Synthesis and properties of some 4H-1, 3, 4 benzothiadiazines /|nby Darko J. Vukov. -- 260 St. Catharines, Ont. : [s. n.],

The work herein has been divided into five sections. In the first section, a new method of converting N-aroyl- hydrazines to hydrazidic halides is described. The second section deals with the products of reaction of hydrazidic halides with thioacetate ion in acetonitrile at room temperature. A number of new acetylthiohydrazides has been isolated together with corresponding hyclrazidic sulphides. Examination of x-ray data for bis-[~ -(2,6- dibromophenylhydrazono) - benZYl] sulphide revealpd the symmetrical structure as the most probable. In the third section, which consists of the three subsections, the synthesis of the 4H-l,3,4 benzothiadiazine ring system has been extended to 4H-l,3,4 benzothiadiazines with substituents in the 5 and 6-positions. Extension of synthesis also involves 4H-l,3,4 benzothiadiazines with mora than one substituent. Nuclear magnetic resonance spectra of 5 and 6 substituted 4H-l,3,4 benzothiadiazines have been ,. recorded. The section ends with a discussion of the mass spectra of some 4H-l.3,4 benzothiadiazines. In the fourth section, which is divided into two sub- -sections, preparation of 7-nitro substituted 4H-l,3,4 benzothiadiazine from N-thiobenzoyl hydrazine and2,4-dinitro -fluorobenzene is found to be satisfactory. Thiohydrazides react with acetic anhydride, in some cases, to give products identical with acetylthiohydrazides obtained from the hydrazidic halides with thioacetate ion at room temperature. In most of the cases thiohydrazides are found to give anomalous products on reaction with acetic anhydride and mechanisms for their formation are discussed. In the fifth section, which forms three subsections, the 4H-l,3,4 benzothiadiazine ring system with a halogen substituent in the 7-position undergoes electrophilic attack preferentially in 5-posi tion. \fuen the 5-posi tion is occupied by a halogen atom, electrophilic substitution occurs at the 7-position of 4H-l,3,4 benzothiadiazine ring system. Substitution at the 4-nitrogen atom in 4H w l,3,4 benzo- -thiadiazine is extremely slow, probably due to delocalisa- -tion of the nitrogen lone pair in the system. Oxidation of 4H-l,3,4 benzothiadiazines occurs at the sulphur atom under relatively mild conditions. t The Appendix deals with the reaction of N-benzoyl-N - -(2,5-dibromophenyl)hydrazine with p-nitrothiophenol~ The proposed p-nitrothiophenoxy - intermediate may undergo benzothiadiazine formation in a proton exchange system.

Reading Instruction and Instructors’ Perceptions of Learners’ Needs in LINC Level 1-3 Classes

This study investigates instructors’ perceptions of reading instruction and difficulties among Language Instruction for Newcomers to Canada (LINC) Level 1-3 learners. Statistics Canada reports that 60% of immigrants possess inadequate literacy skills. Newcomers are placed in classes using the Canadian Language Benchmarks but large, mixed-level classes create little opportunity for individualized instruction, leading some clients to demonstrate little change in their reading benchmarks. Data were collected (via demographic questionnaires, semi-structured interviews, teaching plans, and field study notes) to create a case study of five LINC instructors’ perceptions of why some clients do not progress through the LINC reading levels as expected and how their previous experiences relate to those within the LINC program. Qualitative analyses of the data revealed three primary themes: client/instructor background and classroom needs, reading, strategies, methods and challenges, and assessment expectations and progress, each containing a number of subthemes. A comparison between the themes and literature demonstrated six areas for discussion: (a) some clients, specifically refugees, require more time to progress to higher benchmarks; (b) clients’ level of prior education can be indicative of their literacy skills; (c) clients with literacy needs should be separated and placed into literacy-specific classes; (d) evidence-based approaches to reading instruction were not always evident in participants’ responses, demonstrating a lack of knowledge about these approaches; (e) first language literacy influences second language reading acquisition through a transfer of skills; and (f) collaboration in the classroom supports learning by extending clients’ capabilities. These points form the basis of recommendations about how reading instruction might be improved for such clients.

