排序方式: 共有14条查询结果,搜索用时 15 毫秒
1.
The reaction of epibromohydrin with hydroxyquinazolin-2-(1H)one derivatives. Novel oxazine formation
Mary Lou Cotter Victor Bandurco Elizabeth Wong Zoltan G. Hajos 《Journal of heterocyclic chemistry》1979,16(3):623-624
Epibromohydrin was found to react with 7-hydroxy-2-methylpyrrolo[1,2-c]quinazolin-5(6H)-one ( 4 ) in the presence of sodium hydroxide to form the novel oxazine 5 . The structure of compound 5 was proven by cmr and pmr analysis. 相似文献
2.
3.
The incubation process in polyimid was investigated at 337.1 nm UV photoablation. The threshold number of incubation pulses needed to start the ablation is proportional to a reciprocal cubic function of the fluence and does not depend on the repetition rate of the laser between 0 and 20 pps. A simple model is presented to explain these characteristics. 相似文献
4.
Peter Hajos Gabriella Revesz
Corrado Sarzanini
Giovanni Sacchero Edoardo Mentasti 《Journal of chromatography. A》1993,640(1-2):15-25A retention model is derived for complex anions eluted from an anion-exchange column with multiple ionic eluents containing hydrogencarbonate, carbonate, and hydroxyl species and the sample solution, containing transition metals, anions and complexing ligand. The theory is based on the generalized ion-exchange equilibrium, protonation and complex-formation equilibria. The unknown parameters of chromatographic ion-exchange equilibrium constants for sample and eluent species are determined from the experimental retention data by iterative minimization, using a non-linear regression algorithm. The model was utilized to predict the retention behaviour of CdEDTA2−, CoEDTA2−, MnEDTA2− and NiEDTA2− ions. The capacity factors of complex ions were determined for wide ranges of pH values and eluent concentrations. Good agreement was obtained between the observed and predicted retentions. 相似文献
5.
R. Malathi D. Rajagopal Zoltan G. Hajos S. Swaminathan 《Journal of Chemical Sciences》2004,116(3):159-162
A modified template mechanism based on modelling studies of energy minimised complexes is presented for the asymmetric proline-catalysed
cyclization of triketones1,2 and3 to the 2S,3S-ketols1a,2a and3a respectively. The template model involves a three-point contact as favoured in enzyme-substrate interactions. Our minimisation
studies are in agreement with the divergent behaviour of the 6,5-, 6,6-and 6,7-bicyclic systems. They support the high 93.4%ee observed with the 6,5-bicyclic ketol and the lower 73%ee found with the 6,6-bicyclic ketol. The calculations also explain the lack of asymmetric induction with the 6,7-bicyclic system 相似文献
6.
Jeffery B. Press Victor T. Bandurco Elizabeth M. Wong Zoltan G. Hajos Ramesh M. Kanojia Robert A. Mallory Edward G. Deegan James J. Mcnally Jerry R. Roberts Mary Lou Cotter David W. Graden John R. Lloyd 《Journal of heterocyclic chemistry》1986,23(6):1821-1828
Synthesis of 5,6-dimethoxyquinazolin-2(1H)-one derivatives was the subject of investigations leading to the preparation of title compounds 11, 13, 14 and 26 . Target quinazolines 1 were synthesized in three ways; the route starting from o-vanillin via the intermediacy of 6-amino-2,3-dimethoxyacetophenone ( 19 ) was used for most of the preparative work. The unexpected formation of an acid-labile dimer of 13 was discovered and solid state 13C nmr was used for structural assignment. The 5-methoxy substituent in these systems shows anomalous spectral characteristics and, in one case, was cleaved in acid media to 22 . 相似文献
7.
8.
9.
10.
Marcell Olajos Ákos Szekrényes Peter Hajos Doug T. Gjerde András Guttman 《Analytical and bioanalytical chemistry》2010,397(6):2401-2407
In this paper, the effect of temperature is investigated on the performance of glycoprotein enrichment by boronic acid lectin
affinity chromatography (BLAC). Wheat germ agglutinin and m-aminophenyl boronic acid containing stationary phases were evaluated individually and in a mixed mode using an automated
liquid handling robot with an integrated 96-well plate temperature controller. Glycoaffinity enrichment of the model proteins
of ribonuclease B and trypsin inhibitor was investigated in the presence of the non-glycosylated proteins of myoglobin (neutral)
and lysozyme (basic) at a wide temperature range of 5–65 °C. Our results revealed that glycoaffinity micropartitioning at
the temperature of 25 °C provided the highest recovery rate for glycoprotein enrichment. We have also found that a large amount
of lysozyme was present in the elution fractions of the m-aminophenyl boronic acid containing micropartitioning columns due to ion-exchange mechanism occurring between the positively
charged protein and the negatively charged stationary phase at the operation pH. On the other hand, at high temperature (65 °C),
non-specific interactions with the agarose carrier prevailed, evidenced by the presence of myoglobin in the eluate. 相似文献