Synthesis of pyrophosphatotetraamminediplatinum(II) complex and its transformations in hydrochloric acid solutions

A new method for the synthesis of [Pt₂(NH₃)₄P₂O₇] is proposed. Its transformations in a hydrochloric acid medium are described.     

Oxidation of Zinc Sulfide in the System HNO3-Fe(NO3)3-H2O

The behavior of zinc sulfide in the system HNO₃-Fe(NO₃)₃-H₂O at 25, 55, and 80°C was studied using the simplex-lattice design method.     

Synthetic transformations of sesquiterpene lactones: VII. Palladium-catalyzed cross-coupling of isoalantolactone with 5-halouracils

Palladium-catalyzed cross-coupling of isoalantolactone with 1,3-disubstituted or 1-substituted 5-bromo(iodo)uracils afforded mainly (13E)-13-(2,4-dioxotetrahydropyrimidin-5-yl)eudesma-4(15),11(13)-dien-8β,12-olides whose yields depended on the composition of the catalytic system, base, and additive. The structure of (13E)-13-[3-(2-cyanoethyl)-2,4-dioxotetrahydropyrimidin-5-yl]eudesma-4(15),11(13)-dien-8β,12-olide was proved by X-ray analysis.     

Synthesis and Antibacterial Activity of Caffeine Derivatives Containing Amino-Acid Fragments

Chemistry of Natural Compounds - Cross-coupling of 8-bromocaffeine, 8-bromo-1-butyltheobromine, or 8-bromo-7-butyltheophylline with α-, β-, or ω-amino-acid methyl or t-butyl ester...     

Comprehensive Analysis of the Liquid Fraction of Car Tire Pyrolysis Products by Gas Chromatography–Mass Spectrometry

Russian Journal of Applied Chemistry - The liquid fraction of tire pyrolysis products was comprehensively analyzed by gas chromatography–mass spectrometry and two-dimensional gas...     

Synthesis of a new class of bisheterocycles via the Heck reaction of eudesmane type methylene lactones with 8-bromoxanthines

The eudesmane-type methylene lactones (isoalantolactone, alantolactone, 4,15-epoxyisoalantolactone, 2′,2′-dichloro-4H-spiro[cyclopropane-1′,4-eudesma-11(13)-en-8β,12-olide], and alantolactone) react with 8-bromoxanthines (8-bromocaffeine, 8-bromotheobromine, 8-bromo-3-butyltheobromine, 8-bromotheophylline, 8-bromo-9-butyltheophylline) under Heck reaction conditions to produce the target (E)-13-(2,6-dioxo-2,3-dihydro-1H-purin-8-yl)eudesma-4(15),11(13)-dien-8β,12-olides and the subsequent endocyclic isomers - 11-(2,6-dioxo-2,3-dihydro-1H-purin-8-yl)-13-normethyleudecma-4(15)-7(11)-dien-8α,12-olides. It was revealed that the yield and product ratio depends on the reaction conditions and the structure of methylene lactone. The effectiveness of Pd(OAc)₂–caffeine catalytic system has been demonstrated in this reaction. The electric eel acetylcholinesterase inhibitory activity of the eudecmanolide-xanthine hybrids was evaluated. Among the new type bisheterocycles compound 27 with butyl and 2-oxodecahydronaphtho[2,3-b]furan-3(2H)-ylidene)methyl substituents at C-7 and C-8 of the xanthine core showed moderate activity with IC₅₀ value of 40 μM.     

Multicapillary columns with a porous layer based on the divinylbenzene copolymer

A method for preparing a multicapillary column with a porous layer based on the styrene-divinylbenzene copolymer has been developed. The column makes it possible to quickly separate C₁–C₄ hydrocarbons and oxygen-containing compounds. The main chromatographic properties of the columns were studied.