- Tetrabutyldideazaporphyrin
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McMurry coupling of a dibutylpyrrole diacrylaldehyde afforded an unstable tetrabutyldideazaporphyrin. Although this porphyrin analogue was highly unstable, proton NMR spectroscopy demonstrated that it retained a high degree of diatropic character.
- Laxner, Jonathan T.,Lash, Timothy D.
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- Reduction method of nitroolefin
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Relating to the technical field of organic synthesis, the invention particularly discloses a reduction method of nitroolefin. The method includes: adding a compound 1 into a mixed solvent of alcohol/water in a certain ratio, adding a metal borohydride at 0-50DEG C, and carrying out stirring reaction; concentrating the obtained solution to a constant weight, and adding ethyl acetate and a saturatedammonium chloride solution into the concentrate; separating the liquid to obtain an upper ethyl acetate layer, and conducting drying and concentrating to obtain a reduction product compound 2. The synthesis method provided by the invention is suitable for aromatic rings and straight-chain alkanes, can control dimer impurities at 3.0% or below and the HPLC purity of aliphatic or aromatic nitro compounds at 95.0% or above. The synthesis method provided by the invention has the advantages of cheap raw materials, green and environment-friendly process, economical efficiency and practicability, and is suitable for industrial production.
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Paragraph 0038-0040
(2019/12/11)
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- Green synthesis of low-carbon chain nitroalkanes via a novel tandem reaction of ketones catalyzed by TS-1
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A green and efficient one-pot method has been developed for the synthesis of low-carbon chain nitroalkanes via a novel TS-1 catalyzed tandem oxidation of ketones with H2O2 and NH3. The tandem reaction including ammoxidation, oximation and oxidation of oximes, afforded up to 88% yield and 98% chemo-selectivity requiring only 90 min, at 70 °C and atmospheric pressure. Moreover, this method was even amenable to 100-fold scale-up without loss of chemical efficiency with 87% yield, represents a significant advance towards industrial production of nitroalkanes. Furthermore, the plausible mechanism of TS-1 catalyzed tandem oxidation of ketones to prepare nitroalkanes was proposed.
- Chu, Qingyan,He, Guangke,Xi, Yang,Wang, Ping,Yu, Haoxuan,Liu, Rui,Zhu, Hongjun
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- Green synthesis method for preparing nitroalkanes by oxime oxidation
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The invention belongs to the field of organic chemical industries, and provides a green synthesis method for preparing nitroalkanes by oxime oxidation. At the temperature of 55 to 120 DEG C and under the pressure of 0 to 1.0 MPa, oxime, a solvent and hydrogen peroxide are reacted for 20 to 200min in the presence of certain amounts of nanoporous skeleton metal hybrid catalysts and cocatalysts, a reaction liquid is subjected to membrane separation, the catalysts can be repeatedly used for more than 7 times, and distilled to obtain nitroalkane products, the purity of the products is not less than 99%, and the yield of the products is not less than 95%. Furthermore, the green synthesis method for preparing nitroalkanes by the oxime oxidation disclosed by the invention is a green synthesis method of nitroalkanes, and suitable for large-scale industrialized production.
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Paragraph 0055; 0056
(2017/08/29)
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- Useful extensions of the henry reaction: Expeditious routes to nitroalkanes and nitroalkenes in aqueous media
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The products of the Henry nitroaldol reaction from nitromethane and several aldehydes were reduced to the corresponding nitroalkanes with (n-Bu) 3SnH in water under microwave irradiation (80 °C/10 min), or dehydrated to the corresponding nitroalkenes with K2CO3 in water (generally 0-5 °C/20 min). Both "one-pot" reactions occur in excellent yields across a range of aliphatic and aromatic (including heteroaromatic) substrates. It seems likely that the deoxygenation of the nitroaldols occurs via coordination of an oxygen atom of the nitro group with a tin atom, which facilitates hydride delivery in the transition state. The elimination of water from the nitroaldols in mild base is likely driven by the stability of the conjugated nitroalkene products. The elimination required workup with 2 N HCl, which likely displaces a nitroalkane-nitroalkene equilibrium towards the latter. These extensions of the Henry reaction lead to products not easily obtained otherwise.
