The oxidative-rearrangement of 1-amino-2-indolinones. A synthesis of 2-substituted-3(2H)-cinnolinones

Several 2-substituted-3(2H)-cinnolinones have been synthesized by a ring expansion of the respective 1-substituted-2-indolinones via an oxidative-rearrangement with t-butyl hypochlorite.     

HPLC method transfer study for simultaneous determination of seven angiotensin II receptor blockers

In this study, a sensitive high‐performance liquid chromatography method was developed and validated for the simultaneous determination of seven angiotensin II receptor blockers, namely, hydrochlorothiazide, chlorthalidone, eprosartan mesylate, valsartan, losartan potassium, irbesartan, and candesartan cilexetil. Different chromatographic parameters were tested and fully optimized. Best chromatographic separation was accomplished on a reversed‐phase octadecylsilyl column (250 × 4.6 mm id; 5 μm) under gradient elution using methanol/sodium phosphate monobasic buffer (0.01 M, pH 6.5) as mobile phase. The detection of target analytes was obtained at 254 nm. The pH of the buffer has been selected according to Marvin^® sketch software. The proposed method was validated according to ICH guidelines and showed good precision (relative standard deviation < 1), good linearity (square of correlation coefficient ≥ 0.999), and high accuracy (between 98 and 102%) with detection limit and quantitation limit (40 and 160 ng/mL, respectively) for all the detected analytes.     

Complete and effectively complete inclusive experiments

The experiments required to meadure all the independent amplitudes in any single-particle inclusive process with experimentally available incident particles are determined, and the amplitude (or combination of amplitudes) obtained from each measurement is given. Various kinematic regions are considered, and the measurements which determine the subset of amplitudes expected to be important in each region are found. The prospects of a meaningful separation of exchanged naturalities are also investigated and found to be difficult, due to a kinematic suppression of certain amplitudes.     

DFT Study of a 5‐endo‐trig‐Type Cyclization of 3‐Alkenoic Acids by Using Pd–Spiro‐bis(isoxazoline) as Catalyst: Importance of the Rigid Spiro Framework for Both Selectivity and Reactivity

The reaction pathway of an enantioselective 5‐endo‐trig‐type cyclization of 3‐alkenoic acids catalyzed by a chiral palladium–spiro‐bis(isoxazoline) complex, Pd–SPRIX, has been studied by density functional theory calculations. The most plausible pathway involves intramolecular nucleophilic attack of the carboxylate moiety on the C?C double bond activated by Pd–SPRIX and β‐H elimination from the resulting organopalladium intermediate. The enantioselectivity was determined in the cyclization step through the formation of a π‐olefin complex, in which one of the two enantiofaces of the olefin moiety was selected. The β‐H elimination occurs via a seven‐membered cyclic structure in which the acetate ligand plays a key role in lowering the activation barrier of the transition state. In the elimination step, the SPRIX ligand was found to behave as a monodentate ligand due to the hemilability of one of the isoxazoline units thereby facilitating the elimination. Natural population analysis of this pathway showed that the more weakly electron‐donating SPRIX ligand, compared with the bis(oxazoline) ligand, BOX, facilitated the formation of the π‐olefin complex intermediate, leading to a smaller overall activation energy and a higher reactivity of the Pd–SPRIX catalyst.     

Seifen, Waschmittel

Ohne Zusammenfassung     

Spectroscopic,thermal and toxicity studies of some 2-amino — 3- cyano — 1, 5 -diphenylpyrrole containing Schiff bases copper (II) complexes

Two novel Schiff base ligands of 2-amino-3-cyano-1,5-diphenylpyrrole and salicylaldehyde (HL¹) or 2- hydroxy1-naphthylaldehyde (HL²) and their copper(II) complexes have been synthesized and characterized by elemental analyses, spectral (UV-Vis, IR, EPR, Mass (for ligands)), thermal (DTA-TGA) methods, magnetic and conductance measurements. IR results demonstrate the bidentate binding of the Schiff base ligands involving azomethine nitrogen, phenolic or naphtholic oxygen and suggest the presence of HL² and complexes (1, 2, 4 and 8) in enolimine-ketonamine tautomeric forms in the solid state. The EPR spectral data of complexes (2, 5, 6) show that the metal — ligand bonds have considerable covalent character. The thermal studies show that complexes (1, 2, 4 and 8) that are present in enolimine-ketonamine tautomeric forms exhibit lower thermal stability. The effect of synthesized ligands (HL¹, HL²) and complexes (1, 5) were tested on the mortality of entomopathogenic nematodes (EPN) (Heterorhabditis bacteriophora and Steinernema carpocapsae). The study shows that the mortality of the nematodes increased with increasing concentrations of copper(II) ion, ligands and complexes. Copper(II) ion was the most toxic for EPN.      

Possibilities of low-level determination of silicon in biological materials by activation analysis

The capabilities of neutron and photon activation analysis (NAA and PAA, respectively) for low-level determination of silicon in biological materials have been examined. Sensitivities of a variety of modes of NAA and PAA with radiochemical separation have been evaluated. Results are presented for silicon in reference materials CSRM 12-2-03 Lucerne, Bowen's Kale, NIST SRM-1571 Orchard Leaves, and NIST SRM-1515 Apple Leaves. The results were obtained by employing the 29Si(n,p)29Al reaction with fast reactor neutrons and the radiochemical procedure developed for aluminium separation. Possibilities of further improvement of the silicon determination limit down to the microg g(-1) level by employing NAA and PAA with radiochemical separation are outlined.     

Effect of substitution of blast-furnace slag by fired drinking water sludge on the properties of pozzolanic cement pastes

Journal of Thermal Analysis and Calorimetry - The effect of fired drinking water sludge (FDWS) as a mineral admixture on the physico-mechanical properties and the fire resistance of pozzolanic...     

Irradiated black pepper identification based on thermoluminescence of silicate minerals

In this work we have successfully implemented thermoluninescence TL method for irradiated food identification. First tests are performed on Indian black pepper and show promising results to extend the proposed method to many other foods. The X-ray diffraction (XRD) shows that SiO₂ (p3₂21) is the main component of the separated mineral phase. A saturation dose of ~ 100 Gy is determined for this pepper above which all thermoluminescent centers of the quartz are activated. Thus, above this threshold dose, only the pepper irradiation will be confirmed but no accuracy on the exact dose received.