 10 K, whereas in the hemihydrate crystal it undergoes tunneling rotation. For the hemihydrate crystal, four ENDOR lines associated with transitions within the A and E rotational states were followed in three planes of rotation. Large ENDOR shifts as measured by saturation of the high- and low-field parts of the EPR spectrum indicate that the rotation is rather slow. Sidebands due to mixing of A and E rotational states are expected for slow rotation and were observed in both the EPR and the EIE spectra. The ENDOR shifts and the sideband frequencies indicate a tunneling splitting between 40 and 60 MHz. Estimates of the barrier to rotation in both crystalline systems were calculated using cluster and single-mol. d. functional theory methods, and the results are consistent with those obtained by anal. of the exptl. results.

Journal of Physical Chemistry A published new progress about Electron spin density (of radiolysis products). 58366-64-6 belongs to class pyrimidines, name is 5-Methylcytosinehydrochloride, and the molecular formula is C5H8ClN3O, Category: pyrimidines.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Stathakis, Christos I. published the artcile(Chloromethyl)dimethylchlorosilane-KF: A Two-Step Solution to the Selectivity Problem in the Methylation of a Pyrimidone Intermediate en Route to Raltegravir, Application of Benzyl (2-(4-((4-fluorobenzyl)carbamoyl)-5-hydroxy-6-oxo-1,6-dihydropyrimidin-2-yl)propan-2-yl)carbamate, the main research area is chloromethyldimethylchlorosilane silylation potassium fluoride desilylation pyrimidone methylation raltegravir synthesis.

The present work describes a two-step process, namely, silylation with (chloromethyl)dimethylchlorosilane and desilylation, to address the selectivity problem in the N-methylation of a pyrimidone intermediate toward the synthesis of the raltegravir active pharmaceutical ingredient [treatment of I with HMDS/(ClCH2)SiMe2Cl, then 4-fluorobenzylamine followed by KF afforded II (75-80%)]. The said methodol. delivers the desired drug substance in which the O-methylated impurity content is below the detection limit by high-performance liquid chromatog. anal. Moreover, this two-step, one-pot procedure provides an apparent advantage in terms of environmental impact with respect to the optimum approach described in the literature, while it compares equally well in terms of cost and operational simplicity.

Organic Process Research & Development published new progress about Chemoselectivity (chemoselective methylation). 519028-33-2 belongs to class pyrimidines, name is Benzyl (2-(4-((4-fluorobenzyl)carbamoyl)-5-hydroxy-6-oxo-1,6-dihydropyrimidin-2-yl)propan-2-yl)carbamate, and the molecular formula is C23H23FN4O5, Application of Benzyl (2-(4-((4-fluorobenzyl)carbamoyl)-5-hydroxy-6-oxo-1,6-dihydropyrimidin-2-yl)propan-2-yl)carbamate.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Regan, Collin F. published the artcileA facile synthesis of 5-halopyrimidine-4-carboxylic acid esters via a Minisci reaction, SDS of cas: 74840-38-3, the main research area is Minisci homolytic alkoxycarbonylation halopyrimidine; bromopyrimidinecarboxylate; pyrimidine halo Minisci homolytic alkoxycarbonylation.

This paper reports the synthesis of various 5-halopyrimidine-4-carboxylic acid esters via the Minisci homolytic alkoxycarbonylation of 5-halopyrimidines. The reaction was found to be highly regioselective, allowing the one-step synthesis of useful amounts (>10 g) of Et 5-bromopyrimidine-4-carboxylate where other methods proved difficult. Et 5-bromopyrimidine-4-carboxylate was used for the preparation of potent CK2 inhibitors including CX-5011. This work represents an interesting application of radical chem. for the preparation of pharmacol. active mols.

Synlett published new progress about Alkoxycarbonylation (Minisci homolytic). 74840-38-3 belongs to class pyrimidines, name is Ethyl 5-bromo-2-(methylthio)pyrimidine-4-carboxylate, and the molecular formula is C8H9BrN2O2S, SDS of cas: 74840-38-3.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Kolar, Michal published the artcileThe strength and directionality of a halogen bond are co-determined by the magnitude and size of the σ-hole, Synthetic Route of 38275-56-8, the main research area is halogen bond strength directionality sigma hole magnitude size effect.

