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Xanthendiones (1,8-dioxooctahydroxanthenes) are a special class of oxygenincorporating tricyclic compounds bearing as a basic feature a pyran nucleus fused on either side with cyclohex-2-enone rings. They are often found as a structural motif in natural products with a wide range of biological activities, such as: antioxidant, antimicrobial, trypanocidal, antiinflammatory, antiproliferative and anticancer. A convenient and efficient approach toward the synthesis of seven aromatically substituted xanthendiones 1‒7 and one structurally-related xanthenone 8 through condensation of dimedone and the appropriate aromatic aldehyde is reported. The relationship between the chemical structure and pharmacological activity was determined empirically using appropriate software packages and in vitro using the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) method. The results of the ABTS assay indicate that five compounds possess the ability to scavenge the ABTS•+ radical cation. Based on the comparison of the IC50 values, the activity of the compounds was found to be as follows: 6 > 1 > 7 > 2 > 8.

A convenient and efficient approach toward the synthesis of seven aromatically substituted xanthendiones 1‒7 and one structurally-related xanthenone 8 through condensation of dimedone and the appropriate aromatic aldehyde is reported. Further, their chemical structure was confirmed by melting points, elemental analysis, FT-IR, 1H-, 13C-NMR and UV–Vis spectroscopic methods. The relationship between the chemical structure and pharmacological activity was determined empirically using appropriate software packages and in vitro using the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) method. The results of in silico prediction suggested that all investigated compounds possess good oral bioavailability. The results of the ABTS assay indicate that five compounds possess the ability to scavenge the ABTS•+ radical cation. Based on the comparison of the IC50 values, the activity of the compounds was found to be as follows: 6 > 1 > 7 > 2 > 8. The effects of solvent dipolarity/polarizability and solute solvent–hydrogen-bonding interactions on the shifts of the absorption maxima were rationalized by means of the linear solvation energy relationship concepts proposed by Kamlet–Taft and Catalán.

A convenient and efficient approach toward the synthesis of seven aromatically substituted xanthendiones 1‒7 and one structurally-related xanthenone 8 through condensation of dimedone and the appropriate aromatic aldehyde is reported. Further, their chemical structure was confirmed by melting points, elemental analysis, FT-IR, 1H-, 13C-NMR and UV–Vis spectroscopic methods. The relationship between the chemical structure and pharmacological activity was determined empirically using appropriate software packages and in vitro using the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) method. The results of in silico prediction suggested that all investigated compounds possess good oral bioavailability. The results of the ABTS assay indicate that five compounds possess the ability to scavenge the ABTS•+ radical cation. Based on the comparison of the IC50 values, the activity of the compounds was found to be as follows: 6 > 1 > 7 > 2 > 8. The effects of solvent dipolarity/polarizability and solute solvent–hydrogen-bonding interactions on the shifts of the absorption maxima were rationalized by means of the linear solvation energy relationship concepts proposed by Kamlet–Taft and Catalán., U ovom radu, predstavljena je jednostavna metoda u dva koraka za sintezu sedam derivata ksantendiona i jednog derivata ksantenona koji sadrže različite aromatične supstituente, polazeći od dimedona i odgovarajućih aromatičnih aldehida. Karakterizacija sintetisanih jedinjenja izvršena je određivanjem temperature topljenja, kao i primenom elementalne analize, FT-IR, 1 H-NMR i 13C-NMR spektroskopskih metoda. Veza između hemijske strukture ovih jedinjenja i njihove farmakološke aktivnosti uspostavljena je empirijski korišćenjem odgovarajućih softverskih paketa (za predikckciju farmakološke aktivnosti) i in vitro određivanjem njihove antioksidativne aktivnosti primenom ABTS metode. Rezultati ABTS metode pokazuju da od celokupne serije testiranih jedinjenja, pet jedinjenja pokazuje značajnu antioksidativnu aktivnost. Na osnovu međusobnog poređenja IC50 vrednosti ispitivanih jedinjenja pokazano je da njihova antioksidativna aktivnost opada u sledećem nizu: 6 > 1 > 7 > 2 > 8. Jedinjenje 6 je najaktivnije u analiziranoj seriji i ima IC50 vrednost približne vrednosti kao askorbinska kiselina. Rezultati solvatohromnih jednačina koje su razvili Kamlet (Kamlet), Taft (Taft) i Katalan (Catalán), ukazuju da položaj apsorpcionih maksimuma proučavanih jedinjenja zavisi od prirode (polarnosti i kiselo-baznih svojstava) upotrebljenih rastvarača. Sa visokim vrednostima antioksidativne aktivnosti i dobrom oralnom bioraspoloživošću, derivati ksantendiona i ksantenona sa aromatičnim supstituentima, predstavljaju dobru polaznu osnovu za sintezu novih farmakološki aktivnih jedinjenja i bolje razumevanje uticaja strukture na farmakološku aktivnost.

