- EQUILIBRIA IN SOLUTIONS OF METHANOL OR ETHANOL, SULFURIC ACID, AND ALKYL SULFATES
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Equilibria in reactions of methanol and ethanol with sulfuric acid or in hydrolyses of alkyl sulfates were followed using 13C NMR, anion-exchange HPLC, and titrations.Variations of equilibrium constant K = (ester)(H2O)/(ROH)(HSO4(1-)) with acidity indicate participation of reactions ROH2(1+) + HSO4(1-) ROH(1+)SO3(1-) + H2O, accompanied by acid base equilibra involving the alcohol and ester.For mixtures containing initially 20percent (w/w) alcohol, pKMeOH2(1+) = -4.2, pKEtOH2(1+) = -3.7, pKMeOH(1+)SO3(1-) = -3.3 and pKEtOH(1+)SO3(1-) = -2.7.
- Almstead, N.,Christ, W.,Miller, G.,Reilly-Packard, S.,Vargas, K.,Zuman, P.
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- A mechanistic change results in 100 times faster CH functionalization for ethane versus methane by a homogeneous Pt catalyst
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The selective, oxidative functionalization of ethane, a significant component of shale gas, to products such as ethylene or ethanol at low temperatures and pressures remains a significant challenge. Herein we report that ethane is efficiently and selectively functionalized to the ethanol ester of H2SO4, ethyl bisulfate (EtOSO3H) as the initial product, with the PtII "Periana-Catalytica" catalyst in 98% sulfuric acid. A subsequent organic reaction selectively generates isethionic acid bisulfate ester (HO3S-CH 2-CH2-OSO3H, ITA). In contrast to the modest 3-5 times faster rate typically observed in electrophilic CH activation of higher alkanes, ethane CH functionalization was found to be ~100 times faster than that of methane. Experiment and quantum-mechanical calculations reveal that this unexpectedly large increase in rate is the result of a fundamentally different catalytic cycle in which ethane CH activation (and not platinum oxidation as for methane) is now turnover limiting. Facile Pt II-Et functionalization was determined to occur via a low energy β-hydride elimination pathway (which is not available for methane) to generate ethylene and a PtII-hydride, which is then rapidly oxidized by H2SO4 to regenerate PtII-X2. A rapid, non-Pt-catalyzed reaction of formed ethylene with the hot, concentrated H2SO4 solvent cleanly generate EtOSO3H as the initial product, which further reacts with the H2SO4 solvent to generate ITA.
- Konnick, Michael M.,Bischof, Steven M.,Yousufuddin, Muhammed,Hashiguchi, Brian G.,Ess, Daniel H.,Periana, Roy A.
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- Preparation method of ethyl glucuronide and ethyl sulfate of ethyl alcohol non-oxidative metabolite
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The invention relates to a preparation method of ethyl glucuronide and ethyl sulfate of ethyl alcohol non-oxidative metabolite, and belongs to the field of compound preparation. According to the preparation method, glucuronolactone is used as a basic reaction raw material, the ethyl glucuronide of the ethyl alcohol non-oxidative metabolite can be obtained by reacting under ultrasonic, water bath heating and other conditions through a triacetyl bromide glucuronic acid methyl ester intermediate, and the preparation method has the advantages of low environmental factors, simple operation and easyrealization; and in addition, absolute ethyl alcohol and sulfuric acid are used as raw materials, and the ethyl sulfate of the ethyl alcohol non-oxidative metabolite is obtained through heating, filtration, precipitation, water bath evaporating and other operations, and the preparation method has the advantages of wide source of raw materials, low requirements for environmental factors, simple operation and easy realization.
