A. G. Mustafin

Preparation and Antihypoxic Activity of Complexes of Uracil Derivatives with Dicarboxylic Acids

Water-soluble low-toxicity complexes of 6-methyluracil and its derivatives with succinic and fumaric acids were synthesized. The synthesized complexes were tested for antihypoxic activity.

New type of interaction of 5-iodopyrimidine nucleosides with alkynes

The interaction of 1-(β-D-xylofuranosyl)-5-iodo(bromo)uracil derivatives with terminal alkynes in the presence of catalytic amounts of 10% Pd/C and Cul affords the corresponding derivatives of 3-(β-D-xylofuranosyl)-6-R-furo[2, 3-d]pyrimidin-2-ones in high yields.

Ozonolysis of ortho-alkenylanilines

Ozonolysis of N-acyl-2-(1-methylbut-2-enyl)- and N-acyl-2-(cyclopent-2-enyl)anilines followed by treatment with NaBH4 afforded the corresponding 2-(2-hydroxyethyl-1-methyl) and 2-(1,5-dihydroxypent-2-yl) derivatives. The reaction can be directed to indole derivatives by varying the nature of both the acyl group and reducing reagent.

Theoretical Models for Quantitative Description of the Acid-Base Equilibria of the 5,6-Substituted Uracils

The acidities of 18 5,6-substituted uracils have been numerically estimated as pKa values in terms of three theoretical models. The first scheme includes the calculation of the gas-phase acidity of uracil with the G3MP2B3 method and taking into account the solvent effect using the polarizable continuum approximation PCM(SMD)-TPSS/aug-cc-pVTZ. The second model is one step and implies calculation of the free Gibbs energies of the hydrate complex of uracil (and its anion) with 5 water molecules by the TPSS/aug-cc-pVTZ method. This model accounts for the solvent effect corresponding to both specific and nonspecific solvation. The third scheme required high time and computational resources and includes the strong features of the two previous schemes. Here, the theoretical estimation of pKa is performed by the CBS-QB3 composite method. As in the second approach, both specific (as pentahydrate) and nonspecific solvent effects are determined. We have analyzed the advantages and model restrictions of the considered schemes for the pKa calculations. All models have systematic errors, which have been corrected with the linear empirical regression relations. In the presented model, the absolute mean deviations of the pKa values of uracils dissociating via the N1-H bonds diminish to 0.25, 0.28, and 0.23 pKa units (respectively, for I, II, and III models), which corresponds to ∼0.3 kcal/mol on the energy scale. The applicability of our computational schemes to uracils dissociating via N3-H, O-H (orotic acids) and C-H bonds is discussed.

Kinetics, mechanism, and mathematical model of the reaction between uracil and hydrogen peroxide in aqueous solution

The kinetics and mechanism of the reaction between uracil and hydrogen peroxide in aqueous solution have been investigated. Iron ion admixtures in the solution have been demonstrated to bring about two reaction pathways, one free-radical and the other molecular. The mechanism of the reaction has been analyzed by mathematical modeling methods, kinetic curves illustrating the variation of intermediate product concentrations have been obtained, and the rate constants of elementary reactions have been calculated.

Investigation of the mechanism of the inhibited oxidation of 1,4-dioxane by mathematical modeling

The free-radical chain oxidation of 1,4-dioxane in the presence of an inhibitor has been investigated by mathematical modeling. The forward kinetic problem has been solved, and complete kinetic information about the reaction has been gained, including the variation of the concentrations of all reaction participants. The inverse kinetic problem has also been solved to determine the rate constants of all elementary steps.

Experimental and quantum-chemical studies of the reactions of 6-methyluracil with succinic and fumaric acids

Possible structures of 6-methyluracil complexes with succinic and fumaric acids are studied by quantum-chemical means. The possibility of complex formation occurring between 6-methyluracil and the acids in the ionized and nonionized states is evaluated. The form of the complexes containing the nonionized acid is found to dominate. The quantum-chemical calculation data are consistent with the experimental results.

Synthesis and antioxidant activity of aminomethylated 6-methyluracil derivatives

The Mannich reactions of 6-methyluracil and 5-nitro-6-methyluracil with piperidine, morpholine, and triazole were studied. The antioxidant activities of the Mannich bases were comparable to that of the known antioxidant ionol.

Intramolecular cyclization ofortho-(cyclohex-2-enyl)anilines. Modified synthesis of ellipticine

It was found that the reactions of arylamines with 3-bromocyclohexene afforded hydrocarbazole compounds in 64–78% yields. A modified procedure for the synthesis of antitumor alkaloid ellipticine was proposed.

Synthesis of ?-D-xylofuranosyl- and 2,2?-anhydro-1-?-D-lyxofuranosylpyrimidine nucleosides

Abstractβ-D-Xylofuranosylpyrimidines were obtained by condensation of silyl derivatives of pyrimidines with 1,2-di-O-acetyl-3,5-di-O-benzoyl-D-xylofuranose with subsequent deprotection of the sugar fragment. Refluxing 2-O-tosyl derivatives of nucleosides with NaI results in the formation of 2,2′-anhydro-compounds.