Milling of cyanoacetamide and acetoacetic ester as reactants, in the presence of KOH as the catalyst and ethanol as a viscous control agent (VCA) was performed in a planetary ball mill with the goal of investigating the effect of mechanochemical treatment for the synthesis of 3-cyano-6hydroxy-4-methyl-2-pyridone at room temperature. The mechanochemical synthesis was performed under various milling parameters, i.e. milling time up to 4 h, number and size of balls, angular velocity as well as molar ratio of reactants and the amount of catalyst. The obtained product was characterized by m.p., UV, IR and NMR data. It was fond that the dominant process parameter is the milling time while others are of less importance. The highest isolated yield after milling was up to 56%. The combination of milling and aging increase yield over 60%.

In the present study, twelve new 1-aryl-3-ethyl-3-methylpyrrolidine-2,5-diones were synthesized and their structures were characterized by FT-IR, 1H NMR, 13C NMR spectroscopy and elemental analysis. In the final step of synthetic rout, condensation between corresponding succinic acid and substituted anilines has been improved using the microwave irradiation. Significantly higher yields compared to conventional condensation have been observed. The preliminary biological results indicated that some of the synthesized compounds showed promising in vitro antifungal activities towards several test fungi. 1-(4-Bromophenyl)-3-ethyl-3-methylpyrrolidine-2,5-dione (8) exhibited significant in vitro inhibitory activities against broad spectra of fungus, and on the basis of obtained data, the investigated bromo derivative has to be observed as novel potential fungicide. The density functional theory (DFT) calculations have been performed in order to study the structure-activity relationship (SAR) of the investigated molecules. In order to prediction of the chemical activity of the molecule, the molecular electrostatic potential (MEP) map was analyzed for the optimized geometry of 1-phenyl-3-ethyl-3-methylpyrrolidine-2,5-dione (4) and 1-(4-bromophenyl)-3-ethyl-3-methylpyrrolidine-2,5-dione (8).

In this paper, spectroscopic and quantum mechanical investigation of nine 4-aryl-5-arylazo-3-cyano-6-hydroxy-2-pyridone dyes was performed, and obtained density functional theory (DFT) results were compared with experimental data. The structural and spectroscopic properties of azo-2-pyridone dyes were studied by DFT using B3LYP, CAM-B3LYP, and M06-2X methods with a 6-311++G(d,p) basis set. Comparison of results reveals that the scaled theoretical vibrational frequencies of azo dyes are in good agreement with experimental data. The time-dependent DFT calculated and experimental ultraviolet-visible (UV-vis) absorption spectra are also in good agreement. The effect of electron-donating -OCH3 and electron-withdrawing -NO2 groups on the structural parameters, vibrational frequencies, UV-vis absorption, and natural bond orbital (NBO) atomic charges were thoroughly analysed. Vibrational, UV-vis, and NBO analyses confirm that investigated dyes exist in the hydrazo tautomeric form in the solid state and ethanol solution. These analyses signify the occurrence of intramolecular charge transfer in these azo-pyridone dyes.

U radu je sintetizovana serija 3-(4-supstituisanih benzil)-1,3-diazaspiro4.4nonan-2,4-diona čija je struktura određena temperaturama topljenja, FT-IR, 1H i 13C NMR i UV/Vis spektroskopijom. Uticaj supstituenata na apsorpcione spektre spirohidantoina, u različitim rastvaračima, proučavan je Hametovom jednačinom. Eksperimentalni rezultati su pokazali zadovoljavajuću saglasnost sa rezultatima kvantnohemijskih proračuna dobijenih primenom DFT metode. Pokazano je da supstituenti značajno utiču na intramolekulski transfer naelektrisanja (ICT) kao i na reaktivnost proučavanih hidantoina razmatranu na osnovu molekulskog elektrostatičkog potencijala (MEP)., In this work, a series of 3(4-substituted benzyl)-1,3-diazaspiro4.4nonane-2,4-dione was synthesized and fully characterized by melting points, FT-IR, 1H, and 13C NMR and UV/Vis spectroscopy. The Hammett equation was used to quantitatively evaluate the effects of substituents on the absorption frequencies in different solvents. The experimental results showed very good agreement with quantum chemical calculations obtained using DFT method. It was shown that substituents change the extent of conjugation, and affect intramolecular charge transfer (ICT) character. To estimate chemical reactivity of the molecules, the molecular electrostatic potential (MEP) surface maps were calculated for the optimized geometries of the investigated molecules.

