628-35-3Relevant articles and documents
HOMOLYTIC REPLACEMENT OF A HYDROGEN ATOM IN 2-METHYLQUINOLINE
Zorin, V. V.,Zelechonok, Yu. B.,Zlotskii, S. S.,Rakhmankulov, D. L.
, p. 20 - 23 (1984)
The reaction of 1,3-dioxolane with sulfuric-acid-protonated 2-methylquinoline initiated by the ROOH + Fe2+ system at 5-10 deg C in water forms 4-(1,3-dioxacyclopent-2-yl)-2-methylquinoline and 4-(1,3-dioxacyclopent-4-yl)-2-methylquinoline.The selectivity of the formation of the first reaction product increases on passing from hydrogen peroxide to cumyl and tert-butyl hydroperoxide and with an increase in the pH of the medium.
Identification of an Adduct Impurity of an Active Pharmaceutical Ingredient and a Leachable in an Ophthalmic Drug Product Using LC-QTOF
Gollapalli, Ramarao,Singh, Gagandeep,Blinder, Alejandro,Brittin, Jeremiah,Sengupta, Arijit,Mondal, Bikash,Patel, Milan,Pati, Biswajit,Lee, James,Ghode, Amit,Kote, Mahesh
, p. 3187 - 3193 (2019)
Impurity investigations are important in pharmaceutical development to ensure drug purity and safety for the patient. The impurities typically found in drug products are degradants or reaction products of the active pharmaceutical ingredient (API) or leachable compounds from the container closure system. However, secondary reactions may also occur between API degradants, excipient impurities, residual solvents, and leachables to form adduct impurities. We hereby report an adduct-forming interaction of API (moxifloxacin) with a leachable compound (ethylene glycol monoformate) in moxifloxacin ophthalmic solution. The leachable compound originated from a low-density polyethylene bottle used in the packaging of drug products. The adduct impurity was tentatively identified as 1-cyclopropyl-6-fluoro-7-(1-(2-(formyloxy)ethyl) octahydro-6H-pyrrolo[3,4-b]pyridin-6-yl)-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (C24H28FN3O6, MW = 473.19621) using accurate mass LC-QTOF analysis. The mass accuracy error between the theoretical mass and the experimental mass of an impurity was found to be 0.2 ppm. An MS/MS analysis was utilized to provide mass spectrometry fragments to support verification of the proposed structure.
Mechanism of the degradation of 1,4-dioxane in dilute aqueous solution using the UV/hydrogen peroxide process
Stefan, Mihaela I.,Bolton, James R.
, p. 1588 - 1595 (1998)
1,4-Dioxane is an EPA priority pollutant often found in contaminated groundwaters and industrial effluents. The common techniques used for water purification are not applicable to 1,4-dioxane, and the currently used method (distillation) is laborious and expensive. This study aims to understand the degradation mechanism of 1,4-dioxane and its byproducts in dilute aqueous solution toward complete mineralization, by using the UV/H2O2 process in a UV semibatch reactor. The decay of 1,4-dioxane generated several intermediates identified and quantified as aldehydes (formaldehyde, acetaldehyde, and glyoxal), organic acids (formic, methoxyacetic, acetic, glycolic, glyoxylic, and oxalic) and the mono- and diformate esters of 1,2- ethanediol. Measurement of the total organic carbon (TOC) during the treatment indicated a good agreement between the experimentally determined TOC values and those calculated from the quantified reaction intermediates, ending in complete mineralization. A reaction mechanism, which accounts for the observed intermediate products and their time profiles during the treatment, is proposed. Considering the efficacy of the 1,4-dioxane removal from dilute aqueous solutions, as shown in this work, the present study can be regarded as a model for industrially affordable Advanced Oxidation Technologies. 1,4-Dioxane is an EPA priority pollutant often found in contaminated groundwaters and industrial effluents. The common techniques used for water purification are not applicable to 1,4-dioxane, and the currently used method (distillation) is laborious and expensive. This study aims to understand the degradation mechanism of 1,4-dioxane and its byproducts in dilute aqueous solution toward complete mineralization, by using the UV/H2O2 process in a UV semibatch reactor. The decay of 1,4-dioxane generated several intermediates identified and quantified as aldehydes (formaldehyde, acetaldehyde, and glyoxal), organic acids (formic, methoxyacetic, acetic, glycolic, glyoxylic, and oxalic) and the mono- and diformate esters of 1,2-ethanediol. Measurement of the total organic carbon (TOC) during the treatment indicated a good agreement between the experimentally determined TOC values and those calculated from the quantified reaction intermediates, ending in complete mineralization. A reaction mechanism, which accounts for the observed intermediate products and their time profiles during the treatment, is proposed. Considering the efficacy of the 1,4-dioxane removal from dilute aqueous solutions, as shown in this work, the present study can be regarded as a model for industrially affordable Advanced Oxidation Technologies.