The σ-holes of halogen atoms on various aromatic scaffolds were described in terms of their size and magnitude. The electrostatic potential maps at the CAM-B3LYP-D3(bj)/def2-QZVP level were calculated and the σ-holes of >100 aromatic analogs were thoroughly analyzed to relate the σ-holes to the binding preferences of the halogenated compounds Both the size and magnitude of the σ-hole increase when passing from chlorinated to iodinated analogs. Also, the σ-hole properties were studied upon chem. substitution of the aromatic ring as well as in the aromatic ring. Further, the angular variations of the interactions were studied on a selected set of halogenbenzene complexes with argon and hydrogen fluoride (HF). To analyze interaction energy components, DFT-SAPT angular scans were performed. The interaction energies of bromobenzene complexes were evaluated at the CCSD(T)/complete basis set level providing the benchmark energetic data. The strength of the halogen bond between halogenbenzenes and Ar atoms and HF mols. increases while its directionality decreases when passing from chlorine to iodine. The decrease of the directionality of the halogen bond is larger for a HF-containing complex and is caused by electrostatic and exchange-repulsion energies. These findings are especially valuable for protein-halogenated ligand-binding studies, applied in the realm of rational drug development and lead optimization.

Physical Chemistry Chemical Physics published new progress about Aryl halides Role: PRP (Properties). 38275-56-8 belongs to class pyrimidines, name is 5-Chloropyrimidine-2-carbonitrile, and the molecular formula is C5H2ClN3, Synthetic Route of 38275-56-8.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Csarnyi, A. H. published the artcileSeparation of 5-alkyluracils and purine bases in hydrolyzates of enzymically synthesized nucleic acids by high-performance ion-pair liquid chromatography, Name: 5-N-Propyluracil, the main research area is DNA alkyluracil purine base chromatog; high performance ion pair chromatog alkyluracil.

Reversed-phase and reversed-phase ion-pair chromatog. methods were used to determine 5-alkyluracils in the presence of purine bases (mainly adenine) in the hydrolyzates of enzymically synthesized DNA. For the reversed-phase separations, a Hypersil ODS column was used with a 2-step gradient of 0.01M KH2PO4 (pH 5.5) in 80% MeOH. The eluate was monitored at 260 nm. For the ion-pair separations, octyl sulfate was the counter-ion and the solvent composition and pH varied. The effect of ionic strength, pH, and concentration of the ion-pairing agent and MeOH on the selectivity between alkyluracils and purine bases was examined in order to simplify the routine work and to reduce the time necessary for anal. Optimal conditions could be developed for the isocratic separation of the various mixtures obtained by hydrolysis of the products of enzymic synthesis.

Journal of Chromatography published new progress about DNA Role: BIOL (Biological Study). 19030-75-2 belongs to class pyrimidines, name is 5-N-Propyluracil, and the molecular formula is C7H10N2O2, Name: 5-N-Propyluracil.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Diaz, E. published the artcile2D NMR studies of the structures of the stereoselective adducts of the dehydrocostus lactone with pyrimidine derivatives, Formula: C7H10N2O2, the main research area is dehydrocostus lactone pyrimidine adduct NMR.

Anal. of 1H-1H n.O.e. effects observed for the adducts (I) (X = O, S; Y = O, NH2; Z = H, Me, F, Br, Pr, OMe), (II) and (III) on C-13 (10-18) of dehydrocostus lactone and different pyrimidine derivatives showed that H-7 and H-11 protons are in trans position. The NOESY cross peaks anal. and x-ray mol. structure of adduct I (X = Y =O, Z = H) are in excellent agreement with the exptl. data. Complete assignments of the 13C signals of some adducts based on 1D and 2D 1H and 13C NMR techniques are reported.

Spectroscopy Letters published new progress about NMR (nuclear magnetic resonance). 19030-75-2 belongs to class pyrimidines, name is 5-N-Propyluracil, and the molecular formula is C7H10N2O2, Formula: C7H10N2O2.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Riand, J. published the artcileProton and carbon-13 nuclear magnetic resonance studies of substituted pyrimidines. 2. Monoprotonation of methyl- and aminopyrimidines, Synthetic Route of 22433-68-7, the main research area is protonation pyrimidine NMR; carbon NMR pyrimidine.

The monoprotonation of methyl- and aminopyrimidines was studied by C13 NMR spectroscopy. The chem.-shift parameters associated with the protonation of methylpyrimidines were determined for the aromatic and Me group C atoms from the salts of certain sym. compounds A significant difference exists for certain parameters for a given C, depending on whether a H atom or a Me group is attached to it. An especially large solvent effect exists for C atoms bearing a Me group para to the site of protonation. The percentages of the forms monoprotonated at sites N-1 or N-3 of pyrimidines were evaluated from their chem. shifts in F3CCO2H and Me2SO. For methylpyrimidines a higher percentage (∼71%) of the form in which the protonated N is in the para position to the Me group is found. For the 4-amino-6-methylpyrimidines, the influence of the amino group is greater than that of the Me group, and the percentage reaches ∼94% for the form in which the protonated N is in the para position to the amino group.