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Paragraph 0055-0071
(2020/06/09)
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- A capillary electrophoresis study of the synthesis and stability of 1,2-decanedisulfate, 1-hydroxy-2-decanesulfate, and 2-hydroxy-1-decanesulfate
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Capillary zone electrophoresis (CZE) was used to study the preparation of 1,2-decanedisulfate from 1,2-decanediol and determine the stability of the two-headed surfactant and the corresponding hydroxydecanesulfates under both acidic and basic conditions. The optimum buffer for the CZE determination was found to be diethylbarbiturate. Resolution of the hydroxydecanesulfate constitutional isomers was facilitated by the addition of magnesium ions. Decanedisulfate was stable in base but hydrolyzed in acid. The hydroxysulfates hydrolyzed much more rapidly, and in both acid and base. Mechanisms were postulated based on differential rates of formation and hydrolysis of the hydroxydecanesulfate constitutional isomers.
- Walker, Richard A.,MacDonald, Aaron C.,MacGillivray, Tanya,Marangoni, D. Gerrard,Smith-Palmer, Truis
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p. 292 - 296
(2007/10/03)
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- The decomposition of aliphatic N-nitro amines in aqueous sulfuric acid. Bisulfate as a nucleophile
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In aqueous sulfuric acid, aliphatic N-nitro amines decompose to N2O and alcohols. An excess acidity analysis of the observed rate constants for the reaction shows that free carbocations are not formed. The reaction is an acid-catalyzed SN2 displacement from the protonated aci-nitro tautomer, the nucleophile being a water molecule at acidities below 82-85% H2SO4, and a bisulfate ion at higher acidities. Bisulfate is the poorer nucleophile by a factor of about 1000. Twelve compounds were studied, of which results obtained for nine at several different temperatures enabled calculation of activation parameters for both nucleophiles. The reaction appears to be mainly enthalpy controlled. The intercept standard-state rate constants are well correlated by the σ* values for the alkyl groups; the slopes are negative, with a more negative value for the slower bisulfate reaction. Interestingly the m?m* slopes also correlate with σ*, although the scatter is bad.
- Cox, Robin A.
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p. 1774 - 1778
(2007/10/03)
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- Mg2+-Promoted P-O vs. S-O Bond Cleavage in the Alcoholyses of Phenyl Phosphatosulfate
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In order to obtain insight into the selectivity of Mg2+ at the site of bond cleavage of P-O and S-O of the P-O-S linkage, metal ion-promoted alcoholyses of phenyl phosphatosulfate were studied.Mg2+ quantitatively promoted P-O bond cleavage in the methanolysis, but mixed cleavage of the P-O bond, which occurred partly due to hydrolysis by trace water and the S-O bond in the reaction of ethanol, 1- or 2-propanol.The ratio of the S-O bond cleavage against the mixed cleavage increased in a order EtOH (11.5percent) 2+ and Zn2+ promoted selective P-O and S-O bond cleavage, respectively, in the reaction of 2-propanol as well as methanolysis.The medium-dependent change in the selectivity of Mg2+ at the site of bond cleavage was discussed.
- Eiki, Toshio,Negishi, Shin-ichi,Izumi, Mitsunori,Ishida, Naoko,Hada, Hiroshi
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p. 2931 - 2935
(2007/10/02)
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- ORGANOPHOSPHORO(THIOPEROXIC) ACIDS: DIRECT OBSERVATION AND REACTIVITY
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Peracid oxidation of organophosphorothioic acids yields novel organophosphoro(thioperoxic) acids (PSOH-isomers) and tentatively their POSH-isomers evident by 31P NMR spectroscopy.These acids or their further oxidation products are phosphorylating and sulfurylating agents.
- Segall, Yoffi,Wu, Shao-Yong,Toia, Robert F.,Casida, John E.
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p. 473 - 476
(2007/10/02)
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- Preparation of azo dyestuffs by diazotization and coupling in the presence of an ester
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Azo disperse dyestuffs are prepared by diazotization and coupling in an aqueous phase, the coupling being carried out in the presence of an ester of a lower aliphatic carboxylic acid.
