Polymeric Coordination Compounds Derived from Transition Metal(II) with Tetradentate Schiff‐base: Synthetic,Spectroscopic, Magnetic and Thermal Approach

The polymeric coordination compounds have been synthesized using the dipotassium salt of N,N′‐di(carboxymethylene)terephthalaldehydediimine (K₂SB¹) or N,N′‐di(carboxyethylene)terephthalaldehydediimine (K₂SB²) with manganese(II), cobalt(II), nickel(II), copper(II), zinc(II), and cadmium(II). The ligands have been characterized by ¹H‐NMR, and ¹³C‐NMR spectra. The polychelates have been characterized by elemental analyses, magnetic measurements, thermogravimetric analyses, electronic spectra and infrared spectra. The coordination compounds are colored, and the central metal ions are octahedrally coordinated with two water molecules and the Schiff bases. The Schiff bases act as di‐negative tetradentate ligands, in which bonding occurs through two oxygen and two nitrogen atoms. The polymers are insoluble in all common organic solvents such as acetone, methanol, ethanol, N,N‐dimethylformamide and dimethylsulfoxide.     

A Mild Procedure for the Preparation of 2-Oxazolines

A general procedure using triphenylphosphine and diethylazodicarboxylate to prepare 2-oxazolines is described.     

Interactions with herring sperm DNA and biological studies of sparfloxacin drug‐based copper(II) compounds

Copper(II) complexes of the type [Cu(SPF)(Lⁿ)Cl] (where SPF is sparfloxacin and Lⁿ = substituted terpyridines) were synthesized and found to have a distorted octahedral geometry. Superoxide dismutase‐like activity of the complexes was measured using a nitroblue tetrazolium/reduced nicotinamide adenine dinucleotide/phenazine methosulfate system and expressed in terms of the concentration of complex which terminates the formation of formazan by 50% (IC₅₀ value), which was found to range from 0.572 to 1.522 µm . Interactions of the complexes with herring sperm DNA were studied by absorption titration, viscosity measurement and gel electrophoresis under physiological conditions. The antimicrobial efficiency of the complexes was tested against five different microorganisms and showed good biological activity. All the complexes showed good cytotoxic activity, with LC₅₀ values ranging from 4.01 to 9.64 µg ml^?1. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis and mesomorphic characterization of azoesters with a coumarin ring

We have synthesized a homologous series of azoesters consisting of a coumaryl moiety as the end group. Eleven derivatives of this series exhibit mesomorphism. The nematic mesophase is exhibited from ethyl homologue onward, while the smectic phase commences at the pentyl derivative and is exhibited along with the nematic phase up to the hexadecyl derivative. The N-I transition temperatures curves show the usual odd-even effect. All the compounds in this series are thermally stable and exhibit a wide mesomorphic range of nearly 120°C. Their thermal stabilities and other characteristics are discussed.     

UTLC: An Advanced Technique in Planar Chromatography

As part of increasing research in the field of separation science, there have been many efforts to undertake planar chromatography with more efficient separation and better resolution in the shortest period of time, together with a specificity and a capability to identify more precisely an unknown compound present in a mixture. Ultra-thin layer chromatography (UTLC) is a modern technique which gives separation within 10–30 mm and development in just 1–6 min, with the consumption of less solvent. The stationary phase of UTLC is made up of a silica gel monolithic layer of 10 μm thickness having 3- to 4-nm mesopores and 1- to 2-μm macropores. Glancing angle deposition (GLAD)-UTLC is a modification of UTLC which gives separation within 15 mm distance and in less than 2 min. Anisotropic media of GLAD UTLC gives a unique migration direction effect. UTLC atmospheric pressure–matrix-assisted laser desorption ionizer–mass spectrometery (UTLC-AP-MALDI-MS) is a choice of technique for the identification of an unknown compound in a mixture or an impure form. ULTC-AP-MALDI-MS allows the fast changing of plates, produces more intact protonated molecules, less fragmentation and less entry of chromatographic material, and yielding less complicated spectra than the vacuum condition. Thus, UTLC is a useful technique for very rapidly giving the separation and identification of new components present in mixtures. This review provides a brief overview of UTLC, the stationary phases used for UTLC, and the detection options and applications of UTLC.     

Efficient Process For The Cyclization Of Diastereomeric Alcohol To A Trans Amide In The Synthesis Of Dopamine D1 Agonist,Abt-431

One of the key steps in the synthesis of ABT-431 is the diastereoselective cyclization of thieny alcohol 1 to trans amide 2. We report a detailed study of the influence of acids, solvents and temperature over the ratio of cis and trans diastereomers.     

Synthetic Route to a Benzooxazole Derivative with Heparanase Inhibitory Activity

The synthesis of a benzooxazol-5-yl acetic acid derivative (9) with strong heparanase and angiogenesis inhibitory activity, and thus possible commercial interest, is described in detail.     

Synthesis and in vitro antimicrobial screening of new pyrano[4,3-b]pyrane derivatives of 1H-pyrazole

A new series of pyrano[4,3-b]pyrane 4a-l bearing 1H-pyrazole has been synthesized by one pot base catalyzed cyclocondensation reaction of 1H-pyrazole-4-carbaldehyde la-1,malononitrile 2 and 4-hydroxy-6-methylpyrone 3.All the synthesized compounds were screened against six bacterial pathogens,namely B.subtilis,C.tetani,S.pneumoniae,S.typhi,V.cholerae, E.coli and antifungal activity against,two fungal pathogens,A.fumigatus and C.albicans using broth microdilution MIC method. Some of the compounds are found to be equipotent or more potent than that of commercial drugs,against most of employed strains.