Nef-Perkow cascade towards imidazo phosphate derivatives

A one-pot four-component synthesis of imidazo phosphates has been achieved using a Nef/Perkow sequence followed by addition of propargylamine to form an intermediate amidrazone. The latter is not isolated but directly cyclized to imidazo phosphate derivatives in the presence of silver carbonate.     

Non-Newtonian ink transfer in gravure-offset printing

The inks used in gravure-offset printing are non-Newtonian fluids with higher viscosities and lower surface tensions than Newtonian fluids. This paper examines the transfer of a non-Newtonian ink between a flat plate and a groove when the plate is moved upward with a constant velocity while the groove is held fixed. Numerical simulations were carried out with the Carreau model to explore the behavior of this non-Newtonian ink in gravure-offset printing. The volume of fluid (VOF) method was implemented to capture the interface during the ink transfer process. The effects of varying the contact angle of the ink on the flat plate and groove walls and geometrical parameters such as the groove angle and the groove depth on the breakup time of the liquid filament that forms between the plate and the groove and the ink transfer ratio were determined. Our results indicate that increasing the groove contact angle and decreasing the flat plate contact angle enhance the ink transfer ratio and the breakup time. However, increasing the groove depth and the groove angle decreases the transfer ratio and the breakup time. By optimizing these parameters, it is possible to achieve an ink transfer from the groove to the flat plate of approximately 92%. Moreover, the initial width and the vertical velocity of the neck of the ink filament have significant influences on the ink transfer ratio and the breakup time.     

Surfactant Assisted Electrochemical Determination of Noscapine and Papaverine by TiO2 Nanoparticles/Multi-Walled Carbon Nanotubes Modified Carbon Paste Electrode

Russian Journal of Electrochemistry - In the present study, simultaneous voltammetric determination of noscapine and papaverine as two important alkaloids in opium was studied for the first time. A...     

Ratio Design of Docetaxel/Quercetin Co-Loading-to-Nanocarrier: Synthesis of PCL–PEG–PCL Copolymer,Study of Drug Release Kinetic and Growth Inhibition of Human Breast Cancer (MCF-7) Cell Line

Russian Journal of Applied Chemistry - The present study aimed to design PCL–PEG–PCL copolymer as novel nanocarrier for co-loading of docetaxel (DTX) and quercetin (Qu) drugs and...     

Tetrakis [<Emphasis Type="Italic">N</Emphasis>-(2-pyridyl) sulfonamide] di palladium: synthesize,X-ray diffraction,antibacterial properties and as a novel binuclear Pd-complex for coupling reactions

The N-(2-pyridyl) 4-toluene sulfonamide as a free ligand (PTS) was prepared from the reaction of 2-amino pyridine and 4-toluenesulfonyl chloride in the presence of potassium hydroxide solution 1 M as a base and THF was used as a solvent. The complex tetrakis [N-(2-pyridyl) sulfonamide] di palladium (1) (Pd₂L₄) was also prepared from the reaction of PdCl₂(CH₃CN)₂ using (PTS) in the presence of NaOH 0.5 M and its application in Heck and Suzuki reactions. This complex consists of a binuclear unit consisting of four ligands linked to two palladium atoms via the nitrogen of pyridines ring and the nitrogen of sulfonamides. These compounds were confirmed by FT-IR and ¹H NMR spectroscopy. Moreover, the structure of the complex was studied by single-crystal X-ray diffraction method. The green crystal of Pd₂L₄ [L = N-(2-pyridyl) sulfonamide](1) was found to crystallize in the monoclinic space group C2/c with a = 18.2013(19), b = 19.7544(16), c = 17.2898(19) Å, β = 120.179(8) °; V = 5374.0(9) ų; Z = 4; the final R ₁ = 0.0894, wR ₂ = 0.1754 (or 5867 observed reflections and 318 variables). The Pd–Pd distance is 2.567(2) Å. In addition, PTS and Pd₂L₄ presented different antibacterial behaviors. The free ligand was active against Staphylococcus aureus and Escherichia coli, but the complex was inactive against them.     

A one-pot three-component reactions for the synthesis of fully substituted spiro indeno[1,2-b]quinoxaline derivatives

An efficient and simple approach of the synthesis of some spiro indeno[1,2-b]quinoxalines via a one-pot three-component reaction of 11H-indeno[1,2-b]quinoxalin-11-one, pyrazolone, and malononitrile in the presence of Na₂CO₃ at 70 °C is reported. This reaction has shown to have high atom economy.     

Determination of mercury(II) ions in seafood samples after extraction and preconcentration by a novel functionalized magnetic metal–organic framework nanocomposite

This work describes a novel functionalized magnetic metal–organic framework nanocomposite [(Fe₃O₄‐2,5‐dimercapto‐1,3,4‐thiadiazole)/metal–organic framework] and its application in the preconcentration of Hg(II) ions. The parameters affecting the preconcentration procedure were optimized by a Box–Behnken design through response surface methodology. Three variables (uptake time, magnetic nanosorbent amount, and pH value) were selected as the main factors affecting the sorption step, while four variables (type, volume, and concentration of the eluent; and elution time) were selected as main factors in the optimization study of the elution step. Following the sorption and elution of analytes, the ions were quantified by cold vapor atomic absorption spectrometry. Under the optimum conditions, the limit of detection was 0.01 ng/mL and all the relative standard deviations were less than 10%. The obtained sorption capacity (in mg/g) of this new sorbent was 124. Ultimately, this nanocomposite was successfully applied to the rapid extraction of trace quantities of Hg(II) ions in seafood samples and satisfactory results were obtained.     

Ionic liquid promoted one-pot synthesis of 3-aminoimidazo[1,2-a]pyridines

3-Aminoimidazo[1,2-a]pyridines have been synthesized in good to excellent yields in the presence of the ionic liquid 1-butyl-3-methylimidazolium bromide [bmim]Br, the reaction workup is simple and the ionic liquid can be easily separated from the product and reused.