- A Study by He I Photoelectron Spectroscopy of Monomeric Nitrosomethane, the Cis and Trans Dimers, and Formaldoxime
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A combination of in situ He I photoelectron and quadrupole mass spectroscopy has been used to study monomeric nitrosomethane, the cis and trans isomers, and formaldoxime.In contrast to earlier results it is shown that cis-(CH3NO)2 sequentially gives CH2=NOH and CH3NO upon vaporization.A photoelectron spectrum of the cis dimer was not observed.In addition, a previous spectrum of "monomeric" CH3NO is shown to belong to the trans dimer.The assignments of the measured ionization potentials for these species are supported by semiempirical HAM/3 results.A breakdown of Koopmans' theorem is confirmed for CH3NO by a calculation involving perturbation corrections.
- Frost, D. C.,Lau, W. M.,McDowell, C. A.,Westwood, N. P. C.
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- New synthesis and fungicidal activity of a phosphinic analogue of glycine
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Aminomethylphosphinic acid, which was found to exhibit fungicidal activity, was synthesised in one step by the interaction of formaldoxime and sodium hypophosphite with HCl.
- Zhukov, Yurii N.,Vavilova, Nelli A.,Osipova, Tat'yana I.,Khurs, Elena N.,Dzhavakhiya, Vitalii G.,Khomutov, Radii M.
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- Complexation of formaldoxime with water. Infrared matrix isolation and theoretical studies
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The 1:1, 1:2 and 2:1 formaldoxime-water complexes isolated in the argon matrices have been studied by help of FTIR spectroscopy and MP2/6-311++G(2d,2p) method. The calculations predicted the stability of the three CH 2NOH?H2O isomeric complexes, three CH 2NOH?(H2O)2 ones and one (CH 2NOH)2?H2O complex. The analysis of the experimental spectra and their comparison with theoretical ones indicated that both the 1:1 and 1:2 complexes trapped in solid argon have the most stable cyclic structures stabilized by the O-H?O and O-H?N bonds between the formaldoxime and water molecules. In the 1:2 complex formaldoxime interacts with the water dimer, one H2O molecule acts as a proton acceptor for the OH group of formaldoxime whereas the second H2O molecule acts as a proton donor toward the nitrogen atom of the formaldoxime molecule. In the (CH2NOH)2?H2O complex the OH group of the water molecule acts as a proton donor toward one of the oxygen atoms of the formaldoxime cyclic dimer.
- Golec, Barbara,Mucha, Ma?gorzata,Mielke, Zofia
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- Electrochemical Reductive N-Methylation with CO2Enabled by a Molecular Catalyst
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The development of benign methylation reactions utilizing CO2 as a one-carbon building block would enable a more sustainable chemical industry. Electrochemical CO2 reduction has been extensively studied, but its application for reductive methylation reactions remains out of the scope of current electrocatalysis. Here, we report the first electrochemical reductive N-methylation reaction with CO2 and demonstrate its compatibility with amines, hydroxylamines, and hydrazine. Catalyzed by cobalt phthalocyanine molecules supported on carbon nanotubes, the N-methylation reaction proceeds in aqueous media via the chemical condensation of an electrophilic carbon intermediate, proposed to be adsorbed or near-electrode formaldehyde formed from the four-electron reduction of CO2, with nucleophilic nitrogenous reactants and subsequent reduction. By comparing various amines, we discover that the nucleophilicity of the amine reactant is a descriptor for the C-N coupling efficacy. We extend the scope of the reaction to be compatible with cheap and abundant nitro-compounds by developing a cascade reduction process in which CO2 and nitro-compounds are reduced concurrently to yield N-methylamines with high monomethylation selectivity via the overall transfer of 12 electrons and 12 protons.
- Rooney, Conor L.,Wu, Yueshen,Tao, Zixu,Wang, Hailiang
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supporting information
p. 19983 - 19991
(2021/12/01)
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- Formaldoxime hydrogen bonded complexes with ammonia and hydrogen chloride
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An infrared spectroscopic and MP2/6-311++G(2d,2p) study of hydrogen bonded complexes of formaldoxime with ammonia and hydrogen chloride trapped in solid argon matrices is reported. Both 1:1 and 1:2 complexes between formaldoxime and ammonia, hydrogen chloride have been identified in the CH2NOH/NH3/Ar, CH2NOH/HCl/Ar matrices, respectively, their structures were determined by comparison of the spectra with the results of calculations. In the 1:1 complexes present in the argon matrices the OH group of formaldoxime acts as a proton donor for ammonia and the nitrogen atom acts as a proton acceptor for hydrogen chloride. In the 1:2 complexes ammonia or hydrogen chloride dimers interact both with the OH group and the nitrogen atom of CH2NOH to form seven membered cyclic structures stabilized by three hydrogen bonds. The theoretical spectra generally agree well with the experimental ones, but they seriously underestimate the shift of the OH stretch for the 1:1 CH2NOH?NH3 complex.
