Vol 52, No 8 (2016)

Application of freons in catalytic olefination for production of fluorinated alkenes is discussed and also the synthesis of versatile fluorinated compounds on this basis.

Mechanism of a multistage reaction between α-bromotrifluoromethylenones and N,N′-dialkylethylenediamines was examined in detail using quantum chemical methods of density functional (non-empirical functional РВЕ, extended split TZp-basis) and multiparticle perturbation theory МР-2, basis 6-311+G(d,p), in the gas phase approximation, and also including solvents molecules (water and 2,2,2-trifluoroethanol). The specific solvation of transition states owing to the hydrogen bonds formation with solvent molecules is the main factor governing the direction of the reaction. Trifluoroethanol forms a strong H-bond with the carbonyl oxygen atom of the trifluoroacetyl group increasing its electrophilicity. It also solvates the departing bromide anion facilitating the occurrence of the S_N2-substitution reaction. An essential but less important factor is the ability of trifluoroethanol to play the role of a nucleophilic partner by forming hydrogen bonds at the expense of the unshared electron pair of the hydroxyl oxygen facilitating the proton abstraction from the nitrogen atom of the diamine attacking the carbon atom in the course of S_N2-substitution.

Adamantylation of carboxylic acids esters was performed with 1,3-dehydroadamantane for the first time. The reaction proceeds under mild conditions and can be used as a convenient single stage procedure for the synthesis of esters of branched carboxylic acids having an adamantyl group in the α-position to the carbonyl group.

1-Phenoxyanthraquinone isomeric conjugates with tetraethylene glycol were prepared. Their photochromic properties and complex formation in solutions were quantitatively studied by spectrophotometry, quantum yields of the arylotropic photoisomerism and stability constants of complexes between para–ana-quinoid isomers and metal cations. The photochemical migration of a phenyl group considerably affects the complex stability thus providing the possibility to regard the synthesized compounds as photocontrolled ionophores. The structure of some complexes was investigated by X-ray diffraction (XRD) analysis and quantum-chemical simulation.

Reaction of 3-amino-8-hydroxy-1,6-dioxo-2,7-diazaspiro[4.4]non-3-en-4-carbonitriles with amines in 2-propanol at room temperature provided the corresponding ammonium salts of 3-amino-8-hydroxy-1,6-dioxo-4-cyano-2,7-diazaspiro[4.4]non-3-en-2-ides.

Reaction of salicilaldehyde and its derivatives with unsaturated cis-, trans-alcohols of the piperidine series in the presence of methyl orthoformate and p-toluenesulfonic acid led to the formation of a new heterocyclic system connecting four fuzed rings (two tetrahydropyrans, a piperidine, and an aromatic ring), 6,6-dimethyl-6а,7,7а,8(9),10,11,11а,12а-octahydrochromeno[3′,4′:5,6]pyranо[3,2-с(b)]pyridine.

Domino reactions of 3-methylpyrazol-5-amine and 1-phenyl-3-methylpyrazol-5-amine with arylglyoxal hydrates and malononitrile in alcohol proceed regioselectively and lead to the formation of 6-aminopyrazolo[3,4-b]pyridine-5-carbonitrile.

In reaction of 6-aminouracyles with ethyl oxochloroacetate ethyl 2-(6-amino-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-5-yl)-2-oxoacetates were obtained, which by further reaction with various amines afforded oxo(pyrimidinyl)acetamides. According to the data of biological tests, the synthesized compounds showed low antibacterial and antitumor activity.

Based on 2-(2,6-difluorophenyl)acetonitrile a synthesis was performed of new bioisosteric prochiral analogs of anti-HIV-1 active derivatives of 2-alkoxy-6-benzylpyrimidin-4(3Н)-one that we had previously obtained. The study using infected and nonifected strains of cells MT-4 made it possible to find in all prepared compounds a high anti-HIV activity whereas the cytotoxicity of the substances depended strongly on the structure of the alkylsulfanyl fragment of the molecule.