Kinetics of the hydroxylation of N-picryl-4-[4-(dimethylamino)styryl]pyridinium salts by molecular oxygen in acetonitrile

The reactions of N-picryl-4-[4-(dimethylamino)styryl]pyridinium salts with molecular oxygen in the presence of 4-[4-(dimethylamino)styryl]pyridine (DASP) in acetonitrile proceeds with the formation of DASP picrate. The reactions are first-order relative to the salt cation, molecular oxygen, and the catalyst (DASP). L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, National Academy of Sciences of Ukraine, 70 R, Lyuksemburg ul., Donetsk 340114, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 34, No. 5, pp. 286–289, September–October, 1998.     

Photochemical Cleavage of the N—O Bond in 1-Benzoyloxy-4-[4-(dimethylamino)styryl]pyridinium Salts

The effect of UV or visible light on solutions of 1-benzoyloxy-4-[4-(dimethylamino)styryl]pyridinium salts in acetonitrile solution lead to cleavage of the N—O bond and formation of 4-[4-(dimethylamino)styryl]pyridine.     

Kinetic and thermodynamic interpretation of the reversible reaction of 2,4,6-trinitrochlorobenzene with 4-[4-(dimethylamino)styryl]pyridine in acetonitrile

The energetic and activation parameters for the reversible reaction of 2,4,6-trinitrochlorobenzene with 4-[4-(dimethylamino)styryl]pyridine in acetonitrile were determined. The rate constants for the forward and reverse reactions were found to be equal at 300 K. L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, National Academy of Sciences of Ukraine, R. Lyuksemburg St., 340114 Donetsk. Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 33, No. 3, pp. 149–152, May–June, 1997.     

Mechanism of the Reaction of Picryl Iodide with 4-[4-(Dimethylamino)styryl]pyridine

We have used semiempirical calculations (PM3, MNDOd) to show that the parabolic dependence of the rate constants (k_obs, s⁻¹) on the picryl iodide (PicI) concentration in the reaction of quaternization of 4-[4-(dimethylamino)styryl]pyridine (DASP) in acetonitrile is due to formation of an inactive σ_1,3 adduct from DASP and PicI. Formation of the σ_1,1 adduct is the rate-limiting step of the S_NAr substitution. __________ Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 41, No. 4, pp. 242–246, July–August, 2005.     

Synthesis,nature of electronic transitions,and absorption spectra of the dye based on 4-(methyl-1-{2-[4-(1-methyl-2-oxo-1,2-dihydroquinolin-3-yl)phenyl]-2-oxoethyl}pyridinium bromide

The reaction of 3-(4-bromoacetylphenyl)-1-methylquinolin-2(1Н)-one with pyridine and 4-methylpyridine has afforded the corresponding pyridinium salts. Condensation of 4-methyl-1-{2-[4-(1-methyl-2-oxo-1,2-dihydroquinolin-3-yl)phenyl]-2-oxoethyl}pyridinium bromide with 4-dimethylaminobenzaldehyde has given a new biscyanine dye, 1-{1-[4-(1,2-dihydro-1-methyl-2-oxo-3-quinolinyl)benzoyl]-2-[4-(dimethylamino)-phenyl]ethynyl}-4-{2-[4-(dimethylamino)phenyl]ethynyl}pyridinium bromide. Its electronic spectrum has been analyzed, and quantum-chemical simulation of spatial and electronic structure of its possible isomers has been performed.     

Isoparametric correlations in reactions of 4-R-N-arylpyridinium salts with arylamines

Isoparametric dependencies of the structure of the reagents (including non-catalytic rate constants, substitution constants σ⁰, basicity constants, and charges at the reaction centers) have been obtained for the reactions between 4-R-N-(2,4-dinitrophenyl)pyridinium salts with arylamines. The electron-acceptor 4-R-substituents studied reduced the positive charge on the reaction center (the α-atom) and the nitrogen atom of the N-arylpyridinium cation. L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, National Academy of Sciences of Ukraine, 70 R. Luxembourg ul., Donetsk 340114, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 4, pp. 231–235, July–August, 1999.     

