Tag: M.W=150-200

Uddin, Kabir M. published the artcileNew insight into the substituent effects on the hydrolytic deamination of saturated and unsaturated cytosine, Related Products of pyrimidines, the main research area is cytosine hydrolytic deamination substituent effect thermodn property.

Ab initio calculations were carried out to understand the effect of electron donating groups (EDG) and electron withdrawing groups (EWG) at the C5 position of cytosine (Cyt) and saturated cytosine (H2Cyt) of the deamination reaction. Geometries of the reactants, transition states, intermediates, and products were fully optimized at the B3LYP/6-31G(d,p) level in the gas phase as this level of theory has been found to agree very well with G3 theories. Activation energies, enthalpies, and Gibbs energies of activation along with the thermodn. properties (ΔE, ΔH, and ΔG) of each reaction were calculated A plot of the Gibbs energies of activation (ΔG ) for C5 substituted Cyt and H2Cyt against the Hammett σ-constants reveal a good linear relationship. In general, both EDG and EWG substituents at the C5 position in Cyt results in higher ΔG and lower σ values compared to those of H2Cyt deamination reactions. C5 alkyl substituents (H, CH3, CH2CH3, CH2CH2CH3) increase ΔG values for Cyt, while the same substituents decrease ΔG values for H2Cyt which is likely due to steric effects. However, the Hammett σ-constants were found to decrease at the C5 position of cytosine (Cyt) and saturated cytosine (H2Cyt) on the deamination reaction. Both ΔG and σ values decrease for the substituents Cl and Br in the Cyt reaction, while ΔG values increase and σ decrease in the H2Cyt reaction. This may be due to high polarizability of bromine which results in a greater stabilization of the transition state in the case of bromine compared to chlorine. Regardless of the substituent at C5, the pos. charge on C4 is greater in the TS compared to the reactant complex for both the Cyt and H2Cyt. Moreover, as the charges on C4 in the TS increase compared to reactant, ΔG also increase for the C5 alkyl substituents (H, CH3, CH2CH3, CH2CH2CH3) in Cyt, while ΔG decrease in H2Cyt. In addition, anal. of the frontier MO energies for the transition state structures shows that there is a correlation between the energy of the HOMO-LUMO gap and activation energies.

International Journal of Quantum Chemistry published new progress about Activation energy. 19030-75-2 belongs to class pyrimidines, name is 5-N-Propyluracil, and the molecular formula is C7H10N2O2, Related Products of pyrimidines.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Hughes, David D. published the artcileOne or two-step Bohlmann-Rahtz heteroannulation of 6-aminouracil derivatives for the synthesis of pyrido[2,3-d]pyrimidines, Formula: C8H7N3O2, the main research area is aminouracil alkynone Bohlmann Rahtz heteroannulation; pyrido pyrimidine preparation.

The Michael addition-cyclodehydration of a 6-aminouracil and alkynone proceeds to give 5-deazapterin derivatives with total control of regiochem. This simple and facile cyclocondensation process is catalyzed by zinc(II) bromide or ytterbium(III) trifluoromethanesulfonate at 110°, providing the heteroannulated products in up to 94% yield.

Synlett published new progress about Bohlmann-Rahtz reaction. 36075-35-1 belongs to class pyrimidines, name is 7-Methylpyrido[2,3-d]pyrimidine-2,4-diol, and the molecular formula is C8H7N3O2, Formula: C8H7N3O2.

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

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

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

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

Arya, V. P. published the artcilePsychoactive agents. Part VI. Synthesis and central nervous system effects of some 2-substituted 5-acetyl-4-methylpyrimidine derivatives, Product Details of C7H9N3O, the main research area is pyrimidine acetyl; central nervous system acetylpyrimidine; bactericide furylvinylpyrimidine.

The synthesis of 2-substituted 5-acetyl-4-methylpyrimidines is described. Thus, amidines and substituted guanidines react with EtOCH:C(COMe)2 to give the 5-acetyl-4-methyl-2-substituted pyrimidines I (R = NH2, MeS, morpholino, Ph, etc.). Aminolysis of I (R = MeS) with cyclic secondary amines gave I (R = piperidino, piperazino, pyrrolidino, etc.). Some of these amines were converted to their guanylhydrazones. Mannich condensation of I (R = morpholino) gave II. Some I had central nervous system and bactericidal activity.

Indian Journal of Chemistry, Section B: Organic Chemistry Including Medicinal 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, Product Details of C7H9N3O.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Wood, Hamish C. S. published the artcileSpecific enzyme inhibitors in vitamin biosynthesis. II. Revised structures for 8-substituted pyrido[2,3d]pyrimidines, Formula: C8H7N3O2, the main research area is structure pyridopyrimidine; inhibition riboflavin synthetase pyridopyrimidine.

Condensation of 6-D-ribitylaminouracil (I) with MeCH:CMeCHO and MeCOCHMeCHO gave the pyridopyrimidines II and III resp. and not, as previously stated by T. Paterson and H. C. S. Wood, 1972, III and II resp. The structures were determined by nuclear Overhauser and photochem. degradation studies. The structures originally proposed were shown to be incorrect byenzyme inhibition studies.

Journal of the Chemical Society, Perkin Transactions 16: Organic and Bio-Organic Chemistry published new progress about Doebner-Miller cyclization. 36075-35-1 belongs to class pyrimidines, name is 7-Methylpyrido[2,3-d]pyrimidine-2,4-diol, and the molecular formula is C8H7N3O2, Formula: C8H7N3O2.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Yoneyama, H. published the artcileMembrane device for holding biomolecule samples for terahertz spectroscopy, Category: pyrimidines, the main research area is membrane device terahertz spectroscopy biosensor laser oligosaccharide.

A device for holding biomol. samples on a membrane allows scanning using terahertz frequency waves. Such scanning has previously been difficult due to the strong attenuation of terahertz frequency waves by water. Several types of biomols. were scanned using terahertz time domain spectroscopy (TDS), and the data showed clear differences in transmittance among the samples. This membrane device is a promising aid for research on biomols. using terahertz waves.

Optics Communications published new progress about Electrochemical biosensors. 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

Javaid, Z. Z. published the artcilePyrimidine nucleobase ligands of orotate phosphoribosyltransferase from Toxoplasma gondii, Synthetic Route of 19030-75-2, the main research area is orotate phosphoribosyltransferase pyrimidine nucleobase ligand Toxoplasma.

Sixty-seven pyrimidine nucleobase analogs were evaluated as ligands of Toxoplasma gondii orotate phosphoribosyltransferase (OPRTase, EC 2.4.2.10) by measuring their ability to inhibit this enzyme in vitro. Apparent Ki values were determined for compounds that inhibited T. gondii OPRTase by greater than 20% at a concentration of 400 μM. 1-Deazaorotic acid (0.47 μM) and 5-azaorotic acid (2.1 μM) were found to bind better (8.3- and 1.9-fold, resp.) to T. gondii OPRTase than orotic acid, the natural substrate of the enzyme. Based on these results, a structure-activity relationship of ligand binding to OPRTase was formulated using uracil, barbituric acid, and orotic acid as reference compounds It was concluded that the following structural features of pyrimidine nucleobase analogs were required or strongly preferred for binding: (i) an endocyclic pyridine-type nitrogen or methine at the 1-position; (ii) exocyclic oxo groups at the 2- and 4-positions; (iii) a protonated endocyclic pyridine-type nitrogen at the 3-position; (iv) an endocyclic pyridine-type nitrogen or methine at the 5-position; (v) an exocyclic hydrogen or fluorine at the 5-position; (vi) an endocyclic pyridine-type nitrogen or methine at the 6-position; and (vii) an exocyclic neg. charged or electron-withdrawing group at the 6-position. A comparison of the results from the present study with those from a previous study on mammalian OPRTase [Niedzwicki et al., Biochem Pharmacol 33: 2383-2395, 1984] identified four compounds (6-chlorouracil, 5-azaorotic acid, 1-deazaorotic acid, and 6-iodouracil) that may bind selectively to T. gondii OPRTase.

Biochemical Pharmacology published new progress about Enzyme inhibition kinetics. 19030-75-2 belongs to class pyrimidines, name is 5-N-Propyluracil, and the molecular formula is C7H10N2O2, Synthetic Route of 19030-75-2.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia