Tag: M.W=100-150

Potyahaylo, A. L. published the artcileProton acceptor and proton donor properties of modified nucleotide bases and their complexing ability: quantum chemical investigation, Category: pyrimidines, the publication is Biopolimeri i Klitina (2004), 20(1-2), 62-70, database is CAplus.

Proton acceptor and proton donor properties of 40 modified nucleotide bases have been investigated by the AM1 semiempirical quantum chem. method, proven to be rather good for such tasks and matters. Based on the data obtained, the orders of the acidity and basicity have been built. The authors have also concluded about the character of self- and hetero-association of some modified nucleotide bases and their specific interactions with both neutral and deprotonated carboxylic groups of amino acids in vacuum. Biol. significance of these findings is briefly discussed.

Biopolimeri i Klitina 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, Category: pyrimidines.

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

Ostakhov, S. S. published the artcileSpectral-luminescence and quantum-chemical study of the anionic forms of 5-fluorouracil, Product Details of C5H6N2O2, the publication is High Energy Chemistry (2017), 51(2), 108-112, database is CAplus.

A spectral-luminescence study of neutral (pH 7) and alk. (pH 11 and 14) aqueous solutions of the anticancer drugs 5-fluorouracil (FU) and tegafur has been performed. The fluorescence spectra of the N3- and N1-centered anions of 5-fluorouracil, its dianion, and the tegafur monoanion with emission maxima at wavelengths (λ_em) of 358, 372, 366, and 358 nm and photoluminescence quantum yields (φ) of 11.2 x 10^-4, 35.1 x 10^-4, 26.5 x 10^-4, and 8.6 x 10^-4, resp., have been recorded for the first time. The fluorescence characteristics of the FU anionic forms have been related to the magnetic shielding constant as one of the criteria of aromaticity.

High Energy Chemistry 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, Product Details of C5H6N2O2.

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

Araki, Koji published the artcileDesign of a fluorescent host for monitoring multiple hydrogen-bonding interaction directly by intramolecular charge-transfer emission, Formula: C5H6N2O2, the publication is Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1998), 1391-1396, database is CAplus.

The hosts 2-dodecanamido-4-methyl-N-[4-(dimethylamino)phenyl]quinoline-7-carboxamide 1 and 2-dodecanamido-4-methyl-N-(4-methoxyphenyl)quinoline-7-carboxamide 2 bearing an aromatic amide unit exhibit an anomalous fluorescence with a large Stokes shift at around 500-600 nm (LW emission) due to an intramol. charge-transfer (ICT) process. The guests 3-ethyl-3-methylglutarimide (bemegride) 4 and 1-methyluracil 5 are associated with the hosts by forming three hydrogen bonds, and the LW emission of the hosts largely increases. On the other hand, the guest 3-methyluracil 6 does not affect the emission of the hosts at all, though formation of two hydrogen bonds with the hosts is confirmed by ¹H NMR measurement. It is concluded that the hosts 1 and 2 can selectively detect the guests 4 and 5 that form hydrogen bonds both at the quinoline ring nitrogen and the amide proton (H_α) of the hosts simultaneously to affect rotation of the amide bond.

Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry 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, Formula: C5H6N2O2.

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

Yamagami, Chisako published the artcileHydrophobicity parameter of diazines. 1. Analysis and prediction of partition coefficients of monosubstituted diazines, HPLC of Formula: 31401-45-3, the publication is Quantitative Structure-Activity Relationships (1990), 9(4), 313-20, database is CAplus.

The octanol/water partition coefficient (P) of a number of monosubstituted diazines was measured. The composition of the π value of substituents, the increment in the log P value accompanying the introduction of substituents, was examined in terms of physicochem. substituent parameters and correlation anal. The diazine-π value of substituents was generally higher than the pyridine-π value of corresponding substituents, indicating that the intramol. electronic interactions between the ring-N atoms and substituent are more pronounced than those in substituted pyridines in governing the log P value of the mol. Except for 2-substituted pyrimidines, the π value of substituents in each series of monosubstituted diazines was in general nicely correlated with the π value of the corresponding substituents in substituted pyridines along with electronic parameter terms representing bidirectional electronic effects on the relative solvation of the ring-N atom(s) and the hydrogen-bondable substituents with partitioning solvents according to the procedure proposed previously for the anal. of the π value in disubstituted benzenes and monosubstituted pyridines. Keeping in mind that 2-pyrimidines substituted by hydrogen-bondable groups sometimes behave as outliers, the correlations were believed to be usable for prediction of log P values of monosubstituted diazines.

