Synthesis of Functionalized (2-Thienylcarbonyl)thiazoles and 4-(2-Thienyl)pyridines by Reaction of (2-Thienylcarbonyl)thioacetanilides and their Enamine Derivatives

Summary. The condensation of two molecules of 2-(2-thienylcarbonyl)thioacetanilides catalyzed by piperidine yielded thiazole derivatives as confirmed by X-ray crystal structure analysis. The reaction of malononitrile with 3-morpholino-3-(2-thienyl)acrylic acid thioanilides furnished 6-amino-1-aryl-4-(2-thienyl)-1,2-dihydro-2-thioxopyridine-5-carbonitriles. A similar reaction of malononitrile with 3-morpholino-3-(2-thienyl)acrylic acid anilides provided 2-oxopyridine-5-carbonitriles.     

Aminoalkylation with Aldehydes Mediated by Solid Lithium Perchlorate

Summary. The solid LiClO₄-mediated one-pot reaction of aldehydes with secondary amines and C nucleophiles afforded the corresponding aminoalkylation products in high yields. Unlike the previous reported procedure, the aminoalkylation of aldehyde was achieved in the presence of only 0.5 equivalents of solid lithium perchlorate in dichloromethane as the solvent with good to high yields at room temperature.     

The application of NMR and MS methods for detection of adulteration of wine,fruit juices,and olive oil. A review

This review covers two important techniques, high resolution nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS), used to characterize food products and detect possible adulteration of wine, fruit juices, and olive oil, all important products of the Mediterranean Basin. Emphasis is placed on the complementary use of SNIF-NMR (site-specific natural isotopic fractionation nuclear magnetic resonance) and IRMS (isotope-ratio mass spectrometry) in association with chemometric methods for detecting the adulteration.     

Radical copolymerization of citraconic acid with styrene in dioxane solution

Styrene and citraconic acid (CA) were copolymerized in the dioxane solution ranging mole fraction of CA in feed from 0.1 to 0.9 at 70 °C. The terminal and penultimate models were used to fit the copolymer composition equation. Curve fitting, Mayo-Lewis, Joshi-Joshi, Fineman-Ross, Ezrielev-Brokhina-Roskin, Kellen-Tüd?s methods were used to solve the copolymer equation in terminal model. Besides these methods Solver in Excel 97 was used to solve copolymer equation in terminal and penultimate models of copolymerization. Experimental mole fractions of CA and those predicted from both models are agreed within the precision of the method used for the copolymer analysis, so the copolymer composition does not permit a definite choice of the adequate copolymerization model.     

Determination of nitrite as pentafluorobenzyl derivative by RP-HPLC and UV detection with and without ion-pair extraction

Summary A reversed-phase high-performance liquid chromatographic (RP-HPLC) method with UV detection (270 nm) for the determination of nitrite as its pentafluorobenzyl derivative with and without ion-pair extraction is described. Ion-pair extraction of nitrite from aqueous solutions was performed by using a 1 mol/l solution of the liquid ion exchanger methyltrioctylammonium chloride in toluene. The residue of the ion-pair extraction or an aliquot of an aqueous nitrite solution or of a biological fluid (100 l) were treated with 400 l of acetone and 10 l of pentafluorobenzyl bromide. Nitrite was converted into its pentafluorobenzyl derivative by heating at 50°C for 90 min. After evaporation of acetone the aqueous phases were diluted with 100 to 400 l of methanol, and up to 100 l were injected into the RP-HPLC system. The method allows accurate analysis of nitrite in the presence of nitrate directly in aqueous solutions and biological fluids in concentrations down to 2.0 mg/l. The method is also applicable to the determination of nitrate following its reduction to nitrite by cadmium.     

An azo dye for photodynamic therapy that is activated selectively by two-photon excitation

Two-photon photodynamic therapy (TP-PDT) is a promising approach for the treatment of cancer because of its better penetration depth and superior spatial selectivity. Here, we describe an azo group containing cyclized-cyanine derivatives (ACC1 and ACC2) as a two-photon activated, type I based photosensitizer (PS). These small-molecule and heavy atom-free organic dyes showed marked reactive oxygen species (ROS)-generating ability under physiological conditions, as well as fast loading ability into the cells and negligible dark toxicity. Live cell analyses with one- and two-photon microscopy revealed that these dyes showed higher ROS generation ability upon two-photon excitation than upon one-photon excitation via the type I process. The PSs have superior PDT properties compared to conventional Visudyne and 5-ALA under mild conditions. These characteristics allowed for precise PDT at the target region in mimic tumor spheroids, demonstrating that the developed TP PS could be useful in efficient PDT applications and in designing various PSs.

