Mono- and Dioses of Glycyrrhiza glabra Root

Simple sugars were isolated from the ethanol extract of Glycyrrhiza glabra L. root. The component composition of the carbohydrate fraction was established using GC-MS (gas-chromatographic separation and mass-spectrometric analysis).     

Synthesis of Macrocyclic Pyrimidine Derivatives

A reaction was studied of previously unknown 1,3-bis(2-hydroxy-3-chloropropyl)uracil, 1,3-bis(2- hydroxy-3-chloropropyl)-6-methyluracil, and 1,3-bis(2-hydroxy-3-chloropropyl)-5-fluorouracil with 1,3-bis[3-(3-methyl-2H-5-pyrazolon-1-yl)-2-hydroxypropyl]-6-methyluracil.     

Hydrolysis of 1,2-disubstituted imidazolines in aqueous media

The kinetics of hydrolysis of 1,2-disubstituted imidazolines in aqueous media was studied (pH 2.0—12.5, T = 25—90 °C) by UV spectroscopy. The hydrolysis products were identified. The introduction of a branched substituent into position 2 of the imidazoline ring increases the hydrolytic stability of the compounds. The effect of the pH on the hydrolysis rate of imidazolines is discussed.     

Gold(III) extraction by 1,3-Bis(2′-acetoxymethylthiobutyl-3′-thiobutylpropyl)-6-methyluracyl from hydrochloric acid solutions

Gold(III) extraction by 1,3-bis(2′-acetoxymethylthiobutyl-3′-thiobutylpropyl)-6-methyluracyl from 0.5 M HCl solutions to chloroform is studied. The reagent has a high efficiency, separates gold(III) ions from the sum of nonprecious and ferrous metals, and can be repeatedly used after stripping. The extraction mechanism is solvation, with Au-S coordination bonds formed with all sulfur atoms of the reagent; the solvation number changes from 1 to 0.25 with increasing gold(III) aqueous concentration.     

CuCl2-Mediated Hydroxylation of 2,3-Dimethyl-5-hydroxy-6-aminopyrimidine-4(3H)-one with Molecular Oxygen in Aqueous and Non-Aqueous Solutions

Russian Journal of General Chemistry - The catalytic hydroxylation of 2,3-dimethyl-5-hydroxy-6-aminopyrimidine-4(3H)-one in an aqueous solution in the presence of copper(II) ions and oxygen...     

Palladium-Promoted Carbon–Nitrogen Bond Cleavage in 1,3,5-Triazinane Derivatives

Russian Journal of General Chemistry - trans-Dichloropalladium(II) complexes with amino acid esters PdCl2L2 have been synthesized via selective hydrolytic cleavage of the nitrogen–carbon bond...     

Activation of molecular oxygen on copper(II) complexes of 5-hydroxy and 5-aminoorotic acids

The fixation and activation of molecular oxygen on copper(II) complexes with 5-hydroxy and 5-aminoorotic acids, leading to oxidation of the ligand.     

Protonation of 1,2-disubstituted imidazolines and other products of condensation of 2-ethylhexanoic acid with diethylenetriamine and triethylenetetramine

The protonation constants for the products of condensation of 2-ethylhexanoic acid with diethylenetriamine or triethylenetetramine were determined by potentiometric titration. The sequence of protonation of the nitrogen atoms in the imidazoline ring was found from the UV, IR, and ¹³C NMR spectra.     

The role of copper(II) ions in the oxidation of 5-hydroxy-6-methyluracil in the ground and electronically excited states with molecular oxygen in aqueous solutions

A spectral fluorescence study of photoinduced reactions in aqueous solutions has been carried out in order to examine the mechanisms of the oxidation of 5-hydroxy-6-methyluracil (I) in the ground and electronically excited states by molecular oxygen in the presence of copper(II) chloride. It has been found that 5,5,6-trihydroxy-6-methylpyrimidine-2,4-dione (II) is formed upon the photolysis of I. The spectral parameters (λ_max) and the quantum yields (φ) of fluorescence (FL) of compounds I (φ = 8 × 10^–4; λ_max = 362 nm) and II (φ = 17 × 10^–4; λ_max = 306, 330 nm) have been determined. A reaction scheme was proposed, according to which the photooxidation of I occurs through the steps of the generation of the radical cation I ^?+ and the superoxide anion О ₂ ^?- with the subsequent formation of 5,5,6-trihydroxy-6-methylpyrimidine-2,4-dione. The catalytic and inhibitory effects of Cu(II) ions on the oxidation of 5-hydroxy-6-methyluracil in the ground and electronically excited states, respectively, by the oxygen radical anion О ₂ ^?- have been revealed.     

Extraction of Iridium(IV) from Hydrochloric Acid Solution with Bis(piperidinoethylthioethyl)-1-phenyl-1-ethanone

A bidentate organic compound containing nitrogen and sulfur donor atoms was tested as a reagent for extraction of iridium(IV) from aqueous solutions. The composition of the extractable Ir(IV) complex was determined by ¹H NMR, UV, and IR spectroscopy and elemental analysis.