A simple and efficient route for preparing 2,3,5,6-tetraaminopyridine hydrochloride salt (TAP x 3HCl x H(2)O) was introduced in this paper. The title compound was synthesized, as usual, in two steps (nitration and hydrogenation) with a total yield of 90%. The use of an oleum and fuming nitric acid mixture in the nitration step improved the yield and purity of the intermediate product. A highly ...

nitration of potassium sulphamate was carried out using a mixture of sulphuric and nitric acid at -30 °c. the reaction time was optimized at the mole ratio of sulphuric to nitric acid of (1:3.5). the difference in product yield by changing the potassium to ammonium sulphamate was studied throughly. it was found that both the yield and purity of the product is better starting with potassium sulp...

The rare earth metal(III) trifluoromethanesulfonate (rare earth metal(III) triflate, RE(OTf)3) was found to be an efficient catalyst for aromatic nitration with carboxylic anhydride-inorganic nitrate as the nitrating agent. In the presence of a catalytic amount of RE(OTf)3, the nitration of substituted benzenes proceeded to afford the corresponding nitrobenzenes. Especially, scandium(III) trifl...

A transition-metal-free, mild, and highly regioselective synthesis of nitroarenes from arenes has been developed. The products are obtained in a sequential one-pot reaction by nitration of iodine(III) reagents with two carbon ligands, which are formed in situ from iodine(I). This novel concept has been extended to formation of aryl azides, and constitutes an important step towards catalytic rea...

Cu(II) complexes of N2O2 type ligands, L(1)H2 and L(2)H2 [L(1)H2 = 6,6'-(((pyridin-2-ylmethyl)azanediyl)bis(methylene))bis(2,4-di-tert-butylphenol); L(2)H2 = 2,4-di-tert-butyl-6-(((3-(tert-butyl)-2-hydroxy-5-methylbenzyl)(pyridin-2-yl-methyl)amino)methyl)phenol], have been synthesized. Addition of nitrogen dioxide (NO2) in THF solutions of the complexes resulted in the nitration at the 4-positi...

Abstract Cellulose nitrate (CN) is used in numerous industrial materials, such as propellants, lacquers, and plastics, exploiting its highly flammable, hydrophobic, plastic characters. The downsizing of cellulose fibers may enhance their properties. Although a direct nitration nanofiber (CNF) prospective method for preparing nanosized CN it difficult because the susceptibility CNF to acids. In ...

Due to the increasing importance of nitrosative stress in pathology and the efficacy displayed by flavonoids in cancelling the effects of peroxynitrite, we decided to conduct a comparative study of three commonly used beverages with the highest polyphenol contents and proven antioxidant properties: mate (Ilex paraguariensis); green tea (Camelia sinensis) extracts and white and red wines of the ...

Neuroinflammation is characterized by activation of microglial cells, followed by production of nitric oxide (NO), which may have different outcomes on neurogenesis, favoring or inhibiting this process. In the present study, we investigated how the inflammatory mediator NO can affect proliferation of neural stem cells (NSCs), and explored possible mechanisms underlying this effect. We investiga...

OBJECTIVE Recently we have shown that diabetes-induced retinal neurodegeneration positively correlates with oxidative stress and peroxynitrite. Studies also show that peroxynitrite impairs nerve growth factor (NGF) survival signaling in sensory neurons. However, the causal role of peroxynitrite and the impact of tyrosine nitration on diabetes-induced retinal neurodegeneration and NGF survival s...

Objective(s):Higher cellular reactive oxygen species (ROS) levels is important in reducing cellular energy charge (EC) by increasing the levels of key metabolic protein, and nitrosative modifications, and have been shown to damage the cardiac tissue of diabetic mice. However, the relation between energy production and heart function is unclear. Materials and Methods:Streptozotocin (STZ, 150 mg...