Quantitative Structure-Activity Relationships 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 C5H6BNO2, HPLC of Formula: 31401-45-3.

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

Palafox, M. Alcolea published the artcileQuantum Chemical Scaling and its Importance: The Infrared and Raman Spectra of 5-Bromouracil, Recommanded Product: 3-Methylpyrimidine-2,4(1H,3H)-dione, the publication is Spectroscopy Letters (2010), 43(1), 51-59, database is CAplus.

This work describes the interest and necessity of scaling to correct the deficiencies in the calculation of the harmonic vibrational wave numbers The use of adequate quantum-chem. methods and scaling procedures reduces the risk in the assignment and can also accurately determine the contribution of the different modes in an observed band. As an example, the IR and laser-Raman spectra of the 5-bromouracil biomol. are shown.

Spectroscopy Letters 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

Liu, Mingyu published the artcileAtom-Economical Cross-Coupling of Internal and Terminal Alkynes to Access 1,3-Enynes, Quality Control of 174456-28-1, the publication is Journal of the American Chemical Society (2021), 143(10), 3881-3888, database is CAplus and MEDLINE.

Herein, a selective and catalytic method for synthesizing 1,3-enynes (E/Z)-RCCC(R¹)=CHR² (R = tris(propan-2-yl)silyl, 4-(acetyloxy)butyl, cyclohexylmethyl, 5-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)pentyl, etc.; R¹ = Et, Ph, pyridin-3-yl, pyrimidin-5-yl, etc.; R² = hydroxymethyl, (phenylformamido)methyl, [(1H-indol-5-yl)carbamoyl]methyl, etc.) without prefunctionalized building blocks was described. This method is facilitated by a tailored P,N-ligand that enables regioselective dimerization and suppresses secondary E/Z-isomerization of the product. The transformation enables several classes of unactivated internal acceptor alkynes R¹CCR² to be coupled with terminal donor alkynes RCCH to deliver 1,3-enynes in a highly regio- and stereoselective manner. The scope of compatible acceptor alkynes includes propargyl alcs., (homo)propargyl amine derivatives, and (homo)propargyl carboxamides. The reaction is scalable and can operate effectively with as low as 0.5 mol% catalyst loading. The products are versatile intermediates that can participate in various downstream transformations. The preliminary mechanistic experiments that are consistent with a redox-neutral Pd(II) catalytic cycle were also presented.

Journal of the American Chemical Society published new progress about 174456-28-1. 174456-28-1 belongs to pyrimidines, auxiliary class Pyrimidine,Alkynyl,Alcohol, name is 3-(Pyrimidin-5-yl)prop-2-yn-1-ol, and the molecular formula is C7H6N2O, Quality Control of 174456-28-1.

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

Iltzsch, Max H. published the artcileStructure-activity relationship of ligands of uracil phosphoribosyltransferase from Toxoplasma gondii, Application of 3-Methylpyrimidine-2,4(1H,3H)-dione, the publication is Biochemical Pharmacology (1994), 48(4), 781-91, database is CAplus and MEDLINE.

One hundred compounds were evaluated as ligands of Toxoplasma gondii, uracil phosphoribosyltransferase (UPRTase, EC 2.4.2.9) by examining their ability to inhibit this enzyme in vitro. Inhibition was quantified by determining apparent K_i values fo those compounds that inhibited T. gondii UPRTase by greater than 10% at a concentration of 2 mM. Five compounds (4-thiopyridine, 2-thiopyrimidine, trihiocyanuric acid, 1-deazauracil and 2,4-dithiouracil) bound to the enzyme better than two known substrates for T. gondii UPRTase, 5-fluorouracil and emimycin, which have antitoxoplasmal activity (Pfefferkorn ER, Exp Parasitol 44: 26-35, 1978; Pfefferkorn et al., Exp Parasitol 69: 129-139, 1989). In addition, several selected compounds were evaluated as substrates for T. gondii UPRTase, and it was found that 2,4-dithiouracil is also a substrate for this enzyme. On the basis of these data, a structure-activity relationship for the binding of ligands to T. gondii UPRTase was determined using uracil as a reference compound

Biochemical Pharmacology 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 of 3-Methylpyrimidine-2,4(1H,3H)-dione.

