Izvestiya of Saratov University.
ISSN 1816-9775 (Print)
ISSN 2541-8971 (Online)


Transformations of substituted cyanoiminooctahydroquinazolines under oxidation conditions

Substituted quinazolines of various degrees of saturation and functionalization possess a wide spectrum of biological activity, in particular, anticancer activity, which predetermines the importance of obtaining new representatives of this type of compounds and studying their practically useful properties. Methods for the preparation of 2-cyanoiminoquinazolines are poorly described in the literature, while their properties and oxidation reactions have not been studied at all.

Microextraction preconcentration with nonionic surfactants and colorometric determination of phenol

The extraction of the tungsten blue complex formed by the reaction of phenol with Folin-Ciocalteu reagent (FCR) in the presence of a nonionic surfactant Triton X-100 in alkaline medium using the methodology of micellar extraction based on «clouding point» has been studied for the fi rst time. Aqueous solutions of sodium carbonate and sodium sulfate were used to create pH and as a desalting agent.

Investigation of the properties of the solid residue of the pyrolysis of sewage sludge

This article presents the results of the thermal processing of sludge from domestic wastewater under laboratory conditions. The pyrolysis process is carried out in a batch reactor with an original design. Gaseous and liquid forms of hydrocarbon compounds, as well as solid carbonaceous residue, were obtained after processing the sludge in a pyrolytic plant. It is established that during pyrolysis of sludge sewage sludge, the output of the process products depends on the heating rate of the raw material.

Study of the activity of bifunctional catalyzers on the transformation of n-hexane

The production of various motor fuels is carried out by processing light fractions of oil with an initial temperature of boiling to 350°С. The current trend shows that oil in new fi elds has more weight than before. New oil reservoirs are deeper with a greater proportion of dark fraction with a boiling point of 350°С. This situation stimulates to fi nd new ways of increasing the processing depth light fractions for synthesis target product. One of the main solution path for the problem is creation of new catalytic systems or modernization of existing ones.

Analytical reactions of 2,4-dinitrophenylhydrazine with some aldehydes in micelles of cationic surfactants

The analytical eff ect of micelles of cationic surfactants in the reactions of some aromatic aldehydes (AA) with 2,4-dinitrophenylhydrazine (DNPH) with the formation of the corresponding aci-forms of hydrazones has been established. It has been established that micelles of nonionic and anionic surfactants do not cause analytically signifi cant eff ects in the system under study.

Smartphone use in solid-phase fl uorimetric determination of some polypeptide antibiotics in medicinal preparations

The analysis of semi-products at diff erent stages of production and fi nished medicinal products is an integral part of an eff ective quality assurance system for pharmaceutical production. The traditional methods used in the pharmaceutical fi eld, such as capillary electrophoresis, gas and liquid chromatography, are quite versatile and eff ective. However, they are distinguished by the high cost of instrumentation and component materials, the need to use high-purity solvents, the lack of mobility and the possibility of in situ studies.

Synthesis and properties of grafted copolymers of xanthan and glucomannan with acrylic monomers

Graft copolymers of polysaccharides with acrylic monomers combine biodegradability, biocompatibility, the environmental friendliness of natural polymers and the increased thermal stability, chemical and mechanical resistance of synthetic polymers. This paper describes our search and analysis of the literature in English for 2002–2022 devoted to the graft polymerization of acrylamide, acrylic acid and 2-acrylamido2-methylpropanesulfonic acid onto xanthan and glucomannan macromolecular chains.

Synthesis of spiropyrrolizidines containing quinoxaline and pyrrole fragments

The reaction of 1,3-dipolar cycloaddition azomethine ylides obtained by the in situ interaction of 11H-indeno[1,2-b]quinoxalin-11-one and proline, and 3-phenyl-1-pyrrolyl-2-en-1-ones has been used for the synthesis of substituted spiropyrrolizidines in continuation of the study the use of new enones as dipolarophiles. The conditions for the implementation of a three-component synthesis (temperature regime, solvent, activation method) are selected. The best performance has been obtained by refl uxing the reaction mixture in ethanol.

Complex organomineral fertilizers and meliorants – a new eco-friendly approach to phosphogypsum utilization

One of the modern approaches to solving environmental problems of accumulation and deposition of production and consumption waste is the implementation of “green economy” and “closed cycle” economy models. This approach makes it possible to increase the resource utilization rate and reduce the negative impact on the environment. The study of the possibility of joint disposal of waste from various industries, for example agricultural and industrial waste, is promising in this area.

Cycvalone in the synthesis of nitrogen-, oxygen-containing heterocycles

Cycvalone is an analogue of curcumin (EE conformation), exhibits a wide range of biological activity (antioxidant, hepatoprotective, membrane stabilizing, anti-ulcer) and is used in medical practice as a choleretic. Numerous methods of producing cycvalone are known, including industrial ones, but its reactions have been studied much less. Some reactions of cycvalone with N, C-nucleophiles (hydrazines, malononitrile) have been carried out.