75-93-4Relevant academic research and scientific papers
Methane oxidation to methyl bisulfate in oleum at ambient pressure in the presence of iodine as a catalyst
Michalkiewicz, Beata
, p. 266 - 268 (2011)
Methane oxidation to methyl bisulfate at ambient pressure in absorption reactor packed with glass balls in presence of iodine as a catalyst was investigated. The process was performed at temperature 120-130 °C, sulfur trioxide concentration in oleum 16-25 wt.%, catalyst concentration 0.008-0.024 mol dm-3, methane flow: 8.69 cm3 min-1. The optimal conditions for high ester concentration were defined.
Direct methane conversion to methanol by ionic liquid-dissolved platinum catalysts
Cheng, Jihong,Li, Zaiwei,Haught, Mark,Tang, Yongchun
, p. 4617 - 4619 (2006)
Ternary systems of inorganic Pt salts and oxides, ionic liquids and concentrated sulfuric acid are effective at catalyzing the direct, selective oxidation of methane to methanol and appear to be more water tolerant than the Catalytica reaction. The Royal Society of Chemistry 2006.
Sulfation of polysaccharides using monomethyl sulfate
Takano, Ryo,Nagai, Tomomi,Wu, Xiaofen,Xu, Xin-Yan,Huy, Nguyen Tien,Kamei, Kaeko,Hara, Saburo
, p. 1185 - 1190 (2000)
The polysaccharides, curdlan, starch and dextran were sulfated when heated in DMSO with sodium methyl sulfate and a catalytic amount of H2SO4 or with pyridinium methyl sulfate. Use of diminished pressure and anhydrous CaSO4 as a desiccant improved the degree of sulfation and recovery. Under conditions using sodium methyl sulfate, H2SO4 and CaSO4 in vacuo, sulfation at 0-6 was predominant in the cases of curdlan and starch, while sulfation at O-2 and O-3 was preferential in the case of dextran.
High yield conversion of methane to methyl bisulfate catalyzed by iodine cations
Periana, Roy A.,Mirinov, Oleg,Taube, Douglas J.,Gamble, Scott
, p. 2376 - 2377 (2002)
Iodine in 2% oleum is an efficient catalyst for the selective, high yield oxidation of methane to methyl bisulfate.
Uptake of methanol vapor in sulfuric acid solutions
Kane, Scan M.,Leu, Ming-Taun
, p. 1411 - 1415 (2001)
The uptake of gas-phase methanol by liquid sulfuric acid has been investigated over the composition range of 40-85 wt% H2SO4 and the temperature range of 210-235 K. Laboratory studies were performed with a flow-tube reactor coupled to an electron-impact ionization mass spectrometer to detect trace gases. While reversible uptake was the primary mechanism at low acid concentrations, an irreversible reaction between methanol and sulfuric acid at low temperatures, forming methyl hydrogen sulfate and dimethyl sulfate, was observed at all concentrations. At compositions >65 wt% H2SO4, more than 90% of uptake was found to be reactive. On the basis of the uptake data and the calculated liquid-phase diffusion coefficients, the product of the effective Henry's law constant (H*) and the square root of the overall liquid-phase reaction rate (k1) was calculated as a function of acid concentration and temperature. The results suggest that the reaction with sulfuric acid forming methyl hydrogen sulfate and dimethyl sulfate is the dominant loss mechanism of methanol and that the oxidation of methanol is only a minor source of hydroxyl radicals in the upper troposphere.
Methods for producing a methanol precursor, methanol, and a methyl ester from methane in high purities
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Page/Page column 10, (2021/06/02)
A method for producing a methanol precursor, methyl trifluoroacetate, having high-purity includes the steps of (a) preparing methyl bisulfate by mixing a catalyst with an acid solution comprising a sulfur-containing acid to provide a first mixture and supplying methane gas to the first mixture to prepare the methyl bisulfate; and (b) preparing methyl trifluoroacetate (CF3CO2CH3) by adding trifluoroacetic acid (CF3CO2H) to the first mixture including the methyl bisulfate to provide a second mixture and distilling the second mixture under heating to prepare, separate and purify the methyl trifluoroacetate (CF3CO2CH3). Methanol may be produced by adding water to the methyl trifluoroacetate (CF3CO2CH3). A methyl ester represented by Formula 2 below may be produced by adding a carboxylic acid represented by Formula 1 below to the methyl trifluoroacetate (CF3CO2CH3): R1CO2H??(1),where R1 is selected from C1-C10 alkyl groups, R1CO2CH3??(2),where R1 is as defined in Formula 1.