Question period of the Liberal Neutrality Conference (May 1-3, 2008)

This is the audio recording of all discussion sessions of the International Conference on the Re-evaluation of Liberal Neutrality organized by CRÉUM, Montreal May 1-3 2008. (The conference announcement is at http://www.creum.umontreal.ca/spip.php?article765) // Ceci est l'enregistrement audio des périodes de discussion du colloque organisé par le CRÉUM (Montréal, 1-3 mai 2008) et portant sur une ré-évaluation de la neutralité libérale. (L'annonce du colloque est à l'adresse http://www.creum.umontreal.ca/spip.php?article765)

Libro de lectura no. 1- [3] : o sea autores selectos españoles e hispano-americanos

UANL

Macrobius, the classical paideia, and table etiquette c. 420 CE : a commentary on the Saturnalia 7.1-3

Ce mémoire traite des Saturnales de Macrobe, haut fonctionnaire du 5ième siècle après J.C. et encyclopédiste latin. Malgré l’opinion reçue, selon laquelle les Saturnales dépendraient presque exclusivement d’un nombre très restreint de sources, souvent copiées mot à mot, on a reconnu depuis longtemps que Macrobe remanie de son propre chef l’une de ces sources, les Propos de Table de Plutarque, dans son septième livre. Ce mémoire démontre que ce modèle, tout comme les sources mineures, latines et grecques, avec lesquelles Macrobe le complète, lui était assez familier pour servir à l’articulation d’une vision propre; les Saturnales ne peuvent donc être cités comme preuve de la décadence de leur époque. Ce mémoire fournit une traduction et un commentaire des chapitres 7.1-3 des Saturnales, avec une explication de leurs rapports avec les Propos de Table 1.1 et 2.1 de Plutarque ainsi que des éléments propre à Macrobe, afin de reconstruire sa méthode de composition et de déterminer ses attentes par rapport à son lecteur de l’empire tardif. Le commentaire est précédé d’une introduction de l’auteur, de l’œuvre, et du septième livre.

La cristallisation de quatre poly(1,3-dioxolannes) de masses molaires différentes

Le poly(1,3-dioxolanne) (PDOL) est un polymère semi-cristallin présentant à l’état solide quatre morphologies différentes (Phases I, IIa, IIb et III). Les transformations d'une phase à l'autre ont été suivies par microscopie optique polarisée (MOP) et microscopie à force atomique (AFM) en fonction de la température de cristallisation et de la masse molaire. La Phase I présente une morphologie sphérolitique tandis que la Phase IIa peut croître à partir de la Phase I ou spontanément. De façon inattendue, la Phase IIa, devient très biréfringente et cette nouvelle morphologie est appelée Phase IIb. Quand la transformation IIa-IIb est terminée, une nouvelle phase, la Phase III, croît à partir de la Phase IIb. La Phase III n'a jamais été observée sans la présence de Phase IIb; en outre, la Phase IIb remplace toujours la Phase IIa. Ce phénomène est appelé germination croisée. La mesure de la température de fusion des phases par MOP a permis d’établir leur stabilité relative: IIb > III >IIa. La vitesse de croissance (G) des sphérolites a été mesurée sur une plage de températures de 10,0 à 24,0 °C et montre une grande dépendance avec la masse molaire. Ces mesures ont révélé l’existence d’une masse molaire critique, autour de 5000 g.mol-1, en-dessous de laquelle nous avons observé GIIa > GIII et au-dessus de laquelle la relation est inversée avec GIII > GIIa. Finalement, nous avons exploré l’influence de l’ajout d’un deuxième polymère amorphe sur l’évolution des phases optiques dans des mélanges PDOL-PMMA, PDOL-PVC et PDOL-PVAc. Nous avons observé les mêmes transitions de phases que pour le PDOL pur et un certain degré de compatibilité dans le cas du PDOL-PMMA et du PDOL-PVC.

La cristallisation du poly(1,3)dioxolanne

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Synthèse et étude de nouvelles molécules potentiellement polymérisables pour la fabrication de matériaux électroluminescents : analogues du 1,3,5 benzènetripyrrole, méthyle 3,5-bipyrrolebenzoate et 6,12-diméthyle-1,5-dipyrrolediazocane