Azo containing dyes as a two-photon selective and type I based photosensitizers (PSs) were developed that exhibit excellent photodynamic therapy properties under mild condition.     

A new convenient synthesis of N-acyl-2-(dimethoxyphosphoryl)glycinates

Easily accessible N-acyl-2-triphenylphosphonioglycinate tetrafluoroborates react smoothly with trimethylphosphite in the presence of methyltriphenylphosphonium iodide to give N-acyl-2-(dimethoxyphosphoryl)glycinates in good or very good yields. The dimethoxyphosphorylglycinates may be isolated by column chromatography, or used directly for the Wadsworth-Emmons synthesis of α,β-dehydro-α-amino acids in a one-pot procedure without purification.     

Influence of nonionic emulsifier included inside carboxylated polymer particles on the formation of multihollow structure by the alkali/cooling method

The influence of nonionic emulsifier, included inside styrene-methacrylic acid copolymer [P(S-MAA)] particles during emulsion copolymerization, on the formation of multihollow structure inside the particles via the alkali/cooling method (proposed by the authors) was examined in comparison to emulsifier-free particles. It was clarified that the nonionic emulsifier included inside the P(S-MAA) particles eased the formation of multihollow structure.Part CCL of the series studies on suspension and emulsion     

Determination of organotin compounds in biological samples using accelerated solvent extraction,sodium tetraethylborate ethylation,and multicapillary gas chromatography–flame photometric detection

A method has been developed for species-selective analysis of organotin compounds in solid, biological samples. The procedure is based on accelerated solvent extraction (ASE) of analytes and includes extraction of the tin species with a methanol–water (90% methanol) solution of acetic acid/sodium acetate containing tropolone (0.03% w/v), their ethylation with NaBEt₄, and separation and detection by GC–FPD. The analytical procedure was optimized with an unspiked sample of harbor porpoise (Phocoena phocoena) liver. Effects of ASE operational variables (extraction temperature and pressure, solvent composition, number of static extraction steps) are discussed. Method detection limits (MDL) were in the range 6–10 ng(Sn) g^–1 dry weight and 7–17 ng(Sn) g^–1 dry weight for butyl- and phenyltin compounds, respectively. Recoveries were comparable with or better than those obtained by use of other procedures reported in the literature. The analytical procedure was validated by analysis of NIES No. 11 (fish tissue) certified reference material.     

Own N-layered integrated molecular orbital and molecular mechanics study of the reaction of OH<Superscript>−</Superscript> with polychlorinated hydrocarbons CH<Subscript>(4−n)</Subscript>Cl<Subscript>n</Subscript> (n=2–4)

The reliability of the two-layer own N-layered integrated molecular orbital and molecular mechanics (ONIOM) method was examined for the S_N2 reaction CH_(4–n)Cl_n+OH^–. In the ONIOM calculation, only the methyl chloride and OH^–were treated at a high level and the effect of polychlorination was taken into account only at a low level. The ONIOM results were compared with the target CCSD(T)/aug-cc-pVDZ//MP2/aug-cc-pVDZ results obtained by Borisov etal. [(2001) J. Phys. Chem. A 105:7724]. The ONIOM[MP2/aug-cc-pVDZ:B3LYP/6-31+G(d)] was found to reproduce well the target geometry and energy at the MP2/aug-cc-pVDZ level. The single-point improved energetics at the ONIOM[CCSD(T)/aug-cc-pVDZ:MP2/6-31+G(d)] is found to give results nearly as accurate as the target CCSD(T)/aug-cc-pVDZ//MP2/aug-cc-pVDZ results. The substantially reduced cost, 20% for optimization and 5% for single-point improved energy of the target cost for n=4, as well as small errors suggest that ONIOM is a powerful tool for accurate potential-energy surfaces of the reaction of large polyhalohydrocarbons.