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Barbiturates, which are derived from the medically significant substance barbituric acid also known as malonylurea or 4-hydroxyuracil, are employed as anaesthetics, sedative-hypnotics, anticonvulsants, and depressants of the central nervous system. In recent years, researchers have paid great attention to compounds and derivatives of barbituric acid, although the first barbituric acid was discovered in 1864 by Adolf Von Baeyer. Due to its great medical and biological importance and wide applications in polymerization catalysts, plastics and textiles, aqueous or oil inks, and polymers. The background, reactions, and methods of preparing barbituric acid have been studied over the last ten years.

Barbiturates, which are derived from the medically significant substance barbituric acid also known as malonylurea or 4-hydroxyuracil, are employed as anaesthetics, sedative-hypnotics, anticonvulsants, and depressants of the central nervous system. In recent years, researchers have paid great attention to compounds and derivatives of barbituric acid, although the first barbituric acid was discovered in 1864 by Adolf Von Baeyer. Due to its great medical and biological importance and wide applications in polymerization catalysts, plastics and textiles, aqueous or oil inks, and polymers. The background, reactions, and methods of preparing barbituric acid have been studied over the last ten years.

Barbiturates, which are derived from the medically significant substance barbituric acid also known as malonylurea or 4-hydroxyuracil, are employed as anaesthetics, sedative-hypnotics, anticonvulsants, and depressants of the central nervous system. In recent years, researchers have paid great attention to compounds and derivatives of barbituric acid, although the first barbituric acid was discovered in 1864 by Adolf Von Baeyer. Due to its great medical and biological importance and wide applications in polymerization catalysts, plastics and textiles, aqueous or oil inks, and polymers. The background, reactions, and methods of preparing barbituric acid have been studied over the last ten years.

A possibility of applying the stripping voltammetry method for the determination of benzylated derivatives of phenobarbital (benzonal and halonal) in tableted forms of medicinal drugs was shown. The regularities of the physicochemical behavior of the barbiturates on the glassy carbon electrode depending on the pH of the solution were studied, and the following accumulation parameters with an analytical value were estimated: the range of variation in the accumulation potential and the accumulation time as well as the voltammetric mode. It was established that the character of the dependence of the magnitude of the electroreduction currents of the barbiturates studied had an adsorption character. The following working conditions were established: the background electrolyte was 0.1 M solutions of Na2SO3 or 0.1 M NaH2PO4, the accumulation potential was -0.6 V, the accumulation time was 30 s, the cathode differential-impulse sweep of the potentials was at the speed of 50 mV / s. A possible interfering effect of auxiliary substances of tableted forms on the voltammetric signal of halonal and benzonal was investigated: under the conditions of real contents of auxiliary and basic components of the tableted form the error in determining the halonal (benzonal) was 3-5% and did not exceed the error of the method. The methods of analysis of tableted forms of medicinal drugs for the content of halonal and benzonal by the method of differential-pulse voltammetry had been developed. The verification of the correctness of the developed algorithm was carried out by the " introduced-found" method. The analysis time of one sample, considering the sample preparation, did not exceed 15 minutes. The detection limit Cmin = 0.33 mg/l, limit of determination Сlim = 1.32 mg/l, and the range of determined concentrations - 2-200 mg/l were determined. The calculation of the basic metrological indices was carried out including the computation of indices of correctness, intralaboratory precision, Показана возможность применения метода инверсионной вольтамперометрии для определения бензоилированных производных фенобарбитала (бензонал и галонал) в таблетированных формах лекарственных препаратов. Изучены закономерности физико-химического поведения определяемых барбитуратов на стеклоуглеродном электроде в зависимости от рН раствора и оценены параметры накопления, имеющие аналитическое значение: диапазон изменения потенциала накопления и времени накопления, режим полярографирования. Найдено, что характер зависимости величины токов электровосстановления изучаемых барбитуратов носит адсорбционный характер. Установлены рабочие условия измерений: фоновый электролит - 0.1 М растворы Na2SO3 или 0.1 М NaH2PO4, потенциал накопления - -0.6 В, время накопления 30 с, катодная дифференциально-импульсная развертка потенциалов, со скоростью 50 мВ/с. Проведено исследование возможного мешающего влияния вспомогательных веществ таблетированных форм на вольтамперометрический сигнал галонала и бензонала: в условиях реальных содержаний вспомогательных и основных компонентов таблетированной формы, погрешность определения галонала (бензонала) составляет 3-5 % и не превышает погрешности метода. Разработаны методики анализа таблетированных форм лекарственных препаратов на содержание галонала и бензонала методом дифференциально-импульсной вольтамперометрии. Проверка правильности разработанного алгоритма методики проведена методом «введено-найдено». Время анализа одной пробы с учетом пробоподготовки не превышает 15 минут. Определены: предел обнаружения С min = 0.33 мг/л, предел определения С lim = 1.32 мг/л, диапазон определяемых концентраций - 2-200 мг/л; проведен расчет основных метрологических показателей: показатель правильности, внутрилабораторной прецизионности, повторяемости.