Pyrroles are found in various natural products and in the chemical composition of certain drugs because of their interesting biological properties. Lipitor, Tolmetin and Amtolmetin are examples of drugs with 1,2,5-substituted pyrroles in their composition, in which biological activities have been certified. Moreover, pyrroles are used as precursors of semiconductor polymers, oligomers and dendrimers useful for the synthesis of electroluminescent materials used in devices, such as organic light-emitting diodes, field-effect transistors, solar and organic photovoltaic cells. We are interested in conjugated polymers based on pyrrole due to their optical properties, electrochemical and the conductivity produced by electron delocalization along their carbon chains. The overall objective of the work presented in this thesis is the synthesis of new molecules based on pyrrole for studying their electronic and electrochemical properties as well for the synthesis of conjugated polymers. Initially, we performed the synthesis of 1,3,5-tri-(1-alkyl-5-methylpyrrol-2-yl)benzenes, which may serve as precursors for the synthesis of conjugated dendrimers. Their synthesis was made in three steps starting from trimethyl 1,3,5-benzene-tricarboxylate which was converted to 1,3,5-tri-(pent-4-enoyl)benzene using vinylmagnesium bromide in a Grignard reaction catalyzed by copper cyanide. The olefins of 1,3,5-tri-(pent-4-enoyl)benzene were oxidized to produce 1,3,5-tri-(4-oxopentanoyl)benzene using a modified protocol of the Tsuji-Wacker reaction. Subsequent, Paal-Knorr condensation reactions on 1,3,5-tri-(4-oxopentanoyl)benzene with different amines were used to synthesize 1,3,5-tri-(1-alkyl-5-methylpyrrol-2-yl)benzenes with different N-substituents in yields between 44 and 60%. Incomplete reaction of vinylmagnesium bromide with trimethyl 1,3,5-benzenetricarboxylate gave the methyl-3,5-di(pent-4-enoyl)benzoate, which was converted to methyl-3,5-dipyrrolylbenzoate following the reaction of Tsuji- Wacker and Paal-Knorr with yields between 30 and 60%. The photochemical and electrochemical properties of the 1,3,5-tri-(1-alkyl-5-methylpyrrol-2-yl)benzenes and methyl-3,5-dipyrrolylbenzoates were studied in collaboration with the research group of professor William Skene. The results have shown that both types of pyrrole have potential for the synthesis of conjugated polymers and dendrimers used in the manufacture of electroluminescent materials. Following these encouraging results, we performed the synthesis of 6,12-dimethyl-1,5-dipyrrolediazocane. Methyl N-(Boc)-β-alaninate was converted to its corresponding homoallylic ketone, which was oxidized to N-(Boc)aminoheptan-3,6-dione. The Paal-Knorr condensation between N-(Boc)aminoheptan-3,6-dione and aminoheptan-3,6-dione hydrochloride gave 6,12-dimethyl-1,5-dipyrrolediazocane in 17% yield. In sum, we have synthesized and characterized seven new molecules, six of them having photochemical and electrochemical properties interesting for the synthesis of conjugated polymers and dendrimers. The latter offering potential as precursor for the conception of compounds of therapeutic interest.

Photophysical and Electrochemical Investigations on Photoconducting Poly(6-tert-butyl-3,4-dihydro-2H- 1,3-benzoxazine)

Poly(6-tert-butyl-3,4-dihydro-2H-1,3-benzoxazine) was synthesized by thermally activated cationic ring opening polymerization. The structure of the polymer was confirmed by spectral and thermal studies. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were estimated using cyclic voltammetry and optical absorption. Modulated photocurrent measurement technique was employed to study the spectral and field dependence of photocurrent. Photocurrent of the order of 1.5 micro A/m2 was obtained for polymer at a biasing electric field of 40 V/mico m.

Potential application of β-1, 3 glucanase from an environmental isolate of Pseudomonas aeruginosa MCCB 123 in fungal DNA extraction

Pseudomonas aeruginosa MCCB 123 was grown in a synthetic medium for β-1,3 glucanase production. From the culture filtrate, β-1,3 glucanase was purified with a molecular mass of 45 kDa. The enzyme was a metallozyme as its β-1,3 glucanase activity got inhibited by the metal chelator EDTA. Optimum pH and temperature for β-1,3 glucanase activity on laminarin was found to be 7 and 50 °C respectively. The MCCB 123 β-1,3 glucanase was found to have good lytic action on a wide range of fungal isolates, and hence its application in fungal DNA extraction was evaluated. β-1,3 glucanase purified from the culture supernatant of P. aeruginosa MCCB 123 could be used for the extraction of fungal DNA without the addition of any other reagents generally used. Optimum pH and temperature of enzyme for fungal DNA extraction was found to be 7 and 65 °C respectively. This is the first report on β-1,3 glucanase employed in fungal DNA extraction

