Solubility Polytherm of the Ternary System Hexamethylenetetramine-Ammonium Dihydrogen Phosphate-Water

The solubility polytherm of the ternary system hexamethylenetetramineammonium dihydrogen phosphate-water was studied in a wide temperature range. The concentration and temperature ranges of crystallization of the starting components and a new compound, NH₄H₂PO₄·2(CH₂)₆N₄·8H₂O, were determined. The properties and structure of the new compound were studied by X-ray phase, thermal, and IR spectroscopic analyses.     

Volterra functional integral equation of the first kind with nonlinear right-hand side and variable limits of integration

We prove a theorem on the existence and uniqueness of a solution of a Volterra functional integral equation of the first kind with nonlinear right-hand side and nonlinear deviation. We use the method of successive approximations combined with the method of contracting mappings. Published in Ukrains’kyi Matematychnyi Zhurnal, Vol. 58, No. 9, pp. 1285–1288, September, 2006.     

Furoylation of alkylbenzenes

The acylation of alkylbenzenes with furoyl chloride in the presence of catalytic amounts of FeCl₃ requires a relatively high reaction temperature (150°C) and is accompanied by the elimination of alkyl groups. It is shown by the method of competitive reactions of furoyl and benzoyl chlorides with aromatic compounds that the activity of furoyl chloride is higher when small amounts of the catalyst are present.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1608–1610, December, 1979.Original article submitted November 9, 1978.     

Interrelationships of the structures and antioxidant activities of some flavonoids from the plants of Central Asia

A study has been made of the influence 27 flavonoids on the processes involved in the peroxide oxidation of lipids. The interrelationship between the chemical structures of isoflavones, flavones, flavanones, and flavonols and their antioxidant activities is discussed.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 350–356, May–June, 1996. Original article submitted November 21, 1994.