Russian Journal of General Chemistry最新文献

The reaction of 1,8-naphthylenediamine with α-nitoketones yielded 9-acetyl- and 6(7)-acetamidoperimidines. The reaction exhibits high atom economy and is based on a tandem of benzoylation reactions of the diamine involving nitoketones, and an acylation-amination of arenes in polyphosphoric acid (PPA) medium, using the acyl forms of nitroalkanes liberated in the first stage. The dependence of the transformation’s course on the concentration of polyphosphoric acid has been investigated.

In this study, we proposed for the first time a synthetic route to 4-aminomethyl 1,3-dihydroxyacridones and their 5-aza derivatives using Mannich reaction between 1,3-dihydroxyacridones and aliphatic amines. This approach offers several advantages, including high product yields, controllable reaction selectivity, and easy handling of reaction. As a result of this study, five acridone Mannich bases were synthesized, and their anticancer evaluation reveals moderate activity against the HCT 116 colorectal cancer (IC₅₀ up to 86 μM, SI > 1.1) and HuTu 80 duodenal adenocarcinoma (IC₅₀ up to 38 μM, SI > 2.7) cell lines.

Heterocyclic enediynes are promising analogues of natural enediyne antibiotics. Here, we report on the synthesis of a benzothiophene-fused azaenediyne with an iso-position of NTs function within the enediyne cycle. The iso-N-enediyne was obtained using the iodoalkyne approach, i.e. iodocyclization of the functionalized iodoalkyne followed by two subsequent one-pot Sonogashira reactions with diiodobenzothiophene, and then the Nicholas cyclization. Despite the successful synthesis of starting acyclic enediyne, the synthetic accessibility of cyclic iso-N-enediyne was poorer than that of its known isomer due to lower regioselectivity during the cobalt complexation stage. The obtained iso-N-enediyne exhibits lower reactivity in Bergman cyclization and it is less cytotoxic against the HeLa cell line. Therefore, the previously reported N-enediyne has advantages over the newly synthesized iso-N-enediyne for the further development of anticancer agents.

A method for the synthesis of 7a,8-dihydrobenzo[5,6]chromeno[2,3-b]pyrrol-9(11H)-ones from β-methoxalyl-substituted 1H-benzo[f]chromenes and primary aliphatic amines in the presence of nitromethane has been developed. A possible reaction route is proposed that includes the Henry reaction, the aza-Michael reaction, intramolecular nucleophilic addition, and the retro-aza-Henry reaction as the main stages.

A variety of N-allyl substituted pyridinium salts based on 1-(Z)-(1,4,4-tribromobut-2-en-2-yl)adamantane were synthesized. It was found that under the action of triethylamine on allyl substituted salts, deprotonation occurs, followed by the elimination of the bromide anion to form a new pyridinium salt of the diene structure. Further, a variety of quinolyzinium salts were obtained as a result of thermal 6π-electrocyclization of dienic salts.

An effective, eco-friendly method was developed for the synthesis of carboxystyryl derivatives of 1,10-phenanthroline, 2,2′-bipyridine, and pyridine via a catalyst- and solvent-free condensation reaction of 4-carboxybenzaldehyde with 2,9-dimethyl-1,10-phenanthroline, 6-methyl-2,2′-bipyridine, 6,6′-dimethyl-2,2′-bipyridine, 4,4′-dimethyl-2,2′-bipyridine, or 2-methylpyridine. For dimethylbipyridines, monosubstituted products were primarily formed, whereas for dimethylphenanthroline, a bis-product was obtained. The formation of a hydrogen bond between the nitrogen atom of the heterocycle and the carboxylic proton of 4-carboxybenzaldehyde enhances the reactivity of the methyl group in the heterocycle.

A new hybrid organic ligand with 2-(2-pyridyl)benzothiazoles and catechol fragments was synthesized and studied in the complexation reaction with copper(II) chloride. Synthesis conditions that allow for obtaining a complex in which copper coordination is carried out by the pyridylbenzothiazole fragment, and the catechol fragment does not participate in the coordination, have been determined. To find the possibility and optimal conditions for a complex without coordination of catechol formation, DFT calculation data were used. The structure of the obtained coordination compound with LCuCl₂ composition was established using as elemental analysis, UV-Vis spectroscopy, cyclic voltammetry and total X-ray scattering with pair distribution function analysis. Measurement of cytotoxicity and the ability to reactive oxygen species (ROS) generation for synthesized complex on MCF-7 cell lines demonstrated reasonable cytotoxicity of 5 µМ, not associated with ROS formation.

Azirinyl ethynyl ketones, containing aryl/n-alkyl substituents at azirine C²/C³ and aryl/n-alkyl/2-thienyl substituents at the C≡C triple bond, undergo isomerization into 5-alkynyloxazoles under nucleophilic assistance in MeOH–K₂CO₃ media at room temperature, with the formation of 5-alkynyloxazoles in 20–84% yield. According to DFT calculations, the addition of the methoxide anion nucleophile to the C=N bond of azirine promotes the opening of the three-membered ring across the C–C bond. The subsequent 5-endo-trig cyclization of formed 2-azabuta-1,3-dien-4-olate and aromatization results in the formation of the alkynyloxazole derivative.

It is shown that the mixture of urea with certain ratios of KOH (in contrast to NaOH, LiOH, and other alkalis), forms liquid eutectic mixtures similar to deep eutectic solvents (DES), which rapidly react with L-amino acids, yielding chiral N-carbamoylamino acids with high yields. At the same time, amino acid esters and aromatic amines do not enter into this reaction. DFT methods were used to confirm the proposed mechanism of carbamoylation of amino acids in discovered conditions. Molecular dynamics and DFT methods were used to investigate the structure of the obtained DES and explain why only KOH, but not other alkalis, forms liquid eutectic mixtures with urea.

A method for the synthesis of pyrazolo[3,4-f]quinolines from 6-aminoindazole and 4H-chromene-3-carbaldehydes or their fused analogs has been developed. It has been established that the reaction of β-trifluoroacetyl-substituted 4H-chromenes with 6-aminoindazole proceeds regioselectively to afford 9-trifluoromethylpyrazolo[3,4-f]quinolines. It has also been demonstrated that in reactions with 4H-chromene-3-carbaldehydes or 1H-benzo[f]chromene-2-carbaldehydes, 3-aminoindazoles act as 1,3-N,N-binucleophiles, thereby providing access to pyrimido[1,2-b]indazoles.