Fluorescent polyacrylamide nanoparticles for naproxen recognition

We present the synthesis of fluorescent acrylamide nanoparticles (FANs) capable of recognizing non-steroidal anti-inflammatory drugs (NSAIDs) in buffered aqueous solutions. Within this important group, we selected naproxen, one of the 2-arylpropionic acids (profens), due to its use for the treatment of moderate pain, fever, and inflammation. The nanosensors were prepared under mild conditions of inverse microemulsion polymerization using aqueous acrylamide as the monomer and N,N′-methylenebisacrylamide as the cross-linker, employing the surfactants polyoxyethylene-4-lauryl ether (Brij?30) and sodium bis(2-ethylhexyl)sulfosuccinate in hexane. Furthermore, a fluorescent monomer, (E)-4-[4-(dimethylamino)styryl]-1-[4-(methacryloyloxymethyl)benzyl]pyridinium chloride (mDMASP) has been synthesized and incorporated into the nanoparticles. The nanosensors exhibit a broad absorbance at around 460 nm and a structureless fluorescence band with maximum at 590 nm in 0.5 M phosphate buffer (pH = 7.2). The recognition process is performed on the basis of ionic interactions which are monitored by the fluorescence increase at 590 nm upon addition of different concentrations of naproxen. The FANs show a size distribution in the range of 20–80 nm, with a hydrodynamic diameter of 34 nm. In order to assess the selectivity of the FANs, a systematic study was conducted on the effect produced by drugs and biomolecules that could interfere with the analysis of naproxen.     

Rate constants for the formation and decomposition of the σ-adduct in the reactions of N-arylpyridinium salts

The rate constants for the formation (k₁) and decomposition (k ₋₁ ,k ₂ ,k ₃ ) of the σ-adduct were determined for the reactions of 4-R-N-(2,4-dinitrophenyl)pyridinium salts [R=Py, CON(C₂H₅)₂] with 4-methoxyaniline, which takes place by the ANRORC substitution mechanism. L. M. Litvinenko Institute of Physical Organic Chemistry and Coal Chemistry, National Academy of Sciences of Ukraine, 70 R. Lyuksemburg ul., Donetsk 340114, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 34, No. 5, pp. 282–285, September–October, 1998.     

Quaternization of 1H-imidazo[4,5-b]pyridine and 4-methyl-4H-imidazo[4,5-b]pyridine

Unsubstituted imidazo[4,5-b]pyridine adds methyl iodide to the pyridine N atom. Treatment of the resulting iodide with base forms 4-methyl-4H-imidazo[4,5-b]pyridine. This nucleophile can readily add methyl iodide to form only one salt, 1,4-dimethylimidazo[4,5-b]pyridinium iodide.L. M. Litvinenko Institute of Physical Organic Chemistry and Coal Chemistry, Ukraine Academy of Sciences, Donetsk 340114. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1232–1233, September, 1994. Original article submitted june 17, 1994.     

Michael reaction in synthesis of 6-amino-4-(4-butoxyphenyl)-3,5-dicyanopyridine-2(1H)-thione

The reaction of 4-butoxybenzalcyanoacetic ester with cyanothioacetamide yielded 6-amino-4-(4-butoxyphenyl)-3,5-dicyanopyridine-2(1H)-thione, also synthesized by recyclization of 2,6-diamino-4-(4-butoxyphenyl)-3,5-dicyano-4H-thiopyran and condensation of 4-butyoxybenzaldehyde with a two-fold excess of cyanothioacetamide. Substituted 2-alkylthiopyridines and thieno[2,3-b]pyridines were obtained with the indicated pyridinethione. T. G. Shevchenko Lugansk State Pedagogical Institute, Lugansk 348011. Ukraine, N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 213–219, February, 1998.     