- Chandrasekhar, Sosale,Shrinidhi, Annadka
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p. 3008 - 3018
(2014/10/16)
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- Temperature dependence of pentyl nitrate formation from the reaction of pentyl peroxy radicals with NO
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Alkyl nitrate yields from the reaction of 1-pentyl, 2-pentyl and 2-methyl-2-butyl peroxy radicals with NO have been determined over the temperature range (261-305 K) and at 1 bar pressure from the photo-oxidation of the iodoalkane precursors in air-NO mixtures. Yields were observed to increase with decreasing temperature and, contrary to previous observations, along the series primary secondary ? tertiary. Our results suggests a significant temperature dependence for the formation of nitrates from the reaction of pentyl peroxy radicals with NO and represent an extension in the temperature range over which this reaction has been studied experimentally in the past. the Owner Societies.
- Cassanelli, Paola,Fox, David J.,Cox, R. Anthony
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p. 4332 - 4337
(2008/09/19)
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- SYNTHESIS OF LOW-MOLECULAR NITROPARAFFINS IN IONIC MELTS
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It was shown that pure low-molecular nitroparaffins can be synthesized by the reaction between alkyl sodium sulfates and nitrite ion in ionic melts.The yield of the product is temperature controlled.Because of the ambident nature of nitrite ion, the main side product is alkyl nitrite, subsequent decomposition of which results in formation of a series of organic oxygen-containing compounds.The formal kinetics of the alkylation of nitrite ion by alkyl sodium sulfates was found to be described by the first-order equation.
- Belobrzhetskaya, M. K.,Laskin, B. M.,Malin, A. S.
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p. 105 - 108
(2007/10/02)
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- Bromonitromethane. A Versatile Electrophile
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Pathways in reactions of bromonitromethane with a variety of nucleophiles have been investigated.With thiolates, the electrophilic centre is bromine and the initial products are disulphides.When the thiolate ion itself carries an electrophilic centre such as carbonyl or cyano β-to sulphur, the product is a nitrothiophene derived from subsequent reaction of the first-formed disulphide with nitronate ion displaced in the initial process.This provides a generalisation of earlier nitrothiophene synthesis by this route.In reactions with arenesulphinate ion, the electrophilic centre is also bromine and equilibration between the initial reactants and the initial products, sulphonyl bromide and nitronate ion, is established.The components of the equilibrium subsequently react either with each other or with the solvent.Reactions with sulphides are slow and distal substituents such as hydroxy- or cyano- so much reduce reactivity that no reaction is observed.Dimethyl sulfide attacks bromonitromethane at the carbon atom,and subsequent attack on the nitromethyl sulphonium salt initially formed gives methylthionitromethane and trimethylsulphonium bromide.Iodide ion attacks at bromine to give iodine, presumably via iodine bromide, but with tervalent phosphorus nucleophiles, attack is at oxygen giving the corresponding oxides and HCN in a double deoxygenation sequence.For hydroxide, methoxide and hydride ions (from sodium borohydride), nucleophilic attack is at hydrogen and the nitronate ion produced is inert to further attack.There is no evidence of carbene formation by α-elimination.When the anion of bromonitromethane is allowed to react with tributylboron, the anionic migration-displacement which follows boron-carbon bond formation, yields 1-nitropentane.The anion of bromonitromethane is unreactive towards aldehydes and electrophilic alkenes.
- Fishwick, Brian R.,Rowles, David K.,Stirling, Charles J. M.
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p. 1171 - 1180
(2007/10/02)
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- Formation of Organic Nitro-compounds in Flowing H2O2+NO2+N2+Organic Vapour Systems. Part 3.-Effects of O2 Addition on H2O2+NO2+N2+Alkane Systems
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The effects of oxygen on the product distribution from the surface-initiated reactions in flowing mixtures of H2O2, NO2, N2 and RH, where RH=ethane, propane, n-butane and n-pentane, at 298 K have been studied.In the absence of O2, the principal products are the corresponding nitroalkane, alkyl nitrite and alkyl nitrate.In the presence of sufficiently large concentrations of O2, the predominant product is the alkyl nitrate and the only other products of significance, in some cases, are the corresponding carbonyl compounds.The variation of the product yields with / gives values for the rate-constant ratios k8/(k3+k4) for reaction at both primary and secondary radical sites:.Possible mechanisms by which the products are formed are discussed.
- Baulch, Donald L.,Campbell, Ian M.,Chappel, Jonathan M.