Theory and Experiment Demonstrate that Sb(V)-Promoted Methane C-H Activation and Functionalization Outcompete Superacid Protonolysis in Sulfuric Acid
Chen, Shu-Sen,Ess, Daniel H.,Koppaka, Anjaneyulu,Periana, Roy A.
supporting information, p. 18242 - 18250 (2021/11/12)
Sb(V) in strong Br?nsted acid solvents is traditionally assumed to react with light alkanes through superacid protonolysis, which results in carbocation intermediates, H2, and carbon oligomerization. In contrast to this general assumption, our density functional theory (DFT) calculations revealed an accessible barrier for C-H activation between methane and Sb(V) in sulfuric acid that could potentially outcompete superacid protonolysis. This prompted us to experimentally examine this reaction in sulfuric acid with oleum, which has never been reported because of presumed superacid reactivity. Reaction of methane at 180 °C for 3 h resulted in very high yields of methyl bisulfate without significant overoxidation. Our DFT calculations show that a C-H activation and Sb-Me bond functionalization mechanism to give methyl bisulfate outcompetes methane protonolysis and many other possible reaction mechanisms, such as electron transfer, proton-coupled electron transfer, and hydride abstraction. Our DFT calculations also explain experimental hydrogen-deuterium exchange studies and the absence of methane carbo-functionalization/oligomerization products. Overall, this work demonstrates that in very strong Br?nsted acid solvent, Sb(V) can induce innersphere reaction mechanisms akin to transition metals and outcompete superacid reactivity.
Preparation method of cefpodoxime acid
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Paragraph 0028, (2021/07/31)
The invention discloses a preparation method of cefpodoxime acid. The method comprises the following steps: adding a proper amount of solvent, 7-amino-3-chloromethyl cephalosporanic acid as shown in a formula (III), sodium methoxide, a quaternary ammonium salt catalyst and potassium iodide into a reaction container, performing stirring reaction at 0-80 DEG C for 2-8 hours, then adding 2-(2-amino-4-thiazolyl)-2-(Z)-methoxy imino acetyl chloride as shown in a formula (IV), performing stirring reaction at 0-30 DEG C for 2-5 hours, and after the reaction is finished, performing post-treatment to obtain cefpodoxime acid as shown in a formula (II). The method is simple and easy to operate, high in reaction yield, green and environmentally friendly, avoids the use of inflammable and explosive raw materials with high toxicity, improves the purity of the product by the post-treatment process, and is suitable for industrial production.
BISPHENOL COMPOSITION CONTAINING AROMATIC ALCOHOL SULFONATE AND METHOD FOR PRODUCING SAME, POLYCARBONATE RESIN AND METHOD FOR PRODUCING SAME, AND BISPHENOL PRODUCTION METHOD
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Paragraph 0253; 0255; 0257; 0258; 0264; 0265, (2020/07/07)
A bisphenol composition including a specific amount of aromatic alcohol sulfonate, and a simple method of producing it are provided. Also provided is a method of producing a polycarbonate resin in which, by using the bisphenol composition including a specific amount of aromatic alcohol sulfonate, melt polymerization reaction can be efficiently allowed to proceed to produce a polycarbonate resin having an excellent color tone. A bisphenol composition including an aromatic alcohol sulfonate at not less than 0.1 ppb by mass with respect to a bisphenol. A method of producing a bisphenol composition, including reacting a ketone or an aldehyde with an aromatic alcohol in the presence of sulfuric acid to produce a bisphenol composition. A method of producing a polycarbonate resin, including producing a polycarbonate resin using the bisphenol composition. A polycarbonate resin including a specific amount of aromatic alcohol sulfonate.
Pt black catalyzed methane oxidation to methyl bisulfate in H2SO4-SO3
Lee, Hee Won,Dang, Huyen Tran,Kim, Honggon,Lee, Ung,Ha, Jeong-Myeong,Jae, Jungho,Cheong, Minserk,Lee, Hyunjoo
, p. 230 - 236 (2019/05/17)
Although chloride-ligated Pt compounds like (bpym)PtCl2, K2PtCl4, and (DMSO)2PtCl2 has been reported to be highly active catalysts for the methane oxidation to methyl bisulfate (MBS) in oleum media, their applications is hampered by the catalyst deactivation to PtCl2. In this study, we investigated Pt black catalyzed methane oxidation, which has no ligand. A MBS yield of 82.1% with a selectivity of 96.5% was obtained at a catalyst loading of 1.6 mM at 180 °C, which proved the highest catalytic activity of Pt-black for this reaction. The reaction was thought to proceed by the dissolved Pt species, and no deactivation was observed during four consecutive experiments. However, at a concentration of over 30 mM, MBS yield fell due to the decomposition of MBS to CO2 on the surface of heterogeneous Pt(0). Vacuum distillation experiments showed the potential for isolating MBS from the oxidation product mixture as a major component.
