558-43-0Relevant academic research and scientific papers
Biotransformation of 12C- and 2-13C-labeled methyl tert-butyl ether, ethyl tert-butyl ether, and tert-butyl alcohol in rats: Identification of metabolites in urine by 13C nuclear magnetic resonance and gas chromatography/mass spectrometry
Bernauer, Ulrike,Amberg, Alexander,Scheutzow, Dieter,Dekant, Wolfgang
, p. 651 - 658 (1998)
The biotransformation of the fuel oxygenates methyl tert-butyl ether (MTBE) and ethyl tertbutyl ether (ETBE) was studied in rats after inhalation exposure; the biotransformation of the initial metabolite of these ethers, tert-butyl alcohol, was studied after oral gavage. To study ether metabolism, rats were exposed for 6 h to initial concentrations of 2000 ppm of MTBE or ETBE, respectively [2-13C]MTBE and [2-13C]ETBE. Urine was collected for 48 h after the end of the exposure, and urinary metabolites were identified by 13C NMR (13C-labeled ethers) and gas chromatography/mass spectrometry (GC/MS) (12C- and 13C-labeled ethers). To study tert-butyl alcohol metabolism, rats were dosed either with tert-butyl alcohol at natural carbon isotope ratio or with 13C-enriched tert-butyl alcohol (250 mg/kg of body weight), urine was collected, and metabolites were identified by NMR and GC/MS. tert-Butyl alcohol was identified as a minor product of the biotransformation of MTBE and ETBE. In addition, small amounts of a tert- butyl alcohol conjugate, likely a glucuronide, were present in the urine of the treated animals. Moreover, the mass spectra obtained indicate the presence of small amounts of [13C]acetone in the urine of [13C]MTBE and [13C]ETBE-treated rats. 2-Methyl-1,2-propanediol, 2-hydroxyisobutyrate, and another unidentified conjugate of tert-butyl alcohol, most probably a surf ate, were major urinary metabolites of MTBE and ETBE as judged by the intensities of the NMR signals. In [13C]-tert-butyl alcohol-dosed rats, [13C]acetone, tert-butyl alcohol, and its glucuronide represented minor metabolites; as with the ethers, 2-methyl-1,2-propanediol, 2- hydroxyisobutyrate, and the presumed tert-butyl alcohol sulfate were the major metabolites present. In one human individual given 5 mg/kg [13C]- tert-butyl alcohol orally, 2-methyl-1,2-propanediol and 2-hydroxyisobutyrate were major metabolites in urine detected by 13C NMR analysis. Unconjugated tert-butyl alcohol and tert-butyl alcohol glucuronide were present as minor metabolites, and traces of the presumed tert-butyl alcohol sulfate were also present. Our results suggest that tert-butyl alcohol formed from MTBE and ETBE is intensively metabolized by further oxidation reactions. Studies to elucidate mechanisms of toxicity for these ethers to the kidney need to consider potential toxicities induced by these metabolites.
An Estimate of the Lifetime of 1,4-Dioxybutane Biradicals
Richardson, William H.,Lovett, Merylyn B.,Olson, Leif
, p. 3523 - 3525 (1989)
Previous kinetic data for the thermolysis of 1,2-dioxetanes has suggested a biradical or biradicaloid decomposition route, but direct evidence for a biradical intermediate has been lacking.We now report the trapping of a 1,4-dioxybutane biradical in the thermolysis of 3,3-dimethyl-1,2-dioxethane, where the lifetime is estimated to be in the range of 30-75 ps.Attempts to trap biradicals from the thermolysis of trimethyl- and tetramethyl-1,2-dioxethane were used unsuccessful, and it was estimated that the maximum lifetimes of these biradicals were 7 ps.
The discovery of a potent and selective pyrazolo-[2,3-e]-[1,2,4]-triazine cannabinoid type 2 receptor agonist
Moir, Michael,Lane, Samuel,Montgomery, Andrew P.,Hibbs, David,Connor, Mark,Kassiou, Michael
, (2020/12/21)
The development of selective CB2 receptor agonists is a promising therapeutic approach for the treatment of inflammatory diseases, without CB1 receptor mediated psychoactive side effects. Preliminary structure-activity relationship studies on pyrazoylidene benzamide agonists revealed the -ylidene benzamide moiety was crucial for functional activity at the CB2 receptor. A small library of compounds with varying linkage moieties between the pyrazole and substituted phenyl group has culminated in the discovery of a potent and selective pyrazolo-[2,3-e]-[1,2,4]-triazine agonist 19 (CB2R EC50 = 19 nM, CB1R EC50 > 10 μM). Docking studies have revealed key structural features of the linkage group that are important for potent functional activity.
Mo–Catalyzed One-Pot Synthesis of N-Polyheterocycles from Nitroarenes and Glycols with Recycling of the Waste Reduction Byproduct. Substituent-Tuned Photophysical Properties
Hernández-Ruiz, Raquel,Rubio-Presa, Rubén,Suárez-Pantiga, Samuel,Pedrosa, María R.,Fernández-Rodríguez, Manuel A.,Tapia, M. José,Sanz, Roberto
supporting information, p. 13613 - 13623 (2021/08/23)
A catalytic domino reduction–imine formation–intramolecular cyclization–oxidation for the general synthesis of a wide variety of biologically relevant N-polyheterocycles, such as quinoxaline- and quinoline-fused derivatives, and phenanthridines, is reported. A simple, easily available, and environmentally friendly dioxomolybdenum(VI) complex has proven to be a highly efficient and versatile catalyst for transforming a broad range of starting nitroarenes involving several redox processes. Not only is this a sustainable, step-economical as well as air- and moisture-tolerant method, but also it is worth highlighting that the waste byproduct generated in the first step of the sequence is recycled and incorporated in the final target molecule, improving the overall synthetic efficiency. Moreover, selected indoloquinoxalines have been photophysically characterized in cyclohexane and toluene with exceptional fluorescence quantum yields above 0.7 for the alkyl derivatives.
