Search

The properties relevant to pharmacokinetics and pharmacodynamics of four series of synthesized s-triazine derivatives have been studied by Quantitative structure-retention relationship (QSRR) approach. The chromatographic behavior of these compounds was investigated by using reversed-phase high performance thin-layer chromatography (RP-HPTLC). Chromatographic retention (R M (0)) was correlated with selected physicochemical parameters relevant to pharmacokinetics, i.e. ADME (absorption, distribution, metabolism and excretion). In addition, the ability to act as kinase inhibitors and protease inhibitors was predicted for all investigated triazine classes. Also, in order to confirm similarities/dissimilarities between series of examined compounds, principal component analysis (PCA) based on calculated ADME properties was conducted. The R M (0) values of the s-triazine derivatives have been recommended for description and evaluation of pharmacokinetic properties. According to results of this study, the synthesized s-triazine derivatives meet pharmacokinetic criteria of preselection for drug candidates.

Linear free energy relationships (LFER) were applied to the kinetic data for the reaction of 5-substituted orotic acids, series 1, with diazodiphenylmethane (DDM) in N,N-dimethylformamide and compared with results obtained for 2-substituted benzoic acids, series 2. The correlation analysis of the kinetic data with sigma substituent parameters was carried out using SSP (single substituent parameter) methods. From the sign and value of proportinality constant rho, lower sensitivity to the substituent effect was obtained in series 1, 0.876, than in the series 2, 1.877. Evaluation of substituent "ortho-effect" was performed using the Charton model, which includes the steric substituent parameter, and Fujita and Nishioka's model, which describes the total ortho-effect as contribution of ordinary polar effect, the ortho-steric and ortho-polar effects. Results of correlations, obtained by using the Charton model, showed highest contribution of the polar effect, 0.861 vs. 2.101, whereas the steric effect is of lowest significance, 0.117 vs. 0.055, for series 1 and 2, respectively. Also, a low negative value of coefficient with the steric effect, -0.08, obtained from the Fujita-Nishioka model indicated low steric effect, influencing a decrease of the reaction rate in series 1. The structural and substituent effects were also studied by using the density functional theory method, and together with kinetic data, it gave a better insight into the influence of the effect of both geometry and substituent on the pi-electron density shift induced reactivity of investigated acids. geometry and substituent on the pi-electron density shift induced reactivity of investigated acids.

Quantitative structure-reactivity correlations for the kinetics of the Hantzsch synthesis of 4-(substituted phenyl)-1,4-dihydropyridines in the reaction between ethyl m- and p-substituted 2-benzylideneacetoacetate and the enamine (ethyl 3-aminocrotonate) was studied. The reaction kinetics was followed spectrophotometrically. It was found that the reaction correspond to second-order kinetics. Quantitative structure-reactivity correlations of log k were obtained with the corresponding substituent constants (s, s+, sI and s + ) using the Hammett and extended Hammett equation (dual substituent parameter, DSP, equation). They showed linear relationships with positive values of reaction constants (r). The obtained data were processed by linear regression analysis. It was confirmed that Michael addition of the enamine to benzylidene represented the slow step of the reaction with a high positive charge at the benzylidene molecule. MO calculations were performed and they were in agreement with the conclusions derived from the structure-reactivity correlations. . Proučavan je kvantitativan odnos strukture i reaktivnosti za kinetiku Hančove sinteze supstituisanih 4-fenil-1,4-dihidropiridina u reakciji etil-m- i p-supstituisanih 2-benziliden-acetoacetata i enamina. Kinetika ispitivane reakcije je praćena spektrofotometrijskim metodom. Zapaženo je da je reč o reakciji drugog reda. Kvantitativne korelacije strukture i reaktivnosti koje izražavaju logaritam određene konstante brzine reakcije (log k) u zavisnosti od odgovarajućih konstanti supstituenata (s, s+,sI i s +) određene su za Hametovu (Hammett) i proširenu Hametovu jednačinu (DSP-jednačinu). Pokazale su linearnu zavisnost sa pozitivnim vrednostima nagiba, odnosno reakcione konstante (r). Time je potvrđeno da Majklova (Michael) adicija enamina na benziliden predstavlja spori stupanj u reakciji sa izraženim pozitivnim naelektrisanjem na molekulu benzilidena. MO proračuni su takođe urađeni i njihovi rezultati su bili u skladu sa zaključcima izvedenim iz korelacija strukture i reaktivnosti. .

