Synthesis and reductive reactions of 2,3-dioxo-2,3-dihydrobenzo[<Emphasis Type="Italic">b</Emphasis>]furo[2,3-<Emphasis Type="Italic">f</Emphasis>]-, -[2,3-<Emphasis Type="Italic">g</Emphasis>]-, and -[3,2-<Emphasis Type="Italic">e</Emphasis>]indoles

The Sandmeyer reaction was used to prepare 2,3-dioxo-2,3-dihydrobenzo[b]furoindoles which could be reduced with diborane or with complex hydrides to give the corresponding unsubstituted as well as the 3-hydroxybenzo[b]furoindoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No 11, pp. 1683–1689, November, 2004.     

Synthesis and properties of <Emphasis Type="Italic">N</Emphasis>-[2,2-bis(2,4-dihydroxyaryl)ethyl]-<Emphasis Type="Italic">N</Emphasis>-methylamines and their hydrohalides

Condensation of one molecule of α-methylaminoacetaldehyde dimethyl acetal with two molecules of resorcinol or methylresorcinol in hydrohalogen acid solutions led to substituted N-(2,2-diarylethyl)-N-methylamine hydrohalides. Reactions of the corresponding amines with acetic anhydride, mono-and diisocyanates, and formaldehyde were studied. Conditions for formation of calixarene from resorcinol and α-methylaminoacetaldehyde dimethyl acetal were invented. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 319–324, February, 2007.     

Synthesis and properties of pyrimido[4,5-<Emphasis Type="Italic">a</Emphasis>]- and pyrido[4,3-<Emphasis Type="Italic">a</Emphasis>]carbazole derivatives

Methods for the synthesis of substituted pyrimido [4,5-a]- and pyrido[4,3-a]carbazoles were proposed. Condensation of 2-(dimethylaminomethylene)-6-methyl-2,3,4,9-tetrahydro-1H-carbazol-1-one with guanidine and thiourea afforded 2-amino-8-methyl-6,11-dihydro-5H-pyrimido[4,5-a]carbazole and 8-methyl-3,5,6,11-tetrahydro-2H-pyrimido[4,5-a]carbazole-2-thione, respectively. The reaction of cyano(6-methyl-2,3,4,9-tetrahydro-1H-carbazol-1-ylidene)acetamide with dimethylformamide dimethyl acetal gave N-(dimethylamino-methylene)cyano(6-methyl-2,3,4,9-tetrahydro-1H-carbazol-1-ylidene)acetamide. Cyclization of the latter yielded 1-cyano-8-methyl-3,5,6,11-tetrahydro-2H-pyrido[4,3-a]carbazol-2-one.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2740–2744, December, 2004.     

Synthesis of 6-aryl-1,6-dihydrodipyrazolo[3,4-<Emphasis Type="Italic">b</Emphasis>:4,3-<Emphasis Type="Italic">c</Emphasis>]pyridines

6-Azido-1H-pyrazolo[3,4-b]pyridino-5-carbaldehydes react with aromatic amines to give the corresponding N-arylimines which cyclize on heating in boiling toluene to give 6-aryl-1,6-dihydrodipyrazolo[3,4-b:4,3-e]pyridines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, 1717–1722, November, 2004.     

Alternative Routes to the Pyrazolo[4,3-<Emphasis Type="Italic">e</Emphasis>][1,2,4]triazolo-[1,5-<Emphasis Type="Italic">c</Emphasis>]pyrimidine System

Formimidic acid esters derived from 1-substituted 5-aminopyrazole-4-carbonitriles reacted with carboxylic acid hydrazides on heating to give 2,7-disubstituted pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine derivatives as a result of double heterocyclization. The same compounds were obtained by thermal recyclization of 1-aroyl-2-(1-R-pyrazolo[3,4-d]pyrimidin-4-yl)hydrazines.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 6, 2005, pp. 934–938.Original Russian Text Copyright © 2005 by Tyurin, Vorob’ev, Minyaeva, Krasnikov, Mezheritskii.     

Reductive Acylamination of Pyridine <Emphasis Type="Italic">N</Emphasis>-Oxide with Aminopyridines and Their <Emphasis Type="Italic">N</Emphasis>-<Emphasis Type="Italic">p</Emphasis>-Tolylsulfonyl Derivatives

Pyridine N-oxide reacts with 2- and 3-aminopyridines and their N-p-tolylsulfonyl derivatives in alkaline medium in the presence of p-toluenesulfonyl chloride to give N-p-tolylsulfonyl-2,2′- and 2,3′-dipyridylamines, respectively, as a result of reductive acylamination. In the reactions with 4-aminopyridine and 4-p-tolylsulfonyl-aminopyridine, their N-p-tolylsulfonyl- and N,N-bis(p-tolylsulfonyl) derivatives are formed, while reductive acylamination does not occur.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 128–130.Original Russian Text Copyright © 2005 by Solekhova, Kurbatov.     

Competitive complexation in the copper(II) chloride-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylformamide-Aerosil system

Competitive complexation in the copper(II) chloride-N,N-dimethylformamide (DMF)-Aerosil system was studied by IR spectroscopy. It was found that adsorption from organic solutions containing copper(II) chloride and DMF resulted in the formation of the following three types of DMF complexes: self-associates of DMF, DMF complexes with surface hydroxyl groups, and DMF complexes with Cu(II) ions. The removal of DMF resulted in the sequential degradation of, initially, self-associates; next, complexes with silanol groups; and, finally, complexes with copper ions.Translated from Kinetika i Kataliz, Vol. 45, No. 6, 2004, pp. 917–920.Original Russian Text Copyright © 2004 by Golubeva, Zubareva.     

Structure and photochromism of 2-(<Emphasis Type="Italic">N</Emphasis>-acyl-<Emphasis Type="Italic">N</Emphasis>-arylaminomethylene)benzo[<Emphasis Type="Italic">b</Emphasis>]thiophen-3(2<Emphasis Type="Italic">H</Emphasis>)-ones

It was shown by electron absorption spectroscopy and X-ray diffraction analysis that steric strains in photochromic 2-(N-acyl-N-arylaminomethylene) benzo[b]thiophen-3(2H)-one molecules ortho-substituted in the N-phenyl ring increase the quantum yield of the N→O photoinduced rearrangement in accord with an increase in the steric constant of the ortho-substituent.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2151–2155, October, 2004.     

Structure-Property Relationship in Bispyrrolizidine Photochromic Compounds Derived from Indolo[4,5-<Emphasis Type="Italic">e</Emphasis>]- and -[7,6-<Emphasis Type="Italic">g</Emphasis>]indoles

The spirocyclic compounds bis[2′,3′-bis(methoxycarbonyl)-5′,6′,6′ -trimethylspirofluoren-9,4′-(1′-aza-2′-cyclopentene)][1′,5′ -a]indolino[4,5-e]indoline and bis[2-,3′-bis(methoxycarbonyl)-5′,6′,6′ -trimethylspiro-fluoren-9,4′-(1′-aza-2′-cyclopentene)][1′,5′ -a]indolino[7,6-g]indoline exhibit photochromic properties with various half-lifes. The AM1 method was used to correlate the structural and electronic properties, on the one hand, and photochromic properties, on the other, and to explain reasons for the difference in the photochromism of the two compounds.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 4, 2005, pp. 670–673.Original Russian Text Copyright © 2005 by Samsoniya, Trapaidze, Tsikoliya, Machaidze, Esakiya.     

Pyrano[4,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidinium salts

5-Aroyl-1,3,6-trimethyluracils were converted to pyrano[4,3-d]pyrimidinium salts. Reactions of the salts obtained with ammonia, primary amines, and hydrazine were studied. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2251–2257, November, 2007.     

UV/Vis Spectroscopic Properties of <Emphasis Type="Italic">N</Emphasis>-(2′-Hydroxy-4′-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethyl-aminobenzylidene)-4-nitroaniline in Various Solvents and Solid Environments

Summary.  N-(2′-Hydroxy-4′-N,N-dimethylaminobenzylidene)-4-nitroaniline [HDBN] has been used as a model for investigating intra- and intermolecular D–A (donor–acceptor) interactions in various environments by means of UV/Vis spectroscopy. UV/Vis spectra of HDBN have been measured in various solvents, ethanolic solutions of different pH, adsorbed on silica, and in the solid state. A bathochromic shift of ν_max is observed with increasing the dipolarity/polarizability and HBD (hydrogen bond donor) capacity of the solvent, which is described by means of a multiple LSE (linear solvation energy) relationship in terms of the empirical Kamlet-Taft solvent polarity parameters. The adsorption of HDBN on Aerosil^? 300-silica particles in non-HBA (hydrogen bond acceptor) solvents is explained in the same sense. Mobile protons and sol–gel entrapping cause a hypsochromic shift due to protonation of the lone electron pair of the 4′-N,N-dimethylamino group. Hydroxide ions attack the 2′-hydroxy group which causes a bathochromic shift. A strong intramolecular hydrogen bond between the 2′-hydroxyl hydrogen and the imine nitrogen atom is present in the solid-state structure causing an unprecedented bathochromic shift. Corresponding author. E-mail: stefan.spange@chemie.tu-chemnitz.de Received July 8, 2002; accepted (revised) September 30, 2002     

Adsorption-luminescence determination of copper concentration using silica gel chemically modified with <Emphasis Type="Italic">N</Emphasis>-(1,3,4-thiadiazol-2-thiol)-<Emphasis Type="Italic">N</Emphasis>′-propylurea groups

Silica gel chemically modified with 1,3,4-thiadiazol-2-thiol groups recovered 99% of the copper(II) from solutions of pH 4–6; the adsorption equilibrium was attained in no more than 5 minutes. During irradiation with ultraviolet light, a yellow-orange luminescence (λ_max = 575 nm) of surface copper complexes appeared in the phase of adsorbent cooled to 77 K; it was used as an analytical signal in the procedure for the low-temperature adsorption-luminescence determination of copper concentration. The detection limit was 0.3 μ g/0.1 g adsorbent. The calibration graph was linear up to 50 μg/0.1 g adsorbent. The determination of copper concentration is not affected by 10000-fold amounts of Zn(II), Cd(II), Mn(II), Co(II), Ca(II), Mg(II), and Al(III) and 300-fold amounts of Fe(III). The procedure was used to determine copper concentration in natural and technogenic waters.     

X-ray structures of iron(III) and cobalt(III) complexes containing 2-<Emphasis Type="Italic">S</Emphasis>-methyl-6-methyl-4-formylpyrimidine-<Emphasis Type="Italic">N</Emphasis>(4)-ethylthiosemicarbazone

Iron(III) and cobalt(III) complexes of types [Fe(LEt)₂]ClO₄·3/2C₆H₆ (1) and [Co(LEt)₂]ClO₄·2CH₂Cl₂ (2) with a new pyrimidine-derived thiosemicarbazone ligand, 2-S-methyl-6-methyl-4-formylpyrimidine-N(4)-ethylt-hiosemicarbazone (HLEt), having N, N, S donor centers have been synthesized and characterized by X-ray crystallography. The structural study shows distorted octahedral geometry for both 1 and 2 with MN₄S₂ chromophores. The space group of 1 is C2/c (monoclinic) and that of 2 is P2₁2₁2₁ (orthorhombic). The electrochemical electron transfer study in MeCN solutions shows a one-electron reductive response presumably due to a metal(III)–metal(II) couple.