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- Solvolysis of N-Sulfonoxyacetanilides in Aqueous and Alcohol Solutions: Generation of Electrophilic Species
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A series of ring-substituted N-sulfonoxyacetanilides (1a-f) were synthesized, and their solvolysis reactions in aqueous and alcohol solvents were studied.These compounds serve as models for the carcinogenic metabolites of polynuclear aromatic amides.Kinetic and product studies yielded evidence for solvolysis via N-O bond cleavage in aqueous solution with generation of tight ion pairs and solvent-separated ion pairs.The tight ion pairs, which cannot be trapped by nucleophiles or reducing agents, give rise to o-sulfonoxyacetanilides, while the solvent-separated ion pairs can be trapped by these reagents to yield ring-substituted compounds and reduction products.The para-substituted N-sulfonoxyacetanilides yield substantial amounts of highly electrophilic p-benzoquinone imine derivatives such as 10 during solvolysis in aqueous media.In ethanol these esters solvolyze exclusively via S-O bond cleavage with apparent production of SO3.This study demonstrates that electrophilic species other than nitrenium ions can be generated during the solvolysis of N-sulfonoxy-N-arylamides.These species may play a role in the in vivo activity of these metabolites.
- Novak, Michael,Pelecanou, Maria,Roy, Ajit K.,Andronico, Anthony F.,Plourde, Francine M.,et al.
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p. 5623 - 5631
(2007/10/02)
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- USE OF ETHYL ARENESULFONATES IN THE SYNTHESIS OF DIARYL SULFONES BY THE PYROSULFONATE METHOD
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The composition of the products from the reaction of liquid sulfur trioxide with ethyl p-toluensulfonate at various temperatures and with the reagents in various molar rations was studied by 1H NMR spectroscopy.In contrast to the corresponding methyl ester, the reaction mixtures did not contain the products from the addition of two or more moles of sulfur trioxide to the ethyl ester.Propyl and butyl p-toluensulfonates do not form pyrosulfonates with sulfur trioxide and cannot therefore be used in the synthesis of diaryl sulfones.
- Moskvichev, Yu. A.,Shapiro, Yu. E.,Timoshenko, G. N.,Gerasimova, N. P.,Shutova, I. V.,Mironov, G. S.
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p. 940 - 944
(2007/10/02)
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- SULFATION OF ALCOHOLS OF DIFFERENT STRUCTURES WITH CONCENTRATED SULFURIC ACID.
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The authors report the results of a study of the applicability of these relationships to the whole series of aliphatic alcohols including industrial products. The concentration equilibrium constants of the reactions of these alcohols with 99. 5 mass % sulfuric acid are determined at 32. 5 degree , and it is shown that all the higher alcohols can be characterized by the same equilibrium constant, 3. 1 plus or minus 0. 5, which can therefore be recommended for practical calculations. The equilibrium constants were calculated from the rate constants of the forward and reverse reactions. It is shown that they depend on the relative basicities of sulfuric acid and monoalkyl sulfates.
- Savelyanov,Yakushin
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p. 1527 - 1531
(2007/10/02)
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- The formation of ozone and peroxyacetyl nitrate (PAN) in the urban atmospheres of Alberta
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Atmospheric temperature inversions frequently trap pollutants in the urban atmospheres of Alberta leading to photochemical air pollution.Peroxyacetyl nitrate (PAN) was monitored, for the first time in Alberta, from November 1980 to August 1981 at the University of Calgary using electron capture gas chromatography.Measurements were made at one-half-hour intervals from July, 1981 to February, 1982 at a downtown location.Maximum PAN concentrations were recorded at the University and downtown sites on August 14 at 1400 h, 1981 and values were 2.4 and 6.6 ppb, respectively.In each case the maximum PAN peak coincided with the afternoon peak in ozone concentrations, 79 ppb at the University and 59 ppb at the downtown site.Surprisingly, a high value of 2.3 ppb PAN was recorded at the University during January of 1981 giving rise to questions regarding the influence of low temperatures and solar radiation on the photochemical formation of PAN.Calculations employinga simple photochemical model for PAN and ozone formation have been carried out and comparisons made between the observed and the computed values.
- Peake, E.,Sandhu, H. S.
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p. 927 - 935
(2007/10/02)
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