2459-09-8Relevant articles and documents
Comparative Studies of 2-, 3-, and 4-Pyridylpalladium(II) Complexes: Synthesis and Properties
Isobe, Kiyoshi,Nakamura, Yukio,Miwa, Toshio,Kawaguchi, Shinichi
, p. 149 - 158 (1987)
Oxidative addition reactions of bromopyridines to tetrakis(triphenylphosphine)palladium(0) gave (1b), trans- (2b), and trans- (3b), which were converted on treatment with triethylphosphine to trans- complexes (1d, 2d, 3d, respectively).Titration with perchloric acid in dioxane-water (1:1 by volume) indicated the basicity sequence of these complexes: 2-pyridyl>>4-pyridyl>3-pyridyl.The bromide ligand in 1b-3b can readily be replaced by Cl-, I-, N3-, NCO-,and NCS-.In each corresponding series the relative thermal stability is in the sequence of 2-pyridyl>4-pyridyl>3-pyridyl.The pyridyl complexes containing triphenylphosphine react with carbon monoxide at ambient temperature and pressure to afford acyl complexes, which produce the corresponding esters by reactions with methanol.They also act as catalysts for cross coupling reactions of bromopyridines.
Thermodynamic properties of three pyridine carboxylic acid methyl ester isomers
Ribeiro Da Silva, Maria D. M. C.,Freitas, Vera L. S.,Santos, Luis M. N. B. F.,Fulem, Michal,Sottomayor,Monte, Manuel J. S.,Acree Jr.
, p. 580 - 585 (2007)
The present work reports the values of the standard (po = 0.1 MPa) molar energies of combustion for the liquid isomers methyl picolinate and methyl isonicotinate and for the crystalline isomer methyl nicotinate measured by static bomb calorimetry. The molar enthalpies of vaporization of the three isomers at T = 298.15 K as well as the molar enthalpies of sublimation of two of them (methyl picolinate and methyl nicotinate) were derived from vapor pressure measurements at different temperatures using a static method. The molar enthalpies of vaporization at T = 298.15 K of methyl picolinate and methyl isonicotinate were also measured using Calvet microcalorimetry. The thermal behavior of the compounds was studied by differential scanning calorimetry, and the temperatures and the molar enthalpies of fusion were determined using this technique. The experimental results were used to derive the gaseous standard molar enthalpies of formation, at 298.15 K, of the three pyridinecarboxylic acid methyl ester isomers and the triple points of the ortho and meta isomers.
Silver-coordination polymer network combining antibacterial action and shape memory capabilities
Wang, Lin,Wang, Wenxi,Di, Shubin,Yang, Xifeng,Chen, Hongmei,Gong, Tao,Zhou, Shaobing
, p. 32276 - 32282 (2014)
In this study, a multifunctional polymer network is achieved by first synthesizing an isonicotinate-functionalized polyester (PIE) via classical melt-condensation polymerization, and secondly, the pendant of the pyrazinamide groups on the polyester side chains is coordinated with Ag ions to form a physically cross-linked network. Thermo property analysis and dynamic mechanical analysis reveal that the Ag-coordination polymer network possesses an excellent thermo-induced shape memory function, both under air and physiological conditions, due to a wide glass transition temperature region. The Ag ion concentration coordinated with the polymer was optimized to achieve the best shape memory effect using atomic absorption spectrometry. Moreover, the coordinated polyester can act as a reservoir of bactericidal Ag ions, in which the Ag ions are released and measured with inductively coupled plasma mass spectrometry, and in turn the antibacterial function is realized. Finally, the result of an Alamar blue assay reveals that the Ag-coordinated polyester has good cytocompatibility despite the introduction of a certain amount of Ag ions. Therefore, the multifunctional polymer has great potential applications in the biomedical field, e.g., burn wound dressings. the Partner Organisations 2014.
Design, synthesis, antibacterial evaluation, and computational studies of hybrid oxothiazolidin–1,2,4-triazole scaffolds
Pathak, Prateek,Novak, Jurica,Shukla, Parjanya K.,Grishina, Maria,Potemkin, Vladimir,Verma, Amita
, (2021/03/08)
Bacterial infections are a serious threat to human health due to the development of resistance against the presently used antibiotics. The problem of growing and widespread antibiotic resistance is only getting worse with the shortage of new classes of antibiotics, creating a substantial unmet medical need in the treatment of serious bacterial infections. Therefore, in the present work, we report 18 novel hybrid thiazolidine–1,2,4-triazole derivatives as DNA gyrase inhibitors. The derivatives were synthesized by multistep organic synthesis and characterized by spectroscopic methods (1H and 13C nuclear magnetic resonance and mass spectroscopy). The derivatives were tested for DNA gyrase inhibition, and the result emphasized that the synthesized derivatives have a tendency to inhibit the function of DNA gyrase. Furthermore, the compounds were also tested for antibacterial activity against three Gram-positive (Bacillus subtilis [NCIM 2063], Bacillus cereus [NCIM 2156], Staphylococcus aureus [NCIM 2079]) and two Gram-negative (Escherichia coli [NCIM 2065], Proteus vulgaris [NCIM 2027]) bacteria. The derivatives showed a significant-to-moderate antibacterial activity with noticeable antibiofilm efficacy. Quantitative structure–activity relationship (QSAR), ADME (absorption, distribution, metabolism, elimination) calculation, molecular docking, radial distribution function, and 2D fingerprinting were also performed to elucidate fundamental structural fragments essential for their bioactivity. These studies suggest that the derivatives 10b and 10n have lead antibacterial properties with significant DNA gyrase inhibitory efficacy, and they can serve as a starting scaffold for the further development of new broad-spectrum antibacterial agents.
Catalyst-Free N-Deoxygenation by Photoexcitation of Hantzsch Ester
Cardinale, Luana,Jacobi Von Wangelin, Axel,Konev, Mikhail O.
supporting information, (2020/02/15)
A mild and operationally simple protocol for the deoxygenation of a variety of heteroaryl N-oxides and nitroarenes has been developed. A mixture of substrate and Hantzsch ester is proposed to result in an electron donor-acceptor complex, which upon blue-light irradiation undergoes photoinduced electron transfer between the two reactants to afford the products. N-oxide deoxygenation is demonstrated with 22 examples of functionally diverse substrates, and the chemoselective reduction of nitroarenes to the corresponding hydroxylamines is also shown.
