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261.
P. Md. Khaja Mohinuddin Ravikrishna Dada Abdulrahman I. Almansour Natarajan Arumugam Srinivasarao Yaragorla 《Tetrahedron letters》2019,60(15):1043-1048
Diastereoselective, three-component annulation reaction involving glyoxals, anilines and dienophiles is developed under calcium catalysis. When indene is the dienophile, the reaction gave excellent diastereoselectivity to yield tetrahydro-indenoquinolines, these were further aromatized to get indenoquinolines in one-pot. Aryl acetylenes are used as dienophiles to get 2-acyl quinolines in good yields. 相似文献
262.
Manh Tran Dinh Nam Nguyen Dang Abdulrahman Gihad Keyany Moradi Rasoul Babazadeh Houman 《Journal of Thermal Analysis and Calorimetry》2020,140(6):2865-2873
Journal of Thermal Analysis and Calorimetry - Computational modeling was employed to scrutinize the nanomaterial influence of flow patterns and thermal treatment within a porous region.... 相似文献
263.
Gholamreza Bahrami Bahareh Mohammadi Amir Farshchi Golbarg Ghiasi 《Chromatographia》2009,70(1-2):323-327
An accurate and sensitive reversed-phase high-performance liquid chromatographic method for analysis of sertraline in human serum, using 4-chloro-7-nitrobenzofurazan as pre-column derivatization agent, is described. The drug and an internal standard (azithromycin) were extracted from serum by use of a mixture of diethyl ether and chloroform, and subjected to pre-column derivatization with the reagent. Analysis of the resulting derivatives was performed on a 250 mm × 4.0 mm cyano column with 63:37 (v/v) methanol–sodium phosphate buffer (0.05 M, pH 3.7) containing 2 mL L?1 triethylamine as mobile phase. Detector response was monitored at excitation and emission wavelengths of 470 and 537 nm, respectively. The calibration plot was linear over the concentration range 2–640 ng mL?1. The lower limits of detection and quantification were 0.5 and 2 ng mL?1, respectively. The method was validated for specificity, sensitivity, linearity, precision, accuracy, and stability and shown to be accurate (intra-day and inter-day accuracy from 0.3 to 4.2%) and precise (intra-day and inter-day precision from 2.4 to 15.5%). The drug was detected at concentrations as low as 2 ng mL?1 in 0.5 mL serum and the method described can be easily applied to human single-dose pharmacokinetic studies of sertraline. 相似文献
264.
The H2O2/SOCl2 reagent system has been used as a new and efficient reagent for deprotection of thiocarbonyls to carbonyl compounds. The salient features of this protocol are short reaction times, good chemoselectivity, clean reaction profiles, and simple work-up that preclude the use of toxic solvents. 相似文献
265.
In this paper, we have investigated the effect of annealing on structural and magnetic properties of La0.8Pb0.2MnO3 (LPMO) polycrystalline samples. Mechanochemical procedure has been used to produce LPMO nanocrystalline samples from oxide precursors. From the AC susceptibility measurements we found that the magnitude of susceptibility increases and the paramagnetic–ferromagnetic (PM–FM) transition width decreases by annealing the ball milled powders. Also, reentrant spin glass (RSG) behavior has been found in high temperature annealed samples. It seems that, due to the evaporation of PbO in high temperature annealed samples, vacancies created in perovskite structure and portion of the Mn3+–O–Mn4+ network is broken. So the FM double-exchange interaction is weakened due to the magnetic dilution and the antiferromagnetc (AFM) phase fraction increases in high temperature annealed samples. The competition between FM double-exchange interaction and AFM super-exchange interaction produces spin frustration and is responsible for the occurrence of RSG. 相似文献
266.
267.
Bhat Shahnawaz Ahmad Zafar Fahmina Mondal Aftab Hossain Kareem Abdul Mirza Azar Ullah Khan Shabnam Mohammad Abdulrahman Haq Qazi Mohd. Rizwanul Nishat Nahid 《Journal of the Iranian Chemical Society》2020,17(1):215-227
Journal of the Iranian Chemical Society - Face-centered cubic structure of nickel oxide (NiO) nanoparticles with 30 nm average size was synthesized by co-precipitation method with some... 相似文献
268.
269.
Saadullah G. Aziz Abdulrahman O. Alyoubi Shaaban A. Elroby 《Molecular physics》2017,115(20):2565-2576
Kojic acid is a polyfunctional heterocyclic compound, with several important reaction centres; it has a wide range of applications in the cosmetic, medicine, food, agriculture and chemical industries. The present study aims at better insight into its electronic structure and bonding characteristics. Thus, density functional theory at the M06-2x /6-311++G** level of theory is used to investigate its ground state electronic and acid–base properties. Protonation and deprotonation enthalpies are computed and analysed. The ability of Kojic acid to form both water complexes and dimers is explored. Several different complexes and dimer structures were examined. Natural bond order and quantum topology features of the charge density were analysed. The origin of the stability of the studied complexes and dimer structures can be traced to hydrogen bonding, π-conjugative and non-covalent dispersive interactions. 相似文献
270.
Raju Suresh Kumar Alagar Ramar Subbu Perumal Abdulrahman I. Almansour Natarajan Arumugam Mohamed Ashraf Ali 《合成通讯》2013,43(20):2763-2772
Three-component reaction of 1-[(4-chlorophenyl)sulfanyl]acetone, malononitrile, and substituted aromatic aldehydes in the presence of sodium ethoxide under simple mixing at ambient temperature for 5–8 min afforded highly functionalized 4H-pyrans in good to excellent yields. 1,3-Dipolar cycloaddition of nitrile oxides over the nitrile functionality of the 4H-pyrans furnished 1,2,4-oxadiazoles in moderate yields.
Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for full experimental and spectral details. 相似文献