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p. 617 - 628
(2007/10/02)
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- Formation of Organic Nitro-compounds in Flowing H2O2+NO2+N2+Organic Vapour Systems. Part 2.-H2O2+NO2+N2+Alkane System
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The principal products from the surface-initiated reactions in flowing mixtures of H2O2, NO2,N2 and RH, where RH=ethane, propane, n-butane and n-pentane, have been identified as the nitroalkane, alkyl nitrite and alkyl nitrate.The product yields have been measured; in the case of propane the variation of the yields with total gas pressure has also been studied.Values have been obtained for the relative rates of primary and secondary H-atom abstraction from each alkane by OH and for the rate-constant ratios k3/k4 and k5/k6 at 298 K:.The trends in the product yields with the variation of pressure and change of R indicate that RO radicals are produced via reactions (4)-(6) rather than by a single-step reaction of R with NO2.
- Baulch, Donald L.,Campbell, Ian M.,Chappel, Jonathan M.
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p. 609 - 616
(2007/10/02)
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- THE C-ALKYLATION OF NITROALKANE ANIONS BY 1-SUBSTITUTED-2-T-BUTYL-4-PHENYL- AND -2,4-DIPHENYL-5,6-DIHYDROBENZOQUINOLINIUM CATIONS.
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The N-substituents are transferred from the title cations to the C-atom of nitroalkane anions in high yield at 25-80 deg C in DMSO solution.The title cations are readily available from the appropriate pyrylium cations and primary amines of types RCH2NH2 and RR'CHNH2, allowing a general 2-step method for the preparation of higher nitroalkanes.Spectral properties of a variety of nitroalkanes are discussed.
- Katritzky, Alan R.,Kashmiri, M. Akram,Wittmann, Dieter K.
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p. 1501 - 1510
(2007/10/02)
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- Chemistry of peroxyacyl nitrates. Part III. The oxidation of thioethers by peroxyhexanoyl nitrate
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The reaction of peroxyhexanoyl nitrate, 1a, a homologue of the atmospheric pollutant "PAN", 1b, with some twenty thioethers, is described.At 0-25 deg C, common thioethers such as Et2S or PhSMe are rapidly converted into sulfoxides in high yields in a variety of solvents, ranging from pentane and chloroform to acetic acid, methanol and aqueous acetonitrile.Rates are essentially solvent-independent, although the reaction is subject to marked steric hindrance.Relative rates for five p-substituted thioanisoles in MeOH at 22 deg C, leading to a Hammett ρ-value of -1.7, show that the sulfur atoms display nucleophilic character.Electron-attracting groups on α-carbon, such as in PhSCCl3 and in MeSCH2OC(O)Ph, inhibit the formation of sulfoxide.Addition of EtSH lowers the yield of sulfoxide, producing instead EtSSEt and EtSNO.Oxidation of Me2S by 1a with the NO2 group labelled by 18O does not give rise to 18O-enriched DMSO.Comparison of (CH3)2S with (CD3)2S revealed an inverse kinetic H/D isotope effect.The products obtained from 1a vary with solvent.In the presence of water or EtSH, hexanoic acid is formed, while methanol gives rise to methyl hexanoate, and in pentane/hexanoic acid, hexanoic anhydride is produced.In aprotic solvents, significant amounts of CO2 are formed.These observations can best be rationalized on the basis of an intermediate sulfurane R1R2S(ONO2)(OCOR), (I), produced from thioether R1SR2 and 1a, in the first step.The fate of (I) under various conditions is discussed.Finally, the features of the oxidation of thioethers by peroxyacylnitrate are compared with those of acyl peroxides and peroxy esters.It is suggested that in each case formation of a sulfurane may well be the first step.
- Noort, Paul C. M. van,Vermeeren, Hans P. W.,Louw, Robert
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p. 312 - 321
(2007/10/02)
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- Bromonitromethane, a Versatile Electrophile: Reactions with Feebly Basic Nucleophiles
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Bromonitromethane reacts with feebly basic sulphur, phosphorus, and halogen nucleophiles at bromine or at carbon; the anion of bromonitromethane reacts with tributylboron to give 1-nitropentane.
- Fishwick, Brian R.,Rowles, David K.,Stirling, Charles J. M.
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p. 835 - 836
(2007/10/02)
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