NMR parameters,isomerism, and conformational analysis of 3-methyl-2-phenyl-5-(3-methyl-2-phenyl-3,4-dehydropiperid-6-yl)-pyridine

The configurational and conformational features of the trans and cis isomers of 3-methyl-2-phenyl-5-(3-methyl-2-phenyl-3,4-dehydropiperid-6-yl)pyridine, formed as by-products in the phenylation of -picoline by phenyllithium, were established. The revealed stereospecificity of the ⁵J_HH and ¹J_CH SSCCs may be utilized as an independent criterion in the conformational analysis of piperideine systems.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 71–74, January, 1993.     

The phenylation of 3βpicoline. Isolation and establishment of the structure of β-pyridyl-α-dehydropiperidine

It was established that the side product that is formed in substantial amounts in the phenylation of -picoline by phenyllithium is 3-methyl-2-phenyl-5-(3-methyl-2-phenyl-3,4-dehydropiperidyl-6)pyridine — a structural analog of anabasine. Its structure was demonstrated by spectral methods and by chemical conversions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 115–119, August, 1984.     

Cyclization of N-alkylazinium cations with bifunctional nucleophiles. 22. Crystal and molecular structure of tetrahydroquinoxaline condensed with the six-membered 1,3,4-thiadiazine ring

X-ray diffraction examination of 4-acetyl-10-methyl-2-phenyl-1,4,4a,5,10,10a-hexahydro-1,3,4-thiadiazino[5,6-b]quinoxaline has shown that the 4a-H and 10a-H hydrogens attached to the carbon atoms common to both heterocycles are cis-oriented, as in the annelation of five-membered heterocycles to the tetrahydropyrazine ring, but in this case the torsion angle H_(4a)C_(4a)C_(10a)H_(10a) is much greater, having a value of 60.For Communication 21, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 701–706, May, 1987.     

Oxidation of 1,3-Dioxacycloalkanes with Complexes of Potassium Chlorochromate and Chlorodiperoxochromate with 15-Crown-5, Catalyzed with 2,2,5,5-Tetramethyl- 4-phenyl-3-oxo-3λ5-imidazolin-1-yloxyl

2,2,5,5-Tetramethyl-4-phenyl-3-oxo-3⁵-imidazolin-1-yloxyl catalyzes oxidation of 2-isopropyl-1,3-dioxolane, 2-phenyl-1,3-dioxolane, 2-phenyl-4-chloromethyl-1,3-dioxolane, and 2-phenyl-1,3-dioxane with 15-crown-5 complexes of potassium chlorodiperoxochromate (KCrO₅Cl·2C₁₀H₂₀O₅) and potassium chlorochromate (KCrO₃Cl·2C₁₀H₂₀O₅). 2-Isopropyl-1,3-dioxolane is oxidized to the corresponding monoester in quantitative yield, and the 2-phenyl derivatives yield benzaldehyde. The spiro ketal, 2,2-pentamethylene-4-methyl-1,3-dioxane, is decomposed to cyclohexanone.     

Synthesis of new polydentate tweezers ligands of amido-amine type

A series of new tweezers amido-amine ligands containing pyrrole, bipyrrole, and dipyrrolylmethane fragments were synthesized by reaction of 2-thioxothiazolidin-3-yl derivatives of α-pyrrolecarboxylic acids {5-[1-(5-carboxy-3-methyl-4-phenyl-1H-pyrrol-2-yl)-1-methylethyl]-4-methyl-3-phenyl-1H-pyrrole-2-carboxylic acid, 5-[(5-carboxy-3-methyl-4-phenyl-1H-pyrrol-2-yl)phenylmethyl]-4-methyl-3-phenyl-1H-pyrrole-2-carboxylic acid, 5-(5-carboxy-3-methyl-4-phenyl-1H-pyrrol-2-yl)-4-methyl-3-phenyl-1H-pyrrole-2-carboxylic acid, and 3,4-dimethyl-pyrrole-2,5-dicarboxylic acid} with o-phenylenediamine. All compounds obtained were characterized by elemental analysis, NMR and mass spectra.     

