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The route of action of sodium methoxide on 5-Arylmethylene-2-Disubstituted amino-4-oxo-2-thiazolines
5-Arylmethylene-2-disubstituted amino-4-oxo-2-thiazolines 1a-d reacted with six and two moles of sodium methoxide to give the 2-mercaptocinnamic acid esters 6 and mixtures of 2,2 -dimethoxy-4-oxothiazolidines 4 and 2,4-dioxothiazolidines 5 , respectively. The intermediate mixture of the sodium salt of 5-aryImethylene-2,2-dimethoxy-4-oxothiazolidines 3 in the above mentioned transofrmations was established. The structures of 3, 4, 5 and 6 were based on analytical and spectral evidence. The route of conversion of 1 into 3, 4,5 and 6 was presented and discussed. 相似文献
13.
Structure and dielectric relaxations of antibacterial sulfonated polystyrene (SPS) and silver nanocomposites (SPS/Ag) were investigated via broadband dielectric spectroscopy, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, differential scanning calorimetry, scanning electron microscopy, and wide‐angle X‐ray diffraction. SPS/Ag nanocomposites were prepared from SPS containing 2, 4, and 7 mol% of acid contents, followed by ion exchange and a reduction process. Silver nanoparticles were formed in the structural cavities of SPS films. The single glass transition temperature of the SPS copolymers was observed and increased with increasing acid contents and more enhanced with embedded silver nanoparticles because of the restriction of the polymer chain movement. The particle size of embedded silver nanoparticles was about 10 nm and well dispersed in SPS matrices. Four dielectric relaxations were observed above the glass transition temperature, and they were attributed to the fast segmental relaxation, the slow‐hindered segmental relaxation, relaxations associated with Maxwell–Wagner–Sillars interfacial polarization and electrode polarization. Weak local relaxations were observed due to the motion of sulfonated phenyl groups. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
14.
A.-Mohsen M. E. Omar M. Gabr Kasem I. M. Laabota J. Bourdais 《Journal of heterocyclic chemistry》1981,18(3):499-501
A novel series of 3-substituted amino-s-triazolo[3,4-a]phthalazine derivatives has been synthesized by the one-pot cyclodesulfurization reactions utilizing 1-hydrazinophthalazine, alkyl, aryl, or aralkylisothiocyanates and dicyclohexylcarbodiimide (DCCD) mixtures. The products did not exhibit any antihypertensive properties. Their pmr and mass spectral analysis is given. 相似文献
15.
The structure and tautomerism of 5-amino-4-arylazopyrazoles (2a-f) are investigated in aqueous media. In solutions of pH>5 these compounds exist as ring N—1 protonated species. At pH>10 they afford anions which are stabilized by delocalization of the negative charge in the ring as well as on the arylazo moiety. Controlled potential electrolysis and polarographic analysis indicate that 2a-f are reduced via a four electron reduction process to triaminopyrazole and the corresponding substituted aniline derivative. A mechanism is suggested and discussed. 相似文献
16.
Mohamed M. Shoukry Ihsan M. Kenawy Afkar K. Abdel Hadi Eman M. Shoukry 《Journal of Chemical Sciences》1988,100(5):381-388
The formation constants of salicyl-4-amino-2,3-dimethyl-1-phenyl-3-pyrazoline-5-one (SAAP) complexes with 3d transition metal
ions [Cu(II), Ni(II), Co(II), Zn(II) and Mn(II)] have been determined in 60% ethanol-water medium ofμ = 0.1M (NaCl) at 25°C. It is observed that the formation constants for chelates with 3d transition metals follow the order
Mn(II) < Co(II) < Ni(II) < Zn(II) < Cu(II). The effects of metal ions, ionic radii, electronegativities and ionization potentials
on chelate formation constants are discussed.
Complexes of UO2(II) and Pd(II) have been synthesized and characterised by elemental analysis, electrolytic conductance, IR spectra and magnetic
measurements. The ligand forms the complexes PdLCl and UO2L2,2H2O, where L is a uninegatively charged tridentate ligand (ONO donor sets). 相似文献
17.