Diplomová práce se týká analýzy minoritních látek ve žlutém pigmentu P.Y. 139. V teoretické části jsou popsány pigmenty, jejich vlastnosti a použití. Dále je zde podrobněji popsána isoindolinová a isoindolinonová skupina pigmentů. Do této skupiny pigmentů patří pigment P.Y. 139, o kterém jsou zde uvedeny základní informace, včetně jeho výroby ve společnosti Synthesia, a.s. Nakonec jsou zde představeny základní informace o HPLC instrumentaci použité pro analýzu nečistot ve výrobních vzorcích pigmentu. V praktické části diplomové práce je uveden postup optimalizace jednotlivých kroků analýzy potenciálních nečistot v pigmentu. Výsledky jsou porovnány a diskutovány., In this diploma thesis, development of the method for the analysis of minor substances in yellow pigment P.Y. 139 is described. The theoretical part chracterizes pigments, their properties and their use. The isoindoline and isoindolinone groups of pigments are described more in detail. Properties and basic production scheme of P.Y. 139 belonging to this group is given. The practical part of the thesis describes the individual steps of method optimizing for the analysis a potential impurities in production samples of the pigment. The results are compared and discussed., Fakulta chemicko-technologická, Studentka seznámila členy zkušební komise s obsahem své diplomové práce zabývající se analýzou minoritních složek v pigmentu P.Y. 139. Studentka dále zodpověděla dotazy členů zkušební komise.

Novel dyes bearing a 5-(methylidene)barbituric acid moiety as a new acceptor/anchor fragment were obtained and exhibited remarkable photophysical properties, according to a preliminary assessment of their sensitization activity as elements for dye-sensitized solar cells. © ARKAT-USA, Inc.

Unsubstituted quinoxaline (I) reacts with dimedone, indanedione, and 1-phenyl-3-methylpyrazol-5-one in dimethylsulfoxide in the presence of acid to form monosubstitution products II-IV. Quinoxaline reacts with 1,3-dimethylbarbituric acid in dimethylsulfoxide solution at room temperature to form monosubstitution product V without external catalysis. Heating of I with resorcinol in ethanol in the presence of acid produced resorcinol derivative VI. In the presence of base, quinoxaline reacts with 1-phenyl-3-methylpyrazol-5-one to form dipyrazolylmethane VII and tetrapyrazolylethane derivative VIII. Compound VIII undergoes cleavage to form dipyrazolylmethane VII in dimethylformamide solution with boiling or in the presence of iodine at room temperature. © 2013 Springer Science+Business Media New York.

A ring-ring transformation in the series of spiro[indole-3,5′- pyrimido[4,5-b]quinoline]-2,2′,4′-trione derivatives prepared by a three-component reaction of (thio)barbituric acids, electron-rich aromatic amines, and isatins was observed. © Georg Thieme Verlag Stuttgart - New York.

Kyselina barbiturová a její deriváty mohou vystupovat jako dobré elektron-akceptorní jednotky v push-pull chromoforech. V této práci byly popsány metody příprav barbiturové kyseliny včetně jejího následného zakomponování do push-pull systémů. Dále bylo pojednáno o využití chromoforů s akceptorní barbiturovou jednotkou jako sloučenin s vnitřním přenosem náboje a nelineárně optickými vlastnostmi. Bylo syntetizováno dvanáct chromoforů s N,N´ dibutylbarbiturovou akceptorní jednotkou a ty byly dále zkoumány pomocí rentgenostrukturní analýzy, elektrochemie, UV-VIS absorpční spektroskopie a výpočetními metodami., Barbituric acid and its derivatives may act as good electron-acceptor units in push-pull chromophores. In this work, the methods of barbituric acid preparation and its subsequent incorporation into the push-pull systems have been described. Utilization of chromophores with barbituric acceptor unit as compounds with intramolecular charge-transfer and nonlinear optical properties has also been discussed. Twelve chromophores with N,N´ dibuthylbarbituric acceptor unit were synthesized and further investigated by X ray analysis, electrochemistry, UV-VIS absorption spectroscopy and computational methods., Ústav organické chemie a technologie, Konfigurační stabilita produktů při ozařování? Mechanismus izomerizace dvojné vazby s použitím jodu. Proč byly zvoleny butylderiváty, byly zkoušeny například hexylderiváty? Student uspokojivě zodpověděl položené dotazy.

An usual method for the preparation of vanadyl(II) barbiturate complex was performed under the chemical reaction of vanadyl(II) sulfate with barbituric acid (H2L) and formulated as: [VO(HL)2].2H2O. This new barbiturate complex was synthesis and characterized by elemental analysis, molar conductivity, magnetic measurements, infrared spectral method and simultaneous thermal analysis (TG/DTG) techniques. The molar conductance measurements proved that barbiturate vanadyl(II) complex is non-electrolytes. The infrared spectra of the barbituric and vanadyl(II) complex are used to identify the mode of coordination. Kinetic and thermodynamic parameters (E*, ΔH*, ΔS* and ΔG*) of H2L ligand and its complex are estimated according to the DTG curves.Â