758-12-3Relevant articles and documents
Kinetic understanding using NMR reaction profiling
Susanne, Flavien,Smith, David S.,Codina, Anna
, p. 61 - 64 (2012)
The combination of kinetic understanding and reaction modeling has been successfully applied to the development of processes from laboratory to manufacturing plant. Although extensively used in bulk chemistry, polymers, and the oil industry [ Bayer Technology Services, http://www.bayertechnology.cn/ uploads/media/0707-e-300dpi.pdf, July 2011; Lawrence Livermore National Laboratory, http://www1.eere.energy.gov/vehiclesandfuels/pdfs/merit-review-2011/ fuel-technologies/ft010-pitz-2 011-o.pdf,July 2011; Shin, S. B.; Han, S. P.; Lee, W. J.; Chae, J. H.; Lee, D. I.; Lee, W. H.; Urban, Z.Hydrocarbon Process. 2007, April) 83; Baumer, C.; Urban, Z.Hydrocarbon Process. 2007, June) 71 ], it has not been exploited to its full potential in the pharmaceutical industry. We present a fast and efficient methodology for kinetic modeling of chemical reactions using 1H NMR reaction monitoring that can be used for the process understanding and development of active pharmaceutical ingredients. The parameters that are important for the development of a good, reliable model for the prediction and optimization of reaction conditions are discussed. The hydrolysis of acetic anhydride was chosen to illustrate the methodology because it is mechanistically and kinetically well established.
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Lewis,Schutz
, p. 493 (1934)
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de la Mare,Dusouqui
, p. 251 (1967)
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Linschitz,Hobbs,Gross
, p. 3234 (1941)
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Tadokoro et al.
, p. 1504,1505 (1961)
Bonner
, p. 2661,2662 (1961)
Stepwise Iodide-Free Methanol Carbonylation via Methyl Acetate Activation by Pincer Iridium Complexes
Yoo, Changho,Miller, Alexander J. M.
supporting information, p. 12633 - 12643 (2021/08/23)
Iodide is an essential promoter in the industrial production of acetic acid via methanol carbonylation, but it also contributes to reactor corrosion and catalyst deactivation. Here we report that iridium pincer complexes mediate the individual steps of methanol carbonylation to methyl acetate in the absence of methyl iodide or iodide salts. Iodide-free methylation is achieved under mild conditions by an aminophenylphosphinite pincer iridium(I) dinitrogen complex through net C-O oxidative addition of methyl acetate to produce an isolable methyliridium(III) acetate complex. Experimental and computational studies provide evidence for methylation via initial C-H bond activation followed by acetate migration, facilitated by amine hemilability. Subsequent CO insertion and reductive elimination in methanol solution produced methyl acetate and acetic acid. The net reaction is methanol carbonylation to acetic acid using methyl acetate as a promoter alongside conversion of an iridium dinitrogen complex to an iridium carbonyl complex. Kinetic studies of migratory insertion and reductive elimination reveal essential roles of the solvent methanol and distinct features of acetate and iodide anions that are relevant to the design of future catalysts for iodide-free carbonylation.
Production of Pure Aqueous13C-Hyperpolarized Acetate by Heterogeneous Parahydrogen-Induced Polarization
Kovtunov, Kirill V.,Barskiy, Danila A.,Shchepin, Roman V.,Salnikov, Oleg G.,Prosvirin, Igor P.,Bukhtiyarov, Andrey V.,Kovtunova, Larisa M.,Bukhtiyarov, Valerii I.,Koptyug, Igor V.,Chekmenev, Eduard Y.
supporting information, p. 16446 - 16449 (2016/11/09)
A supported metal catalyst was designed, characterized, and tested for aqueous phase heterogeneous hydrogenation of vinyl acetate with parahydrogen to produce13C-hyperpolarized ethyl acetate for potential biomedical applications. The Rh/TiO2catalyst with a metal loading of 23.2 wt % produced strongly hyperpolarized13C-enriched ethyl acetate-1-13C detected at 9.4 T. An approximately 14-fold13C signal enhancement was detected using circa 50 % parahydrogen gas without taking into account relaxation losses before and after polarization transfer by magnetic field cycling from nascent parahydrogen-derived protons to13C nuclei. This first observation of13C PHIP-hyperpolarized products over a supported metal catalyst in an aqueous medium opens up new possibilities for production of catalyst-free aqueous solutions of nontoxic hyperpolarized contrast agents for a wide range of biomolecules amenable to the parahydrogen induced polarization by side arm hydrogenation (PHIP-SAH) approach.
