Investigation of 3-(carbazol-9-YL)-1,2-epithiopropane interaction with aromatic amines

In the reaction of 9-(2,3-epithiopropyl)-9H-carbazole with aromatic amines (aniline, 4-methoxy-, 4-methyl-, 4-fluoro-, 4-bromo-, 4-chloro-, 3-chloro-, 2-chloroaniline) and subsequent oxidation of the mixtures formed of propanethiols and disulfides with 25% H₂O₂ in basic solutions the respective disulfides have been synthesized. Carbazolyl-containing derivatives of the thiazolidine have been obtained.Published in Khimiya Geterotsiklicheskikh Soedinenii. No. 1, pp. 90–99, January, 2000.     

Trifluoromethylation and pentafluorophenylation of enamines

A reaction of enamines with Me₃SiCF₃ and Me₃SiC₆F₅ in the presence of carboxylic acids leading to α-CF₃-and α-C₆F₅-substituted amines has been studied. 3-Cyanobenzoic acid was found to be the optimal promoter of these reactions. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1466–1468, August, 2007.     

Synthesis and reactivity of furazanyl- and furoxanyldiazonium salts

Diazotization of aminofurazans (1) and 4-aminofuroxans (2) with nitrosylsulfuric acid in a mixture of conc. H₂SO₄ and H₃PO₄ has been studied and offered as a general method for preparing furazanyl- (3) and furoxanyldiazonium (4) salts. It has been shown that reactions with the retention of the N-N-group (azo coupling, formation of triazenes and azides) are typical of salts3 and4, while elimination of the N₂ molecule (Sandmeyer reaction, hydrolysis, reduction) is not typical.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1949–1953, November, 1993.     

Reaction of perfluoro-2-methylpent-2-en-3-yl isothiocyanate with ethyl and isopropyl alcohols

Perfluoro-2-methylpent-2-en-3-yl isothiocyanate reacts with ethyl or isopropyl alcohols in the presence of NEt₃ to give derivatives of 4,5-dihydrothiazole and ethoxy(ethylthio)methylene-(1,1,1,4,4,5,5,5-octafluoro-2-trifluoromethylpent-2-en-3-yl)amine and isopropoxy(isopropylthio)methylene-(1,1,1,4,4,5,5,5-octafluoro-2-trifluoromethylpent-2-en-3-yl)amine, respectively. Heating of ethyl or isopropylN-(perfluoro-2-methyl-2H-pentylidene-3-amino)thiocarbamate with potassium carbonate in DMF yields the same products plus 3-tetrafluoroethylidene-5,5-bis(trifluoromethyl)thiazolidin-2-one. The structure of the latter was confirmed by X-ray diffraction analysis. The IR spectroscopy data for this compound in solution (CCl₄) and in the solid state (KBr) suggest the formation of the intermolecular NH...O=C hydrogen bond between the NH group and the oxygen atom of the heterocycle. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2021–2026, October, 1998.     

Solid-Phase Microextraction of Aromatic Amines with an Amide Bridged Calix[4]arene Coated Fiber

Detection of aromatic amines without derivatization was carried out using a new solid-phase microextraction fiber coated with 25,27-dihydroxy-26,28-(1,10-dioxo-4,7-diaza-3,8-dioxooctamethylene)-p-tert-butylcalix[4]arene (amide bridged-C[4]). The new fiber shows excellent selectivity and sensitivity for the tested amines (aniline, o-toluidine, 2,4-dimethylaniline, 3,4-dimethylaniline, N-ethyl-m-toluidine, and N,N-diethylaniline). The coating has high thermal stability (up to 380 °C) and solvent stability. Experimental conditions, such as extraction temperature and time, pH and ionic strength were optimized. The method proposed here shows good linearity and low detection limits ranged from 1.2 to 40 ng.L^–1. Application of this method was demonstrated through the determination of aromatic amines in wastewater from a pharmaceutical plant.     