Synthesis and study of 4-aminopyrazolones (5)

Some 4-N-thioureido- and -ureido derivatives are synthesized by reacting 1-phenyl-3-methyl-4-aminopyrazolone(5) hydrochloride at 40–50°, in alcohol solution, with potassium thiocyanate in the presence of sodium acetate plus carbon disulfide, phenylisothiocyanate, and hexamethylenediisocyanate. Acetylation of 1-phenyl-3-methyl-4-aminopyrazolone(5) with C₁–C₈ aliphatic carboxylic acids takes place under more drastic conditions at 100–150°, to give the corresponding 1-phenyl-3-methyl-4-acylaminopyrazolones(5), isolated in 40–60% yield. The UV spectra of the compounds studied are investigated.For Part I, see [1].     

Effect of coordination with rhodium on the selectivity of the mass spectral fragmentation of 4,4-disubstituted 2,5-cyclohexadien-1-ones

Conclusion A comparative study was carried out on the electron impact fragmentation of 4,4-disubstituted 1-oxo-2,5-cyclohexadienes and their rhodium acetylacetonate complexes. The coordination of the diene ligands with rhodium leads to an increase in the selectivity of the decomposition of the molecular ions, which occurs exclusively with loss of the most stable radical located at the geminal unit of the hydrocarbon -ligand and leads to (4-methyl-1-oxocyclohexadienyl) acetylacetonatorhodium cations.2. 15-, 16-, 17-, and 18-Electron complexes containing 4,4-dialkyl-1-oxo-2,5-cyclohexadiene (L) or 4-methyl-1-oxocyclohexadienyl ligands are obtained in the reaction of [acacRh · (CO)_n]⁺ and [(C₅H₅)Rh(CO)_n]⁺ ions (n=0–2) with 4,4-disubstituted 1-oxo-2,5-cyclohexadienes in the gas phase. The formation of [acacRh(CO)L]⁺ and [(C₅H₅)Rh(CO)L]⁺ ions indicated the reduced -donor capacity of 1-oxo-2,5-cyclohexadienes relative to 1-alkylidene-2,5-cyclohexadienes in reactions with rhodium-containing cations.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1088–1093, May, 1986.     

Liquid-liquid extraction separation of zinc and cadmium with 1-phenyl-3-methyl-4-acyl-5-pyrazolones and tri-n-octylphosphine oxide

The extraction of zinc and cadmium with a mixture of a 1-phenyl-3-methyl-4-acyl-5-pyrazolone and trioctylphosphine oxide (TOPO) in various solvents is described. The extraction constants for systems based on eight 4-acyl compounds (C₃C₁₈) are reported. The 1-phenyl-3-methyl-4-stearoyl-5-pyrazolone/benzene system is most effective for the mutual separation of zinc and cadmium at pH 4.5; 20 μg of zinc can be separated efficiently from 20 mg of cadmium.     

Study of the reaction of sulfur with organic compounds

The reaction of sulfur with phenylchloromethanes of the type (C₆H₅)_mCCl_nH_{4-m -n}(m=1–3; n3) is investigated. New simple methods of synthesizing tetraphenylthiophene (from C₆H₅CH₂Cl) and thianaphtheno [3, 2-b] thianapthene or 2-phenyl-3-chlorothianaphthene (from C₆H₅CHCl₂) are developed. All the heterocyclic sulfur compounds synthesized are oxidized to the corresponding sulfones, Diphenylchloromethane when heated with sulfur smoothly gives a high yield of tetraphenylethylene, and triphenylchloromethane treated similarly gives triphenylmethane. C₆H₅CCl₃ and (C₆H₅)₂CCl₂ undergo practically no reaction with sulfur under the conditions investigated.For Part VII see [1].     

