Regioselective Reaction of <Emphasis Type="Italic">N</Emphasis><Superscript>1</Superscript>-Benzyl-<Emphasis Type="Italic">N</Emphasis><Superscript>2</Superscript>-(4-nitrophenyl)ethanediamide and Acetylenic Esters

Summary. The regioselective reaction of N¹-benzyl-N²-(4-nitrophenyl)ethanediamide with dialkyl acetylenedicarboxylates or alkyl propiolates in the presence of triphenylphosphine leads to dialkyl 4-benzylamino-1-(4-nitrophenyl)-5-oxo-2,5-dihydro-1H-pyrrole-2,3-dicarboxylates or alkyl 4-benzylamino-1-(4-nitrophenyl)-2-oxo-5-pyrrolidinecarboxylates in good yields.     

Nitro derivatives of <Emphasis Type="Italic">N</Emphasis>-alkylbenzoaza-15-crown-5: synthesis,structures, and complexation with metal and ammonium cations

A number of N-alkylnitrobenzoaza-15-crown-5 with the macrocycle N atom conjugated with the benzene ring were obtained. The structural and complexing properties of these compounds were compared with those of model nitrobenzo- and N-(4-nitrophenyl)aza-15-crown-5 using X-ray diffraction, ¹H NMR spectroscopy, and DFT calculations. The macrocyclic N atom of benzoazacrown ethers are characterized by a considerable contribution of the sp3-hybridized state and a pronounced pyramidal geometry; the crownlike conformation of the macrocycle is preorganized for cation binding, which facilitates complexation. The stability constants of the complexes of crown ethers with the NH₄ ⁺, EtNH₃ ⁺, Na⁺, K⁺, Ca²⁺, and Ba²⁺ ions were determined by 1H NMR titration in MeCN-d₃. The most stable complexes were obtained with alkaline-earth metal cations, which is due to the higher charge density at these cations. The characteristics of the complexing ability of N-alkylnitrobenzoaza-15-crown-5 toward alkaline earth metal cations are comparable with analogous characteristics of nitrobenzo-15-crown-5 and are much better than those of N-(4-nitrophenyl)aza-15-crown-5.     

Electroreduction mechanism of <Emphasis Type="Italic">N</Emphasis>-phenylhydroxylamines in aprotic solvents: formation of hydrogen bonds between <Emphasis Type="Italic">N</Emphasis>-(3-nitrophenyl)hydroxylamine and its radical anion

The electroreduction of N-(3-nitrophenyl)hydroxylamine in DMF was studied using cyclic voltammetry, chronoamperometry, and numerical simulation. It is shown that the stability of formed radical anion is significantly higher than that of the radical anion of the 4-nitrophenyl derivative. In the range of low concentrations and high potential scan rates, the electroreduction of N-(3-nitrophenyl)hydroxylamine is complicated only by the formation of complexes between the depolarizer molecules, most likely, due to hydrogen bonds, as well as between the depolarizer and its radical anion. The thermodynamic and kinetic parameters of these processes were evaluated.     

C-amidoalkylation of pyrroles with <Emphasis Type="Italic">N</Emphasis>-trifluoromethylsulfonyl and <Emphasis Type="Italic">N</Emphasis>-arylsulfonyl polychloroaldehyde imines

N-(Trifluoromethylsulfonyl) and N-arylsulfonyl polychloroacetaldehyde imines reacted with pyrrole, 1-alkyl-, 1-benzyl-, and 1-(4-nitrophenyl)-substituted pyrroles, and bis-pyrroles to give the corresponding 2-[1-(sulfonylamino)polychloroethyl]-1H-pyrroles or mixtures of 2- and 3-[1-(sulfonylamino)polychloroethyl]-1H-pyrroles, depending on the nature of the Schiff base and substituent on the pyrrole nitrogen atom and reaction conditions. The first synthesis of 2,5-disubstituted NH-pyrrole by reaction of pyrrole with Schiff bases was described.     

