On the nitration of 2-pyrone

A 1:1 adducl of 2-pyrone and nitronium fluoroborate has been delected by nmr and is a possible precursor of 5-nitro-2-pyrone, a subsequently formed product. From comparison of the nmr spectra of the 1:1 adduct and 2-methoxypyrylium fluoroborate, the adduct is believed to be the pyrylium fluoroborate derived from nitration of the carbonyl oxygen of 2-pyrone.     

Thermal behaviour and spectroscopic investigation of some methyl 2-pyridyl ketone complexes

Pyridine derivative complexes are widely employed as biological active materials especially as antibacterial agents. Five transition metal(II) mpk complexes (mpk = methyl 2-pyridyl ketone) were synthesized and investigated using elemental analysis, spectroscopic techniques (IR and UV–Vis–NIR) and conductometric measurements. The general formulae established from experimental data were found to be [M(mpk)₂(NO₃)₂]·xH₂O (x = 0 for M = Cd(II), Zn(II), x = 2 for M = Cu(II)) and [M(mpk)₂(H₂O)₂](NO₃)₂ (M = Co(II), Ni(II)). These compositions were further confirmed by thermal analysis and their thermal stability in dynamic air atmosphere investigated.     

Rheological and spectroscopic behaviour of cosmetic products

Summary A promising approach for evaluating the rheological and spectroscopic behaviour of cosmetic products is described. The method involves an automatic viscometric test by flow curves detection and subsequent spectroscopic analysis without pretreatment steps of the cosmetic sample under investigation. Determination of sulphur content at 0.5 ppm using the ICP (Inductively Coupled Plasma) technique in a low UV region is reported as an example.

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Rheologisches und spektroskopisches Verhalten von kosmetischen ProduktenAnwendung zur Schwefelanalyse durch ICP

Zusammenfassung Eine aussichtsreiche Methode zur Auswertung des rheologischen und spektroskopischen Verhaltens von kosmetischen Produkten wird beschrieben. Das Verfahren beinhaltet einen automatischen viskosimetrischen Test durch Fließkurven und nachfolgende spektroskopische Analyse ohne Vorbehandlung der Probe. Als Beispiel wird die Schwefelbestimmung bei 0,5 ppm mit Hilfe der ICP-Methode im unteren UV-Bereich beschrieben.

     

Orientation in the nitration of 2-pyridones

The ratio of 3- and 5-nitro isomers formed in the nitration of 2-pyridones with nitric acid is determined by the reaction temperature but is independent of the concentration of the nitrating agent. The presence of a phenyl group in the 6 position of the -pyridone ring hinders incorporation of a nitro group in the 5 position.Translated from Khimiya Geterotsikicheskikh Soedinenii, No. 1, pp. 72–75, January, 1978.     

Synthesis of nitro- and aminoindoles

Optimal conditions are proposed for the direct nitration of 2,3-dimethylindoles containing methyl and methoxy groups in the benzene ring. In contrast to 5- and 6-methylindoles and 5- and 6-methoxyindoles, nitration of 7-methyl-and 7-methoxy-2,3-dimethylindoles proceeds differently under the same conditions. A series of previously unreported aminoindoles was obtained by reduction of the nitroindoles.Mordova State Pedagogical Institute, 430007 Saransk, Russia; e-mail:mgpi@si.moris.ru and M. V. Lomonosov State University, 119899 Moscow, Russia, e-mail:yumar@org.chem.msu.su. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1630–1636, December, 1999.     

Synthesis of nitro- and aminoalkylphosphonates

Conclusions Some new O, O-dialkyl nitroalkylphosphonates were synthesized by the addition of dialkyl phosphites and thiophosphites to nitroolefins. The corresponding aminophosphonates were obtained from them by reduction. The hydrolysis of the latter gave the corresponding aminoalkylphosphonic acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1164–1168, May, 1972.     

Thermal behaviour and spectroscopic studies of complexes of some divalent transitional metals with 2-benzoil-pyridil-izonicotinoylhydrazone

New complexes of 2-benzoyl-pyridil-isonicotinoylhydrazone (L) with Cu(II), Co(II), Ni(II) and Mn(II), having formula of type [ML₂] SO₄·xH₂O (M = Cu²⁺, Co²⁺, Ni²⁺, x = 2 and M = Mn²⁺, x = 3), have been synthesised and characterised. All complexes were characterised on the basis of elemental analyses, IR spectroscopy, UV–VIS–NIR, EPR, as well as thermal analysis and determination of molar conductivity and magnetic moments. The thermal behaviour of complexes was studied using thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). The structure of L hydrazone was established by X-ray study on single crystal. The ligand works as tridentate NNO, being coordinated through the azomethine nitrogen, the pyridine nitrogen and carbonylic oxygen. Heats of decomposition, ΔH, associated with the exothermal effects were also determined.     

The structure and ir spectroscopic behaviour of phthalazine hemiperchlorate

X-ray diffraction studies reveal that in phthalazine hemiperchlorate there are short, asymmetric [NH·N]^?1, slightly bent hydrogen bonds, the N·N distance being 2.656(16) Å. The anomalous temperature effect in the far infrared absorption is also observed in this case. Numerous Evans holes can be assigned to skeletal distortion modes.     

Directive nature of the nitration of the oximes of 2-acetylthiophene and 2-propionylthiophene

A method of obtaining pure 2-acetyl- and 2-propionyl-5-nitrothiophenes by nitrating the oximes of the corresponding ketones with the subsequent isolation from the mixtures formed of the pure oximes of the 2-acyl-5-nitrothiophenes and their saponification has been developed. The pure 2-acetyl- and 2-propionyl-4-nitrothiophenes have been isolated by crystallization from the products of the nitration of the corresponding ketones, which form in each case a mixture of the corresponding 2-acyl-4-nitro- and 2-acyl-5-nitrothiophenes containing about 90% of the 4-nitro isomer.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1483–1486, November, 1973.     

Acetylenic derivatives of nitro- and aminonaphthalenes

Conclusions We synthesized a number of acetylenic and diacetylenic alcohols, which are derivatives of nitro- and aminonaphthalenes by the condensation of substituted halonaphthalenes with acetylenic alcohols.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 407–409, February, 1984.     

On the redox behaviour of glycerol at TiO2 electrodes

An experimental work is presented in which alkaline solutions of glycerol are electrochemically treated at TiO₂ electrodes obtained by electrochemical oxidation of Ti foils annealed a 400 °C and 600 °C. The semiconductor properties of the material, strictly correlated to the presence of structural defects, and their different concentration and distribution originated by the different annealing temperature are investigated. In order to derive useful indications for possible application on reduction or photo-oxidation of glycerol, particular attention is paid on the working mechanism of the electrodes in a wide range of potential at which the semiconductor may be under accumulation or depletion regime.     

Coordination behaviour of nicotinamide: an infrared spectroscopic study

A series of Hofmann-type complexes containing two nicotinamide(nia) molecules attached to transition metal (II) (M) tetracyanonickelate frame with the formula: M(nia)₂Ni(CN)₄ (where M=Mn, Co, Ni, Cu or Cd) have been synthesised for the first time. Metal (II) halide complexes of nicotinamide complexes of the type [M(nia)₂X₂ (M=Cd, Ni, Cu, Hg; X=Cl, Br) and Ni(nia)₄Br₂ nia=nicotinamide] have also synthesised. The FTIR spectra are reported in the 4000-400 cm⁻¹ region. Vibrational assignments are given for all the observed bands. The analysis of the vibrational spectra indicates that there are some structure-spectra correlations. A pronounced change was observed in the N-H stretching frequencies of the NH₂ group. It is proposed that the amide NH₂ group influence by the intramolecular hydrogen bond in the complexes. The coordination effect on the nicotinamide modes is analysed.