Pyrroles from ketoximes and acetylene. 24. Acidic hydrolysis of 1-vinylpyrroles

The hydrolysis of 2-methyl-, 2-phenyl-, and 3-methyl-2-phenyl-1-vinylpyrroles and 1-vinyl-4,5,6, 7-tetrahydroindole in the presence of HCl, H₂SO₄, NH₂OH-HCl, acetic acid, and H₂O₂ in aqueous, aqueous dioxane, and aqueous alcohol solutions leads to oligomers with complex structures and compositions, viz., products of acidic catalytic and oxidative condensation of the starting compounds and the resulting pyrroles both with one another and with the liberated acetaldehyde. 2-Phenylpyrrole was obtained in 52% yield from 1-vinyl-2-phenylpyrrole by hydrolysis in a dilute (0.5%) solution [water-dioxane (59)] with excess NH₂OH.HCl, which ties up the acetaldehyde.See [1] for Communication 23.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1631–1639, December, 1982.     

Monte Carlo Studies of the Structural and Thermodynamic Properties of Some Smectic and Ferroelectric Liquid Crystals

Monte Carlo simulation based on the Gaussian overlap model was used to study the thermodynamic properties of smectic C: C₅H₁₁O–(OH)C₆H₃–CH=N–C₆H₄–C₅H₁₁ (A), C₁₀H₂₁O–C₆H₄–CH=CH–C₆H₄–OC₁₀H₂₁ (B), ferroelectric smectic C* liquid crystals (LC): C₇H₁₅O–C₆H₄–C₆H₄–COO–CH₂C*H(CH₃)C₂H₅ (C), C₈H₁₇O–C₆H₄–C₆H₄–C₂H₄C*H(CH₃)C₂H₅ (D), and an equimolar mixture of {A+C} and {A+D}. A system of N = 125 pairwise interacting ellipsoids of revolution placed in a volume V at a temperature T (that is, a system described by a canonical NVT-ensemble) is considered. These interactions were calculated using a specially devised Lennard-Jones potential, allowing for both mild anisotropic repulsion of particles (ellipsoids) and their dispersion attraction. Dipole–dipole interactions were also taken into account, since the molecules have highly polar groups: –O–, OH, CH=N, and COO and hence a high dipole moment (4.2-5.3 D). Calculations were carried out for a rectangular parallelepiped with periodic boundary conditions imposed on its faces. An elementary object of the NVT-ensemble was a two-molecule microcluster (dimer) but not a single molecule from the group under study. Smectic A ordering in the system has been unambiguously proven for different temperatures and fixed densities (0.32 0.44, where is the close packing coefficient). The ordering is attributed to the large (transverse) dipole moment inherent in molecules {A}-{D}. Temperature dependences of free energy, configuration energy, heat capacity C_v, and orientational order parameter were obtained. The curves agree well with the experimental data on variation of the properties of smectic LC.     

Derivatives of α,β-dehydro amino acids: III. Reaction of 4-arylmethylidene-4,5-dihydro-1,3-oxazol-5-ones with hexamethyldisilazane

4-Arylmethylidene-4,5-dihydro-1,3-oxazol-5-ones reacted with hexamethyldisilazane in ethyl acetate, acetonitrile, or DMF at room temperature to give mainly 2-acylamino-3-arylmethylideneprop-2-enamides, whereas in boiling DMF the corresponding 4-arylmethylidene-4,5-dihydro-1H-imidazol-5-ones were formed. The reaction of 2-benzoylamino-3-phenylprop-2-enamide with hexamethyldisilazane also led to the formation of 4-benzylidene-2-phenyl-4,5-dihydro-1H-imidazol-5-one, while its reaction with chlorotrimethylsilane afforded either a 1:1 mixture of 4-benzylidene-2-phenyl-4,5-dihydro-1,3-oxazol-5-one and 4-benzylidene-2-phenyl-4,5-dihydro-1H-imidazol-5-one or only the latter, depending on the solvent.     