Synthesis,structure, and transformations of <Emphasis Type="Italic">N</Emphasis>-(alkyl-, benzyl-, arylsulfonyl)-<Emphasis Type="Italic">N</Emphasis>-(oxiran-2-ylmethyl)bicyclo[2.2.1]hept-5-en-<Emphasis Type="Italic">exo</Emphasis>-2-ylmethanamines

Reactions of N-(alkyl-, benzyl-, arylsulfonyl)bicyclo[2.2.1]hept-5-en-exo-2-ylmethanamines with 2-(chloromethyl)oxirane in the presence of tetramethylammonium iodide gave a number of cage-like N-(oxiran-2-ylmethyl)sulfonamides, as well as N-(exo-5,6-epoxybicyclo[2.2.1]heptan-exo-2-ylmethyl)-4-nitro-N-(oxiran-2-ylmethyl)benzenesulfonamide. The latter was also synthesized by oxidation of oxiran-2-ylmethyl norbornene derivative with peroxy acids. Opening of the epoxide ring in N-(oxiran-2-ylmethyl) sulfonamides in reaction with benzylamine followed the Krasuskii rule, and the aminolysis of N-(exo-5,6-epoxybicyclo[2.2.1]-heptan-exo-2-ylmethyl)-4-nitro-N-(oxiran-2-ylmethyl)benzenesulfonamide chemoselectively occurred at the side-chain epoxy group.     

<Emphasis Type="Italic">bis</Emphasis>(<Emphasis Type="Italic">N,N</Emphasis>-diethylnicotinamide) <Emphasis Type="Italic">p</Emphasis>-chlorobenzoate complexes of Ni(II), Zn(II) and Cd(II)

Three novel mixed ligand complexes of Ni(II), Zn(II) and Cd(II) with p-chlorobenzote and N,N-diethylnicotinamide were synthesised and characterized on the basis of elemental analysis, FTIR spectroscopic analysis, solid state UV-Vis spectrometric and magnetic susceptibility data. The thermal behavior of the complexes was studied by simultaneous TG-DTA methods in static air atmosphere and the mass spectra data were recorded. According to microanalytical results, formulas of complexes are C₃₄H₄₀N₄O₈ClNi, C₃₄H₄₀N₄O₈ClZn and C₃₄H₄₄N₄O₁₀ClCd. The complexes contain two moles of coordination waters, two moles p-chlorobenzoate and two mole N,N-diethylnicotinamide (dena) ligands per formula unit. In these complexes, the p-chlorobenzoate and N,N-diethylnicotinamide behave as monodentate ligand through acidic oxygen and nitrogen of pyridine ring. The decomposition pathways and the stability of the complexes are interpreted in the terms of the structural data. The final decomposition products were found to be as metal oxides.     

Reduction of <Emphasis Type="Italic">N</Emphasis>-(polychloroethylidene)- and <Emphasis Type="Italic">N</Emphasis>-(1-hydroxypolychloroethyl) arenesulfonamides with adamantane in the presence of superacids

N-(2,2,2-Trichloroethylidene)-, N-(2,2-dichloro-2-phenylethylidene)-, and N-(1-hydroxy-2-polychloroethyl) arenesulfonamides reacted with adamantane in carbon tetrachloride in the presence of oleum or concd. H₂SO₄-P₄O₁₀ mixture to give the corresponding N-(2-polychloroethyl)arenesulfonamides as a result of reduc-tion of the azomethine and OH group, respectively.     

Synthesis,structure, and properties of <Emphasis Type="Italic">N</Emphasis>-(nitramino)phthalimide

N-(Nitramino)phthalimide R₂N-NHNO₂ (R₂NH is phthalimide) was synthesized by nitration of N-aminophthalimide with nitronium tetrafluoroborate. The structure of this compound was established by X-ray diffraction and confirmed by ¹H, ¹³C, and ¹⁴N NMR spectroscopy. The methylation of this compound with diazomethane affords a mixture of N-methyl (R₂N-NMeNO₂) and O-methyl (R₂N-N=N(O)OMe) isomers. The latter compound contains the previously unknown high-nitrogen-oxygen fragment. The thermal decomposition of N-(nitramino)phthalimide in vacuo at 80–100 °C gives 2H-3,1-benzoxazine-2,4(1H)-dione (isatoic anhydride) as the major product. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 625–630, March, 2008.     

