Reaction of 2,3-dibromo-3-nitroacrylates with N-amino-N″-nitroguanidine

Russian Journal of Organic Chemistry -     

Modification of biologically active amides and amines with fluorine-containing heterocycles 12.* Endo- and exocyclic modifications of the drug riluzole with trifluoromethyl-containing heterocycles

New derivatives of the drug riluzole, 6-(trifluoromethoxy)benzothiazol-2-ylamine, modified at the endo- and exocyclic nitrogen atoms with trifluoromethyl-containing heterocycles were synthesized via transformations of methyltrifluoropyruvate and hexafluoroacetone N-6-(trifluoromethoxy)benzothiazol-2-ylimines by meams of cycloaddition and cyclocondensation reactions, respectively. The influence of the resulting compounds on neuronal NMDA receptors, as well as on the release and reuptake of the neurotransmitter glutamate was investigated.     

Headspace gas-chromatographic determination of formaldehyde in urine

A method is proposed for determining formaldehyde by headspace gas chromatography using an o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) derivatizing agent. Formaldehyde in urine was derivatized to o-(pentafluorobenzyl)oxime and extracted by heating an urine sample with PFBHA in a sealed vial. Gas-chromatographic analysis of the headspace was performed in the temperature-programmed mode using an HP-5 capillary column with a flame ionization detector. The limit of detection is 3.5 μg/L. The accuracy of the procedure, equivalent to an extended relative uncertainty, does not exceed 21%. The examination of the procedure using urine samples of the population of the Irkutsk region has shown that the regional reference levels of formaldehyde concentration are in the range 44–83 μg/L.     

New representatives of nitroamine-containing 1,2,4-triazoles: Synthesis and structure

The interaction of 1-methyl-1-nitroso-2-nitroguanidine with carboxylic acid hydrazides results in formation of N-(2-nitroguanidino)amides that easily give 3(5)-nitroamino-5(3)-alkyl(aryl)-1,2,4-triazoles under refluxing in aqueous alkaline medium. We have developed a one-pot method to prepare such heterocyclic structures; the synthesis of one of the sample compound has given an example of the method applicability. The compounds structures have been confirmed by UV, IR, ¹H, and ¹³C-{¹H} NMR spectroscopy.     

Acousto-Optic Properties of Germanium-, Selenium-, Silicon-, and Tellurium-Based Alloys

Optics and Spectroscopy - Acoustic, optical, and acousto-optic properties of amorphous germanium-, selenium-, silicon-, and tellurium-based alloys have been studied. The velocities of longitudinal...     

Ion-exchange sorption of silver(I) chloride complexes from aqueous HCl solutions

The ion-exchange sorption of silver(I) chloride complexes from 1–4 M aqueous solutions of HCl on a series of Purolite anionites with various functional groups was studied. The ion-exchange equilibria in the systems were found to be anomalous according to Raman spectroscopy, which does not significantly affect the sorption properties of the ionites.     

Anionic Liposomes in Contact with Cationic Chitosan Particles

Russian Journal of General Chemistry - Nanoparticles of ionically cross-linked chitosan have been prepared from the linear polymer with weight-average molecular mass Mw of 30000, 63000, or 300000...