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71.
M. R. Ganjali B. Larijani H. Shams S. Riahi F. Faridbod P. Norouzi 《Journal of Analytical Chemistry》2010,65(10):1052-1060
Dextromethorphan (DXM) is an antitussive (cough Hyj/UA suppressant) drug found in many cough medicines. Dextromethorphan has also found other uses
in medicine, ranging from pain relief to psychoactive applications. In this study, a potentiometric liquid membrane sensor
for simple and fast determination of dextromethorphan hydrobromide in pharmaceutical formulation and urine was constructed.
For the membrane preparation, DXM-tetraphenylborate complexes were employed as electroactive materials in the membrane. The
wide linear range (10−6–10−2 M), low detection limit (1 × 10−6 M), and fast response time (∼5 s) characterize the proposed sensors. Validation of the method shows suitability of the sensors
for applications in the determination of dextromethorphan hydrobromide in pharmaceutical formulation and urine. 相似文献
72.
Obaid-ur-Rahman Abid Muhammad Farooq Ibad Asad Ali Nasim Hasan Rama Peter Langer 《Tetrahedron letters》2010,51(12):1541-721
The palladium(0)-catalyzed Suzuki cross-coupling reaction of the bis(triflates) of phenyl 1,4-dihydroxy-2-naphthoate afforded various 1,4-diaryl-2-naphthoates. The reactions proceeded with very good site-selectivity. Due to electronic reasons, the first attack occurred at the sterically more hindered position C-1. 相似文献
73.
Munawar Ali Munawar Muhammad Azad Hamid Latif Siddiqui Faiz‐Ul‐Hassan Nasim 《中国化学会会志》2008,55(2):394-400
The quinolinylpyrimidine derivatives were prepared by the condensation of quinolinyl chalcones with urea (or thiourea) under basic conditions by using both conventional and microwave heating. Their IR, 1H NMR, 13C NMR, mass spectra and CHN analyses confirmed the prepared compounds. The newly prepared quinolinylpyrimidine derivatives were screened for antimicrobial activities against the bacterial strains viz. S. aureus, Shigella, Salmonela, P. aeroginosa, B. Subtilus and E. coli and found considerably active against S. aureus, P. aeroginosa and E. coli. 相似文献
74.
Transport of Ag+ as Ag(CN)2− ions through a bulk liquid membrane is reported. The bulk liquid membrane used is a solution of Victoria blue (VB) in chloroform. The effects of pH of the source phase, cyanide concentration in the source phase, sodium hydroxide in the receiving phase, and VB concentration in the organic phase on the efficiency of the transport system were studied. The above system has a high selectivity for Ag+ and can selectively and efficiently transport Ag(CN)2− ion from aqueous solutions containing other cations such as alkali and alkaline earths, Zn2+, Pd2+, Cu2+, Cd2+,Hg2+, Co2+, Fe2+, Pb2+, Ni2+, and Al3+. 相似文献
75.
A sensitive and selective method for the simultaneous determination of copper, zinc and lead is presented. The method is based on the adsorptive accumulation of 2′,3,4′,5,7-pentahydroxyflavone (Morin) complexes of these elements onto a hanging mercury drop electrode, followed by reduction of adsorbed species by voltammetric scan using differential pulse modulation. Optimal analytical conditions were found to be Morin concentration of 2.0 μM, pH of 4.0, and an adsorption potential at −500 mV versus Ag/AgCl. With an accumulation time of 60 s, the peak currents are proportional to the concentration of copper, lead and zinc over the 1 to 60, 0.3-80 and 1-70 ng ml−1 range with detection limits of 0.06, 0.08 and 0.06 ng ml−1, respectively. The procedure was applied to the simultaneous determination of copper, lead and zinc in some real and synthetic artificial real samples with satisfactory results. 相似文献
76.
3,5-Dimethoxyphenylalkan-2-ols react with diethoxymethane and boron trifluoride etherate, or aqueous formaldehyde and hydrochloric acid forming bis(6,8-dimethoxychroman-5-yl)methanes. 相似文献
77.
Rafat Milad Mohareb Suzan Ibrahim Aziz Nadia Iskander Abdel Saved Hoda Zaki Shams 《中国化学会会志》1992,39(2):181-187
Various derivatives of thiophene, thiazoline and thienopyrimidine have been synthesized via the reaction of active methylene reagents (la-j) with benzoyl isothiocyanate in the presence of potassium hydroxide, followed by the subsequent treatment of the potassium salt intermediates 2a-j with phenacyl bromide or ethyl chloroacetate. The stability of the formed adducts 3 and 12 or their selective cyclization depends on both the nature of the active methylene reagent and the α-halocarbonyl compounds. 相似文献
78.
Mehrzad Shams Hasan Sheykhzadeh Mohammad Taghavi 《Journal of Dispersion Science and Technology》2013,34(3):299-306
Turbomolecular pumps are widely used in scientific and industrial applications. The three-dimensional simulation of free molecular flow within a row of blades of a turbomolecular pump is solved using test-particle Monte Carlo method. The solution performed in an inertial reference frame where molecular paths are straight line. The following of molecule paths in both rotor and stator is done in a similar system of coordinates. Good agreement between numerical results and quasi similar previous simulations confirm the validity of the presented algorithm. In this simulation, effects of the flow leakage due to existence of clearance between blade tip wall and casing is considered and the blade thickness is ignored. In addition the flow analysis shows effects of determination of sizes, significant effects of clearance and more importantly the effects of blade's angle on turbo molecular pump's fundamental characteristics. The simulation of turbo molecular pump with the nonparallel blades is done and compared with similar parallel blades. 相似文献
79.
An improved, highly scalable methodology for the multigram-scale preparation of an important synthon, 17-β-(2-carboxyethyl)-1,3,5(10)-estratriene, is described. Previous approaches have failed to provide useful quantities of the analytically pure product because of facile retro-Michael breakdown of the β-alkoxy carbonyl precursors during workup and isolation operations. The synthetic approach described herein has been designed specifically to sidestep this problematic breakdown process. This new scalable method of preparation overcomes a major hurdle in the exploration of structure–activity relationships centered around novel estradiol derivatives with bone-targeting properties and also provides a scalable process for subsequent developmental work. 相似文献
80.
Abd El‐Wareth A. O. Sarhan Shams H. Abdel‐Hafez Hassan El‐Sherief Tarek Aboel‐Fadl 《合成通讯》2013,43(8):987-996
The utilities of the Mannich reaction in synthetic organic chemistry are reviewed. The behaviors of Mannich reactions on several bifunctional heterocyclic compounds have been reported. A new class of heterocyclic compounds, thiadiazino[1,3,5][3,2‐a]benzimidazoles 12a–g, were obtained by reaction of 2‐mercaptobenzimidazole with primary aliphatic amines in a one‐step synthesis. An attempt to apply this reaction using primary aromatic amines lead to the formation of the well‐known Mannich bases 11a–g rather than the N‐substituted thiadiazines 13. 相似文献