New lignans from <Emphasis Type="Italic">Syringa reticulata</Emphasis> var. <Emphasis Type="Italic">mandshurica</Emphasis>

In the search for platelet-activating-factor (PAF) antagonists, two new lignan compounds were isolated from the leaves of Syringa reticulata Hara var. mandshurica. Their structures were elucidated as (7R,8S, 8'S)-3,4,3',4'-dimethylenedioxy-8,9-dihydroxy-8.8', 7-O-9'-lignan (mandshuricol A) and (7R,8S,8'S)-3',4'methylenedioxy-4-methoxy-3,8,9-trihydroxy-8.8', 7-O-9'-lignan (mandshuricol B), Mandshuricol A and B showed antagonistic activity on PAF in the [³H] PAF receptor binding assay with IC₅₀ values of 4.8 × 10^–5 M and 3.5 × 10^–5 M, respectively.     

Synthesis of <Emphasis Type="Italic">N,N</Emphasis>-disubstituted (<Emphasis Type="Italic">Z</Emphasis>)-<Emphasis Type="Italic">O</Emphasis>-methylnicotinamide oximes

A number of (Z)-N,N-dialkyl- and (Z)-N-acyl-N-alkyl-O-methylnicotinamide oximes was synthesized. Their configuration was confirmed by the NOESY experiment. Evaluation of fungicidal activity of compounds obtained was performed.     

Prediction of electron-ionization mass spectra of <Emphasis Type="Italic">O</Emphasis>-Alkyl-<Emphasis Type="Italic">N,N</Emphasis>-dialkylphosphoramido cyanidates

A method is proposed for the prediction of electron-ionization mass spectra of highly toxic O-alkyl-N,N-dialkylphosphoramido cyanidates. The approach is based on the fact that the compounds can be divided into three groups by the type of fragmentation. The main group (O-alkyl, O-methyl, O-ethyl) containing almost all compounds of this class (61440 of 61460), in its turn, can be divided into ten subgroups characterized by different combinations of two N-alkyl radicals. Each subgroup possesses its specific generalized spectral image, i.e., a set of peaks characterized by mass numbers and relative intensities. A spectrum of an individual O-alkyl-N,N-dialkylphosphoramido cyanidate is considered as a sum of the generalized spectral image of a corresponding subgroup and a spectrum of an alkene with a carbon chain identical to the O-alkyl group of the molecule.     

<Emphasis Type="Italic">N</Emphasis>-allyl and <Emphasis Type="Italic">N</Emphasis>-propargyl trifluoromethanesulfonimides. Theoretical analysis

Tautomers of N-allyl- and N-propargyl-substituted trifluoromethanesulfonimides (CF₃SO₂)₂NR (R = CH₂CH=CH₂, Z/E-CH=CHMe, CH₂C≡CH, CH=CH=CH₂, C≡CCH₂) were calculated by the DFT (B3LYP, wB97XD, PBE1PBE), MP2, and CBS-QB3 methods. The results were compared with the theoretical data for the corresponding amines and amides NHRR¹ (R¹ = H, CF₃SO₂). It was shown that there is no conjugation between the nitrogen atom and C=C bond and that conjugation exists with the C≡C bond with electron density displacement toward the nitrogen atom. The calculations of anions derived from N-allyl- and N-propargyl-trifluoromethanesulfonimides revealed the possibility of their rearrangement with elimination of trifluoromethanesulfinate anion and formation of its H-complex with N-(prop-2-en-1-ylidene)trifluoromethanesulfonamide or N-(prop-2-yn-1-ylidene)trifluoromethanesulfonamide.     