Hydroxide Based Integrated CO2 Capture from Air and Conversion to Methanol
Sen, Raktim,Goeppert, Alain,Kar, Sayan,Prakash, G. K. Surya
supporting information, p. 4544 - 4549 (2020/02/27)
The first example of an alkali hydroxide-based system for CO2 capture and conversion to methanol has been established. Bicarbonate and formate salts were hydrogenated to methanol with high yields in a solution of ethylene glycol. In an integrated one-pot system, CO2 was efficiently captured by an ethylene glycol solution of the base and subsequently hydrogenated to CH3OH at relatively mild temperatures (100-140 °C) using Ru-PNP catalysts. The produced methanol can be easily separated by distillation. Hydroxide base regeneration at low temperatures was observed for the first time. Finally, CO2 capture from ambient air and hydrogenation to CH3OH was demonstrated. We postulate that the high capture efficiency and stability of hydroxide bases make them superior to existing amine-based routes for direct air capture and conversion to methanol in a scalable process.
Ruthenium-Catalyzed Synthesis of Cyclic and Linear Acetals by the Combined Utilization of CO2, H2, and Biomass Derived Diols
Beydoun, Kassem,Klankermayer, Jürgen
supporting information, p. 11412 - 11415 (2019/07/18)
Herein a transition-metal catalyst system for the selective synthesis of cyclic and linear acetals from the combined utilization of carbon dioxide, molecular hydrogen, and biomass derived diols is presented. Detailed investigations on the substrate scope enabled the selectivity of the reaction to be largely guided and demonstrated the possibility of integrating a broad variety of substrate molecules. This approach allowed a change between the favored formation of cyclic acetals and linear acetals, originating from the bridging of two diols with a carbon-dioxide based methylene unit. This new synthesis option paves the way to novel fuels, solvents, or polymer building blocks, by the recently established “bio-hybrid” approach of integrating renewable energy, carbon dioxide, and biomass in a direct catalytic transformation.
Oxidative C-C bond cleavage of primary alcohols and vicinal diols catalyzed by H5PV2Mo10O40 by an electron transfer and oxygen transfer reaction mechanism
Khenkin, Alexander M.,Neumann, Ronny
supporting information; experimental part, p. 14474 - 14476 (2009/02/08)
Primary alcohols such as 1-butanol were oxidized by the H5PV2Mo10O40 polyoxometalate in an atypical manner. Instead of C-H bond activation leading to the formation of butanal and butanoic acid, C-C bond cleavage took place leading to the formation of propanal and formaldehyde as initial products. The latter reacted with the excess 1-butanol present to yield butylformate and butylpropanate in additional oxidative transformations. Kinetic studies including measurement of kinetic isotope effects, labeling studies with 18O labeled H5PV2Mo10O40, and observation of a prerate determining step intermediate by 13C NMR leads to the formulation of a reaction mechanism based on electron transfer from the substrate to the polyoxometalate and oxygen transfer from the reduced polyoxometalate to the organic substrate. It was also shown that vicinal diols such as 1,2-ethanediol apparently react by a similar reaction mechanism. Copyright
METHOD OF OBTAINING POLYOXYGENATED ORGANIC COMPOUNDS
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Page/Page column 12, (2008/06/13)
The invention relates to a method of obtaining polyoxygenated organic compounds. The inventive method is characterized in that it comprises the oxidation reaction of a diether, preferably an acetal, with an oxygen source, in the presence of: one or more radical initiating agents, one or more additives that generate a basic reaction medium, and one or more catalysts.
