Vol 89, No 11 (2019)

Benzene alkylation with mono- and bicyclic olefins under the action of an inorganic ionic liquid [Et₃NH]⁺[Al₂Cl₇]⁻ with the formation of benzene cycloalkyl derivatives in 58–98% yield has been performed for the first time. It has been found that the increase in the olefin cycle size improves the selectivity with respect to monocycloalkyl derivatives.

The reactions of 4-methylpiperazin-1-amine, 2-amino- and 4-aminomethylpiperidines with pyridoxal afforded the corresponding azomethines. Their reactions with organic and inorganic acids lead to the formation of salt derivatives of pyridoxal azomethines.

The reactions of tryptamine with aromatic aldehyde and methyl benzoylpyruvate at room temperature leads to the formation of 5-aryl-4-[hydroxy(phenyl)Methylene]-1-[2-(1H-indol-3-yl)ethyl]pyrrolidine-2,3-diones.

An efficient method for the synthesis of 1,2-bisphosphoryl compounds based on the addition of hydrophosphoryl derivatives to O,O-diethyl vinylphosphonate was developed. The reaction proceeds in mild conditions under catalysis with tri-n-butylphosphine and leads to the formation of the corresponding target products with high yield.

It was shown that the direction of the reaction of 2-methyl-1,4-naphthoquinone with H-phosphonium salts obtained from diphenylphosphine and trifluoromethanesulfonic or trifluoroacetic acids depends on the nature of the anion. Structure of the obtained mono- and diphosphinates, as well as the quasi-phosphonium salt, was established by NMR spectroscopy and single crystal X-ray diffraction methods.

Investigation of the structure and conformational properties of ammonia borane molecule in the cavity of C₆₀, C₁₂B₂₄N₂₄, B₃₆N₂₄, C₇₀, B₄₁N₂₉, C₈₀, C₁₄B₃₃N₃₃, and B₄₇N₃₃ fullerenes using the DFT PBE/3ζ method has shown the predominance of the staggered conformation of the encapsulated molecule. The guest molecule has bared a notable negative charge and, as compared to the free molecule of ammonia borane, has a shortened B←N coordination bond. The internal rotation barrier about this bond has depended on the composition of the fullerene shell so that the decrease in the number of carbon atoms due to the replacement with boron-nitrogen fragments has almost always resulted in a notable decrease in the ΔG^≠₂₉₈ value. In this case, the minimal energy of the activation barrier, 1.3–1.8 times lower than that simulated for the free molecule, has been observed for the clusters with the boron-nitrogen-carbon links in the fullerene shell.

A model of a solution of non-electrolytes has been considered, which is a superposition of equilibrium processes of solvation, homo- and heteroassociation. The chemical potentials and activity coefficients of the components have been calculated for a binary solution considering only symmetric solvation. The model has been verified to calculate the density of binary solutions with high agreement with experimental data.

Analysis of the complexing ability of β-substituted porphyrazines toward magnesium acetate and magnesium acetylacetonate in the systems dimethyl sulfoxide-benzene (chlorobenzene) and nitrogen base-benzene has shown that acid-base interaction is the key factor affecting the complexation of porphyrazines with magnesium salts in proton-acceptor media with different basicities. The mechanism of formation of porphyrazine magnesium complexes and the structure and stability of acid-base complexes of porphyrazines with dimethyl sulfoxide and nitrogen bases in benzene (chlorobenzene) are discussed.

Using the DFT method PBE0/6-31G(d, p) and taking into account the solvent, the formation of bi- and pentahedral Ni(II) complexes with carboxylate and N-containing ligands in the gas phase was studied, and ΔG° of their formation from simple compounds was estimated. The functional role of bridging groups and hydrogen bonds in the formation of polynuclear structures was revealed. A model of self-organization of penta-nuclear coordination compounds [Ni^II₅(O₂CR)₈L_2n(μ-OH)₂]⁰ from binuclear complex [Ni^II₂(O₂CR)₄L_n(μ-H₂O)]⁰ was proposed, into the structure of which mononuclear Ni^II cations are embedding and promote proton transfer from bridging aqua ligands.

Europium(III) complexes with p-methylbenzoic acid and nitrogen- or phosphorus-containing neutral ligand with the compositions [Eu(p-MBA)₃·D]₂·xH₂O and [Eu(p-MBA)₃·2H₂O]_n [where p-MBA is p-methylbenzoate anion and D is 1,10-phenanthroline (phen), 2,2′-bipyridine (bipy), dimethylformamide (dmf), triphenylphosphine oxide (tppo), hexamethylphosphoramide (hmpa) (x = 1), or benzotriazole (bt) (x = 2)] have been synthesized, and their thermal decomposition has been studied.

The formation mechanisms for a series of n = 2 Ruddlesden-Popper phases Ln₂SrFe₂O₇ (Ln = La, Nd, Gd, Dy) in the Ln₂O₃-SrO-Fe₂O₃ systems were determined. The solid-state synthesis of Ln₂SrFe₂O₇ (Ln = La, Nd) proceeds by a mechanism involving the stage of formation of LnFeO₃ and LnSrFeO₄ intermediates with their subsequent interaction to form the target product. In the case of Gd₂SrFe₂O₇ formation, two mechanisms are realized, namely, those going through the GdFeO₃ + GdSrFeO₄ and Gd₂O₃ + Gd_0.5Sr_0.5FeO_3-α interaction stages. The limiting stage of the Dy₂SrFe₂O₇ formation is the reaction between Dy₂O₃ and Dy_0.5Sr_0.5FeO_3-α.

In the current study, a series of macrocyclic tripeptide Schiff bases 2–6 were synthesized by using macrocyclic tripeptide hydrazide 1 as starting material. Treatment of hydrazide 1 with active carbonyl cycloalkanones gave cycloalkanone hydrazines 2a–2d. Also, condensation of 1 with aromatic and heterocyclic aldehydes, or aromatic and heterocyclic acetyl derivatives afforded the corresponding Schiff base candidates 3a–3e, 4a–4c, 5a–5c, and 6a–6c, respectively.

A series of novel 7-arylaminopyrazolo[1,5-a]pyrimidine derivatives containing the hydrazone moiety has been synthesized by a five-step procedure including cyclization, chlorination, animation, hydrazinolysis, and condensation. Structures of the products have been characterized by IR, ¹H NMR and MS spectra, and single-crystal X-ray diffraction. The bioassay results indicate most of the compounds as potentially antiproliferation agents against A549 and HT-29 cell lines. Among those, compounds 6e and 6f exhibit remarkable inhibitory activity against HT-29 cell lines, that are comparable with that of the positive control sorafenib. Preliminary structure-activity relationship is considered.

The reactions of substituted 3-dietliylaminopropan-1-ones hydrochlorides with 2-amino-6-(H, alkyl)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitriles and ethyl 2-amino-6-(H, methyl)-4,5,6,7-tetrariydrobenzo[b]-thiophene-3-carboxylate furnished β-aminoketones of 2-aminothiophene series. The latter were converted into the corresponding secondary aminopropanols and oximes. Antioxidant activity of synthesized compounds and effect on some parameters of the blood coagulation system were investigated.