Oxidation of 4-nitro-<Emphasis Type="Italic">o</Emphasis>-xylene with nitric acid using <Emphasis Type="Italic">N</Emphasis>-hydroxyphthalimide under phase transfer conditions

4-Nitro-o-xylene was selectively oxidized to 2-methyl-4-nitrobenzoic acid using dilute nitric acid as the oxidizing agent under atmospheric pressure. The oxidation of 4-nitro-o-xylene was effectively promoted by an addition of radical initiators. Under reflux, 2-methyl-4-nitrobenzoic acid was afforded in high yield using nitric acid combined with N-hydroxyphthalimide, cobalt dichloride (CoCl₂ · 6H₂O), manganese acetate (Mn(OAc)₂ · 4H₂O) and phase transfer catalyst.     

Gas-chromatographic determination of trace <Emphasis Type="Italic">O</Emphasis>-isobutyl-2-<Emphasis Type="Italic">S</Emphasis>-(<Emphasis Type="Italic">N,N</Emphasis>-diethylamino)ethyl ester of methylthiophosphonic acid (VX-type compounds) in slime

A procedure was proposed for the gas-chromatographic determination of trace O-isobutyl-S-2-(N,N-diethylamino)ethyl ester of methylthiophosphonic acid (mixed ester, ME) in burning products formed after the detoxication of elements in building constructions, personal protection equipment, waste degassing solutions, and other production wastes (slime) at a level of (1.0–10.0) × 10^?8 mg/g. The procedure is based on the extraction of ME from an analyzed material with a mixture of aqueous solutions of monoethanolamine and NaOH, its back extraction to hexane, the evaporation of the hexane layer (with the addition of HCl) to dryness, the transformation of ME into methyl ester of O-isobutylmethylphosphonic acid with the use of methanol in the presence of AgNO₃, and the chromatography of the derivative on an open tubular column with the chemically modified HP-INN OWax stationary phase with the use of a flame-photometric detector.     

Synthesis and structure of <Emphasis Type="Italic">N</Emphasis>-(diaminomethylidene)- and <Emphasis Type="Italic">N</Emphasis>-[bis(cyclohexylamino)methylidene]trifluoromethanesulfonamides

N-Trifluoromethylsulfonyl-substituted guanidines CF₃SO₂N=C(NHR)₂ (R = H, cyclohexyl) were synthesized in nearly quantitative yield by reactions of N-sulfinyltrifluoromethanesulfonamide CF₃SO₂N=S=O with urea and of trifluoromethanesulfonamide with N,N′-dicyclohexylcarbodiimide. N-[Bis(cyclohexylamino)-methylidene]trifluoromethanesulfonamide was subjected to protonation with trifluoromethanesulfonic acid and bis(trifluoromethanesulfonyl)imide, and the structure of the resulting salts and initial N-trifluoromethylsulfonylguanidines was studied by NMR and IR spectroscopy and DFT quantum-chemical calculations.     

Synthesis of the <Emphasis Type="Italic">O</Emphasis>-(2-chloropyridin-5-ylmethyl)oxime of 20-hydroxyecdysone

The new ecdysteroid derivative 20-hydroxyecdysone O-(2-chloropyridin-5-ylmethyl)oxime (3) was synthesized via the reaction of 20-hydroxyecdysone (1) and O-(2-chloropyridin-5-ylmethyl)hydroxylamine (2) in Py in the presence of SnCl₄.     

Interaction of Fluosilicic Acid with <Emphasis Type="Italic">N-tert</Emphasis>-Butyl-Substituted Urea. Crystal Structure of <Emphasis Type="Italic">N,N</Emphasis>-Di-<Emphasis Type="Italic">tert</Emphasis>-butylurea

Fluosilicic acid reacts with solutions of N,N-di-tert-butylurea (DTBU) in methanol or acetone to form crystalline compounds 2DTBU ? H₂SiF₆ and 2DTBU ? H₂SiF₆ ? Me₂CO, which were characterized by the IR and ¹⁹F NMR spectra and mass spectroscopy supplemented by theoretical calculations. According to the data of IR and ¹⁹F NMR spectra, the complexes are hexafluorosilicates of O-protonated DTBU. They undergo hydrolysis in organic media with water traces; their solubility in water is very low (0.10 and 0.14 wt %, respectively). In the DTBU structure, two independent ligand molecules are joined by hydrogen bonds NH?O(N?O) 2.888(5)–2.944(5) Å).     