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

Goerner, Helmut published the artcileIon-forming processes on 248-nm laser excitation of uracil and methyl-monosubstituted uracils: a time-resolved transient conductivity study in aqueous solution, HPLC of Formula: 608-34-4, the publication is Radiation Physics and Chemistry (1995), 45(4), 677-88, database is CAplus.

Uracil, thymine and 1-, 3-, and 6-methyluracil were studied by time-resolved optical and conductometric methods after 248-nm excitation with 20-ns laser pulses. The transient conductivity in argon-saturated aqueous solution, showing a maximum increase (Δκ^max) during the pulse, is ascribed to the generation of hydrated electrons (e_aq^–) and protons. Biphotonic photoionization as the primary process is inferred from the almost linear dependence of Δκ^max on the square of the laser pulse intensity (I_L²). The quantum yield, obtained from either Δκ^max or optical detection of e_aq^–, e.g., Φ_e^– = 0.02 for uracil at pH 7 and I_L = 12 MW cm^-2, varies by a factor of about two for the five pyrimidines. The neutralization kinetics depend strongly on pH and the concentrations of laser-induced e_aq^– and H⁺, i.e., on I_L. At pH 6-7 the Δκ signal decays by second-order kinetics. Under argon the electron adds to the (methyl)uracil and neutralization occurs by reaction of the radical anion with a proton, which originates from a fast decay of the radical cation. Virtually the same conductivity pattern was found for the neutralization reaction of OH^– and H⁺ under N₂O. In the acidic pH range the decay changes to first-order kinetics due to reaction of H⁺ with e_aq^– under argon or with OH^– under N₂O. In the alk. pH range OH^– release is involved in the relaxation process resulting from the radical cation after excitation of the conjugate base. No indication of a specific spatial correlation of the charged species, as proposed earlier by Grossweiner for other systems, was found.

Radiation Physics and Chemistry 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, HPLC of Formula: 608-34-4.

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

Huebscher, Joerg published the artcileSynthesis and Structural Characterization of Ethynylene-Bridged Bisazines Featuring Various α-Substitution, HPLC of Formula: 1059705-07-5, the publication is Journal of Heterocyclic Chemistry (2015), 52(4), 1062-1074, database is CAplus.

A series of bispyridines e.g., I and bispyrimidines e.g., II showing the heterocycles attached to both ends of an ethynylene unit and being -substituted with chloro, tert-butylthio, and methoxy groups have been synthesized via cross-coupling technique and their crystal structures were studied by X-ray diffraction anal. Supramol. interactions of C-H···N and π···π stacking type were found to largely dominate the structures according to the compound species. A trial was given to deduce the markedly differing temperatures of melting among the compounds from special features of the crystal structures.

Journal of Heterocyclic Chemistry published new progress about 1059705-07-5. 1059705-07-5 belongs to pyrimidines, auxiliary class Pyrimidine, name is 5-Ethynyl-2-methoxypyrimidine, and the molecular formula is C7H6N2O, HPLC of Formula: 1059705-07-5.

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

Lardenois, Patrick published the artcileTautomerism in heterocyclic compounds. X. Structure of pyrimidine derivatives, Synthetic Route of 31401-45-3, the publication is Bulletin de la Societe Chimique de France (1971), 1858-68, database is CAplus.

The uv, ir, and NMR spectra were used to study tautomerism in 54 hydroxy, thio, amino, and acylamino pyrimidine derivatives, having no Me or Ph group in the 2-position and a functional group in the 4 position. The pyrimidine derivatives were prepared by known methods.

Bulletin de la Societe Chimique de France 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, Synthetic Route of 31401-45-3.

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