Category: pyrimidines

Notario, Rafael published the artcileThermochemistry of Uracils. Experimental and Computational Enthalpies of Formation of 5,6-Dimethyl-, 1,3,5-Trimethyl-, and 1,3,5,6-Tetramethyluracils, Application In Synthesis of 608-34-4, the publication is Journal of Physical Chemistry A (2013), 117(1), 244-251, database is CAplus and MEDLINE.

An exptl. and computational study of three methylated uracils, in particular, the 5,6-dimethyl-, 1,3,5-trimethyl-, and 1,3,5,6-tetra-Me derivatives are presented. The values of the standard (p⁰ = 0.1 MPa) molar enthalpies of formation in the gas phase at T = 298.15 K have been determined The energies of combustion were measured by static bomb combustion calorimetry, and from the results obtained, the standard molar enthalpies of formation in the crystalline state at T = 298.15 K were calculated The enthalpies of sublimation were determined using the transpiration method in a saturated N₂ stream. Values of -(376.2 ± 2.6), -(355.9 ± 3.0), and -(381.7 ± 2.8) kJ·mol^-1 for the gas-phase enthalpies of formation at T = 298.15 K of 5,6-dimethyluracil, 1,3,5-trimethyluracil, and 1,3,5,6-tetramethyluracil, resp., were obtained from the exptl. thermochem. study. An extended theor. study with the G3 and the G4 quantum-chem. methods has been carried out for all the possible methylated uracils. There is very good agreement between exptl. and calculated enthalpies of formation for the three derivatives studied. A Free-Wilson anal. on G4-calculated enthalpies of formation has been carried out, and the contribution of methylation in the different positions of the uracil ring has been estimated

Journal of Physical Chemistry A published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C5H6N2O2, Application In Synthesis of 608-34-4.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Schultes, Sabine published the artcileCombining Quantum Mechanical Ligand Conformation Analysis and Protein Modeling to Elucidate GPCR-Ligand Binding Modes, HPLC of Formula: 56-05-3, the publication is ChemMedChem (2013), 8(1), 49-53, database is CAplus and MEDLINE.

2-Aminopyrimidine ligands with flexible and rigid side chains was synthesized to investigate the role of ligand conformation in H₄R ligand binding. The ligand binding conformations and orientations in the H₄R binding pocket was elucidated. The combined ligand- and protein-ligand modeling method can be used as a general approach to investigate the binding modes of flexible side chains of ligands with other protein targets.

ChemMedChem published new progress about 56-05-3. 56-05-3 belongs to pyrimidines, auxiliary class Pyrimidine,Chloride,Amine,API, name is 2-Amino-4,6-dichloropyrimidine, and the molecular formula is C25H29N9O3, HPLC of Formula: 56-05-3.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Kratochvil, Martin published the artcileMethylated uracil dimers: potential energy and free energy surfaces, Related Products of pyrimidines, the publication is Physical Chemistry Chemical Physics (2000), 2(10), 2419-2424, database is CAplus.

Theor. anal. of the formation of 1-methyluracil, 3-methyluracil and 1,3-dimethyluracil dimers was performed. Stabilization energies of these dimers were evaluated with the Cornell et al. force field (J. Am. chem. Soc., 1995, 117, 5179). In total 16, 13 and 15 energy min. were studied for the 3 dimers. Thermodn. data were obtained with the rigid rotor-harmonic oscillator-ideal gas approximation Also, populations of various structures were determined by mol. dynamic simulations in the NVE microcanonical ensemble and numerical evaluation of the configuration integrals in the NVT canonical ensemble. The potential energy surfaces (PESs) and the free energy surfaces (FESs) of these dimers differ. The largest difference was found for the 1-methyluracil dimer where the global and 1st local min. on the PES and FES do not coincide.

Physical Chemistry Chemical Physics published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C5H6N2O2, Related Products of pyrimidines.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Rezk, Mamdouh R published the artcileChromatographic Methods for the Determination of Aminexil, Pyridoxine, and Niacinamide in a Novel Cosmetic Hair Preparation., SDS of cas: 74638-76-9, the publication is Journal of AOAC International (2020), 103(4), 1167-1172, database is MEDLINE.