Journal of the American Chemical Society published new progress about NMR (nuclear magnetic resonance). 22433-68-7 belongs to class pyrimidines, name is 4-Amino-5-methylpyrimidine, and the molecular formula is C5H7N3, Synthetic Route of 22433-68-7.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Petrov, Alexander P. published the artcileDatabase of free solution mobilities for 276 metabolites, Safety of 5-Methylcytosinehydrochloride, the main research area is metabolite solution electrophoretic mobility database; Capillary electrophoresis; Metabolite database; Sequential injection.

Although databases are available that provide mass spectra and chromatog. retention information for small-mol. metabolites, no publicly available database provides electrophoretic mobility for common metabolites. As a result, most compounds found in electrophoretic-based metabolic studies are unidentified and simply annotated as “”features””. To begin to address this issue, the authors analyzed 460 metabolites from a com. library using capillary zone electrophoresis coupled with electrospray mass spectrometry. To speed anal., a sequential injection method was used wherein six compounds were analyzed per run. An uncoated fused silica capillary was used for the anal. at 20° with a 0.5% (volume/volume) formic acid and 5% (volume/volume) methanol background electrolyte. A Prince autosampler was used for sample injection and the capillary was coupled to an ion trap mass spectrometer using an electrokinetically-pumped nanospray interface. The authors generated mobility values for 276 metabolites from the library (60% success rate) with an average standard deviation of 0.01 × 10-8 m2V-1s-1. As expected, cationic and anionic compounds were well resolved from neutral compounds Neutral compounds co-migrated with electroosmotic flow. Most of the compounds that were not detected were neutral and presumably suffered from adsorption to the capillary wall or poor ionization efficiency.

Talanta published new progress about Capillary zone electrophoresis. 58366-64-6 belongs to class pyrimidines, name is 5-Methylcytosinehydrochloride, and the molecular formula is C5H8ClN3O, Safety of 5-Methylcytosinehydrochloride.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Hatano, Akihiko published the artcileOne-pot approach to functional nucleosides possessing a fluorescent group using nucleobase-exchange reaction by thymidine phosphorylase, COA of Formula: C7H10N2O2, the main research area is fluorescent nucleoside preparation nucleobase exchange reaction thymidine phosphorylase.

Herein, β-selective coupling is described between a modified uracil and a deoxyribose to produce functionalized nucleosides catalyzed by thymidine phosphorylase derived from Escherichia coli. This enzyme mediates nucleobase-exchange reactions to convert unnatural nucleosides possessing a large functional group such as a fluorescent mol., coumarin or pyrene, linked via an alkyl chain at the C5 position of uracil. 5-(Coumarin-7-oxyhex-5-yn)uracil (C4U) displayed 57.2% conversion at 40% DMSO concentration in 1.0 mM phosphate buffer pH 6.8 to transfer thymidine to an unnatural nucleoside with C4U as the base. In the case of using 5-(pyren-1-methyloxyhex-5-yn)uracil (P4U) as the substrate, TP also could catalyze the reaction to generate a product with a very large functional group at 50% DMSO concentration (21.6% conversion). Docking simulations were carried out using MF myPrest for the modified uracil bound to the active site of TP. The uracil moiety of the substrate binds to the active site of TP, with the fluorescent moiety linked to the C5 position of the nucleobase located outside the surface of the enzyme. As a consequence, the bulky fluorescent moiety binding to uracil has little influence on the coupling reaction.

Organic & Biomolecular Chemistry published new progress about Enzyme functional sites, active. 19030-75-2 belongs to class pyrimidines, name is 5-N-Propyluracil, and the molecular formula is C7H10N2O2, COA of Formula: C7H10N2O2.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Guo, Chunfang published the artcileDirect C-H Difluoroalkylation of Heteroarenes with Difluoroalkyl Carboxylic Acids, Application In Synthesis of 42839-08-7, the main research area is difluoroalkylated heteroarene preparation; heteroarene difluoroalkyl carboxylic acid CH difluoroalkylation silver catalyst.

A new method for the difluoroalkylation of heteroaromatic compounds were developed by employing readily available difluoroalkyl carboxylic acids. This silver-catalyzed reaction proceeded under mild conditions and afforded a broad range of difluoroalkylated heteroarenes RCF2Ar [R = Me, Et, CH2CH2Ph; Ar = 4-CN-2-pyridyl, 4-PhO-2-pyridyl, 4-Me-2-quinolinyl, etc.] in moderate to good yields, including pyridines, pyrimidines, pyrazines, quinolines, quinoxalines as well as bioactive compounds

Asian Journal of Organic Chemistry published new progress about Fluoroalkanes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 42839-08-7 belongs to class pyrimidines, name is Ethyl pyrimidine-2-carboxylate, and the molecular formula is C7H8N2O2, Application In Synthesis of 42839-08-7.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia