Month: November 2022

Mosti, Luisa published the artcileReaction of 2-dimethylaminomethylene-1,3-diones with dinucleophiles. III. Synthesis of 5-acylpyrimidines and 7,8-dihydroquinazolin-5(6H)-ones, Synthetic Route of 66373-25-9, the main research area is methylaminomethylene dione cyclocondensation dinucleophile; pyridine acyl; quinazolinone dihydro.

The reaction of open-chain and cyclohexane sym-2-dimethylaminomethylene-1,3-diones with amidines and guanidine in refluxing ethanol gave, generally in good yields, acylpyrimidines I (R = Me, Me2CH, Me3C, Ph; R1 = H, Me, Ph, NH2) and dihydroquinazolinones II (X = CH2, CMe2, CHPh) resp. With formamidine (and in part acetamidine), 2-formylimino-1,3-diones, e.g., III, were formed as sole products or mixtures with pyrimidines or dihydroquinazolinones.

Journal of Heterocyclic Chemistry published new progress about Cyclocondensation reaction. 66373-25-9 belongs to class pyrimidines, name is 1-(2-Amino-4-methylpyrimidin-5-yl)ethanone, and the molecular formula is C7H9N3O, Synthetic Route of 66373-25-9.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Strekowski, Lucjan published the artcileHighly regioselective bromination reactions of polymethylpyrimidines, Related Products of pyrimidines, the main research area is methylpyrimidine regioselective bromination; bσomomethylpyrimidine.

Methylpyrimidines I (R, R1 = H, Me; R2 = H, SMe) are brominated at C(5)-Me with NBS in CCl4 and at C4(6)-Me with Br2 in HOAc to give the bromomethyl derivatives in a high yield. The remaining Me group(s) can also be brominated with high regioselectivity. The 2-methylthio substituent is not oxidized under these conditions.

Journal of Organic Chemistry published new progress about Bromination, regioselective. 84755-30-6 belongs to class pyrimidines, name is 4-Methyl-2-(methylthio)pyrimidine-5-carbaldehyde, and the molecular formula is C7H8N2OS, Related Products of pyrimidines.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Homon, Anton A. published the artcileSynthesis of 3-Azabicyclo[3.2.0]heptane-Derived Building Blocks via [3+2] Cycloaddition, Recommanded Product: 4-Chloro-6-(methoxymethyl)pyrimidine, the main research area is azabicyclo heptane derivative; cyclobuteneraboxylic acid ester cycloaddition.

An efficient approach to synthesis of various substituted 3-azabicyclo[3.2.0]heptane-derived building blocks based on [3+2] cycloaddition of cyclobut-1-eneraboxylic acid ester and in situ generated azomethine ylide was developed and applied on multigram scale. The utility of 1,3-disubstituted 3-azabicyclo[3.2.0]heptane scaffold was demonstrated by addnl. structural anal. using exit vector plot (EVP) tool, and tested in parallel synthesis of compound library.

European Journal of Organic Chemistry published new progress about [3+2] Cycloaddition reaction. 3122-84-7 belongs to class pyrimidines, name is 4-Chloro-6-(methoxymethyl)pyrimidine, and the molecular formula is C6H7ClN2O, Recommanded Product: 4-Chloro-6-(methoxymethyl)pyrimidine.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Rao, P. Surya Prakash published the artcileA validated chiral LC method for enantiomeric separation of intermediate of lopinavir by using cellulose based chiral stationary phase, Product Details of C9H16N2O3, the main research area is lopinavir intermediate enantiomer chiral HPLC.

A rapid isocratic chiral LC method was developed for the separation of 2R-(1-Tetrahydro pyrimid-2-onyl)-3-Me butanoic acid (R-THPA) from 2S-(1-Tetrahydro pyrimid-2-onyl)-3-Me butanoic acid. (S-THPA). Good resolution with Rs > 3 was obtained using cellulose based chiral stationary phase, chiralcel OD-H column (250 × 4.6 mm, 5 μm particle size) and n-hexane, ethanol and trifluoroacetic acid (900:100:2, volume/volume) as the mobile phase at ambient temperature Flow rate was kept at 1.2 mL/min-1 and elution was monitored by UV detection at 210 nm. This method allowed for the detection and quantification of R-THPA of levels at 0.5 and 1.5 μg/mL-1 resp. The method was validated following ICH guidelines.

Analytical Chemistry: An Indian Journal published new progress about HPLC chiral stationary phases. 192725-50-1 belongs to class pyrimidines, name is (S)-3-Methyl-2-(2-oxotetrahydropyrimidin-1(2H)-yl)butanoic acid, and the molecular formula is C9H16N2O3, Product Details of C9H16N2O3.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Spalletta, Robert A. published the artcileSpin-trapping free radicals by solvating x-irradiated crystalline pyrimidines, Recommanded Product: 5-Methylcytosinehydrochloride, the main research area is radiolysis uracil cytosine crystal; nitrone spin trap pyrimidine radical; nitrosobutane spin trap pyrimidine radical; ESR spin trapped radical.

Free radicals formed by x-irradiation of polycrystalline pyrimidines (twenty-one uracil and cytosine derivatives) are examined by the ESR of the spin-trapped radicals formed by dissolving polycrystalline samples in aqueous solutions containing Me3CNO or PhCH:N+(O-)CMe3 spin traps. In general, a good correlation is found between the radicals observed in the powder and those trapped in solution Trapping at N(3) is due to H addition to C(6) and not H abstraction from N(3). The 6-yl and N-Me radicals are trapped more efficiently than the 5-yl radical.

Radiation Research published new progress about ESR (electron spin resonance). 58366-64-6 belongs to class pyrimidines, name is 5-Methylcytosinehydrochloride, and the molecular formula is C5H8ClN3O, Recommanded Product: 5-Methylcytosinehydrochloride.

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

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

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

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

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