BACKGROUND: Aminexil, a new compound patented by L’Oreal, has a stimulating effect on human keratin fibers. Pyridoxine HCl and niacinamide are added to boost the hair tonic effect of aminexil. OBJECTIVE: Two novel chromatographic methods were developed for the determination of aminexil (AX), niacinamide (NA) and pyridoxine HCl (PD) in the novel hair tonic preparation. METHODS: The developed methods were high-performance liquid chromatography (HPLC) and thin layer chromatography (TLC) with densitometric determination. Different experimental parameters were investigated and optimized to achieve complete baseline separation and well resolved peaks. The RP-HPLC separation was achieved using a Thermoscientific BDS hypersil C18 (250 × 4.6 mm, 5 µm) column using 0.005 M hexane sulfonic acid: methanol (80: 20, v/v) as a mobile phase. For the TLC method, the three analytes were partitioned between propanol: toluene: ammonia solution (40:60:2, v/v/v) and fluorescent silica plates. The two methods were validated in compliance with International Conference on Harmonization (ICH) guidelines. The obtained data were statistically analyzed to confirm the existing results. The developed methods were successfully applied for determination of the studied drugs in pure forms and in the cosmetic preparation. RESULTS: For the HPLC method, the RSDs of AX, NA and PD were 0.70, 0.88 and 1.17 respectively. For the TLC method, the RSDs of AX, NA and PD were 1.06, 1.37 and 0.73 respectively. CONCLUSIONS: The proposed chromatographic methods showed high sensitivity and selectivity for the three compounds under analysis in the laboratory prepared mixture and in the hair tonic preparation. HIGHLIGHTS: Aminexil, Pyridoxine, Niacinamide, HPLC. The present work offers two reproducible, accurate, validated, time and cost saving alternatives for the quantitative and qualitative determination of medicated hair preparation.

Journal of AOAC International published new progress about 74638-76-9. 74638-76-9 belongs to pyrimidines, auxiliary class Pyrimidine, name is 2,4-Diaminopyrimidine-3-oxide, and the molecular formula is C4H6N4O, SDS of cas: 74638-76-9.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Gallup, Gordon A. published the artcileVibrational Feshbach resonances in dissociative electron attachment to uracil, Recommanded Product: 3-Methylpyrimidine-2,4(1H,3H)-dione, the publication is Physical Review A: Atomic, Molecular, and Optical Physics (2011), 83(1), 012706/1-012706/7, database is CAplus.

Low-energy dissociative electron attachment to uracil mols. in the gas phase is partly controlled by interaction between the lowest σ* resonance with a dipole-supported anion state. We calculate this contribution using a combination of the finite element discrete model with the resonance R-matrix theory. Deuterated uracil is investigated, also, and a strong isotope effect is found. The results agree qual. and semiquant. with exptl. data, but for a complete description of the process the interaction between a second N-H bond σ* resonance in the mol. and the second p* resonance should be included.

Physical Review A: Atomic, Molecular, and Optical Physics published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C5H6N2O2, Recommanded Product: 3-Methylpyrimidine-2,4(1H,3H)-dione.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Zhang, C. F. published the artcileDensity functional theory studies of methylated uracil: geometries and energies, HPLC of Formula: 608-34-4, the publication is Chemical Physics (2000), 256(3), 275-287, database is CAplus.

D. functional theory studies on the geometries and energies of the methylated derivatives of uracil yield two stable conformations, α and β, for each single-methylated uracil. They are different in the spatial orientation of the substituting Me group and the mol. total energy. Analyzing the calculated structural parameters, we also found an elongation effect in the methylated uracil, which contributes to the increase of dipole moment and mol. size of mols. such as the methylated derivatives of nucleic acid bases.

Chemical Physics published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C3H9ClOS, HPLC of Formula: 608-34-4.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Meng, Qing published the artcileDesign, synthesis and evaluation of novel HIV-1 NNRTIs with dual structural conformations targeting the entrance channel of the NNRTI binding pocket, Computed Properties of 56-05-3, the publication is European Journal of Medicinal Chemistry (2016), 53-62, database is CAplus and MEDLINE.

On the basis of structure-based bioisosteric replacement and mol. hybridization strategy, a series of novel dual structural-conformation inhibitors targeting the “entrance channel” of HIV-1 NNRTIs binding pocket (NNIBP) were designed and synthesized. All of the new compounds were evaluated for their anti-HIV activities in MT-4 cells using the MTT method. Five compounds exhibited moderate to excellent potencies inhibiting wild-type (weight) HIV-1 replication with EC₅₀ values ranging from 31.36 μM to 0.11 μM. Among them, compound I was identified as the most potent inhibitor with EC₅₀ values of 0.11 μM and 2.18 μM against weight and K103N/Y181C double mutant HIV-1 strain (RES056), resp. In addition, preliminary structure-activity relationships (SARs) and mol. simulation studies were discussed, which may provide valuable insights for further optimization.

European Journal of Medicinal Chemistry published new progress about 56-05-3. 56-05-3 belongs to pyrimidines, auxiliary class Pyrimidine,Chloride,Amine,API, name is 2-Amino-4,6-dichloropyrimidine, and the molecular formula is C4H3Cl2N3, Computed Properties of 56-05-3.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Riand, Jacques published the artcileProton and carbon-13 nuclear magnetic resonance studies of substituted pyrimidines. Part 3. Hindered internal rotation in some 4-(NN-dimethylamino)pyrimidines, Application In Synthesis of 31401-45-3, the publication is Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999) (1979), 1248-52, database is CAplus.

The free energy of activation for internal rotation about the C-N exocyclic bond of substituted 4-(N,N-dimethylamino)pyrimidines was determined using ¹H and ¹³C NMR line-shape anal. Substituent effects on the rotational barrier of the NMe₂ group were evaluated. The rotational barrier is higher for a NMe₂ group in the 4-position than for one in the 2 position. There is a linear correlation between the free energies of activation and ¹J(C,H) coupling constants for the 4-NMe₂ group.

Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999) published new progress about 31401-45-3. 31401-45-3 belongs to pyrimidines, auxiliary class Pyrimidine,Amine, name is N,N-Dimethylpyrimidin-4-amine, and the molecular formula is C6H9N3, Application In Synthesis of 31401-45-3.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Riand, Jacques published the artcileProton and carbon-13 nmr study of substituted pyrimidines. IV. Hindered rotation of N,N-dimethylamino-4-pyrimidines in the monoproton state, Product Details of C6H9N3, the publication is Canadian Journal of Chemistry (1980), 58(5), 466-71, database is CAplus.

The free energy of activation for hindered rotation about the C-N exocyclic bond in some N,N-dimethylaminopyrimidine hydrochlorides was determined by ¹H and ¹³C NMR. Monoprotonation of N,N-dimethylaminopyrimidines induces a large increase in the free energy of activation. This increase is larger for the 4-dimethylamino group than for the 2-dimethylamino group due to the predominance of the monoprotonated (N-1 H) form.

Canadian Journal of Chemistry published new progress about 31401-45-3. 31401-45-3 belongs to pyrimidines, auxiliary class Pyrimidine,Amine, name is N,N-Dimethylpyrimidin-4-amine, and the molecular formula is C6H9N3, Product Details of C6H9N3.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Yang, Tianming published the artcileA methylation-switchable conformational probe for the sensitive and selective detection of RNA demethylase activity, SDS of cas: 608-34-4, the publication is Chemical Communications (Cambridge, United Kingdom) (2016), 52(36), 6181-6184, database is CAplus and MEDLINE.

We describe a novel methylation-sensitive nucleic acid (RNA) probe which switches conformation according to its methylation status. When combined with a differential scanning fluorimetry technique, it enables highly sensitive and selective detection of demethylase activity at a single methylated-base level. The approach is highly versatile and may be adapted to a broad range of RNA demethylases.

Chemical Communications (Cambridge, United Kingdom) published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C21H20BrNO4S, SDS of cas: 608-34-4.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia