Reactions of <Emphasis Type="Italic">N</Emphasis>-alkyl- and <Emphasis Type="Italic">N</Emphasis>-aryltrihalogenoacetamides with phosphorus pentachloride

In the study of reactions of N-alkyl- and N-aryltrihalogenoacetamides with PCl₅, it was demonstrated for the first time that 3-alkyl(aryl)-2,2,2,4 tetrachloro-4-trihalomethyl-1,3,2-λ⁵-oxazaphosphetanes are intermediates in the synthesis of trihaloacetimidoyl chlorides. According to quantum-chemical calculations, acyclic N-tetrachlorophosphoranes, which are the primary products in the reactions of trihaloacetamides with PCl⁵, undergo rapid cyclization into the corresponding phosphorates and subsequent 1,3-chlorotropic migration gives rise to oxazaphosphetanes with the five-coordinate P atom.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 739-744, March, 2005.     

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.     

Facile synthesis and biological evaluation of novel fluorine-containing <Emphasis Type="Italic">N</Emphasis>-nitro-<Emphasis Type="Italic">N</Emphasis>′-substituted phenylurea

Twenty-two novel N-nitro-N′-substituted phenyl-N-(2,6-dibromo-4-fluorophenyl)urea derivatives were designed and synthesized via a simple and convenient BTC ‘one-pot’ procedure using DMAP as the catalyst. The structures of all newly synthesized compounds were confirmed by IR, ¹H NMR, and elemental analysis, and a part has been identified by ¹³C NMR. The preliminary bioassay indicates that the target compounds possesses moderate herbicidal activity against Sorghum sudanense. However, some of the title compounds presented high plant growth regulating activity against rape.     

Substitution effects in <Emphasis Type="Italic">N</Emphasis>-pyrazole and <Emphasis Type="Italic">N</Emphasis>-imidazole derivatives along the periodic table

A theoretical study of the monosubstitution effects of all the atoms of the second and third row of the periodic table on the pyrazole and imidazole rings has been carried out by means of B3LYP/6-31+G(d,p) DFT calculations. The geometric and electronic properties, calculated using the atoms in molecules methodology, electrostatic potential, and frontier orbitals have been analyzed. Some of the results have been rationalized based on the electronegativity of the substituents. In addition, the different parameters obtained have been compared with aromaticity indexes (HOMA and NICS). A comparison with the results obtained for the corresponding N-pyrrole derivatives has been carried out.     

<Emphasis Type="Italic">N</Emphasis>-arylsulfinyl-1,4-benzoquinonimines

Stable N-arylsulfinyl-1,4-benzoquinonimines were synthesized by acylation of the corresponding 1,4-benzoquinone monooximes with arenesulfenyl chlorides. The process involves transformation of sulfur(II) into sulfur(IV).Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1340–1343.Original Russian Text Copyright © 2004 by Avdeenko, Pirozhenko, Stanovskii, Konovalova, Yusina.This study was performed under financial support by the ES INTAS program (grant no. 00 157–1999) and by the Ministry of Education and Science of Ukraine.     

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.     

Synthesis of new <Emphasis Type="Italic">N</Emphasis>-aminoglycosides based on halo-substituted <Emphasis Type="Italic">p</Emphasis>-phenylenediamines and <Emphasis Type="Italic">p</Emphasis>-aminophenols

Condensation of the monosaccharides D-glucose and D-galactose with synthesized halo-substituted p-phenylenediamines and 4-amino-2,6-dibromophenol was studied. It was found that glycosylation occurred only at the 4-amino group that was sterically unhindered by the halogen atom. The position of the aglycon in the glycoside was established by PMR spectroscopy.     

Syntheses proceeding from <Emphasis Type="Italic">N</Emphasis>-(oxiran-2-ylmethyl)-<Emphasis Type="Italic">N</Emphasis>-ethylaniline

The preparation of N-(oxiran-2-ylmethyl)-N-ethylaniline was developed. The compound was used in the synthesis of new N-derivatives of aromatic amines containing vicinal aminoalcohol moieties.     

Kinetic characterisation of arylamine <Emphasis Type="Italic">N</Emphasis>-acetyltransferase from <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis>

Background  

Arylamine N-acetyltransferases (NATs) are important drug- and carcinogen-metabolising enzymes that catalyse the transfer of an acetyl group from a donor, such as acetyl coenzyme A, to an aromatic or heterocyclic amine, hydrazine, hydrazide or N-hydroxylamine acceptor substrate. NATs are found in eukaryotes and prokaryotes, and they may also have an endogenous function in addition to drug metabolism. For example, NAT from Mycobacterium tuberculosis has been proposed to have a role in cell wall lipid biosynthesis, and is therefore of interest as a potential drug target. To date there have been no studies investigating the kinetic mechanism of a bacterial NAT enzyme.     

Formation of pyrrolinium derivatives in the bromination reaction of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dipropargyl ammonium salts

Bromination of ammonium salts containing two propargyl groups afforded bromine-substituted derivatives of pyrrolinium salts. The reactions of piperidinium and morpholinium analogs resulted in spirocyclic ammonium salts.     

Electrochemical polymerization of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-bis(3-methoxysalicylidene)-1,3-propylenediamine

The electrochemical oxidation of N,N′-bis(3-methoxysalicylidene)-1,3-propylenediamine leads to the formation of conducting polymer on the electrode surface. The decisive role of phenol oxygen in the formation of the polymeric forms of azomethine bases was elucidated. Optimal conditions for the synthesis of the polymer in the potentiostatic conditions were revealed. The coefficient of the charge diffusion and the activation barrier for the charge transfer in the polymer bulk in the electrolyte medium were determined.     

Thermodynamic characteristics of protolytic equilibria of ethylenediamine-<Emphasis Type="Italic">N,N</Emphasis>′-diacetic-<Emphasis Type="Italic">N,N</Emphasis>′-dipropionic acid

Heat effects of protonation and neutralization of ethylenediamine-N,N′-diacetic-N,N′-dipropionic acid at 298.15 K and ion force values of 0.1, 0.5, and 1.0 (KNO₃) were measured by the direct calorimetric method. Combined use of the results of thermochemical and potentiometric measurements carried out under the identical experimental conditions permitted to evaluate standard thermodynamic characteristics of the equilibria under study. The results obtained were compared with the corresponding data for related compounds considering the specific features of structure of the diamine complexones.     

3,3,3-Trifluoro-<Emphasis Type="Italic">N</Emphasis>′-(3-trifluoromethylphenyl)-1,2-propanediamine and its <Emphasis Type="Italic">N</Emphasis>-mono-and <Emphasis Type="Italic">N,N</Emphasis>-dicarboxyethyl derivatives: synthesis,protolytic and complexation properties

3,3,3-Trifluoro-N′-(3-trifluoromethylphenyl)-1,2-propanediamine (5) was synthesized by the reaction of 2-diazo-1,1,1-trifluoro-3-nitropropane or 3,3,3-trifluoro-1-nitropropene with 3-aminobenzotrifluoride followed by the reduction of the nitro group. The Michael 1,4-addition of diamine 5 to acrylic acid occurs only at the N(1) atom and affords N-mono-or N,N-dicarboxyethyl derivatives 6 and 7, depending on the reactant ratio. Protolytic equilibria 5–7 in aqueous solutions were studied by pH-potentiometry and UV spectroscopy. Only the aliphatic amino group can be protonated in an aqueous solution, while the aromatic amino group remains unprotonated even in 12 M HCl. The stability constants of transition metal (Cu²⁺, Ni²⁺, Zn²⁺) complexes with ligands 5–7 were determined by pH-potentiometric titration. The stability of the complexes and selectivity of the ligands toward Cu²⁺ ions increase with an increase in the number of N-carboxyethyl groups. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2465–2469, November, 2005.