KIF18A INHIBITORS
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Paragraph 0283, (2020/07/14)
Compounds of formula (I): (I), as defined herein, and synthetic intermediates thereof, which are capable of modulating KIF18A protein thereby influencing the process of cell cycle and cell proliferation to treat cancer and cancer-related diseases. The invention also includes pharmaceutical compositions, including the compounds, and methods of treating disease states related to the activity of KIF18A.
Transfer hydrogenation of cyclic carbonates and polycarbonate to methanol and diols by iron pincer catalysts
Liu, Xin,De Vries, Johannes G.,Werner, Thomas
, p. 5248 - 5255 (2019/10/11)
Herein, we report the first example on the use of an earth-abundant metal complex as the catalyst for the transfer hydrogenation of cyclic carbonates to methanol and diols. The advantage of this method is the use of isopropanol as the hydrogen source, thus avoiding the handling of flammable hydrogen under high pressure. The reaction offers an indirect route for the reduction of CO2 to methanol. In addition, poly(propylene carbonate) was converted to methanol and propylene glycol. This methodology can be considered as an attractive opportunity for the chemical recycling of polycarbonates.
Synthesis, Characterization and Catalytic Application of Pyridine-Bridged N-Heterocyclic Carbene–Ruthenium Complexes in the Hydrogenation of Carbonates
Chen, Jiangbo,Zhu, Haibo,Chen, Jinjin,Le, Zhang-Gao,Tu, Tao
supporting information, p. 2809 - 2812 (2017/10/23)
A series of bulky pyridine-bridged NHC–Ru complexes have been rationally designed and synthesized; these exhibited very high catalytic activity in the hydrogenation of cyclic and linear carbonates under mild reaction conditions. In the presence of catalytic amounts of a weak base, a broad range of substrates with different ring size and steric bulk were well tolerated, providing methanol and the corresponding diols in excellent yields with a catalyst loading as low as 0.5 mol %.
A Highly Regioselective Palladium-Catalyzed O,S Rearrangement of Cyclic Thiocarbonates
Mahy, William,Cabezas-Hayes, Sinéad,Kociok-K?hn, Gabriele,Frost, Christopher G.
supporting information, p. 6441 - 6444 (2017/11/13)
This work describes an operationally simple catalytic synthesis of cyclic S-thiocarbonates with predictable regioselectivity in good yields. The reaction utilizes substrates derived from ubiquitous 1,2-diols in an atom economical intramolecular rearrangement, catalysed by an inexpensive and simple catalyst–ligand system. A crystal structure is presented that clearly confirms the regioselectivity of the reaction.
Quinoline or quinazoline derivatives, its preparation process and its use in medicine
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Paragraph 0262-0266, (2018/01/19)
The invention relates to a quinoline or quinazoline derivative, its preparation method and an application in medicines, specifically to new quinoline or quinazoline derivative as shown in a general formula (I) and its medicinal salt or a pharmaceutical composition containing the derivative and a preparation method thereof. The invention further relates to an application of the quinoline or quinazoline derivative and its medicinal salt or the pharmaceutical composition containing the derivative in the preparation of a therapeutic agent, especially a protein kinase inhibitor. Each substituent group in the general formula (I) has the same definition as in the specification.
Dehydrochlorination of 2-chloroethanol, 2-chloro-1-propanol, 1-chloro-2-propanol, 2-chloro-2-methyl-1-propanol and 1-chloro-2-methyl-2- propanol
Pihlaja, Kalevi,Kiuru, Marja-Leena,Sippola, Anne
, p. 120 - 133 (2013/09/24)
The reactions between a few 1,2-chlorohydrins and sodium hydroxide have been studied and shown to involve a two-step nucleophilic elimination of hydrogen chloride. The data are given for the slow rate-determining step of 2-chloroethanol 1, 2-chloro-1-propanol 2, 1-chloro-2- propanol 3, 2-chloro-2-methyl-1-propanol 4 and 1-chloro-2-methyl-2-propanol 5. Compounds 4 and 5 gave 2-methyl-1,2-propanediol as the final product instead of oxiranes given by compounds 13. In contrast to some earlier reports the mere water reaction was shown to be almost negligible. In constant ionic strength the base concentration had no effect on the rates whereas at different base concentrations (0.0500.250 mol dm-3) alone the rate of alkaline dehydrochlorination of 1 clearly decreased (103k2, dm 3 mol-1 s-1: 10.0-8.7, respectively). The rate of 2 at constant base concentration (0.010 mol dm-3) and at different ionic strengths (dm3 mol-1: 0.010-0.500) decreased also (103k2, dm3 mol-1 s-1: 76-65, respectively) indicating that the decrease is mainly due to the change in the ionic strength also in the former case. ARKAT-USA, Inc.
