Polyaromatic amines. Part 3: Synthesis of poly(diarylamino)styrenes and related compounds

The title compounds were synthesised and characterised as part of a study into new aromatic amines for charge transporting materials. Compounds 12-16, 20-24 and 27-34 are alkene linked triarylamines, compounds 35-36 are hydrazone derivatives and compounds 38-41 are pyrrole substituted triarylamines. Each compound was characterised by cyclic voltammetry.     

U-4C-3CR versus U-5C-4CR and stereochemical outcomes using suitable bicyclic β-amino acid derivatives as bifunctional components in the Ugi reaction

Intramolecular Ugi reactions with bicyclic β-amino acids have been performed and the effects of the configuration and N-alkylation have been studied. We have proven that preferential ring contraction or nucleophilic attack by the solvent depend not only on the presence of N-alkylation but also on the relative disposition of the carboxyl group and the amine. Excellent results in terms of stereoselectivity have been obtained in the case of N-alkyl-3-exo-amino-7-oxabicyclo[2.2.1]-2-endo-carboxylic acids.     

Mannich reaction in the synthesis of N,S-containing heterocycles. 1. Synthesis of novel derivatives of imidazo[2,1-<Emphasis Type="Italic">b</Emphasis>][1,3,5]thiadiazine

Reactions of (Z)-5-benzylidene-2-thiohydantoin with formaldehyde and primary aromatic amines afforded novel derivatives of imidazo[2,1-b][1,3,5]thiadiazine in 50–69% yields. Dedicated to Academician N. S. Zefirov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2158–2160, September, 2005.     

Characterisation of Tokaj wines based on free amino acids and biogenic amines using ion-exchange chromatography

Summary Tokaj wines (Szamorodni and Aszu wines) of Hungarian origin were investigated on the basis of free amino acids and biogenic amines. The separation and determination of these compounds was performed by an amino acid analyser equipped with an ion-exchange resin column. The total amount of free amino acids and biogenic amines was higher in Aszu wines than in Szamorodni wines. The main amino acids were proline and arginine, while the major biogenic amines were tyramine and putrescine. The free amino acid and biogenic amine content of Aszu wines depended on the vineyards the wines originated from. Presented at Balaton Symposium '01 on High-Performance Separation Methods, Siófok, Hungary, September 2–4, 2001     

N-Acyltrifluoromethanesulfonamides as new chemoselective acylating agents for aliphatic and aromatic amines

This work describes advances in the study of the internal condensation of ammonium salts of N-acylsulfonamides. N-Acyltrifluoromethanesulfonamides show considerable advantages over the non fluorinated analogues by virtue of their higher reactivity and acidity. The reaction chemoselectivity has been investigated using a wide range of amines. The sensitivity of the reaction to steric and electronic effects confirms the potential application of these reagents in chemoselective acylation of polyamines.     

Fabrication and performance of a three-dimensionally adjustable device for the amperometric detection of microchip capillary electrophoresis

A microchip CE-amperometric detection (AD) system has been fabricated by integrating a two-dimensionally adjustable CE microchip and an AD cell containing a one-dimensionally adjustable disk detection electrode in a Plexiglas holder. It facilitates the precise 3-D alignment between the channel outlet and the detection electrode without a complicated 3-D manipulator. The performance of this unique system was demonstrated by separating five aromatic amines (1,4-phenyldiamine, aniline, 2-methylaniline, 4-chloroaniline, and 1-naphthylamine) of environmental concern. Factors influencing their separation and detection processes were examined and optimized. The five analytes have been well separated within 140 s in a 74 cm long separation channel at a separation voltage of +2500 V using a 10 mM phosphate buffer (pH 3.5). Highly linear response is obtained for the five analytes over the range 20-200 microM with the detection limits ranging from 0.46 to 1.44 microM, respectively. The present system demonstrated long-term stability and reproducibility with RSDs of less than 5% for the peak current (n = 9). The new approach for the microchannel-electrode alignment should find a wide range of applications in CE, flowing injection analysis, and other microfluidic analysis systems.     

Reactions of 5,6,7,8-tetrafluoro-4-hydroxycoumarin derivatives with benzylamine and aniline

5,6,7,8-Tetrafluoro-4-hydroxycoumarin reacted with benzylamine under mild conditions to give a stable salt, while its refluxing with aniline or benzylamine in xylene afforded 5,6,7,8-tetrafluoro-4-phenyl(benzyl)aminocoumarins. Reactions of 3-acetyl(acetimidoyl)-5,6,7,8-tetrafluoro-4-hydroxycoumarins with benzylamine followed different pathways, depending on the solvent. Condensation at the acyl substituent can be accompanied by replacement of the F atom in position 7. 3-Acetylcoumarin formed a salt, while 3-acetimidoylcoumarin yielded a 7-monosubstituted product. 3-Acetyl(acetimidoyl)-5,6,7,8-tetrafluoro-4-hydroxycoumarins reacted with aniline to give only 5,6,7,8-tetrafluoro-4-hydroxy-3-(N-phenylacetimidoyl)coumarin. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1170–1174, July, 2006.     

Ligand exchange separation of amines on copper (II) sorbed on zinc silicate

Summary Papers impregnated with Cu(II) sorbed on zinc silicate have been used to study the ligand exchange chromatographic behavior of amines. R_F values of 16 amines have been studied in 6 different systems. On the basis of differences in R_F values various analytically important qualitative separations of amines on impregnated papers and quantitative separations on columns of copper(II) sorbed on zinc silicate have been achieved.     

Synthesis of Arylidene Derivatives of 1-Aryl-3H-pyrrol-2-ones

The aminolysis of 5-aryl-3-arylidene-3H-furan-2-ones by the action of aromatic amines leads to the formation of substituted amides of 4-oxo acids, the subsequent azacyclization of which in the presence of acetic anhydride leads to the formation of 1,5-diaryl-substituted 3-arylidene-3H-pyrrol-2-ones. The mechanism of the occurring and alternative transformations is discussed.     

Effect of Chamber Gas Phase on Mobile Phase pH and on Separation Efficiency in TLC. A New Mode of Chromatography

A new variant of thin-layer chromatography (TLC), based on a gradual change of mobile phase acidity during elution, is proposed. The pH change occurs in the mobile phase moving along the TLC plate as a result of its contact with an acidic or a basic gas phase that replaces the initial mobile phase vapor in the TLC chamber. The potential of this approach has been demonstrated by using carbon dioxide and ammonia gases to improve the resolution of benzoic acids and aromatic amines on polyamide TLC plates.