Cui L Isbell MA Chawengsub Y Falck JR Campbell WB Nithipatikom K 《Journal of the American Society for Mass Spectrometry》2008,19(4):569-585
The fragmentation characteristics of monohydroxyeicosatetraenoic acids and dihydroxy- and trihydroxyeicosatrienoic acids were
investigated by electrospray ionization Fourier transform ion cyclotron resonance (FTICR) mass spectrometry using sustained
off-resonance irradiation collision-induced dissociation (SORI-CID) and infrared multiphoton dissociation (IRMPD). The fragmentation
patterns of these compounds were associated with the number and positions of the hydroxyl substituents. The fragmentation
is more complicated with increasing number of the hydroxyl groups of the compounds. In general, the major carbon-carbon cleavage
of [M−H]− ions occurred at the α-position to the hydroxyl group, and the carbon-carbon cleavage occurred when there was a double-bond at the β-position to the hydroxyl group. SORI-CID and IRMPD produced some common fragmentation patterns; however, each technique provided
some unique patterns that are useful for structural identification of these compounds. This study demonstrated the application
of FTICR via the identification of regioisomers of trihydroxyeicosatrienoic acids in rabbit aorta samples. 相似文献
18.
Polycarbonate (PC) detector is one of the common detectors for neutron and radon gas detection. Using this detector it is possible to measure the dose in mSv, by counting tracks/cm2 on an etched surface. In this paper, a special procedure has been suggested to determine the dose based on current drain during the etching process. In these experiments the effects of voltage, frequency, effective etched area, PC detector's thickness, etched area (one side or two sides), etching solution temperature and dose absorbed by the PC foil have been studied.The results obtained show the current drain variation for a voltage of 200–1600 V, a frequency of 2–10 kHz, effective area with a diameter of 2–12 cm, PC thickness of 125–250–375– and a temperature of etching solution of 25–.Lexan PC foils were exposed to doses of of neutrons. The unexposed foils were considered as the background (BG) foils. Most of the experiments were performed at a voltage of 800 V, a frequency of 2 and 8 kHz, foil thickness of , diameter of effective etched area of foils of 2, 6 and 12 cm, temperatures of 25 and and the etching process from 0 up to overload stage. Overload stage occurs when the foil becomes so thin due to growth of the tracks that it leads to sparking between phase and null that makes a hole in the foil.Current drain curves versus the function of the etching time are absolutely different for various doses from zero (BG) to 10 rad (BG up to ). This is true especially for the time interval from 3 h of etching up to overload stage. In this way, it is possible to obtain a calibration of PC detector net current drain based on its absorbed dose.In this experiment, the number and diameter of tracks and their relation with drain current and PC foil residual thickness at overload stage have been studied.The same experiment has been performed for various concentrations of radon gas (Bq/m3) as well. 相似文献
19.
Cholpisut Tantapakul Trinop Promgool Kwanjai Kanokmedhakul Kasem Soytong Jiaojiao Song Sarinya Hadsadee 《Natural product research》2020,34(4):494-502
AbstractA new xanthoquinodin B9 (1), together with two known xanthoquinodins, xanthoquinodin A1 (2) and xanthoquinodin A3 (3), three epipolythiodioxopiperazines, chetomin (4), chaetocochin C (5) and dethio-tetra(methylthio)chetomin (6), and four other compounds, chrysophanol (7), emodin (8), alatinone (9), and ergosterol (10) were isolated from the endophytic fungus Chaetomium globosum 7s-1, isolated from Rhapis cochinchinensis (Lour.) Mart. All isolated structures were established based on their spectroscopic data analyses. Compounds 1–6 showed antibacterial activity against Gram positive bacteria with MICs ranging from 0.02?pM to 10.81 µM. Compounds 1–6 also exhibited cytotoxicity against KB, MCF-7 and NCI-H187 cancer cell lines (IC50 0.04–18.40 µM). However, they were cytotoxic towards a normal cell line (Vero cell) with IC50 values ranging from 0.04 to 3.86 µM. 相似文献
20.
Kasem K. Kasem 《Surface and interface analysis : SIA》2011,43(12):1527-1531
Colloidal ZnO, Fe2O3 and Cu2O solutions were used to explore photonic activities at metal oxides/organic semiconductors interfaces. Fluorescence spectroscopic and dynamic electrochemical techniques were performed on colloidal metal oxides articles modified with 3‐dodecyl 2–5 di‐thionyl pyrrole (3‐DODTh‐Py) to investigate the quantum absorbance efficiency at this inorganic/organic interface (IOI). The IOI assemblies were p‐n junction‐type interfaces, where 3‐DODTh‐Py) functions as electron donor. Results were interpreted using the optical and electrochemical parameters of the organic monomer such as IP (ionization potential), EA (electron affinity), and Eg (Energy band gap), and the barrier height at the IOI interface. One of the driving forces for great absorption at IOI was the great difference in electronegativity between inorganic and organic interface. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献