This study represents an integrated approach towards understanding the vibrational, electronic, NMR, and structural aspects, and reactivity of 1-(4-chloro-phenyl)-3-phenyl-succinimide (CPPS). A detailed interpretation of the FT-IR, UV and NMR spectra were reported. The equilibrium geometry, bonding features, and harmonic vibrational frequencies have been investigated with the help of density functional theory (DFT) B3LYP method using 6-31G(d,p) and 6-311++G(d,p) basis set. The scaled theoretical wave-number showed very good agreement with the experimental values. The H-1 and C-13 nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the Gauge-Invariant Atomic Orbital (GIAO) method. Stability of the molecule, arising from hyperconjugative interactions and charge delocalization, has been analyzed using Natural Bond Orbital (NBO) analysis. The results show that ED in the sigma* and pi* antibonding orbitals and second order delocalization energies E(2) confirm the occurrence of intramolecular charge transfer (ICT) within the molecule. UV-Vis spectrum of the compound was recorded and the electronic properties, such as HOMO and LUMO energies, were calculated by Time-Dependent (TD-DFT) approach. To estimate chemical reactivity of the molecule, the molecular electrostatic potential (MEP) surface map is calculated for the optimized geometry of the molecule.

Two new series of hydantoin derivatives, 3-(4-substituted benzyl)-5,5-diphenyl- and 3-(4-substituted benzyl)-5-ethyl-5-phenylhydantoins, were synthesized and their antiproliferative activity was tested against human colon cancer HCT-116 and breast cancer MDA-MB-231 cell lines. The presence of different substituents on both hydantoin and benzyl moieties changed the antiproliferative activity of the investigated hydantoins, whereby most of the compounds showed superior antiproliferative activity against MDA-MB-231 than against the HCT-116 cell line. The structure of three compounds was studied by single-crystal X-ray diffraction. The general structural characteristic is the presence of N-H center dot center dot center dot O hydrogen bonds in crystal packings. The molecular geometry and bonding features of the investigated hydantoins in the ground states were calculated using the density functional method. The relationship between structure and antiproliferative activity was discussed. The data presented in this investigation afford guidelines for the preparation of new hydantoin derivatives with greater antiproliferative activity.

U radu je sintetizovano dvadeset novih 3-(supstituisanih benzil)-5,5'-cikloalkan-spirohidantoina čija je struktura određena temperaturama toplenja, FT-IR, 1H i 13C NMR i UV spektroskopijom. Solvatohromizam ovih jedinjenja je proučavan metodom linearne korelacije energija solvatacije. Kvantitativna procena uticaja rastvarača na pomeranje apsorbcionih maksimuma je nedvosmisleno ukazala na vezu između lipofilnosti i relevantnih farmakoloških karakteristika proučavanih jedinjenja sa njihovim proton-akceptorskim svojstvima., In this work twenty novel 3-(substituted benzyl)-5,5'-cycloalkanespirohydantoins have been synthesized and fully characterized by melting point, FT-IR, 1H and 13C NMR and UV spectroscopy. Solvatochromism of these compounds have been analysed by means of linear solvation energy relationships (LSER) concept. The quantitative relationships beetwen hydrogen bonding interaction and the correspodenting pharmacologically relevant propereties of the studied compounds have been discussed.

Two series of 1-aryl-3-phenyl- and 1-aryl-3,3-diphenylpyrrolidine-2,5-diones were synthesized and their solvatochromic properties were studied in a set of 15 solvents of different polarity. The effect of specific and non-specific solvent-solute interactions on the position of their absorption bands was evaluated by using the solvent parameter sets of Kamlet and Taft. The interpretation of the effect of different substituent patterns on the solvatochromic properties of the investigated compounds was based on quantum chemical calculations performed by the density functional theory (DFT)/CAM-B3LYP method using the 6-311G(d,p) basis set. The theoretical absorption frequencies show very good agreement with the experimental values. The energy gaps between the HOMO and LUMO orbitals were also analyzed. It is demonstrated that different substituents change the conjugation effect and further determine the pathways of intramolecular charge transfer.

Background: A series of some novel arylazo pyridone dyes was synthesized from the corresponding diazonium salt and 6-hydroxy-4-phenyl-3-cyano-2-pyridone using a classical reaction for the synthesis of the azo compounds. Results: The structure of the dyes was confirmed by UV-vis, FT-IR, H-1 NMR and C-13 NMR spectroscopic techniques and elemental analysis. The solvatochromic behavior of the dyes was evaluated with respect to their visible absorption properties in various solvents. Conclusions: The azo-hydrazone tautomeric equilibration was found to depend on the substituents as well as on the solvent. The geometry data of the investigated dyes were obtained using DFT quantum-chemical calculations. The obtained calculational results are in very good agreement with the experimental data.