The ultraviolet absorption spectra of the carboxyl group of three isomeric pyridine carboxylic acids N-oxides (picolinic acid N-oxide, nicotinic acid N-oxide and isonicotinic acid N-oxide) were determined in fourteen solvents in the wavelength range from 200 to 400 nm. The position of the absorption maxima (λmax) of the examined acids showed that the ultraviolet absorption maximum wavelengths of picolinic acid N-oxide are the shortest, and those of isonicotinic acid N-oxide acid are the longest. In order to analyze the solvent effect on the obtained absorption spectra, the ultraviolet absorption frequen­cies of the electronic transitions in the carboxylic group of the examined acids were correlated using a total solvatochromic equation of the form Vmax = V0 + + Sπ*+ aα+ bβ, where Vmax is the absorption frequency (1/λmax), π*is a measure of the solvent polarity, β represents the scale of solvent hydrogen bond acceptor basicities and α represents the scale of solvent hydrogen bond donor acidities. The correlation of the spectroscopic data was carried out by means of multiple linear regression analysis. The solvent effects on the ultra­violet absorption maximums of the examined acids were discussed. UV apsorpcioni spektri pikolinske kiseline N-oksida, nikotinske kiseline N-oksida i izonikotinske kiseline N-oksida određeni su u 14 protičnih i aprotičnih rastvarača u opsegu od 200-400 nm. Položaji maksimuma apsorpcije bili su najniži za pikolinsku kiseline N-oksid, a najviši za izonikotinsku kiseline N-oksid. Da bi se analizirao uticaj ratvarača, apsorpcione frekvence su korelisane Kamlet-Taftovom jednačinom, kojom se uticaj polarnosti/polarizabilnosti, proton-donorskog i proton-akceptorskog dejstva rastvarača može kvantitativno izraziti.

The rate constants for the reactions of diazodiphenylmethane (DDM) with 2-substituted nicotinic acids in nine aprotic solvents at 30°C were determined. The obtained second order rate constants in aprotic solvents were correlated using the Kamlet-Taft solvatochromic equation in the complete form: log k = log k0 + sπ*+ a( + bβ. The correlations of the kinetic data were realized by means of multiple linear regression analysis. The obtained results were analyzed in terms of the initial and the transition state of the reaction and compared with previously determined kinetic data for nicotinic acid. The signs of the equation coefficients (s, a and b) are in agreement with the reaction mechanism and the influence of the solvent on the reaction rate is discussed based on the correlation results. The mode of the transmission of the substituent effect is discussed in light of the contribution of solute-solvent interaction to the reactivity of the acid. The substituent effect was additionally analyzed by the Hammett equation, log k = pσ + log k0. Konstante brzine za reakciju diazodifenilmetana (DDM) sa 2-susptituisanim nikotinskim kiselinama u devet aprotičnih rastvarača su određene na 30 °S. Dobijene konstante brzine za reakciju drugog reda su korelisane Kamlet-Taftovom totalnom solvatohromnom jednačinom u obliku: log k = log k0 + sπ*+ a( + bβ. Korelacija kinetičkih podataka izvršena je višestrukom linearnom regresionom analizom. Dobijeni rezultati su analizirani u odnosu na osnovno i prelazno stanje i upoređeni sa ranije određenim vrednostima za nesupstituisanu kiselinu. Znaci ispred koeficijenata u jednačini su u skladu sa pretpostavljenim mehanizmom reakcije. Diskutovan je prenos efekata supstituenata na reakcioni centar uzimajući u obzir doprinos efekata rastvarača na reaktivnost ispitivanih jedinjenja. Efekat supstituenata je dodatno analiziran Hametovom jednačinom: log k = pσ + log k0.