Condensed pyridine bases. A new approach to the synthesis of 3-phenacylbenzo[b]thiophenes and 3-phenacyl-5-ethylthieno[2,3-b]thiophene. Synthesis of new derivatives of benzothieno[2,3-c]pyrylium and thieno[2′,3′:5,4]thieno-[2,3-c]pyrylium and pyridine bases

A new method is proposed for the production of substituted 3-phenacylbenzo[b]thiophenes by the intramolecular cyclization of 1-phenyl-4-phenylthio-1,3-butanediones in polyphosphoric acid. The analogous cyclization of 1-phenyl-4-(5-ethyl-2-thienylthio)-1,3-butanedione leads to 3-phenacyl-5-ethylthieno[2,3-b]thiophene. The acylation of substituted 3-phenacylbenzo[b]thiophenes and 3-phenacyl-5-ethylthieno[2,3-b]thiophene by the anhydrides of aliphatic acids in the presence of perchloric acid leads to 1-alkyl-3-phenylbenzothieno[2,3-c]pyrylium perchlorates and 2-ethyl-5-phenyl-7-methylthieno[2′,3′:5,4]thieno[2,3-c]pyrylium perchlorate. The action of ammonium acetate on the obtained salts gives the corresponding pyridine bases. L. M. Litvinenko Institute of Physical Organic Chemistry and Coal Chemistry, National Academy of Sciences of Ukraine, Donetsk 340114. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1335–1339, October, 1998.     

Synthesis of 6-methyl-5-phenylcarbamoyl-3,4-dihydropyridinespiro-4-cyclohexane-2(1H)-thione and its derivatives

3-Cyano-6-methyl-5-phenylcarbamoyl-3,4-dihydropyridinespiro-4-cyclohexane-2(1H)-thione was obtained by the condensation of acetoacetic acid anilide with cyclohexylidenecyanothioacetamide. Substituted 2-alkylthio-1,4-dihydropyridines and 3-amino-2-(4-chlorobenzoyl)-6-methyl-5-phenylcarbamoyl-4,7-dihydrothieno[2,3-b]pyridinespiro-4-cyclohexane were synthesized from it. T. G. Shevchenko Lugansk State Pedagogical Institute, Lugansk 348011, Ukraine N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1533–1535, November, 1997.     

Synthesis of N-methylmorpholinium 6-oxo-3,5-dicyano-1,4,5,6-tetrahydro-4-(spirocyclopentane)pyridine-2-thiolate with the Michael reaction

N-Methylmorpholinium 6-oxo-3,5-dicyano-1,4,5,6-tetrahydro-4-(spirocyclopentane)pyridine-2-thiolate was obtained by reaction of cyclopentylidenecyanoacetic ester with cyanothioacetamide or cyclopentylidenecyanothioacetamide with cyanoacetic ester in the presence of N-methylmorpholine; it is used in synthesis of substituted 2-alkylthiotetrahydropyridines, 5-oxo-6,8-dicyano-2,3,6,7-tetrahydro-(5H)-7-(spirocyclopentane)-thiazolo[3,2-a]pyridine, 5-allyl-2-methylthio-3,5-dicyano-4,5-dihydro-4-(spirocyclo-pentane)pyridin-6(1H)-one, and 3-amino-6-oxo-5-cyano-4,5-dihydro-4-(spirocyclopentane)-2H-pyrazolo[5,4-b]pyridin-6(7H)-one. T. G. Shevchenko Lugansk State Pedagogical Institute, Lugansk 348011, Ukraine, N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 208–212, February, 1998.     

Interaction of 2-(2-azahetaryl)-3-oxo-4-chlorobutane nitriles with esters of aromatic amino acids

The reaction of 2-(2-azahetaryl)-3-oxo-4-chlorobutane nitriles with esters of aromatic acids was studied. A series of 1H,4H-3-(2-azahetaryl)pyrrolo[1,2-a] quinazoline-2,5-diones and 1-aryl-2-amino-3-(2-azahetaryl)-4-(5H)-oxopyrroles was obtained. The reaction of the latter with hydrazine and acetic anhydride was investigated. Taras Shevchenko Kiev University, Kiev 252033, Ukraine. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1412–1418, October, 1999.     

Kinetics and Quantum-Chemical Modelling of the Arylation of Aniline and Piperidine by N-Polynitroarylpyridinium Salts

N-Picryl-4-[4-(dimethylamino)styryl]pyridinium salt anions catalyze S _NAr reactions with aniline in acetonitrile. The anion activity increases with increasing basicity. A stepwise substitution mechanism involving the salt anions is confirmed by MNDOd and PM3 semiempirical calculations of the change in free energy of the individual reaction steps of N-polynitrophenylpyridinium chlorides with aniline and piperidine.     

peri-Naphthylenediamines: XL. Solvatochromism of 1-methyl-4-[2-(1-naphthyl)ethenyl]pyridinium salts, including that containing “proton sponge” residue

A number of 1-methyl-4-[2-(1-naphthyl)ethenyl]pyridinium salts were synthesized by condensation of 1,4-dimethylpyridinium iodide with naphthalene-1-carbaldehydes containing dimethylamino groups in positions 4 and 5. The obtained salts are characterized by negative solvatochromism which is the most pronounced for those possessing 1,8-bis(dimethylamino)naphthalene (“proton sponge”) and 1,2,2,3-tetramethyl-2,3-dihydroperimidine residues.     

Investigation of 2-[2-(4-Methoxy-phenylamino)-vinyl]-1,3,3-trimethyl-3H-indolium Chloride as a New Reagent for the Determination of Chromium(VI)

 The complex formation and extraction of chromium(VI) with 2-[2-(4-methoxy-phenylamino)-vinyl]-1,3,3-trimethyl-3H-indolium chloride reagent was studied by means of spectrophotometry. The influence of medium acidity, the concentration of chloride ions and dye reagent, the nature of the extractant and some other factors (time of extraction, stability of color, interference, etc.) on the absorbance of colored extracts were studied. The optimum conditions were found to be 0.02–0.1 M H₂SO₄, 1.0–1.5 M NaCl, (2.0–2.5) × 10⁻⁴ M of reagent. The absorbance of the colored extracts obeys Beer’s Law in the range of 0.26–7.28 mg L⁻¹. The procedure of Cr(VI) extraction and spectrophotometric determination was examined. Author for correspondence. E-mail: andruch@kosice.upjs.sk Received November 19, 2002; accepted March 10, 2003 Published online June 13, 2003     

Synthesis and Electronic Transitions of the Dye Based on 1-{2-[4-(3-Hydroxy-2-oxo-2H-chromen-4-yl)phenyl]-2-oxoethyl}-4-methylpyridinium Bromide

Russian Journal of General Chemistry - 4-[4-(2-Bromoacetyl)phenyl]-3-hydroxy-2H-chromen-2-one reacted with pyridine and 4-methylpyridine to give the corresponding quaternary pyridinium salts. The...     

Aliphatic aldehydes in the synthesis of condensed 4-alkyl(cycloalkyl)-2-amino-3-cyano-4H-pyrans

Substituted 4-alkyl(cycloalkyl)-2-amino-3-cyano-4H-pyrans have been obtained from the reaction of aliphatic aldehydes with malononitrile and some other CH acids in the presence of N-methylmorpholine. T. G. Shevchenko Lugansk State Pedagogical University, Lugansk 348011, Ukraine. N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117813, Russia; Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, 1363–1366, October, 1999.     

Aromatization with dearylation on Hantzsch cyclocondensation of 4-(dimethylamino)benzaldehyde,cyclohexane-1,3-diones,and some 1,3-[N,C]dinucleophiles

The Hantzsch three-component cyclization of 4-(dimethylamino)benzaldehyde, cyclohexane-1,3-diones, and some 1,3-[N,C]-dinucleophiles (5-amino-3-methyl-1-phenylpyrazole, 3,5-dimethoxyaniline, and 4-amino-1,3-dimethylpyrimidine-2,6-dione) proceeds in boiling acetic acid with the splitting off N,N-dimethylaniline and the formation of polycondensed heterocyclic sytems with a γ-unsubstituted pyridine ring (pyrazolo[3,4-b]quinoline, acridine, and pyrimido[4,5-b]quinoline). Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 244-251, February, 2009.