Novel [3+2] annulation reaction of nitrones with Burgess reagent and a few related reactions

Burgess reagent first prepared by E. M. Burgess in 1968, is a mild and selective dehydrating agent for secondary and tertiary alcohols and due to the amphipolar nature it is gainfully employed in a number of creative synthetic ventures. A close examination of the structure of Burgess reagent reveals that it can act as a 1,2-dipole. To the best of our knowledge, no attempts have been made to tap full synthetic potential of the amphipolar nature of this reagent and no reports on 1,3-dipolar addition to a σ-bond in acyclic systems are available in literature. In this context, we propose to unravel novel applications of Burgess reagent based on its amphipolar nature. Rich and multifaceted chemistry of nitrones form the basis of many successful chemical transformations used in attractive synthetic strategies. For the last 50 years special attention has been given to nitrones due to their successful application as building blocks in the synthesis of various natural and biologically active compounds. Our interest in nitrones stems out of its unique character: i.e. it is a 1,3-dipole exhibiting distinct nucleophilic activity. We reasoned that 1,3-dipole possessing significant nucleophilicity should react with amphipolar Burgess reagent with elimination of triethylamine to give the corresponding five-membered ring product by formal dipolar addition to a σ bond. To test this hypothesis we studied the reaction of nitrones with Burgess reagent. This thesis reveals our attempts to explore the [3+2] annulation reaction of nitrones with Burgess reagent which was found to be followed by a rearrangementinvolving C-to-N aryl migration, ultimately resulting in diarylamines and carbamates. We have also examined the reaction of cyanuric chloride with nitrones in DMF with a view to exploit the nucleophilicty of nitrones and to unravel the migratory aptitude, if any, observed in this reaction

4,5-Dihydro-1,3-dioxepine als chirale Bausteine in der enantioselektiven organischen Synthese

Durch asymmetrische Doppelbindungsisomerisierung mittels Me-DuPHOS-modifizierter Dihalogen-Nickel-Komplexe als Katalysatorvorstufen lassen sich aus 2-Alkyl-4,7-dihydro-1,3-dioxepinen hochenantiomerenreine 2-Alkyl-4,5-dihydro-1,3-dioxepine erhalten. Ein Ziel dieser Arbeit war es, die bisher noch unbekannte Absolutkonfiguration dieses Verbindungstyps zu bestimmen und darüber hinaus ihre Einsatzfähigkeit in der enantioselektiven organischen Synthese zu untersuchen. Zu diesem Zweck wurden enantiomerenangereichertes 2-Isopropyl- und 2-tert-Butyl-4,5-dihydro-1,3-dioxepin mit m-Chlorperbenzoesäure epoxidiert. Dabei bildeten sich die entsprechenden 3-Chlorbenzoesäure-(2-alkyl-5-hydroxy-1,3-dioxepan-4yl)-ester in hohen Ausbeuten und Diastereoselektivitäten. Von den vier zu erwartenden Diastereomeren wurden jeweils nur zwei mit einer Selektivität von mehr als 95:5 gebildet. Im Fall des 3-Chlorbenzoesäure-(2-isopropyl-5-hydroxy-1,3-dioxepan-4yl)-esters konnte das Haupt-diastereomer kristallin erhalten werden. Durch röntgenspektroskopische Untersuchung war es möglich, die Relativ-Konfiguration dieser Verbindung zu bestimmen. Die Ester lassen sich unter Ringverengung in 2-Alkyl-1,3-dioxan-4-carbaldehyde umlagern. Ausgehend von diesen Carbaldehyden stehen zwei Synthesewege zur Verfügung, welche zu Verbindungen führen deren Absolutkonfiguration bereits bekannt ist. So erhält man durch Reduktion 2-Alkyl-1,3-dioxan-4-yl-methanole, welche sich in 1,2,4-Butantriol überführen lassen. Oxidation ergibt die 2-Alkyl-1,3-dioxan-4-carbonsäuren, aus denen 3-Hydroxytetrahydrofuran-2-on gewonnen werden kann. Messung des Drehwertes dieser beiden literaturbekannten Verbindungen liefert nicht nur Information über deren Enantiomerenreinheit sondern ebenfalls über die Konfiguration ihres Stereozentrums. In Kombination mit der Relativ-Konfiguration des Esters ist somit ein Rückschluss auf die Absolutkonfiguration der eingesetzten 4,5-Dihydro-1,3-dioxepine möglich. Die auf den beschriebenen Wegen gewonnenen Substanzen finden Anwendung in der stereoselektiven organischen Synthese. Löst man die Chlorbenzoesäureester in Dichlormethan und behandelt sie mit wässriger Salzsäure, so entstehen die bicyclischen 2-Alkyltetrahydrofuro[2,3-d][1,3]dioxole. Auch bei diesen Verbindungen konnten hohe Enantio- und Diastereoselektivitäten erzielt werden. Der intermolekular verlaufende Reaktionsmechanismus der Bicyclus-Bildung, welcher unter Abspaltung eines den Alkylrest tragenden Aldehyds und dessen Neuanlagerung unter Ausbildung eines Acetals verläuft, konnte in dieser Arbeit durch ein Kreuzungsexperiment bestätigt werden. Umacetalisierung der Bicyclen liefert 2-Methoxytetrahydrofuran-3-ol, aus dem durch Acetalspaltung Tetrahydrofuran-2,3-diol erhalten wird, das die Halbacetalform der entsprechenden Desoxytetrose darstellt, die auf diese Weise in einer de novo-Synthese hergestellt werden kann.