The effects of protic and aprotic solvents on the reactivity of picolinic, nicotinic and isonicotinic acid, as well as of some substituted nicotinic acids, with diazodiphenylmethane (DDM) were investigated. In order to explain the kinetic results through solvent effects, the second-order rate constants for the reaction of the examined acids with DDM were correlated using the Camlet-Taft Solvatochromic Equation. The correlations of the kinetic data were realized by means of multiple linear regression analysis and the solvent effects on the reaction rates were analyzed in terms of the contributions of the initial and the transition state. The signs of the coefficients of the Equation support the already known reaction mechanism. Solvation models for all the investigated acids are suggested and related to their specific structure. U ovom radu analiziran je uticaj protičnih i aprotičnih rastvarača na reaktivnost pikolinske, nikotinske i izonikotinske kiseline, kao i nekoliko supstituisanih nikotinskih kiselina sa diazodifenilmetanom (DDM). Da bi se dobijeni kinetički podaci mogli objasniti pomoću efekata rastvarača, konstante drugog reda za reakciju ispitivanih kiselina i DDM-a su korelisane Kamlet-Taftovom totalnom solvatohromnom jednačinom. Korelacija kinetičkih podataka urađena je višestrukom linearnom regresionom analizom i efekat rastvarača je posmatran sa strane osnovnog stanja, odnosno reaktanata, i prelaznog stanja u reakciji. Aritmetički znaci ispred koeficijenata u jednačini su u skladu sa poznatim mehanizmom ispitivane reakcije. Solvatacioni modeli za sve ispitivane kiseline su predloženi i povezani sa specifičnostima njihovih struktura.

Hammett correlations between the 13C-NMR chemical shifts of the azomethine carbon atom and the corresponding substituent constants were established for thirteen Schiff bases. The successful correlation of the chemical shifts with the electrophilic substituent constants s+ indicate a significant resonance interaction of the substituents on the aniline ring with the azomethine carbon atom in the examined series of imines. The demand for electrons in the investigated compounds was compared to that of the N-benzylideneanilines and N-(substituted phenyl)pyridinealdimines. The manner of transmission of the substituent effects is discussed and they were separated into resonance and inductive effects. The inductive effects prevail over the resonance effects. 13C-NMR hemijska pomeranja 13 Šifovih baza korelisana su sa konstantama supstituenata korišćenjem Hametove jednačine. Dobra korelacija hemijskih pomeranja azometinskog ugljenika sa elektrofilnim konstantama supstituenata (s+) pokazuje da postoji izražena rezonantna interakcija supstituenata na anilinskom prstenu sa azometinskim ugljenikom. Ispitivan je prenos elektronskih efekata supstituenata i oni su razdvojeni na induktivne i rezonantne efekte, a pokazano je da preovlađuju induktivni efekti.

The temperature dependence of the retention index was studied for N-substituted amino s-triazines on DB-1, DB-5 and DB-WAX capillary columns within the temperature range 190–230 ºC. Two linear equations with the column temperature and its reciprocal as variables were studied. The first one shows a slightly better precision for 2,4-bis(alky lamino)-6-chloro-s-triazines and 2-alkylamino-4,6-dichloro-s-triazines while the second one shows a better precision for 2,4-bis(cycloalkylamino)-6-chloro-s-triazines. U radu je prikazana linearna zavisnost retencionog indeksa od temperature korišćenjem linearnih zavisnosti retencionog indeksa u funkciji temperature kolone t, ºC ili 1/T, K–1 za s-triazine na kapilarnim kolonama DB-1, DB-5 i DB-WAX u temperaturnom intervalu 190–230 ºC.

Rate constants have been determined for the reactions of diazodiphenylmethane with a number of 6-substituted nicotinic acids and p-substituted benzoic acids in twelve alcohols. A comparative study was used to evaluate and compare the Hammett ρ values and solvent effects. Multiple correlations of the log k values for the reactions of 6-substituted nicotinic acids and p-substituted benzoic acids in 12 alcohols with groups of suitable solvent parameters are very successful. The transmission of electronic effects through the pyridine ring system in compared with that in benzene. Određene su konstante brzine reakcije esterifikacije 6-supstituisanih nikotinskih kiselina sa supstituentima H, Cl, OH i CH3 kao i konstante brzine za 4-CH3 benzoevu kiselinu sa DDM na 30 ˚C u dvanaest alkoholnih rastvarača, korišćenjem poznate UV-spektrofotometrijske metode.Na osnovu dobijenih konstanti brzina reakcija nikotinskih kiselina i p-supstituisanih benzoevih kiselina, korišćenjem Hammett-ove jednačine određene su reakcione konstante ρ za obe serije jedinjenja i diskutovan je način prenošenja efekata supstituenata kroz piridinov i benzolov prsten. Višestrukom regresionom analizom uspostavljena je zadovoljavajuća zavisnost konstanti brzina reakcija kao i reakcione konstante ρ sa parametrima rastvarača kao što su: Kirkwood-ova funkcija relativne permitivnosti f(ε), Taftova σ* konstanta za alkil grupe alkohola i nγH koji predstavlja broj γ-vodonikovih atoma u alkoholu.

