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Catalytic hydrogenation of an aromatic sulfonyl chloride into thiophenolRouckout, Nicolas Julien 15 May 2009 (has links)
The catalytic hydrogenation of an aromatic sulfonyl chloride was investigated in
continuous and semi-batch mode processes using a Robinson-Mahoney stationary basket
reactor. A complete experimental unit was designed and built. The operating and
analytical procedures have been developed and the methodologies to gather the kinetic
data have been described. Hydrogenation reactions were conducted at a reaction pressure
of 364.7 psia, at three different reaction temperatures: 85 °C, 97 °C and 110 °C, at five
different residence times: 0.6 (only at 110 °C), 1.0, 1.5, 2.0, 3.1 hr, with the hydrogen to
the aromatic sulfonyl chloride molar ratio: 8.0 mol/mol and hydrogen to argon molar
ratio: 3.0 mol/mol. Intrinsic reaction rates of the reacting species were obtained on the
surface of a commercial 1 wt% palladium on charcoal catalyst.
The conversion and molar yield profiles of the reacting species with respect to
process time suggest a deactivation of the 1 wt % palladium on charcoal catalyst. Kinetic
data collected in a continuous process mode show that the catalyst is deactivated during
an experiment when the process time equal to two to three times the residence time of
the liquid within the reactor. XRD analysis shows that the active sites are blocked and an
amorphous layer was formed on the surface of the palladium catalyst. Semi-Batch mode
experimental data were obtained at 110 °C after 8 hours of reaction time for several
aromatic sulfonyl chlorides. A kinetic model has been developed, which includes adsorption of individual
components and surface reactions as well as rate equations of the Hougen-Watson type.
A hyperbolic deactivation function expressed in term of process time is implemented in
the Hougen-Watson equation rates. The mathematical model consists of non-linear and
simultaneous differential equations with multiple variables. The kinetic parameters were
estimated from the minimization of a multi-response objective function by means of a
sequential quadratic program, which includes a quasi-Newton algorithm. The statistical
analysis was based on the t- and F-tests and the simulated results were compared to the
experimental data.
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Chemical Derivatization in Combination with Liquid Chromatography Tandem Mass Spectrometry for Detection and Structural Investigation of GlucuronidesLampinen Salomonsson, Matilda January 2008 (has links)
<p>This thesis presents novel approaches for structural investigation of glucuronides using chemical derivatization in combination with liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS<sup>n</sup>).</p><p>Today, LC-ESI-MS<sup>n</sup> is the dominant technique for quantitative as well as qualitative analyses of metabolites, due to its high sensitivity and selectivity. However, for compounds without an easily ionizable group, e.g., steroids, the sensitivity is limited. In the work presented in this thesis, a derivatization procedure forming a basic oxime significantly increased the detection sensitivity for the altrenogest glucuronide. </p><p>Furthermore, in structural evaluations of glucuronides, the limitation of LC-MS<sup>n</sup> becomes evident due to the initial neutral loss of 176 u, i.e. monodehydrated glucuronic acid, which often makes it impossible to elucidate the structures of the conjugates. To solve this problem, the main part of the work described in this thesis was devoted to chemical derivatization as a means of facilitating the determination of the site of conjugation. </p><p>For the first time, the isomeric estriol glucuronides were evaluated using a combination of three reagents 2-chloro-1-methylpyridinium iodide (CMPI), 1-ethyl-3-(3-dimethyl- aminopropyl)-carbodiimide (EDC), and 2-picolylamine (PA). Interestingly, the derivatization gave a selective fragmentation pattern leading to differentiation of the isomers. </p><p>Another derivatization reagent, 1,2-dimethylimidazole-4-sulfonyl chloride (DMISC), was also tested for the first time in structural investigations. The isomeric glucuronides of morphine, formoterol, and hydroxypropranolol were evaluated. They can all be conjugated in aliphatic as well as aromatic positions. DMISC was proven to be useful in two ways. Firstly, the morphine and formoterol glucuronides that contained a free phenol could be differentiated from those that were conjugated in the aromatic position based on different reactivity. Secondly, for the aromatic <i>O</i>-glucuronide of 4’-hydroxypropranolol, DMISC was proven to react with the amine. This product gave a different fragmentation pattern compared to the corresponding derivative of the aliphatic glucuronide. </p>
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Chemical Derivatization in Combination with Liquid Chromatography Tandem Mass Spectrometry for Detection and Structural Investigation of GlucuronidesLampinen Salomonsson, Matilda January 2008 (has links)
This thesis presents novel approaches for structural investigation of glucuronides using chemical derivatization in combination with liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MSn). Today, LC-ESI-MSn is the dominant technique for quantitative as well as qualitative analyses of metabolites, due to its high sensitivity and selectivity. However, for compounds without an easily ionizable group, e.g., steroids, the sensitivity is limited. In the work presented in this thesis, a derivatization procedure forming a basic oxime significantly increased the detection sensitivity for the altrenogest glucuronide. Furthermore, in structural evaluations of glucuronides, the limitation of LC-MSn becomes evident due to the initial neutral loss of 176 u, i.e. monodehydrated glucuronic acid, which often makes it impossible to elucidate the structures of the conjugates. To solve this problem, the main part of the work described in this thesis was devoted to chemical derivatization as a means of facilitating the determination of the site of conjugation. For the first time, the isomeric estriol glucuronides were evaluated using a combination of three reagents 2-chloro-1-methylpyridinium iodide (CMPI), 1-ethyl-3-(3-dimethyl- aminopropyl)-carbodiimide (EDC), and 2-picolylamine (PA). Interestingly, the derivatization gave a selective fragmentation pattern leading to differentiation of the isomers. Another derivatization reagent, 1,2-dimethylimidazole-4-sulfonyl chloride (DMISC), was also tested for the first time in structural investigations. The isomeric glucuronides of morphine, formoterol, and hydroxypropranolol were evaluated. They can all be conjugated in aliphatic as well as aromatic positions. DMISC was proven to be useful in two ways. Firstly, the morphine and formoterol glucuronides that contained a free phenol could be differentiated from those that were conjugated in the aromatic position based on different reactivity. Secondly, for the aromatic O-glucuronide of 4’-hydroxypropranolol, DMISC was proven to react with the amine. This product gave a different fragmentation pattern compared to the corresponding derivative of the aliphatic glucuronide.
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