A series of some monoazaphenoxzines carboxamides evaluated against Salmonella typhi, Stapyhlococcus aureus, Escherichia coli, Klebsiella pneumonia, Streptococcus pyogene and Pseudomonas aeruginosa in a micro dilution broth assay. The results obtained showed that these compounds exhibited considerable antibacterial activity depending on the substituents on the monoazaphenoxazine ring. The best activity were obtained with substituents containing nitro-group as in 3-(-4-nitrobenzamido)-1-azaphenoxazine and chloride-group as in 3-trichloromethanamido-1-azaphenoxazine

Single-enantiomer drug candidates are important to many pharmaceutical companies, and therefore, new methods for the preparation of enantiopure compounds are critical for the development of next-generation pharmaceutical products. The use of microwave (MW) irradiation in organic synthesis has become a popular technique to develop and optimize the libraries of compounds synthesis in short reaction time compare to those obtained with the classical thermal methods in pharmaceutical and academic production. Numerous studies in the past ten years, demonstrated that microwave enhanced chemical reactions and that they are faster than conventional heating methods. In previuos studies, we reported the stereoselective radical addition of organotin hydrides to unsaturated TADDOL diesters. These reactions occurred with intramolecular cyclization under inert atmosphere, radical initiator, toluene and 75°C with high yields and stereoselectivity depending on the reactivity and steric bulk of the organotin hydride employed. Here, we decided to study a new method for the synthesis of these macrocycles through the radical addition of different triorganotin hydrides, R₃SnH (R= Me, n-Bu, Ph; Neophyl), to the same insaturated TADDOL diesters, in THF as solvent and under MW conditions. We compared these results with the previous reported method. Under MW conditions, reactions were completed in very short reaction time and neither the products of double hydrostannation nor the products of cyclopolymerization were obtained in both cases. Furthermore, we evaluated the stereoselectivity by ¹¹⁹Sn-NMR spectroscopic analysis in both methods.

In our previous work (see ECSOC-17, 2013) we found some interesting dependencies of the alkyl protons chemical shift values in 1-monosubstituted linear alkanes 1H NMR spectra upon the position of methyl group (as substituent) in molecule. In continuation of this topic we studied 13C NMR spectra of the same types of monomethyl alkanes.In this communication we describe the effect of the methyl group position in monomethylsubstituted alkane molecule on chemical shift values of all the nuclei of carbon atoms in the molecule of this methylalkane (including the newly introduced methyl group). The position of the methyl group in the alkyl chain denoted by the symbol «N», indicating the carbon atom to which is attached "methyl substituent" number from the beginning of the chain. For this purpose we have studied and analyzed the literature values of carbon chemical shifts in 13C NMR spectra of four "methylalkane families": 2-, 3-, 4- and 5-monomethylalkanes (where N = 2, 3, 4 or 5). Each family consists of molecules, ranging from "short-chain" methylbutanes to the most "longchain" methyldodecanes, for which we can found the "credible" spectral literature data.We compared the carbons chemical shift values of the same type carbon nuclei, for example, of signal of terminal methyl groups in the unsubstituted and studied monomethylsubstituted alkanes. We fixed the differences between the compared chemical shifts only for the cases when the difference is equal or exceeds a value equal to 0.05 ppm. These values of the differences we have identified as "significant" (ie, to be discussed).When researching all four families of N-monomethyl alkanes we reveal that a "significant" difference in carbon chemical shift values are found only in the so-called "decacarbonic fragments": -СN-4HN-42-СN-3HN-32-СN-2HN-22-СN-1HN-12-CNHN(CN'HN'3)-СN+1HN+12-СN+2HN+22-СN+3HN+32-СN+4HN+42-. This fragment comprises a carbon atom N with attached to it "methyl substituent" (N'), the previous (N-1), (N-2) (N-3), (N-4) and the following (N +1), (N +2), (N +3), (N +4) carbon atoms. For other types of carbon atoms nuclei (-СN-5HN-52, -СN+5HN+52, etc.) there is not found the "significant" differences between the values of the chemical shifts in the longchain unsubstituted linear alkanes and the same longchain monomethylalkanes.We calculate and compare the mean values for each carbon types chemical shift in this "decacarbonic fragment" in longchain compounds of abovementioned four families of the monosubstituted alkanes: 2-, 3-, 4- and 5-methylalkanes (where N = 2, 3, 4 or 5). 13C NMR spectral regularities are also found and discussed for short- and midchain monomethylalkanes.

Synthesis of tricyclic hydantoins with angularly fused rings was performed in three-step reaction sequence. Spiro-bicyclic hydantoins with alkenyl moiety, prepared from 2-alkenylcyclohexanones using Bucherer-Bergs reaction, were subjected to amidoselenylation reaction. This selenium-induced intramolecular cyclization is a key step of this sequence. The cyclization is regiospecific and formation of sole regioisomer proceeds via favorable 5-exo-trig ring closure process giving only homotriquinane type tricyclic hydantoins.