Method for producing diol derivatives
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Page 21-23, (2010/02/07)
A method of producing a diol derivative efficiently and to high purity is provided. Specifically, the present invention relates to a method of producing a diol derivative having, as a fundamental step, a step of obtaining an α-hydroxycarboxylic acid ester by reacting (i) one or more 1,2-diols or (ii) a 1,2-diol and a primary alcohol as starting material(s) with oxygen in the presence of a catalyst comprising metal loaded on a carrier.
Kinetic and product studies of the reactions of selected glycol ethers with OH radicals
Aschmann,Martin,Tuazon,Arey,Atkinson
, p. 4080 - 4088 (2007/10/03)
Glycol ethers are widely used as solvents and are hence liable to be released into the atmosphere where they may contribute to the formation of photochemical air pollution in urban and regional areas. The dominant reaction of glycol ethers in the atmosphere has been previously shown to be with OH radicals. Using a relative rate method, rate constants have been measured at 296 ± 2 K for the gasphase reactions of the OH radical with 1-butoxy-2propanol [CH3CH2CH2CH2OCH2CH (OH)CH3], diethylene glycol ethyl ether [CH3CH2OCH2 CH2OCH2CH2OH], and diethylene glycol n-butyl ether [CH3CH2CH2CH2OCH2 CH2OCH2CH2OH] of (in units of 10-11 cm3 molecule-1 s-1) 3.76 ± 0.54, 5.72 ± 0.85, and 7.44 ± 0.94, respectively, where the error limits include the estimated overall uncertainties in the rate constants for the reference compounds. Products of the OH radical-initiated reactions of these glycol ethers have been investigated using gas chromatography with flame ionization detection (GC-FID), combined gas chromatography-mass spectrometry(GC-MS), in situ Fourier transform infrared (FT-IR) spectroscopy, and in situ atmospheric pressure ionization tandem mass spectrometry (API-MS). The products identified and quantified account for 102 ± 11% of the reaction products from 1-butoxy-2-propanol, 87 ± 9% of those from diethylene glycol ethyl ether, and 83 ± 12% of those from diethylene glycol n-butyl ether. An empirical estimation method for calculating reaction rates of alkoxy radicals under atmospheric conditions appears to fairly well predict the products formed and their yields. Detailed reaction schemes after the initial OH radical reactions are formulated for each of these glycol ethers, with the majority of the reactions involving H-atom abstraction from the CH2 groups adjacent to the ether linkage.
Products of the gas-phase reactions of the OH radical with 1-methoxy-2-propanol and 2-butoxyethanol
Tuazon, Ernesto C.,Aschmann, Sara M.,Atkinson, Roger
, p. 3336 - 3345 (2007/10/03)
Glycol ethers are used as solvents and are hence liable to b;e released to the atmosphere, where they react and contribute to the formation of photochemical air pollution. In this work, products of the gas-phase reactions of the OH radical with 1-methoxy-2-propanol and 2-butoxyethanol in the presence of NO have been investigated at 298 ± 2 K and 740 Torr total pressure of air by gas chromatography, in situ Fourier transform infrared spectroscopy, and in situ atmospheric pressure ionization tandem mass spectrometry. The products observed from 1-methoxy-2-propanol were methyl formate, methoxyacetone, and acetaldehyde with molar formation yields of 0.59 ± 0.05, 0.39 ± 0.04, and 0.56 ± 0.07, respectively. The products observed and quantified from 2-butoxyethanol were n-butyl formate, 2-hydroxyethyl formate, propanal, 3-hydroxybutyl formate, and an organic nitrate (attributed to CHsChbCHaCH2OCH(ON02)CH2OH and its isomers), with molar formation yields of 0.57 ± 0.05, 0.22 ± 0.05, 0.21 ± 0.02, 0.07 ± 0.03, and 0.10 ± 0.03, respectively. An additional product of molecular weight 132, attributed to one or more hydroxycarbonyl products, was also observed from the 2-butoxyethanol reaction by atmospheric pressure ionization mass spectrometry. For both glycol ethers, the majority of the reaction products and reaction pathways are accounted for, and detailed reaction mechanisms are presented which account for the observed products.
