Validated Stability-Indicating Method for Alendronate Sodium Employing Zwitterionic Hydrophilic Interaction Chromatography Coupled with Charged Aerosol Detection

Alendronate sodium is widely used in the treatment of osteoporosis and Paget’s disease. The HPLC method development for alendronate sodium, in particular, is challenging owing to the absence of chromophoric group and its high polarity. In the present study, a short and simple isocratic method was developed involving hydrophilic interaction liquid chromatography, coupled with a charged aerosol detector. The developed method was validated according to the ICH Q2(R1) guideline and was successfully applied for the analysis of a marketed formulation containing the drug.

     

A versatile and practical synthesis of bis(indolyl)methanes/bis(indolyl)glycoconjugates catalyzed by trichloro-1,3,5-triazine

A practical and efficient electrophilic substitution reaction of indoles with a variety of aldehydes was carried out using catalytic trichloro-1,3,5-triazine (10 mol %) in acetonitrile to furnish the corresponding bis(indolyl)methanes in excellent yields. Similarly, sugar derived aldehydes gave hitherto unknown bis(indolyl)glycoconjugates in very good yields.     

Laser-Induced Fluorescence (LIF) Probe for <Emphasis Type="Italic">In-situ</Emphasis> Nitric Oxide Concentration Measurement in a Non-thermal Pulsed Corona Discharge Plasma Reactor

Laser-induced fluorescence (LIF) is an effective in-situ probe for NO concentrations below 300 ppm in a non-thermal plasma reactor. A new method has been developed to measure in-situ NO concentration in the reactor discharge region using a long-time—on the order of seconds—averaged fluorescence detection. This method, for quantifying NO concentration in a nonthermal plasma reactor, is simpler than a short-time—on the order of nanoseconds—fluorescence detection. For accurate measurement based on the new method, the LIF intensity must be close to the corona-induced fluorescence (CIF) intensity; the CIF intensity serves as a guide in selecting the LIF intensity. We find that a kinetic model proposed earlier works for two-tube reactors and represents the NO concentration in the middle of the reactor, which verifies the assumption of gas plug flow.     

Palladium(II) complexes ofN-alkyl phenothiazines

Summary Eight square-planar palladium(II) complexes, PdLCl₂ (L=N-alkyl phenothiazine) have been synthesized. Analytical, conductometric, spectral (electronic, i.r. and n.m.r.) and thermal data for the complexes have been discussed.Part of the paper presented at the International Conference The Chemistry of the Platinum Group Metals, Bristol July 20–24th, 1981.     

Synthesis of 2,3-dihydroquinazolin-4(1H)-ones from anthranilamide and ketones over Hβ zeolite in aqueous media*

The synthesis of 2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation of anthranilamide with ketones in aqueous media using Hβ zeolite is reported. The scope of the reaction was explored by various ketones such as aromatic, aliphatic and cyclic ketones. Based on the preliminary mechanistic results, a tentative mechanism for the formation of 2,3-dihydroquinazolin-4(1H)-ones using zeolite catalyst (Hβ) is predicted. The reusability study, large-scale experiment and water as solvent showed significant benefits of this catalytic protocol in comparing to earlier methods.     

Verhalten von Kiesels?ure/Tonerde-Gel als Crack-Katalysator

Ohne Zusammenfassung     

Synthesis and characterization of Al-modified SBA-15 for Fischer–Tropsch synthesis (FTS) reaction

Research on Chemical Intermediates - In this work, we synthesized a Co-based catalyst supported on modified SBA-15 to obtain the uniform particle size of active metal and selective products with...     

First synthesis and determination of the absolute stereochemistry of iso-cladospolide-B and cladospolides-B and C

The syntheses of iso-cladospolide-B, cladospolide-B and cladospolide-C are reported with 4S,5S,11S-configuration. Of the three stereogenic centres, the C-4/C-5 vic-diol was created by Evans aldol condensation, while the C-11 stereocentre was created by Jacobsen’s method. The synthesis of cladospolides 1-3 defined the absolute stereochemistry of these natural products.