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571.
Issa Yavari Zinatossadat Hossaini Elham Karimi 《Monatshefte für Chemie / Chemical Monthly》2007,138(12):1267-1271
Summary. The reaction of dialkyl acetylenedicarboxylates with trialkyl(aryl) phosphites in the presence of isatin, phthalimide, indole,
or pyrrole leads to stable dialkyl(aryl) phosphorylsuccinates in excellent yields. 相似文献
572.
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574.
Roger W. Day Houshang Karimi Cecil V. Francis James F. Kinstle James Q. Chambers 《Journal of polymer science. Part A, Polymer chemistry》1986,24(4):645-654
The low-temperature solution polycondensation reaction between 1,4-bis-(2′-hydroxy-ethoxy)benzene and adipyl chloride has been studied in N,N-dimethylacetamide. The effect of temperature, concentration, and reaction time on the percent yield and product viscosity has been determined. Optimum conditions were established for the preparation of high molecular weight products and then applied to the synthesis of novel tetracyanoquinodimethane polyesters. Products were characterized by gel permeation chromatography. 相似文献
575.
Sensitive indirect spectrophotometric determination of isoniazid 总被引:2,自引:0,他引:2
Safavi A Karimi MA Hormozi Nezhad MR Kamali R Saghir N 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(4):765-769
A simple, rapid, sensitive and accurate indirect spectrophotometric method for the microdetermination of isoniazid (INH) in pure form and pharmaceutical formulations is developed. The procedure is based on the reaction of copper(II) with isoniazid in the presence of neocuproine (NC). In the presence of neocuproine, copper(II) is reduced easily by isoniazid to a Cu(I)-neocuproine complex, which shows an absorption maximum at 454 nm. By measuring the absorbance of the complex at this wavelength, isoniazid can be determined in the range 0.3-3.5 microgml-1. This method was applied to the determination of isoniazid in pharmaceutical formulation and enabled the determination of the isoniazid in microgram quantities (0.3-3.5 microgml-1). The results obtained for the assay of pharmaceutical preparations compared well with those obtained by the official method and demonstrated good accuracy and precision. 相似文献
576.
A high loading sulfonic acid-functionalized ordered nanoporous silica efficiently catalyzes the deprotection of a variety of alcoholic TBDMS (tert-butyldimethylsilyl)ethers in methanol. The catalyst shows high thermal stability (up to 240 °C) and can be recovered and reused for at least seven reaction cycles without loss of reactivity. This method can be used to deprotect TBDMS ethers of alcohols in the presence of TBDMS ethers of phenols. 相似文献
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578.
Results of lattice Monte Carlo simulation are presented for the behavior of a mixture of oil‐water‐amphiphile in different conditions. For the first time, the phase transitions between different types of microemulsion are modeled, in a qualitative manner, using the concept of solvent accessible surface area. All of the simulations are run in canonical (N, V, T) ensemble. Simple cubic lattices with the dimension of 50 have been used to avoid any size or surface effects of the boxes. Periodic boundary conditions and excluded volumes are used to mimic the box of simulation as a bulk of solution. All of the results are in good qualitative agreement with previous theoretical and experimental results. 相似文献
579.
NaHSO4•H2O has been used as an efficient catalyst for the one-pot preparation of 14H-[(un)substituted phenyl]-dibenzo[a,j]xanthene leuco-dye derivatives by condensation of β-naphthol with substituted benzaldehydes under microwave and thermal conditions. This method has the advantages of high yields, a green reaction, an efficient and cost-effective method, simple procedures, short reaction time, and easy workup. 相似文献
580.
R. Karimi Shervedani H. R. Zare Mehrdjardi S. H. Kazemi Ghahfarokhi 《Journal of the Iranian Chemical Society》2007,4(2):221-228
Electrochemical characterization and application of nickel ruthenium dioxide (Ni-RuO2) as a pH sensor for the determination of petroleum oil acid number is described. The sensor consists of RuCl3 thermally decomposed onto the upper side of a polycrystalline nickel electrode at 400 °C in an open furnace. The advantages of the sensor are: (i) easy preparation, (ii) fast response in a large pH range, (iii) high physical and chemical stability, and (iv) excellent reproducibility as determined by the reproducible linear variation of charge transfer resistance (Rct) as a function of overpotential (η) obtained by electrochemical impedance spectroscopy (EIS), and the Nernstian slope of the electrode potential in a wide range of pH (1.5–12.5) obtained by potentiometric measurements. The potentiometric selectivity coefficients of the sensor toward some anions and cations were evaluated in aqueous solution. The characterized Ni-RuO2 pH sensor was successfully tested for the determination of petroleum oil acid number. 相似文献