A new procedure for the synthesis of known azo pyridone dyes is presented. A series of 5-(substituted arylazo)-6-hydroxy-4-methyl-3-cyano-2-pyridones were prepared from ethyl 3-oxo-2-(substituted phenylazo)butanoates and cyanoacetamide in acetone using potassium hydroxide as a catalyst by simple refluxing the reaction mixture. The structure of these dyes was confirmed by FT-IR, NMR and UV-Vis spectroscopy., Novi postupak za sintezu poznatih azo-piridonskih boja je opisan u radu. Serija 5-(supstituisanih fenilazo)-6-hidroksi-4-metil-3-cijano-2-piridona je pripremljena iz etil-3-okso-2-(supstituisanih fenilazo)butanoata i cijanoacetamida u acetonu korišćenjem kalijum-hidroksida kao katalizatora uz zagrevanje.

A series of some new pyridone arylazo dyes was synthesized from the corresponding diazonium salts and 3-cyano-4,6-diphenyl-2-pyridone using the classical reaction for the synthesis of the azo compounds. The structures of these dyes were confirmed by UV-Vis, FT-IR and 1H-NMR spectroscopic techniques. The solvatochromism of the dyes was evaluated with respect to visible absorption properties in various solvents. The effects of solvent dipolarity/polarizability and solvent/solute hydrogen bonding interactions were analyzed by means of the linear solvation energy relationship concept proposed by Kamlet and Taft. The 2-pyridone/2-hydroxypiridine tautomeric equilibration was found to depend on the substituents as well as on the solvents., Serija novih piridonskih arilazo boja je sintetisana reakcijom odgovarajućih diazonijum soli i 3-cijano-4,6-difenil-2-piridona primenom klasične sinteze azo jedinjenja. Struktura sintetisanih boja je potvrđena na osnovu podataka dobijenih iz UV, FT-IR i 1H-NMR spektara. Solvatohromna svojstva boja su procenjena u odnosu na njihovu apsorpciju u vidljivom delu spektra u različitim rastvračima. Efekti rastvarača, dipolarnost/polarizabilnost i vodonične interakcije rastvarač/rastvorak, su analizirane primenom linearne korelacije solvatohromnih efekata predložene od strane Kamlet-a i Taft-a. Tautomerna ravnoteža 2-piridon/2-hidroksipiridin zavisi kako od efekata supstituenta tako i od uticaja rastvarača.

The C-13 NMR chemical shifts of the C2 carbon atom in the heteroaromatic nuclei of seventeen 5-(3- and 4-substituted arylazo)-4,6-dimethyl-3-cyano-2-pyridones were determined in deuterated DMSO solution. For quantitative assessment of the substituent effects on the C-13 NMR chemical shifts simple and extended Hammett equations and Swain-Lupton equation were used. The mode of transmission of substituent effects have been discussed in a relation to the geometry of investigated molecules. The geometry data were obtained using semiempirical MNDO-PM6 energy calculations. The observed C-13 NMR substituent chemical shifts were correlated with literature C-13 NMR data for the corresponding 3- and 4-substituted- 2',6'-dimethylazobenzenes and 3- and 4-substituted azobenzenes. A good linear dependence obtained in this way, provided a basis to discuss the influence of the ortho-methyl groups on the degree of coplanarity of azobenzene and pyridone systems, and on the efficiency of transmission of electronic substituent effect from one ring to the other one.

The effect of various phenyl substituents on the reactivity of the carboxy groups of 3-N-(4-substituted phenyl)-5-caboxy uracils has been investigated. The substitutents at the phenyl nucleus were as follows: H, Br, I, NO2, Me, OMe. The rate constants of the investigated acids in their reaction with diazodiphenylmethane (DDM) were determined in methanol and in ethanol at 30 °C, using the known spectrophotometric method. The obtained kinetic data, as well as the values of the IR stretching vibrations of the carboxy carbonyl group, were treated by semiempirical relationships based on the principals of linear free energy correlations. Considering that the substituted phenyl group resides at the nitrogen atom, having two carbonyl groups as ortho substituents, it is very probable that the effect of the substituents in position 4 of the phenyl nucleus is influenced by resonance interactions between the nitrogen electron pair, the carbonyl groups and the substituent itself. The polarity of the reaction medium also affects the complex resonance interactions in the molecules of the investigated compounds

A series od 4-alkyl-6-methyl-2-pyridone-3-carboxylic acids were synthesized by the hydrolysis of corresponding 3-cyanopyridones. Reactivity and IR data were used in a discussion of substituent effects and of inter- and intramolecular hydrogen bonding. A Hammett type correlation of the IR carbonyl stretching frequencies has been performed, using steric and composite steric electronic parameters.