Kinetic scheme of homogeneous acid-catalyzed transformation of isopentenols

The reactions occurring in an equilibrium mixture of 3-methyl-1-buten-3-ol and 3-methyl-2-buten-1-ol in 24–49 % aqueous solutions of H₂SO₄ yield isoprene, 3-methyl-3-buten-1-ol, isobutylene, formaldehyde, 3-methylbutane-1,3-diol. Isobutylene is rapidly hydrated to give 2-methylpropan-2-ol. The presence of formaldehyde in the reaction mixture indicates that the transformations involve the reverse Prins reaction. On the basis of experimental and literature data, two most probable reaction schemes were suggested.Translated fromIzvestiya Akademii Nauk. Sertya Khimicheskaya, No. 5, pp. 867–870, May, 1995.     

1-Phenyl-1-halo-1-silacyclohexanes

The approaches to synthesis of 1-phenyl-1-halo-1-silacyclohexanes C₅H₁₀Si(Ph)X (X = F, Cl, Br) have been examined. 1-Phenyl-1-chloro-1-silacyclohexane has been prepared via the known reaction of phenyltrichlorosilane with dimagnesium derivative of 1,5-dibromopentane; up to 20% of 1-bromo-1-phenyl-1-silacyclohexane admixture is formed along with the target product. The minor product formation has been prevented using an alternative method of chlorination of 1-phenyl-1-silacyclohexane with N-chlorosuccinimide. 1-Phenyl-1-fluoro-1-silacyclohexane has been obtained in close to quantitative yield via the reaction of 1-phenyl-1-chloro-1-silacyclohexane with SbF₃ and in 70% yield via its reaction with HF. The synthesis of 1-phenyl-1-bromo-1-silacyclohexane via bromination of 1-phenyl-1-chloro-1-silacyclohexane with N-bromosuccinimide has given the target product as a minor one, the major product being disiloxane formed due to hydrolysis of the Si–Br bond.     

Synthesis and properties of ethyl 1-aryl-5-methyl-4-[1-(phenylhydrazinylidene)ethyl]-1<Emphasis Type="Italic">H</Emphasis>-pyrazole-3-carboxylates

Ethyl 1-aryl-4-acetyl-5-methyl-1H-pyrazole-3-carboxylates reacted with phenylhydrazine to give the corresponding hydrazones, ethyl 1-aryl-5-methyl-4-[1-(phenylhydrazinylidene)ethyl]-1H-pyrazole-3-carboxylates, which were converted to ethyl 1′-aryl-4-formyl-5′-methyl-1-phenyl-1H,1′H-3,4′-bipyrazole-3′-carboxylates by treatment with the Vilsmeier–Haack reagent. No indole derivatives were formed from the same hydrazones under the Fischer reaction conditions, but cyclization to 2-aryl-3,4-dimethyl-6-phenyl-2,6-dihydro-7H-pyrazolo[3,4-d]pyridazin-7-ones was observed.     

Synthesis, crystal structures and antibacterial activities of schiff base ligand and its cobalt(II) complex

The Schiff base ligand, HL · 0.5C₂H₅OH (HL = methyl N-[(4-chlorophenyl)(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-ylindene)methyl]valine), was derived from condensation of 1-phenyl-3-methyl-4-(p-chlorbenzyl)-5-pyrazolone with L-valine methyl ester in a 1: 1 molar ratio in methanol, ether and isopropanol solution. Reaction of ligand with Co(ClO₄)₂ · 6H₂O (in a 2: 1 molar ratio) in methanol solution afforded a mononuclear cobalt(II) complex, [Co(L)₂] (I). Molecular structures of HL · 0.5C₂H₅OH and complex I were characterized by elemental analysis, IR and single crystal X-ray diffraction analysis. The enamine-keto form of the ligand has turned to imine form in complex I. Each Co(II) center in complex I is in a octahedral N₂O₄ coordination sphere. Both the Schiff base ligand and its Co(II) complex have been tested in vitro with agar dilution method to evaluate their antibacterial activity against bacteria Escherichia coli and Staphylococcus aureus. It has been found that they have higher activity against Escherichia coli than Staphylococcus aureus, and complex I has higher activity than HL · 0.5C₂H₅OH against the same bacteria.     

Thermal Studies of Cobalt(II), Nickel(II) and Copper(II) Complexes of 4-(Sulfonylazido Phenylazo) Pyrazolones

The thermal decompositions of cobalt(II), nickel(II) and copper(II) complexes of4-(3'-sulfonylazido-6'-methoxyphenylazo)-1-phenyl-3-methyl-2-pyrazolin-5-one H(D¹–SO₂N₃) and 4-(4'-sulfonylazido phenylazo)-3-phenyl-3-methyl-2-pyrazolin-5-one H(D²–SO₂N₃) were studied by thermogravimetry. The decomposition in all cases takes place along two stages. The first stage is due to the elimination of water and nitrogen molecules with the formation of tetracoordinate complexes containing nitrene reactive species[M(DSO₂N:)₂]. The second stage represents the decomposition of the material to the metal oxide. The kinetics of the decomposition were examined by using Coats–Redfern, the decomposition in all complexes was found to be first order for the first and second stages. The activation energies and other activation parameters (H^* and S^* and G^*) were computed and related to the bonding and stereochemistry of the complexes.This revised version was published online in November 2005 with corrections to the Cover Date.     

Die Schwingungsspektren von Trimethylsilyl-alkyl-bzw.-phenyl-aminen

Zusammenfassung Die Infrarot- und die Raman-Spektren der Silylamine (CH₃)₃Si–NH–R (R=CH₃, C₂H₅ und C₆H₅) sowie der analogen N-deuterierten Verbindungen werden mitgeteilt und analysiert. Starke Kopplungen führen zu einer Mischung vonv SiN bei etwa 700 cm^–1 mit anderen Schwingungen des C₃Si–NHR-Skelettes.

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The Infrared and Raman spectra of the silylamino compounds (CH₃)₃Si–NH–R (R=CH₃, C₂H₅, and C₆H₅) and the analogous N-deuterated species are reported and assigned. The SiN stretching mode at about 700 cm^–1 is strongly coupled with other vibrations of the molecules.

     

Bildung von 5,6-Dihydro-1,3(4H)-thiazin-4-carbonsäure-estern aus 4-Allyl-1,3-thiazol-5(4H)-onen

Formation of Methyl 5,6-Dihydro-l, 3(4H)-thiazine-4-carboxyiates from 4-Allyl-l, 3-thiazol-5(4H)-ones . The reaction of N-[1-(N, N-dimethylthiocarbamoyl)-1-methyl-3-butenyl]benzamid ( 1 ) with HCl or TsOH in MeCN or toluene yields a mixture of 4-allyl-4-methyl-2-phenyl-1,3-thiazol-5(4H)-one ( 5a ) and allyl 4-methyl-2-phenyl-1,3-thiazol-2-yl sulfide ( 11 ; Scheme 3). Most probably, the corresponding 1,3-oxazol-5(4H)-thiones B are intermediates in this reaction. With HCl in MeOH, 1 is transformed into methyl 5,6-dihydro-4,6-dimethyl-2-phenyl-1,3(4H)-thiazine-4-carboxylate ( 12a ). The same product 12a is formed on treatment of the 1,3-thiazol-5(4H)-one 5a with HCl in MeOH (Scheme 4). It is shown that the latter reaction type is common for 4-allyl-substituted 1,3-thiazol-5(4H)-ones.     

Unexpected formation of benzofuran derivatives in the C-amidoalkylation of p-cresol with 4-chloro-N-(2,2-dichloro-2-phenylethylidene)benzenesulfonamide*

The C-amidoalkylation of p-cresol with 4-chloro-N-(2,2-dichloro-2-phenylethylidene)benzenesulfon-amide in the presence of H₂SO₄, oleum, or a mixture of H₂SO₄ and P₄O₁₀ was studied for the first time. It was shown that the reaction not only leads to the targeted 4-chloro-N-[2,2-dichloro-1-(2-hydroxy-5-methylphenyl)-2-phenylethyl]benzenesulfonamide but is also accompanied by unexpected formation of the heterocyclic derivatives 4-chloro-N-(5-methyl-2-phenyl-1-benzofuran-3-yl)benzenesulfonamide and 5-methyl-3-phenyl-2-benzofuran-2(3H)-one.