15833-75-7Relevant academic research and scientific papers
Toward Orally Absorbed Prodrugs of the Antibiotic Aztreonam. Design of Novel Prodrugs of Sulfate Containing Drugs. Part 2
Ding, Pingyu,Duncton, Matthew A. J.,Fan, Dazhong,Gordon, Eric M.,Grygorash, Ruslan,Li, Xianfeng,Low, Eddy,Ni, Zhi-Jie,Qi, Longwu,Sun, Jiawei,Wang, Brian J.,Yu, Guijun
supporting information, p. 162 - 165 (2020/01/31)
Aztreonam, first discovered in 1980, is an FDA approved, intravenous, monocyclic beta-lactam antibiotic. Aztreonam is active against Gram-negative bacteria and is still used today. The oral bioavailability of aztreonam in humans is less than 1%. Herein we describe the design and synthesis of potential oral prodrugs of aztreonam.
Experimental investigation of the low temperature oxidation of the five isomers of hexane
Wang, Zhandong,Herbinet, Olivier,Cheng, Zhanjun,Husson, Benoit,Fournet, Rene,Qi, Fei,Battin-Leclerc, Frederique
, p. 5573 - 5594 (2014/08/18)
The low-temperature oxidation of the five hexane isomers (n-hexane, 2-methyl-pentane, 3-methyl-pentane, 2,2-dimethylbutane, and 2,3-dimethylbutane) was studied in a jet-stirred reactor (JSR) at atmospheric pressure under stoichiometric conditions between 550 and 1000 K. The evolution of reactant and product mole fraction profiles were recorded as a function of the temperature using two analytical methods: gas chromatography and synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). Experimental data obtained with both methods were in good agreement for the five fuels. These data were used to compare the reactivity and the nature of the reaction products and their distribution. At low temperature (below 800 K), n-hexane was the most reactive isomer. The two methyl-pentane isomers have about the same reactivity, which was lower than that of n-hexane. 2,2-Dimethylbutane was less reactive than the two methyl-pentane isomers, and 2,3-dimethylbutane was the least reactive isomer. These observations are in good agreement with research octane numbers given in the literature. Cyclic ethers with rings including 3, 4, 5, and 6 atoms have been identified and quantified for the five fuels. While the cyclic ether distribution was notably more detailed than in other literature of JSR studies of branched alkane oxidation, some oxiranes were missing among the cyclic ethers expected from methyl-pentanes. Using SVUV-PIMS, the formation of C 2-C3 monocarboxylic acids, ketohydroperoxides, and species with two carbonyl groups have also been observed, supporting their possible formation from branched reactants. This is in line with what was previously experimentally demonstrated from linear fuels. Possible structures and ways of decomposition of the most probable ketohydroperoxides were discussed. Above 800 K, all five isomers have about the same reactivity, with a larger formation from branched alkanes of some unsaturated species, such as allene and propyne, which are known to be soot precursors.
Chemical Activation Study of the Reactions of Methylene with Oxetan and 3,3-Dimethyloxetan
Frey, Henry M.,Pidgeon, Ivy M.
, p. 1237 - 1248 (2007/10/02)
Methylene (singlet) formed by the photolysis of ketene (313 nm) reacts with oxetan to yield 2-methyl- and 3-methyloxetans by insertion in the C-H bonds and probably also tetrahydrofuran.These products are formed chemically activated and undergo unimolecular decomposition unless collisionally stabilized.Using perfluoropropane as the bath gas, the results obtained with 2-methyloxetan have been interpreted using RRKM theory and a step-ladder model with a most probable step size of ca. 9 kJ mol-1.Using 206 nm radiation yields methylene with excess energy, some of which is still present when it reacts, and results in the production of 2-methyloxetan with an average lifetime approximately one-half that of the energised molecule produced when 313 nm radiation is used.Similarly methylene reacts with 3,3-dimethyloxetan to yield chemically activated 3-ethyl-3-methyloxetan and 2,3,3-trimethyloxetan.A third compound tentatively identified as 3,3-dimethyltetrahydrofuran is also formed.The decomposition of these 3 molecules has been followed and in the case of the ethylmethyloxetan the average energy transferred in collision with 3,3-dimethyloxetan has been found to be ca. 6.5 kJ mol-1.Some deductions can be made about the Arrhenius parameters for the thermal decomposition of the (as yet unreported) trimethyloxetan and the dimethyltetrahydrofuran.