Ability to eliminate reactive oxygen species is one of the most promising features of organoselenium compounds in medicinal chemistry. Ebselen (N-phenyl-1,2-benzisoselenazol-3(2H)-one) is a well known GPx mimic with proven antioxidant capacity. However, side effects, and in some cases only moderate activity, leave the search for new highly effective benzisoselenazolone analogues still open. In this work, we present an efficient methodology for the synthesis of ebselen derivatives. Lithium diselenide formed in situ reacts with N-substituted o-iodobenzamides to give the products in high yield - up to 98%. All synthesised compounds were also tested for their antioxidant activity in an NMR assay using dithiothreitol as substrate. The obtained results led us to the conclusion that N-phenyl analogues with p-methoxy, p-nitro and p-iodo moieties are the most active ones.

Epoxidation reaction has been the subject of numerous investigations and a number of useful methodologies have been studied. The electrophilic reagents used in this epoxidation, react preferentially with electron-rich olefins. For this reason, electron-deficient olefins such us α,β-unsaturated esters react very slowly with low yields. Our group has previously reported the synthesis of enantiomerically pure α-β unsaturated diesters of TADDOL and BINOL. Optically active epoxides are highly versatile intermediates that can be converted into a wide variety of enantiomerically enriched molecules. Because of this, we decided to study the stereoselective di-epoxidation of diacrylate derivatives with C₂-symmetry. First, we studied simple substrates with the intention to extend the results to more complex molecules. Thus, several epoxidation methods were tested on α-β-unsaturated esters with the aim to improve the previously reported data. Among all the experimental conditions tested, mCPBA reagent was the best, giving the glycidic esters derivatives with very good yields and short reaction time compared with reported methods. Due to the fact that the reaction conditions were unsuccessful with the C₂-diacrylate systems, we decided to study the reactivity of these substrates applying DFT calculations. The reactivity of mCPBA, in olefins epoxidation reactions, can be rationalized by frontier orbital interactions. For this reason, we evaluated the coefficients and shape of HOMO OMs of a series of simple esters and TADDOL and BINOL derivatives. We achieved interesting results concerning the reactivity of these compounds.

A novel synthesis of 2,3-dihydro-1H-1,3-diazepin-2-ones based on thermal elimination of methanol from 4-methoxy-2,3,4,5-tetrahydro-1H-1,3-diazepin-2-ones has been developed. The prepared dihydrodiazepinones underwent a new rearrangement under basic conditions to give 3-(aminomethylene)-2,3-dihydro-1H-pyrrol-2-ones. Plausible mechanism for the rearrangement is proposed.

A novel series of o-benzoyl benzoic acid based 1,3,4-oxadiazoles were prepared and subjected to anti-inflammatory, analgesic activity as well as molecular docking studies to target cyclooxygenase-2 enzyme.1,3,4-Oxadiazole derivatives were screened for anti-inflammatory activity in carrageenan-induced rat paw edema and analgesic activity by tail immersion method. In synthesized compounds, the free carboxylic group, which is responsible for gastric side effects, was derivatized by heterocyclic 1,3,4-oxadiazole bioactive core, which showed good interaction with COX-2 receptor with good docking score. Among all thesynthesized compound having m-methoxy-p-hydroxy have emerged out as potential COX-2 inhibitor.

In this study a series of twelve n-alkoxy-substituted 2-hydroxynaphthalene-1-carboxanilides was prepared and characterized. The discussed compounds were prepared by microwave-assisted synthesis. The compounds were tested for their activity related to inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. The highest PET inhibition was observed for meta-substituted compounds, whereas 2-hydroxy-N-(3-propoxyphenyl)naphthalene-1-carboxamide showed the highest PET inhibition within the whole series. In spite of medium or moderate PET-inhibiting activity it was found that the compounds inhibit PET in photosystem II. The activity of all positional isomers is strongly influenced by lipophilicity and the length/bulkiness of the alkoxy chain.

Using quantum-chemical methods we studied the possibility and mechanism the photochemical oxidation of epoxy olefins by nitro compounds. It was first found the structure of the corresponding transition state. Methods of DFT / 6-31g + (d) and DFT / 6-311 + g (d) was used to studied the reaction of sulfur oxides (II, IV) with nitro compounds in the ground and excited states. It was first made the assumption that in the course of the photochemical oxidation of various substrates by nitro compounds in excited states formed transition states containing nitrosooxide fragments. Experimentally and theoretically it was studied the oxidation of nitroso compounds by nitro compounds in the excited states. In the course of the reactions of nitrogen oxides and sulfur-containing compounds in the reactions of the photochemical oxidation of nitroso compounds by nitro compounds in the states of different multiplicity. By means of CASSCF we determined the opportunity of appearance of the singlet - triplet transition for nitroso oxides. It was shown the proximity of the S0 and T2 levels.