Rate constants have been determined for the reactions of diazodiphenylmethane (DDM) with 3- and 4-pyridineacetic acid, 3- and 4-pyridineacetic acid N-oxide and some meta- and para-substituted phenylacetic acids in twelve alcohols. The determined rate constants, together with literature data, were used for calculation of Hammett ρ values in a series of alcohols. Secondary ρ constants have been calculated for substituents in meta and para-position of phenylacetic acids not given in literature, and also ρ constants for 3N, 3N-O, 4N and 4N-O in pyridineacetic acids, in alcohols used. The transmission of electronic effects through the phenylacetic acid system and pyridineacetic system is compared with that in benzene and pyridine. The multiple correlation of log k values for reaction of above acids in 12 alcohols with group of suitable solvent parameters was very successful. . Određene su konstante brzine reakcije esterifikacije 3- i 4-piridinsirćetne kiseline, 3- i 4-piridin-N-oksid-sirćetne kiseline i nekih meta i para-supstituisanih fenilsirćetnih kiselina sa diazodifenilmetanom na 30 ºC u dvanaest alkoholnih rastvarača. Na osnovu dobijenih konstanti brzina reakcija piridinsirćetnih kiselina i supstituisanih fenilsirćetnih kiselina izračunate su nove sekundarne ρ konstante supstituenata. Takođe su korišćenjem Hammett-ove jednačine određene reakcione konstante ρ za navedene kiseline i diskutovan je efekat prigušenja metilenske grupe. Višestrukom regresionom analizom uspostavljena je zadovoljavajuća zavisnost konstanti brzina reakcija kao i reakcione konstante ρ sa parametrima rastvarača kao što su: Kirkwood-ova funkcija relativne permitivnosti f(ε), Taftova ρ* konstanta za alkil grupe alkohola i nγH koji predstavlja broj γ-vodonikovih atoma u alkoholu. .

The rate constants for 10 trans-substituted beta-aroylacrylic acids in their reaction with diazodiphenylmethane (DDM) were determined in ethanol at 30 degrees C. The intention was to study the transmission of electronic effects of substituents on the phenyl nuclei to the carboxylic group reaction center, through the -C(=O)-CH=CH-group. The obtained rate constants were analyzed with the classical Hammett equation and the extended Hammett and Taft equation. It was possible, using Taft's relationship, to effect the separation of the overall polar effect into inductive and resonance components. The pattern of transmission through the observed conjugated system has been discussed. Conformational variations caused by variable substituents in an aromatic ring were calculated using the MNDO-AM I semiempirical method. The inclusion of a calculated conformational effect considerably improves the regression.

U cilju proučavanja strukture i svojstava derivata 4,6-disupstituisanih-3-cijano-2-piridona izvršena je sintez a dve serije jedinjenja: N -(supstituisani fenil)-3-cijano - 4,6- dimetil-2-piridona i 3-cijano-4-(supstituisani fenil)-6-fenil-2(1 H )-piridona. Ispitan je uticaj temperature, vremena reakcije i molskog odnosa reaktanata na prinos i čistoću proizvoda dobijenih različitim klasičnim metodama sinteze, kao i mikrotalasnom sintezom sa ili bez rastvarača... In order to study structure and properties of 4,6-disubstituted- 3-cyano-2-pyridones a synthesis of two series of N -(substituted phenyl)-3-cyano-4, 6-dimethyl-2-pyridones and 3- cyano-4-(substituted phenyl)-6-phenyl-2(1 H )-pyridones have been done. Influences of different reaction parameters: temperature, reaction time and reactant molar ratio on the purity and product yield have been studied. The compounds was obtained by different classical methods, as well as microwave method us ing solvent or by solvent free synthesis.