Synthesis of 1,3,4-thiaza- and 1,3,4-oxazaphosphol-2-lines based onN-phosphorylated (thio)ureas

The reactions ofO-phenyl chloromethylisothiocyanatothioxophosphonate andO-phenyl chloromethylisocyanatophosphonate with trimethylsilyldiethylamine lead to the formation of 1,3,4-thiazaphosphol-2-ine and 1,3,4-oxazaphosphol-2-ine, respectively. Phosphorylation ofN-methyl-N-phenyl-N,N-bis(trimethylsilyl)urea withO-phenyl chloromethylchlorophos phonate gives 1,3,4-diazaphospholidin-2-one.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1857–1859, July, 1996.     

In-column field-amplified sample stacking of biogenic amines on microfabricated electrophoresis devices

A novel method for performing in-column field-amplified sample stacking (FASS) in chip-based electrophoretic systems is presented. The methodology involves the use of a narrow sample channel (NSC) injector. NSC injectors allow sample plugs to be introduced directly into the separation channel, and subsequent stacking and separation can proceed without any need for leakage control. More importantly, stacking and separation occur in a single step negating the requirement for complex channel geometries and voltage switching to control sample plugs during the stacking procedure. The chip is composed of six paralleled systems. Using the NSC injector design, the number of reservoirs in the multiplexed chip is reduced to N + 2, where N is the number of paralleled systems. This design feature radically reduces the complexity in chip structures and associated chip operation. The approach is applied to the analysis of fluorescently labelled biogenic amines affording detection at concentrations down to 20 pM.     

烯丙胺与C_(60)的热引发[3+2]环加成反应

烯丙胺类化合物与C_(60)在热引发下发生新型的[3+2]环加成反应。反应有较 好的立体选择性。该反应可能经过了热引发的烯丙胺的单电子转移过程，产生烯丙 基自由基，并进一步与C_(60)加成及环化。文中C_(60)衍生物的结构均经过谱学方 法确证。     

Determination of biogenic amines by RPHPLC with fluorescent detection after derivatization with 2-(9-carbazole)ethyl chloroformate (CEOC)

Summary The use of 2-(9-carbazole)ethyl chloroformate (CEOC) for pre-column derivatization of biogenic amines (BA) has been tested for the first time. The reagent reacts completely with BA within 3 min at ambient temperature in acetonitrile solution to form stable derivatives that are readily analyzed by reversed-phase HPLC. Study of the derivatization conditions revealed derivatization yields to be excellent in borate buffer over the pH range 9.0–10.0. Maximum yields were obtained by use of a three- to fourfold molar excess of reagent. The reaction is extremely tolerant of common buffer salts, no decrease in reaction yield is discernible in well-buffered samples. The emission maximum for the CEOC-derivatives is 360 nm (λ _ex = 293 nm). All the derivatives fluoresced strongly and direct injection of the reaction mixture was possible, with no significant disturbance from the major fluorescent reagent degradation by-products, 2-(9-carbazole)ethanol (CEOC-OH) and bis-(2-(9-carbazole)ethyl) carbonate (CEOC)₂. Separation of the derivatized BA by high-performance liquid chromatography with gradient elution was tested on a Hypersil BDS C18 column. Excellent response linearity was observed over the concentration range from 0.25 to 94.6 μmol L⁻¹ for the labeled BA. Detection limits were 117–840 fmol at a signal-to-noise ratio of 3∶1. Analysis of BA in a shrimp sauce extract was conducted to demonstrate the applicability of the technique to real sample matrixes; results were satisfactory.     

Synthesis of polymeric supports with spacer-modified triazene linkers: aldol and Grignard reactions of immobilized nortropinone

Four new polymeric supports with 3- and 6-carbon atom spacers and triazene linkers derived from meta- and para-aminophenol were synthesized from commercial Merrifield polymer. The supports could be used for immobilization of secondary amines in SPOS. A new strategy based on the use of diethylamine triazenes as masked precursors for the generation of polymer-supported diazonium ions was used. The performance of the new linkers was tested on Grignard and aldol reactions of solid-phase immobilized nortropinone. The new supports with C₃-T2 linkers gave products with better yields and purities than the classical T2 supports or the supports with the C₆-T2 linkers.