- Golec, Barbara,Mucha, Ma?gorzata,Sa?dyka, Magdalena,Barnes, Austin,Mielke, Zofia
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- PROCESS FOR PREPARING SUBSTITUTED ISOXAZOLINE COMPOUNDS AND THEIR PRECURSORS
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Process for preparing substituted isoxazoline compounds and their precursors The present invention relates to a new method of preparing halogenated styrene compounds of Formula (VIII), which are precursors in the process of synthesis of substituted isoxazoline compounds of Formula (I), wherein R1 to R5, R8 and R9 are described as in the description. The present invention relates further to the synthesis of compounds of formula (I) starting from acetophenones. The desired styrenes of formula are prepared from the appropriate substituted acetophenone. Asides bromo anilines react with formoxime. Obtained oximes undergo a cycloaddition with the styrenes and give isoxazolines. Compounds of formula (I) can then be prepared in a palladium catalyzed carbonylative ami- nation reaction of the isoxazolines.
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Page/Page column 40
(2010/11/17)
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- Spiroindolinone Derivatives
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There are provided compounds of the formula and pharmaceutically acceptable salts and esters and enantiomers thereof wherein W, X, X′, Y, V, V′, A, B and R are as described herein. The compounds have utility as antiproliferative agents, especially, as anticancer agents.
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Page/Page column 17
(2009/07/10)
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- Design, synthesis, and evaluation of novel organophosphorus inhibitors of bacterial ureases
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A new group of organophosphorus inhibitors of urease, P-methyl phosphinic acids was discovered by using the structure based inhibitor design approach. Several derivatives of the lead compound, aminomethyl(P-methyl)phosphinic acid, were synthesized successfully. Their potency was evaluated in vitro against urease from Bacillus pasteurii and Proteus vulgaris. The studied compounds constitute a group of competitive, reversible inhibitors of bacterial ureases. Obtained thiophosphinic analogues of the most effective structures exhibited kinetic characteristics of potent, slow binding urease inhibitors, with K i = 170 nM (against B. pasteurii enzyme) for the most active N-(N′-benzyloxycarbonylglycyl)aminomethyl(P-methyl)phosphinothioic acid.
- Vassiliou, Stamatia,Grabowiecka, Agnieszka,Kosikowska, Paulina,Yiotakis, Athanasios,Kafarski, Pawe?,Berlicki, Lukasz
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supporting information; experimental part
p. 5736 - 5744
(2009/08/16)
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- Synthesis and structure-activity relationships of thioflavone derivatives as specific inhibitors of the ERK-MAP kinase signaling pathway
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Condensation of nitrobenzaldehydes 3 and α-[o-(p-methoxybenzylthio) benzoyl] sulfoxide 4 gave α-sulfinyl enones 5. Treatment of 5 with formic acid caused cyclization followed by debenzylation to afford 3-(methylsulfinyl) thioflavanones 6. Double-bond formation with elimination of methanesulfenic acid was performed by refluxing 6 in benzene, and, finally, the nitro group of 2-phenyl-4H-1-benzothiopyran-4-one (thioflavones) 7 was reduced with tin in tetrafluoroboric acid. Various 2′-aminothioflavones 8 thus prepared were evaluated for their inhibitory effects on the ERK-MAP kinase pathway. In a cell-based assay, 2-(2′-amino-3 ′-methoxyphenyl)-4H-1-benzothiopyran-4-one (8b) showed a more potent inhibitory effect than the corresponding oxygen compound (PD98059, 1) on the Raf-induced activation of the ERK-MAP kinase pathway as well as cell proliferation. Furthermore, compound 8b selectively and potently inhibited the proliferation of tumor cells in which the ERK-MAP kinase pathway is constitutively activated.
- Kataoka, Tadashi,Watanabe, Shin-Ichi,Mori, Eiji,Kadomoto, Ryoji,Tanimura, Susumu,Kohno, Michiaki
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p. 2397 - 2407
(2007/10/03)
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- Preparation of 5-(2-methoxy-4-nitrophenyl)oxazole: A key intermediate for the construction of VX-497
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A process for the multigram preparation of 5-(2-methoxy-4-nitrophenyl)oxazole, a key intermediate for the preparation of the hepatitis C drug candidate VX-497 (merimepodib), has been achieved in good yield from a commercially available dye. Early studies focused on the preparation of the requisite aldehyde by the Beech reaction. A second approach utilized a palladium (0)-catalyzed formylation of an aryl diazonium species, which was followed by condensation of the aldehyde with tosylmethyl isocyanide (TosMIC) to provide the required oxazole. This two-step method has been carried out to provide multigram samples of this key intermediate in 75% overall yield and >95% purity from the commercially available Fast Red B tetrafluoroborate salt.
- Herr, R. Jason,Fairfax, David J.,Meckler, Harold,Wilson, Jeffrey D.
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p. 677 - 681
(2013/09/06)
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- Synthesis of alkyl- and aryl-substituted pyridines from (α,β-unsaturated) imines or oximes and carbonyl compounds
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Reaction of a variety of (α,β-unsaturated) imines or oximes with aliphatic aldehydes or cyclic ketones in the presence of a secondary amine afforded alkyl-, and/or aryl-, and/or cycloalkyl-substituted pyridines. To explain their formation, a hetero Diels-Alder reaction has been postulated, in which an 1-aza-1,3-butadiene reacts with an in situ generated enamine.
- Vijn,Arts,Green,Castelijns
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p. 573 - 578
(2007/10/02)
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- Infrared Multiphoton Decomposition of Diethylnitramine
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Irradiation of gaseous diethylnitramine with infrared radiation from a pulsed CO2 laser under collision-free and collisional conditions resulted in the formation of diethylnitrosamine as the main product along with nitrogen dioxide, nitric oxide, formaldoxime, and diethyl nitroxide.Scavenging experiments with Cl2, NO, and (CD3)2NNO2 molecules have shown that the primary channel of unimolecular dissociation of diethylnitramine molecules is the scission of the N-NO2 bond, with a steady-state rate constant of 105.2 +/- 0.1(I/MW cm-2) s-1 for laser intensities in the range 3-15 MW cm-2 at an irradiation frequency of 1075.9 cm-1.A qualitative analysis of the chemical mechanism leading to the formation of final products as well as the importance of the diethylamino radical oxidation reactions is presented.
- Lazarou, Yannis G.,King, Keith D.,Papagiannakopoulos, Panos
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p. 7351 - 7355
(2007/10/02)
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- Oxidation of Hydroxylamine Derivatives. VI. Anodic Oxidation of N-Alkyl-β-hydroxyhydroxylamines in Aqueous Buffer Solution
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Anodic oxidation of N-alkylhydroxylamines with and without a β-hydroxy group was studied by cyclic voltammetry and controlled potential electrolysis in aqueous buffer solution of pH 8.8.The hydroxylamines with a β-hydroxy group were oxidized initially to the corresponding nitroxides and gave the final products via two routes; i) cleavage of the (α)C-(β)C bond to give aldehydes and oximes, and ii) disproportionation of the nitroxides to form the nitroso compounds.The hydroxylamines without a β-hydroxy group did not undergo cleavage of the (α)C-(β)C bond and gave nitroso compounds.Substituents on the α and β carbons affected the product distribution.When a phenyl group or two methyl groups were present on the (β)C, or one methyl group was present on both (α)C and (β)C, (α)C-(β)C bond cleavage was predominant. Keywords - N-alkyl-β-hydroxyhydroxylamine; anodic oxidation; C-C bond fission; C-nitroso compound; aldehyde; oxime; azoxy compound
- Ozaki, Shigeko,Nishiguchi, Susumu,Masui, Masaichiro
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p. 2609 - 2616
(2007/10/02)
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- Photolysis of Dimethylnitrosamine in the Gas Phase
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Photodecomposition of dimethylnitrosamine in the gas phase ( 1 Torr) has been investigated following irradiation into the S1(n?*) 0(363.5 nm) and S2(??'*) 0(248.1 nm) transitions at room temperature.With a quantum yield of unity, excitation into the S1 state yields the fragments (CH3)2N and NO which then recombine leaving no photoproducts.The addition of O2 results in only one photoproduct, (CH3)2NNO2.Irradiating into the S2 state, the products CH2=N-CH3, (CH2=N-CH3)3, CH2=NOH, N2O, NO, H2, and N2 were identified by capillary gas chromatography mass spectrometry.In the presence of N2 as a buffer gas the photoproducts are only CH2=N-CH3, (CH2=N-CH3)3, N2O, and H2.For both excitation conditions a mechanism is proposed involving cleavage of the N,N-bond as the main primary photolytic process.
- Geiger, Georg,Huber, J. Robert
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p. 989 - 995
(2007/10/02)
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