Dipodal Ferrocene Derivatives for Nanostructured Redox-Functionalised Surfaces

Self-assembled monolayers (SAMs) on solid surfaces are of great current interest in science and nanotechnology. This thesis describes the preparation of several symmetrically 1,1’-substituted ferrocene derivatives that contain anchoring groups suitable for chemisorption on gold and may give rise to SAMs with electrochemically switchable properties. The binding groups are isocyano (-NC), isothiocyanato (-NCS), phosphanyl (-PPh2), thioether (-SR) and thienyl. In the context of SAM fabrication, isothiocyanates and phosphanes are adsorbate systems which, surprisingly, have remained essentially unexplored. SAMs on gold have been fabricated with the adsorbates from solution and investigated primarily by X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy. The results of these analytical investigations are presented and discussed in matters of the film quality and possible binding modes. The quality of self-assembled monolayers fabricated from 1,1’-diisocyanoferrocene and 1,1’-diisothiocyanatoferrocene turned out to be superior to that of films based on the other adsorbate species investigated. Films of those absorbates as well as of dppf afforded well-defined SAMs of good quality. All other films of this study based on sulfur containing anchoring groups exhibit chemical inhomogeneity and low orientational order of the film constituents and therefore failed to give rise to well-defined SAMs. Surface coordination chemistry is naturally related to molecular coordination chemistry. Since all SAMs described in this thesis were prepared on gold (111) surfaces, the ferrocene-based ligands of this study have been investigated in their ability for complexation towards gold(I). The sulfur-based ferrocene ligands [fc(SR)2] failed to give stable gold(I) complexes. In contrast, 1,1’-diisocyanoferrocene (1) proved to be an excellent ligand for the complexation of gold(I). Several complexes were prepared and characterised utilising a series of gold(I) acetylides. These complexes show interesting structural motifs in the solid state, since intramolecular aurophilic interactions lead to a parallel orientation of the isocyano moieties, combined with an antiparallel alignment of neighbouring units. The reaction of 1 with the gold(I) acetylide [Au(C≡C–Fc)]n turned out to be very unusual, since the two chemically equivalent isocyano groups undergo a different reaction. One group shows an ordinary coordination and the other one undergoes an extraordinary 1,1-insertion into the Au-C bond. As a sideline of the research of this thesis several ferrocene derivatives have been tested for their suitability for potential surface reactions. Copper(I) mediated 1,3-dipolar cycloadditions of azidoferrocene derivatives with terminal alkynes appeared very promising in this context, but failed to a certain extent in terms of ‘click’ chemistry, since the formation of the triazoles depended on the strict exclusion of oxygen and moisture and yields were only moderate. Staudinger reactions between dppf and azidoferrocene derivatives were also tested. The nucleophilic additions of secondary amines to 1,1’-diisothiocyanatoferrocene led to the respective thiourea derivatives in quantitative yields.

WPMU to Wp3.1.3 Plugin compatibility spreadsheet

Assessment of Plugin compatibility through migration from WPMU 2.7.1 to WP3.1.3