Mononuclear cobalt (III) complexes with <Emphasis Type="Italic">N</Emphasis>-salicylidene-2-hydroxy-5-bromobenzylamine and <Emphasis Type="Italic">N</Emphasis>-salicylidene-2-hydroxy-5-chlorobenzylamine

Cobalt (III) complexes with N-salicylidene-2-hydroxy-5-bromobenzylamine (H₂sbba) and N-salicylidene-2-hydroxy-5-chlorobenzylamine (H₂scba), [n-(C₄H₉)₄N][Co(sbba)₂] (I) and [n-(C₄H₉)₄N][Co(scba)₂] (II), were synthesized. The crystal structure of II was determined by the single-crystal X-ray diffraction method at 90 K confirming its crystallization in the monoclinic space group P2₁/n with a = 11.729(2) Å, b = 16.901(3) Å, c = 21.483(4) Å, β = 98.840(4)°, V = 4208.2(14) ų, D_x = 1.295 g cm^?3, and Z = 4. The R1 [I > 2σ(I)] and wR2 (all data) values of 0.0664 and 0.1920, respectively, for all 9521 independent reflections. The compound is composed of a tetra(n-butyl)ammonium cation and an octahedral cobalt(III) complex anion with two scba^2? ligands in a meridional fashion. The electronic spectral features of I and II are consistent with the octahedral cobalt(III) ion with an N₂O₄ donor set.     

Comparative extraction efficiencies of tri-<Emphasis Type="Italic">n</Emphasis>-butyl phosphate and <Emphasis Type="Italic">N,N</Emphasis>-dihexyloctanamide for uranium recovery using supercritical CO<Subscript>2</Subscript>

Extraction of uranium from tissue paper, synthetic soil, and from its oxides (UO₂, UO₃ and U₃O₈) was carried out using supercritical carbon dioxide modified with methanol solutions of extractants such as tri-n-butyl phosphate (TBP) or N,N-dihexyl octanamide (DHOA). The effects of temperature, pressure, extractant/nitric acid (nitrate) concentration, and of hydrogen peroxide on uranium extraction were investigated. The dissolution and extraction of uranium in supercritical CO₂ modified with TBP, from oxide samples followed the order: UO₃ ≫ UO₂ > U₃O₈. Addition of hydrogen peroxide in the modifier solution enhanced the dissolution/extraction of uranium in dynamic mode. DHOA appeared better than TBP for recovery of uranium from different oxide samples. Similar enhancement in uranium extraction was observed in static mode experiments in the presence of hydrogen peroxide. Uranium estimation in the extracted fraction was carried out by spectrophotometry employing 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Br-PADAP) as the chromophore.     

Synthesis of <Emphasis Type="Italic">N</Emphasis>-and <Emphasis Type="Italic">C</Emphasis>-trimethylsilyl-substituded anililes

N-Metallation of bromoanilines with ethylmagnesium bromide followed by a reaction with trimethylchlorosilane provided N-mono and N-bis(trimethylsilyl)bromoanilines depending on the structure of substrate. The metallation of bissilylated bromoanilines with butyllithium permitted the introduction of a trimethylsilyl substituent in the aromatic ring. Previously unknown 2-bromo-N,N-bis(trimethylsilyl)aniline, 2,6-dibromo-N-trimethylsilylaniline, 2,6-dibromo-N,N-bis(trimethylsilyl)aniline, 2-bromo-6-trimethylsilylaniline, 2-bromo-6-trimethylsilyl-N,N-bis(trimethylsilyl)aniline, 2-bromo-6-trimethylsilyl-N-trimethylsilylaniline, 2,4,6-tribromo-N-trimethylsilylaniline, and 2,4,6-tribromo-N,N-bis(trimethylsilyl)aniline were prepared. The structures of the compounds obtained were established by the chromato-mass spectrometry and ¹H, ¹³